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2021-12-01 | The origin of low δ 18 O signals in zircons from the Early Cretaceous A-type granites in eastern China has long been disputed. It is uncertain whether the 18 O-depleted features were inherited from high-temperature hydrothermal altered source rock or resulted from water-rock interaction after emplacement. In this paper, zircon oxygen isotopes in the ∼130 Ma Kulongshan A-type granites in the northern North China Craton are analyzed. The zircons could be subdivided into 5 types based on their luminescent intensity and internal structures in CL images. Their δ 18 O values also vary in different types and show negative correlation with U and Th contents and accompanying cumulative α-decay doses, implying that their δ 18 O values may have been modified to various degrees by meteoric water-rock interaction after the accumulation of radiation damage. The idea is further confirmed by oxygen isotopic equilibrium calculation between co-existing mineral pairs. It is inferred that only the least-influenced zircons, with slightly elevated δ 18 O values than normal mantle, have preserved the magmatic oxygen isotopes. In combination with other evidences, it is proposed that the A-type granites are lower-crustal-derived, unnecessarily invoking a high-temperature hydrothermal altered source. The proposition is applicable to many other Cretaceous A-type granites that have similar zircon behaviors. | Origin of the Low δ18O Signals in Zircons from the Early Cretaceous A-Type Granites in Eastern China: Evidence from the Kulongshan Pluton | 10.1007/s12583-021-1515-y |
2021-12-01 | This paper presents a theory for the power transfer efficiency of printed circuit board coils to integrated circuit coils, with focus on load-dependence for low-power single-chip systems. The theory is verified with electromagnetic simulations modelled on a 350 nm CMOS process which in turn are verified by measurements on manufactured integrated circuits. The power transfer efficiency is evaluated by on-chip rectification of a 151 MHz signal transmitted by a spiral coil on a printed circuit board at 10 mm of separation to an on-chip coil. Such an approach avoids the influence of off-chip parasitic elements such as bond wires, which would reduce the accuracy of the evaluation. It is found that there is a lower limit for the load below which reducing the power consumption of on-chip circuits yield no increase in voltage generated at the load. For the examined process technology, this limit appears to lie around 56 k $$\Omega$$ Ω . The paper is focused on the analysis and verification of the theory behind this limit. We relate the results presented in this work to the application of wireless single-chip temperature monitoring of power semiconductors and conclude that such a system would be compatible with this limit. | Load-dependent power transfer efficiency for on-chip coils | 10.1007/s10470-021-01904-0 |
2021-12-01 | Abstract Currently, work is under way to create new thermionic reactor-converters. However, when designing an electrogenerating channel, difficulties arise in the complex description of the physical processes occurring in it. Moreover, empirical models of current–voltage characteristics do not always agree with the obtained results in the analysis of reactor experiments of electrogenerating channels. This is due to the fact that the empirical current–voltage characteristics are based on the experimental results of a specific electrode pair in a given mode of operation of a thermionic converter. In this work, we propose a complex mathematical model of a thermionic converter in a nuclear reactor. The mathematical model is based on solving the equations of charged particle transfer, which take into account the features of all operating modes of thermionic converter. | Mathematical Model of a Thermionic Converter in a Nuclear Reactor | 10.1134/S1063778821080020 |
2021-12-01 | The preparation of atomically dispersed catalysts with high metal loading remains a formidable challenge due to the high surface energy of single atoms. Here we prepared PtPd/TiO 2 catalysts possessing metal loading as high as 8.17 wt% by a new versatile method which based on metal oxide carriers with abundant oxygen defects. PtPd/TiO 2 catalysts consist of PtPd nanoparticles and atomically dispersed Pt and Pd atoms, and the content of PtPd nanoparticles is little. Pt 3 Pd 1 /TiO 2 -400 catalyst exhibited the highest catalytic activity in toluene oxidation, and with a 94.7% conversion at 110 °C. Kinetic investigation reveals that the toluene oxidation follows a typical Langmuir-Hinshelwood mechanism. Experimental research indicates that the superior catalytic activity could be attributed to a large number of metal atoms atomically dispersed on the surface of the catalyst. Pt and Pd atoms are close to each other, which produces the synergetic effect and thereby promotes toluene oxidation. This work provides a promising pathway to fabricate single atom catalysts with high loading. | PtPd/TiO2 Catalysts for Low‐Temperature Toluene Oxidation | 10.1007/s10563-021-09335-7 |
2021-12-01 | Abstract Dielectric relaxation spectroscopy is used to study BNKS-18AMN butadiene–nitrile rubber and its vulcanizates modified with low-molecular-weight siloxanes with different substituents on the silicon atoms. It is shown that rubbers are modified due to the structuring action of modifiers capable of both destroying and generating certain types of supramolecular structures. It is found that such modification allows us to change the structure of clusters not only to raise the level of intermolecular interactions in vulcanizates, but to change their glass transition temperatures as well through rearrangement. | Dielectric Spectroscopy Study of the Modification of the Cluster Structures of Butadiene-Nitrile Rubbers and Their Vulcanizates | 10.1134/S0036024421120116 |
2021-12-01 | Termites are dominant soil macro-fauna in tropical forests, yet remain an uncertain component of the carbon budget in many regions. We investigated CH 4 and CO 2 flux patterns from termite mounds and background soils of moist tropical deciduous forests in Indian lower Himalaya from April 2015 till March 2016 using static closed chamber technique. The relation between gas fluxes and soil moisture as well as temperature were examined. Termite ( Odontotermes obesus ) mounds were significant localized source of CH 4 (0.38 ± 0.01 mg m −2 h −1 ) and CO 2 (1837 ± 40 mg m −2 h −1 ) amidst CH 4 consuming (– 0.028 ± 0.001 mg m −2 h −1 ) or lower CO 2 emitting (1120 ± 19 mg m −2 h −1 ) background forest soils. Gas fluxes from termite mounds were seasonally bimodal (monsoon flux being highest followed by a second mild peak in winter) and diurnally variable. Soil moisture was a significant determinant of CH 4 and CO 2 fluxes from termite mounds, explaining more than 50% variability. In the case of background forest soils, the combined effect of soil moisture and temperature best explained CO 2 and CH 4 flux variation. On scaling up, termite mounds contributed negligibly (0.3%) to total soil CO 2 emission while mound-mediated CH 4 emission offset net soil CH 4 uptake by 2.0%. Our results suggest considerable role of termite mounds in influencing source–sink capacity of forest soils. Present data are crucial in reducing error and uncertainty due to spatiotemporal variations in case of large-scale predictions. We suggest careful future land use decisions to minimize the contribution of mound-building termites to net soil CO 2 and CH 4 flux from this region. | Methane and Carbon Dioxide Flux Heterogeneity Mediated by Termite Mounds in Moist Tropical Forest Soils of Himalayan Foothills, India | 10.1007/s10021-021-00630-y |
2021-12-01 | The fibrous silica HZSM-5 (HFZ) was synthesized by microemulsion method assisted with ZSM-5 seed crystallization under different amounts of a silica source, tetraethyl orthosilicate (TEOS, 1.0–1.5 mol) for superior benzene methylation activity. The aptness of the physicochemical properties of HFZ offered an abundance of active sites, allow benzene conversion up to 90% and toluene production at the lower temperature of 300 °C, with the following order of yields: 1.0HFZ (66.1%) > 1.5HFZ (46.2%) > commercial HZSM-5 (41.9%). Additionally, the less extraframework alumina-possessing 1.0HFZ was found to display the lowest activation energy and substrate diffusion limitation, compared to microstructured commercial HZSM-5 (HZ). The 1.0HFZ also possessed a lower Lewis acidic nature and able to decrease subsequent production of ethylbenzene (EB) while significantly improved further methylation to xylene. The in-situ FTIR study gave insights on the adsorption of both methanol and benzene on the active sites of catalyst, revealing that 1.0HFZ followed the associative mechanism in which both methanol and benzene were adsorbed onto the active sites. Meanwhile, HZ followed the consecutive mechanism due to the presence of intermediate methoxy. | Mechanistic insight into low temperature toluene production via benzene methylation over mesopore-rich fibrous silica HZSM-5 zeolite | 10.1007/s10934-021-01121-0 |
2021-12-01 | A batch experiment was conducted to examine the effects of biochar dose and reaction duration on the transformation and immobilization of Cr(VI) in the combined biochar and low-molecular-weight organic acid systems. The results showed that increase in the dosage level of biochar caused increase in the solution pH, particularly for the Biochar300 treatments but did not enhance the reduction of Cr(VI) after 1-day reaction. Over 35% of the converted Cr(III) was immobilized by sorption to the biochar due to increased negatively charged sites on the biochar surfaces driven by pH rise. The elevated pH due to biochar dose increase tended to slow down the reduction of Cr(VI) to Cr(III), resulting in more Cr(VI) being adsorbed at a higher biochar dose. For the higher-temperature biochars, the increase in biochar dose did not markedly change the transformation and immobilization of the added Cr. Increase in the reaction duration markedly increased the pH for Biochar300. This resulted in the disappearance of all Cr(VI) in the solution after the 7-day reaction, possibly through sorption of cationic Cr(III) to the biochar surfaces. Increase in reaction time for the higher-temperature biochars resulted in re-oxidation of Cr(III) to Cr(VI) due to the increased exposure of solution Cr(III) to atmospheric oxygen. The research findings obtained from this study have implications for optimizing treatment procedure for wastewater that contains elevated level of toxic Cr(VI). Simulation experiments are required to determine appropriate biochar dose and reaction time to achieve cost-effective treatment goals. | Transformation and immobilization of hexavalent chromium in the co-presence of biochar and organic acids: effects of biochar dose and reaction time | 10.1007/s42773-021-00117-y |
2021-12-01 | Abstract Technologies for plasma heating of steel in a continuous caster tundish, plasma-arc remelting nitriding, and metal surface modification are developed using an efficient dc low-temperature plasma generator with a self-adjusting arc length, vortex stabilization, and an expanding gas-discharge channel. The temperature stabilization of the cast steel increases the fracture toughness and the critical crack opening in the deformed steel in both the transverse and longitudinal rolling directions. Remelting of steel in nitrogen plasma refines grains; increases the strength, ductility, total fracture work, and wear resistance under dry friction conditions; and decreases the corrosion rate. Plasma treatment saturates the metal surface with nitrogen and forms a wide range of structures with a deep and gradual transition zone, which ensures strong adhesion of the hardened layer to the base metal. | Application of Low-Temperature Atmospheric-Pressure Plasma in Metallurgy | 10.1134/S0036029521120089 |
2021-12-01 | The internal electrical conductivity in plant stem (ECps) reflects its physiological activity including ion and water transport. Thus, monitoring the ECps can be used to predict physiological changes in plants due to environmental stresses that affect water and ion transport in them. The purpose of this study was to determine if ECps monitoring data could be used to indicate environmental stress induced by low temperature and salt by comparing ECps with chlorophyll and proline contents. Capsicum annuum was progressively exposed to day/night temperature of 21/16 °C and 14/9 °C as low-temperature stress. Salt stress was incrementally applied at 20 and 40 mmol/kg NaCl. The ECps of C. annuum was monitored over the experimental period. The ECps was lower under low-temperature stress, although visible changes were not observed. Both chlorophyll a and b contents were lower, and the proline content was higher in leaves under low-temperature stress compared to the control. The initial salt treatment increased the ECps and the subsequent salt treatment at 40 mmol/kg NaCl resulted in a sudden increase of the ECps. The decreased chlorophyll a and b , and the increased proline content of the leaves under salt stress were stress-induced responses. Sodium and chloride accumulation increased, and the potassium/sodium ratio decreased in salt-treated plants. The ECps reflected reduced ion and water transport under low-temperature stress and increased salt transport in stems under salt stress. Therefore, ECps monitoring can be used to diagnose physiological changes in plants caused by environmental stress conditions before symptoms appear. | Early detection of plant stress using the internal electrical conductivity of Capsicum annuum in response to temperature and salinity stress | 10.1007/s10725-021-00747-z |
2021-12-01 | Abstract Influence of low-temperature atmospheric pressure plasma generated by a high-resource arc plasmatron in an air mixture with the addition of an inert gas and in pure inert gas on the culture of Paramecium caudatum cells was studied. The effect of the plasma composition and the time of its exposure on the level of acidity of the aqueous medium and the nature of cell death was found. The obtained results are discussed taking into account the effect of active radicals formed under the action of a plasma jet as well as the delayed reaction of cells to plasma exposure. | Effect of Low-Temperature Atmospheric Pressure Plasma on Paramecium caudatum Cell Culture | 10.3103/S0096392521040027 |
2021-12-01 | A further increase in the efficiency of low-temperature plasma modification of the metal product surface layer is possible on the basis of the process supervision. The article presents an approach and a developed model that allows to receive and study the behavior of signals arising in the electrical circuit of a technological unit under the interaction of electromagnetic and electrostatic fields that form a low-temperature plasma gas discharge near the product surface. Data confirming the validity of the model are presented. The analysis of electrical signals is carried out. The indicator reflecting the stability of the process of plasma interaction with the product surface by the degree of the signal form deviation from the sine curve is substantiated. The study of the possibility to control the modification process was carried out. The dependences of the stability index on the product parameter values as functions of the process operating parameters — bias potential or magnetron anode current — were obtained and studied. The reliability of the theoretical studies results was experimentally confirmed, which showed that the composite structure synthesis process remains the most stable with a smooth decrease in the bias potential, as well as a smooth and abrupt increase in the magnetron anode current. | Substantiation of the technology for controlling the process of low-temperature plasma modification of metal product surface layer by the electrical signal parameters | 10.1007/s00170-021-07258-1 |
2021-12-01 | This investigation was conducted to identify the content of metals in Calluna vulgaris (family Ericaceae ), Empetrum nigrum (family Ericaceae ), Festuca vivipara (family Poaceae ) and Thymus praecox subsp. arcticus (family Lamiaceae ), as well as in the soils where they were growing in eight geothermal heathlands in Iceland. Investigation into the vegetation of geothermal areas is crucial and may contribute to their proper protection in the future and bring more understanding under what conditions the plants respond to an ecologically more extreme situation. Plants from geothermally active sites were enriched with metals as compared to the same species from non-geothermal control sites (at an average from about 150 m from geothermal activity). The enriched metals consisted of Cd, Co, Cu, Fe and Ni in C. vulgaris ; Cd, Mn and Ti in E. nigrum ; Hg and Pb in F. vivipara ; and Cd, Fe and Hg in T. praecox . Notably, C. vulgaris , E. nigrum , F. vivipara and T. praecox had remarkably high concentrations of Ti at levels typical of toxicity thresholds. Cd and Pb (except for C. vulgaris and F. vivipara ) were not accumulated in the shoots of geothermal plants. C. vulgaris from geothermal and control sites was characterised by the highest bioaccumulation factor (BF) of Ti and Mn; E. nigrum and F. vivipara by the highest BF of Ti and Cr; and T. praecox by the highest BF of Ti and Zn compared to the other elements. In comparison with the other examined species, F. vivipara from geothermal sites had the highest concentration of Ti in above-ground parts at any concentration of plant-available Ti in soil. | Metals in Calluna vulgaris, Empetrum nigrum, Festuca vivipara and Thymus praecox ssp. arcticus in the geothermal areas of Iceland | 10.1007/s11356-021-15046-3 |
2021-12-01 | Abstract Temperature flammability limits are one of the key indicators of fire and explosion hazard and are used in the development of measures, ensuring fire and explosion safety of production facilities, in the calculation of safe temperature conditions for storage, transportation, and processing of highly flammable and combustible liquids. Along with the standard methods for determination of the temperature limits of flammability, researchers apply non-standard instruments. This work considers the devices by Eitner, Bradley-Hale, Mack, Fricke, Jones, the US Bureau of Mines, the US Naval Research Laboratory, the All-Russian Research Fire Protection Institute, Yagyu, Gordon, Kong, Hasegawa-Kashiki, Brandes, and a 20-L spherical bomb. It is demonstrated that in many cases non-standard apparatuses make it possible to determine the temperature flammability limits with acceptable accuracy. | Non-Standard Devices for Determination of Temperature Flammability Limits | 10.1134/S1070363221130326 |
2021-12-01 | Flowers have become a part of our daily life, and wind up joining the waste stream, after little use and almost practically no reuse. Disposal of the flowers despite playing an eloquent role in religious faith, rituals, wedding ceremony, etc., finishes up mostly at open dumping or in water bodies. An endeavor has been made to valorize the flower waste generated from the flower market in Puducherry. White Marigold Chrysanthemum morifolium was retrieved in bulk from the market waste stream and was thermally treated into valuable low-cost biochar. The products were synthesized by pyrolysis in slow thermal carbonization conditions at 350 °C and 500 °C. Before treating thermally, the collected waste marigold flowers were analyzed for decomposition behavior via TGA. The biochar products were further characterized, analyzed, and compared, for various physiochemical parameters, namely pH, conductivity, moisture content, ash content, and bulk density. Specific physical and chemical properties and the effect of slow pyrolysis at two different temperatures were further investigated by performing FTIR, SEM, XRD, and BET. Biochar pyrolyzed at 500 °C possessed better characteristics for environmental applications than biochar derived at 350 °C. | Renovation of Waste Chrysanthemum morifolium (Marigold) into Valuable Biochar: A Study on the Utilization of Solid Waste by Pyrolysis | 10.1007/s40034-021-00213-5 |
2021-12-01 | A unique low-to-high friction transition is observed during unlubricated sliding in metals with a gradient nano-grained (GNG) surface layer. After persisting in the low-friction state (0.2–0.4) for tens of thousands of cycles, the coefficients of friction in the GNG copper (Cu) and copper-silver (Cu-5Ag) alloy start to increase, eventually reaching a high level (0.6–0.8). By monitoring the worn surface morphology evolution, wear-induced damage accumulation, and worn subsurface structure evolution during sliding, we found that the low-to-high friction transition is strongly correlated with distinct microstructural instabilities induced by vertical plastic deformation and wear-off of the stable nanograins in the subsurface layer. A very low wear loss of the GNG samples was achieved compared with the coarse-grained sample, especially during the low friction stage. Our results suggest that it is possible to postpone the initiation of low-to-high friction transitions and enhance the wear resistance in GNG metals by increasing the GNG structural stability against grain coarsening under high loading. | A low-to-high friction transition in gradient nano-grained Cu and Cu-Ag alloys | 10.1007/s40544-020-0440-x |
2021-12-01 | Abstract Low cycle fatigue (LCF) behaviour and associated failure mechanisms of a thermo-mechanically treated Fe 500D steel rebar have been experimentally evaluated with a view to assess its performance under seismic condition. The total axial strain-controlled LCF tests have been performed at five different strain amplitudes (± 0.30 to ± 1.00%) at ambient temperature until failure maintaining a constant true strain rate of 1 × 10 − 3 s − 1 and a fixed strain ratio of − 1. Fatigue data have been analysed following both strain–life and plastic strain energy–life relationships; while, macro as well as micro features of the failed specimens, have been critically examined. These are supplemented by microstructural characterizations in addition to tensile and hardness measurements. Significant reduction of yield strength is recorded under dynamic loading which is responsible for considerable cyclic softening of rebar till failure in all strain amplitudes indicating the deterioration of seismic resistance property. Both strain–life and plastic strain energy–life relationships are found to accurately predict the cyclic plastic behaviour of the selected rebar. A near Masing behaviour is established by three different analytical approaches. The fatigue crack is always found to initiate at the transverse rib root and primarily propagates alongside the rim region. Graphic Abstract | Low Cycle Fatigue Performance and Failure Analysis of Reinforcing Bar | 10.1007/s12540-020-00839-x |
2021-12-01 | In the present paper, the damage and life cycle of the last-stage blades (LSB) of a 250-MW low-pressure steam turbine are predicted under low-cycle fatigue conditions. A finite element-based analysis is carried out to compute fatigue life and damage for a blade with a fir-tree root region under the loading condition of centrifugal stresses and using eight possible cases of contact between blade fir-tree root region flank and rotor flank. An experimental modal analysis (EMA) is performed for the identical modeled blade with a fir-tree root in a stationary test rig to find resonant frequencies and mode shapes, and these mode shapes show agreement with the experimental data. Dynamic response analysis of cracked and healthy blades for a case is also done. Further, the minimum number of life cycles, fatigue damage, and safety factor are computed employing mean stress correction approaches such as strain-based life, Morrow and Smith Watson Topper (SWT) to initiate a crack in blades for the same. The results for the lowest minimum life and serious damage among all eight blade–rotor fixity conditions are identified at the leading edge of lower serration when the pressure side lower flank is in contact with the rotor. | Low-Cycle Fatigue Life Prediction of LP Steam Turbine Blade for Various Blade–Rotor Fixity Conditions | 10.1007/s11668-021-01282-9 |
2021-12-01 | A novel lipase, Lip486, which has no obvious homology with known lipases, was discovered using functional metagenomics technology. Phylogenetic tree analysis suggested that the enzyme belongs to a new subfamily called lipolytic enzyme family II. To explore the enzymatic properties, lip486 was expressed heterologously and efficiently in Escherichia coli . The recombinant enzyme displayed the highest activity on the substrate p -nitrophenyl caprate with a carbon chain length of 10, and its optimum temperature and pH were 53 °C and 8.0, respectively. The recombinant Lip486 showed good activity and stability in strong alkaline and medium–low-temperature environments. The results of compatibility and soaking tests showed that the enzyme had good compatibility with 4 kinds of commercial detergents, and an appropriate soaking time could further improve the enzyme activity. Oil stain removal test results for a cotton cloth indicated that the washing performance of commercial laundry detergent supplemented with Lip486 was further improved. In addition, as one of the smallest lipases found to date, Lip486 also has the advantages of high yield, good stability and easy molecular modification. These characteristics reflect the good application prospects for Lip486 in the detergent and other industries in the future. | An uncharacterized protein from the metagenome with no obvious homology to known lipases shows excellent alkaline lipase properties and potential applications in the detergent industry | 10.1007/s10529-021-03203-0 |
2021-12-01 | The extreme floods in the Middle/Lower Yangtze River Valley (MLYRV) during June−July 2020 caused more than 170 billion Chinese Yuan direct economic losses. Here, we examine the key features related to this extreme event and explore relative contributions of SST anomalies in different tropical oceans. Our results reveal that the extreme floods over the MLYRV were tightly related to a strong anomalous anticyclone persisting over the western North Pacific, which brought tropical warm moisture northward that converged over the MLYRV. In addition, despite the absence of a strong El Niño in 2019/2020 winter, the mean SST anomaly in the tropical Indian Ocean during June−July 2020 reached its highest value over the last 40 years, and 43% (57%) of it is attributed to the multi-decadal warming trend (interannual variability). Based on the NUIST CFS1.0 model that successfully predicted the wet conditions over the MLYRV in summer 2020 initiated from 1 March 2020 (albeit the magnitude of the predicted precipitation was only about one-seventh of the observed), sensitivity experiment results suggest that the warm SST condition in the Indian Ocean played a dominant role in generating the extreme floods, compared to the contributions of SST anomalies in the Maritime Continent, central and eastern equatorial Pacific, and North Atlantic. Furthermore, both the multi-decadal warming trend and the interannual variability of the Indian Ocean SSTs had positive impacts on the extreme floods. Our results imply that the strong multi-decadal warming trend in the Indian Ocean needs to be taken into consideration for the prediction/projection of summer extreme floods over the MLYRV in the future. 2020 年 6-7 月份长江中下游地区发生的极端洪涝灾害给我国造成了 1700 多亿的直接经济损失. 本研究调查了与该极端降水事件相关的重要特征, 并探索了热带三大洋不同海盆海温对该极端事件的相对贡献. 研究发现此次长江中下游极端降水与较强的西北太平洋异常反气旋有关, 该反气旋将热带区域水汽向北输送并在长江中下游地区辐合. 另外, 尽管 2019 年冬季赤道太平洋没有发生较强的 El Niño 事件, 热带印度洋暖海温异常在 2020 年 6-7 月份达到了近 40 年来的最大值, 其中 43% (57%) 是由于年代际增暖 (年际变率) 导致的. NUIST CFS1.0 模式 (该模式能够在 3 月份较好地预报出长江中下游地区夏季降水增多现象) 的敏感性试验结果表明, 相比于海洋大陆、 赤道中东太平洋以及北大西洋区域的海温异常, 印度洋暖海温异常在此次长江中下游极端降水事件中起着主要作用, 并且印度洋海温的年代际增暖信号和年际变率信号均起着一定的作用. 我们的研究结果表明在预测未来长江中下游地区夏季极端降水时需要将印度洋海温的年代际增暖趋势考虑进去. | Toward Understanding the Extreme Floods over Yangtze River Valley in June–July 2020: Role of Tropical Oceans | 10.1007/s00376-021-1036-8 |
2021-12-01 | The paper presents some research results to recognize the possibility of realization of the idea of a multi-fuel IC engine. Future construction is planned as a flexible solution for military or special purpose transport means and emergency power generation. The proposed engine would utilize compression ignition mode for combustion of high reactive fuels (JP-8, diesel oil, etc.) or spark ignition mode for gasoline or other low reactive fuels. Practical implementation of the idea requires that highly reactive fuels be burned efficiently at a low compression ratio suitable for both engine modes. For the test diesel oil, JP-8 and its blends with pure rapeseed oil were chosen as easily accessible fuels. The experiment was carried out on naturally aspirated and supercharged AVL research engine with a common rail system and compression ratio CR = 12. The elaborated, unified injection strategy that synchronized the main dose injection timing with the start of the second stage of homogeneous mixture combustion was checked in practice. The proposed injection strategy applied for CI engine with the low compression ratio enabled efficient combustion and comparable, relatively high engine performance for all tested fuels. | The experimental verification of the multi-fuel IC engine concept with the use of jet propellant-8 (JP-8) and its blends with pure rapeseed oil | 10.1007/s40095-021-00398-w |
2021-12-01 | To make coal-fired power generation more environmentally friendly, China has initiated a series of ultra-low emission retrofits to the air pollution control (APC) system of the existing power plants. In this study, a life cycle assessment (LCA) is conducted to analyze the environmental net benefits for the typical ultra-low emission retrofit of a 1000 MW power plant. The key processes, substances, and APC devices are verified and discussed. The results confirm that the retrofit effectively decreases the environmental stress of acidification potential (AP), eutrophication potential (EP), and photochemical ozone creation potential (POCP) by 69%–79%, which can be attributed to significantly reduced emissions at the stack. However, the retrofit has also increased other impact categories by 24%–79%, primarily due to the consumption of additional electricity and adsorbents. The retrofit of selective catalytic reduction, electrostatic precipitator (ESP), and wet limestone flue gas desulfurization devices has a dominant effect on the impacts of EP, human toxicity potential (HTP), and AP. A newly installed wet ESP shows some environmental benefits (only for AP), but causes considerable burdens, in particular for the investigated impact categories global warming potential (GWP), marine aquatic ecotoxicity (MAETP), and abiotic depletion fossil (ADP fossil). The obtained results indicate that the hidden environmental consequences, which are associated with the production of energy and materials, need to be examined more comprehensively to inform the development of ultra-low emission technologies and strategies effectively. | Environmental consequences of an ultra-low emission retrofit in coal-fired power plants from a life cycle perspective | 10.1007/s42768-021-00083-y |
2021-12-01 | Ultrahigh-pressure metamorphism has recently been reported from various crustal rocks in the Seve Nappe Complex (SNC) in which microdiamonds were found. However, in gneiss from the Lower Seve Nappe (LSN), neither any direct petrographic indication for UHP was reported nor the metamorphic evolution was well constrained. We studied a mylonitic gneiss from the Handöl area of the LSN and applied phase-diagram modeling and Ti-in-biotite thermometry. Based on the compositions of garnet and biotite and observed mineral assemblages, a path was reconstructed passing through about 8 kbar and 730 °C at prograde metamorphism. Peak-pressure and initial retrograde stages occurred at 9.0–10.2 kbar at 745–775 °C, and 7–9 kbar at <750 °C, respectively. No ultrahigh-pressure evidence was recognized compatible with medium-pressure metamorphism deduced in earlier studies of gneiss from the SNC. As higher peak pressures were reported recently for metamorphic rocks of the LSN, a possible interpretation is that slices or erased blocks were subducted, metamorphosed at different depths, and exhumed in a subduction channel. However, the dominant gneiss of the SNC experienced only a medium-pressure metamorphism in the upper part of the downgoing Baltica Plate. Rocks from different depth levels were brought together in an exhumation channel located between Baltica and the overlying plate. | Pressure-Temperature Evolution of a Mylonitic Gneiss from the Lower Seve Nappe in the Handöl Area, Central Sweden | 10.1007/s12583-021-1413-3 |
2021-12-01 | Abstract Cross-linkers have great importance in textile due to the widespread utilization of cellulosic fibers for clothing. Unfortunately, the acute toxicity of formaldehyde-based resins and the poor performance of non-formaldehyde resins still keep the research door open for scientists in this area. Herein, we demonstrated copper nanoparticles induced trimesic acid grafted cellulose as a sustainable solution for multifunctional easy-care clothing. Our treated fabric presents crease recovery angle value of 248° comparable to that of most promising citric acid-based cross-linkers at the chemical concentration of trimesic acid as low as 2% with a sweeping improvement of around 30% in strength retention, not reported earlier. The relatively low fabric stiffness, without any yellowing, is contributing to the comfort and aesthetic demand while nanoparticles induction promoting utmost antimicrobial need. For the first time, the superiority of the development was validated by interlacing the fabric/finish traits with sustainability building blocks that provide the step forward for rapid industrialization. Furthermore, environmental, health, and safety mapping comparison provides a better understanding of the intensity of hazards that different finishing crosslinkers pose on the environment and public health. With improved performance and superior sustainability, such fabric can act as a preferable alternative to the multifunctional easy-care fabric market. Graphic abstract | Copper nanoparticles induced, trimesic acid grafted cellulose–an effective, non-hazardous processing approach for multifunctional textile with low chemical induction | 10.1007/s10570-021-04251-5 |
2021-12-01 | Cationization of cotton fabrics was performed by exhaustion procedure utilizing four different reagents provided with quaternary ammonium groups: poly diallyldimethylammonium chloride (PDDACl), poly acrylamide-co-diallyldimethylammonium chloride (PAcD), poly[bis(2-chloroethyl) ether-alt-1,3-bis[3-(dimethylamino)propyl]urea] quaternized (P42) and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC). Pretreated samples were dyed using Reactive Red 195 dye. The cationic fabrics were analyzed by colorimetric and fastness properties, zeta potential, SEM, FTIR and an estimate of the bactericidal effect. Cationic cotton treated with PDDACl and CHPTAC showed a higher affinity for the reactive dye, with color strength (K/S) values varying from 41 to 48, against 32 for conventional dyeing. P42 presented competitive results with K/S of 27–28. The cationic dyeing considerably reduced the amount of effluent, especially for the CHPTAC samples, which requires a single washing bath for complete removal of unfixed dye. The PDDACl and P42 samples presented bactericidal activity. Graphic abstract | Preparation of cationic cotton through reaction with different polyelectrolytes | 10.1007/s10570-021-04260-4 |
2021-12-01 | In this study, Zinc Oxide/Polyaniline (ZnO/PANI) hybrid was successfully synthesized using the combination of in-situ chemical oxidative polymerization and simple hydrothermal route method which was sequentially exposed to gamma radiation. X-ray diffraction analysis of non-irradiated and irradiated samples indicates the crystallinity of the ZnO/PANI hybrid and shows no considerable changes after gamma irradiation. Atomic force microscopy analysis shows that the grain size and roughness of the hybrid increase as the irradiation dose increases. Moreover, with increasing radiation dose, the intensity and peak area of photoluminescence spectra increase. According to electrical measurements, the conductivity of the prepared films increases linearly with increasing gamma dose. | Preparation and characterization of gamma irradiated ZnO/PANI hybrid films | 10.1007/s10967-021-08053-8 |
2021-12-01 | We present a low rank approximation approach for topology optimization of parametrized linear elastic structures. The parametrization is considered on loading and stiffness of the structure. The low rank approximation is achieved by identifying a parametric connection among coarse finite element models of the structure (associated with different design iterates) and is used to inform the high fidelity finite element analysis. We build an Artificial Neural Network (ANN) map between low resolution design iterates and their corresponding interpolative coefficients (obtained from low rank approximations) and use this surrogate to perform high resolution parametric topology optimization. We demonstrate our approach on robust topology optimization with compliance constraints/objective functions and develop error bounds for the the parametric compliance computations. We verify these parametric computations with more challenging quantities of interest such as the p -norm of von Mises stress. To conclude, we use our approach on a 3D robust topology optimization and show significant reduction in computational cost via quantitative measures. | Robust topology optimization with low rank approximation using artificial neural networks | 10.1007/s00466-021-02069-3 |
2021-12-01 | Characterized by large plastic deformation and energy-dissipation capacity, low-yield-strength steel shear panel dampers (LYSPDs) are widely used as energy-dissipating members in seismic engineering. However, the effect of welding on the properties of LYSPDs remains unclear. Hence, in this study, we investigated the matching performance between low-yield-strength steel (LYS) and two different welding materials. Subsequently, the quality of welding between LYS and dissimilar metals was investigated. Furthermore, the fracture characteristics of the welding seam of LYS under large plastic deformation were explored. Finally, the welding performance of LYSPDs under large plastic deformation was verified under cyclic loading. The results of this study are significant in terms of the effect of welding on the properties of LYSPDs. | Welding Performance of Low-Yield-Strength Steel Shear Panel Dampers Under Large Plastic Deformation | 10.1007/s13296-021-00555-1 |
2021-12-01 | Maintaining adequate nitrogen (N) supply to dryland cereal crops remains a critical management issue for optimizing productivity and N-use efficiency. Combinations of crop residue and fertilizer-N inputs can be used to manipulate soil-N supply factors at critical stages of plant N demand. The aim of this study was to understand the effects of residue and N fertilizer combinations on soil-N supply capacity to wheat (Triticum aestivum L.) crop plants under field conditions. Residue decomposition and N release in the field during a fallow period and the subsequent wheat growing season were quantified using litterbags containing wheat or lupin residues placed in the top 1–2 cm of soil. During the growing season, surface (0–10 cm depth) soil-N capacity was assessed in relation to key wheat growth stages by measuring labile organic and inorganic soil-N pools under a combination of different residue (removed, wheat, or lupin residues) and fertilizer-N (0, 20, or 40 kg N ha −1 ) treatments applied at sowing. Around half of the N release by residues occurred in the fallow period. Lupin residues provided a greater N release via net mineralization and dissolved organic N (DON) early in the growing season (up to tillering). As the crop developed, lupin residues had a higher surface soil potentially mineralizable N (PMN) and microbial biomass N (MBN) compared with wheat or removed residues. It was the combination of lupin residues with fertilizer-N that had the highest overall amount of surface soil DON and PMN between seedling and tillering. This study showed that the fallow is an important component of the N cycle in these systems as 40–50% of crop residue N release occurred during this period. However, this release represented less than 15% of subsequent wheat crop N uptake, which highlights the importance of N cycling from recent residues and pre-existing organic matter during the crop growing season for meeting crop N demand. Lupin residues and fertilizer-N inputs, both independently and together, increased soil-N supply capacity at critical crop growth stages in this low-rainfall sandy soil environment. | Increases in Potentially Mineralizable and Dissolved Organic Nitrogen in a Sandy Surface Soil Fertilized with Nitrogen are Greater with Lupin than Wheat Residues | 10.1007/s42729-021-00578-x |
2021-12-01 | RF MEMS switches have been employed in many commercial and defense applications due to their high potentiality at microwave and millimeter wave frequencies. In this paper, an RF MEMS shunt switch is designed with perforations and without perforations and simulated using iterative meanders for millimeter wave 5G applications. The proposed iterative meander offers a low spring-constant of 0.68 N/m and reduces the pull-in-voltage upto 1.8 V. The proposed perforated switch design is more reliable which operates with less transition time of 11.2 µs with a quality factor of 1.69. The switch possesses high capacitance ratio of 63. During ON condition, the switch shows low insertion loss of − 0.24 dB at 41 GHz and high isolation of − 46.7 dB at 38 GHz. The performance of the switch is analyzed by simulating it using COMSOL Multiphysics 5.2v (FEM tool). The obtained simulation results shows close approximation with the theoretical results and the switch is efficiently used for 5G millimeter wave applications. | Low Pull-in-Voltage RF-MEMS Shunt Switch for 5G Millimeter Wave Applications | 10.1007/s42341-021-00304-5 |
2021-12-01 | Abstract —The effects that indolizine derivatives, a tellurium organic compound, rhodanine, sodium diethyldithiocarbamate, and some of their mixtures have on corrosion of steel in 1 M hydrochloric acid are studied by gravimetric analysis, kinetic measurements at different temperatures, polarization measurements, and impedance spectroscopy. The listed compounds and their mixtures are found to be effective inhibitors of acidic corrosion of low-carbon steel. In the presence of inhibitors, the corrosion of steel in hydrochloric acid is shown to be kinetically controlled. The considered additives have different influences on partial reactions in the corrosion process. | New Corrosion Inhibitors for Low-Carbon Steel in Hydrochloric Acid Solutions | 10.1134/S2070205121070042 |
2021-12-01 | Special deposition environment makes organic-rich shales in Ningwu Basin have type III kerogen and high kaolinite content, which are also famous as the kaolinite ore. The specific composition of shale in Ningwu Basin can change the pore structure and thus, influence the shale gas storage and transport. This study focuses on the pore structure and its evolution in shales with type III kerogen and high kaolinite content. In this study, 14 Upper Paleozoic shale samples, whose total organic matter contents (TOC) range from 0.39% to 5.91% and maturities (represented by vitrinite reflectance) range from 1.22% to 2.06%, were collected. Scanning electron microscopy (SEM), high-pressure mercury injection, and low-temperature N 2 adsorption experiments were used to analyze pore structure of these shale samples. Results show that when the TOC content is smaller than 1.4%, the kaolinite content decreases linearly and quartz content increases linearly with increasing the TOC content. In contrast, when TOC content is > 1.4%, the clay content tends to increase with increasing TOC. Based on the SEM images, organic pores and clay pores were identified in shale samples with type III kerogen and high kaolinite content. During the maturation process, the kaolinite content decreases and illite content increases with increasing the vitrinite reflectance. At the same time, the pore volume and pore surface area both increase with increasing the vitrinite reflectance, and it may be because more organic pores and clay pores in the illite were generated during the maturation process. This study can provide further understandings of shale gas accumulation in shale with type III kerogen and high kaolinite content. | Evolution of pore structure in organic shale with type III kerogen and high kaolinite content in Ningwu Basin | 10.1007/s11707-021-0927-4 |
2021-12-01 | Assessment of exposure and mortality attributable to air pollution is one of the most important tasks to inform strategies for mitigation and prevention of the negative effects of degraded air quality. While the vast majority of studies rely on either satellite data or sparse (and expensive) monitoring networks and focus on global- or regional-scale assessments, emerging low-cost citizen science networks are a new source of information that can be used to provide more detailed estimates at urban scale, thereby refining previous estimates and providing spatially resolved information at census tract resolution. In this work, we demonstrate how a citizen science network, validated with a reference air pollution station, provides sensibly different (and spatially resolved) estimates of air pollution levels and associated exposure/mortality than assuming constant air pollution across the analyzed urban area. Specifically we focus on the extreme pollution episode of the 2020 California wildfires that significantly impacted the city of San Francisco. We estimate that during the wildfires, degraded air quality was responsible for an increase between 2 and 4% of the baseline mortality in the same city over the time period of study (August 19, 2020 to September 30, 2020). | Assessing urban mortality from wildfires with a citizen science network | 10.1007/s11869-021-01072-0 |
2021-12-01 | Using the prediction data from the Global Seasonal Forecast version 5 (GloSea5) during the 1993–2016 period, the probabilistic prediction skills of the midsummer (July and August) surface air temperature (SAT) over the middle and lower reach of the Yangtze River valley (MLYR) are evaluated by the ranked probabilistic skill score. We found that the GloSea5 better predicts below-normal (BN) events than above-normal (AN) events at a long lead time, as well as the associated western Pacific subtropical high (WPSH) and circumglobal teleconnection (CGT) anomaly. This result reveals the asymmetry of the probabilistic prediction skills of the midsummer MLYR SAT, which is related to the asymmetric effect of predictability sources: the warm midsummer ENSO favors BN events via promoting the eastward retreat of the WPSH, whereas the cold midsummer ENSO exhibits weak effect on AN events due to the induced southwestward expansion of the WPSH; the warm mid-latitude North Atlantic (MNA) promotes AN events via projecting its influence onto the atmospheric teleconnections such as the CGT, but not vice versa. The GloSea5 exhibits strong response to both two predictability sources, but fails to reproduce the asymmetric effect of predictability sources especially for ENSO, which limits the prediction skills of AN events. On the other hand, the worse (better) simulations of the warm MNA (warm midsummer ENSO) lead to the lower (higher) prediction skills of AN (BN) events. These results are useful for better understanding the predictability of the midsummer SAT over the MLYR. | Asymmetry of probabilistic prediction skills of the midsummer surface air temperature over the middle and lower reach of the Yangtze River valley | 10.1007/s00382-021-05866-x |
2021-12-01 | While the “low salinity waterflooding” (LSWF) has been praised for enhancing oil recovery from different core rocks, the performance of the technique in different wettability environments remains unclear. The consensus is that LSWF does not work well in water-wet carbonate oil reservoirs. The main research objective was to determine the effect of LSWF on the displacement efficiency (DE) in different wettability environments. Carbonate core flooding experiments on rocks with different wettabilities were performed at in-situ reservoir conditions using seawater as a “base water”. Seawater was sequentially diluted 10 to 50 times and spiked 2 and 6 times with sulfate. Following sequential flooding with four different waters, the DEs were measured for different wettabilities. Five different sequential brine floodings were performed on carbonate rocks. Results indicated that optimum low salinity water is a function of system wettability. Seawater (≈ 50,000 ppm) is the optimum brine for oil-wet and intermediate-wettability systems. Sequential flooding consisting of seawater followed by diluted seawater in a water-wet system yielded the highest DE of 88%. Besides, low-salinity brine followed by sulfate performed better in a water-wet environment than in oil- and intermediate-wettability systems. | The effect of carbonate rock wettability on the performance of low salinity waterflooding: an experimental approach | 10.1007/s13202-021-01309-9 |
2021-12-01 | Understanding permeability evolution caused by the nucleation, propagation and coalescence of cracks enables to better assess fluid migration in the vicinity of underground excavations, boreholes or reservoirs. In this study, we propose a three-dimensional approach combining a bonded particle model and a dual-permeability pore network model to investigate the crack permeability behavior of low-permeable rocks. First, we verify the performances of the numerical scheme by comparing its predictions to analytical permeability solutions for microcracked and fractured porous samples, respectively. Then, we simulate a triaxial compression test on an argillaceous rock sample with periodic permeability measurements. The model is able to reproduce the stress–strain–permeability evolution observed experimentally, from the early stage of microcracking up to the residual post-failure state: (i) permeability does not change significantly before reaching the crack damage threshold and (ii) permeability increases by several orders of magnitude after failure due to the appearance of a discrete shear band across the sample. The good agreement between the numerical results and the experimental observations confirms the relevance of the proposed approach to simulate the crack permeability behavior of low permeable rocks during their progressive failure. Based on this result, we simulate triaxial compression tests under different confining pressures to propose relationships between post-failure permeability and residual mean stress. | Discrete Element Modeling of Permeability Evolution During Progressive Failure of a Low-Permeable Rock Under Triaxial Compression | 10.1007/s00603-021-02622-9 |
2021-12-01 | Rapid investment casting based on additive manufacturing has been widely used because of rapid production of patterns without any tooling requirements. However, the precision wax patterns fabricated by commercial additive manufacturing machine directly is costly. The main objective of this study is to demonstrate a cost-efficient approach for low-volume production of wax patterns by integration of rapid tooling technology, low-pressure wax injection molding, and 3D optical inspection technologies. A dimensional compensation method was used to compensate dimensional changes in the manufacturing process of precision wax pattern. Finally, a case study was examined to illustrate the effectiveness of the proposed method. It was found that the radial and axial shrinkage of the entire manufacturing process are approximately 1.75% and 3.34%, respectively. A simple empirical formula that the dimensions of radial and axial in the design layout are compensated by approximately 0.75 mm and 1 mm when the wax pattern dimension is within 10 mm to 45 mm was proposed. The total production cost of fabricating twenty wax patterns by the proposed method in this study can be saved by about 86% compared to that of fabricating twenty wax patterns by commercial additive manufacturing machine directly. The remarkable findings in this study are very practical and provide the greatest application potential for the fabrication of precision wax pattern economically and efficiently in the investment casting industry. | Development of a cost-effective technique for batch production of precision wax patterns using 3D optical inspection and rapid tooling technologies | 10.1007/s00170-021-07763-3 |
2021-12-01 | Silicon photonics has emerged as one of the most prominent technological platforms for photonic integration. Compared with silicon, silicon nitride has a much broader wavelength transparency range, lower propagation loss, and less sensitivity to temperature changes, making it suitable for the manufacture of passive devices. However, silicon nitride films deposited directly on the wafer by low-pressure chemical vapor deposition exhibit large tensile stress, which may cause cracks. In the work presented herein, a process was developed to fabricate crack-free 400-nm-thick silicon nitride films based on the 200-mm complementary metal–oxide–semiconductor platform. The silicon nitride films were deposited in two steps, each followed by annealing. During the annealing, Si–H and N–H bonds in the film were broken and Si–N bonds were formed, thus improving the uniformity of the film and releasing the stress. Fourier-transform infrared measurements indicated that the films were in near-stoichiometric condition. Wafer-level testing showed that the propagation loss of an 800-nm-wide strip waveguide was 0.5 dB/cm to 0.7 dB/cm for the C-band. The insertion loss of waveguide crossing was approximately 0.15 dB, and the crosstalk was below –43 dB. The insertion loss of 1 × 2 multimode interference was less than 0.3 dB, and the nonuniformity was smaller than 10%. | Characteristics of Crack-Free Silicon Nitride Films Deposited by LPCVD for Photonic Applications | 10.1007/s11664-021-09190-2 |
2021-12-01 | The use of low-cost fused filament fabrication (FFF) machines has been growing in the last years. Being widely used in the industry, the biggest challenges for FFF machines is the difficulty to predict quantitatively the influence of the printing parameters on the printed parts and, consequently, on the printed surface of foam lattices. Such variability hinders the prediction of the structural behaviour of printed materials and parts. Recent studies have shown that gyroid-based structures allow higher structural performances. Such complex geometry, used in distinct pattern distributions, is now possible to be widely produced with additive manufacturing (AM) technologies. This work aims to study the influence of this inner infill geometry on the mechanical properties of PLA parts. Thus, experimental specimens for tensile, compression and bending tests were printed in a 3D printer (Creality Ender3) with $$100\%$$ 100 % infill and four different orientations: (1) $$0^{\circ }$$ 0 ∘ ; (2) $$45^{\circ }$$ 45 ∘ ; (3) $$\pm 45^{\circ }$$ ± 45 ∘ ; and (4) $$90^{\circ }$$ 90 ∘ . Additionally tensile, bending, compression, Charpy and impact specimens were printed in a 3D printer based on a Creality CR-10S with gyroid infill and three different densities: (1) $$20\%$$ 20 % ; (2) $$50\%$$ 50 % ; and (3) $$80\%$$ 80 % . Both groups of specimens were tested and the gyroid structure properties were also investigated. The results show that the best tensile and bending properties were obtained when the filament has the same orientation as the load. Furthermore, the mechanical properties and the weight increased with the gyroid infill density. Finally, the influence of outside perimeters on specimens under compression was constant. It was found that the gyroid structure presents low anisotropy under compression and it was demonstrated that the inner foam structure and pattern (in this case the gyroid structure) is more relevant than the material used to build structural part. | Study on 3D printing of gyroid-based structures for superior structural behaviour | 10.1007/s40964-021-00191-5 |
2021-12-01 | The formation of films of barium monosilicide BaSi and dicilicide BaSi 2 on an n -Si(100) substrate of different thicknesses d = 8–800 nm during the low-energy high-dose implantation of barium ions in Si(100) and magnetron sputtering of bulk samples of barium silicides is studied by electron spectroscopy and low-energy electron diffraction. The optimal modes of the formation and band-energy parameters of BaSi and BaSi 2 films on n -Si(100) are determined. | Formation and Electronic Structure of Barium-Monosilicide- and Barium-Disilicide Films | 10.1134/S1027451022020318 |
2021-12-01 | Purpose It is difficult to perform intestinal anastomosis in low-birth-weight infants because the intestinal diameter is small and the discrepancy in diameter of the proximal and distal intestines is often large, but there has been no optimal-sized training model. Therefore, we developed a new intestinal anastomosis training model that imitated the size of the intestine in low-birth-weight infants, and evaluated its face and construct validity. Methods Two intestinal models were developed with crossMedical, Inc. using a hydrophilic acrylic material (wet model) or a polyurethane soft resin (dry model). The inner diameter of the simulated intestinal tract was 15 mm on the oral end and 6 mm on the anal end. Thirteen pediatric surgeons performed anastomosis and responded to the questionnaire. Results In the questionnaire, the wet model had significantly higher scores than the dry model in “appearance”, “softness” and “usefulness for training”. In the anastomotic results of the wet model, the anastomosis leak pressure was significantly correlated with the number of intestinal anastomotic experiences in low-birth-weight infants (correlation coefficient = 0.64, P = 0.035). Conclusions The wet-type intestinal anastomosis model showed good face validity. Its leak pressure had a significant correlation with clinical experience; thus, construct validity was demonstrated. | Face and construct validity assessment of training models for intestinal anastomosis in low-birth-weight infants | 10.1007/s00383-021-04991-2 |
2021-12-01 | This study aimed to investigate the effects of photobiomodulation at a wavelength of 660 and 830 nm at different numbers of application points in the healing of open wounds in mice. In total, 120 mice were divided into 10 groups. The animals were submitted to cutaneous lesion of the open wound type (1.5 × 1.5 cm). Photobiomodulation at a wavelength of 660 and 830 nm and total energy of 3.6 J were used, applied at 1, 4, 5, and 9 points, for 14 days. The animals were subjected to analysis of the lesion area, skin temperature, and histological analysis. Macroscopic analysis results showed a difference ( p < 0.05) between the irradiated groups and the sham group at 14 days PO. There was no statistical difference in skin temperature. Histological analysis findings showed better results for the epidermis thickness. Regarding the number of blood vessels, a difference was found between the 1- and 5-point 830-nm photobiomodulation groups and between the 4-point 660-nm group and the naive group. A significant difference in the number of fibroblasts was observed between the 830- and 660-nm photobiomodulation groups and the naive and sham groups. When comparing photobiomodulation wavelength, the 830-nm groups were more effective, and we emphasize the groups irradiated at 5 points, which showed an improvement in macroscopic analysis and epidermis thickness, an increase in the number of vessels, and a lower number of fibroblasts on the 14th day after skin injury. | Comparison of photobiomodulation in the treatment of skin injury with an open wound in mice | 10.1007/s10103-020-03216-7 |
2021-12-01 | With the growth in electroencephalography (EEG) based applications the demand for affordable consumer solutions is increasing . Here we describe a compact, low-cost EEG device suitable for daily use. The data are transferred from the device to a personal server using the TCP-IP protocol, allowing for wireless operation and a decent range of motion for the user. The device is compact, having a circular shape with a radius of only 25 mm, which would allow for comfortable daily use during both daytime and nighttime. Our solution is also very cost effective, approximately $350 for 24 electrodes. The built-in noise suppression capability improves the accuracy of recordings with a peak input noise below 0.35 μV . Here, we provide the results of the tests for the developed device. On our GitHub page, we provide detailed specification of the steps involved in building this EEG device which should be helpful to readers designing similar devices for their needs https://github.com/Ildaron/ironbci . | Low-cost brain computer interface for everyday use | 10.1007/s00221-021-06231-4 |
2021-12-01 | This paper deals with the development of a portable electronic device that simultaneously measures toxic gases and suspended particles in real time. It is based on a microcontroller board and low-cost sensors including dust sensor, smoke sensor, liquefied petroleum gas sensor, carbon dioxide (CO 2 ) sensor, carbon monoxide (CO) sensor, temperature, and humidity sensors. The proposed electronic device presents several advantages, namely low energy consumption, low-cost equipment, easily deployable in the field, real-time, and large number measurements of parameters (in situ). It can also send automatically alert information and transmit emergency calls to the supervisor if the concentration of measured pollutant (particulate matter PM 2.5 ) is beyond the threshold WHO limit of 25 µg/m 3 . The proposed electronic device can also be used as an outdoor or indoor air quality monitoring system. Compared to WHO limits, all the values of the parameters measured are generally acceptable, except CO value which slightly exceeds the average threshold value allowed in workplaces. A comparative analysis of particulate matter concentrations obtained from the proposed prototype and a conventional method based on the GENT Stacked Filter Unit Sampler (reference method) is carried out by placing both devices on the same fixed sampling site and collecting data at the same time over a period of two months. A statistical analysis based on linear regression highlighted a good agreement between these two methods with R 2 = 0.8897. Furthermore, a reliability coefficient of 1.008 ± 0.01 confirms the effectiveness of the proposed device. | Low-cost air quality monitoring system design and comparative analysis with a conventional method | 10.1007/s40095-021-00415-y |
2021-12-01 | Abstract Photosynthetic organisms have developed a set of mechanisms aimed at preventing photo-oxidative reactions in the photosynthetic apparatus (PSA) initiated by excessively absorbed light energy. Along with high irradiance, other stressors, e.g., chilling temperatures, can lead to the absorption of the excess of light energy and hence to photo-oxidative stress. Here, we studied induction of photoprotective mechanisms in response to chilling (0°C) at a low irradiance (50 µmol PAR photons m –2 ·s –1 ) in the cells of microalga Lobosphaera incisa IPPAS C-2047. After 4 days of incubation at a low temperature, L. incisa IPPAS C-2047 cells showed a notable decrease in the photochemical activity of photosystem II (PSII) and in the efficiency of photosynthetic electron transport, as well as a significant increase in the thermal dissipation of the absorbed light energy in the light-harvesting antenna. In contrast, most conventional markers of PSA acclimation to excess light energy [total chlorophyll and carotenoid content; violaxanthin cycle pigment content and de-epoxidation state; photosynthetic antenna, PSII, and photosystem I (PSI) ratio] remained virtually unchanged. The content of major unsaturated fatty acids also remained almost unaffected, except for arachidonic acid (increased by 40%) recently assumed to activate violaxanthin de-epoxidase by adjusting its lipid microenvironment. Significant changes (4-7-fold increase) were observed in the expression of the gene encoding protective protein LhcSR. Pre-conditioning at 5°C prior to the acclimation to 0°C augmented the PSA photochemical activity. Our data show that the mid-term (4-d) acclimation of L. incisa IPPAS C-2047 to a chilling temperature at a low irradiance triggers the PSA response resembling, in part, the response to high light but relying mostly on the LhcSR protein-dependent quenching of excitation in the photosynthetic antenna. | The Effect of Chilling on the Photosynthetic Apparatus of Microalga Lobosphaera incisa IPPAS C-2047 | 10.1134/S0006297921120087 |
2021-12-01 | Abstract Different ways of synthesizing bis-, tris-, and octakis-adducts of C 60 and C 70 lower fullerenes are considered, and their yield and purity are described. The adducts are identified by physicochemical means: elemental analysis, IR, electron spectroscopy, Raman spectroscopy, HPLC, mass spectrometry, and complex thermal analysis. Their physicochemical properties are modeled using computers, density functional theory, and molecular dynamics at the atomic-molecular level. | Adducts of Lower Fullerenes and Amino Acids: Synthesis, Identification, and Quantum-Mechanical Modeling of Their Physicochemical Properties | 10.1134/S0036024421120049 |
2021-12-01 | Bacteria exposed to environmental stresses often exhibit superior acclimation abilities to environmental change. Acid treatment causes an increase in the cell length of the cyanobacterium Synechocystis sp. PCC6803 under light conditions. We aimed to elucidate the relationship between acidic stress and cell enlargement. After being synchronized under dark conditions, the cells were cultivated at different pH (pH 8.0 or pH 6.0) levels under light conditions. Synechocystis 6803 cells exhibited only cell growth occurred (cell volume expansion) and slow proliferation under the acidic condition. In the recovery experiment of the enlarged cells, they proliferated normally at pH 8.0, and the cell lengths decreased to the normal cell size under light conditions. Inhibition of cell division might be caused by acidic stress. To understand the effect of acidic stress on cell division, we evaluated the expression of FtsZ via Western blotting. The FtsZ concentration in cells was lower at pH 6.0 than at pH 8.0 and was not sufficient for cell division in the photoautotrophic conditions. ClpXP is well known as a regulator of the Z-ring dynamics in E. coli . The transcriptional level of four clpXP genes was upregulated approximately threefold at pH 6.0 after 24 h compared with that in cells grown at pH 8.0. The lack of FtsZ may be caused by the upregulation of clpXP expression under acidic condition. Therefore, ClpXP may participate in the degradation of FtsZ and be involved in the regulation of cell division via FtsZ under acidic stress in Synechocystis 6803. | The lack of the cell division protein FtsZ induced generation of giant cells under acidic stress in cyanobacterium Synechocystis sp. PCC6803 | 10.1007/s11120-020-00792-1 |
2021-12-01 | Wireless transmission of sensor node signal at minimum power consumption and on-site charging of batteries is the key to the success of Wireless Structural Health Monitoring (WSHM) technology. In structures like bridges, vibration-based piezoelectric energy harvesters are generally employed to convert the ambient vibrations available in the bridges into usable electrical energy. Achieving a lower resonance frequency in a compact micromachined structure is the main goal of this work. It is attempted by optimizing various parameters, including the choice of piezoelectric material used, harvester structural configuration, and conditioning of the output of the energy harvesting circuitry. The authors propose to maximize the induced stress and therefore harvested power by proposing a sectioned cantilever with gradually decreasing widths. Such a design analyzed using the analytical model developed in this work and industrial standard MEMS design tools show that two section beams employed harvesters induce more power and it is 22.8% higher than the power induced in conventional uniform section cantilever beam harvesters. With three sections it is found that it can be further improved by 42.47%. This significant improvement without compromising miniaturization is the key contribution of this work. | Miniaturized but efficient cantilever beam vibration energy harvesters for wireless bridge health monitoring applications | 10.1007/s00419-021-02058-1 |
2021-12-01 | The beekeeping sector is facing many challenges. One of the greatest is maintaining healthy colonies that produce high-quality products without any residues of veterinary medicines and with low environmental impact. The main enemy is the ectoparasitic mite Varroa destructor , the most significant honeybee pest and a key factor in high colony losses worldwide. In the previous four decades, three pillars of Varroa control have crystallized to be essential for sustainable management: apitechnical measures, chemical treatments, and resistant stocks of honey bees. In the long term, the latter is probably the most sustainable as it is a step to self-sustaining populations of feral and managed colonies. We recognize the significance of progress in knowledge of all three pillars to conquer Varroa and of their successful usage in accordance with local and global conditions and capabilities. In this review, we present a possible integration of the components of the three pillars of Varroa control strategies in the light of sustainable beekeeping and provide their linkage to the production of high-quality and safe honeybee products and maintaining healthy colonies. | Three pillars of Varroa control | 10.1007/s13592-021-00903-4 |
2021-12-01 | Abstract The infrared absorption spectra of Ge 14 Sb 29 Te 57 and Ge 15 Sb 15 Te 70 chalcogenide alloys in the amorphous and crystalline states are measured and analyzed in the wave-number range 20–400 cm –1 (0.6–12 THz) at room temperature. Absorption at these frequencies is caused by manifestation of the correlated torsional vibrations of structural units of the amorphous alloy and phonon modes of the crystal. Identification of the absorption bands and the observed differences between the infrared spectra make it possible to establish more confidently the possible molecular mechanism of reversible amorphous-to-crystalline transformations in the investigated phase-change materials. | Optical Properties of the Ge14Sb29Te57 and Ge15Sb15Te70 Phase-Change Materials in the Far-Infrared Range | 10.1134/S1063782621070162 |
2021-12-01 | Exhaust fumes from petrol/diesel-powered electric generators contribute significantly to air pollution in many developing countries, constituting health hazards to both humans and animals. This study evaluated the serum concentrations of Troponin I (TnI), C-reactive protein (CRP) and serum levels/activities of oxidative stress markers: catalase (CAT), reduced glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO) and superoxide dismutase (SOD) in dogs experimentally exposed to graded levels of petrol generator exhaust fume (PGEF). Sixteen (16) healthy and adult male Basenji dogs were randomly assigned into four groups (A-D). Group A was the unexposed control while groups B, C and D were exposed to PGEF for 1, 2 and 3 h per day, respectively, for 90 days. Repeated analysis were performed at the baseline, and every thirty days, for a total of 90 days. There was a significant interaction ( p < 0.05) between the effects of PGEF exposure level (in h/day) and duration of exposure (in months) on all the tested serum parameters. There was a significant main effect ( p < 0.05) for PGEF exposure level on the serum parameters. As the level of PGEF exposure was increased, the serum concentrations of TnI, CRP, CAT, MDA and NO increased, GSH decreased, whereas SOD activity increased by day 30 but declined at the end. Moreover, there was a significant simple main effect ( p < 0.05) for duration of PGEF exposure. All the parameters increased as the duration of PGEF exposure was increased to 90 days except GSH concentration which decreased, whereas SOD activity increased initially but declined at the end of the study. Thus, there was increased serum concentrations of TnI, CRP and increased oxidative stress in the PGEF-exposed dogs. These findings are instructive and could be grounds for further studies on air pollutants-induced cardiovascular disease given the widespread use of electricity generators in many low-resource countries. | Effects of Controlled Generator Fume Emissions on the Levels of Troponin I, C-Reactive Protein and Oxidative Stress Markers in Dogs: Exploring Air Pollution-Induced Cardiovascular Disease in a Low-Resource Country | 10.1007/s12012-021-09693-8 |
2021-12-01 | Abstract The possibility of processing and complex use of the domestic low-grade high-silicon aluminum-containing ores is considered. A new method for the separation of aluminum and iron by an electrochemical method in an acidic solution is proposed. The anodic and cathodic processes are considered and their characteristic features are revealed. Cascade and closed systems are proposed for the electrochemical refining of an alumochloride solution from iron impurities. | Refining of Aluminum-Containing Chloride Solutions from Iron | 10.1134/S0036029521120156 |
2021-12-01 | Gallium nitride (GaN) substrates are promising candidates for GaN high-electron-mobility transistors (HEMTs) because of their epitaxial layer growth with low defect density. We perform device simulations to study the influence of substrate acceptor traps in GaN HEMTs on semiinsulating GaN substrates with a thin (0.02 μm) channel layer. When the trap concentration in the GaN substrate increases at a constant channel trap concentration of 1.0 × 10 15 cm −3 , the drain leakage current decreases but the transient response worsens. These phenomena result from an increase of the conduction-band energy due to ionized acceptor traps with negative charge. For GaN buffer structures, we obtain moderate suppression of the drain leakage current (1.7 × 10 −9 A/mm) and a good transient response (with a normalized drain current of 0.86 at 1 ms for the transient response from the off- to on-state condition) at a substrate trap concentration of 5.0 × 10 15 cm −3 . The aluminum gallium nitride (AlGaN) back-barrier structure is highly effective for suppressing the drain leakage current at a low trap concentration of 1.0 × 10 15 cm −3 in GaN substrates. Although its maximum drain current is decreased, this structure exhibits a low drain leakage current (4.7 × 10 −11 A/mm) and a high normalized drain current (0.95) in the transient response. Increasing the Al content in the barriers of the GaN HEMT structure increases its maximum drain current to 1.2 A/mm, whereas the drain leakage current and transient response are well maintained. Moreover, the traps in the GaN substrate affect the low-frequency S 21 , which is important for the linearity of power amplifiers, and the characteristics of S 21 are similar to those of the transient responses. | A simulation study of the impact of traps in the GaN substrate on the electrical characteristics of an AlGaN/GaN HEMT with a thin channel layer | 10.1007/s10825-021-01809-1 |
2021-12-01 | It is of great significance to study the pore heterogeneity of coal because it affects coalbed methane exploration and exploitation. In this study, mercury intrusion porosimetry (MIP) and low-pressure N 2 adsorption methods were adopted to analyze the multifractal characteristics of coal pore structures with different coalification degrees. Next, a comparison was made between the two methods regarding pore structure heterogeneity. The relationships among multifractal parameters and coal ranks, proximate analysis, coal compositions, and pore structures were discussed further. The results show that the multifractal parameters of pore structures determined using the two methods had no obvious correlations. However, they were all found to be influenced by coalification degree. As coalification degree increased, the heterogeneity and complexity of the pore structures increased. Micropores measured by the MIP method had dominantly negative effects on pore connectivity and homogeneity. Meanwhile, the influencing effects of transitional pores, mesopores, and macropores were observed to be the opposite. In addition, increases in vitrinite content could potentially decrease pore connectivity and increase pore complexity, while increases in inertinite content have the opposite effects. | Multifractal Analysis of Pore Structure in Middle- and High-Rank Coal by Mercury Intrusion Porosimetry and Low-Pressure N2 Adsorption | 10.1007/s11053-021-09952-z |
2021-12-01 | Abstract Synthesis of dimethylmethylphenylsiloxane rubbers with terminal hydroxyl groups by copolymerization of cyclosiloxanes can be accompanied by formation of low-molecular weight compounds, impurities, which are difficult to remove (because of target product affinity) and can lead to rubber opalescence. Identification of the impurities (the content of each impurity ≥10 –4 wt % in 1 μL of the sample) can be carried out using a sensitive gas chromatography–mass spectrometry method. The method allows separation of the analyzed mixture into individual components on a capillary column. These components enter a mass analyzer and undergo electron ionization, which leads to their dissociation into pairs “cation–neutral fragment.” Only positively charged ions are observed in the mass spectra, which make it possible to predict the structure of the analyzed siloxane impurities. Rearrangement of linear and cyclic molecules occurring upon mass spectrometric fragmentation results in their transformation into cyclic and bicyclic cations. The structure of the cations formed under ionization conditions depends on the number of silanol bonds and their location in the molecule. To prove the presence of compounds with hydroxyl groups in the composition of impurities and to demonstrate the effect of electron ionization on the fragmentation of compounds with silanol bonds, a sample of oligomethylsiloxane with terminal trimethylsiloxy groups was synthesized in a similar way using the copolymerization method. Compounds with silanol bonds present in the composition of the impurities appear as chromatographic asymmetric peaks with ascending and descending gently sloping zones. Those compounds are rearranged either when passing through a chromatographic column owing to sorption-desorption and enter the detector in a modified form or drift through the column and undergo rearrangements already under conditions of electron ionization. The impurities contain linear and cyclic methylsiloxanes with silanol and phenyl bonds. The chromatography–mass spectrometry method provides a reliable control of the composition and content of undesirable impurities which cause rubber opalescence. | Composition of Low-Molecular Weight Impurities in Dimethylmethylphenylsiloxane Rubbers with Terminal Hydroxyl Groups | 10.1134/S0020168521140132 |
2021-12-01 | Purpose This research aims to improve the efficiency of phytoremediation of Cd in soil using sunflowers and optimizing the model of Cd uptake by plants. Methods Five low molecular weight organic acids (LMWOAs), oxalic acid (OA), acetic acid (AA), tartaric acid (TA), malic acid (MA), and citric acid (CA) at 2, 4, and 6 mmol/kg, were applied to sunflowers at 20, 30, and 40 days after seed emergence. The pH, electric conductivity (EC), total nitrogen (TN), total phosphorus (TP), catalase activity, amylase activity, invertase activity, and Cd content in rhizosphere soil and Cd in plant tissues were analyzed. Results Plant biomass was greater at the application rates of 2 and 4 mmol/kg. For each acid treatment, the Cd content in roots and leaves increased, while that of the stem and bud decreased. The total Cd accumulation increased due to the increase in plant biomass, especially root tissues; LMWOAs applied at 20 or 30 days after seedling emergence achieved higher Cd accumulations by expanding the Cd absorption capacity of rhizosphere soil. Application time had a more significant influence on plant biomass, Cd content, and accumulation in plant tissues than the variation of LMWOAs. Soil invertase activity and pH are the main factors causing the change in Cd form. An improved Freundlich model, using soil EC and pH, had higher accuracy than a model using pH alone. Conclusions LMWOAs can increase Cd accumulation in plants, and a lower application rate (2 mmol/kg) and earlier application date (20 days after seedling emergence) are beneficial for improving the phytoremediation efficiency of sunflower. The increase of root biomass expanded the contact area between plants and soil, which was one of the reasons for the increase of Cd accumulation. EC could be used as a supplementary index to improve the Freundlich model when using pH. | Examination of Cd Accumulation Within Sunflowers Enhanced by Low Molecular Weight Organic Acids in Alkaline Soil Utilizing an Improved Freundlich Model | 10.1007/s42729-021-00551-8 |
2021-12-01 | Low back pain is a widespread and poorly understood condition that is frequently diagnosed as non-specific low back pain. We were intrigued by the presence of painful sacroiliac nodules in patients with this condition. We conducted a historical review to elucidate this relationship. This chronicled review summarizes the overlooked literature from different countries, especially from around the 1950s, regarding the diagnosis and management of these painful nodules. Biopsies have confirmed the adipose nature of these nodules and revealed distinct pathological signs, including oedema and fascial fatty herniation. Studies have suggested both intra-nodule local anaesthetic injection and surgery as successful treatments for managing pain on a short- or long-term basis. Recent ultrasound studies have confirmed these findings. The various terms used for these nodules over time are specifically described. We conclude that it may be necessary to reconsider the role of fatty tissue in the aetiology and treatment of low back pain in today’s mainstream medicine. This could lead to advances in understanding unexplained musculoskeletal pain disorders beyond low back pain. Meanwhile, despite the remaining questions, the treatments identified in these studies can help physicians manage patients’ unresolved pain. We recommend that future research use this review as a foundation for further study. | Historical Review of Studies on Sacroiliac Fatty Nodules (Recently Termed “Back Mice”) as a Potential Cause of Low Back Pain | 10.1007/s40122-021-00321-5 |
2021-12-01 | Low light conditions not only induce leaf senescence, but also photosynthetic acclimation. This study aimed to determine whether plants exhibit photosynthetic acclimation during low-light-induced leaf senescence. The influences of shading on leaf senescence and photosynthetic acclimation were explored in post-anthesis maize plants. The results showed that whole shading (WS) of maize plants accelerated leaf senescence, whereas partial shading (PS) slowed leaf senescence. WS led to larger decreases in the photosynthetic rate (P n ) and stomatal conductance (G s ) compared to those of the PS treatment. Interestingly, chlorophyll a fluorescence (ChlF) demonstrated that the absorption flux (ABS/CS o ) and trapped energy flux (TR o /CS o ) per cross section in leaves remained relatively stable under WS, whereas significant decreases in the active PSII reaction centers (RC/CS o ) resulted in considerable increases in absorption (ABS/RC) and trapped energy flux (TR o /RC) per reaction center. ABS/CS o , TR o /CS o , ABS/RC, and TR o /RC increased markedly under PS, whereas there were slight decreases in RC/CS o and electron transport activity. These results suggest that the PS treatment resulted in obvious improvements in the absorption and capture of light energy in shaded leaves. Further analysis demonstrated that both the WS and PS treatments resulted in a greater decrease in the activity of Rubisco compared to that of phosphoenolpyruvate carboxylase (PEPC). Moreover, PEPC activity in PS was maintained at a high level. Consequently, the current study proposed that the improvement of the absorption and capture of light energy and the maintenance of PEPC activity of mesophyll cells were due to photosynthetic acclimation of low-light-induced leaf senescence in maize plants. In addition, the rate of senescence of vascular bundle cells in maize leaves exceeded that of mesophyll cells under low light, showing obvious tissue specificity. | Photosynthetic acclimation during low-light-induced leaf senescence in post-anthesis maize plants | 10.1007/s11120-021-00851-1 |
2021-12-01 | Key message The roles of root exudates are not to directly solubilize P bound to non-crystalline minerals but to increase organic-P and plant-available P through priming effects for microbes on volcanic soils. Abstract Volcanic soils are generally characterized by low phosphorus (P) availability for plants because the non-crystalline minerals produced during weathering process strongly combine P with ligand binding. How forest trees absorb such bound P in volcanic soils have not been well known. The aim of this study was to investigate the mechanisms of P acquisition by trees in three evergreen broadleaved forests on volcanic soils differing in the concentration of non-crystalline minerals with an emphasis on the role of low-molecular-weight organic acids (LMWOAs). LMWOAs released from tree fine roots were expected (1) to chemically release P bound to non-crystalline minerals, and/or (2) to biologically enhance P availability through priming effects by stimulating soil microbial activities and by increasing the concentration of organic P in the rhizosphere. Compositions of LMWOA exudates were phylogenetically determined but the flux of citric and malic acids tended to increase in soils where the concentration of non-crystalline minerals was higher. The concentration of P bound to non-crystalline minerals was lower in the rhizosphere than in non-rhizosphere soils, suggesting the solubilization of the bound P in the rhizosphere; however, this trend occurred only in one forest. In contrast, the concentrations of organic P, easily soluble P and total P were significantly greater in the rhizosphere than in non-rhizosphere soils in all sites. Our results suggested that LMWOAs exudates did not directly release P from non-crystalline minerals but increased organic P associated with soil microbial biomass in rhizosphere soils, which in turn enhanced plant-available P and total P. | Effects of tree-root exudates on the solubilization of phosphorus adsorbed to non-crystalline minerals in the rhizosphere volcanic soils on Yakushima Island, Japan | 10.1007/s00468-021-02170-3 |
2021-12-01 | To address the problem of dietary restraint of health-conscious people, a techno-feasible process for development of low-fat and high-fibre fabricated potato snack has been standardised. The product was optimised on the basis of fat and fibre content, browning index, hardness, crunchiness, and overall acceptability (OAA) by using the central composite rotatable design (CCRD) of response surface methodology (RSM). The fabricated snacks with an average thickness of 2.06 mm contained 5.04–5.24% moisture. Hardness and browning index of baked potato snack was significantly influenced by peel incorporation followed by fat content and leavening agent. Maximum crunchiness was achieved at lower peel (~1.5%) and fat (~2.25%) addition. Leavening agent and fat demonstrated a positive effect on the overall acceptability of the snack. The maximum OAA (8.58) was achieved when both peel and fat were in range but at maximum level of leavening agent. Incorporation of 1.84% potato peel, 4.80% fat, and 1.60% leavening agent resulted in a well-accepted fabricated potato snack which can be categorised as ‘low fat’ and ‘good source of fibre’ since a 30-g serving of this fabricated snack provided < 3 g fat and 2.5–4.9 g fibre. The developed technology can diversify the present processed potato product range with effective utilisation of its peel. | Utilisation of Potato Peel in Fabricated Potato Snack | 10.1007/s11540-021-09492-2 |
2021-12-01 | Three novel halophilic archaea were isolated from seawater and sediment near Yeoungheungdo Island, Republic of Korea. The genome size and G + C content of the isolates MBLA0076 T , MBLA0077 T , and MBLA0078 T were 3.56, 3.48, and 3.48 Mb and 61.7, 60.8, and 61.1 mol%, respectively. The three strains shared 98.5–99.5 % sequence similarity of the 16 S rRNA gene, whereas their sequence similarity to the 16 S rRNA gene of type strains was below 98.5 %. Phylogenetic analysis based on sequences of the 16 S rRNA and RNA polymerase subunit beta genes indicated that the isolates belonged to the genus Haloferax . The orthologous average nucleotide identity, average amino-acid identity, and in silico DNA-DNA hybridization values were below species delineation thresholds. Pan-genomic analysis indicated that the three novel strains and 11 reference strains had 8981 pan-orthologous groups in total. Fourteen Haloferax strains shared 1766 core pan-genome orthologous groups, which were mainly related to amino acid transport and metabolism. Cells of the three isolates were gram-negative, motile, red-pink pigmented, and pleomorphic. The strains grew optimally at 30 °C (MBLA0076 T ) and 40 °C (MBLA0077 T , MBLA0078 T ) in the presence of 1.28 M (MBLA0077 T ) and 1.7 M (MBLA0076 T , MBLA0078 T ) NaCl and 0.1 M (MBLA0077 T ), 0.2 M (MBLA0076 T ), and 0.3 M (MBLA0078 T ) MgCl 2 ·6H 2 O at pH 7.0–8.0. Cells of all isolates lysed in distilled water; the minimum NaCl concentration necessary to prevent lysis was 0.43 M. The major polar lipids of the three strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and sulphated diglycosyl archaeol-1. Based on their phenotypic and genotypic properties, MBLA0076 T , MBLA0077 T , and MBLA0078 T were described as novel species of Haloferax , for which we propose the names Haloferax litoreum sp. nov., Haloferax marinisediminis sp. nov., and Haloferax marinum sp. nov., respectively. The respective type strains of these species are MBLA0076 T (= KCTC 4288 T = JCM 34,169 T ), MBLA0077 T (= KCTC 4289 T = JCM 34,170 T ), and MBLA0078 T (= KCTC 4290 T = JCM 34,171 T ). | Haloferax litoreum sp. nov., Haloferax marinisediminis sp. nov., and Haloferax marinum sp. nov., low salt-tolerant haloarchaea isolated from seawater and sediment | 10.1007/s10482-021-01661-0 |
2021-12-01 | In this paper, we extend our study of mass transport in multicomponent isothermal fluids to the incompressible case. For a mixture, incompressibility is defined as the independence of average volume on pressure, and a weighted sum of the partial mass densities stays constant. In this type of models, the velocity field in the Navier–Stokes equations is not solenoidal and, due to different specific volumes of the species, the pressure remains connected to the densities by algebraic formula. By means of a change of variables in the transport problem, we equivalently reformulate the PDE system as to eliminate positivity and incompressibility constraints affecting the density, and prove two type of results: the local-in-time well-posedness in classes of strong solutions, and the global-in-time existence of solutions for initial data sufficiently close to a smooth equilibrium solution. | Well-posedness analysis of multicomponent incompressible flow models | 10.1007/s00028-021-00712-3 |
2021-12-01 | Coalbed methane is a lucrative energy source, but its development relies heavily on the fracturing of coal seam and underground extraction during mining. This study of mining stress paths, pore pressure, and permeability of a coal body was aimed to overcome the constraints of low coal permeability under the stress applied to a coal seam group. Variation in the applied stress changes the effective stress in coal and its permeability (which also depends on pore pressure). The effects of different mining intensities, repetitive cyclic loading and unloading, and pore pressure on gas permeability in a coal mine are revealed and discussed. The permeability evolution curve can be described by quadratic polynomial equations and split into three (decreasing, stable, and increasing) stages. When the stress environment with low axial deviatoric stress changes to that with high axial deviatoric stress and when the stability stage becomes longer, the goodness of quadratic polynomial data fitting is reduced. Cyclic loading and unloading with different axial stress paths have different effects on coal permeability. Increased axial and confining pressures decrease the permeability and pore pressure sensitivity of permeability. Because the obtained permeability-pore pressure curves contain a stable stage, this sensitivity is more pronounce in the low and high pore pressure stages. | Repetitive Mining Stress and Pore Pressure Effects on Permeability and Pore Pressure Sensitivity of Bituminous Coal | 10.1007/s11053-021-09902-9 |
2021-12-01 | Abstract Tissue regeneration following radiotherapy occurs due to the survival and regenerative abilities of tissue stem cells and resident or invading mesenchymal stem cells (MSCs), and their functional characteristics depend significantly on their sensitivity to ionizing radiation. The aim of this work was to study the effect of long-term cultivation of adipose tissue–derived MSCs on their radiosensitivity and the ability to repair DNA double-strand breaks (DSBs). To determine whether in vitro expansion influences the sensitivity of MSCs to low and sublethal doses of γ-radiation, we maintained short- and long-term MSC cultures and analyzed their radiosensitivity at early and late passages. MSCs possessed a high telomerase activity at passage 6 (P6) and an extremely low one at passage 30 (P30). The doubling time of cells by passage 30 decreased by 7 h. MSCs irradiated at P30 demonstrated significantly decreased survival seven days after irradiation at 0.1 and 1 Gy compared with the control and P6 cultures. The clonogenic activity of MSCs irradiated at P30 and P6 was the same. MSC cell cycle analysis at P30 and P6 indicated G 0 /G 1 arrest after 24 h, but G 2 /M arrest at 6 Gy after seven days. The P30 MSCs were able to repair DNA DSB efficiently after γ-irradiation. Even after irradiation at a dose of 6 Gy, P30 MSCs maintained their ability for adipocyte differentiation and cytokine secretion. These results demonstrate that, after long-term cultivation, adipose tissue-derived MSCs maintain the ability to repair DNA DSB and possess stable functional characteristics and differentiation potential after irradiation, suggesting their resistance to sublethal doses of γ-radiation. They can also retain their functions in the tissue surrounding the irradiated organ. | Features of the Response of Long-Term Cultured Adipose Tissue–Derived Mesenchymal Stem Cells to γ-Irradiation | 10.1134/S1062359021110078 |
2021-12-01 | Saldigones A–C ( 1 , 3 , 4 ), three new isoprenylated flavonoids with diverse flavanone, pterocarpan, and isoflavanone architectures, were characterized from the roots of Salvia digitaloides , together with a known isoprenylated flavanone ( 2 ). Notably, it’s the first report of isoprenylated flavonoids from Salvia species. The structures of these isolates were elucidated by extensive spectroscopic analysis. All of the compounds were evaluated for their activities on Ca v 3.1 low voltage-gated Ca 2+ channel (LVGCC), of which 2 strongly and dose-dependently inhibited Ca v 3.1 peak current. Graphic Abstract | Isoprenylated Flavonoids as Cav3.1 Low Voltage-Gated Ca2+ Channel Inhibitors from Salvia digitaloides | 10.1007/s13659-021-00307-y |
2021-12-01 | Determination of tritium along Danube River Banks, in shallow waters, from Baziaş to Sulina, led to an average value of 29 TU and to a slight increasing tendency. Upstream/downstream “signatures” of Kozloduy NPP and Cernavoda NPP, and lower values on the left bank than on right bank in Romania, between Ostrov and Tulcea were highlighted. For Black Sea Coast seashore waters, from Periboina to Vama Veche (55 points; average 31 TU), was highlighted tritium decreasing southward, a rising into central area, a difference between exposed and gulf areas, between seawater and adjacent lakes by the sea. | Tritium along the banks of the Danube and the Black Sea shore of Romania | 10.1007/s10967-021-07975-7 |
2021-12-01 | Macrophage to foam cell transition and their accumulation in the arterial intima are the key events that trigger atherosclerosis, a multifactorial inflammatory disease. Previous studies have linked arterial stiffness and cardiovascular disease and have highlighted the use of arterial stiffness as a potential early-stage marker. Yet the relationship between arterial stiffness and atherosclerosis in terms of macrophage function is poorly understood. Thus, it is pertinent to understand the mechanobiology of macrophages to clarify their role in plaque advancement. We explore how substrate stiffness affects proliferation of macrophages and foam cells, traction forces exerted by macrophages and uptake of native and oxidized low-density lipoproteins. We demonstrate that stiffness influences foam cell proliferation under both naïve and inflammatory conditions. Naïve foam cells proliferated faster on the 4 kPa polyacrylamide gel and glass whereas under inflammatory conditions, maximum proliferation was recorded on glass. Macrophage and foam cell traction forces were positively correlated to the substrate stiffness. Furthermore, the influence of stiffness was demonstrated on the uptake of lipoproteins on macrophages treated with lipopolysaccharide + interferon gamma. Cells on softer 1 kPa substrates had a significantly higher uptake of low-density lipoproteins and oxidized low-density lipoproteins compared to stiffer substrates. The results herein indicate that macrophage function is modulated by stiffness and help better understand ways in which macrophages and foam cells could contribute to the development and progression of atherosclerotic plaque. | Inflammation Drives Stiffness Mediated Uptake of Lipoproteins in Primary Human Macrophages and Foam Cell Proliferation | 10.1007/s10439-021-02881-1 |
2021-12-01 | Water treatment for human uses is a vital asset to economic development. This article focuses on a combination of physical, biological, and chemical processes. Methods of water treatment require concrete or steel base structures, rendering them heavy, costly, and time-consuming to establish. Water treatment systems should be economically viable and practicable in design for developing societies; hence, structural builds should be simplified. Novel structures, a series of polyethylene cyclonic ponds for water treatment, were built and tested. Tanks were equipped with a settled material central outlet, water side outlet, and a pump shower system that enabled sludge removal without mechanical intervention. A freely flowing vortex was produced, aerated, given a biological treatment, and finally mixed with a chemical treatment step. Test establishment of the batch system enabled improvement in water quality, with removal performance as follows: TSS (total suspended solids) = 98%, UV 254 absorbance = 50%, DOC (dissolved organic carbon) = 56%, and turbidity=95%. The batch system builds of the current study required short construction time and were economically priced. Cyclonic ponds are suited to diverse usage. The value may be felt in the improvement of water quality for human consumption, utility, and ecosystem services to counter the extensive pollution caused by oil and gas extraction and other industries. | Water purification plantations for oil and gas industries in Iran | 10.1007/s11356-021-15819-w |
2021-12-01 | Purpose Increasing the migration of arsenic in contaminated soil is an important topic in the field of soil remediation. The purpose of this study was to investigate the enhancement of arsenic migration in soil by low molecular weight organic acids. Materials and methods Four different low molecular weight organic acids were used to wash the soil to increase arsenic mobility under different experimental conditions, including the type of LMWOA, reaction time, and pH. The arsenic fractions in the soil were further quantitated and analyzed. Results and discussion In the batch experiment, the LMWOA enhancement of arsenic migration was in the order of 3-mercaptopropionic acid > aspartic acid > succinic acid > propionic acid. At pH 11, 247.29 mg/kg arsenic was leached from the soil with 3-mercaptopropionic acid over 48 h. This was confirmed in column experiments where 3-mercaptopropionic acid was also the most effective, releasing 21.02% of the arsenic after 75 h. This suggests that the sulfhydryl group of 3-mercaptopropionic acid was superior to other groups in accelerating arsenic migration. Conclusions These results enhance our understanding of the interaction between arsenic migration and organic acid functional groups and have applications for the development of soil remediation technology. | Enhanced mobilization of arsenic from tailing soil by four types of low molecular weight organic acids with different functional groups | 10.1007/s11368-021-03057-z |
2021-12-01 | Optimized high-performance thin-layer chromatography‒bioautography screening of Ecuadorian Chenopodium quinoa Willd. leaf extracts for inhibition of α-amylase | 10.1007/s00764-021-00140-6 | |
2021-12-01 | Purpose We previously reported beneficial glucoregulatory effects of a fully provided carbohydrate-reduced, high-protein (CRHP) diet in patients with type 2 diabetes mellitus (T2DM) in a crossover 2 × 6-week trial, in which patients maintained their body weight. Here, we investigated physiological changes during an additional 6-month period on a self-selected and self-prepared CRHP diet. Methods Twenty-eight patients with T2DM were instructed to consume a CRHP diet (30% of energy from carbohydrate and 30% from protein) for 24 weeks, after an initial 2 × 6-week trial when all food was prepared and provided to them. Patients received dietary advice every 2 weeks. At weeks 0, 6, 12 and 36, they underwent a 3-h intravenous glucose tolerance test, a 4-h mixed meal test, and a 48-h continuous glucose monitoring. Liver, muscle, pancreas, and visceral fat contents were measured by magnetic resonance imaging. Results During the 24-week self-selected diet period (weeks 12–36), body weight, visceral fat, liver fat, and glycated haemoglobin were maintained at the same levels achieved at the end of the fully provided diet period, and were still lower than at baseline ( P < 0.05). Postprandial insulinaemia and insulin secretion were significantly greater ( P < 0.05). At week 36, fasting insulin and C-peptide levels increased ( P < 0.01) and daily glycaemia decreased further ( P < 0.05) when compared with the end of the fully provided diet period. Conclusion Substituting dietary carbohydrate for protein and fat has metabolic benefits in patients with T2DM. These beneficial effects are maintained or augmented over the next 6 months when patients self-select and self-prepare this diet in a dietitian-supported setting. Trial registration ClinicalTrials.gov NCT02764021. | Body weight and metabolic risk factors in patients with type 2 diabetes on a self-selected high-protein low-carbohydrate diet | 10.1007/s00394-021-02605-0 |
2021-12-01 | Abstract The analytical capabilities of arc optical emission spectroscopy have been studied for purposes of monitoring the impurities in kaolin clays, the initial feedstock for production of metallurgical alumina. The compositions of samples were preliminarily estimated by semiquantitative X-ray fluorescent analysis. Analytical lines free from superpositions were selected; the analytical conditions and parameters of the spectrometer were determined: current, exposure, anode to cathode distance, type and size of electrode, sample weight. The detection limits and lower thresholds were specified for the following elements: Ca, Cr, Cu, Ga, Mg, Mn, Mo, Nb, Ni, Pb, Sc, Ti, V Y, Zn, Zr, La. The lower thresholds of determined contents were equal to n × 10 –5 — n × 10 –6 wt %. Comparative analysis of kaolin clays was performed after preliminary analysis by other methods. It has been demonstrated that there are no significant discrepancies between the results obtained by the two methods. | Arc Optical Emission Spectroscopy of Initial Feedstock for Production of Metallurgical Alumina | 10.1134/S0020168521140065 |
2021-12-01 | The organic integration of food security and agricultural mechanization has become a challenge to realize a low-carbon economy, which helps promote carbon peaking and carbon neutralization. In this work, a simultaneous equation model has developed to analyze the relationship between food security, agricultural automation, and agricultural carbon emissions in China. The ordinary least square method was used to verify the method. The logarithmic mean Divisia index decomposition was used to decompose further the influencing factors of agricultural carbon emissions. Results show that the organic coupling of a low-carbon economy, food security, and agricultural mechanization positively affects environmental protection. In which, unit fertilizer usage and crop sown area have the greatest impact on carbon emission intensity, followed by agricultural diesel fuel and agricultural plastic film. It is worth noting that the bottom line of the grain sown area cannot be touched. It is a prerequisite for ensuring grain production. Finally, this paper presents suggestions based on China’s achievements, where the top-level design is crucial. | Relationship and integrated development of low-carbon economy, food safety, and agricultural mechanization | 10.1007/s11356-021-15465-2 |
2021-12-01 | Benzene is volatile organic hydrocarbon which is widely used in a wide range of industries. Studies have shown that exposure to benzene consequences serious health risks for human. Understanding the effect and risks of environmental hazard materials in the laser therapy of skin is interesting which can show useful or harmful role of these effects in therapies. In this study, the effect of low-level laser therapy was investigated on benzene-induced cytotoxicity on human skin fibroblast cells (HU02). Human skin fibroblast cells (HU02) were exposed to various concentrations of benzene (0–100 μg/mL) and incubated for 2 h. Then the effect of low-level laser therapy (LLLT) at 660-nm wavelength with 3 J/cm 2 energy for 90 s was investigated on the viability of the cells exposed to benzene using MTT assay and inverted light microscope. The effect of low-level laser therapy on the viability of the cells was positive at concentrations 0–15 μg/mL but negative at higher concentrations than 15 μg/mL. Low-level laser therapy in low concentrations of benzene decreases the cytotoxicity caused by benzene and maintains cell viability. At high concentrations and in the presence of low-level laser therapy, the cell viability decreased compared to dark experiment. The morphology study of the cells using inverted light microscopy has confirmed the MTT results. | Effect of low-level laser irradiation on cytotoxicity of benzene in human normal fibroblast cells | 10.1007/s10103-020-03211-y |
2021-12-01 | Abstract Envenomation by the pit viper Bothrops jararacussu (jararacuçu) ( B. jararacussu ) causes local effects, such as pain, swelling, inflammation, haemorrhage and myonecrosis. Purpose The objective of this study was to examine the effects of ozonated oil therapy (OZT) associated with photobiomodulation therapy (PBMT) on the local effects caused by B. jararacussu venom in vivo. Methods Forty-six mice were randomly allocated to five groups: control ( n = 6) injected with 50 µL 0.9% NaCl (saline), venom (V) ( n = 10) injected with venom alone (30 µg/50 µL of saline), V + PBMT ( n = 10) treated with low-level laser alone (685 nm, 4 J/cm 2 , 100 mW, 12 s), V + OZT ( n = 10) treated with ozonated sunflower oil applied for 15 min (350 mg/L) (corona generator, Ozone & Life®), and V + PBMT + OZT ( n = 10) treated with low-level laser plus ozonated sunflower oil. Each of these groups was divided into two subgroups for evaluation 3 h and 24 h post-venom. All injections were made in the right gastrocnemius muscle, and at the desired time after venom or saline injection, the mice were killed and the muscles removed, fixed and processed for histological analysis by light microscopy after staining with haematoxylin–eosin. The histological alterations were assessed using ImageJ® software, and oedema was determined by weighing the muscles. Blood creatine kinase activity (CK) was quantified colourimetrically. Results Treatment with PBMT and OZT attenuated the venom-induced damage and reduced the extent of myonecrosis, but there was no synergism between these treatments. OZT was effective in protecting against the immediate (3 h) and late (24 h) effects of the venom, with 30.0% and 40.0% protection, respectively, whereas PBMT protected primarily against the late effects on muscle cells (24 h, 21.7% protection). OZT was more effective against the immediate damage caused by the venom than was PBMT (24 h, 47.4%). Venom caused a marked increase in CK release after 3 h (212%) and 24 h (237%) that was prevented by the different treatments. Conclusions The results of this investigation indicate that PBMT and OZT can, individually, partially protect against the myonecrosis and oedema caused by B. jararacussu venom, with OZT being more effective, particularly in the early stages of envenomation. | The use of ozone therapy and photobiomodulation therapy to treat local effects of Bothrops jararacussu snake venom | 10.1007/s42600-021-00184-x |
2021-12-01 | Background Anogenital warts are a common human papillomavirus infection. They cause emotional distress, especially when they are in the anogenital region. Cryotherapy is a first-line treatment. Previous clinical trials and case series have reported variable results with retinoids (isotretinoin) as adjuvant therapy. Objective To determine the safety and efficacy of low-dose oral isotretinoin as adjuvant treatment of anogenital warts. Methods Forty-six patients with anogenital warts were randomly assigned to isotretinoin + cryotherapy ( n = 23) or only cryotherapy ( n = 23). Patients were allocated via an interactive web-based randomization system. Evaluators were blinded to treatments. Isotretinoin 20 mg/daily + cryotherapy or cryotherapy were prescribed for 6 weeks. Patients were followed for 4 months. Genotyping of lesions was performed before treatment started. Dermatology Life Quality Index (DLQI) and Columbia-Suicide Severity Rating Scale (C-SSRS) were measured at the beginning and end of therapy. All patients completed the study. Results Both Groups had 50% clearance at the end of treatment. Recurrence in the combined group was not significantly lower than in the cryotherapy group ( P = 0.59). Improvement was observed in the DLQI of all patients in both groups ( P = 0.001). No suicidal intention was detected with the C-SSRS. Two patients (one in each group) had liver function test abnormalities after treatment. Conclusion Combined therapy showed a slight not significant efficacy for anogenital warts in Hispanic patients. Low-dose isotretinoin seems to be safe even when it is used with cryotherapy on anogenital warts. Trial registration On April 25, 2019 with registration number DE19-00004, CONBIOÉTICA-19-CEI-001–20160404. Prospectively registered. | Cryotherapy plus low-dose oral isotretinoin vs cryotherapy only for the treatment of anogenital warts: a randomized clinical trial | 10.1007/s00403-020-02182-y |
2021-12-01 | I argue that high level causal relationships are often more fundamental than low level causal relationships. My argument is based on some general principles governing when one causal relationship will metaphysically ground another—a phenomenon I term derivative causation . These principles are in turn based partly on our intuitive judgments concerning derivative causation in a series of representative examples, and partly on some powerful theoretical considerations in their favour. I show how these principles entail that low level causation can derive from high level causation, and in particular that neural causation can derive from mental causation. I then draw out several important consequences of this result. Most immediate among these are the implications the result has for aspirations to reduce high level causation to its low level counterpart. But the result also bears on the possibility of downward causation, the relationship between counterfactuals and causation, and the idea—familiar from both the literature on the exclusion problem and the literature on proportionality constraints on causation—that causal relationships at different levels compete for their existence. | Building low level causation out of high level causation | 10.1007/s11229-021-03231-3 |
2021-12-01 | Individuals with chronic low back pain (cLBP) frequently report sleep disturbances. Living in a neighborhood characterized by low-socioeconomic status (SES) is associated with a variety of negative health outcomes, including poor sleep. Whether low-neighborhood SES exacerbates sleep disturbances of people with cLBP, relative to pain-free individuals, has not previously been observed. This study compared associations between neighborhood-level SES, pain-status (cLBP vs. pain-free), and daily sleep metrics in 117 adults (cLBP = 82, pain-free = 35). Neighborhood-level SES was gathered from Neighborhood Atlas, which provides a composite measurement of overall neighborhood deprivation (e.g. area deprivation index). Individuals completed home sleep monitoring for 7-consecutive days/nights. Neighborhood SES and pain-status were tested as predictors of actigraphic sleep variables (e.g., sleep efficiency). Analyses revealed neighborhood-level SES and neighborhood-level SES*pain-status interaction significantly impacted objective sleep quality. These findings provide initial support for the negative impact of low neighborhood-level SES and chronic pain on sleep quality. | Sleep and neighborhood socioeconomic status: a micro longitudinal study of chronic low-back pain and pain-free individuals | 10.1007/s10865-021-00234-w |
2021-12-01 | To gain insight into the potential protective mechanisms of low phenylalanine diet (LPD) in phenylketonuria (PKU), gene expression profiles were studied in the cerebral cortex and hippocampus of a PKU mouse model (BTBR- Pah enu2 ). PKU mice were fed with low Phe diet (LPD-PKU group) and normal diet (PKU group). Wild-type mice were treated with normal diet (WT group) as control. After 12 weeks, we detected gene expression in the cerebral cortex and hippocampus of the three groups by RNA-sequencing, and then screened the differentially-expressed genes (DEGs) among the groups by bioinformatics analyses. We found that the transcriptional profiles of both cerebral cortex and hippocampus changed markedly between PKU and WT mice. Furthermore, LPD changed the transcriptional profiles of the cerebral cortex and the hippocampus of PKU mice significantly, especially in the cerebral cortex, with overlaps of genes that changed with the disease and altered by LPD treatment. In the cerebral cortex, hundreds of DEGs enriched in a wide spectrum of biological processes, molecular function, and cellular component, including nervous system development, axon development and guidance, calcium ion binding, modulation of chemical synaptic transmission, and regulation of protein kinase activity. In the hippocampus, the overlapping genes were enriched in positive regulation of long term synaptic, negative regulation of excitatory postsynaptic potential, positive regulation of synapse assembly. Our results showed that genes impaired in PKU and then rescued by LPD might indicate the potential protective capability of LPD in the PKU brain. | Gene expression profiles in the brain of phenylketonuria mouse model reversed by the low phenylalanine diet therapy | 10.1007/s11011-021-00818-0 |
2021-12-01 | Abstract —The vitality structure of 23 natural coenopopulations of Colchicum bulbocodium subsp. versicolor from the Lower Volga region has been analyzed in 2014–2019. During this period, the viability of coenopopulations of the studied region varied within a wide range (from 0.45 to 1.51). Comparing to coenopopulations of this subspecies growing in the southwestern part of the Lower Volga region, northeastern coenopopulations are characterized by a lower viability, higher instability, and a wider variability of the latter index. The morphological traits studied correlated poorly among themselves. A high correlation was revealed between only two traits, while a medium correlation was confirmed for six pairs of traits. The largest number of relationships with a significant correlation level was observed for traits such as the plant height and diameter, the length and the width of a bottom leaf, and the claw length. Based on the I Q parameter and the Q criterion, the absolute majority of coenopopulations observed in the period studied were considered as prosperous. A depressive state was reported only for some coenopopulations and only in certain years of monitoring (mainly in 2018). In spring of 2018, the average temperatures during the period of active vegetation and flowering of the studied subspecies were extremely low comparing to other years, which that could have resulted in extreme growing conditions in the region studied and, therefore, a decrease in the vitality of coenopopulations. | Vitality Structure of Colchicum bulbocodium subsp. versicolor (Colchicaceae, Liliopsida) Populations in the Lower Volga Region | 10.1134/S1062359021100290 |
2021-11-26 | Background This study was performed to investigate the mid-term results of Ti-Nb-Sn (TNS) alloy stem with a low Young’s modulus. Methods This study was a multicenter prospective cohort study. A total of 40 primary total hip arthroplasties performed between April 2016 and September 2017 was enrolled in this study. With the unique functional gradient properties by heating treatment, the strength of the proximal portion was enhanced, while the distal portion maintained a low Young’s modulus. The surgeries were performed through the posterolateral approach using the TNS alloy stems. Radiographs were taken from immediately after surgeries until 3 years, and stress shielding and subsidence of the stems were evaluated. The incidences of the stem breakage were also assessed. Clinical assessments were performed using Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) scores. Results Among the 40 enrolled patients, 36 patients were female and 4 were male. At 3 years after surgery, there were no radiologic signs of loosening, subsidence, or breakage of the stem. Stress shielding was observed in 26 hips (65%). Of 26 hips, 16 hips (40%) were grade 1 and 10 hips (25%) were grade 2. There was no advanced stress shielding. The JOA and JHEQ scores significantly improved compared with the preoperative scores. Conclusion The current study using a new TNS alloy femoral stem showed good clinical outcomes at 3-year follow-up. Radiologically, there was no loosening or subsidence of the stem. The mild stress shielding was observed in 65% of patients. Trial registration Current Controlled Trials ISRCTN21241251 . The date of registration was October 26, 2021. Retrospectively registered. | Mid-term results of a new femoral prosthesis using Ti-Nb-Sn alloy with low Young’s modulus | 10.1186/s12891-021-04879-1 |
2021-11-26 | In this work, we have described a very simple and low metal loading copper-based ionic liquid as solvent and catalyst for regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles. The proposed protocol proved its efficiency by showing excellent tolerance to a large array of electronically diverse substrates without the use of the external base, solvent and ligands. Moreover, from cytotoxicity analysis the catalyst was found to be non-toxic in nature due to extremely low loading of copper metal (0.1 mol %). Graphical abstract This work describes a very simple and low metal loading catalytic system for efficient synthesis of 1,4-disubstituted-1,2,3-triazoles. The synthesized copper based ionic liquid acted both as solvent and as catalyst. Cytotoxicity analysis indicates that the catalyst is non-toxic in nature due to extremely low loading of copper metal (0.1 mol%). | Cu(II) ionic liquid promoted Simple and Economical Synthesis of 1,4-disubstituted-1,2,3-triazoles with Low Catalyst Loading | 10.1007/s12039-021-01980-9 |
2021-11-25 | Background Although lower temperature (< 45 °C) photothermal therapy (LPTT) have attracted enormous attention in cancer therapy, the therapeutic effect is still unsatisfying when applying LPTT alone. Therefore, combining with other therapies is urgently needed to improve the therapeutic effect of LPTT. Recently reported oxygen-irrelevant free radicals based thermodynamic therapy (TDT) exhibit promising potential for hypoxic tumor treatment. However, overexpression of glutathione (GSH) in cancer cells would potently scavenge the free radicals before their arrival to the specific site and dramatically diminish the therapeutic efficacy. Methods and results In this work, a core–shell nanoplatform with an appropriate size composed of arginine–glycine–aspartate (RGD) functioned polydopamine (PDA) as a shell and a triphenylphosphonium (TPP) modified hollow mesoporous manganese dioxide (H-mMnO 2 ) as a core was designed and fabricated for the first time. This nanostructure endows a size-controllable hollow cavity mMnO 2 and thickness-tunable PDA layers, which effectively prevented the pre-matured release of encapsulated azo initiator 2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIBI) and revealed pH/NIR dual-responsive release performance. With the mitochondria-targeting ability of TPP, the smart nanocomposites (AIBI@H-mMnO 2 -TPP@PDA-RGD, AHTPR) could efficiently induce mitochondrial associated apoptosis in cancer cells at relatively low temperatures (< 45 °C) via selectively releasing oxygen-irrelevant free radicals in mitochondria and facilitating the depletion of intracellular GSH, exhibiting the advantages of mitochondria-targeted LPTT/TDT. More importantly, remarkable inhibition of tumor growth was observed in a subcutaneous xenograft model of osteosarcoma (OS) with negligible side effects. Conclusions The synergistic therapy efficacy was confirmed by effectively inducing cancer cell death in vitro and completely eradicating the tumors in vivo. Additionally, the excellent biosafety and biocompatibility of the nanoplatforms were confirmed both in vitro and in vivo. Taken together, the current study provides a novel paradigm toward oxygen-independent free-radical-based cancer therapy, especially for the treatment of hypoxic solid tumors. Graphical Abstract | Mitochondria-targeted accumulation of oxygen-irrelevant free radicals for enhanced synergistic low-temperature photothermal and thermodynamic therapy | 10.1186/s12951-021-01142-6 |
2021-11-25 | Background Osteonecrosis of the femoral head (ONFH) is a common but intractable disease that appears to involve lipid metabolic disorders. Although numerous studies have demonstrated that high blood levels of low-density lipoprotein (LDL) are closely associated with ONFH, there is limited evidence to explain the pathological role of LDL. Pathological and in vitro studies were performed to investigate the role of disordered metabolism of LDL and oxidized LDL (ox-LDL) in the femoral head in the pathology of ONFH. Methods Nineteen femoral head specimens from patients with ONFH were obtained for immunohistochemistry analysis. Murine long-bone osteocyte Y4 cells were used to study the effects of LDL/ox-LDL on cell viability, apoptosis, and metabolism process of LDL/ox-LDL in osteocytes in normoxic and hypoxic environments. Results In the pathological specimens, marked accumulation of LDL/ox-LDL was observed in osteocytes/lacunae of necrotic regions compared with healthy regions. In vitro studies showed that ox-LDL, rather than LDL, reduced the viability and enhanced apoptosis of osteocytes. Pathological sections indicated that the accumulation of ox-LDL was significantly associated with impaired blood supply. Exposure to a hypoxic environment appeared to be a key factor leading to LDL/ox-LDL accumulation by enhancing internalisation and oxidation of LDL in osteocytes. Conclusions The accumulation of LDL/ox-LDL in the necrotic region may contribute to the pathology of ONFH. These findings could provide new insights into the prevention and treatment of ONFH. | Accumulation of LDL/ox-LDL in the necrotic region participates in osteonecrosis of the femoral head: a pathological and in vitro study | 10.1186/s12944-021-01601-x |
2021-11-24 | Low-carbon materials (the ‘carbon’ is related to carbon dioxide emission potential and not elemental carbon) need to be developed and embraced ubiquitously for the sustainable development of human society and mitigate climate change. In the absence of clear consensus in the literature coupled with the presence of certain miss-information, this ‘discussion’ article seeks to define low-carbon materials as the materials that foster a healthy living environment and a circular economy via the elimination or reduction of associated greenhouse gas (GHG) emissions and resource depletion and wastage. Furthermore, the multidimensional facets of low-carbon products and services are described to promote widespread utilisation of low-carbon materials so as to transition to desired low-carbon or decarbonised economies. Several specific strategies for realising the aforementioned are illustrated, which include radical green chemistry and materials approach, efficient materials extraction and processing, utilising renewable feedstocks and energies, efficient product manufacturing, enhanced recycling rates, designing out wastes, circular flow of materials, and innovative business models. The information provided in this ‘discussion’ article strives to outline a variety of aspects and tools available and necessary to accelerate the growth of low-carbon materials and progress towards a sustainable future. Graphical abstract The integration of low-carbon materials, products and services with natural resource preservation, prosperity and a healthy living environment Low-carbon materials, products and services are explicitly defined Low-carbon materials reduce carbon footprint and promote circular economy model Low-carbon products have parts with low embedded GHG emissions and are recyclable Low-carbon services retain ownership of long-lasting materials/products by lending Strategies to develop low-carbon materials, products and services are provided | Demystifying Low-Carbon Materials | 10.1007/s42824-021-00044-0 |
2021-11-22 | The Vector Electric Field Investigation (VEFI) on the C/NOFS satellite comprises a suite of sensors controlled by one central electronics box. The primary measurement consists of a vector DC and AC electric field detector which extends spherical sensors with embedded pre-amps at the ends of six, 9.5-m booms forming three orthogonal detectors with baselines of 20 m tip-to-tip each. The primary VEFI measurement is the DC electric field at 16 vectors/sec with an accuracy of 0.5 mV/m. The electric field receiver also measures the broad spectra of irregularities associated with equatorial spread-F and related ionospheric processes that create the scintillations responsible for the communication and navigation outages for which the C/NOFS mission is designed to understand and predict. The AC electric field measurements range from ELF to HF frequencies. VEFI includes a flux-gate magnetometer providing DC measurements at 1 vector/sec and AC-coupled measurements at 16 vector/sec, as well as a fast, fixed-bias Langmuir probe that serves as the input signal to trigger the VEFI burst memory collection of high time resolution wave data when plasma density depletions are encountered in the low latitude nighttime ionosphere. A bi-directional optical lightning detector designed by the University of Washington (UW) provides continuous average lightning counts at different irradiance levels as well as high time resolution optical lightning emissions captured in the burst memory. The VEFI central electronics box receives inputs from all of the sensors and includes a configurable burst memory with 1–8 channels at sample rates as high as 32 ks/s per channel. The VEFI instrument is thus one experiment with many sensors. All of the instruments were designed, built, and tested at the NASA/Goddard Space Flight Center with the exception of the lightning detector which was designed at UW. The entire VEFI instrument was delivered on budget in less than 2 years. VEFI included a number of technical advances and innovative features described in this article. These include: (1) Two independent sets of 3-axis, orthogonal electric field double probes; (2) Motor-driven, pre-formed cylinder booms housing signal wires that feed pre-amps within tip-mounted spherical sensors; (3) Extended shadow equalizers (2.5 times the sphere diameter) to mitigate photoelectron shadow mismatch for sun angles along the boom directions, particularly important at sunrise/sunset for a low inclination satellite; (4) DC-coupled electric field channels with “boosted” or pre-emphasized amplitude response at ELF frequencies; (5) Miniature multi-channel spectrum analyzers using hybrid technology; (6) Dual-channel optical lightning detector with on-board comparators and counters for 7 irradiance levels with high-time-resolution data capture; (7) Spherical Langmuir probe with Titanium Nitride-coated sensor element and guard; (8) Selectable data rates including 200 kbps (fast), 20 kbps (nominal), and 2 kbps (low for real-time TDRSS communication); and (9) Highly configurable burst memory with selectable channels, sample rates and number, duration, and precursor length of bursts, chosen based on best triggering algorithm “score”. This paper describes the various sensors that constitute the VEFI experiment suite and discusses their operation during the C/NOFS mission. Examples of data are included to illustrate the performance of the different sensors in space. | The Vector Electric Field Investigation (VEFI) on the C/NOFS Satellite | 10.1007/s11214-021-00859-y |
2021-11-19 | This study involves the preparation of ruthenium oxide (RuO 2 ) thick films by a different method than those reported in the literature and the investigation of their dielectric properties. The substrates were coated with RuO 2 thick films deposited using a mixture of invertase enzyme and ruthenium ions dissolved in water. Scanning electron microscopy-energy dispersive X-ray spectroscopy was employed for surface analysis of the films. Current/potential measurements were used to examine dielectric properties and X-ray diffraction to examine structural properties. The capacitance per unit mass of RuO 2 thick films produced with invertase enzyme in amorphous structure was found to be 845 F g −1 . Regarding energy dispersive X-ray spectroscopy analysis, thick films were found to contain around 79.15% ruthenium, evenly distributed on the surface of the films. In addition, we performed capacitance measurements for different temperatures and got very interesting results. | Synthesis and characterization of RuO2 thick film supercapacitor electrode: the effect of low temperature | 10.1007/s12034-021-02573-5 |
2021-11-19 | The CoSb 3 -based skutterudite, as a medium-temperature thermoelectric material, shows excellent thermoelectric performance, but intrinsic high thermal conductivity suppresses enhancement of the ZT value. Here, the Yb 0.2 (CoSb 2.875 Te 0.125 ) 4 sample was synthesized by the melting reaction, high energy ball milling and the spark plasma sintering, which followed by different processes in order to obtain proper porous structures and eliminate undesirable phases. Elimination of residual stress via annealing results in the formation of micro- and nanopores. The Seebeck coefficient of the S4 sample with the micro- and nanopores is greatly enhanced due to the reduction of the carrier concentration induced by the energy filtering effect of the micro- and nanopores. The power factor achieves 3310 µW m −1 K −2 at 773 K for the sample prepared by pickling and spraying gold particles. The annealed S4 sample with the micro- and nanopores presents a greatly reduced thermal conductivity (~ 1.4 W m −1 K −1 ) due to the existing abundant the irregularly shaped pores and grain boundaries. Eventually, reasonable porous structures improve the thermoelectric merit (ZT) by 56%. | Enhanced thermoelectric properties from pore design via adjustment and elimination of residual stresses for Yb0.2(CoSb2.875Te0.125)4 | 10.1007/s00339-021-05087-3 |
2021-11-16 | Background The National Drug Policy in Bangladesh prohibits the sale and distribution of antibiotics without prescription from a registered physician. Compliance with this policy is poor; prescribing antibiotics by unqualified practitioners is common and over-the-counter dispensing widespread. In Bangladesh, unqualified practitioners such as drug shop operators are a major source of healthcare for the poor and disadvantaged. This paper reports on policy awareness among drug shop operators and their customers and identifies current dispensing practices, barriers and facilitators to policy adherence. Methods We conducted a qualitative study in rural and urban Bangladesh from June 2019 to August 2020. This included co-design workshops ( n = 4) and in-depth interviews ( n = 24) with drug shop operators and customers/household members, key informant interviews ( n = 12) with key personnel involved in aspects of the antibiotic supply chain including pharmaceutical company representatives, and model drug shop operators; and a group discussion with stakeholders representing key actors in informal market systems namely: representatives from the government, private sector, not-for-profit sector and membership organizations. Results Barriers to policy compliance among drug shop operators included limited knowledge of government drug policies, or the government-led Bangladesh Pharmacy Model Initiative (BPMI), a national guideline piloted to regulate drug sales. Drug shop operators had no clear knowledge of different antibiotic generations, how and for what diseases antibiotics work contributing to inappropriate antibiotic dispensing. Nonetheless, drug shop operators wanted the right to prescribe antibiotics based on having completed related training. Drug shop customers cited poor healthcare facilities and inadequate numbers of attending physician as a barrier to obtaining prescriptions and they described difficulties differentiating between qualified and unqualified providers. Conclusion Awareness of the National Drug Policy and the BPMI was limited among urban and rural drug shop operators. Poor antibiotic prescribing practice is additionally hampered by a shortage of qualified physicians; cultural and economic barriers to accessing qualified physicians, and poor implementation of regulations. Increasing qualified physician access and increasing training and certification of drug shop operators could improve the alignment of practices with national policy. | Barriers and facilitators to adherence to national drug policies on antibiotic prescribing and dispensing in Bangladesh | 10.1186/s40545-021-00342-7 |
2021-11-14 | Necrotizing enterocolitis (NEC) is a typical disorder of preterm newborns, with a high mortality and morbidity rate. The therapeutic and nutritional management of disease depends on several factors. Its prognosis is linked, in addition to the severity of the disease and the need for surgery, to a correct enteral feeding in these patients. This study aims to identify the clinical characteristics of 18 patients with NEC, evaluating the different therapeutic paths undertaken, the type of formula used and the survival rate of this population. Average time of enteral nutrition before the NEC onset was 11,3 ± 11,6 days, with an average fasting period since the onset of 24 ± 18.9 days. 77.8% of patients received surgery and resumed enteral nutrition 17.7 ± 17.9 days after the intervention. The overall survival rate of our cohort was 55.5%. More prospective studies are needed to evaluate the long-term outcomes of survived children with NEC. | Necrotizing enterocolitis in the preterm: newborns medical and nutritional Management in a Single-Center Study | 10.1186/s13052-021-01180-8 |
2021-11-12 | We consider near-critical two-dimensional statistical systems with boundary conditions inducing phase separation on the strip. By exploiting low-energy properties of two-dimensional field theories, we compute arbitrary n -point correlation of the order parameter field. Finite-size corrections and mixed correlations involving the stress tensor trace are also discussed. As an explicit illustration of the technique, we provide a closed-form expression for a three-point correlation function and illustrate the explicit form of the long-ranged interfacial fluctuations as well as their confinement within the interfacial region. | Multipoint correlation functions at phase separation. Exact results from field theory | 10.1007/JHEP11(2021)096 |
2021-11-10 | Background Single-cell RNA sequencing (scRNA-seq) provides new insights to address biological and medical questions, and it will benefit more from the ultralow input RNA or subcellular sequencing. Results Here, we present a highly sensitive library construction protocol for ultralow input RNA sequencing (ulRNA-seq). We systematically evaluate experimental conditions of this protocol, such as reverse transcriptase, template-switching oligos (TSO), and template RNA structure. It was found that Maxima H Minus reverse transcriptase and rN modified TSO, as well as all RNA templates capped with m7G improved the sequencing sensitivity and low abundance gene detection ability. RNA-seq libraries were successfully prepared from total RNA samples as low as 0.5 pg, and more than 2000 genes have been identified. Conclusions The ability of low abundance gene detection and sensitivity were largely enhanced with this optimized protocol. It was also confirmed in single-cell sequencing, that more genes and cell markers were identified compared to conventional sequencing method. We expect that ulRNA-seq will sequence and transcriptome characterization for the subcellular of disease tissue, to find the corresponding treatment plan. | Optimization of library preparation based on SMART for ultralow RNA-seq in mice brain tissues | 10.1186/s12864-021-08132-w |
2021-11-09 | We have performed a search for flares and quasi-periodic pulsations (QPPs) from low-mass M-dwarf stars using Transient Exoplanet Survey Satellite (TESS) two-minute cadence data. We find seven stars that show evidence of QPPs. Using Fourier and empirical mode decomposition techniques, we confirm the presence of 11 QPPs in these seven stars with a period between 10.2 and 71.9 minutes, including an oscillation with strong drift in the period and a double-mode oscillation. The fraction of flares that showed QPPs (7%) is higher than other studies of stellar flares, but it is very similar to the fraction of solar C-class flares. Based on the stellar parameters taken from the TESS Input Catalog, we determine the lengths and magnetic-field strengths of the flare coronal loops using the period of the QPPs and various assumptions about the origin of the QPPs. We also use a scaling relationship based on flares from the Sun and solar-type stars and the observed energy, plus the duration of the flares, finding that the different approaches predict loop lengths that are consistent to within a factor of about two. We also discuss the flare frequency of the seven stars determining whether this could result in ozone depletion or abiogenesis in any orbiting exoplanet. Three of our stars have a sufficiently high rate of energetic flares, which are likely to cause abiogenesis. However, two of these stars are also in the range where ozone depletion is likely to occur. We speculate on the implications of the flare rates, loop lengths, and QPPs for life on potential exoplanets orbiting in their host star’s habitable zone. | Transiting Exoplanet Survey Satellite (TESS) Observations of Flares and Quasi-Periodic Pulsations from Low-Mass Stars and Potential Impact on Exoplanets | 10.1007/s11207-021-01899-x |
2021-11-08 | The low cycle fatigue strength properties of the additively manufactured Ti-6Al-4V alloy are experimentally investigated under proportional and nonproportional multiaxial loading. The fatigue tests were conducted using hollow cylinder specimens with and without heat treatments, at room temperature in air. Two fatigue tests were conducted: one for proportional loading and one for nonproportional loading. The proportional loading was represented by a push-pull strain path (PP) and the nonproportional loading by a circle strain path (CI). The failure lives of the additively manufactured specimens were clearly reduced drastically by internal voids and defects. However, the sizes of the defects were measured, and the defects were found not to cause a reduction in fatigue strength above a critical size. The fracture surface was observed using scanning electron microscopy to investigate the fracture mechanisms of the additively manufactured specimens under the two types of strain paths. Different fracture patterns were recognized for each strain paths; however, both showed retention of the crack propagation, despite the presence of numerous defects, probably because of the interaction of the defects. The crack propagation properties of the materials with numerous defects under nonproportional multiaxial loading were clarified to increase the reliability of the additively manufactured components. | Fatigue Property of Additively Manufactured Ti-6Al-4V under Nonproportional Multiaxial Loading | 10.1186/s10033-021-00626-8 |
2021-11-06 | Background Induction of long-term synaptic depression (LTD) is proposed as a treatment mechanism for chronic pain but remains untested in clinical populations. Two interlinked studies; (1) A patient-assessor blinded, randomised, sham-controlled clinical trial and (2) an open-label mechanistic study, sought to examine therapeutic LTD for persons with chronic peripheral nerve injury pain. Methods (1) Patients were randomised using a concealed, computer-generated schedule to either active or sham non-invasive low-frequency nerve stimulation (LFS), for 3 months (minimum 10 min/day). The primary outcome was average pain intensity (0–10 Likert scale) recorded over 1 week, at 3 months, compared between study groups. (2) On trial completion, consenting subjects entered a mechanistic study assessing somatosensory changes in response to LFS. Results (1) 76 patients were randomised (38 per group), with 65 (31 active, 34 sham) included in the intention to treat analysis. The primary outcome was not significant, pain scores were 0.3 units lower in active group (95% CI − 1.0, 0.3; p = 0.30) giving an effect size of 0.19 (Cohen’s D). Two non-device related serious adverse events were reported. (2) In the mechanistic study (n = 19) primary outcomes of mechanical pain sensitivity (p = 0.006) and dynamic mechanical allodynia (p = 0.043) significantly improved indicating reduced mechanical hyperalgesia. Conclusions Results from the RCT failed to reach significance. Results from the mechanistic study provide new evidence for effective induction of LTD in a clinical population. Taken together results add to mechanistic understanding of LTD and help inform future study design and approaches to treatment. Trial registration ISRCTN53432663. | Mechanistically informed non-invasive peripheral nerve stimulation for peripheral neuropathic pain: a randomised double-blind sham-controlled trial | 10.1186/s12967-021-03128-2 |
2021-11-05 | Hatis-1 is a Lower Paleolithic open-air site on the Hrazdan-Kotayk Plateau of central Armenia. Although the site was tested in the 1980s, little has been published regarding the material. Consequently, we reinvestigated the site by expanding the original test pit to better understand the stratigraphy and recover a new sample of artifacts. As a result, more than 300 obsidian artifacts were recovered from colluvial deposits found close to primary obsidian outcrops, which sourcing data show to be the exclusive areas of toolstone procurement used by the inhabitants. The recovered assemblages are Late Acheulian in character and are largely homogenous across strata in terms of techno-typology. Hatis-1 records the use of large flakes for production of cores and tools indicative of the Large Flake Acheulian, but also contains limited evidence for simple prepared cores and the recycling of bifaces as cores, suggesting expansion of the technological repertoire of hominins in this region during the Late Acheulian. The in-depth study of large cutting tools presented here reveals that differences in the shape and typology of these tools are largely determined by different production strategies. While samples suitable for direct chronometric dates were not recovered, constraining geological factors suggest this material was deposited after c.700/480 ka. This study expands our understanding of the Late Acheulian and further contextualizes the later Lower–Middle Paleolithic technological transition in the region. In a broader sense, our interpretation of the techno-typological patterns at Hatis-1 expands the current understanding of geographical and chronological variation in the Acheulian record. | The Techno-typological and 3D-GM Analysis of Hatis-1: a Late Acheulian Open-Air Site on the Hrazdan-Kotayk Plateau, Armenia | 10.1007/s41982-021-00105-5 |
2021-11-04 | Background Plant health and growth are negatively affected by pathogen invasion; however, plants can dynamically modulate their rhizosphere microbiome and adapt to such biotic stresses. Although plant-recruited protective microbes can be assembled into synthetic communities for application in the control of plant disease, rhizosphere microbial communities commonly contain some taxa at low abundance. The roles of low-abundance microbes in synthetic communities remain unclear; it is also unclear whether all the microbes enriched by plants can enhance host adaptation to the environment. Here, we assembled a synthetic community with a disease resistance function based on differential analysis of root-associated bacterial community composition. We further simplified the synthetic community and investigated the roles of low-abundance bacteria in the control of Astragalus mongholicus root rot disease by a simple synthetic community. Results Fusarium oxysporum infection reduced bacterial Shannon diversity and significantly affected the bacterial community composition in the rhizosphere and roots of Astragalus mongholicus . Under fungal pathogen challenge, Astragalus mongholicus recruited some beneficial bacteria such as Stenotrophomonas , Achromobacter , Pseudomonas , and Flavobacterium to the rhizosphere and roots. We constructed a disease-resistant bacterial community containing 10 high- and three low-abundance bacteria enriched in diseased roots. After the joint selection of plants and pathogens, the complex synthetic community was further simplified into a four-species community composed of three high-abundance bacteria ( Stenotrophomonas sp., Rhizobium sp., Ochrobactrum sp.) and one low-abundance bacterium ( Advenella sp.). Notably, a simple community containing these four strains and a thirteen-species community had similar effects on the control root rot disease. Furthermore, the simple community protected plants via a synergistic effect of highly abundant bacteria inhibiting fungal pathogen growth and less abundant bacteria activating plant-induced systemic resistance. Conclusions Our findings suggest that bacteria with low abundance play an important role in synthetic communities and that only a few bacterial taxa enriched in diseased roots are associated with disease resistance. Therefore, the construction and simplification of synthetic communities found in the present study could be a strategy employed by plants to adapt to environmental stress. Video abstract | A simplified synthetic community rescues Astragalus mongholicus from root rot disease by activating plant-induced systemic resistance | 10.1186/s40168-021-01169-9 |
2021-11-04 | The proximate, low-pressure N 2 sorption, X-ray diffraction, and organic petrography parameters have been used to delineate the pore structures and fractal dimensions in the Barakar shales of Rajmahal Basin, India. The information has been utilized for the assessment of shale gas reservoir and to know about the mode of occurrence and storage capacity of shales for the entrapment of methane (CH 4 ). The studied shales are characterized by high fixed carbon contents (10.14–46.09 wt.%) and contain significant abundance of brittle minerals, like quartz (6.0–51.6%) and mica (1.0–41.2%). The petrographic observations show that the studied samples comprise of numerous laths of vitrinite (collotelinite and vitrodetrinite) and semifusinite macerals and quartz grains. The data of low-pressure N 2 sorption analysis indicates the shales encompass mainly meso- to macropores and microfractures. The total pore volume, average pore size, and multipoint BET surface area of the studied shales vary from 0.012 to 0.023 cc/g, 8.295 to 10.840 nm, and 5.752 to 10.390 m 2 /g respectively. Two types of fractal dimensions (D 1 and D 2 ) have been calculated by using FHH (Frankel-Halsey-Hill) method from the N 2 adsorption isotherm. The high values of fractal dimensions (2.1949 < D 1 < 2.4837 and 2.6668 < D 2 < 2.7247) are indicating the highly rugged pore surface or complexity in the pore structures. | Pore structures and fractal dimensions in Early Permian Barakar shales of Rajmahal Basin, Jharkhand, India | 10.1007/s12517-021-08373-9 |
2021-11-04 | Background Gastroesophageal reflux disease (GERD) is associated with lower esophageal sphincter (LES) incompetence. In some patients, GERD is refractory to acid reduction therapy which is the main treatment for GERD. So far, medications that can increase LES tone are few. Arecae pericarpium (A. pericarpium) is a medication in Traditional Chinese Medicine known to promote intestinal motility. Methods We investigated the effect of A. pericarpium extracts on porcine LES motility. In addition, we used tetrodotoxin (TTX) and atropine to study the underlying mechanism of A. pericarpium extracts-induced contractions of LES. Results The results of this study showed that A. pericarpium extracts and their main active ingredient, arecoline, can induce the contractions of porcine LES sling and clasp muscles in a dose-response manner. TTX did not have an inhibitory effect on the contractions induced by A. pericarpium extracts and arecoline in LES. However, atropine significantly inhibited A. pericarpium extracts- and arecoline-induced contractions of LES. Conclusion A. pericarpium extracts can induce the contractions of porcine LES in a dose dependent manner, possibly through muscarinic receptors, and hence, may be worth developing as an alternative therapy for GERD. | Arecae pericarpium extract induces porcine lower-esophageal-sphincter contraction via muscarinic receptors | 10.1186/s12906-021-03442-8 |
2021-11-03 | Geomagnetic storms are an important aspect of space weather and can result in significant impacts on space- and ground-based assets. The majority of strong storms are associated with the passage of interplanetary coronal mass ejections (ICMEs) in the near-Earth environment. In many cases, these ICMEs can be traced back unambiguously to a specific coronal mass ejection (CME) and solar activity on the frontside of the Sun. Hence, predicting the arrival of ICMEs at Earth from routine observations of CMEs and solar activity currently makes a major contribution to the forecasting of geomagnetic storms. However, it is clear that some ICMEs, which may also cause enhanced geomagnetic activity, cannot be traced back to an observed CME, or, if the CME is identified, its origin may be elusive or ambiguous in coronal images. Such CMEs have been termed “stealth CMEs”. In this review, we focus on these “problem” geomagnetic storms in the sense that the solar/CME precursors are enigmatic and stealthy. We start by reviewing evidence for stealth CMEs discussed in past studies. We then identify several moderate to strong geomagnetic storms (minimum Dst < − 50 $< -50$ nT) in solar cycle 24 for which the related solar sources and/or CMEs are unclear and apparently stealthy. We discuss the solar and in situ circumstances of these events and identify several scenarios that may account for their elusive solar signatures. These range from observational limitations (e.g., a coronagraph near Earth may not detect an incoming CME if it is diffuse and not wide enough) to the possibility that there is a class of mass ejections from the Sun that have only weak or hard-to-observe coronal signatures. In particular, some of these sources are only clearly revealed by considering the evolution of coronal structures over longer time intervals than is usually considered. We also review a variety of numerical modelling approaches that attempt to advance our understanding of the origins and consequences of stealthy solar eruptions with geoeffective potential. Specifically, we discuss magnetofrictional modelling of the energisation of stealth CME source regions and magnetohydrodynamic modelling of the physical processes that generate stealth CME or CME-like eruptions, typically from higher altitudes in the solar corona than CMEs from active regions or extended filament channels. | Understanding the Origins of Problem Geomagnetic Storms Associated with “Stealth” Coronal Mass Ejections | 10.1007/s11214-021-00857-0 |
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