id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
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29712091 | Assembly of Encapsulated Transition Metal Catalysts. | Enforced ligand dissociation as a result of steric interactions between Zn<sup>II</sup> porphyrin units and the N atoms of pyridylphosphane ligands determines the catalytic properties of the encapsulated transition metal complexes. These assemblies show increased catalytic activity in the palladium-catalyzed Heck react... |
29712086 | Magnetic Interactions as Supramolecular Function: Structure and Magnetic Properties of Hydrogen-Bridged Dinuclear Copper(II) Complexes. | The self-complementary coordination unit [Cu(H<sub>2</sub> sabhea)]<sup>+</sup> with a pentadentate amino alcohol as ligand enables the synthesis of the first triply hydrogen-bridged dinuclear copper(II) complex. Proton transfer allows the reversible transformation between this triply and the corresponding doubly hydro... |
29712080 | Molecular Recognition of UDP-Gal by β-1,4-Galactosyltransferase T1. | Saturation transfer difference (STD) NMR experiments reveal the binding epitopes of UDP-Gal and UDP-Glc bound to the glycosyltransferase β4Gal-T1. Whereas the enzyme recognizes the galactose residue in UDP-Gal, it does not make any close contacts with the glucose residue in UDP-Glc. This observation explains why β4Gal-... |
23686898 | Patterning of hyperbranched polymer films. | This Review describes new methods for patterning functional hyperbranched poly(acrylic acid) thin polymer films. "Hyperbranched polymer" is a generic term used to describe a wide variety of polymeric materials that contain a high percentage of functional groups, that are highly branched, and that are irregular in struc... |
12116409 | EUDOC: a computer program for identification of drug interaction sites in macromolecules and drug leads from chemical databases. | The completion of the Human Genome Project, the growing effort on proteomics, and the Structural Genomics Initiative have recently intensified the attention being paid to reliable computer docking programs able to identify molecules that can affect the function of a macromolecule through molecular complexation. We repo... |
12545473 | [Separation and determination of pseudoephedrine in bufferin cold tablet by capillary electrophoresis with hydropropyl-beta-cyclodextrin as chiral selective reagent]. | A method for the separation and analysis of the chiral pseudoephedrine enantiomers using capillary electrophoresis was established. The buffer solution for separation was 25 mmol/L Tris-phosphate, including 38 mmol/L hydropropyl-beta-cyclodextrin with pH value of 2.65. (1S, 2S)(+) Pseudoephedrine in Bufferin Cold table... |
12373096 | Localization of Triton-insoluble cAMP-dependent kinase type RIbeta in rat and mouse brain. | In eukaryotic cells, cAMP regulates many different cellular functions. Its effects are in most cases mediated by cAMP-dependent protein kinases. These consist of two regulatory and two catalytic subunits. In mammals, four different isoforms of cAMP-dependent protein kinases regulatory subunits have been characterized (... |
12240155 | Catalysis in supercritical CO2 using dendrimer-encapsulated palladium nanoparticles. | Dendrimer-encapsulated nanoparticles are shown to be versatile catalysts for both the hydrogenation of styrene and Heck heterocoupling of iodobenzene and methacrylate in supercritical CO2 (scCO2). |
12240148 | p-Sulfonatocalix[6]arene is an effective coacervator of poly(allylamine hydrochloride). | p-Sulfonatocalix[6]arene is shown to form insoluble complexes with poly(allylamine hydrochloride) when the charge balance between the negative calixarene sulfonate groups matches the positive charge carried by the polyelectrolyte, this makes this glycosylaminoglycan analog an interesting candidate for controlled releas... |
12240122 | Unexpected solute aggregation in water on dilution. | Studies on cluster-cluster aggregation phenomena in aqueous solutions of fullerene-cyclodextrin conjugates, beta-cyclodextrin, sodium chloride, sodium guanosine monophosphate, and a DNA oligonucleotide revealed that there are larger aggregates existent in dilute aqueous solutions than in more concentrated solutions. |
12240111 | Synthesis and oxygenation of selenophosphate dendrimers. | The backbone of a selenophosphate-based dendrimer of generation 3 having three and four carbon chains is flexible enough to allow its chemical modification by means of partial or complete oxygenation with bulky peroxide. |
12240082 | Hydrogen-bonded capsules in polar, protic solvents. | A kinetically stable, dimeric capsule is formed by tetrahydroxyresorcinarene in methanol; it encapsulates tropylium and tetramethylammonium cations. |
12240059 | Novel photohydration of non-conjugated aryl/olefin bichromophores within cyclodextrin cavities. | Cyclodextrin media are used to achieve photochemical water addition to isolated, acyclic double bonds via intramolecular interaction with excited arenes. |
12099377 | Combination of electroporation and DNA/dendrimer complexes enhances gene transfer into murine cardiac transplants. | Electroporation is a new gene delivery method to increase gene transfer and expression in vivo. Starburst polyamidoamine dendrimers have been demonstrated to augment gene expression in vitro and in vivo. We hypothesized that the combination of electroporation and dendrimer could enhance the gene transfer and gene expre... |
11999713 | Semi-synthetic nucleic acid-protein conjugates: applications in life sciences and nanobiotechnology. | Semi-synthetic conjugates of nucleic acids and proteins can be generated by either covalent coupling chemistry, or else by non-covalent biomolecular recognition systems, such as receptor-ligands of complementary nucleic acids. These nucleic acid-protein conjugates are versatile molecular tools which can be applied, for... |
11936361 | Antibiotic induced endotoxin release and clinical sepsis: a review. | Sepsis and peritonitis have not lost much of their danger for patients. The mortality rate in peritonitis has only marginally decreased during the last 30 years despite aggressive surgical and sophisticated intensive care treatment. In intra-abdominal infection and peritonitis source control remains the mainstay of tre... |
11924511 | Novel approach to the study of the chiral discrimination. Mechanism in a series of imidazole derivatives using HPLC. | In high performance liquid chromatography (HPLC) using poly (octadecylsiloxane) as a stationary phase, phosphate buffer as a mobile phase, a series of R-S imidazole derivatives as solutes, and beta-CD (beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD) as chiral selectors, a study on the hydrophobic effect on both the sol... |
11924510 | [Use of cyclodextrins in the formulation of polyalkylcyanoacrylate nanoparticles charged with different active ingredients]. | Cyclodextrins were used to improve the loading capacity of biodegradable pol(yisobutyl cyanoacrylat)e nanoparticles, which were obtained by anionic polymerization in aqueous medium. We investigated the feasibility of blank nanoparticles in the presence of a series of cyclodextrins (5 mg/ml) and poloxamer 188 (1%). The ... |
11924509 | [Reduction of the volatility of volatile organic compounds with cyclodextrins: application to their capture]. | The interactions existing between beta-cyclodextrin, hydroxypropyl-beta-cyclodextrin and six volatile organic compounds (VOC) were studied and used for capture of such pollutants. The reduction of volatility for these VOC appeared to be equivalent for the two kinds of cyclodextrins at equal concentrations, while a high... |
11924508 | [Effect of cyclodextrins on fungal degradation of fluorene]. | The purpose of this study was to improve the bioavailability of fluorene (PAH) by the use of complexing agents, cyclodextrins. The biodegradation tests were performed in liquid medium batches; fluorene was quantified by HPLC. Experimental results showed the enhancement of fluorene degradation by Penicillium italicum an... |
11899613 | Polymer supports in organic catalysis and synthesis. | Recent developments in the preparation of polymer supports for synthesis and catalysis are reviewed. The use of insoluble supports for synthesis of one molecule per bead and chemistry leading to new ways to use insoluble supports are discussed. New routes to design soluble, high capacity supports for synthesis are high... |
11888214 | Effect of salts on the properties of aqueous sugar systems, in relation to biomaterial stabilization. 1. Water sorption behavior and ice crystallization/melting. | Trehalose and sucrose, two sugars that are involved in the protection of living organisms under extreme conditions, and their mixtures with salts were employed to prepare supercooled or freeze-dried glassy systems. The objective of the present work was to explore the effects of different salts on water sorption, glass ... |
11838970 | Quantification of amino acid enantiomers in single cells by capillary electrophoresis. | An analytical method is described to quantify amino acid enantiomers in single cells. Cellular samples were derivatized with a fluorescence tagging reagent, naphthalene-2,2-dicarboxaldehyde, in a mini-volume (4 microl) prior to separation. Enantiomeric resolution was achieved by beta-cyclodextrin modified micellar elec... |
11831622 | Protein aggregation. | Protein aggregation occurs in vivo as a result of improper folding or misfolding. Diverse diseases arise from protein misfolding and are now grouped under the term "protein conformational diseases", including most of the neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, the prion encephalopa... |
11811065 | [Synthesis of N-acetylglucosamine beta-aryl glycosides catalyzed by crown ethers]. | Glycosylation of phenols of various structure with alpha-D-glucosaminyl chloride peracetate in a solid phase-liquid system catalyzed by crown compounds was studied. The highest yields of aryl beta-glycosides were observed at room temperature in acetonitrile using anhydrous potassium carbonate as a base. The optimum phe... |
11797853 | Enhancing filtration rates by the use of blood flow around the capillaries of plasmafilters: an in vitro study. | As the low clearance rate of plasmaseparation limits its use in the treatment of patients suffering from liver failure, sepsis or MOF, we intend to develop strategies for a plasmaseparation unit which increases plasmafiltration rates. Our first question focused on whether commercially available plasmaseparation filters... |
11797695 | Bioartificial organs in the twenty-first century: nanobiological devices. | Bioartificial organs involve the design, modification, growth and maintenance of living tissues embedded in natural or synthetic scaffolds to enable them to perform complex biochemical functions, including adaptive control and the replacement of normal living tissues. Future directions in this area will lead to an aban... |
11788787 | Lysozyme enhances renal excretion of advanced glycation endproducts in vivo and suppresses adverse age-mediated cellular effects in vitro: a potential AGE sequestration therapy for diabetic nephropathy? | <h4>Background</h4>Lysozyme (LZ), a host-defense protein, contains an 18 amino-acid domain with high affinity binding for sugar-derived proteins or lipids, called advanced glycation endproducts (AGE), that are implicated in diabetes- and age-dependent complications (DC).<h4>Materials and methods</h4>A) The effects of L... |
11787939 | Cyclodextrins in the treatment of a mouse model of Niemann-Pick C disease. | Niemann-Pick type C (NPC) is a neurodegenerative disorder characterized by greatly altered somatic cholesterol metabolism. The NPC1 gene has recently been cloned and shown to have sequence homology to other sterol-sensing proteins. We have used a mouse model with a disrupted npc1 gene to study the effects of the choles... |
11777135 | An assessment of clinical guidelines for the management of acute pancreatitis. | <h4>Background</h4>Recent guidelines have been issued for the management of acute pancreatitis. The aim of this study was to audit the management of acute pancreatitis in one district general hospital, to determine the problems and benefits associated with the implementation of such guidelines.<h4>Methods</h4>Data were... |
11775960 | Interaction of [D-Trp6, Des-Gly10] LHRH ethylamide and hydroxy propyl beta-cyclodextrin (HPbetaCD): thermodynamics of interaction and protection from degradation by alpha-chymotrypsin. | <h4>Purpose</h4>The purpose of this study is to investigate the mechanisms and thermodynamics of the interaction between hydroxypropyl beta-cyclodextrin (HPdetaCD) and [D-Trp6, des-Gly10] LHRH ethylamide (deslorelin), a peptide drug.<h4>Methods</h4>We used UV and fluorescence spectroscopy to study the interaction of HP... |
11757074 | Involvement of the C-terminal end of the prostrate-specific antigen in a conformational epitope: characterization by proteolytic degradation of monoclonal antibody-bound antigen and mass spectrometry. | Prostate-specific antigen (PSA), a 237-amino acid glycoprotein, encoded by the hKLK3 gene, is widely used as a serum marker for the diagnosis and management of prostate cancer. We report here the localization of a conformational epitope recognized by the anti-total PSA monoclonal antibody (mAb) 11E5C6, by proteolytic d... |
11757073 | Oxytocin-induced phosphorylation of myosin light chain is mediated by extracellular calcium influx in pregnant rat myometrium. | Studies of oxytocin-induced phosphorylation of myosin light chain (MLC), resulting in myometrial contraction, suggest that extracellular Ca(2+) influx is involved in its signal transduction. To explore the possibility that intracellular Ca(2+) mobilization by oxytocin may also contribute to MLC phosphorylation, we inve... |
11757072 | Structural determinants of the human idiotype HibId-1. | The human antibody response to the capsular polysaccharide of Haemophilus influenzae type b is predominated by antibodies expressing a light-chain-associated idiotype designated HibId-1. HibId-1 is expressed by kappa light chains encoded by either the A2 or A18 variable region genes. In this report we use site-directed... |
11757071 | Molecularly imprinted polymer using-p-hydroxybenzoic acid, p-hydroxyphenylacetic acid and p-hydroxyphenylpropionic acid as templates. | Molecularly imprinted polymers (MIPs) using p-hydroxybenzoic acid (p-HB), p-hydroxyphenylacetic acid (p-HPA) and p-hydroxyphenylpropionic acid (p-HPPA) as templates were synthesized. The performance of the templates and their analogues on polymer-based high performance liquid chromatography (HPLC) columns was studied. ... |
11757070 | Towards a rational development of anti-endotoxin agents: novel approaches to sequestration of bacterial endotoxins with small molecules. | Endotoxins, or lipopolysaccharides (LPS), present on the surface of Gram-negative bacteria, play a key role in the pathogenesis of septic shock, a common clinical problem and a leading cause of mortality in critically ill patients, for which no specific therapeutic modalities are available at the present time. The toxi... |
11757069 | Applications of novel affinity cassette methods: use of peptide fusion handles for the purification of recombinant proteins. | In this article, recent progress related to the use of different types of polypeptide fusion handles or 'tags' for the purification of recombinant proteins are critically discussed. In addition, novel aspects of the molecular cassette concept are elaborated, together with areas of potential application of these fundame... |
11749583 | Combination of 2D-, 3D-connectivity and quantum chemical descriptors in QSPR. Complexation of alpha- and beta-cyclodextrin with benzene derivatives. | Quantitative models are found to describe the complexation of alpha- and beta-cyclodextrin with mono- and 1,4-disubstituted benzene derivatives by using combinations of 2D-, 3D-connectivity and quantum chemical molecular descriptors. The association constants (K(a)) for the inclusion complexation of cyclodextrins and b... |
11749800 | Nasal absorption enhancement of insulin by sodium deoxycholate in combination with cyclodextrins. | <h4>Aim</h4>To evaluate the nasal absorption enhancement of insulin by sodium deoxycholate (SDC) in combination with cyclodextrins (CD).<h4>Methods</h4>The concentration of glucose in blood was measured. Scanning electron microscopy technique was used to investigate the effect of enhancers on the nasal mucocilia. The e... |
11749799 | Lowering of sodium deoxycholate-induced nasal ciliotoxicity with cyclodextrins. | <h4>Aim</h4>To lower the nasal ciliotoxicity of sodium deoxycholate (SDC) in combination with cyclodextrins (CD).<h4>Methods</h4>The erythrocyte hemolysis test was carried out to evaluate the damaging effect of SDC on the erythrocyte membrane. The in situ toad palate model and scanning electron microscope technique wer... |
11767888 | An N,N'-dialkyl-4,4'-bipyridinium-modified titanium-dioxide photocatalyst for water remediation--observation and application of supramolecular effects in photocatalytic degradation of pi-donor organic compounds. | The photocatalytic activity of TiO2 (Degussa P-25) modified with a 4,4'-bipyridinium monolayer (V2+-TiO2) has been compared with that of conventional TiO2-P-25 by investigating the efficiency of degradation of a series of four organic model compounds with increasing pi-donor capacity (2,4-xylidine, 2,4-dimethylphenol, ... |
11767131 | Novel approach to the study of the chiral discrimination mechanism in a series of dansyl amino acids. | With poly(octadecylsiloxane) as the liquid chromatographic stationary phase, phosphate buffer as the mobile phase, a series of D- and L-dansyl amino acids as solutes, and beta-cyclodextrin as the chiral selector, a study was conducted of the hydrophobic effect on both the solute complexation with the chiral selector an... |
11766883 | Neurocan: a brain chondroitin sulfate proteoglycan. | Neurocan is a chondroitin sulfate proteoglycan of the lectican family and a component of the extracellular matrix of the central nervous system. It is mainly expressed during modeling and remodeling stages of this tissue. Neurocan can bind to various structural extracellular matrix components, such as hyaluronan, hepar... |
11766881 | Lipoxygenase--a versatile biocatalyst for biotransformation of endobiotics and xenobiotics. | Lipoxygenase, a member of the arachidonate cascade enzymes, dioxygenates polyenoic fatty acids to finally yield products with profound and distinct biological activity. This review summarizes the available evidence for another role played by lipoxygenases in the metabolism of endobiotics and xenobiotics. Although other... |
11765782 | Interaction of morin with CTMAB: aggregation and location in micellar. | The aggregation and location of morin in CTMAB micellar solution was studied by light scattering spectra, electronic absorption spectra and pulsed FT NMR techniques. The difference in the light scattering property of morin with and without CTMAB proved that a large particle of the morin-CTMAB associate formed. Morin ha... |
11747114 | Guest-to-host proton transfer in melatonin-beta-cyclodextrin inclusion complex by ionspray, fast atom bombardment and tandem mass spectrometry. | Ionspray (IS) and fast atom bombardment (FAB) positive ionization mass spectrometry (MS) of 1 : 1 beta-cyclodextrin (beta-CD)-melatonin (MLT) host-guest complex allowed the detection of gaseous protonated 1 : 1 beta-CD-MLT. Tandem MS collision-induced dissociation (CID) of such protonated 1 : 1 beta-CD-MLT species show... |
11744280 | Auditory nerve fibers in young and quiet-aged gerbils: morphometric correlations with endocochlear potential. | The number, size and distribution of myelinated nerve fibers were analyzed in the osseous spiral lamina (OSL) of young and old gerbils raised in a quiet environment. Because decreased endocochlear potentials (EPs) play a significant role in age-related hearing loss in the gerbil, we correlated morphometric and topograp... |
11746239 | Determination of bisphenol A and 10 alkylphenols in serum using SDS micelle capillary electrophoresis with gamma-cyclodextrin. | A new micelle capillary electrophoresis based on cyclodextrin micellar electrokinetic chromatography (MEKC) for the determination of bisphenol A and 10 alkylphenols in rat serum is reported. Several surfactants and dextrins were studied. Bisphenol A and alkylphenols were separated using a 50 microm x 50 cm capillary wi... |
11743877 | Synthesis and properties of bacteriorhodopsin analogs containing electron-density labels in the chromophore moiety. | A method for synthesis of retinal analogs labeled with electron-density groups is suggested. The interaction of these polyene compounds with bacterioopsin in apomembrane of Halobacterium salinarum was tested. A retinal analog containing a crown-ether receptor group is able to interact readily with bacterioopsin giving ... |
11742496 | gp100/pmel17 and tyrosinase encode multiple epitopes recognized by Th1-type CD4+T cells. | CD4+ T cells modulate the magnitude and durability of CTL responses in vivo, and may serve as effector cells in the tumour microenvironment. In order to identify the tumour epitopes recognized by tumour-reactive human CD4+ T cells, we combined the use of an HLA-DR4/peptide binding algorithm with an IFN-gamma ELISPOT as... |
11763465 | Comparative supramolecular chemistry of coronene, hexahelicene, and [18]crown-6: hydrated and solvated molecular complexes of [18]crown-6 with 5-hydroxyisophthalic acid and related di- and tricarboxylic acids. | The outer rim of C-H bonds of coronene (COR) and hexahelicene (HEL) is similar to that of the crown conformation of [18]crown-6 (CRO), which is exploited for crystal engineering of molecular complexes of CRO. However, although CRO does form the adduct (TMA)2 x CRO x (H2O)2 (TMA = trimesic acid = 1,3,5-benzenetricarboxy... |
11763464 | What is the difference between the manganese porphyrin and corrole analogues of cytochrome P450's compound I? | Density functional calculations on oxo-manganese complexes of corrole (1) and porphyrin (2 and 3) show a fundamental difference. The ground state of I is the singlet manganese(V) state, 1A(MnV), in which corrole is a closed shell. In contrast, 2 and 3 have high-spin manganese(IV) states, 1A1u and 3A2u respectively. Thi... |
11763459 | Ionic channel structures in [(M+)x([18]crown-6)][Ni(dmit)2]2 molecular conductors. | The [(M+)x[18]crown-6)] supramolecular cations (SC+), in which M+ and [18]crown-6 are alkali metal ions (M+ = Li+, Na+, and Cs+) and 1,4,7,10,13,16-hexaoxacyclooctadecane, respectively, form ionic channel structures through the regular stacks of [18]crown-6 in [Ni(dmit)2]-based molecular conductors (dmit2+ = 2-thioxo-1... |
11763456 | Highly selective optical-sensing membranes, containing calix[4]arene chromoionophores, for Pb2+ ions. | Plasticized poly(vinyl chloride) (PVC) optode membranes containing novel calix[4]arene chromoionophores 1 or 2 and one equivalent of a lipophilic anion respond to Pb2+ ions with high selectivity over alkali, alkaline-earth, and other heavy metal ions. This selectivity stems from the combination of ligand specificity an... |
11763455 | A supramolecular system for quantifying aromatic stacking interactions. | A supramolecular complex for investigating the thermodynamic properties of intermolecular aromatic stacking interactions has been developed. The conformation of the complex is locked in a single well-defined conformation by an array of H-bonding interactions that force two aromatic rings on one end of the complex into ... |
11763453 | Polyphenylene dendrimers with perylene diimide as a luminescent core. | A novel synthesis is presented of a fourfold ethynyl-substituted perylene diimide dye 4, which acts as a core molecule for the buildup of polyphenylene dendrimers. Around the luminescent core 4, a first-generation (5), a second-generation (6), and a third-generation (7) polyphenylene dendritic environment consisting of... |
11763448 | Metal complexation with Langmuir monolayers of histidyl peptide lipids. | Langmuir monolayers made from peptide-lipid molecules represent a novel direction in the research areas of biomimetic interfaces and two-dimensional supramolecular chemistry. Peptide structures and molecular recognition activities toward other guest molecules have been the focus of previous study. This study reports th... |
11762602 | Regiospecific effect of 1-octanol on cis-trans isomerization of unsaturated fatty acids in the solvent-tolerant strain Pseudomonas putida S12. | The solvent-tolerant bacterium Pseudomonas putida S12, which adapts its membrane lipids to the presence of toxic solvents by a cis to trans isomerization of unsaturated fatty acids, was used to study possible in vivo regiospecificity of the isomerase. Cells were supplemented with linoleic acid (C18:2delta9-cis,delta12-... |
11735450 | Purification of recombinant human B-domain-deleted factor VIII using anti-factor VIII monoclonal antibody selected by the surface plasmon resonance biosensor. | The surface plasmon resonance (SPR) biosensor measures the real-time kinetics of noncovalent interaction between a receptor and its ligand. Monoclonal antibodies (mAbs) against recombinant factor VIII (rFVIII) were screened from 127 mAb candidates using the SPR biosensor for the purpose of affinity purification of rFVI... |
11738083 | Self-aggregation characteristics of recombinantly expressed human elastin polypeptides. | Elastin is an extracellular matrix protein found in tissues requiring extensibility and elastic recoil. Monomeric elastin has the ability to aggregate into fibrillar structures in vitro, and has been suggested to participate in the organization of its own assembly into a polymeric matrix in vivo. Although hydrophobic s... |
11763084 | Cyclodextrin-modified biosensors: comparision of cyclodextrin-linked ferrocenes as mediators in sol-gel and screen-printed formats for sensing acetylcholine. | This work reports the comparison of a sol-gel and a screen-printed biosensor format using new mediators and a sensitive thin-film (ref. 1: P. Kataky and D. Parker, Analyst, 1996, 121, 1829) to enhance the sensitivity and stability of biosensors. The new mediators were per-alkylated cyclodextrin linked ferrocenes and a ... |
11763054 | Disorganised self-assembled monolayers (SAMs): the incorporation of amphiphilic molecules. | A new approach for designing a voltammetric selective electrode is presented. The approach is based on the formation of a disorganised inert self-assembled monolayer (SAM), in which an amphiphilic molecule is incorporated. The latter serves as the selectivity factor, which extracts the analyte. The purpose of these exp... |
11762758 | Complex formation analysis of water-soluble calixarenes by capillary zone electrophoresis. | The equilibria of complex formation reactions between various kinds of cations and anionic calixarenes in an aqueous solution were analyzed by capillary zone electrophoresis on the basis of the change in electrophoretic mobility of the calixarenes. The apparent electrophoretic mobility of the calixarenes decreased with... |
11762763 | Solid-phase microextraction of monocyclic aromatic amines using novel fibers coated with crown ether. | Three solid-phase microextraction (SPME) fibers prepared by the sol-gel method, containing hydroxydibenzo-14-crown-4 (OH-DB14C4), dihydroxy-substituted saturated urushiol crown ether (DHSU14C4) and 3,5-dibutyl-unsymmetry-dibenzo-14-crown-4-dihydroxy crown ether (DBUD14C4), respectively, were evaluated for the determina... |
11760477 | [Multiple organ failure. Mechanisms, clinical manifestations and treatment strategies]. | Multiple organ failure (MOV) still represents the leading medical and economical problem in the care of the critically ill surgical patient. Although the incidence of MOF has tended to decrease over the last several years reflecting improved surgical and supportive therapy in the ICU, prognosis still remains serious wh... |
11761004 | Chemical characterisation of the different types of volatile oil constituents by various solute retention ratios with the use of conventional and novel commercial gas chromatographic stationary phases. | Retention ratios of an unknown solute peak from a volatile oil can help to identify its chemical type. Relative retentions on conventional stationary phases can be used to calculate a polar/non-polar ratio which may suggest it is an aromatic solute or a sesquiterpene hydrocarbon. With dipentyl (DA) cyclodextrin phases,... |
11758766 | Stabilizing and solubilizing effects of sulfobutyl ether beta-cyclodextrin on prostaglandin E1 analogue. | <h4>Purpose</h4>Parent cyclodextrins are known to accelerate the degradations such as dehydration and isomerization of E-type prostaglandins in neutral and alkaline solutions. The objective of this study was to attempt the stabilization and solubilization of E1-type prostaglandin analogue in aqueous solution by biocomp... |
11758751 | Chiral separation of 9-fluorenylmethyl chloroformate- and dansyl chloride-derivatized D,L-serine by gamma-cyclodextrin-bonded high-performance liquid chromatography. | When acetate buffer was used in chiral separation of D,L-serine derivatives using a gamma-cyclodextrin (CD) column, both retention factor and resolution were high below the pKa of acetic acid and decreased sharply as the pH approached the pKa. A similar result was obtained by increasing the buffer concentration at a fi... |
11758749 | Impact of triethylamine as a mobile phase additive on the resolution of racemic amino acids on an (+)-18-crown-6-tetracarboxylic acid-derived chiral stationary phase. | Recently, a new HPLC chiral stationary phase (CSP) prepared by covalently bonding (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid on silica gel was successfully employed in resolving various racemic natural and unnatural amino acids containing a primary amino group. Current work details on-going efforts to improve the ... |
11757666 | Supramolecular solubilisation of hydrophilic dyes by using individual dendritic branches. | Individual dendritic branches can solubilise hydrophilic dyes in apolar media. The functional group at the focal point of the dendritic branch plays a key role in the dye uptake process. Supramolecular interactions between carboxylic acid and amine groups have been shown to be effective in enabling efficient solubilisa... |
11757650 | Synthesis and photophysical and cation-binding properties of mono- and tetranaphthylcalix[4]arenes as highly sensitive and selective fluorescent sensors for sodium. | The syntheses and properties of two calixarene-based fluorescent molecular sensors are reported. These comprise tert-butylcalix[4]arene either with one appended fluorophore and three ester groups (Calix-AMN1). or with four appended fluorophores (Calix-AMN4). The fluorophore is 6-acyl-2-methoxynaphthalene (AMN), which c... |
11757644 | Examples of hula-twist in photochemical cis- trans isomerization. | ALiu and Hammond recently reasoned that the hula-twist (HT), a volume-conserving cis-trans isomerization mechanism, is involved in reactions of confined systems. We now show that HT can be applied to various reported photochemical isomerization of chromophores (small organic systems as well as photoactive bio-pigments)... |
11757599 | Interpreting nonracemic ratios of chiral organochlorines using naturally contaminated fish. | Although reports of nonracemic proportions of chiral organochlorine pollutants in the environment are widespread, the interpretation of such data is not well developed. Using GC/MS and a chiral stationary phase consisting of 25% tert-butyldimethylsilylated beta-cyclodextrin in PS086 (beta-BSCD), we followed the change ... |
11733143 | The human tuftelin gene: cloning and characterization. | Tuftelin has been suggested to play an important role during the development and mineralization of enamel. We isolated the full-length human tuftelin cDNA using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (5' RACE and 3' RACE) methods. Sequence analysis of the tuftelin ... |
11728312 | Regulating c-Ras function. cholesterol depletion affects caveolin association, GTP loading, and signaling. | Cholesterol-rich and caveolin-containing microdomains of the plasma membrane, termed "caveolae," have been implicated in signal transduction. However, the role of caveolae in regulating the Ras-MAP kinase cascade is incompletely understood. The mammalian Ras isoforms (H, N, and K) use different membrane anchors to atta... |
11722210 | Controlling factors in the synthesis of cucurbituril and its homologues. | The acid-catalyzed synthesis of cucurbit[n]urils from formaldehyde and glycoluril is poorly understood. In this paper, we examine a wide range of reaction conditions that include the effects of acid type, acid concentration, reactant concentrations, and temperature to both probe the mechanism and optimize the yields of... |
11722201 | Synthesis and conformational property of tannin-like p-tert-butylcalix[4]arene 1,3-diesters stabilized by intramolecular hydrogen bonds. | Tannin-like p-tert-butylcalix[4]arene 1,3-digallate was synthesized, and its conformational property was investigated by dynamic (1)H NMR and X-ray crystallography. It was found that the 3-OH (or 5-OH) group of the galloyl group in p-tert-butylcalix[4]arene 1,3-digallate is placed at the position where an unusual nonbo... |
11723171 | The gamma-aminobutyric acid receptor B, but not the metabotropic glutamate receptor type-1, associates with lipid rafts in the rat cerebellum. | Recent evidence suggests that specialized microdomains, called lipid rafts, exist within plasma membranes. These domains are enriched in cholesterol and sphingolipids and are resistant to non-ionic detergent-extraction at 4 degrees C. They contain specific populations of membrane proteins, and can change their size and... |
11722551 | An extrusion strategy for the FeMo cofactor from nitrogenase. Towards synthetic iron-sulfur proteins. | Iron-sulfur clusters are ubiquitous in biological systems, facilitating functions such as electron transfer (rubredoxins, ferredoxins, rieske centres), isomerization (aconitase) and small molecule activation such as dinitrogen reduction (nitrogenases). Of global importance and recently particular interest, is the iron-... |
11721929 | Enzyme-modulated cleavage of dsDNA for supramolecular design of biosensors. | Supramolecular docking and immobilization of biotinylated dsDNA onto a self-assembled monolayer of avidin have been measured using impedance spectroscopy and quartz crystal microbalance technique. The formation of the serial assembly was first achieved by linearizing circular plasmid dsDNA using BamH I endonuclease enz... |
11721910 | Molecular recognition in a propazine-imprinted polymer and its application to the determination of triazines in environmental samples. | An analytical methodology for the determination of triazines in environmental samples incorporating a molecularly imprinted solid-phase extraction (MISPE) process using a propazine-imprinted polymer was developed. Two different polymers were prepared using acetonitrile or toluene as porogen, and their optimum loading, ... |
11721897 | Development of an intelligent polymerized crystalline colloidal array colorimetric reagent. | We have developed a novel colorimetric reagent for the determination of Pb2+, pH, and temperature. This colorimetric reagent consists of a dispersion of approximately 100-microm particles composed of an intelligent polymerized crystalline colloidal array (IPCCA). The IPCCA particles are composed of a hydrogel polymeriz... |
11721046 | Self-assembly and mineralization of peptide-amphiphile nanofibers. | We have used the pH-induced self-assembly of a peptide-amphiphile to make a nanostructured fibrous scaffold reminiscent of extracellular matrix. The design of this peptide-amphiphile allows the nanofibers to be reversibly cross-linked to enhance or decrease their structural integrity. After cross-linking, the fibers ar... |
11720567 | Synthesis of a metal-free texaphyrin. | The synthesis of a metal-free form of texaphyrin, an aromatic porphyrin-like macrocycle, is described. Previously, texaphyrins could only be obtained reproducibly in the form of metal complexes. Using ferrocenium cation as the oxidizing agent and starting with a reduced porphyrinogen-like nonaromatic form of texaphyrin... |
11720551 | Dewar benzene as a protecting group? Demonstration of photolithographic crystallization. | The concept of Dewar benzene as a supramolecular protecting group for solid-state aryl-aryl interactions is reported. Photoisomerization of 1,4,5,6-tetramethyl-bicyclo[2.2.0]hexa-2,5-diene-2,3-dicarboxylic acid dimethyl ester (1) to the corresponding benzene isomer proceeds with rapid crystal formation. Herein this pro... |
11720548 | Discrete versus infinite molecular self-assembly: control in crystalline hydrogen-bonded assemblies based on resorcinol. | Cocrystallization of 1,2-bis(4-pyridyl)ethane (4,4'-bipyeth) with resorcinol (res), 4-chlororesorcinol (4-Cl-res), and 4,6-dichlororesorcinol (4,6-di-Cl-res) yields molecular solids (4,4'-bipyeth).(res) 1a, 2(4,4'-bipyeth).2(4-Cl-res) 1b, and 2(4,4'-bipyeth).2(4,6-di-Cl-res) 1c with components held together by O-H...N ... |
11720547 | Design and synthesis of photoresponsive poly(benzyl ester) dendrimers with all-azobenzene repeating units. | A novel class of dendrons and dendrimers containing all-azobenzene units (up to 29 azobenzene groups) was designed and synthesized by the convergent method using a protected orthogonal AB(2) monomer (10) and tetra-functionalized core (11) as building blocks. The preparation of the key monomer (10) involved condensation... |
11720425 | Adjuvant 5FU plus levamisole in colonic or rectal cancer: improved survival in stage II and III. | Based on the first favourable results of adjuvant therapy of 5FU plus levamisole in Dukes C colonic cancer in 1990, we conducted a prospective trial. 1029 patients were randomised to receive one year 5FU plus levamisole or no further treatment following curative surgery for stage II or III colon (n = 730) or rectal can... |
11718949 | Towards synthetic viruses. | Gene delivery is too complex to be performed with a single carrier molecule. Synthetic multicomponent vectors are being designed that mimic key properties of viruses. Some solutions, such as diverting cell-anchoring molecules or the endogenous nuclear import machinery from their normal function, are directly copied fro... |
11717449 | Plasma membrane rafts play a critical role in HIV-1 assembly and release. | HIV-1 particle production occurs in a series of steps promoted by the viral Gag protein. Although it is well established that assembly and release take place at the plasma membrane, the nature of membrane assembly sites remains poorly understood. We show here that Gag specifically associates with cholesterol-enriched m... |
11717439 | Role of positively charged transmembrane segments in the insertion and assembly of mitochondrial inner-membrane proteins. | The biogenesis of membrane oligomeric complexes is an intricate process that requires the insertion and assembly of transmembrane (TM) domains into the lipid bilayer. The Oxa1p family plays a key role in this process in organelles and bacteria. Hell et al. (2001, EMBO J., 20, 1281-1288) recently have proposed that Oxa1... |
11716722 | Using structures formed by dirhodium tetra(trifluoroacetate) with polycyclic aromatic hydrocarbons to prospect for maximum pi-electron density: Hückel calculations get it right. | A new class of supramolecular assemblies derived from a powerful Lewis acid in the form of dirhodium(II) tetra(trifluoroacetate) and various planar polycyclic aromatic hydrocarbons (PAHs) as donors has been prepared using a solventless technique. As a result, a number of novel adducts [Rh2(O2CCF3)4]x(L)y with various s... |
11716706 | Unsaturated thiacrown ethers: synthesis, physical properties, and formation of a silver complex. | The 6-, 9-, 12-, 15-, 18-, 21-, 24-, and 27-membered unsaturated thiacrown ethers 1-8 were formed by reaction of cis-1,2-dichloroethylene with sodium sulfide in acetonitrile. Crystal structures of 4-8 were determined by X-ray crystallography, and it was found that all sulfur atoms of 5-8 direct to the inside of the rin... |
11716705 | "Flexiball" toolkit: a modular approach to self-assembling capsules. | We report the synthesis and characterization of new, self-assembling molecular capsules. The modular strategy makes use of glycoluril building blocks available in multigram amounts combined with aromatic spacer elements. The lengthy syntheses encountered with earlier generations of capsules are avoided, and several cap... |
11716689 | Synthesis and biological studies of 5-aminolevulinic acid-containing dendrimers for photodynamic therapy. | Using a convergent growth approach, a series of novel 5-aminolevulinic acid (ALA)-containing dendrimers have been synthesized. In these molecules, ALA residues are attached to the periphery by ester linkages, with amide bonds connecting the dendrons. Three first-generation dendrimers, bearing either 6 or 9 ALA residues... |
11716683 | Construction of a fusion enzyme system by gene splicing as a new molecular recognition element for a sequence biosensor. | A bifunctional fusion enzyme system constructed by gene splicing is proposed as a new model to develop sequence biosensors, taking maltose biosensor as an example. The cDNA fragment of Aspergillus niger glucoamylase (E.C 3.2.1.3, GA) was fused to the 3' end of Aspergillus niger glucose oxidase (E.C 1.1.3.4, GOD) gene w... |
11716673 | In vitro selection of RNA aptamers carrying multiple biotin groups in the side chains. | In vitro selection or the systematic evolution of ligands by an exponential enrichment (SELEX) technique using a biotin-carrying nucleotide monomer was used for the development of a new type of molecular recognition sensor. Cytidine triphosphate (CTP) carrying the biotinyl group at the N4-position was applied for the t... |
11714757 | Intercellular transfer and supramolecular organization of human leukocyte antigen C at inhibitory natural killer cell immune synapses. | After accumulation of target cell human leukocyte antigen (HLA)-C at inhibitory natural killer (NK) cell immune synapses, some HLA-C transfers from target cells to NK cell plasma membranes and cytoplasm. This unexpected intercellular transfer of HLA-C is dependent on NK receptor recognition, since HLA-Cw6 or -Cw4 but n... |
11714747 | Determinants of viral clearance and persistence during acute hepatitis C virus infection. | The virological and immunological features of hepatitis C virus (HCV) infection were studied weekly for 6 months after accidental needlestick exposure in five health care workers, four of whom developed acute hepatitis that progressed to chronicity while one subject cleared the virus. In all subjects, viremia was first... |
11714271 | Modulation of the multisubstrate specificity of Thermus maltogenic amylase by truncation of the N-terminal domain and by a salt-induced shift of the monomer/dimer equilibrium. | The relation between the quaternary structure and the substrate specificity of Thermus maltogenic amylase (ThMA) has been investigated. Sedimentation diffusion equilibrium ultracentrifugation and gel filtration analyses, in combination with the crystal structure determined recently, have demonstrated that ThMA existed ... |
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