id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
15835172 | Synthesis, characterization, and surface immobilization of platinum and palladium nanoparticles encapsulated within amine-terminated poly(amidoamine) dendrimers. | Platinum and palladium dendrimer-encapsulated nanoparticles (DENs) were prepared within commercially available, fourth-generation, amine-terminated, poly(amidoamine) dendrimers (G4-NH2). The synthesis is carried out by selectively encapsulating metal complexes within the dendrimer and then reducing the resulting compos... |
15835162 | Effect of the mobility of ligands in polyrotaxanes on order structure of water clusters. | The effect of the mobility of ligands (maltose groups) in the polyrotaxanes (pRXs) on the structure of the surrounding water molecules was investigated. Raman spectra of collective OH stretching vibration of water molecules in aqueous solutions of maltose-pRX conjugates with different alpha-cyclodextrin (alpha-CD) thre... |
15835154 | Coadsorption of sodium dodecyl sulfate and a polyanion onto poly(ethylenimine) in multilayered thin films. | Mixed surfactant-polyelectrolyte multilayer films were fabricated by both ionic self-assembly and spin assembly. A polycation [PEI = poly(ethylenimine)] was deposited from a dilute solution, while a polyanion (PAZO = poly[1-[4-(3-carboxy-4-hydroxyphenylazo) benzenesulfonamido]-1,2-ethanediyl, sodium salt]) was deposite... |
15835152 | SAMs of shape-persistent macrocycles: structure and binding on HOPG and Au(111). | Self-assembled monolayers of shape-persistent macrocycles have been adsorbed on highly oriented pyrolytic graphite and Au(111) substrates. Their structure and binding characteristics have been investigated by scanning tunneling microscopy, X-ray photoelectron spectroscopy, and ultraviolet photoelectron spectroscopy exp... |
15835150 | Synthesis and supramolecular self-assembly study of a novel porphyrin molecule in Langmuir and Langmuir-Blodgett films. | The self-assembly and supramolecular engineering of porphyrins into ordered arrays have recently attracted much interest because of their promising application potential in molecular and electronic devices, spintronics, energy harvesting and storage, catalysis, and sensor development. We herein report the synthesis and... |
15835132 | Dendritic chelating agents. 1. Cu(II) binding to ethylene diamine core poly(amidoamine) dendrimers in aqueous solutions. | This paper describes an investigation of the uptake of Cu(II) by poly(amidoamine) (PAMAM) dendrimers with an ethylenediamine (EDA) core in aqueous solutions. We use bench scale measurements of proton and metal ion binding to assess the effects of (i) metal ion-dendrimer loading, (ii) dendrimer generation/terminal group... |
15835119 | Antioxidant action by gold-PAMAM dendrimer nanocomposites. | Gold-dendrimer nanocomposites were prepared in the presence of poly(amidoamine) (PAMAM) dendrimer (generation 3, 3.5, 5, and 5.5) via reduction of HAuCl4 with sodium borohydride. The average particle size of the gold nanoparticles was independent of the dendrimer concentration, ranging between 3.0 and 4.3 nm in diamete... |
15801415 | Cloud point of aqueous solutions of tetrabutylammonium dodecyl sulfate is a function of the concentration of counterions in the aqueous phase. | The cloud point of the surfactant tetrabutylammonium dodecyl sulfate is shown to be a function of the tetrabutylammonium counterion concentration in the aqueous phase whether the counterions are provided by the surfactant or both the surfactant and added tetrabutylammonium bromide. The micellized surfactant dissociates... |
15760007 | [Coordination bonding driving supramolecular self-assembly of tetraphenylporphyrinatozinc (II) with imidazolyl tailed porphyrinatoiron (III) studied by fluorescence spectra and 1H NMR]. | Coordination bonding driving supramolecular self-assembly of Zn(TPP) with Fe(p-ImEPTPP)Cl was investigated by fluorescence spectra and 1H NMR. The results indicate that an obvious fluorescence quenching observed from Zn(TPP) by addition of Fe (p-ImEPTPP)Cl is due to the coordination of the terminal imidazolyl group of ... |
15759988 | [Study of the effect of aliphatic alcohol on the inclusion interaction of qucertin-cyclodextrin complexes]. | The inclusion interaction of qucertin with beta-cyclodextrin and its derivatives was studied by fluorimetry. The formation constants of their inclusion complexes were determined, and the stoichiometry ratio on the formation of the inclusion complexes was determined by equimolar continueous variation method. The effect ... |
15759982 | [Preparation and properties of complex of europium lanthanum with crown ether and p-phthalic acid]. | Two complexes of crown ether europium (EuL) and crown ether lanthanum (LaL) were synthesized by europium perchlorate and lanthanum perchlorate with 18-crown-6(18-C-6) respectively. The heternuclear complexes of europium-lanthanum p-phthalic acid crown ether were prepared by the two complexes (EuL and LaL) with p-phthal... |
15712868 | [Cross-linked beta-cyclodextrin polymer used for bilirubin removal]. | A new material for adsorption of bilirubin was synthesized with cross-linking reaction of beta-cyclodextrin. The kinetic adsorption behaviors of bilirubin such as the effects of temperature, pH, the initial bilirubin concentration as well as bovine seum albumin on the removal of bilirubin have been investigated. It is ... |
15712867 | [Chiral two-phase synergistic effect in high performance liquid chromatography]. | Cellulose tribenzoate (CTB) and cellulose triphenylcarbamate (CTPC) were synthesized for the coating of high performance liquid chromatographic stationary phases. Elemental analysis and IR spectra indicated that most of the hydroxy groups of the microcrystalline cellulose had been converted into ester groups. The silan... |
15615045 | Intramolecular fluorescence quenching of crowned 7-aminocoumarins as potential fluorescent chemosensors. | The effects of the nature of solvent, temperature and complex formation with alkali and alkaline-earth metal cations, as well as protonation, on the efficiency and the kinetics of fluorescence of 3-azacrowned 7-diethylaminocoumarins have been studied. For the crown-ethers under investigation, the ratio of a dipole mome... |
15382642 | Cucurbiturils: molecular nanocapsules for time-resolved fluorescence-based assays. | A new fluorescent host-guest system based on the inclusion of the fluorophore 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) into the cavity of the molecular container compound cucurbit[7]uril (CB7) has been designed which possesses an exceedingly long-lived emission (690 ns in aerated water). The large binding constant of (4 ... |
15382638 | S-layer proteins as supporting scaffoldings for functional lipid membranes. | A great challenge is the coupling of very sensitive microelectronic devices to wet biological systems in the generation of biomimetic sensors. Lipid membranes on solid supports (electrodes or semiconductors) may become the matrix of future bioelectronic devices probing and controlling biomolecular processes for scienti... |
15270073 | Cooperation of heat shock protein 90 and p23 in aryl hydrocarbon receptor signaling. | Aryl hydrocarbon receptor (AhR) is a transcription factor that is activated by the binding of xenobiotic and endogenous ligands. AhR interacts with heat shock protein (Hsp) 90 complexes and can be used as a functional substrate to detect chaperone-dependent processes. Yeast Hsp90 (hsp82) mutants that variably affected ... |
15267461 | Self-assembly of peptides into a beta-barrel motif. | We report the results of a study of the self-assembly of four minimalist peptide strands with a native beta-barrel structure. Using a soft-well potential to mimic cellular crowding, molecular dynamics simulations were performed in confining spheres of varying radii. By utilizing a previously introduced scaling factor l... |
15267456 | Molecular binding at gold transport interfaces. IV. Thiol chemisorption. | Alkene thiol/coinage metal molecular interfaces are relatively easy to make, and can result in well-ordered self-assembled monolayer films. The energetics of such formation is complex-differing experimental and theoretical accounts have focused on the nature of the binding, the energetics via different pathways (thiol ... |
15267455 | Molecular binding at gold transport interfaces. III. Field dependence of electronic properties. | The behavior of the electronic structure in a metal/molecular/metal junction as a function of the applied electric field is studied using density functional methods. Although the calculations reported here do not include the electrode bulk, or intermolecular interactions, and do not permit actual transport to occur, ne... |
15267349 | Functionalization of carbon nanotubes using phenosafranin. | Spectroscopic analysis and atomic force microscopy (AFM) phase imaging studies show self-assembly of phenosafranin (PSF) to multiwalled carbon nanotubes (MWNTs). The shift in absorption spectra is associated with charge transfer of valence electrons from PSF to electron accepting sites on the MWNTs. The Raman-active di... |
15214414 | Chiral recognition in NMR spectroscopy using crown ethers and their ytterbium(III) complexes. | Chiral crown ethers 1 and 5 are useful enantiomeric discriminating agents in 1H NMR spectroscopy for neutral and protonated primary amines, amino acids, and amino alcohols. The presence of the carboxylic acid groups in 1 and 5 provide sites at which ytterbium(III) can bind. Adding ytterbium(III) nitrate to crown-substr... |
15214413 | Chiral separation of nanomole amounts of alprenolol with cITP/NMR. | On-line cITP-NMR with chiral selectors separates and concentrates analytes and identifies host-guest interactions of analytes with selectivity enhancers in the electrolyte. An NMR microcoil designed for a 200 microm i.d. capillary creates a high-mass-sensitivity 30 nL NMR cell and is used as an on-line detector for cIT... |
15096580 | Improvement of cyclodextrin glucanotransferase as an antistaling enzyme by error-prone PCR. | In an effort to improve the properties of cyclodextrin glucanotransferase (CGTase) as an antistaling enzyme, error-prone PCR was used to introduce random mutations into a CGTase cloned from alkalophilic Bacillus sp. I-5 (CGTase I-5). A mutant CGTase[3-18] with the three mutations M234T, F259I and V591A was selected by ... |
15113834 | Two additional carbohydrate-binding sites of beta-amylase from Bacillus cereus var. mycoides are involved in hydrolysis and raw starch-binding. | In the previous X-ray crystallographic study, it was found that beta-amylase from Bacillus cereus var. mycoides has three carbohydrate-binding sites aside from the active site: two (Site2 and Site3) in domain B and one (Site1) in domain C. To investigate the roles of these sites in the catalytic reaction and raw starch... |
15113087 | Metal ion-binding ability of tetrapeptides containing alpha-aminoisobutyric acid. | alpha-Aminoisobutyric acid (Aib), one of the Calpha,alpha-disubstituted glycines, is a sterically hindered amino acid that acts as a conformational constraint in peptides. However, studies for the application of the ability of Aib to control conformation are quite few. The paper focuses on the molecular recognition abi... |
15070099 | 3H dendrimer nanoparticle organ/tumor distribution. | <h4>Purpose</h4>To determine the in vivo biodistribution for differently charged poly(amidoamine) (PAMAM) dendrimers in B16 melanoma and DU145 human prostate cancer mouse tumor model systems.<h4>Methods</h4>Neutral (NSD) and positive surface charged (PSD) generation 5 (d = 5 nm) PAMAM dendrimers were synthesized by usi... |
15070097 | Evaluation of generation 2 and 3 poly(propylenimine) dendrimers for the potential cellular delivery of antisense oligonucleotides targeting the epidermal growth factor receptor. | <h4>Purpose</h4>To evaluate low generation, G2 and G3, poly(propylenimine) dendrimers for the potential cellular delivery of antisense oligonucleotides (ODNs) targeting the epidermal growth factor receptor (EGFR) in A431 epidermoid carcinoma cells.<h4>Methods</h4>Cell cytotoxicity of the dendrimers was evaluated using ... |
15070096 | In situ-forming pharmaceutical organogels based on the self-assembly of L-alanine derivatives. | <h4>Purpose</h4>To characterize novel pharmaceutical organogels based on the self-assembly of L-alanine derivatives in hydrophobic vehicles.<h4>Methods</h4>The gelation properties of N-lauroyl-L-alanine (LA) and N-lauroyl-L-alanine methyl ester (LAM) were investigated in the presence of various solvents. Gel-sol and so... |
15067873 | Microarray-based in vitro evaluation of DNA oligomer libraries designed in silico. | We report on the microarray-based in vitro evaluation of two libraries of DNA oligonucleotide sequences, designed in silico for applications in supramolecular self-assembly, such as DNA computing and DNA-based nanosciences. In this first study which is devoted to the comparison of sequence motif properties theoreticall... |
15067867 | Designing systems for a multiple use of light signals. | The photochemical and photophysical behavior of two dendrimers consisting of a benzophenone core and branches that contain dimethoxybenzene units has been investigated. Such dendrimers can undergo a variety of photochemical and photophysical processes, namely: 1) quenching of the fluorescence and phosphorescence of the... |
15068306 | Preparation and characterization of a new p-tert-butyl-calix[8]arene-bonded stationary phase for high-performance liquid chromatography. | A new p-tert-butyl-calix[8]arene-bonded silica gel stationary phase (CABS) was prepared via 3-glycidoxypropyltrimethoxysilane as a coupling reagent for HPLC. Its structure was characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), elemental analysis and thermal analysis. The chromatograph... |
15061690 | Eucaryotic DNA replication complex: study of structure and function using the affinity modification technique. | Eucaryotic DNA replication complex is now one of the most intensively studied subjects of molecular biology and biochemistry. In addition to detailed studies on the structures and functions of individual DNA polymerases involved in this process, other enzymes and protein factors are also given much attention. The struc... |
15058987 | A dynamic mathematical model to clarify signaling circuitry underlying programmed cell death control in Arabidopsis disease resistance. | Plant cells undergo programmed cell death in response to invading pathogens. This cell death limits the spread of the infection and triggers whole plant antimicrobial and immune responses. The signaling network connecting molecular recognition of pathogens to these responses is a prime target for manipulation in geneti... |
15056902 | Retarding effects of cyclodextrins on the decomposition of organic isothiocyanates in an aqueous solution. | One- and two-dimensional (1)H nuclear magnetic resonance ((1)H NMR) spectra were measured in order to estimate the dissociation constants (K(diss)) and molecular geometries of cyclodextrin (CD) with three organic isothiocyanates (ITC), allyl-ITC, 3-butenyl-ITC, and 4-pentenyl-ITC, in an aqueous solution (pH 5.0, I(c)=0... |
15036247 | Cytokine gene promoter polymorphisms and mortality in acute renal failure. | <h4>Background</h4>Although cytokines play a pivotal role in the inflammatory responses that mediate the severity of acute renal failure (ARF), the importance of pro- and anti-inflammatory cytokine gene promoter polymorphisms has been unexplored.<h4>Methods</h4>We prospectively evaluated the relationship of single nucl... |
15032540 | Molecular symmetry perception. | An algorithm for molecular symmetry perception is presented. The method identifies the full set of molecular symmetry elements (proper and improper) and determines their coordinates. The algorithm eliminates the necessity to explore the entire graph automorphism group; as a result its computer application is extremely ... |
15032533 | Quantitative structure-property relationship modeling of beta-cyclodextrin complexation free energies. | CODESSA-PRO was used to model binding energies for 1:1 complexation systems between 218 organic guest molecules and beta-cyclodextrin, using a seven-parameter equation with R2 = 0.796 and Rcv2 = 0.779. Fragment-based TRAIL calculations gave a better fit with R2 = 0.943 and Rcv2 = 0.848 for 195 data points in the databa... |
15034893 | Towards ordered architectures: self-assembly and stepwise procedures to the hexameric metallomacrocycles [arylbis(terpyridinyl)6FeII6-n-RuIIn] (n=0,2,3,5). | Hexameric metallomacrocycles are a new class of ordered rigid-macromolecules which possess unique structural, electronic, and physical characteristics. Directed- and self-assembly methods for the construction of these stable bis(terpyridine)-based materials are investigated by using both Fe(II) and Ru(II) as the coordi... |
15034886 | Oxasmaragdyrin-ferrocene and oxacorrole-ferrocene conjugates: synthesis, structure, and nonlinear optical properties. | Ferrocenyl macrocyclic conjugates involving 22 pi oxasmaragdyrins and 18 pi oxacorroles have been synthesized and characterized. The direct covalent linkage of the ferrocenyl moiety to the meso position of the macrocycle is achieved by simple oxidative coupling of appropriate precursors with trifluoroacetic acid as cat... |
15034885 | Self-assembly of normal alkanes on the Au (111) surfaces. | The self-assembled monolayers (SAMs) of normal alkanes (n-C(n)H(2n+2)) with different carbon chain lengths (n=14-38) in the interfaces between alkane solutions (or liquids), and the reconstructed Au (111) surfaces have been systematically studied by means of scanning tunneling microscopy (STM). In contrast to previous ... |
15034884 | Synthesis and characterization of dendritic multichromophores based on rylene dyes for vectorial transduction of excitation energy. | The synthesis of dendritic multichromophores based on a rigid polyphenylene scaffold is presented. Different rylene chromophores are incorporated into the core, the branches, and the surface of the dendrimer. In this way, two generations of dendritic dyads consisting of a terrylenediimide core, a stiff polyphenylene sc... |
15034883 | Self-assembly of tris(2-ureidobenzyl)amines: a new type of capped, capsule-like dimeric aggregates derived from a highly flexible skeleton. | A set of tris(2-ureidobenzyl)amines 3 was prepared and their dimerization processes thoroughly investigated. In spite of their inherent flexibility, tris(ureas) 3 form dimeric aggregates both in the solid state and in solution. Evidence for the existence of these dimeric species was provided by a combination of techniq... |
15034879 | Ligand design for alkali-metal-templated self-assembly of unique high-nuclearity CuII aggregates with diverse coordination cage units: crystal structures and properties. | The construction of two unique, high-nuclearity Cu(II) supramolecular aggregates with tetrahedral or octahedral cage units, [(mu(3)-Cl)[Li subset Cu(4)(mu-L(1))(3)](3)](ClO(4))(8)(H(2)O)(4.5) (1) and [[Na(2) subset Cu(12)(mu-L(2))(8)(mu-Cl)(4)](ClO(4))(8)(H(2)O)(10)(H(3)O(+))(2)](infinity) (2) by alkali-metal-templated... |
15034877 | Shape-persistent macrocycles: from molecules to materials. | Shape-persistent macrocycles with an interior in the nanometer regime allow the attachment of (functional) side groups at defined positions at the ring. These side groups can have either a fixed orientation relative to the molecular backbone or they can adapt their orientation according to an external stimulus. The pro... |
15025531 | Synthesis of novel, multivalent glycodendrimers as ligands for HIV-1 gp120. | Multivalent neoglycoconjugates are valuable tools for studying carbohydrate-protein interactions. To study the interaction of HIV-1 gp120 with its reported alternate glycolipid receptors, galactosyl ceramide (GalCer) and sulfatide, galactose- and sulfated galactose-derivatized dendrimers were synthesized, analyzed as l... |
15025525 | Molecular binding behavior of pyridine-2,6-dicarboxamide-bridged bis(beta-cyclodextrin) with oligopeptides: switchable molecular binding mode. | Bridged bis(beta-cyclodextrin) 1 with a pyridine-2,6-dicarboxamide linker was synthesized, and its inclusion complexation behavior with some aliphatic oligopeptides was investigated in aqueous buffer solution of pH 2.0 and 7.2 at 25 degrees C by means of circular dichroism, fluorescence, and 2D NMR techniques. The resu... |
15023456 | The use of a dendrimer-propranolol prodrug to bypass efflux transporters and enhance oral bioavailability. | The aim of the study was to determine the effects on the transport of propranolol across monolayers of the human colon adenocarcinoma cell line, Caco-2, of forming a prodrug by conjugating to generation 3 (G3) and lauroyl-G3 PAMAM dendrimers. Propranolol is a poorly soluble drug and known substrate of the P-glycoprotei... |
15019051 | Immunoaffinity solid-phase extraction for pharmaceutical and biomedical trace-analysis-coupling with HPLC and CE-perspectives. | Immunoaffinity solid-phase extraction (SPE) technique is based upon a molecular recognition mechanism. The high affinity and the high selectivity of the antigen-antibody interactions allow the specific extraction and the concentration of the analytes of interest in one step. In pharmaceutical and biological fields, whe... |
15012082 | Synthesis and metalation of a chiral, pyridine-strapped, cyclic bis(benzimidazole) ligand. | [reaction: see text] Synthesis of a chiral, strapped, cyclic bis(benzimidazole) ligand is reported. This compound forms a stable, Jahn-Teller-distorted, octahedral Cu(II) complex in which the elongated axis is positioned within the main macrocycle. The C(2)-symmetric bis(benzimidazole) core adopts a highly ruffled conf... |
15012056 | Synthesis of [323]-p-octiphenyls: orthogonal functionalization along a rigid-rod scaffold for refined supramolecular architecture. | [structure: see text] The synthesis of p-octiphenyls carrying orthogonal tert-butyl esters in the peripheral positions 1(2), 2(2), 3(3), 6(2), 7(3), and 8(2) and either p-methoxybenzyl or benzyl ester substituents in the central positions 4(2) and 5(3) is described. Resolution-enhanced HSQC/HMBC two-dimensional NMR spe... |
15012051 | Synthesis and structure of m-terphenyl-based cyclophanes with nitrogen intra-annular functional groups. | [structure: see text] Herein we describe an efficient synthesis of cyclophanes comprised of intra-annular nitrogen functional groups through a template-promoted cyclization by ring-closing metathesis (RCM). The synthesis proceeds through condensation of meta-styryl anilines with acenaphthenequinone to form the template... |
15007816 | Synthesis and supramolecular association of immobilized NCN-pincer platinum(II) complexes on hyperbranched polyglycerol supports. | Pertosylation of hyperbranched polyglycerol (M(n)=2000; M(w)/M(n)=1.3) followed by partial displacement of the tosyl groups with carboxylic acid functionalized NCN-pincer platinum(II) complexes [PtI-2,6-(NMe(2)CH(2))(2)C(6)H(2)-4-COOH], resulted in covalent attachment of the NCN-pincer complexes to the polyglycerol. Th... |
15007811 | Synthesis and esterolytic activity of catalytic peptide dendrimers. | Peptide dendrimers were prepared by solid-phase peptide synthesis. Monomeric dendrimers were first obtained by assembly of a hexapeptide sequence containing alternate standard alpha-amino acids with diamino acids as branching units. The monomeric dendrimers were then dimerized by disulfide-bridge formation at the core ... |
15007809 | Elevated-temperature metathesis syntheses of structurally novel alkali-metal tetrakis(3,5-di-tert-butylpyrazolato)lanthanoidate(III) complexes: toluene-coordinated discrete bimetallic complexes and supramolecular chains. | Sodium and potassium tetrakis(3,5-di-tert-butylpyrazolato)lanthanoidate(III) complexes [M[Ln(tBu(2)pz)(4)]] have been prepared by reaction of anhydrous lanthanoid trihalides with alkali metal 3,5-di-tert-butylpyrazolates at 200-300 degrees C, and a 1,2,4,5-tetramethylbenzene flux for M=K. On extraction with toluene (or... |
15007808 | A surface-modified dendrimer set for potential application as drug delivery vehicles: synthesis, in vitro toxicity, and intracellular localization. | The synthesis, cytotoxicity, and behavior in cell culture of a new set of first- (G1) and second-generation (G2) dendrimers is reported. The surface functionality of these dendrimers has been varied to see whether structure/toxicity relations can be observed. The outermost functional groups are amines that are decorate... |
15007802 | Photocontrolled release and uptake of a porphyrin guest by dithienylethene-tethered beta-cyclodextrin host dimers. | Two photoswitchable dithienylethene-tethered beta-cyclodextrin dimers were synthesized to function as host molecules with an externally controllable binding affinity. The cyclodextrin cavities of these dimers are linked through their secondary sides by a photochromic dithienylethene unit that is connected to the second... |
15007799 | Chromo- and fluororeactands: indicators for detection of neutral analytes by using reversible covalent-bond chemistry. | Chromo- and fluororeactands are indicator dyes that allow the optical detection of electrically neutral analytes. Unlike complexing agents such as calixarenes, cyclodextrines or cyclophanes, reactands form a reversible covalent bond with the analyte molecule. This chemical reaction causes strong changes in absorbance o... |
15007798 | Approaching supramolecular functionality. | Functional molecules require a high degree of complexity which is difficult to achieve by covalent synthesis. This article discusses supramolecular approaches to the creation of larger architectures through noncovalent bonds, self-assembly, and template strategies. It highlights selected examples for the structural and... |
15003624 | Aaron Klug and the revolution in biomolecular structure determination. | Aaron Klug's group was one of the first to use a combination of X-ray diffraction and electron microscopy to study the structures of macromolecules. He helped to provide the intellectual framework for understanding the self-assembly of regular viruses and developed methods for analyzing their three-dimensional structur... |
15004293 | PNA Technology. | Peptide nucleic acids (PNA) are deoxyribonucleic acid (DNA) mimics with a pseudopeptide backbone. PNA is an extremely good structural mimic of DNA (or of ribonucleic acid [RNA]), and PNA oligomers are able to form very stable duplex structures with Watson-Crick complementary DNA and RNA (or PNA) oligomers, and they can... |
14993926 | A topological view of the replicon. | The replication of circular DNA faces topological obstacles that need to be overcome to allow the complete duplication and separation of newly replicated molecules. Small bacterial plasmids provide a perfect model system to study the interplay between DNA helicases, polymerases, topoisomerases and the overall architect... |
14960371 | Model structures of the N-methyl-D-aspartate receptor subunit NR1 explain the molecular recognition of agonist and antagonist ligands. | Molecular models of the ligand-binding domain of N-methyl-d-aspartate subunit R1 (NR1) were made using the published crystal structures of rat glutamate receptor B (GluRB), the bacterial glutamate receptor (GluR0), and the glutamine-binding protein (QBP) of Escherichia coli. Separate models of NR1 were built to represe... |
14750156 | Functional compartmentalization in the flocculus and the ventral dentate and dorsal group y nuclei: an analysis of single olivocerebellar axonal morphology. | The cerebellar cortex consists of multiple longitudinal bands defined by their olivocerebellar projection. Single olivocerebellar axons project to a narrow longitudinal band in the cerebellar cortex and to the cerebellar nucleus with their axon collaterals. This olivocortical and olivonuclear organization is related to... |
14735572 | An AM1 semiempirical study of host-guest complexation in hemicarcerand complexes. | Semiempirical AM1 calculations have been carried out on host-guest complexes of model hemicarcerands 1a and 2a. The justification for the choice of the AM1 Hamiltonian was based on a comparison between reported X-ray data for the smaller tetrabromocavitand 4a and computational results obtained using several different H... |
14643985 | Optimization of cyclodextrin production from sago starch. | Cyclodextrin (CD) is synthesized by bacterial cyclodextrin glycosyltransferase (CGTase) and is widely used in food, pharmaceutical, cosmetic, and agricultural industries. In this study, Bacillus circulans CGTase was partially purified by ammonium sulfate precipitation at 50-70% saturation. The optimum pH and temperatur... |
14643609 | Self-assembled extracellular matrix protein networks by microcontact printing. | Physiological patterns of the extracellular matrix protein, laminin-1, were obtained on glass substrates by physisorption-assisted microcontact printing. Besides the well-retained antigenicity confirmed by indirect immunofluorescence assays, we investigated the supramolecular organization of the proteins by atomic forc... |
15285345 | Influence of hydroxypropyl-beta-cyclodextrin on the extraction and biodegradation of phenanthrene in soil. | A study was conducted to investigate the effect of hydroxypropyl-beta-cyclodextrin (HPCD) on the aging and biodegradation of phenanthrene (PHE) in soil. Soil was spiked with PHE at 25 mgPHE/kgSOIL and HPCD at a range of concentrations from 0 to 3.5 gHPCD/kgSOIL and aged for 1, 84, and 322 d. At each time point, a varie... |
15261090 | Gliadin effect on fluctuation properties of phospholipid giant vesicles. | Gliadin is a fraction of wheat gluten, a protein supramolecular complex known for its remarkable and biotechnologically relevant viscoelastic properties. Very high molecular mass characterise these systems, thus hindering high-resolution structural investigations. It is known, however, that these proteins comprise rath... |
15261088 | Study of the lignin model compound supramolecular structure by combination of near-field scanning optical microscopy and atomic force microscopy. | In this paper, we present a nanoscale study of the supramolecular structure of the dehydrogenate polymer (ZL-DHP) lignin model compound. The combination of near-field scanning optical microscopy (NSOM or SNOM) and atomic force microscopy (AFM) has been utilized to explore physicochemical properties of the lignin model ... |
15156919 | Activation-threshold tuning in an affinity model for the T-cell repertoire. | Naive T cells respond to peptides from foreign proteins and remain tolerant to self peptides from endogenous proteins. It has been suggested that self tolerance comes about by a 'tuning' mechanism, i.e. by increasing the T-cell activation threshold upon interaction with self peptides. Here, we explore how such an adapt... |
15129982 | Effect of cyclodextrins on the complexation and transdermal delivery of bupranolol through rat skin. | Bupranolol (BPL) is a potent beta-blocking agent, the extensive first-pass metabolism (>90%) and rapid elimination half-life (1.5-2.0 h) of this drug make it well suited to be developed as a transdermal delivery system (TDS). Hydroxypropyl betaCD (HPbetaCD) and partially methylated betaCD (PMbetaCD) were used as penetr... |
15128043 | Three-dimensional modeling of a pre-B-cell receptor. | Signals delivered by the immunoglobulin (Ig)-like pre-B-cell receptor (pre-BCR) are critical for efficient maturation of early precursor B (pre-B) cells. A pre-BCR contains two immunoglobulin mu-heavy chains (muHC), two surrogate light chains (SLC) consisting of the non-covalently associated polypeptides, VpreB and lam... |
15125191 | [Transglycosylation of stevioside by cyclodextrin glucanotransferases of various group of microorganisms]. | Cyclodextrin glucanotransferases (CGTases, EC 2.4.1.19), produced by mesophilic, thermophilic, alkaliphilic, and halophilic bacilli, were used for the transglycosylation of stevioside to remove bitterness and aftertaste, with cyclodextrins (CDs) being used as donors. It was shown that CGTases produced by extremophiic m... |
15114514 | Determination of six major flavonoid glycosides in Saussurea mongolica by capillary electrophoresis. | A new capillary electrophoresis (CE) method was established for simultaneous assay of six flavonoid O-glycosides, asebotin (AS), kaempferol 3- O-beta- D-glucopyranoside (KG), kaempferol 3- O-alpha- L-rhamnopyranoside (KR), 7-methoxykaempferol 3- O-alpha- L-rhamnopyranoside (KMR), quercetin 3- O-beta- D-glucopyranoside ... |
15109029 | Effect of hydroxypropyl beta-cyclodextrin on drug solubility in water-propylene glycol mixtures. | Combined effects of cosolvency and inclusion complexation on drug solubility were studied using a model hydrophobic compound (carbamazepine) and a model hydrophilic compound (Compound S). Propylene glycol (PG) was used as the nonaqueous solvent, and deionized water was employed for the aqueous systems. Hydroxypropyl be... |
15105886 | Comparison of cultural and analytical methods for determination of aflatoxin production by Mississippi Delta Aspergillus isolates. | This study compared cultural and analytical methods for detecting aflatoxin production by Aspergillus species. Aspergillus isolates were obtained from various Mississippi Delta crops (corn, peanut, rice, cotton) and soils. Most of the isolates (99%) were A. flavus and the remainder comprised A. parasiticus and A. nomiu... |
15104242 | Structural determinants of efficacy at A3 adenosine receptors: modification of the ribose moiety. | We have found previously that structural features of adenosine derivatives, particularly at the N6- and 2-positions of adenine, determine the intrinsic efficacy as A3 adenosine receptor (AR) agonists. Here, we have probed this phenomenon with respect to the ribose moiety using a series of ribose-modified adenosine deri... |
15095575 | [Biological availability of ophthalmic drugs. 1. Increasing drug permeability in the cornea]. | Most eye diseases are treated by topical administration of ophthalmic preparations. Low ophthalmic bioavailability is due to a number of physiological and physicochemical factors. The main obstacle to the penetration of active ingredients to the eye is the layered character of the cornea. Formulation of ophthalmic prep... |
15082536 | Neurological proteins are not enriched for repetitive sequences. | Proteins associated with disease and development of the nervous system are thought to contain repetitive, simple sequences. However, genome-wide surveys for simple sequences within proteins have revealed that repetitive peptide sequences are the most frequent shared peptide segments among eukaryotic proteins, including... |
15074602 | Molecular inclusion of rofecoxib with cyclodextrin: pharmacological properties in laboratory animals. | Rofecoxib is practically insoluble in water and its prolonged use is associated with the incidence of side effects like gastrointestinal perforations, ulcerations and bleeding. Therefore, an attempt has been made to improve the aqueous solubility of the drug by making an inclusion complex using dimethyl-beta-cyclodextr... |
15074593 | Effects of 2-hydroxypropyl-beta-cyclodextrin on pharmacokinetics of digoxin in rabbits and humans. | Considering the narrow therapeutic index of digoxin and the low range between the safe and toxic serum concentrations of this drug, to evaluate the relative bioavailability of tablets and oral solution is necessary. The pharmacokinetic properties of digoxin after oral administration of its hydroxypropyl-beta-cyclodextr... |
15071914 | [Effects of a nerve growth factor isolated and purified from the venom of Naja naja atra on injured sciatic nerve in the adult cat]. | <h4>Objective</h4>To investigate the therapeutic effects of a nerve growth factor (NGF) isolated and purified from the venom of Naja naja atra on injured sciatic nerves in adult cat.<h4>Methods</h4>Model of sciatic nerve crush lesion in 20 cats was made. After the operation, in the therapeutic group, NGF(2 micrograms/k... |
15070725 | The arginine finger of bacteriophage T7 gene 4 helicase: role in energy coupling. | The DNA helicase encoded by gene 4 of bacteriophage T7 couples DNA unwinding to the hydrolysis of dTTP. The loss of coupling in the presence of orthovanadate (Vi) suggests that the gamma-phosphate of dTTP plays an important role in this mechanism. The crystal structure of the hexameric helicase shows Arg-522, located a... |
15058978 | Simple surfactant-free route to mesoporous organic-inorganic hybrid silicas containing covalently bound cyclodextrins. | Novel mesoporous organic-inorganic hybrid silicas containing covalently bound cyclodextrins have been synthesized by a simple, surfactant-free sol-gel route and are shown to have high BET surface areas and narrow pore-size distributions. |
15058923 | Cyclic donor-acceptor circuits: synthesis and fluorescence ion sensory properties of a mixed-heterocyclic dehydroannulene-type cyclophane. | The new dehydroannulene-type cyclophane 5 comprising a conjugated helical framework of thiophene (electron donor) and pyridine (electron acceptor) heterocyclic units has been prepared. Macrocycle 5 was characterized by FAB MS and (1)H and (13)C NMR spectroscopy. Cycle 5 was found to function as a selective precipitatio... |
15058918 | Molecular tectonics. Porous hydrogen-bonded networks built from derivatives of pentaerythrityl tetraphenyl ether. | The symmetric four-armed geometry of pentaerythrityl tetraphenyl ether (5) makes it a valuable starting point for building complex molecular and supramolecular structures. In particular, it provides a core to which multiple sites of attractive intermolecular interaction can be attached, thereby creating compounds predi... |
15058581 | Selectivity control in the separation of aromatic amino acid enantiomers with sulphated beta-cyclodextrin. | Control of selectivity in the enantiomeric separation of three aromatic amino acids (phenylalanine, tyrosine and tryptophan) is demonstrated by electrokinetic capillary chromatography utilising temperature variations coupled with the use of sulphated-beta-cyclodextrin (s-beta-CD) as a pseudostationary phase. The concen... |
15058577 | Preparation and chiral recognition of a novel chiral stationary phase for high-performance liquid chromatography, based on mono(6A-N-allylamino-6A-deoxy)-perfunctionalized beta-cyclodextrin and covalently bonded silica gel. | A novel chiral stationary phase (CSP) was prepared by immobilizing mono(6A-N-allylamino-6A-deoxy)-perphenylcarbamoylated beta-cyclodextrin onto the surface of silica gel via hydrosilylation. The chromatographic properties of this column were tested with a wide range of structurally diverse racemic compounds and drugs u... |
15056707 | Pavlovian fear conditioning regulates Thr286 autophosphorylation of Ca2+/calmodulin-dependent protein kinase II at lateral amygdala synapses. | Ca2+/calmodulin-dependent protein kinase II (CaMKII) plays a critical role in synaptic plasticity and memory formation in a variety of learning systems and species. The present experiments examined the role of CaMKII in the circuitry underlying pavlovian fear conditioning. First, we reveal by immunocytochemical and tra... |
15056702 | Constitutive activity of the serotonin2C receptor inhibits in vivo dopamine release in the rat striatum and nucleus accumbens. | Numerous research has pointed out that serotonin2c (5-HT2C) receptor, a subtype of 5-HT receptors belonging to the G-protein-coupled receptor superfamily, modulates the activity of mesencephalic dopamine (DA) neurons, the dysfunction of which is involved in devastating diseases such as schizophrenia, Parkinson's diseas... |
15054902 | Fibulins in development and heritable disease. | Fibulins are a family of five extracellular glycoproteins found in a variety of tissues in association with diverse supramolecular structures, including elastic fibers, basement membrane networks, fibronectin microfibrils, and proteoglycan aggregates. Studies of the developmental expression patterns have indicated that... |
15054900 | Matrix loading: assembly of extracellular matrix collagen fibrils during embryogenesis. | Nothing in biology stimulates the imagination like the development of a single fertilized egg into a newborn child. Consequently, a major focus of biomedical research is aimed at understanding cell differentiation, proliferation, and specialization during child health and human development. However, the fact that the i... |
15049839 | Synthesis and activity of the melanocortin Xaa-d-Phe-Arg-Trp-NH tetrapeptides with amide bond modifications. | The melanocortin receptor (MCR) pathway has been identified as participating in several physiologically important pathways including pigmentation, energy homeostasis, inflammation, obesity, hypertension, and sexual function. All the endogenous MCR agonists contain a core His-Phe-Arg-Trp sequence identified as important... |
15046715 | A touching picture of nicotinic binding. | The snail acetylcholine binding protein (AChBP) is homologous to the extracellular domains of the nicotinic ACh receptors. In this issue of Neuron, Celie et al. show how the crystal structures of AChBP in complexes with carbamylcholine and nicotine reveal the basis for agonist recognition by ACh receptors. |
15043961 | Interaction between heptad repeat 1 and 2 regions in spike protein of SARS-associated coronavirus: implications for virus fusogenic mechanism and identification of fusion inhibitors. | <h4>Background</h4>Studies on the fusion-inhibitory peptides derived from the heptad repeat 1 and 2 (HR1 and HR2) regions of the HIV-1 envelope glycoprotein gp41 provided crucial information on the viral fusogenic mechanism. We used a similar approach to study the fusogenic mechanism of severe-acute-respiratory-syndrom... |
15043924 | HIV Rev self-assembly is linked to a molten-globule to compact structural transition. | By regulating the differential expression of proviral pre mRNA in the host cell, Rev plays a crucial role in the HIV-1 life cycle. The capacity of Rev to function is intimately linked to its ability to self-associate. Nevertheless, little is known about the exact role of self-association in the molecular mechanism defi... |
14999368 | [Clinical course and prognostic significance of immunological and functional parameters after severe trauma]. | Generalized severe trauma leads to an increased incidence of SIRS, sepsis, and MOF. The aim of this prospective study was to investigate the immunological parameters in terms of their predictive value for multiple organ failure (MOF).HLA-DR expression on peripheral monocytes was analyzed by flow cytometry, the ex vivo ... |
15038740 | Liquid-crystalline octopus dendrimers: block molecules with unusual mesophase morphologies. | The synthesis and the mesomorphic properties of several new main-chain liquid-crystalline dendrimers, thereafter designated as octopus dendrimers in accordance with their eight sidearms, are reported. In these dendritic systems, the arborescence is ensured by anisotropic segments, acting as branching cells with a doubl... |
15038734 | Conformational control in the cyclization of hydrogen-bonded supramolecular polymers. | Bifunctional 2-ureido-4[1H]-pyrimidinone (UPy) derivatives can form small cyclic oligomers as well as long supramolecular polymers in chloroform solutions using the quadruple hydrogen-bonding motif. Ring-chain equilibria of a set of supramolecular monomers containing methyl-substituted alkyl linkers between the hydroge... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.