id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
16351199 | Metal-enhanced up-conversion fluorescence: effective triplet-triplet annihilation near silver surface. | Up-conversion phenomena are traditionally related to two- or multiphoton processes occurring under relatively high excitation intensities. Here we present the first results of ultralow excitation intensity (in order of Wcm(-2)) continuous-wave (CW) excited up-conversion fluorescence in Kretschmann surface plasmon geome... |
16351189 | Protein crystals as scanned probes for recognition atomic force microscopy. | Lysozyme crystal growth has been localized at the tip of a conventional silicon nitride cantilever through seeded nucleation. After cross-linking with glutaraldehyde, lysozyme protein crystal tips image gold nanoparticles and grating standards with a resolution comparable to that of conventional tips. Force spectra bet... |
16351185 | Sequence-encoded self-assembly of multiple-nanocomponent arrays by 2D DNA scaffolding. | Regular 2D arrays of multiple types of nanocomponents were constructed by self-assembly to DNA scaffolding with alternating rows of sequence-encoded hybridization sites. Different-sized Au particles coated with DNA complementary to one of the sites were bound to the scaffolding, producing alternating rows of the two na... |
16351181 | Enhanced third-order nonlinear optical properties in dendrimer-metal nanocomposites. | Nonlinear optical (NLO) and time-resolved fluorescence spectroscopic measurements of dendrimer-metal nanocomposites (DNCs) are reported. Third-order NLO effects were investigated by degenerate four-wave mixing (DFWM) measurements for DNCs and DNCs incorporated into thin polymeric films. The results show an enhancement ... |
16351122 | Programming the internal structure and stability of helical pores self-assembled from dendritic dipeptides via the protective groups of the peptide. | The synthesis of dendritic dipeptides (4-3,4-3,5)12G2-CH2-X-L-Tyr-L-Ala-OMe with X = Boc, Moc, and Ac; their self-assembly in bulk and in solution; and the structural and retrostructural analysis of their supramolecular helical porous assemblies are reported. The dimensions, structure, internal order, thermal stability... |
16351119 | Branched coordination multilayers on gold. | A C3-symmetric tridentate hexahydroxamate ligand molecule was specially synthesized and used for coordination self-assembly of branched multilayers on Au surfaces precoated with a self-assembled monolayer (SAM) of ligand anchors. Layer-by-layer (LbL) growth of multilayers via metal-organic coordination using Zr4+ ions ... |
16351112 | RNA-mediated control of metal nanoparticle shape. | RNA sequences previously isolated by in vitro selection were further characterized for their ability to control palladium particle growth. Five pyridyl-modified RNA sequences (Pdases) representing each of the different evolved families were found to form hexagonal plates with a high degree of shape specificity. However... |
16351076 | Structural control of self-assembled nanofibers by artificial beta-sheet peptides composed of D- or L-isomer. | A novel method for the control of peptide self-assembly has been developed by using synthetic triblock-type beta-sheet peptides composed of l- or d-amino acid, 1L and 1D, as building blocks. The peptides 1L and 1D self-assemble into beta-sheet nanofibers with left- and right-handed twists, respectively, under appropria... |
16351073 | Self-assembly of DNA double-double crossover complexes into high-density, doubly connected, planar structures. | We designed a molecular complex, the double-double crossover, consisting of four DNA double helices connected by six reciprocal exchanges. Atomic force micrographs suggest that double-double crossover complexes self-assemble into high-density, doubly connected, two-dimensional, planar structures. Such structures may be... |
16351068 | A polydiacetylene-based fluorescent sensor chip. | Self-assembled diacetylene vesicles were spotted and immobilized on aldehyde-modified glass substrates using conventional microarray technology. Irradiation of the immobilized diacetylenes allowed generation of nonfluorescent "blue-phase" polydiacetylene (PDA) arrays. Specific interaction of the PDA vesicle arrays with... |
16351067 | Supramolecular oxidation of anilines using hydrogen peroxide as stoichiometric oxidant. | 6A,6D-Di-O-(propan-2-on-1,3-diyl) alpha-cyclodextrin-6A,6D-dicarboxylate (2alpha) and 6A,6D-di-O-(propan-2-on-1,3-diyl) beta-cyclodextrin-6A,6D-dicarboxylate (2beta) were found to catalyze the oxidation of aromatic amines in the presence of hydrogen peroxide. The products were the corresponding nitro compounds or in so... |
16339723 | MYST family histone acetyltransferases in the protozoan parasite Toxoplasma gondii. | The restructuring of chromatin precedes tightly regulated events such as DNA transcription, replication, and repair. One type of chromatin remodeling involves the covalent modification of nucleosomes by histone acetyltransferase (HAT) complexes. The observation that apicidin exerts antiprotozoal activity by targeting a... |
16339735 | Molecules into cells: specifying spatial architecture. | A living cell is not an aggregate of molecules but an organized pattern, structured in space and in time. This article addresses some conceptual issues in the genesis of spatial architecture, including how molecules find their proper location in cell space, the origins of supramolecular order, the role of the genes, ce... |
16339032 | Modulation of NMDA receptors by pituitary adenylate cyclase activating peptide in CA1 neurons requires G alpha q, protein kinase C, and activation of Src. | At CA1 synapses, activation of NMDA receptors (NMDARs) is required for the induction of both long-term potentiation and depression. The basal level of activity of these receptors is controlled by converging cell signals from G-protein-coupled receptors and receptor tyrosine kinases. Pituitary adenylate cyclase activati... |
16339545 | Disruption of lipid rafts stimulates phospholipase d activity in human lymphocytes: implication in the regulation of immune function. | Recent evidence suggests that phospholipase D (PLD) can be regulated through its association/dissociation to lipid rafts. We show here that modifying lipid rafts either by cholesterol depletion using methyl-beta-cyclodextrin and filipin or by conversion of sphingomyelin to ceramide with exogenous bacterial sphingomyeli... |
16336125 | Trypsin inhibition by macrocyclic and open-chain variants of the squash inhibitor MCoTI-II. | MCoTI-I and MCoTI-II from the seeds of Momordica cochinchinensis are inhibitors of trypsin-like proteases and the only known members of the large family of squash inhibitors that are cyclic and contain an additional loop connecting the amino- and the carboxy-terminus. To investigate the contribution of macrocycle forma... |
16333296 | Designing dendrimers for biological applications. | Dendrimers are branched, synthetic polymers with layered architectures that show promise in several biomedical applications. By regulating dendrimer synthesis, it is possible to precisely manipulate both their molecular weight and chemical composition, thereby allowing predictable tuning of their biocompatibility and p... |
16333101 | Use of phylogenetic and phenotypic analyses to identify nonhemolytic streptococci isolated from bacteremic patients. | The aim of this study was to evaluate molecular and phenotypic methods for the identification of nonhemolytic streptococci. A collection of 148 strains consisting of 115 clinical isolates from cases of infective endocarditis, septicemia, and meningitis and 33 reference strains, including type strains of all relevant St... |
16332098 | Hydrogen-bonding-driven preorganized zinc porphyrin receptors for efficient complexation of C60, C70, and C60 derivatives. | This paper describes the self-assembly of a new class of foldamer-based molecular tweezers, whose rigid folded conformations are stabilized by intramolecular hydrogen bonding. Two zinc porphyrin units are introduced to the ends of molecular tweezers Zn(2)1 and Zn(2)2, while three zinc porphyrin units are incorporated t... |
16332091 | Uracil-directed ligand tethering: an efficient strategy for uracil DNA glycosylase (UNG) inhibitor development. | Uracil DNA glycosylase (UNG) is an important DNA repair enzyme that recognizes and excises uracil bases in DNA using an extrahelical recognition mechanism. It is emerging as a desirable target for small-molecule inhibitors given its key role in a wide range of biological processes including the generation of antibody d... |
16331970 | Characterization of two distinct beta2-microglobulin unfolding intermediates that may lead to amyloid fibrils of different morphology. | The self-assembly of beta(2)-microglobulin into fibrils leads to dialysis-related amyloidosis. pH-mediated partial unfolding is required for the formation of the amyloidogenic intermediate that then self-assembles into amyloid fibrils. Two partially folded intermediates of beta(2)-microglobulin have been identified exp... |
16331956 | Quantitative 13C and 2H NMR relaxation studies of the 723-residue enzyme malate synthase G reveal a dynamic binding interface. | A detailed understanding of molecular recognition is predicated not only on high-resolution static structures of the free and bound states but also on information about how these structures change with time, that is, molecular dynamics. Here we present a deuterium ((2)H) and carbon ((13)C) NMR relaxation study of methy... |
16332842 | Enantioselective transformation of alpha-hexachlorocyclohexane by the dehydrochlorinases LinA1 and LinA2 from the soil bacterium Sphingomonas paucimobilis B90A. | Sphingomonas paucimobilis B90A contains two variants, LinA1 and LinA2, of a dehydrochlorinase that catalyzes the first and second steps in the metabolism of hexachlorocyclohexanes (R. Kumari, S. Subudhi, M. Suar, G. Dhingra, V. Raina, C. Dogra, S. Lal, J. R. van der Meer, C. Holliger, and R. Lal, Appl. Environ. Microbi... |
16332837 | New multiple-deletion method for the Corynebacterium glutamicum genome, using a mutant lox sequence. | Due to the difficulty of multiple deletions using the Cre/loxP system, a simple, markerless multiple-deletion method based on a Cre/mutant lox system combining a right-element (RE) mutant lox site with a left-element (LE) mutant lox site was employed for large-scale genome rearrangements in Corynebacterium glutamicum. ... |
16332784 | Microarray-based detection and typing of the Rhizobium nodulation gene nodC: potential of DNA arrays to diagnose biological functions of interest. | Environmental screening of bacteria for the presence of genes of interest is a challenging problem, due to the high variability of the nucleotide sequence of a given gene between species. Here, we tackle this general issue using a particularly well-suited model system that consists of the nodulation gene nodC, which is... |
16330715 | Subcellular targeting of oxidants during endothelial cell migration. | Endogenous oxidants participate in endothelial cell migration, suggesting that the enzymatic source of oxidants, like other proteins controlling cell migration, requires precise subcellular localization for spatial confinement of signaling effects. We found that the nicotinamide adenine dinucleotide phosphate reduced (... |
16327490 | Technical refinements and results in full-right full-left splitting of the deceased donor liver. | <h4>Objective</h4>Splitting of the liver at the line of Cantlie of otherwise healthy people is accepted worldwide as a reasonable procedure for the donors in adult living donor liver transplantation. A similar operation is still considered as experimental if performed in the deceased donor liver. The aim of this study ... |
16325226 | Bioavailability assessment and environmental fate of polycyclic aromatic hydrocarbons in biostimulated creosote-contaminated soil. | When hydrocarbon-contaminated soil is subjected to bioremediation technology, hydrocarbon depletion is typically marked by an initially rapid reduction rate. This rate decreases over time and frequently a residual concentration remains in the soil. This kinetic has been attributed primarily to the enrichment of more re... |
16325216 | Plasma membrane requirements for 1alpha,25(OH)2D3 dependent PKC signaling in chondrocytes and osteoblasts. | 1,25-Dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)] acts on chondrocytes and osteoblasts through traditional nuclear Vitamin D receptor (VDR) mechanisms as well as through rapid actions on plasma membranes that initiate intracellular signaling pathways. We have investigated the mechanisms involved in activation of protei... |
16325173 | Cell elongation is key to in silico replication of in vitro vasculogenesis and subsequent remodeling. | Vasculogenesis, the de novo growth of the primary vascular network from initially dispersed endothelial cells, is the first step in the development of the circulatory system in vertebrates. In the first stages of vasculogenesis, endothelial cells elongate and form a network-like structure, called the primary capillary ... |
16324733 | Study of inclusion complex of beta-cyclodextrin and nitrobenzene. | beta-cyclodextrin can react with nitrobenzene to form an inclusion complex which is characterized by (1)H NMR and powder X-ray diffractometry. The ratio of beta-CD to NB in inclusion complex is determined as 1:1. At 25 degrees C, the dissociated constant, K(D), of the inclusion complex is measured as 6.5 x 10(-3) M in ... |
16323935 | Solution self-assembly, spontaneous deprotonation, and crystal structures of bipyrazolate-bridged metallomacrocycles with dimetal centers. | A series of nanosized cavity-containing bipyrazolate-bridged metallomacrocycles with dimetal centers, namely, {[(bpy)M]8L4}(NO3)8 [L=3,3',5,5'-tetramethyl-4,4'-bipyrazolyl, Pd, Pt; 1,4-bis-4'-(3',5'-dimethyl)-pyrazolylbenzene), Pd; and 1,4-bis-4'-(3',5'-dimethyl)-pyrazolylbiphenyl, Pd], {[(phen)M]8L4}(NO3)8 [L=3,3',5,5... |
16323870 | Optically pure calix[6]tris-ammoniums: syntheses and host-guest properties toward neutral guests. | [reaction: see text] Optically pure calix[6]arenes bearing chiral amino arms 4, 7, and 10 have been synthesized in high yields from the known symmetrically 1,3,5-trismethylated calix[6]arene. For both compounds 7 and 10, the key step consists of an efficient selective alkylation on the narrow rim of the calix[6]arene w... |
16327242 | Mapping of the cyclodextrin cavity using the cylindrical coordinate system. | This paper describes the mapping of the inner cavity of cyclodextrin and the guest molecule using the cylindrical coordinate system. Each cavity structure of alpha-, beta-, and gamma-cyclodextrin was examined using the coordinate system, in which, the Z-axis passes through the molecular axis; a normal of the plane that... |
16323855 | Synthesis and structural characterization of carborane-containing neutral, self-assembled Pt-metallacycles. | [structure: see text] We have combined carborane chemistry with the newly developed directional bonding strategy to synthesize neutral macrocycles. The m- and p-carborane dicarboxylates were utilized as the donor linkers in conjunction with 1,8-bis[trans-Pt(PEt3)2NO3]anthracene 3, 2,9-bis[trans-Pt(PEt3)2NO3]phenanthren... |
16323848 | Cucurbit[n]uril analogues: synthetic and mechanistic studies. | [reaction: see text] The synthesis of cucurbit[n]uril analogues (18, 19, (+/-)-20, 33, 34, 35, 36, and 37) is presented. These CB[5], CB[6], and CB[7] analogues all contain bis(phthalhydrazide) walls that are incorporated into the macrocycle. The tailor-made synthesis of these CB[n] analogues proceeds by the condensati... |
16323830 | Carbon networks based on dehydrobenzoannulenes. 5. Extension of two-dimensional conjugation in graphdiyne nanoarchitectures. | [structures: see text] The synthesis and optical properties of a series of multinanometer-sized substructures of the phenyl-diacetylene carbon allotrope, graphdiyne, are described. These molecules are among the largest and most complex annulenic systems yet prepared, with extension of linear conjugation in two-dimensio... |
16323918 | Inorganic supramolecular host architectures: [(M@18c6)2][TlI4].2H2O, M=0.5 Tl, (NH4,NH3), (H3O,H2O). | The compounds [(M@18c6)2][TlI4].2H2O, M=Tl, (NH4,NH3), (H3O,H2O) (cubic, Fd; a=1481.00 pm, for M=0.5 Tl, a=1304.65 pm for M=(NH4,NH3), a=1313.67 pm for M=(H3O,H2O)) can be obtained from solution in the presence of traces of transition metal halides (like copper and mercury halides). Apparently the transition metal cati... |
16323909 | Synthesis, structure, and luminescent property of a heterometallic metal-organic framework constructed from rod-shaped secondary building blocks. | A new heterometallic MOF compound, [ZnNa(m-BDC)2].NH2(CH3)2 (MOF-CJ2), has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, X-ray powder diffraction, ICP, TGA, IR, and photoluminescence spectroscopy analyses. It crystallizes in monoclinic space group C2/c (No. 15) with a=13.277(6) ... |
16323906 | Synthesis and characterization of two isomeric, self-assembled arsenic-thiolate macrocycles. | The use of labile As-S bond formation in the self-assembly of discrete supramolecular structures is extended. Macrocyclic structures of chemical formula As2L2Cl2 (H2L=alpha,alpha'-dimercapto-p-xylene) were prepared and characterized. Diastereomeric syn and anti isomers of these macrocycles were selectively crystallized... |
16323904 | Synthesis and photophysical properties of meso-substituted bisporphyrins: comparative study of phosphorescence quenching for dioxygen sensing. | The 4,6-bis(10-mesityl-5,15-di-p-tolylporpyrinyl)dibenzothiophene (H4DPSN) free base was obtained in five steps from commercially available materials. The metalation of DPSN2- with zinc(II), copper(II), and palladium(II) led to three new homobimetallic systems, (Zn)2DPSN, (Cu)2DPSN, and (Pd)2DPSN, respectively. The cof... |
16323903 | Transformation from a 2D stacked layer to 3D interpenetrated framework by changing the spacer functionality: synthesis, structure, adsorption, and magnetic properties. | Two novel coordination polymers of Cu(II), viz. [Cu(bipy)(1,4-napdc)(H2O)2]n and {[Cu(bpe)1.5(1,4-napdc)](H2O)}n (bipy=4,4'-bipyridine; bpe=1,2-bis(4-pyridyl)ethane; 1,4-napdc2-=1,4-naphthalenedicarboxylate), have been synthesized and structurally characterized by changing only the pillar motifs. Both the compounds cry... |
16323887 | Unprecedented hybrid scorpionate/phosphine ligand able to be anchored to carbosilane dendrimers. | The synthesis of a novel hybrid pyrazolate/phosphine anionic ligand [CH2=CHCH2B(CH2PPh2)(pz)2]- is described. Coordination of this ligand to metals in a fac tridentate fashion occurs in the complexes [CH2=CHCH2B(CH2PPh2)(pz)2M(cod)], prepared by reactions of the lithium salt of the ligand with [M(mu-Cl)(cod)]2 (M=Rh, I... |
16327166 | Sublingual delivery of insulin: effects of enhancers on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity. | The purposes of this study were to evaluate effects of enhancers for sublingual delivering insulin on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity in normal rats. The effects on sublingual mucosa, and aggregation states of insulin were estimated using fluorescence po... |
16327146 | Methyl-beta-cyclodextrin treatment affects the thermotropic behaviour of membranes and detergent-resistant membrane fractions of cultured A431 cells. | Membranes and detergent-resistant membrane fractions isolated from human epidermoid carcinoma A431 cells after treatment with methyl-beta-cyclodextrin, a compound commonly used in pharmaceutical applications and in manipulation of membrane cholesterol content, display thermotropic transitions at about 15 degrees C and ... |
16322570 | A structural model of an amyloid protofilament of transthyretin. | A docking-and-alignment protocol was devised in order to build amyloid protofilaments of Transthyretin (TTR), starting from partially disrupted TTR monomeric subunits and based on experimentally available information. The docking approach is driven by a combination of shape complementarity and energetic criteria, and u... |
16321511 | Effect of NaCl and peptide concentration on the self-assembly of an ionic-complementary peptide EAK16-II. | Previous work has examined the effects of such factors as pH and peptide concentration on the self-assembly of ionic-complementary peptides. This work focused on the effect of sodium chloride on the molecular self-assembly of an ionic-complementary peptide EAK16-II (AEAEAKAKAEAEAKAK). Surface tensions and dimensions of... |
16321801 | The role of an astrocytic NADPH oxidase in the neurotoxicity of amyloid beta peptides. | Amyloid beta peptide (Abeta) accumulates in the CNS in Alzheimer's disease. Both the full peptide (1-42) or the 25-35 fragment are toxic to neurons in culture. We have used fluorescence imaging technology to explore the mechanism of neurotoxicity in mixed asytrocyte/neuronal cultures prepared from rat or mouse cortex o... |
16321015 | Hydrogen bond catalyzed enantioselective vinylogous Mukaiyama aldol reaction. | [chemical reaction: see text]. The concept of hydrogen bonding catalysis was extended to the vinylogous Mukaiyama aldol reaction, which gives rapid access to polyketide derivatives. The reaction of the silyldienol ether shown and a range of aldehydes catalyzed by TADDOL proceeds regiospecifically to produce the additio... |
16321962 | Characterization of the DNA gyrase from the thermoacidophilic archaeon Thermoplasma acidophilum. | Thermoplasma acidophilum is sensitive to the antibiotic drug novobiocin, which inhibits DNA gyrase. We characterized DNA gyrases from T. acidophilum strains in vitro. The DNA gyrase from a novobiocin-resistant strain and an engineered mutant were less sensitive to novobiocin. The novobiocin-resistant gyrase genes might... |
16321936 | The maltodextrin system of Escherichia coli: metabolism and transport. | The maltose/maltodextrin regulon of Escherichia coli consists of 10 genes which encode a binding protein-dependent ABC transporter and four enzymes acting on maltodextrins. All mal genes are controlled by MalT, a transcriptional activator that is exclusively activated by maltotriose. By the action of amylomaltase, we p... |
16320367 | Ground-state equilibrium thermodynamics and switching kinetics of bistable [2]rotaxanes switched in solution, polymer gels, and molecular electronic devices. | We report on the kinetics and ground-state thermodynamics associated with electrochemically driven molecular mechanical switching of three bistable [2]rotaxanes in acetonitrile solution, polymer electrolyte gels, and molecular-switch tunnel junctions (MSTJs). For all rotaxanes a pi-electron-deficient cyclobis(paraquat-... |
16320350 | Identification of polyclonal and monoclonal antibodies against tissue plasminogen activator in the antiphospholipid syndrome. | <h4>Objective</h4>To test the hypotheses that some plasmin-reactive anticardiolipin antibodies (aCL) may bind to tissue plasminogen activator (tPA) and that some of the tPA-reactive aCL may inhibit tPA activity.<h4>Methods</h4>We studied the reactivity of 8 patient-derived monoclonal aCL with tPA and examined the prese... |
16318676 | Responses of the surface membrane and excretory system of Schistosoma mansoni to damage and to treatment with praziquantel and other biomolecules. | Damage to the surface membrane of adult Schistosoma mansoni, and the activity of the excretory system, as shown by resorufin fluorescence, was observed following treatment with praziquantel and incubation with other molecules. Praziquantel treatment induced damage to the surface membrane as measured by the use of a var... |
16319888 | Chemically tailorable colloidal particles from infinite coordination polymers. | Micrometre- and nanometre-sized particles play important roles in many applications, including catalysis, optics, biosensing and data storage. Organic particles are usually prepared through polymerization of suitable monomers or precipitation methods. In the case of inorganic materials, particle fabrication tends to in... |
16319958 | Quality control of protein folding in extracellular space. | The pathologies of many serious human diseases are thought to develop from the effects of intra- or extracellular aggregates of non-native proteins. Inside cells, chaperone and protease systems regulate protein folding; however, little is known about any corresponding mechanisms that operate extracellularly. The identi... |
16317767 | Dendritic catanionic assemblies: in vitro anti-HIV activity of phosphorus-containing dendrimers bearing galbeta1cer analogues. | Two series of water-soluble dendritic catanionic assemblies, acting as multisite analogues of galactosylceramide (Galbeta1cer), have been prepared with the goal of blocking HIV infection prior to the entry of the virus into human cells. Trifunctional and hexafunctional cinnamic acid-terminated dendrimers have been synt... |
16316235 | Shell click-crosslinked (SCC) nanoparticles: a new methodology for synthesis and orthogonal functionalization. | A new methodology for the preparation of well-defined core-shell nanoparticles was developed, based upon the employment of a multifunctional crosslinker to coincidently stabilize supramolecular polymer assemblies and imbed into the shell unique chemical functionalities. Amphiphilic diblock copolymers of poly(acrylic ac... |
16316228 | QZ1 and QZ2: rapid, reversible quinoline-derivatized fluoresceins for sensing biological Zn(II). | QZ1, 2-[2-chloro-6-hydroxy-3-oxo-5-(quinolin-8-ylaminomethyl)-3H-xanthen-9-yl]benzoic acid, and QZ2, 2-[6-hydroxy-3-oxo-4,5-bis-(quinolin-8-ylaminomethyl)-3H-xanthen-9-yl]benzoic acid, two fluorescein-based dyes derivatized with 8-aminoquinoline, have been prepared and their photophysical, thermodynamic, and zinc-bindi... |
16316209 | High resolution printing of DNA feature on poly(methyl methacrylate) substrates using supramolecular nano-stamping. | In recent years, a large number of devices based on organic and biological materials have been developed. To scale-up the production of these systems to industrially acceptable standards, there is a need to develop soft-material stamping approaches with the needed resolution, complexity, and versatility. We have recent... |
16316206 | The bis-urea motif as a tool to functionalize self-assembled nanoribbons. | Here we present a surfactant molecule (1) containing an ammonium headgroup, in which a bis-ureido group is incorporated in its hydrocarbon chain. Due to strong hydrogen bonding interactions, 1 forms well-defined highly ordered ribbon-like aggregates in water. Moreover, we demonstrate that these ribbons can be functiona... |
16316142 | Hydrophobic dendrimers as templates for au nanoparticles. | We report the synthesis, characterization, and extraction of Au dendrimer-encapsulated nanoparticles (DENs) prepared in organic solvents. DENs composed of 31 and 55 Au atoms were prepared using organic solvents and poly(amidoamine) (PAMAM) dendrimer templates modified on their periphery with dodecyl groups. The spectra... |
16316119 | Surface enhanced vibrational (IR and Raman) spectroscopy in the design of chemosensors based on ester functionalized p-tert-butylcalix[4]arene hosts. | Surface-enhanced IR (SEIR) and Raman scattering (SERS) have been employed to study the adsorption of ester functionalized tert-butyl calix[4]arenes on Ag and Au nanostructured surfaces as well as their complexes with pyrene. The influence of adsorption and complexation with pyrene on the host calixarene structure was t... |
16316094 | Self-diffusion NMR studies of the host-guest interaction between beta-cyclodextrin and alkyltrimethylammonium bromide surfactants. | Diffusion measurements by nuclear magnetic resonance (NMR) spectroscopy were used to investigate the host-guest association between beta-cyclodextrin (CD) and alkyltrimethylammonium bromide surfactants with different chain lengths, ranging from 6 up to 16 carbons. The scope and limitations of the method in the study of... |
16316082 | Self-assembly and oligomerization of alkyne-terminated molecules on metal and oxide surfaces. | We report the self-assembly and subsequent oligomerization of organic molecules based on terthiophenes bearing a terminal alkyne moiety. Molecules with thioacetate and phosphonic acid functional groups were synthesized, enabling molecular self-assembly on metal (Au and Pd) and metal oxide [Al(2)O(3), HfO(2), and indium... |
16316077 | Self-assembly of patchy particles into diamond structures through molecular mimicry. | Fabrication of diamond structures by self-assembly is a fundamental challenge in making three-dimensional photonic crystals. We simulate a system of model hard particles with attractive patches and show that they can self-assemble into a diamond structure from an initially disordered state. We quantify the extent to wh... |
16316256 | Three-dimensional self-organization of supramolecular self-assembled porphyrin hollow hexagonal nanoprisms. | A self-assembly technique assisted with surfactant is developed to fabricate one-dimensional (1D) nanostructure of zinc meso-tetra (4-pyridyl) porphyrin. The so-prepared nanostructure appears in a shape of hollow hexagonal nanoprism with uniform size. The length and aspect ratio of the nanoprisms is easily tunable by c... |
16316251 | Search for improved host architectures: application of de novo structure-based design and high-throughput screening methods to identify optimal building blocks for multidentate ethers. | This paper presents a computational approach to the deliberate design of improved host architectures. The approach, which involves the use of computer-aided design software, is illustrated by application to cation hosts containing multiple aliphatic ether oxygen binding sites. De novo molecule building software, HostDe... |
16316249 | Light-activated hydrogel formation via the triggered folding and self-assembly of a designed peptide. | Photopolymerization can be used to construct materials with precise temporal and spatial resolution. Applications such as tissue engineering, drug delivery, the fabrication of microfluidic devices and the preparation of high-density cell arrays employ hydrogel materials that are often prepared by this technique. Curren... |
16316244 | Coordinative properties of highly fluorinated solvents with amino and ether groups. | Despite the widespread use of perfluorinated solvents with amino and ether groups in a variety of application fields, the coordinative properties of these compounds are poorly known. It is generally assumed that the electron withdrawing perfluorinated moieties render these functional groups rather inert, but little is ... |
16316221 | Cucurbit[10]uril. | Melamine diamine 1 is able to displace CB[5] from the CB[10].CB[5] complex resulting in CB[10].12 and precipitated CB[5].1. We were able to isolate free CB[10] by treatment of CB[10].1 with acetic anhydride followed by washing with MeOH, DMSO, and water. The spacious cavity of CB[10] is able to complex large guests, in... |
16316219 | Homopolymer micelles in heterogeneous solvent mixtures. | Amphiphilic homopolymers containing a hydrophilic and a hydrophobic functionality in each monomer unit have been shown to form polar or apolar containers depending on the solvent environment. When presented with a mixture of solvents, these polymeric containers are capable of releasing certain guest molecules. The fund... |
16316200 | In situ fabrication of three-dimensional chemical patterns in fused silica separation capillaries with polymerized phospholipids. | We report a new molecular approach for in situ generation of micron scale, chemically and biochemically functionalized patterns inside three-dimensional, completely enclosed fluidic channels. The formation of chemical patterns is based upon a combination of lipid bilayer self-assembly and UV photopolymerization of phot... |
16316852 | Preparation and evaluation of sustained ophthalmic gel of enoxacin. | The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid precorneal elimination of the drug may be overcome by the use of a gel system. The present work describes the formulation and evaluation of an ophthalmic delivery system containing an antibacterial agent, enoxa... |
16315186 | Effects of processing on the structure of zein/oleic Acid films investigated by x-ray diffraction. | Zein films plasticized with oleic acid were formed by solution casting, by the stretching of moldable resins, and by blown film extrusion. The effects of the forming process on film structure were investigated by X-ray diffraction. Wide-angle X-ray scattering (WAXS) patterns showed d-spacings at 4.5 and 10 A, which wer... |
16314924 | Understanding microtubule dynamics for improved cancer therapy. | Microtubules (MTs), key components of the cytoskeleton, are dynamic polymers of tubulin that form a well-organized network of polarized tube filaments. MT dynamics are highly regulated both spacially and temporally by several MT-related proteins, themselves regulated by several kinases and phosphatases via signaling ca... |
16314457 | Arginine-rich motifs present multiple interfaces for specific binding by RNA. | A number of proteins containing arginine-rich motifs (ARMs) are known to bind RNA and are involved in regulating RNA processing in viruses and cells. Using automated selection methods we have generated a number of aptamers against ARM peptides from various natural proteins. Aptamers bind tightly to their cognate ARMs, ... |
16314218 | Current and future prospects for the prevention of ocular fibrosis. | Significant advances have been made in developing new treatments and refining existing treatments for the prevention of scarring after disease, trauma, or surgical prevention. The advent of new technologies in addition to traditional chemical drugs such as dendrimers, antibodies, aptamers, ribozymes, gene therapy with ... |
16314521 | Specific sequence features, recognized by the SMN complex, identify snRNAs and determine their fate as snRNPs. | The survival of motor neurons (SMN) complex is essential for the biogenesis of spliceosomal small nuclear ribonucleoproteins (snRNPs) as it binds to and delivers Sm proteins for assembly of Sm cores on the abundant small nuclear RNAs (snRNAs). Using the conserved snRNAs encoded by the lymphotropic Herpesvirus saimiri (... |
16314511 | Identification of functionally important amino acids of ribosomal protein L3 by saturation mutagenesis. | There is accumulating evidence that many ribosomal proteins are involved in shaping rRNA into their functionally correct conformations through RNA-protein interactions. Moreover, although rRNA seems to play the central role in all aspects of ribosome function, ribosomal proteins may be involved in facilitating communic... |
16314258 | Computational searches for splicing signals. | The removal of introns from pre-mRNA requires as an initial event the accurate molecular recognition of the proper exon-intron borders. It is now evident that RNA sequence elements in addition to the consensus splice site sequences themselves are required for this recognition. Genomic analyses have contributed to the d... |
16313194 | Coating proteins: structure and cross-linking in fp-1 from the green shell mussel Perna canaliculus. | The protein family known as fp-1 provides mussel byssus with a protective outer coating and has drawn much attention for its water resistant bioadhesive properties in vitro. A new fp-l isolated from the green shell mussel Perna canaliculus (pcfp-1) reveals a composition dominated by only four amino acids: 3,4-dihydroxy... |
16313181 | Characterization of the 3' --> 5' exonuclease activity found in human nucleoside diphosphate kinase 1 (NDK1) and several of its homologues. | Nucleoside diphosphate kinases (NDKs), an evolutionarily conserved family of proteins, synthesize nucleoside triphosphates from nucleoside diphosphates and ATP. Here, we have characterized the kinase activity and DNA processing functions of eight human proteins that contain at least one domain homologous to Escherichia... |
16314482 | Participation of autophagy in storage of lysosomes in neurons from mouse models of neuronal ceroid-lipofuscinoses (Batten disease). | In cathepsin D-deficient (CD-/-) and cathepsins B and L double-deficient (CB-/-CL-/-) mice, abnormal vacuolar structures accumulate in neurons of the brains. Many of these structures resemble autophagosomes in which part of the cytoplasm is retained but their precise nature and biogenesis remain unknown. We show here h... |
16314480 | Primary and secondary elastin-binding protein defect leads to impaired elastogenesis in fibroblasts from GM1-gangliosidosis patients. | G(M1)-gangliosidosis is a lysosomal storage disorder caused by acid beta-galactosidase deficiency. Aside from the lysosomal beta-galactosidase enzyme, the beta-galactosidase gene also encodes the elastin-binding protein (EBP), deficiency in which impairs elastogenesis. Using expression studies and Western blots of COS-... |
16309462 | Surface ultrastructure of SARS coronavirus revealed by atomic force microscopy. | Atomic force microscopy has been used to probe the surface nanostructures of severe acute respiratory syndrome coronavirus (SARS-CoV). Single crown-like virion was directly visualized and quantitative measurements of the dimensions for the structural proteins were provided. A corona of large, distinctive spikes in the ... |
16304662 | Nanoparticles as recyclable catalysts: the frontier between homogeneous and heterogeneous catalysis. | Interest in catalysis by metal nanoparticles (NPs) is increasing dramatically, as reflected by the large number of publications in the last five years. This field, "semi-heterogeneous catalysis", is at the frontier between homogeneous and heterogeneous catalysis, and progress has been made in the efficiency and selecti... |
16304170 | Novel cyclic lipodepsipeptide from Pseudomonas syringae pv. lachrymans strain 508 and syringopeptin antimicrobial activities. | The syringopeptins are a group of antimicrobial cyclic lipodepsipeptides produced by several plant-associated pseudomonads. A novel syringopeptin, SP508, was shown to be produced as two homologs (A and B) by Pseudomonas syringae pv. lachrymans strain 508 from apple and to structurally resemble syringopeptin SP22. SP508... |
16304152 | Discovery and characterization of vicriviroc (SCH 417690), a CCR5 antagonist with potent activity against human immunodeficiency virus type 1. | Inhibiting human immunodeficiency virus type 1 (HIV-1) infection by blocking the host cell coreceptors CCR5 and CXCR4 is an emerging strategy for antiretroviral therapy. Currently, several novel coreceptor inhibitors are being developed in the clinic, and early results have proven promising. In this report, we describe... |
16303961 | Aggregation of lens crystallins in an in vivo hyperbaric oxygen guinea pig model of nuclear cataract: dynamic light-scattering and HPLC analysis. | <h4>Purpose</h4>The role of oxygen in the formation of lens high-molecular-weight (HMW) protein aggregates during the development of human nuclear cataract is not well understood. The purpose of this study was to investigate lens crystallin aggregate formation in hyperbaric oxygen (HBO)-treated guinea pigs by using in ... |
16303630 | Distinction between some saccharides in scattered optical sum frequency intensity images. | Using an optical sum frequency (SF) microscope with visible and infrared light pulses for excitation, we have attempted to distinguish among four saccharide species. The saccharides we studied were d-glucose, amylopectin, beta-cyclodextrin, and amylose. The wavelength of the infrared light was resonant to CH vibration.... |
16302978 | Interaction of gymnemic acid with cyclodextrins analyzed by isothermal titration calorimetry, NMR and dynamic light scattering. | The physiological phenomenon that the antisweet taste effect of gymnemic acid (GA) is diminished by application of gamma-cyclodextrin (gamma-CD) to the mouth was evaluated at the molecular level using isothermal titration calorimetry, NMR and dynamic light scattering. These analyses showed that GA specifically binds to... |
16302962 | Mechanisms of amyloid fibril self-assembly and inhibition. Model short peptides as a key research tool. | The formation of amyloid fibrils is associated with various human medical disorders of unrelated origin. Recent research indicates that self-assembled amyloid fibrils are also involved in physiological processes in several micro-organisms. Yet, the molecular basis for the recognition and self-assembly processes mediati... |
16302961 | The Yin and Yang of protein folding. | The study of protein aggregation saw a renaissance in the last decade, when it was discovered that aggregation is the cause of several human diseases, making this field of research one of the most exciting frontiers in science today. Building on knowledge about protein folding energy landscapes, determined using an arr... |
16302808 | Grafting aminocyclopentane carboxylic acids onto the RGD tripeptide sequence generates low nanomolar alphaVbeta3/alphaVbeta5 integrin dual binders. | Eleven gamma-aminocyclopentane carboxylic acid (Acpca) platforms, including four dihydroxy representatives (19-22), three hydroxy analogues (34-36), and four deoxy derivatives (30-33), were prepared in a chiral nonracemic format. These simple units were then grafted onto an Arg-Gly-Asp (RGD) tripeptide framework by a m... |
16299342 | High susceptibility of human dendritic cells to invasion by the intracellular pathogens Brucella suis, B. abortus, and B. melitensis. | Bacteria from the Brucella genus are able to survive and proliferate within macrophages. Because they are phylogenetically closely related to macrophages, myeloid dendritic cells (DCs) constitute potential targets for Brucella bacteria. Here we report that DCs display a great susceptibility to Brucella infection. There... |
16299313 | Ectophosphorylation of CD36 regulates cytoadherence of Plasmodium falciparum to microvascular endothelium under flow conditions. | The adhesion of Plasmodium falciparum-infected erythrocytes (IRBCs) to human dermal microvascular endothelial cells (HDMECs) under flow conditions is regulated by a Src family kinase- and alkaline phosphatase (AP)-dependent mechanism. In this study, we showed that the target of the phosphatase activity is the ectodomai... |
16292880 | In vivo biodistribution of dendrimers and dendrimer nanocomposites -- implications for cancer imaging and therapy. | Our results indicate that the surface chemistry, composition, and 3-D structure of nanoparticles are critical in determining their in vivo biodistribution, and therefore the efficacy of nanodevice imaging and therapies. We demonstrate that gold/dendrimer nanocomposites in vivo, present biodistribution characteristics d... |
16291682 | Identification of Erwinia amylovora genes induced during infection of immature pear tissue. | The enterobacterium Erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. In this study, we used a modified in vivo expression technology system to identify E. amylovora genes that are activated during infection of immature pear tissue, a ... |
16287867 | Eukaryotic translation initiation factor 4E availability controls the switch between cap-dependent and internal ribosomal entry site-mediated translation. | Translation of m7G-capped cellular mRNAs is initiated by recruitment of ribosomes to the 5' end of mRNAs via eukaryotic translation initiation factor 4F (eIF4F), a heterotrimeric complex comprised of a cap-binding subunit (eIF4E) and an RNA helicase (eIF4A) bridged by a scaffolding molecule (eIF4G). Internal translatio... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.