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15323932 | Interactions in self-organized nanoporous organic crystals. | This Letter reports on the structural analysis of a self-assembly material, the prototype host-guest urea-alkane nanoporous crystal. Different spectroscopic techniques, under hydrostatic pressure, reveal a totally unexpected ordered phase where ordering does not require any apparent deformation of the host. This fundam... |
15340637 | Adjustable cavity for host-guest recognition in cofacial bis-porphyrinic tweezer. | The synthesis of a cofacial bis-porphyrinic tweezer bearing a tris-anthracenic spacer is reported. Its behavior as host has been evidenced as well as the ability of its cavity to adjust to guests of various sizes. |
15340593 | Dendron-grafted sulfur-terminated phenyleneethynylene molecular rods and blue luminescence self-assembly with Au nanoparticles. | Dendron-grafted phenyleneethynylenes with alpha,omega-disulfur containing groups were newly synthesized and characterized for self-assembly with Au nanoparticles; an intense blue photoluminescence of the composite film was observed. |
15303158 | Single and double metallic layer-containing ruthenium dendrimers. Synthesis and catalytic properties. | The reaction of a series of phosphanyl-terminated carbosilane dendrimers displaying only one phosphorus ligand per arm with [RuCl(2)(p-cymene)](2) resulted in the grafting of RuCl(p-cymene) moieties on the periphery of the dendrimer. In these species, the chloride ligand is easily displaced by the organic bases pyridin... |
15280956 | Synthesis of fluorescent oligonucleotide--EYFP conjugate: towards supramolecular construction of semisynthetic biomolecular antennae. | A novel species of DNA--protein conjugate was synthesized by chemically linking DNA oligonucleotides to Aequorea victoria green fluorescent protein mutant EYFP. An additional cysteine was added to the C-terminus of the EYFP by genetic engineering and used to covalently attach amino-modified oligonucleotide with the aid... |
15241659 | Evidence for ditopic coordination of phosphate diesters to [Mg(15-crown-5)]2+. Implications for magnesium biocoordination chemistry. | The interaction of a series of phosphate diesters and triesters (1=diphenyl phosphate,2=dimethyl phosphate,3=bis(2-ethylhexyl) phosphate,4=trimethyl phosphate,5=methyldiphenyl phosphate,6=triphenyl phosphate) with [Mg(15-crown-5)](2+) (15-crown-5=1,4,7,10,13-pentaoxocyclopentadecane) was studied as a simplified model f... |
15306930 | Rigidity extremes in coordination chemistry: a fine energetic balance in the isolation of a trapped ligand inversion intermediate. | An unusual copper(ii) complex of a highly rigid and bulky ligand (a macrocycle-glyoxal condensate) has been synthesized and investigated via DFT calculations and structural characterisation. |
15306889 | A circular tris[2]catenane from molecular 'figure-of-eight'. | A 'figure-of-eight'-shaped molecule with Pd(ii) at the node was self-assembled into an unprecedented circular tris[2]catenane via reversible double catenation at both loops of the 'figure-of-eight' molecule. |
15238167 | Emergency surgery for recurrent intraabdominal cancer. | <h4>Background</h4>Recurrent abdominal cancer can manifest in many ways but there are certain situations that are a great challenge to clinicians. Emergency presentation is one such situation. Surgeons are faced with a therapeutic dilemma that on the one hand most of these patients have a limited life expectancy, and o... |
15238166 | An approach to classifying human resources constraints to attaining health-related Millennium Development Goals. | BACKGROUND: For any wide-ranging effort to scale up health-related priority interventions, human resources for health (HRH) are likely to be a key to success. This study explores constraints related to human resources in the health sector for achieving the Millennium Development Goals (MDGs) in low-income countries. ME... |
15241586 | Role of 5-lipoxygenase in the multiple organ failure induced by zymosan. | <h4>Objective</h4>This study investigated the role of 5-lipoxygenase in the pathogenesis of multiple organ failure (MOF) induced by zymosan.<h4>Design</h4>Male mice with a targeted disruption of the 5-lipoxygenase gene (5-LOKO) and littermate wild-type (WT) controls (5-LOWT) were used to evaluate the role of 5-lipoxyge... |
15346193 | Forward (singlet-singlet) and backward (triplet-triplet) energy transfer in a dendrimer with peripheral naphthalene units and a benzophenone core. | The photochemical and photophysical behaviour of two dendrimers consisting of a benzophenone core and branches that contain four (4) and eight (5) naphthalene units at the periphery has been investigated in CH(2)Cl(2) solution (298 K) and in CH(2)Cl(2)/CHCl(3) 1:1 v/v rigid matrix (77 K). For comparison purposes, the p... |
15238639 | Cation-pi interactions studied in a model coiled-coil peptide. | Cation-pi interactions between aromatic amino acids and the positively charged residues lysine and arginine have been proposed to play an important role in stabilizing protein structure. We have used a peptide that adopts a coiled coil structure as a model system to evaluate the energetic contribution of cation-pi inte... |
15238637 | Biophysical characterization of Z(SPA-1)--a phage-display selected binder to protein A. | Affibodies are a novel class of binding proteins selected from phagemid libraries of the Z domain from staphylococcal protein A. The Z(SPA-1) affibody was selected as a binder to protein A, and it binds the parental Z domain with micromolar affinity. In earlier work we determined the structure of the Z:Z(SPA-1) complex... |
15238634 | A mobile loop order-disorder transition modulates the speed of chaperonin cycling. | Molecular machines order and disorder polypeptides as they form and dissolve large intermolecular interfaces, but the biological significance of coupled ordering and binding has been established in few, if any, macromolecular systems. The ordering and binding of GroES co-chaperonin mobile loops accompany an ATP-depende... |
15280969 | Supramolecular chirality of self-assembled systems in solution. | Self-assembly plays an important role in the formation of many (chiral) biological structures, such as DNA, alpha-helices or beta-sheets of proteins. This process, which is the main tool of Supramolecular Chemistry (i.e. the chemistry of the molecular assemblies and of the intermolecular bonds), starts to play a signif... |
15240890 | Lipid- and mechanosensitivities of sodium/hydrogen exchangers analyzed by electrical methods. | Sodium/hydrogen exchangers (NHEs) are ubiquitous ion transporters that serve multiple cell functions. We have studied two mammalian isoforms, NHE1 (ubiquitous) and NHE3 (epithelial-specific), by measuring extracellular proton (H+) gradients during whole-cell patch clamp with perfusion of the cell interior. Maximal Na(+... |
15240875 | Galmic, a nonpeptide galanin receptor agonist, affects behaviors in seizure, pain, and forced-swim tests. | The pharmacological exploitation of the galanin receptors as drug targets for treatment of epilepsy, depression, and pain has been hampered by the lack of workable compounds for medicinal chemists from random screening of large chemical libraries. The present work uses the tripeptidomimetic galnon and displays its pres... |
15237097 | Calcitonin gene-related peptide (CGRP) modulates nociceptive trigeminovascular transmission in the cat. | Calcitonin gene-related peptide (CGRP) is released into the cranial circulation of humans during acute migraine. To determine whether CGRP is involved in neurotransmission in craniovascular nociceptive pathways, we microiontophoresed onto neurons in the trigeminocervical complex and intravenously administered the CGRP ... |
15280966 | Combined approach using capillary electrophoresis and NMR spectroscopy for an understanding of enantioselective recognition mechanisms by cyclodextrins. | This tutorial review describes the contribution of chiral capillary electrophoresis in combination with other instrumental techniques, especially nuclear magnetic resonance spectroscopy, to a better understanding of the chiral recognition mechanisms by cyclodextrins. Aspects such as affinity pattern of enantiomers towa... |
15303152 | Lanthanide crown ether complexes of p-sulfonatocalix[5]arene. | Two types of arrays are formed in water involving aza-crown ethers, p-sulfonatocalix[5]arene and europium(III) ions. One is a co-ordination polymer connecting calixarenes, sodium ions and lanthanide ions based on "ferris wheel" moieties incorporating aza-18-crown-6 and sodium ions. The second structure is a host-guest ... |
21706728 | The microarray revolution: Perspectives from educators. | In recent years, microarray analysis has become a key experimental tool, enabling the analysis of genome-wide patterns of gene expression. This review approaches the microarray revolution with a focus upon four topics: 1) the early development of this technology and its application to cancer diagnostics; 2) a primer of... |
19003250 | Three-dimensional co-culture of hepatocytes and stellate cells. | Hepatocytes self-assemble in culture to form compacted spherical aggregates, or spheroids, that mimic the structure of the liver by forming tight junctions and bile canalicular channels. Hepatocyte spheroids thus resemble the liver to a great extent. However, liver tissue contains other cell types and has bile ducts an... |
18969506 | Determination of trace osmium by supramolecular catalytic kinetic spectrofluorimetry of beta-CD-osmium-KBrO(3)-o-vanillin furfuralhydrazone. | A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of osmium(IV) and the possible mechanism of catalytic reaction was discussed. The method is based on the fluorescence enhancing reaction of o-vanillin furfuralhydrazone (OVFH) with potassium bromate, which was catalysed by... |
16459620 | Molecular-level control of feature separation in one-dimensional nanostructure assemblies formed by biomolecular nanolithography. | In this paper, we present a convenient and reliable method to organize small gold nanoparticles (d(CORE) = 1.5 nm) into linear chains with precisely controlled interparticle spacing over a range of 1.5-2.8 nm through biomolecular nanolithography. Controlling the feature separations of 1 to a few nanometers with angstro... |
16459600 | An evanescent-field-driven self-assembled molecular photoswitch for macrocycle coordination and release. | Two self-assembled monolayer (SAM) films containing the photoswitchable 4-pyridylazophenoxy chromophore have been deposited onto a gold-coated glass substrate. One film contains the chromophore as a single component, 1 SAM, and the other is doped with a nonphotoactive component as a 1:1 mixture, 2 SAM. The reversible p... |
16459596 | Langmuir and Langmuir-Blodgett films of amphiphilic bistable rotaxanes. | A series of amphiphilic bistable [2]rotaxanes--in which a ring-shaped component, the tetracationic cyclophane, cyclobis(paraquat-p-phenylene), has been assembled around two recognition sites, a tetrathia-fulvalene (TTF) unit and a 1,5-dioxynaphthalene (DNP) ring system, situated apart at different strategic locations w... |
16459580 | Thermodynamics of temperature-sensitive polyether-modified poly(acrylic acid) microgels. | The temperature-induced structural changes and thermodynamics of ionic microgels based on poly(acrylic acid) (PAA) networks bonded with poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) (Pluronic) copolymers have been studied by small-angle neutron scattering (SANS), ultra-small-angle ne... |
16305386 | Synthesis of chitosan microspheres containing pendant cyclodextrin moieties and their interaction with biological active molecules. | A new route to obtain chitosan derivatives containing cyclodextrin moieties as pendant groups was developed. The chitosan microspheres, obtained through crosslinking with glutaraldehyde of an acetic acid solution of chitosan, in an organic suspension medium, were reacted with chloroacyl cyclodextrins in organic basic s... |
15981591 | Ultrasound-enhanced tumor targeting of polymeric micellar drug carriers. | Cancer chemotherapy is often complicated by toxic side effects of anticancer drugs. We are developing a new modality of tumor chemotherapy aimed at circumventing side effects of treatment via drug targeting to tumors. The technique is based on drug encapsulation in polymeric micelles followed by a controlled drug relea... |
15766092 | [A study on inclusion complexes of cyclodextrin with three anticancer xanthines by fluorescence]. | The inclusion complexes of beta-Cyclodextrin (beta-CD) and HP-beta-Cyclodextrin (HP-beta-CD) with 6-Mercaptopurine (6-MP), Azathioprine (BAN) and 8-Azaguanine (Azan) were investigated by fluorescence. Various factors affecting the formation of inclusion complexes were discussed in detail including formation time and pH... |
15766090 | [The fluorescence characteristics of micelle inclusion of pefloxacin and its application]. | A new highly sensitive fluorescence spectrophotometic method for the determination of pefloxacin (PEFX) has been developed based on micella enhancement. The fluorescence characteristic of micelle inclusion complex formed between PEFX and sodium dodecyl sulfate (SDS) was studied. Different variables and parameters affec... |
15709424 | [Enantiomeric separation of mandelic acid and its analogues by high performance liquid chromatography with 2,6-di-O-pentyl-beta-cyclodextrin coated symmetry C8 column]. | 2,6-Di-O-pentyl-beta-cyclodextrin, synthesized from beta-CD in dimethyl sulfoxide (DM-SO), was dynamically coated on a Symmetry C8 column through hydrophobic interaction. Using the coated column, the resolution of six racemic mixtures of mandelic acid and its analogues by reversed-phase high performance liquid chromato... |
15617387 | Photophysics of Calix[4]biscrown-based ditopic receptors of caesium containing one or two dioxocoumarin fluorophores. | The ditopic receptors Calix-COU1 and Calix-COU2 consist of a calix[4]biscrown containing one or two dioxycoumarin fluorophores, respectively, inserted into the crown. They can form 1:1 and 2:1 (metal:ligand) complexes with caesium ions. The photophysical properties of the 1:1 complexes can be explained by (i) cation tu... |
15617382 | Quenched emission of fluorescence by ligand functionalized gold nanoparticles. | A fluorescence-based detection scheme that uses ligand functionalized gold nanoparticles is proposed. The transduction scheme is based on the strong quenching of the fluorescence emission exerted by metallic surfaces on fluorophores positioned in their immediate vicinity (< 5 nm). Binding of fluorophore-labeled anti-bi... |
15580683 | Synthesis and in vitro cytostatic activity of some new 1,3-(oxytetraethylenoxy)-cyclotriphosphazatriene derivatives. | A series of cyclophosphazene crown ether derivatives bearing aziridinyl (ethylene imine) units and also 2-naphthyl or anthraquinone groups as co-substituents has been synthesized and their cytostatic activity against the panel of eight cancer cells in vitro has been studied. The substituents used exhibit different acti... |
15503768 | [Study on preparation of beta-cyclodextrin inclusion complex of volatile oil in xiongdan xiaoyan capsules]. | <h4>Objective</h4>To study optimum inclusion conditions for volatile oil from three medicinal slices in Xiongdan Xiaoyan capsules.<h4>Method</h4>Saturated water solution method (agitation method), ultrasonic method and rubbing method were studied and compared. The preparation conditions of ultrasonic method were invest... |
15458246 | [Mixed monolayers of amphiphile-modified nucleic bases and diynoic acids. I. Phase states at air-water interface and in Langmuir-Blodgett films]. | Monolayers of amphiphile-modified nucleic bases with diynoic acid were obtained and characterized. The synthesized nucleic bases contained in the monolayer complementarily bind the nucleotide molecules contained in the aqueous subphase, and the structure of the resulting monolayers can be fixed by the photopolymerizati... |
15456142 | [The effect of Ca2+ ions on DNA compaction in the complex with non-histone chromosomal protein HMGB1]. | The analysis of absorption and circular dichroism spectra in UV and IR regions showed that Ca2+ ions interact both with the phosphate groups of DNA and with the HMGB1 protein. Not only negatively charged C-terminal part of the protein molecule participates in interaction with metal ions but also its DNA-binding domains... |
15370367 | Bioavailability and anticataract effects of a topical ocular drug delivery system containing disulfiram and hydroxypropyl-beta-cyclodextrin on selenite-treated rats. | <h4>Purpose</h4>To test the effect of aqueous eye drops containing a high concentration of disulfiram (DSF) in a cyclodextrin- based drug delivery system. This system increases both the drug solubility in aqueous eye drops and the permeability of drug into the rabbit eye, by the formation of a drug-cyclodextrin inclusi... |
15369232 | [Separation of enantiomers of phenylcarbamic acid derivatives by HPLC method]. | The chiral stationary phase on the base of beta-cyclodextrin and the mobile phase acetonitrile/0.1 mol/l acetate buffer pH=5.2 (88/12 w/w) were used for the separation of the enantiomers of 1-methoxymethyl, 1-ethoxymethyl, 1-propoxymethyl-2-(1-pyrrolidinyl), (1-piperidino), (1-perhydroazepinyl)ethyl esters of 2-alkoxyp... |
15354440 | Capillary electrochromatography with polymeric continuous beds synthesized via free radical polymerization in aqueous media using derivatized cyclodextrins as solubilizing agents. | A novel synthetic route to amphiphilic acrylamide-based monolithic stationary phases for capillary electrochromatography (CEC) employing water-soluble cyclodextrins as solubilizing agents was explored. N,N'-Octamethylenebisacryamide and N,N'-dodecamethylenebisacryamide were synthesized and their solubilization in aqueo... |
15354438 | Development of reactive thiol-modified monolithic capillaries and in-column surface functionalization by radical addition of a chromatographic ligand for capillary electrochromatography. | Reactive thiol-modified capillary columns for capillary electrochromatography (CEC) were developed by transforming the pendent 2,3-epoxypropyl groups of poly(glycidyl methacrylate-co-ethylene dimethacrylate) (poly(GMA-co-EDMA)) monoliths into 3-mercapto-2-hydroxy-propyl residues by a nucleophilic substitution reaction,... |
15296457 | Affinity precipitation and macroaffinity ligand facilitated three-phase partitioning for refolding and simultaneous purification of urea-denatured pectinase. | Protein refolding is an integral step in the recovery of protein activity from inclusion bodies. It is shown that affinity precipitation and macroaffinity ligand facilitated three-phase partitioning (MLFTPP) led to refolding of urea-denatured pectinase present in a commercial preparation, with simultaneous purification... |
15290851 | Cyclodextrins in nasal delivery of low-molecular-weight heparins: in vivo and in vitro studies. | <h4>Purpose</h4>To test the hypothesis that cyclodextrins reversibly enhance nasal absorption of low-molecular-weight heparins (LMWHs) and to investigate the mechanisms by which cyclodextrins enhance LMWH absorption via the nose.<h4>Methods</h4>Absorption of LMWHs was studied by measuring plasma anti-factor Xa activity... |
15290850 | Pulmonary delivery of deslorelin: large-porous PLGA particles and HPbetaCD complexes. | <h4>Purpose</h4>To compare the systemic delivery of deslorelin following intratracheal administration of different deslorelin formulations. The formulations included dry powders of deslorelin, large-porous deslorelin-poly(lactide-co-glycolide) (PLGA) particles, and small conventional deslorelin-PLGA particles. Also, so... |
15282274 | Lipid rafts mediate the synaptic localization of alpha-synuclein. | Alpha-synuclein contributes to the pathogenesis of Parkinson's disease (PD), but its precise role in the disorder and its normal function remain poorly understood. Consistent with a presumed role in neurotransmitter release and its prominent deposition in the dystrophic neurites of PD, alpha-synuclein localizes almost ... |
15282269 | Slow actions of neuroactive steroids at GABAA receptors. | Neuroactive steroids are potent and efficacious modulators of GABA(A) receptor activity and are potent sedatives and anesthetics. These positive modulators of GABA(A) receptors both potentiate the actions of GABA at the receptor and, at higher concentrations, directly gate the channel. The contribution of direct gating... |
15281268 | Chromatographic behaviour of naproxen-cyclodextrin complexes stationary phase C8 alkyl chain as competitor for the drug release from cyclodextrin cavity. | Cyclodextrins are known to alter the absorptivity of the guest molecules, therefore, analytical methods that are based on the spectrophotometric data present accuracy problems. In this work, using RP-HPLC methods for naproxen-cyclodextrins quantitation, extensive analytical inaccuracies are detected. Competitive comple... |
15281248 | Novel fiber coated with amide bridged-calix[4]arene used for solid-phase microextraction of aliphatic amines. | Solid-phase microextraction (SPME) using a novel fiber coated with 25,27-dihydroxy-26, 28-oxy(2',7'-dioxo-3',6'-diazaoctyl)oxy-p-tert-butylcalix[4]arene/hydroxy-terminated silicone oil has been introduced as a rapid and sensitive pretreatment technique coupled to gas chromatography-flame ionization detection (GC-FID) f... |
15272838 | Identification of symmetries in molecules and complexes. | An algorithm is presented that quickly detects local and global symmetries of single molecules and complexes. Based upon the Morgan Naming Algorithm, the algorithm involves traversing the molecule from a starting atom and building up a molecule name based upon the names of the atoms encountered along the traversal. Add... |
15273996 | Alkali-stable high-pI isoelectric membranes for isoelectric trapping separations. | Alkali-stable, high-pI isoelectric membranes have been synthesized from quaternary ammonium derivatives of cyclodextrins and poly(vinyl alcohol), and bifunctional cross-linkers, such as glycerol-1,3-diglycidyl ether. The new, high-pI isoelectric membranes were successfully applied as cathodic membranes in isoelectric t... |
15271357 | Quantum chemical calculations and mutational analysis suggest heat shock protein 90 catalyzes trans-cis isomerization of geldanamycin. | The affinity of geldanamycin (GA) for binding to heat shock protein 90 (HSP90) is 50- to 100-fold weaker than is the affinity of the structurally distinct natural product radicicol. X-ray crystallography shows that although radicicol maintains its free conformation when bound to HSP90, the conformation of GA is dramati... |
15229655 | Sequence-specific targeting of MSL complex regulates transcription of the roX RNA genes. | In Drosophila, dosage compensation is controlled by the male-specific lethal (MSL) complex consisting of at least five proteins and two noncoding RNAs, roX1 and roX2. The roX RNAs function in targeting MSL complex to the X chromosome, and roX transgenes can nucleate spreading of the MSL complex into flanking chromatin ... |
15229652 | Defective downregulation of receptor tyrosine kinases in cancer. | Most growth factors control cellular functions by activating specific receptor tyrosine kinases (RTKs). While overactivation of RTK signalling pathways is strongly associated with carcinogenesis, it is becoming increasingly clear that impaired deactivation of RTKs may also be a mechanism in cancer. A major deactivation... |
15264872 | Self-assembling nanocomplexes from insulin and water-soluble branched polyesters, poly[(vinyl-3-(diethylamino)- propylcarbamate-co-(vinyl acetate)-co-(vinyl alcohol)]-graft- poly(L-lactic acid): a novel carrier for transmucosal delivery of peptides. | The design of carriers for protein delivery that provide protection against enzymatic degradation and facilitate protein transport across epithelial surfaces, thus avoiding parenteral administration, remains a challenge. Self-assembling nanoscale protein/polymer complexes might present a promising approach. We synthesi... |
15264871 | Cyclodextrin-modified polyethylenimine polymers for gene delivery. | Linear and branched poly(ethylenimines), lPEI and bPEI, respectively, grafted with beta-cyclodextrin are prepared to give CD-lPEI and CD-bPEI, respectively, and are investigated as in vitro and in vivo nonviral gene delivery agents. The in vitro toxicity and transfection efficiency are sensitive to the level of cyclode... |
15264864 | Interaction of poly(amidoamine) dendrimers with supported lipid bilayers and cells: hole formation and the relation to transport. | We have investigated poly(amidoamine) (PAMAM) dendrimer interactions with supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayers and KB and Rat2 cell membranes using atomic force microscopy (AFM), enzyme assays, flow cell cytometry, and fluorescence microscopy. Amine-terminated generation 7 (G7) PA... |
15264854 | Synthesis and characterization of bioconjugates of S-layer proteins. | The self-assembling proteins that form crystalline surface layers (S-layers) on many microbial species have found numerous applications due to their nanostructured nature. To devise a new method to construct surface displays that exploit S-layer self-assembly activity and nanostructural properties, we have constructed ... |
15260644 | Internal structure of dendrimers in the melt under shear: a molecular dynamics study. | The molecular structure of fluids composed of dendrimers of different generations is studied using nonequilibrium molecular dynamics (NEMD). NEMD results for dendrimer melts undergoing planar Couette flow are reported and analyzed with particular attention paid to the shear-induced changes in the internal structure of ... |
15260572 | Embedding and self-organization of nanoparticles in phospholipid multilayers. | Multilayers of various phospholipids on silicon substrates are used to induce spontaneous embedding of nanoparticles deposited from the gas phase. The resulting nanoparticle arrangement on the substrate surface is characterized using atomic force and scanning electron microscopy. In the intermediate phase and the liqui... |
15261022 | Correlation between structure and transfection efficiency: a study of DC-Chol--DOPE/DNA complexes. | The supramolecular structural nature of some cationic liposomes-DNA complexes, currently used as vehicles in non-viral gene delivery, has been elucidated by recent X-ray diffraction experiments. The relationship between the chemico-physical properties of these self-assembled structures and their transfection efficiency... |
15255687 | Dendrimers based on a three-dimensionally disposed AB4 monomer. | [reaction: see text] Design and synthesis of a novel class of dendrons based on an AB(4) monomer are described. These dendrons have been evaluated by using dendritic encapsulation of a redox active core. The electrochemical properties of symmetric ferrocene-cored dendrimers show that significant alterations in redox po... |
15253673 | Enantiomer separations in capillary electrophoresis in the case of equal binding constants of the enantiomers with a chiral selector: commentary on the feasibility of the concept. | It is generally acknowledged that enantiomer separations in capillary electrophoresis are based on differences in the affinities of the analyte enantiomers toward the chiral selector expressed as equilibrium constants of the resulting temporary diastereomeric associates. However, as can be derived from theoretical cons... |
15253662 | Increasing the negative charge of a macroanion in the gas phase via sequential charge inversion reactions. | Protonated and deprotonated biological molecules in the gas phase play an important role in life sciences research. The structural information accessible from the ions is highly dependent upon their charge states. Therefore, it is desirable to develop means for increasing absolute charge states, particularly for ioniza... |
15252804 | A photoswitchable rotaxane with a folded molecular thread. | Novel [2]rotaxanes containing the tetracationic cyclophane cyclobis(paraquat-4,4-biphenylene) and a dumbbell-shaped molecular thread incorporating a photoactive diarylcycloheptatriene station as well as a photoinactive anisol station have been synthesized with yields of nearly 50 % by the alkylative endcapping method. ... |
15252795 | Spectral, structural, and electrochemical properties of ruthenium porphyrin diaryl and aryl(alkoxycarbonyl) carbene complexes: influence of carbene substituents, porphyrin substituents, and trans-axial ligands. | A wide variety of ruthenium porphyrin carbene complexes, including [Ru(tpfpp)(CR(1)R(2))] (CR(1)R(2) = C(p-C(6)H(4)Cl)(2) 1 b, C(p-C(6)H(4)Me)(2) 1 c, C(p-C(6)H(4)OMe)(2) 1 d, C(CO(2)Me)(2) 1 e, C(p-C(6)H(4)NO(2))CO(2)Me 1 f, C(p-C(6)H(4)OMe)CO(2)Me 1 g, C(CH==CHPh)CO(2)CH(2)(CH==CH)(2)CH(3) 1 h), [Ru(por)(CPh(2))] (po... |
15252792 | Supramolecular porphyrin assemblies through amidinium-carboxylate salt bridges and fast intra-ensemble excited energy transfer. | Well-defined supramolecular assemblies of Zn and free-base porphyrins are constructed through the formation of amidinium-carboxylate salt bridges. A one-to-one donor-acceptor pair and a four-to-one antenna-type assembly are investigated. The steady-state and time-resolved fluorescence measurements unequivocally showed ... |
15252785 | Self-assembly, optical behavior, and permeability of a novel capsule based on an azo dye and polyelectrolytes. | A novel capsule composed of an azo dye, Congo red (CR), and different polymers, including poly(styrenesulfonate, sodium salt) (PSS), poly(allylamine hydrochloride) (PAH), and poly(diallyldimethylammonium chloride) (PDDA), have been successfully fabricated by the layer-by-layer self-assembly technique. The stepwise line... |
15252783 | Organic chlorine as a hydrogen-bridge acceptor: evidence for the existence of intramolecular O--H...Cl--C interactions in some gem-alkynols. | The acceptor capabilities of "organic" halogen, CX (X=F, Cl, Br, I), with respect to hydrogen bonding are controversial, and unactivated organic chlorine is generally deemed to be a poor acceptor. Hydrogen bridges of the type O--H...Cl--C are uncommon and occur mainly in an intramolecular situation when the donor group... |
15248970 | Two-dimensional infrared spectroscopy study on phase transition and structural variations of a hydrogen-bonded liquid crystal. | Infrared (IR) spectra have been measured for a liquid crystal (LC) consisting of one trans-butene diacid (BD) molecule as a proton donor and two 4-(2,3,4-tridecyloxybenzoyloxy)-4'-stilbazoles (DBS) molecules as a proton acceptor (DBS:BD:DBS) linked together with each other by inter-molecular hydrogen bonds over a tempe... |
15248954 | A new method for the determination of the critical micelle concentration of Triton X-100 in the absence and presence of beta-cyclodextrin by resonance Rayleigh scattering technology. | A new method for the determination of the critical micelle concentration (CMC) of Triton X-100 in aqueous solution and beta-cyclodextrin solution by resonance Rayleigh scattering (RRS) has been developed. The method is based on the measurement of the RRS intensity of different concentration of Triton X-100 in aqueous s... |
15248737 | Binding of sodium dodecyl sulfate to linear and star homopolymers of the nonionic poly(methoxyhexa(ethylene glycol) methacrylate) and the polycation poly(2-(dimethylamino)ethyl methacrylate): electromotive force, isothermal titration calorimetry, surface tension, and small-angle neutron scattering measurements. | We investigated the binding of sodium dodecyl sulfate (SDS) to various linear and star polymers of the nonionic methoxyhexa(ethylene glycol) methacrylate (PMHEGMA) and the ionic 2-(dimethylamino)ethyl methacrylate (PDMAEMA), the latter being a polycation at low pH. The dodecyl sulfate ion selective electrode (EMF), iso... |
15248728 | Novel molecular recognition via fluorescent resonance energy transfer using a biotin-PEG/polyamine stabilized CdS quantum dot. | A novel functionally PEGylated quantum dot (QD) was prepared by a coprecipitation method in the presence of the biotin-PEG/polyamine block copolymer. When CdCl2 and Na2S were mixed in aqueous media in the presence of the biotin-PEG-b-poly(2-(N,N-dimethylamino)ethyl methacrylate) [biotin-PEG/PAMA], a CdS QD with a size ... |
15248711 | Enantiomeric recognition of amino acids by amphiphilic crown ethers in Langmuir monolayers. | Four new chiral, amphiphilic crown ethers differing by the hydrophobic tailgroups were synthesized, and their capacity to recognize enantiomeric amino acids was examined using Langmuir films. Surface pressure and surface potential measurements performed on the subphases containing L or D enantiomers of alanine, valine,... |
15248705 | Micro- and nanofabrication of robust reactive arrays based on the covalent coupling of dendrimers to activated monolayers. | We report on methods to fabricate robust micro- and nanopatterned platforms, comprising high functional group densities and quasi three-dimensional structures, for possible applications in biochip array technologies. For this purpose, amine-terminated poly(amidoamine) (PAMAM) dendrimers were immobilized via amide linka... |
15248704 | Structural characterization of microcontact printed arrays of hexa(ethylene glycol)-terminated alkanethiols on gold. | This paper reports on the structural characteristics of microcontact printed oligo(ethylene glycol)-terminated alkanethiol layers, HS(CH2)15CONH-(CH2CH2O)6-H (hereafter EG6), on gold. Microwetting, contact angle goniometry, imaging null ellipsometry, and infrared reflection-absorption spectroscopy (IRAS) are used to ch... |
15248699 | Interactions of complementary PEGylated liposomes and characterization of the resulting aggregates. | The interaction of complementary liposomes bearing both recognizable and protective ligands at their external surface has been investigated. Aggregation of hydrogenated phosphatidyl choline/cholesterol (2:1 molar ratio) based liposomes was mediated by the molecular recognition of the complementary phosphate and guanidi... |
15248684 | Dendrimer-activated surfaces for high density and high activity protein chip applications. | Highly functional Si and glass surfaces for protein immobilization have been prepared by a facile activation of native surface silanol groups. Poly(propyleneimine) dendrimers of generations 1-5 were immobilized onto the surface using a facile room-temperature coupling procedure that involved activation of native silano... |
15244472 | AFM study of the elastin-like biopolymer poly(ValGlyGlyValGly). | In this paper, we report an AFM study on the supramolecular structures adopted by the synthetic polypentapeptide poly(ValGlyGlyValGly), whose monomeric sequence is an abundant, simple building block of elastin. The polypeptide was analyzed by deposition from both methanolic and aqueous suspensions, showing different be... |
15244453 | Polyamidoamine (Yet Not PAMAM) dendrimers as bioinspired materials for drug delivery: structure-activity relationships by molecular simulations. | In this paper, we report the results obtained from a comprehensive characterization of newly synthesized dendrimeric molecules in a solvated environment, by computer-aided simulations. The evidences allowed us to formulate some structure-activity relationships (SARs) between the experimentally verified cytotoxicity/non... |
15248266 | Grid-type metal ion architectures: functional metallosupramolecular arrays. | Recent advances in supramolecular coordination chemistry allow access to transition-metal complexes of grid-type architecture comprising two-dimensional arrays of metal ions connecting a set of organic ligands in a perpendicular arrangement to generate a multiple wiring network. General design principles for these stru... |
15242591 | Structures of sortase B from Staphylococcus aureus and Bacillus anthracis reveal catalytic amino acid triad in the active site. | Surface proteins attached by sortases to the cell wall envelope of bacterial pathogens play important roles during infection. Sorting and attachment of these proteins is directed by C-terminal signals. Sortase B of S. aureus recognizes a motif NPQTN, cleaves the polypeptide after the Thr residue, and attaches the prote... |
15017384 | Osteoclast formation, survival and morphology are highly dependent on exogenous cholesterol/lipoproteins. | Osteoporosis is associated with both atherosclerosis and vascular calcification. No mechanism yet explains the parallel progression of these diseases. Here, we demonstrate that osteoclasts (OCL) depend on lipoproteins to modulate cellular cholesterol levels and that this controls OCL formation and survival. Removal of ... |
15240494 | A nanosensor for transmembrane capture and identification of single nucleic Acid molecules. | We have engineered a nanosensor for sequence-specific detection of single nucleic acid molecules across a lipid bilayer. The sensor is composed of a protein channel nanopore (alpha-hemolysin) housing a DNA probe with an avidin anchor at the 5' end and a nucleotide sequence designed to noncovalently bind a specific sing... |
15240493 | Nanostructure of cationic lipid-oligonucleotide complexes. | Complexes (lipoplexes) between cationic liposomes and single-strand oligodeoxynucleotides (ODN) are potential delivery systems for antisense therapy. The nanometer-scale morphology of these assemblies is relevant to their transfection efficiency. In this work the monocationic lipid dioleoyloxytrimethylammoniumpropane, ... |
15240483 | Modeling the backbone dynamics of reduced and oxidized solvated rat microsomal cytochrome b5. | In this article, a description of the statistics and dynamics of cytochrome b(5) in both reduced and oxidized forms is given. Results of molecular dynamics computer simulations in the explicit solvent have been combined with mode-coupling diffusion models including and neglecting the molecule-solvent correlations. R(1)... |
15240482 | The long-wavelength chlorophyll states of plant LHCI at room temperature: a comparison with PSI-LHCI. | The red antenna states of the external antenna complexes of higher plant photosystem I, known as LHCI, have been analyzed by measurement of their preequilibrium fluorescence upon direct excitation at 280 K. In addition to the previously detected F735 state, a hitherto undetected low-energy state with emission maximum a... |
15240473 | Interactions of the human calcitonin fragment 9-32 with phospholipids: a monolayer study. | Human calcitonin and its C-terminal fragment 9-32 (hCT(9-32)) administered in a spray translocate into respiratory nasal epithelium with an effect similar to intravenous injection. hCT(9-32) is an efficient carrier to transfer the green fluorescent protein into excised bovine nasal mucosa. To understand the translocati... |
15240467 | Properties of a self-assembled phospholipid membrane supported on lipobeads. | The overall objective of our work was to make a hydrogel-supported phospholipid bilayer that models a cytoskeleton-supported cell membrane and provides a platform for studying membrane biology. Previously, we demonstrated that a pre-Lipobead, consisting of phospholipids covalently attached to the surface of a hydrogel,... |
15240456 | Molecular dynamics simulations of the lipid bilayer edge. | Phospholipid bilayers have been intensively studied by molecular dynamics (MD) simulation in recent years. The properties of bilayer edges are important in determining the structure and stability of pores formed in vesicles and biomembranes. In this work, we use molecular dynamics simulation to investigate the structur... |
15240453 | The stability and dynamics of the human calcitonin amyloid peptide DFNKF. | The stability and dynamics of the human calcitonin-derived peptide DFNKF (hCT(15-19)) are studied using molecular dynamics (MD) simulations. Experimentally, this peptide is highly amyloidogenic and forms fibrils similar to the full length calcitonin. Previous comparative MD studies have found that the parallel beta-str... |
15240449 | Simulation of the interaction between ScyTx and small conductance calcium-activated potassium channel by docking and MM-PBSA. | Computational methods are employed to simulate interaction of scorpion toxin ScyTx in complex with the small conductance calcium-activated potassium channel rsk2. All of available 25 structures of ScyTx in the Protein Data Bank determined by NMR were considered for improving performance of rigid protein docking of ZDOC... |
15240441 | On the theory of noncovalent binding. | It is widely accepted that the binding constant of a receptor and ligand can be written as a two-body integral involving the interaction energy of the receptor and the ligand. Interestingly, however, three different theories of binding in the literature dictate three distinct integrals. The present study uses theory, a... |
15181633 | High-resolution NMR spectroscopic trends and assignment rules of metal-free, metallated and substituted corroles. | Major advances over the last few years have facilitated the synthesis of a large variety of meso-only substituted corroles that display interesting catalytic, therapeutic and photophysical properties. This work is the first to study extensively the NMR spectral characteristics of both metallated and non-metallated tria... |
15181626 | Reorientational dynamics of p-sulfonatocalix[4]arene and of its La(III) complex in water. | The reorientational dynamics of p-sulfonatocalix[4]arene and of its La(III) complex in deuterated water were studied by 1H NMR longitudinal relaxation rates. It is shown that the relaxation is purely dipolar in the non-extreme narrowing regime. The distance between the geminal protons could be determined from the NMR d... |
15228338 | Selective binding of NH4 + by redox-active crown ethers: application to a NH4 + sensor. | Two redox-active crown ethers, (1,1'- bi-2-naphthyl)-23-crown-6 incorporating 9,10-anthraquinone (BNAQ) and 1,4-benzoquinone (BNBQ), were synthesized and employed in the selective binding of NH(4)(+) over K(+). Their applications to NH(4)(+) detection were studied by cyclic voltammetry and amperometry in aqueous media.... |
15228314 | Characterization of whole fibril-forming collagen proteins of types I, III, and V from fetal calf skin by infrared matrix-assisted laser desorption ionization mass spectrometry. | Fibril-forming collagen proteins of the types I, III, and V were extracted from fetal calf skin, purified by differential salt precipitation, and analyzed by infrared matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (IR-MALDI-TOF-MS). Glycerol was used as liquid IR-MALDI matrix. Noncovalentl... |
15227641 | Determination of alpha-conotoxin binding modes on neuronal nicotinic acetylcholine receptors. | alpha-Conotoxins, from cone snails, and alpha-neurotoxins, from snakes, are competitive inhibitors of nicotinic acetylcholine receptors (nAChRs) that have overlapping binding sites in the ACh binding pocket. These disulphide-rich peptides are used extensively as tools to localize and pharmacologically characterize spec... |
15227640 | Length of the antibody heavy chain complementarity determining region 3 as a specificity-determining factor. | The antigen binding site of an antibody is made up of residues residing in six hypervariable loops of the heavy and light chains. In most cases several or all of these loops are required for the establishment of the antigen-binding surface. Five of these loops display a limited diversity in length and sequence while th... |
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