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14706284 | A role for hTRPC1 and lipid raft domains in store-mediated calcium entry in human platelets. | We have previously suggested that store-mediated Ca2+ entry (SMCE) in human platelets may be activated by a secretion-like coupling model, involving de novo coupling of the type II inositol 1,4,5-trisphosphate receptor (IP(3)RII) to the putative Ca2+ entry channel, hTRPC1. In other cells, hTRPC1 has been reported to be... |
14698427 | Cholesterol is required for Leishmania donovani infection: implications in leishmaniasis. | Leishmania donovani is an obligate intracellular parasite that infects macrophages of the vertebrate host, resulting in visceral leishmaniasis in humans, which is usually fatal if untreated. The molecular mechanisms involved in host-parasite interaction leading to attachment on the cell surface and subsequent internali... |
14698246 | 3-Amino derivative of beta-cyclodextrin: thermodynamics of copper(II) complexes and exploitation of its enantioselectivity in the separation of amino acid racemates by ligand exchange capillary electrophoresis. | The systems that the 3-amino derivative of beta-cyclodextrin (CD3NH2) forms with the proton, the copper(II) ion and each of the enantiomers of certain amino acids (alanine, phenylalanine, tyrosine and tryptophan) were investigated. The enantioselectivity shown by the potentiometric measurements carried out on the pheny... |
14698240 | Plastic substrates based separation channels in electromigration techniques. | Three types of plastic materials (polyester, polyurethane and polymethylmethacrylate) were tested as materials for manufacturing separation columns (polyester and polyurethane capillaries were used) or separation channels (polymethylmethacrylate) in the chip format. A set of 11 fluorescein isothiocyanate amino acid der... |
14696187 | N-H...O, O-H...O, and C-H...O hydrogen bonds in protein-ligand complexes: strong and weak interactions in molecular recognition. | The characteristics of N-H...O, O-H...O, and C-H...O hydrogen bonds are examined in a group of 28 high-resolution crystal structures of protein-ligand complexes from the Protein Data Bank and compared with interactions found in small-molecule crystal structures from the Cambridge Structural Database. It is found that b... |
14696090 | Expression of a naturally occurring constitutively active variant of the epidermal growth factor receptor in mouse fibroblasts increases motility. | Tumor cell motility is one of the rate-limiting steps of invasion, which defines progression toward a more malignant phenotype. Elevated expression of epidermal growth factor receptor (EGFR) in many cancers is associated with progression of superficial to invasive forms of the disease. The naturally occuring type III m... |
14693151 | Polymer-induced structural changes in lecithin/sodium dodecyl sulfate-based multilamellar vesicles. | Aqueous concentrated lecithin mixtures (asolectin from soybean) show typical lamellar liquid crystalline behavior and the individual lamellae tend to form spherical supramolecular structures, i.e., multilamellar vesicles. When part of the lecithin is replaced by the anionic surfactant sodium dodecyl sulfate (SDS), the ... |
15127807 | Preparation and study the 1:2 inclusion complex of carvedilol with beta-cyclodextrin. | An inclusion complex of beta-cyclodextrin with carvedilol was prepared by using a convenient new method of microwave irradiation. Phase-solubility studies demonstrated the ability of beta-cyclodextrins to complex with carvedilol and increase drug solubility. The structure of inclusion complex was determined by fluoresc... |
15127801 | Development and validation of a high-resolution capillary electrophoresis method for multi-analysis of ragaglitazar and arginine in active pharmaceutical ingredients and low-dose tablets. | A selective, sensitive and robust capillary electrophoresis (CE) method has been developed and validated for multi analysis of ragaglitazar (also known as NNC 61-0029 or DRF 2725) and its counter ion arginine in Active Pharmaceutical Ingredients (API) and low-dose tablets (0.5, 1.0 and 2.0 mg). The method covers a tota... |
15102455 | Progress towards a molecular-level structural understanding of amyloid fibrils. | The problem of determining and understanding the molecular structures of amyloid fibrils has attracted considerable attention and effort over the past several years. Although complete, high-resolution structures have not yet been obtained, key features of protein and peptide conformations and supramolecular organizatio... |
15095988 | Molecular determinants for ATP-binding in proteins: a data mining and quantum chemical analysis. | Adenosine 5'-triphosphate (ATP) plays an essential role in all forms of life. Molecular recognition of ATP in proteins is a subject of great importance for understanding enzymatic mechanism and for drug design. We have carried out a large-scale data mining of the Protein Data Bank (PDB) to analyze molecular determinant... |
15095984 | A new mechanism for metal ion-assisted interchain helix assembly in a naturally occurring peptide mediated by optimally spaced gamma-carboxyglutamic acid residues. | Helix-helix interactions, such as those that occur in coiled-coil domains, four-helix bundles, or membrane-spanning helical bundles, are important to the structural organization and function of numerous proteins. However, tractable peptide models for studying such structural elements have been limited to synthetic anal... |
15085953 | What determines differentiation of urothelial umbrella cells? | Cytokeratins, uroplakins and the asymmetric unit membrane are biochemical and morphological markers of urothelial differentiation. The aim of our study was to follow the synthesis, subcellular distribution and supramolecular organization of differentiation markers, cytokeratins and uroplakins, during differentiation of... |
15057652 | Polymer therapeutics - Sixth International Symposium: from laboratory to clinical practice. Industrial development and clinical evaluation. | This biannual conference was organized, as is now customary, by Professor Ruth Duncan of the Welsh School of Pharmacy and focused on novel technology and pharmaceutical compounds in the area of polymer therapeutics. This meeting has established itself as an important interface between discovery research and preclinical... |
15051318 | Nitric oxide in brain: diffusion, targets and concentration dynamics in hippocampal subregions. | Nitric oxide (NO(*)) is a diffusible regulatory molecule involved in a wide range of physiological and pathological events. At the tissue level, a local and temporary increase in NO(*) concentration is translated into a cellular signal. From our current knowledge of biological synthesis and decay, the kinetics and mech... |
15043007 | Virus entry: molecular mechanisms and biomedical applications. | Viruses have evolved to enter cells from all three domains of life--Bacteria, Archaea and Eukaryotes. Of more than 3,600 known viruses, hundreds can infect human cells and most of those are associated with disease. To gain access to the cell interior, animal viruses attach to host-cell receptors. Advances in our unders... |
15031959 | The history of the plague and the research on the causative agent Yersinia pestis. | The plague is an infectious bacterial disease having a high fatality rate without treatment. It has occurred in three huge pandemics since the 6th century with millions of deaths and numerous smaller epidemics and sporadic cases. Referring to specific clinical symptoms of pulmonary plague the disease became known as th... |
15032302 | Solubilizing excipients in oral and injectable formulations. | A review of commercially available oral and injectable solution formulations reveals that the solubilizing excipients include water-soluble organic solvents (polyethylene glycol 300, polyethylene glycol 400, ethanol, propylene glycol, glycerin, N-methyl-2-pyrrolidone, dimethylacetamide, and dimethylsulfoxide), non-ioni... |
15023257 | Gel permeation chromatography of fullerene-centered macromolecules. | Gel permeation chromatography (GPC) behavior of fullerene-centered macromolecules is investigated. Because of the globular shape of the macromolecules, their GPC results are different from those of linear polystyrene standards. These macromolecules may serve as alternative molecular weight standards for polymers or den... |
15023256 | Effect of temperature on enantiomer separation of oxzepam and lorazepam by high-performance liquid chromatography on a beta-cyclodextrin derivatized bonded chiral stationary phase. | A reversed-phase high-performance liquid chromatography (HPLC) method with beta-cyclodextrin (beta-CD) derivatized as chiral stationary phase is used to directly separate oxazepam (Oxa) and lorazepam (Lor) enantiomers. The effect of temperature on the direct HPLC separation of Oxa and Lor enantiomers is studied for the... |
15023255 | Solid-phase microextraction and gas chromatography-electron capture detection analysis of trace organochlorine pesticides in water using novel benzo-15-crown-5 sol-gel coating. | A novel dihydroxy-terminated benzo-15-crown-5 is synthesized and applied to prepare the solid-phase microextraction (SPME) fiber coating with sol-gel technology. Headspace SPME, as a simple, solvent-free method, is applied to the analysis of 16 organochlorine pesticides (OCPs) present at trace levels in a water sample.... |
15022809 | N-acetylcysteine attenuates lung injury in a rodent model of fracture. | <h4>Background</h4>Neutrophil-mediated lung injury is a cause of significant morbidity and mortality in patients with multiple injuries. We have shown previously that fracture hematoma can activate neutrophils and is thus a putative mediator of the systemic inflammatory response syndrome (SIRS), acute respiratory distr... |
15019141 | Efficacy of alpha-cyclodextrin against experimental cryptosporidiosis in neonatal goats. | The efficacy of orally administered tablets containing alpha-cyclodextrin, an excipient used in the pharmaceutical industry with demonstrated anticryptosporidial activity in vitro and in neonatal mice, was evaluated in neonatal goat kids. The formulation was evaluated for hardness and was subjected to in vitro drug rel... |
15013147 | Study of freeze-dried quercetin-cyclodextrin binary systems by DSC, FT-IR, X-ray diffraction and SEM analysis. | The inclusion behavior of 2-hydroxypropyl beta-cyclodextrin (HPbetaCD) and beta-cyclodextrin (betaCD), in solution and solid-state was studied towards a poorly water-soluble bioflavonoid, quercetin (QURC), chemically 3,3',4',5',7-pentahydroxy flavone. Drug-cyclodextrin solid systems were prepared by freeze-drying. Phas... |
15013141 | Separation of purine and pyrimidine bases by capillary electrophoresis using beta-cyclodextrin as an additive. | Capillary electrophoresis was applied to separate purine and pyrimidine bases in the basis of their partial ionization in the alkaline buffer. The effects of buffer pH, buffer and beta-cylclodextrin concentration were systematically investigated using a commercial capillary electrophoresis instrument with UV detector a... |
15013240 | Hepatocyte targeting of 111In-labeled oligo-DNA with avidin or avidin-dendrimer complex. | To establish an effective nonviral gene transfer vector to hepatocytes, various oligo-carrier complexes were developed employing dendrimer (G4) and avidin-biotin systems (Av-bt), and their biodistribution were evaluated. In-111-labeled-oligo, without any carriers, showed low uptake in normal organs other than the kidne... |
15011125 | Functional, electrophysiologic, and morphometric evaluation of nerve regeneration from coaptation on regenerated nerve fibers: experimental study in rabbits. | The importance of a sufficient number of nerve fibers at a proximal coaptation site is indisputable for the successful repair of nerves; however, the quality of nerve fibers required at this site has yet to be defined. The present study deals with the question of whether it is necessary to trim nerves back to unaffecte... |
14999404 | Antifungal proteins: targets, mechanisms and prospective applications. | All organisms have evolved several defence systems in order to protect themselves against bacteria, fungi and viruses. Higher organisms have developed a complex network of humoral and cellular responses, called adaptive immunity. A second defence system, innate immunity, was discovered in the early 1980s, consisting of... |
14999403 | Oxygen intervention in the regulation of gene expression: the photosynthetic bacterial paradigm. | The means by which oxygen intervenes in gene expression has been examined in considerable detail in the metabolically versatile bacterium Rhodobacter sphaeroides. Three regulatory systems are now known in this organism, which are used singly and in combination to modulate genes in response to changing oxygen availabili... |
14999401 | Protein structure to function: insights from computation. | Computation plays an important role in functional genomics. THEMATICS is a computational method that predicts chemical and electrostatic properties of residues in enzymes and utilizes information contained in those predictions to identify active sites. The only input required is the three-dimensional structure of the q... |
14983062 | Thioredoxin links redox to the regulation of fundamental processes of plant mitochondria. | Mitochondria contain thioredoxin (Trx), a regulatory disulfide protein, and an associated flavoenzyme, NADP/Trx reductase, which provide a link to NADPH in the organelle. Unlike animal and yeast counterparts, the function of Trx in plant mitochondria is largely unknown. Accordingly, we have applied recently devised pro... |
14983044 | Potent neutralization of severe acute respiratory syndrome (SARS) coronavirus by a human mAb to S1 protein that blocks receptor association. | Effective prophylaxis and antiviral therapies are urgently needed in the event of reemergence of the highly contagious and often fatal severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) infection. We have identified eight recombinant human single-chain variable region fragments (scFvs) against the S1 domai... |
14983002 | The elongation of yeast prion fibers involves separable steps of association and conversion. | A self-perpetuating change in the conformation of the translation termination factor Sup35p is the basis for the prion [PSI+], a protein-based genetic element of Saccharomyces cerevisiae. In a process closely allied to in vivo conversion, the purified soluble, prion-determining region of Sup35p (NM) converts to amyloid... |
14982369 | Metalloporphyrin solubility: a trigger for catalyzing reductive dechlorination of tetrachloroethylene. | Metalloporphyrins are well known for their electron-transfer roles in many natural redox systems. In addition, several metalloporphyrins and related tetrapyrrole macrocycles complexed with various core metals have been shown to catalyze the reductive dechlorination of certain organic compounds, thus demonstrating the p... |
14981706 | Development and validation of a robust capillary electrophoresis method for impurity profiling of calcium levofolinate including the (6R,2'S)-diastereomer using statistical experimental design. | A chiral capillary electrophoresis assay for the simultaneous determination of the optical purity and of related substances of calcium levofolinate has been developed and validated. Using 2,6-dimethyl-beta-cyclodextrin as chiral selector at a concentration of 20 mg/mL, the method was optimized using a full factorial de... |
14981703 | Combination of cyclodextrins and polymeric surfactants for chiral separations. | A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was applied to the enantioseparation of three binaphthyl derivatives using neutral CDs (i.e., beta- and gamma-CD) in combination with various chiral amino acid-based polymeric surfactants (PSs). Both the D- and L-configurations of poly(sodi... |
14981702 | Dynamics of interconversion of enantiomers in chiral separation systems: a novel approach for determination of all rate constants involved in the interconversion. | When enantiomers separated by chromatography or capillary electrophoresis undergo interconversion reaction (enantiomerization) during the separation, it leads to a typical detection pattern: two individual peaks of the separated enantiomers are connected with a plateau consisting of a mixture of both separated enantiom... |
14981310 | Effects of ionized cyclodextrin on decomposition of allyl isothiocyanate in alkaline solutions. | The secondary hydroxyl ion (alkoxide) ion for cyclodextrin (CD) may affect the decomposition of allyl isothiocyanate (AITC) in alkaline solutions. The equilibrium and kinetic parameters involved in the reaction processes were measured. It was found that the interaction between the alkoxide ion for CD and the included A... |
14978948 | [Preparation of a gel-forming ointment base applicable to the recovery stage of bedsore and clinical evaluation of a treatment method with different ointment bases suitable to each stage of bedsore]. | An ointment base for better treatment of bedsores was developed to improve the release rate of minocycline hydrochloride (MH) and the water absorption capacity using various types of hydrophobic to hydrophilic ointment bases. The effect of purified lanolin (PL) on the release behavior of MH from a hydrophilic ointment ... |
14979656 | Hydrogen bonding interactions of liposomes simulating cell-cell recognition. A review. | Amphiphiles bearing polar heads with the property to form hydrogen bond(s) exhibit unique organizational and aggregational behaviour. Thus appropriate amphiphilic molecules assemble and form liposomes, which further interact through hydrogen bonding with complementary molecules or liposomal counterparts affording large... |
14979640 | Raman spectroscopic protocol for the molecular recognition of key biomarkers in astrobiological exploration. | Raman spectroscopy is proposed as novel instrumentation for the remote, robotic exploration of planetary surfaces, especially Mars. In recent years, information about the chemicals produced by organisms at the terrestrial limits of life, such as those surviving in Antarctic habitats, has facilitated the assembly of a s... |
14978748 | Physicochemical optimisation of plasmid delivery by cationic lipids. | Non-viral gene therapy is based on the use of plasmid expression vectors and chemical or physical plasmid DNA delivery systems. This review discusses the roles of cationic lipids as vectors for gene transfection, reviews different strategies employed to improve cationic lipids for in vivo use, and provides original res... |
14978829 | Adamantanes, nortricyclenes, and dendrimers with extended silicon backbones. | By reaction of the hexabromoheptasilane MeSi(SiMe(2)SiMeBr(2))(3) (1 a) with H(2)O, H(2)S, NH(3), and H(2)NMe the heptasilaadamantanes MeSi(SiMe(2)SiMeO)(3) (4), MeSi(SiMe(2)SiMeS)(3) (5), MeSi(SiMe(2)SiMeNH)(3) (6 a), and MeSi(SiMe(2)SiMeNMe)(3) (6 b), respectively, were prepared in good to moderate yields. Molecular ... |
14978826 | Three-coordinate organoboron compounds BAr2R (Ar = mesityl, R = 7-azaindolyl- or 2,2'-dipyridylamino-functionalized aryl or thienyl) for electroluminescent devices and supramolecular assembly. | Eight novel three-coordinate boron compounds with the general formula BAr(2)L, in which Ar is mesityl and L is a 7-azaindolyl- or a 2,2'-dipyridylamino-functionalized aryl or thienyl ligand, have been synthesized by Suzuki coupling, Ullmann condensation methods, or simple substitution reactions (L = p-(2,2'-dipyridylam... |
14978825 | Supramolecular self-assembly of conjugated diblock copolymers. | This paper describes the synthesis and characterization of a novel series of copolymers with different lengths of oligo(phenylene vinylene) (OPV) as the rod block, and poly(propylene oxide) as the coil block. Detailed characterization by means of transmission electron microscopy (TEM), atomic force microscopy (AFM), an... |
14978815 | Dendrimers as ligands: an investigation into the stability and kinetics of Zn2+ complexation by dendrimers with 1,4,8,11-tetraazacyclotetradecane (cyclam) cores. | We have investigated the complexation of Zn(2+) with 1,4,8,11-tetrakis(naphthylmethyl) cyclam (1; cyclam=1,4,8,11-tetraazacyclotetradecane) and with two dendrimers consisting of a cyclam core with four dimethoxybenzene and eight naphthyl appendages (2), and twelve dimethoxybenzene and sixteen naphthyl appendages (3). A... |
14978814 | Discrete triangle, square and hexametallic alkynyl cyano-bridged compounds based on [cis-Pt(Ctbond;CR)2(CN)2]2- building blocks. | Novel mixed bis(alkynyl)bis(cyano)platinate(II) species [cis-Pt(Ctbond;CR)(2)(CN)(2)](2-) (1 a: R = tBu, 1 b: R = Ph) have been prepared and their potential as building blocks in the generation of self-organized systems with a variable molecular architecture has been studied. The reaction of 1 with the ditopic acceptor... |
14973247 | Acute and chronic ethanol alter glutamatergic transmission in rat central amygdala: an in vitro and in vivo analysis. | The modulation of glutamatergic transmission by ethanol may contribute to ethanol intoxication, reinforcement, tolerance, and dependence. Therefore, we used in vitro electrophysiological and in vivo microdialysis techniques to investigate the effects of acute and chronic ethanol on glutamatergic transmission in the cen... |
14971957 | Dynamic nature of the intramolecular electronic coupling mediated by a solvent molecule: a computational study. | We present a combined Molecular Dynamics/Quantum Chemical study of the solvent-mediated electronic coupling between an electron donor and acceptor in a C-clamp molecule. We characterize the coupling fluctuations due to the solvent motion for different solvents (acetonitrile, benzene, 1,3-diisopropyl-benzene) for the ch... |
14971954 | Nature of one-dimensional short hydrogen bonding: bond distances, bond energies, and solvent effects. | On the basis of recently synthesized calix[4]hydroquinone (CHQ) nanotubes which were self-assembled with infinitely long one-dimensional (1-D) short hydrogen bonds (SHB), we have investigated the nature of 1-D SHB using first-principles calculations for all the systems including the solvent water. The H-bonds relay (i.... |
14971953 | Photoswitchable flexible and shape-persistent dendrimers: comparison of the interplay between a photochromic azobenzene core and dendrimer structure. | Two analogous classes of dendrimers with a single azobenzene moiety at the core have been prepared. Flexible benzyl aryl ether dendrimers 1a-e were obtained in good yields by direct alkylation of diphenolic azobenzene 3 with benzyl aryl ether dendrons [G-n]-Br (n = 0-4). In rigid dendrimers 2a-e, the azobenzene configu... |
14971939 | Four-arm oligonucleotide Ni(II)-cyclam-centered complexes as precursors for the generation of supramolecular periodic assemblies. | The development of a multiarm metal-centered DNA building block as a precursor for the construction of supramolecular assemblies has relied upon the preparation of a Ni(II)-1,4,8,11-tetrazacyclotetradecane ligand (cyclam) functionalized with four linkers. This complex can be incorporated into a support-bound DNA sequen... |
14971934 | Heat-set gel-like networks of lipophilic Co(II) triazole complexes in organic media and their thermochromic structural transitions. | A novel class of thermally responsive supramolecular assemblies is formed from the lipophilic cobalt(II) complexes of 4-alkylated 1,2,4-triazoles. When an ether linkage is introduced in the alkylchain moiety, a blue gel-like phase is formed in chloroform, even at very low concentration (ca. 0.01 wt %, at room temperatu... |
14971915 | Designed self-assembly of molecular necklaces using host-stabilized charge-transfer interactions. | A novel approach to the noncovalent synthesis of molecular necklaces successfully led to the first quantitative self-assembly of a molecular necklace [6]MN, in which five small rings are threaded on a large ring, from 10 components. Our strategy involves the host-guest complex formation between the molecular host cucur... |
14971852 | Effects of fungal bioaugmentation and cyclodextrin amendment on fluorene degradation in soil slurry. | This study assesses the potential of fungal bioaugmentation and the effect of maltosyl-cyclodextrin amendment, as an approach to accelerate fluorene biodegradation in soil slurries. 47 fungal strains isolated from a contaminated site were tested in the biodegradation of fluorene. Results showed the greater efficiency o... |
14971505 | Chiral separation of labetalol stereoisomers in human plasma by capillary electrophoresis. | A newly derivatized cyclodextrin [octakis-(2,3-diacetyl-6-sulfato)-gamma-cyclodextrin] was investigated as a chiral selector in capillary zone electrophoresis in a study of the chiral separation of labetalol stereoisomers. Heptakis(2,3-diacetyl-6-sulfato)-beta-cyclodextrin (HDAS-beta-CD) and octakis(2,3-diacetyl-6-sulf... |
14971504 | Micellar electrokinetic capillary chromatography and data alignment analysis: a new tool in urine profiling. | The complex nature of biofluids demands efficient, sensitive and high-resolution analytical methodologies to examine how the 'metabolic fingerprint' changes during disease. This paper describes how sulphated beta-cyclodextrin-modified micellar electrokinetic capillary chromatography (SbetaCD-MECC) has been combined wit... |
14969543 | Preparation and characterization of inclusion complex of norflurazon and beta-cyclodextrin to improve herbicide formulations. | The formulation of inclusion complexes of the herbicide norflurazon as guest and beta-cyclodextrin (beta-CD) as host has been studied as a first step in the use of cyclodextrins to obtain improved formulations of this herbicide. The interaction of norflurazon with beta-CD produced the formation of an inclusion complex ... |
14969527 | Separation and analysis of diastereomers and enantiomers of cypermethrin and cyfluthrin by gas chromatography. | Synthetic pyrethroid (SP) insecticides are of environmental significance because of their high aquatic toxicity. Due to their chirality, SP compounds contain multiple diastereomers and enantiomers. However, due to great structural similarities and lack of isomer standards, gas chromatographic (GC) analysis of SP diaste... |
14969524 | Determination of enantiomers of synthetic pyrethroids in water by solid phase microextraction - enantioselective gas chromatography. | Solid phase microextraction (SPME) is an ideal sample preparation technique because of its speed and solvent-free features. Sampling by SPME is selective and only the dissolved concentration is measured, which allows measurement of the bioavailable fraction of a contaminant in aqueous media. One potential application o... |
14969680 | Effect of cholesterol-loaded cyclodextrin on the cryosurvival of bull sperm. | Bull sperm were treated with several levels of cholesterol-loaded cyclodextrin (CLC) and frozen in egg yolk diluents containing either Tris or sodium citrate, to determine the CLC concentration that best benefits bull sperm cryosurvival. After thawing, higher percentages of motile (60%) and viable (55%) sperm were obta... |
14970874 | N-hexanoyl-sphingomyelin potentiates in vitro doxorubicin cytotoxicity by enhancing its cellular influx. | Anticancer drugs generally have intracellular targets, implicating transport over the plasma membrane. For amphiphilic agents, such as the anthracycline doxorubicin, this occurs by passive diffusion. We investigated whether exogenous membrane-permeable lipid analogues improve this drug influx. Combinations of drugs and... |
14966978 | Platinum ion uptake by dendrimers: an NMR and AFM study. | The reaction of generation 2 and generation 4 poly(amidoamine) (PAMAM) dendrimers with K2PtCl2 was studied by several NMR methods. The time dependency of the Pt(II) complexation was followed with 195Pt NMR for both dendrimers and the equilibrium product was further characterized with (1)H NMR, and indirectly detected 1... |
14966974 | Axial Ligand exchange in chiral macrocyclic ytterbium(III) complexes. | We investigate the role of axial ligands on the near-IR-optical and paramagnetic NMR spectra of the complex [YbL](+3) where L is the stereodefined enantiopure chiral macrocycle (L = hexaazapentacyclo[25.3.1.1(12,24).0(4,9).0(19,24)]dotriaconta-1(31),2,10,12,14,16(32),17,25,27,29-decaene). The conformation in solution o... |
14966955 | Calix[4]pyrrole Schiff base macrocycles. Novel binucleating ligands for mu-oxo iron complexes. | New bimetallic mu-oxo diferric complexes of several previously reported calix[4]pyrrole Schiff base macrocycles are described. The synthesis of a new member of this class of macrocycles is also reported; it was prepared via an acid-catalyzed condensation between 1,9-bisformyl-5,5-dipropyldipyrromethane and o-phenylened... |
14967470 | Exploring detergent insolubility in bovine hippocampal membranes: a critical assessment of the requirement for cholesterol. | The phenomenon of detergent insolubility of bovine hippocampal membranes in Triton X-100 was monitored by estimating the presence of phospholipids in the insoluble pellet. This represents a convenient and unambiguous assay and reports the dependence of the extent of phospholipid solubilization on detergent concentratio... |
14967059 | Loops, linkages, rings, catenanes, cages, and crowders: entropy-based strategies for stabilizing proteins. | A protein molecule exists in either a compact folded state or a variable and open unfolded state. Since the unfolded state is favored by chain entropy, restricting its entropy is an attractive mechanism for shifting the equilibrium toward the folded state. A number of entropy-based strategies have been engineered or us... |
14967058 | Effective molarities in supramolecular catalysis of two-substrate reactions. | Reactivity data related to processes in which molecular receptors promote the reaction of two simultaneously complexed reactants have been surveyed and analyzed in terms of effective molarity (EM). Methods and criteria for the calculation of reliable EM's have been highlighted. Extension of a previous extrathermodynami... |
14967054 | Copper binding in the prion protein. | A conformational change of the prion protein is responsible for a class of neurodegenerative diseases called the transmissible spongiform encephalopathies that include mad cow disease and the human afflictions kuru and Creutzfeldt-Jakob disease. Despite the attention given to these diseases, the normal function of the ... |
14965293 | Synthetic approaches to the 2002 new drugs. | New drugs are introduced to the market every year and each individual drug represents a privileged structure for its biological target. In addition, these new chemical entities (NCEs) not only provide insights into molecular recognition, but also serve as drug-like leads for designing future new drugs. Therefore, it is... |
14966569 | The calcium-sensing receptor regulates mammary gland parathyroid hormone-related protein production and calcium transport. | The transfer of calcium from mother to milk during lactation is poorly understood. In this report, we demonstrate that parathyroid hormone-related protein (PTHrP) production and calcium transport in mammary epithelial cells are regulated by extracellular calcium acting through the calcium-sensing receptor (CaR). The Ca... |
14961604 | Snowflake-like dendrimers via site-selective synthesis of dendrons. | [structure: see text] Snowflake-shaped dendrimers were prepared via site-selective synthesis of dendrons, where an attachment of encapsulating dendritic branches and an extension of phenylacetylenic units were alternatively manipulated on the structure of AB(2) (diethyltriazeno for A and bromo for B) substituted diphen... |
14961603 | Novel functionalized trisubstituted allylboronates via Hosomi-Miyaura borylation of functionalized allyl acetates. | [reaction: see text] A series of novel functionalized achiral and chiral allylboronates have been synthesized via the nucleophilic addition of boronates on allyl acetates derived via vinylalumination or Baylis-Hillman reaction of aldehydes. These reagents, upon allylboration with aldehydes, furnish beta-substituted-alp... |
14961602 | Unprecedented cyclizations of calix[4]arenes with glycols under the Mitsunobu protocol, part 2.(1) O,O-and O,S-bridged calixarenes. | [reaction: see text] Cycloalkylations of p-tert-butylcalix[4]arene (CA) and p-tert-butylthiacalix[4]arene (TCA) with various aliphatic glycols were performed under the Mitsunobu protocol using the DEAD/TPP system. CA gave 1,3-dialkylated diols, while C(2)-C(10) glycols gave 1,2- and 1,3-bridged calixarenes. The reactio... |
14961600 | A water-soluble m-phenylene ethynylene foldamer. | [reaction: see text] A water-soluble m-phenylene ethynylene (mPE) foldamer was realized by appending hexaethylene glycol side chains to the backbone repeat unit. UV spectra of the oligomer in aqueous solutions were consistent with a helical conformation. The association constant of the oligomer with (-)-alpha-pinene in... |
14961702 | Catalysis in the self-assembly of [2]rotaxanes and [2]pseudorotaxanes. Effect of the length of polyethereal side arms and terminal stoppers. | The template effects exerted by compounds 3, 5, 6, and 8 in the ring closure reaction of the trication 1(3+) to yield the [2]pseudorotaxanes 15(4+) and 17(4+) and the [2]rotaxanes 18(4+) and 20(4+) have been quantitatively evaluated in acetonitrile at 62 degrees C by UV/vis spectrophotometry. The rate of ring closure o... |
14961699 | Salt effects on the apparent stability of the cucurbit[7]uril-methyl viologen inclusion complex. | The effects of the medium ionic composition on the apparent equilibrium association constant (K) for the formation of a 1:1 inclusion complex between the guest methyl viologen (MV(2+)) and the host cucurbit[7]uril (CB7) were studied in aqueous solutions. The K values were found to decrease with increasing ionic strengt... |
14961677 | Planar chiral dianthranilide and dithiodianthranilide molecules: optical resolution, chiroptical spectra, and molecular self-assembly. | Planar chiral dianthranilide (1) was resolved to enantiomers with use of (-)-(1S,4R)-camphanoyl chloride as a chiral derivatizing agent. The (+)-1 enantiomer was assigned the S absolute configuration from the X-ray crystal structure of its N,N'-dicamphanoyl derivative. Optical resolution of dithionodianthranilide (2) w... |
14961650 | Synthesis of diverse macrocyclic peptidomimetics utilizing ring-closing metathesis and solid-phase synthesis. | The synthesis of a range of highly functionalized peptidomimetic macrocycles has been accomplished using ring-closing metathesis and enyne tandem cross-metathesis-ring-closing metathesis reactions. This approach gives access to rigidified macrocycles modeled on the structures of cyclic peptides and designed to be biolo... |
14961723 | Poly(amidoamine) dendrimers as nanoscale diffusion probes in sol-gel films investigated by total internal reflection fluorescence spectroscopy. | Three generations of poly(amidoamine) dendrimers were dye-labeled and chemically modified to have terminal carboxyl groups and used as variably sized probes to study diffusion in thin sol-gel films. Total internal reflection fluorescence spectroscopy experiments, both correlation and concentration-jump measurements, we... |
14961722 | Modifying the adsorption behavior of polyamidoamine dendrimers at silica surfaces investigated by total internal reflection fluorescence correlation spectroscopy. | Polyamidoamine (PAMAM) dendrimers were modified and tested for use as solution-phase diffusion probes in silica nanostructures. In order for the successful application of dendrimers as solution-phase probes, their interactions with silica surfaces must be understood and controlled, so that the motion of the probe is no... |
14962581 | General principles of pharmaceutical solid polymorphism: a supramolecular perspective. | The diversity of solid-state forms that an active pharmaceutical ingredient (API) may attain relies on the repertoire of non-covalent interactions and molecular assemblies, the range of order, and the balance between entropy and enthalpy that defines the free energy landscape. It is recognized that crystallization is a... |
14961116 | A 1.7-kilobase single-stranded DNA that folds into a nanoscale octahedron. | Molecular self-assembly offers a means of spontaneously forming complex and well-defined structures from simple components. The specific bonding between DNA base pairs has been used in this way to create DNA-based nanostructures and to direct the assembly of material on the subnanometre to micrometre scale. In principl... |
14960624 | Postsynaptic density assembly is fundamentally different from presynaptic active zone assembly. | The cellular mechanisms involved in the formation of the glutamatergic postsynaptic density (PSD) are mainly unknown. Previous studies have indicated that PSD assembly may occur in situ by a gradual recruitment of postsynaptic molecules, whereas others have suggested that the PSD may be assembled from modular transport... |
14960604 | Enteric dopaminergic neurons: definition, developmental lineage, and effects of extrinsic denervation. | The existence of enteric dopaminergic neurons has been suspected; however, the innervation of the gut by sympathetic nerves, in which dopamine (DA) is the norepinephrine precursor, complicates analyses of enteric DA. We now report that transcripts encoding tyrosine hydroxylase (TH) and the DA transporter (DAT) are pres... |
14960367 | "Plus-C" odorant-binding protein genes in two Drosophila species and the malaria mosquito Anopheles gambiae. | Olfaction plays a crucial role in many aspects of insect behaviour, including host selection by agricultural pests and vectors of human disease. Insect odorant-binding proteins (OBPs) are thought to function as the first step in molecular recognition and the transport of semiochemicals. The whole genome sequence of the... |
14960286 | Effect of agonal and postmortem factors on gene expression profile: quality control in microarray analyses of postmortem human brain. | There are major concerns that specific agonal conditions, including coma and hypoxia, might affect ribonucleic acid (RNA) integrity in postmortem brain studies. We report that agonal factors significantly affect RNA integrity and have a major impact on gene expression profiles in microarrays. In contrast to agonal fact... |
14871534 | Measurement of antibodies to collagen II by inhibition of collagen fibril formation in vitro. | Antibodies to type II collagen (collagen II) are pathogenic in experimental collagen-induced arthritis (CIA) and possibly also in rheumatoid arthritis (RA). Hitherto, results of assays for anti-collagen II have proven to be inconsistent. We tested whether mouse monoclonal antibodies (mAbs) to collagen II inhibit the na... |
14871120 | Efficiency of various lattices from hard ball to soft ball: theoretical study of thermodynamic properties of dendrimer liquid crystal from atomistic simulation. | Self-assembled supramolecular organic liquid crystal structures at nanoscale have potential applications in molecular electronics, photonics, and porous nanomaterials. Most of these structures are formed by aggregation of soft spherical supramolecules, which have soft coronas and overlap each other in the packing proce... |
14871103 | Bioactivation of self-immolative dendritic prodrugs by catalytic antibody 38C2. | Self-immolative dendrimers have recently been developed and introduced as a potential platform for a multi-prodrug. These unique structural dendrimers can release all of their tail units, through a self-immolative chain fragmentation, which is initiated by a single cleavage at the dendrimer's core. Incorporation of dru... |
14871096 | Paranemic crossover DNA: a generalized Holliday structure with applications in nanotechnology. | Paranemic crossover (PX) DNA is a four-stranded coaxial DNA complex containing a central dyad axis that relates two flanking parallel double helices. The strands are held together exclusively by Watson-Crick base pairing. The key feature of the structure is that the two adjacent parallel DNA double helices form crossov... |
14871093 | Multiple hydrogen bonds tuning guest/host excited-state proton transfer reaction: its application in molecular recognition. | A molecular recognition concept exploiting multiple-hydrogen-bond fine-tuned excited-state proton-transfer (ESPT) was conveyed using 3,4,5,6-tetrahydrobis(pyrido[3,2-g]indolo)[2,3-a:3',2'-j]acridine (1a). The catalytic type 1a/carboxylic acids hydrogen-bonding (HB) complexes undergo ultrafast ESPT, resulting in an anom... |
14871088 | Gatekeeping layer effect: a poly(lactic acid)-coated mesoporous silica nanosphere-based fluorescence probe for detection of amino-containing neurotransmitters. | We have synthesized a poly(lactic acid) coated MCM-41-type mesoporous silica nanosphere (PLA-MSN) material can serve as a fluorescence sensor system for detection of amino-containing neurotransmitters in neutral aqueous buffer. Utilizing the PLA layer as a gatekeeper, we investigated the molecular recognition events be... |
14871087 | Synthesis of readily modifiable cyclodextrin analogues via cyclodimerization of an alkynyl-azido trisaccharide. | A convergent strategy for the synthesis of beta-cyclodextrin analogues is reported, utilizing preferential cyclodimerization of an azido-alkyne trisaccharide via Cu(I)-catalyzed [3 + 2] dipolar cycloaddition of the alkyne and azide functional groups. The resultant oligosaccharide macrocycle retains the binding propensi... |
14871083 | Fine control of the release and encapsulation of Fe ions in dendrimers through ferritin-like redox switching. | Numerous dendrimers incorporating metal ions or clusters have received much attention as catalytic and drug delivery materials. We expanded the variety of metal ions that complex with DPA through a radial stepwise complexation to create novel organic-inorganic hybrid materials. As one of the most common and significant... |
14871070 | Supramolecular catalysts by encapsulating palladium complexes within dendrimers. | Dendrimers are well-defined and highly branched macromolecules. By utilizing their capsular architectures, dendrimers encapsulating various catalytically active species can be prepared, which often bring about unique catalysis. Treatment of the alkylated PPI dendrimer with 4-diphenylphosphinobenzoic acid and [PdCl(C3H5... |
14871931 | Cooperativity in long-range gene regulation by the lambda CI repressor. | Effective repression of cI transcription from PRM by the bacteriophage lambda CI repressor requires binding sites (OL) located 2.4 kb from the promoter. A CI tetramer bound to OL1.OL2 interacts with a tetramer bound near PRM (OR1.OR2), looping the intervening DNA. We previously proposed that in this CI octamer:DNA comp... |
14871951 | Genetic evidence for interaction between eta- and beta-tubulins. | The thermosensitive allelic mutations sm19-1 and sm19-2 of Paramecium tetraurelia cause defective basal body duplication: growth at the nonpermissive temperature yields smaller and smaller cells with fewer and fewer basal bodies. Complementation cloning of the SM19 gene identified a new tubulin, eta-tubulin, showing lo... |
14766891 | Enterococcus cecorum empyema thoracis successfully treated with cefotaxime. | We report the first case of Enterococcus cecorum empyema thoracis and spontaneous bacterial peritonitis in a 44-year-old man with underlying cirrhosis. The patient responded to cefotaxime (MIC, 0.25 microg/ml) treatment and drainage of the empyema. Susceptibility of E. cecorum to expanded-spectrum cephalosporins could ... |
14767933 | Synthesis, fluorescence and photoisomerization studies of azobenzene-functionalized poly(alkyl aryl ether) dendrimers. | A series of azobenzene-functionalized poly(alkyl aryl ether) dendrimers have been synthesized and their photochemical and photophysical properties in solution and as thin films have been investigated. Although the photochemical behavior of the azodendrimers in solution indicated that the azobenzene units behave indepen... |
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