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Research has been conducted on the heterocycles with keto and hydroxy functionalities. The study of these heterocycles as beryllium(II) chelating agents has been carried out in the aqueous solutions is presented.

Research has been conducted on the beryllium(II) ion. The interactions of this ion with the cyclopentadienyltris(diethylphosphito-P)cobaltate monoanion have been examined in aqueous solutions and the results are discussed.

Amyloid propagation by a template-dependent dock-lock mechanism has been hypothesized and modeled. It has been shown that the growth of amyloid plaque is mediated by two distinct kinetic processes, a dock phase, which is first, and a lock phase, which is second. Amyloid plaques are integral in Alzheimer's disease (AD) pathogenesis. They are made up of the peptide A(beta) and were modeled by monitoring the deposition of soluble A(beta) onto amyloid in AD brain tissue or synthetic amyloid fibrils.

Senile plaques made of the peptide Abeta contribute to the pathogenesis of Alzheimer's disease. The process of amyloid plaque growth in human brain was studied by employing size exclusion chromatography, translational diffusion measured by NMR and in vitro models of Abeta amyloid growth to identify the oligomerization state of Abeta that competent to add onto an existing amyloid deposit. Findings showed that, at least in vitro, Abeta exists as a monomer at physiological concentrations and deposition of monomers, rather than of oligomeric Abeta assemblies, mediates the growth of existing amyloid in human brain preparations.

Alzheimer's disease is pathologically characterized by the presence of many insoluble amyloid plaques in the brain composed mainly of a 40-43 amino acid peptide, the human beta-amyloid peptide (A-beta). To study the significance of the central hydrophobic cluster of A-beta for in vitro A-beta deposition, an A-beta(10-35)-NH2 analog with a single point substitution was synthesized and analyzed. Findings agree with previous investigations suggesting that the plaque competence of A-beta correlates with peptide folding.

The first-order kinetics of the formation of amyloid plaques in the brains of patients with Alzheimer's disease (AD) was studied using an in vitro model of plaque growth. The mechanism of aggregation and deposition of the human beta-amyloid peptide (Abeta) in intact sections and homogenates of unfixed AD brain cortex were analyzed by autoradiographic densitometry and radioisotope counting. There were no significant differences in the mechanism of plaque growth in the two systems, suggesting that the aggregation and deposition of Abeta follows distinct biochemical processes.

The N-terminal amyloid peptide fragment, Abeta(1-28)-OH, was found to be inactive at all pH values tested, whereas inactivity below pH 4 and activity between 5-9 pH was found for the central fragment, Abeta(10-35)-NH2, and the full length peptide, Abeta(1-28)-OH as revealed by an in vitro plaque growth assay of abeta congeners and their activity. A pH dependent folding transition in Abeta(10-35)-NH2 on its activation is observed. The presence of many turns and at least two short strands is indicated by the results.

Reaction of organomercury(II) ions with the tripodal ligand (2-diphenylphosphinoethyl)amine produces tetrahedral complexes in which the nitrogen atom of the tripod ligand is uncoordinated. Chromatographic and spectroscopic studies reveal that under mild conditions protonolysis of the Hg-C bond in the complex proceeds at reasonable rates. Kinetic studies suggest that activation of Hg-C bond is responsible for the acceleration of cleavage reaction. The mechanism of the cleavage is similar to enzymatic protonolysis of organomercury(II) derivatives.

The heterometallic complexes (PPh4)2(Mn(MS4)2), where M = Mo or W, are prepared by the reaction of manganese(II) bromide with molybdenum or tungsten tetrathiometalates in methanol solution. The (PPh4)2(Mn(WS4)2) complex consists of dicrete (Mn(WS4)2)2- anions and PPh4(super 1-) cations. The manganese center of the anion is surrounded by four sulfur atoms from two WS4 fragments, the manganese atom having a distorted tetrahedral geometry. The tungsten core displays a tetrahedral coordination.

The complex (Co6(u3-S)8(PEt3)6)(PF6) is synthesized and a study is made on its crystal and molecular structure, magnetic properties and single-crystal EPR spectra. A spin hamiltonian methodology is employed for the determination of the complex's magnetic structure while delocalization parameter p is used for the unpaired electron on the whole cluster. The results indicate the presence of discrete cluster cations and hexafluorophosphate anions in the molecular structure of the complex.

9Be nuclear magnetic resonance spectroscopy and X-ray analysis were utilized to characterize (Be3(mu-OH)3(H2O)6)(picrate)3*6H2O, prepared by isolating the trimeric species (Be(H2O))4(super 2+) as the picrate salt. Results showed that (Be3(mu-OH)3-(H2O)6)(super 3+) cations and picrate anions, with water molecules interspersed in the lattice, comprise the molecular structure of (Be3(mu-OH)3(H2O)6)(C6H2N3O7)3*6H2O. The formation of this trimeric complex is attributed to a hydrolysis process, which was afforded by the dissolution of picric acid in benzene.

Molecular dynamics (MD) simulations at 75-ns was performed for aqueous solutions of a 26-unit NIPAAm oligomer at two temperatures, 302 and 315 K, below and above the experimentally determined lower critical solution temperature (LCST) of p(NIPAAm). The results for the self-diffusion coefficient of water molecules surrounding the oligomers at the two temperatures for selected relevant times is found to characteristically depend on the distance from the solute molecules.

An amine, an aldehyde, and methanol can be readily assembled in one pot under very mild conditions through a free-radical multicomponent reaction by using an aqueous acidic TiCl 3/ t-BuOOH system to afford 1,2-amino alcohols in fair to excellent yields. [ABSTRACT FROM AUTHOR]

Focuses on the chemical properties of beryllium compounds. Reference to the study of the beryllium hydrolysis; Information on the isolation of the trimeric species as the picrate salt; How solvents were used.

The development of multifunctional vectors for efficient and safe gene delivery is one of the major challenges for scientists working in the gene therapy field. In this context, we have designed a novel type of aminoglycoside-rich dendrimers with a defined structure based on polyamidoamine (PAMAM) in order to develop efficient, nontoxic gene delivery vehicles. Three different conjugates, i.e., PAMAM G4-neamine, -paromomycin, and -neomycin, were synthesized and characterized by nuclear magnetic resonance (NMR) and MALDI analysis. The conjugates were found to self-assemble electrostatically with plasmid DNA, and unlike neamine conjugate, each at its optimum showed increased gene delivery potency compared to PAMAM G4 dendrimer in three different cell lines, along with negligible cytotoxicity. These results all disclosed aminoglycosides as suitable functionalities for tailoring safe and efficient multifunctional gene delivery vectors.

In spite of growing interest, a principal obstacle to wider inclusion of improved cookstove projects in carbon trading schemes has been the lack of accountability in estimating CO2-equivalent (CO2-e) savings. To demonstrate that robust estimates of CO2-e savings can be obtained at reasonable cost, an integrated approach of community-based subsampling of traditional and improved stoves in homes to estimate fuel consumption and greenhouse gas emissions, combined with spatially explicit community-based estimates of the fraction of nonrenewable biomass harvesting (fNRB), was used to estimate CO2-e savings for 603 homes with improved Patsari stoves in Purépecha communities of Michoacán, Mexico. Mean annual household CO2-e savings for CO2, CH4, CO, and nonmethane hydrocarbons were 3.9 tCO2-e home(-1) yr(-1) (95% Cl +/- 22%), and for Kyoto gases (CO2 and CH4) were 3.1 tCO2-e home(-1) yr(-1) (95% Cl +/- 26%), respectively, using a weighted mean fNRB harvesting of 39%. CO2-e savings ranged from 1.6 (95% Cl +/- 49%) to 7.5 (95% Cl +/- 17%) tCO2-e home(-1) yr(-1) for renewable and nonrenewable harvesting in individual communities, respectively. Since emission factors, fuel consumption, and fNRB each contribute significantly to the overall uncertainty in estimates of CO2-e savings, community-based assessment of all of these parameters is critical for robust estimates. Reporting overall uncertainty in the CO2-e savings estimates provides a mechanism for valuation of carbon offsets, which would promote better accounting that CO2-e savings had actually been achieved. Cost of CO2-e savings as a result of adoption of Patsari stoves was U.S. $8 per tCO2-e based on initial stove costs, monitoring costs, and conservative stove adoption rates, which is approximately 4 times less expensive than use of carbon capture and storage from coal plants, and approximately 18 times less than solar power. The low relative cost of CO2-e abatement of improved stoves combined with substantial health cobenefits through reduction in indoor air pollution provides a strong rationale for targeting these less expensive carbon mitigation options, while providing substantial economic assistance for stove dissemination efforts.

An amine, an aldehyde, and methanol can be readily assembled in one pot under very mild conditions through a free-radical multicomponent reaction by using an aqueous acidic TiCl3/t-BuOOH system to afford 1,2-amino alcohols in fair to excellent yields.