|
|
|
| Registros recuperados: 601 | |
|
|
| Arun Chauhan; Swaleha Zubair; Qamar Zia; Saba Tufail; Asif Sherwani; Mohammad Sajid; Mohammad Owais. |
| Biomimetic nano-assembly formation offers a convenient and bio friendly approach to fabricate complex structures from simple components with sub-nanometer precision. Recently, extract from cells of microorganism/plant origin have emerged as a simple and viable route for the synthesis of metal and inorganic material nano-particles. In the present study, we have extended biological synthesis of nano-particles to organic molecules, namely the anticancer agent, 5-fluorouracil (5-FU) using Aloe vera leaf extract. The formation of 5-FU nano- particles was assessed by UV, FT-IR and fluorescence spectroscopic techniques. Transmission electron microscopy and atomic force microscopic techniques confirmed nano-size of the synthesized particles. Importantly, the... |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Cancer; Chemistry; Molecular Cell Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6182/version/1 |
| |
|
|
| Andreas Kukol. |
| In order to exploit the advantages of receptor-based virtual screening, namely time/cost saving and specificity, it is important to rely on algorithms that predict a high number of active ligands at the top ranks of a small molecule database. Towards that goal consensus methods combining the results of several docking algorithms were developed and compared against the individual algorithms. Furthermore, a recently proposed rescoring method based on drug efficiency indices was evaluated. Among AutoDock Vina 1.0, AutoDock 4.2 and GemDock, AutoDock Vina was the best performing single method in predicting high affinity ligands from a database of known ligands and decoys. The rescoring of predicted binding energies with the water/butanol partition coeffcient... |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Chemistry; Bioinformatics. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5979/version/1 |
| |
|
|
| Sierra Rayne; Kaya Forest. |
| The large number of historical and current organic chemicals in commerce, and the ability of these compounds to make their way from industrial to remote regions, has resulted in concerted efforts to predict which chemicals have the capacity to migrate from where they are used/disposed to areas such as the Arctic. A suite of 120 high production volume chemicals has been recently screened from an initial dataset of >100,000 compounds and listed as potential Arctic contaminants. In the current work, we critically assess members of this proposed list for their possible rapid reactivity in environmental systems that would prevent substantial accumulation or transport in the environment and accumulation in vivo, as well as whether the investigated... |
| Tipo: Manuscript |
Palavras-chave: Chemistry; Earth & Environment. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4436/version/1 |
| |
|
|
| I. C. Baianu. |
| Chemical imaging is a technique for the simultaneous measurement of spectra (chemical information) and images or pictures (spatial information)^1,2^. The technique is most often applied to either solid or gel samples, and has applications in chemistry, biology^3-8^, medicine^9,10^, pharmacy^11^ (see also for example: Chemical Imaging Without Dyeing), food science, Food Physical Chemistry, Biotechnology^12,13^, Agriculture and industry. NIR, IR and Raman chemical imaging is also referred to as hyperspectral, spectroscopic, spectral or multi-spectral imaging (also see micro-spectroscopy). However, other ultra-sensitive and selective, chemical imaging techniques are also in use that involve either UV-visible or fluorescence microspectroscopy. |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Cancer; Chemistry; Developmental Biology; Genetics & Genomics; Molecular Cell Biology; Pharmacology; Bioinformatics; Plant Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6593/version/1 |
| |
|
|
| Marie-Paule Bassez; Yoshinori Takano. |
| Analogs of organic globules observed in carbonaceous chondrite meteorites and in interplanetary dust particles and of rod to spherical structures observed in terrestrial archean microstructures have been synthesized in our experiments conducted with proton irradiation on a mixture of simple inorganic constituants, CO, N2 and H2O. Our analyses of these laboratory organic globules show that the proton irradiation residue contains proteinous and non-proteinous amino acid precursors. On the basis of morphology, of hydrothermal and mineral environment, we suggest that the meteoritic organic globules and the archean carbon microstructures could be composed of amino acid precursors. |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4694/version/1 |
| |
|
|
| Sierra Rayne; Kaya Forest. |
| The SPARC software program was benchmarked for calculating the solubilities of two representative polyaromatic hydrocarbons (PAHs), naphthalene and anthracene, in a range of organic solvents at various temperatures. Although SPARC was able to reasonably approximate the solubilities of naphthalene in some organic solvents, gross errors were obtained for other solvents. For anthracene, poor prediction performance was observed in all solvents considered. Overall, the results suggest that SPARC is currently not suitable for accurately predicting the solubilities of representative PAHs relevant for the petroleum sector in various organic solvents. |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6648/version/1 |
| |
|
|
| Kikuo Harigaya. |
| Exciton effects are studied in single-wall boron-nitride (BN) nanotubes. Linear absorption spectra are calculated with changing
the chiral index of the zigzag nanotubes. We consider the extended Hubbard model with atomic energies at the boron and nitrogen sites.
Exciton effects are calculated using the configuration interaction technique. The Coulomb interaction dependence of the band gap,
the lowest exciton energy, and the binding energy of the exciton are discussed. The optical gap of the (5,0) nanotube is about 6 eV
at the onsite interaction U=2t with the hopping integral t=1.1 eV. The binding energy of the exciton is 0.50 eV for these parameters.
This energy agrees... |
| Tipo: Presentation |
Palavras-chave: Chemistry. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3879/version/1 |
| |
|
|
| Hong-Sang Low; Christopher J. O. Baker; Alexander Garcia; Markus R. Wenk. |
| Lipids can be systematically classified according to functional properties, structural features, biochemical origin or biological system. However Lipid nomenclature has yet to become a robust research tool since no rigorous definitions exist for membership of specific lipid classes. Lipids need to be defined in a manner that is systematic yet at the same time semantically explicit. We report on the reuse of existing lipid nomenclature, ontology describing chemical structure and the extension of the OWL-DL Lipid Ontology to support the classification of lipid molecules. We applied definitions, DL-axioms, to describe lipids classes and illustrate suitability of the ontology for the classification of Fatty Acyl lipids and Mycolic acids. |
| Tipo: Presentation |
Palavras-chave: Chemistry; Bioinformatics. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3590/version/1 |
| |
|
| |
|
| |
|
|
| Sierra Rayne; Kaya Forest. |
| The gas phase standard state (298.15 K, 1 atm) isomerization enthalpy prediction performance of the major semiempirical, ab initio, and density functional levels of theory was investigated using the linear to branched heptanes. The M062X density functional, MP2 (and higher) levels of Moller-Plesset perturbation theory, and the CBS and Gaussian-n composite methods are best suited for thermodynamic studies of alkane derivative isomerizations expected during the processing of petroleum, biomass, coal, or other fuels. Where large molecular systems prohibit the use of higher levels of theory, the PM6 and PDDG semiempirical methods may offer an appropriate computational cost-accuracy compromise. Non-M062X density functionals are not recommended for theoretical... |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4865/version/1 |
| |
|
| |
|
|
| Sierra Rayne; Kaya Forest. |
| Well-to-well (WWE~S-T~) and adiabatic (AE~S-T~) singlet-triplet excitation energies were calculated at the Gaussian-4 (G4) and W1BD levels of theory for a suite of mono- and disubstituted R~1~R~2~Si=Si silylene derivatives (where R~1~/R~2~=H, CH~3~, NH~2~, OH, and F), as well as H~2~C=Si and HN=Si. Reasonable agreement was obtained with prior E~S-T~ estimates at the CCSD(T)/6-311++G(d,p)//QCISD/6-31G(d) and B3LYP/AUG-cc-pVTZ//B3LYP/6-31+G(d) levels of theory. The G4/W1BD E~S-T~ are systematically higher than these prior estimates by between 1 to 5 kcal/mol, averaging positive deviations of about 1-2 and 3-4 kcal/mol from the CCSD(T) and B3LYP estimates, respectively. Qualitative ground state multiplicity agreement between the four levels of theory was... |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6465/version/1 |
| |
|
|
| Loris Grossi. |
| Alkyl nitrates, _in vivo_, are metabolized to yield nitric oxide, and thiol groups are considered necessary cofactors. This statement is based on studies that underline how these species potentiate hemodynamic responsiveness to nitrates in patients with ischemic heart disease. However, the role of thiols might be mediated by the formation of corresponding S-nitrosothiols, and a redox process is responsible for the nitrates' degradation: an enzyme, probably the cytochrome P450, is involved _in vivo_. Here, we report evidence that, in vitro, no reaction between thiols and alkyl nitrates takes place, but that stronger reducing agents, such as iron (II) derivatives, are necessary: alkoxy radicals and the nitrite anion are the reaction intermediates.... |
| Tipo: Manuscript |
Palavras-chave: Chemistry; Pharmacology. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/235/version/1 |
| |
|
| |
|
|
| Raji Heyrovska. |
| Cisplatin is cis-diamminedichloroplatinum (II) of chemical formula, Pt(NH3)Cl2, abbreviated as cis-DDP and known commercially as platinol. It is used widely as an anticancer drug for various types of cancer, ever since its discovery two centuries ago and has become a target of extensive researches. Transplatin, trans-DDP on the other hand, is found to be less or ineffective to treat cancers. Cisplatin is known to interact mainly with the N(7) nitrogen of guanine in nucleic acids, after a water molecule takes away one of the chlorines by hydrolysis. This initiates the damage of nucleic acids and eventually leads to apoptosis. However the way how this happens and why transplatin is less effective is not completely clear. Here the author brings some new... |
| Tipo: Manuscript |
Palavras-chave: Cancer; Chemistry; Molecular Cell Biology; Pharmacology. |
| Ano: 2012 |
URL: http://precedings.nature.com/documents/6891/version/1 |
| |
|
|
| Sierra Rayne. |
| Modes of carcinogenicity for the well-known environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) have been investigated over the past several decades. However, the mechanisms underlying TCDD carcinogenicity are still unclear. Recent work also suggests TCDD may have anti-cancer activity. Based on established photochemical generation of reactive 2,2'-biphenylquinone intermediates from dioxins, a novel toxicological mechanism for TCDD that may be operative is proposed. 2,2'-Biphenylquinones may be obtained via biochemical activation of dioxins such as TCDD, and these intermediates may play a role in expressing both the carcinogenic and anti-cancer activities of this important contaminant class. The broader research community... |
| Tipo: Manuscript |
Palavras-chave: Cancer; Chemistry. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1929/version/1 |
| |
|
|
| Oh-Hoon Kwon; Omar F. Mohammed. |
| In continuation of comments by Catalán, the latest here questions the steady-state emission spectra of 7-azaindole, and hence the validity of non-concerted proton transfer. In this comment, we show that his results are at fault and not supportive of his claims. We provide possible causes of the misleading claims, including the contamination of the solvent with water moisture. We conclude by calling for an end to such practice, which is counter productive, as it does not follow the scholarly approach of science. |
| Tipo: Manuscript |
Palavras-chave: Chemistry. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2522/version/1 |
| |
|
| |
|
|
| Y-H Percival Zhang; Joe Rollin. |
| Campbell et al. [Report in Science 2009 (May 22), 324, 1055] analyzed two scenarios where bioenergy crops were used for transportation – (1) cellulosic ethanol production by biorefineries for internal combustion engines and (2) bioelectricity generation by power stations for electric motors. Their study suggests the latter approach offers more efficient energy utilization than the former. We argue that the evaluation of a transportation system must be based on complicated metrics rather than only one or two factors. We suggest another out-of-the-box solution biomass carbohydrate-to-hydrogen-to-electricity as a key component of the future transportation sector. |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Chemistry; Earth & Environment. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3725/version/1 |
| |
| Registros recuperados: 601 | |
|
|
|
