Search results for "DISCOVERY"
showing 10 items of 4119 documents
An Efficient Synthesis of γ-Aminoacids and Attempts to Drive Its Enantioselectivity
2008
Addition of carboxylic acid dianions to bromoacetonitrile lead, in good yields,to the corresponding gamma-cyanoacids, which on hydrogenation yielded gamma-amino acids. This two step methodology improves upon previously described results. Poor e.e's resultedfrom our attempts to drive the enantioselectivity of this transformation by chiral amide induction.
A simple synthesis of γ-aminoacids
2007
The addition of dianions of carboxylic acids to bromoacetonitrile, leads, in good yields, to the corresponding γ-cyanoacids that give γ-aminoacids on hydrogenation. This two-step methodology improves the results previously described.
Dual inhibition of cyclooxygenase-1 and 5-lipoxygenase by aerial part of Bupleurum fruticescens methanol extract
2003
The effect of the methanol extract from aerial parts of Bupleurum fruticescens on the release of eicosanoids and hydrolytic enzymes was determined on in vitro cell systems. The extract had a significant effect on 5-lipoxygenase (5-LOX) activity, inhibiting both LTB4 and 5(S)-HETE production with IC50 values of 112 microg/ml and 95 microg/ml, respectively. At concentrations of 200 microg/ml, the extract also inhibited cyclooxygenase-1 (90%) and elastase activities (54%). The 12-LOX activity in intact platelets was not affected; a fact, which suggests that phospholipase A2 (PLA2) activity, is not modified by the extract.
Standard additions-dilution method for absolute quantification in voltammetry of microparticles. Application for determining psychoactive 1,4-benzodi…
2013
A standard additions-dilution solid-state electrochemical method for the determination of psychoactive 1,4-benzodiazepine and antidepressants drugs used as adulterants in commercial slimming herbal formulations is described and compared with conventional standard addition method. The proposed method, based on the voltammetry of microparticles approach, permits quantify, via standard additions methodology, 1,4-benzodiazepine and antidepressants drugs in phytotherapeutic formulations with no need of sample dissolution using dilution with a reference electroactive compound. The method was used to measure 1,4-benzobenzodiazepines (clonazepam, flurazepam, alprazolam, midazolam, bromazepam, chlor…
Neglected diseases caused by bacterial infections.
2009
Bacterial infections represent a major health problem, especially in third world countries. In endemic regions, large populations of people are greatly affected, but the medical care is very limited. In this review, the neglected diseases buruli ulcer and trachoma are elucidated. Buruli ulcer is caused by Mycobacterium ulcerans which produces an outstanding immunosuppressive toxin mycolactone that induces an ulcerative, necrotic skin disease. Until today, only the combination of rifampin/streptomycin is used to treat buruli ulcer. However, this therapy is ineffective and expensive. Here, we report new findings that suggest pharmaceutical formulations such as rifapentine, in combination with…
From Organization Business Model to Information System: One Approach and Lessons Learned
2011
The system ISTechnology and lessons learned of its use in the business modeling and development of information systems are analyzed in the paper. The system consists of the meta-model and applications. The meta-model enables to define a platform independent business model of the organization. The applications provide the definition and interpretation of the business model. Interpretation of the business model provides functionality of the information system in the selected platform. The lessons learned confirm that the development and maintenance cost of information systems can be significantly reduced by use of the ISTechnology.
Amine basicity: measurements of ion pair stability in ionic liquid media
2007
Abstract The stability constants relevant to the formation of amine/p-nitrophenol ion pairs have been determined in [bmim][BF4] solution, in the presence of butylamine, piperidine, and triethylamine, by using spectrophotometric measurements. In order to evaluate how the ion pair stability is affected by ionic liquid structure, piperidine has been chosen as model amine for studies in [bmim][PF6], [bmim][NTf2], [bm2im][NTf2] and in several [bmim][BF4]/1,4-dioxane binary mixtures. Data obtained in ionic liquid solutions have been compared with those previously reported in conventional organic solvents.
Sulfated Lupane Triterpene Derivatives and a Flavone C-Glycoside from Gypsophila repens
2007
A new sulfated lupane triterpene, Gypsophilin (1), and its glucosyl ester, Gypsophilinoside (2) were isolated from the roots of Gypsophila repens whereas a new flavone C-glycoside (3) was obtained from the aerial parts. Their structures were established as (3beta)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid (1), (3beta)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid -28-O-beta-D-glucopyranosyl ester (2) and luteolin-7-O-alpha-L-arabinopyranosyl-6-C-beta-glucopyranoside (3) by spectroscopic methods such as 1D and 2D NMR, HR-ESI-MS and FAB-MS.
Alkali-metal induced C,C-bond cleavage, C,H-bond cleavage, andcyclopolimerization in 1,5-hexadienes
1988
Abstract Reaction of the 1,5-dienes 3,4-homotropilidene ( 3 ) and 2,5-diphenylhexa-1,5-diene ( 4 ) with alkali metals induces C,H-bond cleavage (hydride formation) and cyclopolymerization, respectively, in contrast to the C,C-bond cleavage observed in semibullvalene and barbaralane.
Antigen-independent in vitro expansion of T cells does not affect the T cell receptor V beta repertoire.
1997
Analysis of the variable chains (V alpha/V beta) of the specific T cell receptor (TCR) of organ-infiltrating T cells may provide further insights into the pathogenesis of many infectious diseases, malignancies, and autoimmune disorders. To determine the TCR V beta repertoire of these small T cell populations antigen-independent in vitro expansion is necessary but may select for certain T cell subpopulations. In this study various antigen independent T cell activation protocols were used to stimulate peripheral blood mononuclear cells (PBMC) of six healthy blood donors, and TCR V beta molecules were analyzed by flow cytometry and semiquantitative reverse-transcriptase polymerase chain reacti…