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Convenient Methods (convenient + methods)
Selected AbstractsChemInform Abstract: Convenient Methods for the Synthesis of a Library of Hemilabile Phosphines.CHEMINFORM, Issue 43 2009M. Victoria Jimenez Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Versatile and Convenient Methods for the Synthesis of C-2 and C-3 Functionalized 5-Azaindoles.CHEMINFORM, Issue 20 2006Myriam Lefoix Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Modified and Convenient Methods for the Preparation of Some Nitro Musks.CHEMINFORM, Issue 35 2004Javad Safaei-Ghomi Abstract For Abstract see ChemInform Abstract in Full Text. [source] Convenient methods for the synthesis of d4, d2 and d6 isotopomers of 4-(4-fluorobenzyl)piperidineJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 6 2005Ágnes Proszenyák Abstract Pure 4-(4-fluoro-[2,3,5,6- 2H4]benzyl)piperidine was prepared via the Grignard reaction of 4-fluoro-[2,3,5,6- 2H4]bromobenzene and pyridine-4-aldehyde followed by consecutive deoxygenation and heteroatomic ring saturation in the presence of palladium on carbon catalyst. An improved method for the catalytic H/D exchange in benzylic positions of 4-(4-fluorobenzyl)piperidine and its d4 derivative has also been described. Copyright © 2005 John Wiley & Sons, Ltd. [source] How to determine the number of inner-sphere water molecules in Lanthanide(III) complexes by 17O NMR spectroscopy.CONTRAST MEDIA & MOLECULAR IMAGING, Issue 2 2007A technical note Abstract Lanthanide(III) complexes of polyaminocarboxylates are widely used in MRI as contrast agents. The paramagnetic properties of the metal ion contribute to the increase of 1H relaxation rates, while the chelate offers a stable binding with the metal. The number of water molecules, coordinated directly to the Ln(III) ion, is very important for the relaxivity and, thus, the efficacy of these contrast agents. Here, we describe convenient methods to determine this parameter by measurement of Ln(III)-induced shifts of the water 17O NMR resonance. Copyright © 2007 John Wiley & Sons, Ltd. [source] Screening for gestational diabetes; past, present and futureDIABETIC MEDICINE, Issue 5 2002F. W. F. Hanna Abstract Gestational diabetes is carbohydrate intolerance, with onset or first recognition of hyperglycaemia during pregnancy. Several studies have suggested that gestational hyperglycaemia is associated with adverse maternal and fetal outcomes, promoting the case for screening. Conversely, others argue that screening for gestational diabetes may colour the clinical judgement, influencing further management, e.g. more ,unjustified' caesarean sections. Additionally, the lack of definitive data either on a clear-cut glycaemic threshold for the development of adverse outcomes or on the impact of intervention is emphasized by opponents of screening. This review attempts to evaluate the available data on screening for gestational diabetes. Oral glucose tolerance test is promoted on the basis that the diabetogenic stress of pregnancy is encountered during late gestation and is best recognized in the fed state. There are different tests, including the 1 h/50-g, 2 h/75-g and 3 h/100-g tests, with practical limitations, including the time and cost involved and the unpleasant supra-physiological glucose load that is unrelated to body weight, and issues of reproducibility and sensitivity/specificity profiles. Despite its convenience, the poor sensitivity of random glucose has precluded its routine use for screening. Fasting glucose appears to be promising but further testing is required to ensure satisfactory sensitivity/specificity in different populations. Despite its limitations, the oral glucose tolerance test has become established as the ,most acceptable' diagnostic test for gestational diabetes. More convenient methods, e.g. fasting or random or post-load glucose, have to be validated therefore against the oral glucose tolerance test to gain acceptance for routine screening. Diabet. Med 19, 351,358 (2002) [source] Synthesis of the new adducts of imines and enamines with PH acids and their derivatives,HETEROATOM CHEMISTRY, Issue 2 2009Andrey A. Prishchenko Nucleophilic or radical addition of esters of trivalent organophosphorus acids with PH fragments to various imines and enamines is proposed as convenient methods for the synthesis of new substituted aminomethyl organophosphorus compounds with three-, four-, and five-coordinated phosphorus. Also the new functionalized derivatives of these compounds with acyl and methanesulfonyl moieties are synthesized, and some properties of the obtained compounds are presented. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:70,80, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20513 [source] Synthesis of functionalized 2-trimethylsiloxy-substituted O -trimethylsilyl alkylphosphonites, their analogues, and derivativesHETEROATOM CHEMISTRY, Issue 5 2008Andrey A. Prishchenko Nucleophilic addition of trimethylsilyl esters of tricoordinate organophosphorus acids to several functionalized alkylene oxides is proposed as convenient methods for the synthesis of new 2-trimethylsiloxysubstituted alkylphosphonites, their analogues, and derivatives. Also the new functionalized derivatives of these phosphonites, including amino, carboxy, or sulfo groups as well as certain properties of these compounds, which may be the important precursors of new functionalized 2-hydroxyalkylorganophosphorus acids, are presented. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:450,454, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20453 [source] Comparison of evaporative inlet air cooling systems to enhance the gas turbine generated powerINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2007Mohammad Ameri Abstract The gas turbine performance is highly sensitive to the compressor inlet temperature. The output of gas turbine falls to a value that is less than the rated output under high temperature conditions. In fact increase in inlet air temperature by 1°C will decrease the output power by 0.7% approximately. The solution of this problem is very important because the peak demand season also happens in the summer. One of the convenient methods of inlet air cooling is evaporating cooling which is appropriate for warm and dry weather. As most of the gas turbines in Iran are installed in such ambient conditions regions, therefore this method can be used to enhance the performance of the gas turbines. In this paper, an overview of technical and economic comparison of media system and fog system is given. The performance test results show that the mean output power of Frame-9 gas turbines is increased by 11 MW (14.5%) by the application of media cooling system in Fars power plant and 8.1 MW (8.9%) and 9.5 MW (11%) by the application of fog cooling system in Ghom and Shahid Rajaie power plants, respectively. The total enhanced power generation in the summer of 2004 was 2970, 1701 and 1340 MWh for the Fars, Ghom and Shahid Rajaie power plants, respectively. The economical studies show that the payback periods are estimated to be around 2 and 3 years for fog and media systems, respectively. This study has shown that both methods are suitable for the dry and hot areas for gas turbine power augmentation. Copyright © 2007 John Wiley & Sons, Ltd. [source] Techniques for phosphopeptide enrichment prior to analysis by mass spectrometryMASS SPECTROMETRY REVIEWS, Issue 1 2010Jamie D. Dunn Abstract Mass spectrometry is the tool of choice to investigate protein phosphorylation, which plays a vital role in cell regulation and diseases such as cancer. However, low abundances of phosphopeptides and low degrees of phosphorylation typically necessitate isolation and concentration of phosphopeptides prior to MS analysis. This review discusses the enrichment of phosphopeptides with immobilized metal affinity chromatography, reversible covalent binding, and metal oxide affinity chromatography. Capture of phosphopeptides on TiO2 seems especially promising in terms of selectivity and recovery, but the success of all methods depends on careful selection of binding, washing, and elution solutions. Enrichment techniques are complementary, such that a combination of methods greatly enhances the number of phosphopeptides isolated from complex samples. Development of a standard series of phosphopeptides in a highly complex mixture of digested proteins would greatly aid the comparison of different enrichment methods. Phosphopeptide binding to magnetic beads and on-plate isolation prior to MALDI-MS are emerging as convenient methods for purification of small (µL) samples. On-plate enrichment can yield >70% recoveries of phosphopeptides in mixtures of a few digested proteins and can avoid sample-handling steps, but this technique is likely limited to relatively simple samples such as immunoprecipitates. With recent advances in enrichment techniques in hand, MS analysis should provide important insights into phosphorylation pathways. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:29,54, 2010 [source] Expression and amplification of Her2, EGFR and cyclin D1 in breast cancer: Immunohistochemistry and chromogenic in situ hybridizationPATHOLOGY INTERNATIONAL, Issue 1 2008Eun Y. Cho Determination of Her2, epidermal growth factor receptor (EGFR) and cyclin D1 status is now of major clinical importance due to the development of molecule-targeting drugs in anticancer therapy. Immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) are the most simple and convenient methods for evaluating gene alterations and their protein consequences. The purpose of the present study was to investigate the status of Her2, EGFR and cyclin D1 on both IHC and CISH in 95 primary breast carcinomas. There was substantial consistency between the IHC and CISH results of Her2 and EGFR, showing fair agreement between protein overexpression and gene amplification. However, cyclin D amplification was not related to protein overexpression. Moreover, there was no correlation between Her2, EGFR and cyclin D1. Her2 protein overexpression and amplification were positively associated with histological grade, nuclear grade and inversely correlated with the expression of estrogen receptor (ER) and progesterone receptor (PR). In ER-negative and postmenopausal patients, EGFR gene amplification was strongly associated with worse recurrence-free survival (P = 0.0087, P = 0.0149, respectively). Overall, the present findings suggest that EGFR gene amplification is important in predicting prognosis and this should be evaluated in breast carcinoma in addition to Her2 status in routine pathological practice. [source] Transition metal catalyzed carbon-silicon bond forming reactions using chlorosilanes promoted by Grignard reagentsTHE CHEMICAL RECORD, Issue 1 2007Jun Terao Abstract New catalytic CSi bond-forming reactions using chlorosilanes are described. These reactions proceed efficiently under mild conditions by the combined use of Grignard reagents and transition metal catalysts, such as Ti, Zr, Ni, and Pd. It is proposed that ate complex intermediates formed by the reaction of transition metals with Grignard reagents play important roles as the active catalytic species. The present study demonstrates the practical use of chlorosilanes in transition metal catalyzed silylation reactions providing convenient methods for allyl- or vinylsilane synthesis. The reaction pathways of these transformations as well as the scope and limitations are discussed. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 57,67; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20101 [source] ChemInform Abstract: Catalytic Enantioselective Mannich-Type Reaction with ,-Phenyl Sulfonyl Acetonitrile.CHEMINFORM, Issue 40 2010Pedro B. Gonzalez Abstract Two convenient methods to prepare enantioenriched ,-unsubstituted ,-amino nitriles are reported. [source] Cobalt- and Nickel-Catalyzed Regio- and Stereoselective Reductive Coupling of Alkynes, Allenes, and Alkenes with AlkenesCHEMISTRY - A EUROPEAN JOURNAL, Issue 35 2008Masilamani Jeganmohan Dr. Abstract Transition-metal-catalyzed coupling of two different CC , components through a metallacycle intermediate is a highly atom economical method to construct CC bonds in organic synthesis. The metal-catalyzed coupling of an alkene and alkyne generally gives an Alder-ene or reductive coupling product. In this article, we focus on the cobalt- and nickel-catalyzed reductive coupling of alkynes, allenes, and alkenes with alkenes. These reductive coupling reactions provide convenient methods for the synthesis of various alkenes, dienes, functionalized alkanes, lactones, lactams, and cyclic alcohols in a highly regio- and stereoselective manner. A chemselective formation of metallacyclopentene intermediate from the two different CC , components and a low-valence metal species plays a key role for the high regio- and stereoselectivity of the catalytic reaction. [source] Measurement of testosterone in the diagnosis of hypogonadism in the ageing maleCLINICAL ENDOCRINOLOGY, Issue 4 2008M. J. Wheeler Summary Many males in their old age demonstrate symptoms consistent with hypogonadism. With the introduction of new and more convenient methods of testosterone replacement treatment of these males is more practical. The diagnosis of hypogonadism in the older male has been controversial with some clinicians suggesting that symptoms should be treated without due reliance on testosterone concentrations. However, most professional bodies have proposed that a low testosterone concentration should be part of the diagnosis. This is, in turn, reliant on the testosterone measurement being reliable and read against an appropriate reference range. This review looks at the factors that can influence the interpretation of testosterone results for the ageing male. [source] | |||||||||||||||||||||||||