Improving the enantioselective bioreduction of aromatic ketones mediated by Aspergillus terreus and Rhizopus oryzae: the role of glycerol as a co-solvent

The improvement of the enzymatic performance of Aspergillus terreus and Rhizopus oryzae in enantioselective bioreductions by using glycerol as a co-solvent has been studied. In the most of the bioreductions, glycerol has demonstrated its potential for improved conversions (up to >99%) and enantioselectivities (up to >99%) when compared to reactions in aqueous or other aqueous-organic media (THF, diethyl ether, toluene, DMSO and acetonitrile). Moreover, high isolated yields of the desired chiral alcohols have been obtained on a preparative scale showing the great potential of this green solvent in biocatalysis. (C) 2009 Elsevier Ltd. All rights reserved.

Lipase-Catalyzed Highly Enantioselective Kinetic Resolution of Boron-Containing Chiral Alcohols

The first application of enzymes as catalysts to obtain optically pure boron compounds is described. The kinetic resolution of boron-containing chiral alcohols via enantioselective transesterification catalyzed by lipases was studied. Aromatic, allylic, and aliphatic secondary alcohols containing a boronate ester or boronic acid group were resolved by lipase from Candida antartica (CALB), and excellent E values (E > 200) and high enantiomeric excesses (up to >99%) of both remaining substrates and acetylated product were obtained.

Lithium butylchalcogenolate induced Michael-aldol tandem sequence: easy and rapid access to highly functionalized organochalcogenides and unsaturated compounds

Lithium ""butylchalcogenolates are generated in situ by reacting the elements (S, Se, and Te) with (n)butyl-lithium at 0 degrees C. Reaction of the lithium alkylchalcogenolates with activated alkenes and aldehydes gives the corresponding aldol adducts. The selenium-containing products give Morita-Baylis-Hillman adducts after the oxidation/elimination of the selenoxide. The whole sequence can be performed in a one-pot procedure. (C) 2009 Elsevier Ltd. All rights reserved.

Stereoselective Nucleophilic Addition of Potassium Alkyltrifluoroborates to Cyclic N-Acyliminium Ions: a Simple and Mild Approach to Chiral 5-Alkyl-pyrrolidin-2-ones

The stereoselective nucleophilic addition of potassium alkyltrifluoroborates to cyclic N-acyliminium ions derived from N-benzyl-3,4,5-triacetoxy-pyrrolidin-2-one, which affords 5-substituted-pyrrolidin-2-ones, is described. The products are obtained in moderate to good yields and are produced predominantly as the anti diastereomer.

Mechanistic study of the addition reaction of TeCl(4) to alkynes: Participation of TeCl(3) centered-radical

The mechanism of the addition reaction of TeCl(4) to alkynes was indirectly established by the detection of TeCl(3) centered radicals using EPR spin trapping, ESI-MS and ESI-MS/MS characterization. Crown Copyright (C) 2008 Published by Elsevier B. V. All rights reserved.

Tellurium in organic synthesis: a new approach to trisubstituted gamma-butyrolactones with trans-trans relative stereochemistry. Total enantioselective synthesis of (-)-Blastmycinolactol, (+)-Blastmycinone, (-)-NFX-2, and (+)-Antimycinone

The total synthesis of (-)-Blastmycinolactol, (+)-Blastmycinone, (-)-NFX-2, and (+)-Antimycinone was accomplished in few steps in high yields and ee, starting from enantiomerically enriched (S)-Z-vinylic hydroxytellurides. (C) 2010 Published by Elsevier Ltd.

Mild and efficient one-pot synthesis of chiral beta-chalcogen amides via 2-oxazoline ring-opening reaction mediated by indium metal

A simple and efficient procedure for the synthesis of beta-seleno and beta-thio amides via the ring-opening reaction of chiral 2-oxazolines in the presence of indium metal has been developed. Features of this method include the following: (i) easily and accessible starting materials; (ii) indium metal is more stable and less expensive then its respective salts; (iii) useful to excellent yields of beta-chalcogen amides derivatives. (C) 2008 Elsevier B. V. All rights reserved.

Catalytic Enantioselective alpha-Arylation of Carbonyl Compounds

Enantioselective creation of benzylic quaternary centers still is a continuous challenge to many synthetic organic chemists. Among the existing methods for installation of this type of center, the direct asymmetric alpha-arylation of carbonyl compounds is very attractive due to the ready availability of the coupling substrates. Herein, we present some new tools to the catalytic asymmetric alpha-arylation of carbonyl compounds that overcame many of the drawbacks posted in previous methods for this type of reaction.

Production of hydrogen by ethanol steam reforming on Co/Al2O3 catalysts: Effect of addition of small quantities of noble metals

The catalytic performance of Co/Al2O3 catalysts promoted with small amounts noble metals (Pt, Pd, Ru, Ir) for steam reforming of ethanol (SRE) has been investigated. The catalysts were characterized by the energy dispersive X-ray, X-ray diffraction, BET surface area, X-ray absorption fine structure and temperature reduction programmed techniques. The results showed that the promoting effect of noble metals included a marked decrease of the reduction temperatures of both Co3O4 and cobalt surface species interacting with the support due to the hydrogen spillover effect, leading to a significant increase of the reducibilities of the promoted catalysts. The better catalytic performance for the ethanol steam reforming at 400 degrees C was obtained for the CoRu/Al2O3 catalyst, which presented an effluent gaseous mixture with the highest H, selectivity and the reasonable low CO formation. (C) 2007 Published by Elsevier B.V.

To achieve safe and respectful maternity care in tertiary level hospitals in Nepal, relatives are a valued addition to the provision of maternity care

Introduction: The White Ribbon Alliance for safe motherhood believes respectful maternity care is the universal right of every childbearing woman. Methods: NHRC in 2012 approved an inquiry of respectful care at facility-based childbirth. Individual-, focus group interviews and content analysis was used for gathering and analysis of data. Findings: The participating women and the SBAs shared similar views, and this was that together the SBAs and relatives ensured the women remained within the comfort and safety zone when giving birth in a tertiary level maternity unit. Conclusion: The SBAs strategy of having relatives provides basic care alongside the provision of medical care by the SBAs is a strategy that Nepal could use to improve the quality of its maternity care without any additional costs. Clinical implication: Prenatal classes might contribute to preparing relatives. Further Research: Further research could evaluate such a strategy in order to determine its effectiveness in reduction of morbidity and mortality.

"Jag tänkte bara 15 + 7 – 6" : En empirisk studie om elevers tolkning av likhetstecknet och sambandet mellan addition och subtraktion

Syftet med denna studie är att undersöka elevers förståelse av likhetstecknet och sambandet mellan addition och subtraktion i årskurs 3 samt deras klasslärares uppfattning av den egna matematikundervisningen, som behandlar addition, subtraktion och likhetstecknet. Studiens syfte besvaras genom följande frågeställningar: Vad kan specifikt utformade matematikuppgifter ge för information om elevers förståelse av likhetstecknet och sambandet mellan addition och subtraktion i årskurs 3? samt Vad tänker en lärare om de resultat som framkommit av elevernas matematikuppgifter? Den empiriska undersökningen har genomförts med en kvantitativ metod, i form av en enkät där elever i årskurs 3 fått lösa speciellt utformade matematikuppgifter och en kvalitativ metod, i form av semi-strukturerad intervju med elevernas lärare. Det resultat som framkommit i undersökningen har analyserats med hjälp av en innehållsanalys. Resultatet visar att alla elever inte har kunskap om att likhetstecknet indikerar ekvivalens mellan höger sida och vänster sida om likhetstecknet, men en majoritet av eleverna har den förståelsen. Det var inte väntat från lärarens sida att fyra elever helt hade missförstått likhetstecknets betydelse. Läraren är medveten om att likhetstecknet kan vara svårt att förstå, men hade förväntat att alla elever skulle klara av att lösa minst matematikuppgifterna med de lägsta talen. Resultatet visar även att nio av sexton elever har förstått sambandet mellan addition och subtraktion. Läraren menar att det sambandet återkommer under hela lågstadiet och därför hade förväntat sig att fler elever sett sambandet. Men samtidigt anser läraren att det är positivt att lite mer än halva gruppen har förstått sambandet mellan addition och subtraktion. Slutligen visar resultatet av studien att missförståelse av likhetstecknet har inverkan på elevers resultat vid uppgifter med öppna utsagor, men inte vid uppgifter där talen på vänster sida om likhetstecknet är lika med ett tal på höger sida om likhetstecknet.

Case studies for contract-based systems

Of the ways in which agent behaviour can be regulated in a multiagent system, electronic contracting – based on explicit representation of different parties' responsibilities, and the agreement of all parties to them – has significant potential for modern industrial applications. Based on this assumption, the CONTRACT project aims to develop and apply electronic contracting and contract-based monitoring and verification techniques in real world applications. This paper presents results from the initial phase of the project, which focused on requirements solicitation and analysis. Specifically, we survey four use cases from diverse industrial applications, examine how they can benefit from an agent-based electronic contracting infrastructure and outline the technical requirements that would be placed on such an infrastructure. We present the designed CONTRACT architecture and describe how it may fulfil these requirements. In addition to motivating our work on the contract-based infrastructure, the paper aims to provide a much needed community resource in terms of use case themselves and to provide a clear commercial context for the development of work on contract-based system.