Improved Success of Phenotype Prediction of the Human Immunodeficiency Virus Type 1 from Envelope Variable Loop 3 Sequence Using Neural Networks

We have assembled two sets of HIV-1 V3 sequences with defined epidemiologic relationships associated with experimentally determined coreceptor usage or MT-2 cell tropism. These data sets were used for three purposes. First, they were employed to test existing methods for predicting coreceptor usage and MT-2 cell tropism. Of these methods, the presence of one basic amino acid at position 11 or 25 proved to be most reliable for both phenotypic classifications, although its predictive power for the X4 phenotype was less than 50%. Second, we used the sequence sets to train neural networks to infer coreceptor usage from V3 genotype with better success than the best available motif-based method, and with a predictive power equal to that of the best motif-based method for MT-2 cell tropism. Third, we used the sequence sets to reexamine patterns of variability associated with the different phenotypes, and we showed that the phenotype-associated sequence patterns could be reproduced from large sets of V3 sequences using phenotypes predicted by the trained neural network

Enzymatic esterification of lactones in aqueous buffer

Opening lactones with alcohols to yield esters can traditionally be achieved by acid or base catalysis. The produced esters are intermediates for a vast variety of reactions [1] and can also be used for polymerization reactions like for polycaprolactone. Recently a biocatalytic cascade was reported for the transformation of cyclohexanol to the nylon-6 monomer [2]. A key step was the in-situ capping strategy of the carboxylic functionality by opening ε-caprolactone (1a) with methanol to methyl-6-hydroxyhexanoate (1b) employing a crude preparation of horse liver esterase (HLE). The conversion was performed in aqueous buffer in the presence of 10% v/v methanol. Please click Additional Files below to see the full abstract

Goethes Farbenlehre im Kontext einer zeitgemäßen Didaktik für Schule und Erwachsenenbildung

Goethes Farbenlehre als Motivation für interdisziplinäre Ansätze und Verbindungen zwischen einzelnen Fachdiszipline

Controlling stereoselectivity by enzymatic and chemical means to access enantiomerically pure (1S,3R)-1-benzyl-2,3-dimethyl-1,2,3,4-tetrahydroisoquinoline derivatives

A chemoenzymatic strategy for the synthesis of enantiomerically pure novel alkaloids (1S,3R)- 1-benzyl-2,3-dimethyl-1,2,3,4-tetrahydroisoquinolines is presented. The key steps are the biocatalytic stereoselective reductive amination of substituted 1-phenylpropan-2-one derivatives to yield chiral amines employing microbial x-transaminases, and the diastereoselective reduction of a Bischler– Napieralski imine intermediate by catalytic hydrogenation in the presence of palladium on charcoal, leading exclusively to the desired cis-isomerFil: Orden, Alejandro Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; Argentina;Fil: Schrittwieser, Joerg H.. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria;Fil: Resch, Verena. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria;Fil: Mutti, Francesco G.. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria;Fil: Kroutil, Wolfgang. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria

Virus variation resources at the National Center for Biotechnology Information: dengue virus

<p>Abstract</p> <p>Background</p> <p>There is an increasing number of complete and incomplete virus genome sequences available in public databases. This large body of sequence data harbors information about epidemiology, phylogeny, and virulence. Several specialized databases, such as the NCBI Influenza Virus Resource or the Los Alamos HIV database, offer sophisticated query interfaces along with integrated exploratory data analysis tools for individual virus species to facilitate extracting this information. Thus far, there has not been a comprehensive database for dengue virus, a significant public health threat.</p> <p>Results</p> <p>We have created an integrated web resource for dengue virus. The technology developed for the NCBI Influenza Virus Resource has been extended to process non-segmented dengue virus genomes. In order to allow efficient processing of the dengue genome, which is large in comparison with individual influenza segments, we developed an offline pre-alignment procedure which generates a multiple sequence alignment of all dengue sequences. The pre-calculated alignment is then used to rapidly create alignments of sequence subsets in response to user queries. This improvement in technology will also facilitate the incorporation of additional virus species in the future. The set of virus-specific databases at NCBI, which will be referred to as Virus Variation Resources (VVR), allow users to build complex queries against virus-specific databases and then apply exploratory data analysis tools to the results. The metadata is automatically collected where possible, and extended with data extracted from the literature.</p> <p>Conclusion</p> <p>The NCBI Dengue Virus Resource integrates dengue sequence information with relevant metadata (sample collection time and location, disease severity, serotype, sequenced genome region) and facilitates retrieval and preliminary analysis of dengue sequences using integrated web analysis and visualization tools.</p

Performance of international medical students in psychosocial medicine

Background: Particularly at the beginning of their studies, international medical students face a number of language-related, social and intercultural challenges. Thus, they perform poorer than their local counterparts in written and oral examinations as well as in Objective Structured Clinical Examinations (OSCEs) in the fields of internal medicine and surgery. It is still unknown how international students perform in an OSCE in the field of psychosocial medicine compared to their local fellow students. Methods: All students (N = 1033) taking the OSCE in the field of psychosocial medicine and an accompanying written examination in their eighth or ninth semester between 2012 and 2015 were included in the analysis. The OSCE consisted of four different stations, in which students had to perform and manage a patient encounter with simulated patients suffering from 1) post-traumatic stress disorder, 2) schizophrenia, 3) borderline personality disorder and 4) either suicidal tendency or dementia. Students were evaluated by trained lecturers using global checklists assessing specific professional domains, namely building a relationship with the patient, conversational skills, anamnesis, as well as psychopathological findings and decision-making. Results: International medical students scored significantly poorer than their local peers (p < .001; η2 = .042). Within the specific professional domains assessed, they showed poorer scores, with differences in conversational skills showing the highest effect (p < .001; η2 = .053). No differences emerged within the multiple-choice examination (p = .127). Conclusion: International students showed poorer results in clinical-practical exams in the field of psychosocial medicine, with conversational skills yielding the poorest scores. However, regarding factual and practical knowledge examined via a multiple-choice test, no differences emerged between international and local students. These findings have decisive implications for relationship building in the doctor-patient relationship