645 research outputs found

    Aufnahme und Verbleib von Dicyandiamid in Reben

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    Uptake and stability of dicyandiamide in grapevinesDicyandiamide (DCD) is taken up as a molecule by the roots and translocated via the stem to the Jeaves within 24 h . 15 d after omitting 14C - DCD from the nutrient solution, it is still found in the Jeaves together with other compounds showing 14C-activity. Over the whole experimental period a certain amount of DCD is detected in the leaves. DCD thus strongly differs from cyanamide which is metabolized in plants within a few hours

    Aufnahme und Metabolismus von 15N-markiertem Cyanamid durch Rebenstecklinge

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    Uptake and metabolism ofĀ 15N labelled cyanamide by cuttings of grapevine15NĀ labelled cyanamide was taken up from nutrient solution by rooted grapevine cuttings. Precipitable N in shoots or roots contained up to 2/3 of total supplied 15N. Arginine concentrations were higher during cyanamide feeding than in controls and declined to control levels after transfer into cyanamide free nutrient solution. In arginine extracted from shoots and roots after hydrolysis with 6 M HCl and column chromatography, 6-7 % of l5N originating from cyanamide was recovered

    On the Hardness of a New Boron Phase, Orthorhombic {\gamma}-B28

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    Measurements of the hardness of a new high-pressure boron phase, orthorhombic {\gamma}-B28, are reported. According to the data obtained, {\gamma}-B28 has the highest hardness (~50 GPa) of all known crystalline modifications of boron

    Online Mendelian Inheritance in Man (OMIM), a knowledgebase of human genes and genetic disorders

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    Online Mendelian Inheritance in Man (OMIMā„¢) is a comprehensive, authoritative and timely knowledgebase of human genes and genetic disorders compiled to support human genetics research and education and the practice of clinical genetics. Started by Dr Victor A. McKusick as the definitive reference Mendelian Inheritance in Man, OMIM (http://www.ncbi.nlm.nih.gov/omim/) is now distributed electronically by the National Center for Biotechnology Information, where it is integrated with the Entrez suite of databases. Derived from the biomedical literature, OMIM is written and edited at Johns Hopkins University with input from scientists and physicians around the world. Each OMIM entry has a full-text summary of a genetically determined phenotype and/or gene and has numerous links to other genetic databases such as DNA and protein sequence, PubMed references, general and locus-specific mutation databases, HUGO nomenclature, MapViewer, GeneTests, patient support groups and many others. OMIM is an easy and straightforward portal to the burgeoning information in human genetics

    The Mouse Genome Database (MGD): comprehensive resource for genetics and genomics of the laboratory mouse

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    The Mouse Genome Database (MGD, http://www.informatics.jax.org) is the international community resource for integrated genetic, genomic and biological data about the laboratory mouse. Data in MGD are obtained through loads from major data providers and experimental consortia, electronic submissions from laboratories and from the biomedical literature. MGD maintains a comprehensive, unified, non-redundant catalog of mouse genome features generated by distilling gene predictions from NCBI, Ensembl and VEGA. MGD serves as the authoritative source for the nomenclature of mouse genes, mutations, alleles and strains. MGD is the primary source for evidence-supported functional annotations for mouse genes and gene products using the Gene Ontology (GO). MGD provides full annotation of phenotypes and human disease associations for mouse models (genotypes) using terms from the Mammalian Phenotype Ontology and disease names from the Online Mendelian Inheritance in Man (OMIM) resource. MGD is freely accessible online through our website, where users can browse and search interactively, access data in bulk using Batch Query or BioMart, download data files or use our web services Application Programming Interface (API). Improvements to MGD include expanded genome feature classifications, inclusion of new mutant allele sets and phenotype associations and extensions of GO to include new relationships and a new stream of annotations via phylogenetic-based approaches

    Automated validation of genetic variants from large databases: ensuring that variant references refer to the same genomic locations

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    Summary: Accurate annotations of genomic variants are necessary to achieve full-genome clinical interpretations that are scientifically sound and medically relevant. Many disease associations, especially those reported before the completion of the HGP, are limited in applicability because of potential inconsistencies with our current standards for genomic coordinates, nomenclature and gene structure. In an effort to validate and link variants from the medical genetics literature to an unambiguous reference for each variant, we developed a software pipeline and reviewed 68 641 single amino acid mutations from Online Mendelian Inheritance in Man (OMIM), Human Gene Mutation Database (HGMD) and dbSNP. The frequency of unresolved mutation annotations varied widely among the databases, ranging from 4 to 23%. A taxonomy of primary causes for unresolved mutations was produced

    The high-pressure phase of boron, {\gamma}-B28: disputes and conclusions of 5 years after discovery

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    {\gamma}-B28 is a recently established high-pressure phase of boron. Its structure consists of icosahedral B12 clusters and B2 dumbbells in a NaCl-type arrangement (B2){\delta}+(B12){\delta}- and displays a significant charge transfer {\delta}~0.5- 0.6. The discovery of this phase proved essential for the understanding and construction of the phase diagram of boron. {\gamma}-B28 was first experimentally obtained as a pure boron allotrope in early 2004 and its structure was discovered in 2006. This paper reviews recent results and in particular deals with the contentious issues related to the equation of state, hardness, putative isostructural phase transformation at ~40 GPa, and debates on the nature of chemical bonding in this phase. Our analysis confirms that (a) calculations based on density functional theory give an accurate description of its equation of state, (b) the reported isostructural phase transformation in {\gamma}-B28 is an artifact rather than a fact, (c) the best estimate of hardness of this phase is 50 GPa, (d) chemical bonding in this phase has a significant degree of ionicity. Apart from presenting an overview of previous results within a consistent view grounded in experiment, thermodynamics and quantum mechanics, we present new results on Bader charges in {\gamma}-B28 using different levels of quantum-mechanical theory (GGA, exact exchange, and HSE06 hybrid functional), and show that the earlier conclusion about significant degree of partial ionicity in this phase is very robust
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