757 research outputs found

    Dobivanje galne kiseline iz domaćih taninskih ekstrakata

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    U ovom radu proucavali smo. metode dobivanja galne kiseline iz domacih taninskih ekstrakata. Ponajprije su odredeni optimalni uvjeti za dobivanje galne kiseline hidrolizom u alkalnoj i kiseloj sredini. U tu svrhu upotrebili smo kod pokusa acidum tannicum kao standardnu galotaninsku sirovinu. Dobiveni eksperimentalni podaci posluiili su nam za izradivanje postupka u svrhu dobivanja galne kiseline iz domacih taninskih ekstrakata

    Dobivanje galne kiseline iz domaćih taninskih ekstrakata

    Get PDF
    U ovom radu proucavali smo. metode dobivanja galne kiseline iz domacih taninskih ekstrakata. Ponajprije su odredeni optimalni uvjeti za dobivanje galne kiseline hidrolizom u alkalnoj i kiseloj sredini. U tu svrhu upotrebili smo kod pokusa acidum tannicum kao standardnu galotaninsku sirovinu. Dobiveni eksperimentalni podaci posluiili su nam za izradivanje postupka u svrhu dobivanja galne kiseline iz domacih taninskih ekstrakata

    Molecular Signatures of Quiescent, Mobilized and Leukemia-Initiating Hematopoietic Stem Cells

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    Hematopoietic stem cells (HSC) are rare, multipotent cells capable of generating all specialized cells of the blood system. Appropriate regulation of HSC quiescence is thought to be crucial to maintain their lifelong function; however, the molecular pathways controlling stem cell quiescence remain poorly characterized. Likewise, the molecular events driving leukemogenesis remain elusive. In this study, we compare the gene expression profiles of steady-state bone marrow HSC to non-self-renewing multipotent progenitors; to HSC treated with mobilizing drugs that expand the HSC pool and induce egress from the marrow; and to leukemic HSC in a mouse model of chronic myelogenous leukemia. By intersecting the resulting lists of differentially regulated genes we identify a subset of molecules that are downregulated in all three circumstances, and thus may be particularly important for the maintenance and function of normal, quiescent HSC. These results identify potential key regulators of HSC and give insights into the clinically important processes of HSC mobilization for transplantation and leukemic development from cancer stem cells

    Differential Expression of Novel Potential Regulators in Hematopoietic Stem Cells

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    The hematopoietic system is an invaluable model both for understanding basic developmental biology and for developing clinically relevant cell therapies. Using highly purified cells and rigorous microarray analysis we have compared the expression pattern of three of the most primitive hematopoietic subpopulations in adult mouse bone marrow: long-term hematopoietic stem cells (HSC), short-term HSC, and multipotent progenitors. All three populations are capable of differentiating into a spectrum of mature blood cells, but differ in their self-renewal and proliferative capacity. We identified numerous novel potential regulators of HSC self-renewal and proliferation that were differentially expressed between these closely related cell populations. Many of the differentially expressed transcripts fit into pathways and protein complexes not previously identified in HSC, providing evidence for new HSC regulatory units. Extending these observations to the protein level, we demonstrate expression of several of the corresponding proteins, which provide novel surface markers for HSC. We discuss the implications of our findings for HSC biology. In particular, our data suggest that cellā€“cell and cellā€“matrix interactions are major regulators of long-term HSC, and that HSC themselves play important roles in regulating their immediate microenvironment

    Mobility Disability in Older Adults: At the Intersection of People and Places

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    Mobility disability is associated with poor lower body function among older adults. This study examines whether specific types of neighborhood characteristics moderate that association

    Automatic alignment of stacks of filament data

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    We present a fast and robust method for the alignment of image stacks containing filamentous structures. Such stacks are usually obtained by physical sectioning a specimen, followed by an optical sectioning of each slice. For reconstruction, the filaments have to be traced and the sub-volumes aligned. Our algorithm takes traced filaments as input and matches their endpoints to find the optimal transform. We show that our method is able to quickly and accurately align sub-volumes containing neuronal processes, acquired using brightfield microscopy. Our method also makes it possible to align traced microtubuli, obtained from electron tomography data, which are extremely difficult to align manually

    SynBlast: Assisting the analysis of conserved synteny information

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    <p>Abstract</p> <p>Motivation</p> <p>In the last years more than 20 vertebrate genomes have been sequenced, and the rate at which genomic DNA information becomes available is rapidly accelerating. Gene duplication and gene loss events inherently limit the accuracy of orthology detection based on sequence similarity alone. Fully automated methods for orthology annotation do exist but often fail to identify individual members in cases of large gene families, or to distinguish missing data from traceable gene losses. This situation can be improved in many cases by including conserved synteny information.</p> <p>Results</p> <p>Here we present the <monospace>SynBlast</monospace> pipeline that is designed to construct and evaluate local synteny information. <monospace>SynBlast</monospace> uses the genomic region around a focal reference gene to retrieve candidates for homologous regions from a collection of target genomes and ranks them in accord with the available evidence for homology. The pipeline is intended as a tool to aid high quality manual annotation in particular in those cases where automatic procedures fail. We demonstrate how <monospace>SynBlast</monospace> is applied to retrieving orthologous and paralogous clusters using the vertebrate <it>Hox </it>and <it>ParaHox </it>clusters as examples.</p> <p>Software</p> <p>The <monospace>SynBlast</monospace> package written in <monospace>Perl</monospace> is available under the GNU General Public License at <url>http://www.bioinf.uni-leipzig.de/Software/SynBlast/</url>.</p
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