364 research outputs found

    Darstellung und Strukturen von Chlorostannaten(II). - II : Neue Chlorostannate(II) von zweiwertigen Kationen

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    Metall(II)-chloride MCl2 (M Mn, Fe, Co, Ni, Mg) setzen sich mit SnCl2 in Acetonitril im Molverhältnis 1:2 zu Verbindungen [M(CH3CN)6](SnCl3)2 · 2CH3CN (1a-e) bzw. im Molverhältnis 1:3 zu Verbindungen [M(CH3CN)6](SnCl3)(SnCl3) · l/2 CH3CN (2a-e) um. Die Verbindung [Co(CH3CN)6](SnCl3)2 · 2CH3CN (1a) kristallisiert monoklin, Raumgruppe P21/n, Z = 2 (a = 8,401(7), b = 16,30(2), c = 12,90(1) Å, = 107,00(8)°); die Verbindungen 1b-e sind hierzu isotyp. In 1a treten die SnCl3--Ionen zu Paaren zusammen. Die Verbindung [Ni(CH3CN)6](Sn2Cl5)(SnCl3) · 1/2 CH3CN (2a) kristallisiert im triklinen Kristallsystem, Raumgruppe P, Z = 2 (a = 8,69(1), b = 12,91(2), c = 16,81(1)Å, = 71,0(1)°, = 89,9(l)°, = 71,4(1)°); die Verbindungen 2b-e sind zu 2a isotyp. In 2a sind je 2 SnCl3-- und Sn2Cl5--Ionen über schwache SnCl-Kontakte zu anionischen Aggregaten der Form [(Sn2Cl5)2(SnCl3)2]4- verknüpft

    Darstellung und Strukturen von Chlorostannaten(II). - I : Neue Trichlorostannate(II) einwertiger Kationen

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    KSnCl3 · 1/2 CH3CN wird durch Umkristallisieren von KSnCl3 aus Acetonitril erhalten. Die Verbindung kristallisiert monoklin, Raumgruppe P21/c (a = 4,525(6), b = 20,34(2), c = 8,061(7) Å, = 90,93(9)°). Durch Umsetzung von CuCl mit einer äquimolaren Menge an SnCl2 in Acetonitril erhält man [Cu(CH3CN)3]SnCl3 das in der monoklinen Raumgruppe P21/n kristallisiert (a = 7,984(9), b = 20,77(2), c = 8,34(2) Å = 101,6(1)°). Während in KSnCl3 · 1/2 CH3CN eine dreidimensionale Verknüpfung der SnCl3minus;-lonen vorliegt, an der auch die Kaliumionen beteiligt sind, sind die Trichlorostannationen in [Cu(CH3CN)3]SnCl3 durch SnCl-Brücken zu eindimensionalen Ketten verknüpft

    Culture and establishment of self-renewing human and mouse adult liver and pancreas 3D organoids and their genetic manipulation.

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    Adult somatic tissues have proven difficult to expand in vitro, largely because of the complexity of recreating appropriate environmental signals in culture. We have overcome this problem recently and developed culture conditions for adult stem cells that allow the long-term expansion of adult primary tissues from small intestine, stomach, liver and pancreas into self-assembling 3D structures that we have termed 'organoids'. We provide a detailed protocol that describes how to grow adult mouse and human liver and pancreas organoids, from cell isolation and long-term expansion to genetic manipulation in vitro. Liver and pancreas cells grow in a gel-based extracellular matrix (ECM) and a defined medium. The cells can self-organize into organoids that self-renew in vitro while retaining their tissue-of-origin commitment, genetic stability and potential to differentiate into functional cells in vitro (hepatocytes) and in vivo (hepatocytes and endocrine cells). Genetic modification of these organoids opens up avenues for the manipulation of adult stem cells in vitro, which could facilitate the study of human biology and allow gene correction for regenerative medicine purposes. The complete protocol takes 1-4 weeks to generate self-renewing 3D organoids and to perform genetic manipulation experiments. Personnel with basic scientific training can conduct this protocol.LB is supported by an EMBO Postdoctoral fellowship (EMBO ALTF 794-2014). CH is supported by a Cambridge Stem Cell Institute Seed Fund award and the Herchel Smith Fund. BK is supported by a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society. MH is a Wellcome Trust Sir Henry Dale Fellow and is jointly funded by the Wellcome Trust and the Royal Society (104151/Z/14/Z).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nprot.2016.097

    Neurogenin3 phosphorylation controls reprogramming efficiency of pancreatic ductal organoids into endocrine cells

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    β-cell replacement has been proposed as an effective treatment for some forms of diabetes, and in vitro methods for β-cell generation are being extensively explored. A potential source of β-cells comes from fate conversion of exocrine pancreatic cells into the endocrine lineage, by overexpression of three regulators of pancreatic endocrine formation and β-cell identity, Ngn3, Pdx1 and MafA. Pancreatic ductal organoid cultures have recently been developed that can be expanded indefinitely, while maintaining the potential to differentiate into the endocrine lineage. Here, using mouse pancreatic ductal organoids, we see that co-expression of Ngn3, Pdx1 and MafA are required and sufficient to generate cells that express insulin and resemble β-cells transcriptome-wide. Efficiency of β-like cell generation can be significantly enhanced by preventing phosphorylation of Ngn3 protein and further augmented by conditions promoting differentiation. Taken together, our new findings underline the potential of ductal organoid cultures as a source material for generation of β-like cells and demonstrate that post-translational regulation of reprogramming factors can be exploited to enhance β-cell generation

    Defining Lineage Potential and Fate Behavior of Precursors during Pancreas Development

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    Pancreas development involves a coordinated process in which an early phase of cell segregation is followed by a longer phase of lineage restriction, expansion, and tissue remodeling. By combining clonal tracing and whole-mount reconstruction with proliferation kinetics and single-cell transcriptional profiling, we define the functional basis of pancreas morphogenesis. We show that the large-scale organization of mouse pancreas can be traced to the activity of self-renewing precursors positioned at the termini of growing ducts, which act collectively to drive serial rounds of stochastic ductal bifurcation balanced by termination. During this phase of branching morphogenesis, multipotent precursors become progressively fate-restricted, giving rise to self-renewing acinar-committed precursors that are conveyed with growing ducts, as well as ductal progenitors that expand the trailing ducts and give rise to delaminating endocrine cells. These findings define quantitatively how the functional behavior and lineage progression of precursor pools determine the large-scale patterning of pancreatic sub-compartments

    Staging of uterine cervical cancer with MRI: guidelines of the european society of urogenital radiology

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    Objective: To design clear guidelines for the staging and follow-up of patients with uterine cervical cancer, and to provide the radiologist with a framework for use in multidisciplinary conferences. Methods: Guidelines for uterine cervical cancer staging and follow-up were defined by the female imaging subcommittee of the ESUR (European Society of Urogenital Radiology) based on the expert consensus of imaging protocols of 11 leading institutions and a critical review of the literature. Results: The results indicated that high field Magnetic Resonance Imaging (MRI) should include at least two T2-weighted sequences in sagittal, axial oblique or coronal obliqu

    Психолого-педагогічний аналіз комунікативної діяльності педагога

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    У статті комунікативна діяльність розглядається як структурно-функціональний компонент педагогічної діяльності вчителя, аналізується взаємозв’язок педагогічної й комунікативної задач, розкриваються особливості процесу вирішення комунікативно-педагогічної задачі.In the article communicative activities are considered as structural and functional components of the teacher’s pedagogical activities, the relationship of pedagogical and communicative tasks are analyzed, features of the solution process communicative and pedagogical tasks are revealed

    RNF43/ZNRF3 loss predisposes to hepatocellular-carcinoma by impairing liver regeneration and altering the liver lipid metabolic ground-state

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    RNF43/ZNRF3 negatively regulate WNT signalling. Both genes are mutated in several types of cancers, however, their contribution to liver disease is unknown. Here we describe that hepatocyte-specific loss of Rnf43/Znrf3 results in steatohepatitis and in increase in unsaturated lipids, in the absence of dietary fat supplementation. Upon injury, Rnf43/Znrf3 deletion results in defective hepatocyte regeneration and liver cancer, caused by an imbalance between differentiation/proliferation. Using hepatocyte-, hepatoblast- and ductal cell-derived organoids we demonstrate that the differentiation defects and lipid alterations are, in part, cell-autonomous. Interestingly, ZNRF3 mutant liver cancer patients present poorer prognosis, altered hepatic lipid metabolism and steatohepatitis/NASH signatures. Our results imply that RNF43/ZNRF3 predispose to liver cancer by controlling the proliferative/differentiation and lipid metabolic state of hepatocytes. Both mechanisms combined facilitate the progression towards malignancy. Our findings might aid on the management of those RNF43/ZNRF3 mutated individuals at risk of developing fatty liver and/or liver cancer

    Workplace experience of radiographers: impact of structural and interpersonal interventions

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    PURPOSE: Within the framework of organisational development, an assessment of the workplace experience of radiographers (RGs) was conducted. The aims of this study were to develop structural and interpersonal interventions and to prove their effectiveness and feasibility. METHODS: A questionnaire consisting of work-related factors, e.g. time management and communication, and two validated instruments (Workplace Analysis Questionnaire, Effort-Reward Imbalance Scale) was distributed to all RGs (n = 33) at baseline (T1). Interventions were implemented and a follow-up survey (T2) was performed 18 months after the initial assessment. RESULTS: At T1, areas with highest dissatisfaction were communication and time management for ambulant patients (bad/very bad, 57% each). The interventions addressed adaptation of work plans, coaching in developing interpersonal and team leadership skills, and regular team meetings. The follow-up survey (T2) showed significantly improved communication and cooperation within the team and improved qualification opportunities, whereas no significant changes could be identified in time management and in the workplace-related scales 'effort' expended at work and 'reward' received in return for the effort. CONCLUSION: Motivating workplace experience is important for high-level service quality and for attracting well-qualified radiographers to work at a place and to stay in the team for a longer period

    Epigenetic remodelling licences adult cholangiocytes for organoid formation and liver regeneration.

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    Following severe or chronic liver injury, adult ductal cells (cholangiocytes) contribute to regeneration by restoring both hepatocytes and cholangiocytes. We recently showed that ductal cells clonally expand as self-renewing liver organoids that retain their differentiation capacity into both hepatocytes and ductal cells. However, the molecular mechanisms by which adult ductal-committed cells acquire cellular plasticity, initiate organoids and regenerate the damaged tissue remain largely unknown. Here, we describe that ductal cells undergo a transient, genome-wide, remodelling of their transcriptome and epigenome during organoid initiation and in vivo following tissue damage. TET1-mediated hydroxymethylation licences differentiated ductal cells to initiate organoids and activate the regenerative programme through the transcriptional regulation of stem-cell genes and regenerative pathways including the YAP-Hippo signalling. Our results argue in favour of the remodelling of genomic methylome/hydroxymethylome landscapes as a general mechanism by which differentiated cells exit a committed state in response to tissue damage.RCUK Cancer Research UK ERC H2020 Wellcome Trus
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