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Now showing items 97 - 112 of 131643

  • Activation of E–Cl bonds (E = C, Si, Ge and Sn) by a C,N-chelated stannylene

    Padělková, Zdeňka   ?vec, Petr   Pejchal, Vladimír   R??i?ka, Ale?  

    The reactivity of (L-CN)(2)Sn (1) (where L-CN is 2-(N,N-dimethylaminomethyl)phenyl-) towards various substrates containing E-Cl bond(s) has been studied (E = C, Si, Ge and Sn). Alkyl chlorides like chloroform or dichloromethane reacts with 1 to form (L-CN)(2)SnCl2 and unidentified by-products in poor yields. The reaction of benzoyl chloride with 1 at low temperature yielded a thermally unstable product (L-CN)(2)Sn(Cl)-C(=O)Ph (2) which was isolated and characterized by both multinuclear NMR spectroscopy and X-ray diffraction techniques. The vicinity of the central tin atom in 2 reveals trigonal bipyramidal geometry. Attempts to oxidize 2 by dioxygen to give the corresponding organotin(IV) benzoate failed. On the other hand, the reaction of the in situ prepared (L-CN)(2)Sn=O (synthesized by the reaction of 1 with dioxygen) with PhCOCl resulted in the formation of the desired organotin(IV) benzoate (L-CN)(2)Sn(Cl)C(=O) OPh (3). The reaction of 1 with Ph3GeCl yielded triphenylgermyl-substituted diorganotin(IV) chloride (L-CN)(2)Sn(Cl)-GePh3 (4) which subsequently gave mixed diorganotin(IV) chloride-oxide [(L-CN)(2)SnCl](2)O (5) upon loss of the GePh3 moiety in the air. When the same reaction was carried out in benzene instead of chloroform a unique [Ph3Ge](4)[Sn6O8] cluster (6) was obtained. Similarly, the reaction of 1 with Ph3SiCl provided triphenylsilyl-substituted diorganotin(IV) chloride (L-CN)(2)Sn(Cl)SiPh3 (7) which was then oxidized to (L-CN)(2)Sn(Cl)-OSiPh3 (8). The unprecedented reaction of 1 with (n-Bu)(3)SnCl provided the distannane (L-CN)(2)Sn(Cl)SnBu3 (9) which could be oxidized by dioxygen to a distannoxane (L-CN)(2)Sn(Cl)OSnBu3 (10). In addition, the solid-state structures of 3, 5, 6 and 8 were determined by the X-ray diffraction techniques.
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  • Interobserver agreement of C and E coding in CT colonography

    Vincent Leung   Nicola Cook   Stephen Sammut   Paul Clarke   Ingrid Britton  

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  • Dimerization-driven degradation of C. elegans and human E proteins.

    Sallee, Maria D   Greenwald, Iva  

    E proteins are conserved regulators of growth and development. We show that the Caenorhabditis elegans E-protein helix-loop-helix-2 (HLH-2) functions as a homodimer in directing development and function of the anchor cell (AC) of the gonad, the critical organizer of uterine and vulval development. Our structure-function analysis of HLH-2 indicates that dimerization drives its degradation in other uterine cells (ventral uterine precursor cells [VUs]) that initially have potential to be the AC. We also provide evidence that this mode of dimerization-driven down-regulation can target other basic HLH (bHLH) dimers as well. Remarkably, human E proteins can functionally substitute for C. elegans HLH-2 in regulating AC development and also display dimerization-dependent degradation in VUs. Our results suggest that dimerization-driven regulation of bHLH protein stability may be a conserved mechanism for differential regulation in specific cell contexts. =C2=A9 2015 Sallee and Greenwald; Published by Cold Spring Harbor Laboratory Press.
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  • Berichtigung: Totalsynthese von Coralloidolid A, B, C und E

    Kimbrough, Thomas J.; Roethle, Paul A.; Mayer, Peter; Trauner, Dirk  

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  • Diastereoselective Synthesis of Dibenzo[c,e]azepines

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  • 银屑病抗‐GM‐CSF 治疗

    Papp, K.A.; Gooderham, M.; Jenkins, R.; Vender, R.; Szepietowski, J.C.; Wagner, T.; Hunt, B.; Souberbielle, B.  

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  • Berichtigung: Totalsynthese von Coralloidolid A, B, C und E

    Kimbrough, Thomas?J.   Roethle, Paul?A.   Mayer, Peter   Trauner, Dirk  

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  • Diastereoselective Synthesis of Dibenzo[c,e]azepines

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  • C=C3=A9sar Aira e o Diario de la hepatitis

    Dassie, Franklin Alves  

    Abstract Throughout the work of the argentinian writer C=C3=A9sar Aira, the debate over the production of senses in the present via the procedures appears as a possibility to escape the project and its unproductive relationship with the future. This paper intends to discuss how Aira manages the procedures, calling upon the notions of abandonment and sickness, and how that is articulated with modernity and contemporaneity in the attempt to come up with an political-aesthetic alternative to the Latin-American scenery.=09
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  • Exploring completeness in clinical data research networks with DQ(e)-c

    Estiri, Hossein   Stephens, Kari A.   Klann, Jeffrey G.   Murphy, Shawn N.  

    To provide an open source, interoperable, and scalable data quality assessment tool for evaluation and visualization of completeness and conformance in electronic health record (EHR) data repositories. This article describes the tool's design and architecture and gives an overview of its outputs using a sample dataset of 200 000 randomly selected patient records with an encounter since January 1, 2010, extracted from the Research Patient Data Registry (RPDR) at Partners HealthCare. All the code and instructions to run the tool and interpret its results are provided in the Supplementary Appendix. DQ(e)-c produces a web-based report that summarizes data completeness and conformance in a given EHR data repository through descriptive graphics and tables. Results from running the tool on the sample RPDR data are organized into 4 sections: load and test details, completeness test, data model conformance test, and test of missingness in key clinical indicators. Open science, interoperability across major clinical informatics platforms, and scalability to large databases are key design considerations for DQ(e)-c. Iterative implementation of the tool across different institutions directed us to improve the scalability and interoperability of the tool and find ways to facilitate local setup. EHR data quality assessment has been hampered by implementation of ad hoc processes. The architecture and implementation of DQ(e)-c offer valuable insights for developing reproducible and scalable data science tools to assess, manage, and process data in clinical data repositories.
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  • Seroprevalence of hepatitis E virus in chronic hepatitis C in Brazil

    Bricks, Guilherme   Senise, Jorge Figueiredo   Pott Junior, Henrique   Grandi, Giuliano   Passarini, Amanda   Caldeira, Debora Bellini   Carnauba Junior, Dimas   Bonilha de Moraes, Hamilton Antonio   Hernandes Granato, Celso Franscisco   Castelo, Adauto  

    Background and aims: Hepatitis E virus infection in patients with underlying chronic liver disease is associated with liver decompensation and increased lethality. The seroprevalence of hepatitis E virus in patients with chronic hepatitis C in Brazil is unknown. This study aims to estimate the seroprevalence of hepatitis E virus in patients with chronic hepatitis C and to describe associated risk factors. Methods: A total of 618 patients chronically infected with hepatitis C virus from three reference centers of Sao Paulo, Brazil were included. Presence of anti-HEV IgG was assessed by enzyme-linked immunosorbent assay (WANTAI HEV-IgG ELISA). Results: Out of the 618 patients tested, 10.2% turned out positive for anti-HEV IgG (95% CI 8.0-12.8%). Higher seroprevalence was found independently associated with age over 60 years (OR=3D 2.04; p =3D0.02) and previous contact with pigs (OR =3D1.99; p =3D 0.03). Conclusions: Patients with chronic hepatitis C are under risk of hepatitis E virus superinfection in Sao Paulo. Contact with pigs is a risk factor for the infection, suggesting a possible zoonosis with oral transmission. (C) 2018 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda.
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  • Stemona-amines C–E, new alkaloids from Stemona tuberosa

    Hitotsuyanagi, Yukio   Shigemori, Genta   Fukaya, Haruhiko   Hikita, Maho   Zhu, Shu   Komatsu, Katsuko   Takeya, Koichi  

    Three new alkaloids, stemona-amines C-E, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structures of stemona-amines C and D were determined by X-ray crystallography and that of stemona-amine E was determined by interpretation of spectroscopic data. The absolute structures of stemona-amines C and D were established by VCD spectroscopy. (C) 2013 Elsevier Ltd. All rights reserved.
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  • Synthesis of melicodenines C, D and E

    Harish Hollaa   Ian D. Jenkinsa   Juliette E. Nevea   Rebecca H. Pouwera   Ngoc Phama   Simon J. Teagueb   Ronald J. Quinna  

    A synthesis of the unusual cyclobutane-quinolinone alkaloids melicodenines C, D and E by intermolecular [2+2] cycloaddition is described.
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  • Synthesis of melicodenines C, D and E

    Holla, Harish   Jenkins, Ian D.   Neve, Juliette E.   Pouwer, Rebecca H.   Pham, Ngoc   Teague, Simon J.   Quinn, Ronald J.  

    A synthesis of the unusual cyclobutane-quinolinone alkaloids melicodenines C, D and E by intermolecular [2+2] cycloaddition is described. (C) 2012 Elsevier Ltd. All rights reserved.
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  • Yu-Ray Chen, M.D., and Léonard Bergeron, M.D., C.M., M.Sc., F.R.C.S.(C)

    Hollier, Larry  

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  • Organizing the complete works of C. P. E. Bach

    Corneilson   P.  

    Carl Philipp Emanuel Bach: The Complete Works, an editorial and publishing project of The Packard Humanities Institute, began planning the critical edition in the late 1990s and published its first volumes in 2005. One of the principal problems of the Edition is how to organize more than a thousand works, ranging from short keyboard pieces and songs to major oratorios, cantatas and Passions. C. P. E. Bach, like most of his contemporaries, frequently borrowed music from himself or other composers and also revised his works for different media. The contents of volumes have changed as new discoveries are made, especially the recovery of the Sing-Akademie archive, which was inaccessible from 1943 until 1999.
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