1,931 research outputs found

    HIV Self-testing and the Missing Linkage

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    Rochelle Walensky and Ingrid Bassett discuss new research in <I>PLoS Medicine</I> that assessed the feasibility of home-based oral HIV self-testing in Malawi, and suggest that linkage to care must be demonstrated before the success of oral self-testing can be determined

    Dithio- and Diselenophosphinate Thorium(IV) and Uranium(IV) complexes:molecular and electronic structure, spectroscopy, and transmetalation reactivity

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    We report a comparison of the molecular and electronic structures of dithio- and diselenophosphinate, (E2PR2)1– (E = S, Se; R = iPr, tBu), with thorium(IV) and uranium(IV) complexes. For the thorium dithiophosphinate complexes, reaction of ThCl4(DME)2 with 4 equiv of KS2PR2 (R = iPr, tBu) produced the homoleptic complexes, Th(S2PiPr2)4 (1S-Th-iPr) and Th(S2PtBu2)4 (2S-Th-tBu). The diselenophosphinate complexes were synthesized in a similar manner using KSe2PR2 to produce Th(Se2PiPr2)4 (1Se-Th-iPr) and Th(Se2PtBu2)4 (2Se-Th-tBu). U(S2PiPr2)4, 1S-U-iPr, could be made directly from UCl4 and 4 equiv of KS2PiPr2. With (Se2PiPr2)1–, using UCl4 and 3 or 4 equiv of KSe2PiPr2 yielded the monochloride product U(Se2PiPr2)3Cl (3Se-UiPr-Cl), but using UI4(1,4-dioxane)2 produced the homoleptic U(Se2PiPr2)4 (1Se-U-iPr). Similarly, the reaction of UCl4 with 4 equiv of KS2PtBu2 yielded U(S2PtBu2)4 (2S-U-tBu), whereas the reaction with KSe2PtBu2 resulted in the formation of U(Se2PtBu2)3Cl (4Se-UtBu-Cl). Using UI4(1,4-dioxane)2 and 4 equiv of KSe2PtBu2 with UCl4 in acetonitrile yielded U(Se2PtBu2)4 (2Se-U-tBu). Transmetalation reactions were investigated with complex 2Se-U-tBu and various CuX (X = Br, I) salts to yield U(Se2PtBu2)3X (6Se-UtBu-Br and 7Se-UtBu-I) and 0.25 equiv of [Cu(Se2PtBu2)]4 (8Se-Cu-tBu). Additionally, 2Se-U-tBu underwent transmetalation reactions with Hg2F2 and ZnCl2 to yield U(Se2PtBu2)3F (6) and U(Se2PtBu2)3Cl (4Se-UtBu-Cl), respectively. The molecular structures were analyzed using 1H, 13C, 31P, and 77Se NMR and IR spectroscopy and structurally characterized using X-ray crystallography. Using the QTAIM approach, the electronic structure of all homoleptic complexes was probed, showing slightly more covalent bonding character in actinide–selenium bonds over actinide–sulfur bonds

    Di- and Trinuclear Mixed-Valence Copper Amidinate Complexes from Reduction of Iodine

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    Molecular examples of mixed-valence copper complexes through chemical oxidation are rare but invoked in the mechanism of substrate activation, especially oxygen, in copper-containing enzymes. To examine the cooperative chemistry between two metals in close proximity to each other we began studying the reactivity of a dinuclear Cu(I) amidinate complex. The reaction of [(2,6-Me2C6H3N)2C(H)]2Cu2, 1, with I2 in tetrahydrofuran (THF), CH3CN, and toluene affords three new mixed-valence copper complexes [(2,6-Me2C6H3N)2C(H)]2Cu2(μ2-I3)(THF)2, 2, [(2,6-Me2C6H3N)2C(H)]2Cu2(μ2-I) (NCMe)2, 3, and [(2,6-Me2C6H3N)2C(H)]3Cu3(μ3-I)2, 4, respectively. The first two compounds were characterized by UV-vis and electron paramagnetic resonance spectroscopies, and their molecular structure was determined by X-ray crystallography. Both di- and trinuclear mixed-valence intermediates were characterized for the reaction of compound 1 to compound 4, and the molecular structure of 4 was determined by X-ray crystallography. The electronic structure of each of these complexes was also investigated using density functional theory

    The Evolving Landscape of the Economics of HIV Treatment and Prevention

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    Bohdan Nosyk and Julio Montaner argue that the cost-effectiveness of HAART roll out has been significantly underestimated because economic analyses haven't yet taken into account the beneficial impact of HAART on HIV transmission

    Characterization of a core fragment of the rhesus monkey TRIM5α protein

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    <p>Abstract</p> <p>Background</p> <p>Like all tripartite motif (TRIM) proteins, the retroviral restriction factor TRIM5α consists of RING, B-box 2 and coiled-coil domains, with a C-terminal B30.2(SPRY) domain. Although structures have been determined for some individual TRIM domains, the structure of an intact TRIM protein is unknown.</p> <p>Results</p> <p>Here, we express and characterize a protease-resistant 29-kD core fragment containing the B-box 2, coiled coil and adjacent linker (L2) region of TRIM5α. This BCCL2 protein formed dimers and higher-order oligomers in solution. Approximately 40% of the BCCL2 secondary structure consisted of alpha helices. Partial loss of alpha-helical content and dissociation of dimers occurred at 42°C, with the residual alpha helices remaining stable up to 80°C.</p> <p>Conclusions</p> <p>These results indicate that the B-box 2, coiled-coil and linker 2 regions of TRIM5α form a core dimerization motif that exhibits a high level of alpha-helical content.</p

    The "ART" of Linkage: Pre-Treatment Loss to Care after HIV Diagnosis at Two PEPFAR Sites in Durban, South Africa

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    BACKGROUND. Although loss to follow-up after antiretroviral therapy (ART) initiation is increasingly recognized, little is known about pre-treatment losses to care (PTLC) after an initial positive HIV test. Our objective was to determine PTLC in newly identified HIV-infected individuals in South Africa. METHODOLOGY/PRINCIPAL FINDINGS. We assembled the South African Test, Identify and Link (STIAL) Cohort of persons presenting for HIV testing at two sites offering HIV and CD4 count testing and HIV care in Durban, South Africa. We defined PTLC as failure to have a CD4 count within 8 weeks of HIV diagnosis. We performed multivariate analysis to identify factors associated with PTLC. From November 2006 to May 2007, of 712 persons who underwent HIV testing and received their test result, 454 (64%) were HIV-positive. Of those, 206 (45%) had PTLC. Infected patients were significantly more likely to have PTLC if they lived =10 kilometers from the testing center (RR=1.37; 95% CI: 1.11-1.71), had a history of tuberculosis treatment (RR=1.26; 95% CI: 1.00-1.58), or were referred for testing by a health care provider rather than self-referred (RR=1.61; 95% CI: 1.22-2.13). Patients with one, two or three of these risks for PTLC were 1.88, 2.50 and 3.84 times more likely to have PTLC compared to those with no risk factors. CONCLUSIONS/SIGNIFICANCE. Nearly half of HIV-infected persons at two high prevalence sites in Durban, South Africa, failed to have CD4 counts following HIV diagnosis. These high rates of pre-treatment loss to care highlight the urgent need to improve rates of linkage to HIV care after an initial positive HIV test.US National Institute of Allergy and Infectious Diseases (R01 AI058736, K24 AI062476, K23 AI068458); the Harvard University Center for AIDS Research (P30 AI42851); National Institutes of Health (K24 AR 02123); the Doris Duke Charitable Foundation (Clinical Scientist Development Award); the Harvard University Program on AID

    Global Health Training in U.S. Graduate Psychiatric Education

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    Objective—Global health training opportunities have figured prominently into medical students’ residency program choices across a range of clinical specialties. To date, however, the national scope of global mental health education has not heretofore been systematically assessed. We therefore sought to characterize the distribution of global health training opportunities in U.S. graduate psychiatric education. Methods—We examined the web pages of all U.S. psychiatry residency training programs, along with search results from a systematic Google query designed to identify global health training opportunities. Results—Of the 183 accredited U.S. psychiatry residency programs, we identified 17 programs (9.3%) offering 28 global health training opportunities in 64 countries. Ten psychiatry residency programs offered their residents opportunities to participate in one or more elective-based rotations, eight offered research activities, and six offered extended field-based training. Most global health training opportunities occurred within the context of externally administered, institution-wide initiatives generally available to residents from a range of clinical specialties, rather than within internally administered departmental initiatives specifically tailored for psychiatry residents. Conclusions—There are relatively few global health training opportunities in U.S. graduate psychiatric education. These activities have a clear role in enhancing mastery of Accreditation Council for Graduate Medical Education core competencies, but important challenges related to program funding and evaluation remain
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