957 research outputs found

    Structure of lithium catena-poly[3,4-dihydroxopentaborate-1:5-[mu]-oxo]

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    LiH2B5O9, M(r) = 207.0, monoclinic, P2(1)/a, a = 13.576 (4), b = 9.077 (4), c = 5.543 (3) angstrom, beta = 91.47 (1)degrees, V = 682.8 (4)) angstrom3, Z = 4, D(x) = 2.013 g cm-3, lambda(Mo Kalpha) = 0.7107 angstrom, mu = 2.06 cm F(000) = 408, T = 293 K, R = 0.049 for 1689 independent observed reflections. The structure contains chains of B5O9H2]- anions linked through shared O atoms. In each anionic unit two B3O3 rings, each incorporating two triangular BO3 units, are connected by a shared tetrahedral BO4 unit. The Li atom has four O-atom neighbours arranged in an approximately tetrahedral configuration. The Li polyhedra connect B-O polyanions to form a two-dimensional network. Further connections are provided by hydrogen bonds

    Atypical dopamine efflux caused by3,4-methylenedioxypyrovalerone (MDPV) via the human dopamine transporter

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    Synthetic cathinones are similar in chemical structure to amphetamines, and their behavioral effects are associated with enhanced dopaminergic signaling. The past ten years of research on the common constituent of bath salts, MDPV (the synthetic cathinone 3,4-methylenedioxypyrovalerone), has aided the understanding of how synthetic cathinones act at the dopamine (DA) transporter (DAT). Several groups have described the ability of MDPV to block the DAT with high-affinity. In this study, we demonstrate for the first time, a new mode of action of MDPV, namely its ability to promote DAT-mediated DA efflux. Using single cell amperometric assays, we determined that low concentrations of MDPV (1 nM) can cause reverse transport of DA via DAT. Notably, administration of MDPV leads to hyperlocomotion in Drosophila melanogaster. These data describe further how MDPV acts at the DAT possibly paving the way for novel treatment strategies for individuals who abuse bath salts

    The natural history of degenerative cervical myelopathy and the rate of hospitalization following spinal cord injury: an updated systematic review

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    Study Method: Systematic review (update). Objective: Degenerative cervical myelopathy (DCM) is a degenerative spine disease and the most common cause of spinal cord dysfunction in adults worldwide. The objective of this study is to determine the natural history of DCM by updating the systematic review by Karadimas et al. The specific aims of this review were (1) to describe the natural history of DCM and (2) to determine potential risk factors of disease progression. Method: An updated search based on a previous protocol was conducted in PubMed and the Cochrane Collaboration library for studies published between November 2012 and February 15, 2015. Results: The updated search yielded 3 additional citations that met inclusion criteria and reported the incidence of spinal cord injury and severe disability in patients with DCM. Based on 2 retrospective cohort studies, the incidence rate of hospitalization for spinal cord injury is 13.9 per 1000 person-years in patients with cervical spondylotic myelopathy and 4.8 per 1000 person-years in patients with myelopathy secondary to ossification of the posterior longitudinal ligament (OPLL). In a third small prospective study, the risk of being wheelchair bound or bedridden was 66.7% in DCM patients with OPLL. Conclusion: The overall level of evidence for these estimated rates of hospitalization following spinal cord injury was rated as low. </jats:sec

    Impact of Baseline Magnetic Resonance Imaging on Neurologic, Functional, and Safety Outcomes in Patients With Acute Traumatic Spinal Cord Injury

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    Study Design: Systematic review. Objective: To perform a systematic review to evaluate the utility of magnetic resonance imaging (MRI) in patients with acute spinal cord injury (SCI). Methods: An electronic search of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar was conducted for literature published through May 12, 2015, to answer key questions associated with the use of MRI in patients with acute SCI. Results: The literature search yielded 796 potentially relevant citations, 8 of which were included in this review. One study used MRI in a protocol to decide on early surgical decompression. The MRI-protocol group showed improved outcomes; however, the quality of evidence was deemed very low due to selection bias. Seven studies reported MRI predictors of neurologic or functional outcomes. There was moderate-quality evidence that longer intramedullary hemorrhage (2 studies) and low-quality evidence that smaller spinal canal diameter at the location of maximal spinal cord compression and the presence of cord swelling are associated with poor neurologic recovery. There was moderate-quality evidence that clinical outcomes are not predicted by SCI lesion length and the presence of cord edema. Conclusions: Certain MRI characteristics appear to be predictive of outcomes in acute SCI, including length of intramedullary hemorrhage (moderate-quality evidence), canal diameter at maximal spinal cord compression (low-quality evidence), and spinal cord swelling (low-quality evidence). Other imaging features were either inconsistently (presence of hemorrhage, maximal canal compromise, and edema length) or not associated with outcomes. The paucity of literature highlights the need for well-designed prospective studies. © 2017, © The Author(s) 2017

    T1 vs. T2 weighted magnetic resonance imaging to assess total kidney volume in patients with autosomal dominant polycystic kidney disease

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    Purpose: In ADPKD patients total kidney volume (TKV) measurement using MRI is performed to predict rate of disease progression. Historically T1 weighted images (T1) were used, but the methodology of T2 weighted imaging (T2) has evolved. We compared the performance of both sequences. Methods: 40 ADPKD patients underwent an abdominal MRI at baseline and follow-up. TKV was measured by manual tracing with Analyze Direct 11.0 software. Three readers established intra- and interreader coefficients of variation (CV). T1 and T2 measured kidney volumes and growth rates were compared with ICC and Bland-Altman analyses. Results: Participants were 49.7 +/- 7.0 years of age, 55.0% female, with estimated GFR of 50.1 +/- 11.5 mL/min/1.73 m(2). CVs were low and comparable for T2 and T1 (intrareader: 0.83% [0.48-1.79] vs. 1.15% [0.34-1.77], P = 0.9, interreader: 2.18% [1.59-2.61] vs. 1.69% [1.07-3.87], P = 0.9). TKV was clinically similar, but statistically significantly different between T2 and T1: 1867 [1172-2721] vs. 1932 [1180-2551] mL, respectively (P = 0.006), with a bias of only 0.8% and high agreement (ICC 0.997). Percentage kidney growth during 2.2 +/- 0.3 years was similar for T2 and T1 (9.3 +/- 10.6% vs. 7.8 +/- 9.9%, P = 0.1, respectively), with a bias of 1.5% and high agreement (ICC 0.843). T2 was more often of sufficient quality for volume measurement (86.7% vs. 71.1%, P <0.001). Conclusions: In patients with ADPKD, measurement of kidney volume and growth rate performs similarly when using T2 compared to T1 weighted images, although T2 performs better on secondary outcome parameters; they are more often of sufficient quality for volume measurement and result in slightly lower intra- and interreader variability

    Vacuum Stability Higgs Mass Bound Revisited with Implications for Extra Dimension Theories

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    We take the standard model to be an effective theory including higher dimensional operators suppressed by scale Λ\Lambda and re-examine the higgs mass bounds from the requirements of vacuum stability. Our results show that the effects of the higher dimensional operators on the higgs mass limits are significant. As an implication of our results, we study the vacuum stability higgs mass bounds in theories with extra dimensions.Comment: Latex, 14 pages, 1 figure. Added references. To appear in Phys. Rev.

    Vitamin A supplementation in Tanzania: the impact of a change in programmatic delivery strategy on coverage.

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    BACKGROUND\ud \ud Efficient delivery strategies for health interventions are essential for high and sustainable coverage. We report impact of a change in programmatic delivery strategy from routine delivery through the Expanded Programme on Immunization (EPI+) approach to twice-yearly mass distribution campaigns on coverage of vitamin A supplementation in Tanzania\ud \ud METHODS\ud \ud We investigated disparities in age, sex, socio-economic status, nutritional status and maternal education within vitamin A coverage in children between 1 and 2 years of age from two independent household level child health surveys conducted (1) during a continuous universal targeting scheme based on routine EPI contacts for children aged 9, 15 and 21 months (1999); and (2) three years later after the introduction of twice-yearly vitamin A supplementation campaigns for children aged 6 months to 5 years, a 6-monthly universal targeting scheme (2002). A representative cluster sample of approximately 2,400 rural households was obtained from Rufiji, Morogoro Rural, Kilombero and Ulanga districts. A modular questionnaire about the health of all children under the age of five was administered to consenting heads of households and caretakers of children. Information on the use of child health interventions including vitamin A was asked.\ud \ud RESULTS\ud \ud Coverage of vitamin A supplementation among 1-2 year old children increased from 13% [95% CI 10-18%] in 1999 to 76% [95%CI 72-81%] in 2002. In 2002 knowledge of two or more child health danger signs was negatively associated with vitamin A supplementation coverage (80% versus 70%) (p = 0.04). Nevertheless, we did not find any disparities in coverage of vitamin A by district, gender, socio-economic status and DPT vaccinations.\ud \ud CONCLUSION\ud \ud Change in programmatic delivery of vitamin A supplementation was associated with a major improvement in coverage in Tanzania that was been sustained by repeated campaigns for at least three years. There is a need to monitor the effect of such campaigns on the routine health system and on equity of coverage. Documentation of vitamin A supplementation campaign contacts on routine maternal and child health cards would be a simple step to facilitate this monitoring

    A clinical practice guideline for the management of patients with acute spinal cord injury: recommendations on the use of methylprednisolone sodium succinate

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    Introduction: The objective of this guideline is to outline the appropriate use of methylprednisolone sodium succinate (MPSS) in patients with acute spinal cord injury (SCI). Methods: A systematic review of the literature was conducted to address key questions related to the use of MPSS in acute SCI. A multidisciplinary Guideline Development Group used this information, in combination with their clinical expertise, to develop recommendations for the use of MPSS. Based on GRADE (Grading of Recommendation, Assessment, Development and Evaluation), a strong recommendation is worded as "we recommend," whereas a weaker recommendation is indicated by "we suggest." Results: The main conclusions from the systematic review included the following: (1) there were no differences in motor score change at any time point in patients treated with MPSS compared to those not receiving steroids; (2) when MPSS was administered within 8 hours of injury, pooled results at 6- and 12-months indicated modest improvements in mean motor scores in the MPSS group compared with the control group; and (3) there was no statistical difference between treatment groups in the risk of complications. Our recommendations were: (1) "We suggest not offering a 24-hour infusion of high-dose MPSS to adult patients who present after 8 hours with acute SCI"; (2) "We suggest a 24-hour infusion of high-dose MPSS be offered to adult patients within 8 hours of acute SCI as a treatment option"; and (3) "We suggest not offering a 48-hour infusion of high-dose MPSS to adult patients with acute SCI." Conclusions: These guidelines should be implemented into clinical practice to improve outcomes and reduce morbidity in SCI patients
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