52 research outputs found

    Making prospective registration of observational research a reality

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    The vast majority of health-related observational studies are not prospectively registered and the advantages of registration have not been fully appreciated. Nonetheless, international standards require approval of study protocols by an independent ethics committee before the study can begin. We suggest that there is an ethical and scientific imperative to publicly preregister key information from newly approved protocols, which should be required by funders. Ultimately, more complete information may be publicly available by disclosing protocols, analysis plans, data sets, and raw data

    Influence of gestational age at initiation of antihypertensive therapy: secondary analysis of CHIPS trial data (control of hypertension in pregnancy study)

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    For hypertensive women in CHIPS (Control of Hypertension in Pregnancy Study), we assessed whether the maternal benefits of tight control could be achieved, while minimizing any potentially negative effect on fetal growth, by delaying initiation of antihypertensive therapy until later in pregnancy. For the 981 women with nonsevere, chronic or gestational hypertension randomized to less-tight (target diastolic blood pressure, 100 mm Hg), or tight (target, 85 mm Hg) control, we used mixed-effects logistic regression to examine whether the effect of less-tight (versus tight) control on major outcomes was dependent on gestational age at randomization, adjusting for baseline factors as in the primary analysis and including an interaction term between gestational age at randomization and treatment allocation. Gestational age was considered categorically (quartiles) and continuously (linear or quadratic form), and the optimal functional form selected to provide the best fit to the data based on the Akaike information criterion. Randomization before (but not after) 24 weeks to less-tight (versus tight) control was associated with fewer babies with birth weight 48 hours (Pinteraction=0.354). For the mother, less-tight (versus tight) control was associated with more severe hypertension at all gestational ages but particularly so before 28 weeks (Pinteraction=0.076). In women with nonsevere, chronic, or gestational hypertension, there seems to be no gestational age at which less-tight (versus tight) control is the preferred management strategy to optimize maternal or perinatal outcomes

    Light-Ion-Induced Multifragmentation: The ISiS Project

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    An extensive study of GeV light-ion-induced multifragmentation and its possible interpretation in terms of a nuclear liquid-gas phase transition has been performed with the Indiana Silicon Sphere (ISiS)4 pi detector array. Measurements were performed with 5-15 GeV/c p, pbar, and pion beams incident on 197^{197}Au and 2-5 GeV 3^3He incident on nat^{nat}Ag and 197^{197}Au targets. Both the reaction dynamics and the subsequent decay of the heavy residues have been explored. The data provide evidence for a dramatic change in the reaction observables near an excitation energy of E*/A = 4-5 MeV per residue nucleon. In this region, fragment multiplicities and energy spectra indicate emission from an expanded/dilute source on a very short time scale (20-50 fm/c). These properties, along with caloric curve and scaling-law behavior, yield a pattern that is consistent with a nuclear liquid-gas phase transition.Comment: 67 pages, 44 figures, all included in tar fil

    Extremitäten-, Wirbelsäulen-, Beckentrauma

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    Modulating Inflammatory Cell Responses to Spinal Cord Injury: All in Good Time

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    US Department of Defense’s Congressionally Directed Medical Research Programs (reference W81XWH-10-1-1040) and the Barts and The London Charity (PKY) and Rod Flower Vacation Scholarship (ALB)

    The influence of air conditioning, humidity, temperature and other household characteristics on mite allergen concentrations in the northeastern United States.

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    Background:  Information about the influence of housing and occupant characteristics on mite allergen concentrations is crucial to determine which methods could be used to decrease exposure of susceptible subjects. Objectives:  To identify housing and occupant characteristics that are associated with mite allergen concentrations in house dust collected from living rooms and mattresses. Methods:  We collected dust samples from 750 homes in the northeastern US. The influence of various characteristics on concentrations of mite allergens (Der p 1 and Der f 1) was studied using multiple linear regression analysis. Results:  Some characteristics, like absence of air conditioners, the presence of mold or mildew, and a lower temperature were consistently associated with higher concentrations of both mite allergens in dust from all sampling locations. However, none of these factors changed Der p 1 or Der f 1 concentrations by more than a factor of 2. People of white ethnic background had roughly two times higher mite allergen concentrations, while family income, family size, and education level only marginally influenced mite allergen concentrations. Conclusions:  Various housing characteristics have some influence on mite allergen concentrations, and could possibly be used to decrease exposure of susceptible subjects. However, only a limited percentage of the variation in mite allergen concentrations was explained by these characteristics. &nbsp
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