464 research outputs found

    Effectiveness of Personal Protective Measures to Prevent Lyme Disease

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    Use of protective clothing and tick repellents on the skin or clothing while outdoors is 40% and 20% effective, respectively

    Double-outlet right ventricle: Morphologic demonstration using nuclear magnetic resonance imaging

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    Sixteen patients with double-outlet right ventricle, aged 1 week to 29 years (median 5 months), were studied with a 1.5 tesla nuclear magnetic resonance (NMR) imaging scanner. Two-dimensional echocardiography was performed in all patients. Thirteen patients underwent angiography, including nine who underwent subsequent surgical correction. Three patients underwent postmortem examination.Small children and infants were scanned inside a 32 cm diameter proton head coil. Multiple 5 mm thick sections separated by 0.5 mm and gated to the patient's electrocardiogram were acquired with a spin-echo sequence and an echo time of 30 ms. A combination of standard and oblique imaging planes was used. Imaging times were <90 min. The NMR images were technically unsuitable in one patient because of excessive motion artifact.In the remaining patients, the diagnosis of double outlet right ventricle was confirmed and correlated with surgical and postmortern findings. The NMR images were particularly valuable in demonstrating the interrelations between the great arteries and the anatomy of the outlet septum and the spatial relations between the ventricular septal defect and the great arteries. Although the atrioventricular (AV) valves were not consistently demonstrated, NMR imaging in two patients identified abnormalities of the mitral valve that were not seen with two-dimensional echocardiography. In one patient who had a superoinferior arrangement of the ventricles, NMR imaging was the most useful imaging technique for demonstrating the anatomy.In patients with double-outlet right ventricle, NMR imaging can provide clinically relevant and accurate morphologic information that may contribute to future improvement in patient management

    Etiology, epidemiology and clinical characteristics of acute moderate-to-severe diarrhea in children under 5 years of age hospitalized in a referral pediatric hospital in Rabat, Morocco

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    The objective of the study was to describe the etiology, epidemiology, and clinical characteristics of the principal causes of acute infectious diarrhea requiring hospitalization among children under 5 years of age in Rabat, Morocco. A prospective study was conducted from March 2011 to March 2012, designed to describe the main pathogens causing diarrhea in hospitalized children >2 months and less than 5 years of age. Among the 122 children included in the study, Enteroaggregative E. coli (EAEC) and rotavirus were the main etiologic causes of diarrhea detected. Twelve (9.8%) children were referred to the intensive care unit, while 2, presenting infection by EAEC and EAEC plus a Shigella sonnei respectively, developed a hemolytic uremic syndrome. Additionally, 6 (4.9%) deaths occurred with EAEC being isolated in four of these cases. Diarrheogenic E. coli and rotavirus play a significant role as the two main causes of severe diarrhea while other pathogens such as norovirus or parasites seem to have a minimal contribution. Surveillance and prevention programs to facilitate early recognition and improved management of potentially life-threatening diarrhea-episodes are needed

    Negative life events and suicide risk in college students: Conditional indirect effects of hopelessness and self-compassion

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    Objective: Suicide risk is a significant public health concern for college students and may be exacerbated by hopelessness resulting from negative life events (NLE), yet may be ameliorated by self-compassion. We examined the mediating role of hopelessness in the relation between NLE and suicidal behavior, and the moderating influence of self-compassion on all model paths. Participants: Participants were 338 undergraduates (89% white; 67% female). Data were collected from December 2014 to December 2015. Methods: Participants completed the Life Events Checklist for College Students, Beck Hopelessness Inventory, Self-Compassion Scale, and Suicidal Behaviors Questionnaire – Revised. Results: Negative life events were related to greater hopelessness and, in turn, to more suicidal behavior, yet self-compassion attenuated this effect. Conclusions: Self-compassion may buffer the NLE–hopelessness linkage, thereby reducing suicide risk among college students. Therapeutic promotion of self-compassion, and reduction of hopelessness, may be important suicide prevention strategies on college campuses

    Formation of Long-Lived Color Centers for Broadband Visible Light Emission in Low-Dimensional Layered Perovskites.

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    We investigate the origin of the broadband visible emission in layered hybrid lead-halide perovskites and its connection with structural and photophysical properties. We study ⟨001⟩ oriented thin films of hexylammonium (HA) lead iodide, (C6H16N)2PbI4, and dodecylammonium (DA) lead iodide, (C12H28N)2PbI4, by combining first-principles simulations with time-resolved photoluminescence, steady-state absorption and X-ray diffraction measurements on cooling from 300 to 4 K. Ultrafast transient absorption and photoluminescence measurements are used to track the formation and recombination of emissive states. In addition to the excitonic photoluminescence near the absorption edge, we find a red-shifted, broadband (full-width at half-maximum of about 0.4 eV), emission band below 200 K, similar to emission from ⟨110⟩ oriented bromide 2D perovskites at room temperature. The lifetime of this sub-band-gap emission exceeds that of the excitonic transition by orders of magnitude. We use X-ray diffraction measurements to study the changes in crystal lattice with temperature. We report changes in the octahedral tilt and lattice spacing in both materials, together with a phase change around 200 K in DA2PbI4. DFT simulations of the HA2PbI4 crystal structure indicate that the low-energy emission is due to interstitial iodide and related Frenkel defects. Our results demonstrate that white-light emission is not limited to ⟨110⟩ oriented bromide 2D perovskites but a general property of this class of system, and highlight the importance of defect control for the formation of low-energy emissive sites, which can provide a pathway to design tailored white-light emitters
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