531 research outputs found
Family social environment in childhood and self-rated health in young adulthood
<p>Abstract</p> <p>Background</p> <p>Family social support, as a form of social capital, contributes to social health disparities at different age of life. In a life-course epidemiological perspective, the aims of our study were to examine the association between self-reported family social environment during childhood and self-reported health in young adulthood and to assess the role of family functioning during childhood as a potential mediating factor in explaining the association between family breakup in childhood and self-reported health in young adulthood.</p> <p>Methods</p> <p>We analyzed data from the first wave of the Health, Inequalities and Social Ruptures Survey (SIRS), a longitudinal health and socio-epidemiological survey of a random sample of 3000 households initiated in the Paris metropolitan area in 2005. Sample-weighted logistic regression analyses were performed to determine the association between the quality of family social environment in childhood and self-rated health (overall health, physical health and psychological well-being) in young adults (n = 1006). We used structural equation model to explore the mediating role of the quality of family functioning in childhood in the association between family breakup in childhood and self-rated health in young adulthood.</p> <p>Results</p> <p>The multivariate results support an association between a negative family social environment in childhood and poor self-perceived health in adulthood. The association found between parental separation or divorce in childhood and poor self-perceived health in adulthood was mediated by parent-child relationships and by having witnessed interparental violence during childhood.</p> <p>Conclusion</p> <p>These results argue for interventions that enhance family cohesion, particularly after family disruptions during childhood, to promote health in young adulthood.</p
Large magnetoresistance in (La(1-x)Ca(x)MnO(3))(1-y): ZrO(2) composite
Colossal magnetoresistance (CMR) composite materials have been synthesized to explore the possibility of improving magneto-transport and structural properties in CMR systems. In this work we describe (La(1-x)Ca(x)MnO(3))(1-y) (LCMO) (ZrO(2))(y) (xapproximate to0.3 and 0.0less than or equal toyless than or equal to0.40 mole %) composites that have been synthesized using a modified (non Pechini type) sol-gel technique. Magnetoresistivity of the composites was evaluated at 5 T field and in the temperature range 5-300 K. The composites show higher magnitude of MR compared to pure LCMO. The MR rises from a base value 76%, for the case y=0, to a maximum value of 93.8%, obtained at y=0.05. dc susceptibility measurements show a distinct ferromagnetic to paramagnetic transition in all composites. The ferromagnetic transition temperature (T(C)) drops from 225 K in pure LCMO (y=0) to 121 K in y=0.05 and then slowly rises to 157 K as y increases. The plots of zero field cooled susceptibility chi(ZFC) (T) and field cooled susceptibility chi(FC) (T) diverge clearly below T(C), indicating magnetic irreversibility. The composite exhibits a clear metal-insulator transition (T(MI)) at or just above the magnetic transition. The peak resistivity rho(MI) at the metal-insulator transition also exhibits interesting changes. For pure LCMO polycrystals, rho(MI)=102 Omega cm, but it increases to 228 Omega cm for y=0.05 and then gradually decreases to 1.94 Omega cm for ygreater than or equal to0.10. The phase evolution in the LCMO:ZrO(2) composites was studied by x-ray powder diffraction and correlated to the magnetic and electrical properties. (C) 200
A standard system phantom for magnetic resonance imaging
Purpose:
A standard MRI system phantom has been designed and fabricated to assess scanner performance, stability, comparability and assess the accuracy of quantitative relaxation time imaging. The phantom is unique in having traceability to the International System of Units, a high level of precision, and monitoring by a national metrology institute. Here, we describe the phantom design, construction, imaging protocols, and measurement of geometric distortion, resolution, slice profile, signal-to-noise ratio (SNR), proton-spin relaxation times, image uniformity and proton density.
Methods:
The system phantom, designed by the International Society of Magnetic Resonance in Medicine ad hoc committee on Standards for Quantitative MR, is a 200 mm spherical structure that contains a 57-element fiducial array; two relaxation time arrays; a proton density/SNR array; resolution and slice-profile insets. Standard imaging protocols are presented, which provide rapid assessment of geometric distortion, image uniformity, T1 and T2 mapping, image resolution, slice profile, and SNR.
Results:
Fiducial array analysis gives assessment of intrinsic geometric distortions, which can vary considerably between scanners and correction techniques. This analysis also measures scanner/coil image uniformity, spatial calibration accuracy, and local volume distortion. An advanced resolution analysis gives both scanner and protocol contributions. SNR analysis gives both temporal and spatial contributions.
Conclusions:
A standard system phantom is useful for characterization of scanner performance, monitoring a scanner over time, and to compare different scanners. This type of calibration structure is useful for quality assurance, benchmarking quantitative MRI protocols, and to transition MRI from a qualitative imaging technique to a precise metrology with documented accuracy and uncertainty
THE VULKAN TECHNIQUE: A NOVEL OSTOMY-CLOSURE TECHNIQUE THAT REDUCES COMPLICATIONS AND OPERATIVE TIMES
Generalized joint hypermobility in professional dancers: a sign of talent or vulnerability?
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