76 research outputs found

    Viscomagnetoelastic Interactions in a Vortex Array in the Type–II Superconductor

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    The paper develops considerations on viscomagnetoelastic interactions in a vortex array in a type–II superconductor. It is well known that a magnetic field penetrates such a material along lines called vortices of a special structure. Each of them consists of a core of material in the normal state, i.e. a material in which Ohm’s law works and a surrounding where the supercurrent flows. The mean diameter of a core is called the coherence length. The penetration of the supercurrent outside the core exists in the London penetration depth. Since interactions among the vortices run with the help of the Lorenz force, the vortex field has elastic properties. Moreover, because of the normal state inside the vortex core also the viscosity of that field has been observed. The above situation occurs only between upper and lower magnetic field limits below the critical temperature regarding the phase diagram. The vortex field has a very interesting feature. In the vicinity of the lower magnetic field curve it possesses an ordered (quadratic or triangular) structure. Then going to the upper magnetic field limit that structure is losing its configuration behaving as a fluid. We assume smooth transition from ordered to disordered state althought it is much more complicated in nature. Following the above statements all the “material” coefficients characteristic for the vortex field are also dependent on the magnetic field and temperature. The main aim of the paper is a formulation of the stress – strain constitutive law consisting of the following features:• a coexistence of the ordered and disordered states,• the viscosity of the vortex field,• the dependence of the “material” coefficients related to the vortex field on the magnetic field.An application for YBCO ceramics that deals with the use of the proposed constitutive law in vortex field equations and results coming from that are presented. Numerical calculations concern wave propagation in depinned parallel vortex line field versus magnitude of the applied magnetic field

    Long-Term Gynecological Outcomes in Women with Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency

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    Background. Our knowledge on long-term outcome in CAH remains incomplete. Methods. In a prospective study (33 CAH patients, 33 age-matched controls), reproductive outcomes, self-rating of genital appearance and function, and sexuality were correlated to degree of initial virilisation, genotype, and surgery. Results. Patients had larger median clitoral lengths (10.0 mm [range 2–30] versus 3.5 [2–8], P < .001), shorter vaginal length (121 mm [100–155] versus 128 [112–153], P = .12), lower uterine volumes (29.1 ml [7.5–56.7] versus 47.4 [15.9–177.5], P = .009), and higher ovarian volumes (4.4 ml [1.3–10.8] versus 2.8 [0.6–10.8], P = .09) than controls. Satisfaction with genital appearance was lower and negatively correlated to degree of initial virilisation (rs = ≤−0.39, P ≤ .05). More patients had never had intercourse (P = .001), and age at 1st intercourse was higher (18 yrs versus 16 yrs, P = .02). Conclusion. Despite overall acceptable cosmetic results, reproductive outcomes were suboptimal, supporting that multidisciplinary teams should be involved in adult follow up of CAH patients

    Maternal exposure to UV filters:Associations with maternal thyroid hormones, IGF-I/IGFBP3 and birth outcomes

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    Background: Several chemical UV filters/absorbers ('UV filters' hereafter) have endocrine-disrupting properties in vitro and in vivo. Exposure to these chemicals, especially during prenatal development, is of concern. Objectives: To examine maternal exposure to UV filters, associations with maternal thyroid hormone, with growth factor concentrations as well as to birth outcomes. Methods: Prospective study of 183 pregnant women with 2nd trimester serum and urine samples available. Maternal concentrations of the chemical UV filters benzophenone-1 (BP-1) and benzophenone-3 (BP-3) in urine and 4-hydroxy-benzophenone (4-HBP) in serum were measured by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The relationships between 2nd trimester maternal concentrations of the three chemical UV filters and maternal serum concentrations of thyroid hormones and growth factors, as well as birth outcomes (weight, height, and head and abdominal circumferences) were examined. Results: Positive associations between maternal serum concentrations of 4-HBP and triiodothyronine (T3), thyroxine (T4), insulin-like growth factor I (IGF-I) and its binding protein IGFBP3 were observed in mothers carrying male fetuses. Male infants of mothers in the middle 4-HBP exposure group had statistically significantly lower weight and shorter head and abdominal circumferences at birth compared to the low exposure group. Conclusions: Widespread exposure of pregnant women to chemical UV filters and the possible impact on maternal thyroid hormones and growth factors, and on fetal growth, calls for further studies on possible long-term consequences of the exposure to UV filters on fetal development and children’s health

    Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial

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    IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved
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