100 research outputs found

    Normal state properties of high angle grain boundaries in (Y,Ca)Ba2Cu3O7-delta

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    By lithographically fabricating an optimised Wheatstone bridge geometry, we have been able to make accurate measurements of the resistance of grain boundaries in Y1-xCaxBa2Cu3O7-d between the superconducting transition temperature, Tc, and room temperature. Below Tc the normal state properties were assessed by applying sufficiently high currents. The behaviour of the grain boundary resistance versus temperature and of the conductance versus voltage are discussed in the framework charge transport through a tunnel barrier. The influence of misorientation angle, oxygen content, and calcium doping on the normal state properties is related to changes of the height and shape of the grain boundary potential barrier.Comment: 17 pages, 1 table, 5 figures, submitted to PR

    The Normal State Resistivity of Grain Boundaries in YBa2Cu3O7-delta

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    Using an optimized bridge geometry we have been able to make accurate measurements of the properties of YBa2Cu3O7-delta grain boundaries above Tc. The results show a strong dependence of the change of resistance with temperature on grain boundary angle. Analysis of our results in the context of band-bending allows us to estimate the height of the potential barrier present at the grain boundary interface.Comment: 11 pages, 3 figure

    Zilucoplan in immune-mediated necrotising myopathy: a phase 2, randomised, double-blind, placebo-controlled, multicentre trial

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    BACKGROUND: Immune-mediated necrotising myopathy is an autoimmune myopathy characterised by proximal muscle weakness, high creatine kinase concentrations, and autoantibodies recognising 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) or the signal recognition particle (SRP). No approved therapies exist for people with immune-mediated necrotising myopathy. Previous studies have suggested that complement activation might be pathogenic in immune-mediated necrotising myopathy; therefore, zilucoplan, a complement C5 (C5) inhibitor, could be a potential therapy. We aimed to evaluate the efficacy, safety, and tolerability of zilucoplan in adult participants with anti-HMGCR or anti-SRP autoantibody-positive immune-mediated necrotising myopathy. METHODS: IMNM-01 was a phase 2, multicentre, randomised, double-blind, placebo-controlled study done at 15 hospital sites across the USA, the UK, France, and the Netherlands. Participants aged 18–74 years were eligible for inclusion if they had a clinically confirmed diagnosis of immune-mediated necrotising myopathy, positive serology for anti-HMGCR or anti-SRP autoantibodies, clinical evidence of weakness, serum total creatine kinase concentration of more than 1000 U/L at screening, and no change in glucocorticoids or other immunosuppressive therapies for 30 days before baseline or expected during the first 8 weeks of the study. Participants were randomly assigned (1:1) to receive daily subcutaneous zilucoplan (0·3 mg/kg) or placebo for 8 weeks by use of a computerised randomisation algorithm; with optional enrolment in the study open-label extension. Randomisation was stratified by autoantibody status. Participants and study staff were masked to treatment group assignment. Primary efficacy endpoint (in the intent-to-treat population, defined as all participants who were randomly assigned to a treatment group) was percent change from baseline to week 8 in creatine kinase concentrations. Safety analyses were performed on the safety population (participants who received at least one dose of study drug during the main study, irrespective of whether they continued to the extension period—study participants were analysed on the basis of the treatment received). This study is registered with ClinicalTrials.gov, NCT04025632. FINDINGS: Between Nov 7, 2019, and Jan 7, 2021, we randomly assigned 27 participants (13 female and 14 male) to receive zilucoplan (n=12) or placebo (n=15). All 27 participants completed the 8-week main study. At week 8 there were no significant differences between treatment groups in median percent change of creatine kinase concentrations versus baseline (–15·1% [IQR –31·1 to 3·2] in the zilucoplan group vs –16·3% [–43·8 to 5·9] in the placebo group; p=0·46) and no clinically relevant improvement over time within the treatment group despite target engagement based on mode of action. There were no unexpected adverse safety or tolerability findings. Treatment-emergent adverse events were reported in nine (75%) of 12 participants in the zilucoplan group, and in 13 (87%) of 15 participants in the placebo group, and serious treatment-emergent adverse events were reported in zero participants in the zilucoplan group and three (20%) participants in the placebo group. The most frequent treatment-emergent adverse events were headache (four [33%] participants in the zilucoplan group and four [27%] participants in the placebo group) and nausea (three [25%] participants in the zilucoplan group and three [20%] participants in the placebo group). INTERPRETATION: C5 inhibition does not appear to be an efficacious treatment modality for people with immune-mediated necrotising myopathy. Rather than being the primary driver for disease activity, complement activation might be secondary to muscle injury. FUNDING: Ra Pharmaceuticals (now part of UCB Pharma)

    Using direct observations on multiple occasions to measure household food availability among low-income Mexicano residents in Texas colonias

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    BACKGROUND: It has been recognized that the availability of foods in the home are important to nutritional health, and may influence the dietary behavior of children, adolescents, and adults. It is therefore important to understand food choices in the context of the household setting. Considering their importance, the measurement of household food resources becomes critical.Because most studies use a single point of data collection to determine the types of foods that are present in the home, which can miss the change in availability within a month and when resources are not available, the primary objective of this pilot study was to examine the feasibility and value of conducting weekly in-home assessments of household food resources over the course of one month among low-income Mexicano families in Texas colonias. METHODS: We conducted five in-home household food inventories over a thirty-day period in a small convenience sample; determined the frequency that food items were present in the participating households; and compared a one-time measurement with multiple measurements.After the development and pre-testing of the 252-item culturally and linguistically- appropriate household food inventory instrument that used direct observation to determine the presence and amount of food and beverage items in the home (refrigerator, freezer, pantry, elsewhere), two trained promotoras recruited a convenience sample of 6 households; administered a baseline questionnaire (personal info, shopping habits, and food security); conducted 5 in-home assessments (7-day interval) over a 30-day period; and documented grocery shopping and other food-related activities within the previous week of each in-home assessment. All data were collected in Spanish. Descriptive statistics were calculated for mean and frequency of sample characteristics, food-related activities, food security, and the presence of individual food items. Due to the small sample size of the pilot data, the Friedman Test and Kendall's W were used to assess the consistency of household food supplies across multiple observations. RESULTS: Complete data were collected from all 6 Mexicano women (33.2y +/- 3.3; 6.5 +/- 1.5 adults/children in household (HH); 5 HH received weekly income; and all were food insecure. All households purchased groceries within a week of at least four of the five assessments. The weekly presence and amounts of fresh and processed fruits and vegetables, dairy, meats, breads, cereals, beverages, and oils and fats varied. Further, the results revealed the inadequacy of a one-time measurement of household food resources, compared with multiple measures. The first household food inventory as a one-time measure would have mistakenly identified at least one-half of the participant households without fresh fruit, canned vegetables, dairy, protein foods, grains, chips, and sugar-sweetened beverages. CONCLUSIONS: This study highlights the value of documenting weekly household food supplies, especially in households where income resources may be more volatile. Clearly, the data show that a single HFI may miss the changes in availability--presence and amount--that occur among low-income Mexicano households who face challenges that require frequent purchase of foods and beverages. Use of multiple household food inventories can inform the development and implementation of nutrition-related policies and culturally sensitive nutrition education programs

    A Genetic Basis of Susceptibility to Acute Pyelonephritis

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    For unknown reasons, urinary tract infections (UTIs) are clustered in certain individuals. Here we propose a novel, genetically determined cause of susceptibility to acute pyelonephritis, which is the most severe form of UTI. The IL-8 receptor, CXCR1, was identified as a candidate gene when mIL-8Rh mutant mice developed acute pyelonephritis (APN) with severe tissue damage.We have obtained CXCR1 sequences from two, highly selected APN prone patient groups, and detected three unique mutations and two known polymorphisms with a genotype frequency of 23% and 25% compared to 7% in controls (p<0.001 and p<0.0001, respectively). When reflux was excluded, 54% of the patients had CXCR1 sequence variants. The UTI prone children expressed less CXCR1 protein than the pediatric controls (p<0.0001) and two sequence variants were shown to impair transcription.The results identify a genetic innate immune deficiency, with a strong link to APN and renal scarring

    The Exstrophy-epispadias complex

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    Exstrophy-epispadias complex (EEC) represents a spectrum of genitourinary malformations ranging in severity from epispadias (E) to classical bladder exstrophy (CEB) and exstrophy of the cloaca (EC). Depending on severity, EEC may involve the urinary system, musculoskeletal system, pelvis, pelvic floor, abdominal wall, genitalia, and sometimes the spine and anus. Prevalence at birth for the whole spectrum is reported at 1/10,000, ranging from 1/30,000 for CEB to 1/200,000 for EC, with an overall greater proportion of affected males. EEC is characterized by a visible defect of the lower abdominal wall, either with an evaginated bladder plate (CEB), or with an open urethral plate in males or a cleft in females (E). In CE, two exstrophied hemibladders, as well as omphalocele, an imperforate anus and spinal defects, can be seen after birth. EEC results from mechanical disruption or enlargement of the cloacal membrane; the timing of the rupture determines the severity of the malformation. The underlying cause remains unknown: both genetic and environmental factors are likely to play a role in the etiology of EEC. Diagnosis at birth is made on the basis of the clinical presentation but EEC may be detected prenatally by ultrasound from repeated non-visualization of a normally filled fetal bladder. Counseling should be provided to parents but, due to a favorable outcome, termination of the pregnancy is no longer recommended. Management is primarily surgical, with the main aims of obtaining secure abdominal wall closure, achieving urinary continence with preservation of renal function, and, finally, adequate cosmetic and functional genital reconstruction. Several methods for bladder reconstruction with creation of an outlet resistance during the newborn period are favored worldwide. Removal of the bladder template with complete urinary diversion to a rectal reservoir can be an alternative. After reconstructive surgery of the bladder, continence rates of about 80% are expected during childhood. Additional surgery might be needed to optimize bladder storage and emptying function. In cases of final reconstruction failure, urinary diversion should be undertaken. In puberty, genital and reproductive function are important issues. Psychosocial and psychosexual outcome depend on long-term multidisciplinary care to facilitate an adequate quality of life
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