21 research outputs found

    Critical current degradation in HTS wires due to cyclic mechanical strain

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    HTS wires, which may be used in many devices such as magnets and rotating machines, may be subjected to mechanical strains from electromagnetic, thermal and centripetal forces. In some applications these strains will be repeated several thousand times during the lifetime of the device. We have measured critical current degradation due to repeated strain cycles for both compressive and tensile strains. Results for BSCCO-2223 HTS conductor samples are presented for strain values up to 0.5% and cycle numbers up to and beyond 10/sup 4/

    Spontaneous abortion rate and advanced maternal age: Consequences for prenatal diagnosis

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    Abstract Maternal age related and procedure-related fetal abortion rates were studied in 384 women aged 36 and over scheduled for transabdominal chorionic villus sampling (TA-CVS) at 12-14 weeks of gestation. The pre-TA-CVS abortion rate within 30 days of intake (at 6-10 weeks of gestation) rose from 1·9% at age 35-36 years to 10·9% at 40 years and older. Women entering in the 6th week of gestation had a greater probability of aborting before TA-CVS than women entering after day 48. 26 women aborted spontaneously before TA-CVS, the majority of abortions occuring at 10-12 weeks. TA-CVS was done in 346 women. 11 pregnancies were terminated because of genetic anomalies, and 8 women had spontaneous fetal loss. These findings justify delaying prenatal diagnosis in older pregnant women until 12 weeks of gestation

    Honeybees balance essential fatty acids and suffer cognitively from deficiency

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    Abstract Background and aims. Epidemiological data on autoimmune hepatitis (AIH) are scarce. In this study, we determined the clinical and epidemiological characteristics of AIH patients in the Netherlands (16.7 million inhabitants). Methods. Clinical characteristics were collected from 1313 AIH patients (78% females) from 31 centers, including all eight academic centers in the Netherlands. Additional data on ethnicity, family history and symptoms were obtained by the use of a questionnaire. Results. The prevalence of AIH was 18.3 (95% confidential interval [CI]: 17.3-19.4) per 100,000 with an annual incidence of 1.1 (95% CI: 0.5-2) in adults. An incidence peak was found in middle-aged women. At diagnosis, 56% of patients had fibrosis and 12% cirrhosis in liver biopsy. Overall, 1% of patients developed HCC and 3% of patients underwent liver transplantation. Overlap with primary biliary cirrhosis and primary sclerosing cholangitis was found in 9% and 6%, respectively. The clinical course did not differ between Caucasian and non-Caucasian patients. Other autoimmune diseases were found in 26% of patients. Half of the patients reported persistent AIH-related symptoms despite treatment with a median treatment period of 8 years (range 1-44 years). Familial occurrence was reported in three cases. Conclusion. This is the largest epidemiological study of AIH in a geographically defined region and demonstrates that the prevalence of AIH in the Netherlands is uncommon. Although familial occurrence of AIH is extremely rare, our twin data may point towards a genetic predisposition. The high percentage of patients with cirrhosis or fibrosis at diagnosis urges the need of more awareness for AIH

    Adverse events related to low dose corticosteroids in autoimmune hepatitis

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    Background: Autoimmune hepatitis requires long‐term therapy, and systemic cor‐ ticosteroids are the backbone of therapeutic management. Prolonged use of corti‐ costeroids may lead to adverse events but data from long‐term studies are mainly derived from studies in rheumatic diseases. Aim: To assess cataract, diabetes and fractures in relation to corticosteroid doses in the long‐term maintenance treatment of patients with autoimmune hepatitis. Methods: We retrospectively collected data on 476 patients (77% women) with an established diagnosis of autoimmune hepatitis. Binary logistic regression with a gen‐ eralised estimating equation was used to analyse the association between current corticosteroid use and the incidence of cataract, diabetes and fractures with onset after autoimmune hepatitis diagnosis. We corrected for sex, age, cirrhosis at diagno‐ sis and predniso(lo)ne use in the prior 3 years to account for possible ongoing effects. Results: A total of 6634 years, with a median of 13 (range 1‐40) per patient were recorded. The median age at diagnosis was 44 years (range 2‐88). Adverse events were documented in 120 (25%) patients. Low‐dose predniso(lo)ne (0.1‐5.0 mg/d) in‐ creased the odds of fractures whereas higher doses (>5.0 mg/d) increased the odds of cataracts and diabetes. Budesonide increased the odds of cataract and fractures; this effect was independent of predniso(lo)ne use in the prior 1, 2 or 3 years. Conclusions: Even low doses of corticosteroids frequently lead to substantial ad‐ verse events refuting the assumption that adverse events are prevented by adminis‐ tering low doses

    Model-based analyses: Promises, pitfalls, and example applications to the study of cognitive control

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    We discuss a recent approach to investigating cognitive control, which has the potential to deal with some of the challenges inherent in this endeavour. In a model-based approach, the researcher defines a formal, computational model that performs the task at hand and whose performance matches that of a research participant. The internal variables in such a model might then be taken as proxies for latent variables computed in the brain. We discuss the potential advantages of such an approach for the study of the neural underpinnings of cognitive control and its pitfalls, and we make explicit the assumptions underlying the interpretation of data obtained using this approach
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