A mathematical model of equivalent bending radius was used to analyze the effect of bending strain on the critical current of yttrium barium copper oxide (YBCO) tapes in distorted bending mode. The relationship between critical current and twist pitch under different bending radii was measured. For enough larger twist pitch, even though the bending radius was smaller than the critical bending radius, the equivalent bending radius was always greater than the critical bending radius. Only when the bending radius was less than the critical bending radius and the twist pitch was reduced to a certain extent, the equivalent bending radius was smaller than the critical bending radius. As a consequence, the critical current dropped sharply and cannot be restored. The model and analytical equation was feasible and can be used for the design of solenoid YBCO magnet.

BackgroundThe psychological problems of patients with Systemic lupus erythematosus (SLE) have been widely concerned. Studies found that the SLE patients showed a prevalence of depression in SLE cohorts ranging from 17% to 75%, and anxiety being 6%-52%[1, 2]. Factors contributing to mood disorders are various[3]. As a nontraditional form of media, social media has become increasingly popular worldwide[4]. Previous study has demonstrated that social media use (SMU) plays a significant role in adolescents’ psychological functioning[5-8], whether SMU could impact the mental health of SLE patients, no previous finding of SMU on SLE patients is reported.ObjectivesWe aimed to explore the potential association of the patterns of social media use (SMU) with anxiety and depression in patients with systemic lupus erythematosus (SLE).MethodsThe relevant data were collected from 402 SLE patients aged 18-60 years in the First Affiliated Hospital of Zhengzhou University between July 2018 and October 2018 for subsequent analysis. Demographic and clinical characteristics, the patterns of SMU, the reasons and barriers to SMU were recorded. Anxiety and depression were assessed using hospital anxiety and depression scale (HADS). Adjusted estimates of association were derived using logistic regression.ResultsThe incidence of anxiety and depression were 41.1% and 28.4% respectively among SLE patients with a mean score of 6.71±3.65 and 5.45±3.86 in each subscale. Patients without social media were more likely than those with social media to develop anxiety or depression (P 0.05, P 0.01). A correlation was found between the frequency of SMU and the incidences of anxiety (P 0.05) and depression (P 0.001), besides, the presences of depression also had a association with the duration for SMU (P 0.05).ConclusionDepression and anxiety are prevalent in patients with SLE and high frequency of SMU may decline the risks of anxiety and depression, to educate patients use social media properly may result in alleviation of anxious and depressive symptoms in patients with SLE.References[1] Macedo EA, Appenzeller S, Costallat LTL. Depression in systemic lupus erythematosus: gender differences in the performance of the Beck Depression Inventory (BDI), Center for Epidemiologic Studies Depression Scale (CES-D), and Hospital Anxiety and Depression Scale (HADS). Lupus 2018;27(2):179-89.[2] Jolly M, Sequeira W, Block JA, et al. Sex Differences in Quality of Life in Patients With Systemic Lupus Erythematosus. Arthritis Care Res (Hoboken) 2018[3] Tay SH, Cheung PP, Mak A. Active disease is independently associated with more severe anxiety rather than depressive symptoms in patients with systemic lupus erythematosus. Lupus 2015;24(13):1392-9.[4] Nikiphorou E, Studenic P, Ammitzboll CG, et al. Social media use among young rheumatologists and basic scientists: results of an international survey by the Emerging EULAR Network (EMEUNET). Ann Rheum Dis 2017;76(4):712-15.[5] Escobar-Viera CG, Shensa A, Bowman ND, et al. Passive and Active Social Media Use and Depress...