A Multi-Scale DNN Algorithm for Nonlinear Elliptic Equations with Multiple Scales

Algorithms based on deep neural networks (DNNs) have attracted increasing attention from the scientific computing community. DNN based algorithms are easy to implement, natural for nonlinear problems, and have shown great potential to overcome the curse of dimensionality. In this work, we utilize the multi-scale DNN-based algorithm (MscaleDNN) proposed by Liu, Cai and Xu (2020) to solve multi-scale elliptic problems with possible nonlinearity, for example, the p-Laplacian problem. We improve the MscaleDNN algorithm by a smooth and localized activation function. Several numerical examples of multi-scale elliptic problems with separable or non-separable scales in low-dimensional and high-dimensional Euclidean spaces are used to demonstrate the effectiveness and accuracy of the MscaleDNN numerical scheme.     

嘉兴市新居民儿童心理发育行为问题及影响因素分析

目的调查嘉兴市新居民儿童心理发育行为问题及影响因素，为改善新居民儿童心理健康提供理论依据。方法随机抽取新居民儿童548例，本地儿童1248例，采用自编量表评估儿童家庭影响因素，长处与困难问卷评估儿童心理发育行为问题，心理痛苦温度计评估主观心理痛苦程度，儿童心理虐待与忽视量表评估家庭教养方式，社会支持量表评估社会支持程度。结果新居民儿童主观评定心理痛苦程度高于本地儿童（P=0.002）。新居民儿童亲社会化行为低于本地儿童（P=0.000），多动/注意缺陷问题高于本地儿童（P=0.011）。儿童忽视虐待量表本地儿童5个因子得分低于新居民儿童：责骂因子（P=0.000）、恐吓因子（P=0.000）、情感忽视因子（P=0.000）、教育忽视因子（P=0.000）、身体忽视因子（P=0.000）。社会支持量表本地儿童3个因子得分均高于新居民儿童：客观支持（P=0.032）、主观支持（P=0.000）、对支持的利用度（P=0.000）。新居民儿童在新居民儿童学校、混合学校、本地儿童学校的3类学校中亲社会化行为、忽视因子、虐待因子、社会支持均有统计学差异（均P＜0.05）。结论新居民儿童较本地儿童心理发育行为明显落后，良好的家庭教养方式和有效的社会支持系统能够更快更好地促进其身心发育。     

新形势下八年制医学教育的再思考

新形势下，健康中国建设和我国卫生事业发展迫切需要具有国际竞争力的医学科学家和领军人才。在现行医学教育体系中，培养具有国际竞争力的未来医学科学家和领军人才是八年制医学教育的必然选择。创新八年制医学人才培养模式应汲取长学制试办经验，直面现存问题，聚焦创新能力和创新精神，构建以研究为基础的八年制医学人才培养模式，确立“目标引领、厚植基础、面向临床、聚集创新”的办学原则，为我国卫生事业培养具有国际竞争力的未来领军人才。     

Meta-Analysis of Saturated Fatty Acid Intake and Breast Cancer Risk

The associations between saturated fatty acid (SFA) consumption and risk of breast cancer (BC) remains inconclusive. Therefore, we conducted this meta-analysis to determine the quantitative relations between dietary SFA intake and incidence of BC.Literatures published up to April 2015 were systematically screened through Pubmed and Web of Science. Relevant publication quality was evaluated by conducting the Newcastle-Ottawa scale. We used fixed effects models or random effect models to calculate the summary relative risks (RRs) and odds ratios (ORs), and conducted sensitivity analyses and evaluated the publication bias.We identified a total of 52 studies (24 cohort studies and 28 case–control studies), with over 50,000 females diagnosed with BC. The associations between dietary SFA intake and risk of BC were 1.18 for case–control studies (high vs low intake, 95% confidence interval [CI] = 1.03–1.34) and 1.04 for cohort studies (95% CI = 0.97–1.11). When restricted analyses to population-based studies, positive associations were observed for both cohort (RR [95% CI] = 1.11 [1.01–1.21]) and case–control studies (OR [95% CI] = 1.26 [1.03–1.53]). Additionally, for case–control studies, significant positive associations between higher SFA intake and BC risk were observed for Asian (OR [95% CI] = 1.17 [1.02–1.34]) and Caucasian (OR [95% CI] = 1.19 [1.00–1.41]), as well as for postmenopausal women (OR = 1.33, 95% CI: 1.02–1.73). In contrast, higher dietary SFA intake was not associated with risk of BC among premenopausal women, in cohort studies or hospital-based studies.A positive association between higher dietary SFA intake and postmenopausal BC risk was observed in case–control but not in cohort studies. More studies are warranted to confirm these findings.     

补骨脂素抗增生性瘢痕作用机制研究

目的探讨补骨脂素抗增生性瘢痕的作用机制。方法体外培养成纤维细胞,按随机数字表法分为正常组(培养正常成纤维细胞)、瘢痕组(培养增生性瘢痕成纤维细胞)、TGF-β1组(10 ng/ml TGF-β1处理增生性瘢痕成纤维细胞5 min^12 h)、Smurf2 RNA干扰组[Smad泛素化调节因子2(Smad ubiquitin regulatory factor2,Smurf2)siRNA转染增生性瘢痕成纤维细胞72 h]、补骨脂素组(10μmol/L补骨脂素处理增生性瘢痕成纤维细胞继续培养72 h)、补骨脂素+TGF-β1组(增生性瘢痕成纤维细胞加入补骨脂素培养72 h后加入TGF-β1培养6 h)。采用Western blot法检测Smurf2、α-平滑肌肌动蛋白(α-actin SMA,α-SMA)蛋白表达;RT-PCR法检测Ⅰ型胶原蛋白mRNA表达;ELISA法检测TGF-β1蛋白分泌。结果与正常组比较,瘢痕组Smurf2蛋白[(0.83±0.08)比(0.38±0.07)]表达增加(P<0.05);与瘢痕组比较,Smurf2 RNA干扰组TGF-β1[(2.2±0.18)比(4.2±0.47)]表达降低(P<0.05);TGF-β1组Smurf2[(0.71±0.06)比(0.42±0.04)]、α-SMA[(1.42±0.12)比(0.91±0.09)]蛋白表达增加(P<0.05),Ⅰ型胶原蛋白mRNA[(0.72±0.09)比(0.41±0.07)]表达增加(P<0.05);补骨脂素组Smurf2[(0.05±0.01)比(0.42±0.04)]、α-SMA[(0.71±0.07)比(0.91±0.09)]蛋白表达降低(P<0.05),Ⅰ型胶原蛋白mRNA表达[(0.12±0.04)比(0.41±0.07)]降低(P<0.05)。结论补骨脂素可能通过TGF-β1/Smurf2信号通路抑制α-SMA蛋白表达,从而降低Ⅰ型胶原蛋白表达,起到抑制瘢痕形成的作用。