A High Order Bound Preserving Finite Difference Linear Scheme for Incompressible Flows

We propose a high order finite difference linear scheme combined with a high order bound preserving maximum-principle-preserving (MPP) flux limiter to solve the incompressible flow system. For such problem with highly oscillatory structure but not strong shocks, our approach seems to be less dissipative and much less costly than a WENO type scheme, and has high resolution due to a Hermite reconstruction. Spurious numerical oscillations can be controlled by the weak MPP flux limiter. Numerical tests are performed for the Vlasov-Poisson system, the 2D guiding-center model and the incompressible Euler system. The comparison between the linear and WENO type schemes, with and without the MPP flux limiter, will demonstrate the good performance of our proposed approach.     

以宫腔积液为首发症状的胃型宫颈腺癌1例报道并文献复习

宫腔积液指宫腔内液体积存(积水、积血或积脓),是绝经后女性常见体征之一,常于超声检查时发现。持续宫腔积液患者,需宫腔镜检查寻找病因。本文报道1例以宫腔积液为首发症状,经宫腔镜检查确诊为胃型宫颈腺癌的患者。通过病例回顾并文献复习,以期为更多绝经后宫腔积液及宫颈病变的诊断提供参考,避免漏诊及误诊。1病例资料患者67岁,女,主因"绝经18年,不规则阴道出血2月"于2020年5月就诊于首都医科大学附属北京妇产医院妇科微创中心。     

Glucose starvation induces resistance to metformin through the elevation of mitochondrial multidrug resistance protein 1

Metformin, a drug for type 2 diabetes mellitus, has shown therapeutic effects for various cancers. However, it had no beneficial effects on the survival rate of human malignant mesothelioma (HMM) patients. The present study was performed to elucidate the underlying mechanism of metformin resistance in HMM cells. Glucose‐starved HMM cells had enhanced resistance to metformin, demonstrated by decreased apoptosis and autophagy and increased cell survival. These cells showed abnormalities in mitochondria, such as decreased ATP synthesis, morphological elongation, altered mitochondrial permeability transition pore and hyperpolarization of mitochondrial membrane potential (MMP). Intriguingly, Mdr1 was significantly upregulated in mitochondria but not in cell membrane. The upregulated mitochondrial Mdr1 was reversed by treatment with carbonyl cyanide m‐chlorophenyl hydrazone, an MMP depolarization inducer. Furthermore, apoptosis and autophagy were increased in multidrug resistance protein 1 knockout HMM cells cultured under glucose starvation with metformin treatment. The data suggest that mitochondrial Mdr1 plays a critical role in the chemoresistance to metformin in HMM cells, which could be a potential target for improving its therapeutic efficacy.     

Influences of simulated gastrointestinal environment on physicochemical properties of gold nanoparticles and their implications on intestinal epithelial permeability

Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H₂O₂. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability.     

Ginsenoside Rg1 prevents acetaminophen-induced oxidative stress and apoptosis via Nrf2/ARE signaling pathway

Inappropriate use of acetaminophen (APAP) can lead to morbidity and mortality secondary to hepatic necrosis. Ginsenoside Rg1 is a major active ingredient in processed Panax ginseng, which is proved to elicit biological effects. We hypothesized the beneficial effect of Rg1 on APAP-mediated hepatotoxicity was through Nrf2/ARE pathway. The study was conducted in cells and mice, comparing the actions of Rg1. Rg1 significantly improved cell survival rates and promoted the expression of antioxidant proteins. Meanwhile, Rg1 reduced the excessive ROS and the occurrence of cell apoptosis, which were related to Nrf2/ARE pathway. Expression of Nrf2 has a certain cell specificity.

     

骨形态发生蛋白2及碱性成纤维生长因子2对大鼠骨髓间充质干细胞膜片增殖和成骨分化的影响

文题释义： 细胞膜片技术：是在体外接种培养高密度的细胞，使其相互融合生长至100%而形成的透明致密膜状物。该技术不需要胰酶消化即可收集细胞，因此保留了大量的胞外基质、细胞间连接以及细胞-基质连接等结构。目前细胞膜片技术已成为组织工程领域的研究热点，已被推广应用于牙周膜、角膜、心脏、软骨、食管等多种组织器官修复。 成骨细胞：主要由内外骨膜和间充质始祖细胞分化而来，在复杂的骨形成过程中发挥着主要的功能，承担着骨基质的合成、分泌和矿化。骨髓间充质干细胞具有多向分化潜能，能定向分化为成骨细胞，其成骨分化过程可受多种因素的影响，如细胞因子的调控、遗传因素和激素水平等。背景：现阶段骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖、成骨分化的影响和作用机制还尚未可知，如何将生长因子与组织工程细胞膜片技术相整合，最终将其用于骨缺损修复具有重要意义。 目的：探讨单独及联合应用骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖和成骨分化的影响。 方法：体外分离培养鉴定SD大鼠骨髓间充质干细胞并构建细胞膜片，选用不同质量浓度的骨形态发生蛋白2和碱性成纤维生长因子2单独及联合诱导骨髓间充质干细胞膜片，CCK-8法结合碱性磷酸酶活性检测确定2种因子促进膜片增殖和成骨分化的最佳有效质量浓度；然后对骨髓间充质干细胞膜片进行成骨诱导，通过大体及显微镜观察、Vonkossa染色、茜素红染色、RT-PCR检测相关成骨标志物来评估诱导效果。 结果与结论：单独应用骨形态发生蛋白2可增强骨髓间充质干细胞膜片的碱性磷酸酶活性，最佳质量浓度为100 μg/L(P < 0.001)，单独应用碱性成纤维生长因子2能加速骨髓间充质干细胞膜片的增殖，最佳质量浓度为20 μg/L(P < 0.001)，而联合应用既可以促进膜片增殖又能提高其碱性磷酸酶活性(P < 0.001)；经成骨诱导后，4组膜片在形态学上无明显差异，均能诱导骨髓间充质干细胞膜片的成骨分化，其中联合组钙结节最明显(P < 0.001)，可显著促进膜片晚期成骨分化并抑制其早期成骨分化，具有明显的协同促进作用(P < 0.001)。结果表明，骨形态发生蛋白2和碱性成纤维生长因子2联合应用时具有协同作用，既可以促进骨髓间充质干细胞膜片增殖，又能显著增强其成骨诱导能力。ORCID: 0000-0003-1918-579X(何惠宇) 中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程     

中医健康状态辨识模式的研究现状与展望

健康状态的辨识是把握健康的前提。当前学界已存在专家辨识模式、标准辨识模式、数字辨识模式、智能辨识模式以及微观辨识模式等。联合多种辨识方法,构建健康状态辨识体系,形成常态与动态结合、主观与客观结合、人机互参的中医健康状态个体化辨识方法是研究的趋势所在。文章对未来的研究方向进行展望,探讨了多元辨识模式、远程辨识模式、终身辨识模式、自动辨识模式的思路方法,以期促进全民健康事业,助力"健康中国"战略。