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101.
Skeletal myogenesis is essential for the maintenance of muscle quality and quantity, and impaired myogenesis is intimately associated with muscle wasting diseases. Although microRNA (miRNA) plays a crucial role in myogenesis and relates to muscle wasting in obesity, the molecular targets and roles of miRNAs modulated by saturated fatty acids (SFA) are largely unknown. In the present study, we investigated the role of miR-320-3p on the differentiation of myogenic progenitor cells. Palmitic acid (PA), the most abundant dietary SFA, suppressed myogenic factors expression and impaired differentiation in C2C12 myoblasts, and these effects were accompanied by CFL2 downregulation and miR-320-3p upregulation. In particular, miR-320-3p appeared to target CFL2 mRNA directly and suppress the expression of CFL2, an essential factor for filamentous actin (F-actin) depolymerization. Transfection of myoblasts with miR-320-3p mimic increased F-actin formation and nuclear translocation of Yes-associated protein 1 (YAP1), a key component of mechanotransduction. Furthermore, miR-320-3p mimic increased myoblast proliferation and markedly impeded the expression of MyoD and MyoG, consequently inhibiting myoblast differentiation. In conclusion, our current study highlights the role of miR-320-3p on CFL2 expression, YAP1 activation, and myoblast differentiation and suggests that PA-inducible miR-320-3p is a significant mediator of muscle wasting in obesity.  相似文献   
102.
Sedimentary records of DDT and HCH in the Pearl River Delta,South China   总被引:2,自引:0,他引:2  
Tropical regions in developing countries are thought to be significant sources of organochlorine pesticides in the global context, owing to high rate of use and only a recent production ban or restriction on application of these pesticides. In the present paper, DDT and HCH in eight 210Pb-dated sedimentary cores from the Pearl River Delta, South China, were analyzed in order to reconstruct the time trends of these persistent organic pollutants in this tropical region. The sedimentary inventories of sigmaDDT and sigmaHCH through the cores ranged from 36.6 to 1109.5 ng/cm2 and from 11.2 to 226.3 ng/cm2, respectively, and their spatial distribution implies that the water flows from the Humen, Jiaomen, Hongqili, and Hengmen outlets rather than the Xijiang flow from Modaomen outlet, supplied the major historical input of DDT to the estuary. Although a production ban of technical HCH and DDT was imposed in China in 1983, their sedimentary fluxes display increasing trends or strong rebounds in the 1990s as recorded in the core profiles, characteristic of the increasing ratios of (DDE + DDD)/DDT and DDE/DDT. It is suggested that an enhanced land soil runoff in the process of large-scale land transform, as well as a higher river water flow in early 1990s, had mobilized these pesticides from soil to the sedimentary system in the region.  相似文献   
103.
刘麦 《食品与机械》2020,(10):93-95,109
文章通过阐述机器人原型技术在食品装备设计中的应用实例,阐释了机器人原型技术的基本操作路线及其优势,证明该技术作为降低开发新型食品设备成本的方法具有较好的使用价值和实际意义。  相似文献   
104.
Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and has a unique metastatic route using ascites, known as the transcoelomic root. However, studies on ascites and contained cellular components have not yet been sufficiently clarified. In this review, we focus on the significance of accumulating ascites, contained EOC cells in the form of spheroids, and interaction with non-malignant host cells. To become resistant against anoikis, EOC cells form spheroids in ascites, where epithelial-to-mesenchymal transition stimulated by transforming growth factor-β can be a key pathway. As spheroids form, EOC cells are also gaining the ability to attach and invade the peritoneum to induce intraperitoneal metastasis, as well as resistance to conventional chemotherapy. Recently, accumulating evidence suggests that EOC spheroids in ascites are composed of not only cancer cells, but also non-malignant cells existing with higher abundance than EOC cells in ascites, including macrophages, mesothelial cells, and lymphocytes. Moreover, hetero-cellular spheroids are demonstrated to form more aggregated spheroids and have higher adhesion ability for the mesothelial layer. To improve the poor prognosis, we need to elucidate the mechanisms of spheroid formation and interactions with non-malignant cells in ascites that are a unique tumor microenvironment for EOC.  相似文献   
105.
李颖  逯迈  陈小强 《激光技术》2007,31(4):442-444
为了研究脊槽波导主模截止特性,采用亥姆霍兹方程的有限差分格式,计算在窄边与宽边比为0.45、槽的高度与窄边比为0.4的条件下,脊槽波导中脊和槽的几何尺寸在中间位置连续变化时的归一化截止波长。并且计算了当脊宽为0、脊槽间距为窄边长度加槽高度,即脊槽波导的脊消失,成为单槽波导的归一化截止波长。并将计算结果与单槽波导和单脊波导的进行对比。结果表明,脊槽波导的截止特性较单脊波导和单槽波导更加良好。  相似文献   
106.
熔融聚合法直接合成聚乳酸的研究   总被引:38,自引:5,他引:38  
以L一乳酸单体为原料,系统地研究了熔融聚合法直接合成聚乳酸的最佳工艺条件,即:选择氯化亚锡为催化剂,用量0.5wt%,在聚合温度180℃、绝对压力70Pa下反应10h,可获得较高分子量的聚乳酸。  相似文献   
107.
采用聚丁二烯接枝苯乙烯-丙烯腈共聚物(PB-g-SAN)与苯乙烯-丙烯腈共聚物(SAN)熔融共混,制备了一系列丙烯腈-丁二烯-苯乙烯共聚树脂(ABS),考察了橡胶含量对该ABS树脂物理力学性能的影响。结果表明:随着橡胶含量的增加,ABS树脂的拉伸强度、弯曲强度、弯曲模量、熔体流动速率、热变形温度、密度和硬度均有所降低,而缺口冲击强度和断裂伸长率提高。因此可通过调节橡胶含量来制备具有不同物理力学性能的ABS树脂,以满足不同的应用需要。  相似文献   
108.
The development of chronic kidney disease (CKD) following an episode of acute kidney injury (AKI) is an increasingly recognized clinical problem. Inhibition of toll-like receptor 4 (TLR4) protects renal function in animal models of AKI and has become a viable therapeutic strategy in AKI. However, the impact of TLR4 inhibition on the chronic sequelae of AKI is unknown. Consequently, we examined the chronic effects of TLR4 inhibition in a model of ischemic AKI. Mice with a TLR4-deletion on a C57BL/6 background and wild-type (WT) background control mice (C57BL/6) were subjected to bilateral renal artery clamping for 19 min and reperfusion for up to 6 weeks. Despite the acute protective effect of TLR4 inhibition on renal function (serum creatinine 1.6 ± 0.4 mg/dL TLR4-deletion vs. 2.8 ± 0.3 mg/dL·WT) and rates of tubular apoptosis following ischemic AKI, we found no difference in neutrophil or macrophage infiltration. Furthermore, we observed significant protection from microvascular rarefaction at six weeks following injury with TLR4-deletion, but this did not alter development of fibrosis. In conclusion, we validate the acute protective effect of TLR4 signal inhibition in AKI but demonstrate that this protective effect does not mitigate the sequential fibrogenic response in this model of ischemic AKI.  相似文献   
109.
张媛  杨丹丹  王佳奕  徐迈  王凤武 《广州化工》2020,48(14):10-12,37
对TiO_2纳米管进行改性可进一步提高光催化性能,TiO_2纳米管的改性方式主要有三种:非金属离子掺杂、金属改性和半导体复合。本文主要介绍金属改性TiO_2纳米管的制备方法和光催化性能,金属改性分为金属离子掺杂和贵金属负载,金属离子掺杂主要介绍Fe和Zr,贵金属负载介绍Ag、Au、Pt。改性后的TiO_2纳米管有效地抑制了光生载流子的复合,因此具有比纯TiO_2纳米管更好光催化性能,降解有机污染物的效率更高。  相似文献   
110.
The fatty acid content and composition of 18 species of freshwater fish filets were determined. The fat content and composition varied with anatomical location. The anterior ventral regions of trout and salmon contained more lipids than the posterior dorsal sections. Marked variations in fatty acid composition between species were observed. Palmitic (C16:0), palmitoleic (C16:1), oleic (C18:l), eicosapentaenoic (C20:5 ω3), and docosahexaenoic (C22:6 ω3) were the most abundant fatty acids. The fatty acids were tabulated according to the number and positions of the double bonds. Significant quantities of ω6 C18:2 and C20:4 fatty acids were found in several species.  相似文献   
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