361 research outputs found

    中国文学和日本文学

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    Chinese characters were used solely to transcribe the original Japanese, which is considered nonliterate. But Japanese people gradually began to discover the original meanings of the Chinese characters, and learned to make effective use of the Chinese characters using Japanese techniques, such as Kun-doku. A new culture was created through contact between different cultures, forcing the old culture to adapt. Such contact occurs not only in classical literature, but also in modern society

    瓦斯爆炸冲击波传播过程的数值模拟

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    建立瓦斯爆炸沿巷道传播的分析模型,运用DYTRAN软件进行分析,得到瓦斯爆炸冲击波沿巷道的传播过程的参数变化及障碍物表面的等效应力分布。结果表明,应用DYTRAN可以很好地模拟瓦斯爆炸传播过程及冲击波对障碍物的短暂的瞬态动力学过程,对进行矿难救生系统的设计研究有重要意义

    Dynamic Response of a Life-saving Ball System to the Shock Wave of Gas Explosion

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    介绍矿难救生球系统(简称球)的原理及结构,构建巷道空间和球的分析模型,运用数值分析的方法,分别选择3种球体材料和3种球体厚度进行计算,对该系统在瓦斯爆炸冲击波作用下的动态响应进行研讨,分析冲击波作用下球表面的变形、等效应力、等效塑性应变以及球体材料、厚度等因素对球动态响应的影响。结果表明:运用数值分析的方法,可以为救生球系统设计建立一个仿真的实验环境,为优化系统设计、提高设计效率提供参考数据。The principle and structure of a life-saving ball system(referred to as 'ball' for short hereinafter)were introduced. Analytical model of the laneway space and the ball were established. By selecting three kinds of balls with different materials and thickness for calculation, the dynamic response of the ball to the shock wave of gas explosion was respectively analyzed with numerical analysis methods. The analysis focused on the deformation, the equivalent stress and the equivalent plastic strain of the surface of the ball under shock wave, and the effect of the material and thickness on the dynamic response of the ball. The analysis results show that a simulation experimental environment can be established and reference data can be provided for the design of a life-saving ball system by using numerical analysis methods.福建省重点项目(2006Z0027

    血管紧张素Ⅱ及醛固酮阻滞剂对心肌梗死大鼠骨桥蛋白表达的影响

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    【目的】研究血管紧张素Ⅱ及醛固酮阻滞对心肌梗死大鼠非梗死区心肌组织骨桥蛋白(OPN)表达的影响。【方法】将心肌梗死后24h存活大鼠随机分为3组:盐水组(15只,5mL/d),培哚普利组(18只,2mg/kg·d)和螺内酯组(17只,20mg/kg)。灌胃给药;另设假手术组(15只)作对照。分别于心肌梗死后6周:导管法测定左室有创血流动力学;组织学方法检测非梗死区胶原纤维沉积和心肌细胞横径;Western blot检测非梗死区心肌组织OPN表达。【结果】①假手术组大鼠心肌组织Western blot未检测到OPN表达,心肌梗死大鼠6周后非梗死区心肌组织有大量OPN表达,培哚普利及螺内酯治疗均能显著抑制该蛋白的上调,差别均有统计学意义(P均〈0.01)。②与假手术组相比,所有心肌梗死大鼠均出现显著的心肌间质纤维沉积,左室重量指数增大,非梗死区心肌细胞横径增加,差别均有统计学意义(P均〈0.01)。与盐水组相比,培哚普利及螺内酯组心肌问质纤维沉积减轻,左室重量指数及非梗死区心肌细胞横径降低,差别均有统计学意义(P均〈0.01)。③与假手术组相比,所有心肌梗死大鼠6周后左室内收缩压(LVSP)和±dp/dtmax均显著下降,左室舒张末期压(LVEDP)显著上升,差别均有统计学意义(P均〈0.01);与盐水组相比,培哚普利与螺内酯组大鼠心功能显著改善,差别均有统计学意义(P均〈0.01)。【结论】心肌梗死后大鼠非梗死区心肌组织出现大量OPN表达及显著的心室重构;血管紧张素Ⅱ及醛固酮阻滞均能显著抑制心肌梗死大鼠OPN的表达,并能改善心肌的纤维化,改善心脏功能

    氧化石墨烯改性高温环氧树脂基碳纤维复合材料的热性能与力学性能

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    采用湿法预浸技术和模压工艺,制备了氧化石墨烯(GO)改性碳纤维/环氧树脂(CF/E54-DDS)混杂复合材料,利用差示扫描量热分析(DSC)、动态热机械分析(DMTA)、无损C扫描等开展了GO对复合材料的热固化性能、凝胶工艺性、动态热机械性能以及抗冲击损伤性能等的影响研究。结果表明,GO结构中的羟基、羧基会促进改性树脂体系的固化反应,GO/E54-DDS的固化反应比E54-DDS的提前,反应变得和缓,且会加速固化反应的进行;在GO含量小于0.5%时,GO的活性基团可增加改性体系的交联密度而提高复合材料的玻璃化转变温度,但GO含量大于0.8%时,会因DDS在固化网络结构中的占比下降较大,反而降低复合材料的玻璃化转变温度;GO/CF/E54-DDS预浸料比CF/E54-DDS表现出更好的浸润效果;CF/E54-DDS复合材料破坏后碳纤维表面光洁,破坏主要发生在碳纤维与树脂基体的界面,而GO/CF/E54-DDS复合材料破坏后,碳纤维表面紧密粘附着GO/E54-DDS固化物,破坏主要发生在碳纤维织物层间的GO/E54-DDS区域;GO的存在提高了GO/CF/E54-DDS复合材料抵抗横向裂纹和纵向裂纹扩展的能力,复合材料的损伤投影面积和凹坑深度减小,提高了冲击后压缩强度。航空科学基金(2016ZF68011);;福建省科技创新平台建设计划(2014H2006);;福建省自然科学基金(2015J01222);;厦门大学石墨烯工业技术研究院资助项目(2014I2005

    Hippo Signaling Suppresses Cell Ploidy and Tumorigenesis through Skp2

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    大多数真核生物的体细胞是二倍体,即仅含有两组染色体,分别遗传自父本和母本。而一些特定组织如心脏、肝脏等就含有多倍体细胞,特别是肝脏组织含有较高比例的四、八倍体等多倍体细胞。肝脏是人体的重要解毒器官,同时酒精、肝炎病毒等毒性物质或毒性代谢物容易诱发肝细胞的基因突变,多倍体被认为有利于提供代偿性的正常基因来维持肝脏稳态。然而肝脏受损后,多倍体细胞将会受胁迫进行增殖,再生修复受损的肝组织。因此研究机体调控多倍体细胞产生及多倍体细胞进行细胞分裂的调控机理对于理解肝癌的发病机理和肝癌的治疗至关重要。Hippo信号通路在调节组织成体干细胞的分化和增殖,调控器官再生与尺寸大小中具有重要作用。深入研究发现, Hippo信号通路下游效应分子YAP通过AKT-SKP2信号促进二倍体细胞向多倍体转化及多倍体细胞的生长增殖。本项研究阐明了Hippo缺失及YAP激活促进多倍体细胞产生及增殖作为肝癌发生发展中的一个重要机制,为肝癌诊疗提供了新的策略。 周大旺,博士,厦门大学生命科学学院教授、副院长、国家杰出青年基金获得者。【Abstract】Polyploidy can lead to aneuploidy and tumorigenesis. Here, we report that the Hippo pathway effector Yap promotes the diploid-polyploid conversion and polyploid cell growth through the Akt-Skp2 axis. Yap strongly induces the acetyltransferase p300-mediated acetylation of the E3 ligase Skp2 via Akt signaling. Acetylated Skp2 is exclusively localized to the cytosol, which causes hyper-accumulation of the cyclin-dependent kinase inhibitor p27, leading to mitotic arrest and subsequently cell polyploidy. In addition, the pro-apoptotic factors FoxO1/3 are overly degraded by acetylated Skp2, resulting in polyploid cell division, genomic instability, and oncogenesis. importantly, the depletion or inactivation of Akt or Skp2 abrogated Hippo signal deficiency-induced liver tumorigenesis, indicating their epistatic interaction. Thus, we conclude that Hippo-Yap signaling suppresses cell polyploidy and oncogenesis through Skp2.该研究工作获得了国家自然科学基金委、国家重点基础研究发展计划(973)项目、青年千人计划和中央高校基本科研基金的资助。 The Yap (S127A) transgenic mice were kindly provided by Dr. Fernando Camargo from Harvard Medical School, Boston, MA. D.Z. and L.C. were supported by the National Natural Science Foundation of China (31625010,U1505224, and J1310027 to D.Z.; 81422018, U1405225, and 81372617 to L.C.; 81472229 to L.H.), the National Basic Research Program (973) of China (2015CB910502 to L.C.), the Fundamental Research Funds for the Central Universities of China-Xiamen University (20720140551 to L.C. and 2013121034 and 20720140537 to D.Z.)

    一维平推流反应器动态模型的新型求解方法

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    目前对一维平推流反应器动态模型求解时,常将反应体系中气体的体积流量假设为恒定参数。由于实际过程中气体的体积流量会随着温度等相关参数的改变而不断变化,该假设会对模拟结果带来一定的误差。本文针对此问题提出一种新的求解方法:首先通过有限差分法将动态模型中的空间和时间变量均离散化得到相应的代数方程组,再结合气体状态方程,推导出浓度关于气体摩尔流量和温度的函数,然后联立方程组进行求解;此方法有效克服了动态模拟中由于气体的体积流量变化而导致模型方程难以求解的困难。将所提出的方法应用于丙酮气相裂解生成乙烯酮过程的动态模拟,并将所得到的模拟结果与线上法动态模拟的结果进行比较,结果表明所提出的求解方法得到的模拟结果更加精确。国家自然科学基金面上项目(21576228

    Effect of geniposide on the lipid metabolism and inflammatory injury of nonalcoholic fatty liver disease in the hamster

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    目的:观察栀子苷对高脂饮食诱导的金黄地鼠非酒精性脂肪性肝病模型脂质代谢、肝组织病理变化及炎症损伤的影响,并与栀子进行比较,以明确栀子抗脂肪肝作用的效应成分。方法:24只雄性金黄地鼠按随机数字表法分为正常组、模型组、栀子组和栀子苷组。实验后观察肝组织病理学变化,并检测肝组织Tg含量、血清Tg、CHO含量及AlT、AST活性。结果:与模型组比较,栀子组、栀子苷组肝Tg含量、血清Tg、CHO含量及AlT、AST活性均显著降低,且栀子苷对AlT、AST活性的降低作用优于栀子。结论:栀子苷与栀子对高脂饮食诱导的地鼠脂肪肝均有显著干预作用,且栀子苷抗炎症损伤作用优于栀子。Objective: To observe geniposide's effect on lipid metabolism,hepatic tissue pathological change and inflammatory injury of golden hamsters with nonalcoholic fatty liver disease( NAFLD),caused by high fat diet.Compare the geniposide's effect with gardenia to make clear the effective components in Gardenia that can resist fatty liver.Methods: 24 male golden hamsters were averagely divided into control group,model group,gardenia group and geniposide group.The experiment was based on building the model,and then observe hamsters 'general condition and pathological change of hepatic tissue,examine the content of hepatic tissue TG,serum TG,CHO and the activity of ALT,AST.Results: In gardenia group and gardenoside group,The content of hepatic tissue TG,serum TG,CHO and the activity of ALT,AST are significantly lower than the model group.Besides,gardenoside can lower the activity of ALT,AST better than gardenia.Conclusion: Both gardenoside and gardenia have notable intervention effects on hamsters' NAFLD caused by HFD and gardenoside have better effects on resisting inflammatory injury than gardenia,which suggested that gardenoside was the primary effective component in resisting NAFLD.国家自然科学基金面上项目(81274155); 厦门市重大科技计划项目(3502Z20100006

    Jiangzhi and Hepatoprotective effect of salidroside on nonalcoholic fatty liver disease

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    目的:探讨中药红景天的主要成分红景天苷对高脂饮食诱导的金黄地鼠非酒精性脂肪性肝炎(nASH)的干预作用。方法:18只雄性金黄地鼠随机分成正常组、模型组和红景天苷组,除正常组外,其余两组均给予高脂饮食喂养6周以复制nASH模型;造模第3周起,红景天苷组给予红景天苷药液灌胃4周。6周后处死地鼠,收集标本,检测肝组织甘油三酯(Tg)含量,血清天门冬氨酸氨基转移酶(AST)活性,对肝组织进行HE染色。结果:红景天苷能明显降低肝组织Tg含量及血清AST活性,改善肝组织脂肪变性的病理状态。结论:红景天苷具有显著的抗nASH病理损伤的药理效应。Objective:To explore the intervening effect of the main components of the rhodiola on the nonalcoholic fatty liver disease(NAFLD) for male golden hamsters induced by high-fat diets.Methods:Total 18 male golden hamsters were divided into control group,model group and salidroside group randomly.Male golden hamsters in the model group and salidroside group were fed with high fat diet for 6 weeks to reproduce NAFLD model.After the second week of feeding,male golden hamsters in the salidroside group were given a gavage of salidroside.All male golden hamsters were put to death at the 6 weeks and samples were collected.Hepatic tissue TG contents were detected.Serum AST activities were determined.Hepatic tissues were detected by HE staining.Results:Salidroside decreased hepatic tissue TG contents,serum AST activities and reduced the fatty degeneration in hepatocytes significantly.Conclusion:Salidroside has conspicuous pharmacological effect on the nonalcoholic fatty liver disease in male golden hamsters.国家自然科学基金(No.81274155); 厦门市重大科技计划项目(No.3502Z20100006); 横向课题(No.XDHT2011366A)~

    Mechanism of geniposide in improving free fatty acid metabolism in rats with non-alcoholic fatty liver disease

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    观察栀子苷改善非酒精性脂肪性肝病的效果,从游离脂肪酸探讨栀子苷调节非酒精性脂肪性肝病的作用机制。健康雄性Wistar大鼠40只,随机分为4组:正常组、模型组、栀子苷组和血脂康组,每组大鼠10只,正常组大鼠给予正常大鼠饲料喂养,其余3组大鼠均采用高脂饲料喂养以诱导非酒精性脂肪性肝病,造模时间为8周,从第5周起至第8周末,栀子苷组和血脂康组分别灌服相应的药物。记录大鼠体重、肝湿重、脂肪质量;用相应方法检测肝组织TG,FFA,FAS,AMPK,ACCase及Malonyl-Co A含量,血清CHO,LDL-C的含量,血清AST,ALT的活性;观察肝脏组织肉眼及病理变化(HE染色法)。结果显示,与正常组相比,模型组大鼠的体重;肝湿重;脂肪重;血清CHO,LDL-C,ALT,AST;肝组织TG,FFA,FAS,ACCase及Malonyl-Co A含量皆显著升高(P<0.01);肝组织AMPK活性显著降低(P<0.01),肝组织肉眼外观及病理切片脂肪变性明显,并出现炎症损伤;与模型组相比,栀子苷组大鼠体重、脂肪质量、肝组织FFA含量、血清ALT,AST活性均显著降低(P<0.01),肝湿重,肝组织TG,FAS,ACCase及Malonyl-Co A含量明显降低(P<0.05),肝组织AMPK活性明显增多(P<0.05),肝脏肉眼外观及病理学表现均有所改善;与模型组相比,血脂康组大鼠的肝湿重、脂肪质量、肝组织TG,FFA和血清LDL-C水平明显降低(P<0.05);与血脂康组相比,栀子苷组大鼠的体重、脂肪质量、肝组织FFA含量均显著降低(P<0.01),其他方面无明显差异。结果表明,栀子苷具有显著的改善高脂饮食诱导的大鼠非酒精性脂肪性肝病的药理效应;其改善大鼠非酒精性脂肪性肝病的游离脂肪酸代谢是通过调节"AMPK-ACCase-Malonyl-Co A-FFA"轴来实现的。To observe the effect of geniposide on non-alcoholic fatty liver disease( NAFLD),and discuss the mechanism of geniposide for NAFLD from the aspect of free fatty acid,forty healthy Wistar male rats were randomly divided into normal group,model group,geniposide and Xuezhikang group. The rats in normal group were fed with normal diets,and the rats in other 3 groups were given with high-fat diet for 8 weeks to induce the NAFLD models. From the week 5 to end of week 8,the rats in geniposide and Xuezhikang group were intervened with corresponding medicines. The body weight,liver wet weight,and fat weight of the rats were recorded.Visual and pathological changes in hepatic tissues were observed with HE staining. The contents of TG,FFA,FAS,AMPK,ACCase and Malonyl-Co A in hepatic tissue,contents of CHO and LDL-C in serum and activities of AST and ALT in serum were detected by using corresponding methods. The results showed that the body weight,liver wet weight,and fat weight of the rats,CHO,LDL-C,ALT and AST levels in serum,TG,FFA,FAS,ACCase and Malonyl-Co A levels in hepatic tissues of the rats in model group were significantly higher than those in normal group( P < 0. 01),while AMPK activity was significantly lower than that of the normal group( P < 0. 01),with obvious visual and pathological steatosis in hepatic tissues,and inflammatory injury occurred in model group. Compared with the model group,body weight of the rat,fat weight,levels of FFA in hepatic tissues,ALT and AST activities in serum,liver wet weight,TG,FAS,ACCase and Malonyl-Co A levels were significantly decreased in geniposide group( P < 0. 01),while the AMPK activity in hepatic tissues was significantly increased( P < 0. 05),with improvement in visual and pathological performance.Compared with the model group,liver wet weight,fat weight,TG and FFA levels in hepatic tissues,and LDL-C level in serum were significantly decreased in Xuezhikang group( P < 0. 05). Compared with Xuezhikang group,the body weight of rat,fat weight and FFA level in hepatic tissues were significantly lower in geniposide group( P < 0. 01),but with no significant difference in other aspects. These findings indicated that geniposide was highly effective in improving the pharmacological effect of NAFLD induced by highfat diet,and the mechanism was achieved through AMPK-ACCase-Malonyl-Co A-FFA axis.国家自然科学基金项目(81274155;81503529);; 福建省自然科学基金项目(2014J01374);; 福建省高等学校新世纪人才计划项目;; 厦门市科技计划项目(3502Z20134020);; 福建省中医药科研项目(WZPW201308
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