高糖对人角膜上皮细胞创伤修复中Cyclin D1蛋白表达的影响

目的:研究高糖环境对人角膜上皮细胞损伤修复的影响,初步探讨Cyclin D1蛋白在高糖培养的角膜上皮细胞创伤愈合中表达的意义。方法:模拟糖尿病角膜病变的高糖微环境,人角膜上皮细胞经复苏、培养传代后,分别设置等体积蒸馏水的DMEM完全培养基的正常对照组和含25mmol/L葡萄糖的DMEM完全培养基高糖处理组的两组细胞,细胞长满后进行划伤刺激,倒置相差显微镜下观察比较各组细胞生长状况及其变化,于不同时间点(0、12、24、48和72h)利用Western blot检测分析高糖培养的角膜上皮细胞中Cyclin D1蛋白的表达,qRT-PCR检测Cyclin D1 mRNA水平相对表达情况。结果:体外高糖处理条件下,人角膜上皮细胞划伤后修复速度减慢,漂浮细胞增多,细胞重新贴壁少,细胞间距增加,随着高糖处理时间的延长,细胞状态变差,生长速度慢;正常组细胞损伤修复较快,细胞密度增大,且形态规则,细胞膜光滑。Western blot检测划伤刺激上调Cyclin D1的表达,但随着时间延长上调作用呈逐渐减弱,两组Cyclin D1最高表达量均出现在12h。高糖处理组Cyclin D1表达量低于正常对照组。qRT-PCR结果显示:高糖处理后,Cyclin D1 mRNA表达呈上调趋势,但随着高糖处理时间延长,上调作用减弱,且在48h处mRNA水平恢复至与对照组同一水平。结论:在角膜上皮细胞创伤愈合过程中,高糖呈负性调节,抑制Cyclin D1蛋白的表达,且与角膜上皮细胞增殖能力下降及凋亡相关。

高糖培养人晶状体上皮细胞创伤后Cyclin D1的表达

目的:观察高糖培养的人晶状体上皮细胞在创伤刺激后Cyclin D1的表达情况。方法:采用MTT法观察不同浓度葡萄糖对体外培养的人晶状体上皮细胞(HLEB3)作用24h后细胞增殖活性的影响,确定最适葡萄糖作用浓度。将HLEB3细胞分为高糖预处理组(高糖培养基预处理24h后再更换高糖培养基培养)和非高糖预处理组(正常培养基培养24h后再更换高糖培养基培养),根据更换高糖培养基时是否进行划伤处理将细胞分为对照组和划伤组,分别采用qRT-PCR和Western blot法检测各组细胞创伤后不同时间点Cyclin D1 mRNA和蛋白的表达情况。结果:一定浓度范围的葡萄糖能够增强细胞增殖活性,25.5mmol/L葡萄糖处理时细胞活性最强。高糖预处理细胞Cyclin D1表达在一定时间范围内呈时间依赖性表达下调;非高糖预处理细胞Cyclin D1表达呈不规律性,在12h和48h处表达上调;划伤处理可在一定程度上刺激细胞Cyclin D1表达上调。结论:葡萄糖对人晶状体上皮细胞活性及Cyclin D1表达的影响呈现不规律性,创伤处理可在一定程度上上调细胞Cyclin D1的表达。

End-point dynamic control of basic oxygen furnace steelmaking based on improved unconstrained twin support vector regression

In order to improve the end-point hit rate of basic oxygen furnace steelmaking,a novel dynamic control model was proposed based on an improved twin support vector regression algorithm.The controlled objects were the end-point carbon content and temperature.The proposed control model was established by using the low carbon steel samples collected from a steel plant,which consists of two prediction models,a preprocess model,two regulation units,a controller and a basic oxygen furnace.The test results of 100 heats show that the prediction models can achieve a double hit rate of 90%within the error bound of 0.005 wt.%C and 15℃.The preprocess model was used to predict an initial end-blow oxygen volume.However,the double hit rate of the carbon con tent and temperature only achieves 65%.Then,the oxygen volume and coolant additi ons were adjusted by the regulation units to improve the hit rate.Finally,the double hit rate after the regulation is reached up to 90%.The results indicate that the proposed dynamic control model is efficient to guide the real production for low carbon steel,and the modeling method is also suitable for the applications of other steel grades.

A reliable power management scheme for consistent hashing based distributed key value storage systems

Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing their power consumption. In this paper, we propose GreenCHT, a reliable power management scheme for consistent hashing based distributed key value storage systems. It consists of a multi-tier replication scheme, a reliable distributed log store, and a predictive power mode scheduler （PMS）. Instead of randomly placing replicas of each object on a number of nodes in the consistent hash ring, we arrange the replicas of objects on nonoverlapping tiers of nodes in the ring. This allows the system to fall in various power modes by powering down subsets of servers while not violating data availability. The predictive PMS predicts workloads and adapts to load fluctuation. It cooperates with the multi-tier replication strategy to provide power proportionality for the system. To ensure that the reliability of the system is maintained when replicas are powered down, we distribute the writes to standby replicas to active servers, which ensures failure tolerance of the system. GreenCHT is implemented based on Sheepdog, a distributed key value storage system that uses consistent hashing as an underlying distributed hash table. By replaying 12 typical real workload traces collected from Microsoft, the evaluation results show that GreenCHT can provide significant power savings while maintaining a desired performance. We observe that GreenCHT can reduce power consumption by up to 35%-61%.

Characteristics of atomic layer deposited transparent aluminumdoped zinc oxide thin films at low temperature

Various aluminum-doped zinc oxide （AZO） films were prepared on Si substrate by atomic layer de- position （ALD） at 100 ℃. The effect of the composition of AZO films on their electrical, optical characteristics, structural property and surface topography was investi- gated. The appearance of electrical resistivity shows their semiconducing properties. In most of the visible light band, all the AZO films present transparency of more than 80 %. A1 doping suppresses the AZO film crystallization. When the A1 doping concentration increases up to 3.95 at%, the AZO film has some small multicrystal grains with random orientation. A1 doping improves the roughness of i-ZnO film. The root mean square （RMS） roughness of samples prepared by ALD is much smaller than that pre- pared by radio-frequency magnetron sputtering reported.

Semiconductor performance of rare earth gadolinium-doped aluminum–zinc oxide thin film

Rare earth element gadolinium-doped aluminum–zinc oxide（Gd–AZO） semiconductor thin film material was deposited on both silicon and glass substrate by radio frequency（RF） sputtering at room temperature.Electrical properties and microstructure of Gd–AZO thin film were mainly modulated by altering O2 partial pressure（OPP） during the RF sputtering process.Scanning electron microscope（SEM） and X-ray diffraction（XRD） test were carried out to uncover the microstructure variation trend with the sputtering OPP,and amorphous structure which is beneficial to large mass industry manufacture was also demonstrated by the XRD pattern.Transmittance in visible light spectrum implies the potential application for Gd–AZO to be used in transparent material field.Finally,bottom gate,top contact device structure thin film transistors（TFTs） with Gd–AZO thin film as the active channel layer were fabricated to verify the semiconductor availability of Gd–AZO thin film material.Besides,the Gd–AZO TFTs exhibit preferable transfer and output characteristics.