The efficacy of protective effects of tannic acid, gallic acid, ellagic acid, and propyl gallate against hydrogen peroxide-induced oxidative stress and DNA damages in IMR-90 cells

There is increasing evidence that reactive oxygen species (ROS) are intimately involved in the oxidative damage of tissues for a wide variety of pulmonary diseases. Thus, it is desirable to search for chemopreventive agents that can counteract ROS-mediated injury to the pulmonary tissues. Using a human lung fibroblast IMR-90 cells as the experimental model, we first demonstrated that nearly 90% of intracellular ROS could be removed when H(2)O(2)-treated cells (200 microM) simultaneously incubated with 10 microg/mL of tannic acid (TA), gallic acid (GA), ellagic acid (EA), and propyl gallate (PA). Using C(11)-BODIPY(581/591 )as a lipid peroxidation probe, we also attested that all these compounds examined (10 microg/mL) could alleviate H(2)O(2)-evoked lipid peroxidation phenomena. Next, we examined the protective effects of these compounds on the depletion of intracellular glutathione (iGSH) in H(2)O(2)-treated cells using CMF-DA probe. Interestingly, PA was demonstrated to be the only compound that could effectively protect the integrity of iGSH from being depleted by this system. Finally, the protective effects of these compounds against oxidative DNA damage were evaluated using 8-oxoguanine formation as a marker. Our data indicated that all four compounds suppressed the formation of 8-oxoguanine effectively. Taken together, our data suggested that TA, GA, EA, and PA can protect cells from oxidative stress.     

D-柠檬烯对大鼠酒精性肝损伤脂质代谢紊乱的影响

探讨D-柠檬烯（D-limonene）对大鼠酒精性肝损伤脂质代谢紊乱的保护作用及可能作用机制,利用持续酒精灌胃的方法建立大鼠酒精肝损伤模型,分为A、B、C、D、E、F、G共7 组。A组为空白对照组,每日给予蒸馏水灌胃,前2 周8 mL/（kg·d）,后4 周12 mL/（kg·d）;B组为酒精模型组,每日灌胃体积分数为50%的乙醇,前2 周8 mL/（kg·d）,后4 周12 mL/（kg·d）;C、D、E组分别为D-柠檬烯低、中、高剂量组,每日分别灌胃D-柠檬烯100、200、400 mL/（kg·d）,其中D-柠檬烯与A、B组等量的50%的乙醇混合后灌胃;F组为水和D-柠檬烯空白高剂量组,每日给予D-柠檬烯400 mL/（kg·d）;G组为甘利欣药物对照组,灌胃量200 mL/（kg·d）。HE染色和电镜观察肝组织形态结构和肝组织超微结构的变化,测定血清谷丙转氨酶（alanine transaminase,ALT）、谷草转氨酶（aspartate transaminase,AST）、碱性磷酸酶（phosoporic acid,ALP）、胆碱酯酶（cholinesterase,CHE）、甘油三酯（triglyceride,TG）、胆固醇（cholesterol,CHO）、低密度脂蛋白胆固醇（low densitylipoprotein-cholesterol,LDL-C）水平。结果电镜下观察到A组肝细胞结构正常,核呈圆形或椭圆,线粒体形态正常。B组肝细胞次级溶酶体数量增加,线粒体形状不规则,脂滴多。C组可见少量脂滴,高尔基体正常,线粒体清楚。D组少量脂滴,胆小管有内容物,线粒体正常。E组线粒体高尔基体正常,少量脂滴,核圆。F组细胞器无异常,少量脂滴。G组少量脂滴,偶见溶酶,体线粒体正常。B组大鼠血清ALT、AST、ALP、CHE、TG、CHO、LDL-C均高于空白对照组,差异显著（P＜0.05）;F组大鼠血清所测各指标与空白对照组无明显差异;而D-柠檬烯低、中、高剂量干预组和酒精模型组比较,血清所测各指标水平均有不同程度地降低,其中D-柠檬烯中、高剂量干预组血清所测各指标水平明显低于酒精模型组,差异显著（P＜0.05）。结论：过量酒精摄入引起的肝组织超微结构病理损伤与升高血清ALP、CHE、ALT、AST、TG、CHO、LDL-C水平,在D-柠檬烯干预下有所减轻和降低。因此,D-柠檬烯可调节过量酒精摄入造成的脂质代谢紊乱。     

Strain-rate dependence of surface/subsurface deformation mechanisms during nanoscratching tests of GGG single crystal

Constant- and varied-depth nanoscratching tests of GGG single crystal were carried out at different scratching velocities. The morphologies of the scratched grooves and chips were analysed using scanning electron microscope. The experimental results indicated that higher scratching velocity led to shallower penetration depth, shallower residual depth, and larger continuous chips. Increasing the scratching velocity could effectively improve the plasticity and reduce the brittle-to-ductile transition depth of GGG single crystal. Based on the contact stress and contact area between the analysed sample and Berkovich indenter, a model for predicting the penetration depth was developed, which took into account the strain rate effect and elastic recovery of materials. The model was verified using constant- and varied-depth nanoscratching tests, and the predicted and experimental results were in good agreement. Subsurface damage underneath the ductile surface was characterised using transmission electron microscope. The TEM results demonstrated that higher scratching velocity led to the slipping planes appearing in more directions, which prevented the generation of long slipping plane and reduced the depth of the damage layers. The plastic deformation of GGG at the scratching velocity of 100 μm/s was dominated by poly-crystalline nanocrystallites and amorphous phases, and was similar to that at the low scratching velocity. This study provided a fundamental understanding of the strain-rate dependence of surface/subsurface deformation mechanisms of GGG during ultra-precision machining.     

沙河板鸭加工中的危害分析与关键工艺控制

通过对沙河板鸭加工过程中各个环节可能造成的危害进行分析,确定了活鸭验收与检疫、热烫去毛、宰后检验、腌制、脱水干制5个关键控制工艺点,并制定了HACCP工作表,确定了关键限值、监控措施和纠偏措施。该体系的建立将使板鸭加工过程中的各种潜在危害降到最低水平,对提高板鸭的安全性和产品质量有积极作用。     

基于热红外图像的风力机叶片损伤识别方法研究

针对风力发电机叶片损伤人工检测效率低,受作业人员业务水平制约等因素影响大的问题,提出一种基于热红外图像的风力机叶片损伤识别以及损伤位置判定和损伤大小计算的方法,通过数字图像处理技术在Matlab 2019b平台开发实现.对附有人工损伤的风力机叶片热红外图像采用对比度拉伸、Gabor滤波、二值化阈值分割等方法提取损伤特征...     

一类 p-Kirchhoff 方程无穷多解的存在性

研究一类带有凹凸非线性项的 p‐Kirchhoff 方程无穷多解的存在性。在Kirchhoff 函数 M以及权函数 f 满足更弱的假设下（即 M无正下界,权函数 f 不定号）,利用RN 中两个重要的不等式证明能量泛函 J满足（PS ）c条件。结合喷泉定理,得到该方程的无穷多解的存在性,并且获得了一列能量无界的正能量解。拓展了 p‐Kirchhoff方程解的多重性结果。     

新型表面活性剂的表面张力和电导率性能研究

合成了三种孪连型阳离子季铵盐表面活性剂16-4-16,2Br-1、14-4-14,2Br-1、18-2-18,2Br-1,对三者的性能进行评定,分别通过表面张力和电导率测得临界胶束浓度(CMC)、表面活性剂在气-液界面的吸附量、单个分子的面积和胶束电离度α。结果表明:首先,相对于单头基单尾链的表面活性剂,三种孪连表面活性剂的表面活性更强,CMC值更低;其次,三种表面活性剂都有其各自的特性,16-4-16,2Br-1的粘弹性能较好,而14-4-14,2Br-1、18-2-18,2Br-1表面张力很低。实验表明,通过调节孪连表面活性剂联结基和疏水链的长度会对产品的性能有很大的影响。     

线切割InSb晶片表面损伤研究

利用扫描电子显微镜 (Scanning Electron Microscopy, SEM)、台阶仪和X射线衍射仪 (X-ray Diffraction, XRD) 研究了线切割InSb晶片和内圆切割晶片的表面损伤程度,定量分析了损伤层的厚度,并探讨了影响InSb切割晶片表面损伤的因素。结果表明,线切割InSb晶片的表面较平整,粗糙度小,表面损伤小,损伤层的厚度约为14 μm,小于常规内圆切割晶片。研究结果对大尺寸、大批量InSb晶片的生产及后续加工具有一定的参考价值。     

Genome Integrity and Neurological Disease

Neurological complications directly impact the lives of hundreds of millions of people worldwide. While the precise molecular mechanisms that underlie neuronal cell loss remain under debate, evidence indicates that the accumulation of genomic DNA damage and consequent cellular responses can promote apoptosis and neurodegenerative disease. This idea is supported by the fact that individuals who harbor pathogenic mutations in DNA damage response genes experience profound neuropathological manifestations. The review article here provides a general overview of the nervous system, the threats to DNA stability, and the mechanisms that protect genomic integrity while highlighting the connections of DNA repair defects to neurological disease. The information presented should serve as a prelude to the Special Issue “Genome Stability and Neurological Disease”, where experts discuss the role of DNA repair in preserving central nervous system function in greater depth.     

饲料酵母培养物提高异育银鲫的抗氧化、免疫能力及CyHV-2病毒攻毒保护能力

为了研究饲料中酵母培养物(Yeast culture,YC)代替等质量鱼粉对异育银鲫生长性能和生理健康的影响。在含豆油(正对照)、氧化豆油(负对照)的基础饲料中分别以0%、1%、2%、3%的YC替代等质量的鱼粉,分别记为S、SC1、SC2、SC3、O、OC1、OC2、OC3,在池塘中养殖异育银鲫[初始体重为(7.08±0.01) g] 65 d。养殖实验结束后,用异育银鲫CyHV-2病鱼内脏组织液对各实验组鲫鱼进行攻毒实验。结果显示:SC1、SC2、SC3组与S组比较,SGR和FCR无显著差异(P0.05)。O组与S组比较,SGR下降6.53%(P0.05);FCR提高16.27%(P0.05)。O组结果比较:OC1、OC2、OC3组SGR均提高(P0.05),FCR均下降(P0.05)。各组血细胞和血清指标发生一定程度的变化。攻毒实验结果显示,与S组比较,SC1、SC2、SC3组累积死亡数降低;与O组比较,OC1、OC2、OC3组累积死亡数也降低。本实验结果表明,1)在基础日粮鱼粉为12%的条件下,用1%～3%YC替代等质量的鱼粉具有一定的可行性。2)氧化豆油会导致异育银鲫氧化损伤。3)在含有氧化豆油的日粮中,饲料YC可以一定程度修复氧化损伤。4)本实验条件下,饲料YC可以增强异育银鲫免疫防御能力、抗氧化损伤的能力,综合表现为对CyHV-2病毒攻毒保护具有较好的效果。