Prenatal exposure to the fluoride containing psychiatric drug fluoxetine and anti-oxidative alterations in the neonatal rat brain

Fluoride is a key ingredient of many psychiatric drugs like fluoxetine (Prozac^®, Fluoxetine^®). Pregnant women frequently use this drug as they suffer from depression and anxiety disorders during this period. Fluoxetine is able to reach the fetus through the placenta and passes to the newborn through milk. In the present study, female Wistar rats were treated with 5, 10, and 20 mg/L fluoxetine (containing 94% fluorides) from pregnancy day 10 to day 20. After delivery, the levels of the enzymatic antioxidants in the brain of their offspring at postnatal day 2 were measured. The results showed that, in all fluoxetine exposed groups compared with the control group, there was a significant decrease (P < 0.01) in the glutathione, catalase, glutathione S-transferases and potassium and a non- significant increase (P > 0.05) in the activity of malondialdehyde and creatine kinase. The results suggest that fluoxetine may be a developmental neurotoxicant due to presence of fluoride hence must be used carefully during pregnancy.     

Oxidative stress indicators in human and bottlenose dolphin leukocytes in response to a pro-inflammatory challenge

Marine mammals undergo cycles of tissue ischemia and reperfusion during the dive response. Reperfusion injury can result in oxidative tissue damage and the activation of a pro-inflammatory immune response. The risk of oxidative damage is reduced by antioxidants. Our hypothesis is that the reported higher antioxidant defenses within marine mammal tissues provide additional protection in situations that produce oxidative stress, like inflammation, in comparison to terrestrial mammal tissues. Leukocytes were isolated from the whole blood of Pacific bottlenose dolphins (Tursiops truncatus gilli) and humans (Homo sapiens) and were exposed to lipopolysaccharides (LPS, 10 µg/mL) in vitro to simulate a pro-inflammatory challenge. Oxidative stress indicators, including superoxide radical (O₂^•−) production, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST), as well as oxidative protein damage, were quantified by spectrophotometry. Following 48 h under experimental conditions, bottlenose dolphin leukocytes produced 1.9 times more O₂^•− but displayed 2.0 times lower protein carbonyl concentrations compared to human leukocytes. Following 48 h under experimental conditions, bottlenose dolphin leukocytes displayed 7.9, 2.0, 11.1, and 3.3 times more activities of CAT, GPx, GR, and GST, respectively, compared to human leukocytes. These results suggest that, under cell culture conditions, the antioxidant defenses in bottlenose dolphin leukocytes provide additional protection against pro-inflammatory challenges in comparison to human leukocytes, likely as an adaptive advantage.     

Oxidative effects of glyphosate on the lipophobic intracellular environment in the microalgae <i>Chlorella vulgaris</i>

The studied hypothesis is that the herbicide glyphosate (GLY) can affect the oxidative balance in the hydrophobic intracellular medium in non-target Chlorella vulgaris cells. Analytical GLY and RoundUp (RUP) supplementation, affected the growth profile. A significant 42% decrease in the cellular biomass in stationary (St) phase was observed in cultures supplemented with either 5 µM of GLY or RUP, as compared to control cultures. The treatment with 0.3 µM of GLY generated non-significant effects on the oxidation rate of 2’, 7’ dichlorofluorescein diacetate (DCFH-DA), neither in exponential (Exp) nor in St phase of development, as compared to control cultures. However, the treatment with either 5 µM GLY or 0.3 and 5 µM RUP lead to a significant decrease in the DCFH-DA oxidation rate, as compared to control cultures. The lipid radical (LR^●) generation rate, detected by Paramagnetic Resonance Spectroscopy (EPR), was significantly increased in the presence of RUP, in Lag and Exp phase of growth. The non-enzymatic antioxidants, α-Tocopherol (α-T) and β-Carotene (β-C), are aimed to protect membranes against the damage produced by the radical reactions. The content of β-C was not significantly affected, as compared to control cultures, by any of the treatments, in both growth phases of cellular development. The content of α-T was significantly decreased by the supplementation with either 0.3 or 5 µM of RUP or 5 µM GLY. The LR^●/α-T ratio, used as indicator of the oxidative balance in the hydrophobic cellular media, was significantly different between samples obtained from control and RUP-exposed microalgae in both, Exp and St phase of development, with either 0.3 or 5 μM RUP. The data presented here showed evidence that suggested that oxidative balance in the hydrophobic environment was affected by either GLY or RUP.

     

集装箱喷漆机器人逆运动学分析

集装箱喷漆机器人采用开式运动链,利用Denavit-Hartenberg方法建立五自由度串联型集装箱喷漆机器人的坐标系,采用解析法对机器人进行了逆运动学分析,然后在ADAMS下进行仿真,得到末端点的位移、速度和加速度曲线,验证了机器人机械结构的合理性,为集装箱喷漆机器人的快速设计与制造提供了理论依据。
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Oxidative stress in the hydrophilic medium of algae and invertebrates

The harmful effects of the reactive species may be due to the increase in their steady state concentration either by the enhancement of their production rates and/or the decrease of their consumption rate by antioxidant activity. The ascorbyl radical (A^• ) can be considered as a final product of radical oxidative transformations of ascorbate (AH^-). The ratio A^• content/AH^- content (A^• /AH^-) has been widely used as an interesting tool to estimate mild to moderate oxidative transformations, providing a quick and simple method of diagnosis of stress in the hydrophilic cellular medium. The aim of this work was to summarize studies on the cellular oxidative condition in algae and invertebrates by assessing the A^• /AH^- ratio under environmentally changing conditions. The use of indices of oxidative stress increasingly sensitive and, somewhat more specific, can bring a new light to the still unknown world of oxidative responses in marine organisms     

游梁式抽油机井皮带滑动效率的仿真研究

针对游梁式抽油机皮带传动装置负载扭矩波动大的特点,研究了游梁式抽油机皮带的纵向振动特性、皮带与带轮之间的相对滑动速度以及皮带传动的瞬时滑动效率。将皮带简化为纵向振动的弹性体,建立了皮带在交变摩擦力激励下的纵向振动力学模型与波动方程形式的数学模型;应用振型叠加法建立了皮带纵向振动的数值仿真模型;建立了皮带相对于带轮的瞬时滑动速度、瞬时滑动效率的仿真模型;仿真分析了抽油机曲柄扭矩波动幅值、皮带预紧力对皮带滑动效率的影响。仿真结果表明：抽油机曲柄扭矩波动会降低滑动效率;当抽油机曲柄扭矩存在负扭矩时,皮带滑动效率明显降低;在预紧力能保证皮带传动正常工作的情况下,再增加皮带预紧力会增大皮带的传动效率。
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Investigation of the antioxidant defensive role of both AD-MSCs and BM-MSCs in modulating the alteration in the oxidative stress status in various STZ-diabetic rats’ tissues

Diabetes mellitus (DM) could negatively affect patients’ health via inducing a lot of serious functional hazards in many tissues’ cells at molecular levels. Recently, many scientists had proposed stem cell therapy being an appropriate alternative treatment protocol for numerous health threatening issues including diabetes. Therefore, the current study was designed to investigate the antioxidant potentiality of two MSCs types in alleviating tissues’ oxidative stress dramatic elevation resulting as a consequence of Type 1 DM induction. In our 4 weeks study, animals were divided into four groups: control group, STZ-diabetic group (D), D+AD-MSCs group and D+BM-MSCs group. Data reported that diabetic rats treated with either AD-MSCs or BM-MSCs exhibited a marvelous body tissues (Pancreas, Liver and Kidney) enhancing capabilities in attenuating the oxidative stress status; as evidenced by XO, ROS, and MDA levels down-regulation; with a general concomitant elevation in the antioxidants’ content; evidenced by many enzymatic and non-enzymatic antioxidants up-regulation; relative to the diabetic untreated group. Interestingly, comparing both treatments with each other and to control group, most of the measured parameters were reverted back to near normal levels after AD-MSCs injection; which clearly point out their stunning health benefits and superiority as anti-diabetic agent in overcoming different tissues’ complications; owing to their marked cytoprotective and regenerative potentialities.     

集成电路芯片制造中电化学机械平整化技术的研究进展

大马士革(Damascene)结构的Cu/低k介质材料互连技术为集成电路芯片制造提出了方向和挑战。电化学机械平整化(ECMP)作为化学机械平整化（CMP）的一种拓展加工手段,可对传统CMP技术进行补偿,可对含有易损多孔电介质材料的新型互连结构进行低压力平整化。比较了ECMP和CMP 的特点,
对ECMP技术的研究现状和发展趋势进行了综述。指出ECMP过程控制的深层次的技术基础是摩擦电化学理论,只有深入系统地研究ECMP过程中的外加电势、摩擦磨损、化学反应三者间的相互作用,才能揭示ECMP过程中材料的加速去除原理和超光滑无损伤表面的形成机理。     

Ultrastructural and cytochemical changes in the liver of primary biliary cirrhosis patients

The aim of this paper is to establish whether there are cytochemical or ultrastructural alterations in the hepatocytes of patients with primary biliary cirrhosis (PBC) at stages I and II compared with the biopsies from individuals with normal liver. Cytochemical technique with ATP as substrate, transmission electron microscopy (TEM) and freeze fracture were used for the studies.
In the normal liver biopsies the ultrastructural cytochemical localization of the enzymatic activity was clearly shown in the bile canaliculi. In the PBC biopsies, the enzymatic activity is increased in the bile canaliculi and is also present in the lateral membranes of the hepatocyte.
TEM of the lateral surface of the hepatocyte in normal livers showed a smooth surface without microvilli but in PBC livers a large number of microvilli were seen in the lateral membranes. The Golgi apparatus in these patients was localized not only near the canaliculi (normal livers) but also in front of the microvilli. Freeze-fracture showed normal features in the bile canaliculus junctions of the PBC patients.
We suggest that the localization of the enzymatic reaction, microvilli and Golgi apparatus at the PBC hepatocyte lateral membranes may represent a compensatory mechanism for derivation of bile flow and other components from the hepatocyte to the intercellular space.     

面向产品创新设计的功能模块动态划分方法研究

针对面向产品创新设计的功能模块划分中没有考虑技术进化的问题,从客户需求、流、技术的角度出发,研究功能模块动态划分方法。以产品的功能结构为基础,建立了功能相关矩阵。基于模糊等价矩阵的动态聚类分析,动态划分产品的功能模块。以模块内平均聚合度和模块间平均分离度来评价不同模块划分结果。多绳金刚石串珠锯功能模块动态划分实例说明了该方法具有较强的分辨性,可以进行面向产品创新设计的功能模块动态划分。
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单晶硅纳米级磨削过程的理论研究

对内部无缺陷的单晶硅纳米级磨削过程进行了分子动力学仿真,从磨削过程中瞬间原子位置、磨削力、原子间势能、损伤层深度等角度研究了纳米级磨削加工过程,解释了微观材料去除、表面形成和亚表面损伤机理。研究表明：磨削过程中,单晶硅亚表面损伤的主要形式是非晶结构形式,无明显的位错产生,硅原子间势能的变化是导致单晶硅亚表面损伤的重要原因;另外,发现磨粒原子与硅原子之间有黏附现象发生,这是由于纳米尺度磨粒的表面效应而产生的。提出了原子量级条件下单晶硅亚表面损伤层的概念,并定义其深度为沿磨削深度方向原子发生不规则排列的原子层的最大厚度。     

Zr基大块非晶合金在过冷液相区超塑性成形的摩擦行为及机理研究

采用双杯挤压方法研究了成形温度、应变速率等工艺参数对Zr55Al10Ni5Cu30块体非晶合金在过冷液相区塑性成形时模具和零件之间的摩擦行为的影响。采用有限元模拟方法获得大块非晶合金双杯挤压的摩擦因数标定曲线,有限元模拟中非晶合金的变形采用Kawamura的本构模型,将高温压缩实验的数据拟合,获得本构模型中的参数,结果表明非晶合金在过冷液相区内变形的摩擦因数在0.2~0.7之间。当应变速率较低时,随着温度的升高,摩擦因数总体上降低;而当应变速率较高时,随着温度的升高,摩擦因数先略有上升,然后急剧下降。当温度较低时,随着应变速率增大,摩擦因数显著增大,而在高温时,随着应变速率增大,摩擦因数略微有所减小。按照现代摩擦理论对非晶合金在过冷液相区内成形的摩擦机理进行了分析,认为黏着是摩擦的主导因素。     

Ciprofloxacin increases hepatic and renal lipid hydroperoxides levels in mice

Ciprofloxacin (CFX) is an effective and relatively safe antimicrobial used in a variety of human infections. However, adverse drug reactions and positive results in genotoxic tests are reported.
In order to understand the possible pathophysiological mechanisms of the toxic effects informed for CFX, lipid hydroperoxides (LOOH) -oxidative mediators of peroxidation- were quantified in liver and kidney of mice, after 15 to 360 minutes of the ciprofloxacin administration at doses of 10 mg/ Kg or 100 mg/ Kg by ip route. The peroxidation in the lipid fraction was evaluated by measuring the amount of hydroperoxides through the oxidation of 1- naphthyldiphenylphospine into its oxide and further quantification by high performance liquid chromatography.
The initial content of lipid hydroperoxides (nmol/g tissue) was 253 ± 3 in kidney and 143 ± 12 in liver. CFX induced the maximal variation to 728 ± 101 in kidney (P < 0.05) and 315 ± 31 in liver (P < 0.01), after 15 min of 100 mg/ Kg single dose. The variation in the LOOH levels was significant in kidney with both doses used and in liver after 100 mg/ Kg until 60 min after the CFX administration, and then gradually fell to natural levels.
The results demonstrated the effect of CFX on lipid oxidation, an indicator of oxidative effect. A natural protective capacity against this oxidation, more efficient in liver than in kidney, was observed.     

基于双谱熵的齿轮裂纹故障特征提取

针对裂纹故障导致齿轮振动信号非高斯性变化这一特点,提出采用双谱熵对信号非高斯成分在双频域内的分布形态进行定量描述,并据此提取故障信息,得到裂纹产生期、扩展期的特征趋势。结果表明,双谱熵不基于信号能量信息,受非故障因素影响小,而且能有效抑制高斯噪声,同时又对微弱故障十分敏感。研究结果为后续故障诊断与趋势预测提供了新的有效方法。     

重卡双前桥转向摇臂机构的优化设计 

针对重卡双前桥转向摇臂机构传统单目标优化方法考虑因素的不足,提出了以二轴左轮转角误差最小、转向杆系与悬架运动的最大干涉量最小、左右转向力不均匀性最小为综合优化目标的多目标优化模型。车轮转角误差模型通过将摇臂机构拆分的方法得到,悬架与转向杆系的干涉模型通过建立转向直拉杆与悬架的空间运动模型得到,左右转向力不均匀性通过计算转向传动机构传动比得到。优化结果证明,多目标优化方法优于传统优化方法,有利于减小转向轮的磨损、改善车辆的操纵稳定性及转向轻便性。     

板形模式识别的多输出最小二乘支持向量回归机新方法

为了克服最小二乘支持向量回归机(LS-SVR)算法不能直接应用于多输入多输出(MIMO)系统建模的缺点,通过在目标函数中加入样本绝对误差项,提出了一种多输出最小二乘支持向量回归机(MLSSVR)新算法。将MLSSVR算法应用于板形模式识别研究,提出了一种基于MLSSVR的板形模式识别新方法,将该方法与LS-SVR合成识别方法进行对比实验,并对MLSSVR识别模型的识别能力进行了测试和分析,
结果证明了MLSSVR算法的有效性。MLSSVR板形模式识别方法不仅避免了LS-SVR合成方法的复杂组合运算,具有更高的识别速度,而且具有更高精度和很强的泛化能力。
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串联式混合动力城市客车动力系统研究

基于某一公交线路运营试验和车辆运行数据,对串联式混合动力城市公交车WG6120HD各项行驶参数进行了对比分析,得出了城市公交混合动力系统的工作特点。针对该公交线路,采用线路能量平衡和发动机动态功率跟随控制策略来满足线路总能量需求和车辆瞬态功率供给的要求。该策略将能量和功率分开管理,并通过动态耦合,有效协调了公交车功率配置高和平均需求功率低之间的矛盾。运营试验表明：该混合动力系统运行可靠,控制策略合理有效。
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含呼吸式裂纹的失谐叶盘系统响应特性研究

含张开式裂纹的叶盘系统无法准确地反映其受迫振动响应特性,为此,基于细梁理论和线弹性断裂力学理论建立了含呼吸式裂纹的失谐叶盘系统数学模型,对比分析了呼吸式裂纹、张开式裂纹对失谐叶盘系统固有特性和振动响应的影响,揭示了呼吸式裂纹对叶盘系统振动响应局部化的影响规律。研究表明:呼吸式裂纹使得振动响应呈现复杂的非线性特征;此外,与张开式裂纹模型相比,基于呼吸式裂纹模型的叶盘系统对失谐更敏感。      

超细粉末硬化水玻璃砂的性能特征研究

采用课题组配置的超细复合粉末作固化剂,研究测试了超细粉末硬化水玻璃砂的性能特征,将它与目前大量采用的酯硬化水玻璃砂在性能上作了比较,并通过SEM对常温下和800℃焙烧后粉末硬化水玻璃砂样以及酯硬化水玻璃砂样的粘结桥微观结构进行了观察。试验结果表明：超细粉末硬化水玻璃砂工艺中,当水玻璃加入量占原砂质量的3%,粉末加入量占水玻璃加入量的25%时,砂样的常温强度比酯硬化水玻璃砂的强度提高约23%,残留强度降低约76%;粉末硬化水玻璃砂对水玻璃的模数敏感度不高,硬化过程中使用高模数水玻璃将显著改善水玻璃砂的溃散性和再生回用性能;粉末硬化水玻璃砂的抗湿性远远优于酯硬化水玻璃砂。