No Direct Postconditioning Effect of Poloxamer 188 on Mitochondrial Function after Ischemia Reperfusion Injury in Rat Isolated Hearts

Myocardial infarction is a leading cause for morbidity and mortality worldwide. The only viable treatment for the ischemic insult is timely reperfusion, which further exacerbates myocardial injury. Maintaining mitochondrial function is crucial in preserving cardiomyocyte function in ischemia reperfusion (IR) injury. Poloxamer (P) 188 has been shown to improve cardiac IR injury by improving cellular and mitochondrial function. The aim of this study was to show if P188 postconditioning has direct protective effects on mitochondrial function in the heart. Langendorff prepared rat hearts were subjected to IR injury ex-vivo and reperfused for 10 min with 1 mM P188 vs. vehicle. Cardiac mitochondria were isolated with 1 mM P188 vs. 1 mM polyethylene glycol (PEG) vs. vehicle by differential centrifugation. Mitochondrial function was assessed by adenosine triphosphate synthesis, oxygen consumption, and calcium retention capacity. Mitochondrial function decreased significantly after ischemia and showed mild improvement with reperfusion. P188 did not improve mitochondrial function in the ex-vivo heart, and neither further P188 nor PEG induced direct mitochondrial protection after IR injury in this model.     

Targeting Mitochondria in Diabetes

Type 2 diabetes (T2D), one of the most prevalent noncommunicable diseases, is often preceded by insulin resistance (IR), which underlies the inability of tissues to respond to insulin and leads to disturbed metabolic homeostasis. Mitochondria, as a central player in the cellular energy metabolism, are involved in the mechanisms of IR and T2D. Mitochondrial function is affected by insulin resistance in different tissues, among which skeletal muscle and liver have the highest impact on whole-body glucose homeostasis. This review focuses on human studies that assess mitochondrial function in liver, muscle and blood cells in the context of T2D. Furthermore, different interventions targeting mitochondria in IR and T2D are listed, with a selection of studies using respirometry as a measure of mitochondrial function, for better data comparison. Altogether, mitochondrial respiratory capacity appears to be a metabolic indicator since it decreases as the disease progresses but increases after lifestyle (exercise) and pharmacological interventions, together with the improvement in metabolic health. Finally, novel therapeutics developed to target mitochondria have potential for a more integrative therapeutic approach, treating both causative and secondary defects of diabetes.     

轧制对Mg-3Cu-1Mn合金温度阻尼峰的影响(英文)

经过变形量4.7%的单道次室温轧制变形,Mg-3Cu-1Mn合金的一次温度—阻尼谱出现了3个明显的阻尼峰;在二次温度—阻尼谱中,3个阻尼峰均发生变化,特别是第3阻尼峰P3受到抑制,变得非常不明显。对各阻尼峰峰温处淬火样品进行金相、XRD、EBSD等实验,研究轧制对Mg-3Cu-1Mn合金温度—阻尼峰的影响。结果表明:在一次温度—阻尼谱中的P3峰处出现织构增强、孪晶急剧消失的现象;轧制变形后,3个温度—阻尼峰依次为位错阻尼峰、晶界阻尼峰和孪晶引发的再结晶阻尼峰;另外,随着拉伸孪晶的消失,室温轧制态Mg-3Cu-1Mn合金的应变阻尼性能大幅度恢复,高应变下接近均匀化退火态Mg-3Cu-1Mn的应变阻尼性能。这说明拉伸孪晶对Mg-3Cu-1Mn合金应变阻尼性能有不利的影响。     

Synthesis of strontium (Sr) doped hydroxyapatite (HAp) nanorods for enhanced adsorption of Cr (VI) ions from wastewater

The development of high-efficiency adsorbents for heavy metal ion removal from wastewater is highly desirable and challenging due to their synthesis complexity and low adsorption capacities. Herein, we reported the synthesis of strontium (Sr) doped hydroxyapatite (HAp) for the increased Cr (VI) adsorption. The effects of pH, temperature, and time on adsorption performances were studied. As a result, the Sr-HAp nanorods can achieve a Cr (VI) adsorption capacity of 443 mg/g, which is significantly higher than that of HAp nanorods (318 mg/g). To better understand the adsorption mechanism, the Langmuir isotherm model was established. The modeling results indicated that Langmuir monolayer chemical adsorption contributed to the efficient Cr (VI) ion removal for Sr-HAp nanorods adsorbents. The surface area and surface functional groups (O–H) contributed to the different Cr (VI) adsorption capacities between HAp and Sr-HAp.     

油润滑下不同槽宽网状织构表面润滑特性研究

为了提高油膜承载力、改善润滑效果、优化织构化表面的摩擦学性能,研究不同黏度润滑油下网状织构的润滑性能。设计4种不同凹槽宽度的网状织构,通过测量接触角、油膜承载力以及摩擦因数,得到不同转速、不同黏度润滑油下4种网状织构的油膜承载力以及摩擦因数的变化规律。实验结果表明：在4种织构中,凹槽宽度为0.4 mm的网状织构润滑性能最好,在设定的实验条件下,最大油膜承载力为0.52 N,最小摩擦因数为0.019。此外,接触角测量实验表明凹槽宽度为0.4 mm的网状织构表面疏水性能更好,有比较好的成膜能力,使得织构表面动压承载力有比较大提升,摩擦因数也更小。比较不同黏度润滑油和不同转速下网状织构润滑性能,黏度越大的润滑油,油膜承载力越大,润滑效果更佳。同时,油膜承载力随着转速的增大而增大,在润滑油黏度较高时这种影响更为显著。     

Influence of the nanostructure and morphology of (VO)2P2O7 on its catalytic reactivity

The reoxidability of vanadyl pyrophosphate is studied by thermal analysis and by temporal analysis of product (TAP). The samples differ by surface area, oxidation state of vanadium, crystallite size, and degree of crystallinity. The morphology ranges from platy to prismatic and the microstructure from mosaic crystals exhibiting {100} faces to bulky crystals. The reactivity of these samples during oxidation as well as their catalytic reactivity studied in flow reactor is accounted for by the microstructure. The highest reoxidation capability and the best catalytic properties in oxidation of n-butane to maleic anhydride are obtained with mosaic crystals. This revised version was published online in July 2006 with corrections to the Cover Date.     

滏阳河纳污能力分析

通过对邯郸滏阳河水质现状、排污现状、设计流量、流速和污染物综合衰减系数调查分析和实验研究,建立了动态纳污能力模型,通过模型计算确定了不同河段纳污能力,提出了污染物削减方案。     

水利工程泵送混凝土裂缝的防治措施浅析

摘要：水利工程混凝土结构需要长期承受各种荷载的作用,不可避免会产生裂缝、破损等情况。而泵送混凝土结构中裂缝的存在和发展,破坏了水工建筑结构的整体性,导致水工建筑物内部钢筋锈蚀,从而降低结构物的耐久性,并影响其正常使用,严重时甚至会危害人民群众的生命财产安全。对泵送混凝土裂缝的成因及防治措施进行了探讨,提出了应采取的防治措施,将混凝土裂缝带来的影响减小到最低。     

一般形式的阻力系数公式及其在挟沙力计算中的应用

对不同流态及流区明渠水流阻力系数的计算公式进行总结。考虑到指数型表达式在进行数学推导及应用时较其他形式更为方便,基于该形式并结合尼古拉兹管流试验资料,推导了各流态及流区明渠阻力系数的具体表达式且得到实测资料的验证。推导过程中,借助明渠当量直径实现管流与明渠阻力系数的相互转换,并依据各流区水流特征的不同,对Christoffersen和Jonson提出的糙率高度公式作了不同简化。将所得阻力系数公式应用于河流及海洋近岸水流挟沙力的计算中,结果表明实测值与计算值相吻合,且所有流区阻力系数表达式形式的统一有利于水流挟沙力计算的简便。     

表孔溢流堰体型优化设计及模型试验验证

溢流表孔在水库汛期泄洪中作用显著,成功的表孔溢流堰体型设计是保证其功能有效发挥的重要前提。以浯溪口水利枢纽工程溢流表孔堰面为例,论述了堰面曲线设计及因结构布置需要对WES实用堰体型所作的一些改进,同时通过物理模型试验从泄流能力和堰面动水压力两方面验证了表孔溢流堰体型改进设计的合理性。研究成果对类似工程溢流堰体型优化设计具有一定的借鉴和参考价值。