Localization and temporal regulation of tissue inhibitor of metalloproteinases-4 in mouse ovary

Tissue inhibitors of metalloproteinases (TIMPs) are potential regulators of tissue remodeling in the ovary. The aim of the present study was to examine the localization and temporal regulation of TIMP-4 protein in the mouse ovary. An induced superovulation model (eCG/hCG) was employed in immature mice to evaluate TIMP-4 protein expression profiles in ovaries collected during the follicular phase, the pre ovulatory period, and the luteal lifespan. Immunofluorescence results indicated that TIMP-4 protein was localized to theca of both antral and preovulatory follicles and adjacent ovarian stroma. After the initiation of luteinization with hCG, TIMP-4 was observed within the luteinizing granulosa cells and persisted throughout the lifespan of the corpus luteum. In the cycling ovary, TIMP-4 signaling localized to corpus luteum from previous estrous cycles, the theca of preovulatory follicles, and appeared to be lower in newly forming corpus luteum. Western analysis further showed that the levels of TIMP-4 increased significantly during the luteinization process of granulosa cells, but no significant change was found among all corpus luteum stages. A putative regulatory mechanism of TIMP-4 expression was identified utilizing an in vitro model. Treatment of cultured granulosa cells with hCG significantly augmented TIMP-4 protein expression levels. Together our data indicate that the luteinization process of granulosa cells is associated with up-regulation of TIMP-4 and that TIMP-4 might play an essential role in maintenance of the luteal function during the whole lifespan of corpus luteum.     

The effect of ethanol on carbon-catalysed decomposition of methane

Because of its ecological character, the reaction of catalytic decomposition of methane (CDM) is expected to be an important future method of hydrogen generation. However, the main drawback of this technology is a relatively fast deactivation of the catalyst used, as a consequence of its pores blocking by the low-active methane-originated carbon deposit. This paper reports on an attempt of restricting the catalyst deactivation by introducing into the reaction system ethyl alcohol capable of forming in situ a potentially active in this reaction carbonaceous deposit. The catalyst used was activated carbon obtained from the waste material (hazelnut shells). The reactions of methane and ethanol decomposition were performed by the alternate method (for certain time methane was introduced into the reactor, and then it was replaced by ethanol). Three temperatures of the reactions were applied (750, 850 or 950 °C) and another variable was the duration of the ethanol decomposition. As follows from the results, an addition of ethanol has diverse effect on the catalytic activity of activated carbon and the amount of hydrogen formed depends on the temperatures of methane and ethanol decompositions and on the time of the reagent dosing.     

木质纤维植物制乙醇项目风险评估探讨

木质纤维植物制乙醇技术的研发是一开发周期长、资金投入大、不可预测因素多的系统工程,具有高风险性。文章结合国内外木质纤维植物制乙醇技术的研发现状、经验和发展趋势,从资金来源、政策、技术、市场、生产、管理等风险着手,建立多目标的评估指标体系,并对这6类风险进行评估和应对措施分析。文章旨在为国内纤维素乙醇项目的技术研发、技术比选、厂址选择、技术储备等工作提供参考依据,以保证项目正确的投资决策,减少投资的盲目性,有效地应对各种风险。     

Dithizone modified gold nanoparticles films for potentiometric sensing

For the first time, application of a membrane composed of gold nanoparticles decorated with complexing ligand for potentiometric sensing is shown. Gold nanoparticles drop cast from a solution form a porous structure on a substrate electrode surface. Sample cations can penetrate the gold nanoparticles layer and interact with ligand acting as a charged ionophore, resulting in Nernstian potentiometric responses. Anchoring of complexing ligand on the gold surface abolishes the necessity of ionophore application. Moreover, it opens the possibility of preparation of potentiometric sensors using chelators of significantly different selectivity patterns further enhanced by the absence of polymeric membrane matrix. This was clearly seen, for example, for gold nanoparticles stabilizing the applied ligand-dithizone-thiol conformation leading to a high potentiometric selectivity toward copper ions, much higher than that of ionophores typically used to induce selectivity for polymeric ion-selective membranes.     

New scanning technique for the optical vortex microscope

In the optical vortex microscopy the focused Gaussian beam with optical vortex scans a sample. An optical vortex can be introduced into a laser beam with the use of a special optical element--a vortex lens. When moving the vortex lens, the optical vortex changes its position inside the spot formed by a focused laser beam. This effect can be used as a new precise scanning technique. In this paper, we study the optical vortex behavior at the sample plane. We also estimate if the new scanning technique results in observable effects that could be used for a phase object detection.     

CK3MCuN钢各元素分析曲线的制作

使用布鲁克Q8直读光谱仪分析CK3MCuN钢的化学成分。制作CK3MCuN钢化学元素的工作曲线,并合理设定干扰元素,使分析结果准确稳定,满足生产的需要。     

Cryogenic reliability of composite insulation panels for liquefied natural gas (LNG) ships

The major carrier of liquefied natural gas (LNG) is LNG ships, whose containment system is composed of dual barriers and composite insulation panels. The LNG containment system should have cryogenic reliability and high thermal insulation performance for safe and efficient transportation of LNG. The secondary barrier composed of adhesive bonded aluminum strips should keep tightness for 15 days, when the welded stainless primary barrier fails. However, cracks are generated in the composite insulation panels due to the local stress concentration and the brittleness of insulation materials at the cryogenic temperature of −163 °C. If cracks generated in the insulation panel propagate into the secondary barrier, LNG leakage problem might occur, which is a remaining concern in ship building industries.In this study, crack retardation capability in the composite insulation panel was investigated with glass fabric reinforcement. Finite element analysis was conducted to estimate the thermal stress at the cryogenic temperature and a new experimental method was developed to investigate the failure of secondary barrier of composite insulation panel. From the experimental results, it was found that the glass fabric reinforcement was effective to retard the crack propagation into the aluminum secondary barrier from the polyurethane insulation foam at the cryogenic temperature.