添加钇对Pt-5Cu合金组织结构和性能的影响

采用真空电弧熔炼方法制备了Pt-5Cu、Pt-4.9Cu-0.10Y和Pt-0.48Cu-0.20Y合金。利用X射线衍射仪(XRD)、金相显微镜、显微硬度仪及分光光度计等研究了Pt-Cu及Pt-Cu-Y合金的物相组成、显微组织结构、力学性能及反射率。结果表明,钇对Pt-Cu合金的相结构无明显影响,当钇的添加量为0.20%时,Pt-Cu合金的晶粒尺寸显著细化,晶粒的平均尺寸由约150μm降至约80μm;细晶强化使Pt-Cu合金的维氏硬度显著增加到165;在可见光波段内,Pt-Cu及Pt-Cu-Y合金的反射率无明显差别。

化学气相沉积温度对钽涂层的显微组织及力学性能的影响

为了探究沉积温度对化学气相沉积金属钽涂层组织及性能的影响,利用TaCl5-H2-HCl反应体系,以冷壁式化学气相沉积法(CVD)用不同沉积温度在钼基体表面沉积了钽涂层。研究了不同沉积温度下的化学气相沉积钽涂层的显微组织、力学性能及断口形貌等。结果表明:在1000~1300℃范围内,涂层晶粒尺寸随沉积温度的升高逐渐增大,涂层的抗拉强度和延伸率随温度的升高均逐渐降低,涂层的断裂方式由韧性断裂转变为脆性断裂。

基于材料基因工程的铂基高温合金数据库建设进展

贵金属铂价格昂贵,采用传统的“试错法”进行研究,试验周期长、成本高。材料基因工程将高通量计算、高通量实验和数据库相结合,使新材料研发速度提高一倍、成本降低一半,为铂基高温合金的研发提供了新的思路。基于材料基因工程思想,详细介绍了目前课题组在铂基高温合金高通量计算、高通量实验和数据库建设方面的研究进展情况,旨在为其他贵金属合金产品的研发提供借鉴。

Isolation, Purification and Cryopreservation of Cells from Neonatal Bovine Testis

The development and application of spermatogonial stem cell technology have an important significance in animal cloning, preservation of endangered species and spermatogenesis research. In this study, the seminiferous epithlium cells were isolated and purified, the ceils were cryopreserved after identification, and the effects of different purification and cyopreservation methods on bovine testicular cells were studied. The results showed that there were spermatogonial stem cells and sertoli cells in the neonatal bovine seminiferous tubules, differential adherent selection methods could effectively separate these two cell types. Spermatogonial stem cells were positive after AKP, C-kit, and OCT-4 identification; sertoli ceils were positive after oil red O and vimentin identification. Frozen stock solution supplemented with 10% DMSO had the best effect in spermatogonial stem cell cryopreservation, while fxozen stock solution supplemented with 10% of ethylene glycol and 0.1 mmol. L^-1 trehalose had the best effect in sertoli cells crvooreservation.

CDC25B Involved in Proliferation of Sertoli Cells of New Born Calves Through FSH and Possibly Being Key Regulating Factor

The effects of FSH on the proliferation of sertoli cells of new born calves were studied in order to provide some data for theoretical research and practical use of spermatogenesis in vitro. Different concentrations of FSH （0, 0.01, 0.02, 0.04, and 0.08 IU· mL^-1） were taken to treat bovine sertoli cells in vitro culture, the number of sertoli cells and the expression of seven genes were determined at 6, 12 and 24 h after FSH treatments. FSH could significantly promote the proliferation of in vitro cultured sertoli cells. FSH had no significant effects on the expression of CDC25A and could significantly improve the expression of CDC25B. 0.04 IU· mL^-1 and 0.08 IU· mL^-1 FSH treatments decreased the expression of CDC25C at 12 h. 0.08 IU· mL^-1 FSH treatment decreased the expression of CDC25C at 24 h. 0.04 IU. mLI FSH could significantly decrease the expression of GSK-3β and improve the expression of β-catenin at 6, 12 and 24 h. 0.02, 0.04 and 0.08 IU· mL^-1 FSH treatments enhanced the expressions of CYCLIND1 and C-MYC. In conclusion, FSH promoted the proliferation of sertoli cells and 0.04 IU· mL^-1 FSH concentration could significantly promote the proliferation of in vitro cultured sertoli cells. FSH promoted the proliferation of sertoli cells by CDC25B and WNT/ β-eatenin and CDC25B might be the key regulator to the proliferating rate of sertoli cells of bovine calf.

Influence of FSH Treatment on Expression of CDC25A, TSSK3 and P53 in Vitro Cultured Sertoli Cells of Calf

CDC25A, TSSK3 and P53 expressions in vitro in cultured sertoli cells after FSH treatment were studied in order to provide some data for further researches of spermatogenesis. Different concentrations of FSH（0, 0.01, 0.02, 0.04, and 0.08 IU ·m L^-1） were used to treat sertoli cells cultured in vitro. The expression of CDC25 A, TSSK3 and P53 was determined by real-time-PCR at 6 h,12 h and 24 h after FSH treatment of sertoli cells. The results showed that FSH had no significant effect on expression of CDC25A（p〈0.05）, could significantly improve the expression of TSSK3 and P53（p0.05）, and had no significant effect on expression of CDC25 A in sertoli cells, but it could significantly improve the expression of TSSK3. CDC25 A was likely to play a role in other signaling pathways in sertoli cells. Within the range of certain concentration of FSH, TSSK3 in sertoli cells had the highest expression at about 24 h. TSSK3 protein produced in sertoli cells was likely to play an important role in substrate-level phosphorylationbe in meiosis and mitosis of spermatogenic cells. FSH could promote P53 expression and the highest expression was at about 12 h, and P53 might control the division of spermatogenic cells as well as sertoli cells.

FSH Promoting Proliferation of Calf Sertoli Cells Through Wnt/β-catenin Signaling Pathway with CDC25B Being Involved

The aim of this experiment was to investigate whether FSH could regulate the proliferation of calf Sertoli cells and the relationship with CDC25 B through Wnt/β-catenin signaling pathway. The experimental method was to culture Sertoli cells with different concentrations of FSH(40, 80, 120 and 150 ng · mL) and to treat the cultured cells with XAV939(β-catenin inhibitor) and to detect the expression of CDC25 B, CDC2, C-MYC and β-catenin. The results of the experiment showed that FSH could promote the proliferation of cells and its effect was good at 80 ng · mLconcentration. FSH could promote the expression of CDC25 B, CDC2, C-MYC and β-catenin. The expression of C-MYC and β-catenin in group FSH+XAV939 was lower than that in group FSH. There was no difference in mRNA expression of CDC25 B in group FSH and group FSH+XAV939. The protein expression of CDC25 B in group FSH+XAV939 was lower than that in group FSH. The conclusion was that FSH could promote the proliferation of calf Sertoli cells through Wnt/β-catenin signaling pathway. CDC25 B was upregulated by FSH and CDC2 could promote the proliferation of calf Sertoli cells. The protein level of CDC25 B was affected by Wnt/β-catenin signaling pathway.

Preparation of Mouse Embryonic Stem Cells and Cardiomyocyte Differentiation Induced with Retinoic Acid and Ascorbic Acid

The experiment was designed to study effects of retinoic acid and ascorbic acid on differentiation of mouse embryonic stem cells to cardiomyocytes. Embryonic bodies （EB） were developed from mESC in suspension culture, different levels of concentration of retinoic acid and ascorbic acid were used to determine the optimal conditions for EB formation. The results showed that the optimal concentrations were 10.9 mol. L-1 and 0.1 mg. mL-1 for retinoic acid and ascorbic acids, respectively. 50% of EB which was significantly （p〈0.05） different from the control group developed to cardiomyocytes. In conclusion, rctinoic acid and ascorbic acid had strong ability to promote cardiomyocyte differentiation of mouse embryonic stem cells. 10-9 mol. L-1 retinoic acid and 0.10 mg. mL-1 ascorbic acids were recommended to induce differentiation of mouse ES ceUs toward cardiomyocytes.

Study on Semen Freezing Preservation of German Shepherd Dogs

In order to prolong semen preservation and improve pregnancy rate, semen freezing was studied with German shepherd dogs for experimental animals. The semen of four dogs was collected 40 times in four dilution frozen into two formulations, according to the sperm motility to compare the advantages and disadvantages. The result indicated that the sperm motility of the pellet frozen semen in dilute 2 was significantly higher than that in dilution 1, 3, and 4 （P0.01）. The sperm motility of dogs semen with fried smoked method was notablely higher than that of frozen semen of program method （P0.01）. The dilution which contained yolk-Tris mainly was the best; the pellet semen frozen with fried smoked method was superior to tuble semen frozen with program freezing method; sperm motility of pellet semen was higher than that of tuble semen in the same dilution. The conception rate and litter size of the natural matting were higher than AI.

Study on the Cultivation of the Mycardium and Myocardium Self-disciplining Cell Mass of Mouse Embryonic Bodies with their Own Feeder Layer

Myocardium tissue of Kunming mouse embryonic bodies was cultured with the feeder layer of their embryonic fibroblasts in TCM199.The results indicate that some piece of myocardium tissue can be cultured in the feeder layer;Their contracting frequency changed with the temperature and the morphology changed with the time;It was not all pieces of tissue with the same appearance that could contract,even though some of them grow well.