直流电弧等离子体制备纳米粉技术及其应用

直流电弧等离子体是在电场作用下,气体中存在的自由电子受到电场加速,其速度（动能）达到某一值时,中性原子或分子被电离而获得更多的自由电子,这些电子进一步加速激发其它中性粒子产生类似于雪崩现象的电离过程,结果使气体放电形成等离子体。利用等离子体的高温（可达3000K-30000K）使金属熔化蒸发形成气态金属原子,再将气态金...     

DEVELOPMENT OF A VACUUM SPARK DISCHARGE SOURCE

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Seminal plasma levels of 15-F2α-isoprostane, malondialdehyde and total homocysteine in normozoospermic and asthenozoospermic males

It has been proposed that oxidative stress plays an important role in male infertility. The aims of this study were to compare seminal plasma levels of 15-F2t-isoprostane (8-iso-PGF2α), malondialdehyde (MDA), and total (sum of free and bound) homocysteine (tHcy) from normozoospermic vs. asthenozoospermic men, and to examine the relationships between tHcy and lipid peroxidation products. The study was a case-control study with a simple random sampling. The case group was consisted of 15 asthenozoospermic males. This group was compared with 15 normozoospermic men. Seminal plasma levels of 15-F2α-isoprostane and tHcy were measured using commercially available enzyme immunoassay (EIA) kits. MDA levels were determined by the thiobarbituric acid (TBA) assay. The Mann-Whitney U test was used to compare two groups. Coefficients of correlation were calculated using Spearman’s correlation analysis. All hypothesis tests were two-tailed with statistical significance assessed at the p value <0.05 level. MDA levels were higher in asthenozoospermic subjects than in control subjects (0.72±0.06 μM vs. 0.40±0.06 μM; p<0.05). No differences were seen in 15-F2α-isoprostane levels in asthenozoospermic subjects and controls (65.00±3.20 pg/ml vs. 58.17±4.12 pg/ml; p>0.05). Interestingly, tHcy levels were to be slightly higher in asthenozoospermic subjects than in controls (6.18±1.17 μM vs. 4.8±0.52 μM). Sperm motility was inversely correlated with seminal plasma 15-F2α-isoprostane and MDA levels, respectively (p<0.05). In summary, seminal plasma levels of 15-F2α-isoprostane and tHcy showed no significant difference between normozoospermic and asthenozoospermic men. Sperm motility was not correlated with seminal plasma levels of tHcy. No relationship was found between tHcy and lipid peroxidation.     

离子渗氮化合物层对4Cr5MoSiV1模具钢热疲劳性能的影响

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　 4Ｃｒ5ＭｏＳｉＶ1ｓｔｅｅｌ (ＡＩＳＩＨ13ｏｒ 84 0 7)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｐｏｐｕｌａｒｈｏｔｗｏｒｋｉｎｇｄｉｅｓｔｅｅｌｓ .Ａｓａｍａｊｏｒａｌｕ ｍｉｎｕｍｃａｓｔｉｎｇｄｉｅｍａｔｅｒｉａｌ,ｉｔｈａｓｔｏｅｎｄｕｒｅｔｈｅｒｍａｌａｎｄｍｅｃｈａｎｉｃａｌｉｍｐａｃｔｏｆｍｏｌｔｅｎａｌｕｍｉｎｕｍａｔｅｌｅｖａｔｅｄｔｅｍｐｅｒａｔｕｒｅ ,ｗｈｉｃｈｒｅｓｕｌｔｓｉｎｆａｉｌｕｒｅｓ ,ｓｕｃｈａｓ ,ｈｅａｔｃｈｅｃｋｉｎｇ ,ｃｏｒｒｏｓｉｏｎｏｒｓ…     

Free DNA – new potential analyte in clinical laboratory diagnostics?

The existence of cell free DNA in the human circulatory system has been known since the 1950s, however, intensive research in this area has been conducted for the last ten years. This review paper brings a short overview of the existing literature concerning the cell free DNA research in various clinical fields and pathological states and considers the application possibilities of this new analyte in clinical laboratory diagnostics. At the moment, cell free DNA is most widely used for the purpose of non-invasive prenatal diagnosis of fetal sex or fetal RhD status. The recent discovery of epigenetic changes in placental/fetal DNA and the detection of fetal/placental-specific RNAs have made it possible to use this technology in all pregnancies irrespective of the gender of the fetus. With the application of new techniques such as next generation sequencing, digital PCR and mass spectrometry, it is now possible to detect very small amounts of specific DNA in the presence of excess of other nonspecific nucleic acids. Second most probable application is in oncology, where detection and monitoring of tumors is now possible by the detection of tumor-derived nucleic acids. Third promising field for near future implementation of this analyte is transplantation medicine, where free DNA level could serve as a marker of transplant rejection. Before any further utilization of this new biomarker, pre-analytical and analytical aspects of free DNA analysis remain to be standardized. In the field of noninvasive prenatal diagnosis, important ethical, legal and social questions remain to be discussed.     

ICP-AES法同时测定面粉中钾、镁、钙的含量

湿法消解样品后,用ICP-AES法同时测定面粉中钾、镁、钙3种元素的含量。优化实验条件下,RSD为0.31%-1.37%,加标回收率为97.20%-100.00%。方法简便、快速、准确,灵敏。     

等离子喷涂NiCr涂层的耐强酸腐蚀性能研究

采用等离子喷涂技术在Q235基体表面制备NiCr涂层,并用E-44型环氧树脂与低分子650#聚酰胺1：1配比进行封孔,通过在三种典型强酸环境中的全浸泡试验,对涂层的耐蚀性进行了评价．结果表明,在65％的硝酸和98％的硫酸溶液中浸泡500h后,NiCr涂层表面平整,采用SEM观察微观形貌,涂层较致密,有少量的腐蚀坑,腐蚀速率为0．05—0．5mm／a,处于第二等级,耐蚀性良好;NiCr涂层在36％的盐酸溶液中浸泡500h后,由于活性离子Cl^-的影响,部分涂层呈层片状脱落,采用SEM观察微观形貌,腐蚀坑数目比较多,腐蚀速率为1．21mm／a,处于第三等级,耐蚀性较差．     

Interaction ofLabeo rohita lectin (LRP) with mycobacterial surface oligosaccharide

A C-type mannose specific lectin (LRP) isolated from plasma of fresh water fishLabeo rohita showed 500 times higher specificity towards cell surface oligosaccharide (LAM) ofMycobacterium tuberculosis (H37Rv). Using biotinylated LRP, binding between lectin and LAM was demonstrated by ELISA and it was observed that even 3ng of oligosaccharides might be detected using only 1μg of biotinylated lectin.     

JA750型等离子体光谱仪测控系统的改造及应用

JA750型等离子体光谱仪测控系统的计算机换型、从PDP-8A-IBMPc286-通用微机，解决了专用计算机维修换件难的问题，保证了仪器正常运转，延长了该仪器使用寿命；操作系统升级，从PDP-8A机器语言→DOS操作系统→windows操作系统，解决了原机器语言操作系统功能落后的问题。该文对仪器改造前后的功能及技术指标进行了对比，并利用改造后的等离子体光谱仪进行了矿产勘查样品测试方法的研究，经国家一级标准物质（GBW）分析验证，该方法测量相对误差和相对标准偏差均在标准要求范围内，为矿产勘查样品系统，快速、大批量样品分析提供一种有效手段。     

研究性教学模式在光学实验中的运用

开设研究性实验教学,是实验教学改革的一项重要内容.以一个教学案例的实施,说明学生在完成实验的过程中,从开始实验内容的确定到最后实验结果的讨论,自主学习的应用过程贯穿了整个步骤的始终,从而引发学生的科学研究兴趣,对培养学生的创新意识和实践能力具有重大意义,也对新升本科的地方院校开设研究性实验提供一些参考.