Electrochemical behaviour of Ti–25Nb–3Mo–3Zr–2Sn biomedical alloy in different simulated physiological environments

The electrochemical corrosion behaviour of biomedical Ti–25Nb–3Mo–3Zr-2Sn (TLM) alloy was investigated in various simulated body fluids at 37±0·5°C utilising potentiodynamic polarisation and current–time curves. The Ti–6Al–4V (TC4) alloy was also investigated to make a comparison. The different simulated body fluids comprised of 0·9%NaCl saline, Hank’s and Ringer’s solution were employed. The effect of heat treatment on the electrochemical behaviour of the TLM alloy was also considered. It was discovered that all the test specimens were passivated once immersed into the simulated body fluids. It was also found that the TLM alloy has poorer corrosion resistance in Hank’s solution, due to the chemical composition of the Hank’s. After different heat treated, the TLM alloy had different phases and microstructure, and the corrosion behaviour of the TLM alloy was different. In this study, after the heat treatment of 760°C/1 h/AC+550°C/6 h/AC, the TLM alloy had better corrosion resistance. Owing to the corrosion resistance of the TLM alloy was influenced by numerous factors, such as microstructure and the chemical composition of electrolyte, the corrosion behaviour of the TLM alloy is complex. By comparing with the corrosion behaviour of the TC4 alloy, the TLM alloy has poorer corrosion resistant than the TC4 alloy under the same conditions. But the current–time curves of the TLM alloy were more stable than these of the TC4 alloy with further experiments, because of the more passivation film on the surface of the TLM alloy.     

Entrepreneurial quality and regional development: Characterizing SME sectors in low income areas*

This paper analyses the characteristics of SMEs in less‐developed areas in comparison with more advanced economies. The conceptual framework includes different factors making up the so‐called ‘entrepreneurial quality’ of the SME sector: the personal characteristics of the entrepreneurs (motivations and previous experience), different dimensions of the SMEs’ entrepreneurial orientation, and the patterns of the SMEs’ insertion in national and global value chains. The empirical analysis uses data of SMEs in four different Spanish provinces representing examples of low income economies and comparatively high income ones, respectively. Results show the SMEs in the low income economies to be characterized by a lower entrepreneurial quality.     

低W-W连接度65W-25Cu-10Ni合金的制备及准静态力学性能研究

利用W颗粒表面化学镀Ni结合SPS的方法,制备了低W-W连接度65W-25Cu-10Ni合金,并开展了准静态力学性能研究。结果表明,制得的Ni包W复合粉中Ni包覆层分布均匀且与W结合良好;以Ni包W复合粉和Cu粉为原料制备的65W-25Cu-10Ni合金组织均匀且致密。在准静态压缩加载条件下,与65W-35Cu合金相比,65W-25Cu-10Ni合金的强度及塑性均大幅度提高;在准静态拉伸加载条件下,与65W-35Cu合金相比,65W-25Cu-10Ni合金的强度较高,塑性没有明显提高。机理分析表明,与65W-35Cu合金相比,65W-25Cu-10Ni合金中W-W连接度较低、粘结相由Cu相转变为Cu0.81Ni0.19固溶体,且W与粘结相之间形成了冶金结合,以上三个因素共同导致65W-25Cu-10Ni合金强度的提高;此外,W-W连接度的降低以及W-粘结相界面结合强度的提高是65W-25Cu-10Ni合金在准静态压缩加载条件下塑性提高的原因。     

摇床T25细胞培养瓶流体力学与传质特性研究

细胞培养技术是生物医药产业的支柱,以实现微小体积内的高密度、高通量细胞培养为目的,系统地研究了常用于单层静态培养的T25方瓶置于翘板摇床上在不同操作条件下的流体力学特性和传质性能。结果表明,振荡可以显著提高方瓶的传质速率并降低混合时间,使高密度培养成为可能,但瓶盖上的空气滤膜在高转速时成为传质速率的限制因素;培养瓶对称轴与摇床旋转轴平行时,其相对位置对混合和传质无明显影响,但当二者成45°角时,相同转速下混合时间显著缩短;使用自定义函数实现了基于动态网格的CFD模拟,对不同转速下方瓶内剪切应力和能量耗散在时间与空间上分布进行了分析,为基于T25培养瓶开发一次性高通量微型反应器提供了数据支持和理论基础。     

瑞隆矿经营管理精细化管控模式经验探讨

为了在低迷的煤炭形势下生存发展,山西金晖瑞隆煤业有限公司在全矿推行精细化管理方法。以瑞隆矿经营管理体制精细化为背景,以＂5＋5＂管控模式为管理样板分析探讨了国企控股整合民营企业煤矿精细化管理模式。     

四肽Trp-Gly-Gly-His的合成及其对铜离子的检测

用固相合成法,将能特异性识别Cu2+的三肽Gly-Gly-His(GGH)与具有荧光发射功能的Trp(W)偶联,得到了由天然氨基酸组成的Cu2+分子探针Trp-Gly-Gly-His(WGGH)。该探针具有水溶性好,响应时间快、无毒安全、检测窗口宽、高灵敏度和高选择性等优点。实验优化得到的最佳检测pH为7.5。该探针对Cu2+的检测范围为10~1500 nM,检测限为2 nM。     

Overexpression of microRNAs miR-25-3p,miR-185-5p and miR-132-3p in Late Onset Fetal Growth Restriction,Validation of Results and Study of the Biochemical Pathways Involved

In a prospective study, 48 fetuses were evaluated with Doppler ultrasound after 34 weeks and classified, according to the cerebroplacental ratio (CPR) and estimated fetal weight (EFW), into fetuses with normal growth and fetuses with late-onset fetal growth restriction (LO-FGR). Overexpression of miRNAs from neonatal cord blood belonging to LO-FGR fetuses, was validated by real-time PCR. In addition, functional characterization of overexpressed miRNAs was performed by analyzing overrepresented pathways, gene ontologies, and prioritization of synergistically working miRNAs. Three miRNAs: miR-25-3p, miR-185-5p and miR-132-3p, were significantly overexpressed in cord blood of LO-FGR fetuses. Pathway and gene ontology analysis revealed over-representation of certain molecular pathways associated with cardiac development and neuron death. In addition, prioritization of synergistically working miRNAs highlighted the importance of miR-185-5p and miR-25-3p in cholesterol efflux and starvation responses associated with LO-FGR phenotypes. Evaluation of miR-25-3p; miR-132-3p and miR-185-5p might serve as molecular biomarkers for the diagnosis and management of LO-FGR; improving the understanding of its influence on adult disease.     

Identification and In Silico Characterization of a Novel COLGALT2 Gene Variant in a Child with Mucosal Rectal Prolapse

Rectal prolapse is influenced by many factors including connective tissue dysfunction. Currently, there is no data about genetic contribution in the etiology of this disorder. In this study, we performed trio whole-exome sequencing in an 11-year-old girl with mucosal rectal prolapse and her parents and sibling. Genetic testing revealed a novel heterozygous missense variant c.1406G>T; p.G469V in exon 11 of the COLGALT2 gene encoding the GLT25 D2 enzyme. Sanger sequencing confirmed this variant only in the patient while the mother, father and sister showed a wild-type sequence. The pathogenicity of the novel variant was predicted using 10 different in silico tools that classified it as pathogenic. Further, in silico prediction, according to Phyre2, Project HOPE, I-Mutant3.0 and MutPred2 showed that the missense variant can decrease protein stability and cause alterations in the physical properties of amino acids resulting in structural and functional changes of the GLT25D2 protein. In conclusion, the present study identifies a previously unknown missense mutation in the COLGALT2 gene that encodes the enzyme involved in collagen glycosylation. The clinical features observed in the patient and the results of in silico analysis suggest that the new genetic variant can be pathogenic.     

L.paracasei HD1-7与S.albulus1-25原生质体融合选育产天然防腐剂的优良菌株

为获得更具优良应用特性的微生物源天然防腐剂,采用原生质体融合技术,以Lactobacillus paracasei HD1-7和Streptomyces albulus1-25为亲株选育优良菌株,研究了L.paracasei HD1-7和S.albulus1-25原生质体制备与再生条件,通过表型、抑菌谱、抗药性和总DNA含量比较等手段筛选鉴定融合子,最终选育出3株以L.paracasei HD1-7为受体、获得来自S.albulus1-25的抑酵母菌基因的融合子。     

基于VHDL的出租车计价器设计

采用VHDL编写出租车计费器系统程序,采用MAX＋PLUSⅡ软件作为开发平台,进行了程序仿真,验证设计实现了出租车计价器的相关功能。