Research performance in key medical universities in China observed from the scientific productivity

Research activities in the life sciences during the past few years, have increased appreciably in China, both in regard to relative output of publications and in their impact on the international research community. The purpose of this study is to analyze and evaluate quantitatively the scientific productivity of key medical universities in China by using CBMdisc, MEDLINE and SCI databases. The results showed that Tongji Medical University ranks first in terms of paper output in Chinese and in English languages, while Beijing Medical University is placed second in output but is first in citation impact. Shanghai Medical University had the top annual paper output per scientist, with 2.53 papers in Chinese and 0.13 papers in English. The results also showed that the coverage of Chinese biomedical publications by western indexing services is very poor.     

猪细小病毒PCR检测方法的建立与应用

目的建立猪细小病毒(PPV)PCR检测方法。方法设计一对针对PPV的特异引物,经方阵滴定法确定PCR检测的最佳条件,以多种病毒DNA为模板进行PCR扩增,并对扩增产物进行斑点杂交鉴定。提取已知滴度的病毒培养物DNA为模板,稀释后进行PCR扩增,测定PCR方法的敏感性。采用此方法检测了180份猪各种组织样品的DNA及PPV-猪组织混合感染PK-15细胞模型。结果仅PPV野毒株和北京分离株AV7909能够扩增出一条531bp的片段,测序结果证明为PPV的特异片段。该方法所能检测的最小病毒滴度值为0.398TCID50,可以检测出PPV-猪组织混合感染PK-15细胞模型中0.500 TCID50的感染量。180份组织样品均未检出PPV。结论该方法具有良好的特异性和敏感性。     

幽门螺杆菌尿素酶B亚单位特异性抗体检测方法的建立与评价

目的建立并评价幽门螺杆菌(Hp)尿素酶B亚单位(UreB)特异性抗体的检测方法。方法应用纯化的重组HpUreB作为包被抗原,建立检测HpUreB特异性抗体的ELISA间接法。以Hp抗体Western blot检测作为“金标准”,评价所建立方法的真实性和可靠性。结果检测血清特异性IgG的灵敏度为100·0%,特异度为97·7%,阳性预测值为97·2%,阴性预测值为100·0%,约登指数为0·977,符合率为98·7%,试验的一致率为98·5%;检测血清中总的特异性Ig灵敏度为97·1%,特异度为95·3%,阳性预测值为94·4%,阴性预测值为97·6%,约登指数为0·925,符合率为96·2%,试验的一致率为97·8%;检测唾液中特异性sIgA的灵敏度为96·2%,特异度为94·5%,阳性预测值为89·3%,阴性预测值为98·1%,约登指数为0·907,符合率为95·1%,试验的一致率为97·5%;检测粪便标本中的特异性sIgA的灵敏度为92·0%,特异度为90·2%,阳性预测值为85·2%,阴性预测值为94·9%,约登指数为0·822,符合率为90·9%,试验的一致率为98·6%,CV值均小于15%。结论该检测方法真实性、可靠性、重复性良好,能满足临床标本检测的要求。     

重组水蛭素生物学活性检测参考品的制备和标定

目的制备重组水蛭素(Hirudin)生物学活性检测参考品,并标定其生物学活性。方法按照WHO相关规定制备、分装和冻干参考品,经全面检测合格,用TH生色底物法进行体外生物学活性检测。结果外观、无菌试验合格,水分含量为0.8%。经过10次标定,平均生物学活性为12 701 ATU/支,标准差为2 226 ATU/支,变异系数为17.5%。在-20℃、4℃和25℃条件下,生物学活性可以稳定保持9个月。结论该批重组水蛭素各项指标均符合要求,性质稳定,可作为国家参考品,用于重组水蛭素的生物学活性检测。     

毛细管SDS无胶筛分电泳测定小分子多肽相对分子质量

目的建立快速毛细管SDS无胶筛分电泳法(SDS-NGS),测定小分子多肽相对分子质量。方法涂层毛细管(管长30cm,内径100μm);分离电压为9kV(300V/cm),分离温度为20℃;检测波长为214nm,检测时间为18min;所用SDS-多肽相对分子质量标准范围为2 512~16 949;以橙G(OG)为内标参照物。结果在相对分子质量2512~16949范围内,多肽相对分子质量的对数与其相对迁移率具有良好的线性关系(r=0.996);应用该方法测定了重组人奈西立肽、重组人表皮生长因子、虎纹镇痛肽、重组人心钠肽4种重组小分子多肽的相对分子质量,所测结果变异系数CV均小于3%。结论毛细管SDS无胶筛分电泳方便快速,灵敏度高,重现性好,结果准确,可作为小分子多肽相对分子质量的检测方法。     

云计算中基于改进的布谷鸟算法的资源调度

云计算的资源调度一直以来都是研究的重点,引入布谷鸟算法来解决资源分配问题,首先描述云计算资源模型,其次针对该算法存在局部收敛速度快,容易造成局部最优值的问题,采用三个方面来改进,其一采用变长因子进行调整,减小探索求解质量之间的差别;其二使用差分变异策略更新鸟窝位置;其三使用基于Coelho的混沌全局搜素和局部搜索避免了Levy的随意扰动.通过测试函数说明表明本文算法的性能优于基本布谷鸟算法, Cloudsim仿真平台说明本文的算法在消耗时间,成本和用户满意度方面具有明显的优势.     

Self-assembled silver nanoprisms monolayers at the liquid/liquid interface

A crown ether derivative (4′-aminobenzo-15-crown-5 hydrotetrafluoroborate) can mediate the self-assembly of silver nanoprisms at the liquid/liquid interface in the form of a stable hybrid nanocomposite film. The metallic luster of the interfacial film results from the electronic coupling of Ag nanoprisms, suggesting the formation of closely packed nanoprism thin films. The interfacial film of nanoprisms could be transferred to solid substrates as a Langmuir–Blodgett film. The properties of films were studied by UV–vis spectroscopy and transmission electron microscopy.     

Permeable Resin Applied to Surface of Sealed Demineralized Enamel

The self-made demineralized teeth samples treated with preamble resin to seal or not were observed under electron microscopy and tested microhardness value to show surface structure and hardness of demineralized enamel.The experimental results showed that the permeable resin formed longer resin tags on the surface of the enamel and a lot of cracks in the deep part which has a higher microhardness value than ordinary enamel.     

中国大陆进口冷链食品关联新型冠状病毒疫情调查

目的 新型冠状病毒（SARS-CoV-2）全球大流行以来,中国大陆报道了多起SARS-CoV-2污染进口冷链食品引起的本土新冠疫情,分析此类疫情的特点和传播概况,可以为今后类似疫情防控提出相应建议。方法 收集SARS-CoV-2污染进口冷链食品引起本土新冠疫情文献、官方新闻报道等信息,整理和分析相应数据。结果 2020年6月至2022年11月,共检索到此类疫情20起,包含1 646例病例,涉及9个省（自治区、直辖市）。其中,2020年10起,2021年3起,2022年7起;病例数规模在200例及以上共3起。结论 新冠全球大流行以来中国大陆检索到的20起进口冷链食品相关本土新冠疫情均为冷链从业人员接触进口冷链食品或其外包装感染引起,且大部分（75%）引起了后续社区传播,但是在中国大陆集中监管仓建设等各种有力控制措施下,此类疫情数量和持续时间均呈下降趋势。     

Secreted HSP90α-LRP1 Signaling Promotes Tumor Metastasis and Chemoresistance in Pancreatic Cancer

The extracellular heat shock protein 90α (eHSP90α) has been reported to promote cancer cell motility. However, whether pancreatic cancer (PC) cells expressed membrane-bound or secreted HSP90α, as well as its underlying mechanism for PC progression, were still unclear. Our study demonstrated that the amounts of secreted HSP90α proteins were discrepant in multiple PC cells. In addition, highly invasive Capan-2 cells have a higher level of secreted HSP90α compared with those of less invasive PL45 cells. The conditioned medium of Capan-2 cells or recombinant HSP90α treatment stimulated the migration and invasion of PC cells, which could be prevented with a neutralizing anti-HSP90α antibody. Furthermore, secreted HSP90α promoted elements of epithelial–mesenchymal transition in PL45 cells, including increases in vimentin and Snail expressions, decreases in E-cadherin expression, and changes in cell shape towards a mesenchymal phenotype, but these phenomena were reversed by the anti-HSP90α antibody in Capan-2 cells. In addition, high levels of low-density lipoprotein receptor-related protein 1 (LRP1) were associated with worsened patient survival in pancreatic adenocarcinoma. We demonstrated LRP1 as a receptor of eHSP90α for its stimulatory role in metastasis, by activating the AKT pathway. In addition, silencing LRP1 enhanced the chemosensitivity to gemcitabine and doxorubicin in Capan-2 cells. Therefore, our study indicated that blocking secreted HSP90α underlies an aspect of metastasis and chemoresistance in PC.