Studies on purification and some properties of nisin from Lactococcus lactis subsp. lactis Al2

Protoporphyria is a genetic disorder in which patients may develop severe protoporphyrin-induced liver damage and require transplantation. Because unique problems occur in the perioperative period and because excess production of protoporphyrin by the bone marrow continues after liver transplantation, the efficacy of this procedure for protoporphyric liver disease is uncertain. We present follow-up of nine patients who underwent liver transplantation. Two patients died within 2 months of transplantation, one from complications of abdominal bleeding and the other from sepsis after bowel perforations. The remaining seven patients had follow-up at 14 months to 8 years after transplantation (mean, 3.8 years). Two of the seven had suffered skin burns from exposure to operating room lights, which healed without scarring. Three had axonal neuropathies in the postoperative period requiring prolonged mechanical ventilation, and motor defects persisted in two. Five patients had normal liver chemistries at follow-up (mean, 3.5 years), with liver biopsy results normal or showing mild portal triad abnormalities, but erythrocyte protoporphyrin levels remained significantly elevated (1,765 +/- 365 mcg/dL; normal, < 65). The other two patients, both of whom had rejection, cytomegalovirus infection, and biliary tract obstruction requiring endoscopic therapy, had a recurrence of protoporphyric liver disease as indicated by liver biopsy features. One died 5 years after transplantation from complications of the liver disease. The other was stable 3.3 years after transplantation and was being monitored for possible retransplantation. Thus, liver transplantation can be performed successfully in patients with protoporphyric liver disease, with intermediate survival rates comparable to the general transplant population. However, disease may recur in the graft, particularly if there are complications that cause cholestasis.     

Ranking with uncertain labels and its applications

The techniques for image analysis and classification generally consider the image sample labels fixed and without uncertainties. The rank regression problem studied in this paper is based on the training samples with uncertain labels, which often is the case for the manual estimated image labels. A core ranking model is designed first as the bilinear fusing of multiple candidate kernels. Then, the parameters for feature selection and kernel selection are learned simultaneously by maximum a posteriori for given samples and uncertain labels. The provable convergency Expectation Maximization (EM) method is used for inferring these parameters in an iterative manner. The effectiveness of the proposed algorithm is finally validated by the extensive experiments on age ranking task and human tracking task. The popular FG-NET and the large scale Yamaha aging database are used for the age estimation experiments, and our algorithm outperforms those state-of-the-art algorithms ever reported by other interrelated literatures significantly. The experiment result of human tracking task also validates its advantage over conventional linear regression algorithm. A short version of this paper appeared in ICME07.     

Action of prostanoids on the emetic reflex of Suncus murinus (the house musk shrew)

Several prostanoids were investigated for a potential to induce emesis in Suncus murinus. The TP receptor agonist 11alpha,9alpha-epoxymethano-15S-hydroxyprosta-5Z,13E-dienoic acid (U46619) induced emesis at doses as low as 3 microg/kg, i.p. but the DP receptor agonist 5-(6-Carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropyl) hydantoin (BW245C) was approximately 1000 times less potent. The emetic action of U46619 (300 microg/kg, i.p.) was antagonized significantly by the TP receptor antagonist, vapiprost (P<0.05). EP (prostaglandin E(2), 17-phenyl-omega-trinor prostaglandin E(2), misoprostol and sulprostone), FP (prostaglandin F(2alpha) and fluprostenol) and IP (iloprost and cicaprost) receptor agonists failed to induce consistent emesis at doses up to 300-1000 microg/kg, i.p. Fluprostenol reduced nicotine (5 mg/kg, s.c.)-but not copper sulphate (120 mg/kg, intragastric)-induced emesis; the other inconsistently emetic prostanoids were inactive to modify drug-induced emesis. The results indicate an involvement of TP and possibly DP and FP receptors in the emetic reflex of S. murinus.     

基于PVM的并行调试环境

并行软件开发环境的研究已日益成为并行计算和并行处理的重点。本文简介了可移植的消息传递环境ＰＶＭ，讨论了以此为目标的图形监视环境ＸＰＶＭ，阐明ＸＰＶＭ环境与实际需要的ＰＶＭ并行调试环境之间的差距，并在此基础上探讨了并行调试环境开发中的技术难点及其设计要求。     

Ceramics based on mixed zirconium phosphate prepared by solar-furnace melting

A solar technology to synthesize an NZP structure using the example of Zr(PO₄) was developed. The method is based on high-temperature chemical reactions in the melt and subsequent crystallization of the hexagonal structure of the compounds of this class. Ceramic samples were prepared from the material obtained, and the processes of their sintering were studied.     

碳/环氧复合材料的冲击拉伸

该文研究了T300碳纤维单向增强的环氧复合材料,在应变率从10~(-3)/s到10~3/s范围内的冲击拉伸行为.通过对实验数据进行拟合,得出该范围内材料对应变率具有弱的敏感性,表现在破坏强度及破坏应变随应变率增加不显著变化,平均模量几乎不受应变率的影响.分析了试件的几何尺寸效应,讨论了应力波作用对破坏形态的影响以及实验中观察到的拔出现象.从应变率在10~2～10~3/s附近材料行为某些非确定性,指出在更宽范围内了解其性能的必要性.     

完全子图的邻域重叠社团结构探测

为了能够更准确地对邻域重叠网络进行社团结构探测,对基于完全子图的社团探测算法进行了改进。在合并完全子图团簇时,计算每一对完全子图的重叠节点个数,设置合并完全子图的阈值,如果大于阈值,则合并。当处理不在团簇内的其他节点时,按照比例系数大小为划分规则进行划分。该算法可以应用于空手道俱乐部和科学家合作网当中,其验证算法可以更准确地探测邻域重叠社团结构。     

洪湖沉积物碳氮磷分布特征及污染评价

洪湖是中国第七大淡水湖,富营养化问题日益突出。全面了解洪湖沉积物氮、磷、有机质的含量及分布特征,对掌握其富营养化现状与氮磷污染生态风险具有重要意义。在湖区布设了8个采样点,2019年10月采集50 cm柱状沉积物,分别测定不同深度沉积物总氮(TN)、总磷(TP)以及有机质(OM)含量,分析了TN、TP 和OM 含量的空间分布特征及相关性,并运用综合污染指数法评价其对应的污染程度。结果表明:洪湖沉积物TN含量在467.8~8 454.5 mg/kg之间,平均值2 167 mg/kg,为重度污染,其中近一半的采样点表层沉积物TN含量>5 000 mg/kg;TP含量在502.7~1 252.4 mg/kg之间,平均值693.8 mg/kg,除杨柴湖为重度污染外,其他大部分地区为中度污染;有机质含量占比在5.0%~24.9%之间,平均值9.6%,为重度污染。在垂直空间上,TN、TP 和OM 均在沉积物表层垂向深度0~20 cm存在明显的积累,其含量随垂向深度的增加而迅速降低。研究成果可为洪湖富营养化的控制与治理提供科学数据支撑。