GIS-based distributed model for simulating runoff and sediment load in the Malian River Basin

GIS-based modeling is an effective approach for reflecting spatially-varied complexities in watershed systems. In this study, a GIS-aided distributive hydrological model was developed to simulate runoff and sediment transport in a loess-plateau context with semi-arid climate, sparse vegetation, and serious soil erosion. The model was then applied to a case study in the Malian River Basin, which is one of the largest catchments in the middle reach of the Yellow River. Based on the GIS technique, the DEM of the study basin was successfully used to delineate the stream network and extract information of catchment characteristics. The results show satisfactory accuracy for runoff simulation. Especially, the integrated soil-erosion and hydrological models can be used for simulating both runoff and sediment loads, which provide a useful decision-support tool for water resources management and pollution control. This study is an attempt to develop a distributed rainfall-runoff model for river basins in the loess plateau region. The developed model can also be extended to larger basins. Further works of field survey and investigation would be helpful for better calibrating critical parameters and thus improving performance of the developed model.     

Genetic polymorphisms of glutathione S-transferases are associated with ulcerative colitis in central China

The present study aimed to investigate the association between genetic polymorphisms of glutathione S-transferases (GSTs) and susceptibility to ulcerative colitis (UC) in central China. The prevalence of GSTM1, GSTT1, and GSTP1 gene polymorphisms were examined using polymerase chain reaction methods in 270 consecutive UC patients and 623 age- and sex-matched healthy controls. The frequencies of the GSTM1(null) and GSTT1(null) as well as GSTP1 (Val/Val) genotypes were significantly higher in UC patients than in the controls (70.74% vs. 41.74%, P = 0.0001; 64.82% vs. 47.19%, P = 0.0001; and 48.89% vs. 34.35%, P = 0.0004, respectively). When the UC patients were stratified according to clinical features, we found that the frequencies of the GSTT1(null) and GSTP1 (Val/Val) genotypes but not the GSTM1(null) genotype were significantly higher in patients with distal colitis than in extensive colitis (P = 0.0007, P = 0.001, and P = 0.271, respectively). However, these variant GST genotypes were not significantly linked to severity of the disease (P > 0.05). GST variant genotypes are strongly correlated with prevalence and extent but not with severity of UC in the Hubei Han population in central China.     

Adult peripheral blood mononuclear cells transdifferentiate in vitro and integrate into the retina in vivo

Adult peripheral blood-derived cells are able to differentiate into a variety of cell types, including nerve cells, liver-like cells and epithelial cells. However, their differentiation into retina-like cells is controversial. In the present study, transdifferentiation potential of human adult peripheral blood mononuclear cells into retina-like cells and integration into the retina of mice were investigated. Freshly isolated adult peripheral blood mononuclear cells were divided into two groups: cells in group I were cultured in neural stem cell medium, and cells in group II were exposed to conditioned medium from rat retinal tissue culture. After 5 days, several distinct cell morphologies were observed, including standard mononuclear, neurons with one or two axons and elongated glial-like cells. Immunohistochemical analysis of neural stem cell, neuron and retina cell markers demonstrated that cells in both groups were nestin-, MAP2 (microtubule-associated protein)- and GFAP (glial fibrillary acidic protein)-positive. Flow cytometry results suggested a significant increase in nestin-, MAP2- and CD16-positive cells in group I and nestin-, GFAP-, MAP2-, vimentin- and rhodopsin-positive cells in group II. To determine survival, migration and integration in vivo, cell suspensions (containing group I or group II cells) were injected into the vitreous or the peritoneum. Tissue specimens were obtained and immunostained 4 weeks after transplantation. We found that cells delivered by intravitreal injection integrated into the retina. Labelled cells were not detected in the retina of mice receiving differentiated cells by intraperitoneal injection, but cells (groups I and II) were detected in the liver and spleen. Our findings revealed that human adult peripheral blood mononuclear cells could be induced to transdifferentiate into neural precursor cells and retinal progenitor cells in vitro, and the differentiated peripheral blood mononuclear cells can migrate and integrate into the retina in vivo.     

稀土元素在药用植物细胞和组织培养中的应用

介绍了稀土元素对药用植物细胞、组织的生长及次生代谢产物合成的作用,探讨了稀土的作用机理.大量的实验证明,稀土在药用植物细胞和组织培养中具有广泛的应用前景.     

乳化溶剂挥发法制备纳米粒

目的：建立乳化溶剂挥发法制备纳米粒的方法。方法：采用单因素法和正交设计法考察不同影响因素对乳化溶剂挥发法所制得的纳米粒粒径、包封率和载药量的影响。结果：采用乳化溶剂挥发法,通过改变处方和工艺因素所制得的纳米粒,外观圆整,大小均匀,粒径可控,包封率多数可达50%以上。结论：优化确立了乳化溶剂挥发法制备纳米粒的处方和工艺,可以制备满足不同要求的纳米粒。     

基于二层特征筛选的HIV-1蛋白酶特异位点预测

在抗艾滋病治疗中,HIV-1蛋白酶抑制剂发挥着重要作用。对于HIV-1蛋白酶裂解作用位点的研究有助于找到新的治疗靶点。为了对HIV-1蛋白酶特异位点进行预测,本研究用氨基酸索引数据库(Amino Acid Index,AAIndex)中的531个氨基酸物理化学性质参数直接表征肽样本的结构,通过二层特征筛选,最终将4248个表征参数降为57个表征参数。分别采取四种核函数进行HIV-1蛋白酶特异位点的支持向量机(SVM)建模,并通过10折交叉验证及外部测试集方法来验证建模的准确性。结果表明选取NormalizePolyKernel核函数进行SVM建模效果优于其他核函数(PolyKernel、PUK、RBFKernel),所建立的模型对于训练集的10组交叉验证预测准确率达到93.947%,对于外部测试集的预测正确率达到93.684%。     

广东珠海40种景天科多肉植物的适应性评价

于2015年10月起在广东珠海对40 种景天科多肉植物进行为期2年的生长观测,对其观赏性、生态适应性进行评价,以期筛选适合本土生长的优良多肉植物。结果显示,综合评价等级最优(Ⅴ级)植物9种,分别为姬胧月Graptopetalum ‘Bronze’、胧月Graptopetalum paraguayense、铭月Sedum adolphli、秋丽Graptosedum ‘Francesco Baldi’、江户紫Kalanchoe marmorata、窄叶不死鸟Kalanchoe ‘Fortyniner’、燕子掌Crassula portulacea、丸叶姬秋丽Graptopetalum mendozae、姬秋丽Graptopetalum ‘Mirinae’;综合评价等级优(Ⅳ级)植物6种,分别为子持莲华Orostachys furuser、鲁氏石莲Echeveria runyonii、初恋Echeveria huthspinke、冬美人Pachyphytum oviferum ‘Pachytoides’、青星美人Pachyphytum ‘Doctor Comelius’、千佛手Sedum super ‘Burros’。上述种类可在珠海及周边城市推广应用。     

GoldMag nanocomposite-functionalized graphene sensing platform for one-step electrochemical immunoassay of alpha-fetoprotein

A new flow-through electrochemical immunosensor was designed for sensitive detection of alpha-fetoprotein (AFP) in human serum by using nanogold-functionalized magnetic graphene nanosheets as immunosensing probes. Initially, amino functionalized magnetic beads were covalently immobilized on the surface of graphene oxide nanosheets (MGPs), then nanogold particles were adsorbed on the amino groups of the MGPs to construct GoldMag nanocomposites functionalized graphene nanosheets (GMGPs), and then horseradish peroxidase-anti-AFP conjugates (HRP-anti-AFP) were assembled onto the surface of nanogold particles (bio-GMGP). With the aid of an external magnet, the formed bio-GMGPs were attached onto the base electrode in the flow system. With a non-competitive immunoassay format, the injected sample containing AFP antigens was produced transparent immunoaffinity reaction with the immobilized HRP-anti-AFP on the bio-GMGPs. The formed immunocomplex inhibited partly the active center of HRP, and decreased the labeled HRP toward the reduction of H(2)O(2). The performance and factors influencing the performance of the immunosensor were investigated in detail. Under optimal conditions, the electrochemical immunosensor displayed a wide working range of 0.01-200 ng mL(-1) with a low detection limit (LOD) of 1.0 pg mL(-1) AFP (at 3s(B)). Intra- and inter-assay coefficients of variation (CV) were below 10%. In addition, the methodology was validated with real serum samples, receiving a good correlation with the results obtained from commercially available electrochemiluminescence automated analyzer.     

浙江秀山岛湿地生态系统初探

秀山岛位于东海舟山渔场海域,岛上有大片的湿地资源分布,其滨海部分与舟山渔场的生物资源特别是渔业生物资源密切联系,具有罕见的海岛特色。海岛的特殊地理位置为秀山岛湿地赋予了独特的生态特征。秀山岛湿地内动植物资源丰富,生物多样性高,共有植物种类300余种,栖息的鸟类共有26个科108种,包括国家一级保护动物东方自鹳（Ixobrychus minutus）。还有国家二级保护动物獐（Hydropotes inermis）等珍贵动物自然栖息。秀山岛湿地包括潮下带湿地（浅海湾）、潮间带湿地（泥滩、芦苇丛）、潮上带湿地（咸水沼泽、半咸水沼泽）、异化湿地（盐田、养殖池、稻田）等几个紧密联系的部分。具有多方面的生态功能。由于对湿地的生态功能重视不够,湿地生态系统破碎化严重。目前在秀山岛湿地已经建立了湿地自然保护区,湿地生态系统得到了较好的发展。