基于文献计量学分析泥沙来源研究进展与热点

明确流域或区域泥沙来源对水土保持措施科学布局有重要意义。为了更好地掌握泥沙来源研究的发展动态,研究借助文献计量方法与可视化工具——CiteSpace软件,对中国知网(CNKI)总库和Web of Science数据库迄今关于泥沙来源的所有文献进行收集分析,探寻当前该领域的研究热点,为未来的发展研究提供参考。对检索获取的6 000余篇中文和英文文献的分析发现,当前泥沙来源研究的主要对象包括淤地坝、小流域、河流与盆地。研究热点主题主要包括泥沙输移、泥沙形态和土壤侵蚀; 热点研究内容注重对环境效应、影响因素等进行综合研究; 热点研究手段是复合指纹识别技术。关键词突现图和时区图展现的前沿研究趋势显示,在重点研究区要重建流域泥沙来源历史的演变规律; 指纹识别法作为热点研究手段则亟需科学的试验设计来验证该方法的准确性; 将来的研究则侧重于形成类似“复合指纹系统工具”的工具,服务于流域管理、侵蚀泥沙产生的环境风险预测等方面。     

茶叶多糖铁的合成及其铁含量的测定

用热水浸泡法从粗老茶叶中提取茶叶多糖,在碱性条件下,茶叶多糖水溶液与三氯化铁反应合成茶叶多糖铁配合物(TPC),并用邻菲罗啉分光光度法和原子吸收光谱法测定TPC中铁(Ⅲ)的含量。实验结果表明:TPC是深棕红色无定型粉末,易溶于水,在pH值3~12范围内不沉淀,不水解。TPC中铁(Ⅲ)的含量:邻菲罗啉分光光度法测定结果为20.71%,原子吸收光谱法测定结果为20.13%。     

Change of antithrombin Ⅲ in patients with atherosclerotic cerebral infarction

AIM：To explore the change of antithrombin Ⅲ (AT-Ⅲ) in the patients with atherosclerotic cerebral infarction. METHODS：Chromogenic substrate assay was used to measure the activity of AT-Ⅲ in 55 patients with atherosclerotic cerebral infarction and 55 healthy controls, and the correlation analysis was applied to determine the AT-Ⅲ activity with the severity of damage in central nervous system and general biochemical parameters. The levels of TNF-α and IL-6 in the plasma were detected by ELISA. Immunocomplex in the plasma was measured by enzyme immunoassay （EIA）. The number and phenotype of the monocytes in peripheral blood were analyzed by flow cytometry. ELISA was also applied to determine the secretion of TNF-α and IL-6 from the monocytes after the stimulation of immunocomplex. The expression of AT-Ⅲ in human brain vascular endothelial cells after the stimulation of TNF-α and IL-6 was observed by Western blotting. RESULTS：The activity of AT-Ⅲ significantly decreased in the patients with atherosclerotic cerebral infarction, and negatively correlated with the damage degree of nervous system function, systolic pressure, diastolic pressure, glucose, cholesterol, triglyceride, low-density lipoprotein cholesterol and homocysteine, while positively correlated with high-density lipoprotein. In addition, the plasma levels of TNF-α and IL-6 increased significantly, accompanied with the enhancement of immunocomplex level. The numbers of CD14+ CD16+ and CD14+ CD32+ monocytes in peripheral blood were not changed, while CD14+ CD64+ monocytes increased obviously. The secretion of TNF-α and IL-6 by monocytes were significantly enhanced after stimulated with immunocomplex, while the protein expression of AT-Ⅲ in the human brain vascular endothelial cells was down-regulated after co-incubated with TNF-α or IL-6. CONCLUSION：Decreased AT-Ⅲ activity in the patients with atherosclerotic cerebral infarction is one of the risk factors of cerebral infarction, and related with the disease severity. The production of pro-inflammatory cytokines through immunocomplex from CD14+ CD64+ monocytes may be involved in the mechanism. Improvement of AT-Ⅲ activity may protect against cerebral ischemia.     

豫南地区杨树舟蛾类害虫飞机喷药防治试验

利用飞机喷洒25%阿维·灭幼脲3号悬浮剂,对添加不同比例高效氯氰菊酯和不同施药时期的防治效果进行研究,试验发现每架次添加1.5 kg 5%高效氯氰菊酯油剂(两种药剂的质量比为24∶1.5),能快速有效防治杨树舟蛾类害虫。6月中下旬豫南地区杨树舟蛾类害虫为二代2～3龄幼虫期,是施药防治该类害虫的最佳时期。     

迟钝爱德华氏菌Ⅲ型分泌系统基因的克隆及多重PCR检测方法的建立

采用PCR法扩增大菱鲆Scophthalmus maximus出血性败血症病原菌迟钝爱德华氏菌Edwardsiella tarda L-49231菌株Ⅲ型分泌系统(TTSS)的装置蛋白(esaC)、效应蛋白(eseB、eseC、eseD)和调节蛋白(esrA、esrB)6种基因,并将其克隆到载体PMD19-T中分别进行测序;通过优化反应条件,建立一次检出效应蛋白eseB、eseC和eseD 3种基因片段的多重PCR方法;采用所建立的多重PCR方法检测迟钝爱德华氏菌不同菌株(L-49231、GhAn080310、GhAn080313和GhAn080314)、沙门氏菌Salmonella enterica、大肠杆菌Escherichia coli和肠杆菌Enterobacter中效应蛋白基因的存在情况.结果表明:L-49231菌株中存在esaC、eseB、eseC、eseD、esrA和esrB 6种基因片段,大小分别为837、184、934、445、464、458 bp,与GenBank 中迟钝爱德华氏菌PPD130/91菌株的这6种基因的同源性分别为99％、97％、99％、99％、99％、98％;通过优化反应条件,在退火温度为54 ℃,基因eseB、eseC和eseD引物浓度(μmol/L)组合比为5∶10∶2,Mg2+浓度为1.5 mmol/L时,能够得到清晰、稳定且均一的多重PCR产物,并与目的条带分子量一致;采用所建立的多重PCR方法进行检测,迟钝爱德华氏菌L-49231菌株中存在eseB、eseC和eseD 3种基因片段,迟钝爱德华氏菌GhAn080310、GhAn080313、GhAn080314菌株中存在eseB和eseC基因片段,但未检出eseD基因片段;沙门氏菌、大肠杆菌和肠杆菌中均未检出eseB、eseC和eseD基因.表明所建立的多重PCR方法对迟钝爱德华氏菌具有较好的特异性,可检出具有Ⅲ型分泌系统效应蛋白的菌株.     

Effects of basic fibroblast growth factor on proliferation and collagen production in human umbilical cord mesenchymal stem cells

AIM：To observe the growth pattern and surface markers of human umbilical cord mesenchymal stem cells(hUCMSCs) and to explore the influence of basic fibroblast growth factor (bFGF) on the proliferation and collagen production in hUCMSCs cultured in vitro. METHODS：hUCMSCs were isolated by enzyme digestion method and adherent culture. The surface markers CD45, CD34, CD105, CD29 and HLA-DR of the cells were analyzed by flow cytometry. The osteogenic ability and adipogenic differentiation were confirmed with oil red O and alizarin red staining. The optimal concentration of bFGF to promote the proliferation of hUCMSCs was 20 μg/L. The cells in control group were cultured in the growth medium consisting of DMEM/F12 and 10% volume fraction of fetal bovine serum. The cells in experiment group were cultured under the same condition of control group but plus 20 μg/L bFGF. The proliferation of hUCMSCs was analyzed by MTT assay. The expression of type I and III collagens at mRNA and protein levels was determined by RT-PCR and Western blotting. RESULTS：The growth curves indicated that bFGF promoted the proliferation of hUCMSCs. The hUCMSCs expressed CD29, but did not express CD34, CD45 or HLA-DR in the presence or absence of bFGF unanimously. The cells were alizarin red staining-positive and oil red O staining-positive. Compared with control group, the expression of type I and III collagens significantly decreased at mRNA and protein levels in experiment group. CONCLUSION：bFGF promotes the proliferation of hUCMSCs and does not change the expression of the surface markers. bFGF inhibits the expression of type I and III collagens at mRNA and protein levels, indicating that bFGF enhances the healing of wound without inducing scar hyperplasia.     

省域水资源可持续利用效率分析

我国正面临着严峻的水资源短缺、水质恶化和水生态退化问题,高效、可持续地利用水资源至关重要。为了通过省域之间的相互比较来提高我国省域水资源可持续利用效率,本文从水资源可持续利用的基本要求出发,以国土面积和Ⅲ类以下水资源量为投入变量,以地区生产总值和人口数量为产出变量,应用DEA(BCC)-Tobit两步法测算了中国26个省域水资源可持续利用相对效率,分析了影响省域水资源可持续利用效率的关键因素。结果表明,规模偏大与不合理用水导致我国省域水资源的可持续利用效率总体较低,综合效率均值为0.303,纯技术效率均值为0.592,规模效率均值为0.513。水资源可持续利用效率的省际差异很大,综合效率值的变异系数达1.010,效率提升的潜力很大。第一产业增加值占地区生产总值的比重、单位国土面积环保投资额和耕地占国土面积比重是影响省域水资源可持续利用效率的3个关键因素,影响系数依次为0.015 7、0.014 2和0.004 9。综合分析可知,在充分保护和持续利用耕地的基础上推进工业化、城镇化和农业现代化,调整经济发展结构,加大环保投资有利于提高省域水资源可持续利用效率。     

基于CNKI数据库的茶园土壤酸化文献计量分析

2006年以来,茶园土壤酸化问题广受学术界关注,相关研究成果大量涌现,逐渐发展成为一个新的知识领域。分析茶园土壤酸化领域现有文献,识别茶园土壤酸化研究的知识聚类与研究网络,从整体把握研究动态以及发展趋势,并为将来的研究提供新的思路和参考。利用CiteSpace软件对茶园土壤酸化研究的研究现状、研究热点、研究前沿等进行可视化分析。结果表明：茶园土壤酸化研究大致经历了萌芽阶段（1976—1990年）、缓慢发展阶（1991—2005年）、迅猛增长阶段（2006—2019年）3个阶段;研究群体主要以浙江为代表的高校及科研院所居多,但科研院所发文量较少,有待加强,其中“茶树”受关注度最高;“pH”是出现时间最早且持续时间最长的主题词,成为持续型的研究前沿领域。在茶园土壤酸化现有研究的基础上,将来有必要突破“土壤酸度”的框架,拓展研究范畴,构建研究网络,创新研究方法,从更加广阔的视角进行多元化研究。     

腐植酸、EDTA、Cr(Ⅵ)调控猪粪尿废水异化Fe(Ⅲ)还原偶联VFAs的转化能力比较

以人工合成Fe(OH)3作为电子受体,在猪粪尿废水中添加具有铁还原能力的菌株,厌氧恒温培养,通过对猪粪尿废水中添加不同浓度腐植酸、EDTA、Cr(Ⅵ),揭示3种典型理化因素调控猪粪尿废水中异化Fe(Ⅲ)还原偶联挥发性脂肪酸(Volatile fatty acids,VFAs)转化能力。结果表明,电子穿梭体腐植酸促进Fe(Ⅲ)还原,加速VFAs降解,而络合剂EDTA和重金属Cr(Ⅵ)则会阻碍Fe(Ⅲ)还原,减缓VFAs降解。虽然三种影响因子影响机理不同、途径不同,但最终Fe(Ⅲ)还原和VFAs平衡点不变。     

西藏牦牛mtDNA COⅢ全序列测定及系统进化关系

 【目的】探讨西藏牦牛的遗传多样性和类群间的系统进化关系,为西藏牦牛遗传资源的合理保护和利用提供理论依据。【方法】对11个西藏牦牛类群111个个体的mtDNA COⅢ的全序列进行测定,用多种生物信息学软件分析牦牛类群的遗传多样性和它们间的亲缘关系及分类。【结果】①西藏11个牦牛类群的mtDNA COⅢ全序列长度均为781 bp,基因间没有内含子,共编码260个氨基酸,启始密码子AUG(ATG),含一个游离碱基。4种核苷酸的平均比例分别为29.2%（T）、29.4%（C）、26.1%（A）和15.2%（G）,有一定的偏倚性。②发现西藏牦牛的mtDNA COⅢ共有18种单倍型,11个牦牛类群的单倍型多样性值在0.378—0.844。表明,西藏牦牛具有较丰富的mtDNA COⅢ遗传多样性。③在mtDNA COⅢ的20种氨基酸组成中,亮氨酸平均含量最多,为11.92%,赖氨酸和半胱氨酸平均含量最少,为0.77%。碱性氨基酸、酸性氨基酸、亲水性氨基酸和疏水性氨基酸的含量分别为11.15%、4.62%、29.61%和54.61%。④从mtDNA COⅢ来看,西藏11个牦牛类群可分为3大类,即帕里牦牛（PL）系、巴青牦牛（BQ）系、斯布牦牛（SB）系。【结论】西藏牦牛有丰富的遗传多样性,可分为3大类;结果支持将牦牛划分为牛亚科中一个独立属（牦牛属,Poephagus）的观点。