A field investigation was conducted at the Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, in an aquic brown soil of Northeast China under three land use types (cropland, abandoned cropland, and...A field investigation was conducted at the Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, in an aquic brown soil of Northeast China under three land use types (cropland, abandoned cropland, and woodland) in order to evaluate whether the vertical distribution and seasonal fluctuation for the number of total nematodes and trophic groups could reflect soil ecosystem differences and to determine the relationships between soil chemical properties and soil nematodes. The majority of soil nematodes were present in the 0-20 cm soil layers, and for these land use types plant parasites were the most abundant trophic group. In the abandoned cropland the numbers of plant parasites reached a peak on the August sampling date, whereas the cropland and woodland peaked on the October sampling date. Meanwhile, in all land use types the number of total nematodes, bacterivores, plant parasites, and omnivores-predators was negatively (P < 0.05, except for bacterivores in cropland, which was not significant) correlated with bulk density, and positively (P < 0.05, except for fungivores in abandoned cropland, which was not significant) correlated with total organic carbon and total nitrogen.展开更多
目的探讨非自杀性自伤(non-suicidal self-injury,NSSI)青少年静息态功能磁共振成像下脑功能特征。方法采用病例对照研究设计,纳入NSSI青少年患者23例(NSSI组)与健康青少年18名(healthy control,HC组),进行静息态功能MRI扫描,分析NSSI组...目的探讨非自杀性自伤(non-suicidal self-injury,NSSI)青少年静息态功能磁共振成像下脑功能特征。方法采用病例对照研究设计,纳入NSSI青少年患者23例(NSSI组)与健康青少年18名(healthy control,HC组),进行静息态功能MRI扫描,分析NSSI组与HC组低频振幅(amplitude of low frequency fluctuation,ALFF)有差异的脑区,以差异脑区为种子点计算全脑功能连接(functional connectivity,FC),并分析NSSI组差异脑区的ALFF值与青少年非自杀性自伤行为评定问卷及汉密尔顿抑郁量表评分相关性。结果与HC组比较,NSSI组ALFF升高的脑区包括双侧杏仁核(x=-27,y=3,z=-24,t=2.492,P<0.05,FDR校正;x=27,y=3,z=-12,t=2.746,P<0.05,FDR校正)、右侧背外侧额上回(x=15,y=21,z=45,t=4.051,P<0.05,FDR校正)。以双侧杏仁核作为种子点分别计算全脑FC,与HC组比较,NSSI组左侧杏仁核与右侧前扣带回(t=3.352,P<0.05,FDR校正)、左侧前扣带回(t=2.843,P<0.05,FDR校正)、右侧丘脑(t=3.026,P<0.05,FDR校正)、左侧丘脑(t=2.352,P<0.05,FDR校正)FC强度增高,与左侧眶部额上回(t=-2.181,P<0.05,FDR校正)、左侧眶部额中回(t=-3.378,P<0.05,FDR校正)FC强度减低。NSSI组左侧杏仁核ALFF值与汉密尔顿抑郁量表评分呈正相关(r=0.627,P=0.004)。结论NSSI青少年静息态下多个脑区存在神经元异常活动,左侧杏仁核与多个脑区的FC存在异常,这可能是NSSI神经病理发病机制。展开更多
基金Supported by the National Natural Science Foundation of China (No. 30570337).
文摘A field investigation was conducted at the Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, in an aquic brown soil of Northeast China under three land use types (cropland, abandoned cropland, and woodland) in order to evaluate whether the vertical distribution and seasonal fluctuation for the number of total nematodes and trophic groups could reflect soil ecosystem differences and to determine the relationships between soil chemical properties and soil nematodes. The majority of soil nematodes were present in the 0-20 cm soil layers, and for these land use types plant parasites were the most abundant trophic group. In the abandoned cropland the numbers of plant parasites reached a peak on the August sampling date, whereas the cropland and woodland peaked on the October sampling date. Meanwhile, in all land use types the number of total nematodes, bacterivores, plant parasites, and omnivores-predators was negatively (P < 0.05, except for bacterivores in cropland, which was not significant) correlated with bulk density, and positively (P < 0.05, except for fungivores in abandoned cropland, which was not significant) correlated with total organic carbon and total nitrogen.
文摘为了探究太平洋牡蛎(Crassostrea gigas)在0℃和4℃冷藏过程中的品质变化,首先对牡蛎不同组织(闭壳肌、外套膜、鳃和内脏团)在冷藏过程中的表观变化进行观察,利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulphate-polyacrylamide gel electrophoresis,SDS-PAGE)分析冷藏过程中各组织中全蛋白的变化,进一步通过Western blotting鉴定闭壳肌中肌球蛋白重链(myosin heavy chain,MHC)、肌动蛋白、副肌球蛋白(paramyosin,PM)和原肌球蛋白(tropomyosin,TM)的降解情况,采用荧光光谱分析闭壳肌冷藏过程中内源性丝氨酸蛋白酶和组织蛋白酶B的活力变化,以闭壳肌的pH、K值和质构特性等为评价指标,分析其在冷藏过程中品质的变化。结果显示,随着冷藏时间延长,闭壳肌由紧实变得绵软,表观变化最明显。Western blotting结果显示,在0℃和4℃冷藏过程中,闭壳肌中MHC分别在第3天和第1天开始降解,表明低温有利于降低蛋白酶解速率;但是,肌动蛋白、PM和TM无明显变化。闭壳肌中丝氨酸蛋白酶和组织蛋白酶B活力在冷藏过程中总体呈现先升高后降低的趋势。在0、4℃冷藏过程中,pH值从初始的6.79开始呈现下降趋势,至第11天时分别为6.52、5.84;K值分别在第9天和第5天超过二级鲜度范围(40%);闭壳肌硬度和咀嚼性均在第1天达到峰值,随后逐渐下降,弹性呈现下降趋势;闭壳肌中MHC的降解最为明显,并与牡蛎品质劣化密切相关。研究可为牡蛎冷藏保鲜提供理论参考。
文摘目的探讨非自杀性自伤(non-suicidal self-injury,NSSI)青少年静息态功能磁共振成像下脑功能特征。方法采用病例对照研究设计,纳入NSSI青少年患者23例(NSSI组)与健康青少年18名(healthy control,HC组),进行静息态功能MRI扫描,分析NSSI组与HC组低频振幅(amplitude of low frequency fluctuation,ALFF)有差异的脑区,以差异脑区为种子点计算全脑功能连接(functional connectivity,FC),并分析NSSI组差异脑区的ALFF值与青少年非自杀性自伤行为评定问卷及汉密尔顿抑郁量表评分相关性。结果与HC组比较,NSSI组ALFF升高的脑区包括双侧杏仁核(x=-27,y=3,z=-24,t=2.492,P<0.05,FDR校正;x=27,y=3,z=-12,t=2.746,P<0.05,FDR校正)、右侧背外侧额上回(x=15,y=21,z=45,t=4.051,P<0.05,FDR校正)。以双侧杏仁核作为种子点分别计算全脑FC,与HC组比较,NSSI组左侧杏仁核与右侧前扣带回(t=3.352,P<0.05,FDR校正)、左侧前扣带回(t=2.843,P<0.05,FDR校正)、右侧丘脑(t=3.026,P<0.05,FDR校正)、左侧丘脑(t=2.352,P<0.05,FDR校正)FC强度增高,与左侧眶部额上回(t=-2.181,P<0.05,FDR校正)、左侧眶部额中回(t=-3.378,P<0.05,FDR校正)FC强度减低。NSSI组左侧杏仁核ALFF值与汉密尔顿抑郁量表评分呈正相关(r=0.627,P=0.004)。结论NSSI青少年静息态下多个脑区存在神经元异常活动,左侧杏仁核与多个脑区的FC存在异常,这可能是NSSI神经病理发病机制。
