In order to improve the understanding of the role of a canopy opening/gap on the physical environments in a secondary forest in Northeastern China, a case study was conducted in and around a small irregular gap in a m...In order to improve the understanding of the role of a canopy opening/gap on the physical environments in a secondary forest in Northeastern China, a case study was conducted in and around a small irregular gap in a montane secondary forest. The secondary forest, which was severely disturbed by human beings about 50 years ago, was dominated by Quercus mongolica and Fraxinus rhynchophyllaan. Temporal variation in photosynthetic photon flux density （PPFD）, air temperature （TA） at 10 cm above the ground, soil temperature （Ts） and soil water content （SWC） at top-layer （0-15 cm） and sub-layer （15-30 cm） were measured from May to September after the second year since the formation of the small gap （the ratios of gap diameter to stand height were less than 0.5） in 2006 respectively. Results indicated that the highest value of PPFD occurred at the northern edge of the gap, particularly at the beginning of the growing season in May. On sunny days, the highest value of PPFD appeared earlier than that on overcast days. Maximum and mean values of TAwere higher in the northern part of the gap, and the minimum values of TAwere at the southern edge of the gap. Soil temperature varied obviously in the gap with the range from 1 to 8 ℃. Maximum values of Ts occurred at the northern part of the gap, which was significantly correlated with the maximum values of TA （R = 0.735, P〈0.05）. SWC was higher in the top-layer （0-15 cm） than that in sub-layer （15-30 cm）, but the difference of them was not significant （p〉0.05）, which might be attributed to the small gap size and the effects of aboveground vegetations. From these results, the maximum of PPFD in the study area occurred at the northern part of the gap, which was consistent with the results observed in north hemisphere, but the occurrence time varied with the differences of the latitudes. The highest values of air and soil temperatures also occurred in the northern part of the gap because they were affected by the radiation. However展开更多
旨在从牛、羊监控动物群中,对流行于我国的帕利亚姆血清群病毒(PALV)进行分离、鉴定与序列特征分析,明确我国流行毒株与国外毒株之间的关系。自监控动物采集的PALV阳性血液接种BHK-21细胞进行病毒分离;对所分离PALV毒株的Seg-7与Seg-2...旨在从牛、羊监控动物群中,对流行于我国的帕利亚姆血清群病毒(PALV)进行分离、鉴定与序列特征分析,明确我国流行毒株与国外毒株之间的关系。自监控动物采集的PALV阳性血液接种BHK-21细胞进行病毒分离;对所分离PALV毒株的Seg-7与Seg-2基因节段进行扩增、测序与序列分析;通过高分辨率琼脂糖凝胶电泳分析不同血清型PALV代表毒株基因组的"电泳带型"特征;通过免疫荧光与中和试验分析不同血清型PALV的阳性血清之间的交叉反应特性与中和活性。试验结果如下:2012—2016年,在云南、广西、广东共计分离出19株PALV;Seg-2与Seg-7测序与系统发育分析显示,分离毒株分属Chuzan virus(CHUV)、D’Aguilar virus(DAV)与Bunyip Creek virus(BCV)三种血清型,不同血清型毒株均与日本毒株具有最近的亲缘关系,而与澳洲、非洲毒株亲缘关系较远。病毒基因组电泳结果显示PALV基因组呈现"3-3-4"的电泳带型特征。免疫荧光结果显示针对CHUV的多克隆抗体可使感染CHUV、DAV与BCV的BHK-21细胞呈现特异性荧光。血清学中和试验显示,CHUV、DAV与BCV三种病毒的阳性血清之间无交叉中和保护作用。本研究报道了2012—2016年中国PALV的分离与Seg-2、Seg-7序列特征,并首次报道了PALV的DAV与BCV两种血清型病毒在我国的分离,研究结果将有助于掌握我国PALV的分布与遗传特征,为诊断试剂的开发、流行病学调查与致病性研究提供科学依据。展开更多
Background Small noncoding microRNAs regulate gene expression in cardiac development and disease and have been implicated in the aging process and in the regulation of extracellular matrix proteins. However, their rol...Background Small noncoding microRNAs regulate gene expression in cardiac development and disease and have been implicated in the aging process and in the regulation of extracellular matrix proteins. However, their role in age-related cardiac remodeling and atrial fibrillation （AF） was not well understood. The present study was designed to decipher molecular mechanisms underlying age-related atrial structural remodeling and AF. Methods Three groups of dogs were studied： adult and aged dogs in sinus rhythm and with persistent AF induced by rapid atrial pacing. The expressions of microRNAs were measured by quantitative real-time polymerase chain reaction. Pathohistological and ultrastructural changes were tested by light and electron microscopy. Apoptosis index of myocytes was detected by TUNEL. Results Samples of atrial tissue showed the abnormal pathohistological and ultrastructural changes, the accelerated fibrosis, and apoptosis with aging and/or in AF dogs. Compared to the adult group, the expressions of microRNAs-21 and -29 were significantly increased, whereas the expressions of microRNAs-1 and -133 showed obvious downregulation tendency in the aged group. Compared to the aged group, the expressions of microRNAs-1, -21, and -29 was significantly increased in the old group in AF; contrastingly, the expressions of microRNA-133 showed obvious downregulation tendency. Conclusion These multiple aberrantly expressed microRNAs may be responsible for modulating the transition from adaptation to pathological atrial remodeling with aging and/or in AE展开更多
基金This research was supported by National Natural Science Foundation of China （30671669） and ＂the 100-Young-Researcher Project＂ of Chinese,Academy of Sciences.
文摘In order to improve the understanding of the role of a canopy opening/gap on the physical environments in a secondary forest in Northeastern China, a case study was conducted in and around a small irregular gap in a montane secondary forest. The secondary forest, which was severely disturbed by human beings about 50 years ago, was dominated by Quercus mongolica and Fraxinus rhynchophyllaan. Temporal variation in photosynthetic photon flux density （PPFD）, air temperature （TA） at 10 cm above the ground, soil temperature （Ts） and soil water content （SWC） at top-layer （0-15 cm） and sub-layer （15-30 cm） were measured from May to September after the second year since the formation of the small gap （the ratios of gap diameter to stand height were less than 0.5） in 2006 respectively. Results indicated that the highest value of PPFD occurred at the northern edge of the gap, particularly at the beginning of the growing season in May. On sunny days, the highest value of PPFD appeared earlier than that on overcast days. Maximum and mean values of TAwere higher in the northern part of the gap, and the minimum values of TAwere at the southern edge of the gap. Soil temperature varied obviously in the gap with the range from 1 to 8 ℃. Maximum values of Ts occurred at the northern part of the gap, which was significantly correlated with the maximum values of TA （R = 0.735, P〈0.05）. SWC was higher in the top-layer （0-15 cm） than that in sub-layer （15-30 cm）, but the difference of them was not significant （p〉0.05）, which might be attributed to the small gap size and the effects of aboveground vegetations. From these results, the maximum of PPFD in the study area occurred at the northern part of the gap, which was consistent with the results observed in north hemisphere, but the occurrence time varied with the differences of the latitudes. The highest values of air and soil temperatures also occurred in the northern part of the gap because they were affected by the radiation. However
文摘旨在从牛、羊监控动物群中,对流行于我国的帕利亚姆血清群病毒(PALV)进行分离、鉴定与序列特征分析,明确我国流行毒株与国外毒株之间的关系。自监控动物采集的PALV阳性血液接种BHK-21细胞进行病毒分离;对所分离PALV毒株的Seg-7与Seg-2基因节段进行扩增、测序与序列分析;通过高分辨率琼脂糖凝胶电泳分析不同血清型PALV代表毒株基因组的"电泳带型"特征;通过免疫荧光与中和试验分析不同血清型PALV的阳性血清之间的交叉反应特性与中和活性。试验结果如下:2012—2016年,在云南、广西、广东共计分离出19株PALV;Seg-2与Seg-7测序与系统发育分析显示,分离毒株分属Chuzan virus(CHUV)、D’Aguilar virus(DAV)与Bunyip Creek virus(BCV)三种血清型,不同血清型毒株均与日本毒株具有最近的亲缘关系,而与澳洲、非洲毒株亲缘关系较远。病毒基因组电泳结果显示PALV基因组呈现"3-3-4"的电泳带型特征。免疫荧光结果显示针对CHUV的多克隆抗体可使感染CHUV、DAV与BCV的BHK-21细胞呈现特异性荧光。血清学中和试验显示,CHUV、DAV与BCV三种病毒的阳性血清之间无交叉中和保护作用。本研究报道了2012—2016年中国PALV的分离与Seg-2、Seg-7序列特征,并首次报道了PALV的DAV与BCV两种血清型病毒在我国的分离,研究结果将有助于掌握我国PALV的分布与遗传特征,为诊断试剂的开发、流行病学调查与致病性研究提供科学依据。
基金This study was supported by grants from the Program of National Natural Science Foundation of China （No. 308（~60299~, tlae Program of Natural Science Foundation of the Xiniiang Uygur Autonomous Region （No. 200821143 and No. 201121 IA074）, and the Program of Doctoral Fund of Ministry of Education （No. 200807600004）.
文摘Background Small noncoding microRNAs regulate gene expression in cardiac development and disease and have been implicated in the aging process and in the regulation of extracellular matrix proteins. However, their role in age-related cardiac remodeling and atrial fibrillation （AF） was not well understood. The present study was designed to decipher molecular mechanisms underlying age-related atrial structural remodeling and AF. Methods Three groups of dogs were studied： adult and aged dogs in sinus rhythm and with persistent AF induced by rapid atrial pacing. The expressions of microRNAs were measured by quantitative real-time polymerase chain reaction. Pathohistological and ultrastructural changes were tested by light and electron microscopy. Apoptosis index of myocytes was detected by TUNEL. Results Samples of atrial tissue showed the abnormal pathohistological and ultrastructural changes, the accelerated fibrosis, and apoptosis with aging and/or in AF dogs. Compared to the adult group, the expressions of microRNAs-21 and -29 were significantly increased, whereas the expressions of microRNAs-1 and -133 showed obvious downregulation tendency in the aged group. Compared to the aged group, the expressions of microRNAs-1, -21, and -29 was significantly increased in the old group in AF; contrastingly, the expressions of microRNA-133 showed obvious downregulation tendency. Conclusion These multiple aberrantly expressed microRNAs may be responsible for modulating the transition from adaptation to pathological atrial remodeling with aging and/or in AE
文摘研究主要通过分析虹鳟(Oncorhynchus mykiss)不同繁育群体间肌肉品质和营养成分的种质特性,为虹鳟遗传资源的保护利用、优良性状的筛选及新品种选育提供基础数据资料。采用凯氏定氮、索氏抽提和水解氨基酸等现行国家标准测定肌肉中的营养成分、氨基酸和脂肪酸的含量,对国内6个不同地区虹鳟代表性繁育群体进行肌肉营养成分和品质的系统分析和评价。结果表明,各繁育群体水分含量(66.50%—77.00%)、灰分含量(1.12%—1.43%)、粗蛋白含量(19.00%—21.84%)和粗脂肪含量(2.04%—9.08%)有显著差异(P<0.05);17种氨基酸总量(TAA)为15.27%—18.90%,各群体氨基酸指数(AAS)、化学指数(CS)和必需氨基酸指数(EAAI)均高于联合国粮食及农业组织(Food and Agriculture Organization,FAO)标准;23种脂肪酸中包括8种饱和脂肪酸(SFA)、4种单不饱和脂肪酸(MUFA)和11种多不饱和脂肪酸(PUFA),其含量分别为17.81%—31.75%、27.86%—30.35%和40.25%—54.32%,PUFA/SFA的比值介于1.34—3.05。综上所述,6个虹鳟代表性繁育群体肌肉营养成分较均衡,符合FAO/WHO标准,均为符合人们营养需求优质蛋白质,可作为虹鳟繁育及新品种培育的优异资源。
