Using nine years of Tropical Rainfall Measuring Mission(TRMM)2A25 data,based on the probability density function of rainfall,a comparative analysis of the diurnal cycle and its seasonal and interannual variation for c...Using nine years of Tropical Rainfall Measuring Mission(TRMM)2A25 data,based on the probability density function of rainfall,a comparative analysis of the diurnal cycle and its seasonal and interannual variation for convective rain,stratiform rain,and total rain is made between the Tibetan Plateau and the downstream Yangtze River basin and East China Sea.The diurnal convective rain is stronger than the diurnal stratiform rain over the Yangtze River basin,and the convective rain peaks in the afternoon when the stratiform rain maximum happens in the early morning.Convective rain and stratiform rain both peak in the early morning over the East China Sea.The diurnal total rain over the Tibetan Plateau is stronger than its downstream regions.The diurnal cycle appears quite different among the four seasons over the Yangtze River basin,and the seasonal variation of diurnal convective rain is more apparent than diurnal stratiform rain.The seasonal variation of the diurnal cycle is weak over the East China Sea and Tibetan Plateau.The maximum of total rain happens in the afternoon during1998–2002 over the Yangtze River basin,while it peaks in the early morning during 2003–2006,but no obvious phase differences can be found among years in the diurnal rain over the East China Sea and over the Tibetan Plateau.展开更多
[Objective] The research aimed to analyze the formation reason of a dusty weather in the midwest of Hulun Buir City. [Method] By combining the synoptic method with the ecological environment variation, the occurrence ...[Objective] The research aimed to analyze the formation reason of a dusty weather in the midwest of Hulun Buir City. [Method] By combining the synoptic method with the ecological environment variation, the occurrence and influence of a typical dusty weather which happened in the midwest of Hulun Buir City on May 30, 2006 were analyzed. The occurrence mechanism of dusty weather in the city was elaborated deeply, and the source of dusty weather was put forward from the ecological environment variation angle. [Result] Under the big environment background that Hulun Buir Prairie desertification increased day by day, the unusually arid climate condition in spring was the main factor that caused the dust. The serious drought and the persistent warming in the prior period of dust formation caused the loosened and dry mantle soil, the delayed turning green of pasture grass, the thickening of dry soil layer. These objective natural environments and climatic factors were the decisive elements which induced the dusty weather. The abnormal warming from the ground to the high altitude provided the thermal condition for the formation of dusty weather, and promoted the increase of atmospheric stratification instability. In addition, the existence of jet stream in the high and low altitudes played the role of momentum download on the formation of ground gale. The formation and development of ground Mongolia cyclone provided the power condition for the formation of dusty weather, and the gale was the direct element of dusty weather formation. [Conclusion] The research provided the reference comments for the prevention and control of dusty weather in the city.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
目的探讨β1肾上腺素能受体自身抗体(β1AR)表达增强对心房颤动(简称房颤)及心房电重构的影响。方法 24只新西兰大白兔随机分为对照组(Con组)和β1AR组。β1AR组给予2 mgβ1受体细胞外第二环功能表位肽段与佐剂背部皮下多点注射,对照组...目的探讨β1肾上腺素能受体自身抗体(β1AR)表达增强对心房颤动(简称房颤)及心房电重构的影响。方法 24只新西兰大白兔随机分为对照组(Con组)和β1AR组。β1AR组给予2 mgβ1受体细胞外第二环功能表位肽段与佐剂背部皮下多点注射,对照组给予佐剂背部皮下多点注射。每2周注射1次,共4次。于0、2、4、6 W采耳缘静脉血,离心取血清通过酶联免疫吸附测定血清中抗体滴度,验证造模是否成功。每只兔子在免疫前后,采用S_1S_2递减刺激测量心房有效不应期(AERP),通过Burst刺激测量房颤诱发率和持续时间。免疫结束后取心房肌组织进行蛋白免疫印记法检测各组内离子通道蛋白(Kir3.1及Cav1.2)和缝隙连接蛋白(Cx43和Cx40)总量的表达变化,逆转录聚合酶链反应分析上述指标各组内mRNA的表达变化。结果①与0 w比较,β1AR组在2、4和6 w血清中β1AR水平逐渐增加(P<0.05),而Con组内各个时间点血清中β1AR水平无差异(P>0.05);与Con组相比,除0 w两组比较无差异外,其余β1AR组血清中β1AR水平高于Con组(P<0.05)。②β1AR组免疫后较免疫前AERP缩短[(65±8.5)ms vs (116±23.4)ms,P<0.05],平均心率显著增快[(290±35.3)次/分vs (187±31.1)次/分,P<0.05];与Con组相应时间比较,β1AR组免疫后均出现AERP缩短[(65±8.5) ms vs (116±25.3)ms,P<0.05]和平均心率增快[(290±35.3)次/分vs (198±13.7)次/分,P<0.05]。③β1AR组免疫后较免疫前房颤诱发率增加[83.3%(10/12) vs 0(0/12),P<0.05]及持续时间延长[(24.66±40.92)s vs (0±0)s,P<0.05];与Con组相应时间比较,β1AR组房颤诱发率显著增加[83.3%(10/12) vs 0(0/12),P<0.05]及持续时间延长[(24.66±40.92)s vs (0±0)s,P<0.05];④与Con组相比,β1AR组Cx43和Cav1.2蛋白水平及mRNA水平显著降低(P<0.05)。Kir3.1及Cx40蛋白水平及mRNA含量显著升高(P<0.05)。结论β1AR表达增强能缩短AERP,增加房颤易感性和持续时间,通过改变离子通道特性造成心房肌电重构,促进房颤的发生和维持。展开更多
基金funded by the Third Scientific Experiment of the Tibetan Plateau(Grant No.GYHY201406001)the National Natural Science Foundation of China(Grant Nos.41175046,41205030,and 4140050174)+1 种基金an open funding from the State Key Laboratory of Severe Weather(Gran No.2013LASW-A06)Institute of Plateau Meteorology,China Meteorological Administration(Grant No.LPM2011017)
文摘Using nine years of Tropical Rainfall Measuring Mission(TRMM)2A25 data,based on the probability density function of rainfall,a comparative analysis of the diurnal cycle and its seasonal and interannual variation for convective rain,stratiform rain,and total rain is made between the Tibetan Plateau and the downstream Yangtze River basin and East China Sea.The diurnal convective rain is stronger than the diurnal stratiform rain over the Yangtze River basin,and the convective rain peaks in the afternoon when the stratiform rain maximum happens in the early morning.Convective rain and stratiform rain both peak in the early morning over the East China Sea.The diurnal total rain over the Tibetan Plateau is stronger than its downstream regions.The diurnal cycle appears quite different among the four seasons over the Yangtze River basin,and the seasonal variation of diurnal convective rain is more apparent than diurnal stratiform rain.The seasonal variation of the diurnal cycle is weak over the East China Sea and Tibetan Plateau.The maximum of total rain happens in the afternoon during1998–2002 over the Yangtze River basin,while it peaks in the early morning during 2003–2006,but no obvious phase differences can be found among years in the diurnal rain over the East China Sea and over the Tibetan Plateau.
文摘[Objective] The research aimed to analyze the formation reason of a dusty weather in the midwest of Hulun Buir City. [Method] By combining the synoptic method with the ecological environment variation, the occurrence and influence of a typical dusty weather which happened in the midwest of Hulun Buir City on May 30, 2006 were analyzed. The occurrence mechanism of dusty weather in the city was elaborated deeply, and the source of dusty weather was put forward from the ecological environment variation angle. [Result] Under the big environment background that Hulun Buir Prairie desertification increased day by day, the unusually arid climate condition in spring was the main factor that caused the dust. The serious drought and the persistent warming in the prior period of dust formation caused the loosened and dry mantle soil, the delayed turning green of pasture grass, the thickening of dry soil layer. These objective natural environments and climatic factors were the decisive elements which induced the dusty weather. The abnormal warming from the ground to the high altitude provided the thermal condition for the formation of dusty weather, and promoted the increase of atmospheric stratification instability. In addition, the existence of jet stream in the high and low altitudes played the role of momentum download on the formation of ground gale. The formation and development of ground Mongolia cyclone provided the power condition for the formation of dusty weather, and the gale was the direct element of dusty weather formation. [Conclusion] The research provided the reference comments for the prevention and control of dusty weather in the city.
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
文摘目的探讨β1肾上腺素能受体自身抗体(β1AR)表达增强对心房颤动(简称房颤)及心房电重构的影响。方法 24只新西兰大白兔随机分为对照组(Con组)和β1AR组。β1AR组给予2 mgβ1受体细胞外第二环功能表位肽段与佐剂背部皮下多点注射,对照组给予佐剂背部皮下多点注射。每2周注射1次,共4次。于0、2、4、6 W采耳缘静脉血,离心取血清通过酶联免疫吸附测定血清中抗体滴度,验证造模是否成功。每只兔子在免疫前后,采用S_1S_2递减刺激测量心房有效不应期(AERP),通过Burst刺激测量房颤诱发率和持续时间。免疫结束后取心房肌组织进行蛋白免疫印记法检测各组内离子通道蛋白(Kir3.1及Cav1.2)和缝隙连接蛋白(Cx43和Cx40)总量的表达变化,逆转录聚合酶链反应分析上述指标各组内mRNA的表达变化。结果①与0 w比较,β1AR组在2、4和6 w血清中β1AR水平逐渐增加(P<0.05),而Con组内各个时间点血清中β1AR水平无差异(P>0.05);与Con组相比,除0 w两组比较无差异外,其余β1AR组血清中β1AR水平高于Con组(P<0.05)。②β1AR组免疫后较免疫前AERP缩短[(65±8.5)ms vs (116±23.4)ms,P<0.05],平均心率显著增快[(290±35.3)次/分vs (187±31.1)次/分,P<0.05];与Con组相应时间比较,β1AR组免疫后均出现AERP缩短[(65±8.5) ms vs (116±25.3)ms,P<0.05]和平均心率增快[(290±35.3)次/分vs (198±13.7)次/分,P<0.05]。③β1AR组免疫后较免疫前房颤诱发率增加[83.3%(10/12) vs 0(0/12),P<0.05]及持续时间延长[(24.66±40.92)s vs (0±0)s,P<0.05];与Con组相应时间比较,β1AR组房颤诱发率显著增加[83.3%(10/12) vs 0(0/12),P<0.05]及持续时间延长[(24.66±40.92)s vs (0±0)s,P<0.05];④与Con组相比,β1AR组Cx43和Cav1.2蛋白水平及mRNA水平显著降低(P<0.05)。Kir3.1及Cx40蛋白水平及mRNA含量显著升高(P<0.05)。结论β1AR表达增强能缩短AERP,增加房颤易感性和持续时间,通过改变离子通道特性造成心房肌电重构,促进房颤的发生和维持。
