目的通过比较发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome,SFTS)和肾综合征出血热(hemorrhagic fever with renal syndrome,HFRS)患者在流行病学、临床表现和实验室指标等方面的参数差异,提高对2种疾病的临床...目的通过比较发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome,SFTS)和肾综合征出血热(hemorrhagic fever with renal syndrome,HFRS)患者在流行病学、临床表现和实验室指标等方面的参数差异,提高对2种疾病的临床认识,减少误诊率。方法回顾性分析2021年1月至2023年12月期间,烟台市奇山医院和青岛市第六人民医院收治的219例SFTS患者(SFTS组)和201例HFRS患者(HFRS组)的病历资料,使用独立样本t检验、方差分析、χ^(2)检验等比较2组间流行病学、临床表现、实验室指标等参数的差异,建立鉴别诊断的随机森林模型。结果SFTS与HFRS患者存在差异的参数有年龄、性别、发病季节、接触史、预后、病情程度;结膜出血、皮肤瘀点瘀斑、腰痛、眼眶痛、少尿、神经系统症状、肾区叩击痛等临床表现;白细胞计数、凝血酶原时间、天冬氨酸转氨酶、肌酐、尿素氮、肌酸激酶、蛋白尿等化验指标。随机森林模型筛选出重要性排名前5位的参数为白细胞计数分层、C-反应蛋白、疾病分型、肌酐、粘膜出血。结论本研究中SFTS患者较HFRS患者更易出现心肌、肝脏、中枢神经系统损伤,而HFRS患者较SFTS患者更易表现肾脏损伤,从而呈现相应症状和实验室指标的差异。展开更多
大气环流异常是造成天气和气候变化的直接原因。以往对大气环流形势和中国降水关系的研究绝大部分是在对大气环流形势进行主观分型和进一步诊断的基础上来研究两者的联系。相对于对大气环流形势的主观分析,客观分型方法采用的指标更一...大气环流异常是造成天气和气候变化的直接原因。以往对大气环流形势和中国降水关系的研究绝大部分是在对大气环流形势进行主观分型和进一步诊断的基础上来研究两者的联系。相对于对大气环流形势的主观分析,客观分型方法采用的指标更一致、标准更统一,能够得到较多的大气环流类型,目前得到了较为广泛的应用。利用欧洲中期数值天气预报中心提供的1979—2016年的再分析资料(ERA-Interim),通过选择逐日12UTC的海平面气压、可降水量和700 h Pa风速3个变量,应用倾斜旋转T模态主成分分析方法对中国区域内的大气环流进行了客观分型,并进一步分析了不同大气环流类型与中国区域降水之间的联系。结果表明,不同大气环流类型对中国区域降水趋势和降水量的影响不仅在空间上存在差异,而且在季节上也不尽相同。总体表现为大气环流类型对降水量大的区域和降水量多的月份影响较大,而对降水量小的区域和降水少的月份的影响较小。此外,与环流类型发生频次对中国降水的影响相比,大气环流类型发生频次不变的背景下降水强度变化对中国降水趋势的影响更加显著。展开更多
Two tree-ring MXD (maximum latewood density) chronologies of Abies fabri were developed from the eastern slopes of Gongga Mountain, and a regional chronology (RC) was established based on the two MXD chronologies. The...Two tree-ring MXD (maximum latewood density) chronologies of Abies fabri were developed from the eastern slopes of Gongga Mountain, and a regional chronology (RC) was established based on the two MXD chronologies. There were significant positive correlations between the three MXD chronologies and August-September temperature, and the RC had the highest correlation (r=0.733, n=48, P<0.001) with mean August-September temperature. Based on growth-climate analyses, we reconstructed mean August-September temperature during the past 171 years for the study area. The reconstruction explained 53.5% of the instrumental temperature variance during the period 1960-2007 (F=52.8, R2adj =52.4%). In the past 171 years, there were 22 very warm years and 23 very cold years, four cold periods (1837-1842, 1884-1891, 1899-1905 and 1984-1989) and three warm periods (1966-1973, 1916-1924 and 1876-1881). Our reconstruction was validated by other tree ring-based temperature reconstructions from the surrounding area and documented climate disaster events.展开更多
Tree-ring samples from Dahurian Larch (Larix gmelinii (Rupr.) Rupr.) were collected at three sites in the northern Da Hinggan Mountains. Using samples measured by X-ray densitometry, measurements of tree-ring maximum ...Tree-ring samples from Dahurian Larch (Larix gmelinii (Rupr.) Rupr.) were collected at three sites in the northern Da Hinggan Mountains. Using samples measured by X-ray densitometry, measurements of tree-ring maximum latewood density chronologies of two sites were found to be significantly correlated with summer temperature. These two sites' tree-ring series were combined to form a single standard regional chronology. This was used to reconstruct the May-August monthly mean maximum temperature for the period 1855-2008 AD, and it explained 39.5% of the total temperature variance. In the past 154 years, there were 4 cold periods (1874-1893, 1927-1948, 1951-1960 and 1992-2002) and 4 warm periods (1855-1873, 1894-1916, 1961-1991 and 2003-2008). The summer temperature rose more obviously than that of winter in this region. Having been validated by other temperature reconstructions from the surrounding area, the reconstruction could indicate the summer temperature changes of large-scale regions.展开更多
The absorption and enrichment of heavy metal elements by leaves of Populus×euramericana cv.’Neva’ were analyzed through content assessing of heavy metal elements in soils of three forest lands at Fangshan Distr...The absorption and enrichment of heavy metal elements by leaves of Populus×euramericana cv.’Neva’ were analyzed through content assessing of heavy metal elements in soils of three forest lands at Fangshan District in the southern suburb of Beijing. These forest lands with P.×euramericana cv. ’Neva’plantation were around with the various sources of pollution such as cement mill,stone mill, sewage and garbage.Some of heavy metal elements such as Cd,Pb,Cu,and Zn were found in the soil samples and leaves of P.×euramericana cv.’Neva’ grown on the three forest lands which were investigated.The results of investigation showed that the soils of three forest lands were polluted with Pb, Cd,Cu and Zn in varying degrees.The contents of Pb,Cu and Zn in soils were significantly different among the three forest lands,whereas the average content of Cd(0.077 6 mg·kg<sup>-1</sup>) was less but that of Pb,Cu,and Zn(37.61,26.25 and 90.3 mg·kg<sup>-1</sup> ) were more than the average background value of Beijing.The contents of Pb,Cd,Cu and Zn in leaves of P.×euramericana cv.’Neva’ were different among three forestlands.With the changes of heavy metal contents in soil samples,there was no regularity on the changes of different heavy metal contents in leaves of P.×euramericana cv.’Neva’ grown on different forest land.P.×euramericana cv.’Neva’ can absorb and accumulate Pb,Cd,Cu and Zn in soil but showed different capacities of absorption and accumulation with the order of Cd】Zn】Cu】Pb.Especially,its absorption and accumulation capacity for Cd was strong with maximum enrichment factor higher than 16 and showed high accumulation on low background,whereas its enrichment capacities for Pb and Cu were relatively poorer with average enrichment factor of less than 1.At different forest lands,there existed great difference on absorption capacity of P.×euramericana cv.’Neva’ with the same heavy metal.展开更多
文摘目的通过比较发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome,SFTS)和肾综合征出血热(hemorrhagic fever with renal syndrome,HFRS)患者在流行病学、临床表现和实验室指标等方面的参数差异,提高对2种疾病的临床认识,减少误诊率。方法回顾性分析2021年1月至2023年12月期间,烟台市奇山医院和青岛市第六人民医院收治的219例SFTS患者(SFTS组)和201例HFRS患者(HFRS组)的病历资料,使用独立样本t检验、方差分析、χ^(2)检验等比较2组间流行病学、临床表现、实验室指标等参数的差异,建立鉴别诊断的随机森林模型。结果SFTS与HFRS患者存在差异的参数有年龄、性别、发病季节、接触史、预后、病情程度;结膜出血、皮肤瘀点瘀斑、腰痛、眼眶痛、少尿、神经系统症状、肾区叩击痛等临床表现;白细胞计数、凝血酶原时间、天冬氨酸转氨酶、肌酐、尿素氮、肌酸激酶、蛋白尿等化验指标。随机森林模型筛选出重要性排名前5位的参数为白细胞计数分层、C-反应蛋白、疾病分型、肌酐、粘膜出血。结论本研究中SFTS患者较HFRS患者更易出现心肌、肝脏、中枢神经系统损伤,而HFRS患者较SFTS患者更易表现肾脏损伤,从而呈现相应症状和实验室指标的差异。
文摘大气环流异常是造成天气和气候变化的直接原因。以往对大气环流形势和中国降水关系的研究绝大部分是在对大气环流形势进行主观分型和进一步诊断的基础上来研究两者的联系。相对于对大气环流形势的主观分析,客观分型方法采用的指标更一致、标准更统一,能够得到较多的大气环流类型,目前得到了较为广泛的应用。利用欧洲中期数值天气预报中心提供的1979—2016年的再分析资料(ERA-Interim),通过选择逐日12UTC的海平面气压、可降水量和700 h Pa风速3个变量,应用倾斜旋转T模态主成分分析方法对中国区域内的大气环流进行了客观分型,并进一步分析了不同大气环流类型与中国区域降水之间的联系。结果表明,不同大气环流类型对中国区域降水趋势和降水量的影响不仅在空间上存在差异,而且在季节上也不尽相同。总体表现为大气环流类型对降水量大的区域和降水量多的月份影响较大,而对降水量小的区域和降水少的月份的影响较小。此外,与环流类型发生频次对中国降水的影响相比,大气环流类型发生频次不变的背景下降水强度变化对中国降水趋势的影响更加显著。
基金supported by the Science and Technology Ministry Commonwealth Trade (Meteorology) Scientific Research Specialized Project (GYHY200806011)the National Basic S&T Project of the Ministry of Science and Technology of China (2007FY220200)the National Natural Science Foundation of China (40871058)
文摘Two tree-ring MXD (maximum latewood density) chronologies of Abies fabri were developed from the eastern slopes of Gongga Mountain, and a regional chronology (RC) was established based on the two MXD chronologies. There were significant positive correlations between the three MXD chronologies and August-September temperature, and the RC had the highest correlation (r=0.733, n=48, P<0.001) with mean August-September temperature. Based on growth-climate analyses, we reconstructed mean August-September temperature during the past 171 years for the study area. The reconstruction explained 53.5% of the instrumental temperature variance during the period 1960-2007 (F=52.8, R2adj =52.4%). In the past 171 years, there were 22 very warm years and 23 very cold years, four cold periods (1837-1842, 1884-1891, 1899-1905 and 1984-1989) and three warm periods (1966-1973, 1916-1924 and 1876-1881). Our reconstruction was validated by other tree ring-based temperature reconstructions from the surrounding area and documented climate disaster events.
基金supported by the National Natural Science Foundation of China (40871058)the Science and Technology Ministry Commonwealth Trade (Meteorology) Scientific Research Specialized Project (YHY200806011)the National Basic S&T Project of the Ministry of Science and Technology of China (2007FY220200)
文摘Tree-ring samples from Dahurian Larch (Larix gmelinii (Rupr.) Rupr.) were collected at three sites in the northern Da Hinggan Mountains. Using samples measured by X-ray densitometry, measurements of tree-ring maximum latewood density chronologies of two sites were found to be significantly correlated with summer temperature. These two sites' tree-ring series were combined to form a single standard regional chronology. This was used to reconstruct the May-August monthly mean maximum temperature for the period 1855-2008 AD, and it explained 39.5% of the total temperature variance. In the past 154 years, there were 4 cold periods (1874-1893, 1927-1948, 1951-1960 and 1992-2002) and 4 warm periods (1855-1873, 1894-1916, 1961-1991 and 2003-2008). The summer temperature rose more obviously than that of winter in this region. Having been validated by other temperature reconstructions from the surrounding area, the reconstruction could indicate the summer temperature changes of large-scale regions.
文摘The absorption and enrichment of heavy metal elements by leaves of Populus×euramericana cv.’Neva’ were analyzed through content assessing of heavy metal elements in soils of three forest lands at Fangshan District in the southern suburb of Beijing. These forest lands with P.×euramericana cv. ’Neva’plantation were around with the various sources of pollution such as cement mill,stone mill, sewage and garbage.Some of heavy metal elements such as Cd,Pb,Cu,and Zn were found in the soil samples and leaves of P.×euramericana cv.’Neva’ grown on the three forest lands which were investigated.The results of investigation showed that the soils of three forest lands were polluted with Pb, Cd,Cu and Zn in varying degrees.The contents of Pb,Cu and Zn in soils were significantly different among the three forest lands,whereas the average content of Cd(0.077 6 mg·kg<sup>-1</sup>) was less but that of Pb,Cu,and Zn(37.61,26.25 and 90.3 mg·kg<sup>-1</sup> ) were more than the average background value of Beijing.The contents of Pb,Cd,Cu and Zn in leaves of P.×euramericana cv.’Neva’ were different among three forestlands.With the changes of heavy metal contents in soil samples,there was no regularity on the changes of different heavy metal contents in leaves of P.×euramericana cv.’Neva’ grown on different forest land.P.×euramericana cv.’Neva’ can absorb and accumulate Pb,Cd,Cu and Zn in soil but showed different capacities of absorption and accumulation with the order of Cd】Zn】Cu】Pb.Especially,its absorption and accumulation capacity for Cd was strong with maximum enrichment factor higher than 16 and showed high accumulation on low background,whereas its enrichment capacities for Pb and Cu were relatively poorer with average enrichment factor of less than 1.At different forest lands,there existed great difference on absorption capacity of P.×euramericana cv.’Neva’ with the same heavy metal.
