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71.
儿童最大有氧活动能力的发展特征 总被引:4,自引:1,他引:3
本文报告了我国463名10-19岁儿童青少年的最大有氧活动能力的发展特征。在青春早期,男女童的最大吸氧量绝对值均随年龄增长而增加,男童由1.75升/分增至3.10升/分,女童由1.44升/分增至2.07升/分,女童增长较少;以后女童即稳定于这一水平,男童仍略有增长。按身高及按最大心率计标的相对值与其有相似的特征。按体重和瘦体重计算的相对值,在男女童都未见随年龄增长的规律。男童VO2max绝对值及各 相似文献
72.
Dan Liu Guo Li Dongdong Liu Wen Shi Huimin Wang Qiaoxuan Zhang Min Shen Xianzhang Huang Haibiao Lin 《化学与生物多样性》2023,20(3):e202200720
To determine 15 bile acid metabolic products in human serum by liquid chromatography-tandem mass spectrometry (LC/MS/MS) and value their diagnostic outcome in primary biliary cholangitis (PBC). Serum from 20 healthy controls and 26 patients with PBC were collected and went LC/MS/MS analysis of 15 bile acid metabolic products. The test results were analyzed by bile acid metabolomics, and the potential biomarkers were screened and their diagnostic performance was judged by statistical methods such as principal component and partial least squares discriminant analysis and area under curve (AUC). 8 differential metabolites can be screened out: Deoxycholic acid (DCA), Glycine deoxycholic acid (GDCA), Lithocholic acid (LCA), Glycine ursodeoxycholic acid (GUDCA), Taurolithocholic acid (TLCA), Tauroursodeoxycholic acid (TUDCA), Taurodeoxycholic acid (TDCA), Glycine chenodeoxycholic acid (GCDCA). The performance of the biomarkers was evaluated by the AUC, specificity and sensitivity. In conclusion, DCA, GDCA, LCA, GUDCA, TLCA, TUDCA, TDCA and GCDCA were identified as eight potential biomarkers to distinguish between healthy people and PBC patients by multivariate statistical analysis, which provided reliable experimental basis for clinical practice. 相似文献
73.
Xiaofen Tan Yifan Wen Zhijun Han Xuyang Su Jing Peng Feng Chen Yadong Wang Tianming Wang Changzhong Wang Kelong Ma 《化学与生物多样性》2023,20(2):e202200089
74.
Mengyi Ba Ruonan Chen Qiuchen Huang Yanli Song Wen Li Yuanyuan Zhang Haixin Liu Xiang Xu Weidong Zhang Zhiqiang Cai Tao Sun 《化学与生物多样性》2023,20(8):e202300350
This work firstly reported a new polycaprolactone based material functionalized with guanidinium ionic liquid (PCL-GIL) as the stationary phase with high resolution performance for capillary gas chromatography (GC). It is composed of polycaprolactone (PCL) and guanidinium ionic liquid (GIL) with amphiphilic conformation. The PCL-GIL capillary column coated by static method exhibited high column efficiency of 3942 plates/m and moderate polarity. As a result, the PCL-GIL column exhibited high-resolution capability. For a mixture of 27 analytes with a wide ranging polarity and outperformed the PCL-2OH and HP-35 columns, showing its advantageous separation capability for analytes of diverse types. Moreover, the PCL-GIL column showed high resolving capability for various positional isomers and cis-/trans-isomers, including alkylbenzenes, chlorobenzenes, naphthalenes, bromonitrobenzenes, chloronitrobenzenes, benzaldehydes, phenols, alcohols, respectively. In a word, PCL derivatized by GIL units as a new type of stationary phase has a promising future in GC separations. 相似文献
75.
76.
Gui-Lin Wu De-Xiang Chen Zhang Zhou Qing Ye Andrés Baselga Hui Liu Yin Wen Shou-Qian Nong 《植物分类学报:英文版》2023,61(4):698-708
Diversification rates are critically important for understanding patterns of species richness among clades. However, the effects of climatic niche width on plant diversification rates remain to be elucidated. Based on the phylogenetic, climatic, and distributional information of angiosperms in China, a total of 26 906 species from 182 families were included in this study. We aimed to test relationships between diversification rate and climatic niche width and climatic niche width related variables (including climatic niche divergence, climatic niche position, geographic extent, and climatic niche evolutionary rate) using phylogenetic methods. We found that climatic niche divergence had the largest unique contribution to the diversification rate, while the unique effects of climatic niche width, climatic niche position, geographic extent, and climatic niche evolutionary rate on the diversification rate were negligible. We also observed that the relationship between diversification rate and climatic niche divergence was significantly stronger than the null assumption (artefactual relationship between diversification and clade-level climatic niche width by sampling more species). Our study supports the hypothesis that wider family climatic niche widths explain faster diversification rates through a higher climatic niche divergence rather than through higher geographic extent, higher climatic niche evolutionary rate, or separated climatic niche position. Hence, the results provide a potential explanation for large-scale diversity patterns within families of plants. 相似文献
77.
Professor Wen-Tsai Wang (王文采, June 5, 1926–November 16, 2022) was an academician of the Chinese Academy of Sciences (CAS) and a legendary plant taxonomist at the Institute of Botany of CAS (Fig.1). Herein, we organize a virtual special issue in Journal of Systematics and Evolution (JSE) to celebrate the legacy and life of Professor Wang, who was a leading plant taxonomist in China and made important contributions toward advancing the understanding of the flora of China, the biogeography of eastern Asia, and biodiversity research in the vast Hengduan Mountains. He served as the Editor-in-Chief of Acta Phytotaxonomica Sinica (now JSE) for 6 years from 1982 to 1988, and trained several generations of plant taxonomists in China (Li,2001). 相似文献
78.
外源DNA或染色质在非洲爪蟾卵提取物中可以诱导细胞核样结构的重建。重建核除不具有核仁样结构外,在其它形态结构上与真核细胞核十分相似。前人的工作表明在重建核中具有核仁前体结构。但可能是由于缺少活性核仁组织者的缘故,这些核仁前体不能相互融合形成新生核仁。那么活性核仁组织者在重建核中是否能发挥其功能呢?为了研究这一问题,我们提取纯化了四膜虫的大核与大核的周边核仁。进一步去除大核的核被膜,并将去除核被膜的大核与大核核仁分别加入非洲爪赡卵非细胞体系中。通过电镜超薄切片观察,我们发现无论是与大核染色质相连的周边核仁还是分离纯化的核仁结构在非洲爪赡卵非细胞体系中都不能保持其原有结构特征,而是发生了典型核重建变化,并且在诱导形成的重建核中也看不到核仁样结构。这些结果说明具有活性的核仁组织者在加入非洲爪蟾卵提取物后既不能继续保持其原有的RNA转录功能也不能诱导新的核仁的出现。 相似文献
79.
冬小麦根表面氧化还原活力的研究 总被引:4,自引:1,他引:3
证实了两个不同品种的冬小麦根系表面存在着氧化NADH和还原K3Fe(CN)6的氧化的活力。还原铁氰化物活力在PH5.5到8.5范围内随着PH值升高而增大,温度在15℃到45℃范围内随温度升高还原活力增强,45℃达最高值,55℃时活力急剧下降。 相似文献
80.
高温胁迫对光系统Ⅱ异质性的影响 总被引:1,自引:1,他引:0
高温胁迫可诱导光系统Ⅱ(PSⅡ)活性中心转化为无活性中心。本文讨论了在高温胁迫导致荧光猝灭的情况下如何用叶绿素荧光动力学计算PSⅡ无活性中心相对含量的问题。正常的小麦叶片其PSⅡ无活性中心相对含量(Fvi/FV)约为0.155±0.011。小麦叶片经50℃1分钟高温胁迫后,其Fvi(相对于正常Fv)降至对照的70%,在随后室温下60分钟内又降至50%。而55℃5分钟和55℃10分钟高温胁迫后,在恢复期内其PSⅡ无活性中心的含量从常温的1.4倍左右的基础上分别上升至2.4和2.9倍,说明高温胁迫对PSⅡ中心除了起瞬时钝化作用外,还存在一个间接的较为缓慢的持续钝化作用。 相似文献