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41.
You Qin Rongrong Zhou Jian Jin Jing Xie Hao Liu Ping Cai Jun Shu Yahui Zhao Luqi Huang Shuihan Zhang 《Biomedical chromatography : BMC》2020,34(8):e4841
Ophiocordyceps xuefengensis (O. xuefengensis), a new species of caterpillar fungus, has been identified as the sister taxon of Ophiocordyceps sinensis (O. sinensis). The aims of the present study are to evaluate the anticancer activity and to qualitatively analyze the potential bioactive chemical constituents of O. xuefengensis and O. sinensis, comparatively. An MTT assay was used to evaluate the in vitro anticancer activities of different fractions from O. xuefengensis and O. sinensis. The results show that ethyl acetate fractions of O. xuefengensis and O. sinensis have significant in vitro anticancer activity. These two bioactive fractions were analyzed by ultra-performance liquid chromatography–electrospray ionization with quadrupole–time of flight tandem mass spectrometry technology. A total of 82 compounds and 101 compounds were identified or tentatively characterized in the bioactive fractions of O. xuefengensis and O. sinensis, respectively. Among these compounds, 68 existed in both O. xuefengensis and O. sinensis. A total of 67 compounds were reported in O. xuefengensis and 8 compounds were reported in caterpillar fungus for the first time. This is the first detailed comparative analysis of the in vitro anticancer activity and chemical ingredients between O. xuefengensis and O. sinensis. The application of this work will provide reliable fundamental pharmacological substances for the use of O. xuefengensis by Yao people. 相似文献
42.
Yangang Cheng Yan Liu Jinyan Tan Yanping Sun Wei Guan Yuan Liu Bingyou Yang Haixue Kuang 《Biomedical chromatography : BMC》2020,34(9):e4881
Our previous work demonstrated that total withanolides of Datura metel L. leaves (TWD) exhibited excellent therapeutic effects on psoriasis. However, current knowledge of its mechanisms is incomplete. In this study, integrated spleen and thymus untargeted metabolomics were used to analyze the changes in endogenous metabolites underlying the immunosuppressive activity of TWD on psoriasis animal models induced by imiquimod. The results suggested that TWD treatment markedly attenuated imiquimod-induced psoriasis and showed significant immunosuppressive activity as evidenced by decreased elevation index of spleen and thymus. Meanwhile, TWD significantly reversed the elevation of immunoregulatory factors, including IL-10, IL-17, IL-22 and IL-23. Multivariate trajectory analysis revealed that TWD treatment could restore the psoriasis-disturbed spleen and thymus metabolite profiles towards the normal metabolic status. A total of 25 and 27 metabolites associated with the immunomodulatory effects for which levels changed markedly upon treatment have been identified in spleen and thymus, respectively. These differential metabolites were mainly involved in amino acid metabolism, nucleotide metabolism, fatty acid metabolism and lipid metabolism. Our investigation provided a holistic view of TWD for intervention in psoriasis through immunoregulation and provided further scientific information in vivo about a clinical value of TWD for psoriasis. 相似文献
43.
Dongping Wang Jie Dong Wenjing Fan Prof. Dr. Xiang-Ai Yuan Prof. Dr. Jian Han Prof. Dr. Jin Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(22):8508-8512
An unprecedented Mn(I)-catalyzed selective hydroarylation and hydroalkenylation of unsaturated amides with commercially available organic boronic acids is reported. Alkenyl boronic acids have been successfully employed for the first time in Mn(I)-catalyzed carbon–carbon bond formation. A wide array of β-alkenylated amide products can be obtained in moderate to good yields, which offers practical access to five- and six-membered lactams. This protocol has predictable regio- and chemoselectivity, excellent functional group compatibility and ease of operation in air, representing a significant step-forward towards manganese-catalyzed C−C coupling. 相似文献
44.
Congcong Pei Dr. Chao Liu Dr. You Wang Dan Cheng Rongxin Li Weikang Shu Chaoqi Zhang Wenli Hu Dr. Aihua Jin Dr. Yannan Yang Prof. Jingjing Wan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(27):10923-10927
High-throughput metabolic analysis is of significance in diagnostics, while tedious sample pretreatment has largely hindered its clinic application. Herein, we designed FeOOH@ZIF-8 composites with enhanced ionization efficiency and size-exclusion effect for laser desorption/ionization mass spectrometry (LDI-MS)-based metabolic diagnosis of gynecological cancers. The FeOOH@ZIF-8-assisted LDI-MS achieved rapid, sensitive, and selective metabolic fingerprints of the native serum without any enrichment or purification. Further analysis of extracted serum metabolic fingerprints successfully discriminated patients with gynecological cancers (GCs) from healthy controls and also differentiated three major subtypes of GCs. Given the low cost, high-throughput, and easy operation, our approach brings a new dimension to disease analysis and classification. 相似文献
45.
46.
本文研究表明通过膜厚控制和表面等离激元增强方法可有效区分隐藏界面和空气表面的和频振动光谱信号. 以氟化钙基底支撑的PMMA薄膜为模型,观察到隐藏界面和空气表面对和频信号贡献的变化. 通过监控羰基和甲基伸缩振动基团,发现薄PMMA膜的和频信号来自PMMA/空气表面的化学基团-CH2、-CH3、-OCH3和C=O,而厚PMMA膜的和频信号则来自基底/PMMA埋层界面的-OCH3和C=O基团. 随制膜浓度增大,埋层界面C=O基团的取向角从65°下降到43°,且浓度大于或等于0.5 wt%时,取向角等于45°±2°. 相比之下,空气表面C=O的取向角落在21°∽38°之间. 在金纳米棒存在条件下,表面等离激元可以极大地增强和频信号,尤其是来自埋层界面信号. 相似文献
47.
本文利用时间切片离子速度成像技术在134∽140 nm波段研究了OCS分子经由F 31Π里德堡态的真空紫外光解离动力学. 在选取的5个分别对应OCS(F 31Π, v1=0∽4)的伸缩振动激发的光解波长,实验测得了来自CO(X1Σ+)+S(1D2)产物通道的SS(1D2))实验影像,并获得了总平动能谱和CO(X1Σ+, v)共生产物的振动布居及角分布. 结果分析表明OCS分子解离生成CO(X1Σ+)+S(1D2)产物的过程经历了上态F 31Π 与C?v和Cs构型的下电子态间非绝热耦合过程. 实验结果显示了很强的波长相关性:OCS (F 31Π, v1)的较低转动激发态(v1=0∽2)和较高转动激发态(v1=3, 4)的CO(X1Σ+)产物的振动布居和角分布具有显著差异,表明该解离过程中具有不同的解离机理. 本结果提供了振动耦合可能对真空紫外光解离动力学产生关键作用的相关证据. 相似文献
48.
Sung Jin Yoo 《Nonlinear dynamics》2020,99(2):1115-1128
This paper addresses the problem of global robust fault accommodation tracking for a class of uncertain nonlinear systems with unknown powers and actuator faults. It is assumed that the powers of the concerned system are unknown time-varying functions, all system nonlinearities are unknown, and unknown actuator faults depend on the time-varying power of a control input. A fault accommodation state-feedback controller is explicitly constructed based on the nonlinear error transformation technique using time-varying performance functions. Global tracking with the preselected performance bounds is established in the presence of unknown time-varying powers and unexpected actuator faults. Different from the previous results dealing with the problem of unknown time-varying powers, the proposed tracking strategy does not require the knowledge of the bounds of the time-varying powers and the nonlinear bounding functions of system nonlinearities. An underactuated mechanical system is simulated to validate the effectiveness of the proposed theoretical approach. 相似文献
49.
为探索油-气-水三相流持气率测量难题,该文开展了脉冲透射式超声传感器持气率测量动态实验研究。首先,利用超声传感器与光纤传感器组合,测取了油-气-水三相流中段塞流、混状流、泡状流的响应信号;其次,提取了超声脉冲信号的最大值序列来反映不同流型时超声传感器响应特性,同时,借助双头光纤传感器与相关测速法,计算得到了流体中气泡弦长序列;最后,结合流型与泡径信息,利用超声传感器测量了不同流型下持气率,并分析了不同流型持气率预测的误差来源,为其他油-气-水三相流持气率测量传感器设计提供了借鉴。 相似文献
50.
Propagation dynamics of the cosh-Airy vortex(CAiV) beams in a chiral medium is investigated analytically with Huygens–Fresnel diffraction integral formula. The results show that the CAiV beams are split into the left circularly polarized vortex(LCPV) beams and the right circularly polarized vortex(RCPV) beams with different propagation trajectories in the chiral medium. We mainly investigate the effect of the cosh parameter on the propagation process of the CAiV beams.The propagation characteristics, including intensity distribution, propagation trajectory, peak intensity, main lobe's intensity, Poynting vector, and angular momentum are discussed in detail. We find that the cosh parameter affects the intensity distribution of the CAiV beams but not its propagation trajectory. As the cosh parameter increases, the distribution areas of the LCPV and RCPV beams become wider, and the side lobe's intensity and peak intensity become larger. Besides, the main lobe's intensity of the LCPV and RCPV beams increase with the increase of the cosh parameter at a farther propagation distance, which is confirmed by the variation trend of the Poynting vector. It is significant that we can vary the cosh parameter to control the intensity distribution, main lobe's intensity, and peak intensity of the CAiV beams without changing the propagation trajectory. Our results may provide some support for applications of the CAiV beams in optical micromanipulation. 相似文献