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Structural characterization of monoterpene indole alkaloids in ethanolic extracts of Rauwolfia species by liquid chromatography with quadrupole time-of-flight mass spectrometry

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Journal of Pharmaceutical Analysis 2016年第6期6卷 363-373页

作者： Sunil Kumar Awantika singh Vikas Bajpai Mukesh Srivastava bhim pratap singh Brijesh Kumar Sophisticated Analytical Instrument Facility CSIR-Central Drug Research Institute Lucknow 226031 Uttar Pradesh India Academy of Scientific and Innovative Research (AcSIR) New Delhi 110025 India Biometry and Statistics Division CSIR-Central Drug Research Institute Lucknow 226031 Uttar Pradesh India Department of Biotechnology Mizoram University Tanharil 796004 Aizawl Mizoram India

Rauwolfia species(Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids(MIAs) such as reserpine,ajmalicine,ajmaline,serpentine and ***,ajmalicine and ajmaline are powerful antihypertensive,tranquilizing agents used in *** is an aphrodisiac used in dietary *** there is no report on the comparative and comprehensive phytochemical investigation of the roots of Rauwolfia species,we have developed an efficient and reliable liquid chromatography-tandem mass spectrometry(LC–MS/MS) method for ethanolic root extract of Rauwolfia species to elucidate the fragmentation pathways for dereplication of bioactive MIAs using highperformance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry(HPLC–ESI–QTOF–MS/MS) in positive ion *** identified and established diagnostic fragment ions and fragmentation pathways using reserpine,ajmalicine,ajmaline,serpentine and *** MS/MS spectra of reserpine,ajmalicine,and ajmaline showed C-ring-cleavage whereas E-ring cleavage was observed in serpentine via Retro Diels Alder(RDA).A total of 47 bioactive MIAs were identified and characterized on the basis of their molecular formula,exact mass measurements and MS/MS ***,ajmalicine,ajmaline,serpentine and yohimbine were unambiguously identified by comparison with their authentic standards and other 42 MIAs were tentatively identified and characterized from the roots of Rauwolfia hookeri,Rauwolfia micrantha,Rauwolfia serpentina,Rauwolfia verticillata,Rauwolfia tetraphylla and Rauwolfia *** of LC–MS followed by principal component analysis(PCA) has been successfully used to discriminate among six Rauwolfia species.

关键词： Rauwolfia species Monoterpene indole alkaloids (MIAs) HPLC–ESI–QTOF–MS/MS Principal component analysis (PCA)

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Ethnobotanical survey of medicinal plants used in the management of cancer and diabetes

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Journal of Traditional Chinese Medicine 2020年第6期40卷 1007-1017页

作者： Garima singh Ajit Kumar Passari Marcy D Momin Sakthivel Ravi bhim pratap singh Nachimuthu Senthil Kumar Department of Biotechnology Mizoram UniversityAizawl 796004India Department of Botany Pachhunga University CollegeAizawl 796001India Departamento de Biologia Molecular y Biotecnologia Instituto de Investigaciones BiomedicasUniversidad Nacional Autonoma de Mexico(UNAM)Ciudad de Mexico-04510Mexico Department of Agriculture&Environmental Sciences(AES) National Institute of Food Technology Entrepreneurship&Management(NIFTEM)SonepatHaryanaIndia

OBJECTIVE:To conduct an ethnobotanical survey and document the traditional anticancer and antidiabetic plants used by the local tribes of Mizoram,Northeast ***:A systematic survey was conducted in rural and urban areas of Mizoram by interviewing traditional practitioners,and cancer and diabetes patients.A detailed literature search was carried out using MEDLINE and SCOPUS and available literatures were selected and included in the *** use value(UV)of the selected plants was calculated based on the number of citations per species given by ***:Data was obtained for 201 traditional medicinal plants from Mizoram,Northeast *** plants were from 72 different families and belonged to 140 *** these,103 plants were reported for the first time as possessing either anticancer or antidiabetic potential,and 105 plants were identified that were used for the treatment of both *** plants(Phlogacanthus thysiformis,Solanum gilo and Lobelia angulata)with antidiabetic potential,and six plants(Dillenia scabrella,Circium sinesis,Eupatorium nodiflorum,Pratia begonifolia,Vernonia teres and Plantago erosa)with both as anticancer and antidiabetic potential were documented for the first ***:In this study,we documented several explored and unexplored medicinal plants that may be useful for the management of cancer and *** study suggests that there is a broad scope fordeveloping potent anticancer and antidiabetic agent from the flora of Mizoram,Northeast India.

关键词： Plants medicinal Antineoplastic agents Hypoglycemic agents Ethanobotanical survey Traditional knowledge

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Electronic Load Controller for a Parallel Operated Isolated Asynchronous Generator Feeding Various Loads

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Journal of Electromagnetic Analysis and Applications 2011年第4期3卷 101-114页

作者： bhim singh Gaurav Kumar Kasal Ambrish Chandra Kamal-Al Haddad 不详

This paper presents an investigation on a voltage and frequency controller (VFC), which functions as an improved elec-tronic load controller (IELC) for parallel operated isolated asynchronous generators (IAGs) in an autonomous hydro power generation system. In such type of hydro scheme whole generating system is isolated from the grid and supply electricity to the remote communities. The single point operation of these generators is realized, in such a manner that excitation capacitors, speeds, load, voltage, currents of generators remain constant under various operating conditions. The proposed controller consists of a 3-leg IGBT (Insulated Gate Bipolar Transistor) based voltage source converter (VSC) and a DC chopper with an auxiliary load at the DC bus of the VSC. The IELC controls the reactive and active powers simultaneously for controlling the voltage and frequency under varying consumer loads. Along with voltage and frequency control through single point operation of IAGs driven by uncontrolled pico hydro turbines, the IELC meets the power quality standard an IEEE-519 and it keeps the total harmonic distortion (THD) of the terminal voltage and currents within the limit of 5%. Here the proposed electrical system along with its controller is modeled in MATLAB along with Simulink and PSB (Power System Block-set) toolboxes. Simulation results are presented to demonstrate the capability of proposed controller for an isolated generating system.

关键词： Parallel Operation of Isolated Asynchronous Generators Voltage and Frequency Controller Single Point Operation Hydro Power

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New Control Algorithm for Capacitor Supported Dynamic Voltage Restorer

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Journal of Electromagnetic Analysis and Applications 2011年第7期3卷 277-286页

作者： bhim singh Pychadathil Jayaprakash D.P. Kothari Ambrish Chandra Kamal- Al-Haddad 不详

In this paper, a simple control algorithm for the dynamic voltage restorer (DVR) is proposed to mitigate the power quality problems in terminal voltage such as sag, swell, harmonics, unbalance etc. Two PI (proportional-integral) controllers are used each to regulate the dc bus voltage of DVR and the load terminal voltage respectively. The fundamental component of the terminal voltage is extracted using the synchronous reference frame theory. The control signal for the series connected DVR is obtained indirectly from the extracted reference load terminal voltage. The proposed DVR control strategy is validated through extensive simulation studies using MATLAB software with its Simulink and Sim-power system (SPS) block set tool boxes.

关键词： Power Quality Distribution System Dynamic Voltage Restorer Voltage Source Converter Indirect Control

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Surface ozone scenario and air quality in the north-central part of India

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Journal of Environmental Sciences 2017年第9期29卷 72-79页

作者： Renuka Saini Ajay Taneja Pradyumn singh Department of Chemistry Dr.Bhim Rao Ambedkar UniversityAgra 282002India

Tropospheric pollutants including surface ozone（O3）, nitrogen dioxide（NO2）, carbon monoxide（CO） and meteorological parameters were measured at a traffic junction（78°2′ E and 27°11′ N） in Agra, India from January 2012 to December 2012. Temporal analysis of pollutants suggests that annual average mixing ratios of tropospheric pollutants were： O3— 22.97 ± 23.36 ppbV,NO2— 19.84 ± 16.71 ppb V and CO — 0.91 ± 0.86 ppm V, with seasonal variations of O3 having maximum mixing ratio during summer season（32.41 ± 19.31 ppbV）, whereas lowest was found in post-monsoon season（8.74 ± 3.8 ppbV）. O3 precursors： NO2 and CO, showed inverse relationship with O3. Seasonal variation and high O3 episodes during summer are associated with meteorological parameters such as high solar radiation, atmospheric temperature and transboundary transport. The interdependence of these variables showed a link between the daytime mixing ratios of O3 with the nighttime level of NO2. The mixing ratios of CO and NO2 showed tight correlations, which confirms the influence of vehicular emissions combined with other anthropogenic activities due to office/working hours, shallowing, and widening of boundary layer. FLEXTRA backward trajectories for the O3 episode days clearly indicate the transport from the NW and W to S/SE and SW direction at Agra in different seasons.

关键词： Surface ozone Ozone precursors Diurnal and seasonal variation PCA Ozone transport

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蜂窝状塑料模连锁混凝土路面砖路面的有限元受力分析

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建筑砌块与砌块建筑 2011年第6期 41-46页

作者： DHAKAL bhim P. RYNTATHIANG Teiborlang L. singh Konjengbam D. 崔玉忠印度理工学院土木工程系印度阿萨姆邦高哈啼781039

本文介绍一种以二维有限元(ANSYS)模型对厚度75mm和100mm的一种连锁混凝土路面砖路面,进行车轮通过路面加速试验时的受力分析。路面砖是一种采用蜂窝状塑料模型成型、形成连锁,路面砖铺设在加速试验装置(APTF)的路基上。分析所用模型具... 详细信息

本文介绍一种以二维有限元(ANSYS)模型对厚度75mm和100mm的一种连锁混凝土路面砖路面,进行车轮通过路面加速试验时的受力分析。路面砖是一种采用蜂窝状塑料模型成型、形成连锁,路面砖铺设在加速试验装置(APTF)的路基上。分析所用模型具有一个三层的结构体系,面层是蜂窝状塑料模型连锁混凝土路面砖,第二层是铺设基础层,第三层是路基层;该有限元分析模型的几何性能、路基的当量弹性模量、各层材料的泊桑比,取自试验研究结果,以及通过回归计算机程序BACKGA计算得到性能的估算值。采用K-θ模型和Park-Fernando模型,确定铺设基础层的弹性模量;采用同样的有限元(简写为:FE)模型,分析铺设基础层材料性能(k1,k2和k3),以便采用研究粒状材料特性的Park-Fernando模型,来估算粒状材料基础层的应力关系。研究发现,采用Park-Fernando公式得到的基础层的模量值,接近使用BACKGA计算程序得到基础层模量的回归计算值,这些数值与模型配合,即可通过迭代过程确定蜂窝状塑料模型连锁混凝土路面砖路面的当量弹性模量。试验室研究发现,在经历不同负载往返次数后,75mm厚路面砖的当量弹性模量都稍微高于100mm厚路面砖的当量弹性模量;研究还发现,采用有限元模型得到的弹性模量值接近用回归法计算得到的弹性模量值。本文为选择新建道路的地面材料,提供了一种设计选择方法。

关键词：蜂窝状塑料模混凝土路面砖连锁路面有限元弹性模量受力分析

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