检索结果-南通市图书馆

Analysis of isoquinoline alkaloids from Mahonia leschenaultia and Mahonia napaulensis roots using UHPLC-Orbitrap-MSn and UHPLC-QqQ LIT-MS/MS

引用

Journal of Pharmaceutical Analysis 2017年第2期7卷 77-86页

作者： Awantika Singh Vikas Bajpai Sunil kumar ajay kumar Singh Rawat Brijesh kumar Sophisticated Analytical Instrument Facility Division CSIR-Central Drug Research InstituteLucknow 226031India Academy of Scientific and Innovative Research New Delhi 110001India Pharmacognosy and Ethnopharmacology Division CSIR-National Botanical Research InstituteLucknow 226001India

Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but chemically less identified. Hence, we decided to do extensive phytochemical analysis to explore the potential of these plant extracts. An ultrahigh performance electrospray tandem mass spectrometry（UHPLC-ESI-MS/MS）method was successfully developed for qualitative analysis of the bioactive components in Mahonia species using Orbitrap Velos Pro mass spectrometer. Sixteen compounds were identified by comparison of their retention times and mass spectra（MS） with authentic standards and reported literature. Multi-stage mass spectra（MS（2-8）） for the identification of protoberberine and aporphine alkaloids showed the sequential expulsion of all the substituents attached with their basic skeleton followed by CO loss. Eight of the identified compounds（berberine, jatrorrhizine, palmatine, magnoflorine, isocorydine, glaucine, tetrahydropalmatine and tetrahydroberberine） were simultaneously determined by another UHPLC-ESI-MS/MS method under the multiple reactions monitoring（MRM） mode quantitatively using triple quadrupole linear ion trap mass spectrometer. The analytical method was validated for 8 bioactive compounds with overall recovery in the range98.5%-103.6%（RSD≤2.2%）, precise（RSD≤2.07%） and linear（r≥0.9995） over the concentration range of 0.5-1000 ng/mL and successfully applied in ML and MN roots, which suggests the suitability of the proposed approach for the routine analysis of Mahonia species and their quality control.

关键词： Orbitrap-MS QqQLIT-MS Mahonia leschenaultia Mahonia napaulensis Isoquinoline alkaloids

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Observations on the Function of Mucous Cells in the Epidermis of the Cat-fish Clarias batrachus Exposed to Sodium Dodecyl Sulfate

引用

Biomedical and Environmental Sciences 1993年第2期6卷 119-133页

作者： TARUN kumar GARG ajay kumar MITTAL Skin Skin Physiology LaboratoryDepartment of ZoologyBanaras Hindu UniversityVaranasi-221005IndiaPhysiology LaboratoryDepartment of ZoologyBanaras Hindu UniversityVaranasi-221005India

Response of mucous cells, in the epidermis of the catfish Clarias batrachus, to a sublethal concentration of sodium dodecyl sulfate was studied and correlated with the alteration in the status of their secretory activity after different durations of the treatment. At 4h, 8h, 24h,48h and 72h of the detergent treatment, most mucous cells attained voluminous dimensions and appeared closely approximating to or even overlapping the adjacent ones. At 12h, 36h, and 60h, in contrast, the mucous cells appeared small and slender, and seemed to be located at greater intervals. These changes in dimensions were responsible for the apparent increase or decrease in the density of mucous cells after different durations of detergent treatment. Statistically, however, no significant change was observed in the total number of the mucous cells throughout the experiment.The mucous cells appeared enlarged towards the end of the experiment signifying increased mucus production. This is considered as an adaptation, for protection, assisting the fish to adjust to the changed environment.A shift in the histochemical nature of the secretory contents at the middle and basal parts of the mucous cells, from a mixture of neutral and acid glycoproteins to neutral glycoproteins, during the early stages of the treatment suggests that acid moities could not simultaneously be synthesized as an immediate response to enhanced mucous secretion. The apical parts of the mucous cells, however, showed no histochemical change throughout the experiment.

关键词： Observations on the Function of Mucous Cells in the Epidermis of the Cat-fish Clarias batrachus Exposed to Sodium Dodecyl Sulfate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Electrical conductivity of Gd doped BiFeO3-PbZrO3 composite

引用

Frontiers of Materials Science 2013年第3期7卷 295-301页

作者： Santosh kumar SATPATHY Nilaya kumar MOHANTY ajay kumar BEHERA Banarji BEHERA Pratibindhya NAYAK Materials Research Laboratory School of Physics Sambalpur University Jyoti Vihar Burla-768019 Odisha India

The composite, 0.5（BiGd0.15Fe0.85O3）-0.5（PbZrO3）, was synthesized using the solid-state reaction technique. The formation of the compound was confirmed by XRD with an orthorhombic structure at room temperature. The impedance parameters were studied using an impedance analyzer in a wide range of frequency （10z-106Hz） at different temperatures. The Nyquist plot suggests the contribution of bulk effect and a slight indication of grain boundary effect and the bulk resistance decreases with a rise in temperature. The presence of temperature-dependent relaxation process occurs in the material. Electrical modulus reveals the presence of the hopping mechanism in the materials. The value of exponent n, pre-factor A and adc were obtained by fitting ac conductivity data with Jonscher＇s universal power law. The activation energies calculated from the ac conductivity were found to be 0.50, 0.46, 0.44, 0.43, 0.42 and 0.38 eV at 1, 10, 50, 100, 500 kHz and I MHz respectively in the temperature region of 110℃-350℃. The dc conductivity was found to increase with the rise in temperature. The activation energy calculated from complex impedance plot and from the fitted Jonscher＇s power law are very close, which results similar type of charge carrier exist in conduction mechanism of the material.

关键词： solid state reaction XRD impedance electrical conductivity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nanostructured porous polyaniline(PANI)coated carbon cloth(CC)as electrodes for flexible supercapacitor device

引用

Journal of Materials Science & Technology 2021年第29期88卷 168-182页

作者： Dinesh J.Ahirrao ajay kumar Pal Vikalp Singh Neetu Jha Department of Physics Institute of Chemical TechnologyMatunga(E)Mumbai400019India Department of Physics Ramniranjan Jhunjhunwala CollegeGhatkopar(W)Mumbai 400086India

Nanostructured porous polyaniline(PANI)has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth(CC)substrate using a simple in-situ chemical oxidative polymerization *** coated CC(PANI-CC)based flexible electrodes were further used for the fabrication of flexible supercapacitor *** the comparison purpose,pure PANI has also been synthesized and tested for its electrochemical *** energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV,GCD,and EIS in a potential range from 0 to 0.8 V in 1 M H_(2)SO_(4)***-CC flexible electrodes exhibited the highest specific capacitance of 691 F/g;whereas,pure PANI could only achieve 575 F/g of specific capacitance at 1 A/*** also exhibited outstanding cyclic stability by recollecting 94%of its initial capacitance after 2000 GCD *** actual implementation,a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI-CC flexile *** energy storage performance of the PANI-CC flexible supercapacitor device was tested at several bending angles,which resulted in 72%of capacitance retention at a maximum bending angle of 140°compared to the capacitance obtained at an angle 0°(flat state).PANI-CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and ***,CC helped in enhancing the conductivity and stability;whereas,PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.

关键词： Polyaniline Carbon cloth Flexible supercapacitor Flexible electrode Composite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Potential and performance estimation of free-standing and building integrated photovoltaic technologies for different climatic zones of India

引用

能源与人工环境(英文) 2022年第1期3卷 40-55页

作者： Digvijay Singh ajay kumar Gautam Rubina Chaudhary School of Energy and Environmental Studies Devi Ahilya UniversityIndore 452001India

The role of Photovoltaic technologies integrated or attached to the building envelope is crucial in managing the building energy *** this paper,the performance of PV technologies with the mounting methods of Build-ing integrated and Free-standing(Building attached)is discussed for six different climate zone of the country.A PVGIS program proposed with three PV cell technologies(Crystalline Silicon,Copper indium diselenide,Cad-mium Telluride)is used to evaluate monthly energy generation potential and losses of the 2 kW p grid-connected PV system at the latitude and 90°.A 2 kW p PV system is chosen for Economic Weaker Section(EWS)housing schemes depending upon the roof *** the evaluation,the performance parameter has been estimated.A new parameter Energy Deviation(ED),is proposed to choose the best PV technology in terms of *** results of ED agree with the parameters Performance Ratio(PR)and Capacity Factor(CF)defined under the IEC Standard *** potential generation of PV technologies at 90°varies from 41%(Warm and Humid)to 64%(Cold and Sunny)when compared with the *** case of Cold and Sunny and Cold and Cloudy at 90°,the generation performance of Copper indium diselenide is found better in Building integrated and Free-standing mounting methods,*** the remaining zones,Cadmium Telluride technology shows better *** Percentage loss in the system is found to be minimum in the case of Cold and Sunny,varies between 17%and 25%,and maximum is found for Warm and Humid and varies between 23.2%and 33.4%for the proposed PV *** grid feed-in energy from these EWS houses for all the technologies and climatic zones is found above 45%.It is seen that the combined energy generation from the envelopes(Roof,walls,and facades)makes the houses energy plus in *** study has important implications for the government to promote the building integrated Photovoltaic policies in the country.

关键词： PV technologies Building Integrated Free-standing Energy Deviation Performance Ratio Capacity Factor

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applying real time seismic monitoring technology for slope stability assessment—An Indian opencast coal mine perspective

引用

International Journal of Mining Science and Technology 2014年第1期24卷 75-80页

作者： Vinoth S. ajay kumar L. Department of Mining Engineering College of Engineering GuindyAnna University

This paper outlines the results obtained from real time microseismic monitoring of an opencast coal mine in South *** objective of the study is to investigate the stress changes within the rockmass along the slope due to underground mine development operation and their impact on the stability of the highwall *** installed microseismic systems recorded the seismic triggerings down toà2 moment *** general,most of the events recorded during the monitoring period are weak in seismic *** study adopts a simple and more reliable tool to characterize the seismically active zone for assessing the stability of the highwall in real *** impact of underground working on the slope is studied on the basis of the seismic event impact contours and seismic *** the monitoring period,it is observed that the intensity of the overall microseismic activity along the slope due to the mine development operations did not cause any adverse impact on the highwall stability.

关键词： Seismic monitoring Induced seismicity Seismic clusters Slope stability Opencast mining

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structural, dielectric, and electrical properties of lithium niobate microfibers

引用

Journal of Advanced Ceramics 2016年第1期5卷 84-92页

作者： Cícero Rafael CENA ajay kumar BEHERA Banarji BEHERA UFMS-Federal University of Mato Grosso do Sul CP.549 79070-900 Campo Grande-MS Brazil School of Physics Sambalpur University Jyoti Vihar Burla-7 68019 Odisha India

Lithium niobate (LiNbO3) fibers, obtained from the heat treatment of composite fibers (polymer/inorganic precursors), were successfully prepared by using the blow-spinning technique. A chemical solution containing Li and Nb ions, added to poly(vinyl pyrrolidone) solution, was used as precursor solution. The best condition for producing composite fibers was determined. The morphology of green and crystallized fibers was characterized by scanning electron microscopy (SEM) and revealed fibrous structure with an average diameter around 800 nm. X-ray diffraction (XRD) measurement revealed a pure LiNbO3 (LN) phase formation. Detailed studies of dielectric response at various frequencies and temperatures exhibited a dielectric anomaly at 364 ℃. The electrical properties (impedance, modulus, and conductivity) of the fibers were studied using impedance spectroscopy technique. The contributions of grain and grain boundary effects were observed in the LN fibers. The activation energy of the composite fibers was found to be 1.5 eV in the high temperature region (325–400 ℃).

关键词： ceramics fibers composites chemical synthesis impedance spectroscopy dielectric properties

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Residue recycling options and their implications for sustainable nitrogen management in rice-wheat agroecosystems

引用

Ecological Processes 2023年第1期12卷 733-751页

作者： ajay kumar Bhardwaj Kapil Malik Manu Rani Uttam kumar Mandal Nirmalendu Basak Awtar Singh Rajender kumar Yadav Suresh kumar Chaudhari Dinesh kumar Sharma Central Soil Salinity Research Institute Kachhwa RoadKarnal 132001HaryanaIndia Central Soil Salinity Research Institute Regional Research StationCanning Town 743329West BengalIndia Indian Council of Agricultural Research New Delhi 110012DelhiIndia Central Soil Salinity Research Institute Regional Research StationLucknow 226005Uttar PradeshIndia

Background In the Indo-Gangetic Plain,rice-wheat is the most extensively practiced crop *** escalating issue of crop residue burning,particularly rice straw,and the necessity to lower the exorbitant expenses associated with fertilizer inputs stand out as significant challenges for farmers in the region.A well-suited integrated nutrient management(INM)strategy that focuses on recycling crop residues can serve as a solution to address these *** a strategy not only mitigates air pollution resulting from residue burning but also helps combat water pollution due to nitrate losses from *** experiments were used to evaluate the suitability of eight INM-modules that included various combinations of inorganic fertilizer rates(50%,100%,150%of recommended dose),crop residues(wheat and rice stubble retention at 30 cm standing stubble equivalent to 1/3 the straw yield),rice straw compost(RSC),farmyard manure(FYM),and green manuring(GM),compared to 100%recommended dose of fertilizers(F)and no fertilizer *** There was a considerable improvement in nitrogen mineralization,grain yields,and nitrogen use efficiency under GM+RSC-F50 and GM+*** INM modules would permit a 50%reduction in the use of chemical *** was a little yield penalty with in situ rice residue incorporation at 100%F;however,this could be overcome with 150%F fertilizer *** situ retention of wheat straw with a full application of fertilizer resulted in steadily rising crop yields over *** in the redox potential,soil pH,and soil organic carbon best accounted for the observed trajectories in nitrogen use *** The most promising INM modules for adoption by farmers in the Indo-Gangetic Plain to judiciously use crop residues and curtail chemical fertilizer inputs are green manuring with Sesbania aculeata+rice straw compost at 5 t ha^(−1)+only 50%of recommended dose of fertilizers(GM+RSC-F50),and green manuring with

关键词： Rice–wheat Nitrogen use efficiency Sustainable nitrogen management index Crop residue Rice straw compost

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Response of drainage to tectonics and PS-InSAR derived deformation study in Bilaspur,northwestern Himalaya,India

引用

Geodesy and Geodynamics 2022年第3期13卷 205-218页

作者： Moulishree Joshi Girish Ch Kothyari Kapil Malik ajay kumar Taloor Department of Geology Kumaun University NainitalIndia Institute of Seismological Research GandhinagarGujaratIndia IIT Indian School of Mines DhanbadIndia Department of Remote Sensing and GIS University of JammuJammuIndia

The study of drainage patterns in tectonically active regions is conducive to the prediction of regional *** subsurface changes can be detected by drainage conditions and manifested in the form of drainage *** Satluj valley of Bilaspur,which is traversed by numerous faults in northwest Himalayan region,was selected to analyze the effect of active tectonics on drainage *** the Persistent Scatterer Interferometric Synthetic Aperture Radar(PS-InSAR)technique,SENTINEL-1A data were used to estimate the active surface deformation between September 2015 and December *** results show that the region between Barasar Thrust(BrT)and Main Central Thrust(MCT)is undergoing deformation of±12 mm/*** Stream Power Incision Model(SPIM)was used to predict deformation *** validate the tectonic activity generated by the drainage network,seismic bvalues were calculated,indicating the accumulating *** study shows the importance of drainage anomalies in tectonically active *** used in close combination with other seismotectonic parameters,drainage anomalies can be effective in delineating tectonically active regions.

关键词： Geomorphology Deformation Satluj river Himachal Himalaya

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Management issues in post living donor liver transplant biliary strictures

引用

World Journal of Hepatology 2016年第10期8卷 461-470页

作者： Manav Wadhawan ajay kumar Fortis Escorts Liver and Digestive Diseases Institute

Biliary complications are common after living donor liver transplant(LDLT) although with advancements in surgical understanding and techniques, the incidence is decreasing. Biliary strictures are more common than leaks. Endoscopic retrograde cholangiopancreatography(ERCP) is the first line modality of treatment of post LDLT biliary strictures with a technical success rate of 75%-80%. Most of ERCP failures are successfully treated by percutaneous transhepatic biliary drainage(PTBD) and rendezvous technique. A minority of patients may require surgical correction. ERCP for these strictures is technically more challenging than routine as well post deceased donor strictures. Biliary strictures may increase the morbidity of a liver transplant recipient, but the mortality is similar to those with or without strictures. Post transplant strictures are short segment and soft, requiring only a few session of ERCP before complete dilatation. Long-term outcome of patients with biliary stricture is similar to those without stricture. With the introduction of new generation cholangioscopes, ERCP success rate may increase, obviating the need for PTBD and surgery in these patients.

关键词： Living donor liver transplant Biliary complications Biliary strictures Endoscopic retrograde cholangiopancreatography Percutaneous transhepatic biliary drainage

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：