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Assessment of soil microbial and enzyme activity in the rhizosphere zone under different land use/cover of a semiarid region, India

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Ecological Processes 2021年第1期10卷 225-236页

作者： archana meena K.S.Rao Department of Botany University of RajasthanJaipurRajasthan 302004India. Natural Resource Management Laboratory Department of BotanyUniversity of DelhiNorth CampusDelhi 110007India.

Background:Land use/cover and management practices are widely known to influence soil organic matter(SOM)quality and *** present study investigated the effect of different land use,i.e.,forests *** forest cover(MFC),Prosopis juliflora(Sw.)DC-dominated forest cover(PFC),and cultivated sites *** field(AF),vegetable field(VF),respectively,on soil parameter,microbial activity,and enzymes involved in soil nutrient cycle in a semiarid region of ***:The results showed a significant reduction(P<0.05)in soil carbon(SC),soil nitrogen(SN)content(~30–80%)and consequently the soil microbial biomass carbon(SMBC)(~70–80%),soil basal respiration(SBR),soil substrate-induced respiration(SSIR),and soil enzyme activities(β-glucosidase,acid phosphatase,and dehydrogenase)under cultivated sites in comparison with forest ***’s correlation showed that a positive correlation of SC with SMBC,SBR,SSIR(P<0.01),and enzymatic activities(i.e.,β-glucosidase,dehydrogenase)(P<0.05)may imply the critical role of SC in regulating microbial and enzymatic ***,a positive correlation of soil moisture with urease activity(P<0.01)was found suggesting it as a significant abiotic factor for soil biological ***,based on the PCA analysis,we observed the clustering of SMBC/SC ratio and qCO_(2) nearby ***:Our study suggests that soil microbial parameters(SMBC,SBR,SSIR,SMBC/SC,qCO_(2))and enzyme activity are key indicators of soil health and *** use/cover alters the SOM content and soil microbial *** management strategies focusing on the conservation of natural forest and minimizing the land disturbances will be effective in preventing soil carbon flux as CO_(2) and maintaining the SC stock.

关键词： Land use changes Soil microbes Soil enzymes Semiarid ecosystems Land management practices

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Soil moisture controls the spatio-temporal pattern of soil respiration under different land use systems in a semi-arid ecosystem of Delhi,India

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Ecological Processes 2020年第1期9卷 172-184页

作者： archana meena M.Hanief J.Dinakaran K.S.Rao Department of Botany University of RajasthanJaipurRajasthan 302004India Department of Botany Baba Ghulam Ghulam Shah Badshah UniversityRajouriJammu and Kashmir 185234India Department of Botany Bhaskaracharya College of Applied SciencesUniversity of DelhiDwarkaDelhi 110007India Department of Botany University of DelhiDelhi 110007India

Background:Soil respiration(S_(R))is a critical process for understanding the impact of climatic conditions and land degradation on the carbon cycle in terrestrial *** measured the S_(R) and soil environmental factors over 1 year in four land uses with varying levels of disturbance and different vegetation types viz.,mixed forest cover(MFC),Prosopis juliflora(Sw.)forest cover(PFC),agricultural field(AF),and vegetable field(VF),in a semi-arid area of Delhi,*** primary aim was to assess the effects of soil moisture(S_(M)),soil temperature(S_(T)),and soil microbial activity(S_(MA))on the S_(R).Methods:The S_(R) was measured monthly using an LI-6400 with an infrared gas analyser and a soil *** S_(M) was measured using the gravimetric *** S_(T)(10 cm)was measured with a probe attached to the *** S_(MA) was determined by fluorescein diacetate ***:The S_(R) showed seasonal variations,with the mean annual S_(R) ranging from 3.22 to 5.78μmol m^(−2) s^(−1) and higher S_(R) rates of~15-55%in the cultivated fields(AF,VF)than in the forest sites(MFC,PFC).The VF had significantly higher S_(R)(P0.05).Contrasting results were observed in the VF,which showed high S_(R) during summer(May;11.21μmol m^(−2) s^(−1))and a significant exponential relationship with the S_(T)(R^(2)=0.52;P<0.05).The S_(R) was positively related to the SMA(R2=0.44-0.5;P<0.001).The interactive equations based on the independent variables S_(M),S_(T),and S_(MA) explained 91-95

关键词： Soil respiration Soil moisture Soil microbes Soil temperature Precipitation Land use change Semi-arid ecosystems

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Assessment of above- and belowground carbon pools in a semi-arid forest ecosystem of Delhi, India

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Ecological Processes 2019年第1期8卷 93-103页

作者： archana meena Ankita Bidalia M.Hanief JDinakaran K.S.Rao Department of Botany University of RajasthanJaipurRajasthan 302004India Natural Resource Management Laboratory Department of BotanyUniversity of DelhiNorth CampusDelhi 110007India Department of Botany Baba Ghulam Shah Badshah UniversityRajouriJ&K 185234India

Background:Assessment of carbon pools in semi-arid forests of India is crucial in order to develop a better action plan for management of such ecosystems under global climate change and rapid *** study,therefore,aims to assess the above-and belowground carbon storage potential of a semi-arid forest ecosystem of ***:For the study,two forest sites were selected,i.e.,north ridge(NRF)and central ridge(CRF).Aboveground tree biomass was estimated by using growing stock volume equations developed by Forest Survey of India and specific wood *** biomass was determined by harvest sampling ***(root)biomass was determined by using a developed *** soil organic carbon(SOC),soil samples were collected at 0–10-cm and 10–20-cm depth and carbon content was ***:The present study estimated 90.51 Mg ha−1 biomass and 63.49 Mg C ha−1 carbon in the semi-arid forest of Delhi,*** lower diameter classes showed highest tree density,i.e.,240 and 328 individuals ha−1(11–20 cm),basal area,i.e.,8.7(31–40 cm)and 6.08m2 ha−1(11–20 cm),and biomass,i.e.,24.25 and 23.57 Mg ha−1(11–20 cm)in NRF and CRF,***,a significant contribution of biomass(7.8 Mg ha−1)in DBH class 81–90 cm in NRF suggested the importance of mature trees in biomass and carbon *** forests were predominantly occupied by Prosopis juliflora(Sw.)DC which also showed the highest contribution to the(approximately 40%)tree *** allocation was maximum in aboveground(40–49%),followed by soil(29.93–37.7%),belowground or root(20–22%),and litter(0.27–0.59%).Conclusion:Our study suggested plant biomass and soils are the potential pools of carbon storage in these ***,carbon storage in tree biomass was found to be mainly influenced by tree density,basal area,and species *** belonging to lower DBH classes are the major carbon sinks in these *** the study,native trees contributed to the significan

关键词： Semi-arid forest Carbon pool Forest management Species composition Basal area Carbon allocation pattern

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Development and performance characterization of a compact plasma focus based portable fast neutron generator

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Plasma Science and Technology 2020年第11期22卷 127-135页

作者： Rishi VERMA Ekansh MISHRA Prosenjit DHANG Basanta Kumar DAS Manraj meena Lakshman RONGALI archana SHARMA Pulsed Power&Electromagnetics Division Bhabha Atomic Research Centre FacilityAtchutapuramVishakhapatnam 531011.India Homi Bhabha National Institute AnushaktinagarMumbai 400094India Raja Ramanna Centre for Advanced Technology Rajendra NagarIndore 452013India Variable Energy Cyclotron Centre BidhannagarKolkata 700064India

The design details and performance characterization results of a newly developed plasma focus based compact and portable system(0.5 m×0.5 m×1.2 m,weighing≈100 kg)that produces an average neutron yield of^2×10^8 neutrons/shot(of fast D-D neutrons with typical energy^2.45 Me V)at^1.8 k J energy discharge are *** the detailed analysis of the experimental characterization and simulation results of this system,it has been conclusively revealed that specifically in plasma focus devices with larger static inductance:(i)pinch current is a reliable and more valid neutron yield scaling parameter than peak current,(ii)the ratio of pinch/peak current improves as static inductance of the system reduces,(iii)the benign role of the higher static/pinch inductance ratio enables the supply of inductively stored energy in densely pinched plasma with a larger time constant and it is well depicted by the extended dip observed in the discharge current trace,(iv)there is the need to redefine existing index values of the pinch(Ipinch^4.7)and peak(Ipeak^3.9)currents in neutron yield scaling equations to higher values.

关键词： plasma focus neutrons time of flight pinch current peak current plasma pinch pseudospark switch

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On the photoevaporation,dust polarization and kinematics of two nebulae in Sh2-236

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Research in Astronomy and Astrophysics 2021年第4期21卷 157-167页

作者： archana Soam SOFIA Science Center Universities Space Research AssociationNASA Ames Research CenterM.S.N232-12Moffett FieldCA 94035USA

In the work presented here,the impact of magnetic field on the dynamical evolution of cometary globules Sim 129 and Sim 130 in the Sh2-236 HⅡregion and the ionized gas streaming out of their surfaces is *** magnetic field morphology in the region associated with these globules is inferred using optical polarization measurements with the Sampurnanand Telescope at *** nebular emission is probed through radio continuum mapping at 1.4 GHz with the archival National Radio Astronomy Observatory(NRAO)Very Large Array(VLA)Sky Survey(NVSS)*** correlation of these measurements suggests that photoevaporated gas from the surfaces of Sim 129 and Sim 130 accumulates in clouds and starts streaming along the magnetic field *** ^(12)CO(J=1-0)molecular line observations are performed towards NGC 1893 from the 14-m single dish radio telescope in Taeduk Radio Astronomy Observatory(TRAO).The velocity dispersion in the ^(12)CO(J=1-0)molecular line and the dispersion in polarization angles are considered in the Davis-Chandrasekhar-Fermi formulation to estimate the magnetic field strength towards two Sim *** average value of field strength is found to be~60μG with uncertainty of 0.5 times the estimated value.

关键词： ISM:general polarization:nebulae

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Preparation, characterization and luminescence behavior of some samarium complexes

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Rare Metals 2021年第9期40卷 2618-2626页

作者： archana Chauhan Ritu Langyan Department of Chemistry Kurukshetra UniversityKurukshetra 136119India

The synthesis of luminescent complexes of Sm(III) with the general formula [Sm(L)_(3)·(X)] was done in powder form. In the formula, L is 6-methyl-4-oxo-4 H-1-benzopyran-3-carboxaldehyde and X represents 2H_(2)O(C1), 1,10-phenanthroline(C2), 2,20-bipyridine(C3);bathophenanthroline(C4) and neocuproine(C5). The complexes were characterized by using various analytical and spectroscopic tools like elemental analysis, electrospray ionization mass spectrometry(ESI–MS+), Fourier transform infrared spectroscopy(FTIR), ultraviolet–visible(UV–Vis) spectroscopy, thermo-gravimetric analysis/differential thermal gravimetric analysis(TGA/DTG), field emission scanning electron microscopy(FESEM), powder X-ray diffraction(XRD), and photoluminescence(PL)studies. TGA/DTG showed high thermal stability of synthesized complexes. Powder XRD depicts that the average particle size lies in the nano-range. On monitoring at the excitation wavelength of 370 nm, the complexes display characteristic luminescence peaks of Sm(III) at ~564,~600 and ~647 nm assigned to^(4)G_(5/2)→^(6)H_(5/2),^(4)G_(5/2)→^(6)H_(7/2), and ^(4)G_(5/2)→6H9/2 transitions, respectively, with the most intense transition at ~600(orange emission) and~647 nm(bright red emission) in liquid and powder state, respectively. The investigations demonstrate that the synthesized novel complexes might be practically useful in electroluminescent devices, bio-assays, and liquid lasers due to their attractive photoluminescent properties.

关键词： Samarium complexes Luminescence Thermal analysis Quantum yield

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Changing role of histopathology in the diagnosis and management of hepatocellular carcinoma

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World Journal of Gastroenterology 2018年第35期24卷 4000-4013页

作者： archana Rastogi Department of Pathology Institute of Liver & Biliary SciencesNew Delhi 110070 India

Hepatocellular carcinoma (HCC) is one of the most common and fatal cancer in the world. HCC frequently presents with advanced disease, has a high recurrence rate and limited treatment options, which leads to very poor prognosis. This warrants urgent improvement in the diagnosis and treatment. Liver biopsy plays very important role in the diagnosis and prognosis of HCC, but with technical advancements and progression in the field of imaging, clinical guidelines have restricted the role of biopsy to very limited situations. Biopsy also has its own problems of needle tract seeding of tumor, small risk of complications, technical and sampling errors along with interpretative errors. Despite this, tissue analysis is often required because imaging is not always specific, limited expertise and lack of advanced imaging in many centers and limitations of imaging in the diagnosis of small, mixed and other variant forms of HCC. In addition, biopsy confirmation is often required for clinical trials of new drugs and targeted therapies. Tissue biomarkers along with certain morphological features, phenotypes and immune-phenotypes that serve as important prognostic and outcome predictors and as decisive factors for therapy decisions, add to the continuing role of histopathology. Advancements in cancer biology and development of molecular classification of HCC with clinic pathological correlation, lead to discovery of HCC phenotypic surrogates of prognostic and therapeutically significant molecular signatures. Thus tissue characteristics and morphology based correlates of molecular subtypes provide invaluable information for management and prognosis. This review thus focuses on the importance of histopathology and resurgence of role of biopsy in the diagnosis, management and prognostication of HCC.

关键词： Hepatocellular carcinoma Biomarker Biopsy Histopathology Immunohistochemistry Targeted therapy Molecular Diagnosis Prognosis

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Study of plasma parameters of coaxial plasma source using triple Langmuir probe and Faraday cup diagnostics

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Plasma Science and Technology 2024年第4期26卷 94-100页

作者： Sunil KANCHI Rohit SHUKLA archana SHARMA Pulsed Power and Electromagnetics Division Bhabha Atomic Research CentreVisakhapatnam 531011India Homi Bhabha National Institute Mumbai 400085India Beam Technology Development Group Bhabha Atomic Research CentreMumbai 400085India

Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon *** triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.

关键词： coaxial plasma source triple Langmuir probe Faraday cup plasma density plasma temperature

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Screening of Antioxidant Potential of Selected Barks of Indian Medicinal Plants by Multiple in vitro Assays

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Biomedical and Environmental Sciences 2008年第1期21卷 24-29页

作者： archana KUMARI POONAM KAKKAR Herbal Research Section Industrial Toxicology Research Centre P. O. Box-80 M. G. Marg Lucknow-226001 India

Objective To evaluate the antioxidant potential in herbal extract barks of five therapeutically important medicinal plants native to India, i.e. Crataeva nurvala Buch.-Ham., Buchanania lanzan Spreng., Aegle marmelos Corr., Dalbergia sissoo Roxb. ex DC., and Cedrela toona Roxb. Methods Standardized aqueous alcoholic extracts from the selected barks having different target radicals, such as superoxide radical, nitric oxide, ABTS radical, and peroxidative decomposition of phospholipids, were prepared and screened by multiple in vitro assays. These extracts were also tested for total phenolic and tannin content and correlated with antioxidant capacity. Results Total phenolic and tannin contents were found to be the highest in C. nurvala （195 GAE mg/g and 218.3 mg/g CE）. SOD mimetic activity was found to be the highest in Crataeva nurvula, although all barks showed activity more than IO3 units/mg extract. Lipid peroxidation inhibitory potential was found to be the highest in Crataeva nurvala （83.4% inhibition of MDA formation/10 μg extract）, and also showed a comparatively high NO quenching capacity （45.5% per 10 μg extract）. The highest NO quenching potential was found in Aegle marmelos （47.3% per 10 μg extract）. Cedrela toona showed the lowest LPO inhibitory potential and NO quenching capacity （50.5% and 30.5%, respectively）. Buchanania lanzan, a medicinal plant extensively used for inflammatory disorders and Dalbergia sissoo also showed 72.5% and 69.1% LPO inhibitory potential/10 μg extract. Trolox equivalent antioxidant capacity ranged from 0.24 to 0.39 mmol/L TEAC/mg extract, indicating that all the barks tested had ABTS^＋ radical quenching capacity. Conclusion Bark of Crataeva nurvula has the highest antioxidant capacity and a positive correlation between antioxidant activity and their plendic content was found.

关键词： Superoxide dismutase Lipid peroxidation Nitric oxide quenching Medicinal plant extracts Reactive oxygen species Antioxidants

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Ion Conduction in Superionic Glassy Electrolytes:An Overview

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Journal of Materials Science & Technology 2013年第3期29卷 193-208页

作者： Angesh Chandra Alok Bhatt archana Chandra Department of Applied Physics Shri Shankaracharya Institute of Prof.Manag.& Tech.Raipur 492015C.G.India Department of Applied Physics M.P Christian College of Engg.& Tech.Bhilai 490026C.G.India

The various theoretical and experimental models for ion conduction mechanism of fast ion conducting （FIC） glass electrolytes have been reported in the present review paper. Some characterization techniques of FIC glasses are presented. The experimental methods for determination of some ion transport parameters viz ionic conductivity （σ）, ionic mobility （μ）, mobile ion concentration （n）, ionic drift velocity （Vd）, ionic transference number （tion） and activation energies of FIC glasses are explained. The solid state battery fabrication by using some FIC glasses is also reported.

关键词： Ion conduction Glassy solid electrolyte Fast ion conducting (FIC) glass Superionic solid Relaxation phenomenon

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