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Palaeodepositional environment,implications of Glossopteris flora,and organic matter characteristics from the Lower Permian,Karo Open Cast Mine,East Bokaro Coalfield,Damodar Basin,India

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Journal of Palaeogeography 2024年第3期13卷 528-546页

作者： Sankar Suresh Kumar Pillai Rose Ann Sebastian Runcie Paul Mathews srikanta murthy Anju Saxena Mrutyunjaya Sahoo Suraj Kumar Sahu Gulshan Kumar Dhingra Birbal Sahni Institute of Palaeosciences 53 University RoadLucknow-226007UPIndia Academy of Scientific and Innovative Research(AcSIR) Ghaziabad-201002India Department of Geology School of Earth Science SystemsCentral University of KeralaKasaragod-671316KeralaIndia Department of Geology Ravenshaw UniversityCuttack-753003OdishaIndia Department of Botany Sri Dev Suman Uttarakhand UniversityUttarakhand-249145India

The present study deals with the Early Permian floral diversity,palaeoenvironment,palaeoclimate and depositional setting using a multiproxy approach that includes morphotaxonomy,palynology,and organic geochemistry of Karo OCM(Open Cast Mine),East Bokaro Coalfield,Damodar Gondwana Basin,*** Permian sediments of Peninsular India are widely regarded as fluvial,along with some marine *** macroplant fossil assemblage exhibits the presence of Glossopteridales,comprising Glossopteris,Gangamopteris,and Vertebraria,as well as Coniferales,which includes *** palynological assemblage encompasses the dominance of the striate bisaccate pollen Faunipollenites *** the subdominance of the non-striate bisaccate pollen Scheuringipollenites *** glossopterid *** megafloral and palynofloral assemblage confirms the biostratigraphical age to be Late Barakar palynoflora of Kungurian *** studied morphological characteristics,including small to large Glossopteris leaves exhibiting a lanceolate shape,acute apices,and acute cuneate or tapering bases,as well as entire margins with narrower lamina and narrow meshes,suggest the existence of a dense forest with the prevalence of a warm and humid climate during their *** organic geochemical characterization based on functional group and biomarker analyses reveals the diagenetic effects on organic *** symmetric(~2865-2855 cm^(-1))and asymmetric stretching(~2930-2910 cm^(-1))peaks are identifiable in coal samples,whereas they are absent in carbonaceous *** A-factor vs.C-factor plot suggests that the kerogen type is type Ⅲ,which can generate mainly gaseous *** vitrinite reflectance studies(R_(r) av.1.1%)show increased maturity of the samples,which is supported by the n-alkane distribution pattern and the absence of hopane *** Indian floral assemblages in contemporary of southern Gondwana continents reveal a stronger inclination/affinity with th

关键词： Glossopteris Palynomorph FTIR GCMS Gondwana Permian Palaeoclimate

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Palaeobotanical and biomarker evidence for Early Permian(Artinskian) wildfire in the Rajmahal Basin, India

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Journal of Palaeogeography 2021年第1期10卷 55-75页

作者： srikanta murthy Vinod Atmaram Mendhe Dieter Uhl Runcie Paul Mathews Vivek Kumar Mishra Saurabh Gautam Birbal Sahni Institute of Palaeosciences 53University RoadLucknow 226007India CSIR-Central Institute of Mining and Fuel Research Dhanbad 826015JharkhandIndia Senckenberg Forschungsinstitut und Naturmuseum Frankfurt Senckenberganlage 2560325 Frankfurt am MainGermany

This study provides a combined analysis on the palynology, fossil charcoal and biomarkers of the subsurface coal deposits from a borehole RMB #2 drilled at the Dhulia Coal Block, Rajmahal Basin, India, in attempts to establish the chronology of sedimentation and to propose palaeobotanical as well as geochemical evidence for the occurrence of wildfires in these sediments. The palynological investigation suggests a Scheuringipollenites barakarensis palynoassemblage from the lower Barakar Formation, dated as Artinskian(Early Permian) in age. This assemblage reveals the dominance of Glossopteridales and sub-dominance of taxa belonging to Cordaitales and *** charcoal in sediments is usually recognized as a direct indicator for the occurrence of palaeo-wildfires. More data involving the anatomical features of fossil charcoal analyzed by Field Emission Scanning Electronic Microscope broaden our knowledge on Early Permian wildfires from the peninsula of India. The studied macroscopic charcoal fragments exhibit anatomical details such as homogenized cell walls, uniseriate simple and biseriate alternate pitting on tracheid walls and rays of varying heights pointing to a gymnospermous wood affinitity. The excellent preservation of charcoal fragments, shown by their large sizes and almost unabraded edges, suggests a parautochthonous origin. The embedded biomarker study performed for charcoal sediments and its characterization demonstrate the presence of n-alkanes, isoprenoids, terpenoids and aromatic compounds. A bimodal distribution pattern of n-alkanes with a Cmaxat n-C25 is identified. Diterpenoids and pentacyclic terpenoids are identified, indicating the input of an early conifer vegetation and bacterial activity, respectively. The identified polyaromatic hydrocarbon(PAH) compounds, together with the charcoal fragments, clearly suggest that repeated wildfire events occurred during the deposition of these Artinskian sediments in the Rajmahal Basin.

关键词： Palaeo-wildfire Palynology Fossil charcoal Biomarker Barakar Formation Rajmahal Basin

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Palynomorphs and Oribatid Mites—From the Denwa Formation, Satpura Basin, Madhya Pradesh, India

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International Journal of Geosciences 2012年第1期3卷 195-205页

作者： Vijaya Vijaya srikanta murthy Birbal Sahni Institute of Palaeobotany Lucknow India

Palynological investigation of the Denwa Formation exposed along Denwa river succession at Saptadara picnic point near village Jhirpa, Satpura Basin, Madhya Pradesh, has revealed the presence of spore-pollen, fungal remains and Oribatid mites. Here, the mites are on record for the first time. Presence of fungal remains strongly depicts the prevalence of a very humid climate with high temperature and rainfall in the region. Poor occurrence of spore-pollen restricts the age determination of the studied section;hence, its age assessment is relative. Thus, an over-view of spore-pollen along with dinocysts and insects reported earlier from the subsurface strata comprising Denwa Formation, from other two localities in the nearby area of village Anhoni, is dealt herein, and that had inferred an age—range from Carnian to Rhaetic for the palynoflora and fauna.

关键词： Spore-Pollen Fungal Remains Oribatid mites Denwa Formation Upper Triassic

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A Comprehensive Review on Preclinical Safety and Toxicity of Medicinal Plants

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Clinical Complementary Medicine and Pharmacology 2024年第1期4卷 95-111页

作者： Madhav Nilakanth Mugale Kapil Dev Bhumika S.More Vaishali Sunil Mishra Kaveri R.Washimkar Kishan Singh Rakesh Maurya srikanta Kumar Rath Debprasad Chattopadhyay Naibedya Chattopadhyay Division of Toxicology and Experimental Medicine CSIR-Central Drug Research Institute(CSIR-CDRI)Lucknow 226031India Division of Phytochemistry CSIR-Central Institute of Medicinal and Aromatic Plants(CSIR-CIMAP)Lucknow 226015India Medicinal and Process Chemistry Division CSIR-CDRI Lucknow 226031India Division of Endocrinology CSIR-CDRI Lucknow 226031India Division of Ethnomedicine ICMR-National Institute of Traditional MedicineNehru NagarBelagavi 590010and ICMR-Virus UnitKolkata 700010India Department of Health Research NSHM Knowledge CampusKolkata 700051India

Background:Globally,80%people use plant-derived products for treating or preventing *** prevalent perception about medicinal plants is that they are safe and devoid of adverse ***,approximately 1,50,000 plants contain toxic ***:The present review focuses on medicinal plant extracts/fractions toxicity assessments made in preclin-ical models by oral ***:Detail studies were searched from databases including PubMed and Google Scholar.A manual reference screening of the selected studies was done to identify relevant articles,with no language restriction being imposed at the time of ***:The studies included were performed in rodents,and the test substances were administered *** search revealed 33 widely used plants or products with significant toxicity,and phytochemicals from these plants have been *** a systematic review,we identified a plethora of medicinal plant extracts reporting safety and toxicity ***:In the future,preclinical toxicokinetic studies of herbs and the determination of their no-observed-adverse-effect levels are required for a complete safety ***,the interaction of herbs with com-monly used/over-the-counter drugs in terms of the latter’s metabolic profile should be undertaken.

关键词： Extract Herbal medicine Toxicity Rodent Secondary metabolite

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Fabrication and characterization of a GaN/(4H)SiC vertical pn power diode using direct and interfaced epitaxial-growth approaches

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Journal of Semiconductors 2013年第4期34卷 20-23页

作者： Bose srikanta Mazumder S K Laboratory for Energy and Switching-Electronics Systems Department of Electrical and Computer EngineeringUniversity of Illinois at ChicagoChicagoIL:60607USA

We report the fabrication and characterization of a vertical pn power diode which is realized using two separate epitaxial-growth mechanisms：（a） p-GaN over p-（4H）SiC, and （b） p-GaN over n-（4H）SiC with A1N as the interface layer. In all of the cases, n＋-doped （4H）SiC serves as the cathode substrate. Pd（200 A）/Au（10000 A） is used for the anode contact while Ni（1000A） is used for the bottom cathode contact. The measured forward drop of the pn diode with A1N as the interface material is found to be around 5.1 V; whereas, it is 3 V for the other sample structure. The measured reverse-blocking voltage is found to be greater than 200 V.

关键词： GaN (4H)SiC vertical pn power diode power electronics

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A novel phenol-bound pectic polysaccharide from Decalepis hamiltonii with multi-step ulcer preventive activity

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World Journal of Gastroenterology 2007年第39期13卷 5196-5207页

作者： BM srikanta MN Siddaraju Shylaja M Dharmesh Department of Biochemistry and Nutrition Central Food Technological Research InstituteMysore -570020KarnatakaIndia

AIM: To investigate H+, K+-ATPase inhibition, anti-H pylori , antioxidant, and the in vivo antiulcer potential of a pectic polysaccharide from Swallow root (Decalepis hamiltonii; SRPP). METHODS: SRPP, with known sugar composition [rhamnose: arabinose: xylose: galactose in the ratio of 16:50:2:32 (w/w), with 141 mg/g of uronic acid] was examined for anti-ulcer potency in vivo against swim/ ethanol stress-induction in animal models. Ulcer index, antioxidant/antioxidant enzymes, H+, K+-ATPase and gastric mucin levels were determined to assess the anti- ulcer potency. Anti-H pylori activity was also determined by viable colony count and electron microscopic studies. RESULTS: SRPP, containing phenolics at 0.12 g GAE/g, prevented stress-induced gastric ulcers in animal models by 80%-85%. Down regulation of gastric mucin 2-3 fold, antioxidant/antioxidant enzymes and upregulation of 3 fold of H+, K+-ATPase in ulcerous animals were normalized upon treatment with SRPP. Histopathological analysis revealed protection to the disrupted gastric mucosal layer and epithelial glands. SRPP also inhibited H+, K+-ATPase in vitro, at an IC50 of 77 μg/mL as opposed to that of 19.3 μg/mL of Lansoprazole and H pylori growth at Minimum Inhibitory Concentration (MIC) of 150 μg/mL. In addition, free radical scavenging (IC50-40 μg/mL) and reducing power (3200 U/g) activities were also observed. CONCLUSION: SRPP, with defined sugar composition and phenolics, exhibited multi-potent free radical scavenging, antioxidant, anti-H pylori, inhibition of H+, K+-ATPase and gastric mucosal protective activities. In addition, SRPP is non-toxic as opposed to other known anti-ulcer drugs, and therefore may be employed as a potential alternative for ulcer management.

关键词： Swallow root pectic polysaccharide Gastriculcer H^+, K^+-ATPase Histopathology Antioxidant activity H pylori

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Surface functionalization of BiFeO3： A pathway for the enhancement of dielectric and electrical properties of poly（methyl methacrylate）-BiFe03 composite films

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Frontiers of Materials Science 2017年第1期11卷 82-91页

作者： Mukesh Kumar MISHRA srikanta MOHARANA Banarji BEHERA Ram Naresh MAHALING Laboratory of Polymeric and Materials Chemistry School of Chemistry Sambalpur University Odisha India Materials Research Laboratory School of Physics Sambalpur University Odisha India

A novel two-phase composite film is prepared by the solvent casting method employing poly（methyl methacrylate）（PMMA） as polymer matrix and bismuth ferrite （BFO） as ceramic filler. The surfaces of BFO are functionalized by proper hydroxylating agents to activate their chemical nature. The structural analysis of the composite films confirms that the composites made up of functionalized BFO （BFO-OH） have a distorted rhombohedral structure. The morphological analysis shows that BFO- OH particles are equally distributed over the polymer matrix. The -OH functionality of BFO-OH is confirmed by FTIR. The dielectric and electrical studies at a frequency range from 100 Hz to I MHz reveal that PMMA-（BFO-OH） composites have enhanced dielectric constant as well as electrical conductivities, much higher than that of unmodified composites. According to the ferroelectric measurement result, the hydroxylated composite film shows a superior ferroelectric behavior than that of the unmodified one, with a remanent polarization （2Pr） of 2.764μC/cm2,

关键词： functionalized bismuth ferrite composites AC electrical conductivity dielectric properties

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A Review on Interface Engineering of MXenes for Perovskite Solar Cells

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Nano-Micro Letters 2023年第8期15卷 270-308页

作者： srikanta Palei G.Murali Choong‑Hee Kim Insik In Seul‑Yi Lee Soo‑Jin Park Department of Chemistry Inha University100 InharoIncheon 22212South Korea Department of Polymer Science and Engineering Department of IT‑Energy Convergence(BK21 Four)Chemical Industry InstituteKorea National University of TransportationChungju 27469South Korea

With an excellent power conversion efficiency of 25.7%,closer to the Shockley–Queisser limit,perovskite solar cells(PSCs)have become a strong candidate for a next-generation energy ***,the lack of stability and reliability in PSCs remained challenging for ***,such as interfacial and structural engineering,have a more critical influence on enhanced ***,two-dimensional materials,have emerged as promising materials in solar cell applications due to their metallic electrical conductivity,high carrier mobility,excellent optical transparency,wide tunable work function,and superior mechanical *** to different choices of transition elements and surface-terminating functional groups,MXenes possess the feature of tuning the work function,which is an essential metric for band energy alignment between the absorber layer and the charge transport layers for charge carrier extraction and collection in ***,adopting MXenes to their respective components helps reduce the interfacial recombination resistance and provides smooth charge transfer paths,leading to enhanced conductivity and operational stability of *** review paper aims to provide an overview of the applications of MXenes as components,classified according to their roles as additives(into the perovskite absorber layer,charge transport layers,and electrodes)and themselves alone or as interfacial layers,and their significant importance in PSCs in terms of device performance and ***,we discuss the present research status and future directions toward its use in PSCs.

关键词： MXenes Perovskite solar cells Additives Interfacial layer Electrodes

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Enhanced dielectric and ferroelectric properties of surface hydroxylated Na_(0.5)Bi_(0.5)TiO_(3)(NBT)-poly(vinylidene fluoride)(PVDF)composites

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Journal of Advanced Dielectrics 2018年第3期8卷 34-43页

作者： srikanta Moharana Shraddhakara Sai Ram Naresh Mahaling Laboratory of Polymeric and Materials Chemistry School of Chemistry Sambalpur University Jyoti ViharBurla 768019OdishaIndia Nano Research Centre Sambalpur University Jyoti ViharBurla 768019OdishaIndia

The surface hydroxylation treatment has been carried out by using hydrogen peroxide(H_(2)O_(2))to modify the surface of Na_(0.5)Bi_(0.5)TiO_(3)(NBT)particles in a ferroelectric polymer(PVDF)via solution casting *** FTIR study confirms the presence of hydroxyl groups on the surface of *** FE-SEM analysis reveals that h-NBT particles are dispersed homogeneously within the polymer *** surface hydroxylation treatment plays an important role in high dielectric constant and also reduced loss by conducting the material surface withOH functional *** prepared composite with 40 wt.%of h-NBT showed enhanced dielectric constant(≈114),negligible loss(0.22)and high AC conductivity as compared to that of the unmodified *** significant enhancement in dielectric properties may be due to the strong interaction between h-NBT particles and PVDF matrix at the *** percolation theory is used to explain the dielectric properties of h-NBT-PVDF ***,the remnant polarization of the un-poled h-NBT-PVDF composites(2 Pr–1.19C/cm^(2) for 40 wt.%of h-NBT)is also *** present findings give an idea of high dielectric constant and relatively low loss composite materials as a promising candidate for electronic and energy storage devices.

关键词： Poly(vinylidene fluoride) dielectric properties surface hydroxylation

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Analysis of curcumin interaction with human serum albumin using spectroscopic studies with molecular simulation

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Frontiers in Biology 2017年第3期12卷 199-209页

作者： Turban Kar Pijush Basak srikanta Sen Rittik Kumar Ghosh Maitree Bhattacharyya Department of Biochemistry University of Calcutta 35 Ballygunge Circular Road Kolkata-700019 West Bengal India Jagadis Bose National Science Talent Search Kolkata-700107 India 229A/230 Mira Tower Lake Town Block-A Kolkata-700089 India

BACKGROUND： Curcumin has emerged to be utilized as a superb beneficial agent, due to its naturally occurring anti-oxidant, anti-inflammatory and anti-carcinogenic property. METHODS： The interaction of curcumin with human serum albumin, the main in vivo transporter of exogenous substances, was investigated using absorption spectroscopy, steady-state fluorescence, excited state life-time studies and circular dichroism ***：Isothermal titration calorimetry techniques inferred one class of binding site with binding constant -1.74 × 10^5 M ^-1 revealing a strong interaction. The binding profile was analyzed through the evaluation of the thermodynamic parameters, which indicated the involvement of hydrophobic interactions （burial of non-polar group）. Fluorescence lifetime of tryptophan residue was observed to decrease to 1.94 ns from 2.84 ns in presence of Curcumin. Percentage of ct helicity of human serum albumin was also reduced significantly upon binding with curcumin as evidenced by circular dichroism measurement leading to conformational modification of the protein molecule. CONCLUSIONS： On the basis of such complementary results, it may be concluded that curcumin shows strong binding affinity for human serum albumin, probably at the hydrophobic cavities of the protein and at or around the tryptophan residue. Molecular Docking analysis of liSA and curcumin provided light on the number of binding sites at an atomic level, which were already determined at a molecular level in spectroscopic measurements. Our study unfolds the modes of interaction of curcumin with human serum albumin in the light of different biophysical techniques and molecular modeling analysis.

关键词： curcumin human serum albumin fluorescence quenching conformational change thermodynamic parameters

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