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Comparative study on glutathione transferases of rat brain and testis under the stress of phenobarbitol and β-methylcholanthrene

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第8期6卷 759-769页

作者： THYAGARAJU k HEMAVATHI B VASUNDHARA k RAO A.D DEVI k.N Department of Biochemistry Sri Venkateswara UniversityTirupati 517 502 AP IndiaDepartment of Biochemistry Sri Venkateswara UniversityTirupati 517 502 AP IndiaDepartment of Biochemistry Sri Venkateswara UniversityTirupati 517 502 AP IndiaDepartment of Biochemistry Sri Venkateswara UniversityTirupati 517 502 AP IndiaDepartment of Biochemistry Sri Venkateswara UniversityTirupati 517 502 AP India

A comparative study was made on the tissue specific expression of glutathione transferases (GST) in brain and testis after exposure of rat to phenobarbitol (PB) and β-methylcholanthrene (MC). Glutathione transferases, a family of multifunctional proteins are involved in intracellular transport processes and in detoxication of electrophilic xenobiotics by catalyzing reactions such as conjugation, isomerization, reduction and thiolysis. On purification, the yield of GST proteins by affinity chromatography was 39% in testis and 32% in brain. The affinity purified testis GSTs were resolved by chromatofocusing into six anionic and four cationic isozymes, and in brain glutathione transferases were resolved into four anionic and three cationic isozymes, suggesting the presence of multiple isozymes with Yc, Yb, Yβ and Yδ in both of them. In testis and brain, these isozymes at identical pI values showed variable functions with a battery of substrates and the cationic isozymes of brain and testis showed identical properties in CHP (cumene hydroperoxide) at pH values of above 7.0. Substrate specificity studies and immunoblot analysis of testis and brain proteins revealed that they play a predominant role in the detoxication of phenobarbitol or β-methylcholanthrene. Expression of the isozymes in testis and brain on exposure to PB and MC indicated elevated subunit variation. In both testis and brain, Yδ of π class was expressed on PB treatment and Yc of α class and Yβ of μ class was expressed in MC treated testis and only Yc was predominantly expressed in MC treated brain. Thus these subunits expression is considered as markers for carcinogenesis and specific to chemical toxicity under phenobarbitol and β-methylcholanthrene stress.

关键词： Glutathione transferases Testis Brain Phenobarbitol β-Methylcholanthrene

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Deformation heterogeneity of Ti under cryogenic channel-die compression

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Progress in Natural Science:Materials International 2011年第4期21卷 277-285页

作者： k.H.kIM S.k.HWANG Division of Materials Science and Engineering Inha University

Commercial purity Ti was subjected to channel die compression in liquid nitrogen for the purpose of studying its deformation characteristics from the viewpoint of the grain refinement induced by severe plastic *** specimens showed microstructural heterogeneity in that the initial blocky grains of about 50 urn in size turned into a mixture of the easily deforming soft grains and the hard grains revealing local concentration of dislocations and deformation *** electron back scattered diffraction analysis the in-grain misorientation-axis distribution was studied,from which it was found that the deformation heterogeneity resulted from the anisotropy of individual grains with respect to the compression die:while the soft grains were those oriented favorably for the prismslip,the hard ones were oriented for non-prism slips and deformation *** difference in the response of individual grains,therefore,led to a remarkable effect of the crystal texture of specimens on the maximum strain that can be imposed on specimens without *** on the present results,a way to achieve expedient grain refinement through the cryogenic plane-strain compression was suggested.

关键词： titanium cryogenic deformation texture microstructure

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Dissipative dynamics of an entangled three-qubit system via non-Hermitian Hamiltonian: Its correspondence with Markovian and non-Markovian regimes

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Chinese Physics B 2021年第3期30卷 283-292页

作者： M Rastegarzadeh M k Tavassoly Laser and Optics Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran

We investigate an entangled three-qubit system in which only one of the qubits experiences the decoherence effect by considering a non-Hermitian Hamiltonian,while the other two qubits are isolated,i.e.,do not interact with environment,***,the time evolution of the density matrix(for the pure as well as mixed initial density matrix)and the corresponding reduced density matrices are obtained,by which we are able to utilize the dissipative non-Hermitian Hamiltonian model with Markovian and non-Markovian regimes via adjusting the strange of the non-Hermitian term of the total Hamiltonian of the under-considered system.

关键词： non-Hermitian Hamiltonian entanglement concurrence measure Markovian and non-Markovian regimes

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The promise of γδ T cells and the γδ T cell receptor for cancer immunotherapy

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Cellular & Molecular Immunology 2015年第6期12卷 656-668页

作者： Mateusz Legut David k Cole Andrew k Sewell Division of Infection and Immunity and Svstems Immunitv Universitv Research Institute. Cardiff University School of Medicine Cardiff UK

γδ T cells form an important part of adaptive immune responses against infections and malignant transformation. The molecular targets of humanγδT cell receptors （TCRs） remain largely unknown, but recent studies have confirmed the recognition of phosphorylated prenyl metabolites, lipids in complex with CD1 molecules and markers of cellular stress. All of these molecules are upregulated on various cancer types, highlighting the potential importance of the γδ T cell compartment in cancer immunosurveiliance and paving the way for the use of γδTCRs in cancer therapy. Ligand recognition by the γδ TCR often requires accessorylco-stimulatory stress molecules on both T cells and target cells; this cellular stress context therefore provides a failsafe against harmful self-reactivity. Unlike αβ T cells, γδ T cells recognise their targets irrespective of HLA haplotype and therefore offer exciting possibilities for off-the-shelf, pan-population cancer immunotherapies. Here, we present a review of known ligands of human γδ T cells and discuss the promise of harnessing these cells for cancer treatment.

关键词： cancer γδ T cells immunotherapy phosphoantigens T cell receptor

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Surveillance for gastrointestinal malignancies

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World Journal of Gastroenterology 2012年第33期18卷 4507-4516页

作者： Ashish k Tiwari Heather S Laird-Fick Ramesh k Wali Hemant k Roy Department of Internal Medicine Michigan State University East Lansing MI 48824 United States Department of Internal Medicine North Shore University Health System Evanston IL 60021 United States

Gastrointestinal (GI) malignancies are notorious for frequently progressing to advanced stages even in the absence of serious symptoms, thus leading to delayed diagnoses and dismal prognoses. Secondary prevention of GI malignancies through early detection and treatment of cancer-precursor/premalignant lesions, therefore, is recognized as an effective cancer prevention strategy. In order to efficiently detect these lesions, systemic application of screening tests (surveillance) is needed. However, most of the currently used non-invasive screening tests for GI malignancies (for example, serum markers such as alpha-fetoprotein for hepatocellular carcinoma, and fecal occult blood test, for colon cancer) are only modestly effective necessitating the use of highly invasive endoscopy-based procedures, such as esophagogastroduodenoscopy and colonoscopy for screening purposes. Even for hepatocellular carcinoma where non-invasive imaging (ultrasonography) has become a standard screening tool, the need for repeated liver biopsies of suspicious liver nodules for histopathological confirmation can't be avoided. The invasive nature and high-cost associated with these screening tools hinders implementation of GI cancer screening programs. Moreover, only a small fraction of general population is truly predisposed to developing GI malignancies, and indeed needs surveillance. To spare the average-risk individuals from superfluous invasive procedures and achieve an economically viable model of cancer prevention, it's important to identify cohorts in general population that are at substantially high risk of developing GI malignancies (riskstratification), and select suitable screening tests for surveillance in these cohorts. We herein provide a brief overview of such high-risk cohorts for different GI malignancies, and the screening strategies that have commonly been employed for surveillance purpose in them.

关键词： Gastrointestinal malignancies Surveillance Screening Biomarkers Cancer prevention

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Identification of strategy parameters for particle swarm optimizer through Taguchi method

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第12期7卷 1989-1994页

作者： kHOSLA Arun kUMAR Shakti AGGARWAL k.k. Department of Electronics and Communication Engineering National Institute of Technology Jalandhar 144011 India Centre for Advanced Technology Haryana Engineering College Jagadhari 135003 India Vice Chancellor GGS Indraprastha University Delhi 110006 India

Particle swarm optimization （PSO）, like other evolutionary algorithms is a population-based stochastic algorithm inspired from the metaphor of social interaction in birds, insects, wasps, etc. It has been used for finding promising solutions in complex search space through the interaction of particles in a swarm. It is a well recognized fact that the performance of evolutionary algorithms to a great extent depends on the choice of appropriate strategy/operating parameters like population size, crossover rate, mutation rate, crossover operator, etc. Generally, these parameters are selected through hit and trial process, which is very unsystematic and requires rigorous experimentation. This paper proposes a systematic based on Taguchi method reasoning scheme for rapidly identifying the strategy parameters for the PSO algorithm. The Taguchi method is a robust design approach using fractional factorial design to study a large number of parameters with small number of experiments. Computer simulations have been performed on two benchmark functionsiRosenbrock function and Griewank functionito validate the approach.

关键词： Strategy parameters Particle swarm optimization (PSO) Taguchi method ANOVA

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Modelling of electronegative collisional warm plasma for plasma-surface interaction process

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Plasma Science and Technology 2021年第4期23卷 48-54页

作者： Rajat DHAWAN Hitendra k MALIk Plasma Science and Technology Laboratory Department of PhysicsIndian Institute of Technology DelhiNew Delhi—110016India

An electronegative collisional plasma having warm and massive positive ions,non-extensive distributed electrons and Boltzmann distributed negative ions is modelled for the plasma-surface interaction process that is used for the surface *** the sheath formation is evaluated through the Bohm’s criterion,which is found to be modified,and the variation of the sheath thickness and profiles of the density of plasma species and the net space charge density in the sheath region in addition to the electric *** effect of ion temperature,nonextensivity and collisional parameter is examined in greater detail considering the collisional cross-section to obey power-law dependency on the positive ion *** positive ions are found to enter in the sheath region at lower velocities in the collisional plasma compared to the case of collision-less plasma;this velocity sees minuscule reduction with increasing *** increasing ion temperature and collisional parameter lead to the formation of sheath with smaller thickness.

关键词： electronegative sheath ion temperature non-extensivity sheath thickness power-law dependency collisions

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Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

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Asian Journal of Andrology 2000年第2期2卷 103-109页

作者： Nirmal k Lohiya Lalit k kothari B Manivannan Pradyumna k Mishra Neelam Pathak Reproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India Reproductive Medicine Clinic 50 Gem Enclave Malviya Nagar Jaipur IndiaReproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India Reproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India Reproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India

Aim: To examine if the seed extracts of Carica papaya, which showed anfispermatogenic/sperm immobilizationproperties in animal models, could cause human sperm immobilization in vitro. Methods: Chloroform extract, ben-zene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolatedcompounds from the sub-fractions i. e., ECP 1 & 2 and MCP 1 & 2, of the seeds of Carica papaya were used at con-centrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and ev-ery 5 minutes thereafter for 30 minutes. Results: There were dose-dependent spermicidal effects showing an instantfall in the sperm motility to less than 20% at 2% concentration. Isolated compounds ECP 1 & 2 were more effective in-ducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motilitywas observed within 20-25 rain at all concentrations of all products. Scanning and transmission electron microscopyrevealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability testand the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were *** effects were spermicidal but not spermiostatic as revealed by the sperm revival test. Conclusion: The results re-veal spermicidal activity in vitro of the seed extracts of Carica papaya.

关键词： human sperm sperm immobilization spermicidal agents Carica papaya

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SYNTHESIS AND CHARACTERIZATION OF HYBRID PROTON CONDUCTING MEMBRANES OF POLY(VINYL ALCOHOL) AND PHOSPHOMOLYBDIC ACID

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Chinese Journal of Polymer Science 2006年第5期24卷 449-456页

作者： Arfat Anis A.k. Banthia S. Mondal A.k. Thakur Materials Science Centre Indian Institute of TechnologyKharagpur 721302India Department of Physics & Meteorology Indian Institute of TechnologyKharagpur 721302India

Hybrid proton conducting membranes of poly（vinyl alcohol）（PVA） and phosphomolybdic acid （PMA） were prepared by solution casting method. The effect of PMA doping and PVA crosslinking density on the membrane properties and proton conductivity were investigated. The crosslinking reaction between the hydroxyl group of PVA and the aldehyde group of glutaraldehyde （GA） was characterized by IR spectroscopy. Proton conductivity of the membranes increases with an increase in concentration of the doped PMA and also with an increase in crosslinking density of the membranes. Proton conductivity results indicate that a significant amount of PMA was maintained in the membranes even after several hours of immersion in water. A maximum conductivity of 0.0101 S cm^-1 was obtained for the membrane with 33.3 wt% PMA and crosslinking density of 5.825 mol%. X-ray diffraction studies were carried out to investigate the influence of PMA doping and crosslinking density on the nature of the membranes. These properties make them very good candidates for polymer electrolyte membranes for direct methanol fuel cell application.

关键词： Polymer electrolyte membranes Proton conductor Phosphomolybdic acid Crosslinked PVA membranes.

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Student Behavior Modeling for an E-Learning System Offering Personalized Learning Experiences

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Computer Systems Science & Engineering 2022年第3期40卷 1127-1144页

作者： k.Abhirami M.k.kavitha Devi Department of Computer Science and Engineering Kings College of EngineeringPudukkottai613303India Department of Computer Science and Engineering Thiagarajar College of EngineeringMadurai625015India

With the advent of computing and communication technologies,it has become possible for a learner to expand his or her knowledge irrespective of the place and ***-based learning promotes active and independent *** scale e-learning platforms revolutionized the concept of studying and it also paved the way for innovative and effective teaching-learning *** digital learning improves the quality of teaching and also promotes educational ***,the challenges in e-learning platforms include dissimilarities in learner’s ability and needs,lack of student motivation towards learning activities and provision for adaptive learning *** quality of learning can be enhanced by analyzing the online learner’s behavioral characteristics and their application of intelligent instructional *** is not possible to identify the difficulties faced during the process through evaluation after the completion of e-learning *** is thus essential for an e-learning system to include component offering adaptive control of learning and maintain user’s interest *** this research work,a framework is proposed to analyze the behavior of online learners and motivate the students towards the learning process accordingly so as to increase the rate of learner’s objective *** to the demands of e-learner,an intelligent model is presented in this study for e-learning system that apply supervised machine learning *** adaptive e-learning system suits every category of learner,improves the learner’s performance and paves way for offering personalized learning experiences.

关键词： Learner behavior modeling e-learning intelligent learning system machine learning algorithm

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