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Modification of structural and dielectric properties of polycrystalline Gd-doped BFO–PZO

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Journal of Advanced Dielectrics 2018年第5期8卷 1-21页

作者： Ambika Ray Banarji Behera Tanmoy Basuy Saumitra Vajandar Santosh Kumar Satpathy Pratibindhya Nayak Material Research Laboratory School of Physics Sambalpur UniversityJyoti Vihar BurlaOdisha 768019India Centre for Advanced 2D Materials National University of Singapore Singapore 117546Singapore Centre for Ion Beam Applications National University of Singapore Singapore 117542Singapore Department of Physics School of Applied Science Centurion University of Technology and Management BhubaneswarOdisha 752050India

(1-y)(BiFe_(1-x)GdxO_(3))–y(PbZrO3)composites(y=0:5),having four different Gd concentrations(x=0:05,0.1,0.15,and 0.2),were synthesized and their structural,dielectric,and ferroelectric properties have been studied using different characterization *** addition,to investigate the effect of ion implantation on the microstructure and dielectric properties,these composites were exposed to 2 MeV He+-*** of the structure,surface morphology and electrical properties of the samples before and after ion exposure were demonstrated using powder X-ray diffraction(XRD),scanning electron microscopy(SEM)technique,and LCR *** compositional analysis was carried out using energy dispersive X-ray spectrometry(EDS).XRD results demonstrated a decrease in the intensity profile of the dominant peak by a factor of 6 showing a degradation of the ***–Hall(WH)plots reveal reduction in the grain size after irradiation along with an increase in strain and dislocation density.A decrease in the dielectric constant and loss has been recorded after ion beam exposure with reduction in ac conductivity *** contribution of grain and grain boundary effect in conduction mechanism has been addressed using Nyquist *** the samples demonstrate a lossy ferroelectric loop which shows a clear modification upon *** role of structural defects modifying the physical properties of the composite materials is discussed in this work.

关键词： Ion beam irradiation defects dielectric properties ferroelectricity.

Fe掺杂ZrO_2催化剂上苯酚气相甲基化（英文）

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Chinese Journal of Catalysis 2016年第11期37卷 1991-1996页

作者： Celia F.Braganza A.V.Salker 果阿大学化学系

采用共沉淀法制备了Fe掺杂的ZrO_2样品,并采用X射线衍射、N_2吸附-脱附、紫外漫反射光谱、扫描电镜-电子能谱、氨程序升温脱附、X射线光电子能谱和原位红外光谱进行了表征.结果表明,Fe进入ZrO_2晶格中有效稳定了其晶相结构为单一的四方... 详细信息

采用共沉淀法制备了Fe掺杂的ZrO_2样品,并采用X射线衍射、N_2吸附-脱附、紫外漫反射光谱、扫描电镜-电子能谱、氨程序升温脱附、X射线光电子能谱和原位红外光谱进行了表征.结果表明,Fe进入ZrO_2晶格中有效稳定了其晶相结构为单一的四方相.这些样品可很好地催化苯酚气相甲基化反应,其催化活性取决于Fe含量,并与样品中L酸有关.

关键词：氧化锆铁掺杂甲基化苯酚二甲苯酚

In vitro biofilm forming capacity on abiotic contact surfaces by outbreak-associated Vibrio harveyi strains

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Journal of Coastal Life Medicine 2014年第2期2卷 132-140页

作者： Pallaval Veera Bramha Chari Kuchipudi Viswadeepika Bottu Anand Kumar Department of Biotechnology Krishna UniversityMachilipatnam-521001Andhra PradeshIndia

Objective:To evaluate the in vitro biofilm forming capacity on abiotic food contact surfaces by Vibrio harveyi(***)***:Thirty six Gram-negative *** strains were isolated from various street vended seafood outlets in a food processing line and evaluated for their ability to produce mucoid biofilms on food contact surfaces using a microplate *** characterization of mucoid biofilm producing *** strains were screened on Congo red agar,thiosulfate-citrate-bile salts-sucrose agar and tryptic soy agar,***:Only five *** strains(14%)were mucoid biofilm producers characterized by formation of black colonies,whereas the remaining 31 strains(86%)were not capable of producing biofilm characterized by formation of red colonies or pinkish-red colonies with darkening at the *** morphological,physiological and biochemical characteristics of these isolates were studied using standard *** identification was confirmed by polymerase chain reaction targeted to species-specific polymerase chain reaction primers VH-1 and VH-2 corresponding to variable regions of *** 16S rRNA *** the biofilm-forming strains showed resistance to at least three antimicrobial compounds *** strains isolated from various seafood were able to form biofilms of different capacity,and the strains VB267,VB238 and VB166 isolated from cat fish,shrimp and eel fish exhibited significantly greater biofilm forming ability compared to other ***:It can be concluded from the present study that the strain VB166 was able to better attach and form subsequent biofilms on glass and stainless steel compared to high density *** properties allow these bacteria to survive,proliferate and persist in street vended seafood outlets.

关键词： Mucoid biofilm Congo red agar Vibrio harveyi Polymerase chain reaction High density polyethylene

Ethnomedicinal plants used in the treatment of skin diseases in Hyderabad Karnataka region,Karnataka,India

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Asian Pacific Journal of Tropical Biomedicine 2013年第11期3卷 882-886页

作者： Shivakumar Singh Policepatel Vidyasagar Gunagambhire Manikrao Medicinal Plants and Microbiology Research Laboratory Department of Post Graduate Studies and Research in BotanyGulbarga University

Objective:To document traditional medicinal plants knowledge used in treating skin diseases at Hyderabad Karnataka ***:The information on the use of medicinal plants in the treatment of skin diseases was gathered from traditional herbal healers and other villagers through ***:A total of 60 plants species belonging to 57 genera and 34 families were found useful and herewith described them along with the method of drug preparation,mode of administration,probable dosage and duration of *** new findings on the traditional rural practices were ***:The present study revealed that the Hyderabad Kamataka rural people is primarily dependent on medicinal plants for treating skin diseases.

关键词： Ethno medicinal plants Hyderabad Karnataka Skin diseases Traditional knowledge

Post-fire soil nutrient dynamics in a tropical dry deciduous forest of Western Ghats,India

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Forest Ecosystems 2019年第1期6卷 67-75页

作者： Satyam Verma Dharmatma Singh Ajeet Kumar Singh Shanmuganathan Jayakumar Environmental Informatics and Spatial Modeling Lab Department of Ecology and Environmental Sciences School of Life Sciences Pondicherry University Landscape Level Planning and Management Wildlife Institute of India

Background: The effect of forest fire on soil is complex and relatively less understood than its above ground *** the effect of fire on forest soils can allow improving management of valuable forest ecosystems as adequate and proper information is very important for efficient management. We have studied the recovery of soil properties after fire, using a chronosequence approach(two, five and fifteen years after fire and control). Soil samples were collected from each plot of four fire patches(B0, B2, B5 & B15) from three different depths viz. 0–10(Top), 10–20(Middle), and 20–30 cm(Bottom).Results: Soil organic carbon was lower than unburned plots after the fire and could not recover to the level of unburned plot(B0) even in 15 years. Total N, available P, and extractable K were lower 2-years and 5-years after the fire but are higher than unburned plot after 15-years. Available nitrogen(NO_3^- and NH_4^+) remain unchanged or higher than B0 in burned patches. Soil pH, Bulk Density, Water Holding Capacity, and Electrical Conductivity was lower initially after the fire. Forest fires have affected soil properties considerably. The response of soil properties varied with years after fire and soil ***: Forest fires occur very frequently in the study area. Significant quantities of carbon and total nitrogen are lost to the atmosphere by burning of litter, duff, and soil OM. Because nitrogen is one of the most important soil nutrients, the recapture of N lost by volatilization during a fire must receive special attention. Long-term studies are required to better understand the recovery of soil nitrogen.

关键词： Soil properties Western Ghats Tropical dry deciduous Forest Forest fire Forest soils

Assessment of antimicrobial activity of c-type lysozyme from Indian shrimp Fenneropenaeus indicus

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Journal of Coastal Life Medicine 2014年第10期 757-761页

作者： Viswanathan Karthik Thomas Ancy Dharmaraj Ramkumar Narayanasamy Mathivanan Rangarajan Badri Narayanan Centre for Biotechnology Anna UniversityChennai 600025Tamil NaduIndia Biocontrol and Microbial Metabolites Lab Centre for Advanced Studies in BotanyUniversity of MadrasChennai-600025Tamil NaduIndia

Objective:To assess the multitudinal antimicrobial effects of recombinant lysozyme fromFenneropenaeus indicus(rFi-Lyz)in comparison with commercially available recombinant hen egg white lysozyme(rHEWL).Methods:Antimicrobial activity of the recombinant rFi-Lyz using several Gram positive,Gram negative bacteria and fungi in comparison with rHEWL has been ***-Lyz was expressed and purified using Ni2+affinity *** effect of rFi-Lyz in the growth of yeast Candida krusei,plant molds Rhizoctonia solani and Fusarium solani was assessed by well diffusion assay in petri plates with potato dextrose ***:rFi-Lyz exhibited high inhibitory activity on Gram positive bacteria such as Staphylococcus aureus and Bacillus *** various Gram negative bacteria testedKlebsiella pneumoniae exhibited the highest inhibition followed by Pseudomonas aeruginosa and Shigella ***-Lyz also exhibited significant inhibition on two marine pathogens Aeromonas veronii and Vibrio *** the various fungal strains tested,rFi-Lyz inhibited the growth of budding yeast Candida krusei *** the growth of two other plants fungus Rhizoctonia solani and Fusarium oxysporum were retarded by rFi-Lyz in the plate inhibition ***:rFi-Lyz exhibits a broad spectrum of antimicrobial activity like a natural antibiotic on various pathogenic bacteria and fungal strains.

关键词： Lysozyme Fenneropenaeus indicus Antimicrobial activity

phytochemical investigation and in vitro antioxidant activity of an indigenous medicinal plant Alpinia nigra ***

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Asian Pacific Journal of Tropical Biomedicine 2013年第11期3卷 871-876页

作者： Suprava Sahoo Goutam Ghosh Debajyoti Das Sanghamitra Nayak Centre of Biotechnology Siksha O Anusandhan University School of Pharmaceutical Sciences Siksha O Anusandhan University

Objective:To investigate antioxidant potential of methanol extract of Alpinia nigra ***:The study was done by using various in vitro methods such as 1,1-diphenyl-2-picrylhydrazyl(DPPH),2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)(ABTS),nitric oxide and hydrogen peroxide radical scavenging *** constituents,total phenolic content and total flavonoid content of the extract at different concentrations(10-500μg/mL)were ***:Alpinia nigra leaves showed high free radical scavenging activity as evidenced by the low IG_(50)values in DPPH(64.51μg/mL),in ABTS(28.32μg/mL),in nitric oxide(80.02μg/mL)and in H_2O_2(77.45μg/mL)scavenging *** the TPC and TFC of the extract were found to be 69.25 mg gallic acid equivalent per gram of extract and 78.84 mg quercetin equivalent per gram of extract ***:The results of present comprehensive analysis demonstrated that Alpinia nigra leaves possess high phenolic,flavonoid contents and potential antioxidant activity,and could be used as a viable source of natural antioxidants and might be exploited for functional foods and neutraceutical applications.

关键词： Alpinia nigra Phytochemical screening TPC TFC Antioxidant activity

Investigation on antimicrobial activity and phytochemical screening of Randia spinosa(Thunb.)*** Dillenia pentagyna Roxb.

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Journal of Coastal Life Medicine 2016年第11期4卷 879-883页

作者： Irulandi Kokkaiah Geetha Sethupandian Mehalingam Palanichamy Research Department of Botany V.H.N.Senthikumara Nadar College(an autonomous institution affiliated to Madurai Kamaraj UniversityMadurai)Virudhunagar 626001Tamil NaduIndia

Objective:To evaluate phytochemicals and antimicrobial activity of Randia spinosa(Thunb.)*** Dillenia pentagyna *** extracts against human pathogens such as Gram positive bacteria(Streptococcus faecalis,Bacillus subtilis and Staphyllococcus aureus),Gram negative bacteria(Escherichia coli,Klebsiella pneumoniae and Pseudomonas aeruginosa),and a fungus Candida ***:Antimicrobial activity of methanol,acetone and ethyl acetate extracts of the two plants against the human pathogens was investigated by agar well diffusion method,and qualitative phytochemical screening was conducted for the presence of phytoconstituents such as alkaloids,catechins,coumarins,flavonoids,phenols,quinones,saponins,steroids,tannins and ***:The qualitative phytochemical analysis showed the presence of diverse range of compounds like alkaloids,flavonoids,phenols,steroids,tannins,terpenoids and *** plants exhibited broad spectrum of antimicrobial activities against all the tested bacterial and fungal *** maximum zone of inhibition was observed in methanol extracts when compared with acetone and ethyl acetate *** present study demonstrated that the selected plants had promising effect on the bacterial and fungal ***:The phytochemicals in the plants may be potentially responsible for the antimicrobial efficacy of these medicinal plants.

关键词： Randia spinosa Dillenia pentagyna Antimicrobial activity Phytochemical analysis

Carcinoma of the stomach: A review of epidemiology, pathogenesis, molecular genetics and chemoprevention

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World Journal of Gastrointestinal Oncology 2012年第7期4卷 156-169页

作者： Siddavaram Nagini Department of Biochemistry and Biotechnology Faculty of Science Annamalai University Annamalainagar-608 002 Tamil Nadu India

Carcinoma of the stomach is still the second most common cause of cancer death worldwide, although the incidence and mortality have fallen dramatically over the last 50 years in many regions. The incidence of gastric cancer varies in different parts of the world and among various ethnic groups. Despite advances in diagnosis and treatment, the 5-year survival rate of stomach cancer is only 20 per cent. Stomach cancer can be classified into intestinal and diffuse types based on epidemiological and clinicopathological features. The etiology of gastric cancer is multifactorial and includes both dietary and nondietary factors. The major diet-related risk factors implicated in stomach cancer development include high content of nitrates and high salt intake. Accumulating evidence has implicated the role of Helicobacter pylori (H. pylori) infection in the pathogenesis of gastric cancer. The development of gastric cancer is a complex, multistep process involving multiple genetic and epigenetic alterations of oncogenes, tumor suppressor genes, DNA repair genes, cell cycle regulators, and signaling molecules. A plausible program for gastric cancer prevention involves intake of a balanced diet containing fruits and vegetables, improved sanitationand hygiene, screening and treatment of H. pylori infection, and follow-up of precancerous lesions. The fact that diet plays an important role in the etiology of gastric cancer offers scope for nutritional chemoprevention. Animal models have been extensively used to analyze the stepwise evolution of gastric carcinogenesis and to test dietary chemopreventive agents. Development of multitargeted preventive and therapeutic strategies for gastric cancer is a major challenge for the future.

关键词： Chemoprevention Diet Epidemiology Epigenetic changes Gastric cancer Genetic alterations Helicobacter pylori Risk factors