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Acta Metallurgica Sinica(English Letters) 2015年第11期28卷 1317-1325页

作者： Neena Bachan A.Asha W.Jothi Jeyarani D.arun kumar J.Merline Shyla Department of Physics Energy NanoTechnology Centre(ENTeC)Loyola Institute of Frontier Energy(LIFE)Loyola College Department of Physics Dhanalakshmi Srinivasan College of Engineering and Technology Department of Physics Shri Andal Alagar College of Engineering

The SiO2-Fe3O4 core-shell nanostructures were synthesized by sol-gel chemistry. The morphological features of the nanostructures were examined by field emission scanning electron microscopy which revealed the core-shell nature of the nanoparticles. X-ray diffraction studies evidenced the formation of SiO2-Fe3O4 core-shell nanostructures with high degree of homogeneity. The elemental composition of the SiO2-Fe3O4 core-shell nanostructures was determined by energy-dispersive X-ray spectroscopy analysis. Fourier transform infrared spectroscopy showed the Si-O-Fe stretching vibrations. On analysis of the optical properties with UV-Vis spectra and Tauc＇s plot, it was found that the band gap of SiO2-Fe3O4 core-shell nanostructures diminished to 1.5 eV. Investigation of the electrical properties of the core-shell nanostructures using field-dependent conductivity measurements presented a significant increase in photoconductivity as compared to those of its single components, thereby rendering them as promising candidates for application as photo- electrodes in dye-sensitized solar cells.

关键词： Nanostructures Sol-gel chemistry Optical properties X-ray diffraction Electricalproperties

Structural and photoluminescence studies on europium-doped lithium tetraborate(Eu:Li2B4O7)single crystal grown by microtube Czochralski(μT-Cz)technique

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Chinese Physics B 2016年第5期25卷 429-433页

作者： A kumaresh R arun kumar N Ravikumar U Madhusoodanan B S Panigrahi K Marimuthu M Anuradha GRD Centre for Materials Research PSG College of TechnologyCoimbatoreIndia Department of Physics PSG College of TechnologyCoimbatoreIndia Radiation Safety Division Indira Gandhi Centre for Atomic ResearchKalpakkamIndia Department of Physics Gandhigram Rural UniversityDindigulIndia PSG Institute of Advanced Studies CoimbatoreIndia

Rare earth europium（Eu（3＋））-doped lithium tetraborate（Eu：Li_2B_4O_7） crystal is grown from its stoichiometric melt by microtube Czochralski pulling technique（μT-Cz） for the first time. The grown crystals are subjected to powder x-ray diffraction（PXRD） analysis which reveals the tetragonal crystal structure of the crystals. UV–vis–NIR spectral analysis is carried out to study the optical characteristics of the grown crystals. The crystal is transparent in the entire visible region, and the lower cutoff is observed to be at 304 nm. The existence of BO_3 and BO_4 bonding structure and the molecular associations are analyzed by Fourier transform infrared（FTIR） spectroscopy. The results of excitation and emission-photoluminescence spectra of europium ion incorporated in lithium tetraborate（LTB） single crystal reveal that the observations of peaks at 258,297, and 318 nm in the excitation spectra and peaks at 579, 591, 597, 613, and 651 nm are observed in the emission *** chromaticity coordinates are calculated from the emission spectra, and the emission intensity of the grown crystal is characterized through a CIE 1931（Commission International d＇Eclairage） color chromaticity diagram.

关键词： crystal growth optical material growth from melt photoluminescence study

Expression analysis of reactive oxygen species detoxifying enzyme genes in Anopheles stephensi during Plasmodium berghei midgut invasion

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Asian Pacific Journal of Tropical Medicine 2014年第9期7卷 680-684页

作者： RK Chaitanya P Sridevi K Surendra kumar Babu S Mastan K arun kumar A Dutta-Gupta School of Life Sciences University of Hyderabad

Objective:To investigate the involvement of reactive oxygen species detoxification system in Anopheles stephensi during Plasmodium berghei midgut ***:Eight key reactive oxygen species metabolizing enzymes were cloned and characterized,and their expression was monitored in parasite-infected ***:Superoxide anion detoxifying superoxide dismutases(Fe/Mn SOD,Cu/Zn SOD 2,Cu/Zn SOD 3A,and Cu/Zn SOD 3B)depicted varied expression ***/Mn SOD expression declined,whereas Cu/Zn SOD expression was elevated in the infected ***,catalase and glutathione peroxidase showed lack of induction in expression during the Plasmodium berghei ***,expression of thioredoxin reductase increased in the infected mosquitoes,whereas gluthathione S-transferase levels decreased ***:Detoxification enzymes may play a role in modulating host immunity and parasite transmission.

关键词： Anophelesstephensi Detoxificationenzymes Geneexpression Malaria Oxidativestress Plasmodiumberghei Reactiveoxygenspecies

Structural and luminescence enhancement properties of Eu^(3+)/Ag nanocrystallites doped SiO_2-TiO_2 matrices

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Journal of Rare Earths 2013年第5期31卷 441-448页

作者： arun kumar K V Revathy K P Prathibha Vasudevan Sunil Thomas Biju P R Unnikrishnan N V School of Pure & Applied Physics Mahatma Gandhi University

We reported here the structural and optical characterisation of silver nanocrystallites/Eu3＋：SiO2-TiO2 matrices synthesised through sol-gel route. Structural characterisations were done by using energy dispersive spectroscopy （EDX）, X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, atomic force microscope （AFM） and transmission electron microscopy （TEM） measurements and optical characterisations were performed by absorption and emission spectroscopy. The TEM and XRD measurements confirmed the presence of nanocrystals. A broad absorption band was observed due to surface plasmon resonance of silver nanocrystals. The effect of silver nanocrystals on the emission spectrum of Eu3＋ doped SiO2-TiO2 matrices was discussed. An attempt was made to explain this fluorescence enhancement by invoking phenomena such as energy transfer, asymmetry ratio, surface plasmon, surface roughness, crystallinity and grain boundary. Our analysis, based on the experimental results, suggested that all the phenomena except crystallinity and grain boundary had favourable effects on fluorescence enhancement. We also estimated the relevant parameters associated with the phenomena that affected the fluorescence emission from the Eu3＋ ions in the matrix. It was seen that the theoretical estimate of fluorescence enhancement agreed well with the experimental estimate.

关键词： sol-gel luminescence SiO2-TiO2 silver nanoparticles rare earths

Antioxidant and antipyretic properties of methanolic extract of Amaranthus spinosus leaves

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Asian Pacific Journal of Tropical Medicine 2010年第9期3卷 702-706页

作者： Bagepalli Srinivas Ashok kumar Kuruba Lakshman Jayaveera KN Devangam Sheshadri Shekar Avalakondarayappa arun kumar Bachappa Manoj Department of Pharmacognosy Sri K.V.College of PharmacyChickballapurKarnatakaIndia Department of Pharmacognosy PES College of PharmacyBangaloreKarnatakaIndia Department of Chemistry Jawaharlal Nehru Technological University of College of EngineeringAnantapurAndhra PradeshIndia Department of Pharmacology Sri K.V.College of PharmacyChickballapurKarnatakaIndia

Objective:Methanolic extract of Amaranthus spinosus（***） leaves was screened for antioxidant and antipyretic ***:Antioxidant activity was measured by l,l-diphenyl-2-picryl-hydrazile（DPPH） free radical scavenging,superoxide anion radical scavenging,hydroxyl free radical scavenging,nitric oxide radical scavenging,2,2 -azinobis-3- ethylbenzothiazole-6-sulfonic acid（ABTS） radical scavenging assays and total phenolic content was also *** activity of methanolic extract of *** was measured by yeast induced pyrexia method at concentration of 200 and 400 mg/kg using paracetamol as standard ***:Methanolic extract of *** showed potent antioxidant *** IC50 value was（87.50±3.52）μg/mL,（98.80±1.40）μg/mL,（106.25±0.20）μg/mL,（88.70±0.62）μg/mL and（147.50±2.61）μg/mL for DPPH,superoxide,hydroxyl,nitric oxide and ABTS radical scavenging *** extract of A spinosus showed significant（P<0.01） antipyretic activity.

关键词： Amaranthus spinosus Antioxidant activity Antipyretic activity

Serum uric acid level in newly diagnosed essential hypertension in a Nepalese population:A hospital based cross sectional study

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Asian Pacific Journal of Tropical Biomedicine 2014年第1期4卷 59-64页

作者： Bibek Poudel Binod kumar Yadav arun kumar Bharat Jha Kanak Bahadur Raut Department of Biochemistry Manipal College of Medical Sciences(MCOMS)Manipal Teaching Hospital(MTH) Research Institute of Clinical Medicine Chonbuk National University Medical School and Hospital Department of Biochemistry Institute of MedicineTribhuvan University Teaching Hospital(Institute of MedicineTUTH) Department of Internal.Medicine Institute of MedicineTribhuvan University Teaching Hospital(Institute of MedicineTUTH)

Objective:To develop the missing link between hyperuricemia and ***:The study was conducted in Department of Biochemistry in collaboration with Nephrology Unit of Internal Medicine *** was defined according to blood pressure readings by definitions of the Seventh Report of the Joint National *** 205newly diagnosed and untreated essential hypertensive cases and age-sex matched nonnotensive controls were enrolled in the *** potential confounding factors of hyperuricemia and hypertension in both cases and controls were *** acid levels in all participants were ***:Renal function between newly diagnosed hypertensive cases and nonnotensive healthy controls were *** mean serum uric acid observed in newly diagnosed hypertensive cases and in nonnotensive healthy controls were(290.05±87.03)μmol/L and(245.24±09.38)μmol/L respectively.A total of 59(28.8%)participants of cases and 28(13.7%)participants of controls had hyperuricemia(odds ratio 2.555(95%CI:1.549-4.213),P<0.00l).Conclusions:The mean serum uric acid leveb and number of hyperuricemic subjects were found to be significantly higher in cases when compared to controls.

关键词： Newly diagnosed hypertension Serum uric acid Hyperuricemia Joint National Committee

Study of temporal and spectral characteristics of the X-ray emission from solar flares

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Research in Astronomy and Astrophysics 2018年第10期18卷 33-48页

作者： Veena Choithani Rajmal Jain arun K.Awasthi Geetanjali Singh Sneha Chaudhari Som kumar Sharma Dept.of Physics Sh.M.M.Patel Institute of Sciences&ResearchKadi Sarva VishwavidyalayaGandhinagar 382015India CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary SciencesUniversity ofScience and Technology of ChinaHefei 230026China Physical Research Laboratory NavrangpuraAhmedabad 380009India

Temporal and spectral characteristics of X-ray emission from 60 flares of intensity ≥C class observed by the Solar X-ray Spectrometer （SOXS） during 2003-2011 are presented. We analyze the X-ray emission observed in four and three energy bands by the Si and Cadmium-Zinc-Telluride （CZT） detectors, respectively. The number of peaks in the intensity profile of the flares varies between 1 and 3. We find moderate correlation （R ~=0.2） between the rise time and the peak flux of the first peak of the flare irrespective of energy band, which is indicative of its energy-independent nature. Moreover, the magnetic field complexity of the flaring region is found to be highly anti-correlated （R = 0.61） with the rise time of the flares while positively correlated （R = 0.28） with the peak flux of the flare. The time delay between the peak of the X-ray emission in a given energy band and that in 25-30keV decreases with increasing energy, suggesting conduction cooling is dominant in the lower energies. Analysis of 340 spectra from 14 flares reveals that the peak of differential emission measure （DEM） evolution is delayed by 60-360 s relative to that of the temperature, and this time delay is inversely proportional to the peak flux of the flare. We conclude that temporal and intensity characteristics of flares are dependent on energy as well as the magnetic field configuration of the active region.

关键词： Sun X-rays, gamma rays - Sun magnetic fields - Sun flares - Sun corona

Cynodon dactylon extract ameliorates cognitive functions and cerebellar oxidative stress in whole body irradiated mice

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Asian Pacific Journal of Tropical Biomedicine 2019年第7期9卷 278-283页

作者： Roopesh Poojary Nayanatara arun kumar Reshma kumarchandra Vinodini NA Bhagyalakshmi K Ganesh Sanjeev Department of Physiology Kasturba Medical CollegeMangaloreManipal Academy of Higher EducationManipalKarnatakaIndia Department of Biochemistry Kasturba Medical CollegeMangaloreManipal Academy of Higher EducationManipalKarnatakaIndia Microtron Centre Department of Studies in PhysicsMangalore UniversityMangalagangotriKarnatakaIndia

Objective: To explore the effect of hydroalcoholic extract of Cynodon dactylon on the whole body radiation-induced oxidative status of the cerebellum and cognitive impairments in mice. Methods: Swiss albino mice were randomly divided into the control group, radiation control group, low dose and high dose Cynodon dactylon extract treated groups and pre-treated with Cynodon dactylon extract before irradiation. Cynodon dactylon extract was administered for 7 d daily in low dose(0.25 g/kg) and high dose(1 g/kg). On day 7, mice were irradiated with a sublethal dose of 5 Gy gamma rays. Motor coordination was assessed by elevated rotarod test and spatial memory was studied by water maze test. Subsequently, biochemical markers(glutathione, lipid peroxidation and nitric oxide levels) in the cerebellum were evaluated. Results: The gamma irradiated group showed significant impairment in motor coordination and spatial memory compared to normal mice. Mice treated by Cynodon dactylon extract prior to gamma radiation showed good improvement in both paradigms compared to the radiation control group. Moreover, glutathione level was increased, while lipid peroxidation and nitric oxide levels were significantly reduced in mice receiving low dose and high dose of Cynodon dactylon extract compared to the radiation control group. Conclusions: The present study suggests the neuroprotective role of Cynodon dactylon against radiation-induced cognitive impairment and oxidative stress on the cerebellum of mice.

关键词： Cerebellum Radiation Cognition Cynodon dactylon Memory

Abdominal tuberculosis of the gastrointestinal tract: Revisited

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World Journal of Gastroenterology 2014年第40期20卷 14831-14840页

作者： Uma Debi Vasudevan Ravisankar Kaushal Kishor Prasad Saroj Kant Sinha arun kumar Sharma Division of GE Radiology Department of Superspeciality of Gastroenterology Postgraduate Institute of Medical Education and Research Chandigarh 160 012 India Department of Radiodiagnosis Postgraduate Institute of Medical Education and Research Chandigarh 160 012 India Division of GE Histopathology Department of Superspeciality of Gastroenterology Postgraduate Institute of Medical Education and Research Chandigarh 160 012 India Department of Superspeciality of Gastroenterology Postgraduate Institute of Medical Education and Research Chandigarh 160 012 India Division of GE Virology Department of Superspeciality of Gastroenterology Postgraduate Institute of Medical Education and Research Chandigarh 160 012 India

Abdominal tuberculosis is an increasingly common disease that poses diagnostic challenge,as the nonspecific features of the disease which may lead to diagnostic delays and development of *** condition is regarded as a great mimicker of other abdominal pathology.A high index of suspicion is an important factor in early *** involvement mayoccur in the gastrointestinal tract,peritoneum,lymphnodes or solid *** investigative methods have been used to aid in the diagnosis of abdominal *** diagnosis and initiation of antituberculous therapy and surgical treatment are essential to prevent morbidity and *** of the patients respond very well to standard antitubercular therapy and surgery is required only in a minority of *** plays an important role in diagnosis of abdominal tuberculosis because early recognition of this condition is *** reviewed our experience with the findings on various imaging modalities for diagnosis of this potentially treatable disease.

关键词： Tuberculosis Abdomen Extrapulmonary Gastrointestinal tract

Effect of Exercise on NAFLD and Its Risk Factors:Comparison of Moderate versus Low Intensity Exercise

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Journal of Clinical and Translational Hepatology 2020年第2期8卷 120-126页

作者： Preetam Nath Manas kumar Panigrahi Manoj kumar Sahu Jimmy Narayan Ranjan kumar Sahoo Ananya Apurba Patra Satyaswarup Jena arun kumar Patnaik Anjan Jena Shivaram Prasad Singh Department of Gastroenterology&Hepatology Kalinga Institute of Medical SciencesBhubaneswarOdishaIndia Department of Gastroenterology All India Institute of Medical SciencesBhubaneswarOdishaIndia Department of Gastroenterology IMS and SUM HospitalBhubaneswarOdishaIndia Department of Radiodiagnosis&Imaging Kalinga Institute of Medical SciencesBhubaneswarOdishaIndia Department of Radiology IMS and SUM HospitalBhubaneswarOdishaIndia Dispensary Biju Patnaik State Police AcademyBhubaneswarOdishaIndia Department of Gastroenterology S.C.B.Medical College753007 CuttackOdishaIndia

Background and Aims: Lifestyle (exercise and dietary) modification is the mainstay of treatment for non-alcoholic fatty liver disease (NAFLD). However, there is paucity of data on effect of intensity of exercise in management of NAFLD, and we aimed to study the effect of variable intensities of exercise on NAFLD. Methods: The study was performed in the Department of Gastroenterology of the SCB Medical Col-lege, Cuttack and the Biju Patnaik State Police Academy, Bhu-baneswar. The subjects were police trainees [18 in a moderate intensity exercise group (MIG) and 19 in a low in-tensity exercise group (LIG)] recruited for a 6-month physical training course (261.8 Kcalorie, 3.6 metabolic equivalent in MIG and 153.6 Kcalorie, 2.1 metabolic equivalent in LIG). NAFLD was diagnosed by ultrasonography, with exclusion of all secondary causes of steatosis. All participants were eval-uated by anthropometry (weight, height, body mass index (BMI), waist circumference), assessed for blood pressure and biochemical parameters (blood glucose, liver function test, lipid profile, serum insulin), and subjected to transabdo-minal ultrasonography before and after 6 months of physical training, and the results were compared. Results: Both the groups had similar BMI, fasting plasma glucose, AST, gamma-glutamyl transpeptidase, insulin, and homeostatic model as-sessment-insulin resistance (known as HOMA-IR) (p>0.05). However, subjects in the LIG were older and had lower alanine transaminase, higher triglycerides and lower high-density lip-oproteins than MIG subjects. There was a significant reduc-tion in BMI (27.0±2.1 to 26.8±2.0;p=0.001), fasting blood glucose (106.7±21.6 to 85.8±19.0;p<0.001), serum trigly-cerides (167.5±56.7 to 124.6±63.5;p=0.017), total choles-terol (216.8±29.2 to 196.7±26.6;p=0.037), low-density lipoprotein cholesterol (134.6±21.4 to 130.5±21.9;p=0.010), serum aspartate transaminase (39.3±32.2 to 30.9±11.4;p<0.001), serum alanine transaminase (56.6 ±28.7 to 33.0±11.3;p<0.

关键词： Exercise NAFLD Intensity Physical activity