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Co-Doped ZnO Nanoparticles:Structural,Morphological,Optical,Magnetic and Antibacterial Studies

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Journal of Materials Science & Technology 2014年第11期30卷 1108-1117页

作者： N.Mohamed Basith J.Judith Vijaya l.john kennedy M.Bououdina S.Jenefar V.Kaviyarasan Catalysis & Nanomaterials Research laboratory Department of ChemistryLoyola College (Autonomous) P.G.& Research Department of Chemistry The New College (Autonomous) Materials Division School of Advanced SciencesVellore Institute of Technology (VIT) UniversityChennai Campus Nanotechnology Centre University of BahrainPO Box 32038Bahrain Department of Physics College of ScienceUniversity of BahrainPO Box 32038Bahrain Centre for Advanced Studies in Botany University of Madras

Un-doped and Co-doped ZnO nanoparticles （NPs） with different weight ratios （0.5, 1.0, 1.5, and 2.0 wt% of Co） were synthesized by a facile and rapid microwave-assisted combustion method using urea as a fuel. The prepared NPs were characterized by X-ray diffraction （XRD）, high resolution scanning electron microscopy （HR-SEM）, energy dispersive X-ray analysis （EDX）, diffuse reflectance spectroscopy （DRS）, photoluminescence （Pl） spectroscopy and vibrating sample magnetometry （VSM）. XRD patterns refined by the Rietveld method indicated that Co-doped ZnO had a single pure phase with wurtzite structure suggesting that Co^2＋ ions would occupy Zn^2＋ ionic sites within the ZnO crystal lattice. Interestingly, the morphology was found to convert substantially from grains to nanoparticles with close-packed periodic array of hexagonal-like shape and then into randomly distributed spherical NPs with the variation of Co-content. The optical band gap estimated using DRS was found to be red-shifted from 3.22 eV for the un-doped ZnO NPs then decrease up to 2.88 eV with increasing Co-content. Pl spectra showed a strong green emission band thus confirming the formation of pure single ZnO phase. Magnetic studies showed that Co-doped ZnO NPs exhibited room temperature ferromagnetism （RTFM） and that the saturation magnetization attained a maximum value of 2.203 × 10^-3 emu/g for the highest Co-content. The antibacterial studies performed against a set of bacterial strains showed that the 2.0 wt% Co-doped ZnO NPs possessed a greater antibacterial effect.

关键词： Nanoparticles Optical properties Ferromagnetism Antibacterial activity

Catalytic applications of nano β-PbO in Paal-Knorr reaction

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Chinese Chemical letters 2011年第8期22卷 891-894页

作者： Sk.Khadeer Pasha V.S.V.Satyanarayana A.Sivakumar K.Chidambaram l.john kennedy Physics Division School of Advanced SciencesVIT UniversityVellore 632014India Chemistry Division School of Advanced SciencesVIT UniversityVellore 632014India

Several 2,5-dimethyl-N-substituted pyrroles were prepared by the condensation of different substituted anilines with 2,5- hexanedione using nano lead oxide as an efficient and recyclable *** the synthesized compounds are confirmed through IR, ~1H NMR,^（13）C NMR and mass spectral *** lead oxide β-PbO（P85） was prepared by dissolving lead acetate dihydrate in 1- propanol at a pH 9.0 under stirring at 85℃.The structural study and surface morphology of the lead oxide（PbO） were characterized using X-ray diffraction（XRD）,Scanning electron microscopy（SEM） and the functional groups of the PbO sample were investigated using infrared spectrophotometer.

关键词： 2 5-Dimethyl-N-substituted pyrroles Nano β-PbO Spectral data Catalyst characterization

氧化锌-氧化铜纳米复合物可见光诱导光催化降解2,4-二氯酚性能（英文）

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催化学报 2015年第8期36卷 1263-1272页

作者： E.D.Sherly J.Judith Vijaya l.john kennedy Catalysis and Nanomaterials Research laboratory Department of ChemistryLoyola College Materials Division School of Advanced SciencesVellore Institute of Technology (VIT) UniversityChennai Campus

Nanostructured ZnO and CuO, and coupled oxides, i.e., ZnCu, Zn2Cu, and ZnCu2, with ZnO:CuO molar ratios of 1:1, 2:1, and 1:2, respectively, were successfully prepared through a simple, one-step, microwave-assisted urea–nitrate combustion synthesis, without the use of organic solvents or surfactants. The prepared samples were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, Fourier-transform infrared spectroscopy, diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The optical absorption of Zn O extended into the visible region after CuO loading. The photocatalytic activities of ZnO, CuO, and the coupled oxides were evaluated based on photodegradation of 2,4-dichlorophenol under visible-light irradiation. The coupled metal oxide Zn2Cu showed the best photocatalytic activity; this was mainly attributed to the extended photoresponsive range and the increased charge separation rate in the nanocomposite. The photocatalytic degradation process obeyed pseudo-first-order kinetics. The results suggest that the coupled metal oxide Zn2Cu has potential applications as an efficient catalytic material with high efficiency and recyclability for the photocatalytic degradation of organic pollutants in aqueous solution under visible-light irradiation.

关键词：光催化降解效率纳米复合材料光催化性能对氯酚光诱导 X-射线光电子能谱傅里叶变换红外光谱纳米ZnO

微波合成Zr-AC,Ni-AC和Zn-AC光催化降解印染废水(英文)

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Transactions of Nonferrous Metals Society of China 2015年第12期25卷 4216-4225页

作者： P.SURESH J.JUDITH VIJAYA l.john kennedy Catalysis and Nanomaterials Research laboratory Department of ChemistryLoyola College Materials Division School of Advanced Sciences Vellore Institute of Technology University

采用微波照射法成功制备新型氧化锆、氧化镍和氧化锌负载活性炭纳米颗粒。采用XRD、HR-SEM和BET对合成纳米颗粒进行表征。利用UV-Vis漫反射光谱法研究Zr-AC、Ni-AC和Zn-AC复合材料的光学性能。验证了紫外光照射下印染废水的光催化效率... 详细信息

采用微波照射法成功制备新型氧化锆、氧化镍和氧化锌负载活性炭纳米颗粒。采用XRD、HR-SEM和BET对合成纳米颗粒进行表征。利用UV-Vis漫反射光谱法研究Zr-AC、Ni-AC和Zn-AC复合材料的光学性能。验证了紫外光照射下印染废水的光催化效率。每隔一定时间观察印染废水的化学需氧量,以计算化学需氧量的去除率。结果表明,Zn-AC复合材料具有明显的光催化性,这归因于紫外光区域吸光度的增大、染料分子的有效吸附能力、辅助电荷转移和电子-空穴对抑制重组。利用Zn-AC复合材料降解印染废水可以得到最大的降解率(82%化学需氧量去除率)。在Zn-AC复合材料表面设计一个可能实现的协同机制。Zn-AC复合材料重复使用5次后,其催化活性无明显降低。

关键词：纳米结构半导体印染废水光学性能催化降解

经Opuntia dilenii haw植物提取液绿色合成制备的纳米铝酸锌的催化性质(英文)

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催化学报 2013年第10期34卷 1951-1958页

作者： C.Ragupathi J.Judith Vijaya S.Narayanan l.john kennedy Seeram Ramakrishna Catalysis and Nanomaterials Research laboratory Department of ChemistryLoyola College Materials Division School of Advanced SciencesVellore Institute of Technology University Centre for Nanofibres and Nanotechnology National University of Singapore

Various nanosized zinc aluminate(ZnAl2O4) samples were prepared by a conventional and a mi- crowave method both with and without using Opuntia dilenii haw plant extract,and were charac- terized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),high resolution scanning electron microscopy(HRSEM),energy dispersion scanning(EDX),temperature dependent conductance measurements, thermoelectric power measurements, ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy,and photoluminescence *** formation of a pure ZnAl2O4 phase was confirmed by XRD and FT-IR.A change in morphology from nanosized plates to nanosized sheets with,respectively,the conventional and microwave heating methods was clearly shown by ***-Vis diffusion reflectance spectroscopy measured the band gaps of ZnAl2O4 nanosized plates and nanosized sheets as 3.5 and 3.9 eV,*** synthesized ZnAl2O4 was single crystalline and has three photoluminescence emissions at 482,528,and 540 ***2O4 nanosized sheets prepared by the microwave method showed higher catalytic activity for the oxida- tion of benzyl alcohol(85% conversion) than ZnAl2O4 nanosized plates prepared by the convention- al method(60% conversion).

关键词： Green synthesis Zinc aluminate Spinel Microwave Optical property

Triton X-100辅助合成多级孔道结构ZSM-5沸石催化剂(英文)

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催化学报 2014年第11期35卷 1892-1899页

作者： S.Narayanan J.Judith Vijaya S.Sivasanker Sihai Yang l.john kennedy Catalysis & Nanomaterials Research laboratory Department of Chemistry Loyola College (Autonomous) National Centre for Catalysis Research Indian Institute of Technology School of Chemistry University of Nottingham University Park Materials Division School of Advanced Sciences Vellore Institute of Technology (VIT) University

ZSM-5 zeolite with a hexagonal cubic morphology was synthesized by a hydrothermal method using Triton X-100, a nonionic surfactant. The samples prepared with and without the surfactant were characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy, N2 adsorption, high resolution transmission electron microscopy(TEM), high resolution scanning electron mi-croscopy, energy dispersive X-ray analysis, and NH3 temperature-programmed desorption. The XRD patterns confirmed the formation of a pure ZSM-5 crystalline phase without secondary phases. TEM images revealed that the hexagonal cubes were made of peanut-shaped nanoparticles with *** catalytic activity of the zeolite samples was evaluated using the selective oxidation of benzyl alcohol with tertiary-butyl hydrogen peroxide as the oxidant at 90 °C. The surfactant-assisted prep-aration yielded a zeolite that gave a higher conversion than the one prepared in the absence of the surfactant. The catalyst was retrieved and reused four times without significant loss in activity and selectivity.

关键词： ZSM-5催化剂 Triton 水热法合成 X-100 非离子表面活性剂 ZSM-5沸石高分辨透射电子显微镜傅立叶变换红外光谱

快速微波燃烧法制备的Cu-Ni合金纳米粒子结构和磁性能(英文)

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Transactions of Nonferrous Metals Society of China 2014年第5期24卷 1467-1473页

作者： J.ARUl MARY A.MANIKANDAN l.john kennedy M.BOUOUDINA R.SUNDARAM J.JUDITH VIJAYA Catalysis and Nanomaterials Research laboratory Department of Chemistry Loyola College Materials Division School of Advanced Sciences Vellore Institute of Technology (VIT) UniversityChennai Campus Department of Physics College of Science University of Bahrain Nanotechnology Centre University of Bahrain Department of Chemistry Presidency College

采用微波燃烧法制备Cu2＋和Ni2＋摩尔比分别为3∶7,4∶6,5∶5,6∶4和7∶3的Cu-Ni合金纳米粒子,采用XRD、HR-SEM、EDX和VSM对所制备的样品进行表征.X射线衍射和能谱分析表明,在样品制备过程中形成了纯合金粉末.样品的平均晶粒尺寸为21.56... 详细信息

采用微波燃烧法制备Cu2＋和Ni2＋摩尔比分别为3∶7,4∶6,5∶5,6∶4和7∶3的Cu-Ni合金纳米粒子,采用XRD、HR-SEM、EDX和VSM对所制备的样品进行表征.X射线衍射和能谱分析表明,在样品制备过程中形成了纯合金粉末.样品的平均晶粒尺寸为21.56～33.25 ***-SEM像显示样品具有集群/团簇粒状形态结构.VSM分析结果表明,对于低Ni含量的合金（Cu5Ni5,Cu6Ni4和Cu7Ni3）,样品显示顺磁性,而对于较高Ni含量的合金（Cu3Ni7和Cu4Ni6）,样品呈现铁磁性.

关键词：微波燃烧纳米粒子 Cu-Ni合金磁性能

Outcomes following minimally invasive dorsal cheilectomy for hallux rigidus:A systematic review

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World Journal of Orthopedics 2024年第6期15卷 585-592页

作者： Katherine Esser James J Butler Mackenzie Roof Nathaniel P Mercer Michael C Harrington Alan P Samsonov Andrew J Rosenbaum john G kennedy Department of Orthopaedic Surgery University of Toledo Medical Center University of Toledo College of Medicine and Life SciencesToledoOH 43614United States Department of Orthopedic Surgery NYU Langone HealthNew YorkNY 10002United States Department of Orthopedic Surgery Albany Medical CenterAlbanyNY 12208United States

BACKGROUND Cheilectomy of the 1^(st)metatarsophalangeal joint(MTPJ)is one of the most common procedures for the management of hallux ***,there is no consensus regarding outcomes following minimally invasive dorsal cheilectomy(MIDC)for the management of hallux *** To evaluate outcomes following MIDC for the management of hallux *** During November 2023,the PubMed,EMBASE and Cochrane library databases were systematically reviewed to identify clinical studies examining outcomes following MIDC for the management of hallux *** Six studies were *** total,348 patients(370 feet)underwent MIDC for hallux rigidus at a weighted mean follow-up of 37.9±16.5 *** distribution of patients by Coughlin and Shurna's classification was recorded in 4 studies as follows:Ⅰ(58 patients,27.1%),Ⅱ(112 patients,52.3%),Ⅲ(44 patients,20.6%).Three studies performed an additional 1^(st)MTPJ arthroscopy and debridement following *** intra-articular bone debris was observed in 100%of patients in 1 *** weighted mean American orthopedic foot and ankle society score improved from a preoperative score of 68.9±3.2 to a postoperative score of *** complication rate was 8.4%,the most common of which was persistent joint pain and ***-two failures(8.7%)were ***-three secondary procedures(8.9%)were performed at a weighted mean time of 8.6±3.2 months following the index *** This systematic review demonstrated improvements in subjective clinical outcomes together with a moderate complication rate following MIDC for the management of hallux rigidus at short-term follow-up.A moderate reoperation rate at short-term follow-up was *** marked heterogeneity between included studies and paucity of high quality comparative studies limits the generation of any robust conclusions.

关键词： Minimally invasive dorsal cheilectomy Hallux rigidus The first metatarsophalangeal joint Cheilectomy Minimally invasive surgery

Hospitalizations for alcoholic liver disease during the COVID-19 pandemic increased more for women,especially young women,compared to men

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World Journal of Hepatology 2023年第2期15卷 282-288页

作者： john Patterson Campbell Vinay Jahagirdar Adel Muhanna Kevin F kennedy john H Helzberg Department of Internal Medicine Division of Gastroenterology and HepatologySaint Luke’s Health System of Kansas City and the University of Missouri-Kansas CityKansas CityMO 64111United States Department of Internal Medicine Saint Luke’s Health System of Kansas City and the University of Missouri-Kansas CityKansas CityMO 64111United States Division of Cardiology Saint Luke’s Health System of Kansas CityKansas CityMO 64111United States Department of Internal Medicine Division of Gastroenterology and HepatologyLiver Disease Management UnitSaint Luke’s Health System of Kansas City and the University of Missouri-Kansas CityKansas CityMO 64111United States

BACKGROUND Alcoholic liver disease(AlD)remains one of the major indications for liver transplantation in the United States and continues to place a burden on the national healthcare *** is evidence of increased alcohol consumption during the coronavirus disease 2019(COVID-19)pandemic,and the effect of this on the already burdened health systems remains *** To assess the trends for AlD admissions during the COVID-19 pandemic,and compare it to a similar pre-pandemic *** This retrospective study analyzed all admissions at a tertiary health care system,which includes four regional *** admissions were identified by querying a multi-hospital health system’s electronic database using ICD-10 *** admissions were compared for two one-year periods;pre-COVID-19 from April 2019 to March 2020,and during-COVID-19 from April 2020 to March *** were analyzed using a Poisson regression model and admission rates were compared using the annual quarterly average for the two time periods,with stratification by age and *** increase or decrease in admissions from the Poisson regression model were reported as incident rate *** One thousand three hundred and seventy-eight admissions for AlD were included.80.7%were Caucasian,and 34.3%were *** increase in the number of admissions for AlD during the COVID-19 pandemic was *** women,a sharp rise(33%)was noted in those below the age of 50 years,and an increase of 22%in those above 50 *** men,an increase of 24%was seen for those below 50 years,and a 24%decrease in those above 50 *** The COVID-19 pandemic has had widespread implications,and an increase in AlD admissions is just one of ***,given that women are often prone to rapid progression of AlD,this finding has important preventive health implications.

关键词： Alcoholic liver disease COVID-19 Alcoholic hepatitis Alcoholic liver cirrhosis Alcoholism Pandemic Young women Alcohol-related disorders