检索结果-南通市图书馆

Structural, optical and electron paramagnetic resonance studies on Cu-doped ZnO nanoparticles synthesized using a novel auto-combustion method

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2013年第2期7卷 196-201页

作者： R. ELILARASSI G. chandrasekaran Magnetism and Nanomagnetic Materials Lab Department of Physics School of Physical Chemical and Applied Sciences Pondicherry University Puducherry 605014 India

Nanocrystalline Zn1_xCuxO （x = 0, 0.02, 0.04, 0.06, 0.08） samples were synthesized by a novel auto-combustion method using glycine as the fuel material. The structural, optical and magnetic properties of the samples were characterized using XRD, SEM, photoluminescence （PL） and electron paramagnetic resonance （EPR） spectro- scopies. The XRD spectra of samples reveal the hexagonal wurtzite structures of ZnO. As the copper content increases, a diffraction peak at 28 = 39° corresponding to secondary phase of CuO （[111] crystalline face） appears when x≤ 6 mol.%. PL spectra of the samples show a strong ultraviolet （UV） emission and defect related visible emissions. Cu-doping in ZnO can effectively adjust the energy level in ZnO, which leads to red shift in the emission peak position in UV region. The EPR spectra of Cu-doped ZnO nanoparticles show a distinct and broad signal at room temperature, suggesting that it may be attributed to the exchange interactions within Cu2＋ ions.

关键词： Cu-doped ZnO auto-combustion luminescence electron paramagneticresonance (EPR)

In situ formation of bimetallic FeNi nanoparticles on sand through green technology:Application for tetracycline removal

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2020年第1期14卷 185-197页

作者： Ravikumar KVG Debayan Ghosh M rudula Pulimi chandrasekaran Natarajan Amitava Mukherjee Centre for Nanobiotechnology VITVelloreTamil NaduIndia

In this study,FeNi nanoparticles were green synthesized using Punica granatum(pomegranate)peel extract,and these nanoparticles were also formed in situ over quartz sand(GS-FeNi)for removal of tetracycline(TC).Under the optimized operating conditions,(GS-FeNi concentration:1.5%w/v;concentration of TC:20 mg/L;interaction period:180 min),99±0.2%TC removal was achieved in the batch reactor The removaT capacity was 181±1 mg/g.A detailed characterization of the sorbent and the solution before and after the interaction revealed that the removal mechanism(s)involved both the sorption and degradation of *** reusability of reactant was assessed for four cycles of operation,and 77±4%of TC removal was obtained in the *** judge the environmental sustainability of the process,residual toxicity assay of the interacted TC solution was performed with indicator bacteria(Bacillus and Pseudomonas)and algae(Chlorella sp.),which confirmed a substantial decrease in the *** continuous column studies were undertaken in the packed bed reactors using *** the optimized conditions,quite high removal efficiency(978±5 mg/g)was obtained in the *** application of GS-FeNi for antibiotic removal was further evaluated in lake water,tap water,and ground water spiked with TC,and the removal capacity achieved was found to be 781±5,712±5,and 687±3 mg/g,*** work can pave the way for treatment of antibiotics and other pollutants in the reactors using novel green composites prepared from fruit wastes.

关键词： GS-FeNi nanoparticles Tetracycline removal Re-usability Residual toxicity Column studies

Temporal gradients limit the accumulation of neutrophils toward sources of chemoattractant

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2017年第1期3卷 455-462页

作者： Arvind chandrasekaran Felix Ellett Julianne Jorgensen Daniel Irimia Department of Surgery BioMEMS Resource CenterMassachusetts General HospitalHarvard Medical SchoolShriners Burns HospitalBostonMA 02129USA

Neutrophil trafficking during inflammation is a highly orchestrated process,coordinating neutrophil recruitment,sterilization of the wound,and inflammation *** the chemotactic signals guiding neutrophil recruitment to sites of inflammation are relatively well understood,our knowledge of mechanisms controlling cessation of neutrophil recruitment and return to normal tissue physiology remains *** gain insights into these processes,we designed a microfluidic device with an array of chemoattractant reservoirs,which mimics the microenvironment in infected tissues,when multiple clusters of microbes are *** monitored the temporal dynamics of neutrophil recruitment toward the chemoattractant reservoirs at single cell resolution,for 3 *** observed robust neutrophil recruitment that reached a plateau after 1.5 h,despite the continuous presence of strong chemoattractant gradients around the *** timing of the plateau was dependent on the geometry of the devices and was independent from the number of *** the basis of these observations,we ruled out sub-population sensitivity,chemoattractant scavenging,and production of a self-limiting stop signal as potential mechanisms underpinning the plateau in neutrophil *** found a strong correlation between the temporal stabilization of concentration changes and the plateau in neutrophils *** results suggest that dynamic aspects of chemoattractant gradients are key for maximizing recruitment during the acute phase of infections and limiting the accumulation of neutrophils as soon as the infection is contained.

关键词： chemotaxis leukocyte microfluidic relay signaling scavenging

Synthesis and optical properties of Ni-doped zinc oxide nanoparticles for optoelectronic applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2010年第1期6卷 6-10页

作者： R.Elilarassi G.chandrasekaran Department of Physics School of PhysicalChemical and Applied SciencesPondicherry University

Nanocrystalline undoped and nickel doped zinc oxide (Zn1-xNixO, x=0.00, 0.01) powders are successfully synthesized by a simple and low-temperature "auto-combustion method". The microstructural and optical absorption and emission properties of the as-prepared samples are obtained using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infra-red spectrometer (FTIR), UV-visible and photoluminescence (PL). The structure study confirms the formation of the hexagonal wurtzite ZnO without any secondary phase in the Ni-doped sample. The optical absorption measurements indicate the red shift in the absorption band edge upon nickel doping. The band gap energy decreases from 3.21 eV to 3.17 eV. The photoluminescence spectra of the as-prepared samples under a room temperature show strong ultraviolet (UV) and blue emission peaks. The PL emission research strongly reveals that Ni doping can effectively adjust the energy level which leads to a red shift at the emission peak in UV region.

关键词：纳米掺杂氧化物傅立叶变换红外光谱仪锌镍光电应用光学性质合成扫描电子显微镜

Assessing combined toxic effects of tetracycline and P25 titanium dioxide nanoparticles using Allium cepa bioassay

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2021年第1期15卷 101-112页

作者： Barsha Roy Khushboo Kadam Suresh Palamadai Krishnan chandrasekaran Natarajan Amitava Mukherjee School of Biosciences and Technology VITVellore 632014India Centre for Nanobiotechnology VITVellore 632014India

Usage of titanium dioxide nanoparticles(TiO_(2) NPs)and tetracycline(TC)has increased significantly in the present *** leads to their release and accumulation in the *** the compounds,individually,can have adverse toxic effects on the *** binary mixtures can increase this degree of *** present study aimed to evaluate the toxicity of both the contaminants in individual and binary mixtures in Allium ***,the toxicity of TiO_(2) NPs upon UVA pre-irradiation was also *** showed that UVA pre-irradiated NPs(UVA-TiO_(2) NPs)had a significant decrease in cell viability than their non-irradiated counterparts(NI-TiO_(2)),denoting an increase in photocatalytic activity upon UVA *** low concentrations of TC(EC10=0.016µmol/L)mixed with TiO2 NPs significantly increased the toxicity for both UVA-TiO_(2) and NI-TiO_(2) *** ROS generation was significantly high for UVA-TiO_(2) ***,TC did not have any effects on ROS *** the compounds exhibited genotoxic potential in *** chromosomal abnormalities like anaphase bridges,telophase bridges,laggard chromosomes,binucleate cells,*** *** binary mixture of UVA-TiO_(2) NPs and TC showed the highest chromosomal aberrations(64.0%±1.26%)than the mixture with NI-TiO_(2) or the individual *** decreased significantly after recovery(46.8%±1.92%),denoting the self-repair *** study proved that UVA-TiO2 NPs were more toxic and could be enhanced further when mixed with a sub-lethal concentration of *** work will help to assess the risk of both compounds in the environment.

关键词： Binary toxicity Cell viability Mitotic index Chromosomal aberration Reactive oxygen species Nanoparticles internalization

Network Traffic Prediction Using Radial Kernelized-Tversky Indexes-Based Multilayer Classifier

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2022年第3期40卷 851-863页

作者： M.Govindarajan V.chandrasekaran S.Anitha Department of Computer Applications Velalar College of Engineering and TechnologyErode638012India Department of Electronics and Communication Engineering Velalar College of Engineering and TechnologyErode638012India Department of Information Technology Kongu Engineering CollegePerunduraiIndia

Accurate cellular network traffic prediction is a crucial task to access Internet services for various devices at any *** the use of mobile devices,communication services generate numerous data for every *** the increasing dense population of data,traffic learning and prediction are the main components to substantially enhance the effectiveness of demand-aware resource allocation.A novel deep learning technique called radial kernelized LSTM-based connectionist Tversky multilayer deep structure learning(RKLSTM-CTMDSL)model is introduced for traffic prediction with superior accuracy and minimal time *** RKLSTM-CTMDSL model performs attribute selection and classification processes for cellular traffic *** this model,the connectionist Tversky multilayer deep structure learning includes multiple layers for traffic prediction.A large volume of spatial-temporal data are considered as an input-to-input ***,input data are transmitted to hidden layer 1,where a radial kernelized long short-term memory architecture is designed for the relevant attribute selection using activation function *** obtaining the relevant attributes,the selected attributes are given to the next *** index function is used in this layer to compute similarities among the training and testing traffic *** similarity index outcomes are given to the output *** value is used as basis to classify data as heavy network or normal ***,cellular network traffic prediction is presented with minimal error rate using the RKLSTM-CTMDSL *** evaluation proved that the RKLSTM-CTMDSL model outperforms conventional methods.

关键词： Cellular network traffic prediction connectionist Tversky multilayer deep structure learning attribute selection classification radial kernelized long short-term memory

Synthesis and characterization of ball milled Fe-doped ZnO diluted magnetic semiconductor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2012年第2期8卷 109-112页

作者： R.Elilarassi G.chandrasekaran Magnetism and Nanomagnetic Materials Lab Department of Physics School of Physical Chemical and Applied Sciences Pondicherry University

Fe-doped ZnO (Zn0.99Fe0.01O) powders are successfully prepared by ball milling with different milling time, and are inves- tigated using X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet-visible (UV-VIS) spectroscopy, vibrating sample magnetometer (VSM) and electron paramagnetic resonance (EPR) spectroscopy. The structural analysis using XRD reveals that the Fe-doped ZnO milled at different milling time can crystallize in a wurtzite structure, and in the XRD patterns, the secondary phase related to Fe cluster with the sensitivity of the XRD instrument can not be found. The SEM image of the sample milled for 24 h shows the presence of spherical nanoparticles. From the optical analysis, the optical band gap is found to decrease with increasing the milling time, which indicates the incorporation of Fe2+ ions into the ZnO lattice. The magnetization measurement using VSM reveals that the nanoparticles exhibit ferromagnetic behavior at room temperature, and the magnetization increases gradually with increasing the milling time. The conclusion is further confirmed by the electron paramagnetic resonance of the nanoparticles examined at room temperature, which shows an intense and broad ferromagnetic resonance signal related to Fe ions.

关键词：球磨时间铁掺杂 ZnO 稀磁半导体振动样品磁强计电子顺磁共振 X射线衍射扫描电子显微镜

Multifaceted Signaling Networks Mediated by Abscisic Acid Insensitive 4

在线全文

学校读者我要写书评

暂无评论

Plant Communications 2020年第3期1卷 20-29页

作者： Umashankar chandrasekaran Xiaofeng Luo Wenguan Zhou Kai Shu School of Ecology and Environment Northwestern Polytechnical UniversityXi’an 710012China Institute of Ecological Agriculture Sichuan Agricultural UniversityChengdu 611130China

Although ABSCISIC ACID INSENSITIVE 4(ABI4)was initially demonstrated as a key positive regulator in the phytohormone abscisic acid(ABA)signaling cascade,multiple studies have now shown that it is actually involved in the regulation of several other cascades,including diverse phytohormone biogenesis and signaling pathways,various developmental processes(such as seed dormancy and germination,seedling establishment,and root development),disease resistance and lipid *** with its versatile biological functions,ABI4 either activates or represses transcription of its target *** upstream regulators of ABI4 at both the transcription and post-transcription levels have also been documented in recent ***,a complicated network consisting of the direct target genes and upstreamregulators of ABI4,through which ABI4 participates in several phytohormone crosstalk networks,has been *** this review,we summarize current understanding of the sophisticated ABI4-mediated molecular networks,mainly focusing on diverse phytohormone(including ABA,gibberellin,cytokinin,ethylene,auxin,and jasmonic acid)*** also discuss the potential mechanisms through which ABI4 receives the ABA signal,focusing on protein phosphorylation modification events.

关键词： ABI4 transcription factor target genes phytohormones crosstalk

Electrical stimulation and denervated muscles after spinal cord injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第8期15卷 1397-1407页

作者： Subhalakshmi chandrasekaran John Davis Ines Bersch Gary Goldberg Ashraf S.Gorgey Spinal Cord Injury and Disorders Hunter Holmes McGuire VA Medical CenterRichmondVAUSA Swiss Paraplegic Centre NottwilSwitzerland Institute of Clinical Sciences Department of Orthopedics at the University of GothenburgGothenburgSweden Department of Physical Medicine and Rehabilitation Virginia Commonwealth UniversityRichmondVAUSA Electrodiagnostic Center Hunter Holmes McGuire VA Medical CenterRichmondVAUSA

Spinal cord injury(SCI)population with injury below T10 or injury to the cauda equina region is characterized by denervated muscles,extensive muscle atrophy,infiltration of intramuscular fat and formation of fibrous *** morphological changes may put individuals with SCI at higher risk for developing other diseases such as various cardiovascular diseases,diabetes,obesity and ***,there is no available rehabilitation intervention to rescue the muscles or restore muscle size in SCI individuals with lower motor neuron ***,hereby,performed a review of the available evidence that supports the use of electrical stimulation in restoration of denervated muscle following *** pulse width stimulation(LPWS)technique is an upcoming method of stimulating denervated *** primary objective is to explore the best stimulation paradigms(stimulation parameters,stimulation technique and stimulation wave)to achieve restoration of the denervated *** parameters,such as the pulse duration,need to be 100–1000 times longer than in innervated muscles to achieve desirable excitability and *** use of electrical stimulation in animal and human models induces muscle *** in animal models indicate that electrical stimulation,with a combination of exercise and pharmacological interventions,have proven to be effective in improving various aspects like relative muscle weight,muscle cross sectional area,number of myelinated regenerated fibers,and restoring some level of muscle *** studies have shown similar outcomes,identifying the use of LPWS as an effective strategy in increasing muscle cross sectional area,the size of muscle fibers,and improving muscle ***,displaying promise is an effective future stimulation *** summary,LPWS is a novel stimulation technique for denervated muscles in humans with *** studies on LPWS of denervated muscles will help in translating

关键词： denervation DXA electrical stimulation LMN injury LPWS MRI spinal cord injury stimulation parameters