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Antimutagenic potential of curcumin on chromosomal aberrations in Allium cepa

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2007年第7期8卷 470-475页

作者： RAGUNATHAN Irulappan PANNEERSELVAM natarajan Research Centre and Postgraduate Studies in Botany the Madura College Madurai-625 011 Tamil Nadu India

Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 μg/ml for 3 h and curcumin was given at 5, 10 and 20 μg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 μg/ml in Allium cepa root meristem cells.

关键词： Chromosomal aberrations Sodium azide Genotoxicity Allium cepa

Design concepts of an aircraft wing： composite and morphing airfoil with auxetic structures

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Frontiers of Structural and Civil Engineering 2016年第4期10卷 394-408页

作者： P R BUDARAPU Sudhir Sastry Y B R natarajan Department of Aerospace Engineering Indian Institute of Science Bangalore 560 012 India Department of Aeronautical Engineering College of Engineering Defence University Ethiopia Department of Aeronautical Engineering Institute of Aeronautical Engineering Hyderabad India

This paper is categorized into two parts. （1） A frame work to design the aircraft wing structure and （2） analysis ofa morphing airfoil with auxetic structure. The developed design frame work in the first part is used to arrive at the sizes of the various components of an aircraft wing structure. The strength based design is adopted, where the design loads are extracted from the aerodynamic loads. The aerodynamic loads acting on a wing structure are converted to equivalent distributed loads, which are further converted point loads to arrive at the shear forces, bending and twisting moments along the wing span. Based on the estimated shear forces, bending and twisting moments, the strength based design is employed to estimate the sizes of various sections of a composite wing structure. A three dimensional numerical model of the composite wing structure has been developed and analyzed for the extreme load conditions. Glass fiber reinforced plastic material is used in the numerical analysis. The estimated natural frequencies are observed to be in the acceptable limits. Furthermore, the discussed design principles in the first part are extended to the design of a morphing airfoil with auxetic structure. The advantages of the morphing airfoil with auxetic structure are （i） larger displacement with limited straining of the components and （ii） unique deformation characteristics, which produce a theoretical in-plane Poisson＇s ratio of -1. Aluminum Alloy AL6061-T651 is considered in the design of all the structural elements. The compliance characteristics of the airfoil are investigated through a numerical model. The numerical results are observed to be in close agreement with the experimental results in the literature.

关键词： wing design aerodynamic loads morphing airfoil auxetic structures negative Poisson's ratio

Three-dimensionally interconnected Co9S8/MWCNTs composite cathode host for lithium–sulfur batteries

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Journal of Energy Chemistry 2020年第7期29卷 22-29,I0002页

作者： Shengyu Zhao Xiaohui Tian Yingke Zhou Ben Ma Angulakshmi natarajan The State Key Laboratory of Refractories and Metallurgy Institute of Advanced Materials and NanotechnologyCollege of Materials and MetallurgyWuhan University of Science and TechnologyWuhan 430081 HubeiChina

Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercialization of lithium–sulfur *** this study,a novel three-dimensionally interconnected network structure comprising Co9 S8 and multiwalled carbon nanotubes(MWCNTs)was synthesized by a solvothermal route and used as the sulfur *** assembled batteries delivered a specific capacity of1154 m Ah g-1 at 0.1 C,and the retention was 64%after 400 cycles at 0.5 *** polar and catalytic Co9 S8 nanoparticles have a strong adsorbent effect for polysulfide,which can effectively reduce the shuttling ***,the three-dimensionally interconnected CNT networks improve the overall conductivity and increase the contact with the electrolyte,thus enhancing the transport of electrons and Li *** adsorption is greatly increased with the synergistic effect of polar Co9 S8 and MWCNTs in the three-dimensionally interconnected composites,which contributes to their promising performance for the lithium–sulfur batteries.

关键词： Three-dimensional network structure MWCNTs Polar and catalytic Co9S8 Lithium–sulfur batteries

Chemoprevention of neuroblastoma: progress and promise beyond uncertainties

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Journal of Cancer Metastasis and Treatment 2023年第1期9卷 307-327页

作者： natarajan Aravindan Mohan natarajan Dinesh Babu Somasundaram Sheeja Aravindan Department of Radiation Oncology University of Oklahoma Health Sciences CenterOklahoma CityOK 73104USA Stephenson Cancer Center Oklahoma CityOK 73104USA Department of Pathology and Laboratory Medicine University of Texas Health Sciences Center at San AntonioSan AntonioTX 78229USA

Neuroblastoma is the most common extracranial solid tumor in children and comprises one-tenth of all childhood cancer *** current clinical therapy for this deadly disease is multimodal,involving an induction phase with alternating regimens of high-dose chemotherapeutic drugs and load reduction surgery;a consolidation phase with more intensive chemotherapy,radiotherapy,and stem cell transplant;and a maintenance phase with immunotherapy and immune-activating cytokine *** such intensive treatment,children with neuroblastoma have unacceptable life quality and survival,warranting preventive measures to regulate the cellular functions that orchestrate tumor progression,therapy resistance,metastasis,and tumor relapse/***,active efforts are underway to identify novel chemopreventive agents,define their mechanism(s)of action,and assess their clinical *** chemoprevention strategies(e.g.,retinoids,difluoromethylornithine)have already been adopted clinically as part of maintenance phase *** agents are in the pipeline,while many others are in preclinical *** we review the classes of chemopreventive agents investigated for neuroblastoma,including cellular events targeted,mode(s)of action,and the level of *** review:(i)highlights the pressing need for new and improved chemopreventive strategies for progressive neuroblastoma;(ii)lists the emerging classes of chemopreventive agents for neuroblastoma;and(iii)recognizes the relevance of targeting dynamically evolving hallmark functions of tumor evolution(e.g.,survival,differentiation,lineage transformation).With recent gains in the understanding of tumor evolution processes and preclinical and clinical efforts,it is our strong opinion that effective chemopreventive strategies for aggressive neuroblastoma are a near reality.

关键词： Neuroblastoma chemoprevention secondary and tertiary chemopreventive phytochemicals retinoids polyphenols terpenes DFMO apoptosis

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

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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

Performance enhancement of futuristic airplanes by nature inspired biomimetic fish scale arrays--A design approach

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Biomimetic Intelligence & Robotics 2022年第2期2卷 32-47页

作者： Ganesh natarajan S Bruce Ralphin Rose J Department of Mechanical Engineering Anna University Regional Campus TirunelveliTamilnaduIndia

Biomimetics has an immense potential to drive the next generation of technologies forward by propounding competent solutions from *** decades,the nonsmooth topography of most living creatures has been critical to their existence and *** to human-made smooth surfaces,when adapted for fluid flow applications,nonsmooth surfaces can enhance the overall aerodynamic performance by reducing the drag ***,the bioinspired scale structure of fish has been identified as a key biomimetic derivative for improving the aerodynamic efficiency in various cross-domain *** study investigates the aerodynamics of a fish scale array(FSA)NACA 0021 model at a specific Reynolds number(Re)of approximately 2.46×105 that is meant for laminar flow conditions using Computational Fluid Dynamics(CFD)tools and a subsonic wind tunnel facility.A 3D printed biomimetic FSA film is developed and affixed on the NACA 0021 wing profile for the experimental investigation,followed by flow visualization through the smoke tunnel *** proved qualitatively under specific aerodynamic conditions,the creation of velocity streaks has a major role in the drag reduction *** obtain a clear perspective of flow across the overlapping fish scale structures,the results are focused on the central and overlapping regions of the FSA *** experiment has proved the existence of a combined formation of low and high velocity streaks in central and overlapping *** FSA 0021 model showed a maximum drag reduction of 9.57%,which was attributed to the streak formation phenomenon observed in the overlapping FSA configuration.

关键词： Biomimetics Aerodynamics Fish scale arrays Drag reduction Bioinspired design

Optimization of Performance and Emission Characteristics of PPCCI Engine fuelled with Ethanol and Diesel blends Using Grey-Taguchi Method

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Journal of Thermal Science 2018年第1期27卷 89-94页

作者： S.natarajan K.Pitchandi N.V.Mahalakshmi Department of Mechanical Engineering Sri Venkateswara College of EngineeringSriperumbudur-602117TamilnaduIndia. Department of Mechanical Engineering Sri Venkatcswara College of EngineeringSriperumbudur-602117TamilnaduIndia. Internal combustion Engineering Division Department of Mechanical EngineeringCollege of EngineeringAnna UniversityChennai-600025TamilnaduIndia.

The performance and emission characteristics of a PPCCI engine fuelled with ethanol and diesel blends were car- ded out on a single cylinder air cooled CI engine. In order to achieve the optimal process response with a limited number of experimental cycles, multi objective grey relational analysis had been applied for solving a multiple response optimization problem. Using grey relational grade and signal-to-noise ratio as a performance index, a combination of input parameters was prefigured so as to achieve optimum response characteristics. It was observed that 20% premixed ratio of blend was most suitable for use in a PPCCI engine without significantly affecting the engine performance and emissions characteristics.

关键词： PPCCI Biodiesel Optimization Grey-Taguchi method

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

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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

Recent advances based on the synergetic effect of adsorption for removal of dyes from waste water using photocatalytic process

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Journal of Environmental Sciences 2018年第3期30卷 201-222页

作者： sub.amanian natarajan Hari C.Bajaj Rajesh J.Tayade Inorganic Materials and Catalysis Division (IMCD) CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI)Council of Scientific and Industrial Research (CSIR)

The problem of textile dye pollution has been addressed by various methods,mainly physical,chemical,biological,and *** methods mainly separate and/or remove the dye present in ***,advanced oxidation processes（AOP）have been focused for removal of dye from waste water due to their advantages such as ecofriendly,economic and capable to degrade many dyes or organic pollutant present in *** is one of the advance oxidation processes,mainly carried out under irradiation of light and suitable photocatalytic *** photocatalytic activity of the photocatalytic materials mainly depends on the band gap,surface area,and generation of electron–hole pair for degradation dyes present in *** has been observed that the surface area plays a major role in photocatalytic degradation of dyes,by providing higher surface area,which leads to the higher adsorption of dye molecule on the surface of photocatalyst and enhances the photocatalytic *** present review discusses the synergic effect of adsorption of dyes on the photocatalytic efficiency of various nanostructured high surface area *** addition,it also provides the properties of the water polluting dyes,their mechanism and various photocatalytic materials;and their morphology used for the dye degradation under irradiation of light along with the future prospects of highly adsorptive photocatalytic material and their application in photocatalytic removal of dye from waste water.

关键词： Photocatalysis Dye degradation Adsorption Water pollution Advanced oxidation processes Nanomaterials