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Arabidopsis thaliana T-DNA Mutants Implicate GAUT Genes in the Biosynthesis of Pectin and Xylan in Cell Walls and Seed Testa

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Molecular Plant 2009年第5期2卷 1000-1014页

作者： Kerry H. Caffall sivakumar Pattathil Sarah E. Phillips Michael G. Hahn Debra Mohnen Department of Biochemistry and Molecular Biology University of Georgia Athens GA 30602 USA Complex Carbohydrate Research Center BioEnergy Science Center 315 Riverbend Road University of Georgia Athens GA 30602 USA Department of Plant Biology University of Georgia Athens GA 30602 USA

Galacturonosyltransferase 1 （GAUT1） is an α1,4-D-galacturonosyltransferase that transfers galacturonic acid from uridine 5＇-diphosphogalacturonic acid onto the pectic polysaccharide homogalacturonan （Sterling et al., 2006）. The 25-member Arabidopsis thaliana GAUT1-related gene family encodes 15 GAUT and 10 GAUT-like （GATL） proteins with, respectively, 56-84 and 42-53% amino acid sequence similarity to GAUT1. Previous phylogenetic analyses of AtGAUTs indicated three clades： A through C. A comparative phylogenetic analysis of the Arabidopsis, poplar and rice GAUT families has sub-classified the GAUTs into seven clades： clade A-1 （GAUTs 1 to 3）; A-2 （GAUT4）; A-3 （GAUTs 5 and 6）; A-4 （GAUT7）; B-1 （GAUTs 8 and 9）; B-2 （GAUTs 10 and 11）; and clade C （GAUTs 12 to 15）. The Arabidopsis GAUTs have a distribution comparable to the poplar orthologs, with the exception of GAUT2, which is absent in poplar. Rice, however, has no orthologs of GAUTs 2 and 12 and has multiple apparent orthologs of GAUTs 1, 4, and 7 compared with eitherArabidopsis or poplar. The cell wall glycosyl residue compositions of 26 homozygous T-DNA insertion mutants for 13 of 15 Arabidopsis GAUTgenes reveal significantly and reproducibly different cell walls in specific tissues of gaut mutants 6, 8, 9, 10, 11, 12, 13, and 14 from that of wild-type Arabidopsis walls. Pectin and xylan polysaccharides are affected by the loss of GAUT function, as demonstrated by the altered galacturonic acid, xylose, rhamnose, galactose, and arabinose composition of distinct gaut mutant walls. The wall glycosyl residue compositional phenotypes observed among the gaut mutants suggest that at least six different biosynthetic linkages in pectins and/or xylans are affected by the lesions in these GAUTgenes. Evidence is also presented to support a role for GAUT11 in seed mucilage expansion and in seed wall and mucilage composition.

关键词： Carbohydrate metabolism cell walls Arabidopsis biosynthesis mutant pectin mucilage

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An Efficient 3D CNN Framework with Attention Mechanisms for Alzheimer’s Disease Classification

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Computer Systems Science & Engineering 2023年第11期47卷 2097-2118页

作者： Athena George Bejoy Abraham Neetha George Linu Shine sivakumar Ramachandran Department of Electronics and Communication Engineering College of EngineeringTrivandrum695016India Department of Computer Science and Engineering College of Engineering MuttatharaTrivandrum695008India Department of Electronics and Communication Rajeev Gandhi Institute of TechnologyKottayam686501India Department of Electronics and Communication Engineering Government Engineering CollegeWayanad670644India

Neurodegeneration is the gradual deterioration and eventual death of brain cells,leading to progressive loss of structure and function of neurons in the brain and nervous *** disorders,such as Alzheimer’s,Huntington’s,Parkinson’s,amyotrophic lateral sclerosis,multiple system atrophy,and multiple sclerosis,are characterized by progressive deterioration of brain function,resulting in symptoms such as memory impairment,movement difficulties,and cognitive *** diagnosis of these conditions is crucial to slowing down cell degeneration and reducing the severity of the *** resonance imaging(MRI)is widely used by neurologists for diagnosing brain *** majority of the research in this field focuses on processing the 2D images extracted from the 3D MRI volumetric scans for disease *** might result in losing the volumetric information obtained from the whole brain *** address this problem,a novel 3D-CNN architecture with an attention mechanism is proposed to classify whole-brain MRI images for Alzheimer’s disease(AD)*** 3D-CNN model uses channel and spatial attention mechanisms to extract relevant features and improve accuracy in identifying brain dysfunctions by focusing on specific regions of the *** pipeline takes pre-processed MRI volumetric scans as input,and the 3D-CNN model leverages both channel and spatial attention mechanisms to extract precise feature representations of the input MRI volume for accurate *** present study utilizes the publicly available Alzheimer’s disease Neuroimaging Initiative(ADNI)dataset,which has three image classes:Mild Cognitive Impairment(MCI),Cognitive Normal(CN),and AD *** proposed approach achieves an overall accuracy of 79%when classifying three classes and an average accuracy of 87%when identifying AD and the other two *** findings reveal that 3D-CNN models with an attention mechanism exhibit significantly higher classi

关键词： 3D CNN alzheimer’s disease attention mechanism classification

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Spectral reflectance indices as proxies for yield potential and heat stress tolerance in spring wheat: heritability estimates and marker-trait associations

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Frontiers of Agricultural Science and Engineering 2019年第3期6卷 296-308页

作者： Caiyun LIU Francisco PINTO CMariano COSSANI sivakumar SUKUMARAN Matthew PREYNOLDS International Maize and Wheat Improvement Center(CIMMYT) Texcoco56237Mexico South Australian Research and Development Institute–SARDI Adelaide5001Australia School of Agriculture Food and WineThe University of AdelaideUrrbrae SA5064Australia

The application of spectral reflectance indices(SRIs) as proxies to screen for yield potential(YP) and heat stress(HS) is emerging in crop breeding ***, a comparison of SRIs and their associations with grain yield(GY) under YP and HS conditions is *** this study, we assessed the usefulness of 27 SRIs for indirect selection for agronomic traits by evaluating an elite spring wheat association mapping initiative(WAMI) population comprising 287 elite lines under YP and HS *** and phenotypic analysis identified 11 and 9 SRIs in different developmental stages as efficient indirect selection indices for yield in YP and HS conditions,*** identified enhanced vegetation index(EVI) as the common SRI associated with GY under YP at booting, heading and late heading stages, whereas photochemical reflectance index(PRI) and normalized difference vegetation index(NDVI) were the common SRIs under booting and heading stages in *** association study(GWAS) using 18704 single nucleotide polymorphisms(SNPs) from Illumina i Select90 K identified 280 and 43 marker-trait associations for efficient SRIs at different developmental stages under YP and HS, *** genomic regions for multiple SRIs were identified in 14 regions in 9 chromosomes: 1 B(60–62 cM), 3 A(15, 85–90, 101–105 cM), 3 B(132–134 cM), 4 A(47–51 cM), 4 B(71–75 cM), 5 A(43–49, 56–60, 89–93 cM), 5 B(124–125 cM),6 A(80–85 cM), and 6 B(57–59, 71 cM).Among them,SNPs in chromosome 5 A(89–93 cM) and 6 A(80–85 cM)were co-located for yield and yield related ***,this study highlights the utility of SRIs as proxies for GY under YP and *** heritability estimates and identification of marker-trait associations indicate that SRIs are useful tools for understanding the genetic basis of agronomic and physiological traits.

关键词： genome-wide association study(GWAS) heat tolerance spectral reflectance spring wheat

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A single synonymous mutation determines the phosphorylation and stability of the nascent protein

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Journal of Molecular Cell Biology 2019年第3期11卷 187-199页

作者： Konstantinos Karakostis sivakumar Vadivel Gnanasundram Ignacio Lopez Aikaterini Thermou Lixiao Wang Karin Nylander Vanesa Ollvares-Iliana Robin Fahraeus Equipe Labellisee Ligue Contre le Cancer Universite Paris 7INSERM UMR 116227 Rue Juliette DoduParis 75010France Department of Medical Biosciences Umea UniversityUmea SE-90185Sweden Instituto de Ffsica Universidad Autonoma de San Luis Potosi78290 SLPMexico RECAMO Masaryk Memorial Cancer InstituteZluty kopec 7Brno 656 53Czech Republic

p53 is an intrinsically disordered protein with a large number of post-translational modifications and interacting *** hierarchical order and subcellular location of these events are still poorly *** activation of p53 during the DNA damage response(DDR)requires a switch in the activity of the E3 ubiquitin ligase MDM2 from a negative to a positive regulator of *** is mediated by the ATM kinase that regulates the binding of MDM2 to the p53 mRNA facilitating an increase in p53 *** we show that the binding of MDM2 to the p53 mRNA brings ATM to the p53 polysome where it phosphorylates the nascent p53 at serine 15 and prevents MDM2-mediated degradation of p53.A single synonymous mutation in p53 codon 22(L22L)prevents the phosphorylation of the nascent p53 protein and the stabilization of p53 following genotoxic *** ATM trafficking from the nucleus to the p53 polysome is mediated by MDM2,which requires its interaction with the ribosomal proteins RPL5 and *** results show how the ATM kinase phosphorylates the p53 protein while it is bang synthesized and offer a novel mechanism whereby a single synonymous mutation controls the stability and activity of the encoded protein.

关键词： synonymous mutations intrinsically disordered proteins cell signaling MDM2 p53 messenger RNA ATM kinase

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Intelligent Biomedical Electrocardiogram Signal Processing for Cardiovascular Disease Diagnosis

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Computers, Materials & Continua 2022年第4期71卷 255-268页

作者： R.Krishnaswamy B.sivakumar B.Viswanathan Fahd N.Al-Wesabi Marwa Obayya Anwer Mustafa Hilal Department of Electronics and Communication Engineering University College of Engineering AriyalurAriyalur621704India School of Computing SRM Institute of Science and TechnologyChennai603203India Department of Electronics and Communication Engineering K.Ramakrishnan College of EngineeringTiruchirappalli621112India Department of Computer Science Factually of Science&Art at MahayilKing Khalid UniversitySaudi Arabia Faculty of Computer and IT Sana’a UniversityYemen Department of Biomedical Engineering College of EngineeringPrincess Nourah Bint Abdulrahman UniversitySaudi Arabia Department of Computer and Self Development Preparatory Year DeanshipPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabia

Automatic biomedical signal recognition is an important processfor several disease diagnoses. Particularly, Electrocardiogram (ECG) is commonly used to identify cardiovascular diseases. The professionals can determine the existence of cardiovascular diseases using the morphological patternsof the ECG signals. In order to raise the diagnostic accuracy and reduce thediagnostic time, automated computer aided diagnosis model is necessary. Withthe advancements of artificial intelligence (AI) techniques, large quantity ofbiomedical datasets can be easily examined for decision making. In this aspect,this paper presents an intelligent biomedical ECG signal processing (IBECGSP) technique for CVD diagnosis. The proposed IBECG-SP technique examines the ECG signals for decision making. In addition, gated recurrent unit(GRU) model is used for the feature extraction of the ECG signals. Moreover,earthworm optimization (EWO) algorithm is utilized to optimally tune thehyperparameters of the GRU model. Lastly, softmax classifier is employedto allot appropriate class labels to the applied ECG signals. For examiningthe enhanced outcomes of the proposed IBECG-SP technique, an extensivesimulation analysis take place on the PTB-XL database. The experimentalresults portrayed the supremacy of the IBECG-SP technique over the recentstate of art techniques.

关键词： Biomedical signals ecg disease diagnosis artificial intelligence parameter tuning gru model

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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

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Preparation of cerium and yttrium doped ZnO nanoparticles and tracking their structural,optical,and photocatalytic performances

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Journal of Rare Earths 2023年第5期41卷 682-688,I0002页

作者： Essia Hannachi Yassine Slimani Muhammad Nawaz R.sivakumar Zayneb Trabelsi R.Vignesh Sultan Akhtar Munirah A.Almessiere Abdulhadi Baykal Ghulam Yasin Department of Nuclear Medicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia Department of Nanomedicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPO.Box 1982Dammam31441Saudi Arabia Department of Physics Alagappa UniversityKaraikudi630003India Faculty of Sciences of Bizerte University of CarthageZarzouna7021Tunisi Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP0.Box 1982Dammam31441Saudi Arabia State Key Laboratory of Chemical Resource Engineering College of Materials Science and EngineeringBeijing University of Chemical TechnologyBejing 100029China Institute for Advanced Study College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China

Yttrium(Y)and cerium(Ce)co-doped ZnO nanoparticles(NPs)were synthesized via the simple sol-gel auto-combustion *** effect of Ce and Y doping on the structure,morphology,optical,Zeta potential,and photocatalytic activities of ZnO NPs was examined by Fourier transform infrared(FTIR)spectrometer,X-ray diffraction(XRD),transmission electron microscope(TEM),UV-vis spectrophotometer,and Zetasizer *** data show that the fabricated samples crystallize into a hexagonal wurtzite *** dopants Y and Ce affect the crystal structure of ZnO *** crystallite size is reduced with the co-doping *** results confirm the nano-sized particles of the prepared *** increase in optical bandgap values from 3.19 eV for x=0.0 to 3.22,3.24,and 3.25 eV for x=0.01,0.03,and 0.05 samples was confirmed by UV-Vis spectroscopy analysis.Y and Ce co-doped ZnO nanoparticles show significant alteration of zeta potential and photocatalytic properties compared to undoped ZnO ***,undoped ZnO shows better stability in deionized water as compared to Ce-Y doped ZnO NPs and exhibits high photocatalytic activity(degradation rate,97.92%)for methyl orange(MO)degradation.

关键词： ZnO nanoparticles Co-doping Rare earth Structure Bandgap energy Photocatalytic activity

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Anti-dermatophytic activity of marine sponge,Sigmadocia carnosa(Dendy)on clinically isolated fungi

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Asian Pacific Journal of Tropical Biomedicine 2012年第8期2卷 635-639页

作者： NB Dhayanithi TT Ajith Kumar M Kalaiselvam T Balasubramanian N sivakumar Centre of Advanced Study in Marine Biology Faculty of Marine SciencesAnnamalai University Department of Molecular Microbiology School of BiotechnologyMadurai Kamaraj University

Objective:To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa(***) against four dermatophytic ***:The methanol,ethyl acetate and acetone extract of marine sponge,*** was examined against Trichaphyton mentagrophytes(***),Trichophyton rubrum(***),Epidermophyton floccosum(***) and Microsporum gypseum(***) and qualitative analysed to find out the active ***:The methanol extract of sponge was expressed significant activity than ethyl acetate and *** minimum inhibitory concentration(MIC) of methanol extract of sponge that resulted in complete growth inhibition of ***,***, *** and *** were found to 125,250,250 and 250 μg/mL ***, 100%inhibition of fungal spore germination was observed in *** at 500 μg/mL concentration followed by ***,*** and *** at 1000 μg/mL concentration. Other two extracts showed weak anti spore germination activity against the tested dermatophyte *** extracts showed presence of terpenoids,steroids,alkaloids,saponins and ***:Based on the literature,this is the first study which has conducted to inhibit the growth and spore germination of dermatophytic fungi with *** research also needs to purify and characterize the secondary metabolites from the sponge,*** for the valuable source of novel substances for future drug discovery.

关键词： Dermatophytic fungi Sigmadocia Carnosa Anti-fungal activity Spore germination assay Qualitative analysis of Active compounds

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Production and mechanical properties of nano SiC particle reinforced Ti-6Al-4V matrix composite

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Transactions of Nonferrous Metals Society of China 2017年第1期27卷 82-90页

作者： G.sivakumar V.ANANTHI S.RAMANATHAN CISL Department of PhysicsAnnamalai UniversityTamilnadu 608002India Physics Section FEATAnnamalai UniversityTamilnadu 608002India Manufacturing Engineering Department Annamalai UniversityTamilnadu 608002India

Different mass fractions （0, 5%, 10%, and 15%） of the synthesized nano SiC particles reinforced Ti-6Al-4V （Ti64） alloy metal matrix composites （MMCs） were successfully fabricated by the powder metallurgy method. The effects of addition of SiC particle on the mechanical properties of the composites such as hardness and compressive strength were investigated. The optimum density （93.33%） was obtained at the compaction pressure of 6.035 MPa. Scanning electron microscopic （SEM） observations of the microstructures revealed that the wettability and the bonding force were improved in Ti64 alloy/5% nano SiCp composites. The effect of nano SiCp content in Ti64 alloy/SiCp matrix composite on phase formation was investigated by X-ray diffraction. The correlation between mechanical parameter and phase formation was analyzed. The new phase of brittle interfaced reaction formed in the 10% and 15% SiCp composite specimens and resulted in no beneficial effect on the strength and hardness. The compressive strength and hardness of Ti64 alloy/5% nano SiCp MMCs showed higher values. Hence, 5% SiCp can be considered to be the optimal replacement content for the composite.

关键词： titanium alloy nano SiC particle powder metallurgy hardness compressive strength

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Development of Non-Shrinking Soft Ferrite Composition Useful for Microinductors Applications

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World Journal of Condensed Matter Physics 2011年第3期1卷 105-119页

作者： N Varalaxmi K sivakumar 不详

NiCuZn Ferrites are widely employed for many electronic applications, but can be replaced by MgCuZn ferrites owing to their superior properties like high initial permeability, high resistivity, low magnetostriction, environmental stability and low cost. Three series of NiMgCuZn ferrites were prepared by conventional sintering process. The formation of single phase in these ferrites was confirmed by x-ray diffraction. Initial permeability measurements on these samples were carried out in the temperature range of 30-400℃. The effect of the external applied stress on the open magnetic circuit type coil with these ferrites was studied by applying uniaxial compressive stress parallel to magnetizing direction and the change in the inductance was measured. The variation of ratio of inductance (ΔL/L)% increases upto certain applied compressive stress and there after it decreases, showing different stress sensitivities for different compositions of ferrites studied in the present work. With a view to develop stress insensitive NiMgCuZn ferrite, a low stress sensitivity composition among all the ferrites studied was chosen and different amounts of SiO2 were added to it and a series of ferrite compositions were prepared. The variation of ratio of inductance (ΔL/L)% with external applied compressive stress was examined. These results show that, in a particular composition of 0.05 wt% SiO2added Ni0.3Mg0.3Cu0.1Zn0.3Fe2O4 ferrite exhibited stress insensitivity. It was noticed that addition of SiO2 was found to be effective in reducing the stress sensitivity. This was confirmed from the elastic behaviour studies at room temperature on these ferrite samples. These studies were carried out to develop a ferrite composition for its use as core material for microinductor applications.

关键词： X-ray diffraction Ferrite composites Initial permeability Microinductors Stress Insensitivity SEM photographs

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