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Effect of Milling Time on the Microstructure and Tensile Properties of Ultrafine Grained Ni–SiC Composites at Room Temperature

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Journal of Materials Science & Technology 2015年第9期31卷 923-929页

作者： Hefei Huang Chao Yang massey de los reyes Yongfeng Zhou Long Yan Xingtai Zhou Shanghai Institute of Applied Physics Chinese Academy of Sciences Institute of Materials Engineering Australian Nuclear Science and Technology Organisation

Bulk metallic nickel-silicon carbide nano-particle （Ni-SiCNp） composites, with milling time ranged from 8 to 48 h, were prepared in a planetary ball mill and sintered using a spark plasma sintering （SPS） furnace. The microstructure of the Ni-SiCnp composites was characterized by transmission electron microscopy （TEM） and their mechanical properties were investigated by tensile measurements. The TEM results showed well-dispersed SiCNp particles, either within the matrix, between twins or along grain boundaries （GB）, as well as the presence of stacking faults and twin structures, characteristics of materials with low stacking fault energy. Dislocation lines were also observed to interact with the SiCNp which were plastically nondeformable. A synergistic relationship existed between Hall-Perch strength- ening and dispersion strengthening mechanisms, which was shown to greatly influence the mechanical properties of the Ni-SiCNp composites. Both the maximum yield and tensile strengths were found in the Ni-SiCNp composite with a milling time of 48 h, whereas the increased rate of strengths drastically decreased in material milled above 8 h due to the significant SiCNp agglomeration. The ball milling process resulted in the formation of nano-scale, ultra-fine grained （UFG） Ni-SiCNp composites when the milling time was extended for longer periods, greatly strengthening these materials. The sharp decrease in elongation percentages, however, should be comprehensively considered before irrevers- ible inelastic deformation.

关键词： Ni-SiCNp compositeMechanical alloyingSpark plasma sinteringTransmission electron microscopyTensile testUltra-fine grained (UFG)

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Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 809-816页

作者： Chao Yang He-Fei Huang massey de los reyes Long Yan Xing-Tai Zhou Tian Xia de-Liang Zhang Shanghai Institute of Applied Physics Chinese Academy of Science (CAS) Institute of Materials Engineering Australian Nuclear Science and Technology Organisation State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University

Silicon carbide nanoparticle-reinforced nickel-based composites（Ni–Si CNP）,with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma *** addition,unreinforced pure nickel samples were also prepared for comparative *** characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy（TEM） was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile *** results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was *** homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain *** the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si ***,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling *** all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening（Orowan effects） and particle strengthening（Hall–Petch effects）.For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased *** to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.

关键词： Ni-SiCNP composite Mechanical alloying Spark plasma sintering Transmission electron microscopy Tensile test

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CONSTANS alters the circadian clock in Arabidopsis thaliana

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Molecular Plant 2024年第8期17卷 1204-1220页

作者： Pedro de los reyes Gloria Serrano-Bueno Francisco J.Romero-Campero He Gao Jose M.Romero Federico Valverde Plant development Group-Institute for Plant Biochemistry and Photosynthesis Consejo Superior de Investigaciones CientificasUniversidad de SevillaSevilleSpain department of Computer Science and Artificial Intelligence Universidad de SevillaSevilleSpain department of Plant developmental Biology Max Planck Institute for Plant Breeding ResearchCologneGermany department of Plant Biochemistry and Molecular Biology Universidad de SevillaSevilleSpain

Plants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the *** these processes,the floral transition is essential to ensure reproductive success and is finelyregulated by several internal andexternal genetic *** photoperiodic pathway,which controls plant response to day length,is one of the most important pathways controlling *** Arabidopsis photoperiodic flowering,CONSTANS(CO)is the central gene activating the expression of the florigen FLOWERING LOCUS T(FT)in the leaves at the end of a long *** circadian clock strongly regulates Co ***,to date,no evidence has been reported regarding a feedbackloop from the photoperiod pathway back to the circadian *** transcriptional networks,we have identified relevant network motifs regulating the interplay between the circadian clock and the photoperiod *** expression,chromatin immunoprecipitation experiments,and phenotypic analysis allowed us to elucidate the role of Co over the circadian *** with altered cO expression showed a different internal clock period,measured by daily leaf rhythmic *** showed that co upregulates the expression of key genes related to the circadian clock,such as CCA1,LHY,PRR5,and Gl,at the end of a long day by bindingto specific sites on their ***,a high numberof PRR5-repressed target genes are upregulated by CO,and this could explain the phase transition promoted by *** CO-PRR5 complex interacts with the bZiP transcriptionfactor HY5andhelps to localize the complex in the promoters of clock *** together,our results indicate that there may be a feedback loop in which co communicates back to the circadian clock,providing seasonal information to the circadian system.

关键词： CONSTANS circadian clock photoperiod

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A new oxidative pathway of nitric oxide production from oximes in plants

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Molecular Plant 2024年第1期17卷 178-198页

作者： Pedro Lopez-Gomez Javier Buezo Marina Urra Alfonso Cornejo Raquel Esteban Jorge Fernandez de los reyes Estibaliz Urarte Estefania Rodriguez-Dobreva Alejandro Chamizo-Ampudia Alejandro Eguaras Sebastian Wolf Daniel Marino Victor Martinez-Merino Jose F.Moran Institute for Multidisciplinary Research in Applied Biology(IMAB) Department of SciencesPublic University of Navarre(UPNA)Avda.de Pamplona 12331192 MutilvaSpain Institute for Advanced Materials and Mathematics(INAMAT2) Department of SciencesPublic University of Navarre(UPNA)Campus de Arosadia31006 PamplonaSpain department of Plant Biology and Ecology University of the Basque Country(UPV/EHU)Sarriena s/nApdo.64448080 BilbaoSpain Center for Plant Molecular Biology(ZMBP) University of TubingenGeschwister-Scholl-Platz72074 TubingenGermany Institute of Natural Resources and Agrobiology of Salamanca(IRNASA) Department of Plant-Microorganism InteractionsSpanish National Research Council(CSIC)Cordel de Merinas40-5237008SalamancaSpain department of Biochemistry Area of Molecular BiologyVeterinary FacultyUniversity of LeonCampus de Vegazanas/n.24071 LeonSpain

Nitric oxide(NO)is an essential reactive oxygen species and a signal molecule in *** several studies have proposed the occurrence of oxidative NO production,only reductive routes for NO production,such as the nitrate(NO_(3)^(-))-upper-reductase pathway,have been evidenced to date in land ***,plants grown axenically with ammonium as the sole source of nitrogen exhibit contents of nitrite and NO3−,evidencing the existence of a metabolic pathway for oxidative production of *** hypothesized that oximes,such as indole-3-acetaldoxime(IAOx),a precursor to indole-3-acetic acid,are intermediate oxidation products in NO *** detected the production of NO from IAOx and other oximes catalyzed by peroxidase(POD)enzyme using both 4-amino-5-methylamino-2′,7′-difluorescein fluorescence and *** stimulated the reaction,while superoxide dismutase inhibited ***,mouse NO synthase can also use IAOx to produce NO at a lower rate than *** provided a full mechanism for POD-dependent NO production from IAOx consistent with the experimental data and supported by density functional theory *** showed that the addition of IAOx to extracts from Medicago truncatula increased the in vitro production of NO,while in vivo supplementation of IAOx and other oximes increased the number of lateral roots,as shown for NO donors,and a more than 10-fold increase in IAOx dehydratase ***,we found that in vivo supplementation of IAOx increased NO production in Arabidopsis thaliana wild-type plants,while prx33-34 mutant plants,defective in POD33-34,had reduced *** data show that the release of NO by IAOx,as well as its auxinic effect,explain the superroot ***,our study reveals that plants produce NO utilizing diverse molecules such as oximes,POD,and flavins,which are widely distributed in the plant kingdom,thus introducing a long-awaited oxidative pathway to NO production in plants.T

关键词： ammonium oxidation auxin nitric oxide oxime peroxidase root phenotype

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Generalized Height-Diameter Models for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. Plantations in Michoacan, Mexico

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Open Journal of Forestry 2024年第3期14卷 214-232页

作者： Jonathan Hernández-Ramos Valentín José reyes-Hernández Héctor Manuel de los Santos-Posadas Aurelio Manuel Fierros-González Enrique Buendía-Rodríguez Gerónimo Quiñonez-Barraza Instituto Nacional de Investigaciones Forestales Agrcolas y Pecuarias (INIFAP)-Campo Experimental Bajo Celaya Guanajuato Mxico Colegio de Postgraduados (COLPOS) Campus Montecillo Mxico INIFAP Campo Experimental Valle de Mxico Texcoco Mxico INIFAP Campo Experimental Valle del Guardiana Durango Mxico

Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at the stand level is a valuable support tool in forest inventories. The objective was to fit and propose a generalized H-d model for Pinus montezumae and Pinus pseudostrobus established in forest plantations of Nuevo San Juan Parangaricutiro, Michoacan, Mexico. Using nonlinear least squares (NLS), 10 generalized H-d models were fitted to 883 and 1226 pairs of H-d data from Pinus montezumae and Pinus pseudostrobus, respectively. The best model was refitted with the maximum likelihood mixed effects model (MEM) approach by including the site as a classification variable and a known variance structure. The Wang and Tang equation was selected as the best model with NLS;the MEM with an additive effect on two of its parameters and an exponential variance function improved the fit statistics for Pinus montezumae and Pinus pseudostrobus, respectively. The model validation showed equality of means among the estimates for both species and an independent subsample. The calibration of the MEM at the plot level was efficient and might increase the applicability of these results. The inclusion of dominant height in the MEM approach helped to reduce bias in the estimates and also to better explain the variability among plots.

关键词： Random Covariate Random Effects Variance Structure Forest Inventories Forest Management Mixed Models

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Neural functions of small heat shock proteins

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Neural Regeneration Research 2022年第3期17卷 512-515页

作者： Teresa de los reyes Sergio Casas-Tintó Instituto Cajal CSICMadridSpain

Stress response is a cellular widespread mechanism encoded by a common protein program composed by multiple cellular factors that converge in a defense reaction to protect the cell against *** many mechanisms described,heat shock proteins were proposed as universally conserved protective factors in the stress core proteome,coping with different stress stimuli through its canonical role in protein ***,emerging evidences reveal non-canonical roles of heat shock proteins relevant for physiological and pathological ***,we review the implications of inducible heat shock proteins in the central nervous system *** particular,we discuss the relevance of heat shock proteins in the maintenance of synapses,as a balanced protective mechanism in central nervous system development,pathological conditions and aging.

关键词： aging central nervous system chaperones environment neuroprotection pathology stress synapses

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Heat-induced mortality and expression of heat shock proteins in Colorado potato beetles treated with imidacloprid

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Insect Science 2016年第4期23卷 548-554页

作者： Jie Chen Ai Kitazumi Jasper Alpuerto Andrei Alyokhin Benildo de los reyes School of Biology and Ecology University of Maine Orono ME 04469 USA department of Entomology LouisianaState University Baton Rouge LA 70803 USA.

The Colorado potato beetle is an important pest of solanaceous plants in the Northern Hemisphere. Better understanding of its physiological responses to temperature stress and their interactions with still-prevalent chemical control has important implications for the management of this insect. We measured mortality and expression of the Hsp70 heat shock proteins in the Colorado potato beetle larvae exposed to sublethal concentration of the commonly used insecticide imidacloprid, and to supraoptimal temperatures. Both turned out to be significant stress factors, although induction of Hsp70 by imidacloprid observed in the present study was low compared to its induction by the heat. The two factors also interacted with each other. At an extreme temperature of 43 ~C, exposure to a sublethal dose of imidacloprid resulted in a significant rise in larval mortality, which was not observed at an optimal temperature of 25 ~C. Heat-stressed larvae also failed to respond to imidacloprid by producing more Hsp70. These findings suggest that when field rates of insecticides become insufficient for killing the exposed beetles under optimal temperature conditions due to the evolution of resistance in beetle populations, they may still reduce the probability of resistant beetles surviving the heat shock created by using propane flamers as a rescue treatment.

关键词： chemical stress climate change heat stress insecticide resistance integratedpest management Leptinotarsa decemlineata (Say)

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Regulation of floral senescence in Arabidopsis by coordinated action of CONSTANS and jasmonate signaling

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Molecular Plant 2022年第11期15卷 1710-1724页

作者： Gloria Serrano-Bueno Pedro de los reyes Andrea Chini Gabriel Ferreras-Garrucho Víctor Sánchez de Medina-Hernández Marta Boter Roberto Solano Federico Valverde Plant development Group Institute for Plant Biochemistry and PhotosynthesisCSIC-Universidad de Sevilla41092 SevillaSpain department of Plant Molecular Genetics Centro Nacional de BiotecnologíaCSIC28049 MadridSpain Crop Science Centre University of CambridgeCambridge CB3 OLE CambridgeUK Gregor Mendel Institute(GMI) Austrian Academy of SciencesVienna BioCenter(VBC)ViennaAustria

In Arabidopsis,photoperiodic flowering is controlled by the regulatory hub gene CONSTANS(CO),whereas floral organ senescence is regulated by the jasmonates(JAs).Because these processes are chronologically ordered,it remains unknown whether there are common regulators of both *** this study,we discovered that CO protein accumulates in Arabidopsis flowers after floral induction,and it displays a diurnal pattern in floral organs different from that in the *** observed that altered CO expression could affect flower senescence and abscission by interfering with JA response,as shown by petal-specific transcriptomic analysis as well as CO overexpression in JA synthesis and signaling *** found that CO has a ZIM(ZINC-FINGER INFLORESCENCE MERISTEM)like domain that mediates its interaction with the JA response repressor JAZ3(jasmonate ZIM-domain 3).Their interaction inhibits the repressor activity of JAZ3,resulting in activation of downstream transcription factors involved in promoting flower ***,we showed that CO,JAZ3,and the E3 ubiquitin ligase COI1(Coronatine Insensitive 1)could form a protein complex in planta,which promotes the degradation of both CO and JAZ3 in the presence of *** together,our results indicate that CO,a key regulator of photoperiodic flowering,is also involved in promoting flower senescence and abscission by augmenting JA signaling and *** propose that coordinated recruitment of photoperiodic and JA signaling pathways could be an efficient way for plants to chronologically order floral processes and ensure the success of offspring production.

关键词： CONSTANS flower senescence jasmonic acid

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Intestinal microbiota in health and disease: Role of bifidobacteria in gut homeostasis

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World Journal of Gastroenterology 2014年第41期20卷 15163-15176页

作者： Rafael Tojo Adolfo Suárez Marta G Clemente Clara G de los reyes-Gavilán Abelardo Margolles Miguel Gueimonde Patricia Ruas-Madiedo Gastroenterology department Hospital de Cabue?es Gastroenterology department Hospital Universitario Central de Asturias (HUCA) Respiratory department Hospital Universitario Central de Asturias (HUCA) department of Microbiology and Biochemistry of Dairy Products Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC)

The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. The colon is the most densely populated organ in the human body, although other parts, such as the skin, vaginal mucosa, or respiratory tract, also harbour specific microbiota. This microbial community regulates some important metabolic and physiological functions of the host, and drives the maturation of the immune system in early life, contributing to its homeostasis during life. Alterations of the intestinal microbiota can occur by changes in composition (dysbiosis), function, or microbiota-host interactions and they can be directly correlated with several diseases. The only disease in which a clear causal role of a dysbiotic microbiota has been demonstrated is the case of Clostridium difficile infections. Nonetheless, alterations in composition and function of the microbiota have been associated with several gastrointestinal diseases (inflammatory bowel disease, colorectal cancer, or irritable bowel syndrome), as well as extra-intestinal pathologies, such as those affecting the liver, or the respiratory tract (e.g., allergy, bronchial asthma, and cystic fibrosis), among others. Species of Bifidobacterium genus are the normal inhabitants of a healthy human gut and alterations in number and composition of their populations is one of the most frequent features present in these diseases. The use of probiotics, including bifidobacteria strains, in preventive medicine to maintain a healthy intestinal function is well documented. Probiotics are also proposed as therapeutic agents for gastrointestinal disorders and other pathologies. The World Gastroenterology Organization recently published potential clinical applications for several probiotic formulations, in which species of lactobacilli are predominant. This review is focused on probiotic preparations containing Bifidobacterium strains, alone or in combination with other bac

关键词： Intestinal microbiota Bifidobacterium Probiotics Dysbiosis Inflammatory bowel disease Irritable bowel syndrome Colorectal cancer Liver disease Respiratory disease Functional foods

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Whole lesion histogram analysis of apparent diffusion coefficient predicts therapy response in locally advanced rectal cancer

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World Journal of Gastroenterology 2022年第23期28卷 2609-2624页

作者： Mayra Evelia Jiménez de los Santos Juan Armando reyes-Pérez Victor Domínguez Osorio Yolanda Villaseñor-Navarro Liliana Moreno-Astudillo Itzel Vela-Sarmiento Isabel Sollozo-Dupont department of Radiology National Cancer InstituteMexico 14080Mexico department of Gastrointestinal Surgery National Cancer InstituteMexico 14080Mexico

BACKGROUND Whole-tumor apparent diffusion coefficient(ADC)histogram analysis is relevant to predicting the neoadjuvant chemoradiation therapy(nCRT)response in patients with locally advanced rectal cancer(LARC).AIM To evaluate the performance of ADC histogram-derived parameters for predicting the outcomes of patients with *** This is a single-center,retrospective study,which included 48 patients with *** patients underwent a pre-treatment magnetic resonance imaging(MRI)scan for primary tumor staging and a second restaging MRI for response *** sample was distributed as follows:18 responder patients(R)and 30 non-responders(non-R).Eight parameters derived from the whole-lesion histogram analysis(ADCmean,skewness,kurtosis,and ADC10^(th),25^(th),50^(th),75^(th),90^(th) percentiles),as well as the ADCmean from the hot spot region of interest(ROI),were calculated for each patient before and after *** all data were compared between R and non-R using the Mann-Whitney U *** measures of diagnostic accuracy were applied:the receiver operating characteristic curve and the diagnostic odds ratio(DOR).We also reported intra-and interobserver variability by calculating the intraclass correlation coefficient(ICC).RESULTS Post-nCRT kurtosis,as well as post-nCRT skewness,were significantly lower in R than in non-R(both Ploss of both kurtosis and skewness than non-R(Δ%kurtosis and Δ skewness,Pdemonstrated changes between groups were post-nCRT ADC10^(th),Δ%ADC10^(th),Δ%ADCmean,and ROIΔ%***,the best diagnostic performance was achieved byΔ%kurtosis at a threshold of 11.85%(Area under the receiver operating characteristic curve[AUC]=0.991,DOR=376),followed by post-nCRT kurtosis=0.78×10^(-3)mm^(2)/s(AUC=0.985,DOR=375.3),Δskewness=0.16(AUC=0.885,DOR=192.2)and post-nCRT skewness=1.59×10^(-3)mm^(2)/s(AUC=0.815,DOR=168.6).Finally,intraclass corr

关键词： Apparent diffusion coefficient Diffusion-weighted imaging Histogram analysis Magnetic resonance imaging Locally advanced rectal cancer

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