检索结果-南通市图书馆

Effect of homogenization process on the hardness of Zn-Al-Cu alloys

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of minerals,metallurgy and materials 2015年第10期22卷 1076-1081页

作者： jose D.Villegas-Cardenas maribel L.Saucedo-munoz Victor m.lopez-Hirata Antonio De Ita-De la Torre Erika O.Avila-Davila Jorge Luis Gonzalez-Velazquez Department of metallurgy and materials Instituto Politecnico Nacional(IPN-ESIQIE)Mexico City 07300Mexico Department of Industrial Engineering Universidad Politecnica del Valle de MexicoMexico CityMexico Department of materials Universidad Autonoma Metropolitana(UAM)Unidad AzcapotzalcoMexico

The effect of a homogenizing treatment on the hardness of as-cast Zn–Al–Cu alloys was investigated. Eight alloy compositions were prepared and homogenized at 350 °C for 180 h, and their Rockwell 'B' hardness was subsequently measured. All the specimens were analyzed by X-ray diffraction and metallographically prepared for observation by optical microscopy and scanning electron microscopy. The results of the present work indicated that the hardness of both alloys(as-cast and homogenized) increased with increasing Al and Cu contents; this increased hardness is likely related to the presence of the θ and τ′ phases. A regression equation was obtained to determine the hardness of the homogenized alloys as a function of their chemical composition and processing parameters, such as homogenization time and temperature, used in their preparation.

关键词： zinc–aluminum–copper alloys casting hardness homogenization phases microstructure

Different Roles of microalloying in Thin Slab Direct Rolling Technologies

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 459-465页

作者： Rodriguez-Ibabe jose m Uranga Pello lopez Beatriz CEIT and Tecnun (Univ.of Navarra) P M.Lardizabal 1520018-San SebastianBasque CountrySpain

HSLA steels constitute one of the main types of steels produced worldwide by Thin Slab Direct Rolling technologies (TSDR).Among microalloying elements,the most widely used are V,Nb and *** elements play different roles during the austenite evolution in *** austenite conditioning before transformation,the limitations in the total reduction that can be applied in TSDR technologies need to be considered when composition/process parameters are *** this context,whereas an important number of studies have been focused on Nb microalloyed grades,a less systematic analysis has been performed concerning the role of vanadium on austenite *** paper analyzes these singularities taking into account different process parameter conditions,such as total reduction and initial rolling temperature.

关键词： thin slab direct rolling microalloyed steels vanadium niobium austenite conditioning

Disturbance and forest recovery in the monarch Butterfly Biosphere Reserve,mexico

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2020年第5期31卷 1551-1566页

作者： jose lopez-Garcıa Rafael m.Navarro-Cerrillo Instituto de Geografıa Universidad Nacional Autonoma de MexicoCiudad UniversitariaC.P.04510 CoyoacanDFMexico Departamento de Ingenierıa Forestal Universidad de CordobaCampus de RabanalesCarretera Nacional IV km 39614014 CordobaSpain

Analysis of the change in forest cover is important to determine stand dynamics and the processes involved in disturbance and *** of the core zone of the monarch Butterfly Biosphere Reserve were studied using photo interpretation techniques,considering biennial changes between 1999 and 2013 and changes over the whole period of study 1999–*** matrices were elaborated to determine the processes of change involved in both recovery and *** biennial changes for the whole period amounted to 2274 ha;343 ha accounted as degraded in more than one biennial *** total changes in forest cover between 1999 and 2013 involved 4902 ha,out of which,2912 ha were affected by disturbance,and 1990 ha were *** density and 2013 vegetation cover maps,the overall accuracy was 95.6%and 90.2%,*** combining both maps,gradual processes were revealed that were not evident in separate *** methodology is useful for the management and conservation of natural protected areas.

关键词： Illegal logging Forest density change Forest recovery Conifer forests monarch Butterfly Biosphere Reserve

Survival after pulmonary metastasectomy in colorectal cancer patients:does a history of resected liver metastases worsen the prognosis?A literature review

在线全文

学校读者我要写书评

暂无评论

Cancer Biology & medicine 2017年第3期14卷 281-286页

作者： Jon Zabaleta Borja Aguinagalde Iker lopez Arantza Fernandez-monge jose m.Izquierdo jose I.Emparanza Thoracic surgery service Hospital UniversitarioDonostiaGipuzkoa 20014Spain

Objective: To assess the impact of past liver metastases on the survival duration of patients who are undergoing surgery for lung ***: We conducted a review of literature published from 2007 to 2014. The studies were identified by searching Pub med,mEDLINE, and Embase and were supplemented by a manual search of the references listed by the retrieved studies. The following search terms were used: lung metastasectomy, pulmonary metastasectomy, lung metastases, and lung metastasis. We selected retrospective and prospective studies published from 2007 to 2014 on patients with lung metastases from colorectal cancer and were undergoing surgery with curative intent. We excluded reviews, studies that focused on surgical techniques, patients who were treated non-surgically, analyses of specific subgroups of patients, and those that did not report follow-up of the patients undergoing ***: We identified 28 papers that assessed survival after lung metastases, 21 of which were mostly retrospective studies that identified previous liver metastases to explore their impact on patient survival. In more than half of the papers analyzed(63.2%),patients with a history of resected liver metastases had a lower survival rate than those who did not have such a history, and the difference was statistically significant in eight of these studies. However, data were presented differently, and authors reported mean survival time, survival rates, or hazard ***: A history of liver metastases seems to be a negative prognostic factor, but the individual data need to undergo a meta-analysis.

关键词： Lung metastasis liver colorectal cancer review

Nonlinear parabolic predator-prey coupled system with convection

在线全文

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2021年第2期14卷 83-118页

作者： jose Luis Diaz Palencia mariano Fernandez lopez University Foundation San Pablo CEU Spain

The aim of this work is to provide a formulation of two related nonlinear diffusive convective models in the form of coupled reaction-absorption ***,the postulated models are studied with an analytical *** on,numerical evidences are considered to account for a precise *** problem(P)analyzed is of the form:ut=δΔu+c⋅∇u+v^(n),vt=ϵΔv+c⋅∇v−um,n,m∈(0,1),u_(0)(x),v_(0)(x)>0∈L^(1)_(loc)(RN)∩L^(∞)(R^(N)).(0.1)Afterwards,a related problem P_(T)is studied:ut=δΔu+c⋅∇u−v^(n)(u−d),vt=ϵΔv+c⋅∇v−u^(m)v,n,m∈(0,1),u_(0)(x),v_(0)(x)>0∈L^(1)_(loc)(R^(N))∩L^(∞)(R^(N)).(0.2)The principal aspects for analysis are related to the existence and the derivation of particular solutions to reproduce the dynamic of the interacting *** the problem PT,we make use of the TW approach to study existence of solutions and precise evolution of *** that the term predator is used to refer to an invasive behavior,while the term prey is used for the invaded species.

关键词： Nonlinearity reaction absorption coupled system diffusion,traveling waves

Highly accessible aqueous synthesis of well-dispersed dendrimer type platinum nanoparticles and their catalytic 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

Nano Research 2019年第5期12卷 1083-1092页

作者： Adrian Fernandez-Lodeiro Jamila Djafari David lopez-Tejedor Carlos Perez-Rizquez Benito Rodriguez-Gonzalez jose Luis Capelo jose m.Palomo Carlos Lodeiro Javier Fernandez-Lodeiro BIOSCOPE Group LAQV@REQUIMTEChemistry DepartmentFaculty of Science and TechnologyUniversity NOVA of LisbonCaparica CampusCaparica 2829-516Portugal PROTEOmASS Scientific Society Rua dos InventoresMadan ParqueCaparica CampusCaparica 2829-516Portugal Department of Biocatalysis Institute of Catalysis(CSIC)MadridSpainMarie Curie 2CantoblancoUAM CampusMadrid 28049Spain Scientific and Technological Research Assistance Center(CACTI) University of VigoLagoas-MarcosendeVigo 36310Spain

The application of novel methodologies to the synthesis of nanomaterials is still a challenge in many different technological and scientific *** efficient and reproducible synthetic methodologies,that produce fewer residues and reduce the cost of raw materials must be *** the present work,we have explored the attractive possibility to apply the cheap iron (Ⅱ) sulphate salt in the reduction process of the K2PtCl4 to produce colloids *** synthesis took places in water and was assisted by sodium citrate (SC) using polyvinylpyrrolidone (PVP) as a *** adjustment of this novelty process allows obtaining well-dispersed and sub-20 nm dendrimer-type platinum nanoparticles (Pt D-NPs).The nano-dendrimers produced have been characterized using dynamic light scattering (DLS),transmission electron microscopy (TEm),high-resolution TEm (HR-TEm),XRD spectroscopy,inductive couple plasma (ICP) analysis,Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-vis) *** conformational results derived from the size and shape will be *** application of the Pt D-NPs has been explored in the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) in aqueous media at room temperature obtained TOF value of 253 min^-***,our Pt D-NPs were tested as artificial metalloenzyme showing catechol oxidase activity for oxidation of L-DOPA.

关键词： platinum dendrimer NPs catalytic application green synthesis cateohol oxidase-like activity

Paclitaxel-loaded hollow-poly（4-vinylpyridine） nano- particles enhance drug chemotherapeutic efficacy in lung and breast cancer cell lines

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2017年第3期10卷 856-875页

作者： Rafael Contreras-Caceres maria C. Leiva Raul Ortiz Amelia Diaz Gloria Perazzoli miguel A.Casado-Rodriguez Consolacion melguizo jose m. Baeyens Juan m. lopez-Romero jose Prados Department of Organic Chemistry Faculty of Science University of Mdlaga 29071 Malaga Spain Institute of Biopathology and Regenerative medicine (IBImER) Center of Biomedical Research (CIBM) University of Granada 18100 Granada Spain Department of Anatomy and Embryology Faculty of Medicine University of Granada 18071 Granada Spain Biosanitary Institute of Granada (IBS. GRANADA) SAS-Universidad de Granada 18014 Granada Spain Department of Health Science University of Jaen 23071 Jadn Spain Department of Pharmacology Institute of Neuroscience Biomedical Research Center (CIBM) University of Granada 18100 Granada Spain

Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine）（hollow-p4VP） nanoparticles （NPs） have been used for the first time to generate PTX@p4VP NPs, employing a novel technique in which a gold core in the center of the NP is further oxidized to produce the hollow structure into which PTX molecules can be incorporated. The hollow-p4VP NPs exhibit good physicochemical properties and displayed excellent biocompatibility when tested on blood （no hemolysis） and cell cultures （no cytotoxicity）. Interestingly, PTX@p4VP NPs significantly increased PTX cytotoxicity in human lung （A-549） and breast （mCF-7） cancer cells with a significant reduction of PTX ICs0 （from 5.9 to 3.6 nm in A-549 and from 13.75 to 4.71 nm in mCF-7）. In addition, PTX@p4VP caused a decrease in volume of A-549 and mCF-7 multicellular tumor spheroids （mTS）, an in vitro system that mimics in vivo tumors, in comparison to free PTX. This increased antitumoral activity is accompanied by efficient cell internalization and increased apoptosis, especially in lung cancer mTS. Our results offer the first evidence that hollow- p4VP NPs can improve the antitumoral activity of PTX. This system can be used as a new nanoplatform to overcome the limitations of current breast and lung cancer treatments.

关键词： paclitaxel poly(4-vinylpyridine)(p4VP) nanoparticles lung cancer breast cancer cytotoxicity multicellular tumorspheroids

DNA features beyond the transcription factor binding site specify target recognition by plant mYC2-related bHLH proteins

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Communications 2021年第6期2卷 27-43页

作者： Irene lopez-Vidriero marta Godoy Joaquin Grau maria Penuelas Roberto Solano jose m.Franco-Zorrilla Genomics Unit Centro Nacional de BiotecnologiaCSICC/Darwin 328049 MadridSpain Department of Plant molecular Genetics Centro Nacional de BiotecnologiaCSICC/Darwin 328049 MadridSpain

Transcription factors(TFs)regulate gene expression by binding to cis-regulatory sequences in the promoters of target *** research is helping to decipher in part the cis-regulatory code in eukaryotes,including plants,but it is not yet fully understood how paralogous TFs select their *** we addressed this question by studying several proteins of the basic helix-loop-helix(bHLH)family of plant TFs,all of which recognize the same DNA *** focused on the mYC-related group of bHLHs,that redundantly regulate the jasmonate(JA)signaling pathway,and we observed a high correspondence between DNA-binding profiles in vitro and mYC function in *** demonstrated that A/T-rich modules flanking the mYC-binding motif,conserved from bryophytes to higher plants,are essential for TF recogni*** observed particular DNA-shape features associated with A/T modules,indicating that the DNA shape may contribute to mYC DNA *** extended this analysis to 20 additional bHLHs and observed correspondence between in vitro binding and protein function,but it could not be attributed to A/T modules as in *** conclude that different bHLHs may have their own codes for DNA binding and specific selection of targets that,at least in the case of mYCs,depend on the TF-DNA interplay.

关键词： transcription factor bHLH target specificity plants

First report of L1014F kdr mutation in Culex quinquefasciatus in mexico

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2016年第6期23卷 829-834页

作者： Gustavo Ponce Iram P. Sanchez Selene m. Garcia jose m. Torrado Saul Lozano-Fuentes Beatriz lopez-monroy Adriana E. Flores Facultad de Ciencias Biologicas Universidad Autonoma de Nuevo Leon A v. Universidad sin Cd. Universitaria San Nicolas de los GarzaN.L. 66455 Mexico Department of microbiology Immunology and Pathology Colorado State University Fort Collins CO USA

The L1014F mutation in the voltage-sodium channel gene has been associated with resistance to DDT and pyrethroids in various arthropod species including mosquitoes. We determined the frequency of the L1014F kdr mutation in 16 field populations of Culex quinquefasciatus from Northeastern mexico collected between 2008 and 2013. The L1014F was present in all populations analyzed with the lowest frequency （3.33%） corresponding to the population from monclova collected in 2012, and the highest frequency （63.63%） from the monterrey population collected in 2012. The presence of a kdr mutation in populations of Cx. quinquefasciatus from northeastern mexico provides evidence ofpyrethroid resistance. This requires a special attention, considering that pyrethroid-based insecticides are commonly used in vector-control campaigns, especially against Aedes aegypti （L.）.

关键词： Culex quinquefasciatus insecticide resistance kdr L 1014F mutation