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mechanical properties of the A356 aluminum alloy modified with La/Ce

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journal of Rare Earths 2013年第8期31卷 811-816页

作者： E. Aguirre-de la Torre R. Pérez-Bustamante j. Camarillo-cisneros C.D. Gómez-Esparza H.m. medrano-Prieto R. martínez-Sánchez Advanced materials Research Center (CImAV) National Laboratory of Nanotechnology

The research of rare earths for the synthesis of materials with improved mechanical performance is of great interest when they are considered for potential applications in the automotive industry. In this regard, the effect on the mechanical properties and microstmcture of the automotive A356 aluminum alloy reinforced with 0.2 （wt.%） AI-6Ce-3La （ACL） was investigated. The ACL was added to the melted A356 alloy in the as-received condition and processed by mechanical milling. In the second route, the effect of the ACL processed by mechanical milling and powder metallurgy techniques was investigated, and compared with the results ob- tained from the A356 alloy strengthened with ACL in the as-received condition. microstmctural properties were evaluated by means of X-ray diffraction in order to observe the solubility of Ce/La in the A1 matrix. In addition, electron microscopy was employed in or- der to investigate the effect of milling time on the size and morphology of La/Ce phase under milling process. mechanical properties of the A356 alloy modified with ACL were measured by hardness and tensile test. For comparison unmodified specimens of the A356 were characterized according to the previous procedure. The microstructural and mechanical characterization was carried out in specimens alter solution and artificial aging. Observations in scanning electron microscopy indicated a homogeneous dispersion of La/Ce phases by using both routes; however, mechanical results, in the modified A356 alloy with the ACL in the as-received condi- tion, showed an improvement in the mechanical performance of the A356 alloy over that reinforced with the ACL mechanically milled.

关键词： A356 rare earths mechanical milling mechanical properties

Altitude as environmental filtering influencing phylogenetic diversity and species richness of plants in tropical mountains

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journal of mountain Science 2023年第2期20卷 285-298页

作者： GALVÁn-cisneros Carlos m. VILLA Pedro m. COELHO Alex j.P. CAmPOS Prímula V. mEIRA-nETO joão A.A. Laboratory of Ecology and Evolution of Plants Departamento de Biologia VegetalUniversidade Federal de ViçosaViçosaMG36570-900Brazil Botany Gradute Program Universidade Federal de ViçosaViçosaMG36570-900Brazil

Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology,especially in vulnerable ecosystems such as tropical *** studies are more relevant in global warming scenarios that induce the upward displacement of plant species towards reduced habitats and hostile environments in tropical *** study aimed to analyze how altitude affects taxonomic and phylogenetic diversity in plant communities of tropical ***,we tested if(i)increased altitude works as an environmental filtering promoting decreased species richness,decreased phylogenetic diversity,and increased phylogenetic clustering in these tropical mountains;and if(ii)plant communities of high altitude in tropical mountains are also result of recent diversification with plant species recently split shortening phylogenetic distances between closest related *** tested effects of altitude on species richness and phylogenetic metrics using linear mixed-effects *** Haleakala presented 114 species,mount Kilimanjaro presented 231 species and mount Purace presented 280 *** found an environmental filtering effect with increasing altitude causing phylogenetic clustering,decreased phylogenetic diversity and decreased species *** decreasing phylogenetic distances between closest relatives are congruent with neo-endemics,suggesting recent plant diversification in high altitudes of tropical mountains,possibly driven by geographic isolation and environmental *** of global warming should be monitored in tropical mountains focusing on distribution shifts.

关键词： Tropical mountains Global warming Environmental filtering Phylogenetic ecology Assembly rules Conservation mountaintop vegetation

Use of carbon nanotubes for strain and damage sensing of epoxy-based composites

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International journal of Smart and nano materials 2012年第2期3卷 152-161页

作者： j.Rams m.Sánchez A.Ureña A.j.ménez-Suárez m.Campo A.Güemes materials Science and Engineering Rey Juan Carlos UniversityTulipan s/nMostoles28933 MadridSpain ETSIA Universidad Politécnica de MadridPza.de Cardenal Cisneros 328040 MadridSpain

The interest in structural health monitoring of carbon fiber-reinforced polymers using electrical methods to detect damage in structures is growing because once the material is fabricated the evaluation of strain and damage is simple and *** order to obtain the conductivity,the polymer matrix must be conductive and the use of nanoreinforcement seems to be the most feasible *** this work,the behavior of nanoreinforced polymer with carbon nanotubes(CnTs)and composites with glass and carbon fibers with nanoreinforced matrices was *** composites were evaluated in tensile tests by simultaneously measuring stress,strain and *** elastic deformation,a linear increase in resistance was observed and during fracture of the composite fibers,stronger and discontinuous changes in the resistivity were *** other factors,the percentage of nanotubes incorporated in the matrix turned out to be an important factor in the sensitivity of the method.

关键词： carbon nanotube nanoreinforcement structural health monitoring strain sensing carbon fiber

Radiofrequency electric-field heating behaviors of highly enriched semiconducting and metallic single-walled carbon nanotubes

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nano Research 2015年第9期8卷 2859-2870页

作者： Stuart j. Corr mustafa Raoof Brandon T. cisneros Alvin W. Orbaek matthew A. Cheney justin j. Law nadia C. Lara Andrew R. Barron Lon j. Wilsor Steven A. Curley Division of Surgery Baylor College of Medicine Houston TX 77030 USA department of Surgical Oncology University of Texas M.D. Anderson Cancer Center Houston TX 77030 USA department of Chemistry and the Richard E. Smalley Institute for nanoscale Science and Technology Rice University Houston TX 77005 USA department of Surgery The University of Arizona College of Medicine Tucson AZ 85724 USA department of Chemistry and Biochemistry University of California San Diego La Jolla CA 92093 USA College of Engineering Swansea University Singleton Park Swansea SA2 8PP Wales UK department of mechanical Engineering and materials Science Rice University Houston TX 77005 USA

It is theorized that enhanced thermal heating may result from exposing single-walled carbon nanotubes （SWnTs） embedded in a conductive host to radiofrequency （RF） electric fields. We examine the RF-induced （13.56 mHz） heating behaviors of 95% metallic- and semiconducting-enriched SWnTs （m-/s-SWnTs） suspended in aqueous solutions with varying naC1 molarity （0.001 mm-1 m）. The heating effects were only evident for host molarities below 1 mm （equivalent to 0.1 S/m） at which the s-SWnT heating rates dominated those of the m-SWnTs. The heating effects were localized to aligned and aggregated ＂SWnT ropes＂ -1 cm in length that formed in suspension, parallel to the electric-field vector, during the RF exposure. For molarities above 1 mm, no enhancements were evident, owing to the large heating effects of the bulk ionic naC1 suspensions, which were observed in previous studies. Although larger enhancement effects proportional to the host conductivity have been theoretically predicted for m-/s-SWnT suspensions, this was not observed most likely because of the aggregation and screening effects, which diminished the scattered electric field near the m-/s-SWnTs. Our research may further the development of better nanoparticle heating agents for applications such as non-invasive RF-induced cancer hyperthermia.

关键词： rad.iofrequency,carbon nanotubes,metallic,semiconducting,hyperthermia

Dyslipidaemias and Physical Activity in Children with Cerebral Palsy

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Health 2014年第10期6卷 1030-1037页

作者： maciste Habacuc macías-Cervantes martha Susana Arriola-nunez Francisco j.Díaz-cisneros Antonio E.Rivera-cisneros jose maría de la Roca-Chiapas Victoriano Pérez-Vázquez departamento de Ciencias medicas Division de Ciencias de la SaludUniversidad de GuanajuatoLeonMexico Universidad del Valle de Atemajac GuadalajaraMexico departamento de Ciencias Aplicadas al Trabajo Division de Ciencias de la SaludUniversidad de GuanajuatoLeonMexico Division de Ciencias de la Salud Universidad de GuanajuatoLeonMexico departamento Psicología Division de Ciencias de la SaludUniversidad de GuanajuatoLeonMexico

Cerebral palsy people present movement difficulty and are liable to develop disorders associated with sedentary lifestyles such as dyslipidaemias and cardiovascular diseases. This study aimed to assess physical activity and the prevalence of lipid abnormalities in 29 children with cerebral palsy who were being treated in two care centers in the state of Guanajuato, mexico. Physical activity was calculated using a survey. Blood glucose, total cholesterol, HDL-C, LDL-C, and triglycerides were determined. Forty-eight percent had at least one dyslipidaemia. The most frequent lipid abnormalities were hypertriglyceridaemia and low HDL-C. High prevalence of the atherogenic index was found. The physical activity of children was lower than recommended for their age. Sixty-two percent attended rehabilitation sessions, 10% attended sports classes, 14% rehabilitation plus sports and 14% did not engage in intentional physical activity. There is high frequency of lipid disorders in children with cerebral palsy. Greater participation in physical activity should be promoted in children to improve their metabolic status and quality of life, especially those suffering from cerebral palsy.

关键词： Hypertriglyceridaemia HDL-C Atherogenic Index

Intense exercise increases HDL level in children regardless of body weight

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Health 2013年第12期5卷 1949-1953页

作者： Daniel Romero-Gamboa Victoriano Pérez-Vázquez Katya Vargas-Ortiz Francisco j. Díaz-cisneros Claudia martínez-Cordero maciste H. macías-Cervantes Apply Work Science department Health Science Division University of Guanajuato León México department of medical Sciences Health Science Division University of Guanajuato León México Hospital Regional de Alta Especialidad del Bajio León México

Childhood obesity seems to be increasing at a disturbing rate. Exercise and diet are recommended to combat this epidemic. Light and moderate physical activity is associated with health benefits, whereas intense physical activity is associated with normal BmI and low cardiovascular risk. The aim of this study was to assess the metabolic response to a graded exercise test (GXT) in children with different body weight. Eight boys and nine girls underwent a GXT on a treadmill according to Blake protocol. These children were 7-9 years old. The participants were divided into three groups according to their body weight: normal-weight, overweight, and obese. After GXT, lactate and HDL levels increased significantly in all three groups

关键词： Obesity Insulin Physical Activity

Effect of Aerobic Exercise on Protein Expression in muscle of Obese mexican Adolescents: A Proteomic and Bioinformatic Analysis

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natural Science 2014年第9期6卷 641-650页

作者： maciste H. macías-Cervantes juan m. Guzmán-Flores Katya Vargas-Ortiz Francisco j. Díaz-cisneros joel Ramírez-Emiliano Victoriano Pérez-Vázquez departmento de Ciencias Aplicadas al Trabajo División de Ciencias de la Salud Universidad de Guanajuato León México departmento de Ciencias médicas División de Ciencias de la Salud Universidad de Guanajuato León México

The beneficial effects of exercise have been recognized for many years yet the molecular mechanisms by which exercise show benefits on health are still elusive. A combination of experimental and bioinformatics approaches can be an invaluable tool to increase the cellular understanding of the molecular mechanisms that underlie the aerobic exercise in obese adolescents. muscle skeletal proteins were separated by 2D-PAGE and changes in protein expression were revealed by Imagemaster 2D Platinum analysis software. Proteins with expression changes after aerobic exercise were identified by comparison with 2D maps from SWISS-2DPAGE and interactions of proteins were analyzed with STRInG and DAVID databases. After aerobic exercise, all participants decreased glucose, insulin, total cholesterol, body mass index and waist circumference. Proteomic differential analysis revealed 10 overexpressed proteins after aerobic training, which correspond to carbonic anhydrase III, beta enolase, creatine kinase, ATP synthase beta subunit, aldolase A, glyceraldehyde-3-phosphate dehydrogenase, triosephosphate isomerase, pyruvate kinase, lactate dehydrogenase and adenylate kinase. Exercise increased glycolysis and oxidative phosphorylation pathways, which is likely to be regulated by ubiquitin c protein. In conclusion, our analysis suggested that obese adolescents show changes in their body mass index, waist circumference and serum glucose after aerobic exercise through improved protein expression patterns that aid, especially, glucose metabolism and increase the oxidative phosphorylation. The most likely explanation for the observed pattern is that ubiquitin c protein keeps the glycolytic enzymes bound within skeletal muscle, obtaining a non-degradative role in cell signaling.

关键词： Glycolysis Oxidative Phosphorylation Ubiquitin C Protein Proteomics Exercise

Use of <i>Rosmarinus officinalis</i>as Green Corrosion Inhibitor for Carbon Steel in Acid medium

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American journal of Analytical Chemistry 2014年第2期5卷 55-64页

作者： m. A. Velázquez-González j. G. Gonzalez-Rodriguez m. G. Valladares-cisneros I. A. Hermoso-Diaz Universidad Autonoma del Estado de morelos CIICAp Col. Chamilpa Cuernavaca Mexico Universidad Autonoma del Estado de morelos FCQeI Col. Chamilpa Cuernavaca Mexico

The use of Rosmarinus officinalis as a corrosion inhibitor for 1018 carbon steel in 0.5 m H2SO4 has been evaluated by using weight loss, potentiodynamic polarization curves and electrochemical impedance spectroscopy techniques at 25°. Inhibitor concentrations were included within the range between 0 and 1000 ppm C using three extract solvents, namely acetone, hexane and methanol. Results have shown that Rosmarinus officinalis is a good corrosion inhibitor with its efficiency increasing with the concentration. The best efficiency was obtained with the hexanic extract. The passivating film properties of the steel were improved by the presence of flavonoids in the extract.

关键词： metals Corrosion Fourier Transform Infrared Spectroscopy Electrochemical Techniques

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系统性红斑狼疮患者头痛患病率及其影响因素

世界核心医学期刊文摘（神经病学分册） 2005年第4期1卷 15-16页

作者： Weder-cisneros n.D. T' ellez-Zenteno j.F. Cardiel m.H. 黄卫东 dept. of neurology and Psychiatry Inst. Nac. Cie. Med./Nutr. S. Z. INCMNSZ Mé xico City Mexico

Headache is common in systemic lupus erythematosus with reported prevalence as high as 70% . The aims of this study were: to estimate the prevalence and types of headache in a sample of patients with systemic lupus erythematosus comparing it with rheumatoid arthritis, to determine clinical and serological associations. Eighty- one systemic lupus erythematosus and 29 rheumatoid arthritis consecutive patients seen in our outpatient clinic were interviewed. Headache was evaluated using the diagnostic criteria proposed by the International Headache Society. Additional evaluations were carried out in the 81 systemic lupus erythematosus patients including depression, disease activity, lupus damage, function disability, quality of life, and severity degree using a validated scales. We analysed the following autoantibodies: anti- double stranded DnA, antinucleosomes, anti- histones, anti- ribosomal P, anti- cardiolipin antibodies, anti- β 2- glycoprotein- I (GPI), and antinuclear antibodies. Forty- one per cent of systemic lupus erythematosus and 17% of rheumatoid arthritis patients suffered from headache (P = 0.02). no significant difference for any primary headache type between the two groups was found. Frequency of headache types in systemic lupus erythematosus patients was: migraine 24% , tensional- type headache 11% , and mixed headache 5% . In systemic lupus erythematosus patients the risk factors associated with headaches were Raynaud’ s phenomenon (OR 3.6; 95% CI 1.3- 9.5; P = 0.009) and β 2GPI antibody positivity (OR 4.5; 95% CI 1.2- 16.2; p = 0.016). We conclude that headache is more common in systemic lupus erythematosus than in rheumatoid arthritis patients and was independently associated with Raynaud’ s phenomenon and β 2GP- I antibodies.

关键词：系统性红斑狼疮抗组蛋白抗体抗核小体抗体抗核糖体影响因素风湿性关节炎抗核抗体自身抗体磷脂酰甘油疾病严重程度