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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

Prevention of late complications with coverage agents in endoscopic resection of colorectal lesions: Current landscape in gastrointestinal endoscopy

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World Journal of Gastroenterology 2021年第15期27卷 1563-1568页

作者： Vicente Lorenzo-Zúñiga Marco bustamante-Balén Vicente Pons-Beltrán Endoscopy Unit Department of GastroenterologyHospital Universitari i Politècnic La FeValencia 46026Spain Digestive Diseases Department La Fe Polytechnic University HospitalValencia 46026Spain

Endoscopic removal of large(≥20 mm)non-pedunculated colorectal lesions(LNPCLs)may result in major adverse events,such as delayed bleeding(DB)and delayed perforation(DP),despite closure of the mucosal defects with *** application of a coverage agent refers to the creation of a shield with a biocompatible medical device(tissue or hydrogel)with proven bioactive *** of the eschar after endoscopic resection provides shielding protection to prevent delayed *** aim of the present review was to systematically collect and review the currently available literature regarding the prevention of DB and DP with coverage agents after endoscopic mucosal resection or endoscopic submucosal dissection of LNPCLs.

关键词： Large colorectal lesions Delayed bleeding Topical application Endoscopic mucosal resection Endoscopic submucosal dissection

What can we learn from β-cell failure biomarker application in diabetes in childhood?A systematic review

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World Journal of Diabetes 2021年第8期12卷 1325-1362页

作者： María F Calderón-Hernández Nelly F Altamirano-bustamante Cristina revilla-Monsalve María Belen Mosquera-Andrade Myriam M Altamirano-bustamante Unidad de Investigación en Enfermedades Metabólicas Centro Médico Nacional Siglo XXIIMSSMexico 06720Mexico Department of Endocrinology Instituto Nacional de PediatríaMexico 04530Mexico

BACKGrOUND The prevalence of diabetes as a catastrophic disease in childhood is growing in the *** search for novel biomarkers ofβ-cell failure has been an elusive task because it requires several clinical and biochemical measurements in order to integrate the risk of metabolic *** To determine which biomarkers are currently used to identifyβ-cell failure among children and adolescents with high risk factors for diabetes *** This systematic review was carried out using a modified version of the PICO protocol(Participants/Intervention/Comparison/Outcome).Once our research question was established,terms were individually researched on three different databases(PubMed,BIrEME and Web of Science).The total articles obtained underwent a selection process from which the 78 most relevant articles were retrieved to undergo further *** were assessed individually according to quality *** First,we made the classification of theβ-cell-failure biomarkers by the target tissue and the evolution of the disease,separating the biomarkers in relation to the types of ***,we demonstrated that most biomarkers currently used as early signs ofβ-cell failure are those that concern local or systemic inflammation processes and oxidative stress as well as those related to endothelial dysfunction ***,we explored the novelties of diabetes as a protein conformational disease and the novel biomarker called real human islet amyloid polypeptide amyloid ***,we ended with a discussion about the best practice of validation and individual control of using different types of biomarkers in type 1 and type 2 diabetes in order to assess the role they play in the progress of diabetes in *** This review makes widely evident that most biomarkers currently used as early signs ofβ-cell failure are those that concern local or systemic inflammation processes and oxidative stress as well as those related to endo

关键词： Biomarker β-cell failure Children Adolescents Diabetes mellitus Metabolic syndrome

Effect of treatment failure on the Cag A EPIYA motif in Helicobacter pylori strains from Colombian subjects

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World Journal of Gastroenterology 2017年第11期23卷 1980-1989页

作者： Javier Andres bustamante-rengifo Andres Jenuer Matta Alvaro Jairo Pazos Luis Eduardo Bravo Department of Microbiology School of Basic ScienceUniversidad del Valle registro Poblacional de Cáncer de Cali Department of PathologySchool of MedicineUniversidad del Valle Department of Biology Universidad de Narino

AIM To evaluate effect of treatment failure on cag A and vac A genotypes in Helicobacter pylori(H. pylori) isolates from *** One hundred and seventy-six participants infected with H. pylori from Colombia were treated during 14 d with the triple-standard therapy. Six weeks later, eradication was evaluated by 13C-Urea breath test. Patients with treatment failure were subjected to endoscopy control; biopsies obtained were used for histopathology and culture. DNA from H. pylori isolates was amplified using primers specific for cag A and vac A genes. The phylogenetic relationships among isolates obtained before and after treatment were established by conglomerate analysis based on random amplified polymorphic DNA(rAPD) *** Treatment effectiveness was at 74.6%. Of the par-ticipants with treatment failure, 25 accepted subjected to a second endoscopy. Prevalence of posttreatment infection was 64%(16/25) and 40%(10/25) by histology and culture, respectively. Upon comparing the cag A and vac A genotypes found before and after therapy, multiple cag A genotypes(cag A-positive and cag A-negative) were found before treatment; in contrast, cag A-negative genotypes decreased after treatment. vac A s1m1 genotype was highly prevalent in patients before and after therapy. The 3'cag A region was successfully amplified in 95.5%(21/22) of the isolates obtained before and in 81.8%(18/22) of the isolates obtained after treatment. In the isolates obtained from patients with treatment failure, it was found that 72.7%(16/22) presented alterations in the number of EPIYA motifs, compared to isolates found before *** Unsuccessful treatment limits colonization by lowvirulence strains resulting in partial and selective eradication in mixed infections, and acts on the cag A-positive strains inducing genetic rearrangements in cag A variable region that produces a loss or gain of EPIYA repetitions.

关键词： Helicobacter pylori rAPD-PCr Treatment failure EPIYA motifs 3’ cag A variable region

Microstructural evaluation and nanohardness of an AlCoCuCrFeNiTi high-entropy alloy

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 634-641页

作者： C.D.Gómez-Esparza r.Peréz-bustamante J.M.Alvarado-Orozco J.Mu?oz-Salda?a r.Martínez-Sánchez J.M.Olivares-ramírez A.Duarte-Moller Centro de Investigación en Materiales Avanzados (CIMAV) Laboratorio Nacional de Nanotecnología CONACYT-Corporación Mexicana de Investigación en Materiales S.A.de C.V.(COMIMSA) Centro de Ingeniería y Desarrollo Industrial Querétaro Campus Centro de Investigación y de Estudios Avanzados del IPN Unidad Querétaro Universidad Tecnológica de San Juan del río Escuela de Ingeniería Civil Industrialy Mecánica Universidad De La Salle Bajío

An AlCoCuCrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system. The structural and microstructural characteristics were investigated by X-ray diffraction(XrD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with Cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XrD patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeNi alloy. Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlCoCuCrFeNiTi HEA.

关键词： high-entropy alloys mechanical alloying microstructure nanoindentation

In vitro effect of amoxicillin and clarithromycin on the 3' region of cagA gene in Helicobacter pylori isolates

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World Journal of Gastroenterology 2013年第36期19卷 6044-6054页

作者： Javier Andrés bustamante-rengifo Andrés Januer Matta Alvaro Pazos Luis Eduardo Bravo registro Poblacional de Cáncer de Cali Department of Pathology School of Medicine Universidad del Valle Department of Biology Universidad de Nario

AIM:To evaluate the in vitro effect of amoxicillin and clarithromycin on the cag pathogenicity island(cag PAI).METHODS:One hundred and forty-nine clinical isolates of Helicobacter pylori(***)cultured from gastric biopsies from 206 Colombian patients with dyspeptic symptoms from a high-risk area for gastric cancer were included as study *** susceptibility was determined by the agar dilution *** isolates at baseline and in amoxicillin and clarithromycin serial dilutions were subjected to genotyping(cagA,vacA alleles s and m),Glu-Pro-Ile-Tyr-Ala(EPIYA)polymerase chain reaction and random amplified polymorphic DNA(rAPD).Images of the rAPD amplicons were analyzed by Gel-Pro Analyzer *** analyses was done using SPSS 15.0statistical package,where each of the fingerprint bands were denoted as *** were designed by following Ward’s clustering method and the estimation of distances between each pair of *** isolates was calculated with the squared Euclidean ***:resistance rates were 4%for amoxicillin and 2.7%for clarithromycin with 2%double *** evidenced a high prevalence of the genotype cagA-positive/vacA *** 3’region of cagA gene was successfully amplified in 92.3%(12/13)of the baseline resistant isolates and in 60%(36/60)of the resistant isolates growing in antibiotic *** observing the distribution of the number of EPIYA repetitions in each dilution with respect to baseline isolates,it was found that in 61.5%(8/13)of the baseline isolates,a change in the number of EPIYA repetitions lowered antibiotic *** gain and loss of EPIYA motifs resulted in a diversity of *** subclones after bacterial adjustment to changing conditions product of antibiotic *** PCr evidenced the close clonal relationship between baseline isolates and isolates growing in antibiotic ***:Antibiotic pressure does not induce loss of the cag pathoge

关键词： Helicobacter pylori Antimicrobial susceptibility cag pathogenicity island cagA 3’region random amplified polymorphic DNA-polymerase chain reaction

Genomic variability of Helicobacter pylori isolates of gastric regions from two Colombian populations

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World Journal of Gastroenterology 2017年第5期23卷 800-809页

作者： Andrés Jenuer Matta Alvaro Jairo Pazos Javier Andrés bustamante-rengifo Luis Eduardo Bravo registro Poblacional de Cáncer de Cali Department of PathologySchool of MedicineUniversidad del Valle Department of Biology Universidad de Narino

AIMTo compare the genomic variability and the multiple colonization of Helicobacter pylori (H. pylori) in patients with chronic gastritis from two Colombian populations with contrast in the risk of developing gastric cancer (GC): Túquerres-Nariño (High risk) and Tumaco-Nariño (Low risk).METHODSFour hundred and nine patients from both genders with dyspeptic symptoms were studied. Seventy-two patients were included in whom H. pylori was isolated from three anatomic regions of the gastric mucosa, (31/206) of the high risk population of GC (Túquerres) and (41/203) of the low risk population of GC (Tumaco). The isolates were genotyped by PCr-rAPD. Genetic diversity between the isolates was evaluated by conglomerates analysis and multiple correspondence *** proportion of virulent genotypes of H. pylori was 99% in Túquerres and 94% in Tumaco. The coefficient of similarity of Nei-Li showed greater genetic diversity among isolates of Túquerres (0.13) than those of Tumaco (0.07). After adjusting by age, gender and type of gastritis, the multiple colonization was 1.7 times more frequent in Túquerres than in Tumaco (P = 0.05).CONCLUSIONIn Túquerres, high risk of GC there was a greater probability of multiple colonization by H. pylori. From the analysis of the results of the PCr-rAPD, it was found higher genetic variability in the isolates of H. pylori in the population of high risk for the development of GC.

关键词： Helicobacter pylori Pathogenicity islet cag cagA vacA Multiple colonization PCr-rAPD

Advances in immunotherapy for treatment of lung cancer

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Cancer Biology & Medicine 2015年第3期12卷 209-222页

作者： Jean G.bustamante Alvarez María González-Cao Niki Karachaliou Mariacarmela Santarpia Santiago Viteri Cristina Teixidó rafael rosell Albert Einstein Medical Center Translational Cancer research Unit Instituto Oncológico Dr RosellQuirón Dexeus University Hospital Medical Oncology Unit Human Pathology Department University of Messina Pangaea Biotech S.L Cancer Biology & Precision Medicine Program Catalan Institute of Oncology Germans Trias i Pujol Health Sciences Institute and Hospital Campus Can Ruti Fundación Molecular Oncology research

Different approaches for treating lung cancer have been developed over time, including chemotherapy, radiotherapy and targeted therapies against activating mutations. Lately, better understanding of the role of the immunological system in tumor control has opened multiple doors to implement different strategies to enhance immune response against cancer cells. It is known that tumor cells elude immune response by several mechanisms. The development of monoclonal antibodies against the checkpoint inhibitor programmed cell death protein 1 （PD-1） and its ligand （PD-L1）, on T cells, has led to high activity in cancer patients with long lasting responses. Nivolumab, an anti PD-1 inhibitor, has been recently approved for the treatment of squamous cell lung cancer patients, given the survival advantage demonstrated in a phase III trial. Pembrolizumab~ another anti PD-1 antibod）5 has received FDA breakthrough therapy designation for treatment of non-small cell lung cancer （NSCLC）, supported by data from a phase I trial. Clinical trials with anti PD-1/PD-L1 antibodies in NSCLC have demonstrated very good tolerability and activity, with response rates around 20% and a median duration of response of 18 months.

关键词： Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) immune checkpoint inhibitors lung cancer programmed celldeath protein ligand-1 (PD-L1) programmed cell death protein i (PD-1)

Natural durability of wood of ten native species from northeastern Mexico

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Forestry Studies in China 2013年第2期15卷 160-166页

作者： Artemio CArrILLO rahim FOrOUGHBACHK Verónica bustamante Christian WEHENKEL Humberto GONZáLEZ Universidad Autónoma de Nuevo León (UANL) Facultad de Ciencias ForestalesCarr. Nal. No. 85 Km 145. 66700 041. Linares Nuevo León México Universidad Autónoma de Nuevo León (UANL) Facultad de Ciencias Biológicas San Nicolás de los GarzaNuevo León 66451 México Instituto de Silvicultura e Industria de la Madera Universidad Juárez del Estado de DurangoKm 5.5 Carretera Mazatlán 34120 Durango México

Thorn scrub vegetation in Mexico is distributed over 50 million ha, where native tree species are the source of forage, timber, firewood and charcoal. research describing wood durability of species from this vegetation type has not been fully determined, nor classified according to international standards. Thus, the aim of this study was to determine and classify the natural durability of ten woody species. Their natural durability was determined according to the European Pre-Norm 807, the loss of dynamic modulus of elasticity （MOEdyo）（MPa） was determined and wood mass loss （g） after being exposed to Trametes versicolor and Coniophora puteana fungi. Wood durability was classified accord- ing to the European Norm 350-1. Highly significant differences （p 〈 0.001） were found between the durability of woody species. The more durable species with lower MOEdyn lost were Condalia hooked （57.5% ± 0.6%）, Havardia pallens （58.2% ± 0.4%） and Acacia schaffneri （58.9% ±6.3%）. Species with lower mass loss after exposed to Coniophora puteana were Ebenopsis ebano （6.3% ±1.9%）, Condalia hooked （8.6% ±2.3%） and Cordia boissieri （11.8% ±2.3%）. E. ebano （7.1% ±2.4%）, Condalia hooked （8.2% ± 2.5%） and Cordia boissieri （11.5% ± 3.1%） showed the lower mass lost after exposed to T. versicolor. According to European Norm 350-1, three woody species were classified as very durable and durable species.

关键词： native species natural durability dynamic modulus of elasticity mass loss