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Changes in niche differentiation and environmental filtering over a hydric stress gradient

Journal of Plant Ecology 2020年第2期13卷 185-194页

作者： alejandra martínez-Blancas Carlos martorell Departamento de Ecología y Recursos Naturales Facultad de CienciasUniversidad Nacional Autónoma de MéxicoCoyoacán04510 Ciudad de MéxicoMexico Posgrado en Ciencias Biológicas Universidad Nacional Autónoma de MéxicoAv.Ciudad Universitaria 3000C.P.04510CoyoacánCiudad de MéxicoMexico

Aims Diversity in communities is determined by species’ability to coexist with each other and to overcome environmental stress that may act as an environmental *** differentiation(ND)results in stronger intra-than interspecific competition and promotes *** stress affects interactions,the strength of ND may change along stress gradients.A greater diversity of plant growth forms has been observed in stressful habitats,such as deserts and alpine regions,suggesting greater ND when stress is *** tested the hypothesis that niche differences and environmental filters become stronger with *** In a semiarid grassland in southern Mexico,we sowed six annual species in the field along a hydric stress *** were grown alone(without interactions),with conspecific neighbors(intraspecific interactions)or with heterospecific neighbors(interspecific interactions).We analyzed how the ratio of intra-to interspecific competition changed along the gradient to assess how water availability determines the strength of *** also determined if hydric stress represented an environmental *** Findings We observed stronger intra-than interspecific competition,especially where hydric stress was ***,we found ND in at least some portion of the gradient for all but one *** species were hindered by stress,but others were favored by it perhaps because it eliminates soil *** strong ND was slightly more frequent with stress,our species sample was small and there were exceptions to the general pattern,so further research is needed to establish if this is a widespread phenomenon in nature.

关键词： hydrological niche species interactions environmental constraints species coexistence stabilizing mechanisms equalizing mechanisms

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Improving the Performance of Fixed-Bed Catalytic Reactors by Innovative Catalyst Distribution

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Journal of Applied Mathematics and Physics 2020年第4期8卷 672-683页

作者： Violeta alejandra Chichique martínez Farhang Shadman Department of Chemical and Environmental Engineering University of Arizona Tucson AZ USA Departamento de Ingeniería de Procesos y Ciencias Ambientales Universidad Centroamericana “José Simeón Cañas” (UCA) San Salvador El Salvador

A comprehensive mathematical model is developed to simulate the interactions of the complex processes that take place in typical catalytic chemical reactors. This mathematical model includes correlations representing various modes of mass transport and chemical reactions. To illustrate the application and value of this approach for reactor optimizations, the model is applied to the case of series reactions with a desirable intermediate compound and the risk of degradation of this compound if the process conditions are not optimized. The modeling results show that in such cases, which are very common in practice, replacing the conventional uniform catalyst distribution with a novel non-uniform distribution will significantly improve the performance of the reactor and the production of the desirable compound. Various catalyst distribution options are compared, and a novel non-uniform loading of catalyst is identified that gives a much better performance compared to the conventional approach. The model is versatile and useful for both the design as well as the optimization of the catalytic fixed-bed reactors in a wide variety of reactor and reaction conditions.

关键词： Catalyst Reactor Optimization Series Reactions Uniform Catalyst Distribution Non-Uniform Catalyst Distribution Catalyst Deactivation

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Multi-Sectoral Reflections and Efforts in Strengthening Partnerships to Reduce Disaster Risk in Mexico:The First MuSe-IDRiM Conference

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International Journal of Disaster Risk Science 2020年第5期11卷 686-691页

作者： Irasema Alcantara-Ayala Daniel Rodriguez-Velazquez Ricardo J Garnica-Pena alejandra Maldonado-martinez Institute of Geography National Autonomous University of Mexico(UNAM)04510 Mexico CityMexico National School of Social Work.National Autonomous University of Mexico(UNAM) 04510 Mexico CityMexico Disaster Risk Reduction Consultant 04700 Mexico CityMexico

Notwithstanding the high societal impact of disasters in Mexico,there is a lack of integrated efforts to establish a sound policy for reducing disaster risk to counterbalance the existing concentrated endeavors in disaster *** the face of such segmentation,the science and technology community has advocated for a change of perspective,from civil protection to integrated disaster risk *** first Multi-Sectoral Conference towards Integrated Disaster Risk Management in Mexico:Building a National Public Policy(MuSe-IDRiM Conference)was held in Mexico City at National Autonomous University of Mexico,21-24 October *** support of the implementation of the Sendai Framework for Disaster Risk Reduction 2015-2030,the conference aimed at enhancing the dialogue between the scienee and technology community,citizens,civil society organizations,private and public sectors,and the federtil,state,and municipal governments to foster the process of transforming the current National Civil Protection System into a national public policy oriented towards integrated disaster risk management(DRM).Barriers and challenges to the implementation of integrated DRM were *** of integrated DRM challenges current socioeconomic structures and encourages all releva nt stakeholders to think,decide,and act from a different perspective and within and across spatial,temporal,jurisdictional,and institutional *** disaster risk from an integrated approach,learning skills that authorities have not learned or used,and hence,strengthening disaster risk governance are prerequisites to effectively manage disaster risk.

关键词： Disaster risk reduction Integrated disaster risk management Mexico Science-based policy making SINAPROC

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Marginal discrepancy and microleakage in crown-copings fabricated by three CAD/CAM systems: An <i>in vitro</i>study

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Open Journal of Stomatology 2012年第3期2卷 163-169页

作者： Marcela Herrera Alfonso Catalán Maritza Flores alejandra martínez Department of Oral Pathology Faculty of Dentistry University of Concepción Concepción Chile Department of Public Health School of Medicine University of Concepción Concepción Chile Department of Restorative Dentistry Faculty of Dentistry University of Concepción Concepción Chile

The purpose of this study was to evaluate and compare the microleakage and marginal discrepancy of ceramic crown-copings fabricated by three different CAD/CAM systems. Material and methods: Thirty extracted premolars were prepared for complete all-ceramic crowns with: total convergence 10-degree, 2 mm occlusal reduction, 4.5 mm height, 1.3 mm circular reduction and chamfer marginal preparation. They were divided into three groups and each group (n = 10) received a ceramic crown-coping fabricated by one of three CAD/CAM systems: Procera, KaVo Everest and Cerec inLab. The copings were cemented with Panavia F 2.0. After thermal cycling, the teeth were immersed in 2% basic fuchsine dye for 24 hours. Microleakage was scored using a five-point scale and evaluated under a stereomicroscope at ×18. Marginal discrepancies were assessed with scanning electronic microscope at ×150, with measurements at 50 different points. Data were subjected to a chisquare test, Kolmogorov-Smirnov test and using Rho Spearman’s correlation test (P 0.05). No significant differences were found in marginal discrepancies for the Procera (62.58 ± 8.98 μm) and KaVo Everest systems (65.54 ± 18.56 μm), (P = 0.941). Significant differences were found for Cerec inLab (132.18 ± 27.75 μm) compared with Procera and KaVo Everest (P = 0.0001). No correlation between the marginal discrepancies and microleakage for the three CAD/CAM crown-copings systems. Conclusions: Cerec inLab CAD/CAM crown-copings showed significantly higher values for microleakage and marginal discrepancy in comparison with Procera and KaVo Everest CAD/CAM crown-copings.

关键词： CAD/CAM Copings Microleakage Marginal Discrepancy Panavia F.2

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Carboxylesterase 1 family knockout alters drug disposition and lipid metabolism

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Acta Pharmaceutica Sinica B 2023年第2期13卷 618-631页

作者： Changpei Gan Jing Wang alejandra martínez-Chávez Michel Hillebrand Niels de Vries Joke Beukers Els Wagenaar Yaogeng Wang Maria C.Lebre Hilde Rosing Sjoerd Klarenbeek Rahmen Bin Ali Colin Pritchard Ivo Huijbers Jos H.Beijnen Alfred H.Schinkel Division of Pharmacology the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands Department of Pharmacy&Pharmacology the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands Division of Pharmacoepidemiology and Clinical Pharmacology Utrecht Institute for Pharmaceutical SciencesUtrecht UniversityUtrecht 3584 CSthe Netherlands Experimental Animal Pathology Facility the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands Mouse Clinic for Cancer and Aging(MCCA)Transgenic Facility the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands

The mammalian carboxylesterase 1(Ces1/CES1)family comprises several enzymes that hydrolyze many xenobiotic chemicals and endogenous *** investigate the pharmacological and physiological roles of Ces1/CES1,we generated Ces1 cluster knockout(Ces1^(-/-))mice,and a hepatic human CES1 transgenic model in the Ces1^(-/-)background(TgCES1).Ces1^(-/-)mice displayed profoundly decreased conversion of the anticancer prodrug irinotecan to SN-38 in plasma and ***1 mice exhibited enhanced metabolism of irinotecan to SN-38 in liver and ***1 and hCES1 activity increased irinotecan toxicity,likely by enhancing the formation of pharmacodynamically active ***1^(-/-)mice also showed markedly increased capecitabine plasma exposure,which was moderately decreased in TgCES1 ***1^(-/-)mice were overweight with increased adipose tissue,white adipose tissue inflammation(in males),a higher lipid load in brown adipose tissue,and impaired blood glucose tolerance(in males).These phenotypes were mostly reversed in TgCES1 ***1 mice displayed increased triglyceride secretion from liver to plasma,together with higher triglyceride levels in the male *** results indicate that the carboxylesterase 1 family plays essential roles in drug and lipid metabolism and ***1^(-/-)and TgCES1 mice will provide excellent tools for further study of the in vivo functions of Ces1/CES1 enzymes.

关键词： Ces1/CES1 enzymes Irinotecan Capecitabine Adipose tissue Lipid homeostasis Inflammation Triglyceride mobilization Mouse models

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A Systematic Review of Cannabidiol Effects in Coronary Syndromes: Challenges to Clinical Translation

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Journal of Biosciences and Medicines 2024年第4期12卷 246-263页

作者： Mario E. Zuñiga-Ayala alejandra Meaney-martínez Alejandro Alcocer-Chauvet Vidal Gonzalez-Coronado Nestor Rubio-Infante Gerardo Garcia-Rivas Department of Cardiology Instituto de Seguridad Social and Trabajadores del Estado (ISSSTE) Hospital Regional Primero de Octubre Mexico City Mexico Department of Interventional Cardiology Instituto de Seguridad Social y Trabajadores del Estado (ISSSTE) Hospital Regional Primero de Octubre Mexico City Mexico Instituto Tecnó logico de Monerrey Escuela de Medicina and Ciencias de la Salud C&#225tedra de Cardiolog&#237a and Medicina Vascular Monterrey Mexico

Background: Myocardial ischemia in addition to other several cardiac syndromes represent a pathological proinflammatory state alongside a complex cellular microenvironment that can be modified by using cannabinoids. Cannabidiol (CBD), a non-psychoactive compound of cannabis has been recently proposed as an immudomodulatory and cardioprotective drug. Objectives: In this systematic review we sought to clarify and summarize the clinical and preclinical evidence of potential benefit of the use of CBD in coronary syndromes. Methods: We conducted a systematic search and review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Review of Animal Data from Experimental Studies (CAMARADES) guidelines, in the electronic database from PubMed, Web of Science and Scopus up to April 2022 using predefined search terms. Pre-specified exclusion and inclusion criteria were considered, finally 11 articles were chosen to be included for this peer review. Results: Currently there are no good-quality clinical trials with the use of CBD in acute or chronic coronary syndromes. A total of 11 preclinical studies where prescreened and 5 demonstrated reproducible positive cardiovascular outcomes on in-vivo models treated with CBD. Mechanisms of CBD cardioprotection observed: 1) reduction in oxidative stress and inflammation, 2) activation of adenosine receptors and 3) increased expression of angiotensin type 2-receptor. Experimental models included ischemia/reperfusion injury, myocardial infarction, arrhythmias, and metabolic syndrome-like conditions. Conclusion: No clinical recommendation can be issued with the current evidence, on the use of CBD in acute and chronic coronary syndromes. Based on preclinical evidence, we considered there is enough evidence to propose the development of well-designed clinical trials that include CBD in the management of coronary syndromes.

关键词： Cannabis Cannabidiol Acute Coronary Syndromes Myocardial Infarction Myocardial Ischemia and Oxidative Stress

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Marginal discrepancy and microleakage in crown-copings fabricated by three CAD/CAM systems: An in vitro study

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Open Journal of Stomatology 2012年第3期

作者： Marcela Herrera Alfonso Catalán Maritza Flores alejandra martínez

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Motility and Functional State of the Membrane of Caprine Capacitated Spermatozoa under Different Chemical Agents

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Open Journal of Veterinary Medicine 2012年第3期

作者： alejandra Soberano martínez José Herrera Camacho José Candelario Segura Correa Centro Multidisciplinario de Estudios en Biotecnología Facultad de Medicina Veterinaria y Zootecnia Universidad Michoacana de San Nicolás de Hidalgo Instituto de Investigaciones Agropecuarias y Forestales Universidad Michoacana de San Nicolás de Hidalgo Posta Zootecnia Campus Ciencias Biológicas y Agropecuarias Universidad Autónoma de Yucatán

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Incidence, prevalence, and demographic characteristics of ocular cicatricial pemphigoid in Colombia: data from the National Health Registry 2009-2019

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International Journal of Ophthalmology(English edition) 2021年第11期14卷 1765-1770页

作者： Carlos Cifuentes-González Stefania Amaris-martínez Juliana Reyes-Guanes Pilar Uribe-Reina alejandra de-la-Torre Neuroscience Research Group Escuela de Medicina y Ciencias de la SaludUniversidad del RosarioBogota 111221Colombia Escuela Barraquer Research Group Escuela Superior de Oftalmología del Instituto Barraquer de AméricaBogota 110111Colombia

AIM:To provide an epidemiological characterization of ocular cicatricial pemphigoid(OCP)in ***:We conducted a cross-sectional study using *** applied the specific code of the International Classification of Diseases for Ocular Pemphigoid,from 2009-2019 to estimate prevalence,incidence,and the demographic status of the disease in ***:The estimated average prevalence was 0.22 per 1000000 inhabitants,and the estimated average incidence was 0.24 per 1000000 *** a female predominance of 62.5%,and a male/female ratio of 1:*** group of patients diagnosed with the disease after the age of 80 presented the highest *** departments with the highest prevalence were Antioquia,Bogotá,and ***:There are important differences between worldwide and Colombian prevalence and incidence data,which may be related to genetic and epigenetic factors,and the possible underdiagnosis of the *** to the results,OCP is an extremely rare disease in ***,it is important to encourage awareness of the disease due to its devastating consequences.

关键词： ocular cicatricial pemphigoid epidemiology incidenee ophthalmology Colombia autoimmune diseases

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Clinical Profiles at the Time of Diagnosis of SARS-CoV-2 Infection in Costa Rica During the Pre-vaccination Period Using a Machine Learning Approach

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Phenomics 2022年第5期2卷 312-322页

作者： Jose Arturo Molina-Mora alejandra González Sergio Jiménez-Morgan Estela Cordero-Laurent Hebleen Brenes Claudio Soto-Garita Jorge Sequeira-Soto Francisco Duarte-martínez Centro de Investigación en Enfermedades Tropicales(CIET)and Facultad de Microbiología Universidad de Costa RicaSan José2060Costa Rica Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud(INCIENSA) Tres Ríos 30301Costa Rica Escuela de Medicina Universidad de Costa RicaSan José2060Costa Rica

The clinical manifestations of COVID-19,caused by the SARS-CoV-2,define a large spectrum of symptoms that are mainly dependent on the human host *** Costa Rica,more than 169,000 cases and 2185 deaths were reported during the year 2020,the pre-vaccination *** describe the clinical presentations at the time of diagnosis of SARS-CoV-2 infection in Costa Rica during the pre-vaccination period,we implemented a symptom-based clustering using machine learning to identify clusters or clinical profiles at the population level among 18,974 records of positive *** were compared based on symptoms,risk factors,viral load,and genomic features of the SARS-CoV-2 sequence.A total of 18 symptoms at time of diagnosis of SARS-CoV-2 infection were reported with a frequency>1%,and those were used to identify seven clinical profiles with a specific composition of clinical *** the comparison between clusters,a lower viral load was found for the asymptomatic group,while the risk factors and the SARS-CoV-2 genomic features were distributed among all the *** other distribution patterns were found for age,sex,vital status,and *** conclusion,during the pre-vaccination time in Costa Rica,the symptoms at the time of diagnosis of SARS-CoV-2 infection were described in clinical *** host co-morbidities and the SARS-CoV-2 genotypes are not specific of a particular profile,rather they are present in all the groups,including asymptomatic *** addition,this information can be used for decision-making by the local healthcare institutions(first point of contact with health professionals,case definition,or infrastructure).In further analyses,these results will be compared against the profiles of cases during the vaccination period.

关键词： COVID-19 Costa Rica Machine learning Diagnosis SARS-CoV-2 Clinical profiles

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