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Vapor Phase Decarbonylation of Furfural to Furan over Nickel Supported on SBA-15 Silica Catalysts

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Modern Research in Catalysis 2016年第3期5卷 85-94页

作者： Diana Vargas-Hernández Juan Miguel Rubio-Caballero Ramon Moreno-Tost Josefa María Mérida-Robles José Santamaría-González Antonio Jiménez-López María Ana Pérez-Cruz Rosario Hernández-Huesca pedro maireles-torres Catedrática CONACYT—Universidad de Sonora Hermosillo México Departamento de Química Inorgánica Cristalografía y Minerología (Unidad Asociada al ICP-CSIC) Facultad de Ciencias Universidad de Málaga Málaga Spain Facultad de Ciencias Químicas Benemérita Universidad Autónoma de Puebla Puebla México

Vapor-phase transformations of furfural over SBA-15 silica supported Ni catalysts under H2 in a continuous-flow reactor at atmospheric pressure and 170°C and 230°C were investigated. Two different samples having Ni loadings of 5 and 20 wt% (denoted here by SBA-5Ni and SBA-20Ni, respectively) were prepared by impregnation and characterized by atomic absorption spectroscopy, N2 sorption analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Furan and furfuryl alcohol were two primary products resulting, respectively, from decarbonylation and hydrogenation of furfural. Under the conditions of the study, both reactions exhibited structure sensitivity evidenced by changes in product selectivities with variable Ni loadings. Compared with SBA-20Ni, the 5 wt% Ni catalyst showed better catalytic activity, reaching a furfural conversion of 100 mol% and a selectivity to furan of 98 mol%, after 5 h of time-on-stream at 230°C.

关键词： Ni-SBA-15 Furfural Hydrogenation Furan Furfuryl Alcohol

The Effectiveness of the Havriliak-Negami Model in Predicting the Master Curves of the Asphalt Blends with SBS Triblock Copolymer and Organic-Montmorillonite at Different Temperatures and Frequencies

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Journal of Materials Science and Chemical Engineering 2024年第7期12卷 23-39页

作者： María Ángeles Vargas-Hernández Miguel Ángel Vargas pedro R. García-Morán Humberto Vázquez-torres Divisin de Ingeniera Qumica y Bioqumica TecNMTecnolgico de Estudios Superiores de Ecatepec Edo. de Mxico Mxico Facultad de Qumica Universidad Nacional Autonma de Mxico Cd. de Mxico Mxico Facultad de Ciencias Bsicas Ingeniera y Tecnologa Universidad Autnoma de Tlaxcala Tlaxcala Mxico Departamento de Fsica Universidad Autnoma Metropolitana-Iztapalapa Cd. de Mxico Mxico

The dynamic viscoelastic properties of asphalt AC-20 and its composites with Organic-Montmorillonite clay (OMMt) and SBS were modeled using the empirical Havriliak-Negami (HN) model, based on linear viscoelastic theory (LVE). The HN parameters, α, β, G0, G∞and τHN were determined by solving the HN equation across various temperatures and frequencies. The HN model successfully predicted the rheological behavior of the asphalt and its blends within the temperature range of 25˚C - 40˚C. However, deviations occurred between 40˚C - 75˚C, where the glass transition temperature Tg of the asphalt components and the SBS polymer are located, rendering the HN model ineffective for predicting the dynamic viscoelastic properties of composites containing OMMt under these conditions. Yet, the prediction error of the HN model dropped to 2.28% - 2.81% for asphalt and its mixtures at 100˚C, a temperature exceeding the Tg values of both polymer and asphalt, where the mixtures exhibited a liquid-like behavior. The exponent α and the relaxation time increased with temperature across all systems. Incorporating OMMt clay into the asphalt blends significantly enhanced the relaxation dynamics of the resulting composites.

关键词： Asphalt Blends Master Curve Linear Viscoelasticity Havriliak-Negami Model

Colon Adenocarcinoma in a Retrograde Intussusception: A Case Report and Literature Review

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Open Journal of Gastroenterology 2024年第5期14卷 153-160页

作者： Carlos Hernández Brito pedro Arredondo Ruiz Brenda Paola Sáenz Dávila Arsenio torres Delgado Luis Eduardo Méndez Turrubiates Luis Ángel Amezcua Toledo Omar Josué Herrera López Surgical Oncology Department Centro Oncol&#243gico Onkolid Veracruz Mexico Clinical Oncology Department Centro Oncol&#243gico Onkolid Veracruz Mexico General and Laparoscopic Surgery Corporativo M&#233dico-Quir&#250rgico Torres Veracruz Mexico Radiation Oncology Department Centro Oncol&#243gico Onkolid Veracruz Mexico Radiology Department Centro Oncol&#243gico Onkolid Veracruz Mexico Anatomical Pathology Department Centro Oncol&#243gico Onkolid Veracruz Mexico

Background: Intussusception is defined as a telescoping of a proximal gastrointestinal segment with its mesentery to a distal one, only 5% occur in adults and in colon the probability that it is caused by a malignant disease is up to 65%. Only 1% occurs in a retrograde manner, the rest occur in an anterograde manner. Aim: Describe the clinical presentation of an intussusception in the adult patient as well as its most frequent causes and possible complications that influence decision making for a definitive treatment. Case Presentation: A 66-year-old woman diagnosed with colon adenocarcinoma who underwent elective transverse colectomy and colonic anastomosis with an incidental finding of a transverse colon tumor in a retrograde intussusception was studied. Conclusion: In any adult patient with an intussusception especially in colon a neoplasia should be suspected and the affected segment should be resected without being reduced due to the risk of perforation and tumor dissemination.

关键词： Colon Cancer Colon Adenocarcinoma Colonic Intussusception Intussusception

Noninvasive Ventilation Interfaces in the Treatment of Acute Respiratory Insufficiency: A Critical Review

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Open Journal of Emergency Medicine 2024年第3期12卷 95-103页

作者： Andréa Nóbrega Cirino Nogueira Chakira torres Lima Renata dos Santos Vasconcelos Suzy Maria Montenegro Pontes Arnaldo Aires Peixoto Junior Renan Magalhães Montenegro Junior Clinical Research Unit Walter Cantdio University Hospital Federal University of Cear/EBSERH Fortaleza Brazil

Background: Noninvasive ventilation (NIV) is an important therapeutic modality for the treatment of acute respiratory failure (ARF). In this review, we critically analyze randomized controlled trials on the most used NIV interfaces in the treatments of ARF. Methods: The searches were conducted in the Medline, Lilacs, PubMed, Cochrane, and pedro databases from June to November 2021. The inclusion criteria were Randomized clinical trials (RCTs) published from 2016 to 2021 in Portuguese, Spanish, or English and involving adults (aged ≥ 18 years). The eligibility criteria for article selection were based on the PICO strategy: Population—Adults with ARF;Intervention—NIV Therapy;Comparison—Conventional oxygen therapy, high-flow nasal cannula (HFNC) oxygen therapy, or NIV;Outcome—improvement in ARF. The search for articles and the implementation of the inclusion criteria were independently conducted by two researchers. Results: Seven scientific articles involving 574 adults with ARF due to various causes, such as chest trauma, decompensated heart failure, coronavirus disease 2019 (COVID-19), and postoperative period, among others, were included. The interfaces cited in the studies included an oronasal mask, nasal mask, full-face mask, and helmet. In addition, some favorable outcomes related to NIV were reported in the studies, such as a reduction in the rate of orotracheal intubation and shorter length of stay in the ICU. Conclusions: The most cited interfaces in the treatment of ARF were the oronasal mask and the helmet.

关键词： Noninvasive Ventilation Respiratory Insufficiency Respiration Artificial Continuous Positive Airway Pressure

Dysregulation of the PD-1/PD-L1 pathway contributes to the pathogenesis of celiac disease

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Cellular & Molecular Immunology 2019年第9期16卷 777-779页

作者： Candelaria Ponce de Leon Miguel Angel Lopez-Casado pedro Lorite Teresa Palomeque Maria Isabel torres Department of Experimental Biology University of JaenJaenSpain Department of Pediatrics Gastroenterology Hospital Virgen de las NievesGranadaSpain

In this study,we focus on the alteration of the programmed cell death 1(PD-1)/PD-L1 pathway in celiac *** discuss the diverse roles of the PD-1 pathway in regulating immune responses and how this knowledge can improve celiac disease(CD)*** PD-1 and PD-L1 levels in the serum and in intestinal biopsies of CD patients may be relevant to the determination of a possible correlation between markers of the autoimmune response,inflammation,and disease activity.

关键词： celiac pathogenesis inflammation

Colon Adenocarcinoma in a Retrograde Intussusception: A Case Report and Literature Review

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Microbial Community with Potential for Metal Release Isolated from Palca Mine Tailings Pond in Peru

Open Journal of Gastroenterology（肠胃病学期刊） 2024年第5期 153页

作者： Carlos Hernández Brito pedro Arredondo Ruiz Brenda Paola Sáenz Dávila Arsenio torres Delgado Luis Eduardo Méndez Turrubiates Luis Ángel Amezcua Toledo Omar Josué Herrera López

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Journal of Geoscience and Environment Protection 2024年第7期12卷 109-121页

作者： César Wilber Guzmán Moreno Bruno Karolski Solange Kazue Utimura Roberto Castellanos Cabrera Jhon Albert Centeno torres Daladier Miguel Castillo Cotrina Elisabete de Santis Braga Dayana Sarai Gamonal Fermandez Denise Crocce Romano Espinosa Joel Barbujiani Sigolo Department of Sedimentary and Environmental Geology Institute of Geoscience USP So Paulo Brazil Department of Chemical Engineering LAREX USP So Paulo Brazil CEPEMA Environment Training and Research Center USP So Paulo Brazil Facultad de Ciencias Universidad Nacional Jorge Basadre Grohmann UNJBG Tacna Per Department of Physical Chemical and Geological Oceanography USP So Paulo Brazil Facultad de Ciencias Biolgicas Universidad Nacional Pedro Ruiz Gallo UNPRG Lambayeque Per

The improvement of microbial characterization has increased the comprehension of microbial population and their ability in the microbiological metal dissolution. Bioleaching processes have been expanded to use microorganisms for the recovery of metals from ores and wastes. This study introduces Palca mine tailings pond in Peru which turned into acid mine drainage (AMD). AMD is a source of microbial communities whose microorganisms may support the aqueous extractive metallurgy for metal recovery. Four samples of AMD were collected from different locations and the elemental characterization showed concentrations of metals, such as Cu, Zn, Al, Mn, and Fe. The pH of the samples showed variation between 1.9 - 6.8. Twenty-one microorganisms were isolated and selected according the cell morphology. 16s rRNA gene sequences identified five species of which three belong to the bacterial kingdom and two to the Fungi kingdom. Two of the bacterial species were ferrous ion oxidizing bacteria, identified as Acidithiobacillus ferriphilus and Acidithiobacillus ferridurans;and the other one a ferric ion reducing bacteria identified as Acidiphilium acidophilum. The fungi species identified were Rhodotorula sinensis and Exophiala xenobiotica, a filamentous fungus isolated for the first time from an AMD.

关键词： Acidophilic Microorganisms Acid Mine Drainage—AMD Bioleaching Process Metals Recovery Acidithiobacillus

Reduction Kinetics of Uranium Trioxide to Uranium Dioxide Using Hydrogen

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World Journal of Nuclear Science and Technology 2015年第3期5卷 149-156页

作者： pedro Orrego Alfaro José Hernández torres Fernando Puchi Thiele Sección de Geología y Minería Departamento de Materiales Nucleares Comisión Chilena de Energía Nuclear Santiago Chile Ingeniería Civil Metalurgia Universidad Andrés Bello Santiago Chile

This article presents a study on the kinetics of the uranium conversion process, consisting in the reduction of uranium trioxide to uranium dioxide using hydrogen gas at temperatures of 500°C, 600°C and 700°C. Hydrogen concentrations used in the flow were 0.25 M, 0.50 M and 0.75 M. The mechanism established for the study of the kinetics of reduction of uranium trioxide was through the formation of an intermediate compound, U3O8. For this reason, these tests were divided into 2 stages: the first one the reduction from UO3 to U3O8, and second one from U3O8 to UO2. The results of each test were quantified by the release of H2O(g) produced by both reactions. Tests showed that the ideal working conditions are for hydrogen concentration flows of 0.75 M and temperatures in the range of 500°C - 600°C, with the intent to decrease the occurrence of side reactions that interfere with the process.

关键词： Conversion Uranium Oxides Nuclear Fuel Cycle

<i>In Vitro</i >Culture of <i>Plasmodium falciparum</i>: Obtention of Synchronous Asexual Erythrocytic Stages

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Open Journal of Epidemiology 2015年第1期5卷 71-80页

作者： María Roncalés Jaume Vidal pedro A. torres Esperanza Herreros GlaxoSmithKline R&D Tres Cantos Medicine Development Campus Malaria Discovery Performance Unit Madrid Spain

Cultivation of the erythrocytic stages of Plasmodium parasites, specifically the most important and deadly for humans, Plasmodium falciparum, has required a lot of effort and time in order to develop a continuous in vitro culture. Moreover, the development of methods to synchronize P. falciparum parasites (which grow asynchronously in vitro) has become an essential tool in research to study different immulogical, biochemical or physiological aspects of the parasite. We have compared two different synchronization methods, one based on differential permeability of the membrane of parasitized erythrocytes, and the other on the sedimentation behavior in gelatin solution. An optimized method has been established which allows for maintaining a healthy, highly synchronous culture for longer periods of time. Asexual erythrocytic stages of a complete P. falciparum cycle have been obtained, which is the starting point of the stage-specific assays of the activity of new antimalarial drugs.

关键词： P. falciparum Synchronous Asexual Stages Stage Specificity