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Slope reliability and back analysis of failure with geotechnical parameters estimated using Bayesian inference

Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 628-643页

作者： luis-fernando contreras Edwin T.Brown The University of Queensland St Lucia Campus

A Bayesian approach is proposed for the inference of the geotechnical parameters used in slope *** methodology involves the construction of posterior probability distributions that combine prior information on the parameter values with typical data from laboratory tests and site investigations used in *** posterior distributions are often complex,multidimensional functions whose analysis requires the use of Markov chain Monte Carlo(MCMC)*** procedures are used to draw representative samples of the parameters investigated,providing information on their best estimate values,variability and *** paper describes the methodology to define the posterior distributions of the input parameters for slope design and the use of these results for evaluation of the reliability of a slope with the first order reliability method(FORM).The reliability analysis corresponds to a forward stability analysis of the slope where the factor of safety(FS)is calculated with a surrogate model from the more likely values of the input *** Bayesian model is also used to update the estimation of the input parameters based on the back analysis of slope *** this case,the condition FS?1 is treated as a data point that is compared with the model prediction of *** analysis requires a sufficient number of observations of failure to outbalance the effect of the initial input *** parameters are updated according to their uncertainty,which is determined by the amount of data supporting *** methodology is illustrated with an example of a rock slope characterised with a Hoek-Brown rock mass *** example is used to highlight the advantages of using Bayesian methods for the slope reliability analysis and to show the effects of data support on the results of the updating process from back analysis of failure.

关键词： Bayesian analysis Hoek-Brown criterion Slope reliability Back analysis of failure

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Bayesian data analysis to quantify the uncertainty of intact rock strength

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 11-31页

作者： luis fernando contreras Edwin T.Brown Marc Ruest The University of Queensland St Lucia CampusBrisbaneQLD 4072Australia Golder Associates Pty.Ltd. BrisbaneAustralia

One of the main difficulties in the geotechnical design process lies in dealing with uncertainty. Uncertainty is associated with natural variation of properties, and the imprecision and unpredictability caused by insufficient information on parameters or models. Probabilistic methods are normally used to quantify uncertainty. However, the frequentist approach commonly used for this purpose has some ***, it lacks a formal framework for incorporating knowledge not represented by data. Second, it has limitations in providing a proper measure of the confidence of parameters inferred from data. The Bayesian approach offers a better framework for treating uncertainty in geotechnical design. The advantages of the Bayesian approach for uncertainty quantification are highlighted in this paper with the Bayesian regression analysis of laboratory test data to infer the intact rock strength parameters σand mused in the Hoek-Brown strength criterion. Two case examples are used to illustrate different aspects of the Bayesian methodology and to contrast the approach with a frequentist approach represented by the nonlinear least squares(NLLS) method. The paper discusses the use of a Student’s t-distribution versus a normal distribution to handle outliers, the consideration of absolute versus relative residuals, and the comparison of quality of fitting results based on standard errors and Bayes factors. Uncertainty quantification with confidence and prediction intervals of the frequentist approach is compared with that based on scatter plots and bands of fitted envelopes of the Bayesian approach. Finally, the Bayesian method is extended to consider two improvements of the fitting analysis. The first is the case in which the Hoek-Brown parameter, a, is treated as a variable to improve the fitting in the triaxial region. The second is the incorporation of the uncertainty in the estimation of the direct tensile strength from Brazilian test results within the overall evaluati

关键词： Uncertainty Intact rock strength Bayesian analysis Hoek-Brown criterion

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Nrf2 and Snail-1 in the prevention of experimental liver fibrosis by caffeine

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World Journal of Gastroenterology 2013年第47期19卷 9020-9033页

作者： Daniela Gordillo-Bastidas Edén Oceguera-contreras Adriana Salazar-Montes Jaime González-Cuevas luis Daniel Hernández-Ortega Juan Armendáriz-Borunda nstitute of Molecular Biology in Medicine and Gene Therapy/CUCS University of GuadalajaraGuadalajaraJalisco 44100México

AIM:To determine the molecular mechanisms involved in experimental hepatic fibrosis prevention by caffeine(CFA).METHODS:Liver fibrosis was induced in Wistar rats by intraperitoneal thioacetamide or bile duct ligation and they were concomitantly treated with CFA(15 mg/kg per day).Fibrosis and inflammatory cell infiltrate were evaluated and classified by Knodell *** infiltrate was quantified by immunohistochemistry(anti-CD11b).Gene expression was analyzed by quantitative reverse transcription-polymerase chain reaction for collagenⅠ?(Col-1),connective tissue growth factor(CTGF),transforming growth factorβ1(TGF-β1),tumor necrosis factor alpha(TNF-α),interleukin-1(IL-1),IL-6,superoxide dismutase(SOD)and catalase(CAT).Activation of Nrf2 and Snail-1 was analyzed by ***-αexpression was proved by enzyme-linked immunosorbant assay,CAT activity was performed by ***:CFA treatment diminished fibrosis index in treated *** Knodell index showed both lower fibrosis and *** of profibrogenic genes CTGF,Col-1 and TGF-β1 and proinflammatory genes TNF-α,IL-6 and IL-1 was substantially diminished with CFA treatment with less CD11b positive *** lower values of transcriptional factor Snail-1 were detected in CFA treated rats compared with cirrhotic rats without treatment;in contrast Nrf2was increased in the presence of *** of SOD and CAT was greater in animals treated with CFA showing a strong correlation between mRNA expression and enzyme ***:Our results suggest that CFA inhibits the transcriptional factor Snail-1,down-regulating profibrogenic genes,and activates Nrf2 inducing antioxidant enzymes system,preventing inflammation and fibrosis.

关键词： Liver fibrosis Caffeine Thioacetamide Bile duct ligation Profibrogenic genes Proinflammatory cytokines Antioxidant enzymes

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Sanger Sequencing Implementation in Clinically Ill Patients for Bacterial and Fungal Pathogens Identification

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Advances in Infectious Diseases 2022年第3期12卷 363-382页

作者： Víctor Fong-Flores Andrea Murillo-Gallo luis contreras-Ojeda Aarón Barraza Departamento de Medicina Interna Benemérito Hospital General Juan María de Salvatierra La Paz México Laboratorio Biotechnologika A2 La Paz México CONACyT-CIBNOR Instituto Politécnico Nacional 195 La Paz México

The diagnosis of bacterial or fungal infections requires the identification of the pathogen etiology in the shortest time possible. Although some biomarkers are used as indicators of bacterial infections, their specificity and sensitivity are highly variable, and there is no direct relationship between the level increase of these biomarkers for mycosis. It is common to obtain negative microbiological cultures in patients infected by non-culturable, intracellular bacteria or mycosis, even though there is a high clinical suspicion of infection. This study identifies the pathogen present in critically infected patients through 16S and 18S/eEF1 genes detection by polymerase chain reaction (PCR) coupled with Sanger sequencing. Thirty clinical samples were evaluated by PCR, of which 40% were positive for fungi, 23.33% for bacteria, 26.7% for fungi and bacteria, and 10% for no pathogen. The PCRs outcomes period for bacteria or fungi was one day compared to seven and up to 14 days (on average) of microbiological culture for bacteria and fungi. Then, we assessed the relationship with the most used biomarkers (procalcitonin, C-reactive protein, globular sedimentation velocity, and the neutrophil-lymphocyte index). This combination of molecular techniques has been shown as helpful in identifying intracellular bacteria and fungi that are difficult to culture by conventional methods. Screening with genomic markers 16S and 18S/eEF1 by PCR allowed us to optimize the time to obtain the result of the infection caused by bacteria or fungi. Also, identifying the specific etiological microorganism by Sanger sequencing was very helpful in avoiding the progression of the disease and setting targeted treatment with better clinical outcomes.

关键词： Pathogen Identification Bacteria Fungi PCR Sanger Sequencing

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Melatonin modifies SOX2^+ cell proliferation in dentate gyrus and modulates SIRT1 and MECP2 in long-term sleep deprivation

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Neural Regeneration Research 2019年第10期14卷 1787-1795页

作者： Alan Hinojosa-Godínez luis F. Jave-Suarez Mario Flores-Soto Alma Y. Gálvez-contreras Sonia Luquín Edith Oregon-Romero Oscar González-Pérez Rocio E. González-Castaneda Laboratorio de Microscopía de Alta Resolución Departamento de NeurocienciasCentro Universitario de Ciencias de la SaludUniversidad de GuadalajaraGuadalajaraMéxico Laboratorio de Neurociencias Facultad de PsicologíaUniversidad de ColimaColimaMéxico División de Inmunología Centro de Investigación Biomédica de OccidenteInstituto Mexicano del Seguro SocialGuadalajaraMéxico División de Neurociencias Centro de Investigación Biomédica de OccidenteInstituto Mexicano del Seguro SocialGuadalajaraMéxico Instituto de Investigación en Ciencias Biomédicas (IICB) Departamento de Biología Molecular y GenómicaCentro Universitario de Ciencias de la SaludUniversidad de GuadalajaraGuadalajaraMéxico Unidad de Atención en Neurociencias Departamento de Neurociencias. Centro Universitario de Ciencias de la SaludUniversidad de GuadalajaraGuadalajaraMéxico

Melatonin is a pleiotropic molecule that,after a short-term sleep deprivation,promotes the proliferation of neural stem cells in the adult ***,this effect has not been observed in long-term sleep *** precise mechanism exerted by melatonin on the modulation of neural stem cells is not entirely elucidated,but evidence indicates that epigenetic regulators may be involved in this *** this study,we investigated the effect of melatonin treatment during a 96-hour sleep deprivation and analyzed the expression of epigenetic modulators predicted by computational text mining and keyword *** results showed that the administration of melatonin under sleep-deprived conditions increased the MECP2 expression and reduced the SIRT1 expression in the dentate *** observed that let-7 b,mir-132,and mir-124 were highly expressed in the dentate gyrus after melatonin administration,but they were not modified by sleep *** addition,we found more Sox2^+/5-bromo-2’-deoxyuridine(BrdU)^+cells in the subgranular zone of the sleep-deprived group treated with melatonin than in the untreated *** findings may support the notion that melatonin modifies the expression of epigenetic mediators that,in turn,regulate the proliferation of neural progenitor cells in the adult dentate gyrus under long-term sleep-deprived *** procedures performed in this study were approved by the Animal Ethics Committee of the University of Guadalajara,Mexico(approval ***-16610)on January 2,2016.

关键词： sleep-deprivation melatonin microRNA neurogenesis Sirtuin 1 SIRT1 methyl-CpG-binding protein 2 MECP2 epigenetic text-mining mir-9 let-7b

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Synthesis and Characterization of ZnO Film on Stainless Steel Wire and Bioaerosol Antimicrobial Activity Evaluation

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Journal of Environmental Science and Engineering(A) 2015年第9期4卷 455-466页

作者： Alfonso Espitia Cabrera Jose luis contreras Larios IlyaEspitia-Cabrera Ma-Teresa Nunez Cardona Doris Neri Cortes luis Raul Tovar Galvez Energy Department Metropolitan Autonomous University Azcapotzalco 02200 Mexico Chemical Engineering School Michoacan University of San Nicolas of Hidalgo Morelia 58030 Mexico Man and lts Environment Department Metropolitan Autonomous University Xochimilco 04960 Mexico Biochemistry Department Biological Sciences National School National Polytechnic Institute Mexico D.F. 07738 Mexico Interdisciplinary Centre of Research and Studies on Environment and Development National Polytechnic Institute Mexico D.F.07340 Mexico

ZnO thin films were prepared by electrophoretic deposition on stainless steel wire sieve, using zinc acetate as a precursor. The film was sintered and characterised by Scanning Electron Microscopy （SEM）, X-Ray Diffraction （XRD） and chemisorption of oxygen. A culture bacterial consortium composed by gram negative rod-shaped microbes was prepared in a liquid agar in a flask. It was transported by air through a reactor equipped with a UV lamp with 3 and 5 sieves of a stainless steel wire coated with ZnO film. It was exposed in continuous in five experiments to photocatalytic advanced oxidation. The experiments showed a total efficiency for colony forming unit reduction of a maximum of 99.66% for a residence time of 20 seconds with 5 stainless steel wire where exposed in continuous to UV. Also they were evaluated at 7.5 seconds, observing that the contribution of residence time and amount of catalytic for the CFU reduction was quite similar. Variance analysis showed that the efficiency was significant with the no parametric Kruskal-Wallis test with P 〈 0.05. This technology could be used to clean indoor air of closed environments such as hospitals, crowded buildings or public transportation systems where airborne bacteria has been documented.

关键词： Photocatalytic oxidation ZnO thin film antibacterial activity ZnO film on stainless steel wire. I

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LiMnPO<SUB>4</SUB>: Review on Synthesis and Electrochemical Properties

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Journal of Materials Science and Chemical Engineering 2015年第5期3卷 54-64页

作者： Joel O. Herrera Héctor Camacho-Montes luis E. Fuentes Lorena álvarez-contreras Universidad Autónoma de Ciudad Juárez Cd. Juárez México Centro de Investigación en Materiales Avanzados Chihuahua México

The olivine structured mixed lithium-transition metal phosphates LiMPO4 (M = Fe, Mn, Co) have attracted tremendous attention of many research teams worldwide as a promising cathode material for lithium batteries and for studying their magnetic and electrical properties. High energy density is required for mind- to large-scale batteries because the mounting spaces are quite small for vehicles and other energy storage applications. This constraint necessitates synthesis to yield high volumetric energy density and reliable battery performance. Development of eco-friendly, low cost and high energy density, LiMnPO4 cathode material became attractive due to its high operating voltage, which can be located inside of the electrochemical stability window of conventional electrolyte solutions and it offers more safety features due to the presence of a strong P-O covalent bond. This review is an overview of current research activities on LiMnPO4 cathodes and its carbon coating synthesized by various synthetic techniques.

关键词： Synthesis Properties LiMnPO4

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Modeling of Liquid-Liquid Extraction Process for Glycerol Purification from Biodiesel Production

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Journal of Chemistry and Chemical Engineering 2014年第10期8卷 971-977页

作者： Ignacio contreras-Andrade Maicol Martinez-Gonzalez luis Figueroa-Casallas Jonathan Parra-Santiago Carlos Alberto Guerrero-Fajardo Universidad Autonoma de Sinaloa Culiacan Rosales 80040 Mexico Universidad Nacional de Colombia Bogota 11001 Colombia

This paper shows some generalities about the glycerin byproduct obtained from biodiesel production process, presents an analysis of the ternary equilibrium between methanol, water and glycerol, and shows the influence that temperature has on the balance. This phase diagram illustrates ternary equilibrium at 10, 20 and 50 ℃, keeping the pressure constant at 1 atm （atmosphere） to standardize the analysis. The purpose of it is to establish the best temperature for the purification of glycerol by liquid-liquid extraction method under the ＂extraction in several stages cross flow＂ taking an initial mixture of glycerol with composition 15 wt.% water, 25 wt.% methanol and 60 wt.% glycerol. Water was used as liquid-liquid extraction solvent in order to remove as much methanol as possible from the initial solution due to the existence of a zone of insolubility between the glycerol and water in the ternary equilibrium. By this reason, two solutions are obtained, one consisting of water and methanol containing a trace of glycerin and the other consisting of water, glycerine and traces of methanol, which contain only 4.62% of the total methanol which enter in the process of liquid-liquid extraction, with 60.62% of the total glycerol, which is sent to a fractional distillation process to purify glycerin up to 98% by weight.

关键词： Ternary equilibrium liquid-liquid extraction glycerin purification.

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Lignin in storage and renewable energy applications： A review

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Journal of Energy Chemistry 2018年第5期27卷 1422-1438页

作者： Jose luis Espinoza-Acosta Patricia I. Torres-Chavez Jorge L. Olmedo-Martinez Alejandro Vega-Rios Sergio Flores-Gallardo E. Armando Zaragoza-contreras Department of Engineering and Materials Chemistry Centro de Investigacion en Materiales Avanzados Miguel de Cervantes # 120. Complejo Industrial Chihuahua Chihuahua Mexico Departamento de Investigacion y Posgrado en Alimentos (DIPA) Universidad de Sonora Hermosillo Sonora Mexico

Lignin is a cheap, abundant and non-toxic group of complex phenolic polymers obtained in large amounts from the papermaking and cellulosic biofuel industries. Although the application of lignin has been ex- plored in these and several more industries, there are limited applications of lignin in the energy industry. However, numerous research revealed a great interest in the exploration of this renewable biopolymer in storage energy devices. Some of these applications include the use of lignin as an expander for lead-acid batteries, electrodes for primary and rechargeable batteries, electrodes for electronic double layer capac- itors and electrochemical pseudocapacitors, and to feed different types of fuel cells. The use of lignin in energy storage devices improves not only the performance of these devices but also decreases the price and toxicity, contributing to obtaining greener energy devices. Based on the above, this review provides an overview of the main research work related to the use of lignin as a renewable component, suitable to replace some synthetic and toxic compounds used in the fabrication of energy storage devices with particular emphasis on batteries, advanced supercapacitors, and solar and fuel cells.

关键词： Lignin Batteries Lithium-ion batteries Supercapacitors Solar cells Fuel cells

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Effect of Light on Stability of Anthocyanins in Ethanolic Extracts of Rubus fruticosus

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Food and Nutrition Sciences 2014年第6期5卷 488-494页

作者： Elizabeth contreras-Lopez Araceli Castaneda-Ovando luis Guillermo González-Olivares Javier Anorve-Morga Judith Jaimez-Ordaz Universidad Autonoma del Estado de Hidalgo Academic Area of Chemistry Pachuca Mexico

Blackberry (Rubus fructicosus) is one of the fruit with the highest concentration of anthocyanins;however, its use is limited for making jams, jellies and liqueur, and recently, fruit concentrates in combination with pomegranate, blueberry and grape. One of the main problems with these pigments is their poor stability in solution, mainly in beverages as liqueur and juices, which depends on factors such as chemical structure, pH, temperature, light, water activity, and presence of oxygen. The effect of light on total monomeric anthocyanins content as well as the degradation rates and browning of two blackberry ethanolic extracts is to establish the conditions for storage of liqueur without adding artificial food coloring. The initial content of anthocyanins on extract without storage was 106 mg?l-1. The study assessed the light irradiation effect on the anthocyanins of blackberry ethanolic extract. The anthocyanins degradation followed the second order reaction kinetics with respect to illuminance of the light source. The t1/2 value at high illuminance (3968.30 lx) was 28.20 hours.

关键词： Blackberry Light Anthocyanins Stability Ethanolic Extracts

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