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Hot corrosion mechanism of yttria-stabilized zirconia powder in the presence of molten Na_(2)SO_(4)+V_(2)O_(5) salts

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Rare Metals 2021年第5期40卷 1307-1316页

作者： Jhonattan De la Roche juan manuel Alvarado-Orozco Alejandro Toro Tribology and Surfaces Group Universidad Nacional de ColombiaMedellin 050041Colombia Centro de Ingeniena y Desarrollo Industrial-CIDESI Queretaro 76125Mexico Consorcio de Manufactura Aditiva-CONMAD Queretaro 76125Mexico

The hot corrosion behavior of yttria-stabilized zirconia(YSZ)powder specimens exposed to Na_(2)SO_(4)/V_(2)O_(5) salts mixtures at high temperature was *** tests were carried out at 1000℃ for 10 h,the salt concentrations varied from 0.1 wt%to 1.00 wt%,and the Na_(2)SO_(4)/V_(2)O_(5) mass ratios were between 0.20 and 0.44 following a factorial design 22.X-ray diffraction(XRD)analyses of the tested samples showed with a confidence of95%that the mixture composed of 32 wt%Na_(2)SO_(4)+68 wt%V_(2)O_(5),and 1.00 wt% salt concentration led to high destabilization of the t’-YSZ phase and formation of YVO_(4) products.A second set of experiments were conducted to assess the influence of temperature on the hot corrosion response of the YSZ in the range between 490 and 1100℃.Thermogravimetric analysis(TGA)experiments and Rietveld adjustments of XRD patterns showed that the mass loss of the samples varied with testing temperature and also that the major destabilization of tetragonal phase occurred at 900℃.

关键词： Hot corrosion Molten salts Yttria-stabilized zirconia Thermal barrier coatings

HEART RATE VARIABILITY DURING HIGH-INTENSITY EXERCISE

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Journal of Systems Science & Complexity 2013年第1期26卷 104-116页

作者： SARMIENTO Samuel GARCIA-MANSO juan manuel MARTIN-GONZALEZ juan manuel VA-AMONDE Diana CALDERóN Javier DA SILVA-GRIGOLETTO Marzo Edir Department of Physical Education University of Las Palmas de Gran Canaria Spain. Physics Department University of Las Palmas de Gran Canaria Spain. Department of Morphological Sciences School of Medicine University of Cdrdoba Spain. Physical Activity Sciences Faculty Polytechnic University of Madrid Spain. Andalusian Centre of Sports Medicine Cdrdoba Spain.

The aim of this paper is to describe and analyse the behaviour of heart rate variability(HRV)during constant-load,high-intensity exercise using a time frequency analysis(Wavelet Transform).Eleven elite cyclists took part in the study(age:18.6±3.0 years;VO_(2max):4.88±0.61 litres·min^(-1)).Initially,all subjects performed an incremental cycloergometer test to determine load power in a constant load-test(379.55±36.02 W;89.0%).HRV declined dramatically from the start of testing(p<0.05).The behaviour of power spectral density within the LF band mirrored that of total energy,recording a significant decrease from the outset LF peaks fell rapidly thereafter,remaining stable until the end of the ***-VHF fell sharply in the first 20 to 30 *** relative weighting(%) of HF-VHF was inverted with the onset of fatigue,[1.6%at the start,7.1(p<0.05) at the end of the first phase,and 43.1%(p<0.05) at the end of the test].HF-VHF_(peak) displayed three phases:a moderate initial increase,followed by a slight fall,thereafter increasing to the end of the *** LF/HF-VHF ratio increased at the start,later falling progressively until the end of the first phase and remaining around minimal values until the end of the test.

关键词： Cycling heart rate variability wavelet.

Generalized Height-Diameter Models for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. Plantations in Michoacan, Mexico

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Open Journal of Forestry 2024年第3期14卷 214-232页

作者： Jonathan Hernández-Ramos Valentín José Reyes-Hernández Héctor manuel De los Santos-Posadas Aurelio manuel Fierros-González Enrique Buendía-Rodríguez Gerónimo Quiñonez-Barraza Instituto Nacional de Investigaciones Forestales Agrcolas y Pecuarias (INIFAP)-Campo Experimental Bajo Celaya Guanajuato Mxico Colegio de Postgraduados (COLPOS) Campus Montecillo Mxico INIFAP Campo Experimental Valle de Mxico Texcoco Mxico INIFAP Campo Experimental Valle del Guardiana Durango Mxico

Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at the stand level is a valuable support tool in forest inventories. The objective was to fit and propose a generalized H-d model for Pinus montezumae and Pinus pseudostrobus established in forest plantations of Nuevo San juan Parangaricutiro, Michoacan, Mexico. Using nonlinear least squares (NLS), 10 generalized H-d models were fitted to 883 and 1226 pairs of H-d data from Pinus montezumae and Pinus pseudostrobus, respectively. The best model was refitted with the maximum likelihood mixed effects model (MEM) approach by including the site as a classification variable and a known variance structure. The Wang and Tang equation was selected as the best model with NLS;the MEM with an additive effect on two of its parameters and an exponential variance function improved the fit statistics for Pinus montezumae and Pinus pseudostrobus, respectively. The model validation showed equality of means among the estimates for both species and an independent subsample. The calibration of the MEM at the plot level was efficient and might increase the applicability of these results. The inclusion of dominant height in the MEM approach helped to reduce bias in the estimates and also to better explain the variability among plots.

关键词： Random Covariate Random Effects Variance Structure Forest Inventories Forest Management Mixed Models

BASKETBALL SCORING IN NBA GAMES:AN EXAMPLE OF COMPLEXITY

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Journal of Systems Science & Complexity 2013年第1期26卷 94-103页

作者： DE SA GUERRA Yves MARTíN GONZALEZ juan manuel SARMIENTO MONTESDEOCA Samuel RODRIGUEZ RUIZ David ARJONILLA LóPEZ Nieves GARCíA-MANSO juan manuel Departament of Phisical Education University of Las Palmas de Gran Canaria Departament of Physics University of Las Palmas de Gran Canaria

Scoring in a basketball game is a highly dynamic, non-linear process. NBA teams try to be more and more competitive each season. For instance, they incorporate into their rosters the best players in the world. This and other mechanisms concur to make the scoring process in NBA games exciting and rarely predictable. This paper is to study the behavior of timing and scoring in basketball gaines. The authors analyze all the games in five NBA regular seasons （2005-06, 2006-07, 2007-08, 2008-09, 2009-10）, for a total of 6150 games. Scoring does not behave uniformly; therefore, the authors also analyze the distributions of the differences in points in the basketball games. To further analyze the behavior of the tail of the distribution, the authors also carry out a semilog-plot and a log-log plot to verify whether this trend approaches a Poisson distribution or a PL. This paper reveals different areas of behavior related to the score, with specific instances of time that could be considered tipping points of the game. The presence of these critical points suggests that there are phase transitions where the dynamic scoring of the games varies significantly.

关键词： Complexity NBA non-linear Poisson power law.

Uremic Bleeding in 2 Patients with Dieulafoy’s Lesion: Case Report and Literature Review

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Open Journal of Gastroenterology 2024年第5期14卷 167-173页

作者： Gustavo Adolfo Hernández Valdez Diana Estefanía Ibarra García juan Antonio Contreras Escamilla Janette Alejandra Gamiño Gutierrez Francisco manuel Tonatiuh Carrillo Beltran Ulises Solis Gomez Jocelyn Nataly Quintero Meléndez Ivan Alejandro Medina Jimenez Marco Antonio González Villar Jorge Rojas Morales Department of Internal Medicine ISSSTE APP General Hospital of Tepic Tepic Nayarit Mexico Hospital Civil de Guadalajara Fray Antonio Alcalde Guadalajara Jalisco M&#233xico

Dieulafoy’s lesions are rare vascular malformations of the gastrointestinal tract. A Dieulafoy’s lesion is an aberrant vessel that does not reduce in caliber when it extends from the submucosa to the mucosa. Damage to this artery can cause severe and intermittent arterial bleeding from small vascular stumps that are difficult to visualize. Furthermore, these catastrophic bleeding episodes frequently result in hemodynamic instability and the need for transfusion of multiple blood products. Recently, uremic syndrome has been identified as a risk factor for gastric mucosal lesions. We present two clinical cases of acute digestive bleeding due to Dielafoy lesion with chronic kidney disease as the main cause, where two different therapies were performed endoscopically. We concluded with the results of our patients that the best therapy was the application of the hemostatic hemoclip on the injury vs the injection with adrenaline on the wound site. Uremia is identified as a risk factor for upper gastrointestinal bleeding in patients with pre-existing Dieulafoy’s lesion, as well as a higher incidence of new bleeding.

关键词： Dieulafoy’s Lesion Gastrointestinal Bleeding Endoscopy Endoscopy Hemostatic Clips Kidney Disease Adrenaline Thermal Coagulation Dieulafoy

Hepatopulmonary syndrome: What we know and what we would like to know

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World Journal of Gastroenterology 2016年第25期22卷 5728-5741页

作者： Israel Grilo-Bensusan juan manuel Pascasio-Acevedo Digestive Diseases Department HAR écija APS Bajo Guadalquivir Unit for the Clinical Management of Digestive Diseases IBIS CIBERehd Virgen del Rocío University Hospital

Hepatopulmonary syndrome (HPS) is characterized by abnormalities in blood oxygenation caused by the presence of intrapulmonary vascular dilations (IPVD) in the context of liver disease, generally at a cirrhotic stage. Knowledge about the subject is still only partial. The majority of the information about the etiopathogenesis of HPS has been obtained through experiments on animals. Reported prevalence in patients who are candidates for a liver transplantation (LT) varies between 4% and 32%, with a predominance of mild or moderate cases. Although it is generally asymptomatic it does have an impact on their quality of life and survival. The diagnosis requires taking an arterial blood gas sample of a seated patient with alveolar-arterial oxygen gradient (AaO2) ≥ 15 mm Hg, or ≥ 20 mm Hg in those over 64 years of age. The IPVD are identified through a transthoracic contrast echocardiography or a macroaggregated albumin lung perfusion scan (99mTc-MAA). There is currently no effective medical treatment. LT has been shown to reverse the syndrome and improve survival rates, even in severe cases. Therefore the policy of prioritizing LT would appear to increase survival rates. This paper takes a critical and clinical look at the current understanding of HPS, as well as the controversies surrounding it and possible future research.

关键词： Hepatopulmonary syndrome Liver cirrhosis Liver transplantation Contrast echocardiography Macroaggregated albumin lung perfusion scan

Oxidative effects of glyphosate on the lipophobic intracellular environment in the microalgae Chlorella vulgaris

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BIOCELL 2022年第3期46卷 795-802页

作者： juan manuel OSTERA SUSANA PUNTARULO GABRIELA MALANGA Fisicoquímica Facultad de Farmacia y BioquímicaUniversidad de Buenos AiresBuenos AiresCP 1113Argentina Instituto de Bioquímica y Medicina Molecular(IBIMOL) CONICET-Universidad de Buenos AiresBuenos AiresCP 1113Argentina

The studied hypothesis is that the herbicide glyphosate(GLY)can affect the oxidative balance in the hydrophobic intracellular medium in non-target Chlorella vulgaris *** GLY and RoundUp(RUP)supplementation,affected the growth profile.A significant 42%decrease in the cellular biomass in stationary(St)phase was observed in cultures supplemented with either 5μM of GLY or RUP,as compared to control *** treatment with 0.3μM of GLY generated non-significant effects on the oxidation rate of 2’,7’dichlorofluorescein diacetate(DCFH-DA),neither in exponential(Exp)nor in St phase of development,as compared to control ***,the treatment with either 5μM GLY or 0.3 and 5μM RUP lead to a significant decrease in the DCFH-DA oxidation rate,as compared to control *** lipid radical(LR●)generation rate,detected by Paramagnetic Resonance Spectroscopy(EPR),was significantly increased in the presence of RUP,in Lag and Exp phase of *** non-enzymatic antioxidants,α-Tocopherol(α-T)andβ-Carotene(β-C),are aimed to protect membranes against the damage produced by the radical *** content ofβ-C was not significantly affected,as compared to control cultures,by any of the treatments,in both growth phases of cellular *** content ofα-T was significantly decreased by the supplementation with either 0.3 or 5μM of RUP or 5μM *** LR●/α-T ratio,used as indicator of the oxidative balance in the hydrophobic cellular media,was significantly different between samples obtained from control and RUP-exposed microalgae in both,Exp and St phase of development,with either 0.3 or 5μM *** data presented here showed evidence that suggested that oxidative balance in the hydrophobic environment was affected by either GLY or RUP.

关键词： 2’,7’dichlorofluorescein diacetate oxidation rate Lipid soluble antioxidants Round up Redox balance

Mycobacterium avium subspecies paratuberculosis and its relationship with Crohn's disease

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World Journal of Gastroenterology 2009年第4期15卷 417-422页

作者： juan Luis Mendoza Raquel Lana manuel Díaz-Rubio Inflammatory Bowel Disease Unit Department of GastroenterologyHospital Clínico San CarlosUniversidad Complutense Department of Internal Medicine Hospital Clínico San CarlosUniversidad Complutense

The hypothesis postulating that Mycobacterium avium paratuberculosis(MAP) is the cause of Crohn's disease(CD) has been circulating for many *** in molecular techniques,such as polymerase chain reaction and culture methods,have enabled researchers to demonstrate that there is an association between MAP and ***,genome-wide association studies have identified novel susceptibility genes for CD,which are critical for generation of an adaptive immune response that is protective against intracellular pathogens,including *** ***,the role of MAP as a cause of CD suffered a setback with the report that administration of antimycobacterial therapy failed to lead to a sustained response in CD ***,this review sought neither to confirm nor refute this,but instead to survey recent literature on the role of MAP in CD.

关键词： Mycobacterium avium subspecies paratuber-culosis Crohn's diasease Inflammatory bowel disease

2-Cys Peroxiredoxins Participate in the Oxidation of Chloroplast Enzymes in the Dark

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Molecular Plant 2018年第11期11卷 1377-1388页

作者： Valle Ojeda juan manuel Perez-Ruiz Francisco Javier Cejudo Instituto de Bioquimica Vegetaly Fotosintesis Universidad de Sevilla and Consejo Superior de lnvestigaciones CientificasAvenida Americo Vespucio 4941092SevillaSpain

Most redox-regulated chloroplast enzymes are reduced during the day and oxidized during the *** the reduction mechanism of light-dependent enzymes is well known,the mechanism mediating their oxidation in the dark remains *** thiol-dependent peroxidases,2-Cys peroxiredoxins (Prxs),play a key role in light-dependent reduction of chloroplast *** transfer reducing equivalents of thiols to hydrogen peroxide,suggesting the participation of these peroxidases in enzyme oxidation in the ***,we have addressed this issue by analyzing the redox state of well-known redox-regulated chloroplast enzymes in response to darkness in Arabidopsis thaliana mutants deficient in chloroplastlocalized Prxs (2-Cys Prxs A and B,Prx ⅡE,and Prx Q).Mutant plants lacking 2-Cys Prxs A and B,and plants overexpressing NADPH-dependent thioredoxin (Trx) reductase C showed delayed oxidation of chloroplast enzymes in the *** contrast,the deficiencies of Prx ⅡE or Prx Q exerted no *** vitro assays allowed the reconstitution of the pathway of reducing equivalents from reduced fructose 1,6-bisphosphatase to hydrogen peroxide mediated by Trxs and 2-Cys *** together,these results suggest that 2-Cys Prxs participate in the short-term oxidation of chloroplast enzymes in the dark.

关键词： chloroplast enzyme oxidation peroxiredoxin thioredoxin hydrogen peroxide darkness