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Effect of silver-nanoparticles generated in poly(vinyl alcohol)membranes on ethanol dehydration via pervaporation

Chinese Journal of Chemical Engineering 2019年第7期27卷 1595-1607页

作者： Asmaa Selim Andras Jozsef Toth Daniel Fozer Eniko Haaz nóra valentínyi Tibor nagy Orsolya Keri Lászlo Péter Bakos Imre Miklós Szilágyi Peter Mizsey Department of Chemical and Environmental Process Engineering Budapest University of Technology and Economics1111 BudapestHungary Chemical Engineering Department National Research Centre12611 GizaEgypt Department of Inorganic and Analytical Chemistry Budapest University of Technology and Economics1111 BudapestHungary Department of Fine Chemicals and Environmental Technology University of Miskolc3515 MiskolcHungary

Pervaporation is an important membrane separation method of chemical *** this work,silver-nanoparticles-poly(vinyl alcohol)nanocomposite membranes(AgnPs-PVA)are produced for the sake of improving its potentials for pervaporation of ethanol–water mixture so that the usual opposite trend between membrane selectivity and permeation can be *** nanocomposite membranes are fabricated from an aqueous solution of poly(vinyl alcohol)with silver nanoparticles via the in-situ generation technique in the absence of any reducing *** generation of the nano size silver is measured by the UV–vis spectrum showing a single peak at 419 nm due to the plasmonic effect of silver *** nanocomposite AgnPs-PVA membranes are characterized using scanning electron microscope(SEM),Fourier-transform infrared(FT-IR)spectroscopy,X-ray diffraction and thermogravimetric analysis(TGA).The pervaporation tests of our new AgnPs-PVA membranes show good results since at a higher temperature and higher ethanol concentration in the feed,the prepared membranes are highly permeable for the water having stable selectivity values and therefore our membranes show better performance compared to that of the other PVA-based nanocomposite membranes.

关键词： Silver nanoparticle Poly(vinyl alcohol)nanocomposite membrane Hydrophilicity Swelling degree Pervaporation

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Colorectal cancer diagnosis: Pitfalls and opportunities

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World Journal of Gastrointestinal Oncology 2015年第12期7卷 422-433页

作者： Pablo Vega Fátima valentín Joaquín Cubiella Department of Gastroenterology Complexo Hospitalario Universitario de Ourense

Colorectal cancer(CRC) is a major health problem in the Western world. The diagnostic process is a challenge in all health systems for many reasons: There are often no specific symptoms; lower abdominal symptoms are very common and mostly related to nonneoplastic diseases, not CRC; diagnosis of CRC is mainlybased on colonoscopy, an invasive procedure; and the resource for diagnosis is usually scarce. Furthermore, the available predictive models for CRC are based on the evaluation of symptoms, and their diagnostic accuracy is limited. Moreover, diagnosis is a complex process involving a sequence of events related to the patient, the initial consulting physician and the health system. Understanding this process is the first step in identifying avoidable factors and reducing the effects of diagnostic delay on the prognosis of CRC. In this article, we describe the predictive value of symptoms for CRC detection. We summarize the available evidence concerning the diagnostic process, as well as the factors implicated in its delay and the methods proposed to reduce it. We describe the different prioritization criteria and predictive models for CRC detection, specifically addressing the two-week wait referral guideline from the national Institute of Clinical Excellence in terms of efficacy, efficiency and diagnostic accuracy. Finally, we collected information on the usefulness of biomarkers, specifically the faecal immunochemical test, as non-invasive diagnostic tests for CRC detection in symptomatic patients.

关键词： Colorectal cancer Colonoscopy Primary health care

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Solution of the Center Problem for a Class of Polynomial Differential Systems

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1685-1696页

作者： Chang Jian Liu Jaume Llibre rafael ramírez valentín ramírez School of Mathematics(Zhuhai) Sun Yat-sen UniversityZhuhai519086P.R.China Departament de Matemàtiques Universitat Autònoma de Barcelona08193BellaterraBarcelonaCataloniaSpain Departament d’Enginyeria Informàtica i Matemàtiques Universitat Rovira i VirgiliAvinguda dels Paiïsos Catalans 2643007TarragonaCataloniaSpain

Consider the polynomial differential system of degree m of the form x=-y(1+μ(a_(2)x-a_(1)y))+x(v(a_(1)x+a_(2)y)+Ω_(m-1)(x,y)),y=x(1+μ(a_(2)x-a_(1)y))+y(v(a_(1)x+a_(2)y)+Ω_(m-1)(x,y)),whereμandνare real numbers such that(μ^(2)+v^(2))(μ+v(m-2))(a_(1)^(2)+a_(2)^(2))≠m>2 andΩ_(m−1)(x,y)is a homogenous polynomial of degree m−1.A conjecture,stated in *** Equations 2019,suggests that whenν=1,this differential system has a weak center at the origin if and only if after a convenient linear change of variable(x,y)→(X,Y)the system is invariant under the transformation(X,Y,t)→(−X,Y,−t).For every degree m we prove the extension of this conjecture to any value ofνexcept for a finite set of values ofμ.

关键词： Center problem polynomial differential system

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Glycated hemoglobin and antidiabetic strategies as risk factors for hepatocellular carcinoma

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World Journal of Gastroenterology 2010年第24期16卷 3025-3032页

作者： Valter Donadon Massimiliano Balbi Francesca valent Angelo Avogaro Department of Medicine Internal Medicine 3rdPordenone Hospital Institute of Hygiene and Epidemiology Udine University Hospital Department of Clinical and Experimental Medicine Padova University

AIM: To evaluate the relationship between glycemic control [assessed by glycated hemoglobin (HbA1c)], antidiabetic therapies and the risk of hepatocellular carcinoma (HCC).METHODS: We recruited 465 patients with HCC, 618 cases with liver cirrhosis and 490 controls with no liver disease. Among subjects with type 2 diabetes mellitus (DM2), the associations between the antidiabetic strategies and HbA1c level with HCC were determined through 2 series of multivariate logistic regression models using cirrhotic patients and controls as comparison groups. RESULTS: DM2 prevalence was 31.2% in patients with HCC, 23.2% in cirrhotic patients and 12.6% in controls (P n 86% of study subjects, DM2 had been diagnosed for more than 1 year before the HCC diagnosis. HCC patients with DM2 had a 1.52.5fold increased risk of liver cancer. The HbA1c mean levels were signif icantly higher in DM2 patients with HCC than in cirrhoticand control DM2 patients. Antidiabetic treatment with metformin was more common among cirrhotic and control DM2 subjects than among cases with HCC. In both series of multivariate analyses, treatment with metformin signif icantly reduced the risk of HCC by more than 80% compared with sulphonylureas and insulin therapy. no signif icant differences were seen between sulphonylureas and insulin treatment. Elevated HbA1c levels were positively related to the risk for HCC in diabetic patients, with a 26%50% increase in risk for each 1% increase in HbA1c ***: In patients with preexisting DM2, the risk of HCC is positively associated with poor chronic glycemic control and significantly decreased by metformin therapy.

关键词： Hepatocellular carcinoma Type 2 diabetes mellitus Glycemic control Metformin therapy HbA1c level

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Statistical learning of engineered topological phases in the kagome superlattice of AV_(3)Sb_(5)

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npj Computational Materials 2022年第1期8卷 624-629页

作者： Thomas Mertz Paul Wunderlich Shinibali Bhattacharyya Francesco Ferrari Roser valentí Institut für Theoretische Physik Goethe-UniversitätFrankfurt am MainGermany

Recent experimental findings have reported the presence of unconventional charge orders in the enlarged(2×2)unit-cell of kagome metals AV3Sb5(A=K,Rb,Cs)and hinted towards specific topological *** by these discoveries,we investigate the types of topological phases that can be realized in such kagome *** this context,we employ a recently introduced statistical method capable of constructing topological models for any generic *** analyzing large data sets generated from symmetry-guided distributions of randomized tight-binding parameters,and labeled with the corresponding topological index,we extract physically meaningful *** illustrate the possible real-space manifestations of charge and bond modulations and associated flux patterns for different topological classes,and discuss their relation to present theoretical predictions and experimental signatures for the AV_(3)Sb_(5)***,we predict higher-order topological phases that may be realized by appropriately manipulating the currently known systems.

关键词： topological signature meaningful

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Recent progress on oxygen and hydrogen peroxide reduction reactions on Pt single crystal electrodes

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Chinese Journal of Catalysis 2020年第5期41卷 732-738页

作者： valentín Briega-Martos Enrique Herrero Juan M.Feliu 阿利坎特大学电化学研究所阿利坎特西班牙

The oxygen reduction reaction(ORR)is probably the most important cathodic process in electrocatalysis because of its universal role as comburent in life and key applications in several fields such as fuel cells,corrosion processes or lithium-air *** many experimental and theoretical investigations that have been carried out during the last years and contributed to improve the knowledge about this reaction,the complete mechanism for the ORR is not elucidated yet[1].The ORR involves the exchange of 4 electrons and 4 protons for the complete reduction of O2 to water(Eq.1).The reaction mechanism is complex and implies the formation of several intermediates involving O=O bond scission and O–H bond formation.

关键词：巯基金纳米簇金属氧化物载体巯基配体一氧化碳氧化

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Coping with drought?Effects of extended drought conditions on soil invertebrate prey and diet selection by a fossorial amphisbaenian reptile

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Current Zoology 2023年第4期69卷 367-376页

作者： José Martín Jesús Ortega Roberto García-Roa Gonzalo Rodríguez-Ruiz Ana Pérez-Cembranos valentín Pérez-Mellado Departamento de Ecología Evolutiva Museo Nacional de Ciencias NaturalesCSICMadridSpain Institute of Evolutionary Biology CSIC-Universitat Pompeu FabraBarcelonaSpain Ethology Lab Cavanilles Institute of Biodiversity and Evolutionary BiologyUniversity of ValenciaValenciaSpain Departamento de Biología Animal Universidad de SalamancaSalamancaSpain

Arid climates are characterized by a summer drought period to which animals seem ***,in some years,the drought can extend for unusually longer *** the effects of these current extreme weather events on biodiversity can help to understand the effects of climate change,as models predict an increase in drought ***,we examined the effects of“unusual”extended drought on soil invertebrate prey availability and on diet composition(based on fecal contents)and diet selection of a fossorial amphisbaenian,the checkerboard worm lizard Trogonophis *** data show interannual variations in summer drought *** abundance and diversity of soil invertebrates in spring were high,and similar to those found in a“normal”early autumn,after some rain had ended with the summer *** contrast,in years with“unusual”extended drought,abundance,and diversity of soil invertebrates in early autumn were very ***,there were seasonal changes in amphisbaenians’diet;in autumn with drought,prey diversity,and niche breadth decreased with respect to spring and autumns after some rain had *** did not eat prey at random in any season,but made some changes in prey selection that may result from drought-related restrictions in prey ***,in spite that amphisbaenians showed some feeding flexibility,their body condition was lower in autumn than in spring,and much lower in autumn with *** extended drought became the norm in the future,amphisbaenians might suffer important negative effects for their health state.

关键词： amphisbaenians drought feeding ecology soil invertebrates Trogonophis wiegmanni weather conditions

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Glycaemic control, antidiabetic medications and influenza vaccination coverage among patients with diabetes in Udine, Italy

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Family Medicine and Community Health 2019年第3期7卷 61-67页

作者： Francesca valent Annarita Tullio Igiene ed Epidemiologia Clinica Azienda Sanitaria Universitaria Integrata di UdineUdineItaly

Objective The objectives of this study were to estimate influenza vaccination coverage among patients with diabetes mellitus in an Italian 250000-inhabitant area in the 2017-2018 season and to assess whether glycaemic control and pharmacological treatment were associated with the likelihood of being *** In this cross-sectional study,we analysed anonymous health administrative databases,linked with each other at the individual patient level through a stochastic key:diabetes mellitus registry,vaccinations,drug prescriptions and laboratory *** The study was conducted in the catchment area of the University Hospital of Udine(‘the Udine area’),a 250000-inhabitant area in the northeast of *** The study included all subjects included in the regional registry of patients with diabetes mellitus,living in the Udine area as of 1 October *** outcome measures Vaccination coverage in the 2017-2018 influenza season was *** association between patients’characteristics and the likelihood of being vaccinated was assessed through multivariate log binomial *** 53.0%of 15900 patients with diabetes living in the area were *** increased with age,approaching 75%at≥85 *** lacking recent glycated haemoglobin testing were less likely to be vaccinated(43.4%vaccination coverage),as were those not treated pharmacologically(44.4%vaccination coverage).Patients treated with both insulin,metformin and other antidiabetic medications were more likely to be vaccinated than those treated with metformin alone(58.1%vaccination coverage;adjusted relative risk=1.07,95%CI 1.01 to 1.14).Conclusion Influenza vaccination coverage was suboptimal in this Italian population of patients with *** to improve diabetes management could in turn positively affect influenza coverage.

关键词： vaccination patients influenza

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Solar-assisted photocatalytic water splitting using defective UiO-66 solids from modulated synthesis

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nano Research 2024年第5期17卷 4134-4150页

作者： Celia M.Rueda-navarro María Cabrero-Antonino Paula Escamilla valentín Díez-Cabanes Dong Fan Pedro Atienzar Belén Ferrer Ignacio Vayá Guillaume Maurin Herme G.Baldoví Sergio navalón Departamento de Química Universitat Politècnica de ValènciaCamino de Vera s/nValencia 46022Spain Instituto de Ciencia Molecular(ICMOL) Universitat de ValènciaPaterna 46980Spain ICGM Univ.MontpellierCNRSENSCMMontpellier34095France Instituto de Tecnología Química(UPV-CSIC) Universitat Politècnica de ValènciaAvenida de los Naranjos s/nValencia 46022Spain

Metal-organic frameworks(MOFs)are attracting increasing interests as photocatalysts for solar-driven hydrogen production from *** paper reports on a comparative study of using either acetic acid(AA)or trifluoroacetic acid(TFA)as the representative UiO-66 organic modulators for synthesizing visible light responsive UiO-66(Zr)-X(X:nH_(2) or nO_(2))photocatalysts for water *** results show that photocatalytic hydrogen generation from a water/methanol mixture can be improved by varying the nature and amount of the modulator employed to prepare the different UiO-66(Zr)-X(X:nH_(2) or nO_(2))solid ***-66(Zr)-nH_(2) was the most active photocatalyst,followed by UiO-66(Zr)-nO_(2),both prepared with 12 equivalents of AA with respect to the organic *** UiO-66(Zr)-nH_(2) solid was more active than the parent MOF in photocatalytic overall water splitting(OWS)(H_(2) and O_(2) production of 450 and 160μmol·g^(-1),respectively,in 5 h;apparent quantum yield(AQY)at 400 nm of 0.06%)in the absence of methanol and compares favourably with analogous *** on the photocatalytic activity of the most active solids of both series was obtained by means of a series of techniques,including ultraviolet-visible(UV-vis)diffuse reflectance,X-ray photoelectron spectroscopy(XPS),laser flash photolysis(LFP),electron spin resonance(ESR),photoluminescence and photoelectrochemical measurements together with density functional theory(DFT)*** results showed that organic acid modulators can be used to enhance the photocatalytic activity of missing linker UiO-66 defective materials in solar-powered water splitting.

关键词： heterogeneous photocatalysis metal-organic frameworks(MOFs) UiO-66 materials carboxylic acid modulators water splitting solar light

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Experimental bio-artificial liver:Importance of the architectural design on ammonia detoxification performance

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World Journal of Hepatology 2018年第10期10卷 719-730页

作者： María Dolores Pizarro María Eugenia Mamprin Lucas Damián Daurelio Joaquín valentín Rodriguez María Gabriela Mediavilla Consejo nacional de Investigaciones Científicas y Técnicas(COnICET) Rosario S2002 LRKArgentina Laboratorio de Investigaciones en Fisiología y Biología Molecular Vegetal(LIFiBVe) Facultad de Ciencias AgrariasUniversidad Nacional del LitoralEsperanza 3080Argentina Facultad de Ciencias Bioquímicas y Farmacéuticas Universidad Nacional de RosarioRosario S2002 LRKArgentina Centro Binacional de Criobiología Clínica y Aplicada(CAIC) Universidad Nacional de RosarioRosario S2011 BXNArgentina Instituto de Biología Molecular y Celular de Rosario(IBR CONICET-UNR)Consejo Nacional de Investigaciones Científicas y Tecnológicasy Universidad Nacional de RosarioRosario S2002 LRKArgentina

AIM To determine the influence of the construction design over the biological component's performance in an experimental bio-artificial liver(BAL) *** Two BAL models for liver microorgans(LMOs) were constructed. First, we constructed a cylindrical BAL and tested it without the biological component to establish its correct functioning. Samples of blood and biological compartment(BC) fluid were taken after 0, 60, and 120 min of perfusion. Osmolality, hematocrit, ammonia and glucose concentrations, lactate dehydrogenase(LDH) release(as a LMO viability parameter), and oxygen consumption and ammonia metabolizing capacity(as LMO functionality parameters) were determined. CPSI and OTC gene expression and function were measured. The second BAL, a "flat bottom" model, was constructed using a 25 cm2 culture flask while maintaining all other components between the models. The BC of both BALs had the same capacity(approximately 50 cm3) and both were manipulated with the same perfusion system. The performances of the two BALs were compared to show the influence of *** The cylindrical BAL showed a good exchange of fluids and metabolites between blood and the BC, reflected by the matching of osmolalities, and glucose and ammonia concentration ratios after 120 min of perfusion. no hemoconcentration was detected, the hematocrit levels remained stable during the whole study, and the minimal percentage of hemolysis(0.65% ± 0.10%) observed was due to the action of the peristaltic pump. When LMOs were used as biological component of this BAL they showed similar values to the ones obtained in a normothermic Reoxygenation System(nRS) for almost all the parameters assayed. After 120 min, the results obtained were: LDH release(%): 14.7 ± 3.1 in the BAL and 15.5 ± 3.2 in the nRS(n = 6); oxygen consumption(μmol/min?g wet tissue): 1.16 ± 0.21 in the BAL and 0.84 ± 0.15 in the nRS(n = 6); relative expression of Cps1 and Otc: 0.63 ± 0.12 and 0.67 ± 0.20, respectively,

关键词： Bio-artificial liver Ammonia detoxification Device design Ornithine Transcarbamylase rat liver microorgans Carbamyl Phosphate SynthetaseⅠ

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