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Electrical Properties and Phase Behavior of Proton Conducting Nanocomposites Based on the Polymer System (1 - x)[PVOH + H3PO2+ H2O]·x(Nb2O5)

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American Journal of Analytical Chemistry 2014年第5期5卷 301-307页

作者： angélica maría mazuera Rubén Antonio Vargas TFnoM Group Universidad del Valle Cali Colombia

In the present work, novel blend polymer electrolyte membranes using poly(vinyl alcohol) (PVA), doped with hypophosphorous acid (H3PO2) and reinforced with porous niobium oxide (Nb2O5) microparticles in different compositions were prepared by the solution-casting technique. Their phase behavior and ionic conductivity were studied by differential scanning calorimetric (DSC), thermogravimetric analysis (TGA) and impedance spectroscopy (IS) in the radio-frequency range. Using a constant H3PO2/PVA weigh ratio of 0.25, it was found that the water content in the blended hydrogel membranes increased with increasing the filler Nb2O5 content, thus increasing the electrical conductivity. However, the suitable weight ratio of Nb2O5:(H3PO2/PVA) for the blend performance (both mechanically and electrically) was x = 0.075, with a maximum ionic conductivity of 2.7?× 10﹣3 S·cm﹣1 at 120°C. For all blends prepared, the lost tangent plots show asymmetrical peaks, as a consequence of correlations in the mobile ion diffusion as a function of frequency. Although this “universal dynamic response” was observed at all temperatures, variations in the tan(δ) relaxation peaks indicate a decrease of ionic correlation when the temperature is increased. Both the dc conductivity and tan(δ) peaks frequency dependency are thermally activated, following an Arrhenius-type behavior with activation energy of the same order, indicating that the corresponding ionic processes have the same origin, i.e., proton jump among available sites in the polymer matrix. The additions of oxide particles to the membranes improve their thermal and electrical properties, attributed to an approximation effect.

关键词： Nanocomposite Polymer Blend Impedance Study DSC/TGA Ionic Conductivities Polymer Electrolytes Phase Behavior

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Stress tensors and quantification of fracture patterns to analyze connectivity and potential fluid flow in a mesa landform of the Northern Andes

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Journal of Mountain Science 2024年第1期21卷 271-291页

作者： GARCÍA-ARIAS Sergio VELANDIA Francisco ALVAREZ angélica SANABRIA-GÓMEZ JoséD TARAZONA Yessenia VARGAS maría Camila Escuela de Geología Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia Escuela de Física Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia

This work applies stress tensors inversions and quantification of fracture patterns along the Mesa de Los Santos, in the Eastern Cordillera of Colombia, to better understand the potential fluid flow. It thus contributes to the conceptual hydrogeological model. The area was subdivided into three blocks, separated by the NW Potreros and the Los Santos faults, having minor inner faults of different orientations. This separation facilitates the analysis of the fractures measured in the field, which in general show high dip angles and a conjugate geometry in the northern block, tension fractures(Mode I) in the central block, and a random distribution in the southwestern block. WinTensor treatment of slickensides yielded a maximum horizontal stress(SHmax) of 111o, which coincides with the WNW-ESE tensor observed from the conjugate and tension joints. We then used Frac Pa Q to generate interpolation maps of fracture intensity and density. The maps show the highest values in the central block and the lowest in the northern block,where the precipitation is higher, causing intensive rock weathering and homogenization of the fracture planes. Although the highest values of connectivity by line are found to the south of the mesa, we suggest the possibility of greater flow from the recharge zone(NE) along bedding planes and open NW-SE fractures.

关键词： Mesa de Los Santos Colombia Win-Tensor FracPaQ Strike-slip faults Fractured aquifers

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Metabolomics for the diagnosis of bladder cancer: A systematic review

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Asian Journal of Urology 2024年第2期11卷 221-241页

作者： Herney Andrés García-Perdomo angélica maría Dávila-Raigoza Fernando Korkes Division of Urology/Urooncology Department of SurgerySchool of MedicineUniversidad del ValleCaliColombia UROGIV Research Group School of MedicineUniversidad del ValleCaliColombia Urologic Oncology Division of UrologyABC Medical SchoolSao PauloBrazil

Objective: Metabolomics has been extensively utilized in bladder cancer (BCa) research, employing mass spectrometry and nuclear magnetic resonance spectroscopy to compare various variables (tissues, serum, blood, and urine). This study aimed to identify potential biomarkers for early BCa ***: A search strategy was designed to identify clinical trials, descriptive and analytical observational studies from databases such as Medline, Embase, Cochrane Central Register of Controlled Trials, and Latin American and Caribbean Literature in Health Sciences. Inclusion criteria comprised studies involving BCa tissue, serum, blood, or urine profiling using widely adopted metabolomics techniques like mass spectrometry and nuclear magnetic resonance. Primary outcomes included description of metabolites and metabolomics profiling in BCa patients and the association of metabolites and metabolomics profiling with BCa diagnosis compared to control patients. The risk of bias was assessed using the Quality Assessment of Studies of Diagnostic ***: The search strategy yielded 2832 studies, of which 30 case-control studies were included. Urine was predominantly used as the primary sample for metabolite identification. Risk of bias was often unclear inpatient selection, blinding of the index test, and reference standard assessment, but no applicability concerns were observed. Metabolites and metabolomics profiles associated with BCa diagnosis were identified in glucose, amino acids, nucleotides, lipids, and aldehydes ***: The identified metabolites in urine included citric acid, valine, tryptophan, taurine, aspartic acid, uridine, ribose, phosphocholine, and carnitine. Tissue samples exhibited elevated levels of lactic acid, amino acids, and lipids. Consistent findings across tissue, urine, and serum samples revealed downregulation of citric acid and upregulation of lactic acid, valine, tryptophan, taurine, glutamine, aspartic acid, uridine, rib

关键词： Metabolite Metabolomics Bladder cancer Metabolomicsprofile

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A multi-platform analysis of human gingival crevicular fluid reveals ferroptosis as a relevant regulated cell death mechanism during the clinical progression of periodontitis

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International Journal of Oral Science 2024年第2期16卷 265-279页

作者： Alfredo Torres M.angélica Michea Ákos Végvári marion Arce Valentina Pérez marcela Alcota Alicia Morales Rolando Vernal Mauricio Budini Roman A.Zubarev Fermín E.González Laboratory of Experimental Immunology&Cancer Faculty of DentistryUniversity of ChileSantiagoChile Department of Conservative Dentistry Faculty of DentistryUniversity of ChileSantiagoChile Division of Chemistry I Department of Medical Biochemistry and BiophysicsKarolinska InstitutetStockholmSweden Periodontal Biology Laboratory Faculty of DentistryUniversidad de ChileSantiagoChile Laboratory of Cellular and Molecular Pathology Institute for Research in Dental SciencesFaculty of DentistryUniversity of ChileSantiagoChile

Ferroptosis is implicated in the pathogenesis of numerous chronic-inflammatory diseases,yet its association with progressive periodontitis remains *** investigate the involvement and significance of ferroptosis in periodontitis progression,we assessed sixteen periodontitis-diagnosed *** progression was clinically monitored over twelve weeks via weekly clinical evaluations and gingival crevicular fluid(GCF)collection was performed for further *** metrics,proteomic data,in silico methods,and bioinformatics tools were combined to identify protein profiles linked to periodontitis progression and to explore their potential connection with *** western blot analyses validated key ***,a single-cell RNA sequencing(scRNA-seq)dataset(GSE164241)for gingival tissues was analyzed to elucidate cellular dynamics during periodontitis *** progression was identified as occurring at a faster rate than traditionally *** samples from progressing and non-progressing periodontal sites showed quantitative and qualitatively distinct proteomic *** addition,specific biological processes and molecular functions during progressive periodontitis were revealed and a set of hub proteins,including SNCA,CA1,HBB,SLC4A1,and ANK1 was strongly associated with the clinical progression status of ***,we found specific proteins-drivers or suppressors-associated with ferroptosis(SNCA,FTH1,HSPB1,CD44,and GCLC),revealing the co-occurrence of this specific type of regulated cell death during the clinical progression of ***,the integration of quantitative proteomic data with scRNA-seq analysis suggested the susceptibility of fibroblasts to *** analyses reveal proteins and processes linked to ferroptosis for the first time in periodontal patients,which offer new insights into the molecular mechanisms of progressive periodontal *** findings may le

关键词： finding progression faster

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Experimental implementation of phase triplicator gratings in a spatial light modulator

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Chinese Optics Letters 2024年第2期22卷 64-69页

作者：高尚 maría del mar Sánchez-López Ignacio Moreno Instituto de Bioingeniería Universidad Miguel HernándezElche 03202Spain Departamento de Física Aplicada Universidad Miguel HernándezElche 03202Spain Departamento de Ciencia de Materiales Óptica y Tec.Electr´onicaUniversidad Miguel HernándezElche 03202Spain

In this work,we compare different methods for implementing a triplicator,a phase grating that generates three equiintense diffraction *** design with optimal efficiency features a continuous phase profile,which cannot be easily reproduced,and is typically affected by *** compare its performance with binary and sinusoidal phase *** also analyze the effect of quantizing the phase ***,a random approach is adopted to eliminate the additional harmonic *** all cases,a liquid-crystal-on-silicon spatial light modulator is employed to experimentally verify and compare the different approaches.

关键词： diffraction gratings phase modulation triplicator spatial light modulators

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A transfer learning enhanced physics-informed neural network for parameter identification in soft materials

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1685-1704页

作者： Jing’ang ZHU Yiheng XUE Zishun LIU International Center for Applied Mechanics State Key Laboratory for Strength and Vibration of Mechanical StructuresSchool of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China

Soft materials,with the sensitivity to various external stimuli,exhibit high flexibility and *** prediction of their mechanical behaviors requires advanced hyperelastic constitutive models incorporating multiple ***,identifying multiple parameters under complex deformations remains a challenge,especially with limited observed *** this study,we develop a physics-informed neural network(PINN)framework to identify material parameters and predict mechanical fields,focusing on compressible Neo-Hookean materials and *** improve accuracy,we utilize scaling techniques to normalize network outputs and material *** framework effectively solves forward and inverse problems,extrapolating continuous mechanical fields from sparse boundary data and identifying unknown mechanical *** explore different approaches for imposing boundary conditions(BCs)to assess their impacts on *** enhance efficiency and generalization,we propose a transfer learning enhanced PINN(TL-PINN),allowing pre-trained networks to quickly adapt to new *** TL-PINN significantly reduces computational costs while maintaining *** work holds promise in addressing practical challenges in soft material science,and provides insights into soft material mechanics with state-of-the-art experimental methods.

关键词： soft material parameter identification physics-informed neural network(PINN) transfer learning inverse problem

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First record of abnormal body coloration in a rockfish Sebastes koreanus(Scorpaenoidei:Sebastidae)from coastal water of China based on morphological characteristics and DNA barcoding

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Journal of Oceanology and Limnology 2024年第2期42卷 640-646页

作者： ang LI Huan Wang Changting AN Shufang LIU Yellow Sea Fisheries Research Institute Chinese Academy of Fishery SciencesQingdao 266071China Laboratory for marine Fisheries Science and Food Production Processes Laoshan LaboratoryQingdao 266071China

The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA *** two rockfish specimens were collected from the coastal waters of Qingdao,China,and the whole body and all fins of them were *** the two red-colored rockfish,there were tiny deep red spots on each fin,2 red radial stripes behind and below the eyes and 1 large deep red blotch on the opercula,while the similar stripe and spot patterns are also present in the *** specimens with normal body *** countable characteristics of the two specimens are in the range of the morphometry of *** further clarify the species identity and taxonomic status of the two specimens,DNA barcode analysis was carried *** genetic distance between the red-colored rockfish and *** was 0,and the minimum net genetic distances between the red-colored rockfish and other Sebastes species except for *** were 3.0%,which exceeds the threshold of species *** phylogenetic analysis showed that the DNA barcoding sequences of the two red-colored rockfish clustered with the *** *** above results of DNA barcode analysis also support that the two red-colored rockfish could be identified as the species of *** mechanism of color variation in *** is desirable for further research and the species could be an ideal model to study the color-driven speciation of the rockfishes.

关键词： abnormal body coloration Sebastes koreanus coastal water of China Yellow Sea morphological characteristics DNA barcoding

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Influence of laser parameters on the microstructures and surface properties in laser surface modification of biomedical magnesium alloys

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Journal of Magnesium and Alloys 2024年第1期12卷 72-97页

作者： Chee Ying Tan Cuie Wen Hua Qian ang School of Engineering RMIT UniversityMelbourneVictoria 3001Australia

Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and *** primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the *** surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the *** composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant ***,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.

关键词： Biocompatibility Biodegradability Corrosion Implant applications Laser surface modification Magnesium alloys

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Secure state estimation for cyber-physical systems with unknown input sliding mode observer

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Control Theory and Technology 2024年第2期22卷 244-253页

作者： Panpan Zhang Yuwei Ren Yixian Fang ang Liu School of Information Science and Engineering Shandong Normal UniversityJinan250358ShandongChina School of Information Engineering Shandong Management UniversityJinan250357ShandongChina

In recent years, cyber attacks have posed great challenges to the development of cyber-physical systems. It is of great significance to study secure state estimation methods to ensure the safe and stable operation of the system. This paper proposes a secure state estimation for multi-input and multi-output continuous-time linear cyber-physical systems with sparse actuator and sensor attacks. First, for sparse sensor attacks, we propose an adaptive switching mechanism to mitigate the impact of sparse sensor attacks by filtering out their attack modes. Second, an unknown input sliding mode observer is designed to not only observe the system states, sensor attack signals, and measurement noise present in the system but also counteract the effects of sparse actuator attacks through an unknown input matrix. Finally, for the design of an unknown input sliding mode state observer, the feasibility of the observing system is demonstrated by means of Lyapunov functions. Additionally, simulation experiments are conducted to show the effectiveness of this method.

关键词： Sparse attacks Cyber-physical systems Unknown input sliding mode Secure state estimation Adaptive switching mechanism

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Epidemiology of work-related hand and wrist injuries in a referral center: A descriptive study

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World Journal of Orthopedics 2024年第7期15卷 650-659页

作者： angélica M Rodríguez Ginna P Tocanchón Jessica T Villalba Luis M Pombo Aníbal A Teherán Gabriel Camero-Ramos Karen P Ayala Gerhard M Acero Research Center Fundación Universitaria Juan N.CorpasBogotá111321Colombia Red Cross Cruz Roja Colombiana-Seccional Cundinamarca BogotáBogotá111221Colombia Vigilancia Epidemiológica Instituto Nacional de SaludBogotá111321Colombia

BACKGROUND Occupational hand and wrist injuries(OHWIs)account for 25%of work-related accidents in low-and middle-income *** Colombia,more than 500000 occupational accidents occurred in 2021,and although the rate declined to less than 5%in 2020 and 2021,at least one in four accidents involved a hand or wrist *** To describe the OHWIs in workers seen at the emergency room at a second-level hospital in *** An observational study was performed using data from workers who experienced OHWIs and attended a second-level hospital,between June,2020 and May,*** overall frequency of OHWIs,as well as their distribution by sociodemo-graphic,clinical,and occupational variables,are ***,association patterns between sex,anatomical area(fingers,hand,wrist),and type of job were analyzed by correspondence analysis(CA).RESULTS There were 2.101 workers treated for occupational accidents,423(20.3%)were cases of OHWIs,which mainly affected men(93.9%)with a median age of 31 years and who worked mainly in mining(75.9%).OHWIs were more common in the right upper extremity(55.3%)and comprised different types of injuries,such as contusion(42.1%),laceration(27.9%),fracture(18.7%),and crush injury(15.6%).They primarily affected the phalanges(95.2%),especially those of the first finger(25.7%).The CAs showed associations between the injured anatomical area and the worker’s job that differed in men and women(explained variance>90%).CONCLUSION One out of five workers who suffered occupational accidents in Cundinamarca,Columbia had an OHWI,affecting mainly males employed in *** occupational profile is likely to lead to prolonged rehabilitation,and permanent functional *** results might be useful for adjusting preventive measures in cluster risk groups.

关键词： Accidents Occupational Epidemiology Hand injuries Wrist injuries Occupational health

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