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Immobilization of Gold and Silver on a Biocompatible Porous Silicone Matrix to Obtain Hybrid Nanostructures

Journal of Biomaterials and Nanobiotechnology 2018年第1期9卷 41-50页

作者： solano-umana victor Corrales Urena Yendry Regina Vega-Baudrit Jose Roberto Hologic Surgical Products Costa Rica AlajuelaCosta Rica National Laboratory of Nanotehcnology(LANOTEC-CeNAT-CONARE) San JoseCosta Rica

During the last decade an enormous research effort has been deployed with respect to porous materials. Design, pore size, shape, morphology and density are crucial features for increasing the surface area of silicone materials, aiming for a better biological response so cells can adhere and grow. Many medical applications utilize polydimethylsiloxane (PDMS) in medical implants, despite its hydrophobic surface that does not stimulate cellular adhesion. Porosity and morphology are important factors in the wettability of PDMS, but modifying the hydrophobic surface functionalization is required. To achieve this goal, the use of coatings with gold and silver nanoparticles or nanofilms can be used as a strategy to improve biocompatibility. This is due to the effect on mammalian cell adhesion and proliferation related to gold nanoparticles, as well as the prevention of infections related to silver nanoparticles. In this study, the pores in the silicone matrix were formed using sugar crystals as a template agent, and later passed through a lixiviation process to form a porous silicon matrix. Next, the matrix was placed inside a colloidal suspension;a process that allowed the immobilization of these particles on the surface matrix. A hybrid stable material was synthetized through this process. The water absorption level of the porous silicone matrix with and without the nanoparticles was determined. The water uptake of the matrix was higher when the nanoparticles were immobilized on the surface. Van der Waals and hydrogen bonding interactions account for this, promoting the retention of a higher concentration of water molecules. Higher water uptake has been identified as being a key factor for improving biological response, cellular adhesion and growth, which accelerates implant integration in the body.

关键词： Silicone Porous Gold Silver Water Absorption

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Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： victor V.Chizhikov Igor Y.Iskusnykh Department of Anatomy and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embryonic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in *** cortical hem produces several types of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly important for the development of the hippocampus,which is involved in learning and memory,and the neocortex,which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

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Reduction of NO by CO using Pd–CeTb and Pd–CeZr catalysts supported on SiO_2 and La_2O_3–Al_2O_3

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Journal of Environmental Sciences 2015年第1期27卷 87-96页

作者： victor Ferrer Dora Finol Roger solano Alexander Moronta Miguel Ramos Instituto de Superficies y Catálisis Facultad de Ingeniería Universidad del Zulia Instituto Zuliano de Investigaciones Tecnológicas km 15 carretera Vía a la Ca?ada Apartado 331 Venezuela

The catalytic activity of Pd catalysts supported on Ce0.73Tb0.27Ox/SiO2, Ce0.6Zr0.4Ox/Si O2,Ce0.73Tb0.27Ox/La2O3–Al2O3and Ce0.6Zr0.4Ox/La2O3–Al2O3was studied using the reduction of NO by CO. The catalysts were characterized by X-ray fluorescence, surface area, X-ray diffraction, temperature-programmed reduction, CO chemisorption and oxygen storage capacity. Temperature-programmed reduction results indicated that Tb or Zr incorporation improves the reducibility and oxygen storage capacity. CO chemisorption data suggested the presence of large Pd O particles due to the low CO/Pd ratio. No significant differences were obtained in light off temperatures（T Light off） for all Pd catalysts and the most active was1.5%Pd/Ce0.6Zr0.4Ox/SiO2.

关键词： Mixed oxides OSC Reduction of NO by CO Three way catalysts

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Micro,Meso and Macro Porous Materials on Medicine

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Journal of Biomaterials and Nanobiotechnology 2015年第4期6卷 247-256页

作者： victor solano-umana Jose Roberto Vega-Baudrit Environmental Management Master Degree Senior Chemist Hologic Surgical ProductsDOCINADE Science PhD StudentSan JoseCosta Rica PhD National Nanotechnology Laboratory(LANOTEC-CeNAT-CONARE)San JoseCosta Rica

An enormous development is experimented on the porous materials. The porous was considered a defect on solid materials some years ago, but right now, this defect is an advantage, based on the properties obtained from a micro and mesoporous materials. Microporous, mesoporous and macroporous materials with an uniformed pore distribution offer new properties, such as absorption, adsorption, exchange separation, and catalysis of different compounds, also they can play different roles as hosts for a nanocomposite materials to modify or improve their properties. Today, the structural types of open framework porous compounds have rapidly increased by their unique structural properties, porous size window and accessible void space are critical factors on a medical application.

关键词： Microporous Mesoporous Macro Porous

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“What is a Sociologist Doing Here?”An Unconventional People-Centered Approach to Improve Warning Implementation in the Sendai Framework for Disaster Risk Reduction

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International Journal of Disaster Risk Science 2020年第2期11卷 218-229页

作者： victor Marchezini Cemaden–National Early Warning and Monitoring Center of Natural Disasters Distrito de Eug8nio de Melo 12.247-016Sao Jose dos CamposSPBrazil Doctorate Program on Earth System Science National Institute for Space ResearchSao Jose dos CamposBrazil Programa de Pós-Gradua??o em Desastres Naturais ICT/Unesp-CemadenSao Jose dos Campos.Brazil

The Sendai Framework for Disaster Risk Reduction 2015–2030 recommends several actions for early warning systems(EWSs). However, there is a lack of information about their means of implementation. This article used institutional ethnography to analyze the 2012–2018 implementation of a national warning system in Brazil. The challenges related to daily activities, and the interdisciplinary works in the four axes of EWSs towards multi-hazard and people-centered approaches are discussed. This national experience is then discussed in the light of the global challenges of EWSs considering two main issues:(1) experiences of implementation and barriers related to people-centered warning systems;and(2)types of national/regional warning systems and hazards/threats that are being monitored as an important input for multi-hazard approaches. There are few multi-hazard warning systems in place and EWSs are focused on hydrometeorological hazards, mainly related to floods. The Sendai Framework needs to improve access to data and information, identify views from the frontline, consider political threats and vulnerabilities, and find ways to talk about disaster risk creation processes at a larger scale.

关键词： Risk governance Interdisciplinary research People-centered warning systems

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Cryotic climate conditions and their eventual implication in the high-mountain surface of the Nevado de Toluca volcano, Mexico

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Journal of Mountain Science 2021年第9期18卷 2273-2286页

作者： SOTO victor Facultad de Ciencias Biológicas y Agropecuarias Universidad VeracruzanaPoza Rica-Tuxpan 92870México

The state of the cryosphere in tropical regions is of great importance because the temperature around the glaciers, permafrost and snow cover always fluctuates near the melting point. These thermal conditions and their high sensitivity to climate change cause the accelerated disappearance of these elements;therefore, it is important to know the climatic factors that regulate them, as well as the physical characteristics of each cryospheric element. Unlike glaciers, permafrost and snow cover have not been widely studied. In recent decades, the study of the glacial and periglacial environment has been carried out in intertropical mountains. However, despite the altitude of their relief and the frequent occurrence of snowfall in tropical high mountains, the conditions that determine such events have been barely analyzed;and in the case of Mexico, the volume of snowfall and its thickness have not been quantified either, as well as their corresponding duration. Consequently, this work is aimed to analyze the temperature and precipitation conditions that determine the snowfall at the higher part of the Nevado de Toluca volcano;at the same time, the conditions of the cryotic climate and their possible implication on the surface are studied. The analysis of data from 1965 to 2016, using frequency statistics, allowed to realize that snowfall occurs with low intensity, its accumulation being less than 10 cm thick and 10 mm of snow water equivalent, which causes the snowpack to stay only a few weeks on average. At the same time, it was determined that there is a significant increase in the number of freeze-thaw cycles. Therefore, due to the climate conditions and their influence on the mountain surface, it is probable that the bedrock is subject to a greater gelifraction dynamics, and the unconsolidated soil surface increases;the combination of the above could cause a greater geomorphological dynamic over time, particularly due to debris flows, and by water and wind erosion of

关键词： Air temperature Cryotic conditions High-mountain climatology Periglacial geomorphology Snow precipitation

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Transnational Dialogues on Interdisciplinary Approaches for Advancing People-Centered Warning Systems

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International Journal of Disaster Risk Science 2023年第5期14卷 868-872页

作者： victor Marchezini Cemaden–National Early Warning and Monitoring Centre of Natural Disasters São Josédos Campos12.247-016Brazil Natural Hazards Center Institute of Behavioral ScienceUniversity of Colorado BoulderBoulderCO80309USA

The United Nations Office for Disaster Risk Reduction and the World Meteorological Organization launched in 2022 the executive plan of the world program "Early Warning Systems for All" to be implemented from 2023 to *** program champions an investment of USD 3.1 billion into the four pillars of warning systems and calls for multi-hazard and peoplecentered warning systems(PCWS).However,there is a scientific gap concerning interdisciplinary approaches to promoting *** by the call for action of "Early Warning Systems for All" and warning research gaps on the lack of interdisciplinarity,a workshop series "Interdisciplinary Approaches for Advancing People-Centered Warning Systems" was held in early *** short article shares the preliminary findings and recommendations of this research,which involved a transnational virtual dialogue between one scientific organization in Brazil and one from the United *** findings and recommendations discussed in three virtual sessions and one collective working paper were centered on three aspects:promoting interdisciplinary integration in research;the need to discuss the characteristics of a PCWS;and promoting problem-and solution-based programs with people to integrate them at all phases of the warning system.

关键词： Capacity building Cooperation Interdisciplinary methods Warning implementation Warning research

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Miscellaneous Rotating Solitary Waves to a Coupled Dispersionless System

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Chinese Physics Letters 2009年第9期26卷 61-64页

作者： Kuetche Kamgang victor Ecole Nationale Superieure Polyteehnique University of Yaounde I PO Box 8390 Cameroon Department of Physics Faculty of Science University of Yaounde I PO Box. 812 Cameroon Higher Teacher's Training College of Maroua University of Maroua P.O. Box. 46 Cameroon The A bdus Salam International Centre for Theoretical Physics P.O. Box 586 Strada Costiera II-34014 Trieste Italy

We investigate the soliton structure of a coupled dispersionless system describing a current-conducting string with infinite length within a magnetic field. Thus, following Hirota＇s method, we unwrap three typical localized waves with nonzero angular momentum depending strongly upon their angular velocities. Illustrating the soliton behavior of these waves, we focus our interests on breather-like waves and depict the elastic scattering amongst such waves.

关键词： sea surface nonliear interaction numerical method

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Mathematics of microRNAs: stabilizing gene regulatory networks

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National Science Review 2019年第6期6卷 1189-1190页

作者： victor Ambros Program in Molecular Medicine University of Massachusetts Medical School

Micro RNAs(miRNAs) are fascinating in their versatility. Animal cells express hundreds of distinct micro RNAs, and each micro RNA can regulate hundreds of distinct m RNA ***, in aggregate, the micro RNA compliment of a cell can exert pervasive effects on gene expression. Individual micro RNAs can also be potent determinants of phenotype: The

关键词： RNA stabilizing gene regulatory networks Mathematics of microRNAs

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Processing stages of Gd_2Sr(Al_(1-x)Fe_x)_2O_7 series

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Rare Metals 2014年第1期33卷 47-53页

作者： Ekaterina Tugova victor Gusarov Laboratory of New Inorganic Materials Ioffe Physical Technical Institute of RAS Department of Physical Chemistry St. Petersburg State Institute of Technology Technical University

The continuous series of perovskite-related oxides with the general formula GdzSr（Al1-xFex）207 0 〈 x 〈 1 were prepared by conventional ceramic technology in air. The pro- cessing stages of Gd2Sr（Al1-xFex）207 0 〈 x 〈 1 phases were investigated by means of X-ray powder diffraction （XRD） and scanning electron microscopy （SEM） with the element phase analysis. The three main stages of GdeSr（All_~Fex）aO7 for- marion are pointed out. The analysis of the mutual influence of intermediate compounds on the synthesis of the target solid solutions of complex composition, in particular for Gd2Sr（All-xFex）207 was carried out. It is determined that the closeness of the reactive mixture composition to the composition of individual compounds Gd2SrA1207 or GdaSrFeaO7 is of importance for the realization of a partic- ular way of GdESr（Al1-xFex）207 solid solutions formation. It is shown that at x ,= 0.2 the reversing in scheme of Gd2Sr（Al1-Fex）207 series formation is observed. The formation of the Gd2Sr（Al1-xFex）207 continuous series is indicated by the monotonic dependence of molar unit cell volume on the iron content x.

关键词： Rare-earth metals Oxide materials Solid-state reactions Ceramics X-ray diffraction (XRD) Scanning electron microscopy (SEM)

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