During the rainy season in Brazil,landslides can have catastrophic consequences,including loss of life,damage to urban infrastructure and significant economic impacts.Now,more than eight million people in Brazil live ...During the rainy season in Brazil,landslides can have catastrophic consequences,including loss of life,damage to urban infrastructure and significant economic impacts.Now,more than eight million people in Brazil live in disaster-prone areas.The objective of this article is to present a chronological review of the principal policies and programmes at the national,state,and municipal levels,with an emphasis on their key actions aimed at mitigating the impact of disasters related to natural hazards,particularly landslides.Our analysis was based on official records of public policies from the national,state,and municipal governments.The results show that several initiatives were initially developed at the local and regional level.However,it was not until the late 1980s that a comprehensive organisation of civil protection at the national level emerged as a response measure.It is possible to highlight three phases(understanding,coexistence,and prevention)of institutional action focused on risk management in the face of disasters.Despite the growing knowledge of risk scenarios,disasters continue to occur in Brazil on an annual basis,revealing several obstacles to reducing their impact,particularly given the social and economic disparities between Brazilian regions and the applicability of public policies that must overcome the limitations of each municipality.展开更多
This work describes the use of TiO_(2)nanotubes-based electrodes(TNT)modified with Cu_(2)O nanostructures and gold nanoparticles for the photoelectroreduction of CO_(2)to produce value-added compounds.A thin layer of ...This work describes the use of TiO_(2)nanotubes-based electrodes(TNT)modified with Cu_(2)O nanostructures and gold nanoparticles for the photoelectroreduction of CO_(2)to produce value-added compounds.A thin layer of polydopamine was used as both an adherent agent and an electron transfer mediator,due to itsπ-conjugated electron system.The highest production yield was achieved using a TNT@PDA/Nc/Au40%electrode,with Faradaic efficiencies of 47.4%(110.5μM cm^(-2))and 27.8%(50.4μM cm^(-2))for methanol and methane,respectively.The performance of the photoelectrodes was shown to be Cu_(2)O facet-dependent,with cubic structures leading to greater conversion of CO_(2)to methanol(43%)and methane(27%),compared to the octahedral morphology,while a higher percentage of metallic gold on the nanostructured Cu_(2)O surface was mainly important for CH4production.Density functional theory(DFT)calculations supported these findings,attributing the superior photoelectrocatalytic performance of the TNT@PDA/Nc/Au40%electrode for CH4generation to the formation of an OCH3intermediate bonded to Au atoms.Studies using isotope-labeling and analysis by gas chromatograph-mass(GC-MS)demonstrated that13CO_(2)was the source for photoelectrocatalytic generation of13CH3OH and13CH313CH2OH.展开更多
Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- ...Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- posite is the interfacial interaction between its components,which are carbon fiber and polymeric matrix.The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite.EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests.Experimental results showed that EB irradiation improved the ten- sile strength of carbon fiber samples.The maximum value in tensile strength was reached using doses of about 250 kGy.After breakage,the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated.SEM micrographs showed modifications on the carbon fiber surface.展开更多
Environmentally friendly energy sources alternatives to fossil fuels such as solar and wind are strategic for meeting the needs of an increasingly energy demanding society,despite their periodic/intermittent nature.Th...Environmentally friendly energy sources alternatives to fossil fuels such as solar and wind are strategic for meeting the needs of an increasingly energy demanding society,despite their periodic/intermittent nature.Thus,urge the development of clean and renewable energy sources such as based on solar energy and water in a cyclic way,by photoinduced water-splitting and regeneration in fuel cells.In this context,energy storage devices such as hybrid supercapacitors become fundamental for realization of a sustainable society.In this review,the early discovery and recent advances concerning synthetic strategies,hierarchical structures,and oxygen evolution reaction(OER)/hydrogen evolution reactions(HER) catalytic performances of nickel-vanadium double hydroxides(NiV-LDHs) based nanomaterials are summarized.A discussion about the role of vanadium ions in HER/OER was also included,highlighting the recent progress in theoretical calculations in this field.Finally,some hybrid supercapacitor electrode materials based on NiV-LDHs are described,including the strategies to circumvent the parasitic oxygen evolution reaction during charge-discharge of those energy storage devices.In short,catalysts for HER/OER and hybrid supercapacitor electrode materials based on NiV-LDHs were reviewed considering their key multifunctional role in the way to a more sustainable society.展开更多
The main objective of this paper was to characterize the voltammetric profiles of the Pt/C,Pt/C-ATO,Pd/C and Pd/CATO electrocatalysts and study their catalytic activities for methane oxidation in an acidic electrolyte...The main objective of this paper was to characterize the voltammetric profiles of the Pt/C,Pt/C-ATO,Pd/C and Pd/CATO electrocatalysts and study their catalytic activities for methane oxidation in an acidic electrolyte at 25 ℃ and in a direct methane proton exchange membrane fuel cell at 80 ℃. The electrocatalysts prepared also were characterized by X-ray diffraction( XRD) and transmission electron microscopy( TEM). The diffractograms of the Pt/C and Pt/C-ATO electrocatalysts show four peaks associated with Pt face-centered cubic( fcc) structure,and the diffractograms of Pd/C and Pd/C-ATO show four peaks associated with Pd face-centered cubic( fcc) structure. For Pt/C-ATO and Pd/C-ATO,characteristic peaks of cassiterite( SnO_2) phase are observed,which are associated with Sb-doped SnO_2( ATO) used as supports for electrocatalysts. Cyclic voltammograms( CV) of all electrocatalysts after adsorption of methane show that there is a current increase during the anodic scan. However,this effect is more pronounced for Pt/C-ATO and Pd/C-ATO. This process is related to the oxidation of the adsorbed species through the bifunctional mechanism,where ATO provides oxygenated species for the oxidation of CO or HCO intermediates adsorbed in Pt or Pd sites. From in situ ATR-FTIR( Attenuated Total Reflectance-Fourier Transform Infrared) experiments for all electrocatalysts prepared the formation of HCO or CO intermediates are observed,which indicates the production of carbon dioxide. Polarization curves at 80 ℃in a direct methane fuel cell( DMEFC) show that Pd/C and Pt/C electroacatalysts have superior performance to Pd/C-ATO and Pt/C-ATO in methane oxidation.展开更多
Scanning electrochemical microscopy(SECM)and scanning vibrating electrode technique(SVET)were used to investigate the electrochemical behaviour of the top surface of the 2098-T351 alloy welded by friction stir welding...Scanning electrochemical microscopy(SECM)and scanning vibrating electrode technique(SVET)were used to investigate the electrochemical behaviour of the top surface of the 2098-T351 alloy welded by friction stir welding(FSW).The SVET technique was efficient in identifying the cathodic and anodic weld regions.The welding joint(WJ),which comprises the thermomechanically affected zone(TMAZ)and the stir zone(SZ),was cathodic relative to the heated affected zone(HAZ)and the base metal(BM).The reactivities of the welding joint at the advancing side(AS)and the retreating side(RS)were analyzed and compared using SECM technique in the competition mode by monitoring the dissolved oxygen as a redox mediator in 0.005 mol L^-1 NaCl solution.The RS was more electrochemically active than the AS,and these results were correlated with the microstructural features of the welded alloy.展开更多
The study of corrosion of magnesium and its alloys has emerged a hot topic in the applications of lightweight structural materials. The inherently high electrochemical activity of bare magnesium surfaces still lacks a...The study of corrosion of magnesium and its alloys has emerged a hot topic in the applications of lightweight structural materials. The inherently high electrochemical activity of bare magnesium surfaces still lacks a convincing mechanism to describe the observed experimental characteristics, and it has prompted the development of various types of protective coatings with the aim of slowing metal dissolution. In recent years, new instruments and techniques have been developed to study with spatial resolution the local corrosion processes that occur in metallic materials in general, and for magnesium and its alloys in particular, both for bare surfaces and coated. Scanning microelectrochemical techniques, such as local electrochemical impedance spectroscopy(LEIS), scanning electrochemical microscopy(SECM), scanning vibrating electrode technique(SVET), scanning ion-selective electrode technique(SIET) and scanning Kelvin probe(SKP) can provide information about the local electrochemical activity of metallic surfaces. In the present work, the applications of these techniques in corrosion studies of magnesium and its alloys are reviewed. Assessment of corrosion mechanisms, barrier properties of conventional coatings and active corrosion behavior of self-healing coatings are examined. Limitations and future developments in this area are discussed.展开更多
PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing ...PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction( XRD),energy dispersive analysis( EDX),transmission electron microscopy( TEM),cyclic voltammetry( CV),chronoamperommetry( CA) and polarization curves in alkaline and acidic electrolytes( single cell experiments). The XRD patterns showPtpeaks are attributed to the face-centered cubic( fcc) structure,and a shift of Pt( fcc) peaks indicates that Ru or In is incorporated into Ptlattice. TEMmicrographs showmetal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. Methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature,by CV and CA. PtRu/C( 50 ∶ 50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80 ℃ showPtRuIn/C( 50 ∶ 25 ∶ 25)with superior performance for methanol oxidation,when compared to Pt/C,PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C( 50 ∶ 25 ∶ 25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Ptalloy.展开更多
Huntington’s(HD)and Parkinson’s diseases(PD)are neurodegenerative disorders caused by the death of GABAergic and dopaminergic neurons in the basal ganglia leading to hyperkinetic and hypokinetic symptoms,respectivel...Huntington’s(HD)and Parkinson’s diseases(PD)are neurodegenerative disorders caused by the death of GABAergic and dopaminergic neurons in the basal ganglia leading to hyperkinetic and hypokinetic symptoms,respectively.We review here the participation of purinergic receptors through intracellular Ca^2+signaling in these neurodegenerative diseases.The adenosine A2A receptor stimulates striatopallidal GABAergic neurons,resulting in inhibitory actions on GABAergic neurons of the globus pallidus.A2A and dopamine D2 receptors form functional heteromeric complexes inducing allosteric inhibition,and A2A receptor activation results in motor inhibition.Furthermore,the A2A receptor physically and functionally interacts with glutamate receptors,mainly with the mGlu5 receptor subtype.This interaction facilitates glutamate release,resulting in NMDA glutamate receptor activation and an increase of Ca2+influx.P2X7 receptor activation also promotes glutamate release and neuronal damage.Thus,modulation of purinergic receptor activity,such as A2A and P2X7 receptors,and subsequent aberrant Ca^2+signaling,might present interesting therapeutic potential for HD and PD.展开更多
Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of...Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of gaseous samples. This paper describes a method to fabricate and evaluate aluminum capsules to irradiate gaseous samples in nuclear reactor. A semi-circular slotted die from a hydraulic presshead was modified to seal aluminum tubes. The aluminum capsules were subjected to leak detection tests, which demonstrated the accordance with standard ISO 9978.展开更多
The biocompatibility of orthopedic implants is closely related to their elastic modulus and surface properties.The objective of this study was to determine the effects of cold rolling,recrystallization and laser surfa...The biocompatibility of orthopedic implants is closely related to their elastic modulus and surface properties.The objective of this study was to determine the effects of cold rolling,recrystallization and laser surface melting(LSM)on the microstructure and mechanical properties of a biphase(α″+β)Ti-30Nb-4Sn alloy.X-ray diffraction(XRD)texture analysis of the cold-rolled substrate revealed the[302]α″//ND texture component,while analysis of the recrystallized substrate showed the[302]α″//ND and[110]α″//ND components.Theβ-phase texture could not be directly measured by XRD,but the presence of the[111]β//ND texture component was successfully predicted by considering the orientation relationship between theα″andβphases.Nanoindentation measurements showed that the elastic modulus of the cold-rolled substrate(63GPa)was lower than that of the recrystallized substrate(74GPa).Based on the available literature and the results presented here,it is suggested that this difference is caused by the introduction of crystal defects during cold deformation.The combined nanoindentation/EBSD analysis showed that the nanoindentation results are not affected by crystal orientation.LSM of the deformed alloy produced changes in hardness,elastic modulus and crystallographic texture similar to those produced by recrystallization heat treatment,creating a stiffness gradient between surface and substrate.展开更多
Fuel cycle related activities were accomplished in IPEN-CNEN/SP in laboratory and pilot plant scale and most facilities were built in the 70-80 years. Nevertheless, radical changes of the Brazilian nuclear policy in t...Fuel cycle related activities were accomplished in IPEN-CNEN/SP in laboratory and pilot plant scale and most facilities were built in the 70-80 years. Nevertheless, radical changes of the Brazilian nuclear policy in the beginning of 90＇s determined the interruption of several fuel cycle activities and facilities shutdown. Some laboratory and pilot plant decommissioning activities have been performed in IPEN in the last years. During the operational activities in the decommissioning of old nuclear fuel cycle facilities, the personnel involved in the task had to face several problems. In old facilities, the need of large components dismantling and material removal use to present some difficulties, such as lack of available and near electricity supply. Besides this, the spread out of the superficial contamination in the form of dust or aerosols and the exposure of workers should be as much as possible avoided. Then, the selection and availability of suitable tools for the task, mainly those employed for cutting and segmentation of different materials is of significant importance. Slight hand tools, mainly those powered by rechargeable batteries, facilitate the work, especially in areas where the access is difficult. Based on the experience in the dismantling of some old nuclear facilities of IPEN-CNEN/SP, some tools that would have facilitated the operations were identified and their availability could have improved the quality and efficiency of different individual tasks. In this paper, different cutting problems and techniques, as well as some available commercial hand tools, are presented as suggestion for future activities.展开更多
Thorium was discovered in 1828 by the Swedish chemist Jons J.Berzelius.Despite some advantages over uranium for use in nuclear reactors,its main use,in the almost two centuries since its discovery,thorium was restrict...Thorium was discovered in 1828 by the Swedish chemist Jons J.Berzelius.Despite some advantages over uranium for use in nuclear reactors,its main use,in the almost two centuries since its discovery,thorium was restricted to use for gas mantles,especially in the early 20th century.In the beginning of the nuclear era,many countries had interested on thorium,particularly during the 1950-1970 period.There are about 435 nuclear reactors in the world nowadays.They need more than 65,000 tons of uranium yearly.The future world energy needs will increase and,even if we assumed a conservative contribution of nuclear generation,there will be a significant increasing in the uranium prices occur,taking into account that uranium,as used in the present thermal reactors,is a finite resource.Thorium is nearly three times more abundant than uranium in the Earth's crust.Despite thorium is not a fissile material,^232Th can be converted to^233U(fissile)more efficiently than^238U to^239pu.Besides this,since it is possible to convert thorium waste into non-radioactive elements,thorium is an environment-friendly alternative energy source.Thorium fuel cycle is also inherently resistant to proliferation.Some papers evaluate the thorium resources in Brazil over 1,200,000 metric t.Then,the thorium alternative must be seriously considered in Brazil for strategic reasons.In this paper a brief history of thorium is presented,besides a review of the world thorium utilization and a discussion about advantages and restrictions of thorium use.展开更多
AIM:To evaluate effects of preand postnatal protein deprivation and postnatal recovery on the myenteric plexus of the rat esophagus. METHODS: Three groups of young Wistar rats (aged 42 d) were studied: normalfed (N42)...AIM:To evaluate effects of preand postnatal protein deprivation and postnatal recovery on the myenteric plexus of the rat esophagus. METHODS: Three groups of young Wistar rats (aged 42 d) were studied: normalfed (N42), proteindeprived (D42), and proteinrecovered (R42). The myenteric neurons of their esophagi were evaluated by histochemical reactions for nicotinamide adenine dinucleotide (NADH), nitrergic neurons (NADPH)diaphorase and acetylcholinesterase (AChE), immunohistochemical reaction for vasoactive intestinal polypeptide (VIP), and ultrastructural analysis by transmission electron microscopy.RESULTS: The cytoplasms of large and medium neurons from the N42 and R42 groups were intensely reactive for NADH. Only a few large neurons from the D42 group exhibited this aspect. NADPH detected in the D42 group exhibited low reactivity. The AChE reactivity was diffuse in neurons from the D42 and R42 groups. The density of large and small varicosities detected by immunohistochemical staining of VIP was low in ganglia from the D42 group. In many neurons from the D42 group, the double membrane of the nuclear envelope and the perinuclear cisterna were not detectable. NADH and NADPH histochemistry revealed no group differences in the prof ile of nerve cell perikarya (ranging from 200 to 400 μm2).CONCLUSION: Protein deprivation causes a delay in neuronal maturation but postnatal recovery can almost completely restore the normal morphology of myenteric neurons.展开更多
The development of measurement geometry for medical X-ray computed tomography （CT） scanners was carried out from the first to the fourth-generation. This concept has also been applied for imaging of industrial proce...The development of measurement geometry for medical X-ray computed tomography （CT） scanners was carried out from the first to the fourth-generation. This concept has also been applied for imaging of industrial processes such as pipe flows or for improving design, operation, optimization and troubleshooting. Nowadays, gamma CT permits to visualize failure equipment points in three-dimensional analysis and in sections of chemical and petrochemical industries. The aim of this work is the development of the mechanical system on a third-generation industrial CT scanner to analyze laboratorial process columns which perform highly efficient separation, turning the ^6oCo, ^75Se, ^137Cs and/or ^192Ir sealed gamma-ray source（s） and the NaI（Tl） multidetector array. It also has a translation movement along the column axis to obtain as many slices of the process flow as needed. The mechanical assembly for this third-generation industrial CT scanner is comprised by strength and rigidity structural frame in stainless and carbon steels, rotating table, source shield and collimator with pneumatic exposure system, spur gear system, translator, rotary stage, drives and stepper motors. The use of suitable spur gears has given a good repeatability and high accuracy in the degree of veracity. The data acquisition boards, mechanical control interfaces, software for movement control and image reconstruction were specially development. A multiphase phantom capable to be setting with solid, liquid and gas was testing. The scanner was setting for 90 views and 19 projections for each detector totalizing 11,970 projections. Experiments to determine the linear attenuation coefficients of the phantom were carried out which applied the Lambert-Beer principle. Results showed that it was possible to distinguish between the phases even the polymethylmethacrylate and the water have very similar density and linear attenuation coefficients. It was established that the newly developed third-generation fan-beam arrangement gamma scanner unit has a good spatial resolution acceptable given the size of the used phantom in this study. The tomografic reconstruction algorithm in used 60 ~ 60 pixels images was the Alternative Minimization （AM） technique and was implemented in MATLAB and VB platforms. The mechanical system presented a good performance in terms of strength, rigidity, accuracy and repeatability with great potential to be used for education or program which dedicated to training chemical and petrochemical industry professionals and for industrial process optimization in Brazil.展开更多
A catalyst is a substance that alters the rate of a reaction. The process of catalysis is essential to the modem day manufacturing industry, mainly in FCC （Fluid Catalytic Cracking） process units. However, long-term...A catalyst is a substance that alters the rate of a reaction. The process of catalysis is essential to the modem day manufacturing industry, mainly in FCC （Fluid Catalytic Cracking） process units. However, long-term exploitation of oil and gas processing catalysts leads to formation of carbon- and sulfur-containing structures of coke and dense products on the catalyst surface. They block reactive catalyst sites and reduce the catalytic activity. The main advantage of radiation processing by EB （electron beam） and gamma rays is chain cracking reaction in crude oil. Otherwise, under exposure to ionize radiation, considerable structure modification of equilibrium silica-alumina catalyst from FCC process may occur, in addition to the removal of impurities. The conditions applied in the irradiation range （20-150 kGy） of gamma rays and EB were not sufficient to alter the structure of the catalyst, whether for removal of the contaminant nickel, a major contaminant of the FCC catalyst, either to rupture of the crystalline structure either for the future reutilization of chemical elements. ATR-FTIR （Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy and EDXRFS （Energy Dispersive X-Ray Fluorescence Spectrometry） analysis were used to characterize and evaluate effects of radiation processing on equilibrium catalysts purification. To evaluate and comprehend the reactive catalyst sites, SEM （Scanning Electron Microscopy） and particle size distribution analyses were carried out.展开更多
Water scarcity is pushing the government,industries and researchers to the development of new strategies for water and wastewater management.An approach aimed at the optimization of the water use and minimization of e...Water scarcity is pushing the government,industries and researchers to the development of new strategies for water and wastewater management.An approach aimed at the optimization of the water use and minimization of effluent generation was developed at the Centro Experimental ARAMAR(CEA),a nuclear research facility,located in the State of Sao Paulo,Brazil.Bench scale tests followed by a pilot plant treating effluents from some nuclear research facilities have shown the results leading to the conclusion that the effluent zero release concept is feasible.Based on the gathered data,a project of an integrated effluent treatment system focusing on water recovery and environmental effluent release reduction has been developed.展开更多
Ni/Carbon was prepared in two steps： initially cellulose as carbon source and NiCl2·6H2O as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatme...Ni/Carbon was prepared in two steps： initially cellulose as carbon source and NiCl2·6H2O as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatment at 900 ℃ under argon atmosphere. The obtained material contains Ni nanoparticles with face-centered cubic （fcc） structure dispersed on amorphous carbon with graphitic domains. PtRu/C electrocatalysts （carbon- supported PtRu nanoparticles） were prepared by an alcohol-reduction process using Ni/Carbon as support. The materials were characterized by thermogravimetric analysis, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and tested as anodes in single direct methanol fuel cell （DMFC）. The performances of PtRu/C electrocatalysts using Ni/Carbon as support were superior to those obtained for PtRu/C using commercial carbon black Vulcan XC72 as support.展开更多
Purpose:The objectives of this investigation were to compare the World Health Organization abbreviated instrument for quality of life assessment(WHOQOL-bref)scores of osteoporotic and non-osteoporotic Brazilian patien...Purpose:The objectives of this investigation were to compare the World Health Organization abbreviated instrument for quality of life assessment(WHOQOL-bref)scores of osteoporotic and non-osteoporotic Brazilian patients and to evaluate the correlation between mandibular cortical index(MCI)and bone densitometry(DXA)results in both groups.Methods:This research was conducted with an initial sample of 74 female participants who underwent panoramic radiography and forearm densitometry.Participants were divided into two groups:osteoporotic and non-osteoporotic patients.A quality of life assessment questionnaire was administered.The scores from the questionnaire were compared between the two groups and the correlation between DXA and MCI was analyzed.Results:Psychological and social domains in osteoporotic patients presented lower scores(12.65 and 6.00 respectively)when compared to non-osteoporotic patients(14.70 and 13.97 respectively).MCI was inversely correlated with DXA.Conclusions:According to WHOQOL-bref,osteoporotic patients may have lower quality of life scores when considering psychological and social relationships.MCI is inversely correlated with T-scores but demonstrates greater correlation when considering non-osteoporotic patients with higher T-score values.展开更多
Hydrogels for wound dressings are usually developed for contact surfaces where mechanical properties are conveniently required.In this sense nanocomposite hydrogels based on PVAl(poly(vinyl alcohol))and PVP(poly(N-2-v...Hydrogels for wound dressings are usually developed for contact surfaces where mechanical properties are conveniently required.In this sense nanocomposite hydrogels based on PVAl(poly(vinyl alcohol))and PVP(poly(N-2-vinil-pirrolidone))containing 0.5-1.5 wt%of the synthetic laponite RD clay were prepared by a gamma radiation process and compared with similar membranes composed separately of PVP or PVAl.This study aimed to evaluate the effect of clay on the properties and the differences of the polymer blend instead of a unique polymer.The morphology of the hydrogels was evaluated by spectrometric techniques using XRD(X-ray diffraction),SEM(scanning electron microscopy),swelling assay,and FTIR(infrared spectroscopy).The swelling kinetics at 22℃and the mechanical properties by a tensile test comprised the structural properties that were assessed.The results showed PVA/PVP network depends directly on the clay concentration in the nanocomposite hydrogels.The blend PVP/PVAl proved to have potentially efficient mechanical properties for drug delivery in the treatment of wounds.展开更多
基金supported by the National Council for Scientific and Technological Development(Grant No.310709/2020-2 and 409314/2023-4)the São Paulo Research Foundation(Grant No.2022/13591-6 and 2021/04621-6).
文摘During the rainy season in Brazil,landslides can have catastrophic consequences,including loss of life,damage to urban infrastructure and significant economic impacts.Now,more than eight million people in Brazil live in disaster-prone areas.The objective of this article is to present a chronological review of the principal policies and programmes at the national,state,and municipal levels,with an emphasis on their key actions aimed at mitigating the impact of disasters related to natural hazards,particularly landslides.Our analysis was based on official records of public policies from the national,state,and municipal governments.The results show that several initiatives were initially developed at the local and regional level.However,it was not until the late 1980s that a comprehensive organisation of civil protection at the national level emerged as a response measure.It is possible to highlight three phases(understanding,coexistence,and prevention)of institutional action focused on risk management in the face of disasters.Despite the growing knowledge of risk scenarios,disasters continue to occur in Brazil on an annual basis,revealing several obstacles to reducing their impact,particularly given the social and economic disparities between Brazilian regions and the applicability of public policies that must overcome the limitations of each municipality.
基金FAPESP,Brazil(#2023/10027-5,#2014/50945-4,#2020/15230-5,and#2021/000675-4)CNPq,Brazil(#465571/2014-0,#303269/2021-9,and#307837/2014-9)+6 种基金Instituto Serrapilheira(grant number Serra-2211-41925)FAPEMIG,Brazil(#PPM-00831-15)for support of this workCNPq,Brazil(#105944/2022-0)and PROPEUNESP(13/2022)FAPESP(#2019/00463-7,#2018/22845-6,and#2021/08007-0,respectively)for scholarshipsthe National Institute for Alternative Technologies of Detection,Toxicological Evaluation and Removal of Micropollutants and Radioactives(INCT-DATREM)the support of the Research Centre for Greenhouse Gas Innovation(RCGI),hosted by the University of Sao Paulo(USP)and sponsored by FAPESP and Shell Brasilthe strategic support given by ANP,Brazil(Brazilian National Oil,Natural Gas,and Biofuels Agency)through the R&D levy regulation。
文摘This work describes the use of TiO_(2)nanotubes-based electrodes(TNT)modified with Cu_(2)O nanostructures and gold nanoparticles for the photoelectroreduction of CO_(2)to produce value-added compounds.A thin layer of polydopamine was used as both an adherent agent and an electron transfer mediator,due to itsπ-conjugated electron system.The highest production yield was achieved using a TNT@PDA/Nc/Au40%electrode,with Faradaic efficiencies of 47.4%(110.5μM cm^(-2))and 27.8%(50.4μM cm^(-2))for methanol and methane,respectively.The performance of the photoelectrodes was shown to be Cu_(2)O facet-dependent,with cubic structures leading to greater conversion of CO_(2)to methanol(43%)and methane(27%),compared to the octahedral morphology,while a higher percentage of metallic gold on the nanostructured Cu_(2)O surface was mainly important for CH4production.Density functional theory(DFT)calculations supported these findings,attributing the superior photoelectrocatalytic performance of the TNT@PDA/Nc/Au40%electrode for CH4generation to the formation of an OCH3intermediate bonded to Au atoms.Studies using isotope-labeling and analysis by gas chromatograph-mass(GC-MS)demonstrated that13CO_(2)was the source for photoelectrocatalytic generation of13CH3OH and13CH313CH2OH.
文摘Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- posite is the interfacial interaction between its components,which are carbon fiber and polymeric matrix.The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite.EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests.Experimental results showed that EB irradiation improved the ten- sile strength of carbon fiber samples.The maximum value in tensile strength was reached using doses of about 250 kGy.After breakage,the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated.SEM micrographs showed modifications on the carbon fiber surface.
基金supported by the Sao Paulo Research Foundation(FAPESP 2018/21489-1 and 2013/24725-4)the National Council for Scientific and Technological Development(CNPq 303137/2016-9,401581/2016-0,408222/2016-6)the fellowships granted to J.M.G.(FAPESP 2018/16896-7)。
文摘Environmentally friendly energy sources alternatives to fossil fuels such as solar and wind are strategic for meeting the needs of an increasingly energy demanding society,despite their periodic/intermittent nature.Thus,urge the development of clean and renewable energy sources such as based on solar energy and water in a cyclic way,by photoinduced water-splitting and regeneration in fuel cells.In this context,energy storage devices such as hybrid supercapacitors become fundamental for realization of a sustainable society.In this review,the early discovery and recent advances concerning synthetic strategies,hierarchical structures,and oxygen evolution reaction(OER)/hydrogen evolution reactions(HER) catalytic performances of nickel-vanadium double hydroxides(NiV-LDHs) based nanomaterials are summarized.A discussion about the role of vanadium ions in HER/OER was also included,highlighting the recent progress in theoretical calculations in this field.Finally,some hybrid supercapacitor electrode materials based on NiV-LDHs are described,including the strategies to circumvent the parasitic oxygen evolution reaction during charge-discharge of those energy storage devices.In short,catalysts for HER/OER and hybrid supercapacitor electrode materials based on NiV-LDHs were reviewed considering their key multifunctional role in the way to a more sustainable society.
基金The project was supported by the FAPESP(2014/09087-4,2014/50279-4).
文摘The main objective of this paper was to characterize the voltammetric profiles of the Pt/C,Pt/C-ATO,Pd/C and Pd/CATO electrocatalysts and study their catalytic activities for methane oxidation in an acidic electrolyte at 25 ℃ and in a direct methane proton exchange membrane fuel cell at 80 ℃. The electrocatalysts prepared also were characterized by X-ray diffraction( XRD) and transmission electron microscopy( TEM). The diffractograms of the Pt/C and Pt/C-ATO electrocatalysts show four peaks associated with Pt face-centered cubic( fcc) structure,and the diffractograms of Pd/C and Pd/C-ATO show four peaks associated with Pd face-centered cubic( fcc) structure. For Pt/C-ATO and Pd/C-ATO,characteristic peaks of cassiterite( SnO_2) phase are observed,which are associated with Sb-doped SnO_2( ATO) used as supports for electrocatalysts. Cyclic voltammograms( CV) of all electrocatalysts after adsorption of methane show that there is a current increase during the anodic scan. However,this effect is more pronounced for Pt/C-ATO and Pd/C-ATO. This process is related to the oxidation of the adsorbed species through the bifunctional mechanism,where ATO provides oxygenated species for the oxidation of CO or HCO intermediates adsorbed in Pt or Pd sites. From in situ ATR-FTIR( Attenuated Total Reflectance-Fourier Transform Infrared) experiments for all electrocatalysts prepared the formation of HCO or CO intermediates are observed,which indicates the production of carbon dioxide. Polarization curves at 80 ℃in a direct methane fuel cell( DMEFC) show that Pd/C and Pt/C electroacatalysts have superior performance to Pd/C-ATO and Pt/C-ATO in methane oxidation.
基金CAPES(Capes/Cofecub N°80614)FAPESP(2013/13235-6)for financial support for this work+1 种基金CAPES PROEX for the grants of M.X.Milagre(88882.333479/2019-01),C.S.C.Machado(88882.333459/201901)FAPESP for the grants of U.Donatus(Proc.2017/03095-3)and R.Silva(Proc.2018/06880-6)。
文摘Scanning electrochemical microscopy(SECM)and scanning vibrating electrode technique(SVET)were used to investigate the electrochemical behaviour of the top surface of the 2098-T351 alloy welded by friction stir welding(FSW).The SVET technique was efficient in identifying the cathodic and anodic weld regions.The welding joint(WJ),which comprises the thermomechanically affected zone(TMAZ)and the stir zone(SZ),was cathodic relative to the heated affected zone(HAZ)and the base metal(BM).The reactivities of the welding joint at the advancing side(AS)and the retreating side(RS)were analyzed and compared using SECM technique in the competition mode by monitoring the dissolved oxygen as a redox mediator in 0.005 mol L^-1 NaCl solution.The RS was more electrochemically active than the AS,and these results were correlated with the microstructural features of the welded alloy.
文摘The study of corrosion of magnesium and its alloys has emerged a hot topic in the applications of lightweight structural materials. The inherently high electrochemical activity of bare magnesium surfaces still lacks a convincing mechanism to describe the observed experimental characteristics, and it has prompted the development of various types of protective coatings with the aim of slowing metal dissolution. In recent years, new instruments and techniques have been developed to study with spatial resolution the local corrosion processes that occur in metallic materials in general, and for magnesium and its alloys in particular, both for bare surfaces and coated. Scanning microelectrochemical techniques, such as local electrochemical impedance spectroscopy(LEIS), scanning electrochemical microscopy(SECM), scanning vibrating electrode technique(SVET), scanning ion-selective electrode technique(SIET) and scanning Kelvin probe(SKP) can provide information about the local electrochemical activity of metallic surfaces. In the present work, the applications of these techniques in corrosion studies of magnesium and its alloys are reviewed. Assessment of corrosion mechanisms, barrier properties of conventional coatings and active corrosion behavior of self-healing coatings are examined. Limitations and future developments in this area are discussed.
文摘PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction( XRD),energy dispersive analysis( EDX),transmission electron microscopy( TEM),cyclic voltammetry( CV),chronoamperommetry( CA) and polarization curves in alkaline and acidic electrolytes( single cell experiments). The XRD patterns showPtpeaks are attributed to the face-centered cubic( fcc) structure,and a shift of Pt( fcc) peaks indicates that Ru or In is incorporated into Ptlattice. TEMmicrographs showmetal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. Methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature,by CV and CA. PtRu/C( 50 ∶ 50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80 ℃ showPtRuIn/C( 50 ∶ 25 ∶ 25)with superior performance for methanol oxidation,when compared to Pt/C,PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C( 50 ∶ 25 ∶ 25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Ptalloy.
基金the Sao Paulo Research Foundation(FAPESP,2018/07366-4)a Fellowship from the National Council for Scientific and Technological Development(CNPq,306392/2017-8)+5 种基金postdoctoral fellowships from FAPESP(2015/13345-1,2019/268520,and 2018/17504-5)a doctoral fellowship from FAPESP(2019/24553-5)a master fellowship from CNPq(133396/2019-3)the fellowship from National Key R&D Program of China(2019YFC1709101)The Project First-Class Disciplines Development(CZYHW1901)of Chengdu University of TCM and Sichuan Science and Technology Program(2019YFH0108,2018SZ0257)supported by Russian Science Foundation grant 20-14-00241。
文摘Huntington’s(HD)and Parkinson’s diseases(PD)are neurodegenerative disorders caused by the death of GABAergic and dopaminergic neurons in the basal ganglia leading to hyperkinetic and hypokinetic symptoms,respectively.We review here the participation of purinergic receptors through intracellular Ca^2+signaling in these neurodegenerative diseases.The adenosine A2A receptor stimulates striatopallidal GABAergic neurons,resulting in inhibitory actions on GABAergic neurons of the globus pallidus.A2A and dopamine D2 receptors form functional heteromeric complexes inducing allosteric inhibition,and A2A receptor activation results in motor inhibition.Furthermore,the A2A receptor physically and functionally interacts with glutamate receptors,mainly with the mGlu5 receptor subtype.This interaction facilitates glutamate release,resulting in NMDA glutamate receptor activation and an increase of Ca2+influx.P2X7 receptor activation also promotes glutamate release and neuronal damage.Thus,modulation of purinergic receptor activity,such as A2A and P2X7 receptors,and subsequent aberrant Ca^2+signaling,might present interesting therapeutic potential for HD and PD.
文摘Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of gaseous samples. This paper describes a method to fabricate and evaluate aluminum capsules to irradiate gaseous samples in nuclear reactor. A semi-circular slotted die from a hydraulic presshead was modified to seal aluminum tubes. The aluminum capsules were subjected to leak detection tests, which demonstrated the accordance with standard ISO 9978.
基金supported by the Brazilian Funding Agencies CAPES(Federal Agency for the Support and Improvement of Higher Education)(Grant No.33003017)CNPq(National Council for Scientific and Technological Development)(Grant No.233006/2014-1)FAPESP(Sao Paulo Research Foundation)(Grant No.2011/19982-2)
文摘The biocompatibility of orthopedic implants is closely related to their elastic modulus and surface properties.The objective of this study was to determine the effects of cold rolling,recrystallization and laser surface melting(LSM)on the microstructure and mechanical properties of a biphase(α″+β)Ti-30Nb-4Sn alloy.X-ray diffraction(XRD)texture analysis of the cold-rolled substrate revealed the[302]α″//ND texture component,while analysis of the recrystallized substrate showed the[302]α″//ND and[110]α″//ND components.Theβ-phase texture could not be directly measured by XRD,but the presence of the[111]β//ND texture component was successfully predicted by considering the orientation relationship between theα″andβphases.Nanoindentation measurements showed that the elastic modulus of the cold-rolled substrate(63GPa)was lower than that of the recrystallized substrate(74GPa).Based on the available literature and the results presented here,it is suggested that this difference is caused by the introduction of crystal defects during cold deformation.The combined nanoindentation/EBSD analysis showed that the nanoindentation results are not affected by crystal orientation.LSM of the deformed alloy produced changes in hardness,elastic modulus and crystallographic texture similar to those produced by recrystallization heat treatment,creating a stiffness gradient between surface and substrate.
文摘Fuel cycle related activities were accomplished in IPEN-CNEN/SP in laboratory and pilot plant scale and most facilities were built in the 70-80 years. Nevertheless, radical changes of the Brazilian nuclear policy in the beginning of 90＇s determined the interruption of several fuel cycle activities and facilities shutdown. Some laboratory and pilot plant decommissioning activities have been performed in IPEN in the last years. During the operational activities in the decommissioning of old nuclear fuel cycle facilities, the personnel involved in the task had to face several problems. In old facilities, the need of large components dismantling and material removal use to present some difficulties, such as lack of available and near electricity supply. Besides this, the spread out of the superficial contamination in the form of dust or aerosols and the exposure of workers should be as much as possible avoided. Then, the selection and availability of suitable tools for the task, mainly those employed for cutting and segmentation of different materials is of significant importance. Slight hand tools, mainly those powered by rechargeable batteries, facilitate the work, especially in areas where the access is difficult. Based on the experience in the dismantling of some old nuclear facilities of IPEN-CNEN/SP, some tools that would have facilitated the operations were identified and their availability could have improved the quality and efficiency of different individual tasks. In this paper, different cutting problems and techniques, as well as some available commercial hand tools, are presented as suggestion for future activities.
文摘Thorium was discovered in 1828 by the Swedish chemist Jons J.Berzelius.Despite some advantages over uranium for use in nuclear reactors,its main use,in the almost two centuries since its discovery,thorium was restricted to use for gas mantles,especially in the early 20th century.In the beginning of the nuclear era,many countries had interested on thorium,particularly during the 1950-1970 period.There are about 435 nuclear reactors in the world nowadays.They need more than 65,000 tons of uranium yearly.The future world energy needs will increase and,even if we assumed a conservative contribution of nuclear generation,there will be a significant increasing in the uranium prices occur,taking into account that uranium,as used in the present thermal reactors,is a finite resource.Thorium is nearly three times more abundant than uranium in the Earth's crust.Despite thorium is not a fissile material,^232Th can be converted to^233U(fissile)more efficiently than^238U to^239pu.Besides this,since it is possible to convert thorium waste into non-radioactive elements,thorium is an environment-friendly alternative energy source.Thorium fuel cycle is also inherently resistant to proliferation.Some papers evaluate the thorium resources in Brazil over 1,200,000 metric t.Then,the thorium alternative must be seriously considered in Brazil for strategic reasons.In this paper a brief history of thorium is presented,besides a review of the world thorium utilization and a discussion about advantages and restrictions of thorium use.
基金Supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - CNPq and FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo) grant, No. 04/00746-3
文摘AIM:To evaluate effects of preand postnatal protein deprivation and postnatal recovery on the myenteric plexus of the rat esophagus. METHODS: Three groups of young Wistar rats (aged 42 d) were studied: normalfed (N42), proteindeprived (D42), and proteinrecovered (R42). The myenteric neurons of their esophagi were evaluated by histochemical reactions for nicotinamide adenine dinucleotide (NADH), nitrergic neurons (NADPH)diaphorase and acetylcholinesterase (AChE), immunohistochemical reaction for vasoactive intestinal polypeptide (VIP), and ultrastructural analysis by transmission electron microscopy.RESULTS: The cytoplasms of large and medium neurons from the N42 and R42 groups were intensely reactive for NADH. Only a few large neurons from the D42 group exhibited this aspect. NADPH detected in the D42 group exhibited low reactivity. The AChE reactivity was diffuse in neurons from the D42 and R42 groups. The density of large and small varicosities detected by immunohistochemical staining of VIP was low in ganglia from the D42 group. In many neurons from the D42 group, the double membrane of the nuclear envelope and the perinuclear cisterna were not detectable. NADH and NADPH histochemistry revealed no group differences in the prof ile of nerve cell perikarya (ranging from 200 to 400 μm2).CONCLUSION: Protein deprivation causes a delay in neuronal maturation but postnatal recovery can almost completely restore the normal morphology of myenteric neurons.
文摘The development of measurement geometry for medical X-ray computed tomography （CT） scanners was carried out from the first to the fourth-generation. This concept has also been applied for imaging of industrial processes such as pipe flows or for improving design, operation, optimization and troubleshooting. Nowadays, gamma CT permits to visualize failure equipment points in three-dimensional analysis and in sections of chemical and petrochemical industries. The aim of this work is the development of the mechanical system on a third-generation industrial CT scanner to analyze laboratorial process columns which perform highly efficient separation, turning the ^6oCo, ^75Se, ^137Cs and/or ^192Ir sealed gamma-ray source（s） and the NaI（Tl） multidetector array. It also has a translation movement along the column axis to obtain as many slices of the process flow as needed. The mechanical assembly for this third-generation industrial CT scanner is comprised by strength and rigidity structural frame in stainless and carbon steels, rotating table, source shield and collimator with pneumatic exposure system, spur gear system, translator, rotary stage, drives and stepper motors. The use of suitable spur gears has given a good repeatability and high accuracy in the degree of veracity. The data acquisition boards, mechanical control interfaces, software for movement control and image reconstruction were specially development. A multiphase phantom capable to be setting with solid, liquid and gas was testing. The scanner was setting for 90 views and 19 projections for each detector totalizing 11,970 projections. Experiments to determine the linear attenuation coefficients of the phantom were carried out which applied the Lambert-Beer principle. Results showed that it was possible to distinguish between the phases even the polymethylmethacrylate and the water have very similar density and linear attenuation coefficients. It was established that the newly developed third-generation fan-beam arrangement gamma scanner unit has a good spatial resolution acceptable given the size of the used phantom in this study. The tomografic reconstruction algorithm in used 60 ~ 60 pixels images was the Alternative Minimization （AM） technique and was implemented in MATLAB and VB platforms. The mechanical system presented a good performance in terms of strength, rigidity, accuracy and repeatability with great potential to be used for education or program which dedicated to training chemical and petrochemical industry professionals and for industrial process optimization in Brazil.
文摘A catalyst is a substance that alters the rate of a reaction. The process of catalysis is essential to the modem day manufacturing industry, mainly in FCC （Fluid Catalytic Cracking） process units. However, long-term exploitation of oil and gas processing catalysts leads to formation of carbon- and sulfur-containing structures of coke and dense products on the catalyst surface. They block reactive catalyst sites and reduce the catalytic activity. The main advantage of radiation processing by EB （electron beam） and gamma rays is chain cracking reaction in crude oil. Otherwise, under exposure to ionize radiation, considerable structure modification of equilibrium silica-alumina catalyst from FCC process may occur, in addition to the removal of impurities. The conditions applied in the irradiation range （20-150 kGy） of gamma rays and EB were not sufficient to alter the structure of the catalyst, whether for removal of the contaminant nickel, a major contaminant of the FCC catalyst, either to rupture of the crystalline structure either for the future reutilization of chemical elements. ATR-FTIR （Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy and EDXRFS （Energy Dispersive X-Ray Fluorescence Spectrometry） analysis were used to characterize and evaluate effects of radiation processing on equilibrium catalysts purification. To evaluate and comprehend the reactive catalyst sites, SEM （Scanning Electron Microscopy） and particle size distribution analyses were carried out.
文摘Water scarcity is pushing the government,industries and researchers to the development of new strategies for water and wastewater management.An approach aimed at the optimization of the water use and minimization of effluent generation was developed at the Centro Experimental ARAMAR(CEA),a nuclear research facility,located in the State of Sao Paulo,Brazil.Bench scale tests followed by a pilot plant treating effluents from some nuclear research facilities have shown the results leading to the conclusion that the effluent zero release concept is feasible.Based on the gathered data,a project of an integrated effluent treatment system focusing on water recovery and environmental effluent release reduction has been developed.
基金CNP_q,FAPESPFINEP-MCT-ProH_2 for financial support
文摘Ni/Carbon was prepared in two steps： initially cellulose as carbon source and NiCl2·6H2O as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatment at 900 ℃ under argon atmosphere. The obtained material contains Ni nanoparticles with face-centered cubic （fcc） structure dispersed on amorphous carbon with graphitic domains. PtRu/C electrocatalysts （carbon- supported PtRu nanoparticles） were prepared by an alcohol-reduction process using Ni/Carbon as support. The materials were characterized by thermogravimetric analysis, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and tested as anodes in single direct methanol fuel cell （DMFC）. The performances of PtRu/C electrocatalysts using Ni/Carbon as support were superior to those obtained for PtRu/C using commercial carbon black Vulcan XC72 as support.
文摘Purpose:The objectives of this investigation were to compare the World Health Organization abbreviated instrument for quality of life assessment(WHOQOL-bref)scores of osteoporotic and non-osteoporotic Brazilian patients and to evaluate the correlation between mandibular cortical index(MCI)and bone densitometry(DXA)results in both groups.Methods:This research was conducted with an initial sample of 74 female participants who underwent panoramic radiography and forearm densitometry.Participants were divided into two groups:osteoporotic and non-osteoporotic patients.A quality of life assessment questionnaire was administered.The scores from the questionnaire were compared between the two groups and the correlation between DXA and MCI was analyzed.Results:Psychological and social domains in osteoporotic patients presented lower scores(12.65 and 6.00 respectively)when compared to non-osteoporotic patients(14.70 and 13.97 respectively).MCI was inversely correlated with DXA.Conclusions:According to WHOQOL-bref,osteoporotic patients may have lower quality of life scores when considering psychological and social relationships.MCI is inversely correlated with T-scores but demonstrates greater correlation when considering non-osteoporotic patients with higher T-score values.
文摘Hydrogels for wound dressings are usually developed for contact surfaces where mechanical properties are conveniently required.In this sense nanocomposite hydrogels based on PVAl(poly(vinyl alcohol))and PVP(poly(N-2-vinil-pirrolidone))containing 0.5-1.5 wt%of the synthetic laponite RD clay were prepared by a gamma radiation process and compared with similar membranes composed separately of PVP or PVAl.This study aimed to evaluate the effect of clay on the properties and the differences of the polymer blend instead of a unique polymer.The morphology of the hydrogels was evaluated by spectrometric techniques using XRD(X-ray diffraction),SEM(scanning electron microscopy),swelling assay,and FTIR(infrared spectroscopy).The swelling kinetics at 22℃and the mechanical properties by a tensile test comprised the structural properties that were assessed.The results showed PVA/PVP network depends directly on the clay concentration in the nanocomposite hydrogels.The blend PVP/PVAl proved to have potentially efficient mechanical properties for drug delivery in the treatment of wounds.
