Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 88
Filtrar
1.
Plants (Basel) ; 13(7)2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38611562

RESUMEN

Platonia insignis is a fruit tree native to Brazil of increasing economic importance, with its pulp trading among the highest market values. This study aimed to evaluate the structure and genomic diversity of P. insignis (bacurizeiro) accessions from six locations in the Brazilian States of Roraima, Amazonas, Pará (Amazon biome), and Maranhão (Cerrado biome). A total of 2031 SNP markers were obtained using genotyping-by-sequencing (GBS), from which 625 outlier SNPs were identified. High genetic structure was observed, with most of the genetic variability (59%) concentrated among locations, mainly between biomes (Amazon and Cerrado). A positive and significant correlation (r = 0.85; p < 0.005) was detected between genetic and geographic distances, indicating isolation by distance. The highest genetic diversity was observed for the location in the Cerrado biome (HE = 0.1746; HO = 0.2078). The locations in the Amazon biome showed low genetic diversity indexes with significant levels of inbreeding. The advance of urban areas, events of burning, and expansion of agricultural activities are most probably the main factors for the genetic diversity reduction of P. insignis. Approaches to functional analysis showed that most of the outlier loci found may be related to genes involved in cellular and metabolic processes.

2.
Int Arch Otorhinolaryngol ; 28(1): e115-e121, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38322432

RESUMEN

Introduction Noise obscures speech signal, causing auditory masking. The effects of this masking can be observed through the cortical auditory evoked potentials (CAEPs). White noise, in turn, has an effect on the auditory cortex, interfering, for example, with lexical decision making. Objective To analyze the effect of simultaneous masking by contralateral white noise on CAEPs elicited by speech stimuli. Methods Cross-sectional observational analytical study carried out with 15 participants of both sexes, who were submitted to CAEPs in two conditions: 1) without noise; 2) with white noise at 100 dBSPL intensity, contralaterally and simultaneously. To compare these conditions, the Student t test or the Wilcoxon test were used, depending on the sample normality. Differences with p values < 0.05 were considered significant. Results : When white noise was presented contralaterally and simultaneously to the CAEPs with speech stimulus, an increase in P1, N1 and P2 wave latencies was observed. P1 and P2 amplitudes and N1-P2 peak to peak amplitude also increased, unlike N1 amplitude, which decreased. The differences were significant for P1 and P2 wave latencies and for P2 wave amplitude. Conclusion The simultaneous masking effect was observed from the morphological alterations of the CAEPs with speech stimulus when white noise was presented in the contralateral ear. There was a significant increase in P1 and P2 wave latencies, as well as in P2 wave amplitude.

3.
Seizure ; 115: 68-74, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38218112

RESUMEN

PURPOSE: Drug-resistant epilepsy affects a substantial proportion (30-40 %) of patients with epilepsy, often necessitating video-electroencephalography (video-EEG) monitoring. In 2016, Sauro et al. introduced a set of measures aimed at improving the quality and safety indicators reported in video-EEG evaluations. This study aims to report our experience with the implementation of these measures. METHODS: We analyzed video-EEG data regarding quality and safty from a period spanning January 2016 to January 2018, involving a total of 101 patients monitored in our video-EEG unit. RESULTS: Among the patients included in the study, a definitive diagnosis was attainable for 92.1 %, with 36.6 % experiencing a change in diagnosis and 65.3 % undergoing a change in treatment as a result of the video-EEG evaluation. Additionally, the referral question was fully addressed in 60.4 % of admissions, and video-EEG was considered to be very useful or extremely useful in 66.4 % of cases. Adverse events were observed in 26.7 % of patients, with the most common being the progression of focal seizures to bilateral tonic-clonic seizures (11.9 %) and the occurrence of seizure clusters (5.9 %). CONCLUSION: Our findings support the implementation of Sauro et al.'s set of measures, as they provide valuable criteria for improving the reporting of video-EEG quality and safety indicators. However, challenges may arise due to variations in terminology across studies and the lack of standardized criteria for defining essential questions in video-EEG evaluations. Further research utilizing these measures is necessary to enhance their effectiveness and encourage consistent reporting of results from epilepsy monitoring units.


Asunto(s)
Epilepsia , Indicadores de Calidad de la Atención de Salud , Humanos , Brasil , Grabación en Video/métodos , Convulsiones/diagnóstico , Convulsiones/etiología , Epilepsia/diagnóstico , Epilepsia/etiología , Monitoreo Fisiológico/métodos , Electroencefalografía/métodos
4.
Small ; 20(5): e2305501, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37752688

RESUMEN

Recent progress in synthesizing and integrating surface-supported metal-organic frameworks (SURMOFs) has highlighted their potential in developing hybrid electronic devices with exceptional mechanical flexibility, film processability, and cost-effectiveness. However, the low electrical conductivity of SURMOFs has limited their use in devices. To address this, researchers have utilized the porosity of SURMOFs to enhance electrical conductivity by incorporating conductive materials. This study introduces a method to improve the electrical conductivity of HKUST-1 templates by in situ polymerization of conductive polypyrrole (PPy) chains within the SURMOF pores (named as PPy@HKUST-1). Nanomembrane-origami technology is employed for integration, allowing a rolled-up metallic nanomembrane to contact the HKUST-1 films without causing damage. After a 24 h loading period, the electrical conductivity at room temperature reaches approximately 5.10-6 S m-1 . The nanomembrane-based contact enables reliable electrical characterization even at low temperatures. Key parameters of PPy@HKUST-1 films, such as trap barrier height, dielectric constant, and tunneling barrier height, are determined using established conduction mechanisms. These findings represent a significant advancement in real-time control of SURMOF conductivity, opening pathways for innovative electronic-optoelectronic device development. This study demonstrates the potential of SURMOFs to revolutionize hybrid electronic devices by enhancing electrical conductivity through intelligent integration strategies.

5.
Int. arch. otorhinolaryngol. (Impr.) ; 28(1): 115-121, 2024. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1558003

RESUMEN

Abstract Introduction Noise obscures speech signal, causing auditory masking. The effects of this masking can be observed through the cortical auditory evoked potentials (CAEPs). White noise, in turn, has an effect on the auditory cortex, interfering, for example, with lexical decision making. Objective To analyze the effect of simultaneous masking by contralateral white noise on CAEPs elicited by speech stimuli. Methods Cross-sectional observational analytical study carried out with 15 participants of both sexes, who were submitted to CAEPs in two conditions: 1) without noise; 2) with white noise at 100 dBSPL intensity, contralaterally and simultaneously. To compare these conditions, the Student t test or the Wilcoxon test were used, depending on the sample normality. Differences with p values < 0.05 were considered significant. Results: When white noise was presented contralaterally and simultaneously to the CAEPs with speech stimulus, an increase in P1, N1 and P2 wave latencies was observed. P1 and P2 amplitudes and N1-P2 peak to peak amplitude also increased, unlike N1 amplitude, which decreased. The differences were significant for P1 and P2 wave latencies and for P2 wave amplitude. Conclusion The simultaneous masking effect was observed from the morphological alterations of the CAEPs with speech stimulus when white noise was presented in the contralateral ear. There was a significant increase in P1 and P2 wave latencies, as well as in P2 wave amplitude.

6.
Medisan ; 27(5)oct. 2023. tab
Artículo en Español | LILACS, CUMED | ID: biblio-1529002

RESUMEN

Introducción: La hipertensión arterial constituye un problema de salud pública en casi todo el mundo. Entre los factores de riesgo vinculados a ella se destaca la acumulación de grasa, que puede, a su vez, establecer los riesgos, las comorbilidades y la mortalidad asociados a esta entidad nosológica. Objetivo: Determinar las variaciones de los valores del perímetro abdominal y el índice cintura-cadera en pacientes con hipertensión arterial, según variables epidemiológicas y clínicas seleccionadas. Métodos: Se realizó un estudio descriptivo, prospectivo y transversal de 221 pacientes con hipertensión arterial, pertenecientes al Consultorio 19 del Policlínico Docente Josué País García del municipio de Santiago de Cuba, desde junio del 2019 hasta diciembre del 2020. Resultados: Predominó el sexo femenino y el grupo etario de 65-74 años (28,5 %). Los indicadores antropométricos perímetro abdominal e índice cintura-cadera tuvieron valores que superaron los parámetros normales establecidos para ambos sexos. El cálculo del perímetro abdominal reveló un predominio de la obesidad en el sexo femenino, en tanto se clasificó como aumentado en el sexo masculino. Conclusiones: Los valores del índice cintura-cadera y del perímetro abdominal en ambos sexos estuvieron por encima de los clasificados por la Organización Mundial de la Salud como de alto riesgo de presentar la enfermedad.


Introduction: Hypertension constitutes a problem of public health in almost all over the world. Among the risk factors associated with it, the accumulation of fat is notable, which can, in turn, establish risks and determine comorbidities and mortality associated with this nosological entity. Objective: To determine the variations in the values of the abdominal perimeter and waist-hip ratio in patients with hypertension, according to selected epidemiological and clinical variables. Methods: A descriptive, prospective and cross-sectional study was carried out on 221 patients with hypertension, belonging to doctor's office 19 of Josué País García Teaching Polyclinic in Santiago de Cuba municipality, from June, 2019 to December, 2020. Results: There was a prevalence of the female sex and the 65-74 age group (28.5%). The anthropometric indicators, abdominal perimeter and waist-hip ratio, had values that exceeded the established normal parameters for both sexes. The calculation of the abdominal perimeter revealed a predominance of obesity in the female sex, while it was classified as increased in the male sex. Conclusions: The values of the waist-hip ratio and abdominal perimeter exceeded those classified by the World Health Organization as high risk of presenting the disease in both sexes.


Asunto(s)
Circunferencia de la Cintura , Hipertensión
7.
ACS Nano ; 17(17): 16412-16431, 2023 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-37582231

RESUMEN

The complexity of CRISPR machinery is a challenge to its application for nonviral in vivo therapeutic gene editing. Here, we demonstrate that proteins, regardless of size or charge, efficiently load into porous silicon nanoparticles (PSiNPs). Optimizing the loading strategy yields formulations that are ultrahigh loading─>40% cargo by volume─and highly active. Further tuning of a polymeric coating on the loaded PSiNPs yields nanocomposites that achieve colloidal stability under cryopreservation, endosome escape, and gene editing efficiencies twice that of the commercial standard Lipofectamine CRISPRMAX. In a mouse model of arthritis, PSiNPs edit cells in both the cartilage and synovium of knee joints, and achieve 60% reduction in expression of the therapeutically relevant MMP13 gene. Administered intramuscularly, they are active over a broad dose range, with the highest tested dose yielding nearly 100% muscle fiber editing at the injection site. The nanocomposite PSiNPs are also amenable to systemic delivery. Administered intravenously in a model that mimics muscular dystrophy, they edit sites of inflamed muscle. Collectively, the results demonstrate that the PSiNP nanocomposites are a versatile system that can achieve high loading of diverse cargoes and can be applied for gene editing in both local and systemic delivery applications.


Asunto(s)
Sistemas CRISPR-Cas , Nanopartículas , Ratones , Animales , Sistemas CRISPR-Cas/genética , Silicio , Porosidad , Polímeros
8.
Langmuir ; 39(26): 9025-9034, 2023 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-37338966

RESUMEN

The objective of this article is to investigate how the electric polarizability manifests on the propulsion and collective dynamics of metallodielectric Janus particles by comparing the velocity spectra under rotating and nonrotating AC fields. Janus particles were fabricated by depositing sequential layers of titanium and SiO2 on spherical cores. Model systems of known polarizability were created by varying the thickness of titanium or by adjusting the concentration of electrolyte. We found that the spectra for propulsion velocity displayed features (amplitude and transition frequencies) that were closely matched in the electrorotation spectra. That is, the transition frequency from dielectric- to metal-side forward matched closely the peak in counterfield rotation, while the minima in propulsion velocity matched the transition frequency from counterfield to cofield rotation. Furthermore, based on electroorientation measurements for prolate Janus ellipsoids, we conclude that the propulsion velocity of spherical Janus particles reflects the real part of their polarizability. Solutions of the Poisson-Nernst-Planck equations confirm the thickness of the metal cap facilitates adjusting the behavior from metal- to dielectric-like. These traits translate into different collective behaviors, such as the ability to traverse or become part of a lattice of nonpatchy silica particles. Overall, these results provide experimental evidence to either challenge or refine existing electrokinetic models of propulsion.

9.
PLoS One ; 18(4): e0284587, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37071644

RESUMEN

The fall armyworm (FAW), Spodoptera frugiperda, is a significant pest of many crops in the world and it is native to the Americas, where the species has shown the ability to rapidly evolve resistance to insecticides and transgenic plants. Despite the importance of this species, there is a gap in the knowledge regarding the genetic structure of FAW in South America. Here, we examined the genetic diversity of FAW populations across a wide agricultural area of Brazil and Argentina using a Genotyping-by-Sequencing (GBS) approach. We also characterized samples by their host strain based on mitochondrial and Z-linked genetic markers. The GBS methodology enabled us to discover 3309 SNPs, including neutral and outlier markers. Data showed significant genetic structure between Brazil and Argentina populations, and also among the Argentinian ecoregions. Populations inside Brazil showed little genetic differentiation indicating high gene flow among locations and confirming that structure is related to the presence of corn and rice strains. Outlier analysis indicated 456 loci putatively under selection, including genes possibly related to resistance evolution. This study provides clarification of the population genetic structure of FAW in South America and highlights the importance of genomic research to understand the risks of spread of resistance genes.


Asunto(s)
Metagenómica , Control de Plagas , Animales , Spodoptera/genética , Genotipo , Brasil , Zea mays/genética
10.
Insect Biochem Mol Biol ; 152: 103890, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36496139

RESUMEN

The Neotropical brown stink bug, Euschistus heros, is a major pest of soybean in South America. The importance of E. heros as a pest has grown significantly in recent times due to increases in its abundance and range, and the evolution of insecticide resistance. Recent work has begun to examine the genetic diversity, population structure, and genetic mechanisms of insecticide resistance in E. heros. However, to date, investigation of these topics has been hampered by a lack of genomic resources for this species. Here we address this need by assembling a high-quality draft genome for E. heros. We used a combination of short and long read sequencing to assemble an E. heros genome of 1.4 Gb comprising 906 contigs with a contig N50 of 3.5 MB. We leveraged this new genomic resource, in combination with genotyping by sequencing, to explore genetic diversity in populations of this species in Brazil and identify genetic loci in the genome which are under selection. Our genome-wide analyses, confirm that there are two populations of E. heros co-occurring in different geographical regions in Brazil, and that, in certain regions of the country these populations are hybridizing. We identify several regions of the genome as under selection, including markers associated with putative insecticide resistance genes. Taken together, the new genomic resources generated in this study will accelerate research into fundamental aspects of stinkbug biology and applied aspects relating to the sustainable control of a highly damaging crop pest.


Asunto(s)
Heterópteros , Insecticidas , Animales , Estudio de Asociación del Genoma Completo , Heterópteros/genética , Brasil , Demografía
11.
Rev Assoc Med Bras (1992) ; 68(10): 1376-1382, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36417639

RESUMEN

OBJECTIVE: This study aimed to characterize teleconsultations in neurology executed by Regula+Brasil project in Recife, a capital city in northeastern Brazil. METHODS: A descriptive study carried out by four private hospitals, in a partnership with the Ministry of Health in Brazil. Teleconsultation was performed preferably in the video modality. Conditions eligible for teleconsultation were headache, epilepsy, and cerebrovascular disorders. Period of analysis was May to September 2020. RESULTS: A total of 243 teleconsultations were analyzed, of which 76.95% was a first appointment. In 48.97% of cases, the teleconsultation represented the first opportunity for the patient to be consulted with the specialist. Among cases of first appointment, 20.16% were further referred to a face-to-face consultation and 21.81% could be redirected to primary health care. Headache disorders were the most predominant clinical conditions. CONCLUSIONS: The implementation and development of telemedicine by Regula+Brasil during the COVID-19 pandemic represented an opportunity to assess the value of having teleconsultations added along the line of care from primary care to a medical specialty, promoting the coordination of care across different levels of complexity of care in the health system and improving access to specialized care.


Asunto(s)
COVID-19 , Neurología , Consulta Remota , Telemedicina , Humanos , Pandemias
12.
PLoS One ; 17(11): e0276408, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36327224

RESUMEN

Copernicia prunifera (Miller) H. E. Moore is a palm tree native to Brazil. The products obtained from its leaf extracts are a source of income for local families and the agroindustry. Owing to the reduction of natural habitats and the absence of a sustainable management plan, the maintenance of the natural populations of this palm tree has been compromised. Therefore, this study aimed to evaluate the diversity and genetic structure of 14 C. prunifera populations using single nucleotide polymorphisms (SNPs) identified through genotyping-by-sequencing (GBS) to provide information that contributes to the conservation of this species. A total of 1,013 SNP markers were identified, of which 84 loci showed outlier behavior and may reflect responses to natural selection. Overall, the level of genomic diversity was compatible with the biological aspects of this species. The inbreeding coefficient (f) was negative for all populations, indicating excess heterozygotes. Most genetic variations occurred within populations (77.26%), and a positive correlation existed between genetic and geographic distances. The population structure evaluated through discriminant analysis of principal components (DAPC) revealed low genetic differentiation between populations. The results highlight the need for efforts to conserve C. prunifera as well as its distribution range to preserve its global genetic diversity and evolutionary potential.


Asunto(s)
Arecaceae , Metagenómica , Humanos , Arecaceae/genética , Flujo Genético , Selección Genética , Endogamia , Polimorfismo de Nucleótido Simple , Variación Genética
13.
Rev. Assoc. Med. Bras. (1992, Impr.) ; 68(10): 1376-1382, Oct. 2022. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1406552

RESUMEN

SUMMARY OBJECTIVE: This study aimed to characterize teleconsultations in neurology executed by Regula+Brasil project in Recife, a capital city in northeastern Brazil. METHODS: A descriptive study carried out by four private hospitals, in a partnership with the Ministry of Health in Brazil. Teleconsultation was performed preferably in the video modality. Conditions eligible for teleconsultation were headache, epilepsy, and cerebrovascular disorders. Period of analysis was May to September 2020. RESULTS: A total of 243 teleconsultations were analyzed, of which 76.95% was a first appointment. In 48.97% of cases, the teleconsultation represented the first opportunity for the patient to be consulted with the specialist. Among cases of first appointment, 20.16% were further referred to a face-to-face consultation and 21.81% could be redirected to primary health care. Headache disorders were the most predominant clinical conditions. CONCLUSIONS: The implementation and development of telemedicine by Regula+Brasil during the COVID-19 pandemic represented an opportunity to assess the value of having teleconsultations added along the line of care from primary care to a medical specialty, promoting the coordination of care across different levels of complexity of care in the health system and improving access to specialized care.

14.
Soft Matter ; 18(32): 5949-5959, 2022 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-35920440

RESUMEN

Faradaic reactions often lead to undesirable side effects during the application of electric fields. Therefore, experimental designs often avoid faradaic reactions by working at low voltages or at high frequencies, where the electrodes behave as ideally polarizable. In this work, we show how faradaic processes under ac fields can be used advantageously to effect long-range transport, focusing and assembly of charged colloids. Herein, we use confocal microscopy and ratiometric analysis to confirm that ac fields applied in media of low conductivity induce significant pH gradients below and above the electrode charging frequency of the system. At voltages above 1 Vpp, and frequencies below 1.7 kHz, the pH profile becomes highly nonlinear. Charged particles respond to such conditions by migrating towards the point of highest pH, thereby focusing tens of microns away from both electrodes. Under the combination of oscillating electric fields and concentration gradients of electroactive species, particles experience aperiodic electrodiffusiophoresis (EDP). The theory of EDP, along with a mass transport model, describes the dynamics of particles. Furthermore, the high local concentration of particles near the focusing point leads to disorder-order transitions, whereby particles form crystals. The position and order within the levitating crystalline sheet can be readily tuned by adjusting the voltage and frequency. These results not only have significant implications for the fundamental understanding of ac colloidal electrokinetics, but also provide new possibilities for the manipulation and directed assembly of charged colloids.

15.
Langmuir ; 38(18): 5663-5673, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35467877

RESUMEN

In this work, we present an experimental study of the dynamics of charged colloids under direct currents and gradients of chemical species (electrodiffusiophoresis). In our approach, we simultaneously visualize the development of concentration polarization and the ensuing dynamics of charged colloids near electrodes. With the aid of confocal microscopy and fluorescent probes, we show that the passage of current through water confined between electrodes, separated about a hundred microns, results in significant pH gradients. Depending on the current density and initial conditions, steep pH gradients develop, thus becoming a significant factor in the behavior of charged colloids. Furthermore, we show that steep pH gradients induce the focusing of charged colloids away from both electrodes. Our results provide the experimental basis for further development of models of electrodiffusiophoresis and the design of non-equilibrium strategies for the fabrication of advanced materials.

16.
Environ Sci Pollut Res Int ; 29(20): 29967-29975, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34997483

RESUMEN

Forestry pest management includes biological and chemical methods of pest control. Using insecticides and natural enemies can be compatible in forest pest management programs. The compatibility of the predatory stink bug Podisus distinctus with the insecticide indoxacarb, used in forestry, needs to be evaluated in Brazil. This study investigated the mortality, survival, respiration, preference, prey consumption, and locomotor activity of P. distinctus adults exposed to indoxacarb. In concentration-mortality bioassays, the lethality of indoxacarb (LC50 = 2.62 g L-1 and LC90 = 6.11 g L-1) was confirmed in P. distinctus adults. The survival rate was 100% in predator insects not exposed to indoxacarb, declining to 40.7% in predator insects exposed to 2.62 g L-1 and 0.1% in predators treated with 6.11 g L-1. Indoxacarb reduced the respiration of P. distinctus from 18.45 to 14.41 µL CO2 h-1 at 2.62 g L-1 for up to 3 h after insecticide exposure, inhibiting food consumption and displaying hyperexcitation. The harmful effects of indoxacarb to the natural enemy suggest that it should be better assessed for use with P. distinctus for pest management in forestry.


Asunto(s)
Hemípteros , Heterópteros , Insecticidas , Animales , Insecticidas/farmacología , Oxazinas/farmacología , Conducta Predatoria
17.
Telemed J E Health ; 28(4): 544-550, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34314637

RESUMEN

Introduction: The coronavirus disease 2019 (COVID-19) pandemic led to the suspension or postponement of care for non-urgent conditions worldwide. Regula Mais Brasil is an initiative of the Unified Health System (SUS) in Brazil to optimize the management of referrals to specialized care by using telehealth. Objectives: To report the expansion of telehealth activities of Regula Mais Brasil in response to COVID-19 and to assess qualification of referrals in primary health care (PHC) units as well as the added value of teleconsultation in qualifying referral cases. Methods: Descriptive study of the teleconsultations carried out as an additional strategy to the remotely operated referral management system, responsible for navigating cases from PHC units to specialized care in Recife, Brazil, between May 6, 2020 and September 30, 2020. Teleconsultation was implemented as a tool for reducing delays in the access to health care due to COVID-19 and ultimately allowed for reclassification of the referral adequacy and priority. Changes in referral priority ratings and referral decisions after teleconsultation were analyzed. Results: A total of 622 referral cases were analyzed. Approved referrals represented 51.9% of cases. The main reason for approved referrals was the need for diagnostic resources. There was a reduction in priority ratings in 449 cases (72.2%) after teleconsultation. There was a statistically significant association between the change of priority ratings and the decision on referral (Pearson's χ2, p-value <0.0001). Results show that telemedicine had an impact on the prioritization and qualification of cases referred to specialized services. Conclusions: A need was detected to rapidly adapt tools available for telemedicine in Brazil. Our results demonstrate that teleconsultation as an additional strategy to the remotely operated referral management system has contributed toward improving equitable access to specialized services.


Asunto(s)
COVID-19 , Consulta Remota , Telemedicina , Brasil/epidemiología , COVID-19/epidemiología , Humanos , Atención Primaria de Salud
18.
Small ; 17(45): e2103897, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34596956

RESUMEN

Intermolecular electron-transfer reactions are key processes in physics, chemistry, and biology. The electron-transfer rates depend primarily on the system reorganization energy, that is, the energetic cost to rearrange each reactant and its surrounding environment when a charge is transferred. Despite the evident impact of electron-transfer reactions on charge-carrier hopping, well-controlled electronic transport measurements using monolithically integrated electrochemical devices have not successfully measured the reorganization energies to this date. Here, it is shown that self-rolling nanomembrane devices with strain-engineered mechanical properties, on-a-chip monolithic integration, and multi-environment operation features can overcome this challenge. The ongoing advances in nanomembrane-origami technology allow to manufacture the nCap, a nanocapacitor platform, to perform molecular-level charge transport characterization. Thereby, employing nCap, the copper-phthalocyanine (CuPc) reorganization energy is probed, ≈0.93 eV, from temperature-dependent measurements of CuPc nanometer-thick films. Supporting the experimental findings, density functional theory calculations provide the atomistic picture of the measured CuPc charge-transfer reaction. The experimental strategy demonstrated here is a consistent route towards determining the reorganization energy of a system formed by molecules monolithically integrated into electrochemical nanodevices.


Asunto(s)
Electrones
19.
Soft Matter ; 17(41): 9410-9419, 2021 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-34608476

RESUMEN

Metallodielectric Janus particles (JPs) and electric fields have been a useful combination for the development of innovative concepts on AC electrokinetics, directed transport and collective dynamics. The polarizability, and its frequency dependence, underlie the rich behavior exhibited by JPs. Nonetheless, direct measurements of polarizability are few and the interplay of different mechanisms remains unclear. This paper discusses measurements and strategies to tailor the magnitude of the polarizability of JPs. Our approach uses electrorotation to measure the polarizability of particles with different thicknesses of metal in electrolyte solutions. On the other hand, we gain further insight into the basic polarization mechanisms through modeling based on the fundamental transport equations. JPs exhibit rich polarization spectra that depend strongly on the thickness of the metal layer, the conductivity of the medium and the surface charge. At low frequencies-around 10 kHz-the results indicate that counter-field rotation stems from the charging of the double layer at the particle-electrolyte interface, while the transition to co-field rotation at high frequencies (above 100 kHz) stems from the Maxwell-Wagner relaxation. The latter polarization mechanism is significantly affected by the conductivity within the electrical double layer. The insights from this study provide helpful quantitative information for the design of colloidal machines with desirable features such as targeted propulsion, and tunable collective dynamics.

20.
Int Orthod ; 18(2): 359-365, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32057734

RESUMEN

OBJECTIVE: The present study aimed to compare the force of aesthetic wires and their non-aesthetic equivalents from two commercial brands at different displacement points, during the unloading phase at 36°C. MATERIALS AND METHODS: Forty samples (n=10) were assessed, which were presented in two groups of aesthetic wires and two groups of non-aesthetic wires from the brands GAC® (Dentsply GAC® International, NY, USA) and Aditek®(Cravinhos, SP, Brazil), with 0.016-inch gauge. The orthodontic wires were maintained at a temperature of 36°C throughout the experiment and they were subjected to the three-point bending test at a speed of 1mm/min. The unloading values were recorded as 0.5, 1.5, and 2.5mm of displacement. The data were subjected to Student's t-test and unequal variance t test, at 5% significance level. RESULTS: During the unloading phase, the mean force was significantly higher for aesthetic wires than non-aesthetic ones, in the deflection of 2.5mm, presenting values means of 2.25N (P=.0213). In deflections of 0.5mm and 1.5mm, the orthodontic archwires did not show significant differences in force between the thermally activated wires with aesthetic coating and their non-aesthetic equivalents (P≥0.05). CONCLUSION: It is concluded that during the unloading phase at a temperature of 36°C, the orthodontic archwires analyzed did not show significant difference in force between thermally activated wires with aesthetic coating and their non-aesthetic equivalents at most displacement points analysed, except for the deflection of 2.5mm, which showed higher values.


Asunto(s)
Fenómenos Mecánicos , Níquel , Alambres para Ortodoncia , Titanio , Aleaciones Dentales , Análisis del Estrés Dental , Estética Dental , Técnicas In Vitro , Ensayo de Materiales
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...