Synthesis and Characterization of Highly Crystalline Vertically Aligned WSe2 Nanosheets

Here, we report on the synthesis of tungsten diselenide (WSe2) nanosheets using an atmospheric pressure chemical vapor deposition technique via the rapid selenization of thin tungsten films. The morphology and the structure, as well as the optical properties, of the so-produced material have been studied using electron microscopies, X-ray photoelectron spectroscopy, photoluminescence, UV–visible and Raman spectroscopies, and X-ray diffraction. These studies confirmed the high crystallinity, quality, purity, and orientation of the WSe2 nanosheets, in addition to the unexpected presence of mixed phases, instead of only the most thermodynamically stable 2H phase. The synthesized material might be useful for applications such as gas sensing or for hydrogen evolution reaction catalysis

Low kinetic energy oxygen ion irradiationof vertically aligned carbon nanotubes

International audienceVertically aligned multiwalled carbon nanotubes (v-CNTs) were functionalized with oxygen groups using low kinetic energy oxygen ion irradiation. X-ray photoelectron spectroscopy (XPS) analysis indicates that oxygen ion irradiation produces three different types of oxygen functional groups at the CNTs surface: epoxide, carbonyl and carboxyl groups. The relative concentration of these groups depends on the parameters used for oxygen ion irradiation. Scanning electron microscopy (SEM) shows that the macroscopic structure and alignment of v-CNTS are not affected by the ion irradiation and transmission electron microscopy (TEM) proves tip functionalization of v-CNTs. We observed that in comparison to oxygen plasma treatment, oxygen ion irradiation shows higher functionalization efficiency and versatility. Ion irradiation leads to higher amount of oxygen grafting at the v-CNTs surface, besides different functional groups and their relative concentration can be tuned varying the irradiation parameters

Efeito da evolução temporal da adrenalectomia na secreção de prolactina

OBJECTIVE: To evaluate the modulation of the hypothalamus-pituitary-adrenal axis (HPA) on prolactin secretion in rats after adrenalectomy (ADX). MATERIALS AND METHODS: Plasma corticosterone, ACTH, and prolactin concentrations were measured by radioimmunoassay in rats after bilateral ADX in the short- (3 hours and 1day) and long-term (3, 7, and 14 days). RESULTS: Animals that underwent ADX showed undetectable corticosterone levels and a triphasic ACTH response with a transient increase (3h), a decrease (1d), and further increase in the long-term after ADX. Sham animals showed a marked increase in corticosterone and ACTH levels three hours after surgery, with a decrease to basal levels thereafter. Plasma prolactin levels were not changed after ADX. CONCLUSION: There are different points of equilibrium in the HPA axis after the glucocorticoid negative feedback is removed. Prolactin plasma secretion is not altered in the short or long- term after ADX, suggesting that the peptidergic neurons essential for prolactin release are not activated after ADX

Nível de atividade física e coordenação motora de escolares em diferentes estágios maturacionais

Introduction: Motor development studies and debates reveal that sport and physical activity develop and improve motor skills. These studies seek to understand the changes that occur with movement, which becomes more complex as it develops through physical activity. Objective: To compare the level of physical activity and motor coordination of students in different maturational stages and to relate the level of physical activity with the motor coordination of young people. Methods: Descriptive research with cross-sectional design. A total of 46 male subjects aged 10 to 14 years participated in the study. Baecke's usual physical activity questionnaire was applied; the maturity stage was verified through the Puberal Maturation Prediction Equation; the body composition was evaluated through the Guedes protocol for children and adolescents; Finally, the coordinative performance was classified using the Korperkoordinationstest fur Kinder (KTK) test battery. Results: There were significant differences for the variables Age and Height among all stages: P3, P4 and P5 maturation. The differences found in the variable body weight occurred only between the P3 and P5 stages; P4 and P5. It was also observed that no significant differences were found for motor coordination between maturation stages. The same occurred when physical activity indexes were compared. Conclusion: There is no difference in the level of physical activity between stages 3, 4 and 5 of sexual maturation, nor does the maturational stage seem to influence the level of motor coordination of young students.Introdução: Estudos e debates na área do desenvolvimento motor revelam que o esporte e a atividade física desenvolvem e melhoram as habilidades motoras. Esses estudos buscam compreender as mudanças que ocorrem com o movimento, o qual se torna mais complexo à medida que se desenvolve através da atividade física. Objetivo: Comparar o nível de atividade física e coordenação motora de escolares em diferentes estágios maturacionais e relacionar o nível de atividade física com a coordenação motora de jovens. Método: Pesquisa descritiva com corte transversal. Participaram do estudo 46 indivíduos do sexo masculino, com idades entre 10 e 14 anos. Foi aplicado o questionário de Atividade Física Habitual de Baecke; o estágio de maturidade foi verificado através da Equação de Predição da Maturação Puberal; a composição corporal foi avaliada através do protocolo de Guedes para crianças e adolescentes; por fim, o desempenho coordenativo foi classificado por meio da bateria de testes Korperkoordinationstest fur Kinder (KTK). Resultados: Houve diferenças significativas para as variáveis Idade e Estatura entre todos os estágios: P3, P4 e P5 de maturação. As diferenças encontradas na massa corporal ocorreram apenas entre os estágios P3 e P5; P4 e P5. Observou-se também que não foram encontradas diferenças significativas para a coordenação motora entre os estágios de maturação. O mesmo ocorreu quando os índices de atividade física foram comparados. Conclusão: Não existe diferença no nível de atividade física entre os estágios 3, 4 e 5 da maturação sexual, assim como o estágio maturacional não parece influenciar o nível de coordenação motora de jovens escolares

Incidência de lesões esofágicas em pacientes submetidos a ablação de fibrilação atrial com cateter circular multipolar (PVAC-GOLD®)

Introdução: Lesões do esôfago são descritas como complicação da ablação por radiofrequência da fibrilação atrial. Os trabalhos que avaliaram a formação das lesões esofágicas em ablações de fibrilação atrial tiveram como padrão de fonte de energia a radiofrequência em modo unipolar, utilizando o cateter irrigado. Atualmente está disponível o cateter circular multipolar (PVAC-GOLD®), que utiliza ciclos de aplicação de energia em fases (Duty-Cycled Phased RF). Este trabalho tem como objetivo avaliar a ocorrência de lesão esofágica em pacientes submetidos a ablação de fibrilação atrial utilizando-se o cateter PVAC-GOLD®. Método: Entre agosto de 2014 e agosto de 2017, foram incluídos pacientes submetidos a ablação de fibrilação atrial sintomática com uso do cateter PVAC-GOLD®. Por meio da realização de endoscopia digestiva alta no pós-operatório, buscou-se determinar a ocorrência de lesão esofágica térmica associada ao procedimento. Resultados: O estudo incluiu um total de 117 pacientes (74% com fibrilação atrial paroxística), com média de idade de 54,8 anos, e predominantemente do sexo masculino. Destes, apenas 2 apresentaram lesões esofágicas térmicas diagnosticadas por meio da endoscopia digestiva alta. Conclusão: A lesão esofágica parece ser um achado incomum em pacientes submetidos a isolamento elétrico das veias pulmonares com o cateter circular multipolar (PVAC-GOLD®)

Latin American Consensus Statement for the Use of Contrast-Enhanced Transcranial Ultrasound as a Diagnostic Test for Detection of Right-to-Left Shunt

Background: The role of patent foramen ovale is a field of debate and current publications have increasing controversies about the patients' management in young undetermined stroke. Work up with echocardiography and transcranial Doppler (TCD) can aid the decision with better anatomical and functional characterization of right-to-left shunt (RLS). Medical and interventional strategy may benefit from this information. Summary: a group of experts from the Latin American participants of the Neurosonology Research Group (NSRG) of World Federation of Neurology created a task force to review literature and describe the better methodology of contrast TCD (c-TCD). All signatories of the present consensus statement have published at least one study on TCD as an author or co-author in an indexed journal. Two meetings were held while the consensus statement was being drafted, during which controversial issues were discussed and voted on by the statement signatories. The statement paper was reviewed and approved by the Executive Committee of the NSRG of the World Federation of Neurology. The main objective of this consensus statement is to establish a standardization of the c-TCD technique and its interpretation, in order to improve the informative quality of the method, resulting in expanding the application of TCD in the clinical setting. These recommendations optimize the comparison of different diagnostic methods and encourage the use of c-TCD for RLS screening and complementary diagnosis in multicenter studies

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others