516 research outputs found
Effects of daily administration of a stavudine/nelfinavir association on the fetuses and placentas of female albino rats
OBJETIVO: avaliar o efeito da administração da associação estavudina/nelfinavir durante toda a prenhez da rata, avaliando seu peso e dos conceptos, bem como o número de implantações, fetos, placentas, reabsorções e mortalidades materna e fetal. MÉTODOS: quarenta ratas albinas EPM-1 Wistar, prenhes, foram aleatoriamente divididas em quatro grupos: GCtrl (controle do veículo) e três experimentais, ExpI, ExpII e ExpIII, que receberam, respectivamente, 1/40, 3/120 e 9/360 mg/kg por dia de estavudina/nelfinavir por via oral. As drogas e o veículo (água destilada) foram administrados por gavagem em duas tomadas diárias (12/12 horas), desde o dia 0 até o 20º dia da prenhez. No último dia do experimento, todos os animais foram anestesiados e eutanasiados. Foram avaliados a evolução do peso materno no 7º, 14º e 20º dias, número de fetos, placentas, implantações, reabsorções, óbitos intrauterinos, malformações maiores e o peso dos fetos e das placentas. A análise estatística foi realizada por análise de variância (ANOVA), complementada pelo teste de Kruskal-Wallis (p<0,05). RESULTADOS: em relação ao peso corporal das ratas, houve ganho gradual e progressivo durante o decorrer da prenhez em todos os grupos, sendo este ganho mais evidente no período final; porém não foram constatadas diferenças estatisticamente significantes entre eles. O número de fetos, placentas, implantações, assim como os pesos fetais e placentários também não mostraram diferenças estatisticamente significantes entre os grupos analisados. Não foram observadas, também nos grupos experimentais, reabsorções e malformações fetais maiores externas, no entanto, observamos entre o 8º e o 14º dias de gestação um caso de morte materna em cada grupo experimental. CONCLUSÕES: a administração da associação estavudina/nelfinavir não mostrou efeitos deletérios sobre os conceptos.PURPOSE: to evaluate the effect of administration of a stavudine/nelfinavir combination on the rat pregnancy by assessing maternal and concepts weights, as well as the number of implantations, fetuses, placentas, resorptions and maternal and fetal mortality. METHODS: forty adult pregnant Wistar rats of the EPM-1 strain were randomly divided into four groups: control (GCtrl - drug vehicle control, n=10), and three experimental groups, which were treated with an oral solution of stavudine/nelfinavir (ExpI - 1/40 mg/kg b.w., n=10; ExpII - 3/120 mg/kg b.w., n=10; ExpIII - 9/360 mg/kg b.w., n=10) from day 0 to the 20th day of pregnancy. Maternal body weights were determined at the start of the experiment and on the 7th, 14th and the 20th day thereafter. At term (20th day) the rats were anesthetized and, upon laparotomy and hysterotomy, the number of implantations, resorptions, living fetuses, placentae and intrauterine deaths were recorded. The collected fetuses and placentae were weighed and the concepts were examined under a stereomicroscope for possible external malformations. Statistical analysis was performed by analysis of variance (ANOVA) complemented by the Kruskal-Wallis test (p<0.05). RESULTS: there was a progressive and gradual increase in body weight during the course of pregnancy in all groups, which was more evident in the final period, but with no significant difference between groups. The mean number of fetuses, placentas, implantations, and fetal and placental weights showed no significant differences between groups. Also, no resorptions or external malformations were found in the experimental groups. However, between the 8th and 14th days of gestation, there was one case of maternal mortality in each experimental group. CONCLUSIONS: the administration of a stavudine/nelfinavir combination had no deleterious effects on the concepts
The crude skin secretion of the pepper frog Leptodactylus labyrinthicus is rich in metallo and serine peptidases
Peptidases are ubiquitous enzymes involved in diverse biological processes. Fragments from bioactive peptides have been found in skin secretions from frogs, and their presence suggests processing by peptidases. Thus, the aim of this work was to characterize the peptidase activity present in the skin secretion of Leptodactylus labyrinthicus. Zymography revealed the presence of three bands of gelatinase activity of approximately 60 kDa, 66 kDa, and 80 kDa, which the first two were calcium-dependent. These three bands were inhibited either by ethylenediaminetetraacetic acid (EDTA) and phenathroline; thus, they were characterized as metallopeptidases. Furthermore, the proteolytic enzymes identified were active only at pH 6.0–10.0, and their activity increased in the presence of CHAPS or NaCl. Experiments with fluorogenic substrates incubated with skin secretions identified aminopeptidase activity, with cleavage after leucine, proline, and alanine residues. This activity was directly proportional to the protein concentration, and it was inhibited in the presence of metallo and serine peptidase inhibitors. Besides, the optimal pH for substrate cleavage was determined to be 7.0–8.0. The results of the in gel activity assay showed that all substrates were hydrolyzed by a 45 kDa peptidase. Gly-Pro-AMC was also cleaved by a peptidase greater than 97 kDa. The data suggest the presence of dipeptidyl peptidases (DPPs) and metallopeptidases; however, further research is necessary. In conclusion, our work will help to elucidate the implication of these enzymatic activities in the processing of the bioactive peptides present in frog venom, expanding the knowledge of amphibian biology
Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications.
BACKGROUND: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea.
METHOD: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant. While screening tests for ectasia had been limited to corneal shape (geometry) assessment, clinical biomechanical assessment has been possible since the introduction of the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, USA) in 2005 and the Corvis ST (Oculus Optikgerate GmbH, Wetzlar, Germany) in 2010. Direct clinical biomechanical evaluation is recognized as paramount, especially in detection of mild ectatic cases and characterization of the susceptibility for ectasia progression for any cornea.
CONCLUSIONS: The purpose of this review is to describe the current state of clinical evaluation of corneal biomechanics, focusing on the most recent advances of commercially available instruments and also on future developments, such as Brillouin microscopy.(undefined)info:eu-repo/semantics/publishedVersio
Comparison of the Neutrophil Proteome in Trauma Patients and Normal Controls
Background: Neutrophils have an impressive array of microbicidal weapons, and in the presence of a pathogen, progress from a quiescent state in the bloodstream to a completely activated state. Failure to regulate this activation, for example, when the blood is flooded with cytokines after severe trauma, causes inappropriate neutrophil activation that paradoxically, is associated with tissue and organ damage. Acidic proteomic maps of quiescent human neutrophils were analyzed and compared to those of activated neutrophils from severe trauma patients. The analysis revealed 114 spots whose measured volumes differed between activated and quiescent neutrophils, with 27 upregulated and 87 downregulated in trauma conditions. Among the identified proteins, grancalcin, S100-A9 and CACNB2 reinforce observed correlations between motility and ion flux, ANXA3, SNAP, FGD1 and Zfyve19 are involved in vesicular transport and exocytosis, and GSTP1, HSPA1 HSPA1L, MAOB, UCH-L5, and PPA1 presented evidence that activated neutrophils may have diminished protection against oxidative damage and are prone to apoptosis. These are discussed, along with proteins involved in cytoskeleton reorganization, reactive oxygen species production, and ion flux. Proteins such as Zfyve19, MAOB and albumin- like protein were described for the first time in the neutrophil. In this work we achieved the identification of several proteins potentially involved in inflammatory signaling after trauma, as well as proteins described for the first time in neutrophils
Condition monitoring of bearing faults using the stator current and shrinkage methods
Producción CientíficaCondition monitoring of bearings is an open issue. The use of the stator current to monitor induction motors has been validated as a very advantageous and practical way to detect several types of faults. Nevertheless, for bearing faults, the use of vibrations or sound generally offers better results in the accuracy of the detection, although with some disadvantages related to the sensors used for monitoring. To improve the performance of bearing monitoring, it is proposed to take advantage of more information available in the current spectra, beyond the usually employed, incorporating the amplitude of a significant number of sidebands around the first eleven harmonics, growing exponentially the number of fault signatures. This is especially interesting for inverter-fed motors. But, in turn, this leads to the problem of overfitting when applying a classifier to perform the fault diagnosis. To overcome this problem, and still exploit all the useful information available in the spectra, it is proposed to use shrinkage methods, which have been lately proposed in machine learning to solve the overfitting issue when the problem has many more variables than examples to classify. A case study with a motor is shown to prove the validity of the proposal.CAPES (process BEX552269/2011-5
Broadened T-cell Repertoire Diversity in ivIg-treated SLE Patients is Also Related to the Individual Status of Regulatory T-cells
Intravenous IgG (ivIg) is a therapeutic alternative for lupus erythematosus, the mechanism of which remains to be fully understood. Here we investigated whether ivIg affects two established sub-phenotypes of SLE, namely relative oligoclonality of circulating T-cells and reduced activity of CD4 + Foxp3+ regulatory T-cells (Tregs) reflected by lower CD25 surface density.Octapharma research funding; Fundação para a Ciência e a Tecnologia postdoctoral fellowships: (SFRH/BPD/20806/2004, SFRH/BPD/34648/2007); FCT Programa Pessoa travel grant
Mutual information and meta-heuristic classifiers applied to bearing fault diagnosis in three-phase induction motors
Producción CientíficaThree-phase induction motors are extensively used in industrial processes due to their robustness, adaptability to different operating conditions, and low operation and maintenance costs. Induction motor fault diagnosis has received special attention from industry since it can reduce process losses and ensure the reliable operation of industrial systems. Therefore, this paper presents a study on the use of meta-heuristic tools in the diagnosis of bearing failures in induction motors. The extraction of the fault characteristics is performed based on mutual information measurements between the stator current signals in the time domain. Then, the Artificial Bee Colony algorithm is used to select the relevant mutual information values and optimize the pattern classifier input data. To evaluate the classification accuracy under various levels of failure severity, the performance of two different pattern classifiers was compared: The C4.5 decision tree and the multi-layer artificial perceptron neural networks. The experimental results confirm the effectiveness of the proposed approach.Consejo Nacional de Desarrollo Científico y Tecnológico - (processes 474290/2008-5, 473576/2011-2, 552269/2011-5, 201902/2015-0
and 405228/2016-3
Construindo um módulo de ensino utilizando o tema: Nutrição para a promoção da saúde
Este artigo relata a experiência de construção de um módulo de ensino temático, em que utilizamos as concepções alternativas dos alunos como ponto de partida para o desenvolvimento da estrutura do módulo. Este módulo foi produzido e aplicado no ano de 2010, em uma escola pública do DF, para alunos de 3° ano do Ensino Médio, como proposta de projeto interdisciplinar desenvolvido na carga horária destinada a parte diversificada do currículo. As concepções alternativas dos alunos em relação ao tema mostraram que a utilização do conhecimento cotidiano nas respostas foi muito elevado embora estes alunos já tivessem uma orientação formal/escolar sobre o assunto. E ainda apontam uma compreensão insatisfatória dos conceitos: material, substância, transformação química e energi
Estimation of bearing fault severity in line-connected and inverter-fed three-phase induction motors
Producción CientíficaThis paper addresses a comprehensive evaluation of a bearing fault evolution and its consequent prediction concerning the remaining useful life. The proper prediction of bearing faults in their early stage is a crucial factor for predictive maintenance and mainly for the production management schedule. The detection and estimation of the progressive evolution of a bearing fault are performed by monitoring the amplitude of the current signals at the time domain. Data gathered from line-fed and inverter-fed three-phase induction motors were used to validate the proposed approach. To assess classification accuracy and fault estimation, the models described in this paper are investigated by using Artificial Neural Networks models. The paper also provides process flowcharts and classification tables to present the prognostic models used to estimate the remaining useful life of a defective bearing. Experimental results confirmed the method robustness and provide an accurate diagnosis regardless of the bearing fault stage, motor speed, load level, and type of supply.CAPES (process BEX552269/2011-5)National Council for Scientific and Technological Development (grant #474290/2008-3, #473576/2011-2, #552269/2011-5, #307220/2016-8
A Timely shift from shotgun to targeted proteomics and how it can be groundbreaking for cancer research
Funding The present work was funded by FUB/UnB, CNPq, FAP-DF, CAPES, and FINEP.Peer reviewedPublisher PD
- …
