Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Microbiol Res ; 275: 127465, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37543004

RESUMEN

The identification of antifungal compounds produced by microorganisms is crucial in the context of sustainable agriculture. Bacteria of the genus Bacillus have a broad spectrum of action that can influence plant growth and control pests, vectors of public health relevance and phytopathogens. Lipopeptides are the main compounds related to the biological control of several pathogen species. Strains with biotechnological potential are identified by means of in vitro bioassays and molecular tests. In this study, strains from the Bacillus Bank of Brazilian Agricultural Research Corporation (EMBRAPA/DF/Brazil) were selected to control the fungal pathogens Sclerotinia sclerotiorum and Fusarium oxysporum by pairing assays. The detection of genes for biosynthesis of antifungal compounds from strains with high pathogen-inhibition capacity was correlated with peptide synthesis, such as bacillomycin D, fengycin d, bacilysin and surfactin. Their gene expression in contact with the pathogen was analyzed by Real-Time PCR. The volatile organic compounds produced by selected Bacillus strains were identified and quantified. In co-culture assays, the inhibition zone between Bacillus strains and Sclerotinia sclerotiorum was evaluated by scanning electron microscopy. Thirteen potentially anti-pathogenic strains were selected. Genes related to the synthesis of antifungal peptides were detected in 11 of them. In five strains, all tested genes were detected. Bacillomycin was the most frequently found lipopeptide gene. The fungus-bacteria interaction potentiated the production of volatiles. Several ketones and other volatile compounds with antifungal activity were identified. Relevant morphological changes in the fungus were observed when paired with bacteria. The study demonstrated the efficacy of the selected strains with regard to the biological control of phytopathogens and their biotechnological potential.


Asunto(s)
Ascomicetos , Bacillus , Antifúngicos/farmacología , Antifúngicos/metabolismo , Bacillus/metabolismo , Lipopéptidos/metabolismo , Bacterias/metabolismo , Enfermedades de las Plantas/microbiología
2.
PLoS One ; 18(8): e0290331, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37651433

RESUMEN

Surrogate models are frequently used to replace costly engineering simulations. A single surrogate is frequently chosen based on previous experience or by fitting multiple surrogates and selecting one based on mean cross-validation errors. A novel stacking strategy will be presented in this paper. This new strategy results from reinterpreting the model selection process based on the generalization error. For the first time, this problem is proposed to be translated into a well-studied financial problem: portfolio management and optimization. In short, it is demonstrated that the individual residues calculated by leave-one-out procedures are samples from a given random variable ϵi, whose second non-central moment is the i-th model's generalization error. Thus, a stacking methodology based solely on evaluating the behavior of the linear combination of the random variables ϵi is proposed. At first, several surrogate models are calibrated. The Directed Bubble Hierarchical Tree (DBHT) clustering algorithm is then used to determine which models are worth stacking. The stacking weights can be calculated using any financial approach to the portfolio optimization problem. This alternative understanding of the problem enables practitioners to use established financial methodologies to calculate the models' weights, significantly improving the ensemble of models' out-of-sample performance. A study case is carried out to demonstrate the applicability of the new methodology. Overall, a total of 124 models were trained using a specific dataset: 40 Machine Learning models and 84 Polynomial Chaos Expansion models (which considered 3 types of base random variables, 7 least square algorithms for fitting the up to fourth order expansion's coefficients). Among those, 99 models could be fitted without convergence and other numerical issues. The DBHT algorithm with Pearson correlation distance and generalization error similarity was able to select a subgroup of 23 models from the 99 fitted ones, implying a reduction of about 77% in the total number of models, representing a good filtering scheme which still preserves diversity. Finally, it has been demonstrated that the weights obtained by building a Hierarchical Risk Parity (HPR) portfolio perform better for various input random variables, indicating better out-of-sample performance. In this way, an economic stacking strategy has demonstrated its worth in improving the out-of-sample capabilities of stacked models, which illustrates how the new understanding of model stacking methodologies may be useful.


Asunto(s)
Algoritmos , Ingeniería , Femenino , Embarazo , Humanos , Análisis por Conglomerados , Generalización Psicológica , Aprendizaje Automático
3.
Microb Ecol ; 86(4): 2515-2526, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37392204

RESUMEN

Bacillus thuringiensis is a Gram-positive aerobic bacterium and the most used biopesticide worldwide. Given the importance of B. thuringiensis strain characterization for the development of new bioinsecticides or transgenic events and the identification and classification of new B. thuringiensis genes and strains to understand its distribution and diversity, this work is aimed at creating a gene identification system based on qPCR reactions utilizing core B. thuringiensis genes cry1, cry2, cry3, cry4, cry5, app6, cry7, cry8, cry9, cry10, cry11, vpb1, vpa2, vip3, cyt1, and cyt2 for the characterization of 257 strains of B. thuringiensis. This system was based on the Invertebrate Bacteria Collection from Embrapa Genetic Resources and Biotechnology and analyzed (a) the degree of correlation between the distribution of these strains and the origin of the substrate from which the strain was isolated and (b) between its distribution and geoclimatic conditions. This study made it possible to observe that the cry1, cry2, and vip3A/B genes occur homogeneously in the Brazilian territory, and some genes are found in specific regions. The biggest reservoir of variability is within B. thuringiensis strains in each region, and it is suggested that both geoclimatic conditions and regional crops interfere with the genetic diversity of the B. thuringiensis strains present in the region, and B. thuringiensis strains can constantly exchange genetic information.


Asunto(s)
Bacillus thuringiensis , Animales , Bacillus thuringiensis/genética , Endotoxinas/genética , Endotoxinas/química , Reacción en Cadena en Tiempo Real de la Polimerasa , Toxinas de Bacillus thuringiensis , Brasil , Proteínas Bacterianas/genética , Proteínas Bacterianas/química , Insectos , Variación Genética , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/química
4.
Antonie Van Leeuwenhoek ; 116(7): 599-614, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37178245

RESUMEN

The usage of microorganisms as biocontrol agents and biofertilizers has been recommended and recognized as an ecologically correct alternative to maintaining the productivity and safety of crops. Thus, the objectives of this work were to characterize twelve strains belonging to Invertebrate Bacteria Collection of Embrapa Genetic Resources and Biotechnology by molecular, morphological, and biochemical methods and to evaluate the pathogenicity of these strains against pests and diseases of agricultural interest. The morphological characteristic of the strains was performed according to the principles of Bergy's Manual of Systematic Bacteriology. The genomes of the 12 strains were sequenced in Macrogen, Inc. (Seoul, Korea) using the HiSeq2000 and GS-FLX Plus high-performance platforms. In the determination of antibiotic sensibility profiles, disc-diffusion methods (Cefar Diagnótica Ltda) were adopted©. Selective bioassays were carried out with insects of the Lepidoptera (Spodoptera frugiperda, Helicoverpa armigera, and Chrysodeixis includens), Coleoptera (Anthonomus grandis), Diptera (Aedes aegypti) and Hemiptera (Euschistus heros) orders, and with the nematode Caenorhabditis elegans. In addition, the antagonistic action of the phytopathogens Fusarium oxysporum f. sp. vasinfectum and Sclerotinia sclerotiorum against the strains under study, and in vitro assays of phosphate solubilization were also performed. Sequencing of the complete genome of the 12 strains determined that all of them belonged to the Bacillus subtilis sensu lato group. In the strains genome were detected genic clusters responsible for encoding secondary metabolites such as surfactin, iturin, fengycins/plipastatin, bacillomycin, bacillisin, and siderophores. Due to the production of these compounds, there was a survival reduction of the Lepidoptera order insects and a reduction in the phytopathogens mycelial growth. These results show that the species of group B. subtilis s.l. can become promising microbiological alternatives to pest and disease control.


Asunto(s)
Bacillus , Bacillus/genética , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Antibacterianos/metabolismo , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología
5.
J Microbiol Methods ; 205: 106665, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36592897

RESUMEN

Bacillus thuringiensis is an important bacterium of the group Bacillus cereus sensu lato due to its insecticidal properties. This microorganism has high genetic variability and its strains produce different Cry toxins, known as δ-endotoxins, which are mainly responsible for its toxic effect on insects that are agricultural pests or vector human diseases. Each strain can express a variety of cry genes, out of a total of 789 cry genes described so far. The detection of these genes is very important to characterize strains, as they may indicate their toxic potential. Several methods have been used to characterize B. thuringiensis strains, but one of the most common techniques is Polymerase Chain Reaction (PCR) from primers that detect the presence of cry genes. This technique has been optimized to make real-time multiplex quantitative PCR (qPCR) assays faster, more efficient, and safer, because the presence of three genes can be detected in a single reaction. In this work, a multiplex assay was developed to identify the presence of genes from the cry1A, cry1C, and cry1F families whose respective toxins are present in both bioinsecticides, and commercial transgenic plants used to control caterpillars. Specific primers were designed to identify the families of the cited genes and the system was validated with samples that were sequenced by next-generation sequencing (NGS). The system was implemented and used to characterize 214 strains. Of these, eight were submitted to conventional PCR, and the results matched, again validating the system. Thus, the application of the proposed technique allows the reliable evaluation through this system to detect the presence of the genes of the families cry1A, cry1C, and cry1F in samples of B. thuringiensis.


Asunto(s)
Bacillus thuringiensis , Insecticidas , Animales , Humanos , Bacillus thuringiensis/genética , Endotoxinas/genética , Toxinas de Bacillus thuringiensis , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteínas Bacterianas/genética , Proteínas Hemolisinas/genética
6.
Anat Histol Embryol ; 51(4): 435-442, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35485276

RESUMEN

In this study, atomic force microscopy (AFM), microtomography (MCT-2D and MCT-3D) and energy-dispersive X-ray fluorescence spectrometry (EDXRF) were used to generate parameters of the microstructure of the hoof capsule of pigmented and partial albino buffaloes. Seventy-two digits of adult pigmented buffaloes and 16 of partial albino buffaloes were used and equally divided into thoracic and pelvic limbs and medial and lateral claws. Fragments of 10 mm × 10 mm of the dorsal wall, abaxial wall and pre-bulbar sole were collected. The parametric assumptions were tested using a Shapiro-Wilk test (normality). The independent t-test was used to compare the means at a 5% significance level. AFM demonstrated that the hoof surface of pigmented buffaloes presented with higher average surface roughness (Ra) and root mean square roughness (Rms) (p < 0.05) than the hoof surface of partial albino buffaloes. MCT-2D revealed that pigmented buffaloes had extra tubular keratin with a higher density than intratubular keratin. No pores were observed in the hoof capsule of the buffalo digits. MCT-3D demonstrated that pigmented buffaloes have a higher percentage of large and intermediate horn tubules than partial albino buffaloes. However, this difference was not statistically significant. Partial albino buffaloes showed a statistically higher number of horn tubules/mm2 than pigmented buffaloes (p < 0.05). EDXRF revealed a higher amount of sulphur (S) in the hoof capsule of pigmented buffaloes, and the partial albino buffaloes presented a higher number of minerals such as calcium (Ca), potassium (K), zinc (Zn) and copper (Cu).


Asunto(s)
Pezuñas y Garras , Animales , Miembro Posterior , Queratinas/química
7.
Artículo en Inglés | MEDLINE | ID: mdl-34204344

RESUMEN

This review aimed to investigate the factors associated with suicidal behavior in farmers in the scientific literature. Two researchers participated independently in searching databases, specifically PubMed/MEDLINE, LILACS, Web of Science, Scopus, PsycINFO, and SciELO. Only observational studies were included. The quality of the selected studies was assessed with a critical assessment checklist for cross-sectional analytical and case-control studies, prepared by the Joanna Briggs Institute. Data related to the publication were collected (author and year; city/country); methodological design; sample/population (gender; average age), outcome, measuring instrument and factors associated with suicidal behavior. A total of 14 studies were included in the systematic review, and factors associated with farmers' behavior in mental health (depression), seasonal impacts (drought), and work exposures (herbicides and insecticides) were identified. However, heterogeneity was found in terms of the method, measurement of suicidal behavior, and associated factors, which indicates the need for further studies.


Asunto(s)
Agricultores , Ideación Suicida , Estudios de Casos y Controles , Estudios Transversales , Humanos , Salud Mental
8.
Anat Histol Embryol ; 50(1): 93-101, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32815592

RESUMEN

The aim of this study was to evaluate the effect of daily biotin supplementation on the mineral composition and microstructure of the abaxial hoof wall in dairy heifers. The heifers were housed on a concrete floor and fed for weight gain more than 800 g per day, which is a challenging environment for the hoof. Twelve crossbred dairy heifers (Jersey × Holstein) were divided into two treatment groups. Animals in the control group (n = 6) received a diet without supplemental biotin, while the heifers in the biotin-supplemented feed group (n = 6) each received 20 mg of biotin daily for 120 days. Samples of the abaxial hoof wall were collected from the outer claw of the fore and hind limb, before and after supplementation. The samples were evaluated by X-ray fluorescence spectrometry, computed microtomography, atomic force microscopy and confocal laser scanning microscopy. Biotin supplementation increased the sulphur content and decreased the calcium and potassium content in the abaxial hoof wall. Biotin treatment also increased the percentage of horn tubules with smaller diameter marrow (17-51 µm). However, biotin did not influence the surface relief of the hoof wall, suggesting that its action is limited to the inner layers of the stratum corneum. Daily supplementation with 20 mg of biotin promoted changes in the mineral composition and microstructure of abaxial hoof wall of crossbred dairy heifers. These findings suggest biotin supplementation improves hoof quality and may help to understand the function of biotin in the stratum corneum.


Asunto(s)
Biotina/farmacología , Bovinos/fisiología , Suplementos Dietéticos , Pezuñas y Garras/química , Minerales/química , Complejo Vitamínico B/farmacología , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Biotina/administración & dosificación , Dieta/veterinaria , Femenino , Minerales/metabolismo , Complejo Vitamínico B/administración & dosificación , Microtomografía por Rayos X
9.
Materials (Basel) ; 13(19)2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-33008064

RESUMEN

Bowing is a pathology known by the deformation experienced in some external covering systems in ornamental stones, especially in marble, and thermal action is one of the key factors that lead to this degradation. Previous studies presented remarkable contributions about the mechanical behavior of bowing but they were based on classical beam's theory and improper assumptions might mislead the evaluation of internal stresses. This study proposes to evaluate internal stresses in bowing due to thermal loading considering the true deformed shape in continuum media. Finite displacement concepts are proposed to calculate stress-strain relationship and comparison with linear elastic theory is also addressed. Internal stresses not predictable in the Euler-Bernoulli beam were found in parametric analyses. Moreover, the numerical analysis accomplished in this paper indicates that transient heat flux should induce higher stresses than just considering higher gradients of temperature in steady flux which could explain the larger decohesion through width in bowing tests.

10.
Arch Endocrinol Metab ; 64(4): 337-348, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32813762

RESUMEN

A literature review on the clinical, laboratory, and treatment features of type B insulin resistance syndrome (TBIRS). Data from PubMed, the Virtual Health Library and Cochrane database were selected and analyzed using the REDCap application and R statistical program. From 182 papers, 65 were selected, which assessed 119 clinical cases, 76.5% in females and 42.9% in African-Americans, with an average age of 44 years. A common feature of TBIRS is co-occurrence of autoimmune diseases, such as systemic lupus erythematosus (most frequently reported). Hyperglycemia of difficult control was the mostly reported condition. Tests for anti-insulin receptor antibodies were positive in 44.2% of the cases. Disease management comprised fractional diet, insulin therapy (maximum dose given was 57 600 IU/day), plasmapheresis and immunosuppression with several classes of drugs, mainly glucocorticoids. Remission occurred in 69.7% of cases, in 30.3% of these spontaneously. The mortality rate was 15.38%. There was an inverse relationship between anti-insulin antibodies and remission (p = 0.033); and a positive correlation between combined immunosuppressive therapy and remission (p = 0.002). Relapse occurred in 7.6% of the cases. This rare syndrome has difficult-to-control diabetes, even with high doses of insulin, and it is usually associated with autoimmune diseases. Therapeutic advances using immunomodulatory therapy have led to significant improvements in the rate of remission.


Asunto(s)
Enfermedades Autoinmunes , Diabetes Mellitus , Resistencia a la Insulina , Adulto , Autoanticuerpos , Femenino , Humanos , Masculino , Receptor de Insulina
11.
Syst Rev ; 9(1): 118, 2020 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-32460835

RESUMEN

BACKGROUND: Peripheral nerves are constant targets of traumatic injury which may result in neurotmesis and which invariably requires surgical treatment. In view of this, tissue engineering studies developed biomaterials which were first tested in animal models and used as a guide for nerve stumps in the procedure in order to speed up the healing process. Therefore, the aim of this study is to evaluate the efficacy of biomaterials used in tubing technique on healing and histological and functional recovery after peripheral nerve neurotmesis in rats. METHODS: We will search PubMed/MEDLINE, Embase, Web of Science, LILACS, and CENTRAL (from inception onwards). Grey literature will be identified through searching dissertation databases, guidelines, policy documents, and reports. We will include randomized and non-randomized trials conducted in young adult rats with peripheral neurometsis undergoing surgical repair through tubing technique with biomaterials. Primary outcomes will be histomorphometry, immunohistochemistry of the nerve tissue, and sciatic functional index. Secondary outcome will be nerve macroscopic evaluation. Two reviewers will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The methodological quality (or risk of bias) of individual studies will be appraised using an appropriate tool. If feasible, we will conduct random effects meta-analysis. DISCUSSION: This systematic review of animal studies will identify, evaluate, and synthetize the evidence on the the efficacy of tubing technique with biomaterials compared to direct coaptation technique after peripheral neurotmesis in nerve healing and return to functionality. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018106042.


Asunto(s)
Tejido Nervioso , Traumatismos del Sistema Nervioso , Animales , Materiales Biocompatibles , Metaanálisis como Asunto , Ratas , Revisiones Sistemáticas como Asunto
12.
Movimento (Porto Alegre) ; 25(1): e25095, jan.- dez. 2019. ilus
Artículo en Portugués | LILACS | ID: biblio-1178417

RESUMEN

O artigo inicia com uma resenha do longa-metragem Aos Teus Olhos (2017), estrelado por Daniel Oliveira, no qual o professor de natação Rubens é acusado de praticar pedofilia contra um de seus alunos. O fio condutor do texto é uma discussão feita com base em uma literatura especializada, que mostra que não há um real acréscimo da pedofilia, mas maior controle e punição quando esses crimes ocorrem. Articula-se ainda o enredo do longa com casos ocorridos antes e depois do advento das mídias sociais, nos quais a vida de alguns professores foi destruída graças à disseminação de boatos sem provas. Por fim, espera-se que tanto o filme seja trabalhado como importante recurso didático na formação inicial e continuada de professores quanto este texto, de maneira a potencializar uma discussão acerca da pedofilia e do poder das mídias sociais na destruição da vida dos profissionais da educação


The article starts with a review of "Aos Teus Olhos", a film starred by Daniel Oliveira, in which swimming instructor Rubens is accused of pedophilia against one of his pupils. The text's guiding thread is a discussion based on specialized literature that shows that rather than a real increase in pedophilia, there is greater control of and punishment to that type of crime. The film's plot addresses cases that happened before and after the advent of social media, in which some teachers had their lives destroyed by rumors. Finally, the film and this text are expected to be used as important teaching resources in teachers' initial and continued training, in order to help discussing pedophilia and the power of social media concerning destruction of Education professionals' lives.


El artículo comienza con una reseña del largometraje "Aos Teus Olhos" (2017), protagonizado por Daniel Oliveira, en el que el profesor de natación Rubens es acusado de practicar pedofilia contra uno de sus alumnos. El hilo conductor del texto es una discusión realizada sobre la base de literatura especializada que señala que no existe un real aumento de la pedofilia, sino un mayor control y castigo cuando estos crímenes ocurren. También se articula la trama de la película con casos ocurridos antes y después de la llegada de las redes sociales, en los cuales la vida de algunos profesores fue destruida debido a la diseminación de rumores sin pruebas. Por último, se espera que tanto el largometraje como este texto sean trabajados como importantes recursos didácticos en la formación inicial y continuada de profesores, de manera a impulsar una discusión acerca de la pedofilia y el poder de las redes sociales en la destrucción de la vida de los profesionales de la educación


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Pedofilia , Educación , Medios de Comunicación Sociales , Películas Cinematográficas
13.
Rev Bras Epidemiol ; 22: e190033, 2019.
Artículo en Portugués, Inglés | MEDLINE | ID: mdl-31038614

RESUMEN

OBJECTIVE: To analyze trends in pesticide poisoning incidence rates in Brazilian regions, according to sex and circumstances of poisoning, between 2001 and 2014. METHOD: Ecological time-series study, with data from the national Notifiable Diseases Information System (SINAN). The incidence rates were calculated by dividing the number of confirmed new cases of pesticide poisoning by the total resident population in the same period and location. Both Polynomial regression analysis and Mann-Whitney and Kruskal-Wallis tests were performed. When significant differences were found, these tests were followed by the Bonferroni penalty, in order to identify the difference more precisely. RESULTS: In Brazil, 80,069 notified poisoning cases were recorded from 2001 to 2014. There was a steadily increasing growth of pesticide poisoning in this population, whose growth trend was 0,377 for 100,000 inhabitants per year. The highest incidence of poisoning occurred in the South and Midest Regions. Regarding sex, no significant differences were found (p < 0,347), and attempted suicide was the most significant circumstance of poisoning (p < 0,001). CONCLUSION: The incidence of pesticide poisoning in Brazil has been continuously increasing in the twenty-first century.


OBJETIVO: Analisar as tendências das taxas de incidência da intoxicação por agrotóxicos nas regiões brasileiras, de acordo com sexo e circunstância da intoxicação, no período de 2001 a 2014. MÉTODO: Estudo de séries temporais, com dados do Sistema de Informação de Agravos de Notificação (SINAN). As taxas de incidência foram calculadas por meio da razão entre o número de casos novos confirmados de intoxicações por agrotóxicos e a população residente no mesmo período e local. Foram realizados análise de regressão polinomial e testes de Mann-Whitney e Kruskal-Wallis. Quando encontradas diferenças significativas, os testes foram seguidos pela penalização de Bonferroni com a finalidade de identificar onde residia a diferença. RESULTADOS: No Brasil, foram registrados 80.069 casos de intoxicação nesse período. Houve um crescimento linear de notificações de intoxicação por agrotóxico, cuja taxa de tendência de crescimento encontrada foi de 0,377 por 100 mil habitantes/ano. As regiões Sul e Centro-Oeste apresentam as maiores taxas de intoxicação. Em relação ao sexo, não foram encontradas diferenças significativas (p < 0,347), sendo a tentativa de suicídio a circunstância de intoxicação mais significativa (p < 0,001). CONCLUSÃO: A incidência de intoxicação por agrotóxico no Brasil segue em aumento no século XXI.


Asunto(s)
Notificación de Enfermedades/estadística & datos numéricos , Sistemas de Información en Salud/estadística & datos numéricos , Plaguicidas/envenenamiento , Brasil/epidemiología , Femenino , Humanos , Incidencia , Masculino , Análisis de Regresión , Distribución por Sexo , Estadísticas no Paramétricas , Factores de Tiempo
14.
Eng. sanit. ambient ; 24(3): 515-523, maio-jun. 2019. tab, graf
Artículo en Portugués | LILACS-Express | LILACS | ID: biblio-1012048

RESUMEN

RESUMO A concentração de óleos e graxas em amostras de águas contaminadas com resíduos oleosos pode ser determinada pelos procedimentos estabelecidos no Standard Methods for the Examination of Water and Wastewater. No entanto, sua aplicação nem sempre resulta em valores adequados ou níveis de precisão satisfatórios para atendimento de padrões normativos. Nesse sentido, este artigo apresenta uma proposta de ensaio para determinação da concentração de óleos minerais em águas provenientes de áreas pavimentadas, sujeitas ao derramamento de óleos e graxas. Tal método tem por base o método de partição gravimétrica (5520 B), estabelecido pelo Standard Methods. No novo procedimento, a etapa de separação entre o solvente de extração contendo os resíduos e o restante da fase aquosa foi substituída pela evaporação de toda a água da amostra, em estufa a 85ºC. Para avaliar a eficiência do método, foram preparadas amostras com concentrações conhecidas de óleo de 200, 100, 50, 25 e 15 mg.L-1 em água destilada e realizados ensaios de laboratório para determinação do teor de óleo, conforme tal procedimento. Os valores obtidos para as concentrações de óleo são bastante satisfatórios, apresentando comportamento linear em relação às concentrações de referência. Esse fato evidencia a confiabilidade do método proposto e sua aplicabilidade na determinação da concentração de óleos em amostras de águas contaminadas provenientes do escoamento superficial em pavimentos.


ABSTRACT Oil and grease concentration in water samples contaminated by oily residues can be determined by the procedures established in the Standard Methods for the Examination of Water and Wastewater. However, its application does not always result in adequate values or satisfactory accuracy levels in order to meet regulatory standards. In this sense, this paper presents a test-method proposal for determining mineral oil concentration in water samples from runoff of paved areas subject to oil and grease spillages. This method is based on the partition-gravimetric method (5520 B) established by the Standard Methods. In the new procedure, the separation between the extraction solvent containing residues and the aqueous phase remainder was replaced by the whole water sample evaporation in an oven at 85ºC. In order to assess the proposed method's efficiency, samples were prepared with known oil concentrations of 200, 100, 50, 25 and 15 mg.L-1, in distilled water and laboratory tests were performed to determine the oil content, according to the new procedure. The values obtained for the oil concentrations through the proposed procedure are quite satisfactory, presenting linear behavior in relation to the reference concentrations. This fact evidences the reliability of the new method and its applicability in determining the oil concentration in contaminated water samples from runoff in pavement surfaces.

15.
Rev. bras. epidemiol ; 22: e190033, 2019. tab, graf
Artículo en Portugués | LILACS | ID: biblio-1003484

RESUMEN

RESUMO: Objetivo: Analisar as tendências das taxas de incidência da intoxicação por agrotóxicos nas regiões brasileiras, de acordo com sexo e circunstância da intoxicação, no período de 2001 a 2014. Método: Estudo de séries temporais, com dados do Sistema de Informação de Agravos de Notificação (SINAN). As taxas de incidência foram calculadas por meio da razão entre o número de casos novos confirmados de intoxicações por agrotóxicos e a população residente no mesmo período e local. Foram realizados análise de regressão polinomial e testes de Mann-Whitney e Kruskal-Wallis. Quando encontradas diferenças significativas, os testes foram seguidos pela penalização de Bonferroni com a finalidade de identificar onde residia a diferença. Resultados: No Brasil, foram registrados 80.069 casos de intoxicação nesse período. Houve um crescimento linear de notificações de intoxicação por agrotóxico, cuja taxa de tendência de crescimento encontrada foi de 0,377 por 100 mil habitantes/ano. As regiões Sul e Centro-Oeste apresentam as maiores taxas de intoxicação. Em relação ao sexo, não foram encontradas diferenças significativas (p < 0,347), sendo a tentativa de suicídio a circunstância de intoxicação mais significativa (p < 0,001). Conclusão: A incidência de intoxicação por agrotóxico no Brasil segue em aumento no século XXI.


ABSTRACT: Objective: To analyze trends in pesticide poisoning incidence rates in Brazilian regions, according to sex and circumstances of poisoning, between 2001 and 2014. Method: Ecological time-series study, with data from the national Notifiable Diseases Information System (SINAN). The incidence rates were calculated by dividing the number of confirmed new cases of pesticide poisoning by the total resident population in the same period and location. Both Polynomial regression analysis and Mann-Whitney and Kruskal-Wallis tests were performed. When significant differences were found, these tests were followed by the Bonferroni penalty, in order to identify the difference more precisely. Results: In Brazil, 80,069 notified poisoning cases were recorded from 2001 to 2014. There was a steadily increasing growth of pesticide poisoning in this population, whose growth trend was 0,377 for 100,000 inhabitants per year. The highest incidence of poisoning occurred in the South and Midest Regions. Regarding sex, no significant differences were found (p < 0,347), and attempted suicide was the most significant circumstance of poisoning (p < 0,001). Conclusion: The incidence of pesticide poisoning in Brazil has been continuously increasing in the twenty-first century.


Asunto(s)
Humanos , Masculino , Femenino , Plaguicidas/envenenamiento , Notificación de Enfermedades/estadística & datos numéricos , Sistemas de Información en Salud/estadística & datos numéricos , Factores de Tiempo , Brasil/epidemiología , Incidencia , Análisis de Regresión , Distribución por Sexo , Estadísticas no Paramétricas
16.
Clin Biomech (Bristol, Avon) ; 58: 7-13, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30005425

RESUMEN

BACKGROUND: Given the changes in the patterns of muscular activation and scapular movement in individuals with subacromial pain syndrome, the use of neuromuscular training has been considered in rehabilitation protocols. There is currently no evidence of the effects of the use of three-dimensional (3D) kinematic biofeedback on individuals with subacromial pain syndrome. This study aimed to determine the immediate effect of scapular motor control exercises using 3D kinematic biofeedback on the scapular kinematics, inter-segment coordination and pain of individuals with subacromial pain syndrome. METHOD: The kinematics of the scapulothoracic joint of 26 subjects with subacromial pain syndrome were assessed in the movement arm elevation and lowering in the sagittal plane before and after performance of three scapula-focused exercises using kinematic biofeedback. The individuals were familiarized with the selected exercises to acquire a greater scapular posterior tilt, while kinematic biofeedback, with visual and auditory stimuli, was used in real time. Scapular kinematics, pain, and subjective perception of exertion were the pre- and post-test measures. FINDINGS: In the movement of arm elevation and lowering, no differences were found in scapular tilt and on coordination between the segments pre- and post-test and the effect size was considered small. INTERPRETATION: Our results demonstrate that the performance of scapula-focused exercises using kinematic biofeedback does not cause immediate changes in the magnitude of scapular movement. However, inter-segmental coordination showed evidence of changes for scapular tilt in the lowering of the arm and internal rotation in the elevation and the lowering of the arm in individuals with subacromial pain syndrome.


Asunto(s)
Biorretroalimentación Psicológica/métodos , Terapia por Ejercicio/métodos , Escápula/fisiopatología , Síndrome de Abducción Dolorosa del Hombro/fisiopatología , Síndrome de Abducción Dolorosa del Hombro/rehabilitación , Hombro/fisiopatología , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Movimiento , Rotación , Hombro/fisiología
17.
Microbiology (Reading) ; 163(11): 1525-1531, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29043959

RESUMEN

Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) have been frequently associated with bacterial resistance mechanisms. These mechanisms, in turn, restrict a range of therapeutic opportunities for the treatment of infections caused by these micro-organisms. Faced with this problem, the present study aims to isolate and characterize molecules with antimicrobial activity derived from the fungus Penicillium citrinum isolated from Cerrado soil. Furthermore, we also tested possible antibacterial potential alone and in combination with commercial antimicrobial agents. In this context, citrinin was isolated and characterized by nuclear magnetic resonance and electrospray ionization. Functional analyses showed MIC of 128 µg ml-1 against S. aureus ATCC 25923, E. faecalis ATCC 29212 and a clinical isolate of vancomycin-resistant E. faecium (VRE01). However, for a clinical strain of methicillin-resistant S. aureus (MRSA01), the MIC was 256 µg ml-1. In order to avoid such high concentrations and reduce the collateral effects, additive effects were evidenced by combining citrinin with cefoxitin against MRSA01 (FIC index=0.5) and also citrinin with vancomycin toward VRE01 (FIC index=0.5). In vivo studies with BALB/c-tipe mice (MRSA assay) demonstrated a clinical ineffectiveness of cefoxitin associated with citrinin (9.8 mg kg-1 of cefoxitin +0.2 mg kg-1 of citrinin), with this combination being inefficient to increase animal survival. However, the combination used in the treatment of VRE (23.5 mg kg-1 of citrinin +1.5 mg kg-1 of vancomycin) sepsis model was extremely promising, leading to an animal survival rate of 80 percent. In summary, our data show, for the first time, the possible successful use of citrinin associated with vancomycin for pathogenic bacteria control.


Asunto(s)
Antibacterianos/farmacología , Citrinina/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Penicillium/química , Enterococos Resistentes a la Vancomicina/efectos de los fármacos , Vancomicina/farmacología , Animales , Antibacterianos/aislamiento & purificación , Antibacterianos/toxicidad , Cefoxitina/farmacología , Supervivencia Celular/efectos de los fármacos , Citrinina/aislamiento & purificación , Citrinina/toxicidad , Sinergismo Farmacológico , Femenino , Dosificación Letal Mediana , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Pruebas de Sensibilidad Microbiana , Penicillium/citología , Células RAW 264.7 , Pruebas de Toxicidad
18.
Pesqui. vet. bras ; 36(10): 986-992, out. 2016. ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-841990

RESUMEN

In order to test the performance of bacterial cellulose/polycaprolactone composite (BC/PCL) and pure bacterial cellulose (BC) as tissue substitutes in rabbits' cornea, a superficial ulcer containing 5mm in diameter and 0.2mm deep was made in the right cornea of 36 rabbits, then a interlayer pocket was created from the basis of this ulcer. Twelve rabbits received BC/PCL membrane and 12 were treated with BC membranes, both membranes with 8mm in diameter. The remaining rabbits received no membrane constituting the control group. The animals were clinically followed up for 45 days. Three animals of each group were euthanized at three, seven, 21, and 45 days after implantation for histological examination of the cornea along with the implant. Clinical observation revealed signs of moderate inflammatory process, decreasing from day 20th in the implanted groups. Histology showed absence of epithelium on the membranes, fibroplasia close to the implants, lymph inflammatory infiltrate with giant cells, collagen disorganization, with a predominance of immature collagen fibers in both groups with implants. Although inflammatory response is acceptable, the membranes used does not satisfactorily played the role of tissue substitute for the cornea during the study period.(AU)


Com objetivo de testar o desempenho do compósito celulose bacteriana/policaprolactona (CB/PCL) e da celulose bacteriana pura (CB) como substitutos teciduais em córnea de coelhos, foi realizada uma úlcera superficial de 5 mm de diâmetro e 0,2 mm de profundidade na córnea direita de 36 coelhos, criando-se um bolso interlamelar a partir da base dessa úlcera. Doze animais receberam a membrana do compósito CB/PCL e 12 foram tratados com membranas de CB, ambas com 8 mm de diâmetro, os coelhos restantes não receberam nenhuma membrana, constituindo o grupo controle. Os animais foram acompanhados clinicamente até 45 dias. Três animais de cada grupo sofreram eutanásia aos três, sete, 21 e 45 dias após o implante das membranas para análise histológica da córnea juntamente com o implante. À observação clínica, houve sinais de processo inflamatório moderado, diminuindo a partir do 20º dia nos grupos implantados. A histologia demonstrou ausência de epitélio sobre as membranas, fibroplasia próxima aos implantes, infiltrado inflamatório linfo-histiocitário com células gigantes, desorganização do colágeno, com predominância de fibras imaturas de colágeno em ambos os grupos com implantes. Embora a resposta inflamatória seja aceitável, as membranas utilizadas não desempenharam satisfatoriamente o papel de substituto tecidual para a córnea, no período estudado.(AU)


Asunto(s)
Animales , Conejos , Órganos Artificiales/estadística & datos numéricos , Órganos Artificiales/veterinaria , Biopolímeros/análisis , Celulosa/análisis , Córnea/cirugía , Gluconacetobacter xylinus , Aloinjertos , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Tratamiento Basado en Trasplante de Células y Tejidos/veterinaria
19.
Rev. enferm. UFPE on line ; 10(5): 4396-4398, maio 2016.
Artículo en Inglés, Portugués | BDENF - Enfermería | ID: biblio-1031709

RESUMEN

Objetivos: conhecer a importância da formação stricto sensu para a atuação do enfermeiro como professor de Enfermagem no Ensino Superior; identificar as características dos programas disciplinares, por meio das ementas do Mestrado Profissional em Ensino na Saúde, que constituem instrumentos de capacitação para o enfermeiro que deseja atuar na docência; enunciar as competências pedagógicas do enfermeiro docente de Ensino Superior na perspectiva da formação stricto sensu. Método: estudo exploratório descritivo, de campo, de abordagem qualitativa. Serão realizadas entrevistas com alunos do Mestrado Profissional em Ensino na Saúde e a coleta de dados contemplará documentos oficiais que regem o programa. A análise será documental e descritiva. Resultados esperados: este estudo busca contribuir com a ampliação e qualificação da formação docente de Enfermagem no Brasil; será desenvolvido um vídeo que demonstre as competências necessárias ao enfermeiro docente.(AU)


Objectives: knowing the importance of stricto sensu education so that a nurse works as a Nursing professor in Higher Education; identifying the characteristics of subject programs, through synopses in the Professional Master's Course in Health Education, which consist in training instruments for a nurse who wishes to become a professor; enunciating the pedagogical skills of a nurse teaching in Higher Education from the perspective of stricto sensu education. Method: descriptive exploratory study, a field investigation with qualitative approach. Interviews are going to be conducted with students from the Professional Master's Course in Health Education and data collection will include official documents governing the program. Expected results: this study seeks to contribute to the expansion and qualification of Nursing professor education in Brazil; a video is going to be developed in order to demonstrate the skills needed by the nurse as a professor.(AU)


Objetivos: conocer la importancia de la formación stricto sensu para que un enfermero trabaje como profesor de Enfermería en la Educación Superior; identificar las características de planes de asignaturas, a través de los sumarios en el Curso de Maestría Profesional en Educación para la Salud, que consisten en instrumentos de formación para un enfermero que desea convertirse en profesor; enunciar las competencias pedagógicas del enfermero docente de Educación Superior desde la perspectiva de la formación stricto sensu. Método: estudio exploratorio descriptivo, una investigación de campo con abordaje cualitativo. Entrevistas van a ser llevadas a cabo con estudiantes del Curso de Maestría Profesional en Educación para la Salud y la recogida de datos incluirá documentos oficiales que rigen el programa. Resultados esperados: este estudio busca contribuir a la expansión y calificación de la educación docente de Enfermería en Brasil; un video va a ser desarrollado con el fin de demostrar las competencias necesarias para un enfermero docente.(AU)


Asunto(s)
Humanos , Masculino , Femenino , Docentes de Enfermería , Educación de Postgrado en Enfermería , Educación en Enfermería , Enfermeras y Enfermeros , Epidemiología Descriptiva
20.
PLoS One ; 10(4): e0119544, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25830928

RESUMEN

Brazil ranked second only to the United States in hectares planted to genetically modified crops in 2013. Recently corn producers in the Cerrado region reported that the control of Spodoptera frugiperda with Bt corn expressing Cry1Fa has decreased, forcing them to use chemicals to reduce the damage caused by this insect pest. A colony of S. frugiperda was established from individuals collected in 2013 from Cry1Fa corn plants (SfBt) in Brazil and shown to have at least more than ten-fold higher resistance levels compared with a susceptible colony (Sflab). Laboratory assays on corn leaves showed that in contrast to SfLab population, the SfBt larvae were able to survive by feeding on Cry1Fa corn leaves. The SfBt population was maintained without selection for eight generations and shown to maintain high levels of resistance to Cry1Fa toxin. SfBt showed higher cross-resistance to Cry1Aa than to Cry1Ab or Cry1Ac toxins. As previously reported, Cry1A toxins competed the binding of Cry1Fa to brush border membrane vesicles (BBMV) from SfLab insects, explaining cross-resistance to Cry1A toxins. In contrast Cry2A toxins did not compete Cry1Fa binding to SfLab-BBMV and no cross-resistance to Cry2A was observed, although Cry2A toxins show low toxicity to S. frugiperda. Bioassays with Cry1AbMod and Cry1AcMod show that they are highly active against both the SfLab and the SfBt populations. The bioassay data reported here show that insects collected from Cry1Fa corn in the Cerrado region were resistant to Cry1Fa suggesting that resistance contributed to field failures of Cry1Fa corn to control S. frugiperda.


Asunto(s)
Bacillus thuringiensis/genética , Proteínas Bacterianas/farmacología , Toxinas Bacterianas/farmacología , Spodoptera/efectos de los fármacos , Spodoptera/fisiología , Zea mays/genética , Animales , Proteínas Bacterianas/genética , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Bioensayo , Biotinilación , Brasil , Membranas Intracelulares/metabolismo , Microvellosidades/metabolismo , Plantas Modificadas Genéticamente , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacología , Spodoptera/citología , Análisis de Supervivencia , Zea mays/microbiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...