435 research outputs found

    Essential role of the czc determinant for cadmium, cobalt and zinc resistance in Gluconacetobacter diazotrophicus PAl 5

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    The mechanisms of cadmium, cobalt and zinc resistance were characterized in the plant-growth-promoting bacterium Gluconacetobacter diazotrophicus PAl 5. The resistance level of the wild-type strain was evaluated through the establishment of minimum inhibitory concentrations (MIC) of the soluble compounds CdCl2·H2O, CoCl2·6H2O and ZnCl2. Gluconacetobacter diazotrophicus PAl 5 was resistant to high concentrations of Cd, Co and Zn, with MICs of 1.2, 20 and 20 mM, respectively. Screening of an insertion library from transposon EZ-Tn5<R6Kyori/KAN-2> in the presence of ZnO revealed that the mutant GDP30H3 was unable to grow in the presence of the compound. This mutant was also highly sensitive to CdCl2·H2O, CoCl2·6H2O and ZnCl2. Molecular characterization established that the mutation affected the czcA gene, which encodes a protein involved in metal efflux. In silico analysis showed that czcA is a component of the czcCBARS operon together with four other genes. This work provides evidence of the high tolerance of G. diazotrophicus PAl 5 to heavy metalsand that czc is a determinant for metal resistance in this bacterium. [Int Microbiol 2012; 15(2):69-78

    O impacto das variáveis cognitivas no rendimento escolar

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    Nesta comunicação propomo-nos: (i) discutir o conceito de inteligência no âmbito da psicometria; (ii) analisar em que medida os desempenhos cognitivo e escolar se relacionam; (iii) analisar a importância das variáveis cognitivas na predição do rendimento escolar; e (iv) discutir que aptidões cognitivas específicas (conteúdos) assumem maior relevo no rendimento escolar. Este estudo considerou uma amostra representativa de estudantes portugueses entre o 5º e o 12º ano de escolaridade (n= 4899). Os estudantes realizaram os subtestes que integram a Bateria de Provas de Raciocínio (BPR) na versão apropriada ao seu nível escolar. Juntos dos serviços escolares, obtivemos as classificações escolares destes alunos nas disciplinas de Português e Matemática. Os coeficientes de correlação entre o desempenho cognitivo e o rendimento escolar sugerem uma maior associação entre as habilidades cognitivas e o rendimento escolar nas disciplinas cujo conteúdo curricular mais se aproxima dos conteúdos dos itens das provas. Para além disso, observa-se uma progressiva diminuição nos coeficientes de correlação à medida que se avança na escolaridade, sugerindo uma menor importância das variáveis cognitivas para o rendimento escolar nos níveis de escolaridade mais elevados. Por último, os resultados sugerem que mais do que os processos cognitivos parece ser importante o conteúdo das tarefas, à medida que se avança na escolaridade. Neste sentido, se explica as correlações mais elevadas envolvendo as provas de raciocínio verbal e de raciocínio numérico ao longo dos vários anos de escolaridade.Fundação para a Ciência e a Tecnologia (FCT

    The effect of excess fluid balance on the mortality rate of surgical patients: a multicenter prospective study

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    INTRODUCTION: In some studies including small populations of patients undergoing specific surgery, an intraoperative liberal infusion of fluids was associated with increasing morbidity when compared to restrictive strategies. Therefore, to evaluate the role of excessive fluid infusion in a general population with high-risk surgery is very important. The aim of this study was to evaluate the impact of intraoperative fluid balance on the postoperative organ dysfunction, infection and mortality rate. METHODS: We conducted a prospective cohort study during one year in four ICUs from three tertiary hospitals, which included patients aged 18 years or more who required postoperative ICU after undergoing major surgery. Patients who underwent palliative surgery and whose fluid balance could change in outcome were excluded. The calculation of fluid balance was based on preoperative fasting, insensible losses from surgeries and urine output minus fluid replacement intraoperatively. RESULTS: The study included 479 patients. Mean age was 61.2 ± 17.0 years and 8.8% of patients died at the hospital during the study. The median duration of surgery was 4.0 (3.2 to 5.5) h and the value of the Simplified Acute Physiology Score (SAPS) 3 score was 41.8 ± 14.5. Comparing survivors and non-survivors, the intraoperative fluid balance from non-survivors was higher (1,950 (1,400 to 3,400) mL vs. 1,400 (1,000 to 1,600) mL, P <0.001). Patients with fluid balance above 2,000 mL intraoperatively had a longer ICU stay (4.0 (3.0 to 8.0) vs. 3.0 (2.0 to 6.0), P <0.001) and higher incidence of infectious (41.9% vs. 25.9%, P = 0.001), neurological (46.2% vs. 13.2%, P <0.001), cardiovascular (63.2% vs. 39.6%, P <0.001) and respiratory complications (34.3% vs. 11.6%, P <0.001). In multivariate analysis, the fluid balance was an independent factor for death (OR per 100 mL = 1.024; P = 0.006; 95% CI 1.007 to 1.041). CONCLUSIONS: Patients with excessive intraoperative fluid balance have more ICU complications and higher hospital mortality

    QUANTIFICATION OF RESIDUAL CLOVE OIL, BENZOCAINE AND TRICAINE IN FISH FILLETS USING SPE AND UPLC-DAD

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    Residual quantification of the anesthetics clove oil (CO) – isoeugenol (ISO), eugenol (EUG) and methyleugenol (MET) –,benzocaine (BZN) and tricaine (MS-222) was made in fillets of two fish species: Nile tilapia (Oreochromis niloticus) and acatfish hybrid, cachadia (Pseudoplatystoma reticulatum x Leiarius marmoratus). Samples (n=4) of each fish wereevaluated after submitted to anesthesia in five dosages defined based on the induction time of each species afterdepuration times (0h, 12h, 24h and 48h). Different methodologies of sample preparation were tested and selectedaccording to the better recovery. The quantification of anesthetics was performed by UPLC-DAD. The variance of residualmeans among anesthetics, dosages and fish species was compared. After anesthesia (0h) both species, tilapia andcachadia, presented residual anesthetics. Fishes depurated during 12h, 24h and 48h did not present detectable values, itmeans, values were below the limits of detection. BZN presented the highest mean residual concentration for tilapia andcachadia (p=0.01), while MS-222 presented the lowest residual amounts in tilapias and EUG in cachadias, what may berelated to the metabolism and carcass composition of each fish species. There were no significant differences among thefive dosages, except the lowest MS-222 concentration in tilapias that resulted in higher residual concentrations becauselow dosages increase the induction time and consequently the permanence of the fish in anesthesia. Ultimately, meanvalues of residues in cachadia were higher than in tilapia, and MS-222 and EUG presented the lowest residual values fortilapia and cachadia, respectively

    Transfer?ncia de tecnologia como agente desenvolvedor da cultura de inova??o na UFMG.

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    O presente trabalho tem por objeto as pol?ticas de fomento ? transfer?ncia de tecnologias a partir da ?tica da gest?o de patentes, tipo de inova??o das tecnologias desenvolvidas e grau de participa??o empreendedora de docentes. Para tanto, foi realizado um estudo de caso em que foi realizada uma an?lise descritiva do N?cleo de Inova??o da UFMG, visando identificar e analisar a pertin?ncia das tecnologias produzidas pela UFMG entre 2012 a 2017. A escolha da UFMG como fonte de dados se deu por esta institui??o apresentar a maior quantidade de patentes registradas no Brasil e tamb?m por se tratar da institui??o a que dois dos pesquisadores est?o afiliados. Os resultados apontam que, investindo em transfer?ncias de tecnologias, a institui??o fomenta a cultura da inova??o, fortalecendo tamb?m a cultura empreendedora e a preocupa??o com a prote??o de tecnologias.This study's purpose is promotion of policies for technology transfer from the perspective of patent management, kind of innovation of technologies developed and degree of entrepreneurial participation of teachers. A case study was carried out in which a descriptive analysis of the Innovation Center of UFMG was carried out to identify and analyze the relevance of the technologies produced by UFMG between 2012 and 2017. The choice of UFMG as data source was given by this institution presents the largest number of patents registered in Brazil and also because it is the institution to which two of the researchers are affiliated. The results show that by investing in technology transfer, the institution fosters a culture of innovation, also strengthening the entrepreneurial culture and concern for the protection technologies

    QUALIDADE HIGIÊNICO-SANITÁRIA DA TILÁPIA (Oreochromis spp.) FRESCA E CONGELADA EM MERCADOS PÚBLICOS

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    Objetivou-se verificar a qualidade higiênico-sanitária da tilápia (Oreochromis spp.), comercializada em mercados públicos do município de Mossoró-RN. Para isso, foi realizado, através de checklist,  um estudo observacional, para avaliação das boas práticas de manipulação em 10 estabelecimentos de comercialização do peixe. Foram obtidas 30 amostras de tilápia avaliadas quanto aos aspectos sensoriais, microbiológicos (Salmonella spp., coliformes a 45 ºC, contagem de Staphylococcus ssp., bactérias psicrotróficas e enterobactérias) e quanto ao pH e temperatura interna e externa. Observou-se que nenhum dos estabelecimentos apresentou conformidade com os padrões recomendados pela legislação. Já em relação à avaliação sensorial, 83,3% das amostras analisadas apresentavam conformidade com  as exigências da legislação. Quanto à pesquisa de coliformes a 45 ºC, os resultados variaram de 0,477 a 1,509 log10 UFC/g, na pesquisa de Staphylococcus spp., de 4,854 a 5,397 log10 UFC/g e ainda 3,884 a 4,937 e 4,707 a 5,463 log10UFC/g para enterobactérias e psicrotróficas, respectivamente. As amostras apresentaram-se dentro do exigido para a contaminação por Salmonella spp.(ausência). O   pH variou de 5,99 a 6,18 e as temperaturas indicaram desconformidade com o recomendado. Assim, a qualidade higiênico-sanitária da tilápia comercializada em mercados públicos de Mossoró-RN estava comprometida, apresentando risco à saúde do consumidor pelas condições insatisfatórias. Palavras-chave: boas práticas; físico-química; microbiologia

    Bacterial and Archaeal Communities Change With Intensity of Vegetation Coverage in Arenized Soils From the Pampa Biome

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    Arenization occurs in regions that present sandy soils with normal rainfall levels. Predatory use of environmental sources, the dissolution of arenitic rocks and reworking of non-consolidated surface sands intensify this degradation scenario. Thus, this work aimed to evaluate the impact of the arenization process in the Brazilian Pampa Biome and how this phenomenon affects the soil microbial and plant communities. For this purpose, three arenized areas in Southern Brazil (Pampa Biome) were selected and, in each one, three sampling points were studied: arenized (ARA), arenized to grassland transition (AGT), and grassland (GRA) areas. In the three sampling points, soils presented low levels of nutrients, organic matter, mud and pH acidic in all regions but, the presence of vegetation coverage in AGT and GRA areas preserved the topsoil structure. Our study related ARA with bacterial families Alcaligenaceae, Pseudomonadaceae, and Xanthomonadaceae. AGT with bacterial families Bacillaceae and Burkholderiaceae, and plant species Melinis repens (Willd.) Zizka and Paspalum stellatum Humb. and Bonpl. ex Flüggé, and GRA with bacterial families Koribacteraceae, Hyphomicrobiaceae, and Chthoniobacteraceae, and plant species Croton subpannosus Müll.Arg. ex Griseb., Piptochaetium montevidense (Spreng.) Parodi and Elyonurus sp. The three studied areas (as well as sampling points) present soils extremely poor in nutrients with sandy texture, and the bacterial and plant composition well known to be resistant to environmental stresses were dominant. The vulnerability of these areas causes a degradation scenario, which is worsened by agricultural activities. However, in general, this phenomenon is a natural process that occurs mainly due to soil characteristics (poor soils) and climatic variations

    The VISCACHA survey : III. Star clusters counterpart of the Magellanic Bridge and Counter-Bridge in 8D

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    Context. The interactions between the Small and Large Magellanic Clouds (SMC and LMC) created the Magellanic Bridge; a stream of gas and stars pulled out of the SMC towards the LMC about 150 Myr ago. The tidal counterpart of this structure, which should include a trailing arm, has been predicted by models but no compelling observational evidence has confirmed the Counter-Bridge so far. Aims. The main goal of this work is to find the stellar counterpart of the Magellanic Bridge and Counter-Bridge. We use star clusters in the SMC outskirts as they provide a 6D phase-space vector, age, and metallicity which help characterise the outskirts of the SMC. Methods. Distances, ages, and photometric metallicities were derived from fitting isochrones to the colour-magnitude diagrams from the VISCACHA survey. Radial velocities and spectroscopic metallicities were derived from the spectroscopic follow-up using GMOS in the CaII triplet region. Results. Among the seven clusters analysed in this work, five belong to the Magellanic Bridge, one belongs to the Counter-Bridge, and the other belongs to the transition region. Conclusions. The existence of the tidal counterpart of the Magellanic Bridge is evidenced by star clusters. The stellar component of the Magellanic Bridge and Counter-Bridge are confirmed in the SMC outskirts. These results are an important constraint for models that seek to reconstruct the history of the orbit and interactions between the LMC and SMC as well as constrain their future interaction including with the Milky Way

    Inhibition of Saccharomyces cerevisiae Pdr5p by a natural compound extracted from Brazilian Red Propolis

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    Abstract: Multidrug resistance of cancer cells and pathogenic microorganisms leading to the treatment failure of some forms of cancer or life-threatening bacterial or fungal infections is often caused by the overexpression of multidrug efflux pumps belonging to the ATP-binding cassette transporters superfamily. The multidrug resistance of fungal cells often involves the overexpression of efflux pumps belonging to the pleiotropic drug resistance (PDR) family of ABC transporters. Possibly the best-studied fungal PDR transporter is the multidrug resistance transporter Pdr5p of Saccharomyces cerevisiae. Some research groups have been searching for new inhibitors of these efflux pumps in order to alleviate resistance. Natural products are a great source for the discovery of new compounds with biological activity. Propolis is a complex resinous material collected by honeybees from exudates and buds of certain plant sources and this material is thought to serve as a defense substance for bee hives. Propolis is widely used in traditional medicine and is reported to have a broad spectrum of pharmacological properties. Literature reported some biological functionalities of propolis, such as antibacterial, antiviral, fungicidal, antiinflammatory and anti-carcinogenic activities. The chemical composition of propolis is qualitatively and quantitatively variable. Components isolated from methanolic extract of red Brazilian propolis (Alagoas, Northeast of Brazil) are isoflavonoids (including pterocarpans, isoflavans, isoflavones), flavanones and polyprenylated benzophenones. In this work we demonstrated the effects of five different isolated compounds on the ATPase activity of Pdr5p. Out of all five substances tested, only BRP-1 was able to completely abolish the enzymatic activity while others worked as positive modulators of the enzyme activity. BRP-1also inhibited the efflux of Rhodamine 6G from yeast cells overexpressing Pdr5p. Taken together, these results demonstrate that Brazilian propolis could be a source of promising compounds that can alleviate the MDR phenomenon, particularly in some fungi, where it could be used as an adjuvant for the treatment with azoles
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