285 research outputs found
Avaliação da degradação de polipropileno com aditivos comerciais em diferentes meios de exposição
Polypropylene (PP) is one of the most widely used polymers in the world, mainly due to its versatility, good properties, and low cost. However, since it is not easily degraded in the natural environment, several research projects have been developed to increase its biodegradability. The use of pro-degrading additives has been explored, as they promote the process of polymer degradation. Nevertheless, few studies have evaluated the degradation of these materials in natural aqueous environments such as rivers and lakes, which contain large amounts of PP waste. The goal of this study was to evaluate the degradation of polypropylene, as well as the biodegradation of PP through the incorporation of two additives of different natures, organic and enzymatic. For this purpose, PP blends were produced with 4% additive, which has the purpose of conferring biodegradability to the material, since polypropylene has high resistance to degradation. In order to verify the behavior of the materials against degradation tests with 2 different media (saline and fresh water) for a period of 6 months, the samples were characterized by Fourier Transformed Infrared Spectroscopy and Field emission scanning electron microscopy. The characterizations were carried out in order to verify the changes in the structural characteristics and in the morphology of the materials caused by the incorporation of the additive and by the exposure to the degradation media. From the results obtained, it was observed that the additives influenced the degradation of PP. In addition, the enzyme additive and the saline media caused more significant changes in the properties analyzed, indicating greater influence on the degradation process. It was concluded that the incorporation of commercial additives gives biodegradable properties to PP. Therefore, this study has an important role in the research and development of biodegradable materials in order to minimize the effects caused by plastic waste in the environment. Thus, the studied materials are an alternative in the field of plastic packaging, reducing the effects caused by plastic waste in the environment.O polipropileno (PP) é um dos polímeros mais amplamente utilizados no mundo, principalmente devido à sua versatilidade, boas propriedades e baixo custo. No entanto, como não se degrada facilmente no ambiente natural, vários projetos de pesquisa foram desenvolvidos para aumentar sua biodegradabilidade. O uso de aditivos pró-degradantes tem sido explorado, pois promovem o processo de degradação de polímeros. No entanto, poucos estudos avaliaram a degradação desses materiais em ambientes aquosos naturais, como rios e lagos, que contêm grandes quantidades de resíduos de PP. O objetivo deste trabalho é avaliar a degradação do polipropileno, bem como a biodegradação do PP através da incorporação de dois aditivos de naturezas distintas, orgânica e enzimática. Para este fim, foram produzidas blendas de PP com 4% de aditivo, os quais tem a finalidade de conferir biodegradabilidade ao material, visto que o polipropileno apresenta alta resistência à degradação. No intuito de verificar o comportamento dos materiais frente a ensaios de degradação com 2 diferentes meios (água salina e água doce), por um período de 6 meses, as amostras foram caracterizadas por Espectroscopia de Infravermelho com Transformada de Fourier e por Microscopia Eletrônica de Varredura com Emissão de Campo. As caracterizações foram realizadas com o intuito de verificar as alterações nas características estruturais e na morfologia dos materiais provocadas pela incorporação do aditivo e pela exposição aos meios de degradação. A partir dos resultados obtidos foi observado que os aditivos influenciaram na degradação do PP. Além disso, o aditivo enzimático e o meio salino provocaram alterações mais expressivas nas propriedades analisadas, indicando maior influência sobre o processo de degradação. Concluiu-se que a incorporação dos aditivos comerciais atribui ao PP propriedades biodegradantes. Desta forma, este trabalho possui um importante papel na pesquisa e desenvolvimento de matérias biodegradáveis com o objetivo de minimizar os efeitos causados pelos resíduos plásticos no meio ambiente. Assim, os materiais estudados são uma alternativa no campo das embalagens plásticas, reduzindo os efeitos causados pelos resíduos plásticos no meio ambiente
Avaliação econômica da estação de monta em caprinos utilizando protocolo de sincronização do estro e ração flushing.
Resumo: O objetivo deste estudo foi realizar uma análise econômica do protocolo de sincronização do estro mais a ração flushing oferecida as cabras durante a estação de monta. Foram selecionadas 12 cabras da raça Saanen e um reprodutor, recebendo ração flushing. Utilizou-se esponjas análogas a progesterona, Prostaglandina e Gonadotrofina Coriônica Equina. O custo total foi de R 46,17/animal. The use of protocol of sychronization of estrous is more economically viable the sum natural
Economic indicators of nitrogen fertilization in sunflower cultivars
Sunflower is one of the most important oilseeds in the world. However, cultivation in semi-arid regions requires analysis of production costs and profitability, ensuring effective decision-making, focused on farming procedures and techniques. In two agricultural crops, 2016 and 2017, experiments were conducted to evaluate the economic indicators of sunflower cultivars (‘Aguará 06’, ‘Altis 99’, ‘Multissol’ and ‘BRS 122’) submitted to nitrogen (N) doses (0; 30; 60; 90 and 120 kg ha-1) via fertirrigation under semi-arid conditions. The net margin corresponded to the increase of N doses, reaching a maximum net margin in the 2016 harvest of R 577.41 ha-1 with 118 kg ha-1 of N for ‘Multissol’; and for ‘Aguará 06’ (R 976.66 ha-1) at the dose of 120 kg ha-1 of N. In the 2017 harvest, ‘BRS 122’ obtained R 657.50 in the dose of 85 kg ha-1 of N; the cultivars ‘Aguará 06’ (R 957.14 ha-1) in the dose of 120 kg ha-1 of N. The rate of return and the profitability index were positive for all cultivars in both crops
Gastric bypass versus best medical treatment for diabetic kidney disease: 5 years follow up of a single-centre open label randomised controlled trial
BACKGROUND: We compared the albuminuria-lowering effects of Roux-en-Y gastric bypass (RYGB) to best medical treatment in patients with diabetic kidney disease and obesity to determine which treatment is better. METHODS: A 5 year, open-label, single-centre, randomised trial studied patients with diabetic kidney disease and class I obesity after 1:1 randomization to best medical treatment (n = 49) or RYGB (n = 51). The primary outcome was the proportion of patients achieving remission of microalbuminuria after 5 years. Secondary outcomes included improvements in diabetic kidney disease, glycemic control, quality of life, and safety. For efficacy outcomes, we performed an intention-to-treat (ITT) analysis. This study was registered with ClinicalTrials.gov, NCT01821508. FINDINGS: 88% of patients (44 per arm) completed 5-year follow-up. Remission of albuminuria occurred in 59.6% (95% CI = 45.5–73.8) after best medical treatment and 69.7% (95% CI = 59.6–79.8) after RYGB (risk difference: 10%, 95% CI, −7 to 27, P = 0.25). Patients after RYGB were twice as likely to achieve an HbA1c ≤ 6.5% (60.2% versus 25.4%, risk difference, 34.9%; 95% CI = 15.8–53.9, P < 0.001). Quality of life after five years measured by the 36-Item Short Form Survey questionnaire (standardized to a 0-to-100 scale) was higher in the RYGB group than in the best medical treatment group for several domains. The mean differences were 13.5 (95% CI, 5.5–21.6, P = 0.001) for general health, 19.7 (95% CI, 9.1–30.3, P < 0.001) for pain, 6.1 (95% CI, −4.8 to 17.0, P = 0.27) for social functioning, 8.3 (95% CI, 0.23 to 16.3, P = 0.04) for emotional well-being, 12.2 (95% CI, 3.9–20.4, P = 0.004) for vitality, 16.8 (95% CI, −0.75 to 34.4, P = 0.06) for mental health, 21.8 (95% CI, 4.8–38.7, P = 0.01) for physical health and 11.1 (95% CI, 2.24–19.9, P = 0.01) for physical functioning. Serious adverse events were experienced in 7/46 (15.2%) after best medical treatment and 11/46 patients (24%) after RYGB (P = 0.80). INTERPRETATION: Albuminuria remission was not statistically different between best medical treatment and RYGB after 5 years in participants with diabetic kidney disease and class 1 obesity, with 6–7 in ten patients achieving remission of microalbuminuria (uACR <30 mg/g) in both groups. RYGB was superior in improving glycemia, diastolic blood pressure, lipids, body weight, and quality of life. FUNDING: The study was supported by research grants from Johnson & Johnson Brasil, Oswaldo Cruz German Hospital, and by grant 12/YI/B2480 from Science Foundation Ireland (Dr le Roux) and grant 2015-02733 from the Swedish Medical Research Council (Dr le Roux). Dr Pereira was funded by the Chevening Scholarship Programme (Foreign and Commonwealth Office, UK)
Cost-Effectiveness Analysis for Surgical, Angioplasty, or Medical Therapeutics for Coronary Artery Disease 5-Year Follow-Up of Medicine, Angioplasty, or Surgery Study (MASS) II Trial
Background-The Second Medicine, Angioplasty, or Surgery Study (MASS II) included patients with multivessel coronary artery disease and normal systolic ventricular function. Patients underwent coronary artery bypass graft surgery (CABG, n = 203), percutaneous coronary intervention (PCI, n = 205), or medical treatment alone (MT, n = 203). This investigation compares the economic outcome at 5-year follow-up of the 3 therapeutic strategies. Methods and Results-We analyzed cumulative costs during a 5-year follow-up period. To analyze the cost-effectiveness, adjustment was made on the cumulative costs for average event-free time and angina-free proportion. Respectively, for event-free survival and event plus angina-free survival, MT presented 3.79 quality-adjusted life-years and 2.07 quality-adjusted life-years; PCI presented 3.59 and 2.77 quality-adjusted life-years; and CABG demonstrated 4.4 and 2.81 quality-adjusted life-years. The event-free costs were 19 967.00 for PCI; and 18 263.00 for CABG. The paired comparison of the event-free costs showed that there was a significant difference favoring MT versus PCI (P<0.01) and versus CABG (P<0.01) and CABG versus PCI (P<0.01). The event-free plus angina-free costs were 16 553.00, 24 614.00, respectively. The paired comparison of the event-free plus angina-free costs showed that there was a significant difference favoring MT versus PCI (P=0.04), and versus CABG (P<0.001); there was no difference between CABG and PCI (P>0.05). Conclusions-In the long-term economic analysis, for the prevention of a composite primary end point, MT was more cost effective than CABG, and CABG was more cost-effective than PCI
VARIAÇÃO ESPACIAL DOS ATRIBUTOS FÍSICOS E ESTOQUES DE CARBONO DO SOLO EM PLANTIO DE Schizolobium amazonicum NA AMAZÔNIA
Tree plantations provide an increase in soil carbon stocks, but studies involving native Amazonian species are incipient. The objective was to evaluate the spatial variation of physical attributes and soil organic carbon stock in a paricá plantation. In the study area, soil samples were collected at depths of 0 to 20 cm and 20 to 40 cm and the parameters analyzed were: soil texture, macroporosity, microporosity, soil bulk density, mechanical soil resistance to penetration, and soil organic carbon content and stocks. The data were interpolated by the inverse of the square of the distance. The spatial variation of soil physical attributes at planting was influenced by texture. There was a low range of spatial variation in soil organic carbon content and stocks. Paricá planting was efficient in fixing soil carbon at depth.Plantios de árvores proporcionam aumento dos estoques de carbono do solo, mas estudos envolvendo espécies nativas da Amazônia são incipientes. Objetivou-se avaliar a variação espacial dos atributos físicos e estoque de carbono orgânico no solo em plantio de paricá. Na área de estudo, coletaram-se amostras de solo nas profundidades de 0 a 20 cm e de 20 a 40 cm e os parâmetros analisados foram: textura do solo, macroporosidade, microporosidade, densidade aparente do solo, resistência mecânica do solo à penetração, teores e os estoques de carbono orgânico do solo. Interpolou-se os dados pelo inverso do quadrado da distância. A variação espacial dos atributos físicos do solo no plantio foi influenciada pela textura. Houve baixa amplitude da variação espacial dos teores e estoques de carbono orgânico do solo. O plantio de paricá apresentou eficiência na fixação de carbono no solo em profundidade.
Palavras-chave: silvicultura; sequestro de carbono; física do solo; mudança climática.
Spatial variation of physical attributes and soil carbon stocks in a Schizolobium amazonicum plantation in the amazon
ABSTRACT: Tree plantations provide an increase in soil carbon stocks, but studies involving native Amazonian species are incipient. The objective was to evaluate the spatial variation of physical attributes and soil organic carbon stock in a paricá plantation. In the study area, soil samples were collected at depths of 0 to 20 cm and 20 to 40 cm and the parameters analyzed were: soil texture, macroporosity, microporosity, soil bulk density, mechanical soil resistance to penetration, and soil organic carbon content and stocks. The data were interpolated by the inverse of the square of the distance. The spatial variation of soil physical attributes at planting was influenced by texture. There was a low range of spatial variation in soil organic carbon content and stocks. Paricá planting was efficient in fixing soil carbon at depth.
Keywords: silviculture; carbon sequestration; soil physics; climate change
Perfil sorológico do vírus John Cunningham (JCV) em pacientes com esclerose múltipla
Treatment options for multiple sclerosis (MS) have changed over the last few years, bringing about a new category of drugs with more efficient profiles. However, these drugs have come with a whole new profile of potential adverse events that neurologists have to learn well and quickly. One of the most feared complications of these MS treatments is progressive multifocal leukoencephalopathy caused by the reactivation of the John Cunningham virus (JCV). Objective: To identify the serologic profile of JCV in patients with MS. Methods: Data on serum antibodies for JCV were obtained using the enzyme-linked immunosorbent assay provided by the STRATIFY-JCV program. Results: A total of 1,501 blood tests were obtained from 1,102 patients with MS. There were 633 patients (57.1%) who were positive for antibodies for JCV and 469 patients who were negative (42.9%). Twenty-three patients became positive after initially having negative JCV antibody status. The rate of seroconversion was 18.5% over 22 months. Conclusion: The JCV serologic profile and seroconversion in Brazilian patients were similar to those described in other countries.As opções terapêuticas para esclerose múltipla (EM) modificaram-se ao longo dos últimos anos, trazendo uma nova categoria de drogas com melhor perfil de eficácia. No entanto, estas drogas vieram com um novo perfil de potenciais eventos adversos que exigem que o neurologista os reconheça bem e rapidamente. Uma das complicações mais temidas destes tratamentos para a EM é a leucoencefalopatia multifocal progressiva (LEMP), causada pela reativação do vírus John Cunningham (JCV). Objetivo: Identificar o perfil sorológico de JCV em pacientes com EM. Métodos: Dados sorológicos de JCV foram obtidos através do ensaio por enzimas imuno-adsorvidas (ELISA) fornecido pelo programa STRATIFY-JCV. Resultados: Um total de 1.501 testes sanguíneos foram obtidos de 1.102 pacientes com EM. O grupo teve 633 pacientes (57,1%) soropositivos para anticorpos anti-JCV e 469 pacientes negativos (42,9%). Vinte e três pacientes se tornaram posivitos após resultados iniciais negativos para anticorpos anti-JCV. A taxa de soroconversão foi 18,5% em 22 meses. Conclusão: O perfil sorológico do JCV e a soroconversão nos pacientes brasileiros foi semelhante àquela descrita em outros países
Prevalência e fatores associados à infecção pelo Mycobacterium tuberculosis entre agentes comunitários de saúde no Brasil, usando-se a prova tuberculínica
Variáveis de impacto na queda da mortalidade infantil no Estado de São Paulo, Brasil, no período de 1998 a 2008
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