313 research outputs found

    Application of endograft to treat thoracic aortic pathologies: A single center experience

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    PurposeTo evaluate our experience of thoracic endoluminal graft (ELG) repair of various thoracic aortic pathologies using a commercially available device approved by the Food and Drug Administration. Our patient population includes patients eligible for open surgical repair and those with prohibitive surgical risk.MethodsFrom March 1998 to March 2006, endovascular stent repair of the thoracic aorta was performed on 406 patients with 324 patients (median age 72; 200 male) receiving the Gore Excluder endograft. Patient demographics, procedural characteristics, complications, including endoleak, spinal cord ischemia, and mortality, were retrospectively reviewed during follow-up. All patients were followed with chest computer tomography at 6 months and yearly. Statistical analysis was performed utilizing the SPSS Windows 11.0 program. Logistic regression (univariate) analysis used to identify risk factors for paraplegia; analysis of variance (ANOVA) for endoleak distribution; and χ2 used to analyze variables. Survival analysis was done using SAS version 9.1 (SAS Institute, Cary, NC).ResultsThree hundred twenty-four patients were treated with Gore Excluder graft between March 1998 and March 2006. One hundred fifty-seven patients (48.5%) had atherosclerotic aneurysms, 82 (25.3%) had dissections type B (DTB), 34 (10.5%) had penetrating ulcers (PU), 26 (8.0%) with pseudoaneurysms (PSA), 11 (3.4%) had transections (MVAT), 9 (2.8%) aorto-bronchial fistulas (AoBF), 4 (1.2%) embolization, and 1 (0.3%) aorto-esophageal fistula (AoEF). Preoperative aneurysm sac size in TAA ranged from 5 to 12 centimeters, average size 6.3 cm. Sac shrinkage occurred in 65% (102 of 157) of patients. Average postoperative sac size of 5.4 cm in a mean follow-up of 20.4 months. One hundred cases (31.5%) were nonelective; 49 (15.1%) were ruptures. Overall complication was 22.7%, 14.2% (46) in elective cases and 8.5% (28) in nonelective cases. Paraplegia occurred in five (1.5%) patients and paresis in three (0.9%); two of the latter improved and one resolved completely prior to discharge. Incidence of paraplegia was statistically significant (P value < .05) with retroperitoneal approach, perioperative blood loss greater than 1000 cc, and aortic coverage greater than 40 cm. Early endoleaks included 18 (5.5%) type I, four (1.2%) type II, and two (0.6%) type III. Thirty-day mortality was 5.5% (18 related deaths, including three intraoperative deaths). A log rank test did not find statistical differences in actuarial survival with 30-day related mortality between TAA and other pathologies (P = .29) or between DTB and other pathologies (P = .97). Late mortality was 9.6% with 31 unrelated deaths. Follow-up ranged between 1 month and 70 months, average 17 months.ConclusionsEndoluminal grafting is a feasible alternative to open surgical repair for thoracic aortic pathologies. After more than 300 cases, 30-day morbidity and mortality compares favorably with open repair. Paraplegia remains low as a complication and increases in incidence with retroperitoneal approach, increased perioperative blood loss, and increased aortic coverage

    Biotite (Black Mica) as an Adsorbent of Pesticides in Aqueous Solution

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    Chemical contamination of water resources on the planet generates a range of environmental disturbances which impair ecosystems. Humans ingest such chemicals often present in water. Conventional treatments fail to remove these contaminants from water, requiring complementary methods such as activated carbon filters, reverse osmosis, or distillation, which are expensive and seldom used in the public water supply. In recent years, there has been a search for alternative eco-friendly, low-cost methods which can effectively remove these contaminants. This study was conducted to test the effectiveness of biotite (black mica), an igneous mineral of the mica group, in removing pesticides from water. A trial was designed to assess the rate of pesticide removal using a methodology based on axes of variation of pH, temperature, concentration,and time. The pesticides tested were atrazine, fluazifopp- butyl, lambda-cyhalothrin, chlorpyrifos, and lactofen. The results showed higher removal rates in acidic conditions (pH 3) and temperatures between 20 and 30 °C, requiring about 6 h to reach maximum adsorption. More than 80 % of all the pesticides were adsorbed. The best result was obtained for fluazifop (94.2 %) in 6 h, under pH 3, and temperature of 25 °C. The study revealed that biotite has a high absorption capacity of complex and varied compounds. These findings signal the need for further studies and tests. Due to the high cost of pesticide analysis, which can only be made using a chromatograph mass spectrometer, financial resources will be required.CNPq (National Counsel of Technological and Scientific Development-Brazil) for the scholarship granted

    Aplicação da metodologia P+L na redução de desperdícios dentro das empresas de beneficiamento de tabaco

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    The production, marketing and processing of tobacco are the base of the municipalities of Vale do Rio Pardo / RS economy. Although it is the raw material for various products, this region is intended almost exclusively for the production of cigarettes. Dominated by a few large multinational, this market moves this imposing financial values, where tobacco is much of the cost of production. Thus, this paper seeks to prove the efficiency of the methodology application Cleaner Production (CP) in tobacco waste reduction within the tobacco processing and cigarette manufacturing companies. This analysis was conducted as a case study, carrying out visits to the knowledge production process, identifying the points of waste, taking measurements and developing a set of measures to be taken to minimize these losses. The Cleaner Production method was chosen because it is a relatively new concept and it has shown good results in companies where it is located. Through the measurements, the main points of breaks were identified and then an analysis was performed by applying the concepts of CP, and a set of measures has been proposed to reduce losses. As a result, it was achieved a reduction of 83% in the rate of tobacco waste in the production process. It was concluded that the CP, within the tobacco processing industry, was efficient, impacting directly on production costs, rationalizing the use of raw materials and reducing the total volume of waste generated.A produção, comercialização e beneficiamento do tabaco são à base da economia dos municípios do Vale do Rio Pardo/RS. Apesar de ser matéria-prima para diversos produtos, nesta região destina-se quase que exclusivamente para a produção de cigarros. Dominado por um pequeno número de grandes multinacionais, esse mercado movimenta imponentes valores financeiros, onde o tabaco representa grande parte do custo de produção. Sendo assim, o presente trabalho busca comprovar a eficiência da aplicação da metodologia P+L na redução de desperdícios de tabaco dentro das empresas de beneficiamento e fabricação de cigarros. Esta análise foi realizada na forma de um estudo de caso, realizando-se visitas para conhecimento do processo produtivo, identificação dos pontos de desperdício, realização de medições e desenvolvimento de um conjunto de medidas a serem tomadas para minimizar estas perdas. A Produção mais Limpa (P+L) foi o método escolhido por ser um conceito relativamente novo e que vem apresentando bons resultados nas empresas onde é implantada. Através das medições realizadas, os principais pontos de quebras foram identificados e em seguida uma análise foi realizada aplicando-se os conceitos da P+L, e um conjunto de medidas foi proposto para redução das perdas. Como resultado, conseguiu-se uma redução de 83% no índice de desperdício de tabaco dentro do processo produtivo. Concluiu-se que a P+L, dentro da indústria de beneficiamento de tabaco, mostrou-se eficiente, impactando diretamente nos custos de produção, racionalizando a utilização de matéria-prima e reduzindo o volume total de resíduos gerados

    Genomics and epidemiology of the P.1 SARS-CoV-2 lineage in Manaus, Brazil

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    Cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Manaus, Brazil, resurged in late 2020 despite previously high levels of infection. Genome sequencing of viruses sampled in Manaus between November 2020 and January 2021 revealed the emergence and circulation of a novel SARS-CoV-2 variant of concern. Lineage P.1 acquired 17 mutations, including a trio in the spike protein (K417T, E484K, and N501Y) associated with increased binding to the human ACE2 (angiotensin-converting enzyme 2) receptor. Molecular clock analysis shows that P.1 emergence occurred around mid-November 2020 and was preceded by a period of faster molecular evolution. Using a two-category dynamical model that integrates genomic and mortality data, we estimate that P.1 may be 1.7- to 2.4-fold more transmissible and that previous (non-P.1) infection provides 54 to 79% of the protection against infection with P.1 that it provides against non-P.1 lineages. Enhanced global genomic surveillance of variants of concern, which may exhibit increased transmissibility and/or immune evasion, is critical to accelerate pandemic responsiveness

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe
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