Development of a sequential injection system for the determination of nitrite and nitrate in waters with different salinity: Application to estuaries in NW Portugal

In this work, a sequential injection methodology for monitoring nitrite and nitrate in estuarine waters without any previous treatment is described. The developed system was applied to the measurement of nitrite and nitrate in estuarine waters of three rivers in the NW Portugal, allowing an automatic, fast (ca 60 h 1) and precise method (relative standard deviation lower than 2%). The procedure was based on the reaction between nitrite, sulfanilamide and N-(1-naphthyl)-ethylenediamine dihydrochloride (N1NED), whereas the determination of nitrate resulted from its reduction to nitrite, using an in-line cadmium column, followed by the same reaction. The samples were collected in three locations for each river (Douro, C avado and Ave) covering the lower, middle and upper section of the estuaries. Despite the presence of a salinity gradient, this parameter showed no interference in the accuracy of the determinations. The results obtained for the described method for nitrite were statistically comparable to those obtained by the reference procedure. For the determination of nitrate, recovery tests confirmed that the sequential injection methodology provided good quality results.info:eu-repo/semantics/publishedVersio

Forage intake and botanical composition of feed for cattle fed Brachiaria/legume mixtures

Uma contribuição fundamental para o estudo da ciclagem de nutrientes no sistema solo/planta/ animal é a avaliação do consumo pelo gado de forragem e dos nutrientes nela contidos. Testaram-se, sob condições controladas, técnicas para avaliar a produção fecal, digestibilidade in vitro, consumo de forragem e a proporção de leguminosa ingerida na dieta. Cinco novilhos de Zebu foram confinados e alimentados com quantidades conhecidas de cinco rações com diferentes proporções de Brachiaria dictyoneura e Desmodium ovalifolium. Todas as fezes bovinas foram recolhidas e pesadas e estes valores foram comparáveis com as estimativas da produção fecal derivadas do uso da técnica de óxido de cromo. A digestibilidade in vitro variou de 7 a 10% acima da digestibilidade in vivo atual. Amostras de fezes de novilhos alimentados com dietas com 25% ou mais de capim na mistura apresentaram abundância de 13C por entre 1,7 e 2,1, mas este empobrecimento isotópico não foi observado quando a dieta era com 100% D. ovalifolium. Houve correlação positiva linear (r² = 0,97***) entre δ13C da dieta com o δ13C das fezes, mas o conteúdo de leguminosa foi subestimado em mais de 10% quando a dieta ingerida foi de 100% de leguminosa. Nenhum dos indicadores internos, como o conteúdo de lignina ou cinzas, foram úteis para prever o consumo de forragem, mas os resultados da técnica utilizando óxido crômico como indicador externo foram satisfatórios. A abundância de 13C das fezes foi indicador adequado da proporção da leguminosa na dieta.A key contribution to study the cycling of nutrients in soil/plant/animal systems is the evaluation of the consumption of forage and their nutrients by cattle. The objective of this study was to test techniques to evaluate faecal production, in vitro digestibility, forage consumption and the proportion of legume in the acquired diet. Five Zebu steer calves were confined and fed five diets of different combinations of Brachiaria dictyoneura and Desmodium ovalifolium. All quantities of faeces were collected per animal and these values were found to compare favourably with those derived from using the chromium oxide technique. In vitro digestibility ranged from 7 to 10% higher than the actual in vivo digestibility. Faecal samples from steers fed with diets with 25% or more of grass in the mixture were found to be depleted in δ13C between 1.7 and 2.1, but no depletion was observed when the diet was 100% D. ovalifolium. There was a positive linear regression (r² = 0.97***) of the δ13C of the diet with the δ13C of faeces, but if the acquired diet contained a very high proportion of legume, the legume content could be underestimated by as much as 10%. None of the internal indicators, such as lignin or ash content of the diets, were useful to predict feed intake, but the chromium oxide external indicator performed satisfactorily. The 13C analysis of the faeces was an effective predictor of the proportion of the legume in the consumed diet

Fixação biológica de nitrogênio e fertilizantes nitrogenados no balanço de nitrogênio em soja, milho e algodão

The subject of this work was to evaluate the effect of biological nitrogen fixation (BNF) of soybean, and the nitrogen fertilizer use efficiency (NFUE) by maize and cotton, on the N balance of an Oxisol (Typic Haplorthox) under no-tillage, in Dourados, MS. The study was carried out for two consecutive years, focusing the summer crops. The BNF contribution to soybean was evaluated by the 15N natural abundance technique. The NFUE was evaluated by the substitution of conventional N fertilizers used for maize and cotton crops by 15N enriched ones. In the first year, both crops were fertilized with 115 kg N ha-1 split in three doses; only plant aerial parts were evaluated. In the second year, only the maize crop was evaluated and received 70 kg ha-1 N, as a dressing fertilization at 29 DAE. In that year, the aerial part of maize plants and the soil of a 0–20 cm layer were evaluated. For two consecutive harvests, the BNF contribution to soybean was over 80%, bringing about high yields and a positive N balance to the soil. In the first year, NFUE for aerial parts of maize and cotton were 48 and 61%, respectively. In the second year, NFUE for maize was 46%, and the soil layer of 0–20 cm also retained 24% of de N fertilizer applied. For the yield levels of maize and cotton, the fertilizer management results in negative N balances to the soil.O objetivo deste trabalho foi avaliar os efeitos da fixação biológica de nitrogênio (FBN) da cultura da soja, e a eficiência do uso de fertilizantes nitrogenados (EUFN) pelas culturas de milho e algodão, no balanço de N de um Latossolo Vermelho distroférrico, sob plantio direto, em Dourados, MS. O estudo foi feito em dois anos, concentrando-se nas safras de verão. A contribuição da FBN para a soja foi avaliada pela técnica de abundância natural de 15N. A EUFN foi avaliada mediante a substituição dos fertilizantes nitrogenados convencionais pelos enriquecidos com 15N, nas culturas do milho e algodão. No primeiro ano, foram adicionados 115 kg ha-1 de N, de forma parcelada, para ambas as culturas; somente a parte aérea das plantas foi avaliada. No segundo ano, somente a cultura do milho foi avaliada, tendo recebido 70 kg ha-1 de N aos 29 DAE. Nesse ano, além da parte aérea do milho, amostrou-se também o solo, na profundidade de 0–20 cm. Nos dois anos de avaliação, a FBN foi superior a 80% do N nas plantas de soja, o que resultou em alta produtividade e em balanço positivo de N para o solo. A EUFN na parte aérea de milho e algodão, no primeiro ano, foi de 48 e 61%, respectivamente. No segundo ano, a EUFN, na parte aérea do milho, foi de 46%, tendo-se observado que 24% do N do fertilizante permaneceu nos primeiros 20 cm de solo. Para os níveis de produtividade das culturas de milho e algodão, o manejo do fertilizante nitrogenado resulta em balanços negativos de N para o solo

Response of patients with acute respiratory failure caused by COVID-19 to awake-prone position outside the intensive care unit based on pulmonary involvement

OBJECTIVES: Since there are difficulties in establishing effective treatments for COVID-19, a vital way to reduce mortality is an early intervention to prevent disease progression. This study aimed to evaluate the performance of patients with COVID-19 with acute hypoxic respiratory failure according to pulmonary impairment in the awake-prone position, outside of the intensive care unit (ICU). METHODS: A prospective observational cohort study was conducted on COVID-19 patients under noninvasive respiratory support. Clinical and laboratory data were obtained for each patient before the treatment and after they were placed in the awake-prone position. To identify responders and non-responders after the first prone maneuver, receiver operating characteristic curves with sensitivity and specificity of the PaO2/FiO2 and SpO2/FiO2 indices were analyzed. The maneuver was considered positive if the patient did not require endotracheal intubation for ventilatory assistance. RESULTS: Forty-eight patients were included, and 64.6% were categorized as responders. The SpO2/FiO2 index was effective for predicting endotracheal intubation in COVID-19 patients regardless of lung parenchymal damage (area under the curve 0.84, cutoff point 165, sensitivity 85%, specificity 75%). Responders had better outcomes with lower hospital mortality (hazard ratio [HR]=0.107, 95% confidence interval [CI]: 0.012-0.93) and a shorter length of stay (median difference 6 days, HR=0.30, 95% CI: 0.13-0.66) after adjusting for age, body mass index, sex, and comorbidities. CONCLUSIONS: The awake-prone position for COVID-19 patients outside the ICU can improve oxygenation and clinical outcomes regardless of the extent of pulmonary impairment. Furthermore, the SpO2/FiO2 index discriminates responders from non-responders to the prone maneuver predicting endotracheal intubation with a cutoff under or below 165. &nbsp

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Use of subepithelial conjunctive tissue graft in root covering

Gingival recession may cause cosmetic changes and root hypersensitivity, which can alter mastication and tooth brushing, and thus contribute to the progression of periodontal disease. Treatment of gingival recessions with subepithelial conjunctive tissue grafting is very predictable due to its bilaminar nature. However, some factors may influence the success of the procedure, among them: selection of the lesion; characteristics of the defect with regard to the depth and width of the recession, the deeper and wider the recession, the worse the prognosis, and also the presence of restorations. Furthermore, it is necessary to control the etiologic factors of recessions, such as inflammation and traumatic brushing, control of systemic factors, occlusal trauma, smoking and harmful habits, technical considerations and asepsis. The success of the procedure must be based on observing the possible factors that might influence their predictability, as well as respecting the basic principles of mucogingival surgery

Qualidade de dados em gestão de dados de pesquisa: um estudo bibliométrico

Research data management is recognized by the scientific community as an important part of best practices in research, so that these data should be available for access and reuse. Within the context of research data management, data curation and data quality are understood as strategic elements. This work aims to characterize and specify the existing scientific production on the theme “data quality in research data management” through the measurement of bibliometric indicators. In methodological terms, this research has a quantitative and qualitative nature, is exploratory in its objectives and uses the Web of Science and Scopus databases to compose the corpus of the bibliometric study. As a result, it was identified from a corpus of 77 articles a period of relevant publications between the years 1984 and 2020, being 2019 the year with more published works. Additionally, 7 publication vehicles presented more than one publication for the researched topic, being the United States the country with more published papers, totaling 34 articles. The area of Computer Science was the one that produced the most on this topic and constitutes a trend in its interdisciplinarity with biological, applied social and health sciences. Finally, we conclude that, based on the awareness that data quality is a relative parameter, the implementation of research data management services must go through preparation, focusing on meeting requirements such as those concerning the domain and the intended uses.A gestão dos dados de pesquisa é reconhecida pela comunidade científica como parte importante das boas práticas de pesquisa. Desta maneira, acredita-se que os mesmos devem estar sempre disponíveis para acesso e reuso. Neste contexto, a curadoria e a qualidade de dados são entendidas como elementos estratégicos. Este trabalho tem como objetivo caracterizar e especificar a produção científica existente sobre o tema “qualidade de dados em gestão de dados de pesquisa”, por meio da aferição de indicadores bibliométricos. Em termos metodológicos, esta pesquisa possui natureza quantitativa e qualitativa, é de tipo exploratória quanto a seus objetivos e utilizasse das bases de dados Web of Science e Scopus para a composição do corpus do estudo bibliométrico. Como resultado, identificou-se, a partir de um corpus de 77 artigos, um período de publicações relevantes entre os anos de 1984 e 2020, sendo o ano de 2019 aquele com mais trabalhos publicados. Adicionalmente, 7 veículos de publicação apresentaram mais de um artigo no tópico pesquisado, sendo os Estados Unidos o país com mais trabalhos publicados, totalizando 34. A área da Ciência da Computação foi a que mais produziu nesse tema e constitui uma tendência em sua interdisciplinaridade com as ciências biológicas, sociais aplicadas e da saúde. Finalmente, conclui-se que, a partir da consciência de que a qualidade de dados é um parâmetro relativo, a implementação de serviços de gestão de dados de pesquisa deve passar por preparação, com foco no atendimento a requisitos como os concernentes ao domínio e aos usos pretendidos

Development of a sequential injection gas diffusion system for the determination of ammonium in transitional and coastal waters

This work describes the development of a sequential injection system for the ammonium determination in transitional and coastal waters with a wide salinity range. Estuarine waters are rather complex matrices as their characteristics change considerably along the salinity gradient, as well as the ammonium levels. The developed system effectively solves these issues by converting ammonium into ammonia and using a gas diffusion unit (GDU) for matrix removal. The ammonium determination in a wide quantification range (0.1–5.0 mg L−1) was obtained with small changes in the protocol sequence and was applied, not only to estuarine samples, but also well water samples (low salinity) and coastal waters (higher salinity). Spectrophotometry was the chosen detection system to measure the absorbance change in the bromothymol blue acid base indicator caused by the diffusion of ammonia through the GDU. Additionally, the developed system used a green chemistry approach, as there was no indicator reagent consumption per determination, still maintaining a good precision (relative standard deviation lower than 2%) and a low detection limit, 27 μg L−1 (1.5 μM).info:eu-repo/semantics/acceptedVersio

Fixação biológica de nitrogênio e fertilizantes nitrogenados no balanço de nitrogênio em soja, milho e algodão

O objetivo deste trabalho foi avaliar os efeitos da fixação biológica de nitrogênio (FBN) da cultura da soja, e a eficiência do uso de fertilizantes nitrogenados (EUFN) pelas culturas de milho e algodão, no balanço de N de um Latossolo Vermelho distroférrico, sob plantio direto, em Dourados, MS. O estudo foi feito em dois anos, concentrando-se nas safras de verão. A contribuição da FBN para a soja foi avaliada pela técnica de abundância natural de 15N. A EUFN foi avaliada mediante a substituição dos fertilizantes nitrogenados convencionais pelos enriquecidos com 15N, nas culturas do milho e algodão. No primeiro ano, foram adicionados 115 kg ha-1 de N, de forma parcelada, para ambas as culturas; somente a parte aérea das plantas foi avaliada. No segundo ano, somente a cultura do milho foi avaliada, tendo recebido 70 kg ha-1 de N aos 29 DAE. Nesse ano, além da parte aérea do milho, amostrou-se também o solo, na profundidade de 0-20 cm. Nos dois anos de avaliação, a FBN foi superior a 80% do N nas plantas de soja, o que resultou em alta produtividade e em balanço positivo de N para o solo. A EUFN na parte aérea de milho e algodão, no primeiro ano, foi de 48 e 61%, respectivamente. No segundo ano, a EUFN, na parte aérea do milho, foi de 46%, tendo-se observado que 24% do N do fertilizante permaneceu nos primeiros 20 cm de solo. Para os níveis de produtividade das culturas de milho e algodão, o manejo do fertilizante nitrogenado resulta em balanços negativos de N para o solo