39 research outputs found
Características de crescimento, composição química, física e estimativa de massa seca de madeira em clones e espécies de Eucalyptus jovens
O objetivo deste trabalho foi avaliar o efeito do material genético, clones e espécies, e da classe de diâmetro nas características de crescimento, composição química, densidade básica e a estimativa de massa seca de madeira. Foram avaliados quatro clones e cinco espécies, aos quatro anos de idade, de Eucalyptus procedentes da empresa RIMA Industrial S.A. Foram avaliadas cinco árvores por clone e espécie em três e quatro classes diamétricas, respetivamente. Avaliaram-se as características individuais de crescimento da árvore, a densidade básica, a estimativa de massa seca, o teor de lignina, extrativos totais, holocelulose e cinzas. O volume, com e sem casca, e a estimativa de massa seca apresentaram efeito significativo de material genético (clone e espécie) e classe diamétrica. O teor de lignina não foi influenciado significativamente pelo material genético e classe diamétrica. A densidade básica apresentou efeito significativo de classe diamétrica para os clones e de material genético para as espécies. O teste de identidade de modelos somente foi não significativo para a estimativa de massa seca para as espécies, possibilitando usar a equação comum independente da espécie. Os clones apresentaram madeira mais homogênea, com menor densidade básica, extrativos totais e lignina total e maior teor de holocelulose, características mais adequadas à produção de polpa celulósica. As espécies apresentaram madeira mais heterogênea, com maior densidade básica, estimativa de massa seca, extrativos totais e lignina total e menor teor de cinzas e holocelulose, características desejáveis à produção de bioenergia. (Résumé d'auteur
Qualidade do carvão vegetal produzido a partir da madeira do cafeeiro, para usobioenergético
The objective of this study was to evaluate the quality of charcoal from Coffea arabica L., for bioenergy purposes, using three existing cultivation systems in the South of Minas Gerais (natural agroforestry, organic and conventional) and two cultivars (Mundo Novo and Catuaí). Univariate and multivariate statistical techniques were used, besides the identification of mineral components for the selection and evaluation of the quality from coffee charcoal. The following properties were quantified in charcoal: apparent relative density, actual relative density, immediate chemical composition (volatiles, ash and fixed carbon), fixed carbon stock, energy densities, porosity, heating values; besides carbonization yields. The charcoal of the cultivar Catuaí, with organic and conventional systems, stood out for steel and energy use, mainly by the higher values of apparent relative density, energy densities, fixed carbon stock and yields in charcoal and in fixed carbon. The effect of cultivar on apparent relative density was responsible for the formation of a similar group between the wood charcoal from organic and conventional systems for cultivar Catuaí. Coffee charcoal from the conventional system showed the best K/Ca ratio. It is therefore best suited to be used as fuel in boilers, gasifiers and other energy conversion systems.Objetivou-se, neste trabalho, avaliar a qualidade do carvão vegetal de Coffea arabica L. para fins bioenergéticos, utilizando três sistemas de cultivo existentes no Sul de Minas Gerais (natural agroflorestal, orgânico e convencional) e duas cultivares (Mundo Novo e Catuaí). Foram utilizadas as técnicas estatísticas univariada e multivariada, além da identificação dos componentes minerais para seleção e avaliação da qualidade do carvão vegetal do cafeeiro. No carvão vegetal, foram quantificadas as seguintes propriedades: densidade relativa aparente, densidade relativa verdadeira, composição química imediata, estoque de carbono fixo, densidades energéticas, porosidade, poderes caloríficos; além dos rendimentos da carbonização. O carvão vegetal da cultivar Catuaí, dos sistemas orgânico e convencional, destacou-se para o uso siderúrgico e energético, principalmente, pelos maiores valores de densidade relativa aparente, densidades energéticas, estoque em carbono fixo e rendimentos em carvão vegetal e em carbono fixo. O efeito da cultivar, na densidade relativa aparente, foi responsável pela formação de um grupo similar entre o carvão vegetal proveniente da madeira dos sistemas orgânico e convencional, para a cultivar Catuaí. O carvão vegetal do cafeeiro, proveniente do sistema convencional, apresentou a melhor relação K/Ca. Logo, é o mais indicado para ser utilizado como combustível em caldeiras, gaseificadores e demais sistemas de conversão energética
Ghrelin expression in human and rat fetal lungs and the effect of ghrelin administration in nitrofen-induced congenital diaphragmatic hernia
Ghrelin is a strong physiologic growth hormone secretagogue that exhibits endocrine and non-endocrine actions. In this study, ghrelin expression in humans and rats was evaluated throughout development of normal and hypoplastic lungs associated with congenital diaphragmatic hernia (CDH). Additionally, the effect of antenatal treatment with ghrelin in the nitrofen-induced CDH rat model was tested. In normal lungs, ghrelin was expressed in the primitive epithelium at early stages of development and decreased in levels of expression with gestational age. In hypoplastic lungs ghrelin was overexpressed in both human and rat CDH fetuses when compared with controls. Exogenous administration of ghrelin to nitrofen-treated dams led to an attenuation of pulmonary hypoplasia of CDH pups. Furthermore, the growth hormone, secretagogue receptor (GHSR1a), could not be amplified from human or rat fetal lungs by RT-PCR. In conclusion, of all the lungs studied so far, the fetal lung is one of the first to express ghrelin during development and might be considered a new source of circulating fetal ghrelin. Overexpression of ghrelin in hypoplastic lungs and the effect of exogenous administration of ghrelin to nitrofen-treated dams strongly suggest a role for ghrelin in mechanisms involved in attenuation of fetal lung hypoplasia, most likely through a GHSR1a-independent pathway
Cardiomiopatia de Takotsubo: uma breve revisão sistemática: Takotsubo Cardiomiopathy: a brief systematic review
A cardiomiopatia de Takotsubo é uma nova cardiomiopatia que foi noticiada pela primeira vez em 2001. A doença é definida por disfunção reversível do ventrículo esquerdo e manifesta-se normalmente como uma síndrome coronária aguda. Este estudo teve como objetivo discutir as principais características da cardiomiopatia takotsubo. Para isso, foi desenvolvida uma revisão sistemática de literatura, recorrendo-se às bases de dados Scielo, Medline e Lilacs, selecionando-se estudos publicados nos últimos 5 anos. A partir da análise e interpretação dos dados das fontes foi possível concluir que a cardiomiopatia de takotsubo é desencadeada pelo estresse físico e é vista como uma complicação para outras doenças não cardíacas, se apresentando geralmente em mulheres pós-menopausa, acima dos 70 anos de idade. Manifesta-se com início súbito de dor torácica e dispneia, após um evento emocional estressante que precede o início dos sintomas. Com principais consequências, tem-se choque cardiogênico, obstrução da via de saída do ventrículo esquerdo, trombo da parede ventricular esquerda, arritmias ventriculares, ruptura da parede ventricular e paragem cardíaca, registrando-se alguns casos de morte súbita
Estudo da degradação térmica da madeira de Eucalyptus através de termogravimetria e calorimetria
Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab
The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension
Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension
OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030