310 research outputs found
Pregnancy after Gastric Banding for the Treatment of Morbid Obesity
Obesity is known to have a negative impact on pregnancy outcome, as it is associated with an increase in the incidence of gestational diabetes, hypertension, preeclampsia, neural tube defects, macrosomia, and late fetal death. Gastric banding is considered an appropriate intervention for morbid obesity when other weight-loss measures are unsuccessful, and this treatment has been shown to be effective in causing a sustainable weight loss. Some women will become pregnant after bariatric surgery, and the nutritional and metabolic challenges brought by gastric banding may have a profound impact on maternal health and pregnancy outcome.
The authors report the case of a 27 year old pregnant woman, with a past medical history of gastric banding surgery for morbid obesity. At 18 weeks of gestation, the patient started complaining of severe nausea and vomiting, The situation deteriorated three weeks later when she rapidly developed severe desnutrition, dehydration and early signs of liver and renal failure. Migration of the gastric band was diagnosed, and laparoscopy conducted to remove it. In the day following surgery the patient complained of absent fetal movements, and an intrauterine demise was diagnosed on ultrasound. Pathological examination of the fetus and placenta failed to reveal the cause of death, but no growth restriction was documented, suggesting the occurrence of an acute event
Polyvinylpyrrolidone Nanofibers Incorporating Mesoporous Bioactive Glass for Bone Tissue Engineering
Publisher Copyright:
© 2023 by the authors.Composite biomaterials that combine osteoconductive and osteoinductive properties are a promising approach for bone tissue engineering (BTE) since they stimulate osteogenesis while mimicking extracellular matrix (ECM) morphology. In this context, the aim of the present research was to produce polyvinylpyrrolidone (PVP) nanofibers containing mesoporous bioactive glass (MBG) 80S15 nanoparticles. These composite materials were produced by the electrospinning technique. Design of experiments (DOE) was used to estimate the optimal electrospinning parameters to reduce average fiber diameter. The polymeric matrices were thermally crosslinked under different conditions, and the fibers’ morphology was studied using scanning electron microscopy (SEM). Evaluation of the mechanical properties of nanofibrous mats revealed a dependence on thermal crosslinking parameters and on the presence of MBG 80S15 particles inside the polymeric fibers. Degradation tests indicated that the presence of MBG led to a faster degradation of nanofibrous mats and to a higher swelling capacity. The assessment of in vitro bioactivity in simulated body fluid (SBF) was performed using MBG pellets and PVP/MBG (1:1) composites to assess if the bioactive properties of MBG 80S15 were kept when it was incorporated into PVP nanofibers. FTIR and XRD analysis along with SEM–EDS results indicated that a hydroxy-carbonate apatite (HCA) layer formed on the surface of MBG pellets and nanofibrous webs after soaking in SBF over different time periods. In general, the materials revealed no cytotoxic effects on the Saos-2 cell line. The overall results for the materials produced show the potential of the composites to be used in BTE.publishersversionpublishe
Raízes da terra: semeando experiências alternativas em agricultura sem queima.
Buscando alternativas ao uso do fogo, o Projeto ?Mudanças de práticas agrícolas, biodiversidade e capacitação: semeando alternativas agroecológicas para redução do desmatamento e das queimadas?, conhecido por ?Raízes da Terra?, objetiva implementar alternativas à agricultura de derruba e queima baseadas em princípios agroecológicos, visando o uso sustentado da terra, melhoria da qualidade de vida dos agricultores familiares e recomposição da paisagem agrícola. Realizou-se um seminário para identificar de forma participativa os avanços e dificuldades no uso da tecnologia proposta, especialmente as atividades desenvolvidas pelos agricultores participantes do Projeto Raízes da Terra. Com relação à tecnologia de corte-e-trituração e plantio direto na capoeira, os agricultores já possuem a percepção da importância do aproveitamento da biomassa para o sistema solo-planta-água. A introdução de leguminosas de rápido crescimento na capoeira possibilita o aumento da biomassa e a ciclagem de nutrientes no solo. A formação de Sistemas Agroflorestais com espécies frutíferas e florestais promove a recuperação das áreas alteradas e o enriquecimento do lote. A falta de equipamentos (trituradora) para atender a demanda, e de apoio dos órgãos públicos são algumas das limitações ao avanço da tecnologia. As informações obtidas permitem avaliar os avanços alcançados e definir novas estratégias para melhorar a tecnologia de corte e trituração da capoeiraEditores técnicos: Roberto Porro, Milton Kanashiro, Maria do Socorro Gonçalves Ferreira, Leila Sobral Sampaio e Gladys Ferreira de Sousa
Electroanalytical Determination of Oxadiazon and Characterization of Its Base-Catalyzed Ring-Opening Products
Phenolic acids and derivatives: studies on the relationship among structure, radical scavenging activity, and physicochemical parameters
The antiradical activity of caffeic acid (1), dihydrocaffeic acid (5), and their corresponding n-alkyl esters was evaluated by using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(*)) method. Dihydrocaffeic acid (5) was the most potent compound, having an antiradical effect higher than that of (+/-)-alpha-tocopherol, whereas caffeic acid (1) was less efficient. Esterification of the carboxyl group of dihydrocaffeic acid (5) had a dramatic effect on its antiradical potency, but similar effects were not observed for caffeic acid (1) derivatives. The n-alkyl esters of both phenolic series had similar potencies, and their antiradical activities were independent of the alkyl chain length. Dose-dependent scavenger effects were found in both series. Acid-base properties of the compounds, evaluated by using potentiometry and spectrophotometry, showed that the catechol moiety had pK(a2) and pK(a3) values of 9. 24-9.02 and 11.38-10.99 in the dihydrocaffeic series and 8.48-8.24 and 11.38-11.07 in the caffeic series, respectively. Antiradical activity and pK(a) values of the compounds were not related.info:eu-repo/semantics/publishedVersio
Voltammetric Oxidation of Drugs of Abuse II. Codeine and Metabolites
The oxidation of codeine on glassy carbon electrodes has been studied in detail using differential pulse voltammetry. The results obtained using a glassy carbon electrode clearly show a much more complex oxidation mechanism than that previously reported when platinum and gold electrodes were used. To clarify the codeine oxidative profile, several metabolites and analogues of this alkaloid, codeine N-oxide, norcodeine, dihydrocodeine, acetylcodeine and 6-chlorodesoxycodeine, were synthesized and studied. It was deduced that the anodic waves observed in codeine oxidation are related to the presence of methoxy, hydroxy and tertiary amine groups. Due to the similarity of potentials at which these oxidative processes take place, at some pHs an overlap of peaks occurs and only one anodic wave is observed
Electrochemical oxidation of propanil and related N-substituted amides
The electrochemical behaviour of propanil and related N-substituted amides (acetanilide and N,N-diphenylacetamide) was studied by cyclic and square wave voltammetry using a glassy carbon electrode. Propanil has been found to have chemical stability under the established analytical conditions and showed an oxidation peak at +1.27 V versus Ag/AgCl at pH 7.5. N,N-diphenylacetamide has a higher oxidation potential than the other compounds of +1.49 V versus Ag/AgCl. Acetanilide oxidation occurred at a potential similar to that of propanil, +1.24 V versus Ag/AgCl. These results are in agreement with the substitution pattern of the nitrogen atom of the amide. A degradation product of propanil, 3,4-dichloroaniline (DCA), was also studied, and showed an oxidation peak at +0.66 V versus Ag/AgCl. A simple and specific quantitative electroanalytical method is described for the analysis of propanil in commercial products that contain propanil as the active ingredient, used in the treatment of rice crops in Portugal.http://www.sciencedirect.com/science/article/B6TF4-430G3H9-5/1/43d591ce02cac4cb03b04dbedd1ac99
Electrochemical oxidation of propanil and related N-substituted amides
The electrochemical behaviour of propanil and related N-substituted amides (acetanilide and N,N-diphenylacetamide) was studied by cyclic and square wave voltammetry using a glassy carbon electrode. Propanil has been found to have chemical stability under the established analytical conditions and showed an oxidation peak at +1.27 V versus Ag/AgCl at pH 7.5. N,N-diphenylacetamide has a higher oxidation potential than the other compounds of +1.49 V versus Ag/AgCl. Acetanilide oxidation occurred at a potential similar to that of propanil, +1.24 V versus Ag/AgCl. These results are in agreement with the substitution pattern of the nitrogen atom of the amide. A degradation product of propanil, 3,4-dichloroaniline (DCA), was also studied, and showed an oxidation peak at +0.66 V versus Ag/AgCl. A simple and specific quantitative electroanalytical method is described for the analysis of propanil in commercial products that contain propanil as the active ingredient, used in the treatment of rice crops in Portugal.http://www.sciencedirect.com/science/article/B6TF4-430G3H9-5/1/43d591ce02cac4cb03b04dbedd1ac99
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