Physicochemical characterization of fruits, biometry and dormancy of marula seeds / Caracterização físico-química de frutos, biometria e dormência de sementes de marula

This study recorded the physicochemical properties of the marula fruits, the biometry and breaking the dormancy in the marula seeds. Using 200 ripe fruits, the physicochemical characterization was done. From a random sample of 400 seeds, an assessment of the biometrics was performed, and the weight, length, width and thickness of the fruits and seeds were evaluated. Two experiments were conducted to study dormancy breaking using pre-germination treatments, which included immersing the marula seeds five times (0, 15, 30, 45 and 60 minutes) in concentrated sulfuric acid (96%) and water, at 65 ºC temperature. The control was time zero, using plain distilled water, with 25 seeds per treatment and four replications. The marula fruits revealed average values of 21.65 ± 3.44 g, 35.5 ± 2.38 and 34.8 ± 2.73, respectively, for weight, diameter and length. The soluble solids (SS), Hydrogenonic Potential (pH), titratable acidity (AT) and ratio (AT/SS) were 14.74 ± 1.0º Brix, 3.93 ± 0.49 pH, 0.63 ± 0.22 and 27.07 ± 12.10, respectively. For the weight of one thousand seeds, the average value was 3.576 ± 188.4 g. The mean values for the dimensions of the width, length and diameter of the seeds were 22.9 ± 2.11; 23.7 ± 2.04; and 14.9 ± 2.09 mm, respectively. The physiological quality of these seeds was enhanced by immersing the seeds from freshly picked fruits in sulfuric acid for a maximum of 30 minutes and storing them for six months.

Objetivou-se com este trabalho estudar as características físico-químicas de frutos, biometria e superação da dormência de sementes de marula. Para a caracterização físico-química foram utilizados 200 frutos maduros. Realizou-se a biometria utilizando uma amostra aleatória de 400 sementes e foram avaliados: peso, comprimento, largura e espessura de frutos e sementes. Para o estudo da superação de dormência foram realizados dois experimentos com os tratamentos pré-germinativos constituídos pela imersão das sementes em ácido sulfúrico concentrado (96%) e água a temperatura de 65 ºC por cinco tempos (0, 15, 30, 45 e 60 minutos), sendo o tempo zero a testemunha, onde utilizou-se apenas água destilada, com quatro repetições de 25 sementes por tratamento. Os frutos de marula apresentaram valores médios de 21,65 ± 3,44 g, 35,5±2,38 e 34,8±2,73 mm de peso, diâmetro e comprimento, respectivamente e sólidos solúveis (SS), Potencial Hidrogeniônico ( pH), acidez titulável (AT) e ratio (AT/SS) foram de 14,74 ± 1,0 ºBrix, 3,93 ± 0,49 pH, 0,63 ± 0,22 e 27,07 ± 12,10 respectivamente. As sementes apresentaram valores médios de 3.576 ± 188,4 g para o peso de mil sementes. Para as dimensões, largura, comprimento e diâmetro de sementes, apresentaram valores médios de 22,9 ± 2,11; 23,7 ± 2,04; e 14,9 ± 2,09 mm respectivamente. A imersão das sementes procedentes de frutos recém colhidos em ácido sulfúrico por até 30 minutos e o armazenamento por seismeses promove incrementos na sua qualidade fisiológica.

Influência de diferentes tratamentos de superfície na resistência de união entre PEEK e materiais de revestimento estético: revisão sistemática e metaanálise / The influence of different surface treatments on the bond strength between PEEK and aesthetic coating materials: a systematic review and meta-analysis

Poliéter-éter-cetona (Polyetheretherketone - PEEK) é um polímero de excelentes propriedades mecânicas, o que o torna um potencial candidato para substituir ligas metálicas em diversas especialidades odontológicas. Quando utilizado como infraestrutura para confecção de próteses odontológicas, a adesão do PEEK ao material de revestimento estético é determinante para a longevidade do tratamento, embora a baixa energia de superfície e grande estabilidade química do polímero tornem essa adesão um desafio a ser superado. Objetivo: Responder à pergunta: "Outros tratamentos de superfície do PEEK geram resistências de união superiores ao adesivo comercial?" Métodos: A busca foi feita nas bases Pubmed, , LILACS, Scopus, Web of Science, EMBASE, ProQuest e Google Scholar em junho de 2023 e não houve restrição relativa ao idioma ou à data de publicação dos estudos. Foram utilizados os seguintes termos e operadores booleanos: "polyether ether ketone" [MH] OR "polyether ether ketone" OR "polyetheretherketone" OR "polyetherketoneketone" OR "PEEK" AND "shear strength" [MH] OR "shear strength" OR "shear bond strength" OR "tensile bond strength" OR "shear" OR "tensile" OR "microtensile" OR "microshear" OR "bonding" OR "bond strength" OR "microtensile strength" OR "microshear bond strength" OR "bond" OR "adhesion" OR "bond integrity" OR "bonded" OR "Bonding Strength" OR "Bonding Behavior" OR "Adhesive Performance" OR " surface bonding" OR "tensile strength" [MH] OR "tensile strength". Foram incluídos exclusivamente estudos in vitro. Resinas compostas e resinas acrílicas foram consideradas como materiais de revestimento para PEEK. A média e o desvio padrão expressos em MPa e obtidos a partir de testes de cisalhamento e tração foram utilizados para relatar a resistência de união entre o PEEK e os materiais de revestimento. As meta-análises foram realizadas e a ferramenta Cochrane Collaboration avaliou o risco de viés (RoBDEMAT). Resultados: Foram selecionados 23 estudos. A resistência de união entre PEEK e resina composta foi favorecida pelo uso do adesivo (P<0,00001), independentemente do tipo de adesivo. O pré-tratamento com jato de areia Al2O3 (P<0,00001), ácido sulfúrico (P<0,00001), plasma frio (P=0,0006) e laser (P<0,00001) mostrou-se eficiente, embora o condicionamento com solução piranha não tenha tido efeito estatisticamente significativo (P=0,47). Conclusão: A aplicação de ácido sulfúrico antes do adesivo apresentou melhores resultados de resistência de união em comparação ao uso isolado do adesivo.

Polyether-ether-ketone (Polyetheretherketone - PEEK) is a polymer with excellent mechanical properties, which makes it a potential candidate to replace metallic alloys in several dental specialties. When used as an infrastructure for the manufacture of dental prostheses, the adhesion of PEEK to the aesthetic coating material is decisive for the longevity of the treatment, although the low surface energy and great chemical stability of the polymer make this adhesion a challenge to be overcome. Objective: Answer the question: "Do other PEEK surface treatments generate bond strengths superior to commercial adhesive?" Methods: The search was carried out in the Pubmed, LILACS, Scopus, Web of Science, and EMBASE, ProQuest and Google Scholar databases in June 2023 and there were no restrictions regarding the language or publication date of the studies. The following terms and bolean operators were used: "polyether ether ketone" [MH] OR "polyether ether ketone" OR "polyetheretherketone" OR "polyetherketoneketone" OR "PEEK" AND "shear strength" [MH] OR "shear strength" OR " shear bond strength" OR "tensile bond strength" OR "shear" OR "tensile" OR "microtensile" OR "microshear" OR "bonding" OR "bond strength" OR "microtensile strength" OR "microshear bond strength" OR "bond" OR "adhesion" OR "bond integrity" OR "bonded" OR "Bonding Strength" OR "Bonding Behavior" OR "Adhesive Performance" OR "surface bonding" OR "tensile strength" [MH] OR "tensile strength". Only in vitro studies were included. Composite resins and acrylic resins were considered as coating materials for PEEK. The mean and standard deviation expressed in MPa and obtained from shear and tensile tests were used to report the bond strength between PEEK and coating materials. Meta-analyses were performed and the Cochrane Collaboration tool assessed the risk of bias (RoBDEMAT). Results: 23 studies were selected. The bond strength between PEEK and composite resin was favored by the use of the adhesive (P<0,00001), regardless of the type of adhesive. Pretreatment with Al2O3 sandblasting (P<0,00001), sulfuric acid (P<0,00001), cold plasma (P=0,0006) and laser (P<0,00001) proved to be efficient, although conditioning with piranha solution did not have a statistically significant effect (P=0,47). Conclusion: The application of sulfuric acid before the adhesive showed better results in bond strength compared to the use of the adhesive alone.

Acid Hydrolysis of Pectin and Mucilage from Cactus (Opuntia ficus) for Identification and Quantification of Monosaccharides.

Pectin and mucilage are polysaccharides from the cactus Opuntia ficus-indica, which are also known as hydrocolloids, with useful properties in industries such as food, pharmaceuticals, and construction, among others. In the present work, cactus hydrocolloids were hydrolyzed characterized using two techniques: first, thin-layer chromatography, to identify the monosaccharides present in the sample, followed by the phenol-sulfuric acid method to determine the monosaccharide content. The hydrolyzing method allowed us to reduce the processing time to 180 min and, considering the identification and quantification procedures, the proposed methodology is much simpler and more cost-effective compared to other methods, such as high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and mass spectrometry. The analysis of the results revealed that the maximum concentration of monosaccharides was obtained after hydrolyzing for 90 min. Under such conditions, with pectin being the main component contained in the cactus hydrocolloids analyzed here, galacturonic acid was found in the largest quantities.

Method to overcome dormancy in seeds from unconventional food plant: Phytolacca Americana (Phytolaccaceae) / Método para superação de dormência em sementes de uma planta alimentícia não convencional: Phytolacca americana (Phytolaccaceae)

Plant species Phytolacca americana (Phytolaccaceae) can be classified as UFP (Unconventional Food Plant); it is used for food and/or medicinal purposes due to its analgesic, anti-inflammatory, anti-rheumatic and anti-arthritic properties; moreover, it is suitable to treat different skin diseases. However, its seeds present integumentary dormancy caused by uneven germination. The aim of the present study is to assess the effect of chemical scarification in sulfuric acid on dormancy overcome in Phytolacca Americana (Phytolaccaceae) seeds. Seeds were immersed in 4 ml sulfuric acid, which was concentrated through different immersion times (2, 5, 8, 11 and 15 min), and compared to the control treatment (without sulfuric acid). The study followed a completely randomized design with six treatments and four repetitions, with 50 seeds per treatment. The following parameters were assessed: days to start germination (DSG), germination (G), germination speed index (GSI), abnormal plantlets (AP), dead seeds (DS), hard seeds (HS) and total dry mass (TDM). Data were subjected to Shapiro-Wilk test for variance normality. The analysis of variance and regression were carried out in RStudio software, version 4.1.0. Means recorded for treatments were compared through Tukey test (p ≤ 0.05). The treatment based on immersion in sulfuric acid for 2 min was the most efficient in overcoming dormancy in this species, since it led to the best results for germination variables and total biomass accumulation in plantlets.

A Phytolacca americana (Phytolaccaceae) é uma espécie que pode ser classificada como PANC (Planta Alimentícia Não Convencional), utilizada para fins alimentícios e/ou medicinais com propriedades analgésicas, antiinflamatórias, antirreumáticas, antiartríticas e, também é adequada para o tratamento de várias doenças de pele. Contudo, suas sementes apresentam dormência tegumentar causando desuniformidade na germinação. Objetivou-se com o presente trabalho avaliar o efeito da escarificação química com ácido sulfúrico na superação da dormência em sementes de Phytolacca americana (Phytolaccaceae). As sementes foram imersas em 4 ml de ácido sulfúrico concentrado por diferentes períodos de imersão (2, 5, 8, 11 e 15 min) comparadas ao tratamento controle (sem ácido sulfúrico). O delineamento utilizado foi o inteiramente casualizado com seis tratamentos e quatro repetições de 50 sementes por tratamento. Foram avaliados os seguintes parâmetros: dias para iniciar a germinação (DIG), germinação (G), índice de velocidade de germinação (IVG), plântulas anormais (PA), sementes mortas (SM), sementes duras (SD), e massa seca total (MST). Os dados foram submetidos ao teste de Shapiro-Wilk para normalidade das variâncias. E a análise de variância e de regressão por meio do software RStudio versão 4.1.0. Sendo as médias dos tratamentos comparadas pelo teste Tukey (p ≤ 0,05). O tratamento de imersão em ácido sulfúrico por 2 min mostrou-se o mais eficiente na superação da dormência dessa espécie, proporcionando melhores resultados nas variáveis germinativas e acúmulo de biomassa total das plântulas.

Use of Piranha Solution as An Alternative Route to Promote Bioactivation of PEEK Surface with Low Functionalization Times.

This study aimed to achieve bioactivity on the PEEK surface using piranha solution through a lower functionalization time. For this purpose, the functionalization occurred with piranha solution and 98% sulfuric acid in the proportions of 1:2, 1:1, and 2:1 at periods of 30, 60, and 90 s. The samples treated for longer times at higher concentrations registered the characteristic spectroscopy band associated with sulfonation. Additionally, both chemical treatments allowed the opening of the aromatic ring, increasing the number of functional groups available and making the surface more hydrophilic. The piranha solution treatments with higher concentrations and longer times promoted greater heterogeneity in the surface pores, which affected the roughness of untreated PEEK. Furthermore, the treatments induced calcium deposition on the surface during immersion in SBF fluid. In conclusion, the proposed chemical modifications using sulfuric acid SPEEK 90 and, especially, the piranha solution PEEK-PS 2:1-90, were demonstrated to be promising in promoting the rapid bioactivation of PEEK-based implants.

Surface Bioactivation of Polyether Ether Ketone (PEEK) by Sulfuric Acid and Piranha Solution: Influence of the Modification Route in Capacity for Inducing Cell Growth.

The aim of this study was to promote bioactivity of the PEEK surface using sulfuric acid and piranha solution. PEEK was functionalized by a sulfuric acid treatment for 90 s and by piranha solution for 60 and 90 s. Chemical modification of the PEEK surface was evaluated by infrared spectroscopy, contact angle analysis, cytotoxicity, cell adhesion and proliferation. The spectroscopy characteristic band associated with sulfonation was observed in all treated samples. PEEK with piranha solution 60 s showed an increase in the intensity of the bands, which was even more significant for the longer treatment (90 s). The introduction of the sulfonic acid functional group reduced the contact angle. In cytotoxicity assays, for all treatments, the number of viable cells was higher when compared to those of untreated PEEK. PEEK treated with sulfuric acid and piranha solution for 60 s were the treatments that showed the highest percentage of cell viability with no statistically significant differences between them. The modified surfaces had a greater capacity for inducing cell growth, indicative of effective cell adhesion and proliferation. The proposed chemical modifications are promising for the functionalization of PEEK-based implants, as they were effective in promoting bioactivation of the PEEK surface and in stimulating cell growth and proliferation.

Controlled Reduction of Graphene Oxide Using Sulfuric Acid.

Sulfuric acid under different concentrations and with the addition of SO3 (fuming sulfuric acid) was studied as a reducing agent for the production of reduced graphene oxide (RGO). Three concentrations of sulfuric acid (1.5, 5, and 12 M), as well as 12 M with 30% SO3, were used. The reduction of graphene oxide increased with H2SO4 concentration as observed by Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy. It was observed that GO lost primarily epoxide functional groups from 40.4 to 9.7% and obtaining 69.8% carbon when using 12 M H2SO4, without leaving sulfur doping. Additionally, the appearance of hexagonal domain structures observed in transmission electron microscopy and analyzed by selected area electron diffraction patterns confirmed the improvement in graphitization. Although the addition of SO3 in H2SO4 improved the GO reduction with 74% carbon, as measured by XPS, the use of SO3 introduced sulfur doping of 1.3%. RGO produced with sulfuric acid was compared with a sample obtained via ultraviolet (UV) irradiation, a very common reduction route, by observing that the RGO produced with sulfuric acid had a higher C/O ratio than the material reduced by UV irradiation. This work showed that sulfuric acid can be used as a single-step reducing agent for RGO without sulfur contamination.

Effects of fructans and probiotics on the inhibition of Klebsiella oxytoca and the production of short-chain fatty acids assessed by NMR spectroscopy.

Generally, the selection of fructans prebiotics and probiotics for the formulation of a symbiotic has been based on arbitrary considerations and in vitro tests that fail to take into account competitiveness and other interactions with autochthonous members of the intestinal microbiota. However, such analyzes may be a valuable step in the development of the symbiotic. The present study, therefore, aims to investigate the effect of lactobacilli strains and fructans (prebiotic compounds) on the growth of the intestinal competitor Klebsiella oxytoca, and to assess the correlation with short-chain fatty acids production. The short-chain fatty acids formed in the fermentation of the probiotic/prebiotic combination were investigated using NMR spectroscopy, and the inhibitory activities were assessed by agar diffusion and co-culture methods. The results showed that Lactobacillus strains can inhibit K. oxytoca, and that this antagonism is influenced by the fructans source and probably associated with organic acid production.

Effects of acidic attack on chemical, mineralogical, and morphological properties of geomaterials.

Exposure of geomaterials to acidic leachates may compromise their structure and functionality due to changes in physicochemical, mineralogical, and hydraulic behavior. The literature identifies the need to evaluate changes in a pure state and in conditions of extreme acidity. This study aimed to evaluate changes in the chemical, mineralogical, and morphological properties of Osorio fine uniform sand (OFS), basalt residual soil (BRS), kaolin (KAO), and bentonite (BEN) exposed to sulfuric acid in concentrations of 0.00 mol/L (distilled water), 0.01 mol/L, and 1.00 mol/L. The tested samples were characterized using X-ray fluorescence spectrometry, X-ray diffraction, thermogravimetry, differential scanning calorimetry, and scanning electron microscopy. The acid attack on geomaterials by contact with the solution 1.00 mol/L has resulted in the solubilization of some constituent minerals, as well as the formation of sulfate minerals, changes in the water dehydration peak in the pores, and mass loss. The morphology of the sand and bentonite particles did not change with exposure to sulfuric acid. The acidic attack resulted in changes in the morphology of the particles for BRS and KAO. The results of this study are important for determining operational parameters of waste containment systems and contaminated areas, as well as for applying geomaterials as founding materials.

Xylooligosaccharides production from a sugarcane biomass mixture: Effects of commercial enzyme combinations on bagasse/straw hydrolysis pretreated using different strategies.

Xylooligosaccharides (XOS) are non-digestible food ingredients with prebiotic properties for selectively promoting the growth of probiotics, which provide many health benefits and several applications in the food and pharmaceutical industry. The objective of this study was to optimize the concentration of commercial hemicellulases for the production of XOS, with a 2-6 polymerization degree, using a mixture of sugarcane bagasse and straw pretreated with ionic liquid or diluted sulfuric acid. The concentrations of enzymes endo-1,4-xylanase (NS50030, Novozyme®) and α-L-arabinofuranosidase (GH51) (Megazyme®) were optimized using a central composite rotatable design (CCRD). The xylooligosaccharides (XOS) released by hydrolysis were analyzed via capillary electrophoresis and quantified with HPAEC-PAD. The XOS profile obtained from the hydrolisis of the pretreated sugarcane biomass mixture (MPSA) was similar to that obtained with the hydrolisis of MBX, which provided higher xylobiose (X2) concentration. Our results also demonstrated that pretreatment with an ionic liquid favored the requirement of lower enzyme concentration in enzymatic hydrolysis for having provided a biomass with lower lignin content than the pretreatment with dilute sulfuric acid. It required up to 20% less of the optimum concentration of the endo-1,4-xylanase mixture to achieve similar values to those obtained with the biomass pretreated with dilute sulfuric acid, representing a possible alternative to reduce enzymatic cost.

Low cost in situ digital image method, based on spot testing and smartphone images, for determination of ascorbic acid in Brazilian Amazon native and exotic fruits.

In this work, we propose a method that employed a smartphone to capture images obtained from a colorimetric spot test to determine ascorbic acid (AA) in Brazilian Amazon native and exotic fruits. The spot test reaction was based on reduction of Fe(III) by AA and further complexation with 1,10-phenanthroline. After optimization, the limit of detection was 8.5 × 10-7 mol L-1. Brazilian Amazon native fruits such as bacuri, cupuaçu, muruci, yellow mombin, as well as others as cashew, mango, orange and passion fruit, were analyzed. In order to determine the accuracy of this method, iodometric titration was used; results were in close agreement with a confidence level of 95% (paired t-test). Moreover, recoveries ranged from 87.1 to 116%. The method is economic, environmentally friendly, and portable, and might useful for small producers and family agriculture businesses unable to afford specialized laboratory analysis in the north region of Brazilian Amazon.

Effect of pretreatments on corn stalk chemical properties for biogas production purposes.

Different pretreatments were evaluated on corn stalk (Zea mays) applied as a lignocellulosic source in anaerobic co-digestion with swine manure, using sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) for biogas production purposes. Using H2SO4 we achieved a 75.1% removal of the hemicellulose fraction, in low acid concentrations (0.75% v.v-1). However, this technique inhibited the co-digestion process. Pretreatment with 12% of H2O2 (pH 11.5) increased the cellulose fraction by 73.4% and reduced the lignin content by 71.6%. This pretreatment is recommended for biogas production, as it increased the final volume of biogas by 22% and reduced the digestion time by one third. So, a promising alternative was obtained in order to facilitate the anaerobic digestion of the carbohydrates present in this biomass.

Industrial waste as a source of surface and groundwater pollution for more than half a century in a sector of the Río de la Plata coastal plain (Argentina).

Environmental liabilities have become one of the most important problems of the last years, especially those of contaminated sites located in urban areas which have been abandoned by pollution intensive industries. Such sites may contain hazardous materials that pose risks to human health and the environment. Industrial waste from the ancient sulfuric acid industry is scattered in a local area at the petrochemical pole in a sector of the Río de la Plata coastal plain. The aim of this work is to define the geochemical processes that determine the alteration of waste in the old sulfuric acid industry (OSAI) area and to study the migration of soluble pollutants to groundwater. A survey of soil and waste deposit was carried out and samples were examined by X-ray diffraction, under a scanning electron microscope and a polarizing microscope. Surface water and groundwater samples, both to the unconfined and semi-confined aquifers, were collected to determine electrical conductivity, pH and major elements. The results show the presence of minerals composed of sulfur associated with jarosite and iron oxides on superficial sediments. The detailed study of soil sediments together with that of the water physicochemical characteristics make it possible to understand the geochemical processes developed in soil that cause the high concentrations of sulfates in groundwater. Furthermore, high SO4-2 concentration registered in the semi-confined aquifer due to its infiltration from the unconfined aquifer shows that the industrial pollution has an important impact at local level. These results may contribute to the understanding of chemical processes and pollutants distribution in highly industrialized coastal plain areas.

Tropical soils characterization at low cost and time using portable X-ray fluorescence spectrometer (pXRF): Effects of different sample preparation methods / Caracterização de solos tropicais a baixo custo e tempo usando espectrômetro portátil de fluorescência de raios-X (pXRF): Efeitos de diferentes métodos de preparo de amostras

ABSTRACT Portable X-ray fluorescence spectrometer (pXRF) has been recently adopted by the Soil Science community for uses in both field and laboratory, obtaining the total content of several chemical elements in a few seconds. Sulfuric acid digestion is an expensive and time-consuming laboratory analysis that provides contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5, important for soil studies. Due to few pXRF studies in tropical soils, this work aimed to compare contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5 obtained by pXRF with sulfuric acid digestion results, and to evaluate the effects of varying forms of preparing soil samples and scanning with pXRF on the resulting values in Brazilian soils. Soils were scanned in five conditions in-field (in situ) and in laboratory, evaluating varying sample preparation methods, particle sizes and soil moisture. Four pXRF scanning operational modes were tested. Linear regressions were adjusted between results of pXRF and sulfuric acid digestion. Equations were validated with an independent set of samples. Statistical analyses compared the methods of preparing the samples. Adequate linear models reached R2 of 0.99 and 0.89 for Fe2O3 and TiO2, respectively. Validation promoted R2 greater than 0.97 and RMSE and ME close to zero for both oxides. Statistical differences of pXRF results were found among the methods of preparing samples. pXRF spectrometer has great potential to obtain Fe2O3 and TiO2 content rapidly and economically with high correspondence with laboratory results of sulfuric acid digestion analysis. Varying methods of preparing the samples promote differences in the results of pXRF.

RESUMO O espectrômetro portátil de fluorescência de raios-X (pXRF) foi recentemente adotado pela Ciência do Solo, para uso em campo e laboratório, para obtenção do conteúdo total de vários elementos químicos em poucos segundos. A digestão com ácido sulfúrico é uma análise laboratorial cara e demorada que fornece teores de Fe2O3, Al2O3, SiO2, TiO2 e P2O5, importantes para estudos sobre solos. Devido aos poucos estudos sobre o pXRF em solos tropicais, este trabalho objetivou comparar os teores de Fe2O3, Al2O3, SiO2, TiO2 e P2O5 obtidos pelo pXRF com os resultados de digestão com ácido sulfúrico e avaliar os efeitos de diferentes formas de preparo de amostras de solo e leitura com o pXRF sobre seus resultados para solos brasileiros. Os solos foram submetidos a leituras com o pXRF em cinco condições, em campo (in situ) e em laboratório, avaliando variados métodos de preparo de amostras, tamanhos de partículas e umidade do solo. Quatro modos de operação do pXRF foram testados. Regressões lineares foram ajustadas entre os resultados do pXRF e digestão com ácido sulfúrico. As equações foram validadas com um conjunto independente de amostras. Análises estatísticas compararam os métodos de leitura de amostras. Modelos lineares adequados atingiram R2 de 0,99 e 0,89 para Fe2O3 e TiO2, respectivamente. A validação promoveu R2 maior que 0.97 e RMSE e ME próximos a zero para ambos os óxidos. Foram encontradas diferenças estatísticas dos resultados do pXRF entre os métodos de preparo de amostras. O pXRF possui um grande potencial para obter rápida e economicamente os teores de Fe2O3 e TiO2 com elevada correspondência com os resultados laboratoriais da análise da digestão com ácido sulfúrico. Métodos variáveis ​​de preparo das amostras promovem diferenças nos resultados de pXRF.

Optimized acid hydrolysis of the polysaccharides from the seaweed Solieria filiformis (Kützing) P.W. Gabrielson for bioethanol production / Hidrólise ácida otimizada dos polissacarídeos da macroalga Solieria filiformis (Kützing) P.W.Gabrielson para produção de bioetanol

The seaweeds are bio-resource rich in sulfated and neutral polysaccharides. The tropical seaweed species used in this study (Solieria filiformis), after dried, shows 65.8% (w/w) carbohydrate, 9.6% (w/w) protein, 1.7% (w/w) lipid, 7.0% (w/w) moisture and 15.9% (w/w) ash. The dried seaweed was easily hydrolyzed under mild conditions (0.5 M sulfuric acid, 20 min.), generating fermentable monosaccharides with a maximum hydrolysis efficiency of 63.21%. Galactose and glucose present in the hydrolyzed were simultaneously fermented by Saccharomyces cerevisiae when the yeast was acclimated to galactose and cultivated in broth containing only galactose. The kinetic parameters of the fermentation of the seaweed hydrolyzed were Y(PS) = 0.48 ± 0.02 g.g1, PP = 0.27 ± 0.04 g.L1.h1, h = 94.1%, representing a 41% increase in bioethanol productivity. Therefore, S. filiformis was a promising renewable resource of polysaccharides easily hydrolyzed, generating a broth rich in fermentable monosaccharides for ethanol production.(AU)

As algas marinhas são recursos naturais ricos em polissacarídeos sulfatados e neutros. A espéciede macroalga tropical utilizada neste estudo (Solieria filiformis) apresentou teores de carboidratos de 65,8%(m/m), proteínas de 9,6% (m/m), lipídios de 1,7% (m/m), umidade de 7,0% (m/m) e 15,9 % (m/m) decinzas. A macroalga seca foi facilmente hidrolisada em condições brandas, na presença de ácido sulfúrico0,5 M, por 20 min, produzindo monossacarídeos fermentáveis com uma eficiência de hidrólise máxima de63,21%. A galactose e a glicose presentes no hidrolisado foram fermentadas simultaneamente porSaccharomyces cerevisiae, após aclimatação da levedura cultivada em meio contendo apenas galactose comofonte de carbono. Os parâmetros cinéticos da fermentação do hidrolisado algáceo pela levedura aclimatada agalactose foram Y(P/S) = 0,48 ± 0,02 g.g-1, PP = 0,27 ± 0,04 g.L-1.h-1, η = 94,1%. Portanto, a macroalga S.filiformis se mostrou um recurso renovável promissor como fonte de polissacarídeos facilmente hidrolisados,gerando um meio nutritivo rico em glucose e galactose para a produção de etanol.(AU)

Optimized acid hydrolysis of the polysaccharides from the seaweed Solieria filiformis (Kützing) P.W. Gabrielson for bioethanol production / Hidrólise ácida otimizada dos polissacarídeos da macroalga Solieria filiformis (Kützing) P.W. Gabrielson para produção de bioetanol

The seaweeds are bio-resource rich in sulfated and neutral polysaccharides. The tropical seaweed species used in this study (Solieria filiformis), after dried, shows 65.8% (w/w) carbohydrate, 9.6% (w/w) protein, 1.7% (w/w) lipid, 7.0% (w/w) moisture and 15.9% (w/w) ash. The dried seaweed was easily hydrolyzed under mild conditions (0.5 M sulfuric acid, 20 min.), generating fermentable monosaccharides with a maximum hydrolysis efficiency of 63.21%. Galactose and glucose present in the hydrolyzed were simultaneously fermented by Saccharomyces cerevisiae when the yeast was acclimated to galactose and cultivated in broth containing only galactose. The kinetic parameters of the fermentation of the seaweed hydrolyzed were Y(P/S) = 0.48 ± 0.02 g.g−1, PP = 0.27 ± 0.04 g.L−1.h−1, η = 94.1%, representing a 41% increase in bioethanol productivity. Therefore, S. filiformis was a promising renewable resource of polysaccharides easily hydrolyzed, generating a broth rich in fermentable monosaccharides for ethanol production.

As algas marinhas são recursos naturais ricos em polissacarídeos sulfatados e neutros. A espécie de macroalga tropical utilizada neste estudo (Solieria filiformis) apresentou teores de carboidratos de 65,8% (m/m), proteínas de 9,6% (m/m), lipídios de 1,7% (m/m), umidade de 7,0% (m/m) e 15,9 % (m/m) de cinzas. A macroalga seca foi facilmente hidrolisada em condições brandas, na presença de ácido sulfúrico 0,5 M, por 20 min, produzindo monossacarídeos fermentáveis com uma eficiência de hidrólise máxima de 63,21%. A galactose e a glicose presentes no hidrolisado foram fermentadas simultaneamente por Saccharomyces cerevisiae, após aclimatação da levedura cultivada em meio contendo apenas galactose como fonte de carbono. Os parâmetros cinéticos da fermentação do hidrolisado algáceo pela levedura aclimatada a galactose foram Y(P/S) = 0,48 ± 0,02 g.g-1, PP = 0,27 ± 0,04 g.L- 1.h-1, η = 94,1%. Portanto, a macroalga S. filiformis se mostrou um recurso renovável promissor como fonte de polissacarídeos facilmente hidrolisados, gerando um meio nutritivo rico em glucose e galactose para a produção de etanol.

Bacterial cellulose nanocrystals produced under different hydrolysis conditions: Properties and morphological features.

Bacterial cellulose (BC) is a polymer with interesting physical properties owing to the regular and uniform structure of its nanofibers, which are formed by amorphous (disordered) and crystalline (ordered) regions. Through hydrolysis with strong acids, it is possible to transform BC into a stable suspension of cellulose nanocrystals, adding new functionality to the material. The aim of this work was to evaluate the effects of inorganic acids on the production of BC nanocrystals (BCNCs). Acid hydrolysis was performed using different H2SO4 concentrations and reaction times, and combined hydrolysis with H2SO4 and HCl was also investigated. The obtained cellulose nanostructures were needle-like with lengths ranging between 622 and 1322nm, and diameters ranging between 33.7 and 44.3nm. The nanocrystals had a crystallinity index higher than native BC, and all BCNC suspensions exhibited zeta potential moduli greater than 30mV, indicating good colloidal stability. The mixture of acids resulted in improved thermal stability without decreased crystallinity.

A highly improved method for sensitive determination of amitriptyline in pharmaceutical formulations using an unmodified carbon nanotube electrode in the presence of sulfuric acid.

The present paper describes a novel, simple and reliable differential pulse voltammetric method for determining amitriptyline (AMT) in pharmaceutical formulations. It has been described for many authors that this antidepressant is electrochemically inactive at carbon electrodes. However, the procedure proposed herein consisted in electrochemically oxidizing AMT at an unmodified carbon nanotube paste electrode in the presence of 0.1 mol L(-1) sulfuric acid used as electrolyte. At such concentration, the acid facilitated the AMT electroxidation through one-electron transfer at 1.33 V vs. Ag/AgCl, as observed by the augmentation of peak current. Concerning optimized conditions (modulation time 5 ms, scan rate 90 mV s(-1), and pulse amplitude 120 mV) a linear calibration curve was constructed in the range of 0.0-30.0 µmol L(-1), with a correlation coefficient of 0.9991 and a limit of detection of 1.61 µmol L(-1). The procedure was successfully validated for intra- and inter-day precision and accuracy. Moreover, its feasibility was assessed through analysis of commercial pharmaceutical formulations and it has been compared to the UV-vis spectrophotometric method used as standard analytical technique recommended by the Brazilian Pharmacopoeia.

Propranolol impairs the closure of pressure ulcers in mice.

AIMS: ß-Adrenoceptors modulate acute wound healing; however, few studies have shown the effects of ß-adrenoceptor blockade on chronic wounds. Therefore, this study investigated the effect of ß1-/ß2-adrenoceptor blockade in wound healing of pressure ulcers. MAIN METHODS: Male mice were daily treated with propranolol (ß1-/ß2-adrenoceptor antagonist) until euthanasia. One day after the beginning of treatment, two cycles of ischemia-reperfusion by external application of two magnetic plates were performed in skin to induce pressure ulcer formation. KEY FINDINGS: Propranolol administration reduced keratinocyte migration, transforming growth factor-ß protein expression, re-epithelialization, and necrotic tissue loss. Neutrophil number and neutrophil elastase protein expression were increased in propranolol-treated group when compared with control group. Propranolol administration delayed macrophage mobilization and metalloproteinase-12 protein expression and reduced monocyte chemoattractant protein-1 protein expression. Myofibroblastic differentiation, angiogenesis, and wound closure were delayed in the propranolol-treated animals. Propranolol administration increased neo-epidermis thickness, reduced collagen deposition, and enhanced tenascin-C expression resulting in the formation of an immature and disorganized collagenous scar. SIGNIFICANCE: ß1-/ß2-Adrenoceptor blockade delays wound healing of ischemia-reperfusion skin injury through the impairment of the re-epithelialization and necrotic tissue loss which compromise wound inflammation, dermal reconstruction, and scar formation.

Ar seco e aquecido no processo de dormência e germinação de sementes de Urochloa humidicola / Dry and heated air in the process of dormancy overcoming and germination of Urochloa humidicola

O ácido sulfúrico (H2SO4) mostra-se eficaz na superação da dormência em sementes, porém trazendo riscos efetivos aos trabalhadores e ambiente. O objetivo do trabalho foi estudar a efetividade do tratamento com ácido sulfúrico, preconizado pelas RAS, e o emprego de ventilação com ar seco e aquecido na superação da dormência e desempenho germinativo de sementes de seis lotes de Urochloa humidicola cv. Tully. Os efeitos fisiológicos entre tratamentos térmicos (45, 55, 65 e 75 ºC), por 24 ou 48 h, a escarificação com H2SO4 concentrado por 10 min e um controle, foram comparados pela germinação, o índice de velocidade de germinação, o teste de tetrazólio e a massa seca das plântulas. O uso de temperaturas variadas e controladas e de H2SO4 são mecanismos de superação de dormência, porém em lotes com maior vitalidade os resultados foram similares ao H2SO4, podendo ser considerado uma alternativa. De maneira geral, o trabalho não indicou o melhor período (24 ou 48 h), para emprego da ventilação com ar seco, entretanto a temperatura de 60 °C, para os lotes de maior vitalidade (L1, L3 e L5), pode ser recomendada. O H2SO4 nos lotes com maior vitalidade não mostrou significância estatística em relação à testemunha, porém para os lotes com menor vitalidade ocorreu deterioração fisiológica das sementes.(AU)

Sulfuric acid (H2SO4) has shown effectiveness in overcoming dormancy, but its use carries effective workers and environmental risks. The objective of this work was to study the sulfuric acid treatment effectiveness, recommended by the RAS, and the use of ventilation with dry, heated air to overcome the dormancy and germination performance of six seed lots Urochloa humidicola cv. Tully. Comparison between the physiological effects of heat treatments at 45, 55, 65 and 75 ºC, with periods 24 and 48 h and chemical scarification (immersion in concentrated H2SO4) for 10 min, constituting eight treatments and two controls was performed. The seed germination, the germination velocity index, the tetrazolium test and seedling dry weight was evaluated. The use of controlled temperatures and of H2SO4 are mechanisms to overcome dormancy, but in lots with greater vitality were equal to conventional treatment with sulfuric acid results and can be considered as an alternative. In general, the work did not show the best indicated time (24 or 48 h) for use with dry air ventilation, however a temperature of 60 °C for lots of high vitality (L1, L3 and L5) might be recommended. The H2SO4 in plots with high vitality was not statistically significant compared to control, but for lots with less vitality occurred physiological deterioration of seeds.(AU)