This study researched the steam explosion effect catalysed by citric acid and sodium hydroxide on the chemical and structural properties of sugarcane bagasse and on the enzymatic hydrolysis process. ...Chemical and structural characterisation of raw and pretreated biomass was performed by reference methodologies for lignocellulosic materials, FTIR, XRD, TGA and SEM. Enzymatic hydrolysis was performed with a final volume of 20 mL consisting 3% sugarcane bagasse (dry weight), sodium citrate buffer 50 mM (pH = 5.0) and 1 g enzyme/100 g cellulose of Cellic
®
Cetec 3 enzyme complex. The total reducing sugars were determined by a 3,5-dinitrosalicilic acid method. In explosion pretreatment catalysed by citric acid, a biomass was obtained with a lesser amount of hemicelluloses (16.16%), a higher initial degradation temperature and formation of cracks in fibre cell wall. Pretreated bagasse by NaOH steam explosion showed complete destructuring of fibre, lignin removal of 65% and hemicellulosic fraction preservation. Sugarcane bagasse obtained after NaOH steam explosion showed the highest production of reducing sugars (9.07 g L
−1
), which can be attributed to greater exposure of carbohydrate fraction promoted by lignin removal, since these parameters showed a strong negative correlation (r = −0.99, p < 0.05).
Furfural is a platform molecule obtained from hemicellulosic monosaccharides present in lignocellulosic biomass. Due to the possibility of converting this molecule into several value-added chemicals ...and the need to search for more sustainable production processes, the present work aimed to produce and characterize different sulfonated activated carbons (AC-S) from sugarcane bagasse (SCB) for application in furfural production in aqueous media. ACs were produced by chemical activation using salts of ZnCl2, NiCl2, and CuCl2 and a temperature and activation time of 550 °C and 3 h under nitrogen flow, respectively. Sulfonation was carried out with H2SO4 (98%) at a solid/liquid ratio of 1:10 at 160 °C for 2 h. Catalytic tests were performed using 5% catalyst mass regarding xylose, a temperature of 180 °C, and a reaction time of 2 h. ACs with high surface areas, ranging from 290 to 1100 m2 g−1, were produced. All catalysts had an increased sulfur content and total acidity after sulfonation, indicating the successful attachment of the sulfonic group (-SO3H) in the carbon matrix of the CAs. The AC-S/CuCl2 catalyst achieved the best catalytic performance compared to AC-S/ZnCl2, AC-S/NiCl2, and other acidic solids reported in the literature, achieving yield and selectivity of 55.96% and 83.93%, respectively. These results evidence the importance of the synergy between the Lewis and Brønsted acid sites on selective xylose dehydration and make AC-S/CuCl2 a promising acid catalyst for converting xylose to furfural in an aqueous medium.
NLRP3 Inflammasome Mediates Aldosterone-Induced Vascular Damage Bruder-Nascimento, Thiago; Ferreira, Nathanne S; Zanotto, Camila Z ...
Circulation (New York, N.Y.),
2016-December-6, 2016-Dec-06, 2016-12-06, 20161206, Letnik:
134, Številka:
23
Journal Article
Recenzirano
Odprti dostop
BACKGROUND:Inflammation is a key feature of aldosterone-induced vascular damage and dysfunction, but molecular mechanisms by which aldosterone triggers inflammation remain unclear. The NLRP3 ...inflammasome is a pivotal immune sensor that recognizes endogenous danger signals triggering sterile inflammation.
METHODS:We analyzed vascular function and inflammatory profile of wild-type (WT), NLRP3 knockout (NLRP3), caspase-1 knockout (Casp-1), and interleukin-1 receptor knockout (IL-1R) mice treated with vehicle or aldosterone (600 µg·kg·d for 14 days through osmotic mini-pump) while receiving 1% saline to drink.
RESULTS:Here, we show that NLRP3 inflammasome plays a central role in aldosterone-induced vascular dysfunction. Long-term infusion of aldosterone in mice resulted in elevation of plasma interleukin-1β levels and vascular abnormalities. Mice lacking the IL-1R or the inflammasome components NLRP3 and caspase-1 were protected from aldosterone-induced vascular damage. In vitro, aldosterone stimulated NLRP3-dependent interleukin-1β secretion by bone marrow–derived macrophages by activating nuclear factor-κB signaling and reactive oxygen species generation. Moreover, chimeric mice reconstituted with NLRP3-deficient hematopoietic cells showed that NLRP3 in immune cells mediates aldosterone-induced vascular damage. In addition, aldosterone increased the expression of NLRP3, active caspase-1, and mature interleukin-1β in human peripheral blood mononuclear cells. Hypertensive patients with hyperaldosteronism or normal levels of aldosterone exhibited increased activity of NLRP3 inflammasome, suggesting that the effect of hyperaldosteronism on the inflammasome may be mediated through high blood pressure.
CONCLUSIONS:Together, these data demonstrate that NLRP3 inflammasome, through activation of IL-1R, is critically involved in the deleterious vascular effects of aldosterone, placing NLRP3 as a potential target for therapeutic interventions in conditions with high aldosterone levels.
Heterogeneous catalysis for biodiesel production via esterification has emerged as a preferred route as it permits to overcome the disadvantages associated to homogeneous catalysis, which presents ...serious drawbacks that affect biodiesel production and increase its costs such as corrosivity, difficult removal, and non-reuse of the catalyst. This study evaluated the esterification of oleic acid (OA) using CoFe
2
O
4
and MnFe
2
O
4
ferrite magnetic nanoparticles (MNPs) coated with sulfonated lignin (SL). SL was synthesized from sugarcane bagasse lignin employing acetyl sulfate (sulfonating agent). Two different proportions of reactants were adopted, obtaining the solids SL5 and SL7.5—posteriorly incorporated into the MNPs. Reaction parameters evaluated were as follows: time (4 and 6 h) and temperature (80 and 100 °C), with other parameters fixed. The catalysts were characterized by XRD, BET method, SEM, TGA, and elemental analysis. The sulfonic group contents were determined by acid–base titration. The conversion of OA into methyl esters was determined by GC–MS and FTIR. Elemental analysis showed that SL5 and SL7.5 have 2.68% of sulfur content by mass and the following minimal molecular formulas C
9
H
10,52
O
5,62
(SO
3
H)
0,18
and C
9
H
10,52
O
5,62
(SO
3
H)
0,17
. XRD and TGA data evidenced that coated MNPs exhibit incorporation percentage of SL higher than 50%, with the best results for CoFe
2
O
4
-SL5 (79.5%) and CoFe
2
O
4
-SL7.5 (78.5%). GC–MS and FTIR data revealed that the highest OA conversions were achieved under 6 h and 100 °C. In addition, CoFe
2
O
4
-SL5 and MnFe
2
O
4
-SL7.5 exhibited the best catalytic performances in the esterification reactions with conversions of OA into fatty acid methyl esters of approximately 80%.
Graphical abstract
Aim
The Theory of Island Biogeography posits that ecological and evolutionary processes regulate species richness of isolated areas. We assessed the influences of an island area and distance from the ...mainland on species richness, phylogenetic diversity, and phylogenetic composition of snakes on coastal islands.
Location
Coastal islands of the megadiverse Atlantic Forest in southeastern Brazil.
Methods
We compiled the species composition of 17 coastal islands in southeastern Brazil. Species richness and phylogenetic diversity were calculated for each island. Phylogenetic composition was measured using principal coordinates of phylogenetic structure. We then employed generalized linear models to test the influence of area and distance from the mainland on the diversity metrics.
Results
We found a prominent influence of area on species richness, whereas phylogenetic diversity was more affected by distance from the mainland. Snake clades were distinctly associated with area and distance. The Boidae family was associated with nearer and larger islands, whereas Elapidae was broadly distributed. Distance from the mainland was associated with the distribution of Dipsadidae, whereas Colubridae was influenced by both the area and distance. The Viperidae family attained higher values of phylogenetic diversity in smaller and more remote islands.
Main conclusions
This island system conserved a considerable piece of snake richness from southeastern Brazil, including island endemic species. Area and distance from the mainland were important drivers of snake diversity in the Atlantic Forest coastal islands. However, these predictors affected the different components of diversity in different ways. Phylogenetic composition analysis enables us to understand how basal nodes contributed to high levels of phylogenetic diversity on smaller and farther islands regardless of the decrease in species richness.
This manuscript contains an innovator method to assess the influence of ecological predictors on diversity of snakes from coastal islands in the megadiverse Atlantic Forest, southeastern, Brazil.
Mineralocorticoid receptors (MRs), which are activated by mineralocorticoids and glucocorticoids, actively participate in mechanisms that affect the structure and function of blood vessels. Although ...experimental and clinical evidence shows that vascular damage in diabetes is associated with structural alterations in large and small arteries, the role of MR in this process needs further studies. Thus, we tested the hypothesis that MR, through redox-sensitive mechanisms, plays a role in diabetes-associated vascular remodelling. Male, 12-14-weeks-old db/db mice, a model of type 2 diabetes and their non-diabetic counterpart controls (db/+) were treated with spironolactone (MR antagonist, 50 mg/kg/day) or vehicle for 6 weeks. Spironolactone treatment did not affect blood pressure, fasting glucose levels or weight gain, but increased serum potassium and total cholesterol in both, diabetic and control mice. In addition, spironolactone significantly reduced serum insulin levels, but not aldosterone levels in diabetic mice. Insulin sensitivity, evaluated by the HOMA (homoeostatic model assessment)-index, was improved in spironolactone-treated diabetic mice. Mesenteric resistance arteries from vehicle-treated db/db mice exhibited inward hypertrophic remodelling, increased number of smooth muscle cells and increased vascular stiffness. These structural changes, determined by morphometric analysis and with a myography for pressurized arteries, were prevented by spironolactone treatment. Arteries from vehicle-treated db/db mice also exhibited augmented collagen content, determined by Picrosirius Red staining and Western blotting, increased reactive oxygen species (ROS) generation, determined by dihydroethidium (DHE) fluorescence, as well as increased expression of NAD(P)H oxidases 1 and 4 and increased activity of mitogen-activated protein kinases (MAPKs). Spironolactone treatment prevented all these changes, indicating that MR importantly contributes to diabetes-associated vascular dysfunction by inducing oxidative stress and by increasing the activity of redox-sensitive proteins.
Flaxseed gum (FG)-based films were developed with the addition of glycerol as a plasticizer and glutaraldehyde as a crosslinking agent. HCl was added to improve crosslinking and decrease the ...hydrophilicity of the matrix. Different cellulose nanocrystal (CN) amounts were used as reinforcements in the optimum FG formulation. The crosslinking process at pH 3.5 led to a lower solubility of FG in water (from 100% to 53%) and an increase in thermal stability (from 160 ºC to 209 ºC). FTIR analysis confirmed a reduction in the -OH band due to crosslinking between the hydroxyl groups of FG. A diffuse diffraction pattern was observed for all FG films. The addition of 4% w/w of CN contributed to reduction of water solubility (from 53% to 20.8%) and absorption (from 21.9% to 6.8%). Finally, an improvement was observed in the tensile mechanical properties in the nanocomposites, showing satisfactory results for the proposed formulations, mainly with 8% w/w of CN added to the matrix. Overall, this study demonstrated that FG/CN nanocomposites are promising materials to be use as a sustainable biopolymer for application as bioplastics.
O objetivo deste trabalho consistiu em propor uma nova metodologia experimental e investigativa para o ensino taxo-morfológico da classe insecta por meio de um estudo de caso em Entomologia Forense, ...direcionada ao Ensino Médio. A proposta baseia-se na Teoria da Aprendizagem Significativa, na Aprendizagem Baseada em Problemas e na Experimentação Investigativa. Propõe-se a utilização de um estudo de caso em entomologia forense, que desencadeará na realização de uma atividade prática investigativa intitulada como “Montando um minicadáver”. Na realização da atividade experimental os educandos irão coletar ativamente insetos adultos e imaturos buscando solucionar o estudo de caso e realizar o estudo taxo-morfológico desses até a categoria taxonômica de Ordem. As bases conceituais utilizadas nesta proposta de ensino, criam um ambiente investigativo e desafiador, levando os estudantes a desenvolver habilidades cognitivas para resolução de problemas e assumir o papel de sujeitos ativos na construção do conhecimento científico, a partir da ressignificação dos conhecimentos prévios que possuem. Por fim, salienta-se que a metodologia proposta neste estudo, pode servir como subsídio para os professores de Biologia, uma vez que a experimentação investigativa se mostra eficiente e inovadora para o Ensino de Ciências quando comparada ao ensino tradicional.
Protease inhibitors are involved in the regulation of endogenous cysteine proteases during seed development and play a defensive role because of their ability to inhibit exogenous proteases such as ...those present in the digestive tracts of insects.
seeds, which can be used in human and animal feed, were investigated for their potential for the development of agricultural biotechnology and in the field of human health. In the pine nuts extract, which blocked the activities of cysteine proteases, it was detected potent insecticidal activity against termites (
) belonging to the most abundant termite genus in tropical regions. The cysteine inhibitor (AaCI-2S) was purified by ion-exchange, size exclusion, and reversed-phase chromatography. Its functional and structural stability was confirmed by spectroscopic and circular dichroism studies, and by detection of inhibitory activity at different temperatures and pH values. Besides having activity on cysteine proteases from
digestive tract, AaCI-2S inhibited papain, bromelain, ficin, and cathepsin L and impaired cell proliferation in gastric and prostate cancer cell lines. These properties qualify
seeds as a protein source with value properties of natural insecticide and to contain a protease inhibitor with the potential to be a bioactive molecule on different cancer cells.
To investigate predictors of low back and lower extremity musculoskeletal injury in a cohort of Naval cadets.
Prospective Cohort Study
545 Naval cadets (Males, n = 394, 72%) were followed-up over ...eight months. Nine variables were investigated as predictors: history of musculoskeletal symptoms in the last 12 months, ankle dorsiflexion range of motion, sit and reach test, isometric hip abduction and external rotation strength, alignment during the single leg squat test, single leg hop test for distance, prone plank and side plank tests. All injuries that required medical attention were registered. Predictive associations were examined using univariable and multivariable logistic regression analyses.
The incidence of all injuries was 7%. Cadets who failed the 60-second plank test (OR = 3.3; 95% CI, 1.2−8.8, P = 0.04), had ≤18 cm in the sit and reach test (OR = 4.0; 95% CI, 1.4−11.2, P = 0.01), or reported pain in the last 12 months in two or more body regions (OR = 2.7; 95% CI, 1.02−7.3, P = 0.04), had greater odds of sustaining an overuse injury. No predictors were identified for acute injuries.
Decreased trunk endurance on the prone plank test, reduced posterior chain flexibility on the sit and reach test, and a history of pain reported in two or more sites in the last 12 months were predictors of overuse injuries in Naval cadets. Assessment and intervention of these modifiable risk factors may be clinically relevant in injury screening and prevention.
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