Several studies have reported the adverse effects of recalcitrant compounds and emerging contaminants present in industrial effluents, which are not degradable by ordinary biological treatment. Many ...of these compounds are likely to accumulate in living organisms through the lipid layer. At concentrations above the limits of biological tolerance, these compounds can be harmful to the ecosystem and may even reach humans through food chain biomagnification. In this regard, advanced oxidation processes (AOPs) represent an effective alternative for the removal of the pollutants. This study focused on the AOP involving the use of ultraviolet radiation in homogeneous and heterogeneous systems. Based on the literature review, comparisons between natural and artificial light were established, approaching photoreactors constructive and operational characteristics. We concluded that the high availability of solar power in Brazil would make the implementation of the AOP using natural solar radiation for the decontamination of effluents feasible, thereby contributing to clean production and biodiversity conservation. This will serve as an important tool for the enforcement of environmental responsibility among public and private institutions.
•The synergic effect between ZnO and NaX was positive, which increased its activity.•The best results were obtained at pH 3 and 9 with ZnO/NaX and at pH 3 with Nb2O5/AC.•High degradation and ...considerable mineralization were attained with 10% ZnO/NaX.•ZnO and Nb2O5 supported on NaX and AC are promising alternatives as photocatalysts.
This study aimed to evaluate the photocatalytic activity of ZnO and Nb2O5 catalysts, both supported on NaX zeolite and activated charcoal (AC). The synergistic effect between oxide and support and the influence of solution pH (3, 7 and 9) on photocatalytic degradation of reactive blue 5G (C.I. 222) were analyzed. The catalysts Nb2O5/NaX, Nb2O5/AC and ZnO/NaX, ZnO/AC with 5 and 10% (wt%) were prepared by wet impregnation. The results showed that the catalysts exhibit quite different structural and textural properties. The synergic effect between ZnO and NaX support was higher than that with the activated charcoal, showing that these catalysts were more efficient. The most photoactive catalyst was 10% ZnO/NaX which showed 100% discoloration of the dye solution at pH 3, 7 and 9 after 0.5, 5 and 2h of irradiation, respectively. The hydrolytic nature of zeolite favored the formation of surface hydroxyl radicals, which increased the activity of the photocatalyst. Thus, catalysts supported on NaX zeolite are promising for use in photocatalysis.
Xylooligosaccharides (XOS) are oligomers with recognized and important prebiotic properties, whose consumption is associated with several health benefits, including a positive impact on the immune ...system. In this work, XOS were produced through a green process of enzymatic hydrolysis performed directly on an intermediate product from a pulp and paper industry,
Eucalyptus
bleached
kraft
pulp. Focusing on an industrial, sustainable and more economical application, two goals were defined and validated: (i) no pretreatment of the substrate and (ii) the replacement of the commonly used buffer solution as reaction medium for only water. The influence of the most relevant operating conditions on the production of XOS as well as the respective yields obtained were very similar when using either buffer or water as the reaction medium. For the use of water, although the solution pH decreases during the enzymatic reaction, this change did not affect the production of XOS. For the optimized conditions, 80 °C and 100 U/g pulp, a maximum yield of 31.4 ± 2.6% per total xylan in the pulp was obtained, resulting in more than 50 kg of XOS per ton of pulp. The correspondent hydrolysate was mainly composed by xylobiose (66%) and xylotriose (29%), oligomers with the highest prebiotic effect.
The production of xylooligosaccharides (XOS) by acid hydrolysis using an alkaline extraction filtrate from the bleached kraft pulp of Eucalyptus globulus is a rapid and effective process. The ...reaction kinetics knowledge is, however, extremely important to optimize the experimental conditions that maximize XOS production and limit the formation of xylose (unwanted product). In this work, a pseudo-homogeneous model of irreversible first-order reactions is proposed, considering the sequential degradation of fast-reacting xylan into high- and low-molecular-weight oligomers, followed by their conversion to xylose. A kinetic parameter estimation based on the Arrhenius equation was performed, considering the temperature and acid concentration effects. The kinetic model presented good fittings to the experimental results (R 2 mostly between 0.97 and 0.99), proving its suitability to describe xylan hydrolysis over time. The mapping of XOS maximum yields as a function of pH, temperature, and time was also represented, allowing fast prediction for other operating conditions.
Background: Children living at high altitude in San Antonio de los Cobres (SAC), Argentina, were shown to have lower high-density lipoprotein cholesterol (HDL-C) levels than Buenos Aires (BA) ...children. HDL antioxidant capacity is mainly attributed to paraoxonase1 (PON1).
Objective: To compare PON1 activity in indigenous SAC vs. BA children.
Methods: A cross-sectional study compared 158 SAC vs. 97 BA children (6-16 years). Anthropometric data and lipoprotein profile were measured. PON1 was evaluated employing paraoxon (PON) and phenylacetate (ARE) activity.
Results: The prevalence of overweight/obesity was lower in SAC than in BA children (18.3 vs. 30.9%). Triglycerides (1.34 vs. 0.90 mmol/l), apo B (0.84 vs.0.72 g/l), apo A-I (1.33 vs. 1.27 g/l), and ARE activity (100 vs. 90 µmol/ml/min) were higher, while HDL-C (1.16 vs. 1.32 mmol/l) and PON activity (170 vs. 203 nmol/ml/min) were lower in SAC than in BA. Separate multiple linear regression analyses showed that SAC children had significantly higher triglyceride (Beta −0.38), apo B (Beta −0.34), and ARE (Beta −0.36) plus lower HDL-C (Beta 0.33) and PON (Beta 0.25) compared with BA; adjusted for age, gender, and BMI.
Conclusion: SAC showed an unfavorable lipoprotein profile, lower PON and higher ARE activities compared with BA children, suggesting the presence of altered HDL metabolism and antioxidant capacity.
•Use of Fe(III)-EDDS complex as a source of iron for photo-Fenton at neutral pH.•Photolysis of Fe(III)-EDDS generates radical species other than HO that can act in the presence of carbonates.•Radical ...generation by Fe(III)-EDDS photolysis dependent on aeration but not on the presence of H2O2.•Decreased degradation performance at elevated temperatures.•Classical photo-Fenton at acidic pH remains more robust for treating high contaminant concentrations.
This study evaluates the use of the Fe(III)-EDDS complexing agent as an alternative to conventional acidic pH photo-Fenton for the treatment of the pesticide imidacloprid in natural water. The main objective is to estimate whether Fe(III)-EDDS is a viable alternative when treating waters containing high concentrations of contaminants. To this end, the mode of action of Fe(III)-EDDS is examined in the presence of carbonates, at different aeration conditions and at different temperatures. The role of HO2/O2− radical species and some aspects of the Fe(III)-EDDS complexation mechanism are discussed. Degradation kinetics and toxicities of generated intermediates are compared between Fe(III)-EDDS and conventional photo-Fenton treatment. An overview of the benefits and limitations of the process is presented.
Summary
Context
Acromegaly is characterized by GH excess and insulin resistance. It is not known which of these disorders is responsible for the increased atherogenic risk in these patients.
...Objective
To analyse the associations of GH and homoeostasis model assessment (HOMA) with biomarkers of cardiovascular disease and to compare the above‐mentioned variables between patients with active acromegaly and controls.
Design and setting
This open cross‐sectional study was conducted at a University Hospital.
Patients
Twenty‐two outpatients were compared with sex‐ and age‐matched control subjects.
Main outcomes
Included clinical features, hormonal status, markers of insulin resistance, lipoprotein profile and biomarkers of cardiovascular disease.
Results
Patients presented higher triglyceride (median IQR) (1·21·1–1·6 vs 0·90·6–1·1 mm, P < 0·05), low‐density lipoprotein‐cholesterol (LDL‐C) (mean ± SD) (3·5 ± 0·9 vs 3·0 ± 0·7mm, P < 0·05), apoB (0·98 ± 0·23 vs 0·77 ± 0·22 g/l, P < 0·05), free fatty acid (0·69 ± 0·2 vs 0·54 ± 0·2 mM, P < 0·05), oxidized‐LDL (120 ± 22 vs 85 ± 19 U/l, P < 0·05) and endothelin‐1 (0·90 ± 0·23 vs 0·72 ± 0·17 ng/l, P < 0·05) levels, increased cholesteryl ester transfer protein (CETP) activity (179 ± 27 vs 138 ± 30%/ml/h, P < 0·01) and lower C reactive protein (CRP) (0·250·1–0·9 vs 0·850·4–1·4 mg/l; P < 0·05) levels than control subjects. Vascular cell adhesion molecule (VCAM‐1) concentration was not different. By multiple linear regression analyses, HOMA explained the variability of triglycerides (25%), high‐density lipoprotein‐cholesterol (HDL‐C) (30%) and CETP activity (28%), while GH independently predicted LDL‐C (18%), oxidized‐LDL (40%) and endothelin‐1 levels (19%).
Conclusions
In patients with active acromegaly, GH excess contributes to the development of insulin resistance, and the interaction between both disturbances would be responsible for the appearance of atherogenic pro‐oxidative and pro‐inflammatory factors. Insulin resistance would be preferably associated with an atherogenic lipoprotein profile and to high CETP activity, while high GH levels would independently predict the increase in LDL‐C, ox‐LDL and endothelin‐1.
Among natural fillers, cork has been acknowledged as a suitable alternative of other cellular materials that are widely employed in engineering applications due to their low conductivity to heat, ...noise and vibration, high abrasion resistance and flexibility, high compressibility ratio, among other characteristics 1. The eco-friendly features of natural fillers based composites make them a very promising and sustainable solution to large markets mainly if additive manufacturing technologies, such as 3D printing, are used 2. Through 3D printers, engineers, designers and architects can create design and decor products with a free complexity of geometry. In this research work, plastic matrices of HDPE – obtained from conventional suppliers – were reinforced with different ratios of cork waste and natural cork powders – obtained from cork transformation industries – to find the optimum mixture for 3D printing. The effects of cork powders content in the plastic on the morphological, physical and mechanical properties of the composites were investigated through the density, optical microscopy, wettability, thermal analysis and tensile testing. Cork-based composites were processed by an extrusion system, and the mixture of polymer, adhesive and fillers is discussed. The results show that the addition of pure cork and cork waste can be processed with polymers such as HDPE, having adequate physical and mechanical properties.
Metabolic syndrome (MS) and type 2 diabetes are highly associated with an abnormal lipoprotein profile, which may be generated and accentuated by high cholesteryl ester transfer protein (CETP) ...activity. Given the difficulty in measuring CETP activity, the aim was to identify simple biochemical predictors of high CETP activity.
Eighty five subjects at risk for type 2 diabetes were classified according to the presence of MS. Lipoprotein profile, HOMA-IR and endogenous CETP activity were evaluated.
As expected, MS patients presented higher concentration of glucose, insulin, triglycerides and non-HDL-C and lower HDL-C levels. Moreover, MS patients exhibited increased HOMA-IR and CETP activity. Employing a ROC curve for MS, high CETP activity was defined as >250%ml−1h−1. The predictive variables of high CETP were non-HDL-C≥160mg/dl (OR=11.1;95%IC=3.3–38.2;p<0.001) and HOMA-IR>2.1 (OR=4.4;95%IC=1.3–14.8;p<0.05).
High non-HDL-C and insulin resistance were predictors for increased CETP activity which measurement is not accessible for clinical laboratories.
► CETP measurement is not suitable for clinical laboratories. ► Increased non-HDL-C and HOMA-IR were predictors of high CETP activity. ► Identifying subjects with high CETP activity might improve CVD risk assessment.
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