15 research outputs found

    Strong Acid-Nonionic Surfactant Lyotropic Liquid-Crystalline Mesophases as Media for the Synthesis of Carbon Quantum Dots and Highly Proton Conducting Mesostructured Silica Thin Films and Monoliths

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    Lyotropic liquid-crystalline (LLC) materials are important in designing porous materials, and acids are as important in chemical synthesis. Combining these two important concepts will be highly beneficial to chemistry and material science. In this work, we show that a strong acid can be used as a solvent for the assembly of nonionic surfactants into various mesophases. Sulfuric acid (SA), 10-lauryl ether (C12E10), and a small amount of water form bicontinuous cubic (V1), 2D-hexagonal (H1), and micelle cubic (I1) mesophases with increasing SA/C12E10 mole ratio. A mixture of SA and C12E10 is fluidic but transforms to a highly ordered LLC mesophase by absorbing ambient water. The LLC mesophase displays high proton conductivity (1.5 to 19.0 mS/cm at room temperature) that increases with an increasing SA content up to 11 SA/C12E10 mole ratio, where the absorbed water is constant with respect to the SA amount but gradually increases from a 2.3 to 4.3 H2O/C12E10 mole ratio with increasing SA/C12E10 from 2 to 11, respectively. The mixture of SA and C12E10 slowly undergoes carbonization to produce carbon quantum dots (c-dots). The carbonization process can be controlled by simply controlling the water content of the media, and it can be almost halted by leaving the samples under ambient conditions, where the mixture slowly absorbs water to form photoluminescent c-dot-embedded mesophases. Over time the c-dots grow in size and increase in number, and the photoluminescence frequency gradually shifts to a lower frequency. The SA/C12E10 mesophase can also be used as a template to produce highly proton conducting mesostructured silica films and monoliths, as high as 19.3 mS/cm under ambient conditions. Aging the silica samples enhances the conductivity that can be even larger than for the LLC mesophase with the same amount of SA. The presence of silica has a positive effect on the proton conductivity of SA/C12E10 systems. © 2015 American Chemical Society

    The performance of UNIFAC and related group contribution models part I. Prediction of infinite dilution activity coefficients

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    Infinite dilution activity coefficients have been calculated for 24 systems including highly non-ideal and nearly non-ideal using original, modified UNIFAC and UNIFAC-FV models. The calculations are compared with experimental results. The performance of the models in predictions and the significance of free volume effects on solvent activities in solutions containing small compounds are discussed

    The performance of UNIFAC and related group contribution models .1. Prediction of infinite dilution activity coefficients

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    WOS: A1996VU72400006Infinite dilution activity coefficients have been calculated for 24 systems including highly non-ideal and nearly non-ideal using original, modified UNIFAC and UNIFAC-FV models. The calculations are compared with experimental results. The performance of the models in predictions and the significance of free volume effects on solvent activities in solutions containing small compounds are discussed

    Leucine tolerance in children with MSUD is not correlated with plasma leucine levels at diagnosis.

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    © 2022 Maple syrup urine disease (MSUD) is an inborn metabolic disease. The nutritional treatment with restricted intake of branched chain amino acids and prevention of leucine toxicity are crucially important for a favorable outcome. The aim of this study is to analyze the relation of blood leucine levels at diagnosis with future leucine tolerances, to determine whether any prediction about the future leucine tolerances or plasma leucine levels is possible by evaluating blood leucine levels at diagnosis. The study group consisted of 45 MSUD patients. Leucine levels at diagnosis were compared with age at diagnosis, leucine tolerances, maximum leucine levels/ages, and average blood leucine levels. The mean plasma leucine level at diagnosis was 2,355.47 ± 1,251.7 μmol/L (ref: 55-164 μmol/L). The median age at diagnosis was 17 days. Leucine tolerances per kg body weight declined until the age of 8 years and stabilized subsequently. The average age of maximum leucine level during follow-up was 3.14 ± 1.92 years, and the mean maximum lifetime plasma leucine level on follow-up was 1,452.13 ± 621.38 μmol/L. The leucine levels at diagnosis did not have any significant relationship with lifetime leucine tolerances, maximum plasma leucine levels or mean plasma leucine levels. The plasma leucine levels at diagnosis did not have a predictive value for later leucine tolerances or plasma leucine levels. The maximum lifetime leucine level is likely to happen within the first 3 years of life, underlining the importance of good metabolic control and compliance to dietary treatment at early ages

    Etanercept for the Treatment of Chronic Arthritis Related to Chronic Granulomatous Disease: A Case

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    Introduction: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency, in which infections are the main presenting symptoms. Moreover, patients may also experience inflammatory and autoimmune manifestations. With proper management of infections, patients now survive to adulthood, and inflammatory manifestations have become more prominent problems. Treatment of the inflammatory manifestations in CGD is challenging and requires a multidisciplinary approach. Since tumor necrosis factor (TNF)-? has been cited as having a possible role on inflammatory conditions in CGD, etanercept, an anti-TNF agent, may represent a major advance in the management of inflammatory manifestations. Case Presentation: In this report, we described a 15-year-old boy, suffering concurrently both from human leukocyte antigen (HLA)-B27-positive chronic arthritis and CGD, whose arthritis did not respond to treatment with methotrexate and ibuprofen. Remission was achieved 6 months after etanercept initiation and during the next 18 months on medication, we did not encounter any signs of severe infections. Conclusion: Treatment of inflammatory conditions in CGD patients is still challenging in view of the lack of evidence-based therapeutic options. In this study, we report the first pediatric CGD case, in which chronic arthritis was successfully treated with etanercept. © Copyright 2019, Mary Ann Liebert, Inc., publishers 2019

    Technetium Tc 99m sulphur colloid seminal vesicle scintigraphy: A novel approach for the diagnosis of the ejaculatory duct obstruction

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    OBJECTIVES To define a novel technique in the diagnosis of partial and complete ejaculatory duct obstruction (EDO)

    Renal changes and apoptosis caused by subacute exposure to Aroclor 1254 in selenium-deficient and selenium-supplemented rats

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    Aroclor 1254 (A1254), a mixture of polychlorinated biphenyls, exerts hepatic, renal, and reproductive toxicity in rodents. This study aimed to determine a protective role of selenium on histopathological changes, oxidative stress, and apoptosis caused by A1254 in rat kidney. It included a control group, which received regular diet containing 0.15 mg/kg Se (C), a Se-supplemented group (SeS) receiving 1 mg/kg Se, a Se-deficient group (SeD) receiving Se-deficient diet of ≤0.05 mg/kg Se, an A1254-treated group (A) receiving 10 mg/kg of Aroclor 1254 and regular diet, an A1254-treated group receiving Se-supplementation (ASeS), and an A1254-treated group receiving Se-deficient diet (ASeD). Treatments lasted 15 days. After 24 h of the last dose of A1254, the animals were decapitated under anaesthesia and their renal antioxidant enzyme activities, lipid peroxidation (LP), glutathione, protein oxidation, and total antioxidant capacity levels measured. Histopathological changes were evaluated by light and electron microscopy. Apoptosis was detected with the TUNEL assay. Kidney weights, CAT activities, and GSH levels decreased significantly in all A1254-treated groups. Renal atrophic changes and higher apoptotic cell counts were observed in the A and ASeD groups. Both groups also showed a significant drop in GPx1 activities (A-34.92 % and ASeD-86.46 %) and rise in LP (A-30.45 % and ASeD-20.44 %) vs control. In contrast, LP levels and apoptotic cell counts were significantly lower in the ASeS group vs the A group. Histopathological changes and renal apoptosis were particularly visible in the ASeD group. Our findings suggest that selenium supplementation provides partial protection against renal toxicity of Aroclor 1254. © 2020 Naciye Dilara Zeybek et al., published by Sciendo 2020
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