103 research outputs found

    A novel approach to treat the Thiel-Behnke corneal dystrophy using 3D printed honeycomb-shaped polymethylmethacrylate (PMMA)/Vancomycin (VAN) scaffolds

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    Thiel-Behnke corneal dystrophy, or honeycomb corneal dystrophy, is an autosomal dominant corneal disorder. Tissue engineering can be a novel approach to regenerate this dystrophy. In this study, the honeycomb geometry of the dystrophy mimicked with a 3D printing technology, and 40% PMMA, 40% PMMA/(0.1, 0.5, 2, and 10)% VAN scaffolds were fabricated with honeycomb geometry. As a result of the biocompatibility test with mesenchymal stem cells (MSCs), it can be said that cells on the scaffolds showed high viability and proliferation for all incubation periods. According to the antibacterial activity results, the 40% PMMA/10% VAN showed antibacterial activity against S. aureous. Mechanical results reported that with the addition of VAN into the 40% PMMA, the tensile strength value increased up to 2% VAN amount. The swelling behaviours of the scaffolds were examined in vitro, and found that the swelling rate increased with a high VAN amount. The release of VAN from the scaffolds showed sustained release behaviour, and it took 13 days to be released entirely from the scaffolds

    Investigating the coenzyme specificity of phenylacetone monooxygenase from Thermobifida fusca

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    Type I Baeyer–Villiger monooxygenases (BVMOs) strongly prefer NADPH over NADH as an electron donor. In order to elucidate the molecular basis for this coenzyme specificity, we have performed a site-directed mutagenesis study on phenylacetone monooxygenase (PAMO) from Thermobifida fusca. Using sequence alignments of type I BVMOs and crystal structures of PAMO and cyclohexanone monooxygenase in complex with NADP+, we identified four residues that could interact with the 2â€Č-phosphate moiety of NADPH in PAMO. The mutagenesis study revealed that the conserved R217 is essential for binding the adenine moiety of the nicotinamide coenzyme while it also contributes to the recognition of the 2â€Č-phosphate moiety of NADPH. The substitution of T218 did not have a strong effect on the coenzyme specificity. The H220N and H220Q mutants exhibited a ~3-fold improvement in the catalytic efficiency with NADH while the catalytic efficiency with NADPH was hardly affected. Mutating K336 did not increase the activity of PAMO with NADH, but it had a significant and beneficial effect on the enantioselectivity of Baeyer–Villiger oxidations and sulfoxidations. In conclusion, our results indicate that the function of NADPH in catalysis cannot be easily replaced by NADH. This finding is in line with the complex catalytic mechanism and the vital role of the coenzyme in BVMOs

    Applying the ALARA concept to the evaluation of vesicoureteric reflux

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    The voiding cystourethrogram (VCUG) is a widely used study to define lower urinary tract anatomy and to diagnose vesicoureteric reflux (VUR) in children. We examine the technical advances in the VCUG and other examinations for reflux that have reduced radiation exposure of children, and we give recommendations for the use of imaging studies in four groups of children: (1) children with urinary tract infection, (2) siblings of patients with VUR, (3) infants with antenatal hydronephrosis (ANH), and (4) children with a solitary functioning kidney. By performing examinations with little to no radiation, carefully selecting only the children who need imaging studies and judiciously timing follow-up examinations, we can reduce the radiation exposure of children being studied for reflux

    Alternative low-cost adsorbent for water and wastewater decontamination derived from eggshellwaste: an overview

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    As the current global trend towards more stringent environmental standards, technical applicability and cost-effectiveness became key factors in the selection of adsorbents for water and wastewater treatment. Recently, various low-cost adsorbents derived from agricultural waste, industrial by-products or natural materials, have been intensively investigated. In this respect, the eggshells from egg-breaking operations constitute significant waste disposal problems for the food industry, so the development of value-added by-products from this waste is to be welcomed. The egg processing industry is very competitive, with low profit margins due to global competition and cheap imports. Additionally, the costs associated with the egg shell disposal (mainly on landfill sites) are significant, and expected to continue increasing as landfill taxes increase. The aim of the present review is to provide an overview on the development of low-cost adsorbents derived from eggshell by-products

    Thrombosis in vasculitis: from pathogenesis to treatment

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    In recent years, the relationship between inflammation and thrombosis has been deeply investigated and it is now clear that immune and coagulation systems are functionally interconnected. Inflammation-induced thrombosis is by now considered a feature not only of autoimmune rheumatic diseases, but also of systemic vasculitides such as Behçet’s syndrome, ANCA-associated vasculitis or giant cells arteritis, especially during active disease. These findings have important consequences in terms of management and treatment. Indeed, Behçet’syndrome requires immunosuppressive agents for vascular involvement rather than anticoagulation or antiplatelet therapy, and it is conceivable that also in ANCA-associated vasculitis or large vessel-vasculitis an aggressive anti-inflammatory treatment during active disease could reduce the risk of thrombotic events in early stages. In this review we discuss thrombosis in vasculitides, especially in Behçet’s syndrome, ANCA-associated vasculitis and large-vessel vasculitis, and provide pathogenetic and clinical clues for the different specialists involved in the care of these patients

    Sustainable conversion of agro-wastes into useful adsorbents

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    Preparation and characterization of raw andactivated carbon derived from three different selectedagricultural wastes: kola nut pod raw and activated (KNPRand KNPA), bean husk raw and activated (BHR and BHA)and coconut husk raw and activated (CHR and CHA) wereinvestigated, respectively. Influences of carbonization andacid activation on the activated carbon were investigatedusing SEM, FTIR, EDX, pHpzcand Boehm titration tech-niques, respectively. Carbonization was done at 350°C for2 h followed by activation with 0.3 M H3PO4(ortho-phosphoric acid). Results obtained from SEM, FTIR, andEDX revealed that, carbonization followed by acid acti-vation had a significant influence on morphology and ele-mental composition of the samples. SEM showed well-developed pores on the surface of the precursors after acidtreatment, FTIR spectra revealed reduction, broadening,disappearance or appearance of new peaks after acid acti-vation. EDX results showed highest percentage of carbonby atom respectively in the order BHA[KNPA[CHArespectively. The pHpzcwas found to be 5.32, 4.57 and 3.69for KNPA, BHA and CHA, respectively. Boehm titrationresult compliments that of pHpzc, indicating that the sur-faces of the prepared adsorbents are predominantly acidic.This study promotes a sustainable innovative use of agro-wastes in the production of cheap and readily availableactivated carbons, thereby ensuring more affordable waterand effluent treatment adsorbents
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