783 research outputs found

    Properties and morphology of poly(vinyl alcohol) blends with sago pith bio-filler as biodegradable composites

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    The effects of sago pith as a bio-filler (SPB) on the mechanical and thermal properties of poly(vinyl alcohol) (PVA) were studied. The SPB was obtained from sago pith waste after starch extraction from sago palm. Sago pith waste was dried and ground to produce SPB. The SPB was blended with PVA in a twin-screw co-rotating extruder in order to produce PVA-SPB composites for mechanical, morphology, and thermal analyses. Blending of SPB and PVA improved the tensile modulus, whereas the tensile strength was reduced. This result occurred because SPB increased the rigidity of PVA. However, lack of interfacial adhesion between PVA and SPB caused the loss of reinforcing effects. The morphology analysis showed that a high loading of SPB (>70 wt%) tended to form clusters, as implied by the presence of elongated cavities due to droplet coalescence restricting chain mobility. Besides that, the enthalpy of melting (Delta H(m)) for 50 wt% of SPB was higher than that of PVA. This observation means that the molecular interaction forces between PVA and SPB were so great as to overtake those of the PVA itself. Thus it was concluded that 40-50 wt% of SPB was preferably blended with PVA to form a biodegradable composite in order to reduce the overall materials cost, rather than to act as a strong reinforcing filler

    Comparative effectiveness of telemedicine strategies on type 2 diabetes management: A systematic review and network meta-analysis

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    The effects of telemedicine strategies on the management of diabetes is not clear. This study aimed to investigate the impact of different telemedicine strategies on glycaemic control management of type 2 diabetes patients. A search was performed in 6 databases from inception until September 2016 for randomized controlled studies that examined the use of telemedicine in adults with type 2 diabetes. Studies were independently extracted and classified according to the following telemedicine strategies: teleeducation, telemonitoring, telecase-management, telementoring and teleconsultation. Traditional and network meta-analysis were performed to estimate the relative treatment effects. A total of 107 studies involving 20,501 participants were included. Over a median of 6 months follow-up, telemedicine reduced haemoglobin A1c (HbA1c) by a mean of 0.43% (95% CI: −0.64% to −0.21%). Network meta-analysis showed that all telemedicine strategies were effective in reducing HbA1c significantly compared to usual care except for telecase-management and telementoring, with mean difference ranging from 0.37% and 0.71%. Ranking indicated that teleconsultation was the most effective telemedicine strategy, followed by telecase-management plus telemonitoring, and finally teleeducation plus telecase-management. The review indicates that most telemedicine strategies can be useful, either as an adjunct or to replace usual care, leading to clinically meaningful reduction in HbA1c

    Targeted profiling of chlorinated transformation products and the parent micropollutants in the aquatic environment: A comparison between two coastal cities

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    This study investigated chlorinated transformation products (TPs) and their parent micropollutants, aromatic pharmaceuticals and personal care products (PPCPs) in the urban water bodies of two metropolitan cities. Nine PPCPs and 16 TPs were quantitatively or semi-quantitatively determined using isotope dilution techniques and liquid chromatography-tandem mass spectrometry. TPs and most PPCPs were effectively removed by conventional wastewater treatments in a wastewater treatment plant (WWTP). Chlorinated parabens and all PPCPs (at concentrations below 1000 ng/L) were present in the waters receiving treated wastewater. By contrast, the waters receiving untreated wastewater contained higher levels of PPCPs (up to 9400 ng/L) and more species of chlorinated TPs including chlorinated parabens, triclosan, diclofenac, and bisphenol A. The very different chemical profiles between the water bodies of the two cities of similar geographical and climatic properties may be attributed to their respective uses of chemicals and policies of wastewater management. No apparent increase in the number of species or abundances of TPs was observed in either the chlorinated wastewater or the seawater rich in halogens. This is the first study to elucidate and compare the profiles of multiple TPs and their parent PPCPs in the water bodies of coastal cities from tropical islands. Our findings suggest that chlorinated derivatives of bisphenol A, diclofenac, triclosan, and parabens in the surface water originate from sources other than wastewater disinfection or marine chlorination. Although further studies are needed to identify the origins, conventional wastewater treatments may protect natural water bodies against contamination by those chlorinated substances

    Invasion of Aureobasidium Pullulans in kidney and eyes of immunosuppressed patients

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    There were series of proven cases revealing opportunistic fungal infections in the cornea, cutaneous, subcutaneous and renal transplantpatients. Renal involvements of opportunistic mold in immunocompromised especially in renal transplant recipients have remaineda significant problem and a major cause of death worldwide. However, extensive literature reviews revealed no case of invasion inurolithiasis and rarely reported in endophthalmitis. Here, we report the case series of two rare cases related to a dematiaceous fungus,Aureobasidium pullulans. Both had an atypical presentation. Possible modes of entry and dissemination were discussed. Invasivesurgical procedures, frequent uses of antibiotics and steroid could possibly predispose to its invasion in immunocompromised patients.This organism was identified through molecular techniques since culture yielded no growth. There was a good outcome followingsurgical intervention in both cases

    Predicting the catalytic sites of isopenicillin N synthase (IPNS) related non-haem iron-dependent oxygenases and oxidases (NHIDOX) through a structural superimposition and molecular docking approach

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    Isopenicillin N synthase (IPNS) related Non-haem iron-dependent oxygenases and oxidases (NHIDOX) demonstrated a striking structural conservativeness, even with low protein sequence homology. It is evident that these enzymes have an architecturally similar catalytic centre with active ligands lining the reactive pocket. Deacetoxycephalosporin C synthase (DAOCS), isopenicillin N synthase (IPNS), deacetylcephalosporin C synthase (DACS), clavaminate synthase 1 and 2 (CAS1 and 2) are important bacterial enzymes that catalyze the formation of β-lactam antibiotics belonging to this enzyme family. Most plant enzyme members within this subfamily namely flavonol synthase (FLS), leucoanthocyanidin dioxygenase (LDOX), anthocyanidin synthase (ANS), 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO), gibberellin 20-oxidase (G20O), desacetoxyvindoline-4-hydroxylase (D4H), flavanone 3β-hydroxylase (F3H), and hyoscyamine 6β-hydroxylase (H6H) are involved in catalyzing the biosyntheses of plant secondary metabolites. With the advancement of protein structural analysis software, it is possible to predict the catalytic sites of protein that shared a structural resemblance. By exploiting the superimposition model of DAOCS-IPNS, DAOCS-IPNS-CAS, G20O-LDOX, FLS-LDOX, ACCO-LDOX, D4H-LDOX, F3H-LDOX and H6H-LDOX model; a computational protocol for predicting the catalytic sites of proteins is now made available. This study shows that without the crystallized or nuclear magnetic resonance (NMR) structures of most NHIDOX enzyme, the plausible catalytic sites of protein can be forecasted using this structural bioinformatics approach.Keywords: Enzyme, catalytic sites, isopenicillin N synthase, ligand

    Effect of operating parameter on clarification of bambangan juice using enzymatic treatment of juice quality

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    Bambangan juice that are currently available in local market is relatively viscous, turbid, and cloudy and tend to settle during storage after bottling of the juice. The turbidity and viscosity of bambangan juice might be due to the presence of polysaccharides in the juice such as pectin and starch, which would lead to instability and deterioration. Clarification is necessary to obtain a bright, clear product with low viscosity which generally can be conducted through enzymatic treatment. Therefore, this study aims to determine the best operating parameters (enzyme concentration, incubation temperature, and incubation time) for clarification of bambangan juice using pectinase from Aspergillus aculeatus. The juice qualities were evaluated based on yield and physicochemical properties. The best operating parameters for bambangan juice clarification using pectinase were obtained at 0.10% v/v enzyme concentration, temperature of 40°C, and incubation time of 30 minutes. Under these conditions, a significant improvement in juice qualities was achieved in terms of yield, clarity, and colour (L*, a*, b*) with values of 87%, 0.5, L* - 61.1; a* - 2.7; b* - 1.4, respectively
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