306 research outputs found
Conversion of Sago (Metroxylon sagu) Pith Waste to Fermentable Sugars via a Facile Depolymerization Process
The conversion of starchy sago (Metroxylon sagu) pith waste (SPW), a lignocellulosic biomass waste, to fermentable sugars under mild conditions had been successfully demonstrated. The optimum depolymerization of SPW was achieved at 2 wt% sample loading which was catalyzed by 100 mM of oxalic acid in the presence of 25 wt% NaCl solution at 110 °C for 3 h. Up to 97% SPW sample was being converted into fermentable sugars with limited formation of by-products after two sequential depolymerization cycles. Both reaction temperature and concentration of oxalic acid were crucial parameters for the depolymerization of SPW which exhibited a high selectivity for the production of glucose over other reducing sugars. © 2017, Springer Science+Business Media, LLC
Porous Cellulose Beads Fabricated from Regenerated Cellulose as Potential Drug Delivery Carriers
Highly porous cellulose beads (CBs) of various mean sizes were successfully prepared from regenerated cellulose of paper wastes. The drug delivery characteristics of CBs with different mean sizes were investigated using curcumin as the model drug under controlled conditions. The loading capacity and efficiency of curcumin onto CBs were substantially influenced by factors such as
their morphological characteristics, curcumin concentration, and duration of loading.The release kinetic profiles of curcumin from CBs of different mean sizes were investigated in media of pH values resembling digestive juices and intestinal fluids. Release kinetic
models were used to simulate and elucidate release kinetics and mechanisms of curcumin from CBs under specific conditions. The loading capacity and efficiency of curcumin onto CBs could be enhanced via the optimization of curcumin solution concentration
and the morphological characteristics of CBs, whereas the release kinetic profiles of curcumin from CBs could be modulated by varying the mean diameter of CBs. Optimized CBs derived from regenerated cellulose of paper wastes are potentially useful as cost-effective drug delivery carriers
Frailty Confers High Mortality Risk across Different Populations:Evidence from an Overview of Systematic Reviews and Meta-Analyses
We performed an overview of systematic reviews and meta-analyses to summarize available data regarding the association between frailty and all-cause mortality. Medline, Embase, CINAHL, Web of Science, PsycINFO, and AMED (Allied and Complementary Medicine) databases were searched until February 2020 for meta-analyses examining the association between frailty and all-cause mortality. The AMSTAR2 checklist was used to evaluate methodological quality. Frailty exposure and the risk of all-cause mortality (hazard ratio [HR] or relative risk [RR]) were displayed in forest plots. We included 25 meta-analyses that pooled data from between 3 and 20 studies. The number of participants included in these meta-analyses ranged between 500,000. Overall, 56%, 32%, and 12% of studies were rated as of moderate, low, and critically low quality, respectively. Frailty was associated with increased risk of all-cause mortality in 24/24 studies where the HR/RRs ranged from 1.35 [95% confidence interval (CI) 1.05-1.74] (patients with diabetes) to 7.95 [95% CI 4.88-12.96] (hospitalized patients). The median HR/RR across different meta-analyses was 1.98 (interquartile range 1.65-2.67). Pre-frailty was associated with a significantly increased risk of all-cause mortality in 7/7 studies with the HR/RR ranging from 1.09 to 3.65 (median 1.51, IQR 1.38-1.73). These data suggest that interventions to prevent frailty and pre-frailty are needed
Regeneration of cello-oligomers via selective depolymerization of cellulose fibers derived from printed paper wastes
tCellulose extracted from printed paper wastes were selectively depolymerized under controlledconditions into cello-oligomers of controllable chain lengths via dissolution in an ionic liquid, 1-allyl-3-methylimidazolium chloride (AMIMCl), and in the presence of an acid catalyst, Amberlyst 15DRY. Thedepolymerization process was optimized against reaction temperature, concentration of acid catalyst,and reaction time. Despite rapid initial depolymerization process, the rate of cellulose depolymerizationslowed down gradually upon prolonged reaction time, with 75.0 wt% yield of regenerated cello-oligomers(mean Viscosimetric Degree of Polymerization value of 81) obtained after 40 min. The depolymeriza-tion of cellulose fibers at 80â—¦C appeared to proceed via a second-order kinetic reaction with respect tothe catalyst concentration of 0.23 mmol H3O+. As such, the cellulose depolymerization process couldafford some degree of control on the degree of polymerization or chain lengths of cello-oligomersformed
Impact of eplerenone on major cardiovascular outcomes in patients with systolic heart failure according to baseline heart rate.
BACKGROUND: Increased resting heart rate is a risk factor for cardiovascular mortality and morbidity. Mineralocorticoid receptor antagonists (MRAs) have been shown to improve cardiac sympathetic nerve activity, reduce heart rate and attenuate left ventricular remodelling. Whether or not the beneficial effects of MRA are affected by heart rate in heart failure patients with reduced ejection fraction (HFREF) is unclear. METHODS: We undertook a secondary analysis of data from the Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure study to assess if clinical outcomes, as well as the efficacy of eplerenone, varied according to heart rate at baseline. RESULTS: High resting heart rate of 80 bpm and above predisposed patients to greater risk of all outcomes in the trial, regardless of treatment allocation. The beneficial effects of eplerenone were observed across all categories of heart rate. Eplerenone reduced the risk of primary endpoint, the composite of cardiovascular death and hospitalisation for heart failure, by 30% (aHR 0.70; 95% CI 0.54-0.91) in subjects with heart rate ≥ 80 bpm, and by 48% (aHR 0.52; 95% CI 0.33-0.81) in subjects with heart rate ≤ 60 bpm. Eplerenone also reduced the risks of hospitalisation for heart failure, cardiovascular deaths and all-cause deaths independently of baseline heart rate. CONCLUSIONS: Baseline heart rate appears to be an important predictor of major clinical outcome events in patients with HFREF, as has been previously reported. The benefits of eplerenone were preserved across all categories of baseline heart rate, without observed heterogeneity in the responses
Rapid Intradermal Delivery of Liquid Formulations Using a Hollow Microstructured Array
Purpose The purpose of this work is to demonstrate rapid intradermal delivery of up to 1.5 mL of formulation using a hollow microneedle delivery device designed for self-application. Methods 3M’s hollow Microstructured Transdermal System (hMTS) was applied to domestic swine to demonstrate delivery of a variety of formulations including small molecule salts and proteins. Blood samples were collected after delivery and analyzed via HPLC or ELISA to provide a PK profile for the delivered drug. Site evaluations were conducted post delivery to determine skin tolerability. Results Up to 1.5 mL of formulation was infused into swine at a max rate of approximately 0.25 mL/min. A red blotch, the size of the hMTS array, was observed immediately after patch removal, but had faded so as to be almost indistinguishable 10 min post-patch removal. One-mL deliveries of commercial formulations of naloxone hydrochloride and human growth hormone and a formulation of equine anti-tetanus toxin were completed in swine. With few notable differences, the resulting PK profiles were similar to those achieved following subcutaneous injection of these formulations. Conclusions 3M’s hMTS can provide rapid, intradermal delivery of 300–1,500 µL of liquid formulations of small molecules salts and proteins, compounds not typically compatible with passive transdermal delivery. KEY WORDS transdermal drug delivery. microneedles. intradermal. hollow microstructures. MT
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