32 research outputs found
Two remarks on generalized entropy power inequalities
This note contributes to the understanding of generalized entropy power
inequalities. Our main goal is to construct a counter-example regarding
monotonicity and entropy comparison of weighted sums of independent identically
distributed log-concave random variables. We also present a complex analogue of
a recent dependent entropy power inequality of Hao and Jog, and give a very
simple proof.Comment: arXiv:1811.00345 is split into 2 papers, with this being on
Development of antibacterial contact lenses containing metallic nanoparticles
Background: Contact lens wear can result in adverse events including bacterially-driven corneal infection and inflammation. These are the result of various kinds of bacteria adhering to contact lenses and either initiating infection of the cornea or producing inflammation of the cornea and conjunctiva. In order to reduce the incidence of these events antimicrobial contact lenses are being developed. In this study, antimicrobial contact lenses containing nanoparticles of silver or copper, or a combination of the two, were produced and evaluated. Methods: Silver and copper nanoparticles were produced in polyvinyl alcohol (PVA) polymers by incorporating salts of these metals and then reducing the salts to nanoparticles with sodium hydroxide. Incorporation of nanoparticles into the PVA was confirmed using transmission electron microscopy, attenuated total reflection (ATR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The nanoparticle-containing polymers were then evaluated for physical characteristics such as tensile strength, water content and coloration. PVA containing polymers were evaluated for cytotoxicity to mammalian cells using a standard assay, and for antimicrobial activity using three different assays that measured their ability to inhibit microbial growth on agar plates, inhibit microbial growth in bacterial suspensions, and to inhibit the viability of adherent bacteria. Results: Nanoparticles of between 50 and 75 nm were produced in PVA polymers. The production of nanoparticles was also confirmed by characteristic spectral peaks in ATR and XPS. The addition of silver or copper nanoparticles doubled the strength of PVA polymers but halved their elongation before fracture. Silver-containing PVA was cytotoxic but PVA containing copper alone was not cytotoxic. In the agar diffusion assay and inhibition of microbial growth in suspension only silver-containing lenses produced antibacterial activity, but silver and copper nanoparticle-containing lenses reduced bacterial adhesion to lenses. Conclusion: both silver and copper nanoparticle-containing lenses were antibacterial, but this depended on the assay used. PVA containing only copper was not cytotoxic. This indicates the copper nanoparticle-containing lenses might be useful to control bacterial colonisation of lenses, and hence the production of bacterially-drive adverse events during lens wear
Wet-spun bi-component alginate based hydrogel fibers: Development and in-vitro evaluation as a potential moist wound care dressing
In this study, bi-component alginate-hyaluronic acid (AHA) fibers were developed by using two different routes. In the first method, sodium alginate dope solution was extruded into a coagulation bath containing CaCl 2 and subsequently dip-coated with hyaluronic acid (HA) whereas, in the second method, hyaluronic acid-containing sodium alginate dope solution was directly extruded into CaCl 2 bath. The resulting AHA fibers were then dehydrated in 25–100% v/v acetone solutions and dried in air. The fibers were characterized by surface morphology, physicochemical analysis, mechanical performance, swelling percentage, and total liquid absorption (g/g), cell viability, and release behavior. The results showed that AHA fibers produced by the second method have better mechanical performance, high liquid absorption, and swelling percentage with a more controlled release of hyaluronic acid. The AHA fibers showed high biocompatibility toward nHDF cell line in in-vitro testing, and the MVTR values (650–800 g/m 2/day) are in a suitable range for maintaining a moist wound surface proving to be appropriate for promoting wound healing. </p
Targeted Gene Panel Sequencing for Early-onset Inflammatory Bowel Disease and Chronic Diarrhea
Background: In contrast to adult-onset inflammatory bowel disease (IBD), where many genetic loci have been shown to be involved in complex disease etiology, early-onset IBD (eoIBD) and associated syndromes can sometimes present as monogenic conditions. As a result, the clinical phenotype and ideal disease management in these patients often differ from those in adult-onset IBD. However, due to high costs and the complexity of data analysis, high-throughput screening for genetic causes has not yet become a standard part of the diagnostic work-up of eoIBD patients.
Methods: We selected 28 genes of interest associated with monogenic IBD and performed targeted panel sequencing in 71 patients diagnosed with eoIBD or early-onset chronic diarrhea to detect causative variants. We compared these results to whole-exome sequencing (WES) data available for 25 of these patients.
Results: Target coverage was significantly higher in the targeted gene panel approach compared with WES, whereas the cost of the panel was considerably lower (approximately 25% of WES). Disease-causing variants affecting protein function were identified in 5 patients (7%), located in genes of the IL10 signaling pathway (3), WAS (1), and DKC1 (1). The functional effects of 8 candidate variants in 5 additional patients (7%) are under further investigation. WES did not identify additional causative mutations in 25 patients.
Conclusions: Targeted gene panel sequencing is a fast and effective screening method for monogenic causes of eoIBD that should be routinely established in national referral centers.info:eu-repo/semantics/publishedVersio
The Effects of Swelling and Porosity Change on Capillarity: DEM Coupled with a Pore-Unit Assembly Method
The fabrications and characterizations of antibacterial PVA/Cu nanofibers composite membranes by synthesis of Cu nanoparticles from solution reduction, nanofibers reduction and immersion methods
Stormwater Control Measures: Optimization Methods for Sizing and Selection
Stormwater management in urban areas remains a challenging water-resources and environmental problem worldwide. This work develops and tests two methods for optimizing stormwater control measures. The first method relies on a linear programming formulation to find the optimal sizes of stormwater control measures to be deployed at selected locations. The second method uses binary linear integer programming to determine the optimal type of stormwater control measures of standardized dimensions to be deployed at selected locations. Both methods minimize the total cost of deploying stormwater control measures, subject to constraints on available budget, volumetric water balance, allowable stormwater volumes, and water-quality characteristics. Two examples illustrate the step-by-step formulation of the linear programming and the binary linear integer programming methods for the optimization of stormwater control measures, and provide solutions to the problems of their optimal sizing and selection. Our results demonstrate the feasibility of meeting stormwater retention and water-quality objectives by the optimal deployment of stormwater control measures as proposed in this work
