Effect of Ag2O substituted in bioactive glasses: a synergistic relationship between antibacterial zone and radiation attenuation properties

In this study, a promising relationship between antibacterial zone and radiation attenuation properties was investigated in Ag2O doped bioactive glasses with a chemical composition of xAg2O–20Li2O–25TeO2-(55-x)B2O3 (where x = 0, 0.5, 1.0, 1.5, and 2.0 mol%). For this aim, a wide-ranging radiation attenuation characterization procedure was performed on Ag2O substituted bioactive glasses. The general-purpose Monte Carlo code MCNPX (v.2.7.0) was used to model bioactive glasses. The mass attenuation coefficients were calculated using a gamma-ray transmission setup. The coefficients obtained were used to determine other important attenuation properties. Finally, for particular behaviors, exposure (EBF) and energy absorption (EABF) build-up factors were calculated for specific attitudes of Ag2O substitutions in bioactive glasses during the interaction process. The results showed that there is direct relationship between Ag2O substitution amount and radiation attenuation properties. In addition to its well-behaviors on inhibition zone against bacterial occurrences, it can be concluded that increasing Ag2O would increase the gamma-ray attenuation properties of studied bioactive glass system. © 2021 The AuthorsThe authors thank for the scholar and research grant under Universiti Putra Malaysia , Taif University Researchers Supporting Project number (TURSP-2020/12), Taif University , Saudi Arabia and Deanship of Scientific Research at King Khalid University for financial support through General Research Project under grant number ( G.R.P/81/42 )

A 1-Year Prospective French Nationwide Study of Emergency Hospital Admissions in Children and Adults with Primary Immunodeficiency.

PURPOSE: Patients with primary immunodeficiency (PID) are at risk of serious complications. However, data on the incidence and causes of emergency hospital admissions are scarce. The primary objective of the present study was to describe emergency hospital admissions among patients with PID, with a view to identifying "at-risk" patient profiles. METHODS: We performed a prospective observational 12-month multicenter study in France via the CEREDIH network of regional PID reference centers from November 2010 to October 2011. All patients with PIDs requiring emergency hospital admission were included. RESULTS: A total of 200 admissions concerned 137 patients (73 adults and 64 children, 53% of whom had antibody deficiencies). Thirty admissions were reported for 16 hematopoietic stem cell transplantation recipients. When considering the 170 admissions of non-transplant patients, 149 (85%) were related to acute infections (respiratory tract infections and gastrointestinal tract infections in 72 (36%) and 34 (17%) of cases, respectively). Seventy-seven percent of the admissions occurred during winter or spring (December to May). The in-hospital mortality rate was 8.8% (12 patients); death was related to a severe infection in 11 cases (8%) and Epstein-Barr virus-induced lymphoma in 1 case. Patients with a central venous catheter (n = 19, 13.9%) were significantly more hospitalized for an infection (94.7%) than for a non-infectious reason (5.3%) (p = 0.04). CONCLUSION: Our data showed that the annual incidence of emergency hospital admission among patients with PID is 3.4%. The leading cause of emergency hospital admission was an acute infection, and having a central venous catheter was associated with a significantly greater risk of admission for an infectious episode

Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch

Tuning the selectivity and sensitivity of mesoporous dielectric multilayers by modifiying the hydrophobic–hydrophilic balance of the silica layer

We investigate the possibility of tuning the selectivity and sensitivity of SiO2/TiO2 mesoporous dielectric multilayers for the adsorption of analytes with different chemical polarities. The hydrophilic– hydrophobic balance of the mesoporous SiO2 layer was controlled by one-pot co-condensation of mixtures of methyltriethoxysilane (MTES) and tetraethyl orthosilicate (TEOS) in variable contents. Infrared spectroscopy analysis combined with water contact angle measurement confirmed the gradual increase of the hydrophobic behavior of the hybrid silica layer obtained by increasing the MTES content, without losing its porosity. Hybrid silica layers included into the dielectric multilayer material enabled controlling the surface properties of the Bragg stacks. UV-visible spectroscopy showed a Bragg peak red-shift. This shift depends on the affinity of the adsorbed molecule toward the functional groups present on the surface of the constituting materials. This procedure enabled the dramatic change of the adsorption properties of the mesoporous dielectric multilayer and correspondingly the optical response of the photonic crystal

Photocatalytic degradation of Rhodamine 6G on mesoporous titania films:Combined effect of texture and dye aggregation forms

Titania films with different textural properties have been synthesized using the sol–gel spin-coating process. Titania sols were prepared with and without non ionic template agents, Pluronic P123 and Brij56, in order to evaluate the effect of the surface developed by the films on their photocatalytic activity. The morphology, surface composition, open porosity and pore size distribution of these films were investigated by transmission electronic microscopy, X-ray photoelectron spectroscopy and atmospheric ellipsometric porosimetry. The optical properties of the titania films were evaluated by UV–vis transmittance spectroscopy. The porosity released after burning the template at 400 °C reduces the refractive index of the coatings and the transmittance in the visible range becomes equal for naked and coated soda lime glasses. In parallel, the photocatalytic activity of the non porous and porous titania films was evaluated by following the photodegradation kinetics of Rhodamine 6G dye. Results show that the increase of the available active surface of the titania films affects the photocatalytic activity. However, this feature was not the only parameter responsible for the improvement of the photocatalytic efficiency. The aggregation form of the Rhodamine 6G dye was also related to titania film texture. This proved to have a marked impact on the photocatalytic performances

Theoretical condition for transparency in mesoporous layered optical media: application to switching of hygrochromic coatings

Mesoporous Bragg stacks are able to change color upon infiltration or displacement of liquid compounds inside their porous structure. Reversible switching from transparency to coloration offers additional functionality. Based on Bruggeman&apos;s effective medium theory, we derive a transparency master equation, which is valid for bilayers of arbitrary host materials and pore-filling compounds. The transparency condition fixes pore volume fractions such that the effective refractive index is homogenized through the bilayer, hence, through arbitrary layered optical media built from this bilayer. This general concept is applied to the case of switching of hygrochromic coatings made of mesoporous mixed oxide Bragg stacks

Optical properties of thermochromic VO 2 thin films on stainless steel: Experimental and theoretical studies

Thermochromic films of VO 2 were deposited by DC reactive magnetron sputtering on stainless steel substrate. Complex refractive indexes of VO 2 were determined by ellipsometric spectroscopy (0.35-16.5 μm) for different film thicknesses. Optical simulations were performed to model the spectral reflectance of the film/substrate system for a film thickness of 100 nm and 200 nm and to monitor the optical contrast of the thermochromic layers by comparing the spectral reflectance at 25 °C and 100 °C. The good agreement observed between experimental and theoretical spectra demonstrates the adequacy of the model for predicting the optical properties of the samples. © 2010 Elsevier B.V. All rights Reserved