Nutritional components as mitigators of cellular senescence in organismal aging: a comprehensive review

Food Science and Biotechnology - The process of cellular senescence is rapidly emerging as a modulator of organismal aging and disease. Targeting the development and removal of senescent cells is...     

A low-noise-figure 1.5 μm multiple-quantum-well opticalamplifier

The authors report on the noise characteristics of InGaAs/InGaAsP multiple-quantum-well optical amplifiers operating near 1.5 μm. A noise figure of 4.4 dB is reported, verifying the predicted low-noise properties of quantum-well amplifiers     

Deposition of hydroxyapatite coatings by axial plasma spraying: Influence of feedstock characteristics on coating microstructure,phase content and mechanical properties

Axial plasma spray is one of the thermal spray techniques to deposit multifunctional advanced coatings. The present work explores the use of this process to deposit thin, continuous, and adherent Ca₅ (PO₄)₃OH (hydroxyapatite, HAp) coatings and characterize its microstructure, phases, hardness and adhesion strength. Three different suspension-deposited HAp coatings were investigated and compared with powder-deposited HAp coating on a Ti6Al4V substrate. The effect of mean solute particle size and solid-loading in the suspension has been explored on the evolution of microstructure, phase content and mechanical properties of axial suspension plasma sprayed (ASPS) coatings. Phase-characterization has shown retention of hydroxyapatite phase and coating crystallinity in the deposited coatings, whereas the adhesion strength of the HAp coating decreased from ～40 MPa to ～13 MPa when bioglass was added to the feedstock material. The lower solid load content and lower mean solute particle size in the suspension were found to be beneficial in achieving porous, rougher, and well-adhering coatings. This work concludes that ASPS can potentially deposit thin HAp coatings (< 50 μm) with high adhesion strength.     

Development of microbiologically safe mung bean sprouts using combination treatment of sodium hypochlorite and gamma radiation

Specific group of people, with impaired immune system, are recommended to consume pathogen‐free foods. In this study, microbiologically safe ready‐to‐eat (RTE) mung bean sprouts were developed using combination treatment (CT) with 200 ppm sodium hypochlorite and 12 kGy dose of gamma radiation. Microbiological analysis of combination‐treated sprout samples showed complete elimination (<10 CFU g^?1 of sprouts) of microbial load in these samples, even during storage at 4 °C up to 12 days. Combination treatment and storage period did not have any significant effect on the sensory qualities of RTE mung bean sprouts. However, reduction in the firmness and vitamin C content of combination‐treated sprout samples, similar to other food processing methods, was observed. These results suggest that CT is effective in sterilisation of mung bean sprouts. These sprouts can be included in the diets of special target groups and thereby improve in their quality of life.     

A Role Based Privacy-Aware Secure Routing Protocol for Wireless Mesh Networks

Wireless Mesh Networks (WMNs) have drawn much attention for emerging as a promising technology to meet the challenges in next generation networks. Security and privacy protection have been the primary concerns in pushing towards the success of WMNs. There have been a multitude of solutions proposed to ensure the security of the routing protocol and the privacy information in WMNs. However, most of them are based on the assumptions that all nodes cooperate with routing and forwarding packets and the attacks are from outside. In order to defend against the internal attacks and to achieve better security and privacy protection, this paper proposes a role based privacy-aware secure routing protocol (RPASRP), which combines a new dynamic reputation mechanism with the role based multi-level security technology and a hierarchical key management protocol. Simulation results show that RPASRP implements the security and privacy protection against the inside attacks more effectively and efficiently and performs better than the classical hybrid wireless mesh protocol in terms of packet delivery ratio and average route length.     

Properties of Noncentral Dirichlet Distributions

Let X₁,…, X_r+1 be independent random variables, X_iGa (a_i, θ, δ_i), i = 1,…, r + 1. Define and V_i = X_i/X_r+1, i = 1,…, r. Then, (U₁,…, U_r) and (V₁,…, V_r) follow noncentral Dirichlet Type 1 and Type 2 distributions, respectively. In this article several properties of these distributions and their connections with the uniform, the noncentral multivariate-F and the noncentral multivariate-t distributions are discussed.     

Frequency tuning and pulse generation in a fiber laser with anintracavity semiconductor active filter

The authors demonstrate optical frequency tuning by direct electrical means as well as FM and AM mode-locking in an erbium-doped fiber laser with an intracavity distributed Bragg reflector active filter/modulator. They obtained a 6 nm discrete tuning range and pulses of 38 and 78 ps duration in AM and FM mode-locking, respectively     

Structured selective coatings

Nickel-impregnated anodized Al₂O₃ films on aluminium substrates were investigated as possible selective coatings for the photothermal conversion of solar energy. A purely chemical dip process for producing these spectrally selective coatings was developed as an alternative to the electrochemical process reported earlier. The process parameters were optimized to give α = 0.92 and ε = 0.19. These coatings are cheap, efficient and durable.X-ray diffraction, scanning electron microscopy and electron spectroscopy for chemical analysis investigations were performed at various stages during the formation of these coatings and their structure was determined from the data obtained. The proposed structure agrees with that reported earlier. Maxwell Garnett theory and the concept of the equivalent homogeneous medium were used to determine the theoretical optical properties of these films as a function of (1) the thickness and porosity of the Al₂O₃ layer and (2) the thickness of nickel deposited in the pores. The optimum values of the theoretical parameters are in good agreement with those determined experimentally.     

In vitro model improves the prediction of soil arsenic bioavailability: worst-case scenario

There is a strong interest in developing an in vitro arsenic (As) model that satisfactorily estimates the variability in in vivo relative oral bioavailability (RBA) measurements. Several in vitro tests have been developed, but none is universally accepted due to their limited success in predicting soil As RBA. A suite of amorphous and crystalline solid As phases were chosen, utilizing a worst-case scenario (WCS) that simulated fasting children's gastric solution chemistry. The objectives of this study were to (i) determine the effects of residence time, pH, and solid-to-solution ratio on As bioaccessibility and speciation in the in vitro gastric test; (ii) provide the fundamental basis for an optimized in vitro model constrained by the WCS; and (iii) validate the optimized in vitro test with the in vivo RBA obtained with BALB/c mice. The gastric pH was the only significant (p < 0.05) factor influencing solid As bioaccessibility. Bioaccessible As retained the oxidation state after its release from the solid into the gastric solution. The optimized in vitro model adequately predicted RBA values for a suite of solid As phases typically encountered in soils, with the exception of aluminum-based solids. This study is an excellent starting point for developing an in vitro test applicable to different As-contaminated soils.