Fabrication and characterization of Cd-enriched CdTe thin films by close spaced sublimation

Cd-enriched cadmium telluride (CdTe) polycrystalline films were grown on corning glass substrates by close spaced sublimation (CSS) technique. To our knowledge, Cd-enriched CdTe thin films by CSS have not been reported earlier. The structural investigations performed by means of X-ray diffraction (XRD) technique, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX) showed that the deposited films exhibit a polycrystalline structure with 〈111〉 as preferred orientation. The structural, optical, and electrical properties of these films were analyzed as a function of the Cd concentration. For the films having an excess of Cd, the electrical resistivity dropped several orders of magnitude. The deposited films also showed that the value of resistivity decreased with increasing temperature manifesting the semiconducting behavior of the films. The results showed that using this deposition technique, n-type Cd-enriched CdTe polycrystalline film could be produced.     

Anticarcinogenecity of microbiota and probiotics in breast cancer

Breast cancer is one of the most important causes of cancer related morbidity and mortality in the world. Along with genetic, environmental factors also play a multifaceted role in the development of disease. Breast contains several bacterial species performing specialized functions. Probiotics, as functional food, play pivotal role against breast cancer development in vivo and in vitro. Current review summarized all the available data related to diet, probiotics, and their association with breast cancer risk along with underlying mechanisms. Presently, it was believed that many of the commercially available probiotic products were safe to use and had some beneficial health effects for the host. Probiotics had a potential to act against breast cancer progression evidenced by many animal model and cell-based experiments. Some probiotics strains may be useful as an adjuvant therapy for breast cancer prevention or treatment, by modulating immune response or breast microbial community. However, large-scale clinical trials and intense research are mandatory to explore probiotics-related metabolic and molecular mechanisms in breast cancer.     

Mixed convection in laminar film flow of a micropolar fluid

In this paper, the steady mixed convection boundary layer in laminar film flow of a micropolar fluid is considered. The resulting nonlinear coupled ordinary differential equations are solved numerically using an efficient implicit finite-difference scheme. The numerical results obtained for the skin friction coefficient and the local Nusselt number, as well as the velocity, angular velocity or microrotation and temperature profiles are presented in tables and figures for different values of the material parameter K and the Richardson number Ri when the Prandtl number Pr = 0.7 and Pr = 1.     

MHD boundary-layer flow of a micropolar fluid past a wedge with variable wall temperature

Summary The steady laminar MHD boundary-layer flow past a wedge immersed in an incompressible micropolar fluid in the presence of a variable magnetic field is investigated. The governing partial differential equations are transformed to the ordinary differential equations using similarity variables, and then solved numerically using a finite-difference scheme known as the Keller-box method. Numerical results show that the micropolar fluids display drag reduction and consequently reduce the heat transfer rate at the surface, compared to the Newtonian fluids. The opposite trends are observed for the effects of the magnetic field on the fluid flow and heat transfer characteristics.     

Development and evaluation of pH-dependent interpenetrating network of acrylic acid/polyvinyl alcohol

The objective of the present work was to synthesize interpenetrating networks (IPNs) of acrylic acid/polyvinyl alcohol (AA/PVA) by free radical polymerization using N,N-methylenebisacrylamide (MBAAm) and glutaraldehyde as cross-linkers. The IPNs were evaluated for swelling, diffusion coefficient and network parameters by using Flory–Huggins theory, i.e., the average molecular weight between cross-links (M _c), polymer volume fraction in swollen state (V _2,s), number of repeating units between cross-links (M _r) and cross-linking density (N). It was found that the degree of swelling of AA/PVA interpenetrating network increases greatly within the pH range 5–7 depending on composition. The gel fraction and porosity increased by increasing the concentration of AA or PVA, while by increasing the degree of cross-linking, porosity decreased and gel fraction increased. Selected samples were loaded with chlorpheniramine maleate as a model drug. Drug release was studied in USP, hydrochloric acid buffer solution of pH 1.2 and phosphate buffer solutions of pH 5.5 and 7.5. Drug release data were fitted into various kinetics models, e.g., zero-order, first-order, Higuchi and Peppas models. The results of the kinetics investigation showed that the drug release from IPNs followed non-Fickian diffusion. Fourier transform infrared spectra confirmed the formation of cross-linked IPNs as there was a shifting to lower frequency of 1,713–1,718 cm^?1 with reduced intensity, while scanning electron microscopy revealed uniform distribution of drug in IPNs.