A DFT study of BeX (X = S,Se, Te) semiconductor: Modified Becke Johnson (mBJ) potential

The electronic, optical and elastic properties of BeX were performed within full potential liberalized augmented plane wave method based on density functional theory (DFT). Generalized gradient approximation (GGA) and modified Becke Johnson (TB-mBJ) potential were used for exchange correlation. The mBJ gives improved band gap as compare to GGA and in close agreement with the experimental results. The present band gaps of BeS, BeSe and BeTe calculated within mBJ are 4.40, 4.0 and 2.40 eV respectively.     

The role of fluid polarity in the swelling of sodium-montmorillonite clay: A molecular dynamics and Fourier transform infrared spectroscopy study

Swelling clays are found extensively in various parts of the world, and sodium-montmorillonite (Na-MMT) is the main constituent of an expansive clay mineral. In this work, the swelling behavior of Na-MMT clay with a wide range of organic fluids, high polar through low polar fluids, is studied using a combination of Fourier transform infrared (FTIR) technique and molecular dynamics (MD) simulations. The construction of the representative clay–fluid models is carried out, and the nature of nonbonded interactions between clay and fluids is studied using MD. Our FTIR and MD simulations results suggest the significant nonbonded interactions between Na-MMT clay and polar fluids, such as formamide and water. The nonbonded interactions of Na-MMT with methanol and acetone are significantly less than those in Na-MMT with polar fluids. The interactions of the fluids with various entities of the clay such as SiO, FeOH, MgOH, and AlOH captured via the spectroscopy experiments and modeling provide a finer understanding of the interactions and their contributions to swelling. The MD simulations are able to capture the band shifts observed in the spectra obtained in the spectroscopy experiments. This work also captures the conformations of interlayer sodium ions with formamide, water, methanol, and acetone during swelling. These nonbonded interactions provide insight into the molecular mechanism that the polarity of fluids plays an important role in the initiation of interlayer swelling, alteration in the orientations, and evolution of microstructure of swelling clays at the molecular scale.     

Control of testicular vasomotion by testosterone and tubular factors in rats

We have compared the pharmacological and molecular characteristics of 2 cell lines derived from the C6 rat glioblastoma, and selected for resistance either to doxorubicin (C6 0.5 line) or to vincristine (C6 IV line). Each line displays a preferential 400-fold resistance towards the drug used for selection, the C6 IV line being especially weakly resistant to doxorubicin (13-fold). Verapamil completely restored doxorubicin sensitivity in the C6 IV line as well as vincristine resistance in the C6 0.5 line, but could not completely reverse doxorubicin resistance in the C6 0.5 line or vincristine resistance in the C6 IV line. This suggests that specific mechanisms of resistance against each drug were added to a common P-glycoprotein-mediated multidrug-resistance mechanism. Doxorubicin efflux was total within 2 hr in the C6 IV line, whereas it remained 8 to 10% of drug in the C6 0.5 line 4 hr after drug removal, despite a more rapid efflux of the drug in the first 30 min. This 2-compartment behavior could be related to a special sub-cellular distribution of doxorubicin in C6 0.5 cells. Northern and Western blot analysis of the mdrI gene and of the P-glycoprotein expressed by the 2 resistant cell lines made it possible to quantify their degree of over-expression; when compared with the C6 wild strain, the C6 0.5 line over-expressed both the mdrI gene and the P-glycoprotein to a slightly higher level than the C6 IV line. Northern and Western blot analysis also suggested that C6 0.5 cell preferentially over-expressed the mdrIa gene, whereas the C6 IV cells preferentially over-expressed the mdrIb gene. This differential over-expression was confirmed after polymerase-chain-reaction amplification of the cDNA sequences transcribed from total RNA extracted from the 2 lines. It can be concluded therefore that the mdrIa gene product is more efficient than the mdrIb gene product in extruding anti-cancer drugs from the cells; and that the mdrIb gene product might preferentially extrude vincristine rather than doxorubicin.     

Understanding the role of ICT and study circles in enabling economic opportunities: Lessons learned from an educational project in Kenya

In this paper, we explore how the combination of Information and Communication Technologies (ICT) and self‐organised study circles improves rural communities' ability to enhance their economic opportunities. We present the case study of an adult study‐circle project in the Kwale County of Kenya with the objective of providing rural communities with viable and sustainable livelihoods. Study circles can be seen as a democratic and emancipatory method for learning, where community groups regularly meet for participatory discussions to educate themselves on a variety of topics of their own interest. The main goal of the study‐circle members was to increase economic opportunities using ICT and, more specifically, to start micro‐businesses, improve production efficacy and methods, and obtain employment. Using the capability approach and affordances as theoretical lenses, our analysis of the explorative case study shows that the outcomes of the study circle were dependent on various conversion factors and facilitating conditions, such as resources, skills, socio‐cultural norms, and infrastructure. The main contributions from our work are represented by the five practical lessons learned from the study‐circle members' goals (starting micro‐businesses, product efficiency, and obtaining employment) from the self‐organised training approach (study circles) and from our theoretical approach (combining the capability approach and affordances).     

Enlarged Photonic Band Gap in Heterostructure of Metallic Photonic and Superconducting Photonic Crystals

We show theoretically that the frequency range of photonic band gap of a hetero-structure which is made of a metallic photonic and superconducting photonic crystal can be enlarged due to the combination of the reflection band properties of the superconductor–dielectric (PC1) and metallic–dielectric (PC2) periodic structures. The transmittance and band structure of the considered structures are calculated using simple transfer matrix method and the Bloch theorem. Beside this, we have also calculated the transmittance of the superconducting photonic structure (PC1), metallic photonic structure (PC2) and heterostructure of metallic photonic and superconductor photonic crystals (PC1/PC2) for TE and TM-mode at the different angles of incidence.     

Genoprotective Effects of Essential Oil Compounds Against Oxidative and Methylated DNA Damage in Human Colon Cancer Cells

Essential oils (EO) are widely used in foods as flavoring and preservative agents. Many of the biological activities of EO have been attributed to major essential oil compounds (EOC) but their direct interaction with colonic epithelial cells and their genotoxic and genoprotective effects are not well established. In this study, the cytotoxicity and genotoxicity of EOC including nerolidol, thymol, geraniol, methylisoeugenol, eugenol, linalool, and a commercial blend (Agolin) were determined. Furthermore, the genoprotective effects of EOC against oxidative and methylating damage were assessed using the comet assay in HT‐29 colorectal adenocarcinoma cells. The majority of EOC were cytotoxic to HT‐29 cells at or above 250 ppm after 24 hr exposure. At noncytotoxic doses, none of the EOC was genotoxic in the comet assay. Genoprotection against oxidative DNA damage was observed for nerolidol (at 62.5 ppm), thymol (at 12.5 ppm), geraniol, and methylisoeugenol (both at 125 ppm), as well as linalool and Agolin (both at 250 ppm). Thymol was the most protective compound against oxidative DNA damage and geraniol (at 125 ppm) also protected cells against methylating DNA damage. This study highlights the potential of EOC such as thymol to protect the colonic epithelium against oxidative DNA damage and geraniol against methylating DNA damage. Further in vivo studies are needed to confirm these findings for safety and efficacy to exploit their potential pharmaceutical or nutraceutical uses for colonic health.     

Mortality due to prostatic carcinoma in northern Sweden

In a retrospective study 6890 patients with prostate cancer from the North Swedish Cancer Register were analyzed according to cancer specific survival. Prostate cancer mortality was 40% in patients with well differentiated cancers, 54% in patients with moderate differentiated prostate cancer and 72% in men with low differentiated prostate cancer. Prostate cancer mortality was 80% in men younger than 60 years, 63% in men 60-69 years old, 53% in men 70-79 years old and 49% in men older than 80 years.     

Combined orchiectomy and external radiotherapy versus radiotherapy alone for nonmetastatic prostate cancer with or without pelvic lymph node involvement: a prospective randomized study

PURPOSE: We compare the combination of orchiectomy and radiotherapy to radiotherapy alone as treatment for pelvic confined prostate cancer, that is T1-4, pN0-3, M0 (TNM classification). MATERIALS AND METHODS: In this prospective study 91 patients with clinically localized prostate cancer were, after surgical lymph node staging, randomized to receive definitive external beam radiotherapy (46) or combined orchiectomy and radiotherapy (45). Patients treated with radiotherapy alone had androgen ablation at clinical disease progression. The effects on progression-free, disease specific and overall survival rates were calculated. RESULTS: After a median followup of 9.3 years (range 6.0 to 11.4) clinical progression was seen in 61% of the radiotherapy only patients (group 1) and in 31% of the combined treatment patients (group 2) (p = 0.005). The mortality was 61 and 38% (p = 0.02), and cause specific mortality was 44 and 27%, respectively (p = 0.06), in groups 1 and 2. The differences in favor of combined treatment were mainly caused by lymph node positive tumors. For node negative tumors there was no significant difference in survival rates. CONCLUSIONS: The progression-free, disease specific and overall survival rates for patients with prostate cancer and pelvic lymph node involvement are significantly better after combined androgen ablation and radiotherapy than after radiotherapy alone. These results strongly suggest that early androgen deprivation is better than deferred endocrine treatment for these patients.