New highly efficient 2D SiC UV-absorbing material with plasmonic light trapping.

The present paper is a systematic analysis of the thermoelectric and optical properties of the SiC monolayer. Based on the density functional theory (DFT) combined with the Boltzmann transport theory, the thermal conductivity, the electrical conductivity and the figures of merit are all determined and discussed for the SiC hybrid. At room temperature, it is found that SiC shows interesting values with respect to its counterparts graphene and silicene. To improve the absorption of the SiC sheet, a strategy is proposed using finite-difference time-domain (FDTD) combing with PSO-based approach. The absorbance of the UV-photodector with SiC monolayer and the SiC-based photodector with Au plasmonic grating are studied. Among our findings, the Au plasmonic grating enhances the absorbance of SiC to reach a maximum absorbance of 99.6% at the resonance wavelength of ([Formula: see text] nm), which significantly improves the performance of UV-sensors. Therefore, by combining optical DFT analysis with FDTD simulation supported by global PSO optimization, we have been able to develop a new SiC monolayer high performance UV photodetector suitable for advanced optoelectronic applications.

Electron-phonon dynamics in 2D carbon based-hybrids XC (X = Si, Ge, Sn).

The effect of the presence of electron-phonon (e-ph) coupling in the SiC, GeC and SnC hybrids is studied in the framework of the ab initio perturbation theory. The electronic bang gap thermal dependence reveals a normal monotonic decrease in the SiC and GeC semiconductors, whereas SnC exhibits an anomalous behavior. The electron line widths were evaluated and the contributions of acoustic and optical phonon modes to the imaginary part of the self-energy were determined. It has been found that the e-ph scattering rates are globally controlled by the out-of-plane acoustic transverse mode ZA in SiC while both ZA and ZO are overriding in GeC. In SnC, the out-of-plane transverse optical mode ZO is the most dominant. The relaxation lifetime of the photo-excited electrons shows that the thermalization of the hot carrier occurs at 90 fs, 100 fs and 120 fs in SiC, GeC and SnC, respectively. The present study properly describes the subpicosecond time scale after sunlight illumination using an approach that requires no empirical data. The results make the investigated structures suitable for providing low cost and high-performance optical communication and monitoring applications using 2D materials.

Effect of pantoprazole to enhance activity of docetaxel against human tumour xenografts by inhibiting autophagy.

BACKGROUND: Autophagy allows recycling of cellular components and may facilitate cell survival after chemotherapy. Pantoprazole inhibits proton pumps and is reported to inhibit autophagy. Here we evaluate the effects of pantoprazole to modify cytotoxicity of the anticancer drug docetaxel, and underlying mechanisms. METHODS: Effects of docetaxel±pantoprazole were studied against wild-type and autophagy-deficient PC3 cells and against four human xenografts. Effects of pantoprazole on autophagy were evaluated by quantifying LC3-I, LC3-II and p62 proteins in western blots, and by fluorescent microscopy of cells transfected with RFP-GFP-LC3. The distribution of drug effects and of autophagy was quantified in tumour sections in relation to blood vessels and hypoxia by immunohistochemistry using γH2AX, cleaved caspase-3, Ki67 and LC3/ p62. RESULTS: Pantoprazole increased the toxicity of docetaxel in vitro, increased docetaxel-induced expression of γH2AX and cleaved caspase-3, and decreased Ki67 in tumour sections. Pantoprazole increased growth delay of four human xenografts of low, moderate and high sensitivity to docetaxel, with minimal increase in toxicity. Docetaxel led to increased autophagy throughout tumour sections. Pantoprazole inhibited autophagy, and effects of pantoprazole were reduced against genetically modified cells with decreased ability to undergo autophagy. CONCLUSIONS: Autophagy is a mechanism of resistance to docetaxel chemotherapy that may be modified by pantoprazole to improve therapeutic index.

[Hepatocellular carcinoma (HCC) observed in Abidjan: aspects and role of ultrasonography]. / Carcinomes hépatocellulaires (CHC) observés a Abidjan: aspects et place de l'échographie.

In this retrospective study, we define the localization and ultrasound appearances of hepatocellular carcinomas observed in Abidjan. The study included 31 inpatients (23 males and 8 females), aged from 24 to 76 years (mean, 47.4). All patients had serum alphafetoprotein dosage and 21 patients had cytologic examination. Diagnosis was based on a high level of serum alpha-fetoprotein (> 500 ng/ml), with or without cytological proof. Tumor characteristics (size, number, echogenicity, nodular or diffuse form) and associated extratumoral signs were noted. Ultrasound identified 19 cases of small tumors (size < 5 cm), and 12 large tumors (size > or = 5 cm). The tumor forms were mostly nodular and multiple (24 cases), solitary nodule (3 cases), diffuse or infiltrative (4 cases). The liver was heterogeneous with hyperechoic tumoral nodules (16 cases), hypoechoic tumoral nodules (5 cases), hyperechoic and diffuse form (4 cases), and 2 cases of mixed form. We have noted a particular form in 4 cases represented by a heterogeneous liquid-like mass simulating tropical abscesses. Ascites (12 patient) was the most common extratumoral sign. Portal vein invasion or thrombus was rare (3 patients). Of the 31 patients, ultrasound was abnormal in all cases, alpha-fetoprotein test was positive in 12 cases (57.14%) and negative in 9 cases (42.8%). Cytological test was positive in 17 cases (80.95%), and negative in 4 cases (19.04%). Alphafetoprotein and cytologic tests were both positive in 8 cases and, nonconcordant in 13 cases; in 4 cases alphafetoprotein was positive while cytological tests were negative and, in 9 cases alphafetoprotein was negative while cytological tests were positive. Two negative tests were never observed. In Abidjan, hepatocellular carcinomas are commonly small or large, multinodular and hyperechoic tumors contrasting with the small nodular and hypoechoic tumors usually reported in western series. Ultrasound associated with cytologic examination, appears to us to be more usefulness than alphafetoprotein dosage in the diagnosis of hepatocellular carcinoma.