Multilayer-grown nanomembrane GaAs represents an enabling materials platform for cost-efficient III–V photovoltaics. Herein we present for the first time 10-fold-stack ultrathin (emitter + base: 300 ...nm) GaAs solar cells. Photovoltaic performance of 10-fold-stack GaAs solar cells exhibited promising uniformity, with only slight efficiency degradation, where comparatively poor short-wavelength response was mainly responsible for the slightly reduced performance in early grown materials. Secondary ion mass spectrometry revealed the concentration of p-type dopant has been changed due to the out-diffusion of beryllium, while the extent of diffusion increasingly diminished in early grown stacks because of the reduced concentration gradient as well as the decrease of beryllium diffusivity at longer annealing times. It is therefore concluded that the performance degradation in 10-fold-stack GaAs solar cells does not develop continuously throughout the growth, but instead becomes spontaneously saturated at longer growth times, providing promising outlook for the practical application of multilayer epitaxy toward cost-competitive GaAs solar cells.
Glioblastoma multiforme (GBM), the most commonly occurring primary intracranial tumor, is associated with a negative outcome, regardless of the availability of multimodal therapies. However, the ...identification of glioma stem cells (GSCs), which are small groups of cells within the GBM, has resulted in novel avenues for research. GSCs are resistant to numerous types of environmental stress, such as irradiation, antitumor drugs and hypoxia. Nuclear factor erythroid 2-related factor 2 (Nrf2) has a significant role the cellular response to oxidative stress and previous studies have supported the significance of Nrf2 in GBM; however, the role of Nrf2 in GSCs remains unclear. In the present study, Nrf2 in CD133− GBM cells and CD133+ GSCs from GBM were compared. GSCs from GBM, which express the surface marker CD133, were separated by magnetic cell sorting and analyzed by immunofluorescence in 24-well clusters and cell counting using flow cytometry. The expression of Nrf2 was detected at the transcriptional and translational levels in CD133+ and CD133− cells, and the result indicated that GSCs were successfully isolated from the GBM. The percentage of tumor stem cells in total cells was between 0.49 and 0.91%. Nrf2 was overexpressed in CD133+ GSCs when compared with CD133− GBM cells, which indicated that the expression of Nrf2 in GSCs was closely correlated with malignant proliferation and differentiation of the GBM. Therefore, it was concluded that Nrf2 may be a potential biomarker and rational therapeutic target in GBM.
Glioma stem cells (GSCs) are key in the progression and recurrence of glioblastoma. Inducing the differentiation of GSCs is an important therapeutic target for glioblastoma. Nuclear factor erythroid ...2-related factor 2 (Nrf2) has been reported to be important in maintaining the stem cell status of GSCs; however, its association with differentiation has not been studied. Herein, we knocked down Nrf2 from GSCs to investigate the role of Nrf2 in the differentiation of GSCs. First, Nrf2 expression was observed at different stages of differentiation; then, Nrf2 was knocked down and the association of Nrf2 with differentiation degree was observed in vitro. Finally, GSCs were planted in nude mice to study the association of Nrf2 with differentiation in vivo. The expression of Nrf2 decreased with the differentiation process. Following Nrf2 knockdown, the proportion of sphere-like colonies decreased and the dendritic cells in spheres increased; the expression of Nrf2 significantly decreased while the expression of differentiation marker glial fibrillary acidic protein (GFAP) and βIII-tubulin increased both at the protein and the gene level. In the xenografts of nude mice, the differentiation of tumor cells was improved. These results suggest that Nrf2 is a key factor inhibiting the differentiation of GSCs, and knockdown of Nrf2 may promote the differentiation process, providing a therapy target for GSCs.
Abstract
Oxidative intramolecular CC bond formation
via
double
sp
2
CH activation between the 2‐position of imidazoles and a benzene ring catalyzed by palladium(II) has been developed, which ...provides an atom‐economical, concise and efficient methodology to synthesize imidazole‐ or benzimidazole‐fused isoquinoline polyheteroaromatic compounds.
Objective To investigate the association of retinal vascular calibers with hyperuricemia in a middle‐aged and elderly population. Methods A cross‐sectional design was applied in this study and 869 ...participants aged ≥40 years from a high‐risk group for diabetes were recruited. All participants received the anthropometrical measurements and laboratory tests. Retinal arteriolar and venular caliber of the participants were measured with a semi‐automated system. Hyperuricemia was defined as a serum uric acid level 420 μmol/L in men and 360 μmol/L in women. Linear regression models were used to assess the association of hyperuricemia with retinal vascular calibers. These models were additionally adjusted for age, central obesity, hypertension, dyslipidemia, weekly activity, smoking status, and education. Results Among the 869 participants, 133 （15.3%） suffered from hyperuricemia. The crude mean serum uric acid level was 312.3 μmol/L （Standard Deviation 79.5）; mean concentration was 355.0 μmol/L （SD 75.5） in male participants, and 288.0 μmol/L （SD 71.1） in female participants （age‐adjusted difference 58.1 μmol/L, 95% Confidence Internal 48.5, 67.6）. After adjusting for additional covariates, male participants with hyperuricemia had 3.77 μm （95% CI ‐0.46, 8.00） smaller arteriolar caliber and 6.20 μm （95% CI 0.36, 12.04） larger venule than those without hyperuricemia; the corresponding numbers among female participants were 1.57 μm （95% CI ‐1.07, 4.21） for retinal arteriolar caliber and 2.28 μm （95% CI ‐1.72, 6.27） for retinal venular caliber. Conclusion Hyperuricemia was associated with smaller retinal arteriolar caliber and larger venular caliber mainly in male participants in this study.
The Fenwei Basin can be the most developed area of ground fissures as well as the associated geo-hazard in China and even in the world .Considering the ground fissure disasters influence on site ...condition, especially on the dynamic characteristics and dynamic response of site soil, in this paper, under the condition of constant pressure consolidation, consolidated undrained dynamic triaxial tests are carried on Xi'an area ground fissures belt loess with different confining pressures and dynamical parameters are obtained. Based on the experimental results, the dynamic stress-strain relationship, the change laws of dynamic shear modulus and damping ratio are analyzed. The equivalent visco-elastic constitutive model is also established.
To support large scale video delivery, we carried out a hybrid packet/circuit multicasting field trial with 26000 users. Each end user has 40 Mb/s guaranteed bandwidth. The results of 1040 concurrent ...users testing ware reported. (2 pages)
A field trial of dynamic P2MP connections across two domains was successfully achieved in the ASON layer of the 3TNet testbed in Yangtze River Delta, China for the first time using web service ...mechanism.
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