The Renaissance of Poly(3-hexylthiophene) as a Promising Hole-Transporting Material Toward Efficient and Stable Perovskite Solar Cells.

To push the commercialization of the promising photovoltaic technique of perovskite solar cells (PSCs), the three-element golden law of efficiency, stability, and cost should be followed. As the key component of PSCs, hole-transporting materials (HTMs) involving widely-used organic semiconductors such as 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD) or poly(triarylamine) (PTAA) usually suffer high-cost preparation and low operational stability. Fortunately, the studies on the classical p-type polymer poly(3-hexylthiophene) (P3HT) as an alternative HTM have recently sparked a broad interest due to its low-cost synthesis, excellent batch-to-batch purity, superior hole conductivity as well as controllable and stable film morphology. Despite this, the device efficiency still lags behind P3HT-based PSCs mainly owing to the mismatched energy level and poor interfacial contact between P3HT and the perovskite layer. Hence, in this review, the study timely summarizes the developed strategies for overcoming the corresponding issues such as interface engineering, morphology regulation, and formation of composite HTMs from which some critical clues can be extracted to provide guidance for further boosting the efficiency and stability of P3HT-based devices. Finally, in the outlook, the future research directions either from the viewpoint of material design or device engineering are outlined.

[Study on improving the practical ability of specialized nurses in micro-endodontics by cooperative medical and nursing training].

PURPOSE: To explore the effect of cooperative training between doctors and nurses on improving the practical ability of micro-endodontics specialist nurses. METHODS: Twenty-two nurses in the Department of Endodontics were trained by specialist directors and doctors. The head of department nursing explained in the form of teaching and simulated exercises of medical and nursing training. Before and after the training, theoretical and practical abilities of the trained nurses were assessed, and self-made questionnaires were used to investigate the training effect. The results were analyzed by SPSS 10.0 software package. RESUITS: Twenty-two trained nurses were compared before and after training in theoretical knowledge and practical ability. Statistical analysis showed that the difference was statistically significant (P<0.05). Questionnaire survey showed that 95.5% of trained nurses believed that they could enhance the sense of solidarity and cooperation, 100% of trained nurses believed that they could increase the efficiency of operative therapy, 100% of doctors believed that medical and nursing cooperation training could increase the nursing skill proficiency of trained nurses, and the cooperation of trained nurses was predictable. CONCLUSIONS: Cooperative training broadens the specialty knowledge of endodontic specialist nurses, improves their proficiency in cooperation with endodontic specialists and their tacit understanding with doctors, and evidently improves their theoretical and practical abilities.

Vitamin C promotes the proliferation of human adipose-derived stem cells via p53-p21 pathway.

Although adipose-derived stem cells (ADSCs) have demonstrated a promising potential for the applications of cell-based therapy and regenerative medicine, excessive reactive oxygen species (ROS) are harmful to ADSCs cell survival and proliferation. Vitamin C is an important antioxidant, and is often added into culture media as an essential micronutrient. However, its roles on the proliferation of human ADSCs have not been studied. Therefore, in this study, human ADSCs were isolated, and detected by flow cytometry for the analysis of their cell surface antigens. Cell proliferation and cell cycle progression were measured with cell counting kit-8 assay and flow cytometry, respectively. Western blotting was used to detect the expression levels of cyclin E1, p53, p21, and CDK2 proteins. The effect of vitamin C pretreatment on the production of hydrogen peroxide (H2O2)-mediated ROS in the ADSCs was evaluated by flow cytometry. Our results indicated that vitamin C treatment significantly increased cell proliferation, and changed the cell cycle distribution of ADSCs by decreasing the percentage of G1 phase, and concurrently increased the percentage of S and G2/M phase. Western blot analysis indicated that vitamin C treatment up-regulated the expression levels of cyclin E1 and CDK2, but down-regulated p53 and p21 proteins expression, which contributed to cell proliferation and cell cycle progression. Vitamin C pretreatment significantly reduced the production of H2O2-induced ROS in the ADSCs. These findings suggest that vitamin C can promote the proliferation and cell cycle progression in the ADSCs possibly through regulation of p53-p21 signal pathway.