Recent progress of PSCs in efficiency and stability enhancement is addressed to the change of perovskite composition and crystal optimization. By introducing mixed cations and halide to adjust the composition of the organicinorganic hybrid perovskite, the crystal structure of the perovskite can be effectively improved, which ultimately led to the increased stability and efficiency of the PSCs. Compared with the single cation/ halide perovskite (methylammonium halide, formamidinium lead halide, and cesium lead halide), the mixed perovskite not only has higher PCE but also has better heat and humid air stability. [9][10][11][12] For mixed cation/halide perovskites, despite good optoelectronic properties, the mixing of multiple cations and halogens is prone to localized ionic enrichment during preparation, annealing, and operation. At the same time, as the cation and halide ions move in the builtin electric field of the device, local positive and negative ion vacancies are formed. These defects will cause significant hysteresis in the device and ultimately affect the performance of the device. [13][14][15][16][17] A series of studies on both experimental and theoretical methods [13,18,19] have been reported. Constraining Mixed cation/halide perovskites have led to a significant increase in the efficiency and stability of perovskite solar cells. However, mobile ionic defects inevitably exacerbate the photoinduced phase segregation and selfdecomposition of the crystal structure. Herein, ultrathin 2D nanosheets of oxo-functionalized graphene/dodecylamine (oxo-G/DA) are used to solve ion migration in cesium (Cs)-formamidinium (FA)-methylammonium (MA) triple-cation-based perovskites. Based on the superconducting carbon skeleton and functional groups that provide lone pairs of electrons on it, the ultrathin 2D network structure can fit tightly on the crystals and wrap them, isolating them, and thus reducing the migration of ions within the built-in electric field of the perovskite film. As evidence of the formation of sharp crystals with different orientation within the perovskite film, moiré fringes are observed in transmission electron microscopy. Thus, a champion device with a power conversion efficiency (PCE) of 21.1% (the efficiency distribution is 18.8 ± 1.7%) and a remarkable fill factor of 81%, with reduced hysteresis and improved long-term stability, is reported. This work provides a simple method for the improvement of the structural stability of perovskite in solar cells.

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Between 1952 and 1992 more than 200 large radiobiology studies were conducted in research institutes throughout Europe, North America and Japan to determine the effects of external irradiation and internal emitters on the life span and tissue toxicity development in animals. At Argonne National Laboratory, 22 external beam studies were conducted on nearly 700 beagle dogs and 50,000 mice between 1969 and 1992. These studies helped to characterize the effects of neutron and gamma irradiation on lifespan, tumorigenesis, and mutagenesis across a range of doses and dosing patterns. The records and tissues collected at Argonne during that time period have been carefully preserved and redisseminated. Using these archived data ongoing statistical work has been done and continues to characterize quality of radiation, dose, dose rate, tissue, and gender specific differences in the radiation responses of exposed animals. The ongoing application of newly developed molecular biology techniques to the archived tissues has revealed gene specific mutation rates following exposure to ionizing irradiation. The original and ongoing work with this tissue archive is presented here as a case study of a more general trend in the radiobiology mega studies. These experiments helped form the modern understanding of radiation responses in animals, and continue to inform development of new radiation models. Recent archival efforts have facilitated open access to the data and materials produced by these studies and so a unique opportunity exists to expand this continued research.

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Abstract:The aim of this present study is to investigate the effect of Zanthoxylum bungeanum oil (essential oil from Z. bungeanum Maxim.) on cytotoxicity and the transdermal permeation of 5-fluorouracil and indomethacin. The cytotoxicity of Z. bungeanum oil on dermal fibroblasts and epidermal keratinocytes was studied using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The rat skin was employed to determine the percutaneous penetration enhancement effect of Z. bungeanum oil on hydrophilic and lipophilic model drugs, i.e., 5-fluorouracil and indomethacin. The secondary structure changes of the rat stratum corneum (SC) were determined using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and saturated solubilities and SC/vehicle partition coefficients of two model drugs with and without Z. bungeanum oil were also measured to understand its related mechanisms of action. It was found that the half maximal inhibitory concentration (IC 50 ) values of Z. bungeanum oil were significantly lower in HaCaT and CCC-ESF-1 cell lines compared to the well-established and standard penetration enhancer Azone. The Z. bungeanum oil at various concentrations effectively facilitated the percutaneous penetration of two model drugs across the rat skin. In addition, the mechanisms of permeation enhancement by Z. bungeanum oil could be explained with saturated solubility, SC/vehicle partition coefficient, and secondary structure changes of SC.

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A thorough understanding of how ICT support provided by teacher preparation programmes influences preservice teachers' technological pedagogical content knowledge (TPACK) has become increasingly essential. This study aimed at exploring the mediating role of ICT perception, perceived ICT competence and ICT self-efficacy between university ICT support and preservice teachers' TPACK. Data were collected through an online self-assessment questionnaire translated and adapted from existing studies and verified with confirmatory factor analysis (CFA). A total of 298 preservice teachers, who were senior students studying at three different normal universities in China, participated in this study. Structural equation modelling revealed the following: (a) university ICT support significantly predicted preservice teachers' ICT perception, perceived ICT competence and ICT self-efficacy, but had no significant direct effects on their TPACK; (b) ICT self-efficacy was a strong predictor of preservice teachers' TPACK and ICT perception was a weak one, while perceived ICT competence did not predict TPACK at all; and (c) among three potential mediators, ICT self-efficacy mediated the most effects of university ICT support

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