A Simple and Effective Phosphine-Doping Technique for Solution-Processed Nanocrystal Solar Cells.

Solution-processed cadmium telluride (CdTe) nanocrystal (NC) solar cells offer the advantages of low cost, low consumption of materials and large-scale production via a roll-to-roll manufacture process. Undecorated CdTe NC solar cells, however, tend to show inferior performance due to the abundant crystal boundaries within the active CdTe NC layer. The introduction of hole transport layer (HTL) is effective for promoting the performance of CdTe NC solar cells. Although high-performance CdTe NC solar cells have been realized by adopting organic HTLs, the contact resistance between active layer and the electrode is still a large problem due to the parasitic resistance of HTLs. Here, we developed a simple phosphine-doping technique via a solution process under ambient conditions using triphenylphosphine (TPP) as a phosphine source. This doping technique effectively promoted the power conversion efficiency (PCE) of devices to 5.41% and enabled the device to have extraordinary stability, showing a superior performance compared with the control device. Characterizations suggested that the introduction of the phosphine dopant led to higher carrier concentration, hole mobility and a longer lifetime of the carriers. Our work presents a new and simple phosphine-doping strategy for further improving the performance of CdTe NC solar cells.

Patient-specific 3D printed models for enhanced learning of immediate implant procedures and provisionalization.

INTRODUCTION: This study aimed to describe the fabrication, implementation and evaluation of 3D-printed patient-specific models for unskilled students to enhance learning in immediate implant procedures and provisionalization. MATERIALS AND METHODS: The individualized simulation models were designed and processed based on CT and digital intraoral scanning of a patient. Thirty students performed simulation implant surgery and provisionalized the implant sites on the models and answered questionnaires to assess their perceptions before and after the training. The scores of the questionnaires were analysed using the Wilcoxon signed-rank test. RESULTS: Significant differences before and after training were found in the students' responses. Students reported better results in understanding of surgical procedures, knowledge in prosthetically driven implantology, understanding of minimally invasive tooth extraction, confirming the accuracy of surgical template, usage of the guide rings and usage of the surgical cassette after simulation training. The overall expenditure on the simulation training involving 30 students amounted to 342.5 USD. CONCLUSIONS: The patient-specific and cost-efficient 3D printed models are helpful for students to improve theoretical knowledge and practical skills. Such individualized simulation models have promising application prospects.

Enhanced Cyclability of Cr8O21 Cathode for PEO-Based All-Solid-State Lithium-Ion Batteries by Atomic Layer Deposition of Al2O3.

Cr8O21 can be used as the cathode material in all-solid-state batteries with high energy density due to its high reversible specific capacity and high potential plateau. However, the strong oxidation of Cr8O21 leads to poor compatibility with polymer-based solid electrolytes. Herein, to improve the cycle performance of the battery, Al2O3 atomic layer deposition (ALD) coating is applied on Cr8O21 cathodes to modify the interface between the electrode and the electrolyte. X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscope, and Fourier transform infrared spectroscopy, etc., are used to estimate the morphology of the ALD coating and the interface reaction mechanism. The electrochemical properties of the Cr8O21 cathodes are investigated. The results show that the uniform and dense Al2O3 layer not only prevents the polyethylene oxide from oxidization but also enhances the lithium-ion transport. The 12-ALD-cycle-coated electrode with approximately 4 nm Al2O3 layer displays the optimal cycling performance, which delivers a high capacity of 260 mAh g-1 for the 125th cycle at 0.1C with a discharge-specific energy of 630 Wh kg-1.

"Mosquito-Free Villages": Practice, Exploration, and Prospects of Sustainable Mosquito Control - Zhejiang, China.

Mosquitoes and mosquito-borne diseases have always been a great threat to human health. Mosquito control based on sustainable vector management strategy is particularly important. In Zhejiang Province, exemplary villages of sustainable mosquito control ("mosquito-free villages") have been successful operated, providing a new model of mosquito control in rural areas based on local conditions. The construction of "mosquito-free village" will apply environmentally-friendly and appropriate technologies to eliminate and transform mosquito breeding sites and to establish mechanisms of cultivating villagers' health literacy of scientific mosquito control and voluntary participation in control activities to keep mosquito density low long-term.

Effect of dietary supplementation of Bacillus subtilis B10 on biochemical and molecular parameters in the serum and liver of high-fat diet-induced obese mice.

While a high-fat diet (HFD) is assumed to be related to fat-mediated oxidative stress decreasing antioxidant enzyme activity, probiotics are believed to have positive effects on the regulation of HFD-induced obesity as well as lipid metabolism, energy homeostasis, and anti-oxidation. Because Bacillus subtilis B10 has beneficial effects on the abnormal lipid metabolism and the oxidative stress in HFD-induced obese mice, ICR mice were randomly assigned into an HFD group and the HFD was supplemented with 0.1% (w/w) Bacillus subtilis B10 (HFD+B10 group). Thereafter, 30-d treatments were run, and then hepatic lipid level and antioxidant status were measured. The expression of genes related to lipid metabolism and oxidative stress in the liver was determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). We found that HFD-induced obese mice treated with B10 showed a decrease in weight gain, serum glucose activity as well as hepatic triglyceride (TG), glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) activities. In addition, the gene expressions of antioxidant genes, glutathione reductase (GR), xanthine oxidase (XO), heat-shock protein 90 (Hsp90), and lipid synthesis gene 3ß-hydroxysteroid-∆24 reductase (DHCR24) in the HFD+B10 group were down-regulated, suggesting alleviation of oxidative stress, while the lipolysis gene 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), energy metabolism gene peroxisome proliferator-activated receptor α (PPARα) and the gene encoding tumor-suppressor protein p53 were up-regulated. The regulatory and positive effect of dietary supplementation of probiotic B10 suggests that it has a beneficial effect on the homeostasis of the lipid metabolism and on alleviating oxidative stress in HFD-induced obese mice.

[Acute heat stress increases HSP70 expression in the testis, epididymis and vas deferens of adult male mice].

OBJECTIVE: To investigate the effects of acute heat stress on the expression patterns of heat shock protein 70 (HSP70) in the testis, epididymis and vas deferens of adult male mice. METHODS: Thirty-two 8-week-old male mice were randomly divided into a control and 3 heat stress groups. After a week of pretreatment, the latter 3 groups were exposed to heat stress at (39 +/- 0.5) degrees C for 0.5, 1 and 3 hours, respectively, followed immediately by collection of the blood and determination of glutamic oxaloacetic transaminase (GOT) concentration. Sperm suspension was made from one epididymis for the detection of sperm concentration and abnormal acrosome rate, while the testis, epididymis and vas deferens on the other side were harvested for immunohistochemical analysis. RESULTS: Heat stress induced different degrees of decrease in epididymis indexes and sperm concentration and a dramatic increase in GOT concentration (P < 0.01), but caused no significant changes in the body weight, testis indexes and abnormal acrosome rate in the mice (P > 0.05). There was a tendency of gradual descent in sperm concentration and ascent in abnormal acrosome rate with the increasing time of heat stress. The most decrease in body weight, testis indexes and epididymis indexes was observed in the 0.5 h group. Immunohistochemical results showed that HSP70 was expressed in the testis, epididymis and vas deferens, mildly in the Leydig cells of the testis and distributed in the nuclei of the Leydig cells, spermatoblasts and spermatocytes. In the epididymis, HSP70 was expressed mainly in the cytoplasm of principal and ciliated cells, but not in the basal and clear cells, while in the vas deferens, it was observed mainly in the cytoplasm of the basal cells, but not in the principal cells. With the increase of heating time, the HSP70 expression was markedly elevated in the testis and epididymis, but not so obviously in the vas deferens. CONCLUSION: Acute heat stress was harmful to the reproductive system of adult male mice. The region- and cell-specific patterns of HSP70 expressions in the testis, epididymis and vas deferens suggested that HSP70 might play an important role in spermatogenesis and sperm maturation. The dramatic increase of HSP70 expression after heat stress might be responsible for the prevention of cells from high temperature.