다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

In the past few decades, there has been a wide research interest in titanium dioxide (TiO2) nanomaterials due to their applications in photocatalytic hydrogen generation and environmental pollution removal. Improving the optical absorption properties of TiO2 nanomaterials has been successfully demonstrated to enhance their photocatalytic activities, especially in the report of black TiO2 nanoparticles. The recent progress in the investigation of black TiO2 nanomaterials has been reviewed here, and special emphasis has been given on their fabrication methods along with their various chemical/physical properties and applications.

Black titanium dioxide (TiO2) nanomaterials

Materials research has driven the development of modern nano-electronic devices. In particular, research in magnetic thin films has revolutionized the development of spintronic devices1,2 because identifying new magnetic materials is key to better device performance and design. Van der Waals crystals retain their chemical stability and structural integrity down to the monolayer and, being atomically thin, are readily tuned by various kinds of gate modulation3,4. Recent experiments have demonstrated that it is possible to obtain two-dimensional ferromagnetic order in insulating Cr2Ge2Te6 (ref. 5) and CrI3 (ref. 6) at low temperatures. Here we develop a device fabrication technique and isolate monolayers from the layered metallic magnet Fe3GeTe2 to study magnetotransport. We find that the itinerant ferromagnetism persists in Fe3GeTe2 down to the monolayer with an out-of-plane magnetocrystalline anisotropy. The ferromagnetic transition temperature, Tc, is suppressed relative to the bulk Tc of 205 kelvin in pristine Fe3GeTe2 thin flakes. An ionic gate, however, raises Tc to room temperature, much higher than the bulk Tc. The gate-tunable room-temperature ferromagnetism in two-dimensional Fe3GeTe2 opens up opportunities for potential voltage-controlled magnetoelectronics7-11 based on atomically thin van der Waals crystals.

Gate-tunable Room-temperature Ferromagnetism in Two-dimensional Fe 3 GeTe 2

SnO2: A comprehensive review on structures and gas sensors

Sb2Se3, a binary compound containing non-toxic and Earth-abundant constituents, is a promising absorber material for low-cost, high-efficiency photovoltaics. Current Sb2Se3 thin-film solar cells use toxic CdS as the buffer layer and suffer from unsatisfactory stability. Here we selected ZnO as the buffer layer and constructed superstrate Sb2Se3 solar cells with a certified power conversion efficiency of 5.93%. Randomly oriented ZnO produced by spray pyrolysis induced the growth of Sb2Se3 with preferred [221] orientation, and hence resulted in devices with fewer interfacial defects and better efficiency. Moreover, our unencapsulated device survived the stringent damp-heat (85 ∘C, 85% humidity, 1,100 h), light-soaking (50 ∘C, 1.3 sun, 1,100 h), thermal cycling, and ultraviolet preconditioning tests. The combined features of stability, Earth-abundant constituent and potentially low-cost manufacturing highlight the great potential of Sb2Se3 solar cell as a possible non-toxic alternative to CdTe photovoltaics. Thin-film photovoltaic devices are often based on toxic or rare materials. Here, Wang et al. grow oriented Sb2Se3 thin film on a ZnO buffer layer, and fabricate solar cells with a certified 5.9% conversion efficiency and which pass harsh stability tests under humidity, heat and illumination.

Stable 6%-efficient Sb 2 Se 3 solar cells with a ZnO buffer layer

https://onlinelibrary.wiley.com/doi/pdf/10.1002/inf2.12028

Machine learning in materials science

In halide perovskite solar cells the formation of secondary-phase excess lead iodide (PbI2) has some positive effects on power conversion efficiency (PCE) but can be detrimental to device stability and lead to large hysteresis effects in voltage sweeps. We converted PbI2 into an inactive (PbI2)2RbCl compound by RbCl doping, which effectively stabilizes the perovskite phase. We obtained a certified PCE of 25.6% for FAPbI3 (FA, formamidinium) perovskite solar cells on the basis of this strategy. Devices retained 96% of their original PCE values after 1000 hours of shelf storage and 80% after 500 hours of thermal stability testing at 85°C. Description Managing excess lead iodide In hybrid perovskite solar cells, the formation of lead iodide (PbI2) can provide some passivation effects but can lead to device instability and hysteresis in current–density changes with voltage. Zhao et al. show that doping with rubidium chloride (RbCl) can create a passive inactive (PbI2)2RbCl phase that stabilizes the perovskite phase and lowers its bandgap. Devices exhibited 25.6% certified power efficiency and maintained 80% of that efficiency after 500 hours of operation at 85°C. —PDS Converting PbI2 into inactive (PbI2)2RbCl by RbCl doping can stabilize the perovskite phase and increase efficiency.

Inactive (PbI2)2RbCl stabilizes perovskite films for efficient solar cells

Perovskite light-emitting diodes (PeLEDs) have showed significant progress in recent years; the external quantum efficiency (EQE) of electroluminescence in green and red regions has exceeded 20%, but the efficiency in blue lags far behind. Here, a large cation CH3CH2NH2+ is added in PEA2(CsPbBr3)2PbBr4 perovskite to decrease the Pb–Br orbit coupling and increase the bandgap for blue emission. X-ray diffraction and nuclear magnetic resonance results confirmed that the EA has successfully replaced Cs+ cations to form PEA2(Cs1-xEAxPbBr3)2PbBr4. This method modulates the photoluminescence from the green region (508 nm) into blue (466 nm), and over 70% photoluminescence quantum yield in blue is obtained. In addition, the emission spectra is stable under light and thermal stress. With configuration of PeLEDs with 60% EABr, as high as 12.1% EQE of sky-blue electroluminescence located at 488 nm has been demonstrated, which will pave the way for the full color display for the PeLEDs. Blue light-emitting diodes (LEDs) are critical for displays. Employing a large organic cation into a quasi-two dimensional perovskite with green emission, Chu et al. achieve LEDs exhibiting a high external quantum efficiency of 12.1% and stable spectra in the sky-blue region.

/pdf/large-cation-ethylammonium-incorporated-perovskite-for-2jrapbjdj1.pdf

Hui-Xiong Deng

Papers

Stable 6%-efficient Sb 2 Se 3 solar cells with a ZnO buffer layer

Machine learning in materials science

Inactive (PbI2)2RbCl stabilizes perovskite films for efficient solar cells

Large cation ethylammonium incorporated perovskite for efficient and spectra stable blue light-emitting diodes

Recent Advances of 2D Materials in Nonlinear Photonics and Fiber Lasers