Van der Waals Schottky Junction Photodetector with Ultrahigh Rectifying Ratio and Switchable Photocurrent Generation.

Metal-semiconductor junctions play an important role in the development of electronic and optoelectronic devices. A Schottky junction photodetector based on two-dimensional (2D) materials is promising for self-powered photodetection with fast response speed and large signal-to-noise ratio. However, it usually suffers from an uncontrolled Schottky barrier due to the Fermi level pinning effect arising from the interface states. In this work, all-2D Schottky junctions with near-ideal Fermi level depinning are realized, attributed to the high-quality interface between 2D semimetals and semiconductors. We further demonstrate asymmetric diodes based on multilayer graphene/MoS2/PtSe2 with a current rectification ratio exceeding 105 and an ideality factor of 1.2. Scanning photocurrent mapping shows that the photocurrent generation mechanism in the heterostructure switches from photovoltaic effect to photogating effect at varying drain biases, indicating both energy conversion and optical sensing are realized in a single device. In the photovoltaic mode, the photodetector is self-powered with a response time smaller than 100 µs under the illumination of a 405 nm laser. In the photogating mode, the photodetector exhibits a high responsivity up to 460 A/W originating from a high photogain. Finally, the photodetector is employed for single-pixel imaging, demonstrating its high-contrast photodetection ability. This work provides insight into the development of high-performance self-powered photodetectors based on 2D Schottky junctions.

Emphasizing clinical investigation on anti-inflammatory therapy of dry eye / 中华实验眼科杂志

Inflammation is a defensive reaction and the most common pathological manifestation of dry eye.In addition,excessive inflammatory response is considered to be the most common pathogenic factor and main cause of dry eye.Currently,the active mechanism of anti-inflammatory drugs has been well-known,and topical antiinflammatory therapy for dry eye is exerting a role at certain extend.However,some adverse responses of these drugs are emerging during the treating procedure.Therefore,it is emphasized that a large sample size of and multicenter randomized-controlled clinical trial is needed to identify the different effects of various anti-inflammatory drugs for different types of dry eye diseases,which will offer a basis for standardized anti-inflammatory treatment for dry eye.

Effect of Qi-protecting powder (Huqi San) on expression of c-jun, c-fos and c-myc in diethylnitrosamine-mediated hepatocarcinogenesis.

AIM: To study the inhibitory effect of Huqi San (Qi-protecting powder) on rat prehepatocarcinoma induced by diethylinitrosamine (DEN) by analyzing the mutational activation of c-fos proto-oncogene and over-expression of c-jun and c-myc oncogenes. METHODS: A Solt-Farber two-step test model of prehepatocarcinoma was induced in rats by DEN and 2-acetylaminofluorene (AAF) to investigate the modifying effects of Huqi San on the expression of c-jun, c-fos and c-myc in DEN-mediated hepatocarcinogenesis. Huqi San was made of eight medicinal herbs containing glycoprival granules, in which each milliliter contains 0.38 g crude drugs. gamma-glutamy-transpeptidase-isoenzyme (gamma-GTase) was determined with histochemical methods. Level of 8-hydroxydeoxyguanosine (OHdG) formed in liver and c-jun, c-fos and c-myc proto-oncogenes were detected by immunohistochemical methods. RESULTS: The level of 8-OHdG, a mark of oxidative DNA damage, was significantly decreased in the liver of rats with prehepatocarcinoma induced by DEN who received 8 g/kg body weight or 4 g/kg body weight Huqi San before (1 wk) and after DEN exposure (4 wk). Huqi San-treated rats showed a significant decrease in number of gamma-GT positive foci (P < 0.001, prevention group: 4.96 +/- 0.72 vs 29.46 +/- 2.17; large dose therapeutic group: 7.53 +/- 0.88 vs 29.46 +/- 2.17). On the other hand, significant changes in expression of c-jun, c-fos and c-myc were found in Huqi San-treated rats. CONCLUSION: Activation of c-jun, c-fos and c-myc plays a crucial role in the pathogenesis of liver cancer. Huqi San can inhibit the over-expression of c-jun, c-fos and c-myc oncogenes and liver preneolastic lesions induced by DEN.

Pericytes are correlated with the permeability of rat corneal neovascular vessels induced by alkali burn / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Corneal neovascular leakage can lead to edema and secondary scarring. Previous studies have shown that pericytes play a key role in maturation of angiogenesis. The present studies investigate the relationship between vascular permeability and pericyte coverage of endothelial cells in rat corneal neovascular induced by alkali burns.</p><p><b>METHODS</b>Corneal neovascular vessels induced by alkali burns was performed in Sprague-Dawley rats. Corneas were excised on 1, 2, 3, 5, 7 and 10 days after cauterization. The vascular permeability rate was measured by the Evans blue method. The microvessel pericyte coverage index (MPI) was applied to quantify the pericyte coverage through double immunofluorescent staining of frozen sections of corneas with CD31 as the endothelial and alpha-smooth muscle actin (alpha-SMA) as the pericyte markers. The correlation between permeability rate and MPI was analyzed. Pericyte coverage was confirmed ultrastructually using transmission electron microscopy.</p><p><b>RESULTS</b>The vascular permeability rate was (1.14 +/- 0.17), (0.24 +/- 0.08), (0.29 +/- 0.16), (0.14 +/- 0.10), (0.09 +/- 0.06) and (0.05 +/- 0.04) microg x ml(-1) x mm(-2) respectively on 1, 2, 3, 5, 7 and 10 days after cauterization. The MPI was 0, 16.07%, 11.95%, 43.84%, 73.97% and 86.21% respectively at the above mentioned time points. The correlation coefficient between MPI and the permeability rate was -0.943 (P = 0.005).</p><p><b>CONCLUSIONS</b>Pericyte recruitment was significantly correlated with the permeability of corneal neovascularization induced by alkali burns in rats. Therapeutic strategies aiming at anti-leakage should be most effective if they promote pericytes proliferation in the course of corneal neovascularization.</p>