Self-Powered Wavelength-Dependent Dual-Polarity Response Photodetector Based on CdS@PEDOT:PSS@Au Sandwich-Structured Core-Shell Nanorod Arrays.

Self-powered operation and multifunctionality have significantly oriented the development of photodetectors (PDs), which could be realized through nanoarchitecture construction and energy band structure design. Herein, a self-powered wavelength-dependent dual-polarity response PD based on (CdS@PEDOT:PSS@Au) sandwich-structured core-shell nanorod arrays (NRAs) is proposed. The synthesis approach of this three-layer heterostructure consists of a hydrothermal reaction, spin coating, and thermal evaporation. The n-CdS/p-PEDOT:PSS junction and the PEDOT:PSS/Au Schottky junction at the interfaces provide two photocurrent driving forces in opposite directions, and their contribution to the net photocurrent is controlled by the incident light wavelength due to the different light absorption ranges of the CdS core and the PEDOT:PSS shell. As a result, the polarity of the photocurrent switches from negative to positive as the wavelength increases. In addition, the response speed of negative photocurrents (∼10 ms) is faster than that of positive photocurrents (∼100 ms), which is consistent with the underlying mechanism of the dual-polarity response. Furthermore, color discrimination and imaging capabilities are demonstrated by deploying the PDs as sensing pixels and recognizing green and red patterns. The sandwich-structured core-shell NRA heterojunction system introduces a novel idea for dual-polarity response PDs.

Improved Dual-Polarity Response via Pyro-phototronic Effect for Filterless Visible Light Communication.

Dual-polarity response photodetectors (PDs) take full advantage of the directivity of the photocurrent to identify optical information. The dual-polarity signal ratio, a key parameter that represents the equilibrium degree of responses to different lights, is proposed for the first time. The synchronous enhancement of dual-polarity photocurrents and the amelioration of the dual-polarity signal ratio are beneficial to the practical applications. Herein, based on the selective light absorption and energy band structure design, a self-powered CdS/PEDOT:PSS/Au heterojunction PD consisting of a p-n junction and a Schottky junction exhibits unique wavelength-dependent dual-polarity response, where the photocurrent is negative and positive in the short and long wavelength regions, respectively. More importantly, the pyro-phototronic effect inside the CdS layer significantly improves the dual-polarity photocurrents with the maximum enhancement factors of 120%, 343%, 1167%, 1577%, and 1896% at 405, 450, 532, 650, and 808 nm, respectively. Furthermore, the dual-polarity signal ratio tends to 1:1 due to different degrees of the enhancement. This work provides a novel design strategy for dual-polarity response PDs with a simple working principle and improved performance, which can supply a substitution for two traditional PDs in the filterless visible light communication (VLC) system.

Construction of acetyl-CoA and DBAT hybrid metabolic pathway for acetylation of 10-deacetylbaccatin III to baccatin III.

10-Deacetylbaccatin III (10-DAB) C10 acetylation is an indispensable procedure for Taxol semi-synthesis, which often requires harsh conditions. 10-Deacetylbaccatin III-10-ß-O-acetyltransferase (DBAT) catalyzes the acetylation but acetyl-CoA supply remains a key limiting factor. Here we refactored the innate biosynthetic pathway of acetyl-CoA in Escherichia coli and obtained a chassis with acetyl-CoA productivity over three times higher than that of the host cell. Then, we constructed a microbial cell factory by introducing DBAT gene into this chassis for efficiently converting 10-DAB into baccatin III. We found that baccatin III could be efficiently deacetylated into 10-DAB by DBAT with CoASH and K+ under alkaline condition. Thus, we fed acetic acid to the engineered strain both for serving as a substrate of acetyl-CoA biosynthesis and for alleviating the deacetylation of baccatin III. The fermentation conditions were optimized and the baccatin III titers reached 2, 3 and 4.6 g/L, respectively, in a 3-L bioreactor culture when 2, 3 and 6 g/L of 10-DAB were supplied. Our study provides an environment-friendly approach for the large scale 10-DAB acetylation without addition of acetyl-CoA in the industrial Taxol semi-synthesis. The finding of DBAT deacetylase activity may broaden its application in the structural modification of pharmaceutically important lead compounds.

Specific Combination of Salvianolic Acids As Core Active Ingredients of Danhong Injection for Treatment of Arterial Thrombosis and Its Derived Dry Gangrene.

Although single-targeting anti-platelet agents are used extensively in clinics, their limitations in resistance and bleeding have started a trend of combination therapy. Danhong injection (DHI) is a widely prescribed injection medicine for cardiovascular and cerebrovascular diseases in China. However, its precise clinical efficacy and functional components remain unexplored. In this study, we investigated the anti-thrombotic role and its chemical basis of DHI. In a photochemically-induced thrombosis model, DHI effectively dissolved thrombus and ameliorated its derived dry gangrene. DHI inhibited multiple GPCR agonists-induced platelet adhesion, aggregation and downstream Ca2+ and cAMP signaling pathways. A functional screen of DHI library identified its major active components as a cluster of seven salvianolic acids. A combination of salvianolic acid A and C synergistically inhibited platelet aggregation in vitro while salvianolic acid B antagonized this effect. Our study revealed the anti-thrombotic activity of DHI. The multi-targeting mechanism of DHI proves the effectiveness of a natural anti-thrombotic combination therapy. The identification of salvianolic acids as a core anti-thrombotic activity of DHI and the discovery that their different combinations could either synergistically or antagonistically provide a better guidance for safer clinical application and paves the way for further development of DHI.

Serum heparanase concentration and heparanase activity in patients with retinal vein occlusion.

PURPOSE: To investigate the serum heparanase concentration and heparanase activity of the patients with central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO). METHODS: This prospective study included 23 CRVO patients, 13 BRVO patients and 28 control subjects. Serum heparanase concentration was measured by ELISA. Serum heparanase activity was determined using a heparan degrading enzyme assay kit (Mountain View, CA, USA). Multivariate logistic regression was used to adjust for the possible confounding factors when comparing the difference in serum heparanase concentration and activity between patients with RVO and control subjects. RESULTS: Patients with CRVO (3.963 ± 0.816 U/l) or BRVO (3.371 ± 1.522 U/l) had significantly higher levels of heparanase protein compared to controls (1.055 ± 0.902 U/l). This significance remained after adjusting for aforementioned confounding factors (CRVO versus control, p = 0.000, 95%CI: 2.450-4.488; BRVO versus control, p = 0.006, 95%CI: 0.776-4.050). Patients with CRVO (0.3587 ± 0.1498 U/ml) or BRVO (0.3616 ± 0.0570 U/ml) had significantly higher levels of heparanase activity compared to controls (0.1449 ± 0.0952 U/ml). The significance was maintained after adjusting for the aforementioned confounding factors (CRVO versus control, p = 0.012, 95%CI: 0.036-0.275; BRVO versus control, p = 0.000, 95%CI: 0.150-0.395). There was no significant difference in serum heparanase protein levels and activities between CRVO and BRVO groups before and after confounding factor adjustment. CONCLUSION: Our study provides the first direct clinical link between systemic heparanase protein levels and heparanase activity with RVO, suggesting a critical role for heparanase in the pathophysiology of RVO.

[Visual field analysis after laser in situ keratomileusis].

OBJECTIVE: To evaluate the effects of laser in situ keratomileusis (LASIK) on the patients' visual field. METHODS: 92 eyes of 46 patients with mild, moderate, and high degrees of myopia were undergone LASIK. Perimetry was performed before and 1 day, 1 month, 3 months, 6 months after LASIK surgery by Humphrey II-750 visual field analysis. The central 30 - 2 fast threshold program was used to examine the change in central 30 degree. Mean defect (MD) and pattern standard deviation (PSD) were record. All operations were performed by an experienced surgeon. Statistical analyses were performed by SPSS using the randomized complete block design ANOVA (two factors analysis of variance). Differences among variables were evaluated by q-test (Student-Newman-Kueuls method). RESULTS: 93.5% patients obtained estimated best correct visual acuity or better at six months after LASIK. No complications were found in the subjects. No difference was found in fundus examinations before and after surgery. Intraocular pressure was normal at all preoperative and postoperative examinations. MD was significant differences among preoperative and postoperative values (P < 0.05, for all comparisons) and was correlated with visual acuity post-LASIK significantly (P < 0.05). While PSD did not show significant differences before and after LASIK (P > 0.05) and was not correlated with visual acuity post-LASIK. The indexes of visual field were not correlated with the degree of myopia and the other surgical parameters (P > 0.05). CONCLUSION: In current research, no significant visual field change was demonstrated pre-LASIK and post-LASIK after 6 months follow-up. The study suggests that LASIK does not affect the retinal physiological functions.