Analysis of therapeutic targets for SARS-CoV-2 and discovery of potential drugs by computational methods, Acta Pharmaceutica Sinica B, https://doi. Graphical abstractTwenty structures including 19 SARS-CoV-2 targets and 1 human target were built by homology modeling. Library of ZINC drug database, natural products, 78 anti-viral drugs were screened against these targets plus human ACE2. This study provides drug repositioning candidates and targets for further in vitro and in vivo studies of SARS-CoV-2. (Mengzhu Zheng), xingzhouli@aliyun.com (Xingzhou Li). † These authors made equal contributions to this work.Abstract SARS-CoV-2 has caused tens of thousands of infections and more than one thousand deaths. There are currently no registered therapies for treating coronavirus infections. Because of time consuming process of new drug development, drug repositioning may be the only solution to the epidemic of sudden infectious diseases. We systematically analyzed all the proteins encoded by SARS-CoV-2 genes, compared them with proteins from other coronaviruses, predicted their structures, and built 19 structures that could be done by homology modeling. By performing target-based virtual ligand screening, a total of 21 targets (including two human targets) were screened against compound libraries including ZINC drug database and our own database of natural products. Structure and screening results of important targets such as 3-chymotrypsin-like protease (3CLpro), Spike, RNA-dependent RNA polymerase (RdRp), and papain like protease (PLpro) were discussed in detail. In addition, a database of 78 commonly used anti-viral drugs including those currently on the market and undergoing clinical trials for SARS-CoV-2 was constructed. Possible targets of these compounds and potential drugs acting on a certain target were predicted. This study will provide new lead compounds and targets for further in vitro and in vivo studies of SARS-CoV-2, new insights for those drugs currently ongoing clinical studies, and also possible new strategies for drug repositioning to treat SARS-CoV-2 infections.

Surface exfoliation: A Ta3 N5 photoanode prepared by a thermal oxidation and nitridation method shows a high solar photocurrent. This photocurrent is currently the highest achieved by a Ta3 N5 photoanode. The photocurrent is obtained mainly because of facile thermal and mechanical exfoliation of the surface passivation layer of the Ta3 N5 photoanode.

COVID-19 has broken out since the end of December 2019 and is still spreading rapidly, which has been listed as an international concerning public health emergency. We found the Spike protein of SARS-CoV-2 contains a furin cleavage site, which did not exist in any other betacoronavirus subtype B. Based on a series of analysis, we speculate that the presence of a redundant furin cut site in its Spike protein is responsible for SARS-CoV-2’s stronger infectious than other coronaviruses, which leads to higher membrane fusion efficiency. Subsequently, a library of 4,000 compounds including approved drugs and natural products were screened against furin through structure-based virtual screening and then assayed for their inhibitory effects on furin activity. Among them, an anti-parasitic drug, Diminazene , showed the highest inhibition effects on furin with an IC 50 of 5.42 ± 0.11 μM, which might be used for the treatment of COVID-19.

photovoltaic (PV) cell (using, for example, silicon or gallium arsenide), though capable of achieving a high conversion effi ciency, faces the main obstacle of high cost for largescale application because of the requirement of high purity and low defect density.In the past few decades, some novel cells of low cost have been explored to convert solar energy into electrical or chemical energy, such as organic photovoltaic cells (OPV), photoelectrochemical solar cells, and photoelectrochemical solar water splitting cells. [1][2][3][4][5] In these devices, a key limit in a planar structure cell for high effi ciency is the incompatibility between a short diffusion length of minority carriers and a long optical absorption length. To overcome the limit, bulk heterojunction (BHJ) concept is fi rst introduced in an OPV cell, [ 6 ] which consists of an interpenetrating network of donor and acceptor materials. [ 7,8 ] The performance of the BHJ solar cell depends on the morphology very sensitively. A large interface area is usually necessary for high separation effi ciency. In a photoelectrochemical solar cell or water splitting cell, one-dimensional nanostructure (nanowires, nanorods, or nanotubes), [9][10][11][12] branched nanostructure, [ 13,14 ] and porous structures, [15][16][17][18][19] are used to increase light capture and decrease diffusion distance of minority carriers to the interface. In a nanostructured photoelectrochemical cell, electrolyte can penetrate into the bulk of a solid photoelectrode. Therefore, analogically, a nanostructured photoelectrochemical cell can be considered as a solid-electrolyte bulk heterojunction.Generally, higher light absorption and/or charge separation effi ciency are considered as the main reasons for improved performance in a nanostructured cell than a planar structure. However, quantitative analysis and defi nite experimental evidence remain elusive. It is diffi cult to directly compare a nanostructured cell with a planar cell because the controlled samples are usually prepared by different methods or different conditions. Especially, in an OPV, it is diffi cult to investigate the details once the cell is assembled and a solid-solid interface forms. Therefore, it is impossible to identify quantitative contribution of each factor. Only some qualitative conclusions are given in previous studies.In the past few decades, some novel low-cost nanostructured devices have been explored for converting solar energy into electrical or chemical energy, such as organic photovoltaic cells, photoelectrochemical solar cells, and solar water splitting cells. Generally, higher light absorption and/or charge separation effi ciency are considered as the main reasons for improved performance in a nanostructured device versus a planar structure. However, quantitative analysis and defi nite experimental evidence remain elusive. Here, using BiVO 4 as an example, comparable samples with porous and dense structures have been prepared by a simple method. The porous and dense fi lms are assembled into a sol...