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Two rearranged triterpenoids, representing new subtypes of pentacyclic triterpenoids, with unique 6/6/6/7/5 and 6/6/5/6/6/6 ring systems were isolated from Alstonia scholaris. Their structures were established by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Both compounds exhibited potent antihyperuricemic bioactivity in vitro and in vivo.

Two rearranged triterpenoids, representing new subtypes of pentacyclic triterpenoids, with unique 6/6/6/7/5 and 6/6/5/6/6/6 ring systems were isolated from

Endophytic fungi play important roles for host's stress tolerance including invasion by pathogenic microbes. Small molecules are common weapons in the microbe-microbe interactions. Panax notoginseng is a widely used traditional Chinese medicinal plant and harbors many endophytes, some exert functions against pathogens. Here, we report six new compounds named myrothins A-F (1-6) produced by Myrothecium sp. BS-31, an endophyte isolated from P. notoginseng, and their antifungal activities against pathogenic fungi causing host root-rot disease. Their structures were elucidated with analysis of spectroscopic data including 1D and 2D NMR, HR-ESI-MS. Myrothins B (2) and E (5) showed the weak activity against Fusarium oxysporum and Phoma herbarum, and myrothins F (6) showed weak activity against F. oxysporum.

Image deraining is a fundamental, yet not well-solved problem in computer vision and graphics. The traditional image deraining approaches commonly behave ineffectively in medium and heavy rain removal, while the learning-based ones lead to image degradations such as the loss of image details, halo artifacts and/or color distortion. Unlike existing image deraining approaches that lack the detail-recovery mechanism, we propose an end-to-end detail-recovery image deraining network (termed a DRD-Net) for single images. We for the first time introduce two sub-networks with a comprehensive loss function which synergize to derain and recover the lost details caused by deraining. We have three key contributions. First, we present a rain residual network to remove rain streaks from the rainy images, which combines the squeeze-and-excitation (SE) operation with residual blocks to make full advantage of spatial contextual information. Second, we design a new connection style block, named structure detail context aggregation block (SDCAB), which aggregates context feature information and has a large reception field. Third, benefiting from the SDCAB, we construct a detail repair network to encourage the lost details to return for eliminating image degradations. We have validated our approach on four recognized datasets (three synthetic and one real-world). Both quantitative and qualitative comparisons show that our approach outperforms the state-of-the-art deraining methods in terms of the deraining robustness and detail accuracy. The source code has been available for public evaluation and use on GitHub.

Based on image processing of SF6 gas leakage on-line pattern recognition method, this paper achieves gas leakage feature extracting, on-line identification of gas leakage and leakage points, SF6 gas leakage can be on-line automatic identification. The simulation results show the feasibility of the algorithm. Compared with the traditional method, paper provides a more intuitive discrimination basis for field staff , as well as for the depth of the late testing data mining provides a research way of thinking

We prepared chitosan-grafted quarternary phosphonium ionic liquid (1-butyl-triphenylphosphonium bromide) by a simple method and used it as catalyst for the synthesis of cyclic carbonates through CO 2 cycloaddition to epoxides in the absence of co-catalyst and solvent. High yield of propylene carbonate (96.3%) is obtained at 120 °C and 2.5 MPa in 4 h. We studied the roles of chitosan hydroxyl groups and ionic liquid counter anions on catalytic activity. It is proposed that the facilitation of ring opening of epoxides is a combined result of polarization (by hydrogen bonding due to hydroxyl groups), electronic interaction (by [BuPh 3 P] + ), and nucleophilic attack (by bromide anion). The catalyst can be easily recovered and reused as demonstrated in a test of five runs without showing any significant loss of activity. From the view point of commercial application, the catalyst is attractive because it is low-cost, ecology-safe, stable and efficient. Furthermore, it is potentially applicable for fixed-bed continuous flow reactors.

A heuristic particle swarm optimization algorithm is proposed to solve the problem of test point selection with unreliable test. Firstly, a heuristic function is established to value the capability of test point detection, coverage and reliance. Then based on the heuristic function and least test cost principle, a fitness function of unreliable test is created. Lastly, the method for test point selection using improved particle swarm optimization algorithm is presented. Comparing with other method of test point selection, the results show that the method is easy to find the global optimal test point in large-scale system. It can also minimize test cost on requirement of testability targets.