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Article  |  2020-04-02

Synthesis, Characterization, and Antifungal Evaluation of Thiolactomycin Derivatives

5-Substituted benzylidene 3-acylthiotetronic acids are antifungal. A series of 3-acylthiotetronic acid derivatives with varying substitutions at the 5-position were designed, synthesized, and characterized, based on the binding pose of 3-acyl thiolactone with the protein C171Q KasA. Fungicidal activities of these compounds were screened against Valsa Mali, Curvularia lunata, Fusarium graminearum, and Fusarium oxysporum f. sp. lycopersici. Most target compounds exhibited excellent fungicidal activities against target fungi at the concentration of 50 μg·mL−1. Compounds 11c and 11i displayed the highest activity with a broad spectrum. The median effective concentration (EC50) values of 11c and 11i were 1.9–10.7 and 3.1–7.8 μg·mL−1, respectively, against the tested fungi, while the EC50 values of the fungicides azoxystrobin, carbendazim, and fluopyram were respectively 0.30, 4.22, and > 50 μg·mL−1 against V. Mali; 6.7, 41.7, and 0.18 μg·mL1 against C. lunata; 22.4, 0.42, and 0.43 μg·mL−1 against F. graminearum; and 4.3, 0.12, and > 50 μg·mL−1 against F. oxysporum f. sp. Lycopersici. The structures and activities of the target compounds against C. lunata were analyzed to obtain a statistically significant comparative molecular field analysis (CoMFA) model with high prediction abilities (q2 = 0.9816, r2 = 0.8060), and its reliability was verified. The different substituents on the benzylidene at the 5-position had significant effects on the activity, while the introduction of a halogen atom at the benzene ring of benzylidene was able to improve the activity against the tested fungi.

Pei Lv

Perspective  |  2020-03-31

Discovery for New Herbicide Sites of Action by Quantification of plant Primary Metabolite and Enzyme Pools

No herbicide with a new molecular site of action (SOA) has been introduced since the 1980s. Since then, the widespread evolution of resistance of weeds to most commercial herbicides has greatly increased the need for herbicides with new SOAs. Two untried strategies for the discovery on new herbicide SOAs are discussed. Some primary metabolism intermediates are phytotoxic (e.g., protoporphyrin IX and sphingoid bases), and, because of this, the in vivo concentrations of these compounds are maintained at very low levels by plants. The determination of all primary metabolite phytotoxicities and pool sizes will identify targets of interest. Targeting SOAs that result in accumulation of phytotoxic compounds is the first novel approach to herbicide discovery. The second approach is to identify potential SOAs with very low in vivo enzyme levels. We know that higher numbers of enzyme molecules for a SOA requires more herbicide to kill a plant. Modern proteomic methods can identify low enzyme level SOAs for biorational herbicide discovery. These approaches might be useful in discovery of herbicides more closely related to natural compounds and that can be used in lower doses.

Franck E. Dayan

Article  |  2020-04-03

Multi-Domain Knowledge Convergence Trajectory Analysis of Strategic Emerging Industries Based on Citation Network and Text Information

 The analysis of technology convergence process for strategic emerging industries is helpful to deeply understand the generation process and development law of industrial technology, thereby helping master the development trend of the field and promoting the healthy development of the industry. To identify the trajectory and degree of technology convergence of the strategic emerging industries, this study conducts a multi-case study on four fields which present a trend of convergence and attract social attention, namely, high-end equipment manufacturing, new-generation information technology, new medicine, and new energy. This study adopts a knowledge convergence trajectory analysis method based on citation network and text information. It utilizes a graph neural network model and encodes the citation network, title, and abstract of the publications as vectors. Five knowledge convergence trajectories are identified, after analyzing the data of the selected four technical fields. The research results show that information technology and numerical control equipment, biomedicine and solar photovoltaic technology have shown a trend of deep convergence, respectively; and the convergence of the information technology and numerical control equipment is deeper. Numerical control equipment and solar photovoltaic technology, information technology and solar photovoltaic technology have shown a converging trend, respectively; however, the current degree of convergence is still insufficient, due to the late start of convergence. Numerical control equipment and biomedicine have not shown any trend of convergence.

Liu Yufei

Article  |  2020-04-03

Research on the Development of Machine Tool Industry in China

This study focuses on the development of the high-end manufacturing equipment industry in China, represented by machine tools. The machine tool referred to herein includes not only the machine tools in traditional definition, such as lathes, milling machines, planers, drilling machines, boring machines, grinders, and gear making machines, but also additive manufacturing equipment and additive-subtractive hybrid manufacturing equipment. This study analyzes the development trends of the machine tool industry in China and the globe, and then studies the problems existing in China’s machine tool industry. Compared with world’s advanced level, China’s machine tool industry still has weaknesses in (1) basic research and key technologies for ultra-precision machine tools, (2) the machining accuracy and efficiency of large-scale machine tools, (3) the reliability and accuracy retention of the whole machine performance, (4) the research and development of common technologies of the advanced additive manufacturing and hybrid manufacturing equipment, and (5) the level of intelligence of high-end machine tools. Furthermore, we propose the key direction of China’s machine tool industry during the 14th Five-Year Plan and the following five to ten years, and put forward some policy measures for the development of machine tool industry in China, including coordinating national science and technology plans with national policy supporting and evaluation systems, and establishing and strengthening the common technology collaborative innovation system for the high-end manufacturing equipment represented by machine tools.

Wang Lei

Article  |  2020-04-01

Simulation and Evaluation of Real-Time and Intelligent Space-Based Information Service System of China

The real-time and intelligent space-based information service system is a next-generation space-based information system featuring multi-satellite coordination and multi-network interconnection. It will be widely used in satellite communications, navigation, and remote sensing. To support the top-level design and construction of the real-time and intelligent space-based information service system, this paper studies the modeling simulation and performance evaluation of the system, and analyzes the necessity, requirements, and development trends of system simulation and evaluation. The key technologies such as scalable and efficient distributed simulation, spatial-temporal dynamic evaluation, and systematic modeling are discussed, considering the characteristics of the system, such as dynamic time-varying, diverse business, and heterogeneity. Based on the design of the distributed simulation and evaluation system, the transmission support capabilities of different low-orbit communication satellite systems are compared and evaluated, taking high-resolution remote sensing as an example. The results show that during the remote sensing data transmission process, the OneWeb satellite constellation has smaller delay, less packet loss, and higher capacity and stability, owing to its dense coverage; however, its capacity per satellite is inferior to that of the Hongyun satellite constellation which has a smaller coverage density. This study can provide technical supports for the feasibility evaluation and construction of the real-time and intelligent space-based information
service system.

Jiang Hao

Article  |  2020-03-27

Future Modes of Fuel Bioethanol Industry

The fuel bioethanol industry is one of the strategic emerging industries that China focuses on cultivating and developing. Against the background of the country’s deep integration of industrialization and informatization, intelligent and safety production, which can be realized relying on China’s advantages in the Industrial Internet and 5G technology and supported by new technologies such as big data, digital twins, and blockchain, can promote the high-quality development of the fuel bioethanol industry in China. This paper summarizes and analyzes the status and problems of the fuel bioethanol industry, and proposes the general idea for future modes in intelligent production, safety production, and industrial management of the fuel bioethanol industry. The development of the fuel bioethanol industry should be guided at the national strategic level and requires cooperation among the state, local governments, and enterprises, thus to promote the characteristic, joint, and intelligent development of bioethanol industrial bases. The cooperation between industry, universities, and research institutions should be strengthened to innovate production modes and technologies and to promote international competitiveness. Furthermore, key technologies should be developed to realize the production of fuel bioethanol using cellulose-based biomass as the raw material, thereby providing strategic reserves for ensuring national food security.

Wang Meng