COVID-19 has broken out rapidly in nearly all countries worldwide, and has blossomed into a pandemic. Since the beginning of the spread of COVID-19, many scientists have been cooperating to study a vast array of old drugs and new clinical trial drugs to discover potent drugs with anti-COVID-19 activity, including antiviral drugs, antimalarial drugs, immunosuppressants, Chinese medicines, M pro inhibitors, JAK inhibitors, etc. The most commonly used drugs are antiviral compounds, antimalarial drugs and JAK inhibitors. In this review, we summarize mainly the antimalarial drugs chloroquine and hydroxychloroquine, the antiviral drugs Favipiravir and Remdesivir, and JAK inhibitor Ruxolitinib, discussing their biological activities, clinical trials and synthesis progress.
An efficient hydrazine substitution of p‐nitro‐aryl fluorides with hydrazine hydrates catalyzed by FeO(OH)@C nanoparticles is described. This hydrazine substitutions of p‐nitro‐aryl fluorides bearing electron‐withdrawing groups proceeded efficiently with high yield and selectivity. Similarly, hydrogenations of p‐nitro‐aryl fluorides containing electron‐donating groups also smoothly proceeded under mild conditions. Furthermore, with these prepared aryl hydrazines, some phthalazinones, interesting as potential structures for pharmaceuticals, have successfully been synthesized in high yields.
Automatic welding technology has been widely used in China’s industrial production. Welding robots with the characteristics of high efficiency and high qualification rate began to appear in the industrial production line. However, in order to protect their own competitiveness, most companies use closed source control mode for welding robots, resulting in high control cost, low system openness and poor flexibility. Therefore, it is of great significance to design an open-source and low-cost six degree of freedom welding robot motion control system based on STM32 microcontroller. According to the requirements of motion control system, the development board of dual core processor is selected as the core to complete the hardware design of motion control system. The software design of the control system adopts the framework of cooperative work between the upper computer and the lower computer, and the upper computer is developed with software, which has good human-computer interaction function; The lower computer is programmed through the modular idea, which is convenient for secondary development and has good expansibility. According to the standard DH method, the trajectory planning of the 6-DOF robot is realized, and the S-type acceleration and deceleration algorithm and other related algorithms are used to realize its more efficient and smooth motion control.
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