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The nickel carbon conductive HTV silicone rubber was prepared by additional silicone rubber as the base rubber, nickel carbon particles as conductive fillers, with coupling agent, thickening agent, and hydrogen containing silicone oil. The optimal formula for silicone rubber was explored and its performance was tested. The results showed that the optimal formula was that 100 parts of additional cured silicone rubber, 150 parts of nickel carbon particle A, 1. 5 parts of TTS coupling agent, 1 part of tackifier and 3 parts of hydrogen containing silicone oil. The silicone rubber by this formula has the surface resistance of 29. 47 mΩ, the adhesion of 23. 66 N, the density of 1. 93 g/ cm3, Shore A hardness of 65, the tensile strength of 1. 21 MPa, the elongation at break of 119%, and the resistance remains stable after 1,000 hours of double "85" aging test, which can meet the basic requirements for the conductive silicone rubber. [ABSTRACT FROM AUTHOR]

As a typical food safety industrial model strain, Bacillus subtilis has been widely used in the field of metabolic engineering due to its non-pathogenicity, strong ability of extracellular protein secretion and no obvious codon preference. In recent years, with the rapid development of molecular biology and genetic engineering technology, a variety of research strategies and tools have been used to construct B. subtilis chassis cells for efficient synthesis of biological products. This review introduces the research progress of B. subtilis from the aspects of promoter engineering, gene editing, genetic circuit, cofactor engineering and pathway enzyme assembly. Then, we also summarized the application of B. subtilis in the production of biological products. Finally, the future research directions of B. subtilis are prospected.

Genome-scale metabolic network model (GSMM) is an extremely important guiding tool in the targeted modification of industrial microbial strains, which helps researchers to quickly obtain industrial microbes with specific traits and has attracted increasing attention. Here we reviewe the development history of GSMM and summarized the construction method of GSMM. Furthermore, the development and application of GSMM in industrial microorganisms are elaborated by using four typical industrial microorganisms (Bacillus subtilis, Escherichia coli, Corynebacterium glutamicum, and Saccharomyces cerevisiae) as examples. In addition, prospects in the development trend of GSMM are proposed.

Industrial fermentation focuses on realizing the uniform of high titer, high yield, and high productivity. Multi-scale analysis and regulation, including molecule level, cell level, and bioreactor level, facilitate global optimization and dynamic balance of fermentation process, which determine high efficiency of biosynthesis, targeted directionality of bioconversion, process robustness, and well-organized system. In this review, we summariz and discuss advances in multi-scale analysis and regulation for fermentation process focusing on the following four aspects: 1) kinetic modeling of metabolic pathways, 2) characteristic of cell metabolism, 3) co-coupling fermentation and purification, and 4) bioreactor design. Integrating multi-scale analysis of fermentation process and integrating multi-scale regulation are expected as an important strategy for realizing highly efficient fermentation by industrial microorganisms.

Chitinase has a wide industrial application prospect. For example, it can degrade shrimp shells, crab shells and other crustacean waste into high value-added chitooligosaccharides. However, the low catalytic efficiency of chitinase greatly limits the production of chitooligosaccharides. In previous study, the we expressed a chitinase Chisb with high catalytic efficiency and studied its enzymatic properties. In order to further improve the catalytic efficiency of Chisb, with R13NprB-C-SP-H as the parent, here error-prone PCR was used to construct random mutant library to conduct directed evolution of chitinase Chisb. Two mutants C43D and E336R were obtained with 96-well plate primary screening and shaker-screening, and their enzymatic properties were also studied. The optimum temperature of C43D and E336R was 55 °C, and the optimum pH of C43D was 5.0, while that of E336R was 9.0. The catalytic efficiency of C43D and E336R was 1.35 times and 1.57 times higher than that of control. The chitooligosaccharide concentration of E336R and C43D was 2.53 g/L and 2.06 g/L, improved by 2.84 times and 2.31 times compared with the control (0.89 g/L), respectively. In addition, the substrate conversion rate of mutants E336R and C43D was 84.3% and 68.7%, improved by 54.6% and 39% compared with the control (29.7%), respectively. In summary, the study indicates that random mutation introduced by error-prone PCR can effectively improve the catalytic efficiency of chitinase Chisb. The positive mutants with higher catalytic efficiency obtained in the above study and their enzymatic property analysis have important research significance and application value for the biosynthesis of chitooligosaccharides.

Objective: To investigate the features and application of diaphragmatic electromyography (DEMG) in amyotrophic lateral sclerosis (ALS) patients., Methods: We recorded the electromyography of 43 diaphragms from 43 ALS patients by inserting concentric needle electrode from intercostal space, when they held their breath, breathed smoothly and drew deep breath, and took electromyography of 22 healthy diaphragms as controls. The percentage of forced vital capacity (%FVC) was performed simultaneously in 28 ALS patients., Results: All subjects showed no side-effect. The spontaneous activities could be found when ALS patients held their breath. During the period of their smooth breath, the duration of their diaphragmatic motor unit action potential (DMUAP) (12.1 ms +/- 2.7 ms) was longer than those of controls, and the common logarithmic value of the amplitude (2.585 +/- 0.132) and the area (2.722 +/- 0.208) of DMUAP were larger than those of controls. The percentage of polyphasic (53%) and satellite potential (5%) was also increased in ALS patients. The duration (13.6 ms +/- 3.6 ms) of the ALS patients with clinical dyspnoea was longer than that (11.6 ms +/- 2.2 ms) of others without it. The spontaneous activities were correlated with clinical dyspnoea and %FVC., Conclusion: DEMG with needle electrode could evaluate the respiratory state of ALS patients at the level of electrophysiology. The duration and the spontaneous activity were its sensitive indexes.

Objective: To evaluate the value of glucocorticoid receptor (GR) number in predicting the glucorticoid (GC) therapeutic efficacy., Methods: GR number in peripheral blood mononuclear cells (PBMC) from thirty patients with myasthenia gravis (MG) was measured with (3)H-dexamethansone (DEX) radio-ligand binding assay. The efficacy of GC treatment was assessed with relative clinical score one month and six months after the treatment. Twenty-four patients with MG were monitored for GR number at different time points after GC treatment., Results: The pre-treatment GR number was positively correlated with relative clinical score one month and six months after the treatment (r = 0.916 and r = 0.891, P < 0.01, respectively). The higher the pre-treatment GR number, the higher the clinical relative score and the better the efficacy of GC treatment. After GC treatment, GR number had a tendency to decline gradually., Conclusion: Pre-treatment GR number can be used as an adjuvant parameter for predicting GC therapeutic efficacy. GC treatment down-regulates GR.

Objective: To investigate the features and application of diaphragmatic motor evoked potential (DMEP) in amyotrophic lateral sclerosis (ALS) patients., Methods: To record the latency and amplitude of diaphragmatic compound muscle action potential (DCMAP) from 37 ALS patients and 31 control subjects with surface electrodes after transcranial and transcervical magnetic stimulation, central motor conduction time (CMCT) was calculated. The percentage of forced vital capacity (%FVC) was performed in 22 ALS patients simultaneously., Results: Cortical and cervical latencies of the ALS patients were longer than those of the controls, and cortical and cervical amplitudes of the ALS patients were lower than those of the controls. CMCT of the ALS patients were longer than that of the controls. Cortical latency, cortical amplitude and CMCT were all correlated with the dysfunction of the pyramidal tract. Cortical latency and CMCT were also correlated with the clinical respiratory dysfunction, cervical latency was correlated with %FVC., Conclusions: CMCT, Cortical and cervical latencies are sensitive index in DMEP parameters reflecting respiratory dysfunction in ALS, CMCT reflects cortical spinal tract function of ALS patients associated with respiration. It would be helpful to detect the neurological basis of the respiratory disturbance in ALS combining CMCT with cervical latency.

Objective: To investigate the features and application of phrenic nerve conduction in amyotrophic lateral scle-rosis (ALS) patients., Methods: The latency and amplitude of diaphragmatic compound muscle action potential (DCMAP) were recorded among 44 ALS patients and 31 control subjects with surface electrodes after the cervical part of phrenic nerve was stimulated with electricity. The percentage of forced vital capacity (%FVC) was examined in 28 ALS patients simultaneously., Results: Right and left phrenic distal motor latencies (PDML) of ALS patients were 8.4 ms +/- 2.2 ms and 7.6 ms +/- 1.4 ms respectively, longer than those of the controls, and the logarithmic value of amplitudes among ALS patients was 2.68 +/- 0.37, lower than that among the controls. Take the right side for example, although PDML was correlated with %FVC, it had no correlation with clinical respiratory dysfunction. Neither %FVC nor clinical respiratory dysfunction was correlated with the amplitude of DCMAP. The rate of abnormal PDML (47.7%) was higher than the rate of clinical dyspnea (25%)., Conclusion: PDML is a sensitive index in phrenic conduction parameter reflecting respiratory dysfunction in ALS. Only when the PDML is combined with the central motor conduction time of the diaphragmatic motor evoked potential the nervous system basis of the respiratory disturbance in ALS can be revealed.