Objective To study the performance evaluation of integration rendezvous and docking(RVD)control by man and machine in order to provide reference for function allocation between man and machine.Method By a rendezvous and docking experimental system,30 male volunteers aged 20～40 took part in the performance evaluation experiments.The RVD integration control success rates and total thruster ignition time were chosen as evaluation indices.Result The experiment showed that if less than three RVD parameters control tasks were completed by the subjects and the rest of parameters control task completed by automation,the RVD success rate would be larger than 80.47% and the fuel consumption would be optimized.In addition,there were ten subjects who finished the whole 6 RVD parameters control tasks by enough train.Conclusion If the astronauts role should be integrated into the RVD control,it is suitable for them to finish the heading,pitch and roll control in order to assure the man-machine system high performance.When astronauts were needed to finish all parameters control,two points should be taken into consideration,enough fuel and unconstraint operation time.

AIM: To construct HBx eukaryotic expression vector pEYFP-C1-X and eukaryotic expression vector pGL3-P4 driven by P4 promoter of human IGF-II gene and to investigate the effect of HBx on the transcription activity of IGF-II gene P4 promoter. METHODS: HBx gene and P4 promoters were cloned into pEYFP-C1 and pGL3-basic vectors respectively by gene recombination techniques to construct recombinant plasmids pEYFP-C1-X and pGL3-P4. HepG2 cells were transfected with pEYFP-C1-X and the resistant cell clones were selected by G418. Then methylated pGL3-P4 was transiently transfected into the above cell clones, and the transcription activity of P4 promoter was determined by dual-luciferase reporter assay system. RESULTS: (1) Aim fragments HBx gene and P4 promoter that were cloned were 465 bp and 1 246 bp, respectively and the DNA sequences were accordant with GenBank data confirmed by restricted enzyme digestion and sequencing. (2) HepG2-EYFP-X cells that expressed HBx protein were obtained. (3) Luciferase activity of methylated P4 promoter in the HepG2-EYFP-X was more than that of control cell HepG2-EYFP (P<0.01). CONCLUSION: HBx may enhance the transcription activity of the P4 promoter.

Objective:This retrospective study aims to determine the efficacy of chemotherapy and improve a salvage chemother-apy agent for metastatic colorectal cancer (MCRC) after failure of treatment with irinotecan and oxaliplatin. Methods:Between Janu-ary 2002 and March 2013, 37 patients with metastatic MCRC who had progressed after treatment with irinotecan and oxaliplatin were analyzed for their response rate (RR) and progression-free survival (PFS). Results:The overall RR of the 37 patients was 13.51%, with 5 cases of partial response (PR), 12 cases of disease stabilization (SD), and 20 cases of progression (PD). Compared with other chemo-therapy regimens, treatment with a pemetrexed-based chemotherapy agent had a higher RR (17.64%vs. 10.00%, P=0.64) without a lon-ger PFS (2.00 months vs. 1.63 months, HR=0.79, 95%, CI:0.35 to 1.78, P=0.58). Compared with other chemotherapy regimens, treat-ment with a raltirexed-based chemotherapy agent had a higher RR (16.67%vs. 12.00%, P=0.34) without a longer PFS (1.58 months vs. 1.90 months, HR=2.24, 95%, CI:0.98 to 5.12, P=0.06).Conclusion:In patients with MCRC after failure of treatment with irinotecan and oxaliplatin, a pemetrexed-based or raltirexed-based chemotherapy agent may beneficial during salvage treatment and is therefore worthy of further study.

Objective To explore the protective effect and mechanism of the dihydromyricetin (DHM) on cognitive dysfunction in Alzheimer’s disease (AD) rat model. Methods The AD model of rats was established by injecting Aβ1-42 oligomolymer into the hippocampus. According to the random number table,30 successfully constructed AD model rats were divided into AD group,AD+DHM1 group and AD+DHM2 group,with 10 in each group. And the rats in the three groups were intraperitoneally injected with nor-mal saline,100 mg/kg DHM and 200 mg/kg DHM for 21 days,respectively. Another 10 rats with body mass matching were taken as the control group. Morris water maze was used to evaluate the spatial learning and memory ability of rats in each group,the expression of inflammatory cytokines were detected by Elisa,and the expressions of AMPK and SIRT1 proteins were detected by Western blot. Results Compared with the con-trol group,the escape incubation period of rats in AD group was prolonged,and the difference was statistically significant (day 5 :(10. 36±2. 80)s,(22. 40±2. 98)s;t=-18. 63,P<0. 05). Compared with AD group,the escape latency of rats in AD+DHM1 group and AD+DHM2 group were shortened (day 5:AD+DHM1 group (15. 68±3. 06) s,AD+DHM2 group (18. 85±3. 22) s; t=10. 65,4. 13,both P<0. 05). Compared with AD group,rats in AD+DHM1 group and AD+DHM2 group had more crossing times ((1. 87± 0. 76),( 2. 75± 0. 63) and (3. 78±0. 71);t=-6. 86,-9. 83,both P<0. 05),and the target quadrant residence time were ex-tended ((17. 08±1. 99) s,(16. 33±4. 33) s,(22. 59±4. 21) s;t= 28. 5,8. 63,both P<0. 05). Compared with the control group,the levels of IL-1β,IL-6 and TNF-α in the serum and hippocampus of the AD group were significantly increased (serum: t=4. 98, 7. 87, 5. 43, all P<0. 05; hippocampus: t=11. 13, 30. 50, 23. 38,all P<0. 05). Compared with the AD group,the levels of IL-1β,IL-6 and TNF-α in the serum and hippocampus of the AD+DHM1 group and the AD+DHM2 group were significantly decreased,the difference was statistically significant ( serum: AD+DHM1 group t=-4. 13,-10. 70,-9. 22, AD+DHM2 group t=-1. 75,-3. 63,-18. 75,all P<0. 05;hippocampus:AD+DHM1 group t=-69. 13,-15. 13,-6. 50,AD+DHM2 group t=-10. 25,-39. 00,-8. 00,all P<0. 05). Compared with the control group,the expression of p-AMPK/AMPK protein and SIRT1 protein in the AD group were decreased. The expression of the two pro-teins in the AD+DHM1 group and the AD+DHM2 group were increased,comparing with those of AD group, and the difference was statistically significant(all P<0. 05). Conclusion DHM exerts protective role in AD model rats,which may be related to the activation of AMPK/SIRT1 pathway and the inhibition of inflammato-ry response.

Objective: To establish a model for evaluating the upper limb load intensity of workers based on biomechanical methods, and to verify its effectiveness. Methods: 15 male volunteers participated in lifting test of 3 kinds of external force load in March 2015. Volunteers’ operating postures, forces, and subjective load intensities were collected. The biomechanical models of lifting operation were established with the input of operating postures and forces, and to output joint torque of shoulder, elbow and wrist. The simulation results were normalized by the maximum torque of each joint, and the relative joint torque was obtained. Then the upper limb load intensity evaluation model, which related with relative joint torque of shoulder, elbow and wrist, was established based on analytic hierarchy process. In order to validate the validity of the model, the assessment results of the model and the subjective load intensities of the volunteers were contrasted. Results: The weight of shoulder joint (0.56) was larger than the weights of elbow and wrist (0.27 and 0.17) in the influence factors of the upper limb load. Pearson correlation analysis showed that the upper limb load intensities of the model were significantly correlated with the subjective load intensities of volunteers (r=0.863, P<0.05) . There was no significant difference between the two groups (t=0.105, P>0.05) . Conclusion The evaluation model of the upper limb load intensity based on biomechanical methods could be used for predicting and evaluating the upper limb load intensities of workers.

Objective: To explore the protective effect and mechanism of the dihydromyricetin (DHM) on cognitive dysfunction in Alzheimer’s disease (AD) rat model. Methods: The AD model of rats was established by injecting Aβ1-42 oligomolymer into the hippocampus. According to the random number table, 30 successfully constructed AD model rats were divided into AD group, AD+ DHM1 group and AD+ DHM2 group, with 10 in each group.And the rats in the three groups were intraperitoneally injected with normal saline, 100 mg/kg DHM and 200 mg/kg DHM for 21 days, respectively.Another 10 rats with body mass matching were taken as the control group.Morris water maze was used to evaluate the spatial learning and memory ability of rats in each group, the expression of inflammatory cytokines were detected by Elisa, and the expressions of AMPK and SIRT1 proteins were detected by Western blot. Results: Compared with the control group, the escape incubation period of rats in AD group was prolonged, and the difference was statistically significant (day 5 : (10.36±2.80)s, (22.40±2.98)s; t=-18.63, P<0.05). Compared with AD group, the escape latency of rats in AD+ DHM1 group and AD+ DHM2 group were shortened (day 5: AD+ DHM1 group (15.68±3.06) s, AD+ DHM2 group (18.85±3.22) s; t=10.65, 4.13, both P<0.05). Compared with AD group, rats in AD+ DHM1 group and AD+ DHM2 group had more crossing times ((1.87±0.76), (2.75±0.63) and (3.78±0.71); t=-6.86, -9.83, both P<0.05), and the target quadrant residence time were extended ((17.08±1.99) s, (16.33±4.33) s, (22.59±4.21) s; t= 28.5, 8.63, both P<0.05). Compared with the control group, the levels of IL-1β, IL-6 and TNF-α in the serum and hippocampus of the AD group were significantly increased (serum: t=4.98, 7.87, 5.43, all P<0.05; hippocampus: t=11.13, 30.50, 23.38, all P<0.05). Compared with the AD group, the levels of IL-1β, IL-6 and TNF-α in the serum and hippocampus of the AD+ DHM1 group and the AD+ DHM2 group were significantly decreased, the difference was statistically significant(serum: AD+ DHM1 group t=-4.13, -10.70, -9.22, AD+ DHM2 group t=-1.75, -3.63, -18.75, all P<0.05; hippocampus: AD+ DHM1 group t=-69.13, -15.13, -6.50, AD+ DHM2 group t=-10.25, -39.00, -8.00, all P<0.05). Compared with the control group, the expression of p-AMPK/AMPK protein and SIRT1 protein in the AD group were decreased.The expression of the two proteins in the AD+ DHM1 group and the AD+ DHM2 group were increased, comparing with those of AD group, and the difference was statistically significant(all P<0.05). Conclusion DHM exerts protective role in AD model rats, which may be related to the activation of AMPK/SIRT1 pathway and the inhibition of inflammatory response.

Since the outbreak of corona virus disease 2019 (COVID-19), viral strains have mutated and evolved. Vaccine research is the most direct and effective way to control COVID-19. According to different production mechanisms, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines included inactivated virus vaccine, live attenuated vaccine, mRNA vaccine, DNA vaccine, viral vector vaccine, virus-like particle vaccine and protein subunit vaccine. Among them, viral protein subunit vaccine has a wide application prospect due to its high safety and effectiveness. Viral nucleocapsid protein has high immunogenicity and low variability which could be a new direction for vaccine production. We summarized the current development of vaccine research by reviewing the current progress, vaccine safety and vaccine immune efficiency. It is hoped that the proposed possible development strategies could provide a reference for epidemic prevention work in future.
Humans ; SARS-CoV-2/genetics* ; COVID-19/prevention & control* ; Protein Subunits ; Vaccines, DNA ; Nucleocapsid Proteins