Addressing the challenge of traditional physical/semi physical simulation methods being difficult to achieve full process and full element simulation of extravehicular activities,virtual reality technology is utilized to break through the limitations of physical environments and establish a virtual reality simulation system for extravehicular activities.Based on the application characteristics of space station extravehicular activity engineering,with the goal of improving system practicality and usability,integrating the visual immersion of virtual images,the ontology of real operation,and the consistency of virtual and real space perception,a three-dimensional scene simulation,multi-mode joystick interaction paradigm,continuous operation actions simulation of extravehicular operations,and interactive operation virtual/real space consistency method that were proposed and designed for the realistic visual perception and extravehicular operation.The system has been successfully applied to astronaut training,program validation,joint exercise,and flight control support for sixteen extravehicular activities from SZ-12 to SZ-18.The results showed that the complete reproduction of the static/dynamic realistic comprehensive scene was achieved on the ground for the human-machine operation in the entire process of extravehicular activity,and the system is an essential and important means of ground simulation for extravehicular activity.

Objective To explore the accuracy and clinical application value of artificial intelligence(AI)-based coronary computed tomography angiography(CCTA)in the evaluation of coronary artery stenosis in patients with acute coronary syndrome(ACS).Methods Fifty-four patients with suspected ACS who underwent CCTA examination and invasive coronary angiography(ICA)within 72 h were retrospectively selected.The CCTA images of all patients were processed by AI(AI group)and manual post-pro-cessing(manual group),respectively.The image quality,work efficiency and detection rate of coronary artery stenosis were compared between AI group and manual group.With ICA results as the gold standard,the sensitivity,specificity,positive predictive value,negative predictive value and accuracy of AI in the diagnosis of ACS patients with coronary artery stenosis(≥50％)in CCTA were analyzed,and the consistency of AI and ICA examination results was tested.Results The image quality of CCTA in AI group(grade Ⅰ 27.8％)was better than that in manual group(grade Ⅰ 14.8％),but there was no statistical difference between the two groups(X2=2.707,P＞0.05).The average diagnosis time of AI group(89.67 s±33.21 s)was significantlyshorter than that of manual group(813.33 s±301.84 s)and the difference was statistically significant(t=-17.512,P＜0.001),and the average time gain rate was 88.97％.There was no statistical difference in the detection rate of coronary artery stenosis(≥50％)between AI group and manual group(x2=0.003,P＞0.05).The sensitivity,specificity,positive predictive value,negative predictive value,and accuracy of AI in diagnosis of ACS were 87.60％,96.44％,80.30％,97.92％,and 95.19％,respectively,which were significantly consistent with the results of ICA examina-tion(Kappa=0.810,P＜0.05).Conclusion AI-assisted diagnosis can correctly identify the coronary artery tree with better image,significantly shorten the diagnosis time of CCTA in ACS patients with high accuracy,and can provide a strong basis for the early treat-ment of patients with acute chest pain.

Despite exciting achievements with some malignancies, immunotherapy for hypoimmunogenic cancers, especially glioblastoma (GBM), remains a formidable clinical challenge. Poor immunogenicity and deficient immune infiltrates are two major limitations to an effective cancer-specific immune response. Herein, we propose that an injectable signal-amplifying nanocomposite/hydrogel system consisting of granulocyte-macrophage colony-stimulating factor and imiquimod-loaded antigen-capturing nanoparticles can simultaneously amplify the chemotactic signal of antigen-presenting cells and the "danger" signal of GBM. We demonstrated the feasibility of this strategy in two scenarios of GBM. In the first scenario, we showed that this simultaneous amplification system, in conjunction with local chemotherapy, enhanced both the immunogenicity and immune infiltrates in a recurrent GBM model; thus, ultimately making a cold GBM hot and suppressing postoperative relapse. Encouraged by excellent efficacy, we further exploited this signal-amplifying system to improve the efficiency of vaccine lysate in the treatment of refractory multiple GBM, a disease with limited clinical treatment options. In general, this biomaterial-based immune signal amplification system represents a unique approach to restore GBM-specific immunity and may provide a beneficial preliminary treatment for other clinically refractory malignancies.

Objective:To investigate the effect of prospective intervention on emergence agitation and postoperative recovery in patients with chronic sinusitis during preoperative visits.Methods:A total of 80 patients with chronic sinusitis who underwent general anesthesia in Dayi County People′s Hospital of Chengdu City from December 2019 to October 2020 were selected and randomly divided into group D and group G, with 40 patients in each group. Group D received preoperative visit with conventional methods and group G received preoperative visit with prospective intervention methods. The hemodynamic changes of patients in the two groups at 30 min before the operation (T 1) and 1 (T 2), 5 (T 3), 10 (T 4) and 30 min (T 5) after tracheal tube extraction were recorded. The anxiety and depression scores of patients before the intervention and 1 d after the operation were compared between the two groups. The incidence of emergence agitation after the operation and complications during anesthesia awakening period were observed in the two groups, sino-nasal outcome test-20 (SNOT-20) was used to assess the postoperative recovery. Results:The incidence of emergence agitation in group G was lower than that in group D: 7.5%(3/40) vs. 25.0%(10/40), the difference was statistically significant ( χ2 = 4.50, P<0.05). There was no significant difference in systolic blood pressure, diastolic blood pressure and heart rate between the two groups at T 1 and T 5 ( P>0.05), but the level of above indicators in group G at T 2, T 3 and T 4 were significantly higher than those in group D ( P<0.05). The scores of State-Trait Anxiety Inventory(S-AI) and Self-Rating Depression Scale (SDS) in group G at the first day after the operation were significantly lower than those in group D: (35.45 ± 5.32) scores vs. (39.35 ± 4.91) scores, (35.42 ± 7.82) scores vs. (38.76 ± 5.21) scores, the differences were statistically significant ( P<0.05). The incidence of complications during anesthesia awakening period in group G was slightly lower than that in group D ( P>0.05). After the operation, the scores of sinusitis symptoms and nasal symptoms in the two groups were significantly decreased compared with those before the operation, and the scores of group G were significantly lower than those in group D ( P<0.05). Conclusions:Prospective intervention before anesthesia in patients with chronic sinusitis surgery can reduce stress response, improve bad mood, reduce the incidence of emergence agitation, and promote the postoperative recovery.

Objective To investigate plantar pressure distributions in patients with posttraumatic foot-drop deformity with Ilizarov treatment,so as to provide biomechanical data of such patients for surgery and rehabilitation.Methods Thirty adult patients with posttraumatic foot-drop deformity who underwent Ilizarov treatment were designated as the experimental group,while another 30 healthy individuals with the same age were selected as the control group.Changes in the distribution of plantar pressure at walking stance were evaluated by comparing the peak pressure (PP),the contact area (CA),the pressure-time integral(PTI) in both groups.Results Compared with those of the control group,the affected feet in the experimental group displayed lower PP,CA and PTI in the toe area,while on the other hand higher PP,CA and PTI were shown in the 5the metatarsal and lateral heel zone.Conclusion Plantar pressure distribution was still abnormal after Ilizarov treatment in the patients with posttraumatic foot-drop deformity.In lateral forefoot there was still overload risk in such patients.For this reason,a long-term rehabilitation treatment was required for full recovery of normal plantar pressure distribution.

Objective To evaluate the effects of isokinetic quadriceps training with different ranges of motion for improving mal-patellar tracking after total knee replacement (TKR). Methods Isokinetic quadriceps training was administered to 52 TKR cases, involving 66 knee joints with poor patellar tracking. The subjects were randomly allocated into 3 groups for isokinetic training with ranges of 0-30°, 30-60° or 60-90°, with 22 knee joints in each group. The angular velocity was set at 30°/second. X-rays with loading and with 45° knee flexion were taken before and after the training. The lateral patello-femoral angle,the patella index and the patello-femoral index were recorded along with the maximum torque ( MT), the total work ( TW ), and the average work(AW) in the three different ranges of motion. Hospital for Special Surgery (HSS) scores were also recorded. Results After 3 months of training, the average lateral patello-femoral angle, patella index, and patello-femoral index in the 0-30° training group were all significantly better than before the training. However, there was no significant difference in these measures for the 30-60° and 60-90° groups. After training average MT, TW and AW increased significantly in all groups, but the improvements were significantly correlated with the differences in lateral patello-femoral angles, patella indices and patello-femoral indices only for the 0-30°group. When compared with the baseline values, a statistically significant difference in HSS score after training was observed only in the 0-30° training group. Conclusions Isokinetic quadriceps training with a 0-30° range of motion can best realign patellar tracking after TKR, and best improve knee function.

Objective To research a new algorithm to get the relative pose parameters of spacecraft during the final approach phase of spacecraft rendezvous and docking(RVD).Methods The method was based on the shape of five non-coplanar points and the model of the pinhole,and the conception of 3D reconstruction was employed.For the shape of the mark was known,the 3-D shape of the cross-mark was reconstructed based on the single visual system,and the closed-form algorithm for relative pose parameters of spacecraft was given.Results The algorithm had been validated by the mathematical simulation,and the precise results of the relative pose parameters were calculated.Conclusion The simulation results show that the algorithm is rather simple and with relative accuracy.Furthermore it is meets exact the need in real time.

Space flight training simulator is one of the important equipments for astronaut training on ground.Based on general international classification criteria,technology principle and engineering implementation of simulators developed in our country were introduced.The key technology of developing simulators was discussed.The prospect of development for future studies and applications were looked forward to.