BACKGROUND: The biomechanical studies of ankle joint focus on methodology, and the biomechanical characteristics of the ankle joint under combined modes are little reported. OBJECTIVE: To analyze the kinematics and dynamics characteristics of the ankle joints in the movement of stop-jump of volleyball players. METHODS: Twenty male and 20 female volleyball players at Tianjin University of Sport were selected. The three-dimensional motion capture system (Vicon) and the three-dimensional force plate (Kistler) were mainly used to synchronously collect the kinematics and dynamics parameters of the ankle joint when the subjects were taking off and landing. Statistical methods were used to conduct comparative analysis of the data. The study was in accordance with the ethical requirements of Tianjin University of Sport, and the subjects signed the informed consents. RESULTS AND CONCLUSION: (1) Under this mode, the plantar flexion angle of the ankle joint in males was less than that in females. During the take-off phase, the ankle joint was in an inversion and internal rotation state, during the landing buffer phase, the ankle joint was in an inversion and external rotation state, and the angle in males was slightly larger than in the females, which was likely to cause ankle injury. (2) The three-dimensional peak torque and force value when stop-jump in males were higher than those in females. The appearing time of peak torque and force value in different directions in males was later than that in females, and imbalances between two legs and landing at different time occurred.

Proposed in this paper are expanding the access channels of information resources, providing knowledge service needed by the users, and constructing a complex subjects-oriented information service team in order to keep close to the scientific research work and realize the sustainable development of information service according to the positioned function of logistic service institute and understanding of changed information needs in scientific research on logistic service in Chinese People's Police Armed Forces.

Objective To analyze the different clinical effects of colpohysterectomy combined with anterior and posterior wall colporrhaphy with or without biological mesh for uterine prolapse.Methods From January 2010 to May 2015, colpohysterectomy combined with anterior and posterior wall colporrhaphy was performed in 106 cases of uterine prolapse, including 75 cases receiving biological mesh repair (experimental group) and 31 cases of non-biological mesh (control group).Clinical and surgical information of all patients was collected, and satistial analysis was done between the two groups.Results All the operations were accomplished successfully.There were no statistical differences in bleeding amount during operation [(34.5±7.3) ml vs.(32.1±4.9) ml, t=1.973, P=0.051], time to first flatus [(29.2±4.8) d vs.(30.2±5.3) d, t=-0.907, P=0.366], postoperative hospital stay [(6.1±1.5) d vs.(6.0±1.4) d, t=0.328, P=0.744], as well as the operative time [(91.4±3.4) min vs.(95.1±10.2) min, t=-1.970, P=0.051].At one year after surgery, in the experimental group there were 74 patients cured, 1 patient improved, and no invalid or recurrence case, while in the control group there were 27 patients cured, 1 patient improved, 3 cases of recurrence and no invalid case.The treatment effect of the experimental group was significant better than that of the control group (Z=-2.571, P=0.010).Conclusions Colpohysterectomy with anterior and posterior wall colporrhaphy with biological mesh can be selected for uterine prolapse patients without contraindications.The results of surgery are better with biological mesh, with low recurrence rate.

Objective To explore SIRT4 gene expression in tumor tissue and investigate the clinicol-pathological features in osteosarcoma .Methods In this study ,SIRT4 protein expression was detected in 106 os-teosarcoma tissues and 36 paired neighboring non -tumorous tissues by immunohistochemistry and determined the correlation between the SIRT 4 expression and the clinicopathological features .Results SIRT4 protein was dra-matically decreased in osteosarcoma cells compared with neighboring non -tumorous bone cells .The low expres-sion of SIRT4 was notably associated with a poor overall survival and disease -free survival in osteosarcoma pa-tients.By using univariate and multivariate analyses ,we confirmed that the increased SIRT 4 expression was an in-dependent factor in predicting better prognosis for patients .Conclu is on SIRT4 expression might be an inde-pendent biomarker for prognostic evaluation of osteosarcoma .

Rotating wall vessel (RWV) was used for the ex-vivo expansion of umbilical cord blood stem cells to meet the requirement of clinical application in the aspect of quantity and quality of the stem cells. The mononuclear cells (MNCs) from umbilical cord blood were cultured in T-flasks for 24 h, and then inoculated in RWV to culture for 200 h. The nucleated-cell numbers, pH and osmolality of the culture medium were determined every 24 h. The CD34+ cells content was measured and CFU-GM culture was carried out at 144 h and 197 h. Nucleated cells (NC) and CD34+ cells had a 435.5 +/- 87.6 fold expansion and a 32.7 +/- 15.6 fold expansion respectively in 197 h, and CFU-GM (colony-forming unit-granulocyte/macrophage) cells had a 21.7 +/- 4.9 fold expansion. In the whole course of culture, the pH and osmolality of the medium in the RWV were kept in the optimal hematopoietic stem cells' expansion conditions. pH was kept from 7.2 to 7.4, and the osmolality was kept from 290 mmol/kg to 310 mmol/kg. Owing to its structural particularity, the RWV could ensure cells to grow in the suspension state, could simulate the micro-environment of umbilical cord blood, and thus could make the hematopoietic stem cells expand largely in the RWV in short time.
Antigens, CD34 ; metabolism ; Bioreactors ; Cell Culture Techniques ; methods ; Cell Proliferation ; Cells, Cultured ; Culture Media ; Cytokines ; pharmacology ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; physiology ; Humans

Objective:To systematically evaluate the effect of physical exercises on the treatment of constipation by Meta-analysis.Methods:Randomized controlled trials of the effects of physical exercises on constipation were retrieved in databases of CNKI, WanFangData, VIP, SinoMed, PubMed, Web of Science and Cochrane Library from inception to December 2020. According to the inclusion and exclusion criteria, two reviewers independently selected literature, extracted data. The quality of included literature was evaluated by referring to the Cochrane collaboration's tool. And then the funnel plot was used to evaluate the risk of bias of included literature. Revman 5.3 software was used to conduct meta-analysis.Results:A total of 12 clinical trials include 1 004 patients were involved based on the inclusion and exclusion criteria. The physical exercise group was subjected to physical exercise or added other conventional treatment, and the control group had no regular exercise or only conventional treatment during the test. The fixed effects model was employed. The total effect of the value of the merger was calculated, the combined OR(95% CI) was 4.75(3.47, 6.51). Compared with the control group, exercise significantly relieved the patient's constipation symptoms( Z=9.69, P<0.000 01). Funnel figure shows a basic symmetry, which indicated the publication bias is small. Conclusions:Physical exercise is beneficial to constipation should be encouraged.

Objective:To investigate the effect of polypeptide N-acetylgalactosaminaminyltransferase 2 (GALNT2) on the proliferation and apoptosis of human retinal vascular endothelial cells (HRCECs) cultured in high glucose and its possible mechanism.Methods:The small hairpin RNA (shRNA) targeting GALNT2 gene was constructed to interfere with the lentiviral vector and infect HRCECs.HRCECs were divided into blank control group, model group, NC-shGALNT2 group and shGALNT2 group, which were cultured in medium containing 5.5 mmol/L glucose, 25 mmol/L glucose, shGALNT2 negative control virus 25 mmol/L glucose and shGALNT2 knockdown virus 25 mmol/L glucose for 24 hours, respectively.The relative expression of GALNT2 mRNA in the four groups was detected by real-time fluorescence quantitative PCR.The relative expression levels of GALNT2, epidermal growth factor (EGF), EGF receptor (EGFR) and phosphorylated EGFR (p-EGFR) were detected by Western blot.The proliferative values of HRCECs were detected by cell counting kit-8 method.The apoptosis rate of different groups was detected by flow cytometry. Results:The relative expression levels of GALNT2 mRNA and protein were significantly higher in model group than in blank control group, and were significantly lower in shGALNT2 group than in blank control group (all at P<0.05). The cell proliferation value was significantly lower in model group than in blank control group, and was significantly higher in shGALNT2 than in model group and NC-shGALNT2 group (all at P<0.05). The apoptosis rates of blank control group, model group, NC-shGALNT2 group and shGALNT2 group were (4.73±0.26)%, (8.66±0.25)%, (9.26±1.12)% and (5.47±0.18)%, respectively, with a significant overall difference ( F=342.921, P<0.001). The apoptosis rate was significantly higher in model group than in blank control group, and was significantly lower in shGALNT2 group than in model group and NC-shGALNT2 group (all at P<0.05). The relative expression level of EGFR protein was significantly higher and the relative expression level of p-EGFR protein was significantly lower in model group than in blank control group (all at P<0.05). The relative expression of p-EGFR protein was significantly higher in shGALNT2 group than in model group (all at P<0.05). Conclusions:Knocking down GALNT2 can improve the proliferative ability of HRCECs under high glucose culture and reduce apoptosis, which may be related to the activation of EGFR signaling pathway.

Objective To explore the influence of biomechanical characteristics of badminton players on sports risk at the moment of foot and ankle landing, so as to provide references basis for avoiding the sports risk of high-frequency and high-intensity landing of ankle joint of beginners. Methods Using three-dimensional force measuring platform and motion capture system, the kinematic and dynamic data of 30 badminton beginners (experimental group) and 30 high-level athletes (control group) at the kick-off (1 step) moment during ankle landing were collected. Results The angles of metatarsal flexion and dorsiflexion in experimental group were significantly smaller than those in control group, and the angles of varus and internal rotation in experimental group were significantly larger than those in control group. The left-right forces in experimental group were significantly larger than those in control group, and there was no significant difference in anterior-posterior force and vertical force between experimental group and control group. The valgus and external rotation torque of experimental group were significantly higher than those of control group, and the internal rotation torque of control group was significantly higher than that of experimental group. Conclusions Compared with beginners, the ankle movement of professional athletes has good dynamic stability and flexibility, the cushioning task can be completed with a smaller range of movement and force in left-right direction, and the angle of metatarsal flexion and dorsiflexion of professional athletes is relatively increased. It is also the embodiment of good training effect, so that the buffer time is slightly longer to prevent the impact of sudden landing of the ankle.

Due to damage to the hemi-advanced central nervous system of stroke hemiplegic patients, their ability of sit-to-stand transfer is impaired, and they are prone to fall during the sit-to-stand transfer. This article describes the characteristics of sit-to-stand transfer for hemiplegic patients at different foot placement from a biomechanical perspective, discusses the correlation between different features, analyzes the reasons for their fall, and describes the application of sit-to-stand transfer training in postoperative rehabilitation of hemiplegic patients， so as to provide references for postoperative rehabilitation of hemiplegic patients.