Objective To find a biomechanical evaluation methods of manual performance fatigue,for providing the feasible methods for the hand fatigue of spacesuit glove.Method Twelve females and forteen males in two groups served as the subjects and participated in the experiments of changeless force fatigue,including gripping,pinching and screwing,and took part in the nondimensional force fatigue.Result Manual performance fatigue could be fully evaluated based on gripping,pinching and screwing.The nondimensional force fatigue had widely applied ranges and well veracity.The combination of nondimensional subjective and objective evaluations was the optimal fatigue evaluation method.Conclusion The results can provide the feasible methods for performance evaluation of spacesuit glove system.

Objective To evaluate the efficacy of pressure support ventilation ( PSV ) in the infants undergoing laparoscopic hernia repair under sevoflurane anesthesia. Methods Thirty ASA physical statusⅠpediatric children, aged 9 months-1 yr, weighing 8.0-11.5 kg, undergoing elective laparoscopic hernia repair, were randomly assigned into 3 groups ( n=10 each) using a random number table: pressure control ventilation ( PCV) used for muscle relaxants in combination with low?concentration sevoflurane group ( group PCV1 ) , PCV used for high?concentration sevoflurane group ( group PCV2 ) , and PSV used for low?concentration sevoflurane group ( group PSV) . Anesthesia was induced with inhalation of 4%-6%sevoflurane and iv fentanyl 2 μg∕kg and succinylcholine 1.5 mg∕kg. The pediatric children were endotracheally intubated and mechanically ventilated. In PCV1 and PCV2 groups, PCV was used during operation. In group PSV, PCV was used first after intubation, and then PSV was applied after spontaneous breathing recovered. Anesthesia was maintained as follows: in group PCV1 , the end?tidal concentration of sevoflurane was maintained at 2.5% - 3.0%, and cisatracurium besylate 0.1 mg∕kg was injected intermittently as required; in group PCV1 , the end?tidal concentration of sevoflurane was maintained at 3.5%-4.0%; in group PSV, the end?tidal concentration of sevoflurane was maintained at 2.5%-3.0%, and succinylcholine 1.0 mg∕kg was injected intravenously before pneumoperitoneum. Narcotrend index value was maintained at 50-60 in PCV1 and PSV groups, or at 37-45 in PCV2 group. Heart rate ( HR) and mean arterial pressure (MAP) were recorded before induction of anesthesia (baseline), at the beginning of pneumoperitoneum, at 5 and 10 min of pneumoperitoneum, at the end of pneumoperitoneum, at the end of operation and immediately after extubation. The time interval from the end of surgery to extubation was recorded. Results Pulse oxygen saturation was 100% during anesthesia, and>95% during recovery from anesthesia in the three groups. Compared with the baseline value, HR was significantly faster, and MAP was increased during extubation in PCV1 and PCV2 groups, and no significant change was found in HR and MAP at each time point in group PSV. The time interval from the end of surgery to extubation was 30.3± 5.4, 18.4±4.3 and (4.1±1.2) min in PCV1, PCV2 and PSV groups, respectively. Compared with PCV1 and PCV2 groups, the time interval from the end of surgery to extubation was significantly shortened in group PSV. Conclusion When PSV is applied in the infants undergoing laparoscopic hernia repair under sevoflurane anesthesia, it can provide adequate ventilation, recovery from anesthesia is rapid, and no cardiovascular responses occur during extubation.

ObjectiveTo investigate the effects of isoflurane anesthesia on the expression of brain-derived neurotrophic factor (BDNF) and phosphorylated extracellular signal-regulated kinase (p-ERK) in neonatal rat hippocampus.MethodsForty-eight SD rats of both sexes,aged 7 days,weighing 12-17 g,were randomly divided into 2 groups ( n =24 each):control group (group C) and isoflurane anesthesia group (group Ⅰ).In group Ⅰ,the rats were exposed to2.5％ isotlurane for 3 min and then 1.5％ isoflurane was inhaled for 4 h,while in group C the rats were exposed to air for4 h.Arterial blood samples were collected immediately after anesthesia for blood gas analysis and for determination of the blood glucose concentration.Five rats in each group were sacrificed at 0,6,24 and 48 h after anesthesia (T1-4) and hippocanpi were removed for determination of the expression of potassiumchloride cotransporter 2 (KCC2),potassium-chloride cotrmsporter 1 (NKCC1),BDNF and p-ERK by Western blot.NKCC1/KCC2 ratio was calculated.ResultsAcid-base imbalance,hypoxemia and glycopenia were not found immediately after anesthesia in both groups.Compared with group C,KCC2 expression was significantly down-regulated and NKCC1/KCC2 ratio was increased at T3 and T4,and the expression of BDNF and p-ERK was dewn-regnlated at T1 and T2 in group Ⅰ (P＜0.05).There was no significant difference in NKCCI expression at each time point between groups Ⅰ and C ( P ＞ 0.05 )、ConclusionIsoflurane anesthesia delays the neuronal development in neonatal rat hippocampus through down-regulating the expression of BDNF and p-ERK.

Objective To investigate the effect of precondition with Toll-like receptor 4 monoclonal antibody (TLR4mAb) on lipopolysaccharide (LPS) -induced acute lung injury in mice.Methods A total of 45 male BALB/c mice were randomly divided into 3 groups:the control group ( group C),the sepsis group (group S) and the pretreatment group (group P).Mice in the group P and group S were injected intraperitoneally with LPS ( 10 mg/kg) to produce acute lung injury models.Mice in the group P was injected intraperitoneally with TLR4mAb (5 μg/g) 1 h before the injection of LPS.Expression of TLR4mRNA in lung tissue,expression of TNF-α and IL-6 in serum,water content of lung,and the pathomorphologic changes of lung were detected after 6 h,12 h and 24 h.One-way ANOVA was used for inter-group comparison and two-way ANOVA was used for intra-group comparison.Results Compared to group C,water content significantly increased at 12 h and 24 h in group S and group P; compared to group S,water content significantly decreased in group P at 12 h and 24 h.Compared to group C,the expression of IL-6 and TNF-α significantly increased in group S and group P at 6 h,12 h and 24 h; compared to group S,the expression of IL-6 and TNF-α significantly decreased at 6 h,12 h and 24 h in group P.Compared to group C,the expression of TLR4 mRNA increased significantly in group S and group P at 6 h,12 h and 24 h; compared to group S,the expression of TLR4 mRNA decreased significantly in group P at6 h,12 h and 24 h.Compared to group S,pathological damage of the lung was improved significantly in group P.Conclusions Precondition with TLR4mAb can attenuate LPS-induced acute lung injury,suppress the expression of inflammatory factors.Regulation of TLR4 pathway may be a promising therapeutic strategy for ALI.

Objective To investigate the effects of different concentrations of isoflurane on the caspase-3 expression in the hippocampus and S100β level of plasma in fetal rats. Methods 18 pregnant rats at gestational day 21 were divided into control group, 1. 3% isoflurane group,3% isoflurane group. Rats in the control group spontaneously breathed 100% oxygen for 1 h. Rats in the treatment groups breathed 1.3% or 3% isoflurane in 100% oxygen through an endotracheal tube, with mechanical ventilation for 1 h. Rat pups were delivered by cesarean section 6 h after treatment, and fetal blood was sampled from the left ventricle of each fetal heart and evaluated for S100β. Fetal brains were then evaluated for apoptosis, using caspase-3 immunohistochemistry in the CA1 region of the hippocampus. Results Compared to the control group ((1. 48 ± 0. 08) μg/L) and the 1. 3% isoflurane group( (1.53 ±0. 12)μg/L) ,the 3% isoflurane group showed significantly higher level of S100β( (3. 12 ±0. 15) μg/L, P＜0.05) . There was no differences in densities of caspase-3-positive cells between the control ((33 ±4) cell/mm ) and 1.3% isoflurane groups((31 ±5)cell/mm2). Compared to 1.3% isoflurane,isoflurane at a concentration of 3%((75 ± 7) cell/mm2, P＜0.05) for lh increased neurodegeneration in the hippocampal CA1 area in the developing brain of fetal rats. Conclusion Isoflurane can dose-dependently induce brain damage. Isoflurane at a concentration of 3% for lh can induce apoptosis in the hippocampal CA1 area and increase S100β levels of fetal rats.

Objective To investigate the effects of propofol on the development of spatial learning and memory and neuron proliferation of neonatal rats at different doses. Methods 60 neonatal rats were divided into four groups among per litter by using a randomized block design. Three different doses of propofol group were induced with propofol 10 mg/kg( group P10) ,50 mg/kg( group P50) or 50 mg/kg twice( group P50D) by subcutaneous injection respectively. Neuron proliferation at dentate gyrus was detected by using BrdU marker 3 days later.Morris water maze test was carried out on postnatal day 28. Escape latency,time in probe quadrant were recorded.Results Compared to the control group,neuron marked with BrdU at dentate gyrus in group P50D was significantly decreased( (840±76) vs (225 ±66), P＜0.05) ,group P10 was significantly increased( (840 ±76) vs ( 1225± 154), P＜0.05). Compared to the control group,latency of group P50D was significantly increased( ( 15.12 ±3.43 ) s vs (42.68 ± 6. 18 ) s, P ＜ 0. 05 ), time in probe quadrant of group P50D were significantly decreased ( ( 55.66 ± 8.57 ) s vs (32. 18 ± 5. 38 ) s, P＜ 0. 05 ). Compared to the control group, there was no significant difference between group P50 and group P10. Conclusion Propofol given to seven-day-old rats with 50 mg/kg twice by subcutaneous injection suppresses neuron proliferation and impairs development of memory and learning in neonatal rats,but propofol given with 10 mg/kg once promotes neuron proliferation.

Objective To investigate the effects of isoflurane anesthesia on proliferation and differentiation of neural stem cells (NSCs) in the dentate gyrus of neonatal rats.Methods Ten SD rats,aged 7 days,weighing 16-20 g,were randomly divided into 2 groups ( n =5 each):control group (group C) and isoflurane group (group 1) .The rats in group Ⅰ inhaled 2.5％ isoflurane for 3 min for induction and then anesthesia was maintained with 1.5 ％ isoflurane for 4 h,while the rats in group C only breathed the room air for 4 h.Bromodeoxyuridine (BrdU) 100 mg/kg was injected intraperitoneally right before the induction and after the end of administration to label NSCs and their progeny in the dentate gyrus.At 24 h after the 2nd administration of BrdU,double immunofluorescence for BrdU and NeuroD (a marker of neuroblasts and immature neurons) was used to assess NSC proliferation and neuronal differentiation.Results Compared with group C,the number of BrdU+ cells in group Ⅰ was significantly decreased,whereas the fraction of NeuroD+/BrdU+ differentiated cells was increased in the dentate gyrus( P ＜ 0.05 or 0.01 ).Conclusion Isoflurane anesthesia suppresses the proliferation of NSCs and induces neuronal differentiation of NSCs in the dentate gyrus of neonatal rats.

Objective To evaluate the effects of ulinastatin pretreatment on cognitive dysfunction induced by chronic exposure to ketamine in immature mice.Methods Thirty-six healthy male C57BL/6 mice,aged 21 days,weighing 20-30 g,were randomly divided into 3 groups (n =12 each) using a random number table:control group (group C),ketamine group (group K),and ulinastatin pretreatment group (group U).In K and U groups,ketamine 30 mg/kg was injected intraperitoneally three times a day at 30-minute intervals for 21 consecutive days,while in group U,ulinastatin 50 000 U/kg was injected intraperitoneally at 30 min before the first injection of ketamine everyday.Cognitive function was assessed using Morris water maze and open field tests at 24 h after the last administration of ketamine.Mice in each group were sacrificed immediately after the end of the tests and hippocampi were harvested to determine the contents of interleukin-6 (IL-6),IL-1 and tumor necrosis factor-α (TNF-α) using ELISA.Results Compared with group C,the escape latency was significantly prolonged,the time spent in the original platform and in the central area for the open field was shortened,the frequency of crossing the original platform was decreased,and the contents of IL-1,IL-6,and TNF-α were increased in group K (P ＜ 0.05),while there were no significant differences in the indexes mentioned above in group U (P ＞ 0.05).Compared with group K,the escape latency was significantly shortened,the time spent in the original platform and in the central area for the open field was prolonged,the frequency of crossing the original platform was increased,and the contents of IL-1,IL-6,and TNF-α were decreased in group U (P ＜ 0.05).Conclusion Ulinastatin pretreatment can improve cognitive dysfunction induced by chronic exposure to ketamine in immature mice,and inhibition of inflammatory responses in hippocampi may be involved in the mechanism.

Objective To explore the effects of mild and moderate acute hypobaric hypoxia on manual performance.Methods Using hypobaric chamber to simulate hypoxia conditions and devising 4 kinds of objective ergonomic testing items(Insert sticks into holes-board,ISIHB;nut-bolt assembly task,NBAT;shape discrimination,SD;and Grip strength,GS including fatigue and tolerance)and one subjective research item(questionnaire subjective sense)to examine manual work efficiency varieties of 9 subjects exposed to a hypobaric chamber with 5 simulated altitudes(3 500,4 000,4 500,5 000 and 5 500 m),for(25?5)min.Results Compared to control group(50 m,the altitude of Beijing):Accomplish time(AT)performance of ISIHB and NBAT significantly decreased(P

Objective To search for perfect and logical evaluation indexes of range of motion of manual performance and maximal voluntary range of motion. Methods From mechanism of hand movement and characteristics of manual action,some relative comprehensive evaluation indexes on range of motion of manual performance were provided.Twenty six undergraduates (14 male and 12 female)participated in the test for 16 indexes. Results The maximal voluntary range of motion of thumb,four fingers and wrist were obtained. Conclusion The results can provide foundation for ergonomics design of spacesuit gloves.