The following articles briefly introduced the symbolic developments of aviation oxygen supply equipment and the physiological researches on high altitude environment home and abroad for about 100 years since human explored the sky. The four development landmarks were mainly elaborated: oxygen supply and sky exploration, pressured cabin and high altitude exposure limit, pressure oxygen and airplane altitude ceiling, and onboard oxygen generation and airplane voyage.

Objective To study changes in ACE, LDH and AKP in BALF and blood after rapid decompression in rabbits. Methods Thirty healthy New-Zealand rabbits were randomly divided into low decompression group and rapid decompression group. The respective activity of ACE, LDH and AKP in BALF and blood of rabbits was measured. Results Various degrees of increase in activity of ACE, LDH and AKP in BALF were observed after rapid decompression. Conclusion The simultaneous enhancement of activity of these enzymes suggest that there was injury to the lung consistent with the degree of injury after rapid decompression.

Objective To study the effect of rapid decompression on ultrastructure of the lung in rabbits. Methods Thirty healthy New-Zealand rabbits were randomly divided into low decompression group and rapid decompression group. The pulmonary ultrastructure of rabbits was observed with transmission electron microscope (TEM). Results In rabbits of the rapid decompression group, a number of pathological changes were found, such as disruption of cell membrane structure of types Ⅰ and Ⅱ alveolar cells, loosening of intercellular linkage, edematous mitochondria, expanded rough endoplasmic reticulum, engorged capillary of alveolar wall, edematous capillary endothelium cells, and increased capillary permeability. These changes became especially obvious when the decompression peak value was above 9.8 kPa. Conclusion Rapid decompression could inflict injury to the lung, which was aggravated with the increase of the decompression peak value.

Objective To observe physiological and ultrastructure changes in rabbits breathing various contents of oxygen during exposure to high altitude. Methods Twenty healthy rabbits were randomly divided into air-breathing group, 63% oxygenbreathing group, 83% oxygenbreathing group and pure oxygen breathing group. All rabbits were exposed to an atmosphere corresponding to an altitude of 11 000m in hypobaric chamber for 30min. The amount of air bubble in the heart and ECG of rabbits were recorded, the ultrastructural changes in the heart and brain were examined, and the expression of kidney erythopoietin (EPO) was also observed. Results The amount of air bubbles in the air breathing group was increased remarkably, and most of the rabbits developed arrhythmia. With the increase of oxygen concentration, the changes in ultrastructure were alleviated and the expression of kidney EPO decreased. Conclusion Oxygenconcentration above 80% could provide obvious protection for rabbits during their exposure to high altitude.

Objective To assess the performance of onboard oxygen generating and supplying system. Methods A model of a person and 8 volunteers in hypobaric chamber and rapid decompression chamber underwent the tests of producing oxygen ability of the oxygen concentrator of board oxygen generating system normal performance tests on oxygen supply at 0～8 000m, performance tests at cruising altitude for longrange, warning performance tests, secondary oxygen switch tests, positive pressure oxygen performance tests and rapid decompression performance tests. Results All the ability of producing and supply of oxygen, and the normal and the emergency performance of onboard oxygen generating system could fulfill the system physiological requirements. Conclusion On board oxygen generating and supplying system could meet pilots normal and emergeney needs when pilots aviate for long range in high altitude.

0 05). But significant difference was found between them in blood pressure. So far as altitude hypoxia tolerance test is concerned, Chinese female pilots can fly a fighter as male pilots.

To study injurious effects on rabbit lung from rapid decompression, slow decompression and the rapid decompression were used in two respective groups consisting of 30 rabbits. Slow decompression did not bring about obvious lung injury, but the lung injury in different severity occurred after rapid decompression. The greater the decompression peak value was, the more severe lung injuries was. These results indicated that rapid decompression could inflict lung injury, and the main cause of lung injury might be the temporary high pressure in lungs induced by rapid decompression, leading to over expansion of the alveoli and strong impact of the lung on the chest wall

Objective To study the effect of overexpression of TRPC6 on Ang Ⅱ-induced apoptosis of mouse podocytes in vitro and to explore the possible mechanisms. Methods Mouse TRPC6 cDNA eukaryotie expression vector pEGFP-NI-mTRPC6 was transfected to conditionally immortalized routine podocyte cell line by liposome. The fluorescent microscopy was used to examine the expression of EGFP after 24 hours. The change of TRPC6 protein expression was observed by Western-blot. Podocytes were treated by different concentrations of Ang Ⅱ. The podocyte intracellular calcium concentration was measured with laser-scanning con_focal microscope. The expression of Bax and Bcl-2 mRNA was assessed by RT-PCR and the expression of Bax and Bcl-2 protein was measured by Western-blot. The apoptotic ratio of podocytes was monitored by flow cytometry and Hoechst staining. Results About 35% of the cells expressed EGFP. An up-regulation of protein expression of TRPC6 was detected in podocytes when transfected with pEGFP-N1-mTRPC6 (P<0.01). The overexpression of TRPC6 promoted the Ang Ⅱ-induced influx of extracellular calcium and elevated the expression of Bax but decreased the expression of Bcl-2 (P<0.01, P<0.05). The apoptotic ratio of podocyte was (2.50±0.72)% when treated by low-dose Ang Ⅱ (10-10 mol/L), and it was increased to (4.33±0.45)% when transfected with pEGFP-N1-mTRPC6 (P <0.05 ). Transfection with pEGFP-NI-mTRPC6 increased apoptosis rate from (15.46± 1.40)% to (18.33±0.87)%(P<0.01) by high-dose Ang Ⅱ (10-6 mol/L). Conclusion TRPC6 plays an important role in the Ang Ⅱ-induced apoptosis of podocytes by promoting the influx of extraeellular calcium, which leads to the apoptosis cascade initiation.

Objective To develop the measuring system used for the parameters of onboard oxygen supply equipment in the hypobaric chamber. Methods The programmable controller was applied to acquisition, processing and analysis of the data from the sensor. The host computer was used to accomplish control and information display. Results The system could display the parameters through digital, simulating meters, and recording curve. The numerical value in the recording curve was marked by the date and time. All data were saved in the computer for futural analysis and procession. Conclusion The measurement system of oxygen supply parameters can satisfy the desired requirements for the performance and precision.

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