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 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.

Poor and monotonous work could easily lead to a decrease of arousal level of the monitoring work personnel. In order to improve the performance of monitoring work, low arousal level needs to be recognized and awakened. We proposed a recognition method of low arousal by the electroencephalogram (EEG) as the object of study to recognize the low arousal level in the vigilance. We used wavelet packet transform to decompose the EEG signal so the EEG rhythms of each component were obtained, and then we calculated the parameters of relative energy and energy ratio of high-low frequency, and constructed the feature vector to monitor low arousal state in the operation. We finally used support vector machine (SVM) to recognize the low arousal state in the simulate operation. The experimental results showed that the method introduced in this article could well distinguish low arousal level from arousal level in the vigilance and it could also get a high recognition rate. Have been compared with other analysis methods, the present method could more effectively recognize low arousal level and provide better technical support for wake-up mechanism of low arousal state.
Arousal ; Brain ; physiology ; Electroencephalography ; Humans ; Signal Processing, Computer-Assisted ; Support Vector Machine ; Wavelet Analysis

Objective To study the expression of triggering receptor expressed on myeloid cells-1 (Trem-1)in psoriatic vulgaris and normal skin tissues and blood,and to explore the potential pathogenesis of psoriasis.Methods Immunohistochemistry and Real-time PCR were used to detect the expression of Trem-1 in the blood and tissues of normal skin and psoriasis.Results The positive expression rate of Trem-1 in psoriatic lesion was significantly higher than normal tissue.Trem-1 was expressed in the whole epidermis,with a significant difference (P<0.05). The mRNA expression of Trem-1 was significantly higher in psoriatic skin tissues and blood than in normal skin tissues and blood (P<0.05).Moreover,the mRNA expression of Trem-1 was positively correlated with PASI (P<0.05).Conclusion Abnormal expression of Trem-1 might be related to the pathogenesis of psoriasis.Trem-1 will cure psoriasis vulgaris as the potential therapeutic target.

To design a new method to simulate the micro-motion of human body surface due to respiration and heartbeat, and to provide detection object and calibration signal for the bio-radar technology. Precision lin-ear module was used to transform rotational movement to linear displacement, with AC servo motor to precisely control the module's rotation. Ultimately, ultralow-frequency micro-motion was produced with its displacement being quantitatively controlled. A system simulating the micro-motion of human body surface was newly built. Compared with the old system, the new one produced micro-motion with better constancy, and realized quantitative control of the motion's dis-placement. The method lays technological foundation for simulating the micro-motion of human body surface due to respiration and heartbeat and may promote the development of bio-radar technology towards intensive and compre-hensive levels.

Objective To provide the oxygen supply apparatus when the civil aviator and airforce pilot are inspected the hypoxia tolerance and altitude tolerance in the hypobaric environment.Methods Demand oxygen and contstant flow oxygen were supplied.Results The portable hypobaric oxygen supply apparatus can supply mixed oxygen below the altitude 8 000 m,and the oxygenous concentration of mixed oxygen was adjusted according to the altitude.The pure oxygen was supplied when the altitude was at 8 000～12 000 m.Conclusion The normal and emergency oxygen supply performance can fulfill the system physiological requirements.The portable hypobaric oxygen supply apparatus may be used by the persons engaging in special task on plateau also.

Objective To characterize the inheritance of erythropoietic protoporphyria (EPP) by detecting the mutations of ferroehelatase (FECH) gene in a Chinese family with EPP. Methods Peripheral blood samples were obtained from 4 patients and 3 unaffected individuals in a family with EPP, as well as from 50 unrelated healthy human controls. PCR was performed to amplify all the 11 exons and flanking sequence of FECH gene followed by direct sequencing. Results A splicing mutation,I.e., IVS3+1G→A, was identified in the proband as well as his symptomatic sister, cousin, grandfather and asymptomatic mother, but not in his asymptomatic father, grandmother, or unrelated healthy controls. The genotypes IVS1-23 T/C and IVS3-48 C/T were noted in the proband, his father, sister, cousin and grandfather, but absent in his mother or grandmother who carried IVS1-23 C/C and IVS3-48 T/T genotypes. Conclusions A novel splicing mutation is found in the FECH gene in a Chinese EPP family, which, together with two lowly expressed alleles IVS1-23T and IVS3-48C, is likely to be responsible for the clinical phenotype of EPP in this family.