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.

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

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 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.

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 provide an important tool for the study of diagnose and treatment of prostate cancer (PCa) osseous metastasis and change of bone stress force on prostate cancer (PCa) osseous metastasis and a platform, which is more congruous to clinical process, for prevention and cure of neoplastic bone metastases, and to carry out the construction and improvement of animal models of PCa with different positional osseous metastasis in vivo.Methods: Different gradient concentrations of RM-1 cells were inoculated into the cavity of left femoral bone or lumbar vertebra of mice (C57BL/6) respectively.The change of mouse activity, tumor formation, tumor size and survival time were observed respectively.And the femur tissue and spinal tissue were obtained from the mice after death.The gray value of iconography were measured by imageological examination of femur tissue, and the final histopathological examination were taken to determine the tumor type in both femur and spinal tissue.Results: The tumor growth could be touched at the puncture site in all the mice after inoculated for 7 days.There were no obvious differences in the time of tumorigenesis, the rate of tumor growth and tumor size among the mice in the same group (P>0.05).As the result, the construction femoral bone and lumbar vertebra metastatic models of PCa had been confirmed by iconography and pathology detection.At the same time, the survival time of the mice inoculated with low concentrations of PCa cells was obviously longer than that of high concentrations of PCa cells (at least 2 weeks longer).Conclusion: The animal models with different positional osseous metastasis (limbs and axial skeleton) of PCa using the same PCa cells (RM-1) had been first constructed successfully in our study.At the same time, a high success rate of construction of PCa animal model with bone metastasis was obtained by femoral bone marrow cavity injection of PCa cells.The rate of tumor growth was rapid, animal survival time was appropriate, and the PCa animal model with bone metastasis can be stably reproduced by our method.These animal models can be used to explore the pathogenesis of different positional PCa bone metastasis and provide a new platform, which were more congruous to clinical process, for prevention and cure of neoplastic bone metastases.

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.