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Obiective To study the compartment environmental quality of ambulance against biological contamination for safe and comfortable transportation and treatment of patients. Methods The experimental research and numerical simulation were carried to master the state of compartment environmental quality, Results Compartment environment indexes excel technology demands, such as overpressure/negative-pressure, temperature, biological contamination, vibration and shock as well as noise and luminance, Conclusion The compartment environmental quality of this ambulance is in a good state.
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Objective To investigate the influences of blast wave overpressure created by explosion on rat's blood-brain barrier (BBB),and to provide an experimental evidence for further elucidating the mechanism of craniocerebral blast injury,to help direct the clini- cal therapeutic strategy.Methods Twenty male Sprague-Dawley rats were randomly divided into four groups:15min,12h and 24h post- explosion groups and normal control group with five rats for each group.Rats were injured with blast wave produced by explosion.Evan 's blue(EB)was intravenously injected into the injured rats,and the overpressure-induced leakage of BBB was examined under the fluores- cence microscope and by quantitative observation with opacimeter.Results Extensive impairment of BBB could be seen all over the brain 15 min after the overpressure explosion,and bright red EB fluorescent patches appeared as a method distributing along the capillary vessels. These patches were more distinct near the cerebral cortex,and with the lapse of time,their number decreased gradually from the inner to the outer areas.The changes in EB contents in brain tissue matched with that of the BBB.The EB contents in brain tissues in 15min group were(330.4?53.6)?g/g,and it was much higher compared with that of other groups(P
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Objective Mobile operating compartment with overpressure protection can provide a safety environment for the patients and the surgical team by minimizing the risk of biochemical contamination through appropriate air filtration, steady overpressure foundation and air distribution scheme. Methods The air movement and the temperature distribution inside the mobile operating compartment with the overpressure protection performance were simulated by the technique of computational fluid dynamics(CFD), the air pattern and the temperature distribution were analyzed. Results The air velocity was under 0.5m/s in the most zone of person activity and the air velocity were distributed uniformly in the mobile operating compartment under the condition of the overpressure protection system. The obvious temperature gradient didn't exist in the vertical plane of the mobile operating compartment. The temperature distribution in the mobile operating compartment was quite uniform and the temperature was almost at 27℃ with the temperature difference of almost 2℃. Conclusion The human thermal comfort is good in the mobile operating compartment and the environment in the mobile operating compartment can satisfy requirements of the operation.
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The compartment temperature- environment of mobile medical equipment is simulated by using computational fluid dynamics (CFD) and finite element method (FEM). Simulation results indicate that the airflow shape is reasonable and the compartment temperature can be kept at (25?3)℃, and that the velocity of airflow is less than 0.5m/s. The collective overpressure protection system is established according to the following 5 procedures, including alarming, controlling, filtering toxin, establishing overpressure and overpressure monitoring. It's proved that the protection system can form the overpressure not less than 300 pascal and make the compartment free of the air containing biological toxin, noxious chemical fumes and radioactive dust. The contamination process of the compartment is simulated in case of some toxic and noxious contaminant flowing into the compartment. The results are obtained that concentration distribution of contaminant attenuates rapidly from 5,000ppmv to 10ppmv during 130 seconds.
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Thirty-four dogs were inflicted with blast injury from a shock tube with a diameter of 348 mm. The peak value of the overpressure was 1.05~1.33kg/ cm2, the effective time of the overpressure 40~45 milliseconds, and the speed of the blast wave 473~509m/s. There were 11 dogs (32.4%) with very severe damage, 5 (14.7%) with severe damage, 17 (50%) with moderate damage and 1 with mild damage. The peak value and the effective time of the overpressure were the decisive factors to determine the severity'of the damage, and the posture of the animal at the time of blast impact might also be important. The sensivity of different organs to the blast wave was not uniform, it was related to the position, size, degree of dissociation, and structural characteristics of the organ concerned. The order of the sensitivity of various organs, from highly to less sensitive, could be arranged as follows; the audotory apparatus, the liver, the lungs, the spleen, the heart, the urinary bladder, and the kidneys. It is suggested that in diagnosing a case of blast injury, an examination of the audotory apparatus and a total and differential white count be of value.The pathological changes caused by the blast wave from a shock tube were similar to those caused by nuclear explosion in nature but milder in degree since the effective time of the overpressure of the shock tube wave was shorter. The chief causes of early death of the animals with blast injury were massive hemorrhage and cranial injury.