RESUMO
[Abstract] Objective To explore underwater shock wave-induced injuries of the lung and brain in canines. Methods Eighteen Beagle dogs were randomly divided into six groups according to the distances to the explosion source: control group and 5 experimental groups (5 m, 7 m, 9 m, 11 m and 13 m groups). The animals were exposed to underwater shock wave via a self-designed underwater explosive instrument. The dynamic explosive process was recorded by the underwater high-speed camera. Computed tomography (CT) scans of brain and chest were performed 6 h after injury. Pathological examination and H-E staining for hippocampus and lung were conducted 24 h after injury. The expression levels of interleukin (IL)-6, IL-1β, IL-10, tumor necrosis factor α (TNF-α) and transforming growth factor β (TGF-β) in the hippocampus were measured by immunohistochemical staining. Results The underwater high-speed camera showed that the injury process included blast wave and bubble pulsation. The total mortality of the animals was 40.0% (6/15) in the experimental groups. CT examination revealed no major alterations in the brain of the animals, while there were pleural effusion and pneumothorax in the chest of animals in the experimental groups. H-E staining showed inflammatory cells infiltration in the hippocampal tissue and erythrocyte deposition in the alveoli of animals in the experimental groups. The expression levels of IL-6, IL-1β, IL-10, TNF-α, and TGF-β in the hippocampus of animals in the experimental groups were significantly elevated compared with those in control group (all P0.05). Conclusion Brain and chest are damaged significantly after underwater explosion, which may be the main causes for the death of animals. It is important to elucidate the underlying mechanisms of brain injury caused by underwater explosive wave for the protection of underwater blast injuries.
RESUMO
Bloodstain pattern analysis is a forensic discipline that reconstruct events of a crime scene by analyzing sizes, shapes, distributions, positions of bloodstains. Bloodstain pattern can be classified into the low velocity, medium velocity, and high velocity system. Velocities in this system represent the velocity of the wounding agent (the force applied) and not to the velocity of the blood in flight. Thus there is no reference system about the velocity of the blood in flight in the existing bloodstain classification system. Applying bloodstain pattern analysis to the real crime case, we needed to have the reference system of velocities of impact spatter, cast-off spatter, and expectorate spatter. Therefore we measured the velocities of these spatters using high speed camera and we analyzed the results. In this experiments the average velocity of impact spatter that generated by swinging a hammer with all experimenter's strength at the pool of blood is about 4.7 times faster than that of swing cast-off spatter that generated by swinging a red-wat hammer with all experimenter's strength, and about 3.9 times faster than that of expectorate spatter that generated by emitting blood from the mouth with all experimenter's strength. The velocities of cast-off spatter and expectorate spatter, however, showed similar distributions. Our experiments that measure the velocities of droplets of blood spatters in flight under the specific conditions that generated at fastest speed can give some reference to the classification system of velocities of bloodstains which is not distinct up to now, as well as some real bloodshed crime cases.