Objective To analyze the cost-benefit of large-scale medical instruments and provide the reference for medical instruments' purchasing.Methods The application of classical economic model,on the basis of cost-benefit analysis model of the practice of hospital's medical instruments,the evaluation system was established.Results The combination of practical work in hospital radiology department,recruitment evaluation of mathematic model is verified repeatedly by obtained dates;the magnetic resonance,the evaluations of CT economic benefit and overall efficiency of division are fulfilled.Conclusion This system can effectively evaluate the cost-benefit of large-scale medical instruments.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been widely used on clinic; however, there are still few reports addressing rhBMP-2-induced osteogenesis in intervertebral disc.OBJECTIVE: To verify the effect of rhBMP-2 to induce interbody fusion in rabbits.DESIGN, TIME AND SETTING: Randomized controlled animal study and multi-level evaluation, which was performed in Affiliated Hospital of Medical College of Qingdao University from February to July 2007.MATERIALS: 24 adult New-Zealand rabbits weighing 3.5-4.5 kg were used to expose L4-5 and L5-6 intervertebral disc; rhBMP-2 (1 mg/ampoule, purity≥95%) was provided by Beijing Bailingke Biological Products Co., Ltd.METHODS: 24 rabbits were randomly divided into experimental group and control group with 12 rabbits for each. In the experimental group, saline (20 μL, containing 200 μg rhBMP-2) was injected into nucleus pulposus of L4-5 intervertebral disc; equivalent saline was inserted into nucleus pulposus of L5-6 intervertebral disc as controls. Rabbits in the control group were injected with saline (20 μL) into nucleus pulposus of L4-5 intervertebral disc.MAIN OUTCOME MEASURES: Morphological changes of injected segments were observed by hand-feeling check together with histological and imaging tests at 10, 30, 60, and 90 days postoperatively.RESULTS: 24 rabbits were included in the final analysis. ①In the experimental group, the motion range of L4-5 segment was not limited at 10 days postoperatively, and lightly limited at 30 days, but severely limited at 60 days postoperatively; L4-5 segment was fixed tightly at 90 days postoperatively. Moreover, motion range of L5-6,segment and articular motion range in the control group were not changed remarkably. ② L4-5 interbedy space was narrowed at 10 days or even disappeared at 90 days postoperatively, and then osteogenesis fusion was formed. Transmittance of intervertebral space in the L5-6 segment and in the control group was not changed obviously. ③ Nucleus pulposus was gradually shrunk at 10 days postoperatively; partial cartilage endplate transformed into mature woven bone, and collagen fiber structure of annulus fibrosus gradually disappeared at 90 days postoperatively. A lot of mesenchymal cells were aggregated surrounding annulus fibrosus at 10 and 30 days postoperatively. Moreover, mature woven bone was formed in annulus fibrosus near to cartilage endplate at 90 days postoperatively. However, histological and morphological changes were not found in the control group at those four time points.CONCLUSION: rhBMP-2 can induce intervertebral disc osteogenesis so as to achieve interbody fusion.

Objective:To summarize the clinical characteristics and first aid measures of children with drowning，and to provide scientific basis for the treatment and prevention of drowning in children.Methods:The clinical data of drowning children admitted to the Children's Medical Center of the First Affiliated Hospital of Hunan Normal University（Hunan Provincial People's Hospital）from January 2011 to December 2021 were retrospectively summarized. Baseline characteristics，prehospital emergency care and prognosis of the included children were analyzed.According to the time span, drowning children were divided into two stages, the first stage (2011-2016) and the second stage (2017-2021). According to cerebral performance category assessment scale,drowning children with cardiac arrest were divided into two groups: a group with good neurological prognosis and a group with poor neurological prognosis. The baseline characteristics,pre-hospital emergency care, and prognosis of drowning children during different periods and with different prognosis were analyzed.Results:A total of 53 children were enrolled during the study period，with 24 cases in the first phase（2011-2016）and 29 cases in the second phase（2017-2021）.Boys accounted for 73.6%（39/53）of the cases, the age ranged from 1 month and 24 days to 14 years old，with 1-4 years old being the most common，accounting for 58.5%（31/53）, and the season in which drowning occurred was more common in the summer（39.6%, 21/53）.Six cases (11.3%) had significant neurological sequelae, and the mortality rate was 3.8%（2/53）.There was a decrease in the proportion of drowning with water control in the second stage compared to the first stage（37.5% vs. 13.79%, P=0.046）.Thirty-two（60.4%）children experienced on-site cardiopulmonary resuscitation(CPR) after drowning，with 24 cases in the group with good neurological prognosis and 8 cases in the group with poor neurological prognosis.Children in the poor neurological prognosis group required CPR for a long duration [10.00（1.50, 25.00）min]，had lower body temperature，Glasgow Coma Score，pH and higher blood glucose levels on admission（all P < 0.05）. Conclusion:Drowning is most common in preschool children，common in boys，and drowning prevention measures for young children deserve focused attention. Children found to be in cardiac arrest at the time of drowning have a long duration of drowning and CPR，which predicts a poor neurological prognosis，and timely and effective on-site CPR is the key to reducing the drowning rate.