常用应急抢险装备的合理选择和配备

我国自然灾害频发,地震、洪水、泥石流等灾害极容易对道路,房屋等建筑造成巨大的损坏,从而对抢险过程直接或间接地增加了难度。为了高效遂行抢险任务和提高抢险能力,就有必要提高处理交通基础设施的能力。而抢险设备的选择和合理的配置能够大大提高抢险任务效率。一方面,对于不同的抢险任务,有着不同的作业内容,其中所需要的抢险器械也各不相同。另一方面,同一种工程机械又有着不同的型号,各自又具有独特的技术性能和适用范围。一种机械可以完成多种作业,而一种作业又可以使用多种工程机械。因此如何对工程机械的选择以及合理的配置是本文的重点。     

加拿大交通见闻

2006年8月,我有机会到加拿大进行学术交流和培训。这使我们有机会直接感触到了加拿大的风土人情,但给我留下印象最深刻的还是加拿大的交通状况。由于加拿大的经济发展比较成熟,人均收入也不错,所以,很早以前,轿车就进入加拿大酱通百姓家,不仅成年人大多都有自己的小车,而且还准许高中生驾车上学,甚至七八十岁的老人也有自己的车。加拿大人上学、上班、走亲访友、上餐馆、去商场购物、开会、做礼拜等全是开车去,路上几乎看不到步行的人。自行车、摩托车在这里只作为体育器械,用来锻炼身体,而非交通工具,不能在高速公路和市区街道上骑用。与汽车的普及相配套,加拿大的公路建设也很发达,公路笔直宽畅,通顺平整。高速公路上设有指路标志,标明此路起止地点、里程,以及欲去某地应从何处走、路程有多远等,都写得一清二楚,开车者只看标志就行了,完全不必问路。     

新型多功能心血管内径测量器的研制及应用

新型多功能心血管内径测量器 ,使用纯钛材料制成 ,由连杆采用氩弧焊方式两端联接测量探头组成。连杆长 1 50 mm,直径 2 .5mm,可任意弯曲 ;测量探头长 55mm,直径 1 9mm～ 35mm,探头上刻有直径刻度。用于心脏手术二尖瓣替换及三尖瓣成形、室间隔缺损修补、Bentall手术、法乐氏三联症等心血管内径的测量和扩张。经临床 50例的手术应用 ,效果满意     

门奇断流术200例疗效分析

目的 分析门奇断流术的疗效。方法 回顾性总结１９８０年６月－１９９７年１２月所施行的门奇断流术２００例。结果 急诊手术止血率为９２．２２％,手术死亡率为１２．５％,４８ｈ内急诊手术死亡率明显低于４８ｈ以上手术者,存活１７５例随访１４７例（８４％）,术后远出血率为２１．０９％,死亡率为１９．７％。术后５年生存率为８０．５％,１０年为６４．５％。预防性手术近期无出血,其术后５年出血率为３．２５％,１０     

Histological changes following surgically-assisted rapid tooth movement through resistance reduction and distraction osteogenesis in dogs

Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis, aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement, while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks, followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly, and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However, there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.