Permanent transvenous cardiac pacing

Transvenous cardiac pacing is a commonly employed treatment for symptomatic bradyarrhythmias in dogs. Medical management of these conditions has not proven to be successful leaving pacing as the only viable alternative. The technique of pacemaker implantation is not difficult, but successful pacemaker therapy requires an understanding of electrophysiology, cardiac fluoroscopic anatomy, pacemaker instrumentation, and programming. Proper patient selection and identification of the underlying rhythm disturbance is essential to a successful clinical outcome. This article discusses the indications, equipment, techniques, complications, and outcome of permanent transvenous cardiac pacing.     

负载戊唑醇的聚乙二醇-聚己内酯胶束的制备与性能研究

通过开环聚合法合成了聚乙二醇-聚己内酯嵌段共聚物(PEG-b-PCL),以PEG-b-PCL为囊壁、以戊唑醇为囊芯,采用自组装的方法制备了载药胶束。分别利用动态光散射仪(DLS)和透射电镜(TEM) 对其粒径进行了表征,通过紫外分光光度计和高效液相色谱仪测定了其载药量、包覆率和体外释药性能,用滤纸片法测试了载药胶束对木霉 Trichoderma viride 的抑菌性能。结果表明:PEG-b-PCL载戊唑醇胶束平均粒径为 250 nm,均匀度良好,载药量为 26.4%,包覆率为18.0%,体外释放192 h的释药率为83.35%,其对木霉的抑菌效果明显高于同浓度下的戊唑醇乙酸乙酯溶液。     

加拿大一枝黄花燃烧块燃烧特性试验研究

对不同压力和温度下压制的加拿大一枝黄花(Solidago canadensis L.)燃烧块的燃烧特性进行了试验分析。结果表明,不同压力压制的燃烧块其燃烧效率差异显著;不同温度下压制出的燃烧块其燃烧效率差异极显著,燃烧时间和无焰燃烧温度差异显著;不同压力、温度及两者的交互作用与各指标间的差异均不显著。经多重比较,各种压力下,60℃压制出的燃烧块是最优的,可以为用户提供优质的燃烧块。同时,压制燃烧块过程中,加温不应超过70℃,否则燃烧块的燃烧特性会明显变差。     

实用AutoLISP程序设计

介绍了几个用AutoLISP语言设计的实用CAD指令——图块计数、双边等距、门安装、求透视等。这些指令短小精悍,对于建筑制图有很好的辅助作用。详细论述了它们各自具备的功能和操作过程,同时在论文中提供了全部原程序代码供读者上机检验。     

液控式垄向区田筑垱机的设计及仿真

为了实现垄向区田筑的高质量和高效率作业,设计一种液压控制式垄向区田筑机。介绍其工作原理,应用Pro/E和ADAMS软件进行筑机的设计、建模和运动学仿真分析。结果表明,此种设计方法缩短了筑机的设计周期,仿真分析结果验证了其工作原理的可行性,所设计的液控式垄向区田筑机能够实现最佳距的方便、快速调节,满足设计要求,为实现垄向区田技术提供了一种新机具。     

Approaches to Promote China＇s Low Carbon Agricultural Development

Low carbon agriculture is a new production mode of green agriculture development to face the challenge of the global climate change, and a kind of innovation on developing circular agriculture. Up to n...     

Study on high and steep slope stability Based on 3D laser scanning

Dangerous mountain construction projects block of high and steep slope stability is the important issue of security and disaster prevention, investigation on the surface of the dangerous mountain high and steep slope rock mass structure is the key to the analysis of the problem. The high slope of a major project of the Lancang River, the application of 3D laser scanning technique to study the long-distance survey analysis of rock mass structure analysis method to analyze the distribution of the surface space of the high and steep slope rock mass structure, statistical analysis direction of the advantages of the structure surface and the distribution of rock blocks, as the basis for the application of limit equilibrium analysis method to study the stability of rock blocks of the high and steep slope.     

建筑节能型环保砌块在新农村住房建设中的应用性研究

通过对新型建筑节能型环保砌块在技术和环境保护等方面的调查研究,针对目前新农村建设中农村居住环境改善的技术问题,阐述了该类砌块在新农村住房建设中的应用性。     

Comparison of bupivacaine femoral and sciatic nerve block versus bupivacaine and morphine epidural for stifle surgery in dogs

ObjectiveTo evaluate the efficacy of combined femoral and sciatic nerve blocks as an alternative to epidural anesthesia and analgesia in dogs undergoing stifle surgery under general anesthesia.Study designProspective, blinded, randomized, clinical comparison.AnimalsTwenty dogs weighing 37 ± 11 (mean ± SD) kg, aged 3 (1–8) [median (minimum–maximum)] years undergoing elective unilateral tibial-plateau leveling osteotomy.MethodsDogs were assigned randomly to receive either epidural anesthesia (bupivacaine 0.5%, 0.5 mg kg^?1 + morphine 0.1%, 0.1 mg kg^?1, in 0.2 mL kg^?1; EPID) or femoral and sciatic nerve blocks (Bupivacaine 0.5%, 0.1 mL kg^?1, was administered at each site; F + S) guided by electrolocation. All patients received a standard general anesthesia technique. Pain and sedation were scored (on scales of 0–10 and 0–3, respectively) pre-operatively, at extubation, and at 1, 4 and then every 4 hours thereafter up to 24 hours. Postoperatively, hydromorphone was administered to any patient with a pain score of >5 or whenever the blinded caregiver determined that more hydromorphone was necessary. Intraoperative heart rate (HR), mean arterial pressure (MAP), end tidal isoflurane (FE′ISO), body temperature, post-operative pain scores, time to first hydromorphone dose after surgery, time to first feeding, time to first drinking, time to first urination, time to first ambulation (walk on a lead) and cumulative dose of hydromorphone were recorded.ResultsIntra-operatively, FE′ISO and MAP were significantly lower in the EPID group (p = 0.05 and p = 0.04, respectively). Postoperatively, the cumulative hydromorphone consumption (p = 0.04) and the incidence of urinary retention (p = 0.03) were higher in the EPID group.Conclusion and clinical relevance F + S is a practical alternative to EPID that produces less urine retention and reduces opioid consumption in the 24 hours after surgery. EPID might be associated with a lower isoflurane requirement and lower systemic blood pressure.     

恩拉霉素高产菌株的快速选育

为筛选恩拉霉素高产菌株,降低生产成本,以生产用Streptomyces-483为出发菌株,进行紫外-氯化锂复合诱变。以金黄色葡萄球菌为指示菌,用琼脂块法测定抑菌圈大小,筛选出84株突变株,经摇瓶初筛、复筛、5L发酵罐验证,最终获得4株高产突变株。筛选得到的4株高产突变株经稳定性考察完全适用于生产。