钛缆联合钢板或皮质骨条治疗Vancouver B型股骨假体周围骨折

目的：探讨应用钛缆联合钢板或皮质骨条治疗Vancouver B型股骨假体周围骨折的效果。方法：回顾分析2005年1月—2010年12月采用钛缆联合钢板或皮质骨条治疗的34例Vancouver B型股骨假体周围骨折患者的临床资料。均采用AO锁定钢板或Zimmer钛缆钢板。结果：所有患者最终达到骨愈合。出现1例骨慢连接（B1型）,1例再骨折（B1型）,1例伤口渗出（B3型）。结论：钛缆联合钢板、异体皮质骨条治疗Vancouver B型股骨假体周围骨折的效果较为可靠。应用锁定钢板相对钛缆钢板手术时间更短,出血量更少。     

Cable-Pin系统在髌骨骨折手术中的应用

目的 探讨Cable-Pin系统在治疗髌骨骨折中的临床效果.方法 对80例髌骨粉碎性骨折患者根据内固定方式分Cable-Pin系统治疗组、张力带钢丝固定组、胸骨针钢丝环扎术组、聚髌器固定组四组,各20例,观察各组患者术后膝关节功能恢复情况.结果 术后随访12～18个月,平均13.2个月.采用Cable-Pin系统治疗组优良率100%,其中优占85%,占四组中首位.结论 Cable-Pin系统对髌骨粉碎性骨折固定稳固,具有膝关节功能恢复好、并发症少等优点,是治疗髌骨骨折的一种新的选择方法.     

A novel anchoring system for use in a nonfusion scoliosis correction device

Background contextInsertion of a pedicle screw in the mid- and high thoracic regions has a serious risk of facet joint damage. Because flexible implant systems require intact facet joints, we developed an enhanced fixation that is less destructive to spinal structures. The XSFIX is a posterior fixation system that uses cables that are attached to the transverse processes of a vertebra.PurposeTo determine whether a fixation to the transverse process using the XSFIX is strong enough to withstand the loads applied by the XSLATOR (a novel, highly flexible nonfusion implant system) and thus, whether it is a suitable alternative for pedicle screw fixation.Study designThe strength of a novel fixation system using transverse process cables was determined and compared with the strength of a similar fixation using polyaxial pedicle screws on different vertebral levels.MethodsEach of the 58 vertebrae, isolated from four adult human cadavers, was instrumented with either a pedicle screw anchor (PSA) system or a prototype of the XSFIX. The PSA consisted of two polyaxial pedicle screws and a 5 mm diameter rod. The XSFIX prototype consisted of two bodies that were fixed to the transverse processes, interconnected with a similar rod. Each fixation system was subjected to a lateral or an axial torque.ResultsThe PSA demonstrated fixation strength in lateral loading and torsion higher than required for use in the XSLATOR. The XSFIX demonstrated high enough fixation strength (in both lateral loading and torsion), only in the high and midthoracic regions (T10–T12).ConclusionsThis experiment showed that the fixation strength of XSFIX is sufficient for use with the XSLATOR only in mid- and high thoracic regions. For the low thoracic and lumbar region, the PSA is a more rigid fixation. Because the performance of the new fixation system appears to be favorable in the high and midthoracic regions, a clinical study is the next challenge.     

加长PFNA结合钛缆环扎术治疗股骨转子下长斜形及螺旋形骨折疗效观察

目的:探讨应用加长亚洲型股骨近端髓内钉(PFNA)结合钛缆环扎术治疗股骨转子下长斜形及螺旋形骨折的方法及疗效。方法:2010年8月至2013年2月,收治22例股骨转子下长斜形及螺旋形骨折患者,按Zickel分型均为1B型;其中男16例,女6例;年龄24-78岁,平均66.3岁。均在C型臂X线机透视下采用加长PFNA结合钛缆环扎术治疗,术后髋关节功能采用Harris评分。结果:所有患者均获得随访,随访时间6-36个月,平均20.2个月。骨折全部愈合,愈合时间为9-16周,平均12.4周。均未出现感染、髋内翻畸形、下肢外旋及短缩畸形、螺旋刀片切割股骨头、股骨干骨折、内固定失效及延迟骨愈合等并发症。患者按Harris髋关节功能评分标准优13例,良7例,可2例,优良率为90.9%。结论:PFNA结合钛缆环扎术治疗股骨转子下长斜形及螺旋形骨折具有操作简单、创伤小、内固定牢靠、可早期功能锻炼及术后并发症少等优点,临床疗效良好。     

美国新泽西州与长岛之间的电缆连接

代替在人口稠密的地区建设新的发电厂,美国长岛电力公司（Long Island Power Authority LIPA）选择与大陆建设新的电缆连接。采用海皇星（Neptune）电缆系统直接供电给两个独立的电力系统—宾夕法尼亚、新泽西及马里兰（Pennsylvania,New Jersey and Maryland PJM）及新英伦市场。因为长岛快速增长的电力需求,已经超出在岛上建设新发电厂的可能性。采用海皇星电缆供电,能提供环保、高效、廉价的电力能源。     

微创截骨钢缆接骨术治疗儿童肘内翻畸形

目的 探讨应用微创截骨钢缆接骨术治疗儿童肘内翻畸形的可行性与有效性.方法 自2004年3月至2007年10月对11例儿童(10～14岁,平均12.9岁)肘内翻患者(其中2例同时存在10°内旋)进行微创肱骨髁上楔形截骨,保留对侧骨皮质与骨膜的完整,存骨折上下端钻人2枚螺丝钉,调整旋转角度,螺钉间用钢缆进行接骨固定,术后石膏固定2 周后行功能操练.结果 11例患儿骨折全部愈合,愈合时间30～45 d,平均36.3 d,无一例感染与神经损伤发生;术前肘关节内翻角度35°±5°,肘关节功能:屈曲125°±10°,伸直10°±5°.所有患者获得20～42个月(平均33.5个月)随访,术后肘关节外翻角度8°±2°.,与术前相比,差异有统计学意义(t=16.632,P<0.05);肘关节屈曲130°±8°,伸直8°±3°,与术前相比,差异均无统计学意义(P>0.05),2例术前伴有内旋患者术后内旋得到改善.结论 采用微创截骨钢缆接骨术的方法对儿童肘内翻进行治疗,具有骨膜剥离少、骨折端稳定、骨折愈合快的优势,并可以改善旋转畸形,对肘关节伸屈功能无明显影响.     

Mathematical Simulation of Slowing of Cardiac Conduction Velocity by Elevated Extracellular [K+] in a Human Atrial Strand

We have studied the dependence of conduction velocity () on extracellular potassium concentration ([K⁺]_o) in a model of one-dimensional conduction using an idealized strand of human atrial cells. Elevated [K⁺]_o in the 5–20 mM range shifts the resting potential (V _rest) in the depolarizing direction and reduces input resistance (R _in) by increasing an inwardly rectifying K⁺ conductance, I _Kl.Our results show that in this model: (1) depends on [K⁺] in a biphasic fashion. Moderate elevations of [K⁺]_o (to less than 8 mM) result in a small increase in , whereas at higher [K⁺]_o (8–16 mM) is reduced. (2) This biphasic relationship can be attributed to the competing effects of (i) the smaller depolarization needed to reach the excitation threshold (V _thresh-V _rest) and (ii) reduced availability (increased inactivation) of sodium current, I _Na, as the cell depolarizes progressively. (3) Decreasing R _in reduces due to the increased electrical load on surrounding cells. (4) The effect on of [K⁺]_o-induced changes in R _inin the atrium (as well as other high-R _in tissue, such as that of the Purkinje system or nodes) is likely to be small. This effect could be substantial, however, under conditions in which R _in is comparable in size to gap junction resistance and membrane resistance (inverse slope of the whole-cell current–voltage relationship) when sodium channels are open, which is likely to be the case in ventricular tissue. © 2000 Biomedical Engineering Society.PAC00: 8716Uv, 8719Hh, 8716Ac     

钢缆接骨术在骨不连治疗中的应用

目的报告钢缆接骨术与内固定或外固定支架联合应用治疗骨不连的效果及其价值。方法自2001年9月～2003年9月,我们结合内固定或支架外固定应用钢缆接骨术治疗骨不连5例,其中2例为股骨干骨折髓内钉固定术后感染性骨不连,1例为股骨转子下骨折畸形愈合后再骨折,1例为股骨骨折钢板螺丝钉固定失效,1例为肱骨中下段骨折髓内钉固定后骨不连接。结果2例股骨感染性骨不连病例分别在术后7和10个月获得骨连接;转子下骨折截骨矫形3个月后连接,股骨轴线排列良好,畸形没有复发;钢板内固定失效病例,辅助应用钢缆后重新获得固定的稳定性,术后6个月股骨骨折完全愈合;肱骨骨不连者术后4个月获得愈合。结论在缺乏合适治疗手段的情况下,钢缆接骨术结合内固定或支架外固定不失为治疗骨不连的有效选择。     

Effects of dinitrophenol on active-transport processes and cell membranes in the Malpighian tubule of Formica

In Formica Malpighian tubules KCl secretion is driven by a V-type H⁺ ATPase in the luminal membrane in parallel with a H⁺/K⁺ antiporter. The effect of the protonophore dinitrophenol (DNP) was investigated on the isolated, symmetrically perfused tubule. DNP was applied in two different concentrations: 0.2 mmol/l and 1 mmol/l. The effects were fast and rapidly reversible. The equivalent short-circuit current (I _sc) was reduced significantly to respectively 25±3% Cn=4) and –3±7% (n=11) of the control value when 0.2 mmol/ l or 1 mmol/l was added to the bath. When 1 mmol/l DNP was applied the transepithelial resistance (R _te) decreased significantly to 74±11% of the control value (n=11), and the luminal over basolateral voltage divider ratio (VDR), providing an estimate of luminal over basolateral membrane resistance, decreased to 37±12% of the control (n=6). A concentration of 1 mmol/l DNP was also applied from the lumen. The decrease in I _sc was significant, but much less pronounced (74±5% of control; n=6) and no significant changes in R _te and VDR were observed. It is argued that, when the concentration in the bath is high enough, DNP may cross the cell and have a protonophoric effect not only on the mitochondria but also across the luminal cell membrane explaining the drop in transepithelial and in relative luminal membrane resistance. The diminished effectiveness of DNP, when applied from the luminal side, suggests that the luminal membrane is somehow less permeable to toxic substances, but that DNP very rapidly enters the cell via the basolateral membrane and may bring about an initial protonophoric effect across this membrane.