目的探讨二孔法腹腔镜疝囊高位结扎术治疗小儿腹股沟斜疝的价值。方法建立气腹（压力8~10 mmHg）,脐上5 mm trocar作为观察孔放置30°腹腔镜,于脐水平线对侧腹直肌外缘3 mm trocar作为操作孔。疝内环口体表投影处做一约2 mm微小切口...目的探讨二孔法腹腔镜疝囊高位结扎术治疗小儿腹股沟斜疝的价值。方法建立气腹（压力8~10 mmHg）,脐上5 mm trocar作为观察孔放置30°腹腔镜,于脐水平线对侧腹直肌外缘3 mm trocar作为操作孔。疝内环口体表投影处做一约2 mm微小切口,经此切口刺入带7号丝线的GraNee针（卡钩针）,沿内环口的外半周用缝荷包法缝合腹膜,至内环口下方,打开卡钩针,取下缝合线,闭合卡钩针,取出,再次刺入,沿内环口内半周缝合,至与第1针汇合时再次打开卡钩针,将腹腔内留置的缝线置于卡钩针的针孔内,闭合卡钩针并退出,将缝线带出腹腔,体外打结。结果 553例在腹腔镜下完成疝囊高位结扎术,每侧手术时间2~5 min,平均3 min。3例因肠管胀气明显,手术操作空间狭小而中转开放手术。97例患儿对侧存在隐匿性疝,一并行疝囊高位结扎术。426例随访3~18个月,平均10个月,3例术后7~16 d复发,分别于术后3~6个月再次行腹腔镜下疝内环口高位结扎术,未再复发;1例术后3个月出现线结异物反应,给予换药处理,6个月后拆除缝线,斜疝未复发;无阴囊红肿及阴囊积气病例。结论二孔法腹腔镜疝囊高位结扎术治疗小儿腹股沟斜疝效果满意,值得推广应用。展开更多
The startup process of a thermoacoustic engine is a self-excited oscillation process generated in inhomogeneous acoustic media. To reveal these coupling relations between various influential factors is an important ta...The startup process of a thermoacoustic engine is a self-excited oscillation process generated in inhomogeneous acoustic media. To reveal these coupling relations between various influential factors is an important task of basic research on thermoacoustics. In this paper thermoacoustic engines are regarded as thermoacoustic oscillators consisting of the active network and the passive network. Accordingly, the two-port Y-parameter for relevant component is derived, and standing wave and traveling wave thermoacoustic engine are described by the negative-resistance and feedback model, respectively. The relevant two-port network topology is given as well. The startup criteria for thermoacoustic oscillators are obtained by using Nyquist instability criterion. The model prediction of startup parameters, particularly, startup frequency and mode characteristic are in agreement with that of experimental results reported in the literature. Moreover, with topological graphs it is verified that standing wave engines would start up in a negative-resistance state and there would exist high frequency modes in thermoacoustic-Stirling engines. By investigating into the frequency response of thermoacoustic system, this method proposed can achieve such an objective that these effects of operating and structural parameters of engine on startup modes and startup temperature can be revealed in an analytical way. Thus this approach to test and check thermal stability can be provided in a design phase, instead of using empirical frequency to design thermoacoustic systems.展开更多
目的:探讨经脐缘两孔法腹腔镜阑尾切除术的临床疗效。方法:回顾分析2017年7月至2020年6月为166例患者采用经脐缘两孔单器械打结法行腹腔镜阑尾切除术的临床资料。分别于脐缘上、下穿刺10 mm、5 mm Trocar,双极电凝阶梯式电凝阑尾系膜并...目的:探讨经脐缘两孔法腹腔镜阑尾切除术的临床疗效。方法:回顾分析2017年7月至2020年6月为166例患者采用经脐缘两孔单器械打结法行腹腔镜阑尾切除术的临床资料。分别于脐缘上、下穿刺10 mm、5 mm Trocar,双极电凝阶梯式电凝阑尾系膜并离断,系膜无需结扎。经腹壁一次性注射器9号针头将7号丝线带入腹腔,线尾留于体外,腹腔镜下单器械打结结扎阑尾根部,切除阑尾。分析手术时间、中转开腹、术后并发症等指标,以明确手术安全性与可行性。结果:164例患者经两孔法顺利完成手术,手术成功率98.80%。2例因回盲部粘连严重,无法游离暴露阑尾,其中1例增加一枚Trocar完成手术,另1例中转开腹。手术时间22~95 min,平均(51.02±12.74)min;术后无相关并发症发生,患者均治愈出院。住院3~8 d,平均(6.34±1.03)d。结论:在熟练掌握腹腔镜下单器械打结技术的条件下,经脐缘两孔法行腹腔镜阑尾切除术操作方便,成功率较高,创伤较小,临床可推广应用。展开更多
目的探讨两孔法腹腔镜治疗先天性肥厚性幽门狭窄的可行性.方法对21例术前明确诊断先天性肥厚性幽门狭窄的患儿,经二孔法腹腔镜治疗.于脐环下缘置5 mm trocar,放入腹腔镜,于右侧肋缘下锁骨中线处做3 mm trocar,放入微型电钩及弯钳进行操...目的探讨两孔法腹腔镜治疗先天性肥厚性幽门狭窄的可行性.方法对21例术前明确诊断先天性肥厚性幽门狭窄的患儿,经二孔法腹腔镜治疗.于脐环下缘置5 mm trocar,放入腹腔镜,于右侧肋缘下锁骨中线处做3 mm trocar,放入微型电钩及弯钳进行操作.结果21例患儿均无中转开腹手术.手术时间23～65 min,平均31.3 min.术后4～6 d出院.无并发症.18例随访2～7个月,平均3.2月,所有患儿均生长发育正常.结论二孔腹腔镜治疗先天性肥厚性幽门狭窄是一种行之有效的方法.展开更多
基金Supported by National Natural Science Foundation of China (Grant Nos. 50576024 and 51076013)
文摘The startup process of a thermoacoustic engine is a self-excited oscillation process generated in inhomogeneous acoustic media. To reveal these coupling relations between various influential factors is an important task of basic research on thermoacoustics. In this paper thermoacoustic engines are regarded as thermoacoustic oscillators consisting of the active network and the passive network. Accordingly, the two-port Y-parameter for relevant component is derived, and standing wave and traveling wave thermoacoustic engine are described by the negative-resistance and feedback model, respectively. The relevant two-port network topology is given as well. The startup criteria for thermoacoustic oscillators are obtained by using Nyquist instability criterion. The model prediction of startup parameters, particularly, startup frequency and mode characteristic are in agreement with that of experimental results reported in the literature. Moreover, with topological graphs it is verified that standing wave engines would start up in a negative-resistance state and there would exist high frequency modes in thermoacoustic-Stirling engines. By investigating into the frequency response of thermoacoustic system, this method proposed can achieve such an objective that these effects of operating and structural parameters of engine on startup modes and startup temperature can be revealed in an analytical way. Thus this approach to test and check thermal stability can be provided in a design phase, instead of using empirical frequency to design thermoacoustic systems.
文摘目的探讨两孔法腹腔镜治疗先天性肥厚性幽门狭窄的可行性.方法对21例术前明确诊断先天性肥厚性幽门狭窄的患儿,经二孔法腹腔镜治疗.于脐环下缘置5 mm trocar,放入腹腔镜,于右侧肋缘下锁骨中线处做3 mm trocar,放入微型电钩及弯钳进行操作.结果21例患儿均无中转开腹手术.手术时间23～65 min,平均31.3 min.术后4～6 d出院.无并发症.18例随访2～7个月,平均3.2月,所有患儿均生长发育正常.结论二孔腹腔镜治疗先天性肥厚性幽门狭窄是一种行之有效的方法.
