Plasma Post Oxidation of Plasma Nitrocarburized SKD 61 Steel

Plasma nitrocarburizing and plasma oxidizing treatments were performed to improve the wear and corrosion resistance of SKD 61 steel.Plasma nitrocarburizing was conducted for 12 h at 540℃in the nitrogen, hydrogen and methane atmosphere to produce theε-Fe-（2-3）（N,C） phase.The compound layer produced by plasma nitrocarburising was predominantly composed ofε-phase,with a small proportion ofγ′-Fe-4 （N,C） phase. The thickness of the compound layer and the diffusion layer are about 10μm and about 200μm,respectively. Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at constant temperature of 500℃for 1 h.The very thin magnetite （Fe-3O-4） layer of 1-2μm in thickness on top of the compound layer was obtained.Anodic polarization test revealed that plasma nitrocarburizing process contributed a significant improvement of corrosion resistance of SKD 61 steel.However,the corrosion characteristics of the nitrocarburized compound layer was deteriorated by oxidation treatment.

Plasma post oxidation of nitrocarburized AISI 4140 steel

Plasma nitrocarburizing and plasma oxidizing treatments were performed to improve the wear and corrosion resistance of AISI 4140 steel. Plasma nitrocarburizing was conducted for 3 h at 570 ℃ in the nitrogen, hydrogen and methane atmosphere to produce the ε-Fe2-3(N,C) phase. It was found that the compound layer produced by plasma nitrocarburising was predominantly composed of ε-phase, with a small proportion of γ′-Fe4(N,C) phase. The thickness of the compound layer was about 10 μm and the diffusion layer was about 300 μm in thickness, respectively. Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at a constant temperature of 500 ℃ for 1 h. The very thin magnetite (Fe3O4) layer 1-2 μm in thickness on top of the compound layer was obtained by plasma post oxidation. It was confirmed that the corrosion characteristics of the nitrocarburized compound layer can be further improved by the application of the superficial magnetite layer.

子宫颈锥形切除术后全子宫切除95例临床分析

目的：分析子宫颈锥形切除术（宫颈锥切）后全子宫切除的指征，重点探讨宫颈锥切后腹腔镜子宫切除（LH）的可行性、安全性和手术要点。方法：回顾性分析2005年11月～2007年10月北京协和医院开展的95例宫颈锥切后全子宫切除术的手术指征、手术时间、出血量、残余宫颈病理、术中及术后并发症等。结果：（1）95例宫颈锥切后全子宫切除中，80例为LH，15例为开腹子宫切除（AH）。患者年龄43．2±5．9岁，术前诊断包括宫颈上皮内瘤变（CIN）Ⅲ及以下18例（18．9％）、CINⅢ累腺35例（36．8％）、宫颈原位癌（CIS）23例（24．2％）、宫颈浸润性鳞癌ⅠA1期19例（20．0％）；（2）15例AH和25例LH是在宫颈锥切6周后施术，55例LH是在宫颈锥切后72h内。LH组和AH组手术时间分别为60．8±17．1min和88．0±19．8min（P〈0．01），术中出血分别为54．3±24．4ml和103．3±48．1ml（P〈0．01）。LH组和AH组的术后住院时间为4．5±1．1天和5．8±1．4天（P〈0．01）；（3）子宫切除标本的阴道断端边缘均未见病变，但残余宫颈中48例（50．5％）存在持续性病变（39例为CINⅡ及以下病变，4例为CINⅢ，3例为CIS，2例为浸润癌）；（4）全组无1例需术中／术后输血，无膀胱、输尿管和肠道损伤发生。LH组患者无1例中转开腹，但4例放置专用举宫器困难，其中1例发生子宫穿孔但未引起并发症；（5）宫颈锥切后72h内行LH的55例中，7例（12．7％）术后出现发热（超过38．5℃），宫颈锥切6周后行LH或AH的40例中，仅1例（2．5％）术后发热。LH组1例患者术后发生阴道残端出血。结论：全子宫切除是某些诊断性宫颈锥切患者锥切后再处理措施之一。对于宫颈锥切后全子宫切除，LH具有优势和特点，其手术时间短，术中出血少，术后住院时间短。正确放置LH专用举宫器最大限度地上举子宫、锐性分离子宫膀胱腹膜返折是减少锥切后LH并发症的关键。

子宫颈锥形切除术相关问题探讨(附390例临床分析)

目的:探讨子宫颈锥形切除术(宫颈锥切)在宫颈疾病诊治中的价值、手术方法、指征、范围和锥切后再处理问题。方法:对北京协和医院2005年11月～2007年10月的390例宫颈锥切资料进行回顾分析,其中210例为普通电刀锥切,180例为冷刀锥切结果:1)患者的宫颈活检诊断包括宫颈上皮内瘤样变3级(CIN_3)311例(79.7%),不排除早期宫颈浸润癌39例(10.0%),CIN_2 31例(7.9%),CIN_1和非CIN病变9例(2.3%)。2)全组平均锥切高度(锥高)1.95cm,其中81例(20.8%)切缘阳性,电刀锥切组的锥高和切缘阳性率与冷刀锥切组相近,但手术时间短,出血少。3)锥切病理诊断包括CIN_2或以下病变110例,CIN_3 242例,宫颈浸润癌38例,3组的切缘阳性率分别为4.5%,22.5%和57.9%(P<0.05)。4)锥切后再处理包括随诊278例(71.3%),全子宫切除95例(24.4%),广泛子宫切除术15例(3.8%),再次锥切2例(0.5%)。结论:锥切是诊治CIN和早期宫颈癌的重要手术,不能被阴道镜多点活检取代;电刀锥切是一种可行的手术方法;切缘状况与宫颈病变严重程度有关。锥切后再处理的选择需根据锥切病理、患者年龄、生育要求和切缘状况综合考虑。

宫颈锥切术后全子宫切除临床探讨

目的探讨宫颈锥切术后子宫切除术的指征、术式、安全性和手术要点。方法选择宫颈锥切术后行子宫切除152例,其中行经阴道子宫切除术(total vaginal hysterectomy,TVH)99例,腹腔镜辅助下经阴道子宫切除(laproscopic assistedvaginal hysterectomy,LAVH)53例,比较两组手术时间、术中出血量、住院时间、术后康复等。结果 TVH组手术时间、术中出血量均低于LAVH组,差异有统计学意义(P<0.05);在术后康复、住院时间方面无统计学差异。结论宫颈锥切后行全子宫切除,TVH具有手术时间短,术中出血少,术后康复快等优点。