不同消毒方法对口腔琼脂藻酸钾印模精度的影响

目的探讨藻酸钾印模和琼脂藻酸钾联合印模对2%戊二醛、1%“84“消毒剂浸泡不同时间或喷涂处理后其尺寸精度的变化.方法分别用藻酸钾、琼脂印模材料对标准试件制取45个印模,分9组,各组5个印模.分别采用清水处理(为对照组),2%戊二醛、1%“84“消毒剂喷涂(为喷涂组),用上述消毒液浸泡10、20、30min(为浸泡组),用超硬石膏灌模,静止2 h后螺旋测位器测量模型.结果对照组分别与相应印模材料消毒的喷涂组比较,差异无显著性意义(均P＞0.05);藻酸钾和琼脂藻酸钾印模材料浸泡的各时段组比较,差异有显著性意义(均P＜0.01),且随着时间的增加其尺寸变化呈正相关;两种消毒液浸泡消毒对两种印模材料精度的影响比较,差异无显著性意义(均P＞0.05).结论2%戊二醛、1%“84“消毒剂浸泡消毒印模10 min最为理想,20 min以内不影响修复体制作的精度,可用于临床.     

新型消毒溶液IMPRESEPT对印模材料尺寸稳定性的影响

目的:研究新型浸泡消毒剂(IMPRESEPT)浸泡后,对藻酸盐、硅橡胶和聚醚精细印模材料尺寸稳定性的影响,为临床应用提供依据。方法:用60mm×10mm×10mm金属试件制取印模,在IMPRESEPT消毒溶液中分别浸泡10min、20min、30min。用读数显微镜测量浸泡后各时段印模材料的线性长度。结果:除硅橡胶外,藻酸盐及聚醚印模材料在使用IMPRESEPT消毒溶液浸泡前的体积与浸泡后各时段都有显著的统计学差异(P<0.05)。但在30min浸泡时间内,藻酸盐及聚醚印模材料在使用IMPRESEPT消毒溶液浸泡消毒后不会对活动修复体或固定修复体的精确度造成显著影响。结论:新型消毒溶液(IMPRESEPT)在有效浸泡消毒时间内不会影响印模材料的尺寸稳定性,可试用于临床印模的浸泡消毒。     

五种硅橡胶印模材料对牙冠颈缘复制精度的比较

目的：比较五种硅橡胶印模材料对牙冠颈缘复制精度上的差异。方法：用Express硅橡胶；Aquasil硅橡胶；EXAFINE硅橡胶；Zetaplus硅橡胶及silagum硅橡胶对同一实验模具上已行烤瓷全冠预备的A2基牙制取印模。用秩和检验比较所取印模对牙冠颈缘复制精度上的差异。结果：添加亲水基团的硅橡胶印模材料在对牙冠颈缘复制精度上和传统的疏水型硅橡胶印模材料无显著差异。而四种添加亲水基团的硅橡胶印模材料中，添加亲水基团的加成型硅橡胶印模材料在对牙冠颈缘复制精度上和添加亲水基团的缩聚型硅橡胶印模材料也无显著差异。五种硅橡胶印模材料之间无显著性差异。结论：在这五种硅橡胶印模材料中，在对牙冠颈缘复制精度上效果无显著性差异，都可以达到临床要求，值得在临床中应用，尤其是前牙固定义齿印模制取中进一步普及和推广。     

气雾熏蒸法与浸泡消毒法消毒吸痰管效果比较

目的比较2％强化戊二醛（下称戊二醛）气雾熏蒸法与浸泡消毒法消毒吸痰管的效果。方法消毒按5周期（1个周期12d）进行，每周期将200根使用过的吸痰管经初步处理，即5％84消毒液浸泡30min后清水冲洗干净晾干。将每周期200根吸氮管随机均分为实验组和对照组，实验组采用戊二醛原液气雾熏蒸法消毒4h，对照组采用戊二醛原液浸泡消毒30min，12d为1个周期。两组分别于第1、6、12天对消毒后的吸痰管及消毒过程中的戊二醛采样行细菌菌落数计数，并观察有无细菌生长。结果两组每周期第1、6天吸痰管和消毒液标本均未检测出细菌，且无致病微生物生长；每周期第12天对照组吸痰管和消毒液标本均检测出细菌，实验组未检测出细菌。结论气雾熏蒸法消毒灭菌效果可靠，具有节约开支、使用方便、有利于吸痰管的保存与放置等优点。     

卡式高压蒸汽灭菌器用于连台腹腔镜手术器械快速灭菌的效果观察

目的探讨连台腹腔镜手术器械快速、有效的灭菌方法。方法将使用后的腹腔镜器械分别采用卡式高压蒸汽灭菌器灭菌9rain，2％戊二醛浸泡10h、1h，3种方法各灭菌50例次，比较其灭菌效果。结果2％戊二醛浸泡1h其合格率为80．0％，而卡式高压蒸汽灭菌与2％戊二醛浸泡10h灭菌合格率均达100％，显著优于2％戊二醛浸泡1h（均P〈0．05）。结论卡式高压蒸汽灭菌器在保证灭菌效果的前提下，缩短了腹腔镜连台手术的等待时间，有利于腹腔镜手术的开展。关键词：卡式高压蒸汽灭菌     

高分子聚合材料表面润湿性对成纤维细胞贴附能力的影响

目的：研究高分子聚合体表面润湿性对成纤维细胞初期贴附能力的影响。方法：使用薄膜等离子体聚合法在圆形盖玻片表面生成六甲基二硅氧烷（Hexamethyldisiloxane，HMDSO）薄膜聚合体，然后用低温氧等离子体轰击聚合体表面，根据轰击时间的不同形成一系列的不同润湿性表面，将成纤维细胞系L929接种于不同润湿性表面，观察6h、12h时细胞的贴附率，并观察细胞的形态。结果：随着氧等离子体轰击时间的增加，HMDSO聚合体表面接触角从106&#176;下降为0&#176;，显示表面由高度憎水变为高度亲水。成纤维细胞在亲水表面较憎水表面有更高的早期贴附率，细胞伸展更充分。结论：高分子聚合体的表面润湿性对成纤维细胞的早期贴附和伸展有显著的影响。亲水性表面更有利于细胞的早期贴附和伸展。     

84消毒液浓度及作用时间对其灭菌效果的影响

为探讨８４消毒液对日常医疗器械消毒的最佳浓度及放置时间,以确保其消毒效果,将８４消毒液配制成０．５％、１．０％、１．５％、２．０％４种浓度,检测不同时间消毒液中的氟含量及细菌增减阳性数,同时采用酶联免疫吸附法检测４种逍度对ＨＢsＡg的杀灭力。结果,４种浓度的８４消毒液随时间延长有效氟含量下降;２４ｈ后,０．５％、１．０％组检测细菌阳性数逐渐增多;２．０％对ＨＢsＡg杀灭力最强。揭示．０％８４消毒液浸泡     

组蛋白去乙酰化酶抑制剂对50％总体表面积烫伤大鼠存活率和脏器功能的影响

目的：研究组蛋白去乙酰化酶抑制剂对无液体复苏时致死性烫伤休克大鼠存活率和脏器功能的改善作用.方法：64只SD雄性大鼠随机分为4组：假烫组（n=10）,烫伤组（n=18）,烫伤＋2-甲基-2-乙酸组（2M2P组,n=18）和烫伤＋丙戊酸钠组（VPANa组,n=18）.烫伤组于80 ℃水浴浸泡背部15 s、双下肢15 s、腹部8 s,造成50%TBSAⅢ度烫伤.假烫组于37 ℃水浴浸泡,部位和时间与烫伤组相同. 2M2P组和VPANa组致伤方法同烫伤组,并于烫伤后即刻皮下注射2M2P或VPANa 300 mg/kg.各组大鼠烫伤深度经组织病理证实,于伤后2h和6h取腹主动脉血检测血清丙氨酸转氨酶（ALT）、肌酐（Cr）和肌酸激酶同工酶（CK-MB）等脏器功能指标.另66只大鼠随机分为烫伤组（n=18）、2M2P组（n=24）和VPANa组（n=24）,观察其伤后6 h和12 h生存率.结果：VPANa组生存时间为（776.7±89.5）min,显著高于烫伤组[（360.8±27.4）min]和 2M2P组[（512.5±52.2）min],差异具有显著性（P＜0.05）.VPANa组伤后6 h和12 h生存率分别为83.3%和50.0%,显著高于烫伤组（50.0%和0）和2M2P组（66.7%和16.7%）,差异具有显著性（P＜0.05）;2M2P组6 h和12 h生存率也显著高于烫伤组（P＜0.05）.烫伤及烫伤后各处理组伤后2 h和6 h ALT、Cr和CK-MB均显著高于假烫组（P＜0.05）.伤后6 h VPANa组ALT、Cr和CK-MB显著低于烫伤组和2M2P组（P均＜0.05）,2M2P组虽低于烫伤组,但差别无统计学意义.结论：组蛋白去乙酰化酶抑制剂能显著改善致死性烫伤休克大鼠脏器功能指标,延长动物生存时间.丙戊酸钠作用明显强于2M2P,有希望成为战场或灾害现场无液体复苏条件下救治致死性烧伤休克的潜力药物.     

腹腔镜手术应用帕瑞昔布联合右美托咪定的麻醉效果

目的 探究腹腔镜手术应用不同剂量帕瑞昔布联合右美托咪定的麻醉效果。方法 选取2022年1月至2023年1月在本院接受腹腔镜手术治疗的268例患者,根据麻醉方法的不同将其分为对照组（n=134）和观察组（n=134）。两组患者均给予全身麻醉,对照组给予小剂量帕瑞昔布（20 mg）,观察组给予大剂量帕瑞昔布（40 mg）,两组均联合右美托咪定麻醉。比较两组麻醉效果。结果 两组患者的心率（HR）、平均动脉压（MAP）、白细胞介素（IL）-6及肿瘤坏死因子（TNF）-α水平均随时间发展而呈先升高后降低的趋势,且观察组气管插管后即刻（T1）、手术完毕（T2）、手术后12 h(T3)时的HR、MAP、IL-6及TNF-α水平均明显低于对照组（P<0.05）。两组患者的VAS评分均随时间发展而逐渐降低,RSS评分均随时间发展而逐渐升高,MMSE评分均随时间发展而呈先降低后升高的趋势;且观察组术后1 d及3 d的VAS评分均明显低于对照组（P<0.05）,术后1 d及3 d的RSS及MMSE评分均明显高于对照组（P<0.05）。观察组术后1 d、3 d的POCD发生率均明显低于对照组...     

硅橡胶隆鼻术失败原因分析

硅橡胶隆鼻术失败原因分析青海省人民医院美容整形室（８１０００７）高东旺硅橡胶隆鼻术后临床上常遇到一些并发症，因施术者的不同而发生并发症的类型也不同。现将我院美容整形专科门诊成立两年多来共遇到的７例隆鼻术失败病例总结分析如下：１临床资料７例失败病例中２...     

Roller Pump Induced Tubing Wear of Polyvinylchloride and Silicone Rubber Tubing: Phase Contrast and Scanning Electron Microscopic Studies

Tubing wear and spallation have long been recognized as complications of roller pumps used in cardiopulmonary bypass (CPB) although the reported results of studies of polyvinylchloride (PVC) and silicone rubber tubing wear are still controversial. We conducted phase-contrast microscope (PCM) and scanning electron microscope (SEM) studies of roller pump induced tubing wear. A closed CPB circuit was constructed, and both PVC and silicone rubber tubing (½ inch internal diameter [ID]) were tested under normal and tight occlusions of a dual roller pump at a typical CPB flow rate (4,500 ml/min) for 1, 2, 4, and 6 h in quintet. After each pump run, the tubing was removed. It was first examined with PCM, and suspicious portions were then analyzed in detail using SEM. In silicone rubber tubing of longer running time, the external diameter often decreased. Wear was invariably found on the luminal surfaces at the junction of the inner and outer walls of both the PVC and silicone rubber tubing with no significant differences between normal and tight occlusion. The grooves in the PVC tubing were narrow and continuous with occasional deep cracks in the tubing after more than 3 h of pump run. The grooves in the silicone rubber tubing were wide and often interrupted with occasional V-shaped elevated areas. Craters of less than 50 μ occurred sporadically in both types of tubing. Neither PVC nor silicone rubber tubing offers advantages in terms of roller pump induced tubing wear and spallation.     

Skin needling in the treatment of the aging neck

The aim of this study was to estimate the efficacy of skin needling in the treatment of the aging neck. Eight patients with aging necks were included in the study. Each patient was treated with 2 sessions of needling. The evaluation of treatment effectiveness was based on changes from baseline on the Global Aesthetic Improvement Scale, the Wrinkle Severity Rating Scale, photographic and ultrasonographic images, and silicone rubber microrelief impressions of a selected neck region before and after therapy. Analysis of the photographs, the degree of irregularity of the surface microrelief, and the ultrasound images showed that, after 2 sessions, the lesions' severity grade was reduced in almost 90% of the patients. The present study presents evidence for the efficacy of skin needling for the aging neck.     

The wettability of intrasynovial and extrasynovial tendons

PURPOSE: The surface properties of biologic materials are important to their observed physiochemical responses, mechanical interactions, and compatibility with other materials. The purpose of this study was to characterize further the surface properties of canine tendons, specifically how they interface with fluids--that is, their wettability. METHODS: Drop-shape analysis was used to study contact angles on intrasynovial and extrasynovial tendon surfaces. This standard goniometric method was used to estimate tendon-wettability properties. RESULTS: This study showed that extrasynovial tendon portions (particularly the dorsal sides) are more wettable than intrasynovial tendons. We also showed that trypsin digestion of tendon surfaces increases their wettability. CONCLUSIONS: The wettability differences between intrasynovial and extrasynovial canine tendons may help to explain known differences in the propensities of these 2 different tendon types to form adhesions after surgery.     

Diffusion of anaesthetic gases through different polymers

Background. Improvement of working conditions and anaesthesia with closed systems includes reduction of gas leaks during anaesthesia. One source of contamination is the permeation of gases through plastic materials. The volume of gas permeating through a polymer depends on its molecular structure, the solubility and the diffusion coefficient.
Methods. We designed an experimental set-up to measure the permeation rates of nitrous oxide, enflurane and isoflurane through components of the anaesthetic ventilator made of silicone, latex, rubber and polyvinylchloride (PVC). Reservoir bags, ventilation tubes and endotracheal tubes were investigated.
Results. The highest permeation rates of anaesthetic gases were observed with silicone materials. Permeation through silicone exceeded that of the least permeable material by more than 10.000 times. By summarizing the permeation rates of the single items, the use of silicone increases the anaesthetic system's leakage rate by 4 ml/min, which means an increase of 18% in a modern anaesthetic ventilator and of 31% in a closed system.
Conclusions. The highest permeation rates were found for nitrous oxide through silicone, although nitrous oxide has a known low solubility in plastic materials. The result demonstrates the dependency of the leakage rate on the diffusibility. The leakage of anaesthetic gases caused by silicone items does not alone lead to unacceptable pollution of operating theatres. To minimize the total leakage rates of minimal-flow-systems, however, plastic materials with low solubility and low diffusion coefficients have to be used.     

Evaluation of porous polyethylene for external ear reconstruction

Autogenous rib cartilage and silicone rubber are materials currently used for ear reconstruction. Increased morbidity and operative time with rib cartilage grafts and a high rate of extrusion with silicone implants render them less than ideal for reconstruction of the human ear. The purpose of the current investigation is to determine the efficacy of porous polyethylene as an alternative synthetic material for ear reconstruction. Porous polyethylene and silicone rubber discs of equal sizes in two thicknesses were implanted in lieu of the cartilage in the external ear of eight baboons. Histological evaluation of the sites after nine weeks revealed excellent anchorage of the thin porous polyethylene implants (1.5 mm) in the surrounding tissues. Silicone rubber implants, however, were encapsulated in a thickened granulation tissue capsule. When thicker implants (3.0 mm) were used, exposure or extrusion occurred in all cases. Porous polyethylene implants demonstrated only partial exposure; half of the silicone rubber implants were extruded; and the other two silicone rubber implants were almost completely extruded. Porous polyethylene was thus better incorporated into the soft tissues than silicone rubber as long as the overlying soft tissues were not stressed by an oversized implant or inadequate soft tissue coverage.     

Anaesthetic uptake and washout characteristics of patient circuit tubing with special regard to current decontamination techniques

The amounts of halothane and isoflurane trapped after exposure for up to 3 h at 2 MAC in commonly used anaesthesia circuit tubing were quantitated by gas chromatography. The decontaminating effects of procedures such as flushing with oxygen, thermal disinfection and/or routine storage were assessed in a similar way. After halothane exposure, anaesthetic content was highest in silicone (398 +/- 55 mg 100 g-1). Lower quantities were found in all other tubings investigated (electrically conductive latex: 64 +/- 4, conductive rubber: 62 +/- 4, polyethylene-vinyl-acetate (PEVA): 293 +/- 10 and 149 +/- 17 for non-conductive corrugated and spiral tubes, respectively, polysulfone (Hytrel): 155 +/- 10 mg 100 g-1). The isoflurane contents were substantially lower (silicone: 278 +/- 23; others: 55 +/- 7, 61 +/- 6, 163 +/- 9 and 86 +/- 8, 74 +/- 4 mg 100 g-1). The tubings' content did not correlate with the material's partition coefficient as full saturation was not achieved during exposure. Decontamination procedures reduced the content of volatile anaesthetics to a variable extent. Conductive latex and rubber showed the highest residual content, even after thermal disinfection and subsequent storage. Twenty-minute flushing with oxygen (8 l min-1) decreased effluent gas concentrations below 5 p.p.m. in all tubings. With silicone, after 1 h flushing, halothane concentrations still exceeded 10 p.p.m. (isoflurane: 8 p.p.m.). It is concluded that urgent decontamination by a 20-min flush warrants the safe re-use of previously 'contaminated' conductive rubber and latex as well as polysulfone tubings in critical situations, e.g. in malignant hyperthermia patients if disposable tubing is not immediately available.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preservation of compliance in a small diameter microporous, silicone rubber vascular prosthesis

Compliance is believed to be a significant factor in maintaining the patency of small diameter vascular grafts. This study evaluated the compliance changes with time of microporous Replamineform silicone rubber prostheses. The compliance of 15 canine femoral artery interpositions (4 mm internal diameter X 6 cm length) was measured by in-vivo electromagnetic rheoangiometry immediately following implantation and at intervals to eight months. At implantation, silicone rubber grafts were overcompliant (15.0 +/- 1.1% radial change/mmHg X 10(-2); mean +/- S.E.) compared to the proximal artery (7.7 +/- .6%). The compliance of the prostheses decreased within two weeks (6.3 +/- .9%) and remained isocompliant to the proximal artery for eight months. The compliance determinations for the silicone rubber grafts were compared with those from PTFE prostheses and vein grafts acquired by the same method in a previous study. The analysis demonstrates the preservation of isocompliance of the silicone rubber prostheses compared to the native arteries. In contrast, the minimally compliant vein grafts and PTFE prostheses continued to decrease in compliance following implantation. This microporous silicone rubber graft may improve the success of small internal diameter arterial reconstructions by eliminating failures caused by compliance mismatch between the artery and the prosthesis.     

外伤性额面部骨凹陷与缺损畸形的手术治疗

目的　介绍应用几种生物性、非生物性材料修复额面部骨凹陷和缺损畸形的经验和体会。方法　自 1 993年 6月应用自体骨、羟基磷灰石人工骨、硅橡胶、高密度多孔聚乙烯 ,修复额面部骨凹陷和缺损畸形 30例。结果　共治疗 30例 ,2 9例术后外观良好 ,曲线流畅 ,无感染 ,无明显移位或外露。结论　临床中应根据病变的部位、形状、大小选择合适的移植物 ,Medpor是目前修复额面部骨凹陷和缺损畸形较理想的生物材料之一     

Sustained-release implants of chemical carcinogens in the canine tracheobronchial tree

A proved carcinogen, benzo[a]pyrene (BP), was incorporated into liquid silicone rubber polymer which was then vulcanized into solid form. Discs of BP polymer containing 9.05 to 12.12% BP were sutured into the trachea and right main bronchi of 10 dogs which were observed for 3 to 8 months. The discs were either in contact with the endobronchial surface of the mucosa or placed into submucosal pockets. All discs that were implanted submucosally remain in place. Only 2 discs implanted by the fixation method were extruded. The pocket implants of BP polymer caused ulceration and erosion of the mucosa; these changes did not occur from discs of polymer without carcinogen. To date these implants have induced squamous metaplasia with atypical changes. A method for sustained-release implantation of carcinogens in the canine tracheobronchial tree has been developed.     

Comparison of alloplastic implants for facial bones by scintigraphy and histology: an experimental study

Reconstruction of bone defects and contour irregularities in the craniofacial region is difficult and often requires complex solutions. This study investigated the tissue response, vascularization and bone ingrowth, in hydroxyapatite, porous polyethylene and silicone elastomer when used as bone graft substitutes. 24 albino rabbits (8 rabbits for each implant) were used in this investigation. Hydroxyapatite 500 particles, silicone rubber and porous high-density polyethylene were placed in the cavities formed with a drill in the rabbit frontal bones. As a part of a prospective study the vascularization rates of all implant materials were analyzed 10 days and 2 months after surgery using ^99mTechnetium-MDP (Methylene diphosphonate) scintigraphy of the skull. The scintigraphic studies were performed 2 hours after intravenous injection of 4 mCi (148 MBq) ^99mTc-MDP. The frontal bone was excised on the 10th and 60th days. All tissue specimens were placed first in 10% formalin and then in 10% nitric acid solution for decalcification. The vascularization, connective tissue ingrowth, foreign body reaction and bone regeneration around the implant were evaluated. Results of this study suggested that hydroxyapatite and porous polyethylene were stabilized in bone while as expected silicone was mobile, also hydroxyapatite implants are vascularized better and are more biocompatible than porous polyethylene. Received: 19 July 1998 / Accepted: 27 November 1998