天然胶乳气囊医用导管的开孔和用途

天然胶乳综合性能优异,应用模具拼装、凝固剂与硫化胶乳多次交替浸渍和干燥工艺,制作各种规格和结构复杂的气囊医用导管。介绍天然胶乳气囊导尿管、气囊前列腺医用导管、气囊女性生育医用导管和三腔双囊胃管的开孔和用途。建议根据不同导管,在不同工序下选择不同的开孔方式,使导管充分发挥临床使用功效,满足临床治疗需求。     

天然胶乳气囊导尿管多次浸渍工艺的特点

天然胶乳气囊导尿管通过拼装和凝固剂与硫化胶乳的多次交替浸渍和干燥工艺制备而成。通过调整凝固剂和硫化胶乳的组分或固形物质量分数,分别形成首层湿凝胶、形成充液腔和注药腔的胶膜层及装球囊后覆盖在球囊上的胶膜层等。分析每次浸渍凝固剂和硫化胶乳的工艺特点,以适应不同规格和结构的天然胶乳气囊导尿管的需求。     

胶乳气囊导尿管堵塞的研究

使用充液漏斗向天然胶乳气囊导尿管(以下简称导尿管)的气囊中注入额定容量的空气或无菌水时,会遇到难注入或注不入的问题;在气囊正常膨胀条件下,使用充液漏斗抽出气囊中的空气或无菌水时,会遇到难抽出或抽不出(简称堵塞)的问题。针对前述2类问题进行了研究。结果表明,采用黑胶丝代替尼龙丝作形成导尿管毛细管腔的模具材料,规范夹孔操作工艺杜绝小胶屑掉落到生产环境中,控制用作隔离剂的硅橡胶溶液浓度不超过2%,规范隔离剂涂覆工艺避免出现隔离剂涂层脱落,在浓缩天然胶乳中掺入20份天甲胶乳(MG49)用作基础管身胶料或在基础管身硫化胶乳中加入30份碳酸钙分散体提高管身硬度等,是减少导尿管毛细管腔发生堵塞的有效途径。     

球囊导尿管材料的研究进展

综述以天然胶乳为基础材料的球囊导尿管材料的研究进展。鉴于球囊导尿管临床使用中常见感染、包壳、堵塞和断裂等问题,总结为解决这些问题而使用的球囊导尿管材料。水凝胶、聚四氟乙烯和硅橡胶涂层都能改变球囊导尿管表面性能,硅橡胶是唯一能代替天然胶乳用于球囊制备的材料。目前球囊导尿管的设计和材料仍需改进。建议丰富球囊导尿管相关标准,为开发新型球囊导尿管提供参考,并确保产品的安全性和有效性。     

胶乳气囊导尿管球偏的研究

使用充液漏斗向天然胶乳气囊导尿管(以下简称导尿管)气囊注入额定容量的空气或无菌水时,会遇到气囊膨胀使对称轴偏离管身轴向中心线(简称球偏)的问题,针对球偏问题进行了研究。结果表明,选用鼓球气囊比选用平球气囊的球偏现象少;控制气囊半成品胶膜厚度均匀、气囊半成品裁剪口与气囊轴向呈直角状态、套气囊后的胶乳浸渍操作达到气囊胶膜厚度均匀、套气囊后的胶乳浸渍干燥程度达到气囊呈灰白色以及一次凝固剂浸渍干燥程度达到管端无游离凝固剂和临床使用时严格按产品使用说明书注入额定容量的无菌水等是减少导尿管球偏的有效途径。     

天然胶乳医用制品的发展状况

以天然胶乳避孕套、外科和检查手套及气囊导尿管为主,介绍各类天然胶乳医用制品的发展历程、规格和分类及存在问题,并简介我国天然胶乳医用制品的生产状况。天然胶乳因其独有的特性在医用橡胶制品原材料中占主要地位,但天然胶乳医用制品也因含有过敏性水溶性蛋白质以及加工过程中产生亚硝胺而导致对人体健康存在一定的潜在风险,今后应通过减小天然胶乳中蛋白质含量、实现硫化促进剂绿色化和应用新型纳米材料来提高天然胶乳医用制品的使用安全性。     

水性聚氨酯在乳胶类制品领域的应用概况

介绍水性聚氨酯替代天然胶乳和合成胶乳在乳胶类制品领域的应用状况。水性聚氨酯具有优良的耐磨、耐油、耐低温、耐老化性能及生物相容性,可制备安全套、医用手套和气球等制品。目前需要通过优化聚合配方和工艺以及成型工艺来促进水性聚氨酯在乳胶类制品领域的广泛应用。     

仿生化硅橡胶/羟基磷灰石复合材料的力学性能及生物相容性

硅橡胶和羟基磷灰石均为临床上常用的填充材料。为了综合两者的优点,将两种材料复合得到力学性能、生物性能优良,且能随意塑形的硅橡胶/羟基磷灰石复合材料。对仿生化硅橡胶/羟基磷灰石复合材料的力学性能及生物相容性进行了分析。     

丝胶接枝改性医用天然胶乳手套的研究

利用丝胶生物相容性强、抗过敏的特点,采用丝胶直接改性天然胶乳和丝胶接枝改性天然胶乳两种方法制备医用天然胶乳手套,研究手套的物理性能和过敏性。结果表明,丝胶直接改性天然胶乳会降低天然胶乳手套的物理强度,同时对过敏性改善效果不大;丝胶接枝改性天然胶乳可以提高天然胶乳手套的物理强度并破坏胶乳蛋白的结构,达到改善过敏性的目的。     

胶乳三腔双囊前列腺摘除导尿管的研究

简述了胶乳三腔双囊前列腺摘除导尿管的产品结构及临床使用原理,详细介绍了其原材料选择、配方和生产工艺设计。结果表明,在双腔气囊导尿管基础上研制而成的胶乳三腔双囊前列腺摘除导尿管,能同时满足前列腺摘除的患者术后压迫止血和留置导尿。     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

责任和责任心的涵义与结构

责任是人应主动承担的角色义务和对其因过失所造成后果应承担的责罚.有两层涵义:一是义务;二是后果.责任心是个体自觉做好分内事务和履行道德义务的心理倾向,是个性心理品质成分中自我特征维度上的重要内容.责任心具有两个方面的涵义:一是角色分内职责;二是角色道德义务.责任心是一种通过责任认知、责任个性和责任适应的动态形式表现出来的静态品质,责任心是责任心过程结构与责任心关系结构相互制约、相互影响的统一体.     

二甲基二烯丙基氯化铵和丙烯酰胺的合成及应用

用复合引发体系(过硫酸盐-偶氮类引发剂)和脂肪胺类氧化还原体系引发,在实验室获得了单体转化率≥98%,特性粘数高于13.6 dL/g的阳离子共聚物PDA,探讨了控制聚合物分子量的影响因素.     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.