Polypropylene

聚丙烯
  • 文章类型: Journal Article
    背景:聚丙烯材料通常用于疝修补术中的后壁重建,与Shouldice医院使用的经典描述的不锈钢丝相反。进行这项研究是为了评估使用聚丙烯或不锈钢丝缝线进行Shouldice修复结果的可能差异。
    方法:对2021年12月6日至2022年9月1日在Shouldice医院接受选择性单侧Shouldice原发性腹股沟疝修补术的连续患者进行前瞻性随访。数据来自随访电话以及手动检查患者的图表。主要目的是确定聚丙烯的使用是否不劣于不锈钢丝的使用,关于Shouldice原发性腹股沟疝修补术后最低随访1年的患者报告的复发率。
    结果:共通过电话联系了1120名患者(聚丙烯:560;不锈钢丝:560)。中位随访期为16个月(四分位距:15-18)。在22例(1.96%)中,诊断出手术部位感染。患者总共报告了18例复发(1.6%)。两组之间没有统计学差异(聚丙烯:7(1.25%)与不锈钢丝:11(1.96%),p>0.05)为复发率。
    结论:在选择性单侧腹股沟疝修补术后的中位随访期为16个月时,使用聚丙烯的复发率不劣于使用不锈钢丝。这一发现可能会鼓励其他不容易使用不锈钢丝进行Shouldice修复的中心。
    BACKGROUND: Polypropylene material is commonly used for posterior wall reconstruction in hernia repair, in contrast with the classically described stainless-steel wire used at Shouldice Hospital. This study was conducted to evaluate possible differences in Shouldice Repair outcomes using polypropylene or stainless-steel wire sutures.
    METHODS: A prospective follow-up of consecutive patients who underwent elective unilateral Shouldice primary inguinal hernia repair at Shouldice Hospital between December 6, 2021, and September 1, 2022, was conducted. Data was collected from follow-up telephone calls as well as manually reviewing patient\'s charts. The primary objective was to determine whether the use of polypropylene was non-inferior to the use of stainless-steel wire, regarding the recurrence rate reported by the patients with a minimum follow-up of 1 year after Shouldice primary inguinal hernia repair.
    RESULTS: A total of 1120 patients were contacted by telephone (polypropylene: 560; stainless-steel wire: 560). The median follow-up period was 16 months (interquartile range: 15-18). In 22 (1.96%) cases a surgical site infection was diagnosed. There was a total of 18 recurrences reported by the patients (1.6%). There was no statistical difference between the groups (polypropylene: 7 (1.25%) vs. stainless steel wire: 11 (1.96%), p > 0.05) for the recurrence rate.
    CONCLUSIONS: The use of polypropylene is non-inferior to the use of stainless-steel wire regarding recurrence rate at a median follow-up period of 16 months after elective unilateral Shouldice primary inguinal hernia repair. This finding may encourage other centers where stainless-steel wire is not easily available to perform the Shouldice Repair.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    微塑料,5毫米以下的颗粒,遍及水生环境,特别是在塔拉戈纳的沿海地区(东北伊比利亚半岛),托管一个主要的塑料生产综合体。为了研究风化和黄度对塑料颗粒毒性的影响,海胆胚胎测试是用来自三个地点的颗粒进行的-靠近源头和距离越来越远。引人注目的是,远处的样本显示出对无脊椎动物早期的毒性,与生产现场附近无害的结果形成对比。后续实验强调了风化和黄化在颗粒毒性升高中的重要性,更多的风化和有色颗粒表现出毒性。这项研究强调了塑料渗滤液对海洋生物影响的被忽视领域,同时提出塑料颗粒在环境中的长期暴露可能导致毒性。尽管阐明了潜在的化学吸附作为毒性来源,必须进一步调查以了解风化,变黄,和塑料颗粒中的化学积累。
    Microplastics, particles under 5 mm, pervade aquatic environments, notably in Tarragona\'s coastal region (NE Iberian Peninsula), hosting a major plastic production complex. To investigate weathering and yellowness impact on plastic pellets toxicity, sea-urchin embryo tests were conducted with pellets from three locations-near the source and at increasing distances. Strikingly, distant samples showed toxicity to invertebrate early stages, contrasting with innocuous results near the production site. Follow-up experiments highlighted the significance of weathering and yellowing in elevated pellet toxicity, with more weathered and colored pellets exhibiting toxicity. This research underscores the overlooked realm of plastic leachate impact on marine organisms while proposes that prolonged exposure of plastic pellets in the environment may lead to toxicity. Despite shedding light on potential chemical sorption as a toxicity source, further investigations are imperative to comprehend weathering, yellowing, and chemical accumulation in plastic particles.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Letter
    暂无摘要。
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Case Reports
    UNASSIGNED:描述一种用双臂法兰聚丙烯缝合线修复宽虹膜透析(>180°)的新技术。
    未经评估:私人执业,武汉,中国。
    未经评估:病例报告。
    未经评估:在虹膜透析侧附近,用30-G针将巩膜从角膜缘外部2毫米处穿刺入前房,然后去插虹膜的根部被刺穿。通过相对侧的角膜切口将7-0聚丙烯线放入前房并插入针中。针头被拔出,将缝合线的一侧留在眼睛之外。然后,巩膜在距第一穿刺点2mm处被新的针刺穿,并穿过距原始虹膜穿刺点2mm处的虹膜根部。将线的另一端插入针中并从眼睛中取出。收紧缝合线以使虹膜根粘附到角膜缘。最后,缝线被切断了,两端被烧灼并留在巩膜内。可以重复该过程直到解决虹膜透析。
    UNASSIGNED:上述技术应用于四种情况。在行动结束时,所有病人的瞳孔几乎都是圆的,直径约3毫米。无患者发生术中及术后并发症。
    UNASSIGNED:双臂法兰聚丙烯缝合线是一种简单安全的操作方法,可应用于修复广泛的虹膜透析。
    UNASSIGNED: To describe a new technique for repairing wide iridodialysis (>180°) with a double-armed flanged polypropylene suture.
    UNASSIGNED: Private practice, Wuhan, China.
    UNASSIGNED: Case report.
    UNASSIGNED: Adjacent to the iridodialysis side, the sclera was punctured 2 mm exterior to the corneal limbus into the anterior chamber with a 30-G needle, then the root of the de-inserted iris was punctured. A 7-0 polypropylene thread was placed into the anterior chamber through a corneal incision on the opposite side and inserted into the needle. The needle was withdrawn, leaving one side of the suture out of the eye. Then, the sclera was punctured by a new needle 2 mm from the first puncture site and passed through the iris root 2 mm from the original iris puncture point. The other end of the thread was inserted into the needle and taken out of the eye. The suture was tightened to make the iris root adhere to the corneal limbus. Finally, the suture is was cut, and the ends were cauterized and left inside the sclera. This procedure can be repeated until the iridodialysis is solved.
    UNASSIGNED: The abovementioned technique was applied in four cases. At the end of the operations, the pupils of all patients were nearly round, with a diameter of about 3 mm. No patient suffered from intraoperative and postoperative complications.
    UNASSIGNED: The double-armed flanged polypropylene suture is a simple and safe operation method that can be applied to repair wide iridodialysis.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    评价了在有偶联剂和无偶联剂的情况下通过注射成型获得的henequen纤维和聚丙烯复合材料的性能。Henequen纤维是主要用于纺织领域或热固性基质复合材料的天然非木纤维。在这项工作中,henequen纤维已被用作上浆玻璃纤维的可能的替代增强材料。评估所用材料的表面电荷密度,以及材料内部纤维的形态。作为加工的结果,观察到纤维长度的显著减少。发现使用基于纤维含量的4%偶联剂可有效地在所研究的增强范围内实现复合材料拉伸强度的显着改善。确定了纵横比对耦合因子的影响,以及界面质量的评价。获得的结果证明了henequen纤维作为复合材料增强材料的巨大潜力,产生具有耦合的强接口。最后,henequen纤维复合材料与上浆玻璃纤维复合材料的比较表明,可以用20wt代替聚丙烯复合材料。50重量%的玻璃纤维。%henequen纤维。
    The performance of henequen fibers and polypropylene composites obtained by injection molding with and without coupling agent was evaluated. Henequen fibers are natural non-wood fibers mainly used in textile sector or in thermosetting matrix composites. In this work, henequen fibers have been used as a possible substitute reinforcement material for sized glass fibers. The surface charge density of the materials used was evaluated, as well as the morphology of the fibers inside the material. A significant reduction in the length of the fibers was observed as a consequence of the processing. The use of a 4% coupling agent based on fiber content was found to be effective in achieving significant improvements in the tensile strength of the composites in the reinforcement range studied. The influence of the aspect ratio on the coupling factor was determined, as well as the evaluation of the interface quality. The results obtained demonstrate the great potential of henequen fibers as reinforcement of composite materials, giving rise to strong interfaces with coupling. Finally, the comparison of henequen fiber composites with sized glass fiber composites showed that it is possible to substitute polypropylene composites with 20 wt.% glass fiber for 50 wt.% henequen fibers.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Case Reports
    暂无摘要。
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    轻量化是汽车行业面临的挑战,发泡是解决这一问题的关键技术。研究了一种新的实用方法,通过在泡沫注射成型过程中利用石墨烯纳米片(xGnP)作为加工助剂来调节共聚物聚丙烯(co-PP)的细胞形成。该方法被设计为通过调节xGnP母料的量来实现调整部件性能的工艺自由度。研究了两种不同水平的1-2wt%xGnP和0.25-0.35wt%超临界流体(SCF)。将制备的样品与通过传统方法(双螺杆挤出,然后进行泡沫注射成型)制备的样品进行比较。具有2重量%xGnP的纳米复合材料相对地显示出约两倍的孔径大小减小。尽管SCF量的增加使弯曲模量和强度提高了47%和122%,分别,悬臂梁无缺口冲击强度损失45%,与纯泡沫相比,关于低熔体强度,泡孔尺寸倾向于增加。总之,通过利用2重量%的xGnP作为加工助剂,12%的重量减少在机械和隔音方面满足了所需的性能参数。
    Lightweighting is a challenge for the automotive industry, and foaming is a key technology used to address this problem. A new practical approach is studied to regulate the cell formation of copolymer polypropylene (co-PP) by utilizing graphene nanoplatelets (xGnP) as a process aid during foam injection molding. The approach was designed to enable process freedom to tune part performance by adjusting the amount of xGnP masterbatch. Two different levels of 1-2 wt % xGnP and 0.25-0.35 wt % supercritical fluid (SCF) were investigated. Prepared samples were compared with samples prepared by the traditional method (twin-screw extrusion followed by foam injection molding). The nanocomposite with 2 wt % xGnP comparatively showed about twofold reduction in cell size magnitude. Although the increment in SCF amount resulted in a 47% and 122% enhancement in flexural modulus and strength, respectively, and a 45% loss in Izod unnotched impact strength, the cell size was prone to increasing with regard to low melt strength as compared to neat foams. In conclusion, a 12% weight reduction fulfilled the desired performance parameters in terms of mechanical and sound insulation by utilizing 2 wt % xGnP as a process aid.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    在这项研究中,通过聚丙烯(PP)基复合材料的微观力学模型估算了henequen纤维的杨氏模量,并在应用校正方法后通过单丝拉伸试验进一步证实。PP和henequen股线,切成1毫米长,在马来酸酐接枝聚丙烯(MAPP)存在下混合。4wt一。%的MAPP显示界面粘附力的有效增强。将复合材料模具注射到狗骨样品中并进行拉伸测试。复合材料的杨氏模量稳定且线性增加至50重量%。纤维含量的百分比从1.5到6.4GPa,相当于增加了327%。当然,henequen纤维显示出与玻璃纤维相当的PP复合材料的硬化能力。纤维的固有杨氏模量是通过建立良好的模型,如Hirsch或Tsai-Pagano,产量平均值为30.5和34.6GPa,分别。对henequen股线进行的单丝测试根据标距长度得出16至27GPa之间的值。虽然,在应用校正方法后,获得33.3GPa的杨氏模量。总的来说,目前的工作提出了henequen纤维作为PP增强的巨大潜力。此外,探讨了微观力学模型和长丝测试之间的关系,以估计纤维的杨氏模量。
    In this study, Young\'s modulus of henequen fibers was estimated through micromechanical modeling of polypropylene (PP)-based composites, and further corroborated through a single filament tensile test after applying a correction method. PP and henequen strands, chopped to 1 mm length, were mixed in the presence of maleic anhydride grafted polypropylene (MAPP). A 4 wt.% of MAPP showed an effective enhancement of the interfacial adhesion. The composites were mold-injected into dog-bone specimens and tensile tested. The Young\'s modulus of the composites increased steadily and linearly up to 50 wt.% of fiber content from 1.5 to 6.4 GPa, corresponding to a 327% increase. Certainly, henequen fibers showed a comparable stiffening capacity of PP composites than glass fibers. The intrinsic Young\'s modulus of the fibers was predicted through well established models such as Hirsch or Tsai-Pagano, yielding average values of 30.5 and 34.6 GPa, respectively. The single filament test performed to henequen strands resulted in values between 16 and 27 GPa depending on the gauge length, although, after applying a correction method, a Young\'s modulus of 33.3 GPa was obtained. Overall, the present work presents the great potential for henequen fibers as PP reinforcement. Moreover, relationships between micromechanics models and filament testing to estimate Young\'s modulus of the fibers were explored.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Case Reports
    Epithelial ovarian cancer relapse is a devastating condition with a poor prognosis. Synthetic mesh carcinogenicity is an entity scarcely reported in the literature. We present a rare case of an ovarian serous tumor relapsed in a polypropylene mesh previously inserted for pelvic organ prolapse correction and a review of the available literature. Our case report point to a possible association between synthetic mesh and ovarian cancer relapse.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    废塑料的机械回收是解决废塑料处理问题的环境解决方案,并已成为业界的普遍做法。然而,关于工业塑料回收或回收材料的信息有限,尽管再生塑料的使用已经扩展到汽车生产。本研究调查了中国一家塑料回收公司机械塑料回收实践的生命周期环境影响。各种来源的废塑料,例如农业废物,塑料制品生产厂家,收集的固体塑料废物和从废弃的电气和电子设备中拆除的零件,经过三条路线加工,产品最终销往不同的市场。生命周期评估结果表明,挤压工艺对环境的影响最大,其次是使用填料和添加剂。与原始塑料和复合材料的生产相比,机械回收被证明是一个优越的替代在大多数环境方面。用再生塑料复合材料代替原始塑料复合材料取得了最高的环境效益,在每个ReCiPe终点损害因子中,原始复合材料生产的影响几乎是回收复合材料生产的4倍。敏感性分析表明,收集网络的覆盖范围对整体环境影响的影响很小,集中化在减少整体环境影响方面发挥着重要作用。在填料和添加剂中,抗冲改性剂对再生复合材料的环境影响贡献最大。这项研究提供了有关现有工业化塑料回收实践的必要信息,并给出了建议。提出了研究意义,目的是实现更高的替代率和更低的环境影响。
    Mechanical recycling of waste plastics is an environmental solution to the problem of waste plastic disposal, and has already become a common practice in industry. However, limited information can be found on either the industralised plastic recycling or the recycled materials, despite the use of recycled plastics has already extended to automobile production. This study investigates the life cycle environmental impacts of mechanical plastic recycling practice of a plastic recycling company in China. Waste plastics from various sources, such as agricultural wastes, plastic product manufacturers, collected solid plastic wastes and parts dismantled from waste electric and electronic equipments, are processed in three routes with products end up in different markets. The results of life cycle assessments show that the extrusion process has the largest environmental impacts, followed by the use of fillers and additives. Compared to production of virgin plastics and composites, the mechanical recycling is proved to be a superior alternative in most environmental aspects. Substituting virgin plastic composites with recycled plastic composites has achieved the highest environmental benefits, as virgin composite production has an impact almost 4 times higher that of the recycled composite production in each ReCiPe endpoint damage factor. Sensitivity analysis shows that the coverage of collecting network contribute affect little to overall environmental impact, and centralisation plays an important role in reducing overall environmental impacts. Among the fillers and additives, impact modifiers account for the most significant contributions to the environmental impacts of recycled composites. This study provides necessary information about the existing industrialised plastic recycling practice, and recommendations are given. Research implications are presented with the purpose to achieve higher substitution rate and lower environmental impact.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

公众号