polytetrafluoroethylene

聚四氟乙烯
  • 文章类型: Journal Article
    OBJECTIVE: The aim of this randomized clinical trial was to compare the qualitative (linear alveolar ridge changes) and quantitative (healing complications) outcomes after guided bone regeneration (GBR) using a custom-made 3D printed titanium mesh versus titanium reinforced dense PTFE membrane for vertical and horizontal augmentation of deficient alveolar ridges.
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  • 文章类型: Journal Article
    支架迁移和污泥形成仍然是与覆盖的自膨胀金属支架(CSEMS)相关的重大问题。EGIS胆道支架完全覆盖耀斑型(EGIS胆道支架),一种新型的聚四氟乙烯涂层自膨胀金属支架,具有低轴向力和抗迁移系统,是为了克服这些缺点而开发的。我们进行了这项研究,以评估该支架与常规CSEMS(c-CSEMS)的有效性和安全性。
    我们回顾性分析了因远端恶性胆道梗阻而接受初次CSEMS治疗的无法切除的胰腺癌患者。主要结果是复发性胆道梗阻(RBO)的时间。次要结果包括技术成功率,功能成功率,支架相关不良事件,RBO的原因,重新干预。
    共纳入40例患者(EGIS组:20例;c-CSEMS组:20例)。两组的技术和功能成功率相似。支架相关不良事件发生率(20%vs.15%,p>0.99)和总体RBO率(56%与50%,p>0.99)两组间无显著差异。支架迁移是EGIS组中RBO的最常见原因,而c-CSEMS组是支架闭塞。RBO的中位时间(102vs.434天,p=0.10)两组间无显著差别。在两组的大多数患者中,经乳头内镜再介入均成功。
    与c-CSEMS相比,EGIS胆道支架与更长的RBO时间无关。进一步改进,特别是针对支架迁移,需要提高其疗效。
    UNASSIGNED: Stent migration and sludge formation remain significant problems associated with covered self-expandable metal stents (CSEMSs). The EGIS biliary stent fully covered flare type (EGIS biliary stent), a new type of polytetrafluoroethylene-coated self-expandable metal stent with low axial force and an anti-migration system, was developed to overcome these disadvantages. We conducted this study to evaluate the efficacy and safety of this stent in comparison with conventional CSEMS (c-CSEMS).
    UNASSIGNED: We retrospectively analyzed consecutive patients with unresectable pancreatic cancer who received initial CSEMS for distal malignant biliary obstruction. The primary outcome was time to recurrent biliary obstruction (RBO). Secondary outcomes included technical success rate, functional success rate, stent-related adverse events, causes of RBO, and re-intervention.
    UNASSIGNED: A total of 40 patients were included (EGIS group: 20; c-CSEMS group: 20). The technical and functional success rates were similar between the two groups. Stent-related adverse event rates (20% vs. 15%, p > 0.99) and overall RBO rates (56% vs. 50%, p > 0.99) were not significantly different between the two groups. Stent migration was the most common cause of RBO in the EGIS group, while stent occlusion was in the c-CSEMS group. The median time to RBO (102 vs. 434 days, p = 0.10) was not significantly different between the two groups. Endoscopic transpapillary re-intervention was successful in most patients in both groups.
    UNASSIGNED: The EGIS biliary stent was not associated with a longer time to RBO compared to c-CSEMS. Further improvements, especially against stent migration, are needed to improve its efficacy.
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  • 文章类型: Journal Article
    有效的阴极再生是电化学水软化过程中的重大挑战。这项工作探讨了为此目的使用具有低表面能的化学镀Ni-P-PTFE电极。Ni-P-PTFE电极在高电流密度下表现出改进的自清洁性能。通过将电极的低表面能与流体冲洗剪切力相结合,在Ni-P-PTFE电极上的沉淀速率在延长的操作期间保持稳定在约18g/m2·h。此外,Ni-P-PTFE电极的清洁效率超过不锈钢的66.34%。Ni-P-PTFE电极可以保持更大的有效面积和更长的使用寿命,这归因于其低表面能的自清洁性能。此外,在电化学水软化过程中,电极表面的松散水垢层很容易被去除,提出了一种新颖的阴极表面设计方法。
    Efficient cathode regeneration is a significant challenge in the electrochemical water softening process. This work explores the use of an electroless plating Ni-P-PTFE electrode with low surface energy for this purpose. The Ni-P-PTFE electrode demonstrates improved self-cleaning performance at high current densities. By combining the low surface energy of the electrode with fluid flushing shear force, the precipitation rate on the Ni-P-PTFE electrode remains stable at approximately 18 g/m2·h over extended periods of operation. Additionally, the cleaning efficiency of the Ni-P-PTFE electrode surpasses that of stainless steel by 66.34%. The Ni-P-PTFE electrode can maintain a larger active area and a longer operational lifespan is attributed to its self-cleaning performance derived from low surface energy. Furthermore, the loose scale layers on the electrode surface are easily removed during electrochemical water softening processes, presenting a novel approach to cathode surface design.
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  • 文章类型: Journal Article
    背景:在柔性内窥镜的再处理中常用的清洁刷通常会在工作通道内造成损坏。
    目的:开发一种喷雾冲洗系统,以实现对工作通道的有效清洁,同时最大程度地减少损坏。
    方法:这项前瞻性研究包括60个使用过的内窥镜和60个Teflon管,随机分为对照组(n=30)和实验组(n=30)。Teflon管的材料与内窥镜工作通道的材料相同。对照组使用传统清洁刷手动清洁内窥镜,而实验组则使用新开发的喷雾冲洗系统进行清洁。ATP水平,清洁度,和微生物测试的工作通道进行了测量。此外,对照组的聚四氟乙烯管用清洁刷经过500次,而实验组的人接受了喷雾冲洗系统,并对通道损伤进行了评估。
    结果:两组的ATP水平(RLU)分别为32.5(13-66)和26(16-40),分别为(P>0.05)。清洁度评分分别为1.5(1-2)和1(1-2),分别为(P>0.05)。在对照组的73.3%中发现了碎片,显著高于实验组的46.7%(P<0.05)。两组的微生物测试均产生阴性结果。对照组的Teflon管损伤评分为4(4-5.25),显著高于实验组4(3~4)(P<0.01)。
    结论:与传统清洁刷相比,喷雾冲洗系统在清除碎屑方面表现出优异的功效,并且对内窥镜工作通道的损伤更小。
    BACKGROUND: Commonly used cleaning brushes in the reprocessing of flexible endoscopes often cause damage within the working channels.
    OBJECTIVE: To develop a spray flushing system to achieving effective cleaning of the working channels while minimizing damage.
    METHODS: This prospective study included 60 used endoscopes and 60 Teflon tubes randomly divided into a control group (n = 30) and an experimental group (n = 30). The material of Teflon tubes was the same as that of the endoscope working channel. Endoscopes in the control group were manually cleaned using traditional cleaning brushes, while those in the experimental group were cleaned using the newly developed spray flushing system. ATP levels, cleanliness, and microbiological testing of the working channels were measured. Additionally, Teflon tubes in the control group underwent 500 passes with a cleaning brush, while those in the experimental group were subjected to the spray flushing system, and channel damage was evaluated.
    RESULTS: The ATP levels (RLU) in the two groups were 32.5 (13-66) and 26 (16-40), respectively (P > 0.05). Cleanliness scores were 1.5 (1-2) and 1 (1-2), respectively (P > 0.05). Debris was found in 73.3% of the control group, which was significantly higher than 46.7% in the experimental group (P < 0.05). Microbiological tests for both groups yielded negative results. Teflon tube damage in the control group was rated at 4 (4-5.25), which was significantly higher than in the experimental group 4 (3-4) (P < 0.01).
    CONCLUSIONS: The spray flushing system demonstrated superior efficacy in removing debris and resulted in less damage to the endoscope working channels compared with traditional cleaning brushes.
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  • 文章类型: Journal Article
    原发性下腔静脉平滑肌肉瘤(IVC)是一种罕见的侵袭性间质瘤,到目前为止,报告的病例不到400例。完全切除具有清晰边缘的肿瘤是唯一经证实的治愈性治疗方法,提供生存福利。尽管如此,中段的平滑肌肉瘤或在下腔静脉(IVC)内延伸至中段的平滑肌肉瘤通常需要进行肾脏再植或肾切除术,比率在56%到75%之间。在这个案例报告中,我们介绍了一位65岁的女性,患有下段IVC平滑肌肉瘤,中段延伸,成功切除和重建,同时避免相关的肾脏再植入或肾切除术的发病率。
    Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare and aggressive mesenchymal tumor, with less than 400 reported cases to date. Complete resection of the tumor with clear margins is the only proven curative treatment, providing survival benefits. Nonetheless, leiomyosarcomas in the middle segment or those extending up to it within the inferior vena cava (IVC) frequently necessitate renal reimplantation or nephrectomy, with rates varying between 56% and 75%. In this case report, we present a 65-year-old female with lower segment IVC leiomyosarcoma with middle segment extension, successfully resected and reconstructed while avoiding associated renal reimplantation or nephrectomy morbidity.
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  • 文章类型: Journal Article
    接触电催化(CEC)通常在机械刺激条件下使用聚合物电介质作为其催化剂,虽然具有良好的催化染料降解效果,但仍有必要提高性能。基于极化内部电场的载流子分离促进策略可以有效改善铁电材料在光催化和压电催化中的性能。因此,作为CEC的必要过程的载流子分离也可以被推广,并且在很大程度上期望从理论上提高CEC性能。然而,在CEC实验中还没有实现内部电场策略对载流子分离的增强,因为难以在惰性聚合物电介质中建立内部电场。在这里,聚四氟乙烯(PTFE)电介质通过驻极体工艺充电,KPFM证明了CEC催化剂的内部电场,XPS,和摩擦电纳米发电机电压输出分析。1.5h时甲基橙的降解速度最快,达到90%以上,而PTFE驻极体的羟基自由基(·OH)产率几乎是原始PTFE的三倍。密度泛函理论(DFT)计算证实,在内部电场下,PTFE和H2O之间原子间电子转移的势垒降低了37%。本文用于优化PTFE催化剂的驻极体策略为CEC中其他通用塑料的使用提供了基础,并促进了易于制备的生产,易于回收,和廉价的聚合物介电催化剂,可以通过CEC促进大规模污染物降解。
    Contact-electro-catalysis (CEC) usually uses polymer dielectrics as its catalysts under mechanical stimulation conditions, which although has a decent catalytic dye degradation effect still warrants performance improvement. A carrier separation promotion strategy based on an internal electric field by polarization can effectively improve ferroelectric material performance in photocatalysis and piezocatalysis. Therefore, carrier separation as a necessary process of CEC also can be promoted and is largely expected to improve CEC performance theoretically. However, the carrier separation enhancement by the internal electric field strategy has not been achieved in the CEC experiment yet, because of the difficulty of building an internal electric field in an inert polymer dielectric. Herein, a polytetrafluoroethylene (PTFE) dielectric was charged through an electret process, which was believed to establish an internal electric field for CEC catalysts proved by KPFM, XPS, and triboelectric nanogenerator voltage output analysis. The fastest degradation rate of methyl orange reached over 90% at 1.5 h, while the hydroxyl free radical (•OH) yield of the PTFE electret was nearly three times that of the original PTFE. Density functional theory (DFT) calculations verified that the potential barrier of interatomic electron transfer between PTFE and H2O was reduced by 37% under the internal electric field. The electret strategy used herein to optimize the PTFE catalyst provides a base for the use of other general plastics in CEC and facilitates the production of easily prepared, easily recyclable, and inexpensive polymer dielectric catalysts that can promote large-scale pollutant degradation via CEC.
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  • 文章类型: Journal Article
    聚四氟乙烯暴露于氩等离子体导致表面附近的聚合物的化学改性。有趣的是,PTFE改性可以通过子带隙紫外线照射来诱导。在后一种情况下,化学结构的变化非常微妙,它们对传统的实验技术几乎是不可见的。辐照样品和原始样品的拉曼光谱显示出实际上相同的峰。然而,通常被认为是不需要的光谱成分的基线,包含反映微小结构变化的重要信息。有了正确的数据分析,这使我们能够可视化氩等离子体和子带隙UV辐照对聚合物的影响。
    Exposure of polytetrafluoroethylene (PTFE) to argon plasma results in chemical modification of the polymer near the surface. Interestingly, PTFE modification can be induced by the sub-band gap ultraviolet (UV) irradiation. In the latter case, the changes in the chemical structure are very subtle, and they are practically invisible to conventional experimental techniques. Raman spectra of irradiated and raw samples show practically identical peaks. However, the baseline that is commonly considered as an unwanted spectral component contains an important information that reflects the minor structural changes. With the proper data analysis, this allows us to visualize the effects of the argon plasma and sub-band gap UV irradiation on the polymer.
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  • 文章类型: Journal Article
    目的:引导骨再生(GBR)是用于再生骨缺损的核心程序。该研究的目的是研究白色念珠菌在GBR手术中使用的六种市售聚四氟乙烯(PTFE)膜上的粘附性以及随后的临床后果。
    方法:测试了六种市售的PTFE膜。其中两个膜具有纹理表面,另外四个膜具有平面,无纹理的一个。白色念珠菌(ATCC24433)培养24小时,并使用改进的方法评估其细胞表面疏水性。通过扫描电子显微镜(SEM)和实时聚合酶链反应(PCR)研究了白色念珠菌对膜盘的粘附。
    结果:C.白色念珠菌被发现是疏水性的(77.25%)。SEM分析表明,白色念珠菌粘附在所有检查的膜上的特征是斑片状,分散,和小的簇状图案,除了一个无纹理的膜具有最粗糙的表面,其中观察到厚的生物膜。实时PCR定量显示,与对照膜相比,白色念珠菌细胞对PTFE膜的粘附力明显更大(p≤.001),其中具有纹理表面的膜表现出最高的2680×104个细胞/ml的计数,而非纹理膜的计数为707×104个细胞/mL(p≤.001)。一层表面无纹理的膜,但发现最粗糙的表面表现出最高的3010×104细胞/ml(p≤.05)。
    结论:本研究的结果表明,白色念珠菌在膜表面上的粘附取决于表面粗糙度的程度和/或取决于纹理的存在。纹理化的PTFE膜和/或膜高粗糙度显示出显著更多的粘附白色念珠菌细胞。这些发现会影响外科医生对GBR膜的选择和术后维护。
    OBJECTIVE: Guided bone regeneration (GBR) is a core procedure used to regenerate bone defects. The aim of the study was to investigate the adherence of Candida albicans on six commercially available polytetrafluoroethylene (PTFE) membranes used in GBR procedures and the subsequent clinical consequences.
    METHODS: Six commercially available PTFE membranes were tested. Two of the membranes had a textured surface and the other four a plane, nontextured one. C. albicans (ATCC 24433) was cultured for 24 h, and its cell surface hydrophobicity was assessed using a modified method. C. albicans adhesion to membrane discs was studied by scanning electron microscopy (SEM) and real-time polymerase chain reaction (PCR).
    RESULTS: C. albicans was found to be hydrophobic (77.25%). SEM analysis showed that C. albicans adherence to all membranes examined was characterized by patchy, scattered, and small clustered patterns except for one nontextured membrane with a most rough surface in which a thick biofilm was observed. Real-time PCR quantification revealed significantly greater adhesion of C. albicans cells to PTFE membranes than the control membrane (p ≤ .001) with the membranes having a textured surface exhibiting the highest count of 2680 × 104 cells/ml compared to the count of 707 × 104 cells/mL on those with a nontextured one (p ≤ .001). One membrane with nontextured surface, but with most rough surface was found to exhibit the highest count of 3010 × 104 cells/ml (p ≤ .05).
    CONCLUSIONS: The results of this study indicate that C. albicans adhesion on membranes\' surfaces depends on the degree of surface roughness and/or on the presence of a texture. Textured PTFE membranes and/or membranes high roughness showed significantly more adhered C. albicans cells. These findings can impact the surgeon\'s choice of GBR membrane and postoperative maintenance.
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  • 文章类型: Journal Article
    目前,三种膨体聚四氟乙烯(ePTFE)假体类型最常用于需要长期血管通路进行血液透析的终末期肾病(ESKD)患者.然而,比较三种ePTFE移植物的研究有限。本研究比较了三种用于ESKD患者上肢动静脉移植(AVG)手术的ePTFE假体移植的临床疗效和术后并发症。纳入2016年1月至2019年9月入住我们中心的需要上肢AVG手术的ESKD患者。总的来说,282名完成2年随访的患者被纳入,并根据ePTFE移植类型分为以下三组:GPVG组采用PROPATEN®移植,带有直型GORE®ACUSEAL的GAVG组,以及带有VENAFLO®II的BVVG组。分析比较两组患者的通畅率和通路相关并发症发生率。术后对患者进行随访,数据收集于术后6,12,18和24个月.根据这些随访时间点,在GPVG组中,原发性通畅率为74.29%,65.71%,51.43%,42.86%;辅助原发通畅率为85.71%,74.29%,60.00%,和48.57%;二次通畅率为85.71%,80.00%,71.43%,和60.00%。在GAVG组中,原发性通畅率为73.03%,53.93%,59.42%,38.20%;辅助原发通畅率为83.15%,68.54%,59.55%,53.93%;二次通畅率为85.39%,77.53%,68.54%,62.92%,分别。在BVVG组中,原发性通畅率为67.24%,53.45%,41.38%,29.31%;辅助原发通畅率为84.48%,67.24%,55.17%,和44.83%;二次通畅率为86.21%,81.03%,68.97%,和60.34%,分别。三种移植物的通畅率差异无统计学意义。总的来说,GPVG中的18、4和12名患者,GAVG,和BVVG组,分别,经历血清肿。在三个移植物中,GORE®ACUSEAL吻合止血时间最短。三个移植物的首次插管时间为GPVG为16(±8.2),GAVG为4(±4.9),和BVVG在18(±12.7)天。GPVG组与其他两组的术后肿胀率差异无统计学意义。此外,关于术后血管通路狭窄和血栓形成,三种移植物类型之间没有发现统计学上的显着差异。缺血盗血综合征,假性动脉瘤,或感染。总之,术后原发性无统计学差异,辅助小学,在三组中观察到或继发性移植物通畅率。吻合止血时间较短,第一次插管时间,ACUSEAL®移植物比其对应物观察到血清肿的发生。PROPATEN®移植物术后上肢肿胀的发生率高于其他移植物。在其余并发症方面,三个移植物之间未观察到统计学上的显着差异。
    Currently, three expanded polytetrafluoroethylene (ePTFE) prosthetic graft types are most commonly used for patients with end-stage kidney disease (ESKD) who require long-term vascular access for hemodialysis. However, studies comparing the three ePTFE grafts are limited. This study compared the clinical efficacy and postoperative complications of three ePTFE prosthetic graft types used for upper limb arteriovenous graft (AVG) surgery among patients with ESKD. Patients with ESKD requiring upper limb AVG surgery admitted to our center between January 2016 and September 2019 were enrolled. Overall, 282 patients who completed the 2-year follow-up were included and classified into the following three groups according to the ePTFE graft type: the GPVG group with the PROPATEN® graft, the GAVG group with the straight-type GORE® ACUSEAL, and the BVVG group with the VENAFLO® II. The patency rate and incidence of access-related complications were analyzed and compared between groups. The patients were followed up postoperatively, and data were collected at 6, 12, 18, and 24 months postoperatively. Respective to these follow-up time points, in the GPVG group, the primary patency rates were 74.29%, 65.71%, 51.43%, and 42.86%; the assisted primary patency rates were 85.71%, 74.29%, 60.00%, and 48.57%; and the secondary patency rates were 85.71%, 80.00%, 71.43%, and 60.00%. In the GAVG group, the primary patency rates were 73.03%, 53.93%, 59.42%, and 38.20%; the assisted primary patency rates were 83.15%, 68.54%, 59.55%, and 53.93%; and the secondary patency rates were 85.39%, 77.53%, 68.54%, and 62.92%, respectively. In the BVVG group, the primary patency rates were 67.24%, 53.45%, 41.38%, and 29.31%; the assisted primary patency rates were 84.48%, 67.24%, 55.17%, and 44.83%; and the secondary patency rates were 86.21%, 81.03%, 68.97%, and 60.34%, respectively. The differences in patency rates across the three grafts were not statistically significant. Overall, 18, 4, and 12 patients in the GPVG, GAVG, and BVVG groups, respectively, experienced seroma. Among the three grafts, GORE® ACUSEAL had the shortest anastomosis hemostatic time. The first cannulation times for the three grafts were GPVG at 16 (±8.2), GAVG at 4 (±4.9), and BVVG at 18 (±12.7) days. No significant difference was found in the postoperative swelling rate between the GPVG group and the other two groups. Furthermore, no statistically significant differences were found across the three graft types regarding postoperative vascular access stenosis and thrombosis, ischemic steal syndrome, pseudoaneurysm, or infection. In conclusion, no statistically significant differences in the postoperative primary, assisted primary, or secondary graft patency rates were observed among the three groups. A shorter anastomosis hemostatic time, first cannulation time, and seroma occurrence were observed with the ACUSEAL® graft than with its counterparts. The incidence of upper extremity swelling postoperatively was greater with the PROPATEN® graft than with the other grafts. No statistically significant differences were observed among the three grafts regarding the remaining complications.
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  • 文章类型: Journal Article
    由于水中痕量铊(Tl)对人类和生态系统是致命的,利用先进技术进行有效的Tl去除至关重要。为了回应这一关切,开发了一种创新的复合膜,采用聚四氟乙烯(PTFE),并具有聚多巴胺(PDA)和聚乙烯亚胺(PEI)的双支持系统,以及双金属普鲁士蓝类似物(Co@Fe-PBA)作为共载体。当用于处理含低浓度Tl(0.5mg·L-1)的水时,复合膜表现出优异的Tl吸附能力(qm)为186.1mg·g-1。透射电子显微镜在特殊的空心Co@Fe-PBAs晶体内部显示出明显的Tl+映射,证明了Tl+通过离子交换和扩散的深层嵌入。共存Na+对复合膜的Tl+-吸附能力影响不大,Ca2+和Mg2+以及棘手的K+,说明优良的抗干扰性。共掺杂的PBA增强了具有Tl+的复合膜的离子交换和嵌入,导致优异的Tl+去除效率。复合膜可以有效地从受污染的河水中去除Tl+以满足USEPA标准。这项研究提供了一种经济有效的基于膜的解决方案,用于从含Tl+的废水中高效去除Tl+。
    As trace levels of thallium (Tl) in water are lethal to humans and ecosystems, it is essential to exploit advanced technologies for efficient Tl removal. In response to this concern, an innovative composite membrane was developed, incorporating polytetrafluoroethylene (PTFE) and featuring a dual-support system with polydopamine (PDA) and polyethyleneimine (PEI), along with bimetallic Prussian blue analogues (Co@Fe-PBAs) as co-supports. The composite membrane exhibited an exceptional Tl+-adsorption capacity (qm) of 186.1 mg g-1 when utilized for the treatment of water containing low concentration of Tl+ (0.5 mg⋅L-1). Transmission electron microscopy displayed the obvious Tl+ mapping inside the special hollow Co@Fe-PBAs crystals, demonstrating the deep intercalation of Tl+ via ion exchange and diffusion. The Tl+-adsorption capability of the composite membrane was not greatly affected by coexisting Na+, Ca2+ and Mg2+ as well as the tricky K+, indicating the excellent anti-interference. Co-doped PBAs enhanced ion exchange and intercalation of the composite membrane with Tl+ leading to excellent Tl+ removal efficiency. The composite membrane could efficiently remove Tl+ from thallium-contaminated river water to meet the USEPA standard. This study provides a cost-effective membrane-based solution for efficient Tl+ removal from Tl+-containing wastewater.
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