Ethers

醚类
  • 文章类型: Journal Article
    这项研究调查了电膜提取(EME)作为肽的通用技术的能力,通过提取包含总共5953种不同物质的肽的复杂池,大小从7到16个氨基酸不等。从调节至pH3.0的样品中进行电膜提取,并使用由2-硝基苯基辛基醚和香芹酚(1:1w/w)组成的液膜,含有2%(w/w)磷酸二(2-乙基己基)酯。受体相为50mM磷酸(pH1.8),提取时间为45分钟,使用10V。提取效率高,定义为受体中的肽信号高于提取后的样品,3706种不同的肽。提取效率主要受肽的疏水性及其在样品中的净电荷的影响。以净电荷+1提取疏水性肽,而当净电荷为+2或更高时提取亲水性肽。开发了基于机器学习的计算模型,用于基于肽描述符预测肽的可提取性,包括pH3.0(样品pH)时的亲水指数和净电荷的总平均值。这项研究表明,EME对肽具有普遍的适用性,代表了对提取效率进行计算机预测的第一步。
    This study investigated the capability of electromembrane extraction (EME) as a general technique for peptides, by extracting complex pools of peptides comprising in total of 5953 different substances, varying in size from seven to 16 amino acids. Electromembrane extraction was conducted from a sample adjusted to pH 3.0 and utilized a liquid membrane consisting of 2-nitrophenyl octyl ether and carvacrol (1:1 w/w), containing 2% (w/w) di(2-ethylhexyl) phosphate. The acceptor phase was 50 mM phosphoric acid (pH 1.8), the extraction time was 45 min, and 10 V was used. High extraction efficiency, defined as a higher peptide signal in the acceptor than the sample after extraction, was achieved for 3706 different peptides. Extraction efficiencies were predominantly influenced by the hydrophobicity of the peptides and their net charge in the sample. Hydrophobic peptides were extracted with a net charge of +1, while hydrophilic peptides were extracted when the net charge was +2 or higher. A computational model based on machine learning was developed to predict the extractability of peptides based on peptide descriptors, including the grand average of hydropathy index and net charge at pH 3.0 (sample pH). This research shows that EME has general applicability for peptides and represents the first steps toward in silico prediction of extraction efficiency.
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  • 文章类型: Journal Article
    该研究分两个阶段进行。首先,聚合在二氧化硅气凝胶的三个磁化表面上进行,沸石Y,和MIL-101(Cr)。然后,通过中心复合设计-响应面法确定了最佳分子印迹聚合物和最佳提取条件。随后,研究了基于分散固相萃取的最佳分子印迹聚合物萃取燃料醚含氧化合物的验证参数。最佳条件包括吸附剂的类型:沸石-磁性分子印迹聚合物,吸附剂的量:40毫克,pH:7.7,和吸收时间:24.8分钟,其被选择为具有等于0.996的可取性。校准图在1至100μgL-1之间呈线性关系,相关系数良好。检测限为0.64,0。4,甲基叔丁基醚为0.34μgL-1,乙基叔丁基醚,和甲酸叔丁酯,分别。该方法被证明可用于分析饮用水中的燃料醚含氧化合物。
    The study was performed in two phases. First, the polymerization was carried out upon three magnetized surfaces of silica aerogel, zeolite Y, and MIL-101(Cr). Then, optimal molecularly imprinted polymer and optimal extraction conditions were determined by the central composite design-response surface method. Subsequently, the validation parameters of dispersive solid-phase extraction based optimal molecularly imprinted polymer were examined for the extraction of the fuel ether oxygenates. The optimal conditions include the type of adsorbent: Zeolite-magnetic molecularly imprinted polymer, the amount of adsorbent: 40 mg, pH: 7.7, and absorption time: 24.8 min which was selected with desirability equal to 0.996. The calibration graphs were linear between 1 and 100 μg L-1, with good correlation coefficients. The limits of detection were found to be 0.64, 0. 4, and 0.34 μg L-1 for methyl tert-butyl ether, ethyl tert-butyl ether, and tert butyl formate, respectively. The method proved reliable for analyzing fuel ether oxygenates in drinking water.
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  • 文章类型: Journal Article
    方法:回顾性研究。
    目的:本研究的目的是比较颈椎前路椎间盘切除术和融合术(ACDF)与新型零轮廓可变角度(Zero-PVA)垫片和传统的聚醚醚酮(PEEK)笼和板系统在涉及神经根病/脊髓病的病例中的临床和放射学结果。有两种常规类型的ACDF程序旨在治疗症状性颈椎病。第一种是利用植骨/笼子的无仪器“独立”方法,而第二个结合了骨移植物/保持架以及位于椎体之前的前板。两种程序都有其固有的优点和缺点。Zero-PVA间隔物,然而,通过合并两种传统典型程序的优点,代表了一种独特的合成。值得注意的是,这种垫片可以潜在地规避与椎前软组织紊乱相关的问题,并减少吞咽困难的发生.
    方法:使用我们的手术数据库,作者对2018年1月至2019年1月接受单水平ACDF的所有患者进行了回顾性分析,至少随访两年.患者接受了Zero-PVA植入物或PEEK笼以及电镀。记录了日本骨科协会(JOA)评分和手臂和颈部疼痛的视觉模拟评分(VAS)。使用进食评估工具-10(ETA-10)评估吞咽困难。其他参数,如子宫颈排列,评估融合率和术后并发症的发生率。
    结果:根据统计分析的结果,在JOA和VAS指标中观察到的两个研究队列之间的进展没有显著差异.值得注意的是,然而,与笼型和平板组相比,Zero-PVA组的ETA-10评分显著降低(p<0.05).在最后的后续行动中,手术段的高度没有统计学上的显着差异,融合段的Cobb角,C2-C7Cobb角及融会率两组间比较(p>0.05)。然而,Zero-PVA组患者的术后并发症(7.69%)略低于cage和plating组(16.67%).
    结论:发现用于单水平ACDF的Zero-PVA间隔区的临床结果令人满意。该装置在防止术后吞咽困难和减轻与使用板相关的潜在并发症方面的性能与传统的笼和平板方法相当或甚至优于传统的笼和平板方法。
    METHODS: A retrospective study.
    OBJECTIVE: The aim of this study was to compare clinical and radiological outcomes of the anterior cervical discectomy and fusion (ACDF) with a novel zero-profile variable-angle (Zero-P VA) spacer and a traditional poly-ether-ether-ketone (PEEK) cage and plate system in cases pertaining to cervical radiculopathy/myelopathy. There are two conventional types of ACDF procedures aimed at treating symptomatic cervical spondylosis. The first one involves an uninstrumented \"stand-alone\" approach utilizing bone graft/cage, while the second incorporates bone graft/cage in conjunction with a front plate positioned before the vertebral bodies. Both procedures have their own inherent advantages and disadvantages. The Zero-P VA spacer, however, represents a unique synthesis by amalgamating the advantages of both traditionally typical procedures. Notably, this spacer can potentially circumvent the issue related to prevertebral soft-tissue disturbance and reduce the occurrence of dysphagia.
    METHODS: Using our surgical database, the authors systematically conducted a retrospective analysis encompassing all patients who underwent single-level ACDF between January 2018 and January 2019, with a minimum two-year follow-up. Patients either received a Zero-P VA implant or PEEK cage coupled with plating. The Japanese Orthopedic Association (JOA) score and Visual Analogue Scale (VAS) for arm and neck pain were documented. Dysphagia was evaluated using the Eating Assessment Tool-10 (ETA-10). Additional parameters such as cervical alignment, fusion rate and the incidence of postoperative complications were assessed.
    RESULTS: According to the outcomes of the statistical analysis, there was no substantial disparity that emerged in the advancements observed in the JOA and VAS metrics between the two study cohorts. Noteworthy, however, the ETA-10 scores were statistically significantly reduced in the Zero-P VA group compared to the cage and plating group (p < 0.05). At the final follow-up, there were no statistically significant differences in the height of the operated segment, Cobb angle of the fused segment, C2-C7 Cobb angle and fusion rate between the two groups (p > 0.05). However, postoperative complications were slightly lower in patients with the Zero-P VA group (7.69%) as compared to the cage and plating group (16.67%).
    CONCLUSIONS: The clinical outcomes observed with the Zero-P VA spacer used for single-level ACDF were found to be satisfactory. The performance of this device is comparable or even superior to the traditional cage and plating method in preventing postoperative dysphagia and mitigating potential complications associated with the use of a plate.
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  • 文章类型: Journal Article
    具有不同烷基链长度的新型末端含有全氟丁基的醚连接的磷脂酰胆碱(di-O-F4-Cn-PC,n=14,16和18)被开发为稳定脂质体的可能材料,旨在应用膜蛋白的结构和功能分析。水合二O-F4-Cn-PC双层的热致转变的差示扫描量热研究表明,与相应的非氟化PC相比,每个二O-F4-Cn-PC的转变温度降低了约20°C,di-O-Cn-PC。随着疏水链的延长,另一方面,过渡焓(ΔH)和熵(ΔS)呈线性增加。ΔH和ΔS值与di-O-F4-Cn-PC和di-O-Cn-PC之间的净烃链长度的比较强烈表明,在di-O-F4-Cn-PC膜的热致转变中,全氟丁基链段经历非常有限的结构变化;因此,烃段主要负责相变。
    Novel terminally perfluorobutyl group-containing ether-linked phosphatidylcholines with different alkyl chain lengths (di-O-F4-Cn-PCs, n = 14,16 and 18) were developed as possible materials for stable liposomes aiming at applications of structural and functional analyses of membrane proteins. Differential scanning calorimetric investigations of the thermotropic transition of hydrated di-O-F4-Cn-PC bilayers demonstrated that the transition temperature of every di-O-F4-Cn-PC decreases by ~20 °C compared to their corresponding non-fluorinated PCs, di-O-Cn-PCs. With the elongation of the hydrophobic chain, on the other hand, the transition enthalpy (ΔH) and entropy (ΔS) increased in a linear manner. Comparison of ΔH and ΔS values against the net hydrocarbon chain length between di-O-F4-Cn-PCs and di-O-Cn-PCs strongly suggests that in the thermotropic transition of the di-O-F4-Cn-PC membrane, the perfluorobutyl segments undergo very limited structural changes; therefore, the hydrocarbon segments are mainly responsible for the phase transition.
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  • 文章类型: Journal Article
    染料敏化太阳能电池(DSSC)由于其易于制造,是有前途的第三代光伏电池技术,在漫射光条件下的灵活性和更好的性能。天然色素敏化剂是大量可用的和环境友好的。然而,天然色素的窄吸收光谱导致DSSC的低效率。因此,结合两个或两个以上的颜料与互补的吸收光谱被认为是适当的方法,以扩大吸收带和提高效率。这项研究报告了三种复杂分子:brazilin-betanidin-oxane(Braz-Bd-oxane),brazilin-betanidin-ether(Braz-Bd-ether)和brazilin-betanidin-ether(Braze-Bd-ether),从brazilin染料和brazilein染料与betanidin染料的醚化和双醚化反应中获得。平衡几何结构性质,前沿分子轨道,静电表面电位,重组能源,化学反应,用密度泛函理论(DFT)/B3LYP方法研究了染料的非线性光学性质,6-31+G(d,p)分别用于轻原子和重原子的基集和LANL2DZ。使用TD-DFT/B3LYP/6-31+G(d,p)用于分离染料和TD-DFT/CAM-B3LYP/6-31G(d,p)/LANL2DZ为染料@(TiO2)9H4。结果表明,与单独选择的染料相比,Braz-Bd-恶烷和Braze-Bd-醚络合物的光谱发生了红移。与游离染料相比,(TiO2)9H4上吸附的染料的模拟吸收光谱发生了红移。此外,Braz-Bd-恶烷和Braz-Bd-醚表现出比形成这些络合物的所选天然染料更好的电荷转移和光伏性能。基于染料的光电特性和光伏特性,设计的分子Braz-Bd-oxane和Braze-Bd-ether被认为是染料太阳能电池中用作光敏剂的更好候选物。
    Dye-sensitized solar cells (DSSCs) are promising third-generation photovoltaic cell technology owing to their easy fabrication, flexibility and better performance under diffuse light conditions. Natural pigment sensitizers are abundantly available and environmentally friendliness. However, narrow absorption spectra of natural pigments result in low efficiencies of the DSSCs. Therefore, combining two or more pigments with complementary absorption spectra is considered an appropriate method to broaden the absorption band and boost efficiency. This study reports three complex molecules: brazilin-betanidin-oxane (Braz-Bd-oxane), brazilin-betanidin-ether (Braz-Bd-ether) and brazilein-betanidin-ether (Braze-Bd-ether), obtained from the etherification and bi-etherification reactions of brazilin dye and brazilein dye with betanidin dye. The equilibrium geometrical structure properties, frontier molecular orbital, electrostatic surface potential, reorganization energy, chemical reactivities, and non-linear optical properties of the studied dyes were investigated using density functional theory (DFT)/B3LYP methods, with 6-31+G(d,p) basis sets and LANL2DZ for light atom and heavy atoms respectively. The optical-electronic properties were calculated using TD-DFT/B3LYP/6-31+G(d,p) for isolated dye and TD-DFT/CAM-B3LYP/6-31G(d,p)/LANL2DZ for dyes@(TiO2)9H4. The results reveal that spectra for Braz-Bd-oxane and Braze-Bd-ether complexes red-shifted compared to the individually selected dyes. The simulated absorption spectra of the adsorbed dyes on (TiO2)9H4 are red-shifted compared to the free dye. Moreover, Braz-Bd-oxane and Braz-Bd-ether exhibit better charge transfer and photovoltaic properties than the selected natural dyes forming these complexes. Based on the dyes\' optoelectronic properties and photovoltaic properties, the designed molecules Braz-Bd-oxane and Braze-Bd-ether are considered better candidates to be used as photosensitizers in dye solar cells.
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  • 文章类型: Journal Article
    拓扑指数为捕获分子结构提供了一种数学语言,对称性,并预测属性。树枝状聚合物是微观的双侧对称分子,具有明确的均质纳米颗粒结构,通常由一个对称中心组成,内壳,和外壳。在这项工作中,首先,我们计算卟啉(DnPn)的一些基于度的拓扑指数,聚丙醚亚胺(PETIM),锌卟啉(DPZn),和聚酰胺胺(PAMAM)树枝状聚合物。然后,我们使用多准则决策(MCDM)技术来建立基于某些拓扑指数的树枝状聚合物类的加权评估。对于加权分析,我们将苯衍生物的性质与拓扑不变量相关联。最后,基于多准则决策技术,即TOPSIS,SAW和MOORA方法,我们根据树枝状聚合物的性质对它们进行了排序。
    Topological indices provide a mathematical language for capturing molecular structure, symmetry, and predicting properties. Dendrimers are microscopic bilaterally symmetrical molecules with a well-defined homogeneous nanoparticles structure, often consisting of a symmetric center, inner shell, and outer shell. In this work, first we compute some degree-based topological indices of Porphyrin (DnPn),Poly (Propyl) Ether Imine(PETIM), Zinc porphyrin (DPZn), and Polyamidoamine (PAMAM) dendrimers. Then, we use multi-criteria decision making (MCDM) techniques to establish the weighted evaluation of dendrimer classes based on certain topological indices. For weighted analysis we correlate the properties of benzene derivatives with topological invariants. Finally, based on the multi-criteria decision making techniques namely TOPSIS, SAW and MOORA method, we have ranked the dendrimer structures based on their properties.
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  • 文章类型: Journal Article
    背景:全膝关节置换术是治疗晚期膝关节炎最有效的方法,大部分膝关节假体都是用金属制成的.然而,金属假体仍然有几个问题。这项研究的目的是介绍由聚醚醚酮(PEEK)制成的新型无金属膝关节假体,并将其水泥粘结强度与金属假体进行比较。
    方法:将12套膝关节假体分为四组(无负载PEEK,卸载的金属,1000万次(MC)PEEK,10MC金属,每个N=3),然后用骨水泥附着在复合骨上。10MCPEEK和10MC金属组都进行了10MC的动态步态模拟,而其他两组没有。之后,对股骨假体进行拉脱强度试验,对胫骨假体进行剪切强度试验.
    结果:对PEEK和金属组进行1000万次动态模拟后,在骨水泥中未观察到明显的裂纹。在无负载PEEK与无负载PEEK的强度测试中,没有观察到统计学上的显着差异(p>.05)。卸载的金属,股骨拉脱试验中的10MCPEEKvs.10MC金属和卸载的PEEKvs.胫骨剪切试验中的卸载金属。10MCPEEK的剪切强度显著低于10MC金属的剪切强度(p<.05)。
    结论:通过将先前对膝关节假体的研究的力分析与本研究的PEEK膝关节假体中观察到的故障模式进行比较,它复制了金属假体。我们认为,皮克膝关节假体与骨水泥的结合是可靠的。我们预计,无金属的PEEK膝关节假体将在未来的全膝关节置换术(TKA)中找到应用,从而使患者受益。
    Total knee arthroplasty is the most effective treatment for advanced-stage knee arthritis, and the majority of knee prostheses are made of metal. Nevertheless, metal prostheses still have several problems. The objective of this study is to introduce new metal-free knee prostheses made of polyether-ether-ketone (PEEK) and to compare their cement bond strength with metal prostheses.
    Twelve sets of knee prostheses were divided into four groups (unloaded PEEK, unloaded Metal, 10 million cycles (MC) PEEK, 10 MC Metal, N = 3 each), and then attached to composite bones using bone cement. Both the 10 MC PEEK and 10 MC Metal groups were subjected to dynamic gait simulations of 10 MC, whereas the other two sets were not. Afterwards, a pull-off strength test was performed on the femoral prostheses and a shear strength test was performed on the tibial prostheses.
    No apparent cracks were observed in the bone cement after subjecting the PEEK and Metal groups to 10 million cycles of dynamic simulation. No statistically significant differences were observed (p > .05) in the strength tests for unloaded PEEK vs. unloaded Metal, 10 MC PEEK vs.10 MC Metal in the femoral pull-off test, and for unloaded PEEK vs. unloaded Metal in the tibial shear test. The shear strength of 10 MC PEEK was significantly lower (p < .05) compared to that of 10 MC Metal.
    By comparing the force analysis of previous investigations on knee prostheses with the failure pattern observed in the PEEK knee prosthesis of this study, which replicates that of the metal prosthesis. We believe that the combination of the peek knee prosthesis with bone cement is reliable. We anticipate that metal-free PEEK knee prostheses will find application in Total Knee Arthroplasty (TKA) in the future, thereby benefiting patients.
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  • 文章类型: Journal Article
    背景:改善骨科脊柱植入物骨整合的方法仍然是临床挑战。由聚醚-醚-酮(PEEK)和钛组成的材料由于其固有的生物相容性性质而通常用于骨科应用。钛具有耐久性和骨亲和力的临床声誉,和PEEK提供的优点是模量接近骨结构并且是射线可透过的。当前研究的假设是,与未涂覆的对照相比,钛等离子喷涂(TPS)涂层可能会增加PEEK和钛植入物的周向和并置骨小梁整合的速率和幅度。
    目的:使用体内绵羊模型,当前的调查比较了钛等离子喷涂PEEK和钛销钉与非等离子喷涂销钉。使用术后6周和12周的时程研究,量化骨整合的实验测定包括显微计算机断层扫描(microCT),生物力学测试,和组织形态计量学。
    方法:体内绵羊模型。
    方法:将12只骨骼成熟的杂交绵羊随机分为术后6周和12周。四种类型的销钉植入物-PEEK,钛等离子喷涂PEEK(TPSPEEK),钛,并将钛等离子喷涂钛(TPS钛)植入股骨远端和肱骨近端的圆柱形干phy端缺损(每个肢体一个缺损,n=48个站点)。16个非手术标本(8个股骨和8个肱骨)用作零时间点对照。一半的标本进行了破坏性的生物力学拔出测试,剩下的一半进行了定量的显微CT,以量化植入物表面1.0mm和2.0mm内的圆周骨体积,并进行组织形态计量学以计算直接的小梁贴壁。
    结果:没有术中或围手术期并发症。与未涂覆的对照相比,TPS涂覆的植入物在6周和12周时在销钉拔出时表现出显著更高的峰值载荷(p<0.05)。在零时间点的销钉处理中没有观察到差异(p>0.05)。MicroCT结果显示,在销钉表面1.0mm或2.0mm内,植入物之间的圆周骨整合没有显着差异(p>0.05)。TPS涂层组基于组织形态计量学的小梁骨直接并位骨整合较高,无论基础材料,与两个时间间隔的未涂覆处理相比(p<0.05)。
    结论:目前的体内研究证明了等离子喷涂涂层的生物学和机械优势。TPS改善了植入物提取所需的组织学结合和峰值力。
    结论:等离子喷涂涂层可能通过在术后前6至12周内改善生物固定和骨整合而提供临床益处-这是基于植入物的关节固定术的关键愈合期。
    BACKGROUND: Methods to improve osseointegration of orthopedic spinal implants remains a clinical challenge. Materials composed of poly-ether-ether-ketone (PEEK) and titanium are commonly used in orthopedic applications due to their inherent properties of biocompatibility. Titanium has a clinical reputation for durability and osseous affinity, and PEEK offers advantages of a modulus that approximates osseous structures and is radiolucent. The hypothesis for the current investigation was that a titanium plasma spray (TPS) coating may increase the rate and magnitude of circumferential and appositional trabecular osseointegration of PEEK and titanium implants versus uncoated controls.
    OBJECTIVE: Using an in vivo ovine model, the current investigation compared titanium plasma-sprayed PEEK and titanium dowels versus nonplasma-sprayed dowels. Using a time course study of 6 and 12 weeks postoperatively, experimental assays to quantify osseointegration included micro-computed tomography (microCT), biomechanical testing, and histomorphometry.
    METHODS: In-vivo ovine model.
    METHODS: Twelve skeletally mature crossbred sheep were equally randomized into postoperative periods of 6 and 12 weeks. Four types of dowel implants-PEEK, titanium plasma-sprayed PEEK (TPS PEEK), titanium, and titanium plasma-sprayed titanium (TPS titanium) were implanted into cylindrical metaphyseal defects in the distal femurs and proximal humeri (one defect per limb, n=48 sites). Sixteen nonoperative specimens (eight femurs and eight humeri) served as zero time-point controls. Half of the specimens underwent destructive biomechanical pullout testing and the remaining half quantitative microCT to quantify circumferential bone volume within 1 mm and 2 mm of the implant surface and histomorphometry to compute direct trabecular apposition.
    RESULTS: There were no intra- or perioperative complications. The TPS-coated implants demonstrated significantly higher peak loads at dowel pullout at 6 and 12 weeks compared with uncoated controls (p<.05). No differences were observed across dowel treatments at the zero time-point (p>.05). MicroCT results exhibited no significant differences in circumferential osseointegration between implants within 1 mm or 2 mm of the dowel surface (p>.05). Direct appositional osseointegration of trabecular bone based on histomorphometry was higher for TPS-coated groups, regardless of base material, compared with uncoated treatments at both time intervals (p<.05).
    CONCLUSIONS: The current in vivo study demonstrated the biological and mechanical advantages of plasma spray coatings. TPS improved histological incorporation and peak force required for implant extraction.
    CONCLUSIONS: Plasma spray coatings may offer clinical benefit by improving biological fixation and osseointegration within the first 6 to 12 weeks postoperatively- the critical healing period for implant-based arthrodesis procedures.
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  • 文章类型: Journal Article
    在某些临床情况下,人工植入材料可以与天然关节软骨连接,并且优选选择导致关节软骨磨损最小的植入材料以维持正常的关节结构和功能。该项目比较了关节对猪股骨髁的磨损,钛合金(Ti6Al4V),超高分子量聚乙烯(UHMWPE),和碳纤维增强的聚醚醚酮(CFR-PEEK)通过离体实验装置。30-160N的正弦压缩载荷,在3Hz的频率下,关节压力约为0.19-1MPa,并在3Hz下旋转位移为+/-10,用于模拟生理关节运动。在43,200个周期后,通过大体检查和使用OARSI评分系统在组织学上对磨损进行表征。与钛合金和UHMWPE相比,CFR-PEEK对关节软骨的磨损最为明显,而钛合金和UHMWPE的磨损水平相似。与软骨上软骨测试相比,所有材料都会造成更多的磨损。磨损机制的特征在于组织学样品中软骨中蛋白聚糖含量的逐渐损失。
    Artificial implant materials may articulate against native articular cartilage in certain clinical scenarios and the selection of an implant material that results in the least wear on articular cartilage is preferred to maintain normal joint architecture and function. This project compared the wear on porcine femoral condyles induced by articulation against porcine patellae, titanium alloy (Ti6Al4V), ultra high molecular weight polyethylene (UHMWPE), and carbon fibre reinforced polyether-ether-ketone (CFR-PEEK) through an ex vivo experimental setup. A sinusoidal compressive load of 30-160 N, representing an approximate joint pressure of 0.19-1 MPa at a frequency of 3 Hz coupled with a rotational displacement of +/- 10⁰ at 3 Hz was used to simulate physiological joint motion. Wear was characterized via gross examination and histologically using the OARSI scoring system after 43,200 cycles. CFR-PEEK resulted in the most significant wear on articular cartilage compared to titanium alloy and UHMWPE whereas titanium alloy and UHMWPE resulted in similar levels of wear. All materials caused more wear compared to cartilage-on-cartilage testing. The wear mechanism was characterized by progressive loss of proteoglycan content in cartilage in histology samples.
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  • 文章类型: Journal Article
    背景:当完成正畸治疗以避免由于牙周纤维弹性引起的复发并允许牙槽骨再生时,保留器是必要的程序。比较垂直力对三种固定保持器失效的影响:CAD/CAM聚醚醚酮(PEEK),CAD/CAM玻璃纤维增强复合材料(FRCs),和舌侧固定线“Bond-A-Braid™”。
    方法:将108颗上颌第一前磨牙随机分为三组:A组(CAD/CAMPEEK),B组(CAD/CAMFRC),和C组(舌侧固定线“Bond-A-Braid™”)。这些固定器使用AssurePlus粘合树脂和GOTO糊剂进行粘合。对于每个样本,使用装载循环和热循环机。使用万能试验机以1mm/min的十字头速度在邻间段上测量失效脱结力。在用立体显微镜以(X20)放大倍数鉴定失效类型之后,计算粘合剂剩余指数(ARI)。
    结果:B组和C组显示出最高的失效结合力,平均值为209.67±16.15和86.81±4.59N,分别。然而,A组具有统计学上显著较低的粘结破坏力,平均值为45.73±4.48N。基线时,三个研究组之间的连接器保持器位移差异有统计学意义(p<.001).三个研究组之间的ARI评分无统计学意义(p<.001);对于A组和B组,ARI主要分为3分,C组分为2分和3分.使用光学立体显微镜研究了保持器的失效模式。B组,保持器出现了内聚性故障,A和C组主要在保持器界面处的粘合剂中表现出失效。
    结论:所有组差异显著,A组的脱粘力最低,B组的脱粘力最高。此外,ARI没有实质性变化,但三组间的连接器保持器位移和失效类型存在显著差异。
    Retainer is a necessary procedure when orthodontic treatment complete to avoid relapse due to periodontal fiber elasticity and to allow for alveolar bone regeneration. Compare the influence of vertical force on the failure of three fixed retainers: CAD/CAM polyether ether ketone (PEEK), CAD/CAM fiber glass reinforced composites (FRCs), and lingual retainer wire \"Bond-A-Braid™\".
    One hundred and eight maxillary first premolars teeth were randomly allocated to three groups: Group A (CAD/CAM PEEK), Group B (CAD/CAM FRC), and Group C (lingual retainer wire \" Bond-A-Braid™\"). These retainers were bonded using Assure Plus Bonding Resin and GO TO Paste. For each specimen, a loading cycling and thermocycling machine was used. The failure debonding forces were measured on the interproximal segments using a universal testing machine with a cross-head speed of 1 mm/min. The adhesive remnant index (ARI) was calculated after identifying types of failure with a stereomicroscope at (X 20) magnification.
    Group B and group C showed the highest failure bonding forces, with a mean of 209.67 ± 16.15 and 86.81 ± 4.59 N, respectively. However, Group A had a statistically significant lower bond failure force, with a mean value of 45.73 ± 4.48 N. At baseline, there was a statistically significant difference in connector retainer displacement between the three studied groups (p < .001). The ARI score was not statistically significant (p < .001) between the three study groups; for groups A and B, the ARI was predominantly score 3, and group C showed a mixed score of 2 and 3. The failure mode of retainers was investigated using an optical stereomicroscope. In group B, there was a cohesive breakdown in the retainer, and groups A and C exhibited failures primarily in the adhesive at the retainer interface.
    All groups differed significantly, with group A having the lowest debonding force and group B having the highest. Furthermore, there was not a substantial variation in ARI, but there was a significant difference in connector retainer displacement and the types of failure amongst the three groups.
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