Surface Properties

表面特性
  • 文章类型: Journal Article
    本实验和模型研究的目的是研究pH的影响,并确定表面覆盖率加上吸附在TiO2锐钛矿表面的牛血清白蛋白(BSA)蛋白的吸附常数(Ka),分别。在流通池中使用原位傅里叶变换红外衰减全反射光谱来研究BSA在多孔TiO2锐钛矿膜上的吸附。实验是在水溶液中进行的,在不同的pH值,浓度为10-6mol/l。理论上,我们扩展了两状态模型,基于耦合微分方程组,对于展开状态,通过添加解吸参数Kd2。考虑吸附(Ka),对模型进行了求解,解吸(Kd1,2),变换(Kf)系数,和初始溶液蛋白质浓度(C0)。研究结果清楚地表明,溶液的pH急剧改变了BSA的吸附行为,而数学解析解允许我们确定自然状态(θ1),展开状态(θ2),和完整的一个(θ)表面覆盖。最后,近似模型在实验工作中的良好应用,在pH=1.7时,吸附在TiO2锐钛矿上的膨胀BSA的值为Ka=(408.36±0.996)×102mol-1lmin-1。
    The purpose of this experimental and modeling research is to study the pH effect and to determine the surface coverage plus the adsorption constant (Ka) of bovine serum albumin (BSA) protein adsorbed on TiO2 anatase surface, respectively. In situ Fourier transform infrared-attenuated total reflection spectroscopy in a flow-through cell was used to study the BSA adsorption on porous TiO2 anatase films. The experiments were performed in water solution, under different pH values, at a concentration of 10-6 mol/l. Theoretically, we extended the two-state model, based on a system of coupled differential equations, by adding a desorption parameter Kd2, for unfolded state. The model was solved taking into account the adsorption (Ka), desorption (Kd1,2), transformation (Kf) coefficients, and the initial solution protein concentration (C0). The findings clearly illustrated that the solution pH drastically changed the behavior of BSA adsorption, whereas the mathematical analytical solutions allowed us to determine the native state (θ1), the unfolded state (θ2), and the full one (θ) surface coverages. Finally, a good application of the approximated model on the experimental work, expanded BSA adsorbed on TiO2 anatase at pH = 1.7, indicated a value of Ka = (408.36 ± 0.996) × 102 mol-1 l min-1.
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  • 文章类型: Journal Article
    据报道,紫外线/臭氧(UV/O3)处理是一种有效的方法,可以改变润湿性等性能。塑料表面的粘附或吸附。通过接触角分析测量表面的变化,它采用液体及其表面张力(ST)来估计表面能(SE)。我们在科学界发现了两种不同的做法:(1)大多数研究人员采用了文献中液体的ST值,而(2)其他研究人员在SE估计之前在实验室中在环境条件下进行了实时测量。据我们所知,没有研究比较两种做法之间的差异。发现一项研究显示不同的SE方法对同一衬底产生不相等的SE值。然而,没有明确的结论支持一般的热力学规则。在这项研究中,我们提出了(1)统计显著性检验,显示文献和实验ST值显著不同,并研究了(2)不同液体对对UV/O3处理的聚(对苯二甲酸乙二醇酯)(PET)基材的SE估计的影响。先前研究了诸如大气压等离子体或化学改性之类的改性技术,以检查PET的润湿性和SE。研究了UV/O3处理以提高附着力并修饰其化学性质以进行吸附。相比之下,我们研究了(3)UV/O3在不同时间范围内对润湿性的影响,并讨论了(4)如何基于在严格的热力学三相系统上完善的方法来控制不等SE。必须注意,该方法可以推广到其他类型的固体表面,以估计热力学自洽的SE值。这项工作还提供了(5)基于Web的计算器,该计算器补充了数据可用性部分中读者可用的计算结果。
    Ultraviolet/ozone (UV/O3) treatment has been reported to be an effective method to modify properties such as wettability, adhesion or adsorption of plastic surfaces. The change in the surface is measured by contact angle analysis, which employs liquids and their surface tensions (ST) to estimate the surface energy (SE). We found two different practices in the scientific community: (1) the majority of researchers adopted the ST value of liquids from the literature, while (2) other researchers conducted real-time measurements in the lab under ambient conditions prior to SE estimation. To the best of our knowledge, there is no study that compares the difference between the two practices. One study was found to show different SE methods generating unequal SE values for the same substrate. However, there was no definitive conclusion backed by general thermodynamics rules. In this study, we presented (1) a statistical significance test that showed the literature and experimental ST values are significantly different, and studied (2) the effect of different liquid pairs on the SE estimation for UV/O3 treated poly(ethylene terephthalate) (PET) substrate. Modification techniques such as atmospheric pressure plasma or chemical modification were studied previously to examine PET\'s wettability and the SE. The UV/O3 treatment was studied to improve adhesion and to modify its chemical properties for adsorption. In contrast, we studied (3) the effect of UV/O3 on wettability at different timeframes and addressed (4) how to control unequal SE based on a method that was refined on a rigorous thermodynamic three-phase system. It must be noted that this method can be generalized to other types of solid surfaces to estimate thermodynamically self-consistent SE values. This work also provides (5) a web-based calculator that complements computational findings available to the readership in the data availability section.
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  • 文章类型: Journal Article
    对医学应用材料的研究从天然存在或合成的表面中汲取灵感,就像许多其他研究方向一样。对于材料的医疗应用,必须特别注意生物相容性,骨整合,和细菌粘附行为。为了了解它们的性质和行为,实验研究与天然材料如牙齿是非常必要的。结果,然而,可能是高度依赖于情况,因为自然表面具有受到广泛变化的缺点,比如它们的化学成分,结构,形态学,粗糙度,和孔隙度。模拟釉质在细菌粘附和生物相容性方面的性能的合成表面将,因此,更好地促进系统研究。在这项研究中,我们讨论了使用羟基磷灰石(HAp)颗粒来模拟牙齿表面的可能性,并显示了使用模型表面的可能性和局限性。我们对单个金黄色葡萄球菌细胞进行了单细胞力光谱法,以测量与粘附相关的参数,例如与HAp和釉质结合的细胞壁蛋白的粘附力和破裂长度。我们还检查了血浆和唾液对金黄色葡萄球菌粘附特性的影响。这些测量的结果与水润湿性相匹配,样品的元素组成,以及吸附在表面上的大分子随时间的变化。我们发现在所有条件下,金黄色葡萄球菌在HAp和牙釉质样品上的粘附特性相似:在两个表面上存在唾液或血浆的情况下,同样发现粘附强度的显著降低。因此,我们得出结论,HAp颗粒是天然牙科材料的良好替代品。当天然材料的物理化学性质的轻微变化可能影响实验系列时,尤其如此。
    Research into materials for medical application draws inspiration from naturally occurring or synthesized surfaces, just like many other research directions. For medical application of materials, particular attention has to be paid to biocompatibility, osseointegration, and bacterial adhesion behavior. To understand their properties and behavior, experimental studies with natural materials such as teeth are strongly required. The results, however, may be highly case-dependent because natural surfaces have the disadvantage of being subject to wide variations, for instance in their chemical composition, structure, morphology, roughness, and porosity. A synthetic surface which mimics enamel in its performance with respect to bacterial adhesion and biocompatibility would, therefore, facilitate systematic studies much better. In this study, we discuss the possibility of using hydroxyapatite (HAp) pellets to simulate the surfaces of teeth and show the possibility and limitations of using a model surface. We performed single-cell force spectroscopy with single Staphylococcus aureus cells to measure adhesion-related parameters such as adhesion force and rupture length of cell wall proteins binding to HAp and enamel. We also examine the influence of blood plasma and saliva on the adhesion properties of S. aureus. The results of these measurements are matched to water wettability, elemental composition of the samples, and the change in the macromolecules adsorbed over time on the surface. We found that the adhesion properties of S. aureus were similar on HAp and enamel samples under all conditions: Significant decreases in adhesion strength were found equally in the presence of saliva or blood plasma on both surfaces. We therefore conclude that HAp pellets are a good alternative for natural dental material. This is especially true when slight variations in the physicochemical properties of the natural materials may affect the experimental series.
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  • 文章类型: Case Reports
    Adequate removal of residual bonded materials from the enamel surface after orthodontic bracket debonding is critical, since any remaining composite may compromise enamel surface morphology and esthetics. The following clinical case reports present the association of at-home dental bleaching using 10% carbamide peroxide and the removal of residual bonded material using a super fine, tapered diamond bur followed by the use of an enamel microabrasion product after orthodontic bracket debonding. The proposed treatment considerably improved the esthetics and successfully removed the grooves created during the removal of the bonding composite, resulting in a smooth enamel surface.
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  • 文章类型: Case Reports
    The two-step approach of applying hydrofluoric acid followed by silane is deemed the gold-standard surface treatment protocol before bonding to glass ceramics. Given hydrofluoric acid is a toxic conditioning agent and with the intention to simplify this step, the dental company Ivoclar Vivadent (Schaan, Lietchtenstein) released a self-etching ceramic primer, Monobond Etch & Prime in 2015, claiming that hydrofluoric acid and silane application would no longer be required prior to luting glass ceramics. Therefore, this clinical case report and retrospective analysis describes the replacement of unsatisfactory anterior veneers due to clinical failures for new feldspathic glass ceramic veneers, using the aforementioned self-etching ceramic primer. After two years, feldspathic glass ceramics presented satisfying clinical performance with absence of debonding, tooth sensitivity, recurrent carious lesions, or marginal infiltration.
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  • 文章类型: Case Reports
    结论:乳房植入物相关的间变性大细胞淋巴瘤(BIA-ALCL)是一种与纹理化乳房植入物相关的恶性肿瘤。BIA-ALCL通常限于假体周围囊,在放置有纹理的乳房植入物多年后表现为单侧复发性血清肿。目前的估计表明,使用AllerganBiocell纹理植入物的患者的发病率为3300分之一。截至2019年2月6日,与BIA-ALCL相关的美国医疗器械报告显示,BIA-ALCL有457例独特病例,24例“未经证实和可能不准确”的病例与无纹理植入物相关。截至2019年2月,全球共有688例报告病例。迄今为止,没有发表的BIA-ALCL病例报告仅与光滑植入物或纹理扩张器后光滑植入物相关,并且在任何注册表中都没有报告过平稳的案例,数据库,或世界各地的杂志。作者介绍了一例与光滑圆形植入物和纹理组织扩张器相关的BIA-ALCL。一名56岁的妇女接受了左侧IIA期浸润性导管癌的治疗,并进行了双侧乳房切除术,并立即用双侧胸膜下纹理组织扩张器进行了重建。她接受了Mentor光滑圆形植入物的交换,完成辅助化疗.植入物放置4.5年后的磁共振成像和检查未显示异常发现。患者在服用阿达木单抗时植入植入物后5年出现左乳房外伤,并形成了需要外植术的开放性伤口。出现复发性血清肿,细胞学检查BIA-ALCL呈阳性.全囊切除术后的手术病理检查显示IABIA-ALCL期。就作者所知,这是首例BIA-ALCL患者出现纹理扩张器后长期暴露于光滑圆形植入物的病例报告.
    CONCLUSIONS: Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is a malignancy associated with textured breast implants. BIA-ALCL is typically restricted to the periprosthetic capsule, presenting as a unilateral recurrent seroma years after placement of a textured breast implant. Current estimates suggest an incidence of one in 3300 for patients with Allergan Biocell textured implants. As of February 6, 2019, U.S. Medical Device Reporting associated with BIA-ALCL showed 457 unique cases of BIA-ALCL, with 24 \"unverified and potentially inaccurate\" cases associated with a nontextured implant. As of February of 2019, there were 688 reported cases to date worldwide. To date, there are no published case reports of BIA-ALCL associated exclusively with smooth implants or with smooth implants after textured expanders, and there has been no reported smooth-only case in any registry, database, or journal worldwide. The authors present a case of BIA-ALCL associated with smooth round implants and textured tissue expanders. A 56-year-old woman was treated for left stage IIA invasive ductal carcinoma with bilateral mastectomies and immediate reconstruction with bilateral subpectoral textured tissue expanders. She underwent exchange to Mentor smooth-round implants, and completed adjuvant chemotherapy. Magnetic resonance imaging and examination 4.5 years after implant placement showed no abnormal findings. The patient had left breast trauma 5 years following implant placement while taking adalimumab, and developed an open wound requiring explantation. A recurrent seroma developed, and tested positive for BIA-ALCL on cytology. Surgical pathologic examination after total capsulectomy demonstrated stage IA BIA-ALCL. To the authors\' knowledge, this is the first case report of BIA-ALCL in a patient with textured expanders followed by prolonged exposure to smooth round implants.
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  • 文章类型: Journal Article
    The present paper assesses the heterogeneous nucleation of a small-molecule drug and its relationship with the surface chemistry of engineered heteronucleants. The nucleation of aspirin (ASA) was tuned by different functional groups exposed by self-assembled monolayers (SAMs) immobilized on glass surfaces. Smooth topographies and defect-free surface modification allowed the deconvolution of chemical and topographical effects on nucleation. The nucleation induction time of ASA in batch crystallization was mostly enhanced by methacrylate and amino groups, whereas it was repressed by thiol groups. In this perspective, we also present a novel strategy for the evaluation of surface-drug interactions by confining drug crystallization to thin films and studying the preferential growth of crystal planes on different surfaces. Crystallization by spin coating improved the study of oriented crystallization, enabling reproducible sample preparation, minimal amounts of drug required, and short processing time. Overall, the acid surface tension of SAMs dictated the nucleation kinetics and the extent of relative growth of the ASA crystal planes. Moreover, the face-selective action of monolayers was investigated by force spectroscopy and attributed to the preferential interaction of exposed groups with the (100) crystal plane of ASA.
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  • 文章类型: Journal Article
    电化学生物传感器具有极其强大的应用,同时易于制备,小型化,和可调性。通过调整固定探针在传感器表面上的排列和性质来优化目标-探针的缔合,一个可以设计高灵敏度和高效的传感器。在电化学核酸生物传感器中,自组装单层(SAM)被广泛用作具有插入的DNA或RNA探针的可调表面以检测靶序列。由于分辨率不足,难以通过实验研究表面上不均匀探针分布的影响。高探针密度区域可能会抑制与靶标的杂交,并且效果的大小可以根据给定表面上的杂交机制而变化。另一个基本问题涉及在表面上发生的DNA扩散和杂交,以及它是否加速或阻碍分子识别。我们使用全原子布朗动力学模拟,通过模拟单链DNA(ssDNA)靶标与ssDNA探针在极性上的杂交过程来帮助回答这些问题,非极性,和阴离子SAMs在三个不同的探针表面密度。此外,我们通过对两个不同表面上具有不同探针间距的簇进行建模,模拟了三个紧密堆积的探针簇。我们的结果表明,杂交效率在很大程度上取决于找到一种平衡,该平衡允许吸引力将靶DNA导向探针而不将其锚定到表面。此外,我们发现,当探针间间距小于或等于靶DNA长度时,杂交速率变得严重受阻,证明需要精心设计,以增强目标探针的关联并避免空间位阻。我们开发了一个通用的动力学模型来预测杂交时间,并发现它可以准确地适用于典型的探针密度。这些发现阐明了纳米级生物传感器的基本特征,这可以帮助合理的设计努力,并有助于解释不同探针密度下实验杂交率的趋势。
    Electrochemical biosensors have extremely robust applications while offering ease of preparation, miniaturization, and tunability. By adjusting the arrangement and properties of immobilized probes on the sensor surface to optimize target-probe association, one can design highly sensitive and efficient sensors. In electrochemical nucleic acid biosensors, a self-assembled monolayer (SAM) is widely used as a tunable surface with inserted DNA or RNA probes to detect target sequences. The effects of inhomogeneous probe distribution across surfaces are difficult to study experimentally due to inadequate resolution. Regions of high probe density may inhibit hybridization with targets, and the magnitude of the effect may vary depending on the hybridization mechanism on a given surface. Another fundamental question concerns diffusion and hybridization of DNA taking place on surfaces and whether it speeds up or hinders molecular recognition. We used all-atom Brownian dynamics simulations to help answer these questions by simulating the hybridization process of single-stranded DNA (ssDNA) targets with a ssDNA probe on polar, nonpolar, and anionic SAMs at three different probe surface densities. Moreover, we simulated three tightly packed probe clusters by modeling clusters with different interprobe spacing on two different surfaces. Our results indicate that hybridization efficiency depends strongly on finding a balance that allows attractive forces to steer target DNA toward probes without anchoring it to the surface. Furthermore, we found that the hybridization rate becomes severely hindered when interprobe spacing is less than or equal to the target DNA length, proving the need for a careful design to both enhance target-probe association and avoid steric hindrance. We developed a general kinetic model to predict hybridization times and found that it works accurately for typical probe densities. These findings elucidate basic features of nanoscale biosensors, which can aid in rational design efforts and help explain trends in experimental hybridization rates at different probe densities.
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  • 文章类型: Journal Article
    Information regarding profilometric changes at a soft tissue level following implant placement with different protocols is insufficient. Therefore, this study aimed to comparatively investigate the profilometric tissue changes with respect to late implant placement following alveolar ridge preservation (LP/ARP) and early implantation (EP) in periodontally compromised non-molar extraction sites. Sixteen patients were randomly assigned to the following groups: implant placement 4 months post-ARP (group LP/ARP) and tooth extraction and implant placement 4-8 weeks post-extraction (group EP). Dental impressions were obtained immediately after final prosthesis insertion and at 3, 6, and 12 months. At the time of implant placement, bone augmentation was performed in the majority of the patients. Profilometric changes of the tissue contour were minimal between the final prosthesis insertion and 12 months in the mid-facial area (0.04-0.35 mm in group LP/ARP, 0.04-0.19 mm in group EP). The overall tissue volume increased in both groups (1.70 mm3 in group LP/ARP, 0.96 mm3 in group EP). In conclusion, LP/ARP and EP led to similar stability of the peri-implant tissue contour between the final prosthesis insertion and at 12 months. Moreover, the change of peri-implant tissue on the soft tissue level was minimal in both modalities.
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  • 文章类型: Journal Article
    Phage display biopanning with Illumina next-generation sequencing (NGS) is applied to reveal insights into peptide-based adhesion domains for polypropylene (PP). One biopanning round followed by NGS selects robust PP-binding peptides that are not evident by Sanger sequencing. NGS provides a significant statistical base that enables motif analysis, statistics on positional residue depletion/enrichment, and data analysis to suppress false-positive sequences from amplification bias. The selected sequences are employed as water-based primers for PP-metal adhesion to condition PP surfaces and increase adhesive strength by 100% relative to nonprimed PP.
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