XPS, X-ray photoelectron spectroscopy

XPS,X射线光电子能谱
  • 文章类型: Journal Article
    本研究通过直流磁控溅射成功地在Si(100)衬底上沉积了掺杂Si的CrN涂层。通过在沉积期间改变Si靶电流来改变CrSiN涂层中的Si浓度。通过X射线衍射测定微观结构和机械性能,X射线光电子能谱,原子力显微镜,和纳米压痕测试。根据结果,该涂层具有3.3at.%Si含量(CrSiN-2)显示微晶尺寸和涂层表面粗糙度的增加和减少,分别,导致固溶硬化,最佳硬度和弹性模量为21.37GPa和205.68GPa,分别。随着Si的继续添加,涂层粗糙度增加,机械性能逐渐降低,对于最大Si浓度为9.2at的涂层的弹性模量和硬度,涂层的机械性能分别达到184.08GPa和18.95GPa。%(CrSiN-5)。
    This study successfully deposited Si-doped CrN coatings onto Si (100) substrate by direct current magnetron sputtering. The concentration of Si in the CrSiN coatings was varied by changing the Si target current during deposition. The microstructural and mechanical properties were determined by employing X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, and nanoindentation test. According to the results, the coating with 3.3 at.% Si contents (CrSiN-2) show an increase and decrease in the crystallite size and coating surface roughness, respectively, leading to solid solution hardening with an optimum hardness and elastic modulus of 21.37 GPa and 205.68 GPa, respectively. With continued Si addition, the coating roughness increased and the mechanical properties gradually decreased and attained 184.08 GPa and 18.95 GPa for the elastic modulus and hardness of the coating with a maximum Si concentration of 9.2 at.% (CrSiN-5).
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  • 文章类型: Journal Article
    残疾,由于电离辐射(IR)引起的骨质疏松性骨折的死亡率和费用是巨大的,并且没有有效的治疗方法存在。电离辐射增加细胞氧化损伤,导致骨转换失衡,这主要是由骨吸收破骨细胞的活性增强引起的。我们证明暴露于亚致死水平的IR的大鼠会发展成脆弱的,骨质疏松骨.在反应性表面位点,铈离子具有容易进行氧化还原循环的能力:大幅调整其电子配置和通用的催化活性。这些特性使氧化铈纳米材料令人着迷。我们展示了一种由氧化铈组成的工程人工纳米酶,并设计为具有更高比例的三价(Ce3+)表面位点,减轻IR诱导的骨区域损失,骨骼结构,和力量。这些研究还表明,我们的纳米酶提供了几种机械保护途径,并选择性地靶向高破坏性的活性氧。保护大鼠免受IR诱导的DNA损伤,细胞衰老,体外和体内破骨细胞活性升高。Further,我们发现,我们的纳米酶是以前未报道的一个关键调节的破骨细胞形成的衍生自巨噬细胞,同时也直接靶向骨祖细胞,尽管在体外暴露于有害水平的IR,但仍有利于新骨形成。这些发现为使用合成介导的设计多功能纳米材料特异性预防IR诱导的骨丢失开辟了新方法。
    The disability, mortality and costs due to ionizing radiation (IR)-induced osteoporotic bone fractures are substantial and no effective therapy exists. Ionizing radiation increases cellular oxidative damage, causing an imbalance in bone turnover that is primarily driven via heightened activity of the bone-resorbing osteoclast. We demonstrate that rats exposed to sublethal levels of IR develop fragile, osteoporotic bone. At reactive surface sites, cerium ions have the ability to easily undergo redox cycling: drastically adjusting their electronic configurations and versatile catalytic activities. These properties make cerium oxide nanomaterials fascinating. We show that an engineered artificial nanozyme composed of cerium oxide, and designed to possess a higher fraction of trivalent (Ce3+) surface sites, mitigates the IR-induced loss in bone area, bone architecture, and strength. These investigations also demonstrate that our nanozyme furnishes several mechanistic avenues of protection and selectively targets highly damaging reactive oxygen species, protecting the rats against IR-induced DNA damage, cellular senescence, and elevated osteoclastic activity in vitro and in vivo. Further, we reveal that our nanozyme is a previously unreported key regulator of osteoclast formation derived from macrophages while also directly targeting bone progenitor cells, favoring new bone formation despite its exposure to harmful levels of IR in vitro. These findings open a new approach for the specific prevention of IR-induced bone loss using synthesis-mediated designer multifunctional nanomaterials.
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  • 文章类型: Journal Article
    癌症治疗的主要挑战是如何有效消除原发性肿瘤并充分诱导免疫原性细胞死亡(ICD)以激发强大的免疫反应来控制转移。这里,开发了一种自组装的级联生物反应器,以增强肿瘤渗透和饥饿的协同治疗来改善癌症治疗,化学动力学(CDT)和光热疗法。以葡萄糖氧化酶(GOx)为模板合成超小FeS-GOx纳米点,紫杉醇(PTX)通过疏水作用诱导形成自组装FeS-GOx@PTX(FGP)。在肿瘤部位积累后,FGP分解为较小的FeS-GOx,以增强肿瘤的深层渗透。GOx维持高的酶活性以在氧的辅助下催化葡萄糖以产生过氧化氢(H2O2)作为饥饿疗法。涉及再生H2O2的Fenton反应进而产生更多的羟基自由基以增强CDT。跟随808nm的近红外激光,通过联合治疗,FGP在体外和体内显示出显著的肿瘤抑制。随之而来的钙网织蛋白暴露增加了ICD并促进了树突状细胞的成熟。结合抗CTLA4检查点封锁,由于细胞毒性T淋巴细胞的肿瘤内浸润增强,FGP可以绝对消除原发性肿瘤并积极抑制远处肿瘤。我们的工作提出了一种有希望的原发性肿瘤和转移抑制策略。
    Major challenges for cancer treatment are how to effectively eliminate primary tumor and sufficiently induce immunogenic cell death (ICD) to provoke a robust immune response for metastasis control. Here, a self-assembled cascade bioreactor was developed to improve cancer treatment with enhanced tumor penetration and synergistic therapy of starvation, chemodynamic (CDT) and photothermal therapy. Ultrasmall FeS-GOx nanodots were synthesized with glucose oxidase (GOx) as template and induced by paclitaxel (PTX) to form self-assembling FeS-GOx@PTX (FGP) via hydrophobic interaction. After accumulated at tumor sites, FGP disassembles to smaller FeS-GOx for enhanced deep tumor penetration. GOx maintains high enzymatic activity to catalyze glucose with assistant of oxygen to generate hydrogen peroxide (H2O2) as starvation therapy. Fenton reaction involving the regenerated H2O2 in turn produced more hydroxyl radicals for enhanced CDT. Following near-infrared laser at 808 nm, FGPs displayed pronounced tumor inhibition in vitro and in vivo by the combination therapy. The consequent increased exposure to calreticulin amplified ICD and promoted dendritic cells maturation. In combination with anti-CTLA4 checkpoint blockade, FGP can absolutely eliminate primary tumor and avidly inhibit distant tumors due to the enhanced intratumoral infiltration of cytotoxic T lymphocytes. Our work presents a promising strategy for primary tumor and metastasis inhibition.
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  • 文章类型: Journal Article
    高度传染性严重急性呼吸道综合症冠状病毒2(SARS-CoV-2)的快速和敏感诊断是目前尚无有效治愈方法的全球大流行爆发的关键问题之一。这里,我们提出了一种SARS-CoV-2抗体缀合的基于磁性石墨烯量子点(GQDs)的磁弛豫开关(MRSw),该开关专门识别SARS-CoV-2。MRSw的探针可以直接与测试样品在完全密封的小瓶中混合,无需样品预处理,这大大降低了测试人员在手术过程中感染的风险。使用自制的超低场核磁共振(ULFNMR)弛豫仪以118μT的速度开发了检测SARS-CoV-2的闭管一步策略。基于GQDs的磁性探针由于其高的磁弛豫率,在SARS-CoV-2的检测中显示出超高灵敏度,检测限优化为248颗粒mL~1。同时,ULF核磁共振系统的检测时间仅为2分钟,可以显著提高检测效率。总之,基于磁性GQDs的MRSw与ULFNMR耦合可以实现快速、安全,和SARS-CoV-2的灵敏检测。
    The rapid and sensitive diagnosis of the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the crucial issues at the outbreak of the ongoing global pandemic that has no valid cure. Here, we propose a SARS-CoV-2 antibody conjugated magnetic graphene quantum dots (GQDs)-based magnetic relaxation switch (MRSw) that specifically recognizes the SARS-CoV-2. The probe of MRSw can be directly mixed with the test sample in a fully sealed vial without sample pretreatment, which largely reduces the testers\' risk of infection during the operation. The closed-tube one-step strategy to detect SARS-CoV-2 is developed with home-made ultra-low field nuclear magnetic resonance (ULF NMR) relaxometry working at 118 μT. The magnetic GQDs-based probe shows ultra-high sensitivity in the detection of SARS-CoV-2 due to its high magnetic relaxivity, and the limit of detection is optimized to 248 Particles mL‒1. Meanwhile, the detection time in ULF NMR system is only 2 min, which can significantly improve the efficiency of detection. In short, the magnetic GQDs-based MRSw coupled with ULF NMR can realize a rapid, safe, and sensitive detection of SARS-CoV-2.
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  • 文章类型: Journal Article
    纳米医学在新的研究工具和临床功能设备的开发方面取得了显着增长。在这方面,制药和骨科行业有望取得重大进展和新的商业应用。对于先进的骨科植入技术,适当的纳米级表面修饰是非常有效的策略,并且在文献中广泛研究用于改善植入物性能。众所周知,与没有纳米形貌的植入物相比,具有纳米管状表面的植入物在新骨生成和基因表达方面显示出极大的改善。然而,对混合氧化物纳米管(MONs)及其潜在应用的科学和临床理解,尤其是在生物医学领域的应用还处于早期发展阶段。这篇综述旨在为MONs在纳米医学中的当前和未来作用建立一个可靠的平台,特别是在先进的骨科植入物。我们首先介绍了MONS的概念,然后讨论了制备策略。接下来是对MONs在生物医学应用中的最新进展的回顾,包括矿化能力,生物相容性,抗菌活性,细胞培养,和动物试验,以及临床可能性。最后,我们提出,纳米管表面修饰与结合传感器的结合使临床医生能够精确记录患者数据,作为循证医学的关键贡献者.
    Nanomedicine has seen a significant rise in the development of new research tools and clinically functional devices. In this regard, significant advances and new commercial applications are expected in the pharmaceutical and orthopedic industries. For advanced orthopedic implant technologies, appropriate nanoscale surface modifications are highly effective strategies and are widely studied in the literature for improving implant performance. It is well-established that implants with nanotubular surfaces show a drastic improvement in new bone creation and gene expression compared to implants without nanotopography. Nevertheless, the scientific and clinical understanding of mixed oxide nanotubes (MONs) and their potential applications, especially in biomedical applications are still in the early stages of development. This review aims to establish a credible platform for the current and future roles of MONs in nanomedicine, particularly in advanced orthopedic implants. We first introduce the concept of MONs and then discuss the preparation strategies. This is followed by a review of the recent advancement of MONs in biomedical applications, including mineralization abilities, biocompatibility, antibacterial activity, cell culture, and animal testing, as well as clinical possibilities. To conclude, we propose that the combination of nanotubular surface modification with incorporating sensor allows clinicians to precisely record patient data as a critical contributor to evidence-based medicine.
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  • 文章类型: Journal Article
    金属有机框架(MOFs)的进展已经从基础化学发展到工程工艺和应用,带来新的产业机遇。MOFs的独特功能,比如它们的永久孔隙度,高表面积,和结构的灵活性,继续吸引传统MOF领域之外的工业兴趣,既要解决现有的挑战,又要创造新的业务。在这种情况下,多样化的研究一直致力于将MOF商业化,但是这样的研究是根据各种个人目标进行的。因此,分享挑战的机会有限,目标,以及大部分MOF领域的发现。在这次审查中,我们研究了MOF商业化的问题和要求,并调查了MOF工艺工程和应用的最新进展。具体来说,我们从稳定性的角度讨论了MOF商业化的标准,可生产性,法规,和生产成本。这篇综述涵盖了MOF的批量生产和形成方面的进展,以及目前尚不为人所知但在MOF商业化新领域具有很高潜力的未来应用。
    Progress in metal-organic frameworks (MOFs) has advanced from fundamental chemistry to engineering processes and applications, resulting in new industrial opportunities. The unique features of MOFs, such as their permanent porosity, high surface area, and structural flexibility, continue to draw industrial interest outside the traditional MOF field, both to solve existing challenges and to create new businesses. In this context, diverse research has been directed toward commercializing MOFs, but such studies have been performed according to a variety of individual goals. Therefore, there have been limited opportunities to share the challenges, goals, and findings with most of the MOF field. In this review, we examine the issues and demands for MOF commercialization and investigate recent advances in MOF process engineering and applications. Specifically, we discuss the criteria for MOF commercialization from the views of stability, producibility, regulations, and production cost. This review covers progress in the mass production and formation of MOFs along with future applications that are not currently well known but have high potential for new areas of MOF commercialization.
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  • 文章类型: Journal Article
    植入物周围的软组织密封充当牙槽骨和口腔环境之间的屏障,保护植入物免受细菌或外部刺激的侵袭。在这项工作中,通过等离子体浸没离子注入技术将镁(Mg)和锌(Zn)引入钛中,研究了它们对人牙龈成纤维细胞(HGFs)行为的影响以及潜在的机制。表面表征证实Mg和Zn以金属和氧化态存在于表面上。接触角测试表明,离子注入后钛的表面润湿性会发生变化,从而影响表面的蛋白质吸附。体外研究表明,镁离子注入样品上的HGF表现出更好的粘附和迁移,而锌离子注入样品上的细胞具有更高的增殖率和量。免疫荧光染色和实时逆转录聚合酶链反应(RT-PCR)的结果表明,Mg主要通过激活MAPK信号通路调节HGFs的运动和粘附,而Zn通过触发TGF-β信号通路影响HGFs的增殖。Mg和Zn离子的协同作用确保了在共植入样品上培养的HGFs具有高的增殖率和运动性。这对植入物的软组织密封至关重要。
    Soft tissue sealing around implants acts as a barrier between the alveolar bone and oral environment, protecting implants from the invasion of bacteria or external stimuli. In this work, magnesium (Mg) and zinc (Zn) are introduced into titanium by plasma immersed ion implantation technology, and their effects on the behaviors of human gingival fibroblasts (HGFs) as well as the underlying mechanisms are investigated. Surface characterization confirms Mg and Zn exist on the surface in metallic and oxidized states. Contact angle test suggests that surface wettability of titanium changes after ion implantation and thus influences protein adsorption of surfaces. In vitro studies disclose that HGFs on Mg ion-implanted samples exhibit better adhesion and migration while cells on Zn ion-implanted samples have higher proliferation rate and amounts. The results of immunofluorescence staining and real-time reverse-transcriptase polymerase chain reaction (RT-PCR) suggest that Mg mainly regulates the motility and adhesion of HGFs through activating the MAPK signal pathway whereas Zn influences HGFs proliferation by triggering the TGF-β signal pathway. The synergistic effect of Mg and Zn ions ensure that HGFs cultured on co-implanted samples possessed both high proliferation rate and motility, which are critical to soft tissue sealing of implants.
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  • 文章类型: Journal Article
    通过光沉积法用银纳米颗粒(NPs)修饰八面体锐钛矿颗粒(OAP)。OAP的性质影响银矿床的性质,以及由此获得的银改性OAP的光催化活性。在紫外线和可见光照射下测试了乙酸的氧化分解和2-丙醇的氧化的光催化活性,分别。通过XRD研究了银修饰OAP的性能,STEM,DRS,XPS和时间分辨微波电导率(TRMC)方法。发现电子陷阱(ET)是银的成核位点,导致在具有较大ET含量的较小OAP上形成较小的银NP。用银修饰在UV和可见光照射下都提高了光催化活性。发现较大微晶尺寸的银NP,因此,银沉积物的更大的多分散性导致广泛而强烈的等离子体共振峰,从而导致可见活性增强。光催化活性和TRMC数据之间的相关性,例如,对于更活跃的样本,TRMC信号衰减较慢,讨论了银改性二氧化钛的性能控制光催化活性。
    Octahedral anatase particles (OAPs) were modified with silver nanoparticles (NPs) by photodeposition method. The properties of OAPs influenced the properties of silver deposits, and thus the photocatalytic activity of the obtained silver-modified OAPs. Photocatalytic activities were tested under UV and vis irradiation for oxidative decomposition of acetic acid and oxidation of 2-propanol, respectively. The properties of silver-modified OAPs were investigated by XRD, STEM, DRS, XPS and time-resolved microwave conductivity (TRMC) method. It was found that electron traps (ETs) worked as nucleation sites for silver, resulting in formation of smaller silver NPs on smaller OAPs with larger content of ETs. The modification with silver resulted in enhanced photocatalytic activity under both UV and vis irradiation. It was found that larger crystallite size of silver NPs, and thus larger polydispersity of silver deposits resulted in broad and intense plasmon resonance peak causing enhanced visible activity. The correlation between photocatalytic activity and TRMC data, e.g., slower decay of TRMC signal for more active samples, allowed discussion on property-governed photocatalytic activities of silver-modified titania.
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