IrOx

IROX
  • 文章类型: Journal Article
    铂(Pt)已被广泛用作析氢反应(HER)的阴极电催化剂,但不幸的是,由于与水分解电解槽中的氧物种的结合过强,因此被忽略为析氧反应(OER)的阳极电催化剂。在这里,我们报告说,通过掺杂铱(Ir)对富PtPtPbCu纳米线(NWs)的电子结构和局部配位环境的精细控制降低了OER的过电势,同时抑制了水电解过程中IrPtPbCuNWs中Pt的过氧化。鉴于一维形态具有原子分散的IrOx物种和电子调制的Pt位点,IrPtPbCuNW在酸性介质中表现出增强的OER(在10mAcm-2时为175mV)和HER(在10mAcm-2时为25mV)电催化性能,并产生高周转频率。对于过电位为250mV的OER,IrPtPbCuNWs的质量活性比Ir/C增强了1.51Amg-1PtIr(约高19倍)。对于她在50mV的过电位,NWs表现出显著的质量活性为1.35mg-1Pt+Ir,相对于Pt/C是2.6倍。实验结果和理论计算证实,在NWs中掺杂Ir具有抑制Ptx>4衍生物的形成并改善水电解过程中反应中间体的吸附自由能的能力。这种方法能够实现以前未观察到的阳极电催化剂机理。
    Platinum (Pt) has been widely used as cathodic electrocatalysts for the hydrogen evolution reaction (HER) but unfortunately neglected as an anodic electrocatalyst for the oxygen evolution reaction (OER) due to excessively strong bonding with oxygen species in water splitting electrolyzers. Herein we report that fine control over the electronic-structure and local-coordination environment of Pt-rich PtPbCu nanowires (NWs) by doping of iridium (Ir) lowers the overpotential of the OER and simultaneously suppresses the overoxidation of Pt in IrPtPbCu NWs during water electrolysis. In light of the one-dimensional morphology featured with atomically dispersed IrOx species and electronically modulated Pt-sites, the IrPtPbCu NWs exhibit an enhanced OER (175 mV at 10 mA cm-2) and HER (25 mV at 10 mA cm-2) electrocatalytic performance in acidic media and yield a high turnover frequency. For OER at the overpotential of 250 mV, the IrPtPbCu NWs show an enhanced mass activity of 1.51 A mg-1Pt+Ir (about 19 times higher) than Ir/C. For HER at the overpotential of 50 mV, NWs exhibit a remarkable mass activity of 1.35 A mg-1Pt+Ir, which is 2.6-fold relative to Pt/C. Experimental results and theoretical calculations corroborate that the doping of Ir in NWs has the capacity to suppress the formation of Ptx>4 derivates and ameliorate the adsorption free energy of reaction intermediates during the water electrolysis. This approach enabled the realization of a previously unobserved mechanism for anodic electrocatalysts.
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  • 文章类型: Journal Article
    未经批准:转移胰腺癌(mPC)的二线治疗方案有限。我们旨在探讨奥沙利铂联合伊立替康(IROX)在mPC患者中的疗效和安全性。
    UNASSIGNED:这是一个开放标签,2期,使用吉西他滨联合S-1作为一线治疗失败的mPC患者(年龄18-75岁)的随机研究。在2015年10月至2017年12月之间,使用区组大小为4的区组随机分组(1:1)患者接受IROX(奥沙利铂85mg/m2和伊立替康160mg/m2)或伊立替康单一疗法(伊立替康180mg/m2),直至疾病进展。不可接受的不良事件,或同意撤回。主要终点是总生存期,次要终点是无进展生存期,总反应率,和不良事件发生率。
    未经证实:本研究共纳入74名患者,包括44名男性和30名女性,平均年龄61岁。中位总生存期为10.2和6.7个月(调整后的风险比[HR],0.7;95%置信区间[CI],0.4-1.2;P=0.20),中位无进展生存期为5.1和2.3个月(校正后的HR,0.4;95%CI,0.2-0.6;P<0.01)在IROX组和伊立替康组中,分别。IROX组的总有效率为18.4%(7/38),伊立替康组为5.5%(2/36)(P=0.06)。IROX组34%(13/38)的患者和伊立替康组19%(7/36)的患者发生3-4级不良事件(P=0.15)。
    未经证实:在我们的研究中,IROX与伊立替康单药治疗相比没有显著的生存获益。然而,IROX将疾病进展的风险降低了60%,具有可接受的毒性。
    UNASSIGNED: Limited second-line therapeutic options are available for metastasis pancreatic cancer (mPC). We aimed to explore the efficacy and safety of oxaliplatin plus irinotecan (IROX) in mPC patients.
    UNASSIGNED: This is an open-label, Phase 2, randomized study of mPC patients (aged 18-75 years) who failed when using gemcitabine plus S-1 as first-line therapy. Block randomization with a block size of four was used to randomly assign patients (1:1) between October 2015 and December 2017 to receive either IROX (oxaliplatin 85 mg/m2 and irinotecan 160 mg/m2) or irinotecan monotherapy (irinotecan 180 mg/m2) until disease progression, unacceptable adverse events, or consent withdrawal. The primary end point was overall survival, and the secondary end points were progression-free survival, overall response rate, and adverse event rate.
    UNASSIGNED: A total of 74 patients were enrolled in this study, including 44 males and 30 females, with an average age of 61 years. The median overall survival was 10.2 and 6.7 months (adjusted hazard ratio [HR], 0.7; 95% confidence interval [CI], 0.4-1.2; P = 0.20) and the median progression-free survival was 5.1 and 2.3 months (adjusted HR, 0.4; 95% CI, 0.2-0.6; P < 0.01) in the IROX group and irinotecan group, respectively. The overall response rates were 18.4% (7/38) in the IROX group and 5.5% (2/36) in the irinotecan group (P = 0.06). Grade 3-4 adverse events occurred in 34% (13/38) of patients in the IROX group and 19% (7/36) of patients in the irinotecan group (P = 0.15).
    UNASSIGNED: IROX had no significant survival benefit over irinotecan monotherapy in our study. However, IROX reduced the risk of disease progression by 60%, with acceptable toxicity.
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  • 文章类型: Journal Article
    抗生素治疗引起的细菌耐药性是一个严重的问题。因此,迫切需要找到克服细菌耐药性的替代方法。在这里,我们合成了一种新型的氧化铱(IrOx)作为抗生素的替代品。氧化铱不仅具有良好的催化性能,而且还具有光热特性,然后实现“一体两翼”策略以增强抗菌效果。研究结果表明,近红外光可以增强IrOx的过氧化物酶催化活性,并通过催化过氧化氢(H2O2)产生高毒性的羟基自由基(·OH)。羟基自由基具有高氧化还原电位,能克服革兰阳性菌和阴性菌的耐药性。重要的是,IrOx无明显的细胞和体内毒性。因此,新型光热纳米酶有望应用于细菌感染性疾病,比如伤口愈合,脓毒症,和植入物相关的感染。
    Bacterial resistance caused by antibiotic therapy is a serious problem. Therefore, there is an urgent need to find alternative methods to overcome bacterial resistance. Herein, we synthesized a new type of iridium oxide (IrOx) as an alternative to antibiotics. Iridium oxide not only has good catalytic properties, but also has photothermal properties, and then realizes the \"one body and two wings\" strategy to enhance the antibacterial effect. Research results show that near-infrared light can enhance the peroxidase catalytic activity of IrOx and generate highly toxic hydroxyl radicals (·OH) by catalyzing hydrogen peroxide (H2O2). Hydroxyl radicals have a high redox potential, which can overcome the drug resistance of gram-positive and negative bacteria. Importantly, IrOx has no obvious cellular and in vivo toxicity. Accordingly, the novel photothermal nanozyme is expected to be applied to bacterial infectious diseases, such as wound healing, sepsis, and implant-related infections.
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  • 文章类型: Journal Article
    Multi-field coupling, especially photo-assisted electrocatalysis, has recently been studied to further improve the oxygen evolution reaction (OER). In this study, an n-type cubic In2 O3 semiconductor is employed for the first time to load IrOx species (Ir-In2 O3 mass ratio: 17.6 %). Consequently, the IrOx @In2 O3 heterojunction, which exhibits outstanding OER performance promoted by weak-light irradiation, is formed. Notably, IrOx (approximately 1.7 nm in size) and In2 O3 are observed to crystallize independently during heterogeneous nucleation with no Ir atoms doped in the In2 O3 lattice. This avoids Ir loss and ensures the full exposure of all Ir-based sites. The IrOx @In2 O3 heterojunction exhibits enhanced electrocatalytic water oxidation with overpotential values of 190 and 231 mV at current densities of 10 and 50 mA cm-2 , surpassing all IrOx -based catalyst results reported to date. Nano-sized IrOx on the surface, irradiated by the weak-light beam of LED-365 (1.8 mW cm-2 ), can be fully activated as an OER site. Moreover, the overpotential is further reduced to 176 and 210 mV to deliver the corresponding current. This work is anticipated to aid in the design of more efficient multi-field coupling OER systems.
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  • 文章类型: Journal Article
    可穿戴技术的快速发展正在大力推动纺织化学传感器设计,旨在实时收集重要参数以改善医疗保健。在最有前途的应用中,不愈合伤口的监测是一个很少探索的医学领域,仍然缺乏定量工具来管理愈合过程。在这项工作中,开发了一种智能绷带,用于实时监测伤口的pH值,据报道,这与愈合阶段相关,因此,有可能在不干扰伤口床的情况下直接获得伤口状态。全纺织设备通过集成传感层来实现,包括由半导体聚合物和氧化铱颗粒制成的两端pH传感器,和吸收层,所述吸收层确保跨所述传感器区域递送连续的伤口渗出物流。两端传感器表现出可逆响应,在医学相关的pH范围内(pH6-9),灵敏度为(59±4)μApH-1,用于伤口监测,其性能基本上不受最常见的化学干扰物的存在或22至40°C的温度梯度的影响。由于基于电位转换的强大传感机制和简单的设备几何形状,完全组装的智能绷带在使用合成伤口渗出物的流动分析中成功验证.
    The rapid evolution of wearable technologies is giving rise to a strong push for textile chemical sensors design targeting the real-time collection of vital parameters for improved healthcare. Among the most promising applications, monitoring of nonhealing wounds is a scarcely explored medical field that still lacks quantitative tools for the management of the healing process. In this work, a smart bandage is developed for the real-time monitoring of wound pH, which has been reported to correlate with the healing stages, thus potentially giving direct access to the wound status without disturbing the wound bed. The fully textile device is realized by integrating a sensing layer, including the two-terminal pH sensor made of a semiconducting polymer and iridium oxide particles, and an absorbent layer ensuring the delivery of a continuous wound exudate flow across the sensor area. The two-terminal sensor exhibits a reversible response with a sensitivity of (59 ± 4) μA pH-1 in the medically relevant pH range for wound monitoring (pH 6-9), and its performance is not substantially affected either by the presence of the most common chemical interferents or by temperature gradients from 22 to 40 °C. Thanks to the robust sensing mechanism based on potentiometric transduction and the simple device geometry, the fully assembled smart bandage was successfully validated in flow analysis using synthetic wound exudate.
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  • 文章类型: Journal Article
    Today, electrochemical sensors are used for a broad range of applications. A fundamental challenge is still the achievement of long-term sensor stability by ensuring good adhesion between the deposited sensing layer and the substrate material, e.g., a metal electrode. Until now, the most applied strategy to overcome this problem is to increase the surface roughness of the metal layer by mechanical etching or by electroplating of additional material layers, which both imply an increase in manufacturing steps and thus the final cost of the overall device. Alternatively, to overcome these adhesion problems, we propose the direct printing of a novel platinum nanoparticle ink, which is compatible with low-cost additive digital inkjet and with flexible low-cost substrates. This water-based platinum ink has two unique features: it leads to highly rough surfaces, which promotes the adhesion of deposited sensing material, and it is a highly low-temperature curing ink, compatible with polymeric substrates that cannot withstand high temperatures. Based on this concept, we report about a long-term stable and highly sensitive solid-state pH sensor functionalized by anodic electrodeposited iridium oxide on a rough nanostructured platinum printed layer. The sensors showed an excellent reproducibility with a linear super-Nernstian response (71.3 ± 0.3 mV/pH unit) in a wide pH range (pH 2-11). Long-term stability tests for over 1 year of application demonstrate an excellent mechanical sensor layer stability, which is correlated to the distinct roughness of the printed platinum layer. This novel approach is useful to simplify the fabrication process and with that the sensor costs.
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  • 文章类型: Journal Article
    Lactate detection by an in situ sensor is of great need in clinical medicine, food processing, and athletic performance monitoring. In this paper, a flexible, easy to fabricate, and low-cost biosensor base on lactate oxidase is presented. The fabrication processes, including metal deposition, sol-gel IrOx deposition, and drop-dry enzyme loading method, are described in detail. The loaded enzyme was examined by scanning electron microscopy. Cyclic voltammetry was used to characterize the sensors. Durability, sensibility, and selectivity of the biosensors were examined. The comparison for different electrode sizes and different sensing film materials was conducted. The sensor could last for four weeks with an average surface area normalized sensitivity of 950 nA/(cm² mM) and 9250 nA/(cm² mM) for Au-based electrodes, and IrOx-modified electrodes respectively, both with an electrode size of 100 × 50 μm. The self-referencing method to record noises simultaneously with the working electrode greatly improved sensor sensitivity and selectivity. The sensor showed little response to interference chemicals, such as glutamate and dopamine.
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  • 文章类型: Journal Article
    A sensitive, label-free immunosensor based on iridium oxide (IrOx, 0≤x≤2) nanofibers, which were synthesized through a simple one-spinneret electrospinning method, was first developed for immunoassay of the cancer biomarker α-fetoprotein (AFP). The specific wire-in-tube nanostructure could be obtained and the composition of IrOx nanofibers also could be controlled through changing the annealing temperature. The unique structure and properties of IrOx nanofibers obtained at 500 °C not only led to increased electrode surface area and accelerated electron transfer kinetics but also could provide a highly stable matrix for the convenient conjugation of biomolecules together with chitosan (CS). The good electrochemical properties of the IrOx-nanofiber-modified immunosensor allowed one to detect AFP over a wide concentration range from 0.05 to 150 ng/mL, with a detection limit of 20 pg/mL. The proposed immunosensor also has been used to determine AFP in human serum with satisfactory results. The present protocol was shown to be quite promising for clinical screening of cancer biomarkers and point-of-care diagnostics applications.
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