12 research outputs found

    Copper Ion Inks Capable of Screen Printing and Intense Pulsed-Light Sintering on PET Substrates

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    A copper ion ink capable of screen printing and intense pulsed-light (IPL) sintering on poly­(ethylene terephthalate) (PET) substrates was developed. Using copper nitrate trihydrate as a copper precursor, we prepared this ink with 2-butoxyethanol solvent and an ethyl cellulose additive to ensure excellent wettability with PET substrates and screen printability. After screen printing on PET substrates with this transparent ion ink, the printed ink patterns dry quickly at a low temperature of 100 °C, and an excellent electrical resistivity of 5 μΩ·cm was obtained by short IPL sintering of 20 ms. Because of the high boiling point of 2-butoxyethanol used as a solvent, this ink has a very low evaporation rate at room temperature, so it is suitable for screen printing without clogging of the screen mesh. With this ion ink, it was possible to screen-print copper patterns with a line width of 200 μm. We compared screen-printing properties using this copper ion ink with those of silver and copper nanoparticle inks. Nanoparticle inks showed significant spread in the printed patterns during the screen printing, whereas this copper ion ink showed the lowest spread to enable the formation of fine patterns. In addition, it was confirmed that this ion ink had the least damage to the PET substrate during the IPL sintering process compared to other nanoparticle inks. This ink also has a long storage stability over 4 weeks without precipitation or phase separation. The optimal ink composition and process conditions for securing such excellent copper pattern printing characteristics were suggested in this study

    Self-Assembled 4‑Aminopyridine Monolayer as a Nucleation-Inducing Layer for Transparent Silver Electrodes

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    The role of a self-assembled monolayer obtained by vacuum deposition of 4-aminopyridine (4-AP), a small organic molecule having amine and pyridine groups, as a metal nucleation inducer and adhesion promoter was verified, and the applicability was evaluated. 4-AP deposited to an extremely thin thickness effectively changed the substrate surface properties, increasing the nucleation density of silver (Ag) more than 3 times and eventually forming a more transparent, low-resistance Ag thin film. The optical transmittance of the Ag thin film, which was less than 60% when 4-AP was not applied, could be increased to about 77% by simply applying 4-AP, and the electrical resistance could be lowered from 37 to 14 Ω/square at the same time. Transmittance could be further improved to higher than 90% by depositing an antireflection layer for use as a transparent Ag electrode. It was also verified that 4-AP not only serves as a nucleation inducer but also contributes to improving interfacial adhesion. The Ag transparent electrode using 4-AP provided the improved performance of the organic light-emitting device due to higher transmittance, lower resistance, and surface roughness. Small organic molecules including functional groups that can be vacuum deposited, such as 4-AP, are expected to be used as surface pretreatment materials for various depositions because they can be easily patterned and can efficiently modify the surface even with extremely thin thickness

    Development of Novel VEGFR2 Inhibitors Originating from Natural Product Analogues with Antiangiogenic Impact

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    A novel natural small molecule, voacangine (Voa), has been discovered as a potent antiangiogenic compound. Notably, Voa directly binds the kinase domain of the vascular endothelial growth factor receptor 2 (VEGFR2) and thereby inhibits downstream signaling. Herein, we developed synthetic small molecules based on the unique chemical structure of Voa that directly and specifically target and modulate the kinase activity of VEGFR2. Among these Voa structure analogues, Voa analogue 19 (V19) exhibited increased antiangiogenic potency against VEGF-induced VEGFR2 phosphorylation without cytotoxic effects. Moreover, treatment with V19 resulted in significant tumor cell death in a mouse xenograft model. In conclusion, this new VEGFR2 modulator, inspired from the rigid scaffold of a natural compound, Voa, is presented as a potent candidate in the development of new antiangiogenic agents

    Development of Novel VEGFR2 Inhibitors Originating from Natural Product Analogues with Antiangiogenic Impact

    No full text
    A novel natural small molecule, voacangine (Voa), has been discovered as a potent antiangiogenic compound. Notably, Voa directly binds the kinase domain of the vascular endothelial growth factor receptor 2 (VEGFR2) and thereby inhibits downstream signaling. Herein, we developed synthetic small molecules based on the unique chemical structure of Voa that directly and specifically target and modulate the kinase activity of VEGFR2. Among these Voa structure analogues, Voa analogue 19 (V19) exhibited increased antiangiogenic potency against VEGF-induced VEGFR2 phosphorylation without cytotoxic effects. Moreover, treatment with V19 resulted in significant tumor cell death in a mouse xenograft model. In conclusion, this new VEGFR2 modulator, inspired from the rigid scaffold of a natural compound, Voa, is presented as a potent candidate in the development of new antiangiogenic agents

    Flexible and Mechanically Robust Organic Light-Emitting Diodes Based on Photopatternable Silver Nanowire Electrodes

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    We developed a simple methodology for fabricating silver nanowire (AgNW) micropatterns on a plastic substrate using a photocurable polymer. The patterning method began with the lamination of a UV-curable prepolymer film onto the AgNW-coated rigid glass substrate. Selective UV exposure of the UV-curable prepolymer film through a photomask solidified the exposed regions, and the unexposed regions were simply removed by the solvent. AgNW micropatterns of various sizes and shapes could be readily formed across the entire plastic substrate. Importantly, this photopatterning process enabled the embedding of the AgNW structures into the polymer matrix, which dramatically reduced the surface roughness and enhanced the mechanical stability of the AgNW film. The AgNW structures served as transparent anode electrodes in organic light-emitting diodes (OLEDs) that performed well compared to OLEDs fabricated using conventional indium tin oxide (ITO) or conducting polymer electrodes. This simple, inexpensive, and scalable AgNW patterning technique provides a novel approach to realizing next-generation flexible electronics

    Palliative Care Utilization in Patients Requiring Extracorporeal Membrane Oxygenation: An Observational Study

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    Palliative care (PC) is a model of care centered around improving the quality of life for individuals with life-limiting illnesses. Few studies have examined its impact in patients on extracorporeal membrane oxygenation (ECMO). We aimed to describe demographics, clinical characteristics, and complications associated with PC consultation in adult patients requiring ECMO support. We analyzed data from an ECMO registry, including patients aged 18 years and older who have received either venoarterial (VA)- or venovenous (VV)-ECMO support between July 2016 and September 2021. We used analysis of variance and Fisher exact tests to identify factors associated with PC consultation. Of 256, 177 patients (69.1%) received VA-ECMO support and 79 (30.9%) received VV-ECMO support. Overall, 115 patients (44.9%) received PC consultation while on ECMO. Patients receiving PC consultation were more likely to be non-white (47% vs. 53%, p = 0.016), have an attending physician from a medical versus surgical specialty (65.3% vs. 39.6%), have VV-ECMO (77.2% vs. 30.5%, p < 0.001), and have longer ECMO duration (6.2 vs. 23.0, p < 0.001). Patients were seen by the PC team on an average of 7.6 times (range, 1-35), with those who died having significantly more visits (11.2 vs. 5.6, p < 0.001) despite the shorter hospital stay. The average time from cannulation to the first PC visit was 5.3 ± 5 days. Congestive heart failure in VA-ECMO, coronavirus disease 2019 infection in VV-ECMO, and non-white race and longer ECMO duration for all patients were associated with PC consultation. We found that despite the benefits of PC, it is underused in this population

    NDUFA12 as a Functional Target of the Anticancer Compound Ertredin in Human Hepatoma Cells As Revealed by Label-Free Chemical Proteomics

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    Many attempts have been made to develop new agents that target EGFR mutants or regulate downstream factors in various cancers. Cell-based screening showed that a natural small molecule, Ertredin, inhibited the growth of EGFRvIII mutant cancer cells. Previous studies have shown that Ertredin effectively inhibits anchorage-independent 3D growth of sphere-forming cells transfected with EGFRvIII mutant cDNA. However, the underlying mechanism remains unclear. In this study, we investigated the target protein of Ertredin by combining drug affinity-responsive target stability (DARTS) assays with liquid chromatography–mass spectrometry using label-free Ertredin as a bait and HepG2 cell lysates as a proteome pool. NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 12 (NDUFA12) was identified as an Ertredin-binding protein that was responsible for its biological activity. The interaction between NDUFA12 and Ertredin was validated by DARTS and cellular thermal shift assays. In addition, the genetic knockdown of the identified target, NDUFA12, was shown to suppress cell proliferation. NDUFA12 was identified as a biologically relevant target protein of Ertredin that is responsible for its antitumor activity, and these results provide insights into the role of NDUFA12 as a downstream factor in EGFRvIII mutants

    Petal-Inspired Diffractive Grating on a Wavy Surface: Deterministic Fabrications and Applications to Colorizations and LED Devices

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    Interestingly, the petals of flowering plants display unique hierarchical structures, in which surface relief gratings (SRGs) are conformably coated on a curved surface with a large radius of curvature (hereafter referred to as wavy surface). However, systematic studies on the interplay between the diffractive modes and the wavy surface have not yet been reported, due to the absence of deterministic nanofabrication methods capable of generating combinatorially diverse SRGs on a wavy surface. Here, by taking advantage of the recently developed nanofabrication composed of evaporative assembly and photofluidic holography inscription, we were able to achieve (i) combinatorially diverse petal-inspired SRGs with controlled curvatures, periodicities, and dimensionalities, and (ii) systematic optical studies of the relevant diffraction modes. Furthermore, the unique diffraction modes of the petal-inspired SRGs were found to be useful for the enhancement of the outcoupling efficiency of an organic light emitting diode (OLED). Thus, our systematic analysis of the interplay between the diffractive modes and the petal-inspired SRGs provides a basis for making more informed decisions in the design of petal-inspired diffractive grating and its applications to optoelectronics
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