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