Publications by authors named "Dong H Son"

Background: The left pulmonary artery (LPA) may be kinked and stenotic, especially in tetralogy of Fallot, because of ductal tissue and anterior deviation of the conal septum. If LPA stenosis is not effectively treated during total correction, surgical angioplasty is occasionally performed. However, whether pulmonary artery (PA) angioplasty in adolescents or adults improves perfusion in the ipsilateral lung remains unclear.

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  • This study investigated the effectiveness of lymphadenectomy (removal of lymph nodes) in patients with early-stage epithelial ovarian cancer (EOC) to see if it improves survival rates compared to those who did not undergo the procedure.
  • The research included 586 patients and found no significant difference in survival rates between the lymphadenectomy group and the non-lymphadenectomy group, although those with serous histology did experience better disease-free survival with lymphadenectomy.
  • Despite some potential benefits, the lymphadenectomy group had longer surgery times and higher rates of complications, suggesting it should be considered carefully based on individual patient factors.
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Soft lattices of metal halide perovskite (MHP) nanocrystals (NCs) are considered responsible for many of their optical properties associated with excitons, which are often distinct from other semiconductor NCs. Earlier studies of MHP NCs upon compression revealed how structural changes and the resulting changes in the optical properties such as the bandgap can be induced at relatively low pressures. However, the pressure response of the exciton transition itself in MHP NCs remains relatively poorly understood due to limitations inherent to studying weakly or nonconfined NCs in which exciton absorption peaks are not well-separated from the continuum interband transition.

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We synthesized novel polyelectrolytes based on naphthalene diimide with quaternary amine featuring hydroxyl groups at the side chain, along with different counteranions (PF-NDIN-Br-OH and PF-NDIN-I-OH) for polymer solar cell (PSC) application as the interlayer. The polyelectrolytes establish a beneficial interface dipole through the ionic moieties and synergistic effects arising from the hydroxyl groups located at the side chain. Incorporating polyelectrolytes as the cathode interlayer resulted in an enhancement of the power conversion efficiency (PCE).

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A defect-passivated photosensor based on cesium lead bromide (CsPbBr) perovskite quantum dots (QD) was fabricated using parylene films, and the photosensor was applied for the microbial detection. The CsPbBr perovskite QDs were synthesized to be homogeneous in size under thermodynamic control, and the perovskite QD-based photosensor was fabricated using MoS flakes as the electron transfer layer. In this work, a parylene film with functional groups was deposited on a photosensor for physical protection (waterproof) and defect (halide vacancy) passivation of the perovskite QD.

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Wearable devices that can mechanically conform to human skin are a necessity for reliable monitoring and decoding of biomechanical activities through skin. Most inorganic piezoelectrics, however, lack deformability and damage tolerance, impeding stable motion monitoring. Here, we present an air-permeable fabric-based ZnO nanogenerator with mechanical adaptivity to diverse deformations for wearable piezoelectric sensors, collecting biomechanical health data.

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In this work, we investigated the effect of hole transporting poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) interfacing with Mn-doped CdS/ZnS quantum dots (QDs) deposited on an indium tin oxide (ITO) substrate on the photoemission of upconverted hot electrons under weak continuous wave photoexcitation in a vacuum. Among the various factors that can influence the photoemission of the upconverted hot electrons, we studied the role of PEDOT:PSS in facilitating the hole transfer from QDs and altering the energy of photoemitted hot electrons. Compared to hot electrons emitted from QDs deposited directly on the ITO substrate, the addition of the PEDOT:PSS layer between the QD and ITO layers increased the energy of the photoemitted hot electrons.

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  • Semiconductor nanocrystals (NCs) like cesium lead halide (CsPbX) are effective in generating stable radicals, but face challenges with charge recombination, especially during photoinduced chemical reactions.
  • The study demonstrates that varying the solvent composition allows CsPbX NCs to selectively generate either aminium or aminyl radicals from amines, with dihalomethane facilitating the formation of aminium radicals through a unique photoinduced process.
  • Without dihalomethane, a different mechanism involving charge transfer leads to the production of aminyl radicals, highlighting how the negative charge of halide ions promotes this process and competes with charge recombination.
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A series of medium bandgap polymer donors, named poly(1-(5-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo [1,2-:4,5-']dithiophen-2-yl)thiophen-2-yl)-5-((4,5-dihexylthiophen-2-yl)methylene)-3-(thiophen-2-yl)-4-cyclopenta[c]thiophene-4,6(5)-dione) (IND-T-BDTF), poly(1-(5-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo [1,2-:4,5-']dithiophen-2-yl)-4-hexylthiophen-2-yl)-5-((4,5-dihexylthiophen-2-yl)methylene)-3-(4-hexylthiophen-2-yl)-4-cyclopenta[]thiophene-4,6(5)-dione (IND-HT-BDTF), and poly(1-(5-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo [1,2-:4,5-']dithiophen-2-yl)-6-octylthieno [3,2-]thiophen-2-yl)-5-((4,5-dihexylthiophen-2-yl)methylene)-3-(6-octylthieno [3,2-]thiophen-2-yl)-4-cyclopenta[]thiophene-4,6(5)-dione (IND-OTT-BDTF), are developed for non-fullerene acceptors (NFAs) polymer solar cells (PSCs). Three polymers consist of donor-acceptor building block, where the electron-donating fluorinated benzodithiophene (BDTF) unit is linked to the electron-accepting 4-cyclopenta[]thiophene-4,6(5)-dione (IND) derivative via thiophene (T) or thieno [3,2-]thiopene (TT) bridges. The absorption range of the polymer donors based on IND in this study shows 400~800 nm, which complimenting the absorption of Y6BO (600~1000 nm).

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Nanostructures─coupled with mass spectrometry─have been intensively investigated to improve the detection sensitivity and reproducibility of small biomolecules in laser desorption/ionization mass spectrometry (LDI-MS). However, the impact of laser-induced shock wave on the ionization of the nanostructures has rarely been reported. Herein, we systematically elucidate the laser shock wave effect on the ionization in terms of the development of atomic defects and piezoelectricity in two-dimensional graphitic carbon nitride nanosheets (g-CN NS) by short laser pulses.

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A 32-year-old woman diagnosed with Turner syndrome presented to the hospital for an evaluation of cardiovascular complications. Preoperative computed tomography (CT) and echocardiography showed progression of aortic root and ascending aorta dilatation, as well as a bicuspid aortic valve. There was no evidence of aortic regurgitation.

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Purpose: To evaluate the correlation between the two methods of measuring the choroidal thickness around the optic nerve head (ONH).

Methods: We conducted a cross-sectional study. Sixty-two eyes of 62 healthy subjects were included.

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Hot electrons play a crucial role in enhancing the efficiency of photon-to-current conversion or photocatalytic reactions. In semiconductor nanocrystals, energetic hot electrons capable of photoemission can be generated via the upconversion process involving the dopant-originated intermediate state, currently known only in Mn-doped cadmium chalcogenide quantum dots. Here, we report that Mn-doped CsPbBr nanocrystals are an excellent platform for generating hot electrons via upconversion that can benefit from various desirable exciton properties and the structural diversity of metal halide perovskites (MHPs).

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One-step homogeneous immunoassay was developed for detecting influenza viruses A and B (Inf-A and Inf-B) using the switching peptide H2. As the fluorescence-labeled switching peptide dissociated from the binding pocket of detection antibodies, the fluorescence signal could be directly generated by the binding of Inf-A and Inf-B without washing (i.e.

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Circularly polarized optical excitation of plasmonic nanostructures causes coherent circulating motion of their electrons, which in turn gives rise to strong optically induced magnetization, a phenomenon known as the inverse Faraday effect (IFE). In this study we report how the IFE also significantly decreases plasmon damping. By modulating the optical polarization state incident on achiral plasmonic nanostructures from linear to circular, we observe reversible increases of reflectance by up to 8% and simultaneous increases of optical field concentration by 35.

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Purpose: The purpose of this study was to investigate whether the lamina cribrosa (LC) curve changes in response to intraocular pressure (IOP) reduction following administration of topical ocular hypotensive eye drops in eyes with normal tension glaucoma (NTG).

Methods: Ninety-three eyes of 93 patients with treatment naïve NTG at initial examination and with ≥20% reduction from baseline IOP following administration of topical ocular hypotensive eye drops were included. Serial horizontal B-scan images of the optic nerve head (ONH) were obtained from each eye using enhanced depth imaging spectral domain optical coherence tomography (OCT) before and 1 year after IOP-lowering treatment.

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We investigated the magnetic effect of Mn ions on an exciton of Mn-doped CsPbI quantum dots (QDs), where we looked for the signatures of an exciton magnetic polaron known to produce a large effective magnetic field in Mn-doped CdSe QDs. In contrast to Mn-doped CdSe QDs that can produce ∼100 T of magnetic field upon photoexcitation, manifested as a large change in the energy and relaxation dynamics of a bright exciton, Mn-doped CsPbI QDs exhibited little influence of a magnetic dopant on the behavior of a bright exciton. However, a μs-lived dark exciton in CsPbI QDs showed 40% faster decay in the presence of Mn, equivalent to the effect of ∼3 T of an external magnetic field.

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Energetic hot electrons generated in Mn-doped quantum dots (QDs) via exciton-to-hot-electron upconversion possess long-range transfer capability. The long-range hot electron transfer allowed for superior efficiency in various photocatalytic reduction reactions compared to conventional QDs, which solely rely on the transfer of band edge electrons. Here we show that the synergistic action of the interfacial hole transfer to the initial reactant and subsequent long-range hot electron transfer to an intermediate species enables highly efficient photocatalytic reactions, thereby extending the benefits of Mn-doped QDs beyond reduction reactions.

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Chemiluminescence immunoassays have been widely employed for diagnosing various diseases. However, because of the extremely low intensity chemiluminescence signals, highly sensitive transducers, such as photomultiplier tubes and image sensors with cooling devices, are required to overcome this drawback. In this study, a hypersensitive photosensor was developed based on cesium lead bromide (CsPbBr) perovskite quantum dots (QDs) with sufficient high sensitivity for chemiluminescence immunoassays.

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Metal-halide perovskites have rapidly emerged as one of the most promising materials of the 21st century, with many exciting properties and great potential for a broad range of applications, from photovoltaics to optoelectronics and photocatalysis. The ease with which metal-halide perovskites can be synthesized in the form of brightly luminescent colloidal nanocrystals, as well as their tunable and intriguing optical and electronic properties, has attracted researchers from different disciplines of science and technology. In the last few years, there has been a significant progress in the shape-controlled synthesis of perovskite nanocrystals and understanding of their properties and applications.

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Purpose: To compare the characteristics of the peripapillary choroid (PPC) between the 2 eyes of patients with unilateral treatment-naïve normal-tension glaucoma (NTG).

Design: Observational case series.

Participants: Sixty-nine patients (138 eyes) with treatment-naïve unilateral NTG.

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ConspectusSemiconducting metal halide perovskite (MHP) nanocrystals have emerged as an important new class of materials as the source of photons and charges for various applications that can outperform many other semiconductor nanocrystals utilized for the same purposes. However, the majority of the studies of MHP nanocrystals focused on weakly or nonconfined systems, where the quantum confinement giving rise to various size-dependent and confinement-enhanced photophysical properties cannot be explored readily. This was partially due to the challenge in producing strongly quantum-confined MHP nanocrystals, since the traditional kinetic control approach was less effective for the size control.

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The fine structure of the band edge exciton and the dark exciton photoluminescence (PL) are topics of significant interest in the research of semiconducting metal halide perovskite nanocrystals, with several conflicting reports on the level ordering of the bright and dark states and the accessibility of the emitting dark states. Recently, we observed the intense dark exciton PL in strongly confined CsPbBr nanocrystals at cryogenic temperatures, in contrast to weakly confined nanocrystals lacking dark exciton PL, which was explained by the confinement enhanced bright-dark exciton splitting. In this work, we investigated the size-dependence of the dark exciton photoluminescence properties in CsPbBr and CsPbI quantum dots in the strongly confined regime, showing the clear role of confinement in determining the bright-dark energy splitting (ΔE) and the dark exciton lifetime (τ).

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Dark exciton as the lowest-energy (ground) exciton state in metal halide perovskite nanocrystals is a subject of much interest. This is because the superior performance of perovskites as the photon source combined with long lifetime of dark exciton can be attractive for many applications of exciton. However, the direct observation of the intense and long-lived dark exciton emission, indicating facile access to dark ground exciton state, has remained elusive.

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