Publications by authors named "Heesuk Kim"

Candida auris is a pathogen of growing public health concern worldwide. However, risk factors contributing to C. auris infection in patients colonized with C.

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Porous thermoelectric materials offer exciting prospects for improving the thermoelectric performance by significantly reducing the thermal conductivity. Nevertheless, porous structures are affected by issues, including restricted enhancements in performance attributed to decreased electronic conductivity and degraded mechanical strength. This study introduces an innovative strategy for overcoming these challenges using porous BiSbTe (BST) by combining porous structuring and interface engineering via atomic layer deposition (ALD).

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Background: Multidrug-resistant organism (MDRO) screening may identify high-risk patients for MDRO infection and curb the spread of these resistant pathogens. However, the heterogeneous practices in MDRO screening and the diversity of MDRO risk factors necessitate a tailored approach for successful implementation. This study aimed to evaluate the performance of tailored MDRO screening in predicting MDRO carriage compared to universal screening.

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Thermoelectric technology, which has been receiving attention as a sustainable energy source, has limited applications because of its relatively low conversion efficiency. To broaden their application scope, thermoelectric materials require a high dimensionless figure of merit (ZT). Porous structuring of a thermoelectric material is a promising approach to enhance ZT by reducing its thermal conductivity.

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As the turnaround time of diagnosis becomes important, there is an increasing demand for rapid, point-of-care testing (POCT) based on polymerase chain reaction (PCR), the most reliable diagnostic tool. Although optical components in real-time PCR (qPCR) have quickly become compact and economical, conventional PCR instruments still require bulky thermal systems, making it difficult to meet emerging needs. Photonic PCR, which utilizes photothermal nanomaterials as heating elements, is a promising platform for POCT as it reduces power consumption and process time.

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For next-generation wearable and implantable devices, energy storage devices should be soft and mechanically deformable and easily printable on any substrate or active devices. Herein, we introduce a fully stretchable lithium-ion battery system for free-form configurations in which all components, including electrodes, current collectors, separators, and encapsulants, are intrinsically stretchable and printable. The stretchable electrode acquires intrinsic stretchability and improved interfacial adhesion with the active materials a functionalized physically cross-linked organogel as a stretchable binder and separator.

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As power-conversion devices, flexible thermoelectrics that enable conformal contact with heat sources of arbitrary shape are attractive. However, the low performance of flexible thermoelectric materials, which does not exceed those of brittle inorganic counterparts, hampers their practical applications. Herein, we propose inorganic chalcogenide-nanostructured carbon nanotube (CNT) yarns with outstanding power factor at a low temperature using electrochemical deposition.

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As viruses have been threatening global public health, fast diagnosis has been critical to effective disease management and control. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is now widely used as the gold standard for detecting viruses. Although a multiplex assay is essential for identifying virus types and subtypes, the poor multiplicity of RT-qPCR makes it laborious and time-consuming.

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With the continuous development of flexible and wearable thermoelectric generators (TEGs), high-performance materials and their integration into convenient wearable devices have to be considered. Herein, we have demonstrated highly aligned wet-spun carbon nanotube (CNT) fibers by optimizing the liquid crystalline (LC) phase via hydrochloric acid purification. The liquid crystalline phase facilitates better alignment of CNTs during fiber extrusion, resulting in the high power factor of 2619 μW m K, which surpasses those of the dry-spun CNT yarns.

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Softening of thermoelectric generators facilitates conformal contact with arbitrary-shaped heat sources, which offers an opportunity to realize self-powered wearable applications. However, existing wearable thermoelectric devices inevitably exhibit reduced thermoelectric conversion efficiency due to the parasitic heat loss in high-thermal-impedance polymer substrates and poor thermal contact arising from rigid interconnects. Here, we propose compliant thermoelectric generators with intrinsically stretchable interconnects and soft heat conductors that achieve high thermoelectric performance and unprecedented conformability simultaneously.

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We report two organocompatible strategies to enhance the output performance of all-solution-processed poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thermoelectric generators (TEGs): introducing an additive spray printing process and functionalized polymer interlayers to reduce the module resistance. The spray printing enabled the deposition of 1-μm-thick PEDOT:PSS layers with a high degree of design freedom, resulting in a significantly reduced sheet resistance of 16 Ω sq that is closely related to the thermoelectric output performance. Also, by inserting an ultrathin silane-terminated polystyrene (PS) interlayer between the PEDOT:PSS thermoelectric layers and inkjet-printed Ag interconnects selectively, the contact resistivity extracted by the transmission line method was reduced from 6.

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As practical interest in stretchable electronics increases for future applications in wearables, healthcare, and robotics, the demand for electrical interconnects with high electrical conductivity, durability, printability, and adhesion is growing. Despite the high electrical conductivity and stretchability of most previous interconnects, they lack stable conductivity against strain and adhesion to stretchable substrates, leading to a limitation for their practical applications. Herein, we propose a stretchable conductive adhesive consisting of silver particles with carbon nanotube as an auxiliary filler in silicone adhesives.

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With the increase in practical interest in flexible thermoelectric (TE) generators, the demand for high-performance alternatives to brittle TE materials is growing. Herein, we have demonstrated wet-spun CNT fibers with high TE performance by systematically controlling the longitudinal carrier mobility without a significant change in the carrier concentration. The carrier mobility optimized by CNT alignment increases the electrical conductivity without decreasing the thermopower, thus improving the power factor.

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Objectives: To compare and evaluate the characteristics of hypertensive choroidopathy with serous retinal detachment in preeclampsia and malignant hypertension (HTN) and explore choroidal ischemia as a pathogenesis using multimodal imaging.

Methods: A retrospective multicenter case series. Medical charts were reviewed.

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Long-term operation of wearable pressure sensors to detect body movement requires self-powered human-based energy sources to minimize the need for recharging. Recently, pressure sensors with thermoelectric properties based on conducting polymers have been reported; however, these devices are limited in their ability to simultaneously achieve sufficient power generation and sensitivity of the sensor. In this article, we suggest a coaxial strut structure of poly(styrene-ethylene/butylene-styrene)(SEBS)-poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)-melamine foam (MF) with a fractured microstructure for a highly sensitive, efficient self-powered pressure sensor.

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Purpose: This study investigated visual acuity (VA) values and differences depending on optical coherence tomography (OCT) findings in patients with acute central retinal artery occlusion (CRAO).

Methods: A retrospective chart review was performed on patients with acute CRAO who underwent macular and disc OCT. We evaluated changes in macular thickness and retinal nerve fiber layer (RNFL) thickness after acute CRAO onset based on OCT.

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Purpose: This study aimed to investigate the diagnosis and severity of patients who were referred to tertiary medical centers according to the type and function of the referral hospitals.

Methods: First-visit patients referred from July 2015 to June 2016 were retrospectively reviewed with regard to referral hospital, final diagnosis, treatment necessity, and medical fees for the six months after their first hospital visit. Based on these data, differences in type and function of medical institution were examined.

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As practical interest in flexible/or wearable power-conversion devices increases, the demand for high-performance alternatives to thermoelectric (TE) generators based on brittle inorganic materials is growing. Herein, we propose a flexible and ultralight TE generator (TEG) based on carbon nanotube yarn (CNTY) with excellent TE performance. The as-prepared CNTY shows a superior electrical conductivity of 3147 S/cm due to increased longitudinal carrier mobility derived from a highly aligned structure.

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Organic thermoelectric materials based on conducting polymers have focused on increasing electrical conductivity and optimizing thermoelectric properties via dedoping processes. To control the crystallinity and crystal alignment for enhanced electrical conductivity, a confinement geometry in nanostructures with grapho-epitaxial growth of conducting polymers during in situ polymerization could be a promising approach. We obtained highly ordered lamellar, cylindrical and disordered nanostructures from PEO--PPO--PEO block copolymer (BCP) and iron(III) tosylate (Fe(Tos)) oxidant blended films and solvent evaporation-induced self-assembly (EISA) processes.

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The bioinspired design of ligands for nanoparticle coating with remarkable precision in controlling anisotropic connectivity and with universal binding efficiency to the membrane has made a great impact on nanoparticle self-assembly. We utilize the HIV-1-derived trans-activator of transcription peptide (TAT), a member of the cell-penetrating peptides, as a soft shell coating on gold nanoparticles (GNPs) and characterize TAT pepide-mediated binding behaviors of GNPs on the lipid membrane. Whereas the peptides enable GNPs to firmly attach to the membrane, the binding structures are driven by two electrostatic forces: the interparticle peptide repulsion and the peptide-membrane attraction.

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The preventive effect of a processed Aloe vera gel (PAG) on colon carcinogenesis was examined using an azoxymethane (AOM)-initiated and dextran sodium sulfate (DSS)-promoted mouse colon carcinogenesis model. Oral administration of PAG (200, or 400mg/kg/day) significantly reduced the multiplicity of colonic adenomas and adenocarcinomas compared with the AOM/DSS only-treated mice. In the mice treated with 400mg/kg of PAG, adenoma and adenocarcinoma development was reduced to 80% and 60%, respectively, compared to 100% in the PAG-untreated AOM/DSS-treated mice.

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Thick inorganic shells endow colloidal nanocrystals (NCs) with enhanced photochemical stability and suppression of photoluminescence intermittency (also known as blinking). However, the progress of using thick-shell heterostructure NCs in applications has been limited due to the low photoluminescence quantum yield (PL QY ≤ 60%) at room temperature. Here, we demonstrate thick-shell NCs with CdS/CdSe/CdS seed/spherical quantum well/shell (SQW) geometry that exhibit near-unity PL QY at room temperature and suppression of blinking.

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We investigated the cellular uptake efficiencies of differently-sized silica nanoparticles in the presence and the absence of trans-activator of transcription (TAT) peptide. Silica nanoparticles incorporating fluorescent dye molecules with diameters of 30 to 800 nm were synthesized, and the surfaces of the silica nanoparticles were functionalized with TAT peptides or 3-aminopropyltriethoxysilane (APTES). Confocal microscopy and flow cytometry were used to determine the cellular locations and the uptake efficiencies of positively-charged silica nanoparticles (APTES- and TAT-) of various sizes from 30 to 800 nm.

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