Publications by authors named "D G Ahn"

In this study, a novel phenomenon is identified where precise control of topology and generation of polyglycerol induce the retention of Na ions in biological buffer systems, effectively inhibiting ice crystal growth during cryopreservation. Unlike linear and hyperbranched counterparts, densely-packed hydroxyl and ether groups in 4th-generation dendritic polyglycerol interact with the ions, activating the formation of hydrogen bonding at the ice interface. By inhibiting both intra- and extracellular ice growth and recrystallization, this biocompatible dendritic polyglycerol proves highly effective as a cryoprotectant; hence, achieving the cell recovery rates of ≈134-147%, relative to those of 10% dimethyl sulfoxide, which is a conventional cryoprotectant for human tongue squamous carcinoma (HSC-3) cell line and human umbilical vein endothelial (HUVEC) cells.

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Storage of shell eggs converts natural ovalbumin (N-OVA) into its more thermostable forms (S-OVA). This conversion may be associated with deterioration in the foaming properties of the stored shell egg. Thus, the foaming behavior of N-OVA and S-OVA, especially their performance at different pH conditions, was conducted.

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Article Synopsis
  • - The study focuses on creating Sn-doped GeSe (SnGS2) films via atomic layer deposition (ALD) for arsenic-free Ovonic threshold switch (OTS) devices that have low off-current and a desirable threshold voltage.
  • - Undoped GeSe films display high performance and endurance but suffer from a large mobility gap; doping with Sn improves these properties by transforming pre-deposited SnN into SnSe through a special process involving NH and Se precursors.
  • - The resulting SnGS2 films, with about 9.6% Sn concentration, allow for the fabrication of both planar and vertical OTS devices, showing impressive switching performance with a low threshold voltage of around 3.5 V and enduring
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The application of extracellular vesicles (EVs) as vehicles for anti-Parkinson's agents represents a significant advance, yet their clinical translation is hampered by challenges in efficient brain delivery and complex blood-brain barrier (BBB) targeting strategies. In this study, we engineered dopamine onto the surface of adipose-derived stem cell EVs (Dopa-EVs) utilizing a facile, two-step cross-linking approach. This engineering enhanced neuronal uptake of the EVs in primary neurons and neuroblastoma cells, a process shown to be competitively inhibited by dopamine pretreatment and dopamine receptor antibodies.

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Excessive fluoride ions (F) in drinking water and food is harmful for human health and the environment. Therefore, a fluorescent probe tetraphenylethylene-quinoline (P-1) is developed with multiple sensing properties for the sequential detection of tert-butyldiphenylsilyl chloride (TBDS), F, and viscosity. Sensor P-1 first recognized TBDS and then observed an intramolecular charge transfer process, which produced an intermediate sensor P-2 in addition to fluorescence quenching at 576 nm.

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