• 전기화학회지
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• 제10권2호
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• pp.88-93
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• 2007

Nano-sized Sn particles were coated with Ni-P layer using an electroless deposition method and their anodic performance was tested for lithium secondary batteries. Uniform coating layers were obtained, of which the thickness was controlled by varying the $Ni^{2+}$ concentration in the plating bath. It was found that the Ni-P layer plays two important roles in improving the anodic performance of Sn powder electrode. First, it prevents the inter-particle aggregation between Sn particles during the charge/discharge process. Second, it provides an electrical conduction pathway to the Sn particles, which allows an electrode fabrication without an addition of conductive carbon. A pseudo-optimized sample showed a good cyclability and high capacity ($>400mAh\;g^{-1}$) even without conductive carbon loading.

• Journal of Applied Biological Chemistry
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• 제65권4호
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• pp.463-469
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• 2022

Cudrania tricuspidata (C. tricuspidata), a medicinal plant widely employed throughout Asia in ethnomedicine, has various bioactive properties, including antidiabetic, antiobesity, antitumor, and anti-inflammatory activities. In addition, the C. tricuspidata root extract reportedly inhibits platelet aggregation. Therefore, we focused on the active substances present in the C. tricuspidata extract. Sanggenon N (SN) is a flavonoid found in the root bark of C. tricuspidata. In the present study, we examined the inhibitory effects of SN on platelet aggregation, phosphoproteins, thromboxane A₂ generation, and integrin αIIbβ3 activity. SN inhibited collagen-induced human platelet aggregation in a dose-dependent manner without cytotoxicity. Furthermore, SN suppressed Ca²⁺ mobilization and influx through associated signaling molecules, such as inositol 1, 4, 5-triphosphate receptor I (Ser¹⁷⁵⁶), and extracellular signal-regulated kinase. In addition, SN inhibited thromboxane A₂ generation and associated signaling molecules, including cytosolic phospholipase A₂ and mitogen-activated protein kinase p38. Finally, SN could inhibit integrin (αIIb/β₃) activity by regulating vasodilator-stimulated phosphoprotein and Akt. Collectively, SN possesses potent antiplatelet effects and is a potential therapeutic drug candidate to prevent platelet-related thrombosis and cardiovascular disease.

• 청정기술
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• 제30권3호
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• pp.258-266
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• 2024

Rechargeable Li-SnO₂ batteries suffer from issues such as poor electronic/ionic conductivity and huge volume changes. In order to overcome these inherent limitations, this study designed a cell with a unique hierarchical structure, denoted as SnO₂@PCNF. The SnO₂@PCNF cell design incorporates in-situ generated SnO₂ nanoparticles strategically positioned within N-doped porous carbon nanofibers (PCNF). The in-situ generated SnO₂ nanoparticles can alleviate strains during cycling and shorten the pathway for the ions and electrons, improving the utilization of active materials. Moreover, the N-doped PCNF establishes a continuously conductive network to further increase the electrical conductivity and also buffers the significant volume changes that occur during charging and discharging. The resulting SnO₂@PCNF cell exhibits outstanding electrochemical performance and stable cycling characteristics. Notably, a reversible capacity of 520 mAh g^-1 was achieved after 100 cycles at 70 mA g^-1. Even under a higher current density of 1 A g^-1, the cell maintained a capacity retention of 393 mAh g^-1 after 1,000 cycles. These results highlight the SnO₂@PCNF cell's exceptional cycling stability and superior rate capability.

• Advances in nano research
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• 제5권3호
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• pp.203-214
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• 2017

In this study we present the reaction mechanism of $Cu_2ZnSnSe_4$ (CZTSe) nanoparticles synthesized by microwave-assisted chemical synthesis. We performed reactions every 10 minutes in order to identify different phases during quaternary CZTSe formation. The powder samples were analyzed by x-ray diffraction (XRD), Raman spectroscopy, energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results showed that in the first minutes copper phases are predominant, then copper and tin secondary phases react to form ternary phase. The quaternary phase is formed at 50 minutes while ternary and secondary phases are consumed. At 60 minutes pure quaternary CZTSe phase is present. After 60 minutes the quaternary phase decomposes in the previous ternary and secondary phases, which indicates that 60 minutes is ideal reaction time. The EDS analysis of pure quaternary nanocrystals (CZTSe) showed stoichiometric relations similar to the reported research in the literature, which falls in the range of Cu/(Zn+Sn): 0.8-1.0, Zn/Sn: 1.0-1.20. In conclusion, the evolution pathway of CZTSe synthesized by this novel method is similar to other synthesis methods reported before. Nanoparticles synthesized in this study present desirable properties in order to use them in solar cell and photoelectrochemical cell applications.

• Bulletin of the Korean Chemical Society
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• 제29권10호
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• pp.1927-1931
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• 2008

Rate of solvolysis of diphenylthiophosphinyl chloride in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone, 2,2,2-trifluoroethanol (TFE) or 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) are reported. Solvolyses were also carried out in TFE-ethanol mixtures. For five representative solvents, studies were made at several temperatures and activation parameters determined. The 29 solvents gave a reasonably precise extended Grunwald-Winstein equation plot, correlation coefficient (R) of 0.933, which improved to 0.983 when the four TFE-ethanol points were excluded. The sensitivities (l = 1.00 and m = 0.64) were similar to those obtained for dimethyl phosphorochloridate and phosphorochloridothionate and diphenylphosphinyl chloride (1). As with the four previously studied solvolyses, an $SN_2$ pathway is proposed for the solvolyses of diphenylthiophosphinyl chloride. The activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$, were determined and they are also in line with values expected for an $S_N2$ reaction.

• Molecules and Cells
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• 제42권9호
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• pp.646-660
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• 2019

Abscisic acid (ABA) is a phytohormone essential for seed development and seedling growth under unfavorable environmental conditions. The signaling pathway leading to ABA response has been established, but relatively little is known about the functional regulation of the constituent signaling components. Here, we present several lines of evidence that Arabidopsis Raf-like kinase Raf10 modulates the core ABA signaling downstream of signal perception step. In particular, Raf10 phosphorylates subclass III SnRK2s (SnRK2.2, SnRK2.3, and SnRK2.6), which are key positive regulators, and our study focused on SnRK2.3 indicates that Raf10 enhances its kinase activity and may facilitate its release from negative regulators. Raf10 also phosphorylates transcription factors (ABI5, ABF2, and ABI3) critical for ABA-regulted gene expression. Furthermore, Raf10 was found to be essential for the in vivo functions of SnRK2s and ABI5. Collectively, our data demonstrate that Raf10 is a novel regulatory component of core ABA signaling.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.499-504
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• 2012

The specific rates of sovolysis of 4-methylthiophene-2-carbonyl chloride (1) have been determined in 26 pure and binary solvents at $25.0^{\circ}C$. Product selectivities are reported for solvolyses of 1 in aqueous ethanol and methanol binary mixtures. Comparison of the specific rates of solvolyses of 1 with those for p-methoxybenzoyl chloride (2) in terms of linear free energy relationships (LFER) are helpful in mechanistic considerations, as is also treatment in terms of the extended Grunwald-Winstein equation. It is proposed that the solvolyses of 1 in binary aqueous solvent mixtures proceed through an SN1 and/or ionization (I) pathway rather than through an associative $S_N2$ and/or addition-elimination (A-E) pathway.

• 한국재료학회지
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• 제27권3호
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• pp.149-154
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• 2017

Transparent conducting oxides (TCOs) were fabricated using solution-based ITO (Sn-doped $In_2O_3$) nanoinks with nanorods at an annealing temperature of $200^{\circ}C$. In order to optimize their transparent conducting performance, ITO nanoinks were composed of ITO nanoparticles alone and the weight ratios of the nanorods to nanoparticles in the ITO nanoinks were adjusted to 0.1, 0.2, and 0.5. As a result, compared to the other TCOs, the ITO TCOs formed by the ITO nanoinks with weight ratio of 0.1 were found to exhibit outstanding transparent conducting performance in terms of sheet resistance (${\sim}102.3{\Omega}/square$) and optical transmittance (~80.2 %) at 550 nm; these excellent properties are due to the enhanced Hall mobility induced by the interconnection of the composite nanorods with the (440) planes of the short lattice distance in the TCOs, in which the presence of the nanorods can serve as a conducting pathway for electrons. Therefore, this resulting material can be proposed as a potential candidate for solution-based TCOs for use in optoelectronic devices requiring large-scale and low-cost processes.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 제3회 추계심포지움
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• pp.49-57
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• 1995

Protein kinase C (PK-C) represents a central element transducing signals generated by a broad range of pathways which produce the lipid second messenger sn-1,2-diacylglycerol (DAG) directly or indirectly. Many dominant oncogenes have proven to function, at least in part, through this pathway Likewise, this pathway is involved in expression of other aspects of the transformed phenotype, such as tumor invasion or multidrug resistance. As expected from its broad role in cell signaling, PK-C Is also important in a range of other physiological and pathophysiological processes, including inflammation, differentiation, and nerve function.

• Korean Journal of Acupuncture
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• 제39권1호
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• pp.8-15
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• 2022

Objectives : Saam acupuncture is one of the indigenous therapeutic modalities in traditional Korean medicine. In this study, the neuroprotective effect of Saam acupuncture of kidney tonification was investigated using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice. Methods : Twelve-week-old male C57BL/6 mice were intraperitoneally administered with 30 mg/kg of MPTP at 24-h intervals for 5 days and acupuncture stimulation at LU8, KI7, SP3 and KI3 was performed once a day for 12 days from the first MPTP injection. The pole test and the rotarod test were performed to evaluate motor function, and dopaminergic neuronal survival in the substantia nigra (SN) and striatum was evaluated using tyrosine-hydroxylase immunohistochemistry. Results : MPTP administration caused behavioral impairment and dopaminergic neuronal death in the nigrostriatal pathway. Whereas the Saam acupuncture treatment alleviated the MPTP-induced motor dysfunction and dopaminergic neuronal death in the SN and striatum. Conclusions : Saam acupuncture of kidney tonification can alleviate the MPTP-induced motor dysfunction and dopaminergic neuronal death in the nigrostriatal pathway, suggesting a possible role for acupuncture in the treatment of Parkinson's disease.