Seoul National University · 物理学・天文学
Professor J.-G. Park's research lab specializes in experimental condensed matter physics and cancer pharmacology, with a strong focus on understanding quantum phenomena in quantum materials and optimizing cancer chemotherapy through molecular mechanisms. The lab investigates magnetic excitations and electronic structures in heavy fermion and rare-earth compounds—such as URu₂Si₂ and CeNiSn—using high-energy inelastic neutron scattering, aiming to uncover the origins of unconventional quantum behavior. In parallel, the lab explores the biological mechanisms of anticancer drug efficacy, particularly the role of leucovorin in enhancing fluoropyrimidine-based chemotherapy in colorectal and gastric cancer cell lines, with translational implications for clinical treatment strategies. These dual research directions reflect a unique integration of advanced physical techniques and biomedical applications.
Figures are computed from collected data and may differ slightly.
Some widely used anticancer agents might be ineffective for treating hepatocellular carcinoma in clinical situations even when combined with reversing agents.
Reduced folates have been shown to increase the cytotoxicity of 5-fluorouracil (5-FU) by stabilizing the 5-fluoro-2'-deoxyuridine-5'-monophosphate-thymidylate synthase complex, thus increasing the block in the DNA synthetic pathway. Using an in vitro colorimetric [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] cytotoxicity assay, we tested the effects of 5-FU and 5-fluoro-2'-deoxyuridine (FdUrd) with and without leucovorin (LV) on a panel of 11 human colorectal carcinoma cell line
We compared the in vitro sensitivity patterns to cytotoxic drugs and expression of the multidrug resistance-associated MDR1 gene (also known as PGY1 gene) in four gastric carcinoma cell lines with those obtained in a panel of 11 colorectal carcinoma cell lines. In addition, we tested the effects of leucovorin on enhancement of fluorinated pyrimidine-induced cytotoxicity. We used a semiautomated tetrazolium dye assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (tetrazolyl blue)]
We investigated dc and ac susceptibilities of ${\mathrm{Pr}}_{0.63}{\mathrm{Sr}}_{0.37}{\mathrm{MnO}}_{3}$ and ${\mathrm{Nd}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$ single crystals. Surprisingly, real components of the ac susceptibility of both samples are frequency dependent below ${T}_{C},$ indicating competition between ferromagnetic and antiferromagnetic interactions even in the ferromagnetic phase. We also found evidence of rare-earth moment ordering at low temperatures. Our ac suscept
We have investigated the magnetic excitations of ${\mathrm{URu}}_{2}{\mathrm{Si}}_{2}$ up to 800 meV using high energy inelastic neutron scattering. There is clear evidence of magnetic scattering in the energy range up to 200 meV. This scattering can be fitted to four broad peaks which we attribute to heavily damped crystal field excitations. We also observed the ${\mathrm{U}}^{4+}$ ${}^{3}{\stackrel{\ensuremath{\rightarrow}}{{\mathrm{H}}_{4}}}^{3}{\mathrm{F}}_{2}$ intermultiplet transition at 3
Chromosomal phase separation is involved in a broad spectrum of chromosome organization and functional processes. Nonetheless, the intricacy of this process has left its molecular mechanism unclear. Here, we introduce the principles governing phase separation and its connections to physiological roles in this context. Our primary focus is contrasting two phase separation mechanisms: self-association-induced phase separation (SIPS) and bridging-induced phase separation (BIPS). We provide a compre
We present inelastic-neutron-scattering results for single-crystal CeNiSn. Apart from phonon-related structures appearing mainly below 30 meV, we have observed clear indications of a crystal-field excitation centered around 40 meV. However, we cannot yet determine whether there is another crystal-field excitation at a lower energy because of the presence of strong phonon peaks. We have also made measurements to investigate the quasielastic response of CeNiSn. We discuss the current understanding
${\text{PrFe}}_{4}{\text{P}}_{12}$ exhibits a unique transition at 6.5 K with an order parameter whose nature is still controversial. In order to elucidate the origin of the transition, we have carried out inelastic neutron scattering experiments in a range of temperatures and magnetic fields. Our data reveal a different type of low-lying excitations centered at 1.5 and 3.5 meV in the ordered phase with an unusual $Q$ dependence. With increasing field or temperature, the well-defined excitations
Open papers in the app to read, cite, and organize with AI.