Jeong-Hwa Lee

A novel coumarin-based fluorogenic probe bearing the 2-picolyl unit (1) was developed as a fluorescent chemosensor with high selectivity and suitable affinity in biological systems toward Cu(2+) over other cations tested. The fluorescence on-off mechanism was studied by femtosecond time-resolved fluorescence (TRF) upconversion technique and ab initio calculations. The receptor can be applied to the monitoring of Cu(2+) ion in aqueous solution with a pH span 4-10. To confirm the suitability of 1

Acinetobacter baumannii is an important nosocomial pathogen that causes a high morbidity and mortality rate in infected patients, but pathogenic mechanisms of this microorganism regarding the secretion and delivery of virulence factors to host cells have not been characterized. Gram-negative bacteria naturally secrete outer membrane vesicles (OMVs) that play a role in the delivery of virulence factors to host cells. A. baumannii has been shown to secrete OMVs when cultured in vitro, but the role

Gram-negative bacteria produce outer membrane vesicles that play a role in the delivery of virulence factors to host cells. However, little is known about the membrane-derived vesicles (MVs) produced by gram-positive bacteria. The present study examined the production of MVs from Staphylococcus aureus and investigated the delivery of MVs to host cells and subsequent cytotoxicity. Four S. aureus strains tested, two type strains and two clinical isolates, produced spherical nanovesicles during in

Acinetobacter baumannii is increasingly becoming a major nosocomial pathogen. This opportunistic pathogen secretes outer membrane vesicles (OMVs) that interact with host cells. The aim of this study was to investigate the ability of A. baumannii OMVs to elicit a pro-inflammatory response in vitro and the immunopathology in response to A. baumannii OMVs in vivo. OMVs derived from A. baumannii ATCC 19606(T) induced expression of pro-inflammatory cytokine genes, interleukin (IL)-1β and IL-6, and ch

Gram-negative bacteria produce extracellular outer membrane vesicles (OMVs) that interact with host cells. Unlike Gram-negative bacteria, less is known about the production and role of extracellular membrane vesicles (MVs) in Gram-positive bacteria. The food-borne pathogen Listeria monocytogenes can survive under extreme environmental and energy stress conditions and the transcription factor σ(B) is involved in this survival ability. Here, we first determined the production of MVs from L. monocy

A 3-step asymmetric approach toward the optically active chiral cyclohex-2-enones from anisoles has been developed. The crucial asymmetric induction step is an unprecedented catalytic enantioselective isomerization of β,γ-unsaturated cyclohex-3-en-1-ones to the corresponding α,β-unsaturated chiral enones. This new asymmetric transformation was realized by cooperative iminium-base catalysis with an electronically tunable new organic catalyst. The synthetic utility of this methodology is highlight

One-pot ketone synthesis has been developed with in situ activation of alkyl halides to alkylzinc halides in the presence of thioesters and Pd-catalyst. The new method provides us with a reliable option for a coupling at a late stage in a convergent synthesis of complex molecules, with use of a near 1:1 molar ratio of coupling partners. First, two facile, orthogonal methods have been developed for preparation of alkylzinc halides: (1) direct insertion of zinc dust to 1°- and 2°-alkyl halides in

본 연구에서는 상담자와 상담자가 되기 위해 대학원 과정을 이수하고 있는 예비 상담자의 상담 진로 결정 동기 척도를 개발하고, 이에 대한 타당성을 검증하고자 하였다. 그 결과 상담의 긍정적 영향력, 상담에 대한 관심, 인정받는 진로, 융통성이 있는 직업이라는 4개의 요인으로 구성된 척도가 개발되었으며, 모두 15개의 문항으로 구성되어 있다. 내적합치도와 확인적 요인분석 결과는 상담자 진로결정 동기척도의 타당성을 지지하였다. 또한 기존의 작업선호도검사(WPI), 진로결정자기효능감척도(CDMSES), 상담자소진척도(CBI)를 통해 공인타당도를 검증한 결과 기대했던 방향으로 유의미한 상관관계가 있는 것으로 나타났다. 이상의 결과를 종합하였을 때, 본 연구에서 개발된 상담자 진로결정 동기척도는 타당한 것으로 보이며, 추후 상담자로의 진로 결정 동기 양상을 이해하고, 이를 통해 상담자 교육 프로그램 개발하는데 중요한 기초 자료가 될 것이다. 또한 상담전문가로서 성장하는 과정 중에서 자기-자각

Rapsyn is a postsynaptic protein required for clustering of nicotinic acetylcholine receptors (nAChRs) at the neuromuscular junction. Here we report the mechanism for posttranslational control of rapsyn protein stability. We confirmed that C18H9.7-encoded RPY-1 is a rapsyn homolog in Caenorhabditis elegans by showing that human rapsyn rescued rpy-1 mutant phenotypes in nematodes, as determined by levamisole assays and micropost array behavioral assays. We found that RPY-1 was degraded in the abs

Numerous types of cells have been shown to undergo apoptosis when exposed to oxidant agent such as hydrogen peroxide. In order to understand the functional relationship between the anti- and pro-apoptotic regulatory proteins in the cells under oxidant stress, we have studied the level of expression of apoptosis regulatory proteins, bcl-2 and bax, in human leukemia HL-60 cells. The exposure of HL-60 cells to different concentrations of H2O2 for 6 h resulted in a typical apoptosis of the cells as