Won Lee | Sungkyunkwan University (original) (raw)

Papers by Won Lee

Analytica Chimica Acta, 1997

A new styrene-DVB based chelating resin containing 4-(2-thiazolylazo)resorcinol (TAR) functional ... more A new styrene-DVB based chelating resin containing 4-(2-thiazolylazo)resorcinol (TAR) functional groups has been synthesized and its sorption behaviour for thirteen metal ions including U(VI) has been investigated by batch and column experiments. The chelating resin is highly selective for Cu(II) and U(VI) in the pH range 1~2, whereas alkali metal and alkaline earth metal ions such as Na(I), Mg(II) and

Local structures in MBE-grown HfO2:Co films with different Co concentration has been investigated... more Local structures in MBE-grown HfO2:Co films with different Co concentration has been investigated using the EXAFS technique. The average local environment surrounding Co exhibited by our EXAFS data consists of two major near shells attributed to O and Co neighboring atoms at distances of 2.04 åand 2.49 åfrom the central Co atom, respectively. As the Co concentration increases, the average

Oncotarget, 2015

Snake venom toxin (SVT) from Vipera lebetina turanica contains a mixture of different enzymes and... more Snake venom toxin (SVT) from Vipera lebetina turanica contains a mixture of different enzymes and proteins. Peroxiredoxin 6 (PRDX6) is known to be a stimulator of lung cancer cell growth. PRDX6 is a member of peroxidases, and has calcium-independent phospholipase A2 (iPLA2) activities. PRDX6 has an AP-1 binding site in its promoter region of the gene. Since AP-1 is implicated in tumor growth and PRDX6 expression, in the present study, we investigated whether SVT inhibits PRDX6, thereby preventing human lung cancer cell growth (A549 and NCI-H460) through inactivation of AP-1. A docking model study and pull down assay showed that SVT completely fits on the basic leucine zipper (bZIP) region of c-Fos of AP-1. SVT (0-10 μg/ml) inhibited lung cancer cell growth in a concentration dependent manner through induction of apoptotic cell death accompanied by induction of cleaved caspase-3, -8, -9, Bax, p21 and p53, but decreased cIAP and Bcl2 expression via inactivation of AP-1. In an xenograf...

Advanced drug delivery reviews, Jan 14, 2015

MicroRNAs (miRNAs) are key components of a broadly conserved post-transcriptional mechanism that ... more MicroRNAs (miRNAs) are key components of a broadly conserved post-transcriptional mechanism that controls gene expression by targeting mRNAs. miRNAs regulate diverse biological processes, including the growth and differentiation of stem cells as well as the regulation of both endogenous tissue repair that has critical implications in the development of regenerative medicine approaches. In this review, we first describe key features of miRNA biogenesis and their role in regulating self-renewal, and then discuss the involvement of miRNAs in the determination of cell fate decisions. We highlight the role of miRNAs in the emergent field of reprogramming and trans-differentiation of somatic cells that could further our understanding of miRNA biology and regenerative medicine applications. Finally, we describe potential techniques for proper delivery of miRNAs in target cells.

Marine pollution bulletin, Jan 24, 2015

To assess the potential for nutritional exploitation of caged-fish-derived waste through the use ... more To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, δ(13)C and δ(15)N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient en...

Journal of Korean Neurosurgical Society, 2015

This study aims to visualize the subjective symptoms before and after the treatment of whiplash i... more This study aims to visualize the subjective symptoms before and after the treatment of whiplash injury using infrared (IR) thermography. IR thermography was performed for 42 patients who were diagnosed with whiplash injury. There were 19 male and 23 female patients. The mean age was 43.12 years. Thermal differences (ΔT) in the neck and shoulder and changes in the thermal differences (ΔdT) before and after treatment were analyzed. Pain after injury was evaluated using visual analogue scale (VAS) before and after treatment (ΔVAS). The correlations between ΔdT and ΔVAS results before and after the treatment were examined. We used Digital Infrared Thermal Imaging equipment of Dorex company for IR thermography. The skin temperature of the neck and shoulder immediately after injury showed 1-2℃ hyperthermia than normal. After two weeks, the skin temperature was normal range. ΔT after immediately injuy was higher than normal value, but it was gradually near the normal value after two weeks....

Complementary therapies in medicine, 2015

The effectiveness of traditional herbal medicine (THM) as an adjunctive therapy for cancer pain i... more The effectiveness of traditional herbal medicine (THM) as an adjunctive therapy for cancer pain is unclear. To assess the effectiveness of THM as an adjunctive therapy for cancer pain using randomized controlled trials (RCTs). Five electronic databases, including those from the UK and China, were systematically searched for the period before September 2013. All RCTs involving the use of THM in combination with conventional cancer therapy for cancer pain were included. Twenty-four RCTs involving 4889 patients with cancer pain were systematically reviewed. Among them, nine studies of 952 patients reported a significant decrease in the number of patients with cancer pain in the treatment group. Four studies of 1696 patients reported a significant decrease in the degree of pain in the treatment group. The results of these studies suggest that THM combined with conventional therapy is efficacious as an adjunctive therapy for patients with cancer pain. However, more research, including we...

Nature Nanotechnology, 2015

Assembling inorganic nanomaterials on graphene is of interest in the development of nanodevices a... more Assembling inorganic nanomaterials on graphene is of interest in the development of nanodevices and nanocomposite materials, and the ability to align such inorganic nanomaterials on the graphene surface is expected to lead to improved functionalities, as has previously been demonstrated with organic nanomaterials epitaxially aligned on graphitic surfaces. However, because graphene is chemically inert, it is difficult to precisely assemble inorganic nanomaterials on pristine graphene. Previous techniques based on dangling bonds of damaged graphene, intermediate seed materials and vapour-phase deposition at high temperature(,) have only formed randomly oriented or poorly aligned inorganic nanostructures. Here, we show that inorganic nanowires of gold(I) cyanide can grow directly on pristine graphene, aligning themselves with the zigzag lattice directions of the graphene. The nanowires are synthesized through a self-organized growth process in aqueous solution at room temperature, which indicates that the inorganic material spontaneously binds to the pristine graphene surface. First-principles calculations suggest that this assembly originates from lattice matching and π interaction to gold atoms. Using the synthesized nanowires as templates, we also fabricate nanostructures with controlled crystal orientations such as graphene nanoribbons with zigzag-edged directions.

Circulation, Jan 24, 2015

We are thankful for the interest and comments of Li and Hong concerning our recent findings demon... more We are thankful for the interest and comments of Li and Hong concerning our recent findings demonstrating that exogenous administration of hypoxia-inducible factor-1 (HIF-1) could modulate the ischemic microenvironment, rendering it more favorable for the survival of transplanted stem cells, effects that are partially mediated by exosomal transfer of miR-126 and miR-210. ! Indeed, (Circulation. 2015;131:e385.

Background: A relationship between plasma adiponectin level and a number of metabolic conditions,... more Background: A relationship between plasma adiponectin level and a number of metabolic conditions, including insulin resistance, obesity, and type 2 diabetes, has been reported. This study aimed to assess whether urinary adiponectin concentration is correlated with vascular complications. Methods: The study comprised 708 subjects who enrolled in the Seoul Metro City Diabetes Prevention Program and were carefully monitored from September 2008 to December 2008. Levels of urinary adiponectin were measured using an enzyme linked immunosorbent assay (ELISA) kit (AdipoGen, Korea). Urinary albumin excretion was assessed by the ratio of urinary albumin to creatinine (A/C ratio). Participants were divided into three groups based on tertiles of urinary adiponectin concentration, and we investigated whether urinary adiponectin levels are associated with microalbuminuria and pulse wave velocity.

Journal of Chemical Engineering of Japan, 1989

ABSTRACT

Fertility and Sterility, 2006

Objective: To compare the clinical outcomes between letrozole and clomiphene citrate (CC) in gona... more Objective: To compare the clinical outcomes between letrozole and clomiphene citrate (CC) in gonadotropincombined intrauterine insemination (IUI) cycles. Design: Prospective pilot study. Setting: One university hospital and two private infertility clinics. Patient(s): Ninety-three infertile couples eligible for superovulation and IUI. Intervention(s): A letrozole dose of 2.5 mg/day (n ϭ 66) or a CC dose of 100 mg/day (n ϭ 27) was given on day 3-7 of the menstrual cycle, combined with human menopausal gonadotropin (hMG) at a dose 150 IU every other day starting on day 5. Main Outcome Measure(s): The number of mature follicles, serum estradiol (E 2 ) and progesterone (P) levels, endometrial thicknesses on the day of human chorionic gonadotropin (hCG), and clinical pregnancy rates.

19th International Symposium in Robot and Human Interactive Communication, 2010

Attempts to put robots to practical use have been increasing, as robot becomes more human-friendl... more Attempts to put robots to practical use have been increasing, as robot becomes more human-friendly. In the human-robot interaction field, main issues are how variously the robot can express its emotion and how much the expression is socially acceptable. This paper proposes a robot&amp;amp;amp;#39;s expression generation method based on the context information and combination of behavior database for emotional interactive

In vivo (Athens, Greece)

Renal function measurements using (99m)Tc-DTPA and (99m)Tc-MAG(3) dynamic scintigraphs were compa... more Renal function measurements using (99m)Tc-DTPA and (99m)Tc-MAG(3) dynamic scintigraphs were compared to those obtained using (99m)Tc-DMSA static scintigraphy. Eighteen experimental rabbits were randomly divided into (99m)Tc-DTPA-, (99m)Tc-MAG(3)-, and (99m) Tc-DMSA-injected groups. Experimental unilateral renal damage was induced by ligating a unilateral right ureter in 18 rabbits. Scintigraphic images were obtained at 2 and 5 h after intravenous injection of (99m)Tc-DMSA, or immediately after administration of (99m)Tc-DTPA or (99m)Tc-MAG(3). For the dynamic images using (99m)Tc-DTPA and (99m)Tc-MAG(3), rapid sequential images were obtained every 2 s for 30 images up to 1 min. The three groups presented different relative renal functions between the left normal and the right abnormal kidneys at 1, 2, 3, and 4 weeks post-ligation (p<0.05). However, the between-group comparisons showed no significant differences at any time. These results suggest that dynamic images of (99m)Tc-DTPA...

Circulation, Jan 9, 2014

Despite the promise shown by stem cells for restoration of cardiac function after myocardial infa... more Despite the promise shown by stem cells for restoration of cardiac function after myocardial infarction, the poor survival of transplanted cells has been a major issue. Hypoxia-inducible factor-1 (HIF1) is a transcription factor that mediates adaptive responses to ischemia. Here, we hypothesize that codelivery of cardiac progenitor cells (CPCs) with a nonviral minicircle plasmid carrying HIF1 (MC-HIF1) into the ischemic myocardium can improve the survival of transplanted CPCs. After myocardial infarction, CPCs were codelivered intramyocardially into adult NOD/SCID mice with saline, MC-green fluorescent protein, or MC-HIF1 versus MC-HIF1 alone (n=10 per group). Bioluminescence imaging demonstrated better survival when CPCs were codelivered with MC-HIF1. Importantly, echocardiography showed mice injected with CPCs+MC-HIF1 had the highest ejection fraction 6 weeks after myocardial infarction (57.1±2.6%; P=0.002) followed by MC-HIF1 alone (48.5±2.6%; P=0.04), with no significant protect...

Rheumatology (Oxford, England), 2013

To assess the effectiveness of acupuncture as complementary therapy for gouty arthritis from rand... more To assess the effectiveness of acupuncture as complementary therapy for gouty arthritis from randomized controlled trials (RCTs). Five electronic databases, including English and Chinese, were systematically searched until August 2012. All RCTs involving acupuncture in combination with conventional therapy for gouty arthritis were included. Ten RCTs involving 852 gouty arthritis patients were systematically reviewed. Among them six studies of 512 patients reported a significant decrease in uric acid in the treatment group compared with a control group, while two studies of 120 patients reported no significant decrease in uric acid in the treatment group compared with the control group. The remaining four studies of 380 patients reported a significant decrease in visual analogue scale score in the treatment group. The results of the studies included here suggest that acupuncture is efficacious as complementary therapy for gouty arthritis patients. More research and well-designed, rig...

Biochemical and biophysical research communications, Jan 18, 2011

Folate co-enzymes play a pivotal role in one-carbon transfer cellular processes. Many eukaryotes ... more Folate co-enzymes play a pivotal role in one-carbon transfer cellular processes. Many eukaryotes encode the tri-functional tetrahydrofolate dehydrogenase/cyclohydrolase/synthetase (deh/cyc/syn) enzyme, which consists of a N-terminal bifunctional domain (deh/cyc) and a C-terminal monofunctional domain (syn). Here, we report the first analogous archeal enzyme structures, for the bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase from Thermoplasma acidophilum (TaMTHFDC) as the native protein and also as its NADP complex. The TaMTHFDC structure is a dimer with a polar interface, as well as a NADP binding site that shows minor conformational change. The orientations of the residues in the NADP binding site do not change on ligand binding, incorporating three water molecules which are hydrogen bonded with phosphate groups of NADP in the structure of the complex. Our structural information will contribute to an improved understanding of the basis of THF and one-carbon meta...

Tissue engineering. Part C, Methods, 2010

In conventional hanging drop (HD) methods, embryonic stem cell aggregates or embryoid bodies (EBs... more In conventional hanging drop (HD) methods, embryonic stem cell aggregates or embryoid bodies (EBs) are often maintained in small inverted droplets. Gravity limits the volumes of these droplets to less than 50 microL, and hence such cell cultures can only be sustained for a few days without frequent media changes. Here we present a new approach to performing long-term HD methods (10-15 days) that can provide larger media reservoirs in a HD format to maintain more consistent culture media conditions. To implement this approach, we fabricated hollow sphere (HS) structures by injecting liquid drops into noncured poly(dimethylsiloxane) mixtures. These structures served as cell culture chambers with large media volumes (500 microL in each sphere) where EBs could grow without media depletion. The results showed that the sizes of the EBs cultured in the HS structures in a long-term HD format were approximately twice those of conventional HD methods after 10 days in culture. Further, HS cult...

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2009

The goal of this study was to experimentally investigate the influence of the white matter (WM) a... more The goal of this study was to experimentally investigate the influence of the white matter (WM) anisotropy on the EEG source localization. We acquired both visual evoked potential (VEP) and functional MRI (fMRI) data from three human subjects presented with identical visual stimuli. A finite element method (FEM) head model with or without incorporating the WM anisotropy was built to solve the EEG forward problems, and single-dipole source localization was subsequently performed based on the N75 VEP component. The localized dipole positions were quantitatively compared with the locations of the fMRI activations within the primary visual cortex (V1). The results show that the distance between the localized N75 dipole position and the fMRI V1 activation center was slightly smaller when using an anisotropic model than when using an isotropic model. This experimental study suggests that compared to the conventional isotropic model, the anisotropic models incorporating realistic WM anisot...

Medical engineering & physics, 2012

This study proposes an advanced finite element (FE) head modeling technique through which high-re... more This study proposes an advanced finite element (FE) head modeling technique through which high-resolution FE meshes adaptive to the degree of tissue anisotropy can be generated. Our adaptive meshing scheme (called wMesh) uses MRI structural information and fractional anisotropy maps derived from diffusion tensors in the FE mesh generation process, optimally reflecting electrical properties of the human brain. We examined the characteristics of the wMeshes through various qualitative and quantitative comparisons to the conventional FE regular-sized meshes that are non-adaptive to the degree of white matter anisotropy. We investigated numerical differences in the FE forward solutions that include the electrical potential and current density generated by current sources in the brain. The quantitative difference was calculated by two statistical measures of relative difference measure (RDM) and magnification factor (MAG). The results show that the wMeshes are adaptive to the anisotropic...