Synthetic studies toward Eurycolactone C

Over the last decades, organic synthesis has played an essential role in the pharmaceutical industry. The development of synthetic methodologies and strategies allow us to access complex natural products in an efficient way and fuel the drug discovery. Chapter one describes the study of aryl triflates and aryl pivalates reactions with electrophiles and provides extensive information about the regioselectivities of the reactions. Chapter two introduces a novel method to generate 6- and 8-substituted 1-methoxynaphthalene (or alpha-naphthol). Chapter three describes synthetic studies toward eurycolactone C

INTEGRATED APPROACHES FOR SCALABLE AQUIFER NUMERICAL MODELING, INVERSION, AND UPSCALING

Ph.D

A Proposal of Storytelling Direction as a Process of Narrowing the Gap between Designers and Users

OAIID:RECH_ACHV_DSTSH_NO:A201701933RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A080155CITE_RATE:FILENAME:HCIK2017_디자이너와 사용자의 간극을 좁히는 프로세스로서 스토리텔링 방향성 제안_paper_242_FINAL.pdfDEPT_NM:디자인학부EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/b8b39b27-ce50-4d0f-b403-08849291b068/linkCONFIRM:

A Study of Solids and Gas Mixing in a Partitioned Fluidized Bed

A partitioned fluidized bed gasifier has been developed for improving coal gasification performance. The basic concept is to divide a fluidized bed into two parts, a gasifier and a combustor, by a partition. Char is burnt in the combustor and generated heat is supplied to the gasifier by solid mixing. Therefore, solid mixing should be maximized whereas gas mixing between syngas and the combusted gas should be minimized. In this study, gas and solid mixing behaviors were verified in cold model acrylic beds. For monitoring solid mixing behavior, transient temperature trends in the beds were analyzed. A heat source and a heat sink were installed in each bed. Dozens of thermocouples were used to monitor temperature distribution

Thermoelectric properties of graphene incorporated thermoelectric materials

Thermoelectric materials, which can change the waste heat into the usable electricity, are interested in various field of applications such as vehicle, ship, power plane, and so on. To enhance the thermoelectric properties, high electrical conductivity, high Seebeck coefficient, and low thermal conductivity should be conducted, however, the trade-off relation between electronic property and thermal property in terms of carrier concentration could be the bottle-neck on the enhancement of thermoelectric properties of the materials. In this presentation, we discuss with the graphene incorporation in the conventional thermoelectric materials, which could lead to independently control electric and thermal properties

Methyl 4-(β-D-glucopyranosyloxy)-3-hydroxy-5- methoxybenzoate, isolated from Sanguisorba officinalis, inhibits CpG-DNA-induced inflammation

Purpose: To evaluate the anti-inflammatory effect of methyl-4-(β-D-glucopyranosyloxy)-3-hydroxy-5-methoxybenzoate (comp-1) on immune cells.Methods: Comp-1 was isolated from Sanguisorba officinalis. After treating with comp-1, cell viability and levels of pro-inflammatory cytokines were assessed utilizing MTT assay and ELISA, respectively. Besides, the effects of comp-1 on nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and iNOS were determined using western blotting. Moreover, nitric oxide production was assessed using the Griess reagent.Results: Treatment of dendritic cells (DCs) with CpG DNA upregulated cytokine expression. Comp-1 markedly downregulated the expressions of IL-12 p40, IL-6, and TNF-α, with 50% inhibitory concentrations (IC50) of 1.077 ± 0.04 (p < 0.01), 0.28 ± 0.01 (p < 0.01), and 0.79 ± 0.02 μM (p < 0.01),respectively. Treatment of DCs with CpG DNA upregulated NF-κB and MAPK activation. However, pretreatment of the cells with Comp-1 suppressed CpG DNA-induced NF-κB and MAPK activation. Moreover, comp-1 exhibited a strong anti-inflammatory effect by inhibiting nitric oxide production and iNOS expression.Conclusion: These results reveal that comp-1 has significant anti-inflammatory effect on immune cells. Keywords: Natural compound, Inflammation, Pro-inflammatory cytokine, Toll-like receptor

Rationale of decreasing low-density lipoprotein cholesterol below 70 mg/dL in patients with coronary artery disease: A retrospective virtual histology-intravascular ultrasound study

Background: The associations between statin and coronary plaque compositional changes were re­ported according to the use of high dose or not. An evaluation of the impact of low-density lipoprotein cholesterol (LDL-C) < 70 mg/dL by using real world dosages of statin on coronary plaque composition was undertaken. Methods: The study subjects consisted of 61 patients (mean 59.9 years old, 45 males) who underwent percutaneous coronary intervention, baseline and follow-up (F/U; mean 8.4 months) virtual histology- -intravascular ultrasound (VH-IVUS) examination. Change of plaque composition at peri-stent area, which was selected in order to measure the identical site at F/U study, was compared according to the F/U LDL-C level. Results: Body mass index, prevalence of dyslipidemia, baseline total cholesterol and baseline LDL-C were significantly lower in F/U LDL-C < 70 mg/dL group (14 segments in 10 patients) than F/U LDL-C ≥ 70 mg/dL group (79 segments in 51 patients). F/U high-density lipoprotein cholesterol (HDL-C, OR 1.06, 95% CI 1.00–1.11, p = 0.054) and F/U LDL-C < 70 mg/dL (OR 3.43, 95% CI 0.97–12.17, p = 0.056) showed strong tendency of regression of necrotic core volume (NCV) ≥ 10%. In multivariable logis­tic regression analysis, F/U HDL-C (OR 1.07, 95% CI 1.01–1.14, p = 0.020) and F/U LDL-C < 70 mg/dL (OR 8.02, 95% CI 1.58–40.68, p = 0.012) were the independent factors for regression of NCV ≥ 10%. Conclusions: Follow-up LDL-C level < 70 mg/dL with any types of statins and increase of HDL-C were associated with regression of NCV ≥ 10% in patients with coronary artery disease

Cytohistological study of the leaf structures of Panax ginseng Meyer and Panax quinquefolius L.

AbstractBackgroundBoth Panax ginseng Meyer and Panax quinquefolius are obligate shade-loving plants whose natural habitats are broadleaved forests of Eastern Asia and North America. Panax species are easily damaged by photoinhibition when they are exposed to high temperatures or insufficient shade. In this study, a cytohistological study of the leaf structures of two of the most well-known Panax species was performed to better understand the physiological processes that limit photosynthesis.MethodsLeaves of ginseng plants grown in soil and hydroponic culture were sectioned for analysis. Leaf structures of both Panax species were observed using a light microscope, scanning electron microscope, and transmission electron microscope.ResultsThe mesostructure of both P. ginseng and P. quinquefolius frequently had one layer of noncylindrical palisade cells and three or four layers of spongy parenchymal cells. P. quinquefolius contained a similar number of stomata in the abaxial leaf surface but more tightly appressed enlarged grana stacks than P. ginseng contained. The adaxial surface of the epidermis in P. quinquefolius showed cuticle ridges with a pattern similar to that of P. ginseng.ConclusionThe anatomical leaf structure of both P. ginseng and P. quinquefolius shows that they are typical shade-loving sciophytes. Slight differences in chloroplast structure suggests that the two different species can be authenticated using transmission electron microscopy images, and light-resistant cultivar breeding can be performed via controlling photosynthesis efficiency