• Korean Chemical Engineering Research
• /
• v.62 no.2
• /
• pp.133-141
• /
• 2024

Atherosclerosis, a disease with high morbidity and mortality worldwide, is a chronic inflammatory disease that is a major cause of cardiovascular diseases such as stroke and myocardial infarction. Atherosclerosis is characterized by the accumulation of lipid deposits in the arteries, forming atheromas. This leads to the narrowing of the arteries and thrombosis. Recently, the need to develop bio-derived anti-atherosclerotic materials has been highlighted with concerns about the side effects of synthetic therapeutics. Accordingly, related research (such as the discovery of biomaterials for the improvement and treatment of atherosclerosis and the identification of mechanisms) has been actively conducted. Biomaterials including polysaccharides, polyphenols, and coenzyme Q10 have been reported to inhibit or delay symptoms by modulating factors involved in the development of atherosclerosis. For biomaterials with superior activity, in vivo anti-atherosclerotic activity has been confirmed. In this review, the pathogenesis of atherosclerosis was investigated, and the current status and application prospects of biomaterials with anti-atherosclerotic activity were proposed.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.50 no.3
• /
• pp.251-259
• /
• 2024

The skin barrier plays an important role in maintaining healthy skin by preventing external irritation and water loss in the body. In the skin, hyaluronic acid (HA) is synthesized by the enzyme hyaluronic acid synthase (HAS), which functions as a natural moisturizing factor and is involved in maintaining water retention and barrier function. Therefore, in this study, the effect of the Prunus yedoensis bark ethyl acetate fraction (PYBEAF) on HA synthesis in HaCaT cells was confirmed. Cytotoxicity evaluation was performed through MTT assay, and the amount of HA synthesis in HaCaT cells was confirmed through ELISA through PYBEAF treatment. The levels of HAS-2, HAS-3 mRNA expression were analyzed using qRT-PCR, and the protein expression level and signaling pathway were confirmed through western blotting. Consequently, PYBEAF was involved in the MAPK and CREB signaling pathways, increasing the amount of HA production through HAS-2 synthesis. This suggests that PYBEAF is effective in improving barrier function by increasing HA synthesis, which plays an important role in moisturizing and maintaining skin moisture.

• Journal of IKEEE
• /
• v.28 no.3
• /
• pp.445-450
• /
• 2024

This paper presents a varactor-less voltage-controlled oscillator (VCO) at W-band (75-110 GHz) with a compact size in a 0.15-㎛ GaAs pHEMT technology. For varactor-less frequency tuning, an inductive tuning circuit is employed. An active inductor is realized by the common-gate stage with gate termination and shows a wide tuning range with a high quality factor (Q-factor) compared with the conventional varactor diode. Colpitts topology with source feedback is employed for the oscillation core of the VCO. The varactor-less VCO exhibits a measured tuning range of 5.8 % and peak output power of 5.7 dBm at 88 GHz while the 146 mW of dc power is dissipated. Due to compact layout design, the chip size is only 0.48 mm².

• Journal of Astronomy and Space Sciences
• /
• v.17 no.1
• /
• pp.19-32
• /
• 2000

A total of 1,018 observations (509 in B, 509 in V) of the eclipsing binary VW Cep was made during 7 nights from April through May in 1999 at Sobaeksan Optical Astronomy Observatory, using the CCD camera attached to the 61cm telescope. A time of minimum light of HJD2451327.2282 was determined from our data, and we constructed BV light curves with the data. Using, Wilson-Devinney’s binary model, we analized the light curves. The absolute dimension of $M_1=0.95M_\odot,M_2=0.33M_\odot,R_1=1.02R_\odot,R_2=0.66R_\odot$ of the VW Cep system were derived from our light curve solution and Kaszas et al. (1998) spectroscopic results.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.16 no.4
• /
• pp.3572-3584
• /
• 1974

본 논문은 Thrower의 양곡성능에 관한 예측 방정식을 차원해석법을 적용하여 유도하는데 있다. Thrower의 능률에 큰 영향을 미친다고 생각되는 인자들간의 관계식들을 Buckingham의 $\pi$이론에 의하여 구하여 졌으며 본연구에 사용한 Thrower는 현재 농촌에서 사용되고 있는 자동탈곡기의 Thrower와 유사한 형으로 제작된 것이며 실험에 사용된 시료는 벼의 경우는 통일벼와 미네히까리 품종이고 보리 품종으로서는 나맥이며, Thrower의 Impeller 직경, 속도 및 투입량을 변화시켜 가면서 각 시료에 대하여 양곡높이를 측정하여 그 예측방정식을 유도하였다. 본 논문에서 얻은 결과는 다음과 같다. 1. Thrower의 양곡성능에 지대한 영향을 미친다고 생각되는 주요 인자들을 Thrower의 양정, impeller의 직경과 속도, 투입량, 곡립의 밀도, 중력가속도등이라 간주하여 Buckingham의 $\pi$이론을 적용하여 이들에 관한 $\pi$항들을 결정하였으며 그 결과는 다음과 같다. {{{{ pi 1= { D} over {H } , pi 2= { { DN}^{ { 1} over {2 } } } over { { g}^{ { 1} over { 2} } }, pi 3= { Q} over { { g}^{ { 1} over {2 } } { rho D}^{ { 2} over {6 } } }}}}} 2. 실험에 의하여 구해진 $\pi$항문의 관계식을 합성하여 Thrower의 양곡성능에 관한 시료별 예측방정식을 구하였으며 이 식들은 아래와 같다. 통일 : $\pi$1=0.1223($\pi$2)-1.1813$\times$($\pi$3)-0.1864 미네히까리 : $\pi$1=0.1185($\pi$2)-0.9663$\times$($\pi$3)-0.1575 나맥 : $\pi$1=0.1599($\pi$2)-1.2350$\times$($\pi$3)-0.1382 3. 현재 농촌에서 사용되고 있는 자동탈곡기체 부착된 Thrower의 회전수, Impeller의 직경 및 투입량은 각각 1,100rpm, 30cm 및 150gr/sec 정도로서 이와같은 수준의 변량들을 기초로 하여 본 논문에서 유도한 예측방정식을 적용하여 Thrower의 양정을 산출한 결과, 통일벼의 경우는 2.6m정도였고 미네히까리 품종과 나맥의 양정은 각각 2.4m, 2.9m 정도였다. 이와같은 사실로부터 1m내외의 양정만으로 되어있는 자동탈곡기 Thrower의 경우 제작비절감, 소요동력 감소를 기하고 아울러 과립의 손상을 줄이기 위해서는 설계 또는 작동조건의 변경을 통해 Thrower의 회전수를 현재 수준이하로 줄일 필요가 있다고 판단되었다.

• Journal of Life Science
• /
• v.21 no.9
• /
• pp.1295-1300
• /
• 2011

The AtPGR gene is induced by pathogen infection, jasmonic acid and salicylic acid treatment and may therefore play a role in plant defense responses. Arabidopsis thaliana Plasma membrane Glucose-responsive Regulator (AtPGR) was previously isolated from Arabidopsis, which confers glucose insensitivity on plants. To study its biological functions directly, we have characterized both loss-of-function RNAi mutant and gain-of-function transgenic overexpression plants for AtPGR in Arabidopsis. The AtPGR-overexpressing plants displayed enhanced resistance to a virulent strain of the bacterial pathogen Pseudomonas syringae as measured by a significant decrease in both bacterial growth and symptom development as compared to those in wild-type and RNAi plants. The enhanced resistance in the gain-of-function transgenic plants was associated with increased induction of SA-regulated PDF1.2 and JA-regulated PR1 by the bacterial pathogen. Thus, pathogen-induced AtPGR plays a positive role in defense responses to P. syringae.

• Korean Journal of Food Science and Technology
• /
• v.47 no.1
• /
• pp.119-125
• /
• 2015

The aim of this study was to investigate the synergistic anti-inflammatory effect of rosmarinic acid (RA) and luteolin from perilla (Perilla frutescens L.) leaves in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. A combination of RA and luteolin more strongly inhibited the production of nitric oxide (NO), inducible NOS (iNOS), prostaglandin $E_2$ ($PGE_2$), and COX-2 than higher concentrations of RA or luteolin alone in LPS-stimulated RAW264.7 macrophages. The combined RA and luteolin synergistically inhibited the production of pro-inflammatory cytokines, such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and interleukin-$1{\beta}$ (IL-$1{\beta}$), in LPS-stimulated RAW264.7 macrophages. Furthermore, combined RA and luteolin more strongly suppressed NF-${\kappa}B$ activation than RA or luteolin alone, by inhibiting the degradation of inhibitor of NF-${\kappa}B(I{\kappa}B)$-${\alpha}$ and nuclear translocation of the p65 subunit of NF-${\kappa}B$ in LPS-stimulated RAW264.7 macrophages. Collectively, these results suggest that RA and luteolin in combination exhibit synergistic effects in suppression of LPS-induced inflammation in RAW264.7 macrophages.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.6
• /
• pp.217-225
• /
• 2003

An experimental study was conducted to evaluate the smeared effect due to mandrel penetration into soft ground for a vertical drain installation. Laboratory tests were performed to investigate the formation of a smear zone, the variations of strength, and the consolidation characteristics in the disturbed zone using two types(CL at Yangsan site and OH at Pohang site) of soft clayey soils. The smear zone effect was evaluated focusing on mandrel shape, mandrel size, penetration speed, and ground condition. Based on laboratory test results, the diameter of the smear zone$(d_s)$ ranged from 3.08 and 3.92 times that of mandrel$(d_m)$. It was also found that the $(d_s/d_m)$ value of the circular shape of the mandrel is smaller than those of square and rectangular shapes. The value of $(d_s/d_m)$ decreased with larger mandrel size, lower penetration speed in the CL soil, and higher penetration speed in the OH soil. However, natural water content was minimally affected by $(d_s/d_m)$. Respectively, the coefficients of horizontal consolidation$(C_{hs})$ and horizontal Permeability$(K_s)$ of smear zone ranged from 0.81 to 0.87 times, and 0.73 to 0.83 times those of the undisturbed zone. Based on this study, the values of $C_{hs}, K_s$ and unconfined compressive strength$(q_{us})$ in the smear zone were the lowest at close vicinity of the mandrel and increased linearly with distance from the mandrel. Further, the $(q_{us})$ varied from 0.5 to 0.9 times that of the undisturbed zone strength.

• Korean Journal of Food Science and Technology
• /
• v.48 no.6
• /
• pp.590-596
• /
• 2016

This study was designed to investigate the antioxidant activities of the ethanol extracts (GBE) of grape branches (Campbell Early). The total polyphenol and flavonoid content of GBE was $201.42{\pm}4.16$ and $11.85{\pm}0.44mg\;GAE/g$, respectively. The antioxidant activity of GBE was measured using the ABTS and DPPH assays, and the $IC_{50}$ values were $45.60{\pm}0.09$ and $299.13{\pm}0.22$, respectively. GBE inhibited the production of pro-inflammatory mediators (NO, iNOS, $PGE_2$, COX-2, $IL-1{\beta}$, and IL-6) in lipopolysaccharide-stimulated RAW 264.7 macrophages in a dose-dependent manner. Moreover, GBE treatment significantly suppressed the production of $TNF-{\alpha}$ and IL-6 cytokines in phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated HMC-1 human mast cells. Furthermore, the administration of GBE markedly inhibited the scratching behavior induced by the compound 48/80 in ICR mice. These results suggested that GBE has potential as a therapeutic agent against inflammation and itch-related skin diseases.

• Korean Journal of Environment and Ecology
• /
• v.6 no.1
• /
• pp.25-43
• /
• 1992

A survey of Orimok, Yongsil and Donnaeko area forest in Mt. Halla. was conducted using 71 sample plots of 500$m^2$ size. In the analysis of -actual vegetation, Carpinus tschonoskii and C. laxiflora community covered 53.7%, Quercus grosseserrata - Q. serrata community 25.8%, Pinus densiflora community 8.3%, Abies koreana community 4.5% and these communities covered 92.2% of Mt. Halla forest. The degree of 8, 9 and 10 in human disturbance of vegetation covered 64.5, 28.6 and 6.9% respectively. The classification by TWINSPAN and DCA ordination were applied to the study area in order to classify them into several groups based on woody plants and environmental variables. By two techniques, the plant community were divided into several groups by the aspect and altitude. The dividing groups are C. tschonoskii community, C. tschonoskii - Q. serrata community, P. densiflora - C. tschonoskii community, P. densiflora - C. laxiflora community, C. laxiflora community, C. laxifrora - Daphniphyllum macropodum - Eurya japonica community, P. densiflora community. The successional trends of tree species by both techniques seem to be from P. densiflora. Sorbus alnifolia through Q. serrata. Maackia faurier to C. tsihonoskii in Orimok and Yongsil area and from P. densifiora to C. laxiflora in Donnaeko area. There was no difference between the stand scores of. DCA and environmental variables.