• Macromolecular Research
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• 제16권1호
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• pp.15-20
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• 2008

The enhanced permeability and retention (EPR) effect is used extensively for the passive targeting of many macromolecular drugs for tumors. Indeed, the EPR concept has been a gold standard in polymeric anticancer drug delivery systems. This study investigated the tumoral distribution of self-assembled nanoparticles based on the EPR effect using fluorescein and radio-labeled nanoparticles. Self-assembled nanoparticles were prepared from amphiphilic chitosan derivatives, and their tissue distribution was examined in tumor-bearing mice. The size of the nanoparticles was controlled to be 330 run, which is a size suited for opening between the defective endothelial cells in tumors. The long-circulating polymer nanoparticles were allowed to gradually accumulate in the tumors for 11 days. The amount of nanoparticles accumulated in the tumors was remarkably augmented from 3.4%ID/g tissue at 1 day to 25.9%ID/g tissue at 11 days after i.v. administration. The self-assembled nanoparticles were sustained at a high level throughout the 14 day experimental period, indicating their long systemic retention in the blood circulation. The ${\gamma}$-images provided clear evidence of selective tumor localization of the $^{131}I$-labeled nanoparticles. Confocal microscopy revealed the fluorescein-labeled nanoparticles to be preferentially localized in the perivascular regions, suggesting their extravasation to the tumors through the hyperpermeable angiogenic tumor vasculature. This highly selective tumoral accumulation of nanoparticles was attributed to the leakiness of the blood vessels in the tumors and their long residence time in the blood circulation.

• 한국식생활문화학회지
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• 제34권6호
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• pp.771-778
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• 2019

This study investigated the effect of temperature deviation on the water-holding capacity, tenderness, lipid oxidation, and color stability of Korean Hanwoo (韓牛) beef during long-term aging. The striploins (M. longissimus lumborum) were aged for 56 days at 2±1℃ (T1), 2±2℃ (T2), or 2±3℃ (T3). Drip loss and cooking loss were higher (p<0.05) in T3 than in T1 on day 56. The Warner-Bratzler shear force value was similar for all treatments during aging times. On day 56, the content of 2-thiobarbituric acid reactive substances was higher (p<0.05) in T3 as compared to T1. The CIE L^* and b^* values were similar for all treatments, but the a^* value was lower (p<0.05) in T3 than in T1 on the last day. These findings indicate that high temperature deviation adversely affects the water-holding capacity, lipid oxidation stability, and color stability of Hanwoo beef during long-term aging.

• 대한약침학회지
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• 제21권1호
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• pp.35-40
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• 2018

Objective: The role of BDNF (brain-derived neurotrophic factor), CREB (cAMP response element binding) and VGF neuropeptide has been proved in antidepressant activity of long term saffron administration in the rat hippocampus. In this study we evaluated the role of these proteins in antidepressant activity of saffron in long term administration in the rat cerebellum. Methods: Saffron aqueous extract (40 and 80 mg/kg/day) and imipramine (10 mg/kg/day) were administered intraperitoneally for 21 days to rats. At the end of experiment, animals were sacrificed and cerebellums were separated. The protein levels of BDNF, VGF, CREB and P- CREB in the rat cerebellum were evaluated using western blot analysis. Results: Saffron aqueous extract (80mg/kg/day) caused significant increase in protein level of P-CREB in long term treatment in the rat cerebellum. The increases in the protein levels of VGF, CREB and BDNF were not significant. Conclusion: In summary, our results showed that antidepressant effect of saffron in rat cerebellum might be due to the enhanced phosphorylation of CREB.

• 대한수의학회지
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• 제40권1호
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• pp.1-16
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• 2000

Nowadays, mongolian gerbil is notably utilized for the research of brain and water deprivation because of a congenital incomplete willis circle structure in the brain, audiogenic seizure in low noise, and special cholesterol metabolism without water absorption for a long time. In this study, we are intend to identify the morphological changes of the catecholaminergic neuron of brain according to the time lapse in the condition of long term water deprivation. 55 mongolian gerbil were divided 10 groups(control, 1, 2, 3, 4, 5, 10, 15, 20, 42th day water deprivation group), of which each group include 5 mongolian gerbils and 5 normal mongolian gerbils in control group were also used for brain atlas as a control. The brains were observed by the immunohistochemical stain using the TH, DBH and PMNT antibody. The results were as followings; 1. The nerve fibers of the TH-immunoreactive neuron were observed only in the and corpus striatum of the telencephalon. 2. Intensity of the immunostain of the nerve fiber in the cerebral cortex and corpus striatum was decreased gradually day by day after water deprivation. 3. The TH-immunoreactive nerve cells were observed in the paraventricular and periventricular nucleus of the 3rd ventricular in the hypothalamus of mongolian gerbil but the number of nerve cells were decreased from the first day of the water deprivation to the 10th day and increased until the 20th day, after than redecreased from the 20th day by the continuous water deprivation. The number of nerve fibers in this area were increased in the first day, but decreased from the 2nd day of water deprivation. The shape and density of the dopamine secreting cells in the brain of mongolian gerbil by the immunoreactive stain were changed in the continuous water deprivation. In this results, we can conclude that dopamine concerned in the water metabolism of mongolian gerbil, and mongolian gerbil could be used as an animal model for the research of water deprivation.

• 한국환경과학회지
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• 제21권2호
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• pp.189-202
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• 2012

Power spectral analysis for $PM_{10}$ observed at 10 cities in the Korean Peninsula from 2004 to 2010 was carried out to examine the spatial and temporal features of $PM_{10}$ evolution cycle. The power spectrum analysis proposed 9 typical cycles (0.5 day, 1day, 5.4day, 8~10day, 19~21day, 26day, 56day, 180day and 365day) for $PM_{10}$ evolution and the cycles are strongly associated with dilution and transportation due to the meterological influence. The spectrum intensity of 5.4day and 26day $PM_{10}$ evolution cycles mainly depend on the advection cycles of synoptic pressures system and long-term variation of climatological forcing, respectively. The intensity of $PM_{10}$ evolution with longer temporal cycles than one day tends to be stronger in La ni$\tilde{n}$a period in comparison with that in El ni$\tilde{n}$o period. Mean of typical intensity of $PM_{10}$ evolution in La ni$\tilde{n}$a period estimated to be 30% larger than El ni$\tilde{n}$o period. Thus the global scale meteorological phenomena such as El ni$\tilde{n}$o and La ni$\tilde{n}$a also can influence the variation of wind system in the Korean Peninsula and $PM_{10}$ evolution. but global scale forcing tends to influence different manner for $PM_{10}$ evolution in accordance with its temporal cycles.

• 대한통합의학회지
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• 제8권1호
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• pp.219-228
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• 2020

Purpose : This study highlights the importance of occupational therapy at adult day care centers by examining the current state of this therapy at these centers. Methods : Data on 1,527 adult day care centers in South Korea were retrieved from a long-term care insurance site for the elderly and were statistically processed. Results : Of these centers, 1,331 (87.2 %) were cognitive activity-oriented, 37 (2.4 %) were exclusively for dementia treatment, and 159 were nonspecialized centers (10.4 %). A second finding was that 294 (19.3 %) of the centers operated occupational therapy programs. Third, only 40 occupational therapists (2.6 %) were working at one of these 1,527 care centers nationwide. Fourth, the occupational therapy programs comprised 4.91 ± 3.93 cognitive enhancement programs per center, 2.58 ± 2.26 training assistance programs per center, and other programs 2.56 ± 2.58 per center. Fifth, a regional comparison of the operation of occupational therapy programs at these centers showed a statistically significant difference in the number of programs between Seoul and other regions. Conclusion : Although most adult day care centers currently deliver cognitive enhancement programs, they show a low employment rate of occupational therapists. Therefore, additional research involving workers at adult day care centers is required to investigate perceptions and the necessity of occupational therapy.

• 한국토양환경학회지
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• 제1권1호
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• pp.19-27
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• 1996

물에 쉽게 용해되지 않고 분리된 유체면을 갖는 액체를 NAPO(nonaqueous phase liquids)이라 한다. 유기용제와 석유탄화수소와 같은 NAPL에 의한 지하수 오염은 지하에서의 장기간의 지속성 및 다량의 지하수를 오염시키는 능력 때문에 주요 관심 대상물질이다 누출된 DNAPU(denser- than-water NAPL)은 궁극적으로 포화 대수층을 통과하여 바닥에 DNAPL pool을 이루게 된다. 이러한 pool로부터의 용해는 분자확산계수, 연직분산도, 지하수유속, 용해도 및 pool의 길이에 지배된다. 본 연구에서는 이러한 DNAPL pool의 용해를 모사하기 위해 DNAPL용해실험을 하여 연직 횡분산계수를 산정하였다. 본 연구에서 사용된 실험조건하에서 수행한 실험결과 산정된 연직 횡분산계수는 침투유속이 59.2cm/day, 94.3cm/day 및 158.0cm/day인 경우 각각 1.86$cm^2$/day, 2.90$cm^2$/day 및 4.51$cm^2$/day 이었고, 연직 횡분산도는 0.03024cm 이었다.

• 대한의생명과학회지
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• 제24권4호
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• pp.411-417
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• 2018

The aim of this study was to investigate the impact of participation in the 622 km hyper-ultra-marathon on hepatic metabolism and renal function in middle-aged men. Healthy middle-aged male amateur ultra-marathoners between the ages of 40 and 60. Blood was collected at the pre-race, immediately after 300 km, 622 km hyper-ultra marathon race, 72 hours (3 day) and 144 hours (6 day) after the race, AST (aspartate aminotransferase), ALT (alanine aminotransferase), ALP (alkaline phosphatase), ${\gamma}$-GTP (gamma glutamyl transferase), T-Bil (total bilirubin), D-Bil (direct bilirubin), T-protein (total protein), albumin, uric acid, BUN (blood urea nitrogen), creatinne were analyzed. ALP was significantly increased at 300 km, 622 km, day 3 and day 6 than the pre-race. ${\gamma}$-GTP, T-protein, albumin, uric acid, BUN and creatinine were not significantly different between the distances and the recovery period respectively. AST and ALT were significantly increased at 300 km, 622 km, day 3 and day 6 than the pre-race, respectively (P<0.05) at day 3 and day 6 they showed significant decrease from 300 km and 622 km, respectively (P<0.05). T-Bil and D-Bil increased significantly at 300 km and 622 km, respectively (P<.05) and significantly decreased at day 3 (P<0.05) compared to the pre-race, at day 3 and day 6 they were decreased significantly than 300 km and 622 km, respectively (P<0.05). In conclusion, no disturbance of renal function was observed according to the distances and between the recovery period of 622 km hyper-ultra marathon race, but reversible hepatocyte function could be degraded and some hemolysis of blood vessels was induced.

• 천문학회지
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• 제11권1호
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• pp.47-54
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• 1978

Twelve Chih was sasigned to each day in the old Chinese calendar. This paper clarifres the relations between 12 Chih and the diurnal motion of Big Dipper or the clock, and it shows the long term table and formula for the dayly assignment of 12 Chih in the calendar.

• 지질공학
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• 제20권2호
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• pp.169-181
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• 2010

지질구조 요소 중 산성 암맥은 K-1 유류비축기지에서 지하수 유동에 직접적인 영향을 미칠 수 있다. 산성 암맥의 산출 특성과 기지 주변의 수리지질학적 조건을 토대로 지하수 모델링을 수행하였으며, 자연적 또는 인위적으로 가능한 시나리오를 구성하여 기지 인근 지역의 지하수위 변화 스트레스에 대한 반응을 모의하였다. 기지 주변에서 24개의 가상적인 우물들을 활성화하고 4단계 양수량 변화에 따른 수위 영향반경의 변화를 고려함으로써, 비축기지 내 안정적 수위 유지를 위해 다음과 같이 5개의 구획을 구분하여 양수량 제한 구역 설정을 제안하였다; zone I (기지에서 300 m 이내 범위), 50 $m^3/day$ 이하; zone II (기지에서 300~600 m 범위), 75 $m^3/day$ 이하; zone III (기지에서 600~900 m 범위), 150 $m^3/day$ 이하; zone IV (기지에서 900~1,200 m 범위), 300 $m^3/day$ 이하; zone V (산성암맥 주변). 산성 암맥을 따른 zone V에서는 맥암으로부터 70~100 m 거리까지 양수의 영향이 나타날 수 있으므로 다른 지점들에 비해 특별히 지하수 사용에 대한 제한과 주의가 요구된다.