• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.372-382
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• 2006

Most of the conventional breakwaters impermeable breakwaters which block seawater exchange between the outside and inside of the harbors. The blocking of seawater exchange may cause pollution of water in harbors. To solve the water pollution problem, various kinds of seawater exchange breakwaters have been proposed. Their types can be classified into the current type which uses tidal current, and the overtopping type which uses the wave energy. The overtopping type breakwaters require a discharge coefficient to calculate the rate of overtopping into the harbor. The present study is to compute the rate of overtopping with introduction of a correct discharge coefficient and to evaluate the effect of the overtopping type breakwater on the water qualify inside a harbor. The rate of overtopping was computed by using Forchheimer formula with time dependent mild-slope equation for various wave conditions. The formula has been generally used to calculate the overflow discharge in steady state river flows. The discharge coefficient, which is the key parameter of the calculation, was determined by a series of hydraulic model tests. The present scheme was applied to the seawater exchange section of the western breakwater of Jeju New Harbor's and the efficiency of that section was examined. The calculated results showed that the rate of overtopping into the harbor reached about $27.5m^3/s$ in the wave condition (wave height 3.7 m, wave period 8.5s, and wave direction NNW).

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.95-95
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• 2001

Ciinidipine (FRC-8635) is a newly synthesized novel DHP type of organic Ca$\_$2＋/channel blockers that have been developed so far in Japan (Yoshimoto et al., 1991 : Hosono et at., 1992). It also has a blocking action on L-type voltage-dependent Ca$\^$2＋/channel (VDCCs) in the rabbit basilar artery (Oike et al., 1990) and a slow-onset and long-lasting hypotensive action in clinical and experimental studies (Ikeda et al., 1992 ; Tominaga et al., 1997). Recent electrophysiological data indicate that cilnidipine might be a dual-channel antagonist for peripheral neuronal N-type and vascular L-type Ca$\^$2＋/channels (Oike et al., 1990 ; Fujii et al., 1997; Uneyama et at., 1997). However, little is known about the involvement of N-type VDCCs in contributing to the muscarinic receptor-mediated CA secretion. Therefore, the present study was attempted to investigate the effect of cilinidipine on secretion of catecholamines (CA) evoked by ACh, high K$\^$＋/, DMPP and McN-A-343 from the isolated perfused rat adrenal gland. Cilnidipine (1-10 ${\mu}$M) perfused into an adrenal vein for 60 min produced dose- and time-dependent inhibition in CA secretory responses evoked by ACh (5.32${\times}$10$\^$-3/M), DMPP (10$\^$-4/ M for 2 min) and McN-A-343 (10$\^$-4/ M for 2 min). However, lower dose of lobeline did not affect CA secretion by high K$\^$＋/(5.6${\times}$10$\^$-2/ M), higher dose of it reduced greatly CA secretion of high K$\^$＋/. Cilnidipine itself did also fail to affect basal catecholamine output. Furthermore, in adrenal glands loaded with cilnidipine (10 ${\mu}$M), CA secretory response evoked by Bay-K-8644 (10 ${\mu}$M), an activator of L-type Ca$\^$2＋/channels was markedly inhibited while CA secretion by cyclopiazonic acid (10 ${\mu}$M), an inhibitor of cytoplasmic Ca$\^$2＋/-ATPase was no affected. Moreover, $\omega$-conotoxin GVIA (1 ${\mu}$M), given into the adrenal gland for 60 min, also inhibited time-dependently CA secretory responses evoked by ACh and high K$\^$＋/.

• Journal of Life Science
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• v.20 no.10
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• pp.1490-1497
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• 2010

The present study aimed to investigate the level of accumulated heavy metal in various tissues of Carassius auratus after exposure to Cadmium (Cd), histologically and physiologically. After treating C. auratus with Cd, the accumulated Cd in gill tissues was detected to be of the highest content, and showed the lowest content in integument tissues. Also, Cd content increased in a time dependent manner and showed the highest accumulation in the tissues exposed for 20 days. Antioxidant enzyme activities showedhigher activity in the gill and integument than in the kidney and liver tissues. In the case of SOD, antioxidation activity of SOD in all Cd exposed tissues was higher than in unexposed tissues. The activities of SOD and CAT also became higher after Cd exposure. Gill tissues exposed to Cd showed an increased number of mucous cells between lamella in a time dependent manner. In addition, the gills showed morphological changes such as edema, exfoliation of epithelial cells, and fusion of the secondary lamellae. Also, exposure to Cd for 20 days had an effect on gill tissues, causing membrane damage in the mitochondria and nucleus. In kidney tissues, atrophied glomerulus was observed, and the empty space in Bowman's capsule was wider.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1499-1506
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• 2016

Background: Crocus sativus and its major constituent crocin are well established to have anti-cancer properties in breast cancer cells (MCF-7). However the role of C. sativus extract (CSE) and crocin on caspase signaling mediated MCF-7 cell death at molecular level is remains unclear. In this study, we tried to unravel role of CSE and crocin on caspase mediated MCF-7 cells death and their in vivo preclinical toxicity profiling and immune stimulatory effect. Materials and Methods: CSE extract was fractionated by HPLC and crocin was isolated and characterized by NMR, IR, and MS. MCF-7 cells were treated with both CSE and crocin and expression of Bcl-2 and Bax was assessed after 24 and 36 hours. Furthermore, caspase 3, caspase 8 and caspase 9 expression was determined by Western blotting after 24 hours of treatment. DNA fragmentation analysis was performed for genotoxicity of CSE and crocin in MCF-7 cells. The in vivo toxicity profile of CSE (300 mg/kg of b.wt) was investigated in normal Swiss albino mice. In addition, peritoneal macrophages were collected from crocin (1, 1.5 and 2 mg/kg body weight) treated mice and analyzed for ex vivo yeast phagocytosis. Results: Immunoblot analysis revealed that there was time dependent decline in anti-apoptotic Bcl-2 with simultaneous upregulation of Bax in CSE and crocin treated MCF-7 cells. Further CSE and crocin treatment downregulated caspase 8 and 9 and cleaved the caspase 3 after 24 hours. Both CSE and crocin elicited considerable DNA damage in MCF-7 cells at each concentration tested. In vivo toxicity profile by histological studies revealed no observable histopathologic differences in the liver, kidney, spleen, lungs and heart in CSE treated and untreated groups. Crocin treatment elicited significant dose and time dependent ex vivo yeast phagocytosis by peritoneal macrophages. Conclusions: Our study delineated involvement of pro-apoptotic and caspase mediated MCF-7 cell death by CSE and crocin at the molecular level accompanied with extensive DNA damage. Further we found that normal swiss albino mice can tolerate the maximum dose of CSE. Crocin enhanced ex vivo macrophage yeast phagocytic ability.

• Development and Reproduction
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• v.18 no.3
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• pp.161-166
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• 2014

Previously, we demonstrated that the shift and/or restriction of feeding time during relatively short-term period (4 weeks) could alter the pituitary gonadotropin expression and the weights of seminal vesicle and prostate in rats. We also found that the reverse feeding (RF) schedule (up to 8 weeks) might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues. In the present study, we extended the RF time regimen up to 12 weeks, and measured the reproductive tissue weights. After 4 and 8 weeks of RF, the weights of epididymis were not significantly different. After 12 weeks, however, epididymis weights of RF animals were significantly different (CON 12W : RF 12W = $48.26{\pm}0.62mg$ : $44.05{\pm}1.57mg$, p<0.05). After 4 and 12 weeks of feeding, seminal vesicle weights of RF animals were significantly decreased (CON 4W : RF 4W = $79.36{\pm}8.34mg$ : $46.28{\pm}2.43mg$, p<0.001; CON 12W : RF 12W = $72.04{\pm}3.76mg$ : $46.71{\pm}2.27mg$, p<0.001, respectively). Prostate weights were not changed by RF. Kidney and spleen weights of RF animals were significantly different on weeks 4 and 12 (Kidney, CON 4W : RF 4W = $249.72{\pm}4.20mg$ : $228.41{\pm}3.03mg$, p<0.001; CON 12W : RF 12W = $309.15{\pm}7.49mg$ : $250.72{\pm}6.13mg$, p<0.001, respectively, Spleen, CON 4W : RF 4W = $111.26{\pm}3.76mg$ : $96.88{\pm}4.69mg$, p<0.05; CON 12W : RF 12W = $123.93{\pm}10.72mg$ : $94.68{\pm}5.65mg$, p<0.05, respectively). Histology analysis of seminal vesicle revealed that the thinner epithelial cell layers, reduced complexities of swollen papilla folding in the exocrine glands on weeks 4 and 12 of RF. There was no histological difference between control and RF group on week 8. The present study indicates that up to 12 weeks RF induced differential changes in tissue weights of male mice. In particular, seminal vesicle, kidney and spleen seemed to temporarily adapted to the RF-induced metabolic stress on week 8 of feeding schedule. These results confirmed the our previous study that the RF might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues such as epididymis and seminal vesicle as well as non-reproductive tissues such as kidney and spleen. Further studies will be needed to achieve a better understanding of the how does mealtime shift affect the reproductive function and exact nature of adaptation.

• Journal of Periodontal and Implant Science
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• v.27 no.4
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• pp.923-939
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• 1997

This study was performed to evaluate the effect of mixed culture of rat's calvaria cells and periodontal ligament cells on calcification. These cells have been known to do important role on the periodontal tissue regeneration, especially alveolar bone and cementum. Experimental groups were made which based on the different rate of rat's calvaria cells and periodontal ligament cells, and then these cells were cultured with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum, $50{\mu}g/ml$ ascorbic acid, and 10mM/ ml $Na-{\beta}-glycerophosphate$. Each group was characterized by examining the cell proliferation rate, amount of total protein synthesis, alkaline phosphatase activity, and the number of calcified nodules in vitro. In cell proliferation rate , the cells of control groups were cultured Dulbecco's Modified Eagle's Medium contained with 10 % fetal bovine serum. The results were as follows : 1. The cell proliferation rate in control groups decreased stastically significantly along with the decrease of the rate of bone cells at 7 day and 20 day(P < 0.01). 2. The cell proliferation rate in experimental groups decreased stastically significantly along with decrease of the rate of bone cells at 3 day and 14 day(P < 0.01). 3. The amount of total protein synthesis was significantly decreased along with decrease of the rate of bone cells at 3 day and 6 day(p < 0.01). 4. Alkaline phosphatase activity showed reverse time dependent pattern and was significantly decreased along with decrease of the rate of bone cells during the experimental periods (P < 0.01). 5. Calcified nodules were observed in group 1 (Rat calvaria cells alone) for the first time, and the number of calcified nodule decreased stastically significantly along with the decrease of the rate of bone cells at 12 day(P < 0.01). From the above results, When bone cells and periodontal ligament cells were mixed cultured, the cell proliferation rate was mostly dependent on the actual rate of bone cells and same pattern was showed in amount of total protein synthesis, alkalinephosphatase activity, and the number of calcified nodules. And the calcified nodule forming capacity of bone cells was inhibited by periodontal ligament cells

• Journal of Korean Academy of Nursing
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• v.29 no.4
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• pp.766-779
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• 1999

The purpose of this study was to investigate the relationship between the burden on families who live with an elderly person suffering from senile dementia, and the degree of their depression. There were 400 participants in this study, staying in the Seoul and Kyonggi areas from August 1, 1997 to February 28, 1998. Among the group, 100 participants took care of their patient at home, and another 300 participants left 100 patient at a day-care center, 100 sanatorium for senile dementia(asylum for helpless elderly people), 100 an infirmary for elderly people. Eventually 242 subjects out of the 400 were selected for the data analysis. The Zarit (1980) tool was employed to measure the degree of burden and Zung's(1965) “Self-Rating Depression Scale” was employed for the data analysis. The data was analyzed, and the percentage, t-test, ANOVA and Person's Correlation Coefficient were calculated. The results are as follows : 1. The average degree of burden that care-giving families felt was 49.13, which is somewhat high. 2. The average degree of depression that care -giving families felt was 51.95, which is relatively high. 3. The degree of burden was directly affected by the relation with the patient(F＝2.48, P＜.05), and the socio-economic status of the family(F＝5.17, P＜.05). Its also affected by the patient's educational status(F＝2.17, P＜.05). 4. The degree of depression of the family was significantly dependent on sex(t＝-2.05, P＜.05), age (F＝2.99, P＜.05), the relationship with the patient(F＝3.65, P＜.01), socio-economic status (F＝7.74, P＜.001), occupation(t＝2.82, P＜.01), health status(F＝4.42, P＜.01), and the place of residence(F＝4.30, P＜.01), The patient characteristics was significantly dependent on his/her educational status(F＝3.85, P＜.01), the period of suffering from senile dementia(F＝2.47, P＜.05), and smoking habit(F＝6.17, P＜.001). 5. The relationship between the degree of burden and that of depression reads r＝0.43, which is statistically positive correlation in the high significant level. Upon analyzing the entire summation, most care-givers for elderly patients suffering from senile dementia lack time in caring for themselves. They also experience chronic fatigue and mental discomfort caused by the isolation from society, curtailment of certain activities, a sense of responsibility for their patients, and limits of their endurance in taking care of their patients over time. In conclusion, this study emphasizes the necessity for the following propositions : 1. In order to measure the degree of burden that Korean care-giving families undergo, a new tool must be developed on the basis of Korean culture. 2. An educational program based on the demands that care-giving families undergo must be developed, and its clinical effect also has to be examined.

• Archives of Plastic Surgery
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• v.34 no.3
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• pp.291-297
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• 2007

Purpose: Platelet-rich plasma(PRP) contains protein growth factors, which are actively secreted by platelets to promote wound healing. However, it is not clear whether the injection of PRP into the autologous fat grafts increases the survival rate and the degree of angiogenesis. Methods: New Zealand White rabbit ears were injected fat with PRP, saline, insulin or isoproterenol (n=8/each group) for observation of the survival and degree of angiogenesis of the injected fat. The volume of the harvested fat and the degree of angiogenesis from dorsum of rabbit ears were evaluated 4, 8, and 12 weeks after the autologous fat graft. The degree of angiogenesis was measured with microvascular density (MVD) counts. Results: The volume of harvested fat decreased in a time-dependent manner after autologous fat grafts, but the decrease rate in volume of harvested fat was slower in PRP-injected group compared to that of other control groups. The difference in the volume of the harvested fat between PRP-injected group and other control groups became significant from 4 weeks after the autologous fat graft, and was maintained up to 12 weeks. However, there was no significant difference between PRP-injected group and insulin-injected group 8 and 12 weeks after the autologous fat graft. On the contrary, MVD counts increased in a time-dependent manner after autologous fat grafts. The MVD counts were significantly higher in PRP-and insulin-injected groups than in other control groups from 4 weeks after the autologous fat graft, and these differences were maintained up to 12 weeks. There was no correlation between mean platelet numbers and the volume of harvested fat. Conclusion: The present study demonstrates that PRP-injection into autologous fat grafts increases the survival rate and the degree of angiogenesis. Thus, PRP injection with autologous fat grafts would be a promising tool for maintaining the volume of the grafted fat.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.694-701
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• 2018

Larger crack widths can be observed more in FRP-reinforced concrete members than in steel-reinforced concrete members as a result of the lower elastic modulus and bond strength of FRP reinforcement. The ACI 440.1R-15 design guide provides equations derived as the maximum bar spacing to control the crack widths indirectly. On the other hand, it is not concerned with long-term effects on the crack control design provisions. This study provides suggestions for how to incorporate time-dependent effects into the crack width equation. The work presented herein includes the results from 8 beams composed of four rectangular and T-shaped FRP-reinforced concrete beams tested for one year under four-point bending. Over a one year period, the crack widths increased as much as 2.6~3.0 times in GFRP and AFRP-reinforced specimens and 1.1~1.4 times in the CFRP-reinforced specimens compared to steel-reinforced specimens. In addition, the average multiple for crack width at one year relative to the instantaneous crack width upon the application of the sustained load was 2.4 in the specimens with a rectangular section and 3.1 in the specimens with a T-shaped section. As a result, it is recommended conservatively that the time-dependent coefficient be taken as 2.5 for the rectangular beams and 3.5 for T-beams.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.313-323
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• 2022

Atrial fibrillation (AF) is the most common supraventricular arrhythmia, and it corresponds highly with exercise intensity. Here, we induced AF in mice using acetylcholine (ACh)-CaCl₂ for 7 days and aimed to determine the appropriate exercise intensity (no, low, moderate, high) to protect against AF by running the mice at different intensities for 4 weeks before the AF induction by ACh-CaCl₂. We examined the AF-induced atrial remodeling using electrocardiogram, patch-clamp, and immunohistochemistry. After the AF induction, heart rate, % increase of heart rate, and heart weight/body weight ratio were significantly higher in all the four AF groups than in the normal control; highest in the high-ex AF and lowest in the low-ex (lower than the no-ex AF), which indicates that low-ex treated the AF. Consistent with these changes, G protein-gated inwardly rectifying K⁺ currents, which were induced by ACh, increased in an exercise intensity-dependent manner and were lower in the low-ex AF than the no-ex AF. The peak level of Ca²⁺ current (at 0 mV) increased also in an exercise intensity-dependent manner and the inactivation time constants were shorter in all AF groups except for the low-ex AF group, in which the time constant was similar to that of the control. Finally, action potential duration was shorter in all the four AF groups than in the normal control; shortest in the high-ex AF and longest in the low-ex AF. Taken together, we conclude that low-intensity exercise protects the heart from AF, whereas high-intensity exercise might exacerbate AF.