• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.52-56
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• 1985

For the fundamental studies of radiation breeding in edible marine algae, the biological effects on conchospores of Porphyra species by gamma-irradiation were examined. Two varieties, Keun-cham-gim (Porphyra tenera Kjell. form tamatsuensis Miura) and Saga No.5, were chosen for this study, and their conchospores after r-irradiation($5.0{\sim}20.0$ KR) were cultured for 50 days. The results obtained were summarized as follows. 1. Gamma-irradiation in less than the dose of 20KR did not affect germination of conchospores, and almost all spores grew into two cells germ in 24 hours after irradiation, but withering germs were gradually increased in number according to higher exposure within 5 days old culture. 2. High irradiation caused the induction of giant cells, abnormal useless growth of hold-fast, lumpish thalli and callus-like lumpy tissues. 3. The liberation of neutral spores from young germs and carpospores from mature thalli were observed on the frond exposed at $10{\sim}20$ KR irradiation. All spores were normal in division and its size. 4. The best irradiation effect on growth of Keun-cham-gim was observed at 10 KR dose, whose growth-rates were $140\%$ in wet weight and $108\%$ in mean frond area, but only $48\%$ was recorded in wet weight at 20 KR exposure. Saga No.5 were in contrast with Keun-cham-gim, and their most growth-rate was $400\%$ in wet weight ($258\%$ in frond area) at 10 KR irradiation and the worst was $20\%$ at the dose of 20 KR. 5. The withering phenomenon to death by treatment of gamma-ray presented substantial difference between two varieties. Survival rate compared with control in Keun-cham-gim was $70.7\%$ at 20 KR, but that in Saga No.5 recorded $47.0\%$ at same dose. 6. Synthesizing the results of high and low r-irradiation, it was suggested tat high r-irradiation in more than 5.0 KR inhibited conspicuously the growth of germs derived from conchospores, and about half of them withered at 15.0 KR dose or more.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.47-57
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• 2000

Objective: The effects of cryopreservation with or without coculture on the in vitro development of blastomere-biopsied 8-cell mouse embryos were investigated. This experimental study was originally designed for the setup of a preclinical mouse model for the preimplantation genetic diagnosis (PGD) in human. Methods: Eight-cell embryos were obtained after in vitro fertilization (IVF) from F1 hybrid mice (C57BL(표현불가)/CBA(표현불가)). Using micromanipulation, one to four blastomeres were aspirated through a hole made in the zona pellucida by zona drilling (ZD) with acid Tyrode's solution (ATS). A slow-freezing and rapid-thawing protocol with 1.5M dimethyl sulfoxide (DMSO) and 0.1M sucrose as cryoprotectant was used for the cryopreservation of blastomere- biopsied 8-cell mouse embryos. After thawing, embryos were cultured for 110 hours in Ham's F-10 supplemented with 0.4% bovine serum albumin (BSA). In the coculture group, embryos were cultured for 110 hours on the monolayer of Vero cells in the same medium. The blastocyst formation was recorded, and the embryos developed beyond blastocyst stage were stained with 10% Giemsa to count the total number of nuclei in each embryo. Results: The survival rate of embryos after cryopreservation was significantly lower in the blastomere-biopsied (7/8, 6/8, 5/8, and 4/8 embryos) groups than in the non-biopsied, zona intact (ZI) group. Without the coculture, the blastocyst formation rate of embryos after cryopreservation was not significantly different among ZI, the zona drilling only (ZD), and the balstomere-biopsied groups, but it was significantly lower than in the non-cryopreserved control group. The mean number of cells in embryos beyond blastocyst stage was significantly higher in the control group ($50.2{\pm}14.0$) than in 6/8 ($26.5{\pm}6.2$), 5/8 ($25.0{\pm}5.5$), and 4/8 ($17.8{\pm}7.8$) groups. With the coculture using Vero cells, the blastocyst formation rate of embryos after cryopreservation was significantly lower in 5/8 and 4/8 groups, compared with the control, 7/8, and 6/8 groups. The mean number of cells in embryos beyond blastocyst stage was also significantly lower in 4/8 group ($25.9{\pm}10.2$), compared with the control ($50.2{\pm}14.0$), 7/8 ($56.0{\pm}22.2$), and 6/8 ($55.3{\pm}25.5$) groups. Conclusion: After cryopreservation, blastomere-biopsied mouse embryos have a significantly impaired developmental competence in vitro, but this detrimental effect might be prevented by the coculture with Vero cells in 8-cell mouse embryos biopsied one or two blastomeres. Biopsy of mouse embryos after ZD with ATS is a safe and highly efficient preclinical model for PGD of human embryos.

• Journal of Aquaculture
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• v.22 no.1
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• pp.105-111
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• 2009

In this study, we carried out an experiment for estimation the larval digestibility in aspects which digestive enzymatic activities and nutrition of the rotifers, Brachionus rotundiformis. Thus we enhanced the digestive enzymatic activity through the addition of starch for the increase of digestibility of rotifer (starch-rotifer), and compared with the feed efficiency through rearing of the olive flounder, Paralichthys olivaceus used rotifer lipid-enriched with Algamac $2000^{(R)}$ (CE-rotifer). The digestive enzyme activities (except for TG-lipase), total protein contents, total essential amino acid, essential amino acids (methionin and phenylalanine) of starch-rotifer (the rotifer used a starch as additive, and enriched not) was assayed significantly higher than CE-rotifer (P<0.05). And total lipid, lipid classes (except for sterol) and fatty acids as DHA and EPA showed higher in CE-rotifer than starch-rotifer (P<0.05). But, sterol contents and ST/TG ratio were shown significantly higher in starch-rotifer (P<0.05). The flounder larvae supplied the two rotifers showed standard length and body weight that not significantly differed with ranges $3.72{\sim}3.79\;mm$ and $32.9{\sim}37.8\;mg$/larva on 6 days after hatching (DAH), respectively (P>0.05). However, these of 12 DAH showed the values of significantly higher to $5.94{\pm}0.249\;mm$, $144.0{\pm}23.86\;mg$/larva and $26.2{\pm}12.13%$ in standard length, body weight and survival in CE-flounder than that of starch-flounder (P<0.05). The hydrolytic enzymatic activities of flounder larvae severally supplied the two rotifers showed the significantly higher activities in acidic -amylase, neutral -amylase, TG-lipase, lysozyme and acidic phosphatase in starch-flounder on 5 DAH (P<0.05). But neutral $\alpha$-amylase, three proteases and two phosphatases of CE-flounder on 11 DAH showed the significantly higher activities than that of starch-flounder (P<0.05). Therefore, for the flounder, Paralichthys olivaceus larvae just depleted yolk was more beneficial to supply the feed, rotifer, enhanced the digestibility than to supply the feed lipid-enriched for aspect of larval digestibility up to 6 DAH, thereafter nutrition of absorption due to the development of digestive organs suggested that enrichment effect appeared with larval somatic growth. Consequently, investigation more detailed about the larval digestive physiological and nutritional requirement variations after 6 DAH will be necessary, thereafter.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.136-142
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• 2009

Bone density in the recipient implant site seems to be an important factor for long term success of endosseous implants. Preoperative evaluation of bone density is very helpful to assist the clinician with the treatment planning of implant therapy. Accurate information on bone density will help the surgeon identify suitable implant sites, thereby improving the success rate of the procedure. Purpose; The aim of this study was to evaluate a correlation between bone density measured preoperatively with computerized tomography and histologically measured bone density by bone biopsy. Patients and methods; Twenty seven patients were selected. All the patients were in good health, with no systemic disorder and additional bone graft. Preoperatively the patients underwent CT scanning to evaluate Houmsfield Unit(HU). Each patients wore a surgical template for implant placement. During surgery 2mm in diameter and 6mm in length specimens were taken. Histomorphometric analysis was performed using digitalized image analysis software Axiovision 4.3. Also, the Resonance frequency analysis(RFA) and insertion torque values were recorded. Results; The highest histomorphometric values was found in the posterior mandible $32.3{\pm}3.8$, followed by $29.9{\pm}2.6$ for the posterior maxilla, $29.4{\pm}2.6$ for the anterior maxilla, $28.6{\pm}2.3$ for the anterior mandible(p=0.214). The hounsfield unit was $989.2{\pm}258.1$ in the posterior mandible, $845.0{\pm}241.5$ in the anterior maxilla, $744.5{\pm}92.6$ in the anterior mandible, $697.3{\pm}136.9$ in the posterior maxilla(p=0.045). This results may suggest that there are strong correlation between the histomorphometric values and hounsfield unit(r=0.760, p<0.05). The RF measurements were $81.9{\pm}2.4$ ISQ in the posterior mandible, $79.0{\pm}1.4$ ISQ in the anterior mandible, $78.3{\pm}4.6$ ISQ in the posterior maxilla, $76.5{\pm}5.0$ ISQ in the anterior maxilla(p=0.048). The insertion torque values was $43.2{\pm}4.2\;Ncm$ in the posterior mandible, $42.0{\pm}0.0\;Ncm$ in the anterior mandible, $41.3{\pm}4.1\;Ncm$ in the posterior maxilla, $40.8{\pm}3.8\;Ncm$ in the anterior maxilla(p=0.612). This results may suggest that there are statistical significance between the hounsfield unit and the insertion torque values(r=0.494, p<0.05), the histomorphometric values and the insertion torque values(r=0.689, p<0.05). But there was no correlation between histomorphometric values and ISQ. There was no statistical significance in age and gender effect on parameters. Conclusions; There was significant correlations between bone density and implant stability parameters. The bone density measurements using preoperative CT may help clinicians to predict primary stability before implant insertion, which is associated with implant survival rates.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.371-379
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• 2004

The purpose of this study was to investigate the changes and types of statistical methods used in the Korean Journal of Orthodontics (KJO) and the American Journal of Orthodontics and Dentofacial Orthopedics (AJODO) from )999 to 2003. The frequency of use, transitions, assumption check of statistical methods and types of advanced statistical methods were examined from each journal. The study consisted of 247 articles published in the KJO and randomly chosen 50 articles per year which were original articles and used statistical methods T-test, analysis of variance(ANOVA), correlation analysis, nonparametric analysis. regression analysis chi-square test. factor analysis, were the order of statistical methods most frequently used in the KJO, while t-test. ANOVA, nonparametric analysis, correlation analysis, regression analysis, chi-square test. factor analysis. were the order of statistical methods used in the AJODO The changes of statistical methods observed in the KJO were not significant $(X^2=17.4\;p=0.5881)$ but the changes observed in the AJODO was seen to be significant $(x^2=42.4,\;p=0.0397)$ Some of the studies examined had overlooked the assumptions of the statistical methods employed. Data investigation such as outlier should be performed before analysis and alternative statistical approaches are applied for a small sample size. Types of advanced statistical methods were factor analysis and discriminant analysis in the KJO and Intention-To-Treat (ITT) analysis in clinical trials through multi-center, survival analysis and Generalized Estimating Equations (GEE) in the AJODO. Appropriate analysis approaches and interpretations should be applied for the correlated and repeated measurements of the orthodontic data set.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.127-143
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• 1998

The author evaluated the effects of taxol, a microtubular inhibitor, as a possible radiation sensitizer and the production of prostaglandins on three human cancer cell lines(KB, RPMI-2650 and SW-13) and one murine cell line(L929). Each cell line was divided into four groups (control, taxol only, radiation only and combination of taxol and radiation). The treatment consisted of a single irradiation of 10Gy and graded doses (5, 50, 100, 200, 300, 500 nM) of taxol for a 24-h period. The cytotoxicity of taxol alone was measured at 1 day after(1-day group) and 4 days after(4-day group) the treatment. The survival ratio of cell was analyzed by MTT (3-(4,5-dimethylthiazol-2-yl) -2,5-dimethyl tetrazolium bromide) test. Prostaglandins(PGE2 and PGI2) were measured in the culture medium by a radioimmunoassay. The results obtained were as follows. 1. There was a significantly increased cytotoxicity of KB cells in 4-day group than those in I-day group. There was a high correlation between doses of taxol and cell viability in both groups(l-day group R=0.82741, 4-day group R=0.84655). 2. There was a significantly increased cytotoxicity of RPMI -2650 cells treated with high concentration of taxol in 4-day group than those in I-day group. Also there was a high correlation between doses of taxol and cell viability in 4-day group(R=0.93917). 3. There was a significantly increased cytotoxicity of SW-13 cells treated with high concentration of taxol in 4-day group than those in 1-day group. However no high correlation was observed between doses of taxol and cell viability in both groups(1-day group R=0.46362, 4-day group R=0.65425). 4. There was a significantly increased cytotoxicity of L929 cells treated with low concentration of taxol in 4-day group than those in 1-day group. At the same time, there was a low correlation between doses of taxol and cell viability in both groups(1-day group R=0.34237, 4-day group R=0.23381). 5. In I-day group of L929 cells, higher cytotoxicities were observed in the groups treated with 500 nM taxol than given 10 Gy radiation alone. L929 cells in I-day group alone showed a radiosensitizing effect by taxol.. 6. In addition to L929 cells, all cancer cells treated with a combination of taxol and radiation in 4-day group appeared to have some fragmented nuclei and to float on the medium. In addition, L929 cells appeared to be more confluent. 7. The level of PGE2 production was the highest in the contol KB cells. This appeared to increase in every experimental group of all three cancer cells except L929 cells. There was a significantly increased production of PGE2 in SW -13 cells treated with a combination taxol and radiation compared to the other experimental groups. 8. The level of PGE2 production in the control group of RPMI-Z650 cells was the highest. This appeared to increase in every experimental group of all cells except in SW-13 cells. This also increased significantly in RPMI-2650 cells treated with a combination of taxol and radiation compared to the other experimental groups.

• Journal of Life Science
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• v.21 no.9
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• pp.1234-1243
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• 2011

Liriope platyphylla has been used in oriental medicine as an effective medical plant to improve symptoms of cough, sputum production, neurodegenerative disorders, obesity and diabetes for long time. In order to investigate the effects of novel extracts on nerve growth factors (NGF)-stimulated neuritic outgrowth, the alteration of NGF expression and NGF receptor signaling pathway were detected in neuroblastoma cells and C57BL/6 mice. Of a total of 13 novel extracts, 4 extracts (LP-E, LP-M, LP-M50, LP2E17PJ) showed high viability on MTT assay. Also, all of these extracts induced NGF secretion and NGF mRNA expression in neuroblastoma cells. However, the NGF-induced neuritic outgrowth from PC12 cells was only stimulated by LP-E, LP-M and LP-M50. Furthermore, we selected LP-M as a best candidate, based on method and amounts of extraction, in order to verify its effect in mice. C57BL/6 mice were treated with 50 mg/kg of LP-M for 2 weeks and the effects on NGF regulation were analyzed with various methods. The expression of NGF mRNA was significantly increased in LP-M treated mice compared to vehicle treated mice. Also, the signaling pathway of p75NTR was inhibited in the cortex by LP-M treatment, with no change in the hippocampus of brain. However, the signaling pathway of TrkA was dramatically activated in only hippocampus via LP-M treatment. Therefore, these results suggest that the novel four extracts of L. platyphylla may contribute to the regulation of NGF expression and secretion in neuronal cells. LP-M was especially considered to be an excellent candidate for a neurodegenerative disease-therapeutic drug.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.94-105
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• 2009

Black locust (Robinia pseudoacacia) stand is representative lowland exotic plantation with low ecological quality and arrested succession in South Korea. To facilitate succession and restore natural vegetation, small canopy gaps (${\sim}57m^2$), which can modify minimally structural variables and reduce restoration related disturbances on stand, was established in the black locust stand, and oak (Quercus serrata) seedlings were introduced in the gap. Two types of varying levels were introduced for gap creation; cutting (C) and girdling (G) on canopies. Understory removal (CU and GU) treatment was applied as subtypes of structural modification. Growth (diameter, height and leaf area) of target species and responses (species composition, diversity and coverage) of understory community were monitored during study years (2007~2008). Canopy openness was different significantly among treatments but not for light availability. Based on the result of logistic regression, growth of height and leaf area of seedlings were significant variables on seedling survival. Height and leaf area of seedlings were increased during study years, although radial growth was reduced. During study years, there were no significant differences in species composition and diversity, and total coverage increased about 20%. Increase of resources by gap creation and understory removal likely affect growth of target species. Small gap creation was effective to reduce understory responses in composition and diverstiy. Synthesized, growth of target species and responses of understory community to small canopy gap creation exhibited, in short term, possibility of utilization in alternative forest restoration and management option. Long-term monitoring is necessary to certificate effect of artificial gap creation on forest restoration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1533-1543
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• 2016

The anti-stress effects of Punica granatum L. (family Lythraceae, PG) on $H_2O_2$/corticosterone (CORT)-induced stress in cells and sleep-deprived rats were investigated. The PG extract showed neuroprotective effects in SH-SY5Y cells against $H_2O_2$/CORT-induced stress. Sleep deprivation led to behavioral, hormonal, and biochemical alterations in the animal model. The effects of P. granatum on physiological, behavioral, and biochemical parameters aggravated by sleep deprivation were investigated. Sleep deprivation impaired physiological (survival, body weight, and drowsiness scores) and behavioral (rotarod, passive avoidance, hot hyperalgesia, and Y maze) parameters as well as biochemical factors (cortisol, serotonin, dopamine, testosterone, and growth factor I contents in serum). These parameters were significantly recovered by PG extract in a concentration-dependent manner. The PG extract also enhanced catalase, superoxide dismutase, and non-enzymatic antioxidative activities such as glutathione compared to sleep-deprived rats. On the basis of these results, our findings suggest that Punica granatum prevents impairment of body functions induced by sleep deprivation and related oxidative damage.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.57-67
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• 2020

Pinus densiflora is the most widely distributed tree species in South Korea. Its ecological and socio-cultural attributes makes it one of the most important tree species in S. Korea. In recent times however, the distribution of P. densiflora has been affected by dieback. This phenomenon has largely been attributed to climate change. This study was conducted to investigate the responses of growth and physiology of P. densiflora to drought and nitrogen fertiliz ation according to the RCP 8.5 scenario. A Temperature Gradient Chamber (TGC) and CO₂. Temperature Gradient Chamber (CTGC) were used to simulate climate change conditions. The treatments were established with temperature (control versus +3 and +5℃; aCeT) and CO₂ (control: aCaT versus x1.6 and x2.2; eCeT), watering(control versus drought), fertilization(control versus fertilized). Net photosynthesis (P_n), stomatal conductance (g_s), biomass and relative soil volumetric water content (VWC) were measured to examine physiological responses and growth. Relative soil VWC in aCeT significantly decreased after the onset of drought. P_n and g_s in both aCeT and eCeT with fertiliz ation were high before drought but decreased rapidly after 7 days under drought because nitrogen fertilization effect did not last long. The fastest mortality was 46 days in aCeT and the longest survival was 56 days in eCeT after the onset of drought. Total and partial biomass (leaf, stem and root) in both aCeT and eCeT with fertiliz ation were significantly high, but significantly low in aCeT. The results of the study are helpful in addressing P. densiflora vulnerability to climate change by highlighting physiological responses related to carbon allocation under differing simulated environmental stressors.