• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.305-312
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• 1997

Juveniles of black seabream, Acanthopagrus schlegeli were fed with the diets containing 0, 10, 20, 50 and 100 ppm of 3,5,3'-triiodo-1-thyronine $(T_3)$ respectively to assess the effect of this hormone on skeletal development and the change of physiological conditions for 50 days. $(T_3)$ treatment lasted for initial 40 days. Fish were fed the prescribed diet by hand to satiation in $2\~4$ times per day. After an initial 40 days period, skeletal development and abnormality were examined, and after a 50 days period, food intake, hepatosomatic index (HSI), thyroid cell height (TCH) and body proximate composition were also examined. Although toed intake was not different among 0, 10 and 20 ppm, the food intake of black seabream fed with the diets containing 50 and 100 ppm of $T_3$was significantly lower than those of 10 ppm. After the initial 40 days of $T_3$ administration, $T_3$ increased the relative growth of operculum, head, caudal fin and pectoral fin to body length, resulting in severe morphological abnormalities at the highest dose. Black seabream treated with 50 and 100 ppm of $T_3$ had abnormal shapes such as lordosis and opercular curl. The HSI parameters were reversely correlation with the dietary concentration of $T_3$. After the initial 40 days of this experiment, atrophy of thyroid gland was observed in fish administered with 50 and 100 ppm of $T_3$. On the 50th day of this experiment, atrophy of thyroid gland was observed only in the group administered with 100 ppm of $T_3$, and no difference was observed on TCH among the rest fours of experimental groups. At the end of the experiment the whore body proximate analyses indicated that there were significant effects of $T_3$ level on moisture, protein, lipid and ash contents.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.4
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• pp.293-301
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• 2008

Objective: To evaluate outcomes of patients with non-obstructive azoospermia (NOA) undergoing the testicular sperm extraction (TESE) combined with intracytoplasmic sperm injection (ICSI) with different histopathologic subgroups. Method: A total of 122 embryo-transferred TESE/ICSI cycles were compared among NOA subgroups; Germ-cell aplasia (GA, 40 cycles), Maturation arrest (MA, 32 cycles) and severe hypospermatogenesis (S-HS, 50 cycles). Obstructive azoospermia (OA, 667 cycles) patients were served as a control. TESE/ICSI outcomes such as fertilization rate (FR), clinical pregnancy rate (CPR) and live birth rate (LBR) were evaluated. Results: The 2PN FR of embryo-transferred TESE/ICSI cycle was 58.1% in GA, 42.2% in MA and 48.0% in S-HS, which was significantly lower than that of OA (72.9 %, p<0.001). For ICSI-spermatozoa cycles, there were no significant differences in CPR (22.6%, 29.4% and 26.1%) and LBR (16.1%, 29.4% and 19.6%) among NOA subgroups. The CPR of ICSI-spermatid cycles was 0.0%, 9.1% and 0.0% without a live birth. For ICSI-spermatocyte cycles, no clinical pregnancies occurred in any group. Conclusion: There was no significant difference in the FR of embryo-transferred TESE/ICSI cycles among NOA subgroups. The FR among all NOA subgroups was significantly lower than that of OA. Testicular histopathology in NOA did not affect successful pregnancy if spermatozoa extraction from the testis is successful and embryo transfer is possible.

• The Korean Journal of Malacology
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• v.27 no.4
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• pp.353-358
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• 2011

This study is the result of examining the growth and survival rate of larva and spat when supplied with Enriched live food by adding $B_{12}$, chitosan, PSB, and polysaccharides to microalgae (Chaetoceros gracilis, Isochrysis galbana) to raise the survival rate of larva and spat during artificial clam seed production. Microalge (Chaetoceros gracilis, Isochrysis galbana) was strengthened for nutrition with $B_{12}$ 0.1 ppm, chitosan 0.2 ppm, PSB 3 ppm and polysaccharides 1 ppm and was daily supplied for $3{\times}10^3-15{\times}10^3Cells/mL$ and the growth and survival rates were measured. As the result of experiment, the growth of larva did not show much difference with PSB test section $199{\pm}0.59{\mu}m$, $B_{12}$ test section $198{\pm}0.64{\mu}m$, and chitosan $197{\pm}0.52{\mu}m$, survival rate was highest at PSB test section with 99.3%, followed by $B_{12}$ test section 95.9%, and chitosan 94.5%. Growth of early spat was the highest for PSB test section at $2.74{\pm}0.58mm$, followed by polysaccharides $2.67{\pm}0.55mm$, $B_{12}$ $2.54{\pm}0.48mm$, and chitosan $2.49{\pm}0.51mm$, and the survival rate was the highest for PSB test group at 32.1%, followed by $B_{12}$ test section 31.6%, chitosan 28.5%, and polysacharrides 21.4%. From such results, PSB is found to be very effective with low-quality improvement when breeding early spat of clams, and especially for floor-type early spat breeding, it had the effect of suppressing protozoan and germs so that detailed studies from various perspectives should be conducted with various chemicals in the future.

• Korean Journal of Psychosomatic Medicine
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• v.21 no.1
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• pp.11-17
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• 2013

Objectives : This study was designed to investigate the prevalence of depressive symptoms in patients with breast cancer and to identify demographic variables and clinical characteristics impact on depressive symptoms and health related quality of life in patients with breast cancer in a university hospital. Methods : Fourty-one patients with breast cancer were selected, who had visited the department of General surgery of the Wonkwang University hospital with a diagnosis of breast cancer regularly during the period November, 2010-May, 2011. All of subjects were evaluated for the depression, anxiety and the health related quality of life with Beck Depression Inventory(BDI), anxiety subscale of Personality Assessment Inventory(PAI) and Short-Form 36 Health Survey-Korean version(SF-36-K). Patients were divided into depressive symptoms and non-depressive symptoms group according to the BDI score. We compared SF-36-K between two groups, and analized multiple regression with depression and health related quality of life as criterion variables and demographic and clinical characteristics. Results : The prevalence of depression in patients with breast cancer in a University hospital was 36.4%. Compared to the non-depression, depressed patients with breast cancer appeared significantly lower mean scores on six subscales in SF-36-K : Physical function(p<.01), Role-physical(p<.001), General health(p<.05), Social function(p<.001), Role-emotional(p<.001) and Mental health(p<.001). But there was no significant difference between two groups in Vitality and Bodily pain. Anxiety, level of education and presence of enforcement of chemotherapy(63.6%) were significant explanation variables for depressive symptoms. And type of surgery and age(55.8%) were significant explanation variables for health related quality of life. Conclusions : The prevalence of depressive symptoms in patients with breast cancer in a University hospital was 36%. The depressive symptoms had not only negative impact on the health related quality of life but also important explanation variable for health related quality of life. These results suggest that depressive symptoms in patients with breast cancer should be evaluated and treated for improving patient's health related quality of life.

• Korean Journal of Psychosomatic Medicine
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• v.25 no.2
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• pp.153-165
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• 2017

Objectives : Recent neuroimaging studies focus on dysfunctions in connectivity between cognitive circuits and emotional circuits: anterior cingulate cortex that connects dorsolateral orbitofrontal cortex and prefrontal cortex to limbic system. Previous studies on pediatric depression using DTI have reported decreased neural connectivity in several brain regions, including the amygdala, anterior cingulate cortex, superior longitudinal fasciculus. We compared the neural connectivity of psychotropic drug naïve adolescent patients with a first onset of major depressive episode with healthy controls using DTI. Methods : Adolescent psychotropic drug naïve patients(n=26, 10 men, 16 women; age range, 13-18 years) who visited the Korea University Guro Hospital and were diagnosed with first onset major depressive disorder were registered. Healthy controls(n=27, 5 males, 22 females; age range, 12-17 years) were recruited. Psychiatric interviews, complete psychometrics including IQ and HAM-D, MRI including diffusion weighted image acquisition were conducted prior to antidepressant administration to the patients. Fractional anisotropy(FA), radial, mean, and axial diffusivity were estimated using DTI. FMRIB Software Library-Tract Based Spatial Statistics was used for statistical analysis. Results : We did not observe any significant difference in whole brain analysis. However, ROI analysis on right superior longitudinal fasciculus resulted in 3 clusters with significant decrease of FA in patients group. Conclusions : The patients with adolescent major depressive disorder showed statistically significant FA decrease in the DTI-based structure compared with healthy control. Therefore we suppose DTI can be used as a bio-marker in psychotropic drug-naïve adolescent patients with first onset major depressive disorder.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1119-1126
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• 2009

Purpose:This study compares the maternal characteristics and birth outcomes of infants of Asian immigrant mothers from developing countries with those of the infants of Korean mothers. Methods:In this multicenter and retrospective study, Asian immigrant women who had delivered between January 2005 and June 2008 were enrolled from9 Medical Centers. In all, 333 births to Asian immigrant women from developing countries (Asian-Korean infants) were included in this study. In addition, sex-, birth year-, and gestational age-matched 333 neonates born to Korean mothers were selected as the control group (Korean infants). On the basis of the hospital data, we investigated the nationality, age, and medical history of the mothers and compared the incidence of congenital infection, Apgar score, weight, height, and head circumference of Asian-Korean infants with those of the Korean infants. Results:The average maternal age of Asian women from developing countries at birth term was 26.7 years, which was significantly lower than that of Korean women (30.8 years, P<0.05). The birth weight of Asian-Korean infants (2,869 g) was significantly smaller than that of Korean infants (2,995 g, P<0.05). There was a significant difference in the incidence of congenital syphilis infection between the Asian-Korean infants and Korean infants (5 cases vs. 0 case, P<0.05). Conclusion:There were significant differences in the perinatal outcomes between the Korean and Asian-Korean infants. A multicenter large-scaled study should be performed to analyze the perinatal outcomes of Asian-Korean infants.

• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.227-233
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• 2009

Purpose : Growth hormone (GH) replacement after retesting is necessary because impairment of body composition and cardiovascular health has been more severe in adult patients with persistent GH deficiency (GHD) from childhood to adulthood. This study aimed to investigate the factors for persistent GHD and define a highly probable group of persistent GHD in young adults with childhood-onset GHD. Methods : GHD was reassessed by insulin tolerance test (ITT) in 55 adult patients (39 males, 16 females) with childhood-onset GHD. Twelve patients presented with idiopathic GHD and 43 patients presented with organic GHD caused by tumors involving the hypothalamus-pituitary (H-P) region (n=33), other brain tumors (n=3), meningitis (n=3), leukemia (n=2) and others (n=2). Results : Forty-nine (89.1%) of 55 patients had persistent GHD. IGF-I was positively correlated with log of peak GH (r=0.57, P<0.001). There was no difference in the proportion of persistent GHD between idiopathic and organic GHD. The percentage of patients with persistent GHD was 40%, 80%, and 95.6% for patients with zero, one, two or more additional pituitary hormone deficiencies (PHDs), respectively (P=0.002). The probability of persistent GHD was higher in patients with diseases involving the H-P region (P=0.003). GHD persisted in 15 of 18 patients treated with cranial irradiation. Conclusion : We suggest that the probability of persistent GHD in adulthood was high in patients with 2 or more additional PHDs, and diseases involving the H-P region.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.227-231
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• 1978

Effects of suspended silt and clay on the survival of the rearing bivalves, Meretrix lusoria, Cyclina sinensis and Mactra veneriformis were studied. During sixty-five days of experimental cultures in different concentrations of suspended silt and clay and in different time of immersions, mortalities of the bivalves were checked every day, and the rates of shell movement and oxygen consumption were measured. In general, the higher the concentration of silt and clay and the longer the immersion time, the earlier the occurence, and the higher the rate of the mortalities of the experimental bivalves. M. veneriformis was subjected to earlier mortality than the others, and the period of $50\%$ mortality was the shortest of the three species (37 days in 1,000 ppm), and longer was that of C. sinensis(42 days). Mortality of M. lusoria occured latest and $50\%$ mortality was seen at the immersion time of 50-51 days. Particularly, M. lusoria showed no mortality in the sea water with 100 ppm of suspended silt and clay, and even in the concentrations of 500 or 1,000 ppm they were able to survive without mortality only if the immersion time was short (12-18 hours per day). M. veneriformis and C. sinensis were also able to survive without mortality when the immersion time was short (12 hours per day) in low concentration (100 ppm). Shell movements of experimental bivalves varied depending upon species. In the case of M. veneriformis the shell was opened continuously and C. sinensis opened their shells frequently, while M. lusoria maintained their shells closed in any experimental concentrations of sea water with suspended silt and clay. Total metabolic activity of M. veneriformis was found to be highest while that of M. lusoria showed the lowest. Little difference of oxygen consumption in excised gill tissue was shown between the control group and the experimental groups. Consequently, it may be stated that the mortality results from a immersion in sea water with high concentration of suspended silt and clay for long-time although the survival rates of the experimental bivalves depend also upon the species, physiological conditions, concentration of suspended silt and clay and immersion time. The survival percentage of bivalve y in relation to the time (day) of immersion X in sea water of suspended silt and clay was found to be: $$M.\;lusoria\;(1,000\;ppm):\;y=7.7\times10^9\;\chi^{-4.77}\;(500\;ppm):\;y=259\chi^{-0.26}$$ $$C.\;sinensis\;(1,000\;ppm):\;y=-21\chi+936\;(\chi<44),\;y=-0.65\;\chi+35\;(\chi>44)$$ $$(500\;ppm):\;y=4.4\times10^5\;\chi^{-2.27}$$ $$M.\;veneriformis\;(1,000\;ppm):\;y=-18\chi+716\;(\chi<39),\;y=-0.89\chi+39\;(\chi>39)$$

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.19-47
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• 2015

In this era of knowledge economy, a variety of virtual communities are proliferating for the purpose of knowledge creation and utilization. Since the voluntary contributions of members are the essential source of knowledge, member turnover can have significant implications on the survival and success of virtual communities. However, there is a dearth of research on the effect of membership turnover and even the method of measurement for membership turnover is left unclear in virtual communities. In a traditional context, membership turnover is calculated as the ratio of the number of departing members to the average number of members for a given time period. In virtual communities, while the influx of newcomers can be clearly measured, the magnitude of departure is elusive since explicit withdrawals are seldom executed. In addition, there doesn't exist a common way to determine the average number of community members who return and contribute intermittently at will. This study initially examines the limitations in applying the concept of traditional turnover to virtual communities, and proposes five membership fluidity measures based on a preliminary analysis of editing behaviors of 2,978 featured articles in English Wikipedia. Subsequently, this work investigates the relationships between three selected membership fluidity measures and group collaboration performance, reflecting a moderating effect dependent on work characteristic. We obtained the following results: First, membership turnover relates to collaboration efficiency in a right-shortened U-shaped manner, with a moderating effect from work characteristic; given the same turnover rate, the promotion likelihood for a more professional task is lower than that for a less professional task, and the likelihood difference diminishes as the turnover rate increases. Second, contribution period relates to collaboration efficiency in a left-shortened U-shaped manner, with a moderating effect from work characteristic; the marginal performance change per unit change of contribution period is greater for a less professional task. Third, the number of new participants per month relates to collaboration efficiency in a left-shortened reversed U-shaped manner, for which the moderating effect from work characteristic appears to be insignificant.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.27-37
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• 1990

The extrafetal transfer of $Li^{+}$ in amniotic fluid was studied in 45 pregnant rabbits. LiCl solution was administered either intravenously to mother or directly into the amniotic sac and monitored the appearance and disappearance of $Li^{+}$ in the amniotic fluid, then calculated the transfer rate of $Li^{+}$ of extrafetal origin. To study the transplacental $Li^{+}$ transfer, a solution of 150 mM LiCl was infused continuously via maternal vein (initial dose: 0.7 mmol/kg, maintaining dose: 0.03 mmol/kg/min) and the $Li^{+}$ concentration was measured in maternal blood and amniotic fluid after 60 and 120 minutes of infusion. Change in the volume of aminotic fluid was determined by Congo red dilution method at the same time. Effects of duration of gestation was not considered in this study. Extrafetal transport of $Li^{+}$ into the amniotic fluid was estimated by comparing the $Li^{+}$ concentration and volume of amniotic fluid determined before and after ligating the placental vessels. Extrafetal $Li^{+}$ transport from the amniotic fluid was determined by observing the time dependent disappearance of $Li^{+}$ and Congo red in amniotic fluid after injecting 0.5 ml solution of 15 mM or 90 mM LiCl and 50 mg/ml Congo red. Following are the results obtained: 1) During infusion of LiCl through maternal vein the ratio of the aminotic $Li^{+}$/maternal plasma $Li^{+}$ increased significantly along with the increment of fetal weight. 2) The volume of amniotic fluid of larger fetuses than 20.5 gm increased significantly during administration of LiCl while that of smaller fetuses did not change. 3) After umbilical cord ligation the $Li^{+}$ concentration of amniotic fluid of larger fetuses than 20.5 gm was decreased to $59.9{\pm}10.3%$ and $56.9{\pm}42.9%$ $(mean{\pm}S.D.)$ of those of control group after 60 and 120 minutes of LiCl infusion respectively. In amniotic fluid of smaller fetuses than 20.5 gm, there was no significant difference between control and ligation groups. 4) The disappearance rate of Congo red in the amniotic fluid was $45.2{\pm}8.2%/hr$. 5) The disappearance rate of $Li^{+}$ after intraamniotic injection of LiCl depended on the amount injected. On injecting $7.5\;{\mu}mol$ LiCl, $Li^{+}$ disappeared rapidly from the amniotic fluid and the rates after 60 min and 90 min were $97.0{\pm}2.8,\;98.5{\pm}2.0%$ respectively. On injecting $45\;{\mu}mol$ LiCl, the rates were $56.0{\pm}15.4,\;78.9{\pm}14.5%$ at 60 and 90 min. 6) From the above results it was concluded: a) $Li^{+}$ transfer into the amniotic fluid increased along with the fetal growth and one half of $Li^{+}$ influx is through the extrafetal route even after the maturation of fetal kidney. b) One half of the $Li^{+}$ transfer from the amniotic fluid was through swallowing of fetus, while the remaining half was transfered rapidly through amniotic membrane, which was concentration limited.