• Clinical and Experimental Reproductive Medicine
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• v.17 no.2
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• pp.159-165
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• 1990

It has been reported that endogenous opioid peptides play a role in the control of the reproductive function. The goal of this study was to evaluate changs in the serum levels of ${\beta}$-endorphin during hyperstimulated menstrual cycle and their relationship to serum prolactin levels. Serum ${\beta}$-endorphin and prolactin levels were measured during menstrual cycles of 10 normal cylic women hyperstimulated by human menopausal gonadotropin (HMG) and of 10 women by clomiphene/HMG among in vitro fertilization candidates. The results were summarized as follows. 1. In clomiphene/HMG hyperstimulated menstrual cycle the mean serum ${\beta}$-endorphin level insignificantly on 2 day before aspiration of oocyte compared to basal level and reached maximum level on 1 day after aspiration. 2. There was a significant peak of the mean serum ${\beta}$-endorphin level on 1 day before aspiration in HMG hyperstimulated menstrual cycle. 3. On the same day from aspiration, there was no significant differences in the mean serum ${\beta}$-endorphin levels between HMG and clomiphene/HMG hyperstimulated cycles. 4. No significant correlation was noted between serum ${\beta}$-endorphin levels and prolactin levels.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.52-58
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• 2005

In this paper, we address a real-world periodic vehicle routing problem with time windows (PVRPTW). In addition to the general requirements of single-day vehicle routing problem, each stop has required number of visits within a cycle period in PVRPTW. Thus, we need to determine optimized days of visit for each stop with consideration of the cycle-period days together. The problem also requires consistent vehicle assignment to the stops. We developed a clustering based 3-phase approach for this problem: 1) stop-route assignment, 2) stop-day assignment, and 3) stop sequencing within a single-day route. Using the approach, we could reduce the number of routes and improve the routing efficiency for several real-world problems.

• Journal of Korean Elementary Science Education
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• v.37 no.3
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• pp.309-322
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• 2018

There is no doubt that science -and, therefore, science education- is central to the lives of all (NGSS, 2013). This manuscript focuses on ideas in astronomy that are at the foundation of elementary students' understanding of the discipline: the apparent motion of the sun explaining the day / night cycle on Earth. According to prior research demonstrating that neither children nor adults hold a scientific understanding of the big ideas of astronomy (NRC, 1996), understanding of concepts may base students' progress towards more advanced understanding in the domain of astronomy. We have analyzed the logic of the domain and synthesized prior research assessing children's spatial representation from an earth- and a space based perspective to develop a set of learning trajectories that describe how students' initial ideas about apparent celestial motion as they take school science can be build upon. In this study elementary students' representations were compared by their resident context including urban and rural. This study may present a first look at the use of a learning progression framework in analyzing the structure of astronomy education. We discuss how this work may eventually lead towards the development and empirical testing of how children learn to describe and explain apparent patterns of celestial motion.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.103-110
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• 1997

The present study was carried out to investigate effects of gonadotropin, age of donor, day of estrus cycle gonadotropin injection started and season on embryo production after superovulation in dairy cattles. Embryo collection records were obtained from 177 embryo donor collections from 98 Holstein cows aged from 3 to 9 years during 4 years(1993~1996) at National Livestock Re-search Institute. Superovulation was induced by injections of 3 gonadotropins(FSH-P, FOLLTROPHIN-v* or SUPER-OV*) beginning on days 9 to 14 of the estrus cycle. Em-bryos were collected from donors using a nonsurgical technique on days 6 to 8 after insemi-nation. The results were as follows ;Number of total and freezable embryos per donor cow was affected by gonadotropin(P<0.01). The more number of total and freezable embryos wereobtained by use of FOLLTROPHIN-V (13.2, 7.4) or FSH-P (11.0, 5.7) than SUPER-OV* (5.0, 2.4). Age of donor, the day that gonadotropin was started or season didn't affect total or freezable embryos(P >0.05).

• YAKHAK HOEJI
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• v.44 no.2
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• pp.149-154
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• 2000

Flavin mononucleotide (1,4-butanediamine) Pt(II) complex (7FMN) was synthesized and screened anticancer activity [J. Pharm. Soc. Korea 43(6),762-770 (1999)]. 7FMN have good water solubility and moderate anticancer activiy In this paper cell-cycle specificity and nephrotoxicity were studied. Interaction of DNA with cisplatin and synthesized 7FMN was analyzed by flow cytometry and showed G2 arrest in L1210 cell line. It means that cell-cycle on L1210 was inhibit in S phase by cisplatin and 7FMN. In order to biochemically analyze nephrotoxicity of cisplatin and 7FMN, after injecting each agent intraperitoneally, blood was exsanguinated after 6 hours, 1 day, 3 days and 7 days, respectively. Then, serum was separated from the blood. The serum level of BUN, creatinine and uric acid in cisplatin and 7FMN administated mice (25~35 g, ICR strain, a dose each 8,12 and 16 times of the $IC_{50}$/ value, cisplatin; 7 times) were determined by autochemistry analyzer. In cisplatinadministered mice group, BUN level was elevated than normal control group at 3rd day and repaired at 7th day. In 7FMN administrated group was not elevated. Creatinine and uric acid level were no difference with the normal control group. Therefore synthesized 7FMN is less toxic than cisplatin in nephrotoxiciaty.

• The Korean Journal of Physiology
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• v.14 no.1
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• pp.7-13
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• 1980

In the previous experiment, authors have shown that during the latter half of estrous cycle there was an increase in plasma testosterone level in the rats stimulated with hCG. To determine the physiologic significance of elevated plasma testosterone, changes of the plasma concentrations of TeBG and testosterone following hCG stimulation were analyzed in the rats having a regular 5 day cycle. The rats were divided into three groups; the control, the rats stimulated with single hCG on the day of proestrus and stimulated with hCG throughout the entire cycle. Blood samples were obtained once a day for an estrous cycle and analyzed for the binding capacity of TeBG using ammonium sulphate precipitation method and testosterone concentration by means of radioimmunoassay. Followings were the results; 1) There was no significant variation in the binding capacity of TeBG in peripheral blood during the estrous cycle of the control rats. 2) No cyclic variation in the binding capacity of TeBG was observed in the rats stimulated with single hCG on proestrus. although the levels tended to be higher in the rats with stimulation than in the control rats. 3) Continual stimulation of hCG produced a marked increase in the binding capacity of TeBG especially on the day of metaestrus. 4) The changes in the plasma level of testosterone followed the same basic pattern seen in the TeBG binding capacity. 5) From above results, the followings were suggested. a. hCG related increase of the binding capacity of TeBG is probably secondary to a modest increase in estrogen as well. b. hCG related increase of plasma testosterone in female rats is not entirely due to excess production rather in part due to decreased metabolism induced by the rise in TeBG. c. It seems likely that most of elevated testosterone shown in the rat stimulated with hCG is bound to TeBG and only small portion is unbound form which influence cellular activity. It is rather possible that an increase in TeBG could augment estrogen activity.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.480-485
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• 1998

Application of trans rectal ultrasonography to buffaloes (n=6) to follow the growth of large antral follicles individually, on each day of one interovulatory interval revealed that follicular turnover during oestrous cycle occured in waves. There was a predominance of a two-wave pattern (5/6 animals) compared to that of a three-wave pattern (1/6 animals). For two-wave pattern, the first wave emerged at Day $0.20{\pm}0.19$ (Day 0 = day of ovulation) and was marked by development of a dominant anovulatory follicle which grew in size from $5.40{\pm}0.24mm$ at the day of detection to a maximum diameter of $12.40{\pm}0.81mm$ on Day $8.60{\pm}1.57$, with a growth rate of $0.88{\pm}0.17mm/day$ and then regressed, with a mean persistence of $19.40{\pm}1.54$ days. The second wave emerged at Day $9.20{\pm}1.06$ and was marked by development of a dominant ovulatory follicle which grew in size from $4.20{\pm}0.37mm$ at the day of detection to a maximum diameter of $13.80{\pm}0.37mm$ on Day $21.00{\pm}1.38$, with a growth rate of $0.66{\pm}0.12mm/day$ and then ovulated on Day $21.60{\pm}1.25$, with a mean persistence of $11.80{\pm}1.39$ days. The maximum diameters attained and the growth rates of dominant anovulatory and dominant ovulatory follicles, and the mean number of follicles ${\geq}3mm$ diameter detected at the time of emergence of first and second waves ($11.80{\pm}1.74$ and $9.00{\pm}2.81$, respectively) were not significantly different. In the animal which showed a three-wave pattern, the first, second and third waves emerged on Days 1, 10 and 19, respectively. All animals, except one had at least one subordinate follicle in the first or second or both waves. The subordinate follicles increased in diameter over a few days and then regressed. The results indicate that in buffaloes, the follicular turnover during oestrous cycle occurs predominantly in a two-wave pattern.

• Animal cells and systems
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• v.6 no.3
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• pp.239-245
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• 2002

Plasma melatonin, thyroid-stimulating hormone (TSH) and body temperature were measured simultaneously and continuously before and after the sleep-wake cycle was shifted in 4 healthy males and changes in the circadian rhythm itself and in the phase relationship among these circadian rhythms were determined. Normal sleep-wake cycle (sleep hours: 2300-0700) was delayed by 10 h (sleep hours: 0900-1700) during the experiment. Even after this shift the typical melatonin rhythm was maintained: low during daytime and high during night. The melatonin rhythm was gradually delayed day by day. The TSH rhythm was also maintained fundamentally during 3 consecutive days of altered sleep-wake cycle. The phase was also delayed gradually but remarkably. The daily rhythm of body temperature was changed by the alteration of sleep-wake cycle. The body temperature began to decrease at the similar clock time as in the control but the decline during night awake period was less steep and the lowered body temperature persisted during sleep. The hormonal profiles during the days of shifted sleep/wake cycle suggest that plasma melatonin and TSH rhythms are basically regulated by an endogenous biological clock. The parallel phase shift of melatonin and TSH upon the change in sleep-wake cycle suggests that a common unitary pacemaker probably regulates these two rhythms. The reversal phase relationship between body temperature and melatonin suggests that melatonin may have a hypothermic effect on body temperature. The altered body temperature rhythm suggests that the awake status during night may inhibit the circadian decrease in body temperature and that sleep sustains the lowered body temperature. It is probable but uncertain that there ave causal relationships among sleep, melatonin, TSH, and body temperature.

• Development and Reproduction
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• v.22 no.1
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• pp.1-8
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• 2018

The annual reproductive cycle of the Korean endemic slender catfish, Silurus microdorsalis, was examined histologically regarding water temperature and day length of habitat, gonadosomatic index (GSI), and development characteristics of female and male gonads. The maximum GSI value was found in May, $1.23{\pm}0.33$ and $11.77{\pm}3.23$ for male and female respectively (habitat water temperature $21.5^{\circ}C/13.59hr$ day length). On the other hand, the minimal level was $0.63{\pm}0.10$ in July ($26.5^{\circ}C/14.17$) for male and $1.36{\pm}0.08$ in October ($20^{\circ}C/11.2hr$) for female. We compared and calculated the stages of testis and ovary development process in order to determine the germ cell development characteristics and the reproductive cycle. According to results, we classified the annual reproductive cycle of the slender catfish into five stages: Growing phase (December-February), Mature phase (March-April), Ripe and spawning phase / Releasing phase in male (May-June), Degenerative phase (July-August), and Resting phase (September-November).

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.62-69
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• 1985

The present study was carried out to determine sex hormone levels in serum throughout estrous cycle in Korean native goats. LH, FSH, prolactin, estradiol-$17{\beta}$ and progesterone in serum analyzed every 2 days from the estrus (day 0) to the 20th day of estrous cycle by the radioimmunoassay. The concentration of serum LH was high level with 3.27 mIU/ml on the day of estrus, then decreased rapidly to l.05~1.73 mIU/ml from the day 2 of estrous cycle to the day 18. A similar tendency was observed in the prolactin concentration, however the ranges of variation were not so marked as those of LH concentration. FSH concentrations determined were below 1.25 mIU/ml in all observation time. The concentration of serum estradiol-$17{\beta}$ was the highest, 23.62 pg/ml on the day of estrus, but the levels of 4.56~9.75 pg/ml were maintained during the other days of estrous cycle. Progesterone concentrations were the lowest, 0.45 ng/ml on the day of estrus and thereafter increased gradually to 8.85 ng/ml on the day 14 of estrous cycle, then decreased again. Serum LH concentrations before and after estrus maintained high levels during the 12 hours, i. e., 6 hours before and 6 hours after estrus. The concentrations of FSH were below 1.25 mIU/ml during the observation period. Prolactin concentrations were observed high levels during 24 hours, i.e., 12 hours before and 12 hours after estrus. Estradiol-$17{\beta}$ concentrations before and after estrus maintained high levels during the 24 hours, i.e., 12 hours before and 12 hours after estrus. The tendency of changes in progesterone concentrations were contrary to that of estradiol-$17{\beta}$.