• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.35-43
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• 2012

Purpose : PET/CT performed CT-based attenuation correction generates the beam hardening artifact by metallic implant. The attenuation correction causes over or underestimate of the area adjacent to metallic hip prosthetic material and change of $^{18}F$-FDG uptake. Also, the image quality and the diagnosability on genitourinary disease are reduced. Therefore, this study will evaluate the usefulness of MAR (Metal Artifact Reduction) algorithm method to improve the image quality on PET/CT. Materials and Methods : PET/CT was performed by fixing hip prosthesis in SPECT/PET phantom. In PET images with and Without MAR algorithm, the Bright streak, Dark streak, Metal region and Background area that appeared on CT were confirmed, and the change of each SUV (standardized uptake value) was analyzed. Also, in 15 patients who underwent total hip arthroplasty, each MAR algorithm and Without MAR algorithm and non attenuation correction was evaluated. Results : In PET image Without MAR algorithm, SUV of Bright streak region was $0.98{\pm}0.48$ g/ml; Dark streak region was $0.88{\pm}0.02$ g/ml; Metal region was $0.24{\pm}0.16$ g/ml, Background area was $0.91{\pm}0.18$ g/ml. In SUV of PET image with MAR algorithm, Bright streak region was $0.88{\pm}0.49$ g/ml, Dark streak region was $0.63{\pm}0.21$ g/ml, Metal region was $0.06{\pm}0.07$ g/ml, Background was $0.90{\pm}0.02$ g/ml. SUV generally decreased when applying MAR algorithm. In PET image Without MAR algorithm, SUVs of Bright region were higher than those measured in the Background, and it was false positive uptake. But, in PET image with MAR algorithm, SUVs of Bright region were similar to the Background, and false positive uptake disappeared. Conclusion : MAR algorithm could reduce an increase of $^{18}F$-FDG uptake due to attenuation correction in the hip surrounding tissue. However, decrease of SUV in Dark streak region should be considered in the future. Therefore, this study propose that the diagnostic accuracy can be improved in genitourinary diseases adjacent to metallic hip prosthesis, if provided PET images with and Without MAR algorithm, and non attenuation correction images at the same time.

• Journal of Aquaculture
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• v.9 no.3
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• pp.205-213
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• 1996

Experiments were carried out to investigate the effect of GnRH-analogue (GnRH-a) on the induction of ovulation in catfish, S. asotus. Fully matured female catfish ($250\~600\;g$) received a single intraperitoneal injection of GnRH-a ($50\~200\;{\mu}g/kg{\cdot}body$ weight) showed the successful induction of ovulation. More than $86\%$ of treated females were ovulated after injection of GnRH-a ($90\;{\mu}g/kg$) at $25{\pm}1^{\circ}C$. The majority of spawning took place within 22 to 25 hours after the injection. The gonadosomatic index (GSI) and pseudo-GSI in the group treated with $120\;{\mu}g/kg$ GnRH-a were $23-30\%$ and $18-21\%$, respectively. Average fertilization and hatching rates were $94\%\;and\;81\%$, respectively. Electron microscopically, gonadotrophs of maturing female catfish were characterized by the presence of numerous small, electron-dense granules of approximately $150\~300$ nm in diameter and a few larger, less electron-dense granules of approximately $800\~1000$ nm in size in their cytoplasm. Gonadotrophs of GnRH-a treated catfish showed that their was a distinct decrease in number of small and large granules. The rough endoplasmic reticulum was composed of numerous cisternae conspicuosly dilated to various degrees.

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.105-112
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• 2009

We investigated the degree of obesity, histological development stages of gonads and sexual maturation induction rates of comb pen shell, Atrina pectinata, per the type of micro-algae supplied. Terms of maturation by singular or mixed supply of microalgae, it was found that maturation of the female was the quickest at 60.0% by the Tetraselmis tetrathele (Tet). experiment group followed by 57.1% by the Chlorella ellipsoidea (Chl). experiment group and 16.7% by the Phaeodactylum tricornutum (Pha). experiment group. However, there were no significant differences between Tet. experiment group and Chl. experiment group. As for the male, maturation was the quickest at 60.0% by the Tet. experiment group followed by 16.7% by the Chl. experiment group and 14.3% by the Pha. experiment group. In light of these results, Tet. is concluded to be a very useful feed organism in breeding the mother comb pen shells. Upon completion of the experiment, the sexual maturation induction rate for the female was found to be the highest at 82.0% in the Tet. experiment group followed by 72.0% by the Chl. experiment group, 64.0% by the Pha. experiment group and 58.0% by the mixed micro-algae experiment group. During the period of experiment, the survival rate was the highest at 94.4% by the mixed micro-algae experiment group followed by 90.0% by the Pha. experiment group, 83.1% by the Tet. experiment group and 78.8% by the Chl. experiment group.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.1
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• pp.103-106
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• 1989

Gamete intrafollopian transfer, a varient of IVF, is becoming increasingly popular as a treatment modality for infertility in women with at least one healthy follopian tube. Although GIFT has recently been poprlarized as a safe and effective treatment in selected infertile couples, little discussion of potential complications has been published. Whereas a tubal pregnancy rate of approximately 5% has been noted for IVF, early reports of GIFT have noted ectopic pregnancy to be relativiely rare. We experienced a case of combined pregnancy following GIFT with microsurgery and now present it with brief review of related literatures.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.2
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• pp.185-196
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• 1990

These experiments were performed to know ultrastructural changes of the cumulus expansion in virot. SEM:In expanded oocyte-cumulus complex, the cell surface are characterized by the presence of many evaginations:they are relatively short and round shape. The mucous extracellular material were deposited between cumulus cells. TEM:In compact cumulus cells, golgi apparatus and rough endoplasmic reticulum developed. In expanded cumulus cells, rough endoplasmic reticulum decreased and the smooth endoplasmic reticulum increased. Also, there were numbers of mitochondria. Extracellular mucous material which is presumed to be hyaluronic acid appears when cumulus cell were expanded. In expanded cumulus cell, numbers of smooth endoplasmic reticulum help cumulus cell to develop in steroidogenic cell.

• Korean Aquaculture
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• v.14 no.1
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• pp.88-95
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• 2002

많은 척추동물의 성비는 1:1이며 암수는 각 세대에 거의 같은 수가 태어난다. 생식 행동도, 암컷만이 집단을 형성하는 대형 포유류 등을 제외하면, 암수 1:1로부터 차세대가 재생산 된다. 야생 집단에서는 같은 수의 암수를 전제로 대부분의 생태가 형성되어 있다고 생각되어 지기 때문에, 차세대의 유전적 영향도 암수에 의한 차는 일반적으로 없다. 그러나, 축산을 비롯한 산업 동물에서는 상품 가치, 생산 효율, 재생산 등에 암수의 성에 따른 큰 차이가 나타나는 경우가 있고, 암수 어느 한 쪽이 선택.사육되는 경우도 있다. 낙농의 암컷 소, 양계업의 암컷 병아리의 선택은 좋은 예라고 할 수 있다. 더욱이, 가축에서는 육종 목적으로 유전적으로 우량한 소수의 수컷으로 많은 암컷과 교배시키는 경우가 있고, 극단적으로 치우친 성비로 재생산을 행하는 경우도 있다. 이와 같이 산업동물에서는 성 제어의 유용성이 예상되어 기술 개발이 요구되고 있다. 산업 생산의 대부분은 자연 번식 집단으로부터의 어획물로 되어 있어, 이것들의 성 제어가 곤란하며 무의미하다. 그러나, 양식 대상종 및 종묘 방류를 행하는 재배어업에서는 그 기술 도임에 의한 효과가 기대된다. 인위적 재생산 기술이 확립되어 있는 어종에서는 양식, 증식을 불문하고 기술 개발과 도입여부를 적극적으로 검토하여야 한다. 여기서는, 재생산 기술이 확립되어, 양식 및 인공 부화 방류가 활성화된 연어.송어과 어류의 성 제어 기술 개발 상황과 실용화의 현상을 논하겠다.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.359-369
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• 2015

Stream ecosystems are highly valued natural resources, however, stream environments are currently under threat in several respects. We evaluated vegetation and ecological characteristics according to different revetment types. The distribution of vegetation differed with revetment type, with a 42~45 taxa found in natural revetments, and 23~38 taxa in vertical revetments. Thus, natural revetments host more diverse vegetation than vertical revetments. We also found more plants belonging to the families Labiatae and Cyperaceae growing in natural revetments than in vertical revetments. We proposed that habitat space be apportioned to introduce annual plants as part of stream restoration projects. And, we identified 7 families and 18 taxa of naturalized plants, majority taxa were either biennial or perennial. Moreover, naturalized ratio was higher in vertical(14.3%) than natural(12.1%), we proposed a plan to promote and improve natural streams and revetments. Furthermore, we applied a waterfront evaluation method developed by the Natural Resources Conservation Service of the USDA-NRCS, which confirmed that stream health can be improved in most regions by controlling naturalized plants and ensuring shrub and tree growth. We adopted a new method to remove naturalized plants and establish natural revetments to ensure shrub and tree growth to aid in small-stream restoration and improvement. In future studies, we hope to develop methods for small-stream restoration projects in rural areas.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.1
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• pp.33-39
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• 2007

Objective: The objective of this study was to investigate whether serum levels of vascular endothelial growth factor (VEGF) measured at ovulation triggering day reflect ovarian response in intrauterine insemination (IUI) cycles. Methods: Forty-nine fertile women who undergoing superovulation and IUI were included. Superovulation was performed using clomiphene citrate (100 mg/d on day 3$\sim$7) in combination with human menopausal gonadotropin (150 IU every other day starting on day 5). Serum samples were obtained on the day of hCG administration and the levels of VEGF-A and estradiol were measured. The numbers of mature follicle $\geq$17 mm in diameter were also counted. Results: Serum VEGF-A levels did not correlate with the numbers of mature follicle count nor serum estradiol levels. Serum estradiol level was positively associated with mature follicle count. Serum VEGF-A levels tended to be lower in women with mature follicle count less than three or women with more than five. Conclusion: Our results indicate that serum VEGF-A levels do not have an association with superovulation outcome in IUI cycles. However, a tendency of lower VEGF-A level in poor and high responder suggests that those with extreme response to superovulation may be related with abnormal angiogenesis. Further studies should be warranted in larger populations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.161-170
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• 1982

A trial on the seed production of red sea-bream (Chrysophrys major) was made in Jejudo island at the southern end of Korea, from June, 1980 to August, 1981. Histological observation of the gonads indicated that the main spawning season was June to early July in Jejudo area. The newly-hatched fry were fed Brachionus sp. in the later stages Artemia nauplii, Tigriopus sp. and the minced fish flesh were given. Though during the winter season the water temperature in rearing tanks was decreased as low as $9.2^{\circ}C$, continuous feeding to the juveniles was carried out, showing body weight increase. This implies that winter rearing of juveniles in the near-shore facilities is feasible in the vicinity of Seogwipo area, in Jejudo. Feed coefficient of the juveniles (>23.2 g) was $4.16\sim4.77$ when fed the minced fish flesh.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.61-68
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• 1976

For the artificial precocious breeding of abalone effects of changes in environmental parameters, water temperature and light period, on the induction of spawning have been studied. Subtidal specimens of Haliotis discus hannai were collected irregularly for 6 times from April to June 1975 in Chungmu Bay near Jukdo Island, the southern coast of Korea. One hundred and fifty specimens were reared in 4 aquarium tanks in the laboratory and in a creel submerged in the sea during the period of 60 days from April 24 to June 23, 1975. The all groups kept in the four tanks and a creel showed very high spawning rates $(70\~100\%)$, compared to those inhabited the natural environment at sea until right before the spawning time $(0\~50\%,\;average\;16.4\%)$. From the results of the present induced spawning, the parameters can be discussed as follows: It seems likely that photoenvironment may stimulate to produce and secrete some internal substances which may concern to giving the fertilizing ability to the eggs before spawning and to inducing spawning, but the temperature may not be a factor for this concern. For effective precocious breeding, it seems to require that abalones are to be realoed under controlled conditions of darkness below 2,000 lux even during day time for more than 60 days before inducing spawning.