• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.1-9
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• 2022

An estuary is an area where a freshwater river or stream meets the ocean. Even before the importance of the value of estuaries was recognized, the estuary was lost because of large-scale conversion by draining, filling, damming, and dredging. In South Korea, 643 estuaries are located, and the total area is 3,248,300 ha, accounting for 32.5% of the total area of South Korea. Over 35% of Korean estuaries are closed estuaries which are only temporally connected with the sea, either permanently or periodically. Since 2008, in order to preserve the estuary ecosystem and solve major issues in the estuary by accumulating knowledge about the estuarine ecosystem, the Ministry of Environment of Republic of Korea has been conducting the "Estuarine Ecosystem Monitoring and Assessment Project". At 668 sites of 325 estuaries, epilithic diatom, benthic macroinvertebrate, fish, and vegetation are investigated, and the habitat condition of each site is evaluated using the newly developed biotic index. More than 100 researchers annually record 2,097 species of estuaries according to the standardized survey guidelines over the past 14 years and provide strictly managed data necessary for establishing estuaries conservation policies. As a result of bibliometric analysis of 1,195 research articles related to the monitoring and assessment of the estuarine ecosystem, research on pollutants such as heavy metals and sediment control have recently been conducted. "Estuarine Ecosystem Monitoring and Assessment Project" is an ecological monitoring type of long-term mandated monitoring that is usually focused on identifying trends. Although it is difficult to identify the mechanism influencing a change in an ecosystem through long-term mandated monitoring, providing empirical data for supporting evidence-based policy, decision-making, and the management of ecosystems. In order to increase the efficiency of the project, research to investigate the relationship between sediments and pollutants and organisms can be conducted at specific estuaries or sites to compensate for the shortcomings of mandatory monitoring.

• Development and Reproduction
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• v.2 no.2
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• pp.213-221
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• 1998

Intracytoplasmic sperm injection (ICSI) has been widely used to treat couples with infertility due to severely impaired sperm charateristics and for whom conventional in-vitro fertilization (IVF) had failed. The extent to which the morphology of the oocyte at the light microscopy level is related to the results of ICSI vis controversial. In this study, oocytes from 44 patients were reviewed. The ICSI procedure was recorded through CCD camera. The oocytes were divided into five groups according to the presence of cytoplasmic inclusions, the width of perivitelline space (PVS), the presence of cell debris in PVS, the status of first polar body and the flexibility of oolemma. The results showed that the fertilization rate and embryonic development were not associated with the morphological criteria of oocyte. The degeneraton rate of oocytes after ICSI was significantly higher (P<0.001) in the oocytes whose membranes were broken at the moment of insertion (17.7%) than the oocytes whose membranes were broken by aspiration of cytoplasm (1.6%). More oocytes with cytoplasmic inclusions (48.4% vs. 25.1%, p<0.001), wide PVS (35.2% vs. 19.0%, p<0.001), or cell debris in PVS (53.3% vs. 38.4%, p<0.05) were observed in patients with female factor infertility compared to patients with male factor infertility. These results .suggest that the fertilization rate and embryonic development after ICSI are not correlated with oocyte morphology based on the presence of cytoplasmic inclusions, size of PVS, the presence of cell debris in PVS and the status of polar body. And the degeneration rate of oocytes after ICSI was associated with the flexibility of oolemma.

• 한국해양학회지
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• v.23 no.1
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• pp.24-40
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• 1988

In the Korea Ocean Nodule Development (KONOD)-1 area between the Clarion and Clipperton fracture zones of the northeastern equatorial Pacific, the pelagic sediment layer can be divided into two or three units on air-gun seismic profile. The acoustic units can be also correlated with those in the DSDP site 163 core. The topmost unit (unit I) is acoustically transparent and consists of zeolitic clay and radiolarian ooze of late Oligocene to middle Eocene age. Unit IIA is well-stratified and transparent in the lower part. consisting of the radiolarian ooze intercalated with chert beds and zeolitic clay of early Eocene to Paleocene age. Unit IIB is stratified with layers of silicified and compacted flinty-cherty nannofossil chalk (late Cretaceous) on top of the acoustic basement. Units I and IIA form the Line Islands Formation that overlies an unnamed formation of unit lIB. The entire layers and the unit I layer propressively thin northward, except near the Line Islands Ridge. The distribution of sediment layer has been controlled by the equatorial Cenozoic CCD and the northward spreading of the Pacific plate. The change of CCD corresponding to the subsidence and migration of the plate has determined the sediment composition of the DSDP 163 core passed across the equator of high sedimentation suite. The late Cretaceous sedimentary layer (unit IIB) in the 163 core was formed above the CCD south of the equator. The unit IIA resulted from rapid subsidence of the Pacific plate below the CCD in the Paleocene. The unit IIA is seen only in the west of 149 W. Both the units IIA and I were probably formed during the Pacific plate passing and after leaving the equatorial region respectively since early Eocene. In the south of the KONOD-l area, the unit I was redistributed by bottom current, a branch of the Antarctic Bottom Water flowing eastward guided by the Clipperton fracture zone. The activities of bottom currents were prolonged for a long geological time. Turbidite layers occur more than 350 km from the Hawaiian Ridge to near the Clarion fracture zone. They originated directly from the Hawaiian Ridge, filling the topographic lows.

• Clinical and Experimental Pediatrics
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• v.45 no.6
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• pp.712-718
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• 2002

Purpose : Infantile colic is one of the most commonly encountered problems, characterized by excessive crying in apparently healthy young infants within the first 3 months of life. It is commonly assumed that the infant with colic has distress and possible pain. In recent investigations, it has been found that sucrose has an analgesic effect in newborn infants. The purpose of this study is to examine if sugar solution as sucrose also has an analgesic effect on infant colic. Methods : This prospective randomized, double-blind placebo controlled study examined healthy term infants aged 4 to 12 weeks with colic. A total of 40 infants were randomly assigned into two groups who visited Daedong Hospital from June 1999 to June 2001. Each group received sugar solution or sterile water. All data from parental diaries and interviews were recorded and analysed blindly. Results : The daily crying time and the colic improvement score were significantly better in sugar solution group as compared with the control(P=0.019, 0.045). No significant differences were noted between groups regarding the number of night wakenings(P=0.173). Conclusion : We conclude that sugar solution has an analgesic effect on infantile colic.

• 한국해양학회지
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• v.30 no.4
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• pp.320-331
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• 1995

The closely spaced cores were analyzed to find detailed reconstruction of paleoenvironments and sealable changes along the Delaware Bay coast. Three areas, Kitts Hummock Beach mars, the St. Jones River marsh, and Bowers marsh near the St. Jones River's mouth, were chosen because these areas are compose of their own geomorphic characteristics and sea-level history. since significance of the stratigraphic correlations was to determine sedimentary fancies and paleoenvironments, multidisciplinary methods such as lithological description, grain-size analysis, organic/inorganic content, water content, mineral composition, botanical analysis, micropaleontological analysis, and /SUP 14/C datings were performed. Five major divisions of marsh environments were recognized in the stratigraphic sections: freshwater marsh, initialfreshwater marsh, slightly brackish marsh, brackish marsh, and salt marsh. Most of the lower part in the stratigraphic sections show freshwater marsh. On the top of this, either brackish marsh or tidal flat/tidal stream was recorded. The pro-Holocene sediments consist of sand, mud, and sandy mud, The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene sediments consist of sand, mud, and sandy mud. The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene surface within short distances permitted the concurrent development of variable environments such as freshwater marsh, brackish marsh or salt marsh at similar elevations. The freshwater marsh in this case was formed in the areas of isolation, so saline-water cannot encroach upon these areas. This complex development of paleoenvironments leads to a difficulty in stratigraphic correlation and interpretation of local relative sea-level changes. The deposition of subsurface sediments was affected by sediment supply, compaction, fluvial activity, biological competition, local tectonics and isostacy, climate and local relative sea-level changes. It was interpreted that the positions in the changes from freshwater environments to brackish environments or ice versa are the turning points of transgressions and regressions. Therefore, multiple transgressions and regressions were identified in the stratigraphic sections of the study area.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.488-497
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• 1999

Background : Identification of the histologic cell type of lung cancer is important because it is related to the treatment modality and prognosis. Currently, many diagnostic methods are used to determine the cell type. We have studied to evaluate the histologic accuracy of each diagnostic methods in lung cancer. Method : 168 cases were analysed retrospectively, who underwent curative thoracotomy for lung cancer in Seoul National University Hospital from January, 1994 to February, 1997. Sputum cytology, percutaneous needle aspiration(PCNA), percutaneous needle biopsy(PCNB), bronchial washing cytology and flexible bronchoscopic biopsy were evaluated respectively. The k coefficient was applied to evaluate the degree of concordance between the histologic diagnosis obtained by each methods and the one derived from thoracotomy. Results : The k value in sputum cytology was 0.86. In the 34 cases with squamous cell carcinoma(SQ), 32 cases were finally diagnosed as having such by thoracotomy. 7 of the 8 cases with adenocarcinoma(AD) turned out to have the same. The k value in PCNA was 0.51. In the 31 cases with SQ, only 14 cases were finally diagnosed as having such. All of the 3 cases with small cell carcinoma(SC) turned out to have the same. The k value in PCNB was 0.77. The diagnosis was correct in 13 of the 16 patients with SQ and in 30 of the 32 cases with AD. The k value in bronchial washing cytology was 1.0. In all of the 29 cases with SQ and all of the 7 cases with AD, the diagnosis was correct. The k value in flexible bronchoscopic biopsy was 0.77. The diagnosis was correct in 51 of the 52 cases with SQ and in 1 of the 2 cases with SC. Conclusion : The concordance rate with the final histologic diagnosis in sputum cytology, PCNB, bronchial washing cytology and flexible bronchoscopic biopsy were excellent ($k{\geq}0.75$), while that in PCNA was fair (k=0.53). Because PCNA showed lower concordance rate than other diagnostic methods, PCNA is recommended to perform with PCNB.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.700-708
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• 1993

Background: Lung cancer has become one of the most common cancers in Korea. It is important to determine the accurate histologic types and stages because of different therapeutic modlaity, especially in small cell carcinoma. This study was designed to evaluate diagnostic yields according to variable diagnostic methods in lung cancer. Methods: The records of 683 patients with a confirmed diagnosis of primary lung cancer during the period of 7 years, from January, 1986 until December, 1992 at Presbyterian Medical Center were analyzed retrospectively. Results: 1) Age and sex distributions Male: female sex ratio was 5.57:1 and age distributions were 7th decade 41.4%, 6th decade 30.2%, 8th decade 17.0%, 5th decade 7.9%, 4th decade 2.5%, 9th decade 1.3%, and 3rd decade 0.2% in decreasing order. 2) The frequencies according to histologic cell types were squamous cell carcinoma 44.7%, small cell carcinoma 23.9%, adenocarcinoma 22.8%, alveolar cell carcinoma 2.5%, large cell carcinoma 1.2%. mixed forms 1.2%, undifferenciated cell carcinoma 0.6% and malignant fibrous histiocytoma 0.2%(1 case) in decreasing order. 3) The most common locations of lung cancer were in left upper lobe and right lower lobe, and no differences of diagnostic methods according to locations were noted. 4) In central lesions, bronchoscopic examination was very accurate and frequently used diagnostic method, and in peripheral lesions, transthoracic lung biopsy(TTLB) was apparent1y accurate method. 5) The diagnostic yields of bronchoscopic biopsy, bronchial brushing, sputum cytology, transthoracic lung biopsy and transbronchial lung biopsy(TBLB) were 81.3%, 57.5%, 31.1%, 69.6% and 61.6%, respectively. 6) The concordance rates between the histologic diagnosis with bronchial brushing and sputum-cytology were 91.3% and 98.4%, respectively. 7) It was appropriate in lung cancer to repeat sputum cytology 3 to 5 times. Conclusion: Bronchoscopic examination is important to determine the histologic cell types in lung cancer. In addition, we should be interrested in improving diagnostic yields of sputum cytology as an easy method.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.48-54
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• 2010

Purpose: The objective of this study was to evaluate and compare the accuracy of impression body taking by the closed and the open tray impression technique with 3 types of impression tray. Individual tray, metal stock tray and polycarbonate tray were used. Materials and methods: Nine closed tray impressions were taken by individual tray, metal stock tray and polycarbonate stock tray, respectively with polyether impression material. 9 open tray impressions were also acquired by same manner. Precision analysis on the master models was performed by attaching the reference frameworks with alternate single screws and measuring the vertical fit discrepancy of respective analogues in working cast with a stereo microscope. Data were analyzed by 1 way ANOVA and independent t-test. Results: The average fit accuracy of impression bodies was calculated. With the closed tray impression technique, there were significant statistical differences in vertical fit discrepancy according to the types of tray. The individual tray group showed the lowest value and the polycarbonate stock tray group represented the highest. With the open tray impression technique, there was no significant difference in vertical fit discrepancy. Significant statistical difference in vertical fit discrepancy was found between the open and the closed impression technique with the polycarbonate stock tray. Conclusion: From the results above, more precise impressions could be acquired by the rigid individual tray compared with the polycarbonate stock tray. It was hard to get consistent accuracy impressions by the closed tray impression technique with polycarbonate stock trays.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.66-81
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• 2014

Burnt down during the Imjin War(壬辰倭亂) of 1592, Gyeongbokgung Palace(景福宮) remained in ruins until 1865, when in the second year of King Gojong's(高宗) reign, reconstruction work began. At the time, a royal protocol(uigwe, 儀軌) for the reconstruction was not produced. Instead, the Gyeongbokgung Palace Construction Diary(Gyeongbokgung yeonggeon ilgi, 景福宮營建日記) records the reconstruction process from June to September of 1865. The contents of this diary reveal that the stone used in the construction was obtained from Ganghwa(江華), the Yeongpung field(映楓亭) just beyond Dongdaemun, and Samcheongdong(三淸洞), among other sites. In addition, selected stone remaining from the original Gyeongbokgung Palace site - such as that from the palace astronomical observatory(ganuidae, 簡儀臺) - as reused, while a number of buildings and stonework from Gyeonghuigung Palace(慶熙宮) were moved to Gyeongbokgung Palace. As a result, a number of $17^{th}$ and $18^{th}$ century stonework are currently located at Gyeongbokgung Palace. The Gyeongbokgung Palace Construction Diary contains a record indicating that the bronze dragon(靑銅龍) excavated from the lotus pond at the palace's Gyeonghoeru Pavilion(慶會樓) was created by special technician byeolganyeok(別看役) Kim Jae-su(金在洙) in 1865 for the symbolic purpose of protecting the palace from fire. The diary also reveals that among Kim Jae-su and the other special technicians(byeolganyeok) tasked with the installation and oversight of the palace stonework was Lee Se-ok(李世玉) - aid to have created the haechi statue at Gwanghwamun Gate. This indicates that there were men of court painter(hwawon, 畵員) background among the construction special technicians(byeolganyeok). Moreover, the diary records the names of the stoneworkers(seokjang, 石匠) who worked under these special technicians to actually carve the stonework. These included Jang Seong-bok(張聖福), who participated in the creation of the Geunjeongjeon Hall(勤政殿); and Kim Jin-myeong(金振明), who took part in the construction of Gwanghwamun Gate(光化門). Based on these results, it is possible to identify a number of special iconographic features of the scale-covered animal form(insuhyeong, 鱗獸形) auspicious animal statues at Gyeongbokgung Palace. These include a protruding mouth and large nose, formalized ears, and a mane along the back. Comparing these iconographic features with those found in the stonework of Joseon tombs makes it clear that these palace statues were created in the latter half of the $19^{th}$ century - the period corresponding to Gojong's palace reconstruction. This study was able to confirm that this iconography was taken up by the Gyeongbokgung Palace construction special technicians(byeolganyeok) and stoneworkers(seokjang) as they worked on tomb stonework earlier in their careers.

• Korean Journal of Heritage: History & Science
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• v.47 no.4
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• pp.224-243
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• 2014

This study examined the materials and casting technology(cast, alloy, etc.) used in the manufacturing of bronze artifacts based on old literature such as Yongjae Chonghwa, Cheongong Geamul, and The Korea Review. In the casting experiment for restoration of Sangpyong Tongbo, a bronze and brass mother coin mold was made using the sand mold casting method described in The Korea Review. The cast was comprised of the original mold plate frame, wooden frame, and molding sand. Depending on the material of the outer frame, which contains the molding sand, the original mold plate frame can be either a wooden frame or steel frame. For the molding sand, light yellow-colored sand of the Jeonbuk Iri region was used. Next, the composition of the mother alloy used in the restoration of Sangpyong Tongbo was studied. In consideration of the evaporation of tin and lead during actual restoration, the composition of Cu 60%, Zn 30%, and Pb 10% for brass as stated in The Korea Review was modified to Cu 60%, Zn 35%, and Pb 15%. For bronze, based on the composition of Cu 80%, Sn 6%, and Pb 14% used for Haedong Tongbo, the composition was set as Cu 80%, Sn 11%, and Pb 19%. The mother coin mold was restored by first creating a wooden father coin, making a cast from the wooden frame and basic steel frame, alloying, casting, and making a mother coin. Component analysis was conducted on the mother alloy of the restored Sangpyong Tongbo, and its primary and secondary casts. The bronze mother alloy saw a 5% increase in copper and 4% reduction in lead. The brass parent alloy had a 5% increase in copper, but a 4% and 12% decrease in lead and tin respectively. Analysis of the primary and secondary mother coin molds using an energy dispersive spectrometer showed that the bronze mother coin mold had a reduced amount of lead, while the brass mother coin mold had less tin. This can be explained by the evaporation of lead and tin in the melting of the primary mother coin mold. In addition, the ${\alpha}$-phase and lead particles were found in the mother alloy of bronze and brass, as well as the microstructure of the primary and secondary coin molds. Impurities such as Al and Si were observed only in the brass mother coin mold.