• Tuberculosis and Respiratory Diseases
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• 제68권6호
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• pp.328-333
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• 2010

Background: There are several active tuberculosis (TB) cases in Korean high schools each school year. The risk of transmission in schools is extremely high due to the considerable time spent in closed classrooms. We evaluated the control of latent tuberculosis infection in Korean high schools. Methods: When a student was identified with active TB, tuberculin skin testing was performed on their classmates and on students in their same school grade. When a student had a positive tuberculin skin tests (TST), they underwent follow-up testing with QuantiFERON-TB Gold In-Tube (QFT). The manufacturer recommended a cut-off of 0.35 IU/mL to determine QFT positivity was applied. Results: A total of 131 pulmonary tuberculosis (TB) patients were included based on the criteria for screening TB contacts in the National Tuberculosis Control Program. Seventy-five (57.2%) students tested smear positive. TST were performed on 7,109 students who were classmates of, or in the same grade as, a TB patient. Of the contacts, 1,231 students (17.3%) were TST positive and they were screened with QFT. Six hundred-sixty-six (55.0%) of the tested students returned a positive QFT result and the rate of positivity was significantly associated with the increasing size of TST indurations (p<0.0001). Conclusion: The use of QFT resulted in approximately 45% of TST positive students not being given chemoprophylaxis.

• Fisheries and Aquatic Sciences
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• 제8권3호
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• pp.142-150
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• 2005

The effects of photoperiod, temperature, and fish size on oxygen consumption (OC) in the black porgy Acanthopagrus schlegeli, a euryhaline marine teleost, were studied using a closed recirculating seawater system with a respiratory chamber. Fish reared in indoor recirculating seawater tanks were divided into two groups: small (15.7-55.8 g, mean 38.1$\pm$15.9 g) and large (108.7-238.8 g, mean 181.8$\pm$54.9 g) fish. The OC of the fish showed a clear diel rhythm, with higher values in the daytime and lower values at night, in accordance with light (09:00-20:59 h) and dark (21:00-08:59 h) cycles. The OC of the fish increased linearly with the water temperature. The OC was the highest at 10:00 h, one hour after the onset of daylight and was the lowest at 03:00 h, six hours after dusk. The average OC at $20^{\circ}C$ during the light period was as high as 219.8 mg $O_2$/kg/h in the small fish and 156.3 mg $O_2$/kg/h in the large fish, while during the dark period it was as low as 130.5 and 110.4 mg $O_2$/kg/h, respectively. The OC during the dark period, which showed limited variation, could be regarded as the resting OC, and was 107.6, 130.5, and 219.8 mg $O_2$/kg/h at 15, 20, and $25^{\circ}C$, respectively, in small fish, and 52.3, 110.4, and 171.0 mg $O_2$/kg/h in large fish. As the body weight of black porgy increased, the OC decreased exponentially and the relationship was expressed as OC=1,222.8$BW^{-0.567}$, OC=1,113.2$BW^{-0.448}$, and OC=1,495.3$BW^{-0.468}$ at 15, 20, and $25^{\circ}C$, respectively. At a fish density of 14.5 g/L at $20^{\circ}C$, black porgy had the highest OC per breath compared to fish at the same density at 15 or $25^{\circ}C$. This suggests that the black porgy responds to the stocking density (15 kg/$m^3$) and water temperature ($20^{\circ}C$) conditions commonly observed in intensive aquaculture with the deepest breath and the highest metabolic activity.

• Journal of Ginseng Research
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• 제23권3호
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• pp.164-171
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• 1999

가압형 마이크로웨이브 추출장치를 이용하여 추출조건(에탄올농도, 추출온도 및 추출시간)에 따른 인삼 ginsenosid서 추출특성을 반응표면분석에 의해 모니터링하고, 마이크로파 추출법의 추출효율을 확인하였다. 조건별 추출물의 ginsenoside함량에 대한 회귀식의 $R^2$는 대부분 0.830이상으로 $10\%$이내의 수준에서 유의성이 인정되었다. $Ginsenoside-Rb_2$ -Rc, -Re 및 $-Rg_1$은 추출온도가 높을수록 증가하여 $140^{\circ}C$에서 가장 높게 나타났으며, 에탄을 농도가 $50\~75\%$에서 가장 높은 추출율을 보였다. Ginsenoside의 HPLC 패턴은 MAP 추출온도 $120^{\circ}C$에서 unknown peak가 확인되었으며, $150^{\circ}C$추출에서는 unhown peak가 증가되었다. $Ginsenoside-Rb_2$와 -Re 함량에 미지화합물(unknown peak)을 포함하였을 때 는 최대의 추출온도가 $129^{\circ}C$에서 $147^{\circ}C$로 증가하였고, 동시에 추출시간과 $R^2$가 증가하였다. MAP 추출에서 unknown화합물의 함량이 최소가 되는 조건은 에탄올 농도 $67.33\%$, 추출온도 $99.34^{\circ}C$, 추출시간 3.65분이었다. 추출효율의 확인시험에서 8분간의 MAP추출법은 현행 추출법(40시간) 매우 유사한 수준의 ginsenoside 추출효율을 나타내었다.

• Journal of Yeungnam Medical Science
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• 제19권2호
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• pp.99-106
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• 2002

단순 심실중격결손증은 선천성 심질환중 흔한 질환이지만 어린 나이 혹은 저체중환아에서 시행하는 경우 경험에 따라 만족스럽지 못한 경우도 있어 영아기에 수술을 시행한 단순 심실중격결손증 환자들의 수술 결과를 조사하였다. 1996년부터 2000년까지 첩포봉합술을 시행한 45명을 대상으로 체중 5 kg을 기준으로 수술의 결과를 분석하였다. 수술사망은 없었으며 두 군간의 합병증 발생에 있어 유의한 차이는 없었다. 수술 수기로 사용된 단순 연속봉합법은 전례에서 적용할 수 있었으며 증상이 있는 심실 중격결손증은 체중이 5kg이하의 환아에서도 시기에 관계 없이 안전하게 시행할 수 있었다.

• 한국대기환경학회지
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• 제32권2호
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• pp.216-232
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• 2016

In present, the Seoul City is undergoing traffic congestion problems caused by rapid urbanization and population growth. Thus the City government has reorganized the mass transportation system since 2004 and the subway has become a very important means for public transit. Since the subway system is typically a closed environment, the indoor air quality issues have often raised by the public. Especially since a huge amount of PM (particulate matter) is emitted from ground tunnels passing through the subway train, it is now necessary to assess the characteristics and behaviors of fine PM inside the tunnel. In this study, the concentration patterns of $PM_1$, $PM_{2.5}$, and $PM_{10}$ in the Seoul subway line-2 were analyzed by real-time measurement during winter (Jan 13, 2015) and summer (Aug 7, 2015). The line-2 consisting of 51 stations is the most busy circular line in Seoul having the railway of 60.2 km length. The the one-day average $PM_{10}$ concentrations were $148{\mu}g/m^3$ in winter and $66.3{\mu}g/m^3$ in summer and $PM_{2.5}$ concentrations were $118{\mu}g/m^3$ and $58.5{\mu}g/m^3$, respectively. The $PM_{2.5}/PM_{10}$ ratio in the underground tunnel was lower than the outdoor ratio and also the ratio in summer is higher than in winter. Further the study examined structural types of underground subsections to explain the patterns of elevated PM concentrations in the line-2. The subsections showing high PM concentration have longer track, shorter curvature radius, and farther from the outdoor stations. We also estimated the outdoor PM concentrations near each station by a spatial statistical analysis using the $PM_{10}$ data obtained from the 40 Seoul Monitoring Sites, and further we calculated $PM_{2.5}/PM_{10}$ and $PM_1/PM_{10}$ mass ratios near the outdoor subway stations by using our observed outdoor $PM_1$, $PM_{2.5}$, and $PM_{10}$ data. Finally, we could develop pollution maps for outdoor $PM_1$ and $PM_{2.5}$ near the line-2 by using the kriging method in spatial analysis. This methodology may help to utilize existing $PM_{10}$ database when managing and control fine particle problems in Korea.

• 자원환경지질
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• 제31권2호
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• pp.111-125
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• 1998

Dispersion, migration and enrichment of environmental toxic elements from the Samkwang Au-Ag mine area were investigated based upon major, minor and rare earth element geochemistry. The Samkwang mine area composed mainly of Precambrian granitic gneiss. The mine had been mined for gold and silver, but closed in 1996. According to the X-ray powder diffraction, mineral composition of stream sediments and soils were partly variable mineralogy, which are composed of quartz, orthoclase, plagioclase, amphibole, muscovite, biotite and chlorite, respectively. Major element variations of the host granitic gneiss, stream sediments and soils of mining and non-mining drainage, indicate that those compositions are decrese $Al_2O_3$, $Fe_2O_3$, MgO, $TiO_2$, $P_2O_5$ and LOI with increasing $SiO_2$ respectively. Average compositional ranges (ppm) of minor and/or environmental toxic elements within those samples are revealed as As=<2-4500, Cd=<1-24, Cu=6-117, Sb=1-29, Pb=17-1377 and Zn=32-938, which are extremely high concentrations of sediments from the mining drainage (As=2006, Cd=l1, Cu=71, Pb=587 and Zn=481 ppm, respectively) than concentrations of the other samples and host granitic gneiss. Major elements (average enrichment index=6.53) in all samples are mostly enriched, excepting $SiO_2$, $Na_2O$ and $K_2O$, normalized by composition of host granitic gneiss. Rare earth element (average enrichment index=2.34) are enriched with the sediments from the mining drainage. Minor and/or environmental toxic elements within all samples on the basis of host rock were strongly enriched of all elements (especially As, Br, Cu, Pb and Zn), excepting Ba, Cr, Rb and Sr. Average enrichment index of trace elements in all samples is 15.55 (sediments of mining drainage=37.33). Potentially toxic elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) of the samples revealed that average enrichment index is 46.10 (sediments of mining drainage=80.20, sediments of nonmining drainage=5.35, sediments of confluent drainage=20.22, subsurface soils of mining drainage=7.97 and subsurface soils of non-mining drainage=4.15). Sediments and soils of highly concentrated toxic elements are contained some pyrite, arsenopyrite, sphalerite, galena and goethite.

• 한국환경농학회지
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• 제30권3호
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• pp.243-251
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• 2011

간척지 논 토양에서 석고의 처리는 염의 농도에 관계없이 고염도와 저염도 전체 토양에서 무처리 대비 71.3~98.9%까지 메탄 발생을 저감 할 수 있었다. 석고 처리에 따른 황산염을 증가는 전자수용체, 즉 황산염이온의 양 증대에 따른 전자의 활성저하와 황환원균의 활성증가가 메탄 발생을 저감시키는 가장 큰 요인인 것으로 판단된다. 간척지 논에 석고를 시용할 경우 부족한 칼슘의 공급효과를 통하여 토양의 물리성 및 배수 개선을 통하여 메탄 발생 감소에 영향을 줄 수 있었다. 또한 석고의 시용은 간척지 토양의 높은 pH와 높은 나트륨 이온을 효과적으로 저감할 수 있어 식물 생육 및 수량에 긍정적인 영향을 주었으며, 물리성 개선을 통하여 메탄 발생을 저감 시킬 수 있었다. 간척지 토양에서 석고의 시용은 벼 수량을 13.2~39.1%까지 증수 효과가 있었으나, 과량 처리시 오히려 생산성을 감소시켰다. 결론적으로 간척지에서 토양 개량을 위해 사용되어 지는 석고는 토양의 물리 화학성을 개선할 뿐만 아니라 메탄 발생을 효과적으로 저감할 수 있는 우수한 토양 개량제로서 평가되었다.

• 자원리싸이클링
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• 제7권4호
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• pp.27-34
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• 1998

본 연구에서는 NiCuZn Ferrite(NCZF) 제조공정의 제어에 대하여 연구하였다. $700^{\circ}C$, 3시간 하소한 NCZF를 약 60시간 볼밀링하여 약 $0.5\mu\;extrm{m}$ 입자크기로 분쇄한 후 분무 건조하여 과립화하였다. NCZF의 충전율에 따른 겉보기 고화속도 및 초기투자율에 미치는 영향을 조사한 결과 다음과 같은 결과를 얻었다. 1. 성형압력 유지시간 1분에서 성형압력을 약 20~170 ㎫로 변화시켜 제조한 NCZF 토로이달 상의 출발시편은 성형압이 증가하면서 입자의 충전율은 48.6%에서 56.8%로 증가하였다. 2. 일정 소성온도에서 NCZF의 충전율이 높아질수록 고화속도가 높아지고, 일정 성형압력에서 소성온도가 높아질수록 NCZF의 겉보기 고화속도는 빨라졌다. NCZF의 충전율과 소성온도가 높고, 소성시간이 길어지면 bulk density는 증가하였다. 3. 고정된 조성에서 소성온도($875~925^{\circ}C$)와 소성시간(0~5시간)의 조합에 의해 제조된 NCZF의 초기투자율은 bulk density와 semi-log상에서 직선적인 비례관계를 가지며 NCZF입자의 충전율에 크게 의존하였다. NCZF입자의 충전율과 이들을 소성하였을 때의 bulk density를 알면 초기투자율을 예측할 수 있었다. log $\mu$i=$G1{\times}BD$+$G2{\times}충전율$+b(0), G1;0.8394, G2;-3.6233, (b);0.7053.

• Archives of Plastic Surgery
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• 제36권5호
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• pp.623-628
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• 2009

Purpose: In cases where nasal fractures involve frontal process of maxilla or perpendicular plate of ethmoid, 4 - 5 days of nasal packing may not provide sufficient support for avoiding displacement after packing removal. Therefore a single Kirschner - wire(K - wire) is used as an internal splint when nasal fractures involve the above two areas. Methods: Thirty five patients during the last 3 practical years were treated with a K -wire pinning according to the anatomic locations of nasal fractures. We performed a retrospective study using 13 nasal fractures out of total 35 patients. Among 13 cases, 10 patients involved frontal process of maxilla, and 3 patients were diagnosed as bilateral nasal side wall fractures accompanied with fractures of perpendicular plate of ethmoid. One patient of the last three cases had been augmented with dorsal silicone implant long before the trauma. We analyzed the anteroposterior displacement of key stone area and the width between both lateral walls by comparing immediate postoperative radiographs with 2 month follow - ups. To reduce the errors, the same measurements were taken by two different inspectors, and the mean of each inspector's measurements was compared. Patient satisfaction was analyzed using a questionnaire regarding the esthetic and functional outcomes. Results: Ten patients underwent a longitudinal K - wire fixation in submucoperiosteal plane underneath the frontal process of maxilla. And three patients underwent a transverse K - wire fixation from the one side of lateral wall to the perpendicular plate of ethmoid and to the other side of lateral wall. The mean postoperative anteroposterior displacement of the key stone area measured by two inspectors were 1.84% and 3.06%; mean narrowing of bony pyramid were 1.33% and 1.48%, respectively. Subjective satisfaction scores regarding the esthetic appearance and the maintenance of nasal shape compared with immediate post - operative state with the long term ones were not different (p>0.05). Conclusion: K - wire pinning after closed reduction is a reliable and useful method for the treatment of nasal fractures involving frontal process of maxilla or perpendicular plate of ethmoid. This is because it achieves longer intranasal support after reduction. This method also leaves conspicuous external scar, and minimal soft - tissue injury.

• Ocean and Polar Research
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• 제40권4호
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• pp.237-247
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• 2018

This study aims to estimate optimal harvests, fishing efforts, and stock levels of hairtail harvested by the large pair bottom trawl, the large otter trawl, the large purse seine, the offshore long line, and the offshore angling fisheries by using the surplus production models and the current value Hamiltonian method. Processes of this study are as follows. First of all, this study estimates the standardized fishing efforts regarding the harvesting of the hairtail by the above five fishing gears based on the general linear model developed by Gavaris. Secondly, this study estimates environmental carrying capacity (k), intrinsic growth rate (r), and catchability coefficient (q) by applying the Clarke Yoshimoto Pooley (CY&P) model among various surplus production models. Thirdly, this study estimates the optimal harvests, fishing efforts, and stock levels regarding the hairtail by the current value Hamiltonian method, including the average landing price, the average unit cost, and the social discount rate. Finally, this study attempts a sensitivity analysis to figure out changes in optimal harvests, fishing efforts, and stock levels due to changes in the average landing price and the average unit cost. As results induced by the current value Hamiltonian method, the optimal harvests, fishing efforts, and stock levels regarding the hairtail caught by several fishing gears were estimated as 33,133 tons, 901,080 horse power, and 79,877 tons, respectively. In addition, from the results of the sensitivity analysis, first of all, if the average landing price of the hairtail constantly increases, the optimal harvests of it increase at a decreasing rate, and then harvests finally slightly decrease as a result of decreases in stock levels. Secondly, if the average unit cost of fishing efforts continuously increases, the optimal fishing efforts decreases, but optimal stock levels increase. Optimal harvests start climbing and then decrease continuously due to increases in the average unit cost. In summary, this study suggests that the optimal harvests (33,133 tons) were larger than actual harvests (25,133 tons), but the optimal fishing efforts (901,080 horse power) were much less than estimated standardized fishing efforts (1,277,284 horse power), corresponding to the average of the recent three years (2014-2016). This result implies that the hairtail has been inefficiently harvested and recently overfished due to excessive fishing efforts. Efficient management and conservation policies on stock levels need to be urgently implemented. Some appropriate strategies would be to include the hairtail in the Korean TAC species or to extend the closed fishing season for this species.