• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.19-25
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• 1999

This paper addresses a development work of a SLA apparatus on laboratory basis. The SLA test machine is composed of optical, movement, curing and control subsystems. Optical part is performed by a He-Cd laser with mirror combination and mechanical movement is achieved by X-Y table. The developed system is evaluated by several test runs, and shows a good precision capability in forming a basic part. The technique used in this work can be extended to replace the high technology transfer cost of commercial RP machine.

• 한국식품영양과학회지
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• 제28권1호
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• pp.22-27
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• 1999

This study was performed to investigated the contamination levels of harmful heavy metals were sampled from Aug. 1 to Aug. 31, 1997, at 9 areas in Cheonbuk area. The heavy metal contents were determinated by ICPS(Inductively Coupled Plasma Spectrometer) method. The levels of total lead, cadmium, aluminum, iron and copper were determined and the results were summarized as follows: The minimum and maximum values(ppm) of 9 areas of Carassius auratus were Pb: 2.03~6.19, Cd: 0.06~ 0.76, Al: 8.84~23.5, Zn: 10.68~48.71, Cu: 0.60~1.51ppm. Among the five heavy metals contents, the highest was zinc and the lowest was cadmium. The results showed that the contents of Pb, Cd, Al, Zn and Cu in Carassius auratus were lower than the FAO/WHO maximum allowance.

• 조명전기설비학회논문지
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• 제21권2호
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• pp.15-19
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• 2007

본 연구에서는 절연층으로 둘러 쌓인 수은이 포함되지 않은 15[inch] 평판형광램프에 대하여 연구하였다. 적당한 주기, 펄스폭을 갖는 구형파가 인가되면 평판형램프는 안정되고 균일한 방전이 전면에 걸쳐 발생한다. 균일하고 안정된 방전 상태에서의 프리즘 시트 없이 최대휘도는 $10,330[cd/m^2]$를 얻었다.

• IMMUNE NETWORK
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• 제23권5호
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• pp.39.1-39.15
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• 2023

Coronavirus disease 2019 (COVID-19) vaccination may non-specifically alter the host immune system. This study aimed to evaluate the effect of COVID-19 vaccination on hepatitis B surface Ag (HBsAg) titer and host immunity in chronic hepatitis B (CHB) patients. Consecutive 2,797 CHB patients who had serial HBsAg measurements during antiviral treatment were included in this study. Changes in the HBsAg levels after COVID-19 vaccination were analyzed. The dynamics of NK cells following COVID-19 vaccination were also examined using serial blood samples collected prospectively from 25 healthy volunteers. Vaccinated CHB patients (n=2,329) had significantly lower HBsAg levels 1-30 days post-vaccination compared to baseline (median, -21.4 IU/ml from baseline), but the levels reverted to baseline by 91-180 days (median, -3.8 IU/ml). The velocity of the HBsAg decline was transiently accelerated within 30 days after vaccination (median velocity: -0.06, -0.39, and -0.04 log₁₀ IU/ml/year in pre-vaccination period, days 1-30, and days 31-90, respectively). In contrast, unvaccinated patients (n=468) had no change in HBsAg levels. Flow cytometric analysis showed that the frequency of NK cells expressing NKG2A, an NK inhibitory receptor, significantly decreased within 7 days after the first dose of COVID-19 vaccine (median, -13.1% from baseline; p<0.001). The decrease in the frequency of NKG2A⁺ NK cells was observed in the CD56^dimCD16⁺ NK cell population regardless of type of COVID-19 vaccine. COVID-19 vaccination leads to a rapid, transient decline in HBsAg titer and a decrease in the frequency of NKG2A⁺ NK cells.

• 한국환경농학회지
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• 제18권3호
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• pp.250-258
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• 1999

익산 제 2공단은 1995년 조성 후 생산활동이 진행됨에 따른 토양의 중금속 함량을 비오염지의 자연토양 중 함량과 비교하고, 산업활동의 유형에 따른 토양중 중금속 함량 변화와의 관계를 구명하기 위하여 주로 표층토를 중심으로 $0{\sim}3\;cm$, $3{\sim}6\;cm$ 토양층에 있는 Cd, Cu, Ni, Pb 및 Zn의 함량을 조사${\cdot}$분석한 결과는 다음과 같다. 1. Cd의 함량의 경우 $0{\sim}3\;cm$ 층은 $0.07\;{\sim}\;4.375\;ppm$ 범위로 평균 0.516 ppm, $3{\sim}6\;cm$ 층은 $0.07{\sim}8.52\;ppm$ 범위로 평균 0.380 ppm 이었으며, 화학제품, 염료 및 금속제품을 생산하는 지역이 높았다. 2. Cu의 함량 분포의 경우 $0{\sim}3\;cm$ 층은 $0.61\;{\sim}\;42.62\;ppm$ 범위로 평균 11.087 ppm, $3{\sim}6\;cm$ 층은 $0.16{\sim}35.45\;ppm$ 범위로 평균 7.578 ppm 이었으며, 금속제품을 생산하는 지역이 주로 높았다. 3. Ni의 함량 분포의 경우 $0{\sim}3\;cm$ 층은 $0.19\;{\sim}\;15.93\;ppm$ 범위로 평균 5.525 ppm, $3{\sim}6\;cm$ 층은 $0.39{\sim}15.59\;ppm$ 범위로 평균 5.310 ppm 이었으며, 금속 및 화학제품을 생산하는 지역이 주로 높았다. 4. Pb의 함량 분포의 경우 $0{\sim}3\;cm$ 층은 $3.10\;{\sim}\;55.75\;ppm$ 범위로 평균 23.543 ppm, $3{\sim}6\;cm$ 층은 $3.35{\sim}46.55\;ppm$ 범위로 평균 19.198 ppm 이었으며, 화학제품 및 금속제품을 생산하는 지역이 높았다. 5. Zn의 함량 분포의 경우 $0{\sim}3\;cm$ 층은 $26.50\;{\sim}\;943.00\;ppm$ 범위로 평균 158.329 ppm, $3{\sim}6\;cm$ 층은 $35.45{\sim}882.45\;ppm$ 범위로 평균 127.914 ppm 이었으며, 화학제품, 염료 및 금속제품을 생산하는 지역이 높았다. 이상의 결과를 토대로 세계의 비오염 토양 함량수준과 본조사지역의 평균함량을 비교하면 Cu, Ni은 비오염 수준이었으나, Cd은 기준치를 약간 넘었고, Pb과 Zn은 기준치보다 훨씬 높아 익산 제2공단의 오염정도는 산업(화학제품, 염료 및 금속 제품을 생산)유형에 따라 차이가 있음을 알 수 있었다.

• 한국환경농학회지
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• 제19권4호
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• pp.345-350
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• 2000

하남시 토양 전체를 대상으로 논, 밭, 산림, 하천유역 및 기타 지역(도심지, 나대지, 시 외각 마을)을 대표할 수 있는 지점을 선정하여 총 100점의 시료를 채취하고 As, Cd, Cu, Pb, Zn의 함량을 분석하여 우리나라 자연함량, Taiwan의 도시 토양 중 중금속 함량, 환경부가 정한 토양환경보전법상의 우려기준과 비교한 결과는 다음과 같다. 분석한 중금속 As, Cd, Cu, Pb, Zn의 평균농도는 각각 0.24, 0.14, 3.69, 3.03, 18.31ppm로 환경부가 제정한 토양보전법상의 우려기준보다 모두 낮은 값을 나타내었으며 우리나라의 자연준위와 비슷한 수준이었다. 그러나 Cd의 경우와 같이 일부 지점에서는 토양환경보전법상의 우려기준은 물론 대책기준을 초과하는 높은 값을 보여 정밀 조사가 필요할 것으로 생각된다.

• Korean Journal of Acupuncture
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• 제24권4호
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• pp.163-180
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• 2007

Objective : Oriental medicines have been applied to Membranous nephropathy(MN) for the purpose on increasing renal blood flow and modulating immune activity in according to Oriental medicine theories. Magsungsinyeom-bang (MSSYB) is one of the prescription which is known to show positive results in clinic with lack of laboratorial evidence. Thus, this study was aimed to evaluate the effects of MSSYB and partially investigate the mechanisms of it. Methods : The effect of MSSYB was evaluated by the morphology for the GBM thickening, protein excretion in urine and biochemical parameters in serum using cBSA-induced MN mice model. Mice were administered with MSSYB(250 or 500 mg/kg) or PBS for control group from experimental week 3 for 4 weeks. Results : 24 hrs proteinuria and the concentrations BUN was significantly decreased in the MS groups compared to the control group while the concentrations of serum albumin was higher in the MS groups than control group. MSSYB didn't affect the ratio of CD3e+/CD or 19CD4+/CD8 in the spleen and kidney, but inhibit the expression of IL-1${\beta}$, TNF-${\alpha}$, IL-6, and production of IgG and IgM. In histological analysis of kidney tissue, thickening of GBM was significantly decreased in the MS group compared to control group. Conclusions : MSSYB showed the positive results on the cBSA-induced membranous nephropathy in mice, thus, it could be a useful candidate for oriental drug for treating the membranous nephropathy in clinic.

• 환경위생공학
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• 제3권2호
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• pp.91-98
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• 1988

This study was carried out to investigate the Pollution of heavy metals in Soil, collected from the 50 sampling sites in 1986. The results were as follows; 1. In the average contents of Cd, the highest value was 0.33mg/kg in the Industrial area, the lowest value was 0.06 mg/kg in the Greenbelt and 0.10-0.22mg/kg in the other areas. 2. In the average contents of Cu, the highest value was 33.46mg/kg in the Industrial area, the lawest value was 3.79mg/kg in the Greenbelt and 4.69-12.21mg/kg in the other areas. 3. In the average contents of As, the highest value was 1.80mg kg in the Residential area, the lowest value was 0.43mg/kg in the Greenbelt and 0.64-1.65mg/kg in the other areas. 4. In the average contents of Zn, the highest value was 29.84mg/kg in the out wall of Seoul, the lowest value was 17.32mg/kg in the Greenbelt and 19.62-26.71mg/kg in the other areas. 5. In the average contents of Pb, the highest value was 17.09mg/kg in the Industrial area, the lowest value was 5.21mg/kg in the Reclamated waste and 5.67 -14.10mg/kg in the other areas. 6. Distribution of Heavy metals was Zn>Cu>Pb>As>Cd and the relations of Zn-Cd, Pb-Cd, Pb-Cu, Pb-Zn were shown the correlation significantly (P< 0.01).

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.544-547
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• 2003

The objective of this study is to investigate the contamination levels and dispersion patterns of arsenic and heavy metals and to estimate the bioaccessible fraction of the metals in soil and plant samples in the vicinity of the abandoned Songcheon Au-Ag mine. Tailings, soils, plants (Chinese cabbage, red pepper, soybean, radish, sesame leaves, green onion, lettuce, potato leaves, angelica and groundsel) and waters were collected around the mine site. After appropriate preparation, all samples were analyzed for As, Cd, Cu, Pb and Zn by ICP-AES and ICP-MS. Elevated levels of As and heavy metals were found in tailings. Mean concentrations of As in agricultural soils were higher than the permissible level. Especially, maximum level of As in farmland soil was 513 mg/kg. The highest concentrations of As and Zn were found in Chinese cabbage (6.7 mg/kg and 359 mg/kg, respectively). Concentrations of As, Cd, and Zn in most stream waters which are used for drinking water around this mine area were higher than the permissible levels regulated in Korea. Maximum levels of As, Cd and Zn in stream waters were 0.78 mg/L, 0.19 mg/L and 5.4 mg/L, respectively. These results indicate that mine tailings can be the main contamination sources of As and heavy metals in the soil-water system in the mine area. The average of estimated bioaccessible fraction of As in farmland soils were $3.7\%$ (in simulated stomach) and $10.8\%$ (in simulated small intestine). The highest value of bioaccessible fraction of metal in farmland soils was $46.5\%$ for Cd.

• 대한의생명과학회지
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• 제19권4호
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• pp.295-302
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• 2013

Some of the pituitary adenomas are invasive and spread into neighboring tissues. In previous studies, the invasion of pituitary adenomas is thought to be associated with epithelial-mesenchymal transition (EMT). In addition to that, we thought that mesenchymal stem cells (MSCs) exist in relevant microenvironment in pituitary adenoma. However, it has been little known about the existence of MSCs from pituitary adenoma. So we investigated whether mesenchymal stem-like cells (MSLCs) can be isolated from the pituitary adenoma specimen. We isolated and cultured candidate MSLCs from the fresh pituitary adenoma specimen with the same protocols used in culturing bone marrow derived MSCs (BM-MSCs). The cultured candidate MSLCs were analyzed by fluorescence-activated cell sorting (FACS) for surface markers associated with MSCs. Candidate MSLCs were exposed to mesenchymal differentiation conditions to determine the mesenchymal differentiation potential of these cells. To evaluate the tumorigenesis of candidate MSLCs from pituitary adenoma, we implanted these cells into the brain of athymic nude mice. We isolated cells resembling BM-MSCs named pituitary adenoma stroma mesenchymal stem-like cells (PAS-MSLCs). PAS-MSLCs were spindle shaped and had adherent characteristics. FACS analysis identified that the PAS-MSLCs had a bit similar surface markers to BM-MSCs. Isolated cells expressed surface antigen, positive for CD105, CD75, and negative for CD45, NG2, and CD90. We found that these cells were capable of differentiation into adipocytes, osteocytes and chondrocytes. Tumor was not developed in the nude mice brains that were implanted with the PAS-MSLCs. In this study, we showed that MSLCs can be isolated from a pituitary adenoma specimen which is not tumorigenic.