• 한국정보전자통신기술학회논문지
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• 제16권4호
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• pp.187-192
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• 2023

본 논문은 스퍼터링 장비를 이용하여 ITO 유리 기판에 CdTe 박막을 RF Power로 변화주면서 CdTe 박막을 증착하였다. 박막의 두께를 측정한 결과, 100W 일 때 1481Å, 150W는 2985Å, 200W는 4684Å로 측정되었다. 그리고 이동도는 100W일 때 8.43cm2/Vs, 150W는 7.91cm2/Vs, 200W는 6.57cm2/Vs로 측정되었다. 시편의 두께와 이동도는 반비례한 한다는 것을 알 수가 있었다. 투과율을 확인한 결과, 100W 일 때 905nm에서 투과율은 84%, 150W는 825nm에서 투과율이 71%, 200W는 874nm에서 77%로 측정되었다. 이것은 시편의 두께가 100W일 때 시편의 두께가 얇았으므로 투과율이 높게 측정되었다. 즉 투과율과 두께의 상관관계를 알 수가 있는 부분이다. RF Power를 변화주어 반치폭과 입자의 크기를 측정한 결과, 반치폭은 100W일 때 0.18, 150W는 0.19, 200W는 0.73으로 계산되었다. 입자의 크기는 100W에서는 8.47Å, 150W에서는 7.98Å, 200W일 때 가장 큰 8.7Å으로 형성된 것으로 확인되었다. 결론적으로 반치폭과 입자 크기는 반비례하는 것을 알 수 있었다.

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1794-1798
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• 2018

We have grown famatinite $Cu_3SbS_4$ films by using sulfurization of Cu/Sb stack film. Sulfurization at $500^{\circ}C$ produced famatinite $Cu_3SbS_4$ phase, while $400^{\circ}C$ and $450^{\circ}C$ sulfurization exhibited unreacted and mixed phases. The fabricated $Cu_3SbS_4$ film showed S-deficiency, and secondary phase of $Cu_{12}Sb_4S_{13}$. The secondary phase was confirmed by X-ray diffraction, Raman spectroscopy, photoluminescence and external quantum efficiency measurements. We have also fabricated solar cell in substrate type structure, ITO/ZnO/(Zn,Sn)O/$Cu_3SbS_4$/Mo/glass, where $Cu_3SbS_4$ was used as a absorber layer and (Zn,Sn)O was employed as a Cd-free buffer. Our best cell showed power conversion efficiency of 0.198%. Characterization results of $Cu_3SbS_4$ absorber indicates deep defect (due to S-deficiency) and low shunt resistance (due to $Cu_{12}Sb_4S_{13}$ phase). Thus in order to improve the cell efficiency, it is required to grow high quality $Cu_3SbS_4$ film with no S-deficiency and no secondary phase.

• 한국수산과학회지
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• 제32권5호
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• pp.587-592
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• 1999

우리나라 전 연안의 조간대에 분포하고 있는 총알고둥을 대상으로 TBTCI, Hg 및 Cd의 급성독성과 그에 따른 사망률 및 산소 소비율의 변화를 수온, $15^{\circ}C$와 $23^{\circ}C$ 그리고 개체크기에 따라 살펴보았다. 수온 $15^{\circ}C$에서, 큰 개체 및 작은 개체에 대한 오염원별 급성독성 영향은 TBTCI에서 13일-$LC_{50}$은 각각 0.87 ppm, 0.65 ppm, Hg의 11일-$LC_{50}$은 각각 5.55 ppm, 2.85 ppm, 그리고 Cd의 9일-$LC_{50}$은 각각 13.77 ppm 및 8.46 ppm으로 독성순위는TBTCl > Cd > Hg으로 나타났다. 그리고 수온 $23^{\circ}C$에서는, TBTCl의 8일-$LC_{50}$은 각각 0.68 ppm과 0.15 ppm, Hg의 5일-$LC_{50}$은 각각 10.41 ppm과 5.73 ppm이 었으며, Cd의 4일-$LC_{50}$은 각각 13.31 ppm과 4.47 ppm이었으며, 독성순위는 TBTCl > Cd > Hg으로 나타났다. 실험 오염원에 대해서 큰 개체가 작은 개체보다 내성이 강했으며, Hg과 Cd의 경우 $15^{\circ}C$에서보다 $23^{\circ}C$에서 오염원의 농도가 증가함에 따라 작은 개체의 내성이 더 크게 감소했다 TBTCI와 Cd에서는 $15^{\circ}C$에 비해 $23^{\circ}C$에서 개체가 작을 수록 저해영향은 크게 작용했다. 총알고둥의 산소소비율은 $15^{\circ}C$보다 $23^{\circ}C$에서, 큰 개체보다 작은 개체에서 더 높았으며, 작은 개체가 농도증가에 따라 더 크게 감소했다.

• Toxicological Research
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• 제32권1호
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• pp.73-80
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• 2016

Chronic exposure to cadmium (Cd) is known to adversely affect renal function. Our previous studies indicated that Cd induces p53-dependent apoptosis by inhibiting gene expression of the ubiquitin-conjugating enzyme (Ube) 2d family in both human and rat proximal tubular cells. In this study, the effects of Cd on protein expression of p53 and apoptotic signals in the kidney and liver of mice exposed to Cd for 12 months were examined, as well as the effects of Cd on p53 protein levels and gene expression of the Ube2d family in various cell lines. Results showed that in the kidney of mice exposed to 300 ppm Cd for 12 months, there was overaccumulation of p53 proteins in addition to the induction of apoptosis, which was triggered specifically in the proximal tubules. Interestingly, the site of apoptosis was the same as that of p53 accumulation in the proximal tubules. In the liver of mice chronically exposed to Cd, gene expression of the Ube2d family tended to be slightly decreased, together with slight apoptosis without the accumulation of p53 protein. In rat small intestine epithelial (IEC-6) cells, Cd decreased not only the p53 protein level but also gene expression of Ube2d1, Ube2d2 and Ube2d4. In human brain microvascular endothelial cells (HBMECs), Cd did not suppress gene expression of the Ube2d family, but increased the p53 protein level. In human brain astrocytes (HBASTs), Cd only increased gene expression of UBE2D3. These results suggest that Cd-induced apoptosis through p53 protein is associated with renal toxicity but not hepatic toxicity, and the modification of p53 protein by Cd may vary depending on cell type.

• 한국환경농학회지
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• 제14권3호
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• pp.263-271
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• 1995

중금속에 의한 토양오염을 화학적으로 평가하기 위한 일환으로 토양을 중금속으로 오염시킨 후 토양용액을 추출하여 pH, 이온강도, 이온농도, 화합물형태 변화를 분석했다. 토양이 Cu와 Cd에 의해 오염될수록 토양용액의 이온강도는 증가했다. 이런 변화는 Cd보다 Cu에 의해 더 컸다. 토양용액 중의 Cu와 Cd의 농도는 가한 양(量)에 비해 소량으로 존재했으나 처리량에 비례하여 금속의 농도는 증가했다. 토양용액 중의 Cd의 농도는 Cu보다 훨씬 높았다. 토양용액 중의 Ca, Mg, K의 농도는 중금속에 의해 증가되었으나 주로 free ion상태로 존재했으며 화합물형태는 Cu나 Cd의 처리에 의해 변화되지 않았다. 토양용액 중 중금속이온의 화합물의 변화 경향은 Cu와 Cd이 달랐다. Cu의 경우 토성과 pH에 의해 영향을 받았는데 pH가 낮은 SiCL 및 SL 토양에서는 free $Cu^{2+}$가 95 molar % 이상으로 주된 화합물형태이었고 pH가 높은 LS토양의 경우 free $Cu^{2+}$과 Cu-hydroxide이 주된 화합물형태로 Cu처리량에 따라 이들 화학종의 molar %는 변화되었다. Cd의 경우 free $Cd^{2+}$과 Cd-chloride 화합물이 주된 화합물형태이었고 Cd처리량이 증가함에 따라 $Cd^{2+}$는 감소한 반면 Cd-chloride 화합물 형성은 증가했다. 중금속에 의한 토양용액의 pH감소, 중금속의 흡착에 따른 양이온의 일시적인 증가, 중금속의 화합물 변화들은 식물영양적 측면에서 볼 때 식물에 불리한 변화로 간주되며, 중금속의 생물유효성과 독성을 평가하는 자료로 활용될 수 있을 것이다.

• 한국환경과학회지
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• 제15권2호
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• pp.163-167
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• 2006

To obtain the safety evaluation of the ginseng, residues of heavy metals in culture environment of ginseng on Punggi and Sangju, Kyeongbuk are surveyed. The concentration for component of ginseng on Punggi and Sangju were 14.12mg/kg and 15.74mg/kg, respectively. The concentration for general component such as crude fiber, ash, crude lipid, crude protein, carbohydrate, of ginseng were coincided between Punggi and Sangju. The concentration for As, Pb, Cd, and Hg in soil on Punggi were 14.24 ppb, 43.13 ppb, 8.73 ppb and 0.82 ppb, respectively. The concentration for As, Pb, Cd, and Hg in soil on Sangju were 19.20 ppb, 54.82 ppb, 15.90 ppb and 1.04, respectively. Residual heavy metals are not polluted in the soil with culture ginseng on Punggi and Sangju. The concentration for As, Pb, Cd, and Hg with ginseng on Punggi were 29.30ppb, 21.78 ppb, 1.32 ppb and 2.72 ppb, respectively. The concentration for As, Pb, Cd, and Hg with ginseng on Sangju were 3.22 ppb, 24.43 ppb, 1.44 ppb and 4.74 ppb, respectively. Also the detection concentration for As, Pb, Cd, and Hg in ginseng were also lower than the Korea Food & Drug Administration advisory level for heavy metal in herbal medicines. Residual heavy metals are not polluted in the ginseng on Punggi and Sangju at Kyeongbuk, Korea.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권4호
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• pp.23-30
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• 2011

Risk based pollution level of Pb and Cd in metal contaminated soils depending on physicochemical properties of soil in a target site was assessed using biotic ligand model. Heavy metal activity in soil solution defined as exposure activity (EA) was assumed to be toxic to Vibrio fischeri and soil organisms. Predicted effective activity (PEA) determined by biotic ligand model was compared to EA value to calculate risk quotient. Field contaminated soils (n = 10) were collected from a formes area and their risk based pollution levels were assessed in the present study using the calculated risk quotient. Concentrations of Pb determined by aqua regia were 295, 258, and 268 mg/kg in B, H and J points and concentrations of Cd were 4.73 and 6.36 mg/kg in G and I points, respectively. These points exceeded the current soil conservation standards. However, risk based pollution levels of the ten points were not able to be calculated because concentrations of Pb and Cd in soil solution were smaller than detection limits or one (i.e., non toxic). It was because heavy metal activity in soil solution was dominant toxicological form to organisms, not a total heavy metal concentration in soil. In addition, heavy metal toxicity was decreased by competition effect of major cations and formation of complex with dissolved organic carbon in soil solution. Therefore, it is essential to consider site-specific factors affecting bioavailability and toxicity for estimating reliable risk of Pb and Cd.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제19권4호
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• pp.236-242
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• 2016

Purpose: The aim of this study was to investigate the clinical features and extraintestinal manifestations (EIMs) of Crohn disease (CD) in Korean pediatric patients. Methods: The medical records of 73 children diagnosed with CD were retrospectively reviewed. Data regarding baseline demographic and clinical characteristics, including CD phenotype at diagnosis based on the Montreal classification, and clinical features and course of EIMs were investigated. Results: Fifty-two (71.2%) of the patients were males. The mean age of the patients was 12.5 years. The mean follow-up period was 3.4 years. The disease location was ileal in 3 (4.1%) of the patients, colonic in 13 (17.8%), ileocolonic in 56 (76.7%). The clinical behavior was inflammatory in 62 (84.9%) of the patients, stricturing in 8 (11.0%), and penetrating in 3 (4.1%). Perianal abscesses or fistulas were found in 37 (50.7%) of the patients. EIMs observed during the study period were anal skin tag in 25 patients (34.2%), hypertransaminasemia in 20 (27.4%), peripheral arthritis in 2 (2.7%), erythema nodosum in 2 (2.7%), vulvitis in 1 (1.4%), uveitis in 1 (1.4%), and pulmonary thromboembolism in 1 (1.4%). Conclusion: Perianal diseases and manifestations were present in more than half of Korean pediatric CD patients at diagnosis. Inspection of the anus should be mandatory in Korean children with suspicious CD, as perianal fistulas, abscesses, and anal skin tags may be the first clue to the diagnosis of CD.

• 한국수정란이식학회지
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• 제33권2호
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• pp.85-97
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• 2018

The trans-differentiation potential of mesenchymal stem cells (MSCs) is employed, but there is little understanding of the cell source-dependent trans-differentiation potential of MSCs into corneal epithelial cells. In the present study, we induced trans-differentiation of MSCs derived from umbilical cord matrix (UCM-MSCs) and from dental tissue (D-MSCs), and we comparatively evaluated the in vitro trans-differentiation properties of both MSCs into corneal epithelial-like cells. Specific cell surface markers of MSC (CD44, CD73, CD90, and CD105) were detected in both UCM-MSCs and D-MSCs, but MHCII and CD119 were significantly lower (P < 0.05) in UCM-MSCs than in D-MSCs. In UCM-MSCs, not only expression levels of Oct3/4 and Nanog but also proliferation ability were significantly higher (P < 0.05) than in D-MSCs. In vitro differentiation abilities into adipocytes and osteocytes were confirmed for both MSCs. UCM-MSCs and D-MSCs were successfully trans-differentiated into corneal epithelial cells, and expression of lineage-specific markers (Cytokeratin-3, -8, and -12) were confirmed in both MSCs using immunofluorescence staining and qRT-PCR analysis. In particular, the differentiation capacity of UCM-MSCs into corneal epithelial cells was significantly higher (P < 0.05) than that of D-MSCs. In conclusion, UCM-MSCs have higher differentiation potential into corneal epithelial-like cells and have lower expression of CD119 and MHC class II than D-MSCs, which makes them a better source for the treatment of corneal opacity.

• 혜화의학회지
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• 제20권2호
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• pp.1-16
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• 2012

In order to study the effect of CPS in the treatment of atopic dermatitis (AD), its role on various immune related cytokines were tested. Levels of liver and kidney function markers such as ALT, AST, BUN in NC/Nga mice were all normal indicating no toxicity in CPS treated group. Significant recovery from AD could be observed in CPS treated group through naked eye observation. Dermatitis index was significantly decreased after 11, 12, and 13 weeks of treatment. CD4+, CD8+, CD3+ /CD69+ immune cell ratio in DLN were decreased significantly by 37.2%, 49%, 20.8% in CPS treated group. CD4+ and CD11b+ /Gr-1+ immune cell ratio in dorsal skin were decreased significantly by 50.8% and 59.2% in CPS treated group. Expression of IL-4, IL-5, IL-6, IL-13 and TNF-${\alpha}$ in spleen were decreased by 78.8%, 97.8%, 64.7%, 73.6%, and 68.4%, respectively in CPS treated group. The results above strongly indicated the significant immune modulatory effect of CPS and thus clinical application of CPS on AD treatment.