• Membrane and Water Treatment
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• 제13권1호
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• pp.21-28
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• 2022

The use of plastics in our everyday lives have been drastically increased during the last few decades. However with the usage of commercial plastic products there is a possibility of microplastic consumption, due to the fragmentation of the products. Additionally, the potential for microplastic ingestion may also be increased by using damaged products. Hence, the current study was conducted to understand the potential release of micro/nano plastics and organic matter from damaged teabags. To check the leakage tendency, the amount of damage to the tea bags from 1-10 cm were tested along with temperatures of 25-70℃, and exposure times from 5 min to 1 hr was tested. Release of fibrous micro/nanoplastics, and organic leachate from the damaged teabags were observed to understand the outflow conditions. Results showed that with the increased degree of damage, temperature, and exposure time increased the release of fiberous matter, where the increase of temperature, and exposure time increased organic leachate. Additional analysis confirmed the leachate of nylon polymers into the heated water.

• Nutrition Research and Practice
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• 제17권5호
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• pp.855-869
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• 2023

BACKGROUND/OBJECTIVES: Atopic dermatitis (AD) is a chronic disease with an increasing incidence globally; therefore, there is a growing demand for natural compounds effective in treating dermatitis. In this study, the protective effects of Lycium barbarum leaves with and without chlorophyll (LLE and LLE[Ch-]) on AD were investigated in animal models of AD and HaCaT cells. Further, we investigated whether LLE and LLE(Ch-) show any differences in physiological activity. MATERIALS/METHODS: AD was induced by 2,4-dinitrochlorobenzene (DNCB) for three weeks, while NC/Nga mice were fed LLE or LLE(Ch-) extracts for 7 weeks. Serum immunoglobulin E (IgE) and cytokine (tumor necrosis factor [TNF]-α, interleukin [IL]-6, and IL-4) concentrations and the degree of DNA fragmentation in lymphocytes were examined. A histopathological examination (haematoxylin & eosin staining and blue spots of toluidine) of the dorsal skin of mice was performed. To elucidate the mechanism of action, the expression of the thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) were measured in HaCaT cells. RESULTS: Serum IgE and cytokines (TNF-α and IL-6) levels as well as DNA fragmentation of lymphocytes were significantly decreased in AD-induced mice treated with LLE or LLE(Ch-) compared to those of the control group. The epidermal thickness of the dorsal skin and mast cell infiltration in the LLE group significantly reduced compared to that in the control group. The LLE extracts showed no cytotoxicity up to 1,000 ㎍/mL in HaCaT cells. LLE or LLE(Ch-)-treated group showed a reduction of TARC and MDC in TNF-α-and IFN-γ-stimulated HaCaT cells. CONCLUSIONS: These results suggest that LLE potentially improves inflammation by reducing the expression of chemokines that inhibit T helper 2 cell migration. LLE(Ch-) showed similar effects to LLE on blood levels of IgE, TNF-α and IL-6 and protein expression in HaCat cells, but the ultimate effect of skin improvement was not statistically significant. Therefore, both LLE and LLE(Ch-) can be used as functional materials to alleviate AD, but LLE(Ch-) appears to require more research to improve inflammation.

• 한국환경생태학회지
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• 제22권2호
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• pp.128-137
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• 2008

본 연구는 북한산 국립공원을 대상으로 등산로가 산림경관의 파편화에 미치는 영향을 분석한 후, 이를 토대로 소유역별 경관생태학적 건전성을 평가하였다. 등산로 개설에 의한 영향 분석 결과에 따르면, 산림패치의 크기는 감소한 반면 패치 및 가장자리 밀도는 증가한 것으로 나타났다. 또한, 패치형태는 보다 복잡해지고, 핵심지역의 면적은 뚜렷하게 감소하였고, 패치간의 근접도는 증가하는 것으로 나타났다. 한편, 소유역별 경관생태학적 건전성 평가 결과, 종합적인 건전성은 북한산유역이 3.7점으로 가장 높게 나타났으며, 구기유역이 1.6점으로 가장 낮게 평가되었다. 이상의 결과를 종합해 볼 때, 산림의 경관생태학적 보전과 관리를 위해서는 불필요한 등산로의 개설을 금지하고, 훼손 및 교란 지역에 대한 자연적인 생태학적 복원이 이루어져야 할 것으로 판단된다.

• 한국식품영양과학회지
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• 제21권6호
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• pp.712-718
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• 1992

산 강직근과 알카리 강직근의 사후 자장중 물리, 화학적 변화를 비교 검토하였다. 근섬유의 소편화도는 산강직근이 알카리 강직근에 비하여 저장 3일째부터 월등히 높았다. $Mg^{2+}$-ATPase 활성은 알카리 강직근이 저장 전기간 동안 산 강직근 보다 높았으며, 산 강직근은 저장 1일째, 알카리 강직근은 저장 3일째에 가장 높았다. $Ca^{2+}$-ATPase 활성에 있어서 산 강직근과 알카리 강직근 모두 전 저장기간 동안 약간 증가하는 경향이었으나 산 강직근은 알카리 강직근 보다 전기간 동안 활성도가 낮았다. Actomyosin의 용해성이나 myofibril의 전기영동상은 강직 형태에 따른 유의한 차이가 없었다.

• 무역학회지
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• 제41권1호
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• pp.159-186
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• 2016

본 연구는 1991-2012년간 동아시아 국가 간 산업별 부품무역의 비교우위를 분석하여, 동아시아 FTA 체결 시 예상되는 무역과 생산분할 구조를 분석한다. 분석기간 중 동아시아 내 부품무역의 상호의존도는 지속적으로 증가하여 왔으며, 동아시아 FAT 체결 시 구조적 변화가 없다면 한국과 일본이 동아시아 내 전기 및 전자기기, 수송기기 부품수출을 더 강화하고, 중국과 ASEAN이 최종재를 수출하는 구조는 유지될 것으로 예상된다.

• KDI Journal of Economic Policy
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• 제38권4호
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• pp.45-76
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• 2016

This paper measures the extent to which South Korea participated in global value chains (GVCs) from 1995 through 2011 and scrutinizes the consequences of such participation on the Korean economy. To this end, the World Input Output Database is utilized to calculate GVC income, GVC employment, and value-added exports created by Korean and foreign industries. Our findings show that Korea radically internationalized its production activities during the sample period, widening the gap between gross exports and value-added exports. We also document that Korea's participation in GVCs has changed the value-added and employment structures in domestic industries in accordance with their comparative advantages while exacerbating the degree of wage inequality.

• Nuclear Engineering and Technology
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• 제28권2호
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• pp.103-117
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• 1996

본 논문에서는 증기폭발의 전파과정을 해석하기 위한 수학적 모델을 제시하였다. 이 모델은 용융물, 용융파편, 그리고 냉각재 기상과 액상 등 4상 유체의 2차원적인 천이거동을 지배방정식 및 관련상관식의 수치적 해를 구함으로서 예측할 수 있다. 모델에 사용된 주요 상관식은 용융물 분쇄, 냉각재 상변화, 에너지 교환, 그리고 운동량 교환항으로 구성되어 있다. 그리고, 냉각재(물)의 상태방정식은 냉각재의 기상과 액상 사이의 열역학적 인 비평형을 허용할 수 있는 독특한 형태로 구성되었다. 주석 /물의 중기폭발에 대한 예제계산을 수행한 결과 본 모델이 폭발의 전파속도 및 압력 -비록 그 정량적인 값은 관련상관식의 인자들에 좌우되지마는- 등의 증기폭발 전파과정의 주요현상을 적절히 모사할 수 있음을 알 수 있었다. 또한 중요한 초기변수(중기 분율, 용융물 분율) 및 관련상관식에 대한 민감도 분석도 수행되었다.

• Clinical and Experimental Reproductive Medicine
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• 제26권1호
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• pp.55-65
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• 1999

There have been many reports to date regarding the role of GnRH as a local regulatory factor of ovarian function as studies of human and rat ovaries revealed GnRH and its receptor. In recent studies it has been shown that GnRH directly causes apoptosis in the granulosa cells of the rat ovary, and such results leads to the suggestion that the use of GnRH agonist for more stable long term ovarian hyperstimulation in human IVF-ET programs causes granulosa cell apoptosis which may lead to follicular atresia. Therefore this study attempts to determine if granulosa-luteal cell apoptosis occurs in patients during IVF-ET programs in which GnRH agonist is employed for ovarian hyperstimulation. The quality of oocyte-cumulus complexes obtained during ovum pickup procedures were assessed morphologically and then the fertilization rate and developmental rate was determined. Apoptotic cells among the granulosa-luteal cells obtained during the same procedure were observed after staining with Hematoxylin-eosin. The fragmentation degree of DNA extracted from granulosa-luteal cells was determined and comparatively analyzed. There was no difference in the average age of the patients, the number of oocytes retrieved, and fertilization and developmental rates between the FSH/hMG group and GnRH-long group. There was also no difference in the apoptosis rate and pyknosis rate in the granulosa-luteal cells between the two groups. However, when the oocyte-cumulus complexes were morphoogically divided into the healthy group and atretic group without regard for the method of hyperstimulation, the results showed that the number of oocytes obtained averaged $11.09{\pm}8.75\;and\;10.33{\pm}4.53$ per cycle, respectively, showing no significant difference, but the fertilization rate (77.05%, 56.99%, respectively, p<0.01) and developmental rate (65.96%, 41.51%, respectively, p<0.01) was significantly increased in the healthy group when compared to the atretic group. The degree of apoptosis in the granulosa-luteal cells showed that in the healthy group it was 2.25% which was not significantly different from the atretic group (2.77%), but the pyknosis rate in the atretic group (27.81%) was significantly higher compared to the healthy group (11.35%, p<0.01). The quantity of DNA fragmentation in the FSH/hMG group was 32.22%, while in the GnRH-long group it was 34.27%, showing no significant difference. On the other hand the degree of DNA fragmentation was 39.05% and 11.83% in the healthy group and atretic group, respectively, showing significantly higher increase in the atretic group (p<0.01). The above results suggest that death of granulosa-luteal cells according to the state of the oocyte-cumulus complex is more related to pyknosis rather than apoptosis. Also, the GnRH agonist used in ovarian hyperstimulation does not seem to directly affect the apoptosis of retrieved oocytes and granulosa-luteal cells, and which is thought to be due to the suppression of the apoptogenic effect of GnRH agonist as a result of the high doses of FSH administered.

• 수면정신생리
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• 제18권2호
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• pp.76-81
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• 2011

목 적 : 본 연구는 폐쇄성 수면무호흡증후군 환자에서 수면무호흡지수, 수면관련 척도, 기분관련 척도, 그리고 수면중 신체활동도 간의 연관성을 보고자 하였다. 방 법 : 폐쇄성 수면무호흡증후군을 보이는 122명(평균연령 $43{\pm}11$세)의 남자환자를 선정하였다. 폐쇄성 수면무호흡증후군 진단은 수면무호흡지수>5인 경우로 하였고, 수면무호흡지수의 평균은 $39.6{\pm}26.0$이였다. 수면관련척도로 Stan-ford Sleepiness Scale(SSS), Epworth Sleepiness Scale(E-SS), Pittsburg Sleep Quality Index(PSQI), Morningness-Ev-eningness Scale(MES)이 사용되었고, 기분관련척도로 Beck Depression Inventory(BDI), Beck Anxiety Inventory(BAI), State-Trait Anxiety Inventory(STAI) I, II, Profile of Mood States(POMS)가 사용되었다. 수면중 활동도를 측정하기 위해 양측 손목에 손목 액티그라프(wrist actigraphy, WATG)를 착용한 채 1일밤 야간수면다원검사(nocturnal polysom-nography, NPSG)를 시행하였다. WATG에서 산출된 지수는 총활동도(total activity score), 평균활동도(mean activity score) 및 분절지수(fragmentation index)였다. 수면무호흡지수, 수면 및 기분관련척도, 수면중 활동도 간의 상관관계를 분석하였다. 결 과 : ESS는 PSQI, BDI, BAI, STAI I, II와 각각 유의한 양의 상관관계를 보였다(p<0.01). SSS는 PSQI, BAI와 유의한 양의 상관관계를 보였다(p<0.05, p<0.01). BAI는 총활동도, 평균활동도 및 분절지수(fragmentation index)와 유의한 양의 상관관계를 보였다(p<0.05, p<0.01, p<0.05). 수면중 총활동도는 ESS, BAI와 각각 유의한 양의 상관관계를 보였다(p<0.05). 수면 분절지수는 ESS, PSQI, BAI와 유의한 양의 상관관계를 보였다(p<0.05, p<0.01, p<0.05). 수면무호흡지수는 수면 및 기분관련 척도와 유의한 상관관계를 보이지 않았다. 결 론 : 주간 졸리움을 호소하는 정도가 수면무호흡증의 심한 정도와 연관이 있기 보다는 오히려 야간수면 만족도, 우울 및 불안의 정도, 수면중 활동도와 더 연관성이 있었다.

• Advances in environmental research
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• 제12권1호
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• pp.51-64
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• 2023

The sustainable management of rice straw is essential for protection of human health and environment. This study assesses the impact of stock density of earthworm (Eisenia fetida) and Neem leaves (Azadirachta indica) on the quality of the final vermicompost. The vermicompost is produced using different combinations of rice straw, Neem leaves, and cow dung (bulking agent) by varying stock density of earthworms. The vermicomposting experiments are performed in plastic containers (32 cm × 28 cm × 28 cm) in open for 90 days under laboratory conditions. The stock density of the earthworm is found to be an important factor to influence nutritional quality of the final vermicompost. There is observed significant improvement in the total nitrogen (91.8%), phosphate (73.4%), potassium (38.8%), and calcium (59.05%) content of the vermicompost produced with the highest stock density of the earthworms. All the treatments showed decrease in TOC and C:N content after 90 days of vermicomposting. The treatment with Neem leaves showed maximum growth of earthworms (2.65 fold). Neem leaves brought positive changes in the quality of final vermicompost by enhancing the growth and reproduction of the earthworms. The calcium content increased by 39% in the final vermicompost with the addition of Neem leaves at the same stock density of the earthworms. The stock density of the earthworms and Neem leaves are found to significantly improve quality of the final vermicompost as compared with the compost (control). The surface morphology in SEM images showed high degree of fragmentation in the vermicompost as compared with the compost. The combined action of microbes and earthworms resulted in high degree of disintegration in the vermicompost.