• 생명과학회지
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• 제32권6호
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• pp.476-481
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• 2022

유비퀴틴화는 단백질 안정성 조절을 통해 진핵세포 내 광범위한 과정에서 주요한 역할을 한다. 이 과정에서 탈유비퀴틴화 효소인 deubiquitinating enzymes (DUBs)은 표적단백질의 유비퀴틴 혹은 ubiquitin-like proteins에 결합하여 표적단백질의 분해를 억제하는 기능을 한다. DUBs의 역할은 주로 암생물학에서 다루어져 왔으며, 이를 통해 다양한 암 치료용 DUBs 억제제가 개발 중인 상황이다. 한편, 최근의 연구는 이러한 DUBs가 비만, 당뇨, 지방간을 포함한 대사질환에서 주요한 역할을 할 수 있을 것이라고 보고했다. 대사질환의 발생 및 진행에 있어 각기 다른 종류의 DUBs는 양적 혹은 음적 조절 작용을 갖음을 제시하였다. DUBs는 세포 내 다양한 전사인자의 단백질 발현 등 조절함으로써 대사질환의 발생 및 진행에 기여할 수 있음 생체 내, 외 및 인간 조직을 활용한 연구에서 입증되었다. UCH, USP7 및 USP19는 지방세포의 분화, 체중 증가, 및 인슐린 저항성에 관련이 있음을 식이 혹은 유전자조작으로 인한 비만 유도 마우스에서 검증하였다. CYLD, USP4 및 USP18의 경우 지방간의 발생과 밀접한 관계를 갖는다고 보고되었으며 이는 경우에 따라 체중 변화를 동반한다. 종합적으로, 본 총설에서는 비만 및 이와 관련한 대사질환에서 DUBs의 역할에 대한 최신 연구 결과 및 동향에 대해 기술하였다. 또한 DUBs에 새로운 역할에 관한 기초지식 및 분자적메커니즘을 제공함으로써 궁극적으로는 DUBs가 대사질환의 새로운 유전자 타겟이 될 수 있음을 시사한다.

• 해양환경안전학회지
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• 제28권2호
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• pp.270-279
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• 2022

본 연구에서는 동태성과 시간을 고려한 시스템다이내믹스 관점에서 낚시어선의 낚시활동에 있어서 단속 및 처벌의 강화(정책개입)에 따라 시스템 구조가 어떻게 변화하는지 알아보고 그에 따른 전략수립 방향을 논의하고자 한다. 지금까지 낚시어선의 단속과 처벌은 사고예방이라는 사전적 차원에서 일시적 단기적으로 단속을 실시하고 처벌을 부과했다. 그러나 변칙적이고 다양한 부작용으로 소기의 성과를 거두지 못하였고, 안전사고는 끊임없이 발생하고 또 다시 후속조치가 뒤따라가는 형국을 보이고 있다. 본 연구의 결과에 따르면, 낚시어선의 단속과 처벌이 강화된 안전기준으로 사고 예방을 위한 시설 장비 산업 등 관련 사항 개선 및 기술개발(시간지연 발생)보다는 즉각적이고 큰 저항이 없는 음성적(불법적) 활동을 지속함에 따라 사고예방을 위한 안전사각지대를 최소화하지 못하고 있다. 이와같이 동태적 매커니즘과 시간이라는 변수를 충분히 고려하지 않고 단선적 사고에 입각한 정책개입으로는 정책이 추구하는 기본적 가치를 오히려 왜곡시킬 수 있다. 낚시어선의 단속과 처벌에 있어서 강화된 안전기준의 마련에 앞서 관련 기술의 개선 및 개발, 낚시인·낚시산업체·관련기관 등 다양한 주체들에 대한 교육시간 의무화, 낚시관련 산업 육성을 위한 낚시 관리 및 육성법의 구체적인 방안 제시와 같은 매커니즘을 보완하는 전략을 마련해야 한다.

• Journal of Korea Trade
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• 제27권3호
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• pp.21-42
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• 2023

Purpose - This paper investigates the trade effect of the Korea-China Free Trade Agreement (KCFTA) which coincides with political conflicts between the two countries due to the deployment of the Terminal High Altitude Area Defense (THAAD) in Korea. The two events occurred in the same year and both are likely to affect trade between two countries but in opposite directions. Therefore, it is crucial to distinguish between the trade effects from the KCFTA event and those from the THAAD event to evaluate the true FTA effects. However, this would be difficult when using only annual data. Accordingly, ex post studies to examine the trade effects of KCFTA are lacking in trustworthiness while many ex ante studies that conjecture the positive trade effects neglect the THAAD deployment impact. This paper aims to fill that gap. Design/methodology - Given that the KCFTA and THAAD events occurred in the same year but in different months, we use the monthly data from 2000 to 2019 of Korea's exports to bracket this period. We employ the difference-in-difference (DID) method within a gravity equation specification that uses hi-dimensional fixed effects to address various endogeneity issues and seasonal effects. We identify the net impact of KCFTA ratification from these two near-simultaneous events to quantify the effects of trade liberalization between these two countries. Findings - After isolating the THAAD effects on trade, the analysis creates a positive and statistically significant coefficient estimate of the KCFTA impact. In contrast, failing to isolate the THAAD effect produced a negative and statistically significant coefficient estimate of the KCFTA impact. Our results indicate that KCFTA independently increased Korea's exports to China by 10.2%, but that this increase was fully mitigated by the THAAD event. Further, our results verify that unobserved heterogeneity and multilateral resistance are technically difficult to account for in those estimations as that rely solely upon annual data, as this type of data are inadequate to control for the potential for endogeneity. Originality/value - This paper is one of the first studies to carefully evaluate the net trade effects of the KCFTA on Korea's largest trading partner while isolating the impact of simultaneously occurred political events that may influence trade in opposing directions. Our findings indicate that the lack of prior evidence of positive trade effects of the KCFTA when using annual data may be attributed to a failure to identify the impact of each event separately. This analysis supports using the correct modeling specification to avoid misleading conclusions when evaluating any important international trade policy.

• 한국전기전자재료학회논문지
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• 제36권3호
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• pp.249-254
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• 2023

La_0.7-xCe_xSr_0.3MnO₃ specimens were fabricated by a solid state reaction method and structural and electrical properties with variation of Ce⁴⁺ contents were measured. All specimens exhibited a polycrystalline rhombohedral crystal structure, and the (110) peaks were shifted to low angle side with increasing the amount of Ce⁴⁺ contents. As Ce⁴⁺ ions with different ion radii and charges are substituted with La³⁺ ions, electrical properties are thought to be affected by changes in the double exchange interaction between Mn³⁺-Mn⁴⁺ ions due to distortion of the unit lattice, a decrease in oxygen vacancy concentration, and an increase in lattice defects. Resistivity gradually decrease as the amount of Ce⁴⁺ added increased, and negative temperature coefficient of resistance (NTCR) properties were shown in all specimens. In the La_0.5Ce_0.2Sr_0.3MnO₃ specimens, electrical resistivity, TCR and B-value were 31.8 Ω-cm, 0.55%/℃ and 605 K, respectively.

• 한국식생활문화학회지
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• 제25권5호
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• pp.544-557
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• 2010

This study was performed with Korean adults to investigate Makgeolli drinking behavior, preference, and perception about Makgeolli and health, as well as Makgeolli complaints and prices. A survey questionnaire was formulated to obtain information on demographic variables, drinking habits, and perceptions about Makgeolli's function, price, and complaints. The questionnaire was distributed to 468 adults living in the capital area. The results are as follows. Makgeolli (16.1%) was third preferred, following Soju (45.1%) and beer (30.7%), and no significant differences were observed by gender and income, but the preference for Makgeolli increased with increasing age (p<0.001). According to the survey, the largest reason both genders drank Makgeolli was that it tastes good. Men preferred Makgeolli for its health effects and cheap price, while women preferred it for the atmosphere while drinking it. Also, older people and those with higher incomes preferred drinking Makgeolli for its health effect rather than its good taste (p<0.001 for each). No significant difference was observed by gender for the question "Do you think that Makgeolli has a health-promoting effect?" Overall, 51% of the subjects gave positive answers and only 5.9% gave negative answers. Significantly, older people and those with a higher income had a higher rate of answering positively to this question. Belching (45.1%) and headache (29.9%) were the most common symptoms among the side effects of drinking Makgeolli. No significant difference was observed by gender or income, but older people had a higher rate of belching and fewer headaches than younger people (p<0.001). Women had a significantly higher rate of perceiving that Makgeolli was cheap than men. Age and income differences did not influence price perception. To the question "What is the ideal price for high quality Makgeolli", 32.1% answered that the present rate (1,000 won) was ideal, and 59.4% answered that a price between 1,000 and 2,000 won was ideal. These results indicate that the high preference for Makgeolli is due to its good taste and health effects. However, belching and headache caused by drinking Makgeolli were the most common complaints and, thus, must be solved. Some opinions indicated that Makgeolli must eliminate its low-quality image, but, according to this survey, most subjects answered that the ideal price of higher-quality Makgeolli should be increased slightly, which would cause price resistance.

• Pediatric Infection and Vaccine
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• 제30권1호
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• pp.47-54
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• 2023

최근 광범위 항생제 사용의 증가로 인한 다제내성 그람 음성균의 출현이 전 세계적으로 문제가 되고 있다. 특히 다제내성 녹농균(multidrug-resistant Pseudomonas aeruginosa) 감염의 치료는 어려우며 중환자의 사망률을 증가시키는 원인이 된다. 세프톨로잔-타조박탐(ceftolozane-tazobactam, Zerbaxa^TM)은 5세대 세팔로스포린과 베타락탐 분해효소저해제로 다제내성 녹농균에 의한 복잡성 요로감염과 복잡성 복강내 감염의 치료에 효과가 있는 것으로 입증되었다. 본지에서 저자들은 소아청소년 혈액암 환자에서 발생한 다제내성 녹농균에 의한 균혈증을 세프톨로잔-타조박탐을 사용하여 성공적으로 치료한 국내 첫 번째 사례를 보고하고자 한다.

• 대한토목학회논문집
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• 제26권4A호
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• pp.647-657
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• 2006

허용응력설계법과 극한한계 상태 설계법에 근거한 케이블과 보강형을 갖는 PSC 사장교의 예를 통해서 통계학적 확률분포를 고려한 확률론적인 위험성을 평가하였다. 사용성 한계상태 및 극한 한계상태에서의 케이블요소의 파괴확률과 거더의 최대 정모멘트. 부모멘트 발생단면, 그리고 최대전단력의 작용단면에서 각각의 요소 파괴 확률을 설계변수의 응답면에서 검토하였다. 응답면 기법(RSM)은 복잡한 다자유도 구조물에서 MCS를 사용하여 얻을 수 없는 상대적으로 매우 작은 파괴 확률값을 얻기 위해 사용이 가능할 뿐만 아니라, FOSM으로 쉽게 얻을 수 없는 한계상태방정식의 미분형태에도 성공적으로 적용이 가능 하다. 케이블과 보강형으로 구성된 병렬저항구조를 시스템 해석을 위해 각각 직렬구조로 연결하여 전체구조물의 체계신뢰성을 평가하고, 제안된 붕괴모드조합 예측값과 비교분석하였다. 제안된 붕괴모드의 조합에 의한 파괴확률검토는 조건부 파괴에 대한 동일한 발생확률을 구하며, 순열방법보다 개선된 시간비용과 효율성을 제공하며, 상하한계파괴확률을 구하는 체계 신뢰성해석에서 검토되지 않는 요소파괴의 조합에 의한 시스템의 위험성 검토를 제공한다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.57-57
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• 2022

In many areas of the world, salt damage and drought have had a negative impact on human survival due to a decrease in agricultural productivity. For instance, about 50% of agricultural land will be affected by salt damage by 2050. Biostimulants such as plant extracts can not only increase the nutrient utilization efficiency of plants, but also promote plant growth and increase resistance to abiotic or biotic stress. Therefore, the objective of this study was to determine how selected plant extracts might reduce levels of stress caused by drought and salt and to better understand the physiological response mechanisms of rice plants. In this study, we used Soybean leaves, Soybean stems and Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts were used. These extracts had been used in previous studies and were found to be effective. The materials were dried in a dry oven at 50℃ for 5 days and ground using a blender. Each 50 g of materials was put in 1 L of distilled water, stirred for 24 hours, filtered using 4 layers of mirocloth, and then concentrated using a concentrator. Rice (cv. Hopumbyeo) seeds were immersed and germinated, and then sown in seedbeds filled with commercial soil. In drought experiments, three rice seedlings at 1 week after seeding was transplanted into 100 ml cups filled with commercial soils and grown until the 4-leaf stage. For this experiment, the soil weight in a cup was equalized, and water was allowed to become 100% saturated and then drained for 24 hours. Thereafter, plant extracts at 3% concentrations were applied to the soils. For NaCl treatments, rice plants at 17 days after seeding were treated with either 100 mM NaCl or plant extracts at 1%+ 100 mM NaCl combinations in the growth chamber. Leaf injury, relative water content, photosynthetic efficiency, and chlorophyll contents were measured at 3, 5, and 6 days after treatments. Shoot fresh weight of rice under drought conditions increased 28-37% in response to treatments of Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Shoot fresh weight of rice subjected to 100 mM NaCl treatments also increased by 6-24% in response to Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Compared to the control, rice plants treated with these six extracts and subjected to drought conditions had significantly higher relative water content, Fv/Fm, total chlorophyll and total carotenoids than control plants. With the exception of relative water contents, rice plants treated with the six extracts and subjected to salt stress (100 mM NaCl treatments) had significantly higher Fv/Fm, total chlorophyll and total carotenoids than control plants. However, the type of extract used did not produce significant difference in these parameters. Thus, all the plant extracts used in this study could mitigate drought and NaCl stresses and could also contribute substantially to sustainable crop production.

• Steel and Composite Structures
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• 제49권2호
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• pp.245-255
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• 2023

The present paper summarizes the results of an experimental program on the influence of using waste lathe scraps in the concrete mixture on the shear behavior of RC beams with different amounts of shear reinforcement. Three different volumetric ratios (1, 2 and %3) for the scraps and three different stirrup spacings (160, 200 and 270 mm) were adopted in the tests. The shear span-to-depth ratios of the beams were 2.67 and the stirrup spacing exceeded the maximum spacing limit in the building codes to unfold the contribution of lathe scraps to the shear resistances of shear-deficient beams, subject to shear-dominated failure (shear-tension). The experiments depicted that the lathe scraps have a pronounced contribution to the shear strength and load-deflection behavior of RC beams with widely-spaced stirrups. Namely, with the addition of 1%, 2% and 3% waste lathe scraps, the load-bearing capacity escalated by 9.1%, 21.8% and 32.8%, respectively, compared to the reference beam. On the other hand, the contribution of the lathe scraps to the load capacity decreases with decreasing stirrup spacing, since the closely-spaced stirrups bear the shear stresses and render the contribution of the scraps to shear resistance insignificant. The load capacity, deformation ductility index (DDI) and modulus of toughness (MOT) values of the beams were shown to increase with the volumetric fraction of scraps if the stirrups are spaced at about two times the beam depth. For the specimens with a stirrup spacing of about the beam depth, the scraps were found to have no considerable contribution to the load capacity and the deformation capacity beyond the ultimate load. In other words, for lathe scrap contents of 1-3%, the DDI values increased by 5-23% and the MOT values by 63.5-165% with respect to the reference beam with a stirrup spacing of 270 mm. The influence of the lathe scraps to the DDI and MOT values were rather limited and even sometimes negative for the stirrup spacing values of 160 and 200 mm.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.1040-1052
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• 2023

The objective of this study was to investigate the protective effects of functional nutrients including various functional amino acids, vitamins, and minerals on chicken intestinal epithelial cells (cIECs) treated with oxidative stress. The cIECs were isolated from specific pathogen free eggs. Cells were exposed to 0 mM supplement (control), 20 mM threonine (Thr), 0.4 mM tryptophan (Trp), 1 mM glycine (Gly), 10 μM vitamin C (VC), 40 μM vitamin E (VE), 5 μM vitamin A (VA), 34 μM chromium (Cr), 0.42 μM selenium (Se), and 50 μM zinc (Zn) for 24 h with 6 replicates for each treatment. After 24 h, cells were further incubated with fresh culture medium (positive control, PC) or 1 mM H₂O₂ with different supplements (negative control, NC and each treatment). Oxidative stress was measured by cell proliferation, whereas tight junction barrier function was analyzed by fluorescein isothiocyanate (FITC)-dextran permeability and transepithelial electrical resistance (TEER). Results indicated that cell viability and TEER values were less (p < 0.05) in NC treatments with oxidative stress than in PC treatments. In addition, FITC-dextran values were greater (p < 0.05) in NC treatments with oxidative stress than in PC treatments. The supplementations of Thr, Trp, Gly, VC, and VE in cells treated with H₂O₂ showed greater (p < 0.05) cell viability than the supplementation of VA, Cr, Se, and Zn. The supplementations of Trp, Gly, VC, and Se in cells treated with H₂O₂ showed the least (p < 0.05) cellular permeability. In addition, the supplementation of Thr, VE, VA, Cr, and Zn in cells treated with H₂O₂ decreased (p < 0.05) cellular permeability. At 48 h, the supplementations of Thr, Trp, and Gly in cells treated with H₂O₂ showed the greatest (p < 0.05) TEER values among all treatments, and the supplementations of VC and VE in cells treated with H₂O₂ showed greater (p < 0.05) TEER values than the supplementations of VA, Cr, Se, and Zn in cells treated with H₂O₂. In conclusion, Thr, Trp, Gly, and VC supplements were effective in improving cell viability and intestinal barrier function of cIECs exposed to oxidative stress.