• 마이크로전자및패키징학회지
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• 제27권3호
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• pp.29-34
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• 2020

본 연구에서는 무전해 니켈 도금액 pH 변화에 따른 electroless nickel immersion gold (ENIG)/Sn-3.0wt.%Ag-0.5wt.%Cu(SAC305) 솔더 접합부 취성 파괴 거동에 대하여 평가하였다. ENIG 표면처리를 위한 무전해 니켈 도금액의 pH는 4.0에서 5.5로 변화 시켰다. 무전해 니켈 도금 후 Ni-P 표면 관찰 결과, 도금액의 pH가 낮아질수록 Ni-P 층 nodule 표면에 핀홀이 증가하였다. 솔더링 후 접합부 계면에서는 (Cu,Ni)6Sn5 금속간화합물이 형성되었으며, 무전해 니켈 도금액의 pH가 증가할수록 솔더접합부의 계면 금속간화합물의 두께는 증가하였다. 고속전단 시험을 통하여 ENIG/SAC305 솔더 접합부의 취성파괴 거동을 확인하였으며, 무전해 니켈 도금액의 pH가 증가할수록 솔더접합부의 전단강도는 감소하는 경향을 보였다. 또한, 솔더 접합부의 취성 파괴율은 pH가 5일 때 가장 높은 값을 보였다.

• 디지털융복합연구
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• 제19권1호
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• pp.239-248
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• 2021

본 연구는 코로나바이러스감염증-19 특별재난지역에 근무하는 중등학교 교사의 우울, 불안과 스트레스가 교사효능감에 미치는 영향을 파악하고자 시도되었다. 자료수집은 2020년 5월 9일부터 16일까지 D시 중등학교 교사 123명을 대상으로 하였다. 연구결과 직무 만족도(β=0.27, p=.002), 경제 수준(β=0.18, p=.022), 학력(β=0.18, p=.022), 주관적 건강상태(β=0.16, p=.047), 스트레스(β=-0.16, p=.044), 성별(β=0.16, p=.042)이 교사 효능감에 유의한 영향을 나타내었으며, 설명력은 35%이었다(F=11.80, p<.001). 우울(β=-0.09, p=.468)과 불안(β=-0.12, p=.320)은 교사 효능감에 유의한 영향을 미치지 않았다. 교사 효능감 증진을 위한 프로그램 개발 시 스트레스 관리뿐만 아니라 직무 만족도 증진을 위한 방안 마련이 요구된다.

• Journal of Nutrition and Health
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• 제23권2호
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• pp.115-123
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• 1990

한국인 수유부의 분만 후 0.5개월부터 1,2,3,4,5개월째의 6단계로 나누어 16명의 동일인을 대상으로 모유의 무기질 함량을 초산부와 경산부로 나누어 측정한 결과 모유 100ml중 회분함량은 초산부 0.22g, 경산부 0.22g이며, 칼슘 함량은 초산부 27.36mg,경산부 27.11mg, 인 함량은 초산부 14.94mg 경산부가 14.25mg, 마그네슘 함량은 초산부2.92mg, 경산부 2.54mg이었으며 회분, 칼슘, 인, 마그네슘 함량 모두 초산부와 경산부 간에 유의한 차이가 없었으며, 수유기간이 경과함에 따라 칼슘, 인, 마그네슘 함량은 유의하게 증가하였다(p<0.001)반면에 마그네슘 함량은 유의하게 증가하였다(p<0.001). 모유의 Ca/P의 비율은 초산부 1.86:1, 경산부가 1.92:1, t식이의 Ca/P의 비율은 0.50:1이었다. 수유부의 섭취식이와 모유의 Ca, P과의 상관성은 없었다.

• 한국융합학회논문지
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• 제9권1호
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• pp.377-386
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• 2018

본 연구는 재난간호 융합교육프로그램이 간호학생의 재난간호 지식, 준비도 및 자신감에 미치는 효과를 규명하기 위해 시행되었다. 대조군 전후설계를 적용한 유사실험연구로 연구대상자는 B 광역시 소재 간호학과 4학년 학생 57명으로 실험군 27명, 대조군 30명이었다. 재난관리, 재난상황 실습 및 재난심리교육 등으로 구성된 재난간호 융합교육프로그램을 6월 26일부터 7월 7일까지 2주간 총 56시간 동안 진행하였다. 재난간호 융합교육프로그램을 적용받은 실험군은 대조군에 비해 재난간호 지식(F=81.41, p<.001), 준비도(F=110.62, p<.001), 자신감(t=7.27, p<.001)이 유의하게 증가하였다. 본 연구를 통해 재난간호 융합교육프로그램이 간호학생의 재난간호 지식, 준비도, 자신감 향상에 유용한 과정임을 확인하였다. 융합적 측면에서의 재난교육은 재난상황에 대비할 수 있는 인재 양성에 효과적이므로 다양한 재난관련 교육이 비교과 프로그램으로 개발되고 정착되어야 할 것이다.

• BMB Reports
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• 제46권1호
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• pp.25-30
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• 2013

Gap junctions and their structural proteins, connexins (Cxs), have been implicated in carcinogenesis. To explore the involvement of Cx32 in gastric carcinogenesis, immunochemical analysis of Cx32 and proliferation marker Ki67 using tissue-microarrayed human gastric cancer and normal tissues was performed. In addition, after Cx32 overexpression in the human gastric cancer cell line AGS, cell proliferation, cell cycle analyses, and $p21^{Cip1}$ and $p27^{Kip1}$ expression levels were examined by bromodeoxyuridine assay, flow cytometry, real-time RT-PCR, and western blotting. Immunohistochemical study noted a strong inverse correlation between Cx32 and Ki67 expression pattern as well as their location. In vitro, overexpression of Cx32 in AGS cells inhibited cell proliferation significantly. $G^1$ arrest, up-regulation of cell cycle-regulatory proteins $p21^{Cip1}$ and $p27^{Kip1}$ was also found at both mRNA and protein levels. Taken together, Cx32 plays some roles in gastric cancer development by inhibiting gastric cancer cell proliferation through cell cycle arrest and cell cycle regulatory proteins.

• Molecules and Cells
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• 제28권1호
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• pp.37-42
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• 2009

Iron binding lactoferrin (Lf) is involved in the control of cell cycle progression. However, the molecular basis underlying the effects of Lf on cell cycle control, as well as its target genes, remains incompletely understood. In this study, we have demonstrated that a relatively low level of ironsaturated Lf, Lf($Fe^{3+}$), can stimulate S phase cell cycle entry, and requires Akt activation in MCF-7 cells. Lf($Fe^{3+}$) immediately induced Akt phosphorylation at Ser473, which subsequently induced the phosphorylation of two G1-checkpoint Cdk inhibitors, $p21^{Cip/WAF1}$ and $p27^{kip1}$. The Lf($Fe^{3+}$)-induced phosphorylation of Cdk inhibitors impaired their nuclear import behavior, thereby inducing cell cycle progression. However, the treatment of cells with a PI3K inhibitor, LY294002, almost completely blocked Lf($Fe^{3+}$)-stimulated cell cycle progression. LY294002 treatment abrogated Lf($Fe^{3+}$)-induced Akt activation, and prevented the cytoplasmic localization of $p27^{kip1}$. Higher levels of $p21^{Cip/WAF1}$ were also detected in the cytoplasmic sub-cellular compartment as a measure of cellular response to Lf($Fe^{3+}$). Consequently, the degree of phosphorylation of retinoblastoma protein was enhanced in response to Lf($Fe^{3+}$). Therefore, we conclude that Lf($Fe^{3+}$), as a potential antagonist of Cdk inhibitors, can facilitate the functions of E2F during progression to S phase via the Akt signaling pathway.

• Journal of Cancer Prevention
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• 제23권4호
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• pp.170-175
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• 2018

Background: Human hepatocellular carcinoma (HCC) is a common liver tumor and the main cause of cancer-related death. Tyrosine kinase inhibitors, such as imatinib and GNF5 which were developed to treat chronic myelogenous leukemia, regulate the progression of various cancers. The aim of this study was to confirm the anti-tumor activity of tyrosine kinase inhibitors through regulation of S-phase kinase-associated protein 2 (Skp2), an important oncogenic factor in various cancer cells, in human hepatocarcinoma SK-HEP1 cells. Methods: Cell viability and colony formation assays were conducted to evaluate the effects of imatinib, GNF5 and GNF2 on the growth of SK-HEP1 cells. Using immunoblot analysis, we assessed change of the activation of caspases, PARP, Akt, mitogen-activated protein kinases, and Skp2/p27/p21 pathway by imatinib and GNF5 in SK-HEP1 cells. Using sh-Skp2 HCC cells, the role of Skp2 in the effects of imatinib and GNF5 was evaluated. Results: Imatinib and GNF5 significantly inhibited the growth of SK-HEP1 cells. Treatment of imatinib and GNF5 decreased Skp2 expression and Akt phosphorylation, and increased the expression of p27, p21, and active-caspases in SK-HEP1 cells. In sh-Skp2 HCC cells, cell growth and the expression of Skp2 were inhibited by more than in the mock group treated with imatinib and GNF5. Conclusions: These results suggest that the anti-growth activity of tyrosine kinase inhibitors may be associated with the regulation of p27/p21 and caspases through Skp2 blockage in HCC cells.

• Restorative Dentistry and Endodontics
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• 제43권4호
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• pp.40.1-40.10
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• 2018

Objectives: This study evaluated the microtensile bond strength (${\mu}TBS$) of polymer-ceramic and indirect composite resin with 3 classes of resin cements. Materials and Methods: Two computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated polymer-ceramics (Enamic [ENA; Vita] and Lava Ultimate [LAV; 3M ESPE]) and a laboratory indirect composite resin (Gradia [GRA; GC Corp.]) were equally divided into 6 groups (n = 18) with 3 classes of resin cements: Variolink N (VAR; Vivadent), RelyX U200 (RXU; 3M ESPE), and Panavia F2 (PAN; Kuraray). The ${\mu}TBS$ values were compared between groups by 2-way analysis of variance and the post hoc Tamhane test (${\alpha}=0.05$). Results: Restorative materials and resin cements significantly influenced ${\mu}TBS$ (p < 0.05). In the GRA group, the highest ${\mu}TBS$ was found with RXU ($27.40{\pm}5.39N$) and the lowest with VAR ($13.54{\pm}6.04N$) (p < 0.05). Similar trends were observed in the ENA group. In the LAV group, the highest ${\mu}TBS$ was observed with VAR ($27.45{\pm}5.84N$) and the lowest with PAN ($10.67{\pm}4.37N$) (p < 0.05). PAN had comparable results to those of ENA and GRA, whereas the ${\mu}TBS$ values were significantly lower with LAV (p = 0.001). The highest bond strength of RXU was found with GRA ($27.40{\pm}5.39N$, p = 0.001). PAN showed the lowest ${\mu}TBS$ with LAV ($10.67{\pm}4.37N$; p < 0.001). Conclusions: When applied according to the manufacturers' recommendations, the ${\mu}TBS$ of polymer-ceramic CAD/CAM materials and indirect composites is influenced by the luting cements.

• 한국융합학회논문지
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• 제11권12호
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• pp.391-400
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• 2020

본 연구는 정치효능감, 정치관심도, 세계시민의식이 정치참여에 미치는 영향을 파악하기 위해 시도된 융합 연구이다. 연구대상자는 간호학과 3,4학년 학생 155명이었으며, 수집된 자료는 기술통계, t-test, ANOVA, Pearson's correlation과 다중회귀분석을 사용하여 분석하였다. 연구결과 정치참여는 정치효능감(r=.27, p=.001)과 정치관심도(r=.42, p<.001)와 유의한 정적 상관관계가 나타났고, 세계시민의식 중 태도는 유의한 부적상관관계(r=-.24, p=.003)를 나타냈다. 다중회귀분석 결과 정치관심도(β=.37)와 정치효능감(β=.21)이 높을수록, 세계시민의식 중 태도(β=-.27)가 낮을수록 정치참여도가 높아지는 것으로 나타났으며 모형의 설명력은 25.7%였다. 정치참여를 높이기 위해 대학생에게 맞는 정치효능감, 정치관심도를 높이고 정치참여를 유도할 수 있는 정치교육이 필요하다.

• 한국간호교육학회지
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• 제27권4호
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• pp.381-391
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• 2021

Purpose: This study aimed to identify the influence of learning presence and self-directed learning ability on nursing students' learning satisfaction according to the online learning method. Methods: The participants of this study were 167 nursing students attending three universities in different cities. The data were collected from July 16 to July 23, 2021, via an online self-reported questionnaire. Using SPSS WIN 27.0, data were analyzed by descriptive statistics, Pearson's correlation coefficient and a multiple regression analysis. Results: The most effective online learning method experienced by nursing students was asynchronous online learning according to 58.2% of the respondents, while 30.3% of the respondents answered synchronous online learning. The main merit of asynchronous online learning was that it was possible to listen repeatedly (61.7%) to lectures, and the top advantage of synchronous online learning was that the location of the class was free (53.3%). In asynchronous online learning, the factors that significantly affected nursing students' learning satisfaction were cognitive presence (𝛽=.60, p<.001) and emotional presence (𝛽=.25, p<.001). These variables accounted for 56% of their learning satisfaction (F=54.12, p<.001). Similarly, cognitive presence (𝛽=.64, p<.001) and emotional presence (𝛽=.21, p=.001) in synchronous online learning, were the factors cited for significantly affecting learning satisfaction. The explanatory power was 62% (F=69.19, p<.001). Conclusions: In conclusion, it was found that cognitive and social presence from the learning presence factors in both asynchronous and synchronous online learning influence and enhance nursing students' learning satisfaction. Therefore, these results provide important data for future online class design in nursing education.