웹기반 구조중심 협동학습 시스템의 설계 및 구현

정규옥,양형정,최숙영 한국컴퓨터교육학회 2004 컴퓨터교육학회 논문지 Vol.7 No.3

협동학습 모델 중에서 매우 간단하고 적용이 쉬운 구조중심 협동학습은 다양한 구조의 유기적 연결과 학습내용의 결합을 통해 교수학습이 이루어진다. 본 연구에서는 이러한 구조중심의 협동학습을 위한 교수-학습 모델을 제안하고, 이를 지원하는 웹기반 구조중심 협동학습 시스템을 설계 및 구현하였다. 본 연구에서 제안하는 구조중심 협동학습 모델에서는 교과학습에 적용할 수 있는 구체적인 틀을 제시하여 협동학습을 효과적으로 지원할 수 있도록 하였다. 또한 학습 내용과 형태에 따라 다른 구조를 적용할 수 있도록 지식 습득형, 탐구형, 기능 숙달형 구조로 분류하고 이에 따른 적용 모형들을 제시하고 있다. 이러한 모형들을 기반으로 실제 협동학습을 수행할 수 있도록 시스템을 구현하여, 수업에 적용한 후 그 효과를 분석해 보았다. One of the cooperative learning models, the cooperative learning of structural approach which is very simple and easily applicable accomplishes teaching-learning through combining learning contents and organic connections of various structures. This work proposes a cooperative teaching-learning model for the structural approach, designs and implements a web-based cooperative system supporting it. The model provides a concrete frame which can apply to a subject learning thus could effectively support cooperative learning. Furthermore, it classifies learning into three types such as knowledge learning, investigation, and function mastering and presents a structure application model for each so as to apply different structures according to learning materials and types. We implemented a system that performs cooperative learning on the basis of these models, applied to a class, and analyzed the effect of it.

Sox17 promotes tumor angiogenesis and destabilizes tumor vessels in mice.

Yang, Hanseul,Lee, Sungsu,Lee, Seungjoo,Kim, Kangsan,Yang, Yeseul,Kim, Jeong Hoon,Adams, Ralf H,Wells, James M,Morrison, Sean J,Koh, Gou Young,Kim, Injune American Society for Clinical Investigation 2013 The Journal of clinical investigation Vol.123 No.1

<P>Little is known about the transcriptional regulation of tumor angiogenesis, and tumor ECs (tECs) remain poorly characterized. Here, we studied the expression pattern of the transcription factor Sox17 in the vasculature of murine and human tumors and investigated the function of Sox17 during tumor angiogenesis using Sox17 genetic mouse models. Sox17 was specifically expressed in tECs in a heterogeneous pattern; in particular, strong Sox17 expression distinguished tECs with high VEGFR2 expression. Whereas overexpression of Sox17 in tECs promoted tumor angiogenesis and vascular abnormalities, Sox17 deletion in tECs reduced tumor angiogenesis and normalized tumor vessels, inhibiting tumor growth. Tumor vessel normalization by Sox17 deletion was long lasting, improved anticancer drug delivery into tumors, and inhibited tumor metastasis. Sox17 promoted endothelial sprouting behavior and upregulated VEGFR2 expression in a cell-intrinsic manner. Moreover, Sox17 increased the percentage of tumor-associated CD11b+Gr-1+ myeloid cells within tumors. The vascular effects of Sox17 persisted throughout tumor growth. Interestingly, Sox17 expression specific to tECs was also observed in highly vascularized human glioblastoma samples. Our findings establish Sox17 as a key regulator of tumor angiogenesis and tumor progression.</P>

Research on static and dynamic behaviors of PC track beam for straddle monorail transit system

Yongqing Yang,Deng Yang,Hongye Gou,Yi Bao 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.31 No.5

In this study, in-situ static and dynamic tests of four pre-stressed concrete (PC) track beams with different span lengths and curvatures in a straddle monorail transit system were reported. In the static load tests, the strain and deflection at critical sections of the PC track beams were measured to determine the load bearing capacity and stiffness. The dynamic responses of strain, deflection, acceleration, and displacement at key positions of the PC track beams were measured under different train speeds and train loads to systematically study the dynamic behaviors of the PC track beams. A three-dimensional finite element model of the track beam-vehicle coupled vibration system was established to help understand the dynamic behavior of the system, and the model was verified using the test results. The research results show that the curvature, span length, train speed, and train loads have significant influence on the dynamic responses of the PC track beams. The dynamic performance of the PC track beams in the curve section is susceptible to dynamic loads. Appropriate train loads can effectively reduce the impact of the train on the PC track beam. The PC track beams allow good riding comfort.

Association of adjuvant radiotherapy with long-term overall and recurrence-free survival following hepatectomy for hepatocellular carcinoma: A multicenter propensity-matched study

Xiao-Xue GOU,Hong-Yun SHI,Chao LI,Zheng-Liang CHEN,Wei OUYANG,Li-Yang SUN,Timothy M. PAWLIK,Wan Yee LAU,Feng SHEN,Jun XUE,Tian YANG 한국간담췌외과학회 2022 Annals of hepato-biliary-pancreatic surgery Vol.26 No.-

Effects of L-malic acid on alpha-glucosidase: inhibition kinetics and computational molecular dynamics simulations.

Gou, Lin,Zhan, Yi,Lee, Jinhyuk,Li, Xuan,Lü,, Zhi-Rong,Zhou, Hai-Meng,Lu, Hang,Wang, Xi-Yao,Park, Yong-Doo,Yang, Jun-Mo Humana Press 2015 Applied biochemistry and biotechnology Vol.175 No.4

<P>The inhibitory effect of L-malic acid (MA) on alpha-glucosidase (EC 3.2.1.20) was investigated by combination study between inhibition kinetics and computational simulations. The results from the serial kinetics demonstrated that MA could directly inactivate the enzyme activity in a dose-dependent manner and a typical non-competitive type, as well as in a fast inactivate process without detectable time course. The tertiary conformation study with an application of spectrofluorimetry showed that MA modulated the tertiary structural conformation of alpha-glucosidase both on the overall and on regional active site pocket, which monitored by red-shift intrinsic fluorescence peak with decreases intensities, and the significant intensity increasing of 1-anilinonaphthalene-8-sulfonate (ANS)-binding fluorescence, respectively. To have more insight, we also adapted the computational molecular dynamics (MD) simulations. The results showed that MA was located in the entrance of active pocket for the catalytic reaction and blocked the passage of substrate. It confirmed that MA inhibits as a non-competitive type, not direct docking to the glucose binding site. Our study provides important molecular mechanisms to figure out alpha-glucosidase inhibition that might associate to development of type 2 diabetes mellitus drug.</P>

HSP90 inhibitor (NVP-AUY922) enhances the anti-cancer effect of BCL-2 inhibitor (ABT-737) in small cell lung cancer expressing BCL-2

Yang, Hannah,Lee, Mi-Hee,Park, Intae,Jeon, Hanwool,Choi, Junyoung,Seo, Seyoung,Kim, Sang-We,Koh, Gou Young,Park, Kang-Seo,Lee, Dae Ho Elsevier 2017 Cancer letters Vol.411 No.-

<P><B>Abstract</B></P> <P>Small cell lung cancer (SCLC) cannot be efficiently controlled using existing chemotherapy and radiotherapy approaches, indicating the need for new therapeutic strategies. Although ABT-737, a B-cell lymphoma-2 (BCL-2) inhibitor, exerts anticancer effects against BCL-2-expressing SCLC, monotherapy with ABT-737 is associated with limited clinical activity because of the development of resistance and toxicity. Here, we examined whether combination therapy with ABT-737 and heat shock protein 90 (HSP90) inhibitor NVP-AUY922 exerted synergistic anticancer effects on SCLC. We found that the combination of ABT-737 and NVP-AUY922 synergistically induced the apoptosis of BCL-2-expressing SCLC cells. NVP-AUY922 downregulated the expression of AKT and ERK, which activate MCL-1 to induce resistance against ABT-737. The synergistic effect was also partly due to blocking NF-κB activation, which induces anti-apoptosis protein expressions. However, interestingly, targeting BCL-2 and MCL-1 or BCL2 and NF-κB did not induce the cytotoxicity. In conclusion, our study showed that combination of BCL2 inhibitor with HSP90 inhibitor increased activity in in vitro and in vivo study in only BCL-2 expressing SCLC compared to either single BCL2 inhibitor or HSP inhibitor. The enhanced activity might be led by blocking several apoptotic pathways simultaneously rather than a specific pathway.</P>

The effect of alpha-ketoglutaric acid on tyrosinase activity and conformation: Kinetics and molecular dynamics simulation study

Gou, L.,Lee, J.,Yang, J.M.,Park, Y.D.,Zhou, H.M.,Zhan, Y.,Lu, Z.R. Elsevier 2017 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES Vol.105 No.3

Alpha-ketoglutaric acid (AKG) is naturally found in organisms and is a well-known intermediate in the production of ATP or GTP in the Krebs cycle. We elucidated the effects of AKG on tyrosinase activity and conformation via methods of inhibition kinetics integrated with molecular dynamics (MD) simulations. AKG was found to be a reversible inhibitor of tyrosinase (IC<SUB>50</SUB>=15+/-0.5mM) and induced parabolic slope mixed-type inhibition. Based on our newly established equation, the dissociation constant (K<SUB>islope</SUB>) was determined to be 7.93+/-0.31mM. The spectrofluorimetry studies showed that AKG mainly induced regional changes in the active site of tyrosinase, which reflects the flexibility of the active site. The computational docking and molecular dynamics (MD) simulations further demonstrated that AKG could interact with several residues near the substrate-binding site located in the tyrosinase active site pocket. Our study provides insight into the mechanism by which energy-producing intermediates such as AKG inhibit tyrosinase through its ketone groups. Also, AKG could be a potential natural antipigmentation agent due to its non-toxic property.

Inhibition of tyrosinase by fumaric acid: Integration of inhibition kinetics with computational docking simulations

Gou, L.,Lee, J.,Yang, J.M.,Park, Y.D.,Zhou, H.M.,Zhan, Y.,Lu, Z.R. Elsevier 2017 International Journal of Biological Macromolecules Vol.105 No.3

Fumaric acid (FA), which is naturally found in organisms, is a well known intermediate of the citric acid cycle. We evaluated the effects of FA on tyrosinase activity and structure via enzyme kinetics and computational simulations. FA was found to be a reversible inhibitor of tyrosinase and its induced mechanism was the parabolic non-competitive inhibition type with IC<SUB>50</SUB>=13.7+/-0.25mM and K<SUB>islope</SUB>=12.64+/-0.75mM. We newly established the equation for the dissociation constant (K<SUB>islope</SUB>) for the parabolic inhibition type in this study. Kinetic measurements and spectrofluorimetry studies showed that FA induced regional changes in the active site of tyrosinase. One possible binding site for FA was identified under the condition without L-DOPA. The computational docking simulations further revealed that FA can interact with HIS263 and HIS85 at the active site. Furthermore, four important hydrogen bonds were found to be involved with the docking of FA on tyrosinase. Our study provides insight into the mechanism by which dicarboxylic acids such as FA inhibit tyrosinase. By inhibiting tyrosinase and its central role in pigment production, FA is a potential natural antipigmentation agent.

Effect of anion species on preparation and properties of pitch-based activated carbon fibers by in-situ catalytic activation of metal nanoparticles

Gou Genchang,Wei Wenjie,Yang Jianxiao,Liu Jiahao,Liu Yue,Li Jun,Shi Kui 한국탄소학회 2022 Carbon Letters Vol.32 No.6

The pitch-based activated carbon fibers (ACFs) were prepared from ethylene tar-derived pitches containing nickelocene (CNi) or nickel nitrate (NiN). The effects of different anions and contents of metal salts on the microstructure and surface chemical properties of fibers were investigated. The results revealed that Ni2+ from CNi mainly remained its pristine molecule in the organometal salt-derived pitch (OP-xCNi), while Ni2+ from NiN occurred complexation reaction with polycyclic aromatic hydrocarbons (PAHs) in the inorganic metal salt-derived pitch (IP-xNiN) due to the weaker binding ability between anions and Ni2+ of CNi than CNi. The XRD and SEM results confirmed that IP-3NiN-ACF contained Ni, NiO, Ni2O3 nanoparticles with different size distributions, while OP-3CNi-ACF only contained more uniformly distributed Ni nanoparticles with small size. Furthermore, OP-3.0CNi-ACF presented higher specific surface area of 1862 m2/g and a pore volume of 1.69 cm3/g than those of IP-3.0NiN-ACF due to the formation of pore structure during the in-situ catalytic activation of different metal nanoparticles. Therefore, this work further pointed out that the desired pore structure and surface chemistry of pitch-based ACFs could be obtained through regulating and controlling the interaction of anion species, metal cations and PAHs during the synthesis of pitch precursors.

Alcohol Consumption and Breast Cancer Survival: A Metaanalysis of Cohort Studies

Gou, Yun-Jiu,Xie, Ding-Xiong,Yang, Ke-Hu,Liu, Ya-Li,Zhang, Jian-Hua,Li, Bin,He, Xiao-Dong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.8

Background and Objectives: Evidence for associations between alcohol consumption with breast cancer survival are conflicting, so we conducted the present meta-analysis. Methods: Comprehensive searches were conducted to find cohort studies that evaluated the relationship between alcohol consumption with breast cancer survival. Data were analyzed with meta-analysis software. Results: We included 25 cohort studies. The meta-analysis results showed that alcohol consumption was not associated with increased breast cancer mortality and recurrence after pooling all data from highest versus lowest comparisons. Subgroup analyses showed that pre-diagnostic or post-diagnostic consumpotion, and ER status did not affect the relationship with breast cancer mortality and recurrence. Although the relationships of different alcohol consumption with breast cancer mortality and recurrence were not significant, there seemed to be a dose-response relationship of alcohol consumption with breast cancer mortality and recurrence. Only alcohol consumption of >20 g/d was associated with increased breast cancer mortality, but not with increased breast cancer recurrence. Conclusion: Although our meta-analysis showed alcohol drinking was not associated with increased breast cancer mortality and recurrence, there seemed to be a dose-response relationship of alcohol consumption with breast cancer mortality and recurrence and alcohol consumption of >20 g/d was associated with increased breast cancer mortality.