http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A mechanically enhanced bioprinted hydrogel supplemented by covalent and ionic bonds
Hanjun Hwangbo,Jihoon Kim,JiUn Lee,Hyeongjin Lee,JaeYoon Lee,WonJin Kim,SooJung Chae,Dongyun Kim,Seoyul Jo,Youngwon Koo,JuYeon Kim,GeungHyung Kim 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
Hydrogels are regarded as a golden standard for tissue engineering applications. However, low mechanical strength and stretchability are few of the limiting factors of natural derived hydrogel. To overcome this issue, we have conjugated two natural polymers, collagen and alginate to take advantage of both covalent and ionic bonding. Briefly, various of weight fraction of collagen and Alginate has been conjugated (Col-Alg) and analyzed for the elasticity. Consequently, the dual crosslinked hydrogel exhibited a significantly higher fracture stress indicating in high elasticity.
SLIT3 regulates endochondral ossification by β-catenin suppression in chondrocytes
Kim, Hanjun,Choi, Young-Jin,Lee, Young-Sun,Park, Suk Young,Baek, Ji-Eun,Kim, Ho-Kyoung,Kim, Beom-Jun,Lee, Seung Hun,Koh, Jung-Min Elsevier 2018 Biochemical and biophysical research communication Vol.506 No.4
<P><B>Abstract</B></P> <P>Previously, we noted that SLIT3, slit guidance ligand 3, had an osteoprotective role with bone formation stimulation and bone resorption suppression. Additionally, we found that global <I>Slit3</I> KO mice had smaller long bone. Skeletal staining showed short mineralized length in the newborn KO mice and wide hypertrophic chondrocyte area in the embryo KO mice, suggesting delayed chondrocyte maturation. The recombinant SLIT3 did not cause any change in proliferation of ATDC5 cells, but stimulated expressions of chondrocyte differentiation markers, such as COL2A1, SOX9, COL10A1, VEGF, and MMP13 in the cells. SLIT3 suppressed β-catenin activity in the cells, and activation of Wnt/β-catenin signaling by lithium chloride attenuated the SLIT3-stimulated differentiation markers. ATDC5 cells expressed only ROBO2 among their 4 isotypes, and the <I>Robo2</I> knock-down with its siRNA reversed the SLIT3-stimulated differentiated markers in chondrocytes. Taken together, these indicate that SLIT3/ROBO2 promotes chondrocyte maturation via the inhibition of β-catenin signaling.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Slit3</I> deficiency impairs endochondral ossification of long bones by delayed hypertrophic chondrocyte maturation. </LI> <LI> SLIT3 promotes chondrocyte differentiation by β-catenin inhibition. </LI> <LI> ROBO2 is a receptor for SLIT3 in chondrocytes. </LI> </UL> </P>
Dual Function of Wnt Signaling during Neuronal Differentiation of Mouse Embryonic Stem Cells
Kim, Hanjun,Kim, Sewoon,Song, Yonghee,Kim, Wantae,Ying, Qi-Long,Jho, Eek-hoon Hindawi Publishing Corporation 2015 Stem cells international Vol.2015 No.-
<P>Activation of Wnt signaling enhances self-renewal of mouse embryonic and neural stem/progenitor cells. In contrast, undifferentiated ES cells show a very low level of endogenous Wnt signaling, and ectopic activation of Wnt signaling has been shown to block neuronal differentiation. Therefore, it remains unclear whether or not endogenous Wnt/<I>β</I>-catenin signaling is necessary for self-renewal or neuronal differentiation of ES cells. To investigate this, we examined the expression profiles of Wnt signaling components. Expression levels of Wnts known to induce <I>β</I>-catenin were very low in undifferentiated ES cells. Stable ES cell lines which can monitor endogenous activity of Wnt/<I>β</I>-catenin signaling suggest that Wnt signaling was very low in undifferentiated ES cells, whereas it increased during embryonic body formation or neuronal differentiation. Interestingly, application of small molecules which can positively (BIO, GSK3<I>β</I> inhibitor) or negatively (IWR-1-endo, Axin stabilizer) control Wnt/<I>β</I>-catenin signaling suggests that activation of that signaling at different time periods had differential effects on neuronal differentiation of 46C ES cells. Further, ChIP analysis suggested that <I>β</I>-catenin/TCF1 complex directly regulated the expression of <I>Sox1</I> during neuronal differentiation. Overall, our data suggest that Wnt/<I>β</I>-catenin signaling plays differential roles at different time points of neuronal differentiation.</P>
명중률 향상을 위한 이중추력형 비행모터 개발에 대한 연구
김한준(Hanjun Kim),안용환(Yonghwan Ahn),김은미(Eunmi Kim),김남식(Namsik Kim),이원복(Wonbok Lee),양영준(Youngjun Yang) 한국추진공학회 2013 한국추진공학회 학술대회논문집 Vol.2013 No.12
본 논문은 무유도 로켓탄의 명중률을 향상시키기 위해 개발한 이중추력형 비행모터에 관하여 기술하였다. 고연소속도 특성을 지닌 더블베이스 추진제의 형상 조절을 통해 이중추력형 비행모터를 설계하였으며, 실제 지상연소시험을 통해 이중추력 성능을 확인하였다. 연소시험 결과 서스테이닝 단계와 부스팅 단계의 추력비는 약 1:7.6 으로 정상적인 이중추력 특성을 보였으며, 압력강하에 의한 추진제 소화현상은 나타나지 않았다. This paper describes the development of the dual-thrust flight motor for enhancing the hit probability of unguided rockets. We designed dual-thrust flight motor by shape modification of the double base propellant with high burning rate, and confirmed the dual-thrust performance by static firing tests. The test results showed the thrust ratio of about 1:7.6 between sustaining phase and boosting phase, and had a quitely normal dual-thrust characteristics. And the results showed that there was not the fire extinction phenomenon of propellant due to the pressure drop.
Phosphorylation by NLK inhibits YAP ‐14‐3‐3‐interactions and induces its nuclear localization
Moon, Sungho,Kim, Wantae,Kim, Soyoung,Kim, Youngeun,Song, Yonghee,Bilousov, Oleksii,Kim, Jiyoung,Lee, Taebok,Cha, Boksik,Kim, Minseong,Kim, Hanjun,Katanaev, Vladimir L,Jho, Eek‐,hoon unknown 2017 EMBO reports Vol.18 No.1
<P>Hippo signaling controls organ size by regulating cell proliferation and apoptosis. Yes-associated protein (YAP) is a key downstream effector of Hippo signaling, and LATS-mediated phosphorylation of YAP at Ser127 inhibits its nuclear localization and transcriptional activity. Here, we report that Nemo-like kinase (NLK) phosphory-lates YAP at Ser128 both in vitro and in vivo, which blocks interaction with 14-3-3 and enhances its nuclear localization. Depletion of NLK increases YAP phosphorylation at Ser127 and reduces YAP-mediated reporter activity. These results suggest that YAP phosphorylation at Ser128 and at Ser127 may be mutually exclusive. We also find that with the increase in cell density, nuclear localization and the level of NLK are reduced, resulting in reduction in YAP phosphorylation at Ser128. Furthermore, knockdown of Nemo (the Drosophila NLK) in fruit fly wing imaginal discs results in reduced expression of the Yorkie (the Drosophila YAP) target genes expanded and DIAP1, while Nemo overexpression reciprocally increased the expression. Overall, our data suggest that NLK/Nemo acts as an endogenous regulator of Hippo signaling by controlling nuclear localization and activity of YAP/Yorkie.</P>
Determinants of technology-based spin-offs created by universities in Korea
Kim HanJun 기술경영경제학회 2020 ASIAN JOURNAL OF TECHNOLOGY INNOVATION Vol.28 No.2
This study provides an empirical analysis on how the endogenous and exogenous factors of universities influence the creation of technology-based spin-offs (TBSOs), employing unique datasets from the Korean government-affiliated research institute. The results support the conclusion that universities with experienced technology licensing offices (TLOs), those in possession of incubation policies or business incubators, and those willing to participate in external collaboration with parties in and outside Korea have an edge in creating TBSOs. This study also reveals that the moderating effect between universities’ external collaboration and the personnel sizes at their technology licensing offices negatively affect the creation of TBSOs. The findings of this study shed some lights on policymakers as well as scholars.
Improved Iterative Closest Point Algorithm using Truncated Signed Distance Function
Hanjun Kim,H. K. Hong,B. H. Lee 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10
Truncated signed distance is one of the methods to represent 3D spatial information by using the distance from the surface of an object, and is mainly used for 3D dense reconstruction. When using truncated signed distance value for 3D reconstruction, iterative closest point algorithm is generally used for matching two point clouds. However, iterative closest point algorithm for 3D reconstruction uses only the geometric information of point clouds themselves. Due to lack of information in the surface structure, it is possible to fall in the local minimum or occur convergence failure in iteration process. To solve these problems, we use additional information from truncated signed distance function values. As we optimize the joint objective function composed of the geometric information and the truncated signed distance function information, it is possible to register two point clouds to be more robust in iterative closest point algorithm. Experimental results demonstrate that the proposed method outperforms the conventional method using only a geometric information.