양생조건에 따른 고강도 콘크리트의 건조수축 및 자기수축에 관한 실험연구

이영화,윤종문,김화중 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

High-strength concrete is used in high rise building effectively but it has cracks due to the autogenous shrinkage. Therefore we performed a variety of experiments to analyze the characteristic of the autogenous and drying shrinkage of High-Strength concrete with the temperature and humidity in curing conditions. We measured the length change rate of experimented objects using Contact-Guage Method in the concrete of water-cement ratio 30% with the change of temperature(10, 20, 30℃) and relative humidity(30, 60, 90%). In consequence, on the first, the higher humidity, the lower autogenus shrinkage and drying shrinkage. second, it has the lowest length change of autogenus shrinkage and drying shrinkage in case of 10 ℃, and it is no difference between 20℃ and 30℃ for the constant humidity of 60% test. On the third, the ratio of drying shrinkage to autogenus shrinkage is the highest in case of the 30℃ temperature and 90% of relative humidity.

Greatwall Kinase is Required for Meiotic Maturation in Porcine Oocytes

Ying-Hua Li,Hyoeun Kang,Yong-Nan Xu,Young-Tae Heo,Xiang-Shun Cui,Jeong Su Oh,Nam-Hyung Kim 한국동물생명공학회(구 한국동물번식학회) 2013 Reproductive & Developmental Biology(Supplement) Vol.37 No.2s

Meiotic maturation in many species is initiated by the activation of maturation-promoting factor (MPF) with concomitant inactivation of counteracting phosphatases, most notably protein phosphatase 2A (PP2A). Recently, Greatwall (Gwl) has been identified as a cell cycle regulator that inhibits PP2A activity. In this study, we demonstrate that Gwl is required for meiotic maturation in porcine oocytes. Gwl is expressed from germinal vesicle (GV) to metaphase II (MII) stages of porcine oocytes and dramatically decreases with the progression of the meiotic cell cycle. Gwl is initially localized in the nucleus of GV oocytes and is associated with spindle fibers following GV breakdown (GVBD). Depletion of Gwl inhibits or delays meiotic maturation secondary to defects in chromosome congression and spindle formation. Conversely, overexpression of Gwl overcame meiotic arrest and initiated progression to the MII stage. However, these oocytes had severe spindle defects. Furthermore, MII oocytes depleted of Gwl progressed to pronuclear formation. Taken together, our data demonstrate that Gwl is required not only for meiotic maturation but also for maintenance of MII arrest in porcine oocytes.

New Insights into ARP2/3 Complex Functional Pathway Promoting Porcine Early Embryo Development

Ying-Hua Li,Madhusmita Dhupal,Yong-Nan Xu 한국동물생명공학회(구 한국동물번식학회) 2014 Reproductive & Developmental Biology(Supplement) Vol.38 No.2s

Actin-related protein 2/3 (Arp2/3) complex plays a central role in the de novo nucleation of filamentous actin as branches on existing filaments. Small molecule inhibitor CK-666 bind to Arp2/3 complex and inhibit nucleation, but their modes of action are unknown. Here, we shed light on the functional aspects of Arp2/3 by CK-666 inhibitor on porcine early embryo development. Our data indicated that CK-666 destabilizes the complex, blocking movement of the Arp2 and Arp3 subunits, causing actin degradation and failure of cell division which results in failure of early embryo development. Our results also shows there is decrease in mRNA expression of ICM and trophectoderm related genes such as Sox2, Pou5f1, Nanog. These results provided key insights into the relationship between early embryo dvelopement and critical role of Arp2/3 complex.

A Study on Cutting and Tribology Performances of TiN and TiAlN Coated Tools

Li, Hua-Ying,He, Hui-Bo,Han, Wen-Qiang,Yang, Jun,Gu, Tao,Li, Yuan-ming,Lyu, Sung-Ki Korean Society for Precision Engineering 2015 International Journal of Precision Engineering and Vol.16 No.4

TiN and TiAlN coatings were deposited on the surface of AISI 5140 steel and cemented carbide YT15 by magnetron sputtering technique (MSP). The reciprocating sliding tests of TiN and TiAIN coatings on the surface of AISI 5140 steel were performed to investigate the friction coefficients of coatings affected by various normal loads with friction pair of 304 stainless steel balls. Dry machining tests on AISI 5140 hardened steel were carried out with the TiN and TiAlN coated tools on a CA6140A lathe. The effects of cutting speed on cutting forces and surface roughness of TiN and TiAlN coated tools were obtained and analyzed to assess the cutting performance of coated tools. The microcosmic micrographs of wear areas of coated tools were observed and investigated by scanning electron microscope and energy dispersive spectrum. The results show that the friction coefficients of TiN coatings are lower than that of TiAlN coatings. The cutting force of TiAlN coated tool decreases and flank wear resistance enhances in comparison with TiN coated tool. The wear form and mechanisms of TiN coated tool are mainly crater wear on the rake face and adhesive wear and abrasive wear on the flank face. The wear form and mechanisms of TiAlN coated tool are mainly adhesive wear, the breakage of cutting edge and the damage of tip, accompanied with diffusion and oxidation wear.

Inhibition of the Arp2/3 complex impairs early embryo development of porcine parthenotes

Ying-Hua Li,Yong-Nan Xu,Zi Li Lin,권정우,최향순,김남형 한국통합생물학회 2016 Animal cells and systems Vol.20 No.5

The Arp2/3 complex, which nucleates actin filaments, comprises a stable assembly of seven-protein subunits including two actin-related proteins (Arp2 and Arp3). Previous work showed that Arp2/3 binds to the sides of actin filaments and is concentrated at the leading edges of motile cells. In the present study, we show that the Arp2/3 complex is critical for cytokinesis during early embryonic development in porcine parthenotes. The Arp2/3 complex is concentrated at the cortex of each cell at the 1-, 2-, and 4-cell stages, and at the periphery at the morula stage. The amount of Arp2/3 significantly decreased at the blastocyst stage in parthenogenetically activated porcine embryos. Inhibition of the Arp2/3 complex in the pig embryos by the Arp2/3-specific inhibitor CK666 resulted in abnormal cell division, a decrease in developmental rate and total cell numbers, and an increase in the ratio of trophectoderm cell number to inner cell mass number in blastocyst-stage embryos. In addition, 4-cell stage embryos subjected to CK666 treatment exhibited significantly decreased expression of ZGA genes (Pou5f1, Sox2, and Nanog), suggesting that the Arp2/3 complex plays an important role in early porcine embryo development. Thus, our data demonstrate that the Arp2/3 complex is required for early embryonic development in pigs and appears to regulate the expression of pluripotency genes.

A Genetic Variant in MiR-146a Modifies Digestive System Cancer Risk: a Meta-analysis

Li, Ying-Jun,Zhang, Zhen-Yu,Mao, Ying-Ying,Jin, Ming-Juan,Jing, Fang-Yuan,Ye, Zhen-Hua,Chen, Kun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

MicroRNAs (miRNAs) negatively regulate gene expression and act as tumor suppressors or oncogenes in oncogenesis. The association between a single nucleotide polymorphism (SNP) in miR-146a rs2910164 and susceptibility to digestive system cancers was inconsistent in previous studies. In this study, we conducted a literature search of PubMed to identify all relevant studies published before August 31, 2013. A total of 21 independent case-control studies were included in this updated meta-analysis with 9,558 cases and 10,614 controls. We found that the miR-146a rs2910164 polymorphism was significantly associated with decreased risk of digestive system cancers in an allele model (OR=0.90, 95%CI 0.87-0.94), homozygote model (OR=0.84, 95%CI 0.77-0.91), dominant model (OR=0.90, 95%CI 0.84-0.96), and recessive model (OR=0.85, 95%CI 0.79-0.91), while in a heterozygous model (OR = 0.99, 95% CI 0.89-1.11) the association showed marginal significance. Subgroup analysis by cancer site revealed decreased risk in colorectal cancer above allele model (OR=0.90, 95%CI 0.83-0.97) and homozygote model (OR=0.85, 95%CI 0.72-1.00). Similarly, decreased cancer risk was observed when compared with allele model (OR=0.87, 95%CI 0.81-0.93) and recessive model (OR=0.81, 95%CI 0.72-0.90) in gastric cancer. When stratified by ethnicity, genotyping methods and quality score, decreased cancer risks were also observed. This current meta-analysis indicated that miR-146a rs2910164 polymorphism may decrease the susceptibility to digestive system cancers, especially in Asian populations.

New Safrole Oxide Derivatives: Synthesis and in vitro Antiproliferative Activities on A549 Human Lung Cancer Cells

Li-Ying Wang,Xiu-Hua Wang,Jia-Lian Tan,Shuai Xia,Heng-Zhi Sun,Jin-Wen Shi,Ming-Dong Jiang,Liang Fang,Hua Zuo,Gautam Dupati,장기완,신동수 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

A number of novel small molecules, safrole oxide derivatives 4a-c, 6a-c, 9a-h, were synthesized by the reaction of safrole oxide with anilines 3 and 5, or its alkyl allyl ether derivative 7 with alkyl bromide 8 in moderate yields. The antiproliferative effects of all the target molecules on A549 cell growth were investigated and it was found that the 14 novel compounds could suppress A549 lung cancer cell growth. Among them, compound 6b was the most effective compound in inhibiting the proliferation of A549 cells.

BMP15 and GDF9 Signaling Pathways Involved in In Vitro Maturation of Porcine Oocyte

Ying-Hua Li,Zi-Li Lin,Seul-Ki Lee,Nam-Hyung Kim,Xiang-Shun Cui 한국동물생명공학회(구 한국동물번식학회) 2012 발생공학 국제심포지엄 및 학술대회 Vol.2012 No.1

A Study on Cutting and Tribology Performances of TiN and TiAlN Coated Tools

Hua-Ying Li,Hui-Bo He,Wen-Qiang Han,Jun Yang,Tao Gu,Yuan-ming Li,류성기 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

TiN and TiAlN coatings were deposited on the surface of AISI 5140 steel and cemented carbide YT15 by magnetron sputteringtechnique (MSP). The reciprocating sliding tests of TiN and TiAIN coatings on the surface of AISI 5140 steel were performed toinvestigate the friction coefficients of coatings affected by various normal loads with friction pair of 304 stainless steel balls. Drymachining tests on AISI 5140 hardened steel were carried out with the TiN and TiAlN coated tools on a CA6140A lathe. The effectsof cutting speed on cutting forces and surface roughness of TiN and TiAlN coated tools were obtained and analyzed to assess thecutting performance of coated tools. The microcosmic micrographs of wear areas of coated tools were observed and investigated byscanning electron microscope and energy dispersive spectrum. The results show that the friction coefficients of TiN coatings are lowerthan that of TiAlN coatings. The cutting force of TiAlN coated tool decreases and flank wear resistance enhances in comparison withTiN coated tool. The wear form and mechanisms of TiN coated tool are mainly crater wear on the rake face and adhesive wear andabrasive wear on the flank face. The wear form and mechanisms of TiAlN coated tool are mainly adhesive wear, the breakage ofcutting edge and the damage of tip, accompanied with diffusion and oxidation wear.

Exact solution for free vibration of curved beams with variable curvature and torsion

Li-li Zhu,Ying-hua Zhao,Guang-xin Wang 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.3

For the purpose of investigating the free vibration response of the spatial curved beams, the governing equations are derived in matrix formats, considering the variable curvature and torsion. The theory includes all the effects of rotary inertia, shear and axial deformations. Frobenius’ scheme and the dynamic stiffness method are then applied to solve these equations. A computer program is coded in Mathematica according to the proposed method. As a special case, the dynamic stiffness and further the natural frequencies of a cylindrical helical spring under fixed-fixed boundary condition are carried out. Comparison of the present results with the FEM results using body elements in I-DEAS shows good accuracy in computation and validity of the model. Further, the present model is used for reciprocal spiral rods with different boundary conditions, and the comparison with FEM results shows that only a limited number of terms in the resultant provide a relatively accurate solution.