(The) association between asymptomatic coronary artery disease and CHADS2/CHA2DS2-VASC scores in patients with stroke

차명진 Graduate School, Yonsei University 2013 국내석사

Developmental outcome of very-low-birth-weight infants born in 2013-2015 without major brain injury based on data from the Korean Neonatal Network : a national wide cohort study

차종호 한양대학교 대학원 2020 국내석사

ABSTRACT Developmental outcome of very-low-birth-weight infants born in 2013-2015 without major brain injury based on data from the Korean Neonatal Network : A national wide cohort study Jong Ho CHA Department of Pediatrics The Graduate School Hanyang University Background As preterm infants have shown advances in survival rate, many very-low-birth-weight (VLBW) infants have shown developmental delay even without a major brain injury. Thus, incidence of and risk factors associated with poor neurodevelopmental outcome should be evaluated. Methods A multicenter nationalwide prospective longitudinal cohort study of VLBW infants born in South Korea between 2013 and 2015 was conducted. Adverse neurodevelopmental outcome was assessed using the Bayley Scales of Infant and Toddler Development III in corrected age of 18 to 24 months. Multilevel multivariate logistic regression analysis was used to analyze the odds ratio for poor neurodevelopmental outcome. Results The study included 285 infants, of whom 34 (11.9%) exhibited cognition delay; 59 (20.7%) language delay; and 32 (11.2%), motor delay. The mean gestational age was 29 weeks, and the mean birth weight was 1130 g. Bronchopulmonary dysplasia (BPD) moderate and severe (p=0.056), intraventricular hemorrhage(IVH) grade I (p=0.079) was marginally associated with cognition delay. Higher paternal educational level (p<0.05) was significantly related with the language outcome. Birth weight(p<0.05), head circumference at discharge (p<0.05) were the major predictors of motor delay. Conclusions This population-based nationwide cohort study shows that approximately 20% of VLBW infants with no major brain damage have developmental delay. Developmental delay was predicted by birth weight, head circumference at discharge, BPD and IVH grade I and paternal educational level. We emphasize clinicians should be aware of the risk factors for the adverse neurodevelopmental outcome even VLBW without brain injury. Keywords: Preterm; Developmental delay; Language delay; Bayley Scales of Infant and Toddler Development; Very-low-birth-weight-infants; NICU

Teaching listening skills in English to the Korean high school student through a nation-wide television network

Kyung-whan Cha University of Kansas 1984 해외석사

Structural models for hydrogenase and a reactivity model for methyl coenzymem reductase : Mikyung Cha

Cha, Mikyung University of Washington 1992 해외박사

S₃N₂리간드 (S₃N₂=(H₂N(CH₂)S(CH₂))₂S)를 [Ni(H₂O6]SO₄과 반응하 여 [Ni(S₃N₂)(H₂O)]SO₄(1a)를 합성하였다. BPH₄- 음이온 교환반응과 아세토니트릴 추출로 분석적으로 순수한 결정 [Ni(S₃N₂)(MeCN)] (BPH₄)₂ ·MeCN(1c)을 얻었다. 이 화합물은 monoclinic space group P2₁/n으로 a=19. 036(2)Å,b=12. 022(8)Å,c=24. 953(4)Å,β=107. 78(1)°, V=5438(2)ų 그리고 Z=4이다. 그리고 위의 추출과정을 아세톤에서 했을때 [Ni(S₃N₂)( Cl)](BPh₄). CH₃CO(3)의 결정을 얻었으며 이 결정은 monoclinic space group P2₁/n으로 a=11. 573(7)Å,b=13. 085(2)Å,c=23. 884(4)Å,β=107. 78(1)°, V=3554(2)ų그리고 Z=4이다. 화합물 1c를 NaN₃와 pyridine으로 반응시켜서 각각 [Ni(S₃N₂)(N₃)] (BPh₄)(2)와 [Ni(S₃N₂))(pyridine)](BPh₄)₂(4)을 합성하였다. 화합물 2는 monoclinic space group P2₁/c으로 a=11. 556(19)Å,b=13. 132(3) Å,c=22. 999(4)Å,β=100. 300(1)°,V=3434(2)ų그리고 Z=4로 결정화되었다. 화합물 4는 monoclinic space group P2₁/n으로 a=8. 9742(7)Å,b=6. 9132(16) Å,c=11. 9992(7)Å,β=94. 41°(3),V=740. 3(3)ų그리고 Z=4로 결정화되었다. 리간드 S5(S5=(-S(C6H₄)₂S(CH₂))₂S)와 NiCl₂(PPh₃)₂를 THF에서 반응 시켜 [NiS5](5)를 합성하였다. 이 화합물은 monoclinic space group P2₁/c 으로 a=10. 7587(15)Å,b=11. 2507(7)Å,c=14. 1977(13)Å,β=90. 818(10)°, V=1718. 4(6)ų 그리고 Z=4 로 결정화되었다. NiCl₂(PPh₃)₂을 2배몰의 benezene-1,2-dithiolate(bdt²-)와 반응하여 [Ni(bdt)₂](Na(OPPh₃)₄·1/2CH₃CN)을 합성하였다. 이 화합물은 triclini c space group P₁으로 a=4. 481(3)Å,b=14. 887(3)Å,c=20. 385(4)Å,α=70. 38 (2)°β=70. 55(2)°,γ=88. 75(2)° V=3883(7)ų 그리고 Z=2로 결정화되었 다. NiCl₂(PPh₃)₂과 동몰의 bdt²-를 반응하여 trinuclear cluster[Ni₃( μ ₂)₂-S₂-1,2-C6H₄)₂(PPh₃)₂·2THF]를 합성하였으며 이 화합물은 triclinic space group P₁으로 a=11. 106(2)Å,b=11. 406(2)Å,c=25. 638(5)Å, α=85. 16(1)°,β=85. 80(2)°,γ=61. 46(2)°,V=28. 41(7)ų그리고 Z=2로 결 정화되었다. The S3Nz ligand (S3N2=(H2N(CH&S(CH2))2S) reacts with to yield a [Ni(S3N2)(H2O)]SO4 (la). Anion exchange with BPhq followed by extraction into MeCN afforded analytically pure crystalline [Ni(S3N2)(MeCN)](BPh4)TMeCN . This compound crystallizes in the monoclinic space group PZl/n with a=19.036(2) A, b=12.022(8) A, c=24.953(4) A,@=107.78( l) V= 5438(2) A3 and Z=4. When BaC12 and NaBPh4 are used to exchange the SO42- anion of la, and the BPh4- salt is extracted into acetone, [Ni( S3N2) (Cl)] (BPh&CH$O (3) forms. Compound 3 the monoclinic space group P21/n with a=11.573(7) A, b=13.085(2) A,c=23.884(4) A, 8=107.78(l) V=3554(2) As, and Z=4. Compound lc reacts with NaN3 and pyridine to afford [Ni(S3N2)(N$](BPh4) (2), and [Ni(S3N2) (pyridine)]( BPh4)2 (4), respectively. Compound 2 crystallizes in the monoclinic space group P21/c with a=11556( 19) A, b=13.132(3) A, c=22.999( 13) A, p=100.300( l) V=3434( 1), and Z=4. Compound 4 crystallizes in the monoclinic space group-P2l/n with a=8.9742(7) A, b=6.9132( 16) A, c=11.9992(7) A, p=94.41(3) V= 740.3(3) As, and Z=4. The S5 hgand (Ss=(-S(CHz)2S(CH2))$) reacts with NiC12(PPh3)2 in THF to afford [NiSs] (5). This compound crystallizes in the monoclinic space group P2;/c with a=10.7587( 15) , b=11.2507(7) A, c=14.1977(13) A, 90.818(10) V= 1718.4(6) A3, andZ=4. NiC12(PPh3)2 reacts with two equivalents of benzene-1,2- dithiolate (bdt*-) to afford [Ni(bdt)](Na(OPPh3)41/2CH$N. This compound crystallizes in the triclinic space group Pl with a=4.481(3) A, b=14.887(3) A, 20.385(4) A, a=70.38(2) @=70.55(2) y=88.75(2) V= 3883.1(7) A3, and Z=2. Reaction of NiC12(PPh& with one equivalent of bdt2- affords the trinuclear cluster [Ni3( ( P&J-S2-1,2-C6H4)( (~z.,&)-S2-1,2-C&)2(PPh3)2.2THF]. This compound crystallizes in the tticlinic space group Pl with a=11.106(2), b=11.406(2) A, 85.16(1) @=85.80(2) y=61.46(2) V= 28.41( 1) A3, and Z=2. Electrochemical and chemical reduction (sodium acenaphthylenide) of [NiSs] promotes C-S bond cleavage to afford and ethylene. This provides a model for the in the reductive C-S bond cleaving reaction promoted by the nickel-containing enzyme methyl coenzyme M reductase.

On the ls-energy matrix elements of central interactions for the configurations of 3p, 2f, 1h orbits, by Moon-hoe Cha

Cha, Moon-hoe [s.n.] 1974 국내박사

サイクロトロン-チェレンコフ自由電子レ-ザ-の基礎硏究 : Lee,cha yeol

Lee,cha yeol 金澤大學 1997 해외박사

본 논문은, 플라즈마 가열 및 장래의 고에너지 전자 가속기 드라이브, 그 외의 응용이 기대되고 있는 고출력 미리파 발진기 혹은 증폭기의 하나인 사이클로트론 체렌코프 자유 전자 레이저(Cyclotron-Cherenkov free electron laser)를 실현하는 것을 목적으로 이론적, 실험적인 기초연구를 총괄한 것이다. 사이클로트론-체렌코프 자유 전자 레이저는 원리적으로는 입사 빔 전자에 횡방향의 초속도를 주지 않아도 마이크로파의 발진이 가능하다. 그 때문에, 빔의 질에 부담이 적다. 또한, 위클러(wiggle) 자장과 같은 주기 구조를 사용하지 않으므로, 마이크로파 발진관의 제작이 간단하고, 가이드자장강도 및 빔에너지를 변화시킴으로 인해 보다 용이하게 발진 주파수를 변화시킬 수가 있다. 그러나, 사이클로트론-체렌코프 자유 전자 레이저의 실현에는 곤란한 점이 있다. 사이클로트론-체렌코프 불안정성을 일으키려 하면 체렌코프 불안정성도 동시에 일어날 가능성이 있다. 그 때문에, 사이클로트론-체렌코프 자유 전자 레이저의 설계를 하기 위해서는, 사이클로트론-체렌코프 불안정성의 성장률이 체렌코프 불안정성의 성장률보다 큰 구조를 찾지 않으면 안된다. 그래서, 유전체 장착 원형 도파관과 유전체 장착 동축 원형도파관의 구조를 생각해, 유체근사를 사용해 선형해석에 의해 양 불안정성을 기술할 분산식을 유도하여, 사이클로트론-체렌코프 불안정성의 성장률이 체렌코프 불안정성의 성장률보다 우세한 구조를 찾아 왔다. 그 결과, 사이클로트론-체렌코프 불안정성의 성장률이 체렌코프 불안정성의 성장률보다 큰 유전체 장착 동축 원형 도파관을 발견했다. 이 구조에 있어서 빔 에너지 확산효과를 조사하기 위해 멀티스트리밍 모델(multistreaming model)을 생각해 분산식을 유도하여, 양 불안정성의 빔에너지, 빔전류, 가이드자장강도, 비유전률 등의 파라메트 의존성을 조사했다. 그리고, 실험적인 연구를 하기 위해서, 유전체 장착 동축 원형 도파관에 있어서 실험 가능한 파라메트를 설정해, 실험장치를 설계 제작했다. 실험에서 사용한 대강도상대론적빔(IREB) 발생장치로서는 Physics International Pulserad Model 220G(1 MeV, 50 kA, 200 nsec)를 사용하여, 빔에너지와 가이드자장강도를 변화시켜 유전체 장착 동축 원형 도파관 내의 빔 전달을 조사한 후, 양 불안정성에 의한 마이크로파 방사 실험을 하였다. 그 결과, 사이클로트론-체렌코프 불안정성과 체렌코프 불안정성에 의한 마이크로파의 방사가 확인되었다. 또한, 사이클로트론-체렌코프 뷸안정성에 의한 발진 주파수의 가이드자장강도의 의존성을 확인하였다. 그리고, 실험결과와 이론결과를 비교해 본 결과 잘 일치하는 것을 알았다.

Buxtehude`s organ music as captured in sound recordings

Cha Jooyean Arizona State University 2007 해외석사

Rahmenbedingungen und massnahmen der marktbearbeitung Japanischer automogilhersteller in der bundesrepublik Deutschland

Cha, Soo Ryeon Philipps Univ. 1985 국내박사

Effects of Sizing Materials on the Properties of Carbon Fiber-Reinforced Polyamide 6 Composites Manufactured through Thermoplastic Resin Transfer Molding

Cha, Sang-Hyup Graduate School of UNIST 2019 국내석사

Carbon fiber reinforced plastics (CFRPs) are a combination of high-strength and stiffness carbon fiber and resin, and the weight of the composite is less than one-half the weight of similar rigid, ultra-high tensile steel plates. However, CFRP is 4.4 times more expensive than ultra-high tensile steel parts, and 30 percent lighter than aluminum but 3.8 times more expensive. Therefore, it is necessary to reduce the costs of CFRPs to broaden the market to the mechanical and aerospace industries. A variety of composite manufacturing processes were developed to minimize the processing time. Among them, thermoplastic resin transfer molding (T-RTM) using the anionic ring opening polymerization of ε-caprolactam transfers the monomer into the mold with the catalyst and activator, leading to polymerization and crystallization simultaneously. Melt viscosity of εcaprolactam is 100 times lower than thermoset resins in reaction processing and 160,000 times lower than thermoplastic resins in melting processing. Thus, the T-RTM process has the advantage of fewer limitations in production structure, good resin impregnation, and short production cycle time – in the order of a few minutes. One of the most important factors affecting the properties of composite materials is the adhesion at the fiber-matrix interfaces. The fiber-matrix adhesion is strongly associated with load transfer efficiency inside the composite, and thus affects the overall mechanical properties of the material. In this study, sizing process was used to enhance the fiber-matrix adhesion. Sizing refers to coating the surface of a fiber with a thin polymer, and in a way that has become common, most commercial fibers have already been coated with sizing materials. A total of seven sizing materials, expected to be highly compatible with A-PA6, were used. Physical and chemical changes of the carbon fiber surface by sizing materials were analyzed by TGA, SEM, XPS, and FT-IR. Also, fiber-bundle pull-out test, short beam test, and X-ray micro CT were conducted to measure the IFSS, short beam strength, and void content of the composite manufactured by T-RTM. Consequently, the highest improvements in IFSS and short beam strength were 30 and 50% achieved with epoxy (EP) and polyamide (PA) sizings, respectively, due to enhanced fibermatrix adhesion with A-PA6 resin. The improvement mechanisms of fiber-matrix adhesion by EP and PA were verified by XPS, surface energy, X-ray micro CT and FT-IR analysis. As a results, EP and PA sizing materials were proven to be the most suitable for T-RTM process.

Effects of Cytochalasin B and Cycloheximide on In Vitro Development of Porcine Oocytes Following Parthenogenetic Stimulation

CHA, SOO KYUNG Graduate School of Kon-Kuk University 1998 국내박사

본 연구는 돼지의 성숙된 난자에 전기자극을 한후 cytochalasin B와 cycloheximide를 처리했을 때 난활율과 염색체의 구조, 배발달을 조사하였다. 성숙된 난자에 Ca^(+2) ionophore나 ethanol로 난활성을 유도한 후 cycloheximide를 처리했을 때, 난활성율이 증가되었다. 성숙난자에 cytochalasin B를 처리한 난자가 무처리 난자나 cycloximide를 처리한 난자보다 2개나 2개이상의 전핵 형성율에 높게 유의차를 보였다. 또한 난자의 염색체르 ㄹ조사한 결과, 성숙난자에 cytochalasin B를 처리해을 때에 정상적인 염색체인 diploid가 높게 나타났다. 전기자극후 성숙난자에 cytochalasin B를 처리했을 때가 배반포까지의 배발달율이 24시간정도 빨리 발달했으며 또한 배발달율에서도 높게 나타났다. 결과적으로, 전기적인 자극과 cytochalasin B의 처리는 돼지난자의 배반포로의 체외발달률을 증진시키니다. 또한 더많은 diploid 염색체가 cytochalasin B를 처리한 단위 발생체에서 관찰되어졌다. The activation rate, chromosome constituent and develpmental pattern of porcine oocytes were examined in the presence and avsence with cytochalasin B or cycloheximide following parthenogenetic stimulation. Cycloheximide following ethanol ro Ca^(+2) ionophore treatment increased the incidence of oocyte activation. The percentage of oocytes with more than two female pronuclei was higher (P<0.05) in oocytes treated with cytochalasin B compared to the control or cycloheximide treated oocytes. The combined treatment of electrial stimulation and cytochalasin B increased the incidence of diploid chromosome spreads and acceleated development to the morula and blastocyst stages as compared to the control and cycloheximide treated groups, suggesting a role of ploidy in the development of parthenote. In conclusion, the combined treatment electriacal stimualtion and cytochalasin B enhance and accelerate in vitro development of porcine oocytes to blatocysts. More diploid and chromosome spreads were observed in the cytochalasin B traeted parthenotes, suggesting a role of ploidy in the development of parthenote.