1,721,924 research outputs found
Yu Na Lim
No full text학위논문(박사)--아주대학교 일반대학원 :에너지시스템학과,2017. 2Part 1. Utilization of CO and CO2 as C1 Sources: Synthesis of Carboxylic Acids, Organic carbonates and Polyketones 1
Chapter 1. Background of metal-catalyzed carbonylation / carboxylation of alkenes and alkynes. 2
1.1. Palladium-catalyzed carbonylation of alkenes and alkynes. 2
1.1.1. Introduction 2
1.1.2. Hydroxycarbonylation/hydroesterification of alkenes and alkynes. 2
A. Hydroxycarbonylation of alkenes 2
B. Hydroesterification of alkenes 7
C. Hydroesterification of alkynes 11
1.1.3. Oxidative carbonylation of alkenes and alkynes 15
A. Oxidative carbonylation of alkenes 15
B. Oxidative carbonylation of alkynes 19
1.1.4. Summary 22
1.2. Metal-catalyzed carboxylation of alkenes and alkynes 23
1.2.1. Introduction 23
1.2.2. Hydrocarboxylation of alkenes/alkynes 23
A. Hydrocarboxylation of alkenes. 23
B. Hydrocarboxylation of alkynes 25
1.2.3. Direct carboxylation of alkynes 27
A. Carboxylative coupling of alkynes and alkyl halide. 27
B. Direct carboxylation of terminal alkynes. 29
1.2.4. Summary 32
1.3. References 33
Chapter 2. Pd-catalyzed polymerization of CO and olefins. 36
2.1. Introduction 36
2.2. Development of process for synthesizing antifouling polyketones. 39
2.2.1. Result and discussion. 39
A. Synthesis of polyketones using HMON-SO3H, 1.8μm-SiO2-SO3H and PS-SO3H as co-catalyst 39
B. Plausible mechanism. 45
2.2.2. Conclusions. 46
2.3. Thermal property controlled polyketones: terpolymerization of ethylene, alkynes and CO. 47
2.3.1. Result and discussion 47
2.3.2. Conclusions 52
2.4. References 53
Chapter 3. Synthesis of various organic carbonates and carboxylic acids using CO2 54
3.1. Introduction 54
3.2. Synthesis of acyclic and cyclic carbonate using alcohols. 57
3.2.1. Result and discussion 57
3.2.2. Conclusions 63
3.3. Synthesis of Acyclic carbonate with CO2 derivative (Cs2CO3). 64
3.3.1. Result and discussion 64
3.3.2. Conclusions 68
3.4. Metal-free direct carboxylation of acetylene derivatives 69
3.4.1. Result and discussion 69
3.4.2. Conclusions. 73
3.5. References 74
Part 2. Experimental Section 76
Chapter 2. Pd-catalyzed polymerization of CO and olefins. 77
2.2. Development of process for synthesizing antifouling polyketones. 77
2.3. Thermal property controlled polyketones: terpolymerization of ethylene, alkynes and CO. 81
Chapter 3. Synthesis of various organic carbonates and carboxylic acids using CO2. 90
3.2. Synthesis of acyclic and cyclic carbonate using alcohols. 90
A. Synthesis of 14a 90
B. Synthesis of 18O-labeled 12a 91
3.3. Synthesis of Acyclic carbonate with CO2 derivative (Cs2CO3). 102
3.4. Metal-free direct carboxylation of acetylene derivatives 106DoctoralGreenhouse gas (GHG) generated in the use of fossil fuels that is not consumed naturally in the atmosphere and caused by the human race has resulted in global warming. GHGs generally include carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), nitrogen dioxide (NO2), hydrofluorocarbons (HFCS), and perfluorocarbons (PFC), etc. The utilization of C1 gas like carbon monoxide, carbon dioxide, and, methane as chemical feedstock can be the solution to global warming. I have presented the chemical conversion of CO and CO2 as a C1 source in this thesis.
In Chapter 1, the metal-catalyzed carbonyl/carboxylation of alkene and alkynes reaction have been reviewed overall. Typically, catalysts such as Pd, Ru, and Ni are known as an active catalyst for carbonylation. In particular, Pd catalysts have been successfully used for the synthesis of carboxylic acid and carboxylic acid esters from alkene and alkynes. Thus, in the first section of Chapter 1, I reviewed Pd-catalyzed carbonylation of alkenes and alkynes from CO. On the other hand, in the second section of Chapter 1, I reviewed the metal-catalyzed carboxylation of alkene and alkyne from CO2. The carbonation of CO2 was different from the carbonylation of CO, with the reaction acting according to the metal catalysts acting on the reaction different from each other. The Ni catalyst mainly induces hydrocarbonylation and the Cu or Ag catalyst induces a direct coupling reaction.
In Chapter 2, a Pd catalyst was used to polymerize CO and ethylene. The co-polymers of CO and ethylene, called polyketone, can be used for the same industrial materials used in automotive and electronics as polymers with high impact strength, chemical resistance, flame retardancy, and so on. However, polyketones had the problem of having a "reactor fouling" (disturbed formation of some of the polymer particles attached to the reactor wall and the agitator) and a high melting point (over 250 oC). In this study, we have developed polyketones without reactor fouling by using sulfonated HMON, silica, and polystyrene as heterogonous catalysts. Terpolymerization was performed to add a phenyl acetylene derivative to reduce meting point.
In Chapter 3, the synthesis of the transition metal-free organic carbonates and carboxylic acid was carried out using a CO2 and CO2 derivative (Cs2CO3). The CO2 required vigorous reaction condition using an organometallic catalyst for activating CO2 due to its high thermo-dynamic and kinetic safety. In this research, we developed an environmentally-friendly CO2 activation process with a mild condition that uses a transition metal free method and uses CO2 as low pressure. We used TBD and DBU for CO2 activation and synthesized various organic carbonates by advancing CO2 direct coupling to alcohol. Also, carboxylic acid was synthesized through direct CO2 coupling to acetylene derivatives using TBD
YU NA JO
No full text학위논문(석사)--아주대학교 일반대학원 :의생명과학과,2015. 2위암 (Gastric cancer) 은 매년 전세계에서 암 사망률의 주요 원인 중 하나이다. 위암과 관련된 여러 가지 새로운 종양 유전자와 종양 억제 유전자를 찾는 것은 조기 진단과 표적 치료의 발전을 위해 도움이 될 수 있다. 그 중 Poly (ADP-ribose) polymerase1 (PARP1) 은 많은 암 종류에서 항암치료의 타겟으로 보고되어 왔으며 PARP1억제제를 이용한 임상시험이 다양한 암 종을 바탕으로 진행되었으며 현재까지 수행되고 있다. 하지만, PARP1을 저해하게 되면 종양 발달이 어떻게 억제가 되는지 충분히 설명되어지지 않고 있다. 따라서, 위암 세포를 이용하여 PARP1 저해제인 올라파립 (Olaparib) 뿐만 아니라 PARP1 siRNA를 가지고 PARP1의 저해가 암세포의 성장을 어떻게 조절하는지를 보여주었으며 PARP1저해에 의한 FOXO3의 발현 증가를 통해 종양을 억제하는 효과를 가져온다. 뿐만 아니라, 166개의 tumor stage-matched 위암 환자 샘플을 사용하여 PARP1과 FOXO3 발현을 조직 마이크로 어레이로 평가하였다. 다변량 분석을 통해 PARP1 및 FOXO3 의 발현 차이에 따른 생존 곡선을 비교한 결과, 전체 생존 기간 (overall survival, PARP1; P = 0.021, FOXO3; P = 0.001) 및 무 재발 생존 기간 (relapse-free survival, PARP1; P = 0.021, FOXO3; P = 0.001) 의 영향을 주는 요인으로써 암의 독립적인 예후 지표로 활용 가능하다는 것을 확인하였다. 결론적으로, 우리의 결과는 PARP1- FOXO3 신호는 임상적인 의미와 암세포의 성장에 중요한 역할을 한다는 것을 입증하였고, 이는 암 치료에 있어 PARP1-FOXO3신호는 새로운 메커니즘과 임상 통찰력을 제안 할 수 있다.차 례
국문요약 ⅰ
차례 ⅲ
그림 차례 ⅴ
표 차례 ⅵ
Ⅰ. 서론 1
Ⅱ. 재료 및 방법 7
A. 위암세포 배양 7
B. 약물처리 7
C. siRNA Transfection 8
D. MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylteteazolium bromide)assay 8
E. Cell counting 8
F. Colony forming assay 9
G. Western blotting 9
H. 환자 및 표본 10
I. Tissue microarray 11
J. RNA 분리 및 real-time PCR 12
K. 통계처리 13
Ⅲ. 결과 15
A. 위암 세포에서 PARP1의 억제의 세포 성장 억제 15
B. PAPR1의 억제는 FOXO3의 발현 유도 19
C. PARP1과 FOXO3의 발현과 위암 환자 임상결과 2 1
D. PARP1과 FOXO3 발현은 위암 환자의 생존율에 영향 32
Ⅳ. 고찰 38
Ⅴ. 결론 44
참고문헌 45
ABSTRACT 56Maste
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
FIGURE 1 in Freshwater ostracods (Crustacea) from Hainan Island, southern China, with description of a new species
No full textFIGURE 1. Locations of samples where ostracods were present on Hainan Island.Published as part of Ma, Shunxin & Yu, Na, 2020, Freshwater ostracods (Crustacea) from Hainan Island, southern China, with description of a new species, pp. 201-243 in Zootaxa 4767 (2) on page 202, DOI: 10.11646/zootaxa.4767.2.1, http://zenodo.org/record/377072
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
FIGURE 31. A in Freshwater ostracods (Crustacea) from Hainan Island, southern China, with description of a new species
No full textFIGURE 31. A, Microdarwinula zimmeri (Menzel, 1916). Female. ECNU20170411/HN40. A, A2. B–C, Vestalenula cornelia Smith et al., 2006. Female. ECNU20170417/HN41. B, adductor muscle scars; C, UR and P-abd. Scale bars: 100 μm.Published as part of Ma, Shunxin & Yu, Na, 2020, Freshwater ostracods (Crustacea) from Hainan Island, southern China, with description of a new species, pp. 201-243 in Zootaxa 4767 (2) on page 234, DOI: 10.11646/zootaxa.4767.2.1, http://zenodo.org/record/377072
- …
