구리 촉매를 이용한 설폰아마이드 C(sp3)‒N 결합 형성과 장파장 영역의 밝은 형광을 내는 2-피리돈 형광체 발견

학위논문(박사) -- 서울대학교대학원 : 자연과학대학 화학부, 2024. 2. 이연.Development of Synthetic Strategies for Tertiary Sulfonamide C(sp3)−N Bond via Copper-Catalyzed Cross-Coupling and 2-Pyridone Fluorophores with Bright Emission at Long Wavelengths This thesis describes my research about development of new organic synthesis and development of new molecules. I newly developed new C(sp3)‒N bond methodology under copper catalysis and further utilized organic reactions to synthesize new molecules, 2-pyridone fluorophores. Further, with these newly created 2-pyridone fluorophores, I observed the photophysical properties of the fluorophores for application. In Chapter I, I explain overall streamline for importance of synthetic methods for nitrogen containing molecules and introduce C(sp3)‒N bond methodology which I developed briefly for first part. Also, it includes the contents about synthesis of new 2-pyridone fluorophores. Chapter II delineates my effort to develop organic synthetic methodology: tertiary sulfonamide C(sp3)‒N bond formation under copper-catalyzed oxidative cross-coupling. In this study, I established new protocols for intramolecular and intermolecular C(sp3)‒N bond formation under Et3SiOH and NaIO4 additives for each reaction. Using the developed protocols, I assessed 24 examples successfully using intramolecular reaction and 20 examples using intermolecular reaction. In Chapter III, I focus on the approaches toward the design of new 2-Pyrdone fluorophores via utilizing organic reactions. Newly synthesized 2-Pyridone fluorophores have each own photophysical properties. 8b (Cy- NMe3Ph4COOMe), first newly synthesized 2-Pyridone fluorophore has strong fluorescence emission property (ɸF = 88%) with 433 nm wavelength emission. To overcome the short wavelength emission, I synthesized 2- Pyridone fluorophore, 10a (3COOEt4COOMe6NMe2Ph) that has also strong fluorescence emission property (ɸF = 74%) and 539 nm emission wavelength. Keyword: Tertiary sulfonamide, C(sp3)‒N bond, Fluorescence probe, Bright, Long-wavelength Emission.본 연구는 유기합성법을 이용한 나의 연구를 기술한다. 구리 촉매 하 산화적 교차결합을 이용해 새로운 C(sp3)‒N 결합 형성 반응을 개발하였고, 나아가 다양한 유기합성 반응을 이용하여 새로운 물질인 2-피리돈 형광체를 합성하였다. 또한, 합성한 2-피리돈 형광체의 광물리학적 특성을 관찰하였다. 제 1 장에서는 질소원자를 포함하는 분자들의 중요성과, 이를 위한 합성방법, 그리고 개발한 C(sp3)‒N 결합에 대한 전반적인 설명을 하고 있다. 또한, 유기합성 방법을 통해 합성한 새로운 2-피리돈 형광체에 대해서도 간략히 소개하고 있다. 제 2 장에서는 개발한구리 촉매 하 산화적 교차결합을 이용한 설폰아마이드 C(sp3)‒N 결합 형성 을 주제로 한 유기합성방법론 설명에 중점을 두고 있다. 이 연구에서 C(sp3)‒N 결합 형성이 트리에틸실란올과 과요오드산나트륨 첨가물 하에서 각각 분자내, 그리고 분자간 C(sp3)‒N 결합 형성 반응이 일어난다는 것을 증명하였다. 또한 개발된 방법론은 분자 내 반응으로 24 개의 다양한 예시에 적용 가능하고, 분자 간 반응으로 20 개의 다양한 예시에 적용 가능함을 보였다. 제 3 장에서는 다양한 유기화학 반응을 이용하여 새로운 2-피리돈 형광체의 구조적 특징에 기반해 다양한 광물리학적 특성으로의 접근법을 설명하고 있다. 새로 합성한 8b 물질은, 433 nm 의 형광 파장을 보이는 물질로서, 88%의 양자수율을 가지고 있다. 또한 두번째로 합성한 10a 물질은 539 nm 의 장파장 영역에서 74%의 양자수율을 보였다. 큰 스토크스와 장파장 영역의 형광발광을 보이는 10a 분자는, 분자내 전하 전이 현상으로 인한 결과이고, 이 현상을 증명하기 위해 몇 가지 뒷받침 자료를 제시한다. 이 연구는 장파장에서 밝은 형광을 내는 물질을 어떻게 디자인할 수 있을지에 대한 전략을 설명하는 내용이다.Abstract 3 List of Figures 8 List of Schemes 9 List of Tables 10 Chapter 1. Introduction Introduction 12 Chapter 2. Formation of the Tertiary Sulfonamide C(sp3)−N bond using alkyl boronic ester via intramolecular and intermolecular copper-catalyzed oxidative cross-coupling 2.1 Introduction 18 2.2 Result and Discussion 20 2.2.1 Intramolecular reaction 20 I) Synthesis II) Optimization of reaction conditions III) Substrate scope 2.2.2 Intermolecular reaction 31 I) Synthesis II) Optimization of reaction conditions III) Substrate scope 2.3 The role of Et3SiOH and NaIO4 37 2.4 Conclusion 37 2.5 Experimetal section 37 2.5.1 Materials 38 2.5.2 Synthesis 38 Chapter 3. Design of 2-Pyridone Fluorophores for Brighter Emissions at Longer wavelengths 3.1 Introduction 50 3.2 Result and Discussion 51 3.3 Conclusion 81 3.4 Experimental section 81 3.4.1 Materials 82 3.4.2 Synthesis 83 3.4.3 DFT calcualtion 90 3.5 X-ray Crystallographic Analysis 91 Reference 94 Appendix (NMR spectra) 110 국문초록 261박

Temporal and spatial variatins of particle fluxes in the western Arctic Ocean

We examine the particle fluxes and composition of sinking particle collected at two sites in the western Arctic Ocean: East Siberian Sea and Chukchi Sea. Time-series sediment traps had been deployed at 320 m water for one year from August 2017 to July 2018. In the Chukchi sea, sinking particle fluxes showed a clear seasonal variation with high values in summer and low values in other seasons. Total mass flux displayed the maximum value (337 mg m-2 day-1) in August 2017. Annual mass flux was estimated to be 36.2 g m-2. Biogenic opal was a major component of sinking particles, comprising 45.7%. Lithogenic material was a second major component, comprising 34.8%. Organic carbon and CaCO3 comprise 7.3% and 2.0%, respectively. In the East Siberian sea, sinking particle fluxes also showed a clear seasonal variation with high values in summer and low values in other seasons, but high particle fluxes were not observed in August 2017. Total mass flux displayed the maximum value (475 mg m-2 day-1) in July 2018. Annual mass flux was estimated to be 30.0 g m-2, which a little lower than that in Chukchi Sea. Lithogenic material was a major component of sinking particles, comprising 58.1%. Biogenic opal was a second major component, comprising 23.0%. Organic carbon and CaCO3 comprise 6.8% and 2.5%, respectively.1

실화 발생 선행 지표와 조건부 감시 방법을 이용한 ECU 계산량 감소 방안 및 실차 적용에 대한 연구

학위논문(석사)--서울대학교 대학원 :전기·컴퓨터공학부,2004.Maste

Seasonal variations of calcium carbonate saturation states in Kwaungyang Bay, South Korea

In winter, some of the surface and bottom waters were undersaturated with respect to aragonite; the lower aragonite saturation state (&#61527;arag) values (<1.0) were observed at 3 stations at the surface waters and 1 station at the bottom waters. However, the surface and bottom waters were supersaturated with respect to calcite. In spring, some of the surface waters were also undersaturated with respect to aragonite and calcite; the lower &#61527;arag values (<1.0) were observed at 11 stations among 19 stations, and the lower &#61527;cal values (<1.0) were found at 4 stations. At the surface waters, &#61527;arag values were lowest at the mouth of the Seomjin River and increased toward offshore. Surface salinity was significantly reduced to 1.94 at the mouth of the Seomjin River. Heavy precipitation had occurred just before the survey, which might bring large amounts of freshwaters into Kwaungyang Bay through the Seomjin River.tom waters. However, the surface and bottom waters were supersaturated with respect to calcite. In spring, some of the surface waters were also undersaturated with respect to aragonite and calcite; the lower &#61527;arag values (<1.0) were observed at 11 stations among 19 stations, and the lower &#61527;cal values (<1.0) were found at 4 stations. At the surface waters, &#61527;arag values were lowest at the mouth of the Seomjin River and increased toward offshore. Surface salinity was significantly reduced to 1.94 at the mouth of the Seomjin River. Heavy precipitation had occurred just before the survey, which might bring large amounts of freshwaters into Kwaungyang Bay through the Seomjin River.1

Biologically mediated seasonalinity of aragonite saturation states in Jinhae Bay, Korea

Aragonite saturation states (&#61527 arag) were estimated for the surface and bottom waters of Jinhae Bay over four seasons to assess the major factors controlling the &#61527 arag. The surface and bottom waters of Jinhae Bay were highly supersaturated with respect to aragonite in spring, autumn, and winter. In summer, however, most of the bottom waters are undersaturated with respect to aragonite during summer, even though the surface waters are supersaturated with respect to aragonite. This phenomenon can be explained by the phytoplankton-carbonate saturation state interaction high primary production increases the &#61527 arag in surface waters, while vertical export and subsequent remineralization of organic matter decreases the &#61527 arag in subsurface waters. The strong linear correlation between the &#61527 arag values and dissolved oxygen (DO) concentrations supports that the biological activity is a major factor controlling the &#61527 arag in Jinhae Bay. The ocean acidification induced by the invasion of anthropogenic CO2 also affects considerably the aragonite saturation state in all seasons, particularly in winter when the &#61527 arag values have reduced since the pre-industrial era by 32~35% at the surface waters and 33~37% at the bottom waters. In Jinhae Bay, the undersaturation with respect to aragonite in summer may have large impacts on the calcifying benthic organisms mussel calcification may bepersaturated with respect to aragonite in spring, autumn, and winter. In summer, however, most of the bottom waters are undersaturated with respect to aragonite during summer, even though the surface waters are supersaturated with respect to aragonite. This phenomenon can be explained by the phytoplankton-carbonate saturation state interaction high primary production increases the &#61527 arag in surface waters, while vertical export and subsequent remineralization of organic matter decreases the &#61527 arag in subsurface waters. The strong linear correlation between the &#61527 arag values and dissolved oxygen (DO) concentrations supports that the biological activity is a major factor controlling the &#61527 arag in Jinhae Bay. The ocean acidification induced by the invasion of anthropogenic CO2 also affects considerably the aragonite saturation state in all seasons, particularly in winter when the &#61527 arag values have reduced since the pre-industrial era by 32~35% at the surface waters and 33~37% at the bottom waters. In Jinhae Bay, the undersaturation with respect to aragonite in summer may have large impacts on the calcifying benthic organisms mussel calcification may be1

Seasonal and interannual variations of nutrient and chlorophyll-a concentrations in the northern East China Sea

Nutrients, chlorophyll-a (Chl-a), and environmental conditions were extensively investigated in the northern East China Sea (ECS) during seven research cruises from 2003 to 2009. In the eastern part of the study area, surface waters were characterized only by the Tsushima Current Water (TCW) during all cruises. However, the western surface waters changed with season and were characterized by Yellow Sea Cold Water (YSCW) in spring, Changjiang Diluted Water (CDW) in summer, and Yellow Sea Mixed Water (YSMW) in autumn and winter. In spring, autumn, and winter, relatively high concentrations of nitrate and phosphate were observed in the surface waters in the western part of the study area, where vertical mixing brought large supplies of nutrients from deep waters. In summer, however, nutrients were completely depleted in the surface waters due to strong stratification. Changes in wind direction occasionally varied the inflow of the Changjiang plume in summer, clearly causing the annual variation in surface nitrate and phosphate concentrations in summer. In summer, the surface distribution of nitrate and phosphate did not coincide with that of silicate in the study area, which probably resulted from the significant drop in the Si:N ratio in the Changjiang plume since construction of the Three Gorges Dam (TGD). Despite large temporal and spatial variations in surface Chl-a concentrations, depth-integrated Chl-a concentrations exhibited little variation temporally and spatially. In the study area, surface Chl-a concentration did not well reflect the standing stocks of phytoplankton. The vertical distribution of Chl-a showed large temporal and spatial variations, and the main factor controlling the vertical distribution of Chl-a in summer was the availability of nitrate. The thermohaline Front may play an important role for accumulation of phytoplankton biomass in spring and autumn.1

A study for the development of DICOM toolkit software

의공학과/박사[한글]DICOM은 디지털 의료 영상 장비간의 통신을 위한 표준이며 DICOM 툴킷은 이러한 표준을 구현한 소프트웨어로서 의료 영상과 관련된 제품을 개발할 때 필수적인 요소이다. 기존의 툴킷들은 다음과 같은 문제점들을 가지고 있다. 1) DICOM 관련 기능만을 제공하므로 영상 출력 및 처리와 관련된 부분은 별도로 구현해야 한다. 영상 부분까지 통합된 툴킷도 있지만 의료 영상과 관련된 기능은 제공하지 않는다. 2) 유닉스를 주 기반으로 개발된 후에 윈도우즈용으로 이식된다. 이는 윈도우즈를 주로 하는 병원 환경에서 최상의 성능을 발휘할 수 없다. 3) 속도가 느리거나 메모리 소모가 심하다. 이것은 대량의 영상을 처리해야 하는 병원 환경에 적합하지 않다. 4) 툴킷의 구조가 매우 복잡하다. 이것은 DICOM의 방대함에 기인하며 효율적인 구조가 필요하다 본 논문에서는 기존 툴킷의 단점을 보완한 다음과 같은 특징을 갖는 DICOM 툴킷을 구현하였다. 1) DICOM 관련 기능과 영상 관련 기능을 모두 구현하였으며 추가로 의료 영상 관련 기능들을 구현하였다. 2) 범용 컴퓨터를 주로 사용하는 병원 환경에 적합하도록 윈도우즈 운영체제를 기반으로 하였다. 3) 빠른 영상 출력 속도를 보장하며 물리적 메모리를 거의 사용하지 않도록 설계하였다. 4) 의료 영상 저장 시스템 등의 환경에서 필요한 대부분의 의료 영상 관련 기능이 포함되어 있으며 복잡성을 줄이기 위해 객체 지향적인 구조로 설계하였다. 구현된 툴킷은 다양한 모달리티와 장비회사들에서 생성된 120장의 영상에 대해 테스트한 결과 모든 영상들을 12초 이내에 출력하였으며 메모리를 거의 소모하지 않았다. 그리고 제안된 툴킷으로 의료 영상 저장 시스템 뷰어, 디지털 투시 촬영 장비 콘솔, 전산화 단층 촬영 장비 콘솔 및 디지털 검안기용 영상 관리 시스템 등에 성공적으로 사용되었다. [영문]Digital Imaging and Communications in Medicine (DICOM) is the standard among the digital medical imaging systems. DICOM toolkit is the software to implement DICOM. It is essential to develop any digital medical imaging systems. Commonly accepted toolkits have following obstacles. 1)Since they only support functions for DICOM, developers have to implement the image processing and display related functions by themselves. Some toolkits provide those funtions, but they are not suitable for medical images. 2) Since toolkits are designed and implemented at UNIX, when it is used hospitals which are using the Windows for their PACS, the ported code can not play the best performances. 3) The processing time of the conventional toolkits are slow and the memory requirement is too high. So it is not adequate for the hospital environment that handles mass image data. 4) Since toolkit structure is too complicated, which are mainly due to the complexity of DICOM, we need to develop highly efficient structure for DICOM. In this paper, the developed toolkit has solved the problems in the conventional DICOM toolkits and has following features. 1) It provides not only DICOM and image related functions but also supports medical image specialized functions. 2) It is designed to do best performances at Microsoft Windows which is currently becoming major operating system in hospital computer environment. 3) It guarantees high image processing and display speed and uses less physical memory. 4) It is designed as object oriented structure for the simplification of the structure of DICOM complexity and supports most of functions needed at PACS environment. The developed toolkit took 12 seconds to display 120 images which are collected from different modalities and manufacturers. And the developed DICOM used less physical memory space than others. And the developed DICOM has been successfully applied for the following image modalities such as PACS viewing system, Digital Fluoroscopy, Console of Computed Tomography and the Digital Slit Lamp system.ope

Reduced efficiency of biological pump in the Northwestern Pacific

The western Pacific warm pool (WPWP) area has recently extended, which may influence considerably the marine ecosystems in the tropical Pacific. Here, we show the long-term trends in particle fluxes associated with the marine ecosystem changes in WPWP area. Total mass and biogenic fluxes have an annually decreasing trend from 2009 to 2014, which is mainly derived by the decrease in the biomass of N2 fixing cyanobacteria during summer. In the western tropical Pacific, the decrease in the biomass of N2 fixing cyanobacteria is attributed to the decrease of phosphate concentration associated with the shoaling of the winter mixed layer depth. The efficiency of biological pump has recently reduced in the western tropical Pacific, which might suppress the oceanic sequestration of atmospheric CO2 and thereby accelerate the global warming in the future.1

Seasonal and annual variations of particle fluxes in the northwestern Pacific

A moored time-series sediment trap was deployed at station FM 1 (13o31’N 136 o 03’E) of the northwestern Pacific from October 2007 to May 2011. Total mass fluxes varied from 2.35 to 31.1 mg m-2 day-1, showing a distinct seasonal variation with high fluxes in winter and low in summer. During the El Nino period, however, total mass fluxes were significantly reduced in winter, indicating that particle fluxes in the northwestern Pacific were considerably influenced by the El Nino. Organic carbon fluxes ranged from 0.13 to 4.61 mg m-2 day-1, comprising about 9.7% of total mass fluxes. Organic carbon fluxes showed a large annual variation, with higher fluxes in 2008. CaCO3 fluxes varied from 1.47 to 23.4 mg m-2 day-1, comprising 65.7% of total mass fluxes. CaCO3 fluxes displayed little annual and seasonal variations. Biogenic Si fluxes ranged from 0.04 to 2.07 mg m-2 day-1, comprising about 5.3% of total mass fluxes. Biogenic Si fluxes exhibited a large annual variation, with higher fluxes in 2008. Temporal variations of organic carbon fluxes were rather similar to those of biogenic Si fluxes, implying that the source of organic carbon is siliceous organisms. with high fluxes in winter and low in summer. During the El Nino period, however, total mass fluxes were significantly reduced in winter, indicating that particle fluxes in the northwestern Pacific were considerably influenced by the El Nino. Organic carbon fluxes ranged from 0.13 to 4.61 mg m-2 day-1, comprising about 9.7% of total mass fluxes. Organic carbon fluxes showed a large annual variation, with higher fluxes in 2008. CaCO3 fluxes varied from 1.47 to 23.4 mg m-2 day-1, comprising 65.7% of total mass fluxes. CaCO3 fluxes displayed little annual and seasonal variations. Biogenic Si fluxes ranged from 0.04 to 2.07 mg m-2 day-1, comprising about 5.3% of total mass fluxes. Biogenic Si fluxes exhibited a large annual variation, with higher fluxes in 2008. Temporal variations of organic carbon fluxes were rather similar to those of biogenic Si fluxes, implying that the source of organic carbon is siliceous organisms.1

Temporal and spaitial variation of particle fluxes in the Northwestern Pacific

2