Comparison of PM2.5 in Seoul, Korea Estimated from the Various Ground-Based and Satellite AOD

Based on multiple linear regression (MLR) models, we estimated the PM2.5 at Seoul using a number of aerosol optical depth (AOD) values obtained from ground-based and satellite remote sensing observations. To construct the MLR model, we consider various parameters related to the ambient meteorology and air quality. In general, all AOD values resulted in the high quality of PM2.5 estimation through the MLR method: mostly correlation coefficients >~0.8. Among various polar-orbit satellite AODs, AOD values from the MODIS measurement contribute to better PM2.5 estimation. We also found that the quality of estimated PM2.5 shows some seasonal variation; the estimated PM2.5 values consistently have the highest correlation with in situ PM2.5 in autumn, but are not well established in winter, probably due to the difficulty of AOD retrieval in the winter condition. MLR modeling using spectral AOD values from the ground-based measurements revealed that the accuracy of PM2.5 estimation does not depend on the selected wavelength. Although all AOD values used in this study resulted in a reasonable accuracy range of PM2.5 estimation, our analyses of the difference in estimated PM2.5 reveal the importance of utilizing the proper AOD for the best quality of PM2.5 estimation

New Era of Air Quality Monitoring from Space: Geostationary Environment Monitoring Spectrometer (GEMS)

GEMS will monitor air quality over Asia at unprecedented spatial and temporal resolution from GEO for the first time, providing column measurements of aerosol, ozone and their precursors (nitrogen dioxide, sulfur dioxide and formaldehyde). Geostationary Environment Monitoring Spectrometer (GEMS) is scheduled for launch in late 2019 - early 2020 to monitor Air Quality (AQ) at an unprecedented spatial and temporal resolution from a Geostationary Earth Orbit (GEO) for the first time. With the development of UV-visible spectrometers at sub-nm spectral resolution and sophisticated retrieval algorithms, estimates of the column amounts of atmospheric pollutants (O3, NO2, SO2, HCHO, CHOCHO and aerosols) can be obtained. To date, all the UV-visible satellite missions monitoring air quality have been in Low Earth orbit (LEO), allowing one to two observations per day. With UV-visible instruments on GEO platforms, the diurnal variations of these pollutants can now be determined. Details of the GEMS mission are presented, including instrumentation, scientific algorithms, predicted performance, and applications for air quality forecasts through data assimilation. GEMS will be onboard the GEO-KOMPSAT-2 satellite series, which also hosts the Advanced Meteorological Imager (AMI) and Geostationary Ocean Color Imager (GOCI)-2. These three instruments will provide synergistic science products to better understand air quality, meteorology, the long-range transport of air pollutants, emission source distributions, and chemical processes. Faster sampling rates at higher spatial resolution will increase the probability of finding cloud-free pixels, leading to more observations of aerosols and trace gases than is possible from LEO. GEMS will be joined by NASA's TEMPO and ESA's Sentinel-4 to form a GEO AQ satellite constellation in early 2020s, coordinated by the Committee on Earth Observation Satellites (CEOS)

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

High surface area BaZrO3 photocatalyst prepared by base-hot-water treatment

Barium zirconate (BaZrO3) nanoparticles have been prepared by modified sol–gel route. Low temperature process of base-hot-water treatment (BHWT) was conducted to obtain high surface area BaZrO3. The treatments were carried out at 90 °C and at pH 14 with various concentrations of NaOH solution. Single phase nanocrystalline perovskite structure of BaZrO3 powders was successfully obtained by immersing the BaZrO3 precursor into hot-basic condition of 1 M NaOH solution for 1 h and consecutively calcined at 1000 °C for 2 h. BaZrO3 powders with BHWT showed surface area of 18.4 m2/g which is nearly 8 times larger than those of the powders without BHWT. Photocatalytic activities of BaZrO3 powders upon bleaching of methylene blue in an aqueous solution under UV light irradiation were enhanced by the increment of their surface area

High surface area BaZrO3 photocatalyst prepared by base-hot-water treatment

Barium zirconate (BaZrO3) nanoparticles have been prepared by modified sol–gel route. Low temperature process of base-hot-water treatment (BHWT) was conducted to obtain high surface area BaZrO3. The treatments were carried out at 90 °C and at pH 14 with various concentrations of NaOH solution. Single phase nanocrystalline perovskite structure of BaZrO3 powders was successfully obtained by immersing the BaZrO3 precursor into hot-basic condition of 1 M NaOH solution for 1 h and consecutively calcined at 1000 °C for 2 h. BaZrO3 powders with BHWT showed surface area of 18.4 m2/g which is nearly 8 times larger than those of the powders without BHWT. Photocatalytic activities of BaZrO3 powders upon bleaching of methylene blue in an aqueous solution under UV light irradiation were enhanced by the increment of their surface area

Attachable micropseudocapacitors using highly swollen laser-induced-graphene electrodes

For powering wearable electronics, extensive research has been directed toward microscale flexible and stretchable energy-storage devices. Microsupercapacitors, though promising candidates, remain limited in terms of design flexibility, scalability, reusability, and compatibility with general substrates. This paper reports a high-performance sticker-type flexible microsupercapacitor using highly swollen reduced-graphene-oxide electrodes fabricated by an ultrashort-pulse laser to promote full active-site and durability of the electrodes. Our sticker-type flexible micropseudocapacitor provides a comparable volumetric energy density of 1.08 mWh cm−3 and 13 times higher volumetric power density of 83.5 mW cm−3 compared to conventional lithium thin-film batteries. Bio-inspired surface modifications are additionally applied to the reduced-graphene-oxide electrodes, which provides a six-fold increase (10.38 mF cm−2) of the areal capacitance. A 6 × 2 micropseudocapacitor array embedded in a sub-millimeter thin PDMS film adheres to safety goggles and successfully powers a μ-LED. The total capacitance of the array is maintained at ~97% of its original value after 200 repetitive attachments and detachments showing good durability. In addition, the sticker-type micropseudocapacitor array shows a stable performance under repeated deformation, and up to ~99% of capacitance retention after 200 bending cycles. This novel re-attachable flexible micropseudocapacitor will expedite the widespread use of flexible and wearable devices.National Research Foundation (NRF)Accepted versionThis work was supported by the Research and Development Program of the Korea Institute of Energy Research (KIER) [grant number B9-2461-02, B9-2434-01, B9-2434-03) (to H. Y.); and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2018R1C1B5085456) (to Y. C.). Y.-J. Kim acknowledges financial support by an NRF Fellowship (NRF-NRFF2015-02) from the Singapore National Research Foundation and by a research collaboration agreement by Panasonic Factory Solutions Asia Pacific (PFSAP) and Singapore Centre for 3D Printing (RCA-15/027). S. K. acknowledges financial support from the Creative Materials Discovery Program (NRF-2017M3D1A1039287) and the Basic Research Lab Program (NRF-2018R1A4A1025623) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning

5-aminosalicylic acid suppresses osteoarthritis through the OSCAR-PPARγ axis

Abstract Osteoarthritis (OA) is a progressive and irreversible degenerative joint disease that is characterized by cartilage destruction, osteophyte formation, subchondral bone remodeling, and synovitis. Despite affecting millions of patients, effective and safe disease-modifying osteoarthritis drugs are lacking. Here we reveal an unexpected role for the small molecule 5-aminosalicylic acid (5-ASA), which is used as an anti-inflammatory drug in ulcerative colitis. We show that 5-ASA competes with extracellular-matrix collagen-II to bind to osteoclast-associated receptor (OSCAR) on chondrocytes. Intra-articular 5-ASA injections ameliorate OA generated by surgery-induced medial-meniscus destabilization in male mice. Significantly, this effect is also observed when 5-ASA was administered well after OA onset. Moreover, mice with DMM-induced OA that are treated with 5-ASA at weeks 8–11 and sacrificed at week 12 have thicker cartilage than untreated mice that were sacrificed at week 8. Mechanistically, 5-ASA reverses OSCAR-mediated transcriptional repression of PPARγ in articular chondrocytes, thereby suppressing COX-2-related inflammation. It also improves chondrogenesis, strongly downregulates ECM catabolism, and promotes ECM anabolism. Our results suggest that 5-ASA could serve as a DMOAD

Potential neuron-autonomous Purkinje cell degeneration by 2 ',3 '-cyclic nucleotide 3 '-phosphodiesterase promoter/Cre-mediated autophagy impairments

Studies of neuroglial interaction largely depend on cell-specific gene knockout (KO) experiments using Cre recombinase. However, genes known as glial-specific genes have recently been reported to be expressed in neuroglial stem cells, leading to the possibility that a glia-specific Cre driver results in unwanted gene deletion in neurons, which may affect sound interpretation. 2 ',3 '-Cyclic nucleotide 3 '-phosphodiesterase (CNP) is generally considered to be an oligodendrocyte (OL) marker. Accordingly, Cnp promoter-controlled Cre recombinase has been used to create OL-specific gene targeting mice. However, in this study, using Rosa26-tdTomato-reporter/Cnp-Cre mice, we found that many forebrain neurons and cerebellar Purkinje neurons belong to the lineages of Cnp-expressing neuroglial stem cells. To answer whether gene targeting by Cnp-Cre can induce neuron-autonomous defects, we conditionally deleted an essential autophagy gene, Atg7, in Cnp-Cre mice. The Cnp-Cre-mediated Atg7 KO mice showed extensive p62 inclusion in neurons, including cerebellar Purkinje neurons with extensive neurodegeneration. Furthermore, neuronal areas showing p62 inclusion in Cnp-Cre-mediated Atg7 KO mice overlapped with the neuronal lineage of Cnp-expressing neuroglial stem cells. Moreover, Cnp-Cre-mediated Atg7-KO mice did not develop critical defects in myelination. Our results demonstrate that a large population of central neurons are derived from Cnp-expressing neuroglial stem cells; thus, conditional gene targeting using the Cnp promoter, which is known to be OL-specific, can induce neuron-autonomous phenotypes.N