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Dynamic genetic features of eukaryotic plankton diversity in the Nakdong River estuary of Korea

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Chinese Journal of Oceanology and Limnology 2017年第4期35卷 844-857页

作者： lee Jee Eun CHUNG Ik Kyo lee sang-Rae Division of Earth Environmental System Oceanography Major Pusan National University Marine Research Institute Pusan National University

Estuaries are environments where freshwater and seawater mix and they display various salinity *** construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton *** understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton *** evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in *** samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that *** the 18 S rDNA allowed us to analyze 456 clones and 122 *** sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific *** analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in *** variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater *** phylotypes accounted for the highest proportion of overall diversity in the seawater *** diatoms and dinoflagellates were observed in the freshwater,brackish and seawater *** biological data for species composition demonstrate the transitional state between freshwater and ***,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.

关键词： 18S rDNA clone library metagenome estuary salinity gradient

Estimation of Turbulent Sensible Heat and Momentum Fluxes over a Heterogeneous Urban Area Using a Large Aperture Scintillometer

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Advances in Atmospheric Sciences 2015年第8期32卷 1092-1105页

作者： sang-Hyun lee Jun-Ho lee Bo-Young KIM Department of Atmospheric Science Kongju National University Department of Optical Engineering Kongju National University

The accurate determination of surface-layer turbulent fluxes over urban areas is critical to understanding urban boundary layer （UBL） evolution. In this study, a remote-sensing technique using a large aperture scintillometer （LAS） was investigated to estimate surface-layer turbulent fluxes over a highly heterogeneous urban area. The LAS system, with an optical path length of 2.1 km, was deployed in an urban area characterized by a complicated land-use mix （residential houses, water body, bare ground, etc.）. The turbulent sensible heat （QH） and momentum fluxes （z） were estimated from the scintillation measurements obtained from the LAS system during the cold season. Three-dimensional LAS footprint modeling was introduced to identify the source areas （＂footprint＂） of the estimated turbulent fluxes. The analysis results showed that the LAS-derived turbulent fluxes for the highly heterogeneous urban area revealed reasonable temporal variation during daytime on clear days, in comparison to the land-surface process-resolving numerical modeling. A series of sensitivity tests indicated that the overall uncertainty in the LAS-derived daytime QH was within 20%-30% in terms of the influence of input parameters and the non- dimensional similarity function for the temperature structure function parameter, while the estimation errors in z were less sensitive to the factors of influence, except aerodynamic roughness length. The 3D LAS footprint modeling characterized the source areas of the LAS-derived turbulent fluxes in the heterogeneous urban area, revealing that the representative spatial scales of the LAS system deployed with the 2.1 km optical path distance ranged from 0.2 to 2 km2 （a ＂micro-a scale＂）, depending on local meteorological conditions.

关键词： heterogeneous surface large aperture scintillometer mesoscale modeling surface energy balance turbulentexchange

Effects of 60 Hz electromagnetic field exposure on testiculargerm cell apoptosis in mice

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Asian Journal of Andrology 2004年第1期6卷 29-34页

作者： Jin sang lee sang Seok Ahn Kyeong Cheon Jung Yoon-Won Kim sang Kon lee Institute of Medical Science Hallym University School of Medicine Chunchon 200-060 Korea Department of Urology Hallym University School of Medicine Chunchon 200-060 Korea Department of Pathology Hallym University School of Medicine Chunchon 200-060 Korea Department of Microbiology Hallym University School of Medicine Chunchon 200-060 Korea

Aim: To evaluate the effects of 60 Hz extremely low frequency (ELF) elelctromagnetic field (EMF) exposure on germ cell apoptosis in the testis of mice. Methods: Adult male BALB/c mice (7 weeks of age) were exposed to a 60 Hz EMF of 0.1 mT or 0.5 mT for 24 h/day. A sham-exposed group served as the control. After 8 weeks of exposure, the mice were sacrificed. Germ cell apoptosis in the testis was assessed by histopathological examination, the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) and flow cytometric examination of isolated spermatogenic cells stained with 7 aminoactinomycin D (7-AAD). Results: EMF exposure did not significantly affect the body and testis weights, but significantly increased the incidence of germ cell death. The distinguishing morphological feature of EMF exposure was a decrement in the number of well organized seminiferous tubules. Quantitative analysis of TUNEL-positive germ cells showed a significantly higher apoptotic rate in the 0.5 mT exposed mice than that in the sham controls (P<0.05), while the difference between the two exposed groups was insignificant. The TUNEL-positive cells were mainly spermatogonia. In flow cytometry analysis, the percentage of live cells [forward scatter count (FSC)high7-AAD-] was lower in the exposed groups than that in the controls (Figure 5A), but the decrease in viability was not statistically significant. Conclusion: Continuous exposure to ELF EMF may induce testicular germ cell apoptosis in mice.

关键词： electromagnetic field testis apoptosis TUNEL flow cytometry 7-aminoactinomycin D

Successful treatment of a high-risk nonseminomatous germ cell tumor using etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine: A case report

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World Journal of Clinical Cases 2020年第21期8卷 5334-5340页

作者： Jina yun sang W lee Sung H Lim Se H Kim Chan K Kim Seong K Park Department of Internal Medicine Division of Hematology-OncologySoonchunhyang University Bucheon HospitalSoonchunhyang University School of MedicineBucheon 14584South Korea Department of Urology and Internal Medicine Soonchunhyang University Bucheon HospitalSoonchunhyang University School of MedicineBucheon 14584South Korea

BACKGROUND Choriocarcinoma is an infrequent entity and the most aggressive subtype of germcell *** of early metastatic spread and rapid disease progression,choriocarcinoma patients display poor *** etoposide,methotrexate,actinomycin D,cyclophosphamide,and vincristine(EMA-CO)regimen is widely used to treat gestational trophoblastic tumors in females,its role in treating male choriocarcinoma is seldom *** SUMMARY A 32-year-old man was diagnosed with burned-out primary germ cell tumors(GCT)with retroperitoneum,liver and lung *** of the liver revealed pure *** patient received bleomycin,etoposide,and cisplatin *** two cycles of treatment,response evaluation revealed the mixed ***-CO regimen was used in the second-line *** eight cycles,the patient showed a potentially resectable state and thus,all residual masses were surgically *** patient was completely cured,and 10 years later,he is leading a healthy life without *** This paper is the first case of high-risk nonseminomatous GCT in a male patient to be successfully treated with the EMA-CO *** EMA-CO regimen can be used actively in patients with high-risk nonseminomatous GCT.

关键词： Antineoplastic combined chemotherapy protocols Choriocarcinoma Testicular neoplasms Cyclophosphamide Methotrexate Case report

Significant control of metal-insulator transition temperature through catalytic excessive oxygen doping in high-performance vanadium dioxide nanobeam channel

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Journal of Materials Science & Technology 2020年第9期44卷 96-101页

作者： Minhwan Ko sang Yeon lee Jucheol Park Hyungtak Seo Department of Energy Systems Research Ajou UniversitySuwon16499Republic of Korea Gyeongbuk Science Technology Promotion Center Gumi Electronics&Information Technology Research InstituteGumi39717Republic of Korea Department of Materials Science and Engineering Ajou UniversitySuwon16499Republic of Korea

The strategy of a reliable transition temperature control of vanadium dioxide(VO2)is *** VO2 nanobeams were synthesized by a thermal chemical vapor deposition(TCVD)*** metal-insulator transition(MIT)temperature increases to above 380K when the TiO2 ratio of the source is 5 at.%,although the Ti source is not physically doped into VO2 *** XPS spectra of the V 2p orbital reveal the excessive oxidation of V after the TCVD processes with a higher TiO2 ratio,indicating that the TiO2 precursor is important in the O-doping of the surface V O bonds when forming volatile Ti-O gas ***,TiO2 reactants can be used as a VO2 surface chemical modifier to manipulate the MIT transition temperature and maintain a homogenous VO2 phase,which is useful for a Mott device application with a record on/off switching ratio>104 and Mott transition temperature>380 K.

关键词： VO2 Mott transition Metal-insulator transition temperature Oxygen doping Titanium catalyst

DEM simulation and characterization of copper and iron powders fabricated by ball milling

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Particuology 2024年第11期94卷 96-108页

作者： Khulan Uranchimeg Battsetseg Jargalsaikhan lee sang Eui Heekyu Choi Graduate School of Material Science Engineering Changwon National UniversityChangwonGyoungnam641-773Republic of Korea Citi University Ulaanbaatar 14201Mongolia Department of Mechatronics Convergence Engineering College of Future ConvergenceChangwon National UniversityChangwonGyoungnam641-773Republic of Korea Graduate School of Convergence on Culture Technology Changwon National UniversityChangwonGyoungnam641-773Republic of Korea Research Institute of Future Convergence Changwon National UniversityChangwonGyoungnam641-773Republic of Korea

In this study,the particle morphology,and size changes in copper and iron powders were investigated by using a high-energy ball mill under the same experimental *** particle sizes and morphologies of the powders were examined using a particle size analyzer and scanning electron microscopy(SEM).We also used the discrete element method(DEM)to analyze the ball impaction and the shear energy during the ball milling *** was discovered that the quantity of milling balls and rotational speed had a major impact on energy dissipation through heat and plastic deformation as well as milling *** characteristic(particle morphology and size)of the iron and copper powder were differently changed under the same experimental conditions,shear energy,and ball *** the particle sizes of copper and iron powder were compared under the same experimental conditions,the copper particle size increased from 21.6μm to 280μm,resulting in particle agglomeration,while the iron powder particle size decreased from 154μm to 4.35μm.

关键词： Copper powder Iron powder Ball size Particle morphology Particle size

Stochastic rules for predator and prey hunting and escape behavior in a lattice-based model

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International Journal of Biomathematics 2016年第6期9卷 181-190页

作者： Wonju Jeon sang-Hee lee Department of Mechanical Engineering Korea Advanced Institute of Science and Technology Daejeon 34141 Republic of Korea Division of Integrated Mathematics National Institute for Mathematical Sciences Daejeon 34047 Republic of Korea

Understanding of ecosystem resilience and stability requires comprehending predator- prey dynamics because ecosystems consist of dynamically interacting subsystems that include predator-prey relationships. This relationship is closely related to the hunting- escaping strategies employed by the predator and prey. Therefore, understanding the effects of hunting and escaping strategies on ecosystems will lead to a better under- standing of these systems. As an approach for describing the predator-prey interaction, lattice-based models have been adopted because this approach has strong advantages for simulating various dynamical processes of individual-individual interaction. In the models, each lattice cell is either considered as an attractive/repulsive cell, or an indi- vidual cell, or else it is empty. The attractive （or repulsive cell） can be interpreted as the prey （or predator） of the individual. These states allow us to incorporate the ecological processes of local antagonistic interactions, namely the spread of disturbances （by the predator） and regrowth or recovery （by the prey）. These processes are directly related to the strategic behavior of individuals, such as hunting and escaping. In this study, we suggest a simple and effective mapping formula as a stochastic rule to describe the hunt- ing and escaping behavior. This formula could be widely used not only in the behavior but also in competitive and cooperative relationships.

关键词： Hunting and escaping behavior strategic behavior predator-prey interaction individual-based model.

Development of Precise Geoid Model for the Establishment of Consistent Height System in Geoga Grand Bridge Construction Area

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China Ocean Engineering 2009年第4期23卷 679-694页

作者： Dong-Ha lee Hong-Sic yun Department of Civil Architectural and Environmental System EngineeringSungkyunkwan University

The national benchmarks on islands were mostly established by trigonometric leveling in Korea. This method results in inaccuracy, which is a serious problem in Geoga Grand Bridge construction work that tried to link the mainland and the islands. The Geoga Grand Bridge （Pusan-Geoje fixed link project） was selected as the study area, a huge construction work in Korea that will connect the mainland （Pnsan） and an island （Gecje island）. However, the orthometric heights issued at benchmarks （JINH and GOFJ） were not consistent, because they did not refer to the same zero point, which would make the linking of the sections problematic. This paper introduces the precise local geoidas a vertical datum for the construction area in order to establish a consistent height system. To determine the precise local geoid for the construction area, we firstly developed a precise gravimetric geoid for Korea and its adjoining seas as a whole. This gravimetric geoid was developed by use of all available gravity data, including surface and satellite data on land and on the ocean. The gravimetrie gecid was computed by spherical fast fourier transform with modified Stokes＇ kernels. The remove-restore technique was used to eliminate the terrain effects by use of the RTM reduction and to determine the residual geoid by combining the GGM02S/EGM96 geopotential model, free-air gravity anomalies and high-resolutinn DEM data. Finally, the gravimetric model was fitted to the geoid heights obtained from GPS and tide observations （Ncps/Tiae） by least square coUocatian, to provide the final GPS-consistent local precise geoid model. The post-fit error （std. dev. ） of the final geoid to the NetS/Tide derived from GPS and tide observations was ± 2.2 cm for the construction area. We solved the height inconsistency problem by calculating the orthometric height of the benchmarks and the cnntrol points using the final geoid model. Also, the highly accurate orthometric height was estimated through the GPS/lev

关键词： precise local geoid consistent height system gravity observations GPS! Tide observations least squares fitting

Prediction of Melt Pool Dimension and Residual Stress Evolution with Thermodynamically-Consistent Phase Field and Consolidation Models during Re-Melting Process of SLM

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Computers, Materials & Continua 2021年第1期66卷 87-112页

作者： Kang-Hyun lee Gun Jin yun Department of Aerospace Engineering Seoul National UniversitySeoul08826South Korea Institute of Advanced Aerospace Technology Seoul National UniversitySeoul08826South Korea

Re-melting process has been utilized to mitigate the residual stress level in the selective laser melting(SLM)process in recent ***,the complex consolidation mechanism of powder and the different material behavior after the first laser melting hinder the direct implementation of the re-melting *** this work,the effects of re-melting on the temperature and residual stress evolution in the SLM process are investigated using a thermo-mechanically coupled finite element *** degree of consolidation is incorporated in the energy balance equation based on the thermodynamically-consistent phase-field *** drastic change of material properties due to the variation of temperature and material state is also *** the proposed simulation framework,the single-track scanning is simulated first to predict the melt pool dimension and validate the proposed model with the existing experimental *** obtained thermal histories reveal that the highest cooling rate is observed at the end of the local solidification time which acts as an important indicator for the alleviation of temperature ***,the scanning of a whole single layer that consists of multiple tracks is simulated to observe the stress evolution with several re-melting *** the full melting of powder material in the first scanning process,the increase of residual stress level is observed with one remelting ***,the predicted stress level with the re-melting process shows the variation trend attributable to the accumulated heat in the *** numerical issues and the detailed implementation process are also introduced in this paper.

关键词： Selective laser melting thermo-mechanical analysis Ti-6Al-4V additive manufacturing re-melting residual stress