检索结果-南通市图书馆

^(27)Al MAS-NMR study of inorganic polymer formation at ambient temperature

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 182-187页

作者： Sang-wook AHN Hee-Soo lee Wan-Hee YANG Jung-woo lee young-Keun JEONG National Core Research Center for Hybrid Materials Solution Pusan National University School of Material Science and Engineering Pusan National University INTChem Co. Ltd.

Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and AI atoms to dissolve from a feedstock such as aluminosilicate. A study of 27A1 MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy （SEM） and X-ray diflYactometry （XRD） were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different A1/Si mole ratios from the starting materials. The higher the AI content, the more sufficient the AI atoms that can combine with SiO4, and the longer the reaction time, the more the bonded Si--O--A1--O polymer structure, and then the higher the A1 content, the fewer the octahedral A1 with a uniform Si--O--A1--O structure in four directions, because four AI atoms are combined with SiO4, resulting in a uniform Si--O--AI--O structure in four directions. The results show that they have an amorphous microstructure.

关键词： inorganic polymer amorphous tetrahedral

Development of EMC-based empirical model for estimating spatial distribution of pollutant loads and its application in rural areas of Korea

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2015年第9期27卷 1-11页

作者： Qitao Yi Hui Li Jin-woo lee youngchul Kim School of Earth and Environment Anhui University of Science and Technology Dowha Engineering Consulting Co.Ltd. Department of Environmental Engineering Hanseo University

An integrated approach to easily calculate pollutant loads from agricultural watersheds is suggested and verified in this research. The basic concepts of this empirical tool were based on the assumption that variations in event mean concentrations（EMCs） of pollutants from a given agricultural watershed during rainstorms were only attributable to the rainfall *** one sets of EMC values were obtained from nine different watersheds located in the rural areas of Korea, and these data were used to develop predictive tools for the EMCs in rainfall runoff. The results of statistical tests of these formulas show that they are fairly good in predicting actual EMC values of some parameters, and useful in terms of calculating pollutant loads for any rainfall event time span such as daily, weekly, monthly, and yearly. This model was further checked in for its field applicability in a reservoir receiving stormwater after a cleanup of the sediments, covering 17 consecutive rainfall events from 1 July to 15 August in2007. Overall the predicted values matched the observed values, indicating the feasibility of this empirical tool as a simple and useful solution in evaluating timely distribution of nonpoint source pollution loads from small rural watersheds of Korea.

关键词： EMC Empirical model Nonpoint source pollution Spatial distribution

Beach stabilization by the laying of a drainage layer

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2012年第9期55卷 2625-2639页

作者： HUR Dong-Soo lee woo-Dong CHO Won-Chul Department of Ocean Civil Engineering(Institute of Marine Industry) Gyeongsang National University445 Inpyeong-dongTongyeong 650-160Korea Department of Ocean Civil Engineering Gyeongsang National University445 Inpyeong-dongTongyeong 650-160Korea Department of Civil and Environmental Engineering Chung-Ang University221 Heuksuk-dong Dongjak-guSeoul 156-756Korea

In the present study, the stabilization effects of the laying of a drainage layer in a sandy beach were analyzed. The numerical model developed by Hur et al. （2011） was used to examine the characteristics of wave-sandy beach interaction with/without a drainage layer. This numericai model directly simulates Wave-Structure-Seabed/Sandy （WASS） beach interaction by consid- ering flow through a porous medium with inertia, laminar and turbulent resistances, and determines the eddy viscosity with the Large Eddy Simulation （LES） turbulent model in a 3-D wave field （LES-WASS-3D）. Based on the numerical results, it ap- pears that the installation of a drainage layer in the beach results in a decrease in both the mean groundwater level around the foreshore and the flow moving offshore on the beach surface. Spatial distributions of the mean groundwater level and wave setup around the foreshore with various arrangements of the drainage layer and conditions of the incident wave are also discussed in this paper.

关键词： drainage layer groundwater level foreshore LES-WASS-3D (3-D numerical simulation) beach stabilization swash zone

Spontaneous rupture of adrenal myelolipoma as a cause of acute flank pain:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第22期9卷 6552-6556页

作者： Dong Soo Kim Jeong woo lee Sang Hyub lee Department of Urology School of MedicineKyung Hee UniversitySeoul 02447South Korea

BACKGROUND Adrenal myelolipoma is a rare,benign,non-functioning mass that occurs in the adrenal *** is composed of an admixture of hematopoietic elements and mature adipose tissue,similar to bone *** at large sizes,adrenal myelolipomas are usually asymptomatic and often incidentally found by ultrasonography or computed tomography(CT)*** paper describes an unusual case of adrenal myelolipoma presenting as flank *** SUMMARY A 50-year-old male with severe right flank pain underwent a CT scan revealing a huge mass extending into the suprarenal *** mass showed a fat component with retroperitoneal *** tumor was treated laparoscopically,and pathologic examination revealed features of myelolipoma originating from the adrenal *** Adrenal myelolipomas are generally asymptomatic and can be treated ***,rupture and hemorrhage of the tumor can cause symptoms requiring surgical removal.

关键词： Adrenal neoplasms Myelolipoma Adrenal glands Case report

Observation and Numerical Simulations with Radar and Surface Data Assimilation for Heavy Rainfall over Central Korea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2011年第3期28卷 573-590页

作者： Ji-Hyun HA Hyung-woo KIM Dong-Kyou lee Atmospheric Sciences Program School of Earth and Environmental SciencesSeoul National UniversitySeoul 151-747Korea

This study investigated the impact of multiple-Doppler radar data and surface data assimilation on forecasts of heavy rainfall over the central Korean Peninsula;the Weather Research and Forecasting(WRF) model and its three-dimensional variational data assimilation system(3DVAR) were used for this purpose. During data assimilation,the WRF 3DVAR cycling mode with incremental analysis updates(IAU) was used. A maximum rainfall of 335.0 mm occurred during a 12-h period from 2100 UTC 11 July 2006 to 0900 UTC 12 July *** radar data showed that the heavy rainfall was due to the back-building formation of mesoscale convective systems(MCSs).New convective cells were continuously formed in the upstream region,which was characterized by a strong southwesterly low-level jet(LLJ).The LLJ also facilitated strong convergence due to horizontal wind shear,which resulted in maintenance of the *** assimilation of both multiple-Doppler radar and surface data improved the accuracy of precipitation forecasts and had a more positive impact on quantitative forecasting(QPF) than the assimilation of either radar data or surface data *** back-building characteristic was successfully forecasted when the multiple-Doppler radar data and surface data were *** data assimilation experiments,the radar data helped forecast the development of convective storms responsible for heavy rainfall,and the surface data contributed to the occurrence of intensified low-level *** surface data played a significant role in enhancing the thermal gradient and modulating the planetary boundary layer of the model,which resulted in favorable conditions for convection.

关键词： radar and surface data data assimilation mesoscale convective system heavy rainfall

A lipid nanoparticle platform incorporating trehalose glycolipid for exceptional mRNA vaccine safety

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2024年第8期38卷 486-498页

作者： Seo-Hyeon Bae Soyeon Yoo Jisun lee Hyo-Jung Park Sung Pil Kwon Harin Jin Sang-In Park Yu-Sun lee Yoo-Jin Bang Gahyun Roh Seonghyun lee Sue Bean youn In woo Kim Ho Rim Oh Ashraf K.El-Damasy Gyochang Keum Hojun Kim Hyewon youn Jae-Hwan Nam Eun-Kyoung Bang Department of Medical and Biological Sciences The Catholic University of KoreaGyeonggi-doBucheonRepublic of Korea BK Four Department of Biotechnology The Catholic University of KoreaGyeonggi-doBucheonRepublic of Korea Center for Brain Technology Brain Science InstituteKorea Institute of Science and Technology(KIST)Seoul02792Republic of Korea Center for Advanced Biomolecular Recognition Korea Institute of Science and Technology(KIST)Seoul02792Republic of Korea Division of Bio-Medical Science and Technology KIST SchoolUniversity of Science and Technology(UST)SeoulRepublic of Korea SML Biopharm Gwangmyeong14353Republic of Korea KHU-KIST Department of Converging Science and Technology Graduate SchoolKyung Hee UniversitySeoul02447Republic of Korea Cancer Research Institute Seoul National University College of MedicineSeoul03080Republic of Korea Department of Nuclear Medicine Cancer Imaging CenterSeoul National University HospitalSeoul03080Republic of Korea

The rapid development of messenger RNA(mRNA)vaccines formulated with lipid nanoparticles(LNPs)has contributed to control of the COVID-19 ***,mRNA vaccines have raised concerns about their potential toxicity and clinical safety,including side effects,such as myocarditis,anaphylaxis,and *** this study,we investigated the potential of trehalose glycolipids-containing LNP(LNP S050L)to reduce the risks associated with ionizable *** glycolipids can form hydrogen bonds with polar biomolecules,allowing the formation of a stable LNP structure by replacing half of the ionizable *** efficacy and safety of LNP S050L were evaluated by encapsulating the mRNA encoding the luciferase reporter gene and measuring gene expression and organ toxicity,***,mice immunized with an LNP S050L-formulated mRNA vaccine expressing influenza hemagglutinin exhibited a significant reduction in organ toxicity,including in the heart,spleen,and liver,while sustaining gene expression and immune efficiency,compared to conventional LNPs(Con-LNPs).Our findings suggest that LNP S050L,a trehalose glycolipid-based LNP,could facilitate the development of safe mRNA vaccines with improved clinical safety.

关键词： Trehalose glycolipid Lipid nanoparticle mRNA vaccine Toxicity Immunogenicity

Ultrasound-triggered three dimensional hyaluronic acid hydrogel promotes in vitro and in vivo reprogramming into induced pluripotent stem cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bioactive Materials 2024年第8期38卷 331-345页

作者： Deogil Kim Min-Ju lee Yoshie Arai Jinsung Ahn Gun woo lee Soo-Hong lee Department of Biomedical Engineering Dongguk University-Seoul04620SeoulSouth Korea

Cellular reprogramming technologies have been developed with different physicochemical factors to improve the reprogramming efficiencies of induced pluripotent stem cells(iPSCs).Ultrasound is a clinically applied noncontact biophysical factor known for regulating various cellular behaviors but remains uninvestigated for cellular ***,we present a new reprogramming strategy using low-intensity ultrasound(LIUS)to improve cellular reprogramming of iPSCs in vitro and in *** 3D microenvironment conditions,increased LIUS stimulation shows enhanced cellular reprogramming of the *** cellular reprogramming process facilitated by LIUS is accompanied by increased mesenchymal to epithelial transition and histone *** stimulation transiently modulates the cytoskeletal rearrangement,along with increased membrane fluidity and mobility to increase HA/CD44 ***,LIUS stimulation with HA hydrogel can be utilized in application of both human cells and in vivo environment,for enhanced reprogrammed cells into ***,LIUS stimulation with a combinatorial 3D microenvironment system can improve cellular reprogramming in vitro and in vivo environments,which can be applied in various biomedical fields.

关键词： Induced pluripotent stem cell Cellular reprogramming Low-intensity ultrasound Biophysical stimulation Cytoskeletal rearrangement

CaCO_3 film synthesis from ladle furnace slag: morphological change, new material properties, and Ca extraction efficiency

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1447-1456页

作者： Seung-woo lee Yong-Jae Kim Jun-Hwan Bang Soochun Chae Center for carbon mineralization Korea Institute of Geosciences and Mineral Resources Frontier in extreme physics Korea Research Institute of Standards and Science

A rapidly air-cooled ladle furnace slag(RA-LFS), which is a type of steelmaking slag discharged from a steel mill, was used to synthesize CaCO_3 film. The CaCO_3 film with 35 cm^2 of surface area was synthesized under atmospheric conditions, and the surface morphology of the CaCO_3 films was changed by using additives(CaCl_2 and ethylene glycol). Especially, the addition of CaCl_2 changed the surface morphology of CaCO_3 film with pore and induced new material properties, such as water adsorption. The(012) face of CaCO_3 film(calcite) was rapidly decreased by the addition of CaCl_2. The major components of RA-LFS were calcium(type of CaO, 53.9 wt%) and aluminum(type of Al_2 O_3, 37.9 wt%), and the major crystal phases of RA-LFS were C_3 S, C_(12) A_7, and C_3 A. The calcium extraction efficiency of RA-LFS was significantly increased after the CaCO_3 film synthesis. The material properties(hardness and elastic modulus) and the thermal characteristics of the CaCO_3 films were analyzed by nano-indentation and thermogravimetry–differential thermal analysis. The synthesized CaCO_3 films from RA-LFS and Ca(OH)_2(reagent) showed similarities in terms of their material properties and the decomposition temperature.

关键词： carbon dioxide ladle furnace slag carbonation calcium carbonate film calcium efficiency

Molecular Mechanism of the Specificity of Protein Import into Chloroplasts and Mitochondria in Plant Cells

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2019年第7期12卷 951-966页

作者： Dong wook lee Sumin lee Junho lee Seungjin woo Md.Abdur Razzak Alessandro Vitale Inhwan Hwang Division of Integrative Biosciences and Biotechnology Pohang University of Science and Technology Pohang 37673 Korea Department of Life Sciences Pohang University of Science and Technology Pohang 37673 Korea Istituto di Biologia e Biotecnologia Agraria Consiglio Nazionale Delle Ricerche Milano Italy

Plants possess both types of endosymbiotic organelles, chloroplasts and mitochondria. Transit peptides and presequences function as signal sequences for specific import into chloroplasts and mitochondria, respectively. However, how these highly similar signal sequences confer the protein import specificity remains elusive. Here, we show that mitochondrial- or chloroplast-specific import involves two distinct steps, specificity determination and translocation across envelopes, which are mediated by the N-terminal regions and functionally interchangeable C-terminal regions, respectively, of transit peptides and presequences. A domain harboring multiple-arginine and hydrophobic sequence motifs in the N-terminal regions of presequences was identified as the mitochondrial specificity factor. The presence of this domain and the absence of arginine residues in the N-terminal regions of otherwise common targeting signals confers specificity of protein import into mitochondria and chloroplasts, respectively. AtToc159, a chloroplast import receptor, also contributes to determining chloroplast import specificity. We propose that common ancestral sequences were functionalized into mitochondrial- and chloroplast-specific signal sequences by the presence and absence, respectively, of multiple-arginine and hydrophobic sequence motifs in the N-terminal region.

关键词： transit peptide presequence protein import into chloroplasts and mitochondria N-terminal specificity domain C-terminal common translocation domain import specificity determination