• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2358-2368
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• 2011

Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations, employing the B3LYP method and the LANL2DZ, 6-31G$^*$(LANL2DZ for Tc), 6-31G$^*$(cc-pVDZ-pp for Tc) and DGDZVP basis sets, have been performed to investigate the electronic structures and absorption spectra of the technetium-99m-labeled methylenediphosphonate ($^{99m}Tc$-MDP) complex of the simplest diphosphonate ligand. The bonding situations and natural bond orbital compositions were studied by the Mulliken population analysis (MPA) and natural bond orbital (NBO) analysis. The results indicate that the ${\sigma}$ and ${\pi}$ contributions to the Tc-O bonds are strongly polarized towards the oxygen atoms and the ionic contribution to the Tc-O bonding is larger than the covalent contribution. The electronic transitions investigated by TDDFT calculations and molecular orbital analyses show that the origin of all absorption bands is ascribed to the ligand-to-metal charge transfer (LMCT) character. The solvent effect on the electronic structures and absorption spectra has also been studied by performing DFT and TDDFT calculations at the B3LYP/6-31G$^*$(cc-pVDZ-pp for Tc) level with the integral equation formalism polarized continuum model (IEFPCM) in different media. It is found that the absorption spectra display blue shift in different extents with the increase of solvent polarity.

• Asian-Australasian Journal of Animal Sciences
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• 제26권4호
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• pp.455-462
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• 2013

NLR family pyrin domain containing 3 (NLRP3) is a key component of the inflammasome, whose assembly is a crucial part of the innate immune response. The aim of the present study was to evaluate the association between exon 3 polymorphisms of NLRP3 and the susceptibility to digestive disorders in rabbits. In total, five coding single-nucleotide polymorphisms (cSNPs) were identified; all of which are synonymous. Among them, c.456 C> and c.594 G> were further genotyped for association analysis based on case-control design (n =162 vs n =102). Meanwhile, growing rabbits were experimentally induced to digestive disorders by feeding a fiber-deficient diet, subsequently they were subjected to mRNA expression analysis. Association analysis revealed that haplotype H1 (the two cSNPs: GT) played a potential protective role against digestive disorders (p<0.001). The expression of NLRP3 in the group $H1HX_1$ ($H1HX_1$ is composed of H1H1, H1H3 and H1H4) was the lowest among four groups which were classified by different types of diplotypes. Those results suggested that the NLRP3 gene was significantly associated with susceptibility to digestive disorders in rabbit.

• Wind and Structures
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• 제29권6호
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• pp.431-440
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• 2019

The aim of this study was to explore the influence of structure coupling effect on structural damping of blade based on the blade vibration characteristic. For this purpose, the scaled blade model of NREL 5 MW offshore wind turbine was processed and employed in the wind tunnel test to validate the reliability of theoretical and numerical models. The attenuation curves of maximum displacement and the varying curves of equivalent damping coefficient of the blade under the rated condition were respectively compared and analyzed by constructing single blade model and whole machine model. The attenuation law of blade dynamic response was obtained and the structure coupling effect was proved to exert a significant influence on the equivalent damping coefficient. The results indicate that the attenuation trend of the maximum displacement response curve of the single blade varies more obviously with the increase of elastic modulus as compared to that under the structure coupling effect. In contrast to the single blade model, the varying curve of equivalent damping coefficient with the period is relatively steep for the whole machine model. The findings are of great significance to guide the structure design and material selection for wind turbine blades.

• Wind and Structures
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• 제31권4호
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• pp.373-380
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• 2020

For large-scale 5MW offshore wind turbines, the discrete equation of fluid domain and the motion equation of structural domain with geometric nonlinearity were built, the three-dimensional modeling of the blade considering fluid-structure interaction (FSI) was achieved by using Unigraphics (UG) and Geometry modules, and the numerical simulation and the analysis of the vibration characteristics for wind turbine structure under rotating effect were carried out based on ANSYS software. The results indicate that the rotating effect has an apparent effect on displacement and Von Mises stress, and the response and the distribution of displacement and Von Mises stress for the blade in direction of wingspan increase nonlinearly with the equal increase of rotational speeds. Compared with the single blade model, the blade vibration period of the whole machine model is much longer. The structural coupling effect reduces the response peak value of the blade displacement and Von Mises stress, and the increase of rotational speed enhances this coupling effect. The maximum displacement difference between two models decreases first and then increases along wingspan direction, the trend is more visible with the equal increase of rotational speed, and the boundary point with zero displacement difference moves towards the blade root. Furthermore, the Von Mises stress difference increases gradually with the increase of rotational speed and decreases nonlinearly from the blade middle to both sides. The results can provide technical reference for the safe operation and optimal design of offshore wind turbines.

• Geomechanics and Engineering
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• 제20권2호
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• pp.155-164
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• 2020

In recent years, the stability, safety and comfort of trains has received increased attention. The mechanical characteristics and differential settlement of the foundation are the main problems studied in high-speed railway research. The mechanical characteristics and differential settlement of the foundation are greatly affected by the ground treatment. Additionally, the effects of train load and earthquakes have a great impact. The dynamic action of the train will increase the vibration acceleration of the foundation and increase the cumulative deformation, and the earthquake action will affect the stability of the substructure. Earthquakes have an important practical significance for the dynamic analysis of the railway operation stage; therefore, considering the impact of earthquakes on the railway substructure stability has engineering significance. In this paper, finite element model of the CFG (Cement Fly-ash Gravel) pile + cement-soil compacted pile about composite foundation is established, and manual numerical incentive method is selected as the simulation principle. The mechanical characteristics and differential settlement of CFG pile + cement-soil compacted pile about composite foundation under train load are studied. The results show: under the train load, the neutral point of the side friction about CFG pile is located at nearly 7/8 of the pile length; the vertical dynamic stress-time history curves of the cement-soil compacted pile, CFG pile and soil between piles are all regular serrated shape, the vertical dynamic stress of CFG pile changes greatly, but the vertical dynamic stress of cement-soil compacted pile and soil between piles does not change much; the vertical displacement of CFG pile, cement-soil compacted pile and soil between piles change very little.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4084-4092
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• 2012

Theoretical calculations based on density functional theory (DFT) were performed to study the substituent effect on the geometric and electronic structures as well as the biological behavior of technetium-99m-labeled diphosphonate complexes. Optimized structures of these complexes are surrounded by six ligands in an octahedral environment with three unpaired 4d electrons ($d^3$ state) and the optimized geometry of $^{99m}Tc$-MDP agrees with experimental data. With the increase of electron-donating substituent or tether between phosphate groups, the energy gap between frontier orbitals increases and the probability of non-radiative deactivation via d-d electron transfer decreases. The charge distribution reflects a significant ligand-to-metal electron donation. Based on the calculated geometric and electronic structures and biologic properties of $^{99m}Tc$-diphosphonate complexes, several structure-activity relationships (SARs) were established. These results may be instructive for the design and synthesis of novel $^{99m}Tc$-diphosphonate bone imaging agent and other $^{99m}Tc$-based radiopharmaceuticals.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1046-1056
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• 2016

RV-23 is a melittin-related antibacterial peptide (MRP) with lower cytotoxicity than either melittin or AR-23, another MRP. The aim of this study was to explore the mechanism of RV-23's antibacterial selectivity and its hemocompatibility. The results showed that all the peptides exhibited lytic activity against Staphylococcus aureus and Escherichia coli, with RV-23 showing the highest potency. Moreover, RV-23 had lower cytotoxicity than melittin or AR-23 at their minimal inhibitory concentration. In addition, CD experiments showed that melittin, RV-23, and AR-23 all had a typical α-helical structure, and RV-23 had the lowest α-helix content. The structural information showed that RV-23 has the lowest hydrophobicity and highest hydrophobic moment. Because hydrophobicity and α-helix content are believed to correlate with hemolysis, the results indicate that the selective lytic activity against bacteria of RV-23 may be due to its low hydrophobicity and α-helicity, which lead to low cytotoxicity without affecting antibacterial activity. Furthermore, RV-23 did not affect the structure and function of blood components such as red blood cells, platelets, albumin, and the blood coagulation system. In conclusion, RV-23 is a cell-selective antibacterial peptide with high hemocompatibility due to its unique structure.

• Structural Engineering and Mechanics
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• 제73권5호
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• pp.529-542
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• 2020

As limited well-documented experimental data are available for assessing the attributes of different deformation components of flanged walls, few appropriate models have been established for predicting the inelastic responses of flanged walls, especially those of asymmetrical flanged walls. This study presents the experimental results for three large-scale T-shaped reinforced concrete walls and examines the variations in the flexural, shear, and sliding components of deformation with the total deformation over the entire loading process. Based on the observed deformation behavior, a simple model based on moment-curvature analysis is established to estimate flexural deformations, in which the changes in plastic hinge length are considered and the deformations due to strain penetration are modeled individually. Based on the similar gross shapes of the curvature and shear strain distributions over the wall height, a proportional relationship is established between shear displacement and flexural rotation. By integrating the deformations due to flexure, shear, and strain penetration, a new load-deformation analytical model is proposed for flexure-dominant flanged walls. The proposed model provides engineers with a simple, accurate modeling tool appropriate for routine design work that can be applied to flexural walls with arbitrary sections and is capable of determining displacements at any position over the wall height. By further simplifying the analytical model, a simple procedure for estimating the ultimate displacement capacity of flanged walls is proposed, which will be valuable for performance-based seismic designs and seismic capacity evaluations.

• 교육녹색환경연구
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• 제18권3호
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• pp.39-49
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• 2019

유학자들의 유교적 이념들은 서원의 공간구성에서 강하게 발현되어 '예(禮)'를 기본으로 하는 독특한 질서를 형성하였다. 유학자들은 중국 고대의 삼대(하(夏) 은(殷) 주(周))를 이상적인 사회로 인식하고 각기 신분에 맞는 이상적인 고대의 건축제도인 '묘침제(廟寢制)'를 실제 조선사회에 접목하려고 하였다. 그러나 기원전의 건축형식을 16세기의 조선에서 적용하려다보니 많은 문제가 발생하였기 때문에, 학자별로 다양한 견해를 제시하여 묘침의 관계를 정립해나갔다. 기호사림이 실천주의적 입장에서 고제에 따라 황산서원, 돈암서원, 신항서원, 상현서원, 만동묘 등의 영건에 묘침제를 적용했던 것과 다르게 영남사림에서는 신식의 문암서원을 제외하고는 실제 적용을 위한 실험들이 적었다. 이는 고대의 중국제도와 17세기 조선의 현실에 대한 분명한 차이를 전제하는 실용주의적 태도에서 비롯되었다. 서원의 건축형식은 이러한 인식들의 발발로(發露)인 것이다.

• 한국철학논집
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• 제57호
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• pp.151-181
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• 2018

본 논문은 왕방의 "남화진경신전" 중 "소요유" "제물론" "양생주" "인간세" "천하"를 중심으로 논의를 구성하였다. 본론은 모두 세 부분으로 구성되어있는데 본론 1장에서는 기존의 연구 성과에서 보이는 문헌 검토상의 오류와 불명확한 주제설정에 대하여 지적하였다. 그리고 본론 2장에서는 "남화진경신전" 중 "소요유" "제물론" "양생주" "인간세"에서 목격되는 유불도 경전 인용을 정리하여 도표로 제시하였다. 현재까지 필자의 검토에 의하면, 왕방 이전 "장자" 주석서에서는 "남화진경신전"과 같이 "장자" 이외의 다른 전적을 직접 인용하는 사례는 없다. 필자는 이러한 왕방의 다양한 경전 인용을 통한 "장자" 해석에 대하여 '융복합적 "장자" 해석'으로 정의하였다. 또한 이런 융복합적 "장자" 해석의 의미에 대하여 진화론적 관점을 응용하여 '변화를 위한 융복합' 곧 '사상계의 변화 문화지형의 변동에 적응하여 진화하기 위한 사상적 시도'라고 정리하였다. 마지막 본론 3장에서는 왕방의 "장자" '신인'에 대한 해석에 대하여 정리하였다. 이 부분에서는 왕방이 "장자"의 이상적 인격을 합리적 관점에서 접근하여 "소요유" 등에서 목격되는 '신인'을 '경세자' 곧 '치세의 정치 실력자'로 해석하는 부분에 대하여 집중적으로 논의하였다.