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Comparison of CT and MRI for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma

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World Journal of Gastroenterology 2008年第14期14卷 2208-2212页

作者： Young Chul kim Mi-Suk Park Seung-Whan Cha Yong Eun Chung Joon Suk Lim Myeong-Jin kim ki whang kim Kyung Sik kim Department of Diagnostic Radiology and Institute of Gastroenterology Severance Hospital Research Institute of Radiological Science Yonsei University College of Medicine Seoul 120-752 Korea Department of Diagnostic radiology and Institute of Gastroenterology Yonsei University Wonju College of Medicine Wonju 220-701 Korea Department of General surgery and Institute ofGastroenterology Severance Hospital Yonsei University Collegeof Medicine Seoul 120-752 Korea

AIM:To determine the accuracy of computed tomography (CT) and magnetic resonance (MR) for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma. METHODS:Two radiologists independently evaluated CT and MR imaging of 31 patients who had undergone lymphadenectomy (9 metastatic and 22 non-metastatic paraaortic nodes). Receiver operating characteristic (ROC) curve analysis was performed using a five point scale to compare CT with MRI. To re-define the morphologic features of metastatic nodes, we evaluated CT scans from 70 patients with 23 metastatic paraaortic nodes and 47 non-metastatic ones. The short axis diameter, ratio of the short to long axis, shape, and presence of necrosis were compared between metastatic and non-metastatic nodes by independent samples t-test and Fisher's exact test. P 5.3 mm), irregular margin, and presence of central necrosis are the suggestive morphologic features of metastatic paraaortic nodes.

关键词： Paraaortic lymph node Pancreatico-biliary carcinoma Computed tomography Magnetic resonance imaging

Paraaortic lymph node metastasis in patients with intra-abdominal malignancies:CT vs PET

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World Journal of Gastroenterology 2009年第35期15卷 4434-4438页

作者： Mi-Jung Lee Mi Jin Yun Mi-Suk Park Seung Hwan Cha Myeong-Jin kim Jong Doo Lee ki whang kim Department of Diagnostic Radiology Research Institute of Radiological Science and Institute ofGastroenterology Yonsei University College of Medicine 134Sincheon-Dong Seodaemun-Gu Seoul 120-752 South Korea Department of Nuclear medicine Yonsei University College of Medicine 134 Sincheon-Dong Seodaemun-Gu Seoul 120-752 South Korea Department of Diagnostic Radiology Yonsei University Wonju College of Medicine Wonju 220-701South Korea

AIM： To compare the diagnostic accuracy of computed tomography （CT） and positron emission tomography （PET） for the preoperative detection of paraaortic lymph node （PAN） metastasis in patients with intra- abdominal malignancies. METHODS： Sixty-six patients with intra-abdominal malignancies who underwent both CT and PET before lymphadenectomy were included in this study. Histopathologicaliy, 13 patients had metastatic PAN, while 53 had non-metastatic PAN. The CT criteria for metastasis were： short diameter ：）f 〉 8 mm, Iobular or irregular shape, and/or combined ancillary findings, including necrosis, conglomeration, vessel encasement, and infiltration. The PET criterion was positive fluorodeoxyglucose （FDG） uptake. The sensitivity, specificity, positive predictive value （PPV）, negative predictive value （NPV）, and accuracy of both modalities were compared with the pathologic findings, and the false positive and false negative cases with both CT and PET were ***： The sensitivity, specificity, PPV, NPV, and accuracy of CT were 61.5%, 84.9%, 50%, 90% and 80.3%, respectively. For PET, the percentages were 46.2%, 100%, 100%, 88.3%, and 89.4%. Additionally, there were 8 false positive CT cases （8/53, 15.1%） and zero false positive PET cases. Of the 13 metastatic PANs, there were 5 false negative CT scans （38.5%） and 7 （53.9%） false negative PET ***： For detecting PAN metastasis, CT is more sensitive than PET, while PET is more specific.

关键词： Malignancy Paraaortic lymph node Computed tomography Positron emission tomography Sensitivity Specificity

Characterization of lattice parameters gradient of Cu(In1-xGax)Se2 absorbing layer in thin-film solar cell by glancing incidence X-ray diffraction technique

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Journal of Materials Science & Technology 2020年第16期47卷 193-201页

作者： Yong-Il kim ki-Bok kim Miso kim Department of Nano Science University of Science and Technology217GajeongYuseongDaejeon34113Republic of Korea Korea Research Institute of Standards and Science 267GajeongYuseongDaejseon34113Republic of Korea

In or Ga gradients in the Cu(In1-xGax)Se2(CIGS)absorbing layer lead to change the lattice parameters of the absorbing layer,giving rise to the bandgap grading in the absorbing layer which is directly associated with the degree of absorbing ability of the CIGS solar *** tried to characterize the depth profile of the lattice parameters of the CIGS absorbing layer using a glancing incidence X-ray diffraction(GIXRD)technique,and then investigate the bandgap grading of the CIGS absorbing *** the glancing incident angle increased from 0.50 to 5.00°,the a and c lattice parameters of the CIGS absorbing layer gradually decreased from 5.7776(3)to 5.6905(2)?,and 11.3917(3)to 11.2114(2)?,*** depth profile of the lattice parameters as a function of the incident angle was consistent with vertical variation in the compositionof In or Ga with depth in the absorbing *** variation of the lattice parameters was due to the difference between the ionic radius of In and Ga co-occupying at the same crystallographic *** to the results of the depth profile of the refined parameters using GIXRD data,the bandgap of the CIGS absorber layer was graded over a range of 1.222-1.532 *** approach allows to determine the In or Ga gradients in the CIGS absorbing layer,and to nondestructively guess the bandgap depth profile through the refinement of the lattice parameters using GIXRD data on the assumption that the changes of the lattice parameters or unit-cell volume follow a good approximation to Vegard’s law.

关键词： Cu(In1-xGax)Se2 absorbing layer Depth profile Glancing incidence X-ray diffraction technique Bandgap grading Vegard’s law

Thalidomide effect in endothelial cell of acute radiation proctitis

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World Journal of Gastroenterology 2008年第30期14卷 4779-4783页

作者： ki-Tae kim Hiun-Suk Chae Jin-Soo kim Hyung-Keun kim Young-Seok Cho whang Choi Kyu-Yong Choi Sang-Young Rho Suk-Jin Kang Department of Radiology College of Medicine The Catholic University of Korea Uijeongbu St. Mary’s Hospital Department of Internal Medicine College of Medicine The Catholic University of Korea Uijeongbu St. Mary's Hospital Department of Internal Medicine College of Medicine The Catholic University of Korea Our Lady of Mercy Hospital Department of Internal Medicine College of Medicine The Catholic University of Korea Uijeongbu St. Mary’s Hospital Department of Pathology College of Medicine The Catholic University of Korea St. Vincent Hospital

AIM: To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats. METHODS: Fourteen female Wistar rats were used: six in the radiation group, six in the thalidomide group, and two in normal controls. The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure. The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation. All animals were sacrificed and the rectums were removed on day 8 after irradiation. The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM), von Willebrand Factor (vWF), and vascular endothelial growth factor (VEGF). RESULTS: The microscopic scores did not differ significantly between the radiation and thalidomide groups, but both were higher than in the control group. Expression of TM was significantly lower inthe endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P < 0.001). The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3 ± 6.8) than in the control group (3.7 ± 1.7), and the number of capillaries expressing vWF was attenuated by thalidomide (10.8 ± 3.5, P < 0.001). The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P = 0.003). CONCLUSION: The mechanisms of acute radiation- induced proctitis in the rats are related to endothelial cell injury of microvessel, which may be attenuated with thalidomide.

关键词： Radiation proctitis Von Willebrand factor Thrombomodulin Vascular endothelial growth factor Thalidomide

Effect of reduction in area per pass on strain distribution and microstructure during caliber rolling in twinning-induced plasticity steel

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Journal of Iron and Steel Research International 2020年第1期27卷 62-74页

作者： Joong-ki Hwang Sung Jin kim School of Mechanical Engineering Tongmyong UniversityBusan 48520Republic of Korea Department of Advanced Materials Engineering Sunchon National UniversitySuncheon 57922Republic of Korea

The effects of reduction in area(RA)per pass during caliber rolling on microstructure and strain distribution of twinninginduced plasticity steel have been investigated to find solutions to make a more homogeneous material along the radial direction for wire rod *** steel wires subjected to an average RA per pass of 2.5%(skin pass caliber rolling)and 10.0%(conventional caliber rolling)were *** skin pass caliber-rolled wire was characterized as a duplex fiber texture of majorand minor.and the textures were almost same at/between center and surface area,which is totally different from those of conventional caliber rolling and wire *** skin pass caliber rolling led to more homogeneous microstructure and mechanical properties along the radial direction in comparison with the conventional caliber rolling and wire drawing due to the more homogeneous Hall-Petch hardening,dislocation hardening,and texture behavior with area,resulting in higher formability.

关键词： Twinning-induced plasticity steel Caliber rolling Deformation twin Reduction in area Skin pass

Cutoff characteristics of dielectric-filled circular holes embedded in dispersive plasmonic medium

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Chinese Optics Letters 2009年第10期7卷 904-908页

作者： ki Young kim Department of Physics National Cheng Kung University

The cutoff characteristics of dielectric-filled circular holes embedded in a dispersive plasmonic medium are investigated. Since two distinctive operating modes, surface plasmon polariton and circular waveguide modes, can exist in the slow and fast wave regions, respectively, the cutoff characteristics for each are separately investigated for linear and radial polarizations of the guided fields. As a result, the cutoff wavelengths for the linear and radial polarizations with very small subwavelength hole radii are found to be limited by the plasma resonance wavelength and plasma wavelength, which in turn are dependent and independent, respectively, of the dielectric constant of the dielectric filler material.

关键词： Circular waveguides Polarization Surface plasmon resonance

DC Motor Speed Regulator via Active Damping Injection and Angular Acceleration Estimation Techniques

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IEEE/CAA Journal of Automatica Sinica 2021年第3期8卷 641-647页

作者： Seok-Kyoon kim Choon ki Ahn Department of Creative Convergence Engineering Hanbat National UniversityDaejeon 341-58Republic of Korea School of Electrical Engineering Korea UniversitySeoul 136-701Republic of Korea

This paper suggests a novel model-based nonlinear DC motor speed regulator without the use of a current *** current dynamics,machine parameters and mismatched load variations are *** proposed controller is designed to include an active damping term that regulates the motor speed in accordance with the first-order low-pass filter dynamics through the pole-zero ***,the angular acceleration and its reference are obtained from simple first-order estimators using only the speed *** effectiveness is experimentally verified using hardware comprising the QUBEServo2,myRIO-1900,and LabVIEW.

关键词： Active damping injection angular acceleration estimator DC motor(DCM) speed regulation

In?uence of Carbon Equivalent Value on the Weld Bead Bending Properties of High-Strength Low-Alloy Steel Plates

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Journal of Materials Science & Technology 2017年第4期33卷 321-329页

作者： ki Hyuk kim In Jun Moon ki Won kim ki Bong Kang Byung Gyu Park Kwang Seok Lee R&D Center of Dongkuk Steel Mill Co. Ltd Pohang 790-729 South Korea Korea Institute of Materials Science Implementation Research Division Materials Deformation Department 797 Changwondaero Changwon Gyeongnarn642-831 South Korea

The contribution of chemical compositions in terms of carbon equivalent value（CEV） on impending crack propagation during weld bead bend tests（WBBTs） was studied with five different high-strength lowalloy steel plates that underwent different rolling processes. The test showed that cracks developed at the weld joint, easily passed through the coarse-grain heat-affected zone（CGHAZ）, and finally were arrested within the heat-affected zone（HAZ）. An apparent decrease in the average crack length, which consequently indicated improvement in crack arrestability, was found with decreasing CEV. In addition,the relatively fine microstructure in the HAZ of low-CEV steel plates helped in preventing the crack from further propagation. Special emphasis was placed on the empirical expectation of critical CEV above which WBBT might fail.

关键词： Mechanical characterization Steel Welding Fracture Crack arrestability against bending

Seasonal Prediction of Monthly Precipitation in China Using Large-Scale Climate Indices

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Advances in Atmospheric Sciences 2010年第1期27卷 47-59页

作者： Maeng-ki kim Yeon-Hee kim Department of Atmospheric Science Kongju National University

In this study, seasonal predictions were applied to precipitation in China on a monthly basis based on a multivariate linear regression with an adaptive choice of predictors drawn from regularly updated climate indices with a two to twelve month lead time. A leave-one-out cross validation was applied to obtain hindcast skill at a 1% significance level. The skill of forecast models at a monthly scale and their significance levels were evaluated using Anomaly Correlation Coefficients （ACC） and Coefficients Of Determination （COD）. The monthly ACC skill ranged between 0.43 and 0.50 in Central China, 0.41-0.57 in East China, and 0.41 0.60 in South China. The dynamic link between large-scale climate indices with lead time and the precipitation in China is also discussed based on Singular Value Decomposition Analysis （SVDA） and Correlation Analysis （CA）.

关键词： seasonal prediction precipitation in China climate predictors climate index