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Pre-operative factors that can predict neoplastic polypoid lesions of the gallbladder

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World Journal of Gastroenterology 2011年第17期17卷 2216-2222页

作者： Byung Hyo Cha Jin-Hyeok Hwang Sang Hyub Lee Jang eon kim Jai Young Cho haeryoung kim So Yeon kim Department of Internal Medicine Cheju Halla General HospitalCheju-siCheju-do 690-766South Korea Departments of Internal Medicine Seoul National University College of Medicine Seoul National University Bundang Hospital Seongnam-siGeonggi-do 463-707South Korea Department of Surgery Seoul National University College of Medicine Department of Pathology Seoul National University College of Medicine Department of Radiology Seoul National University College of Medicine

AIM:To investigate the preoperative factors that can predict neoplastic polypoid lesions of the gallbladder(PLGs) as well as malignant ***:A retrospective analysis was conducted on the 210 consecutively enrolled patients who underwent cholecystectomy due to a PLG larger than 10 mm,as was determined by preoperative trans-abdominal ultrasonography or endoscopic *** ana-lyzed the medical,laboratory,radiologic data and the pathologic ***:In 210 cases,146 had non-neoplastic polyps(69.5%) and 64 cases were neoplastic polyps(30.5%).An older age(≥ 65 years),the presence of diabetes mellitus(DM) and the size of polyp(≥ 15 mm) were revealed to be independent predictive variables for neoplastic polyps with odd ratios(OR) of 2.27(P = 0.044),2.64(P = 0.021) and 4.94(P han 10 mm in size,higher risk groups such as elderly patients more than 65 years old,those with DM or a large polyp size(≥ 15 mm) should be managed by cholecystectomy.

关键词： Gallbladder Polyp Neoplastic Cholecystectomy Diabetes Pre-operative factors

Chicken soup for teaching and learning ESD

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World Journal of Gastroenterology 2011年第21期17卷 2618-2622页

作者： Eun Young kim Seong Woo Jeon Gwang ha kim Division of Gastroenterology Department of Internal MedicineCatholic University of Daegu School of Medicine Division of Gastroenterology Department of Internal MedicineKyungpook National University School of Medicine Department of Internal Medicine Pusan National University School of Medicine and Medical Research InstitutePusan National University Hospital

Endoscopic submucosal dissection(ESD) is becoming a popular procedure for the diagnosis and treatment of superficial mucosal lesions,and has the advantage of en bloc resection which yields a higher complete resection and remission rate compared to endoscopic mucosal resection(EMR).However,the learning process of this advanced endoscopic procedure requires a lengthy training period and considerable experience to be proficient.A well framed training protocol which is safe,effective,easily reproducible and cost-effective is desirable to teach *** addition,the training course may need to be tailored around settings such as ethnicity,culture,workload,and disease *** Asian countries with a large volume of early gastric lesions which need endoscopic treatment,endoscopists would be able to learn ESD expanding their skills from EMR to ESD under the supervision of ***,in Western countries due to the low incidence of superficial gastric tumors,trials have utilized simulator models to improve *** Korea,the Korean Society of Gastrointestinal Endoscopy(KSGE) is playing an important role in training many gastroenterologists who have shown an interest in performing ESD by providing an annual live demonstration and a nationwide tutoring *** purpose of this article is to introduce our ESD tutoring experience,review the published papers related to this topic,and propose several suggestions for future directions in teaching and learning ESD.

关键词： Endoscopic submucosal dissection Learning Teaching

A voltage-controlled chaotic oscillator based on carbon nanotube field-effect transistor for low-power embedded systems

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Chinese Physics B 2014年第5期23卷 617-622页

作者： Van ha Nguyen Wonkyeong Park Namtae kim hanjung Song Department of Nano Systems Engineering Inje University Department of Electronics Engineering Inje University Center for Nano Manufacturing Inje University

This paper presents a compact and low-power-based discrete-time chaotic oscillator based on a carbon nanotube field-effect transistor implemented using Wong and Deng＇s well-known model. The chaotic circuit is composed of a nonlinear circuit that creates an adjustable chaos map, two sample and hold cells for capture and delay functions, and a voltage shifter that works as a buffer and adjusts the output voltage for feedback. The operation of the chaotic circuit is verified with the SPICE software package, which uses a supply voltage of 0.9 V at a frequency of 20 kHz. The time series, frequency spectra, transitions in phase space, sensitivity with the initial condition diagrams, and bifurcation phenomena are presented. The main advantage of this circuit is that its chaotic signal can be generated while dissipating approximately 7.8 μW of power, making it suitable for embedded systems where many chaos-signal generators are required on a single chip.

关键词： chaos generator carbon nanotube field-effect transistor bifurcation random noise generator

Thresholdless coherence in a superradiant laser

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Light(Science & Applications) 2024年第11期13卷 2549-2555页

作者： Seung-Hoon Oh Jinuk kim Junseo ha Gibeom Son Kyungwon An Department of Physics and Astronomy&Institute of Applied Physics Seoul National UniversitySeoulKorea Korea Research Institute of Standards and Science DaejeonKorea

Lasing threshold in the conventional lasers is the minimum input power required to initiate laser *** has been widely accepted that the conventional laser threshold occurring around a unity intracavity photon number can be eliminated in the input-output curve by making the so-calledβparameter approach *** recent experiments,however,have revealed that even in this case the photon statistics still undergo a transition from coherent to thermal statistics when the intracavity mean photon number is decreased below *** the coherent output is only available above the diminished threshold,the long-sought promise of thresholdless lasers to produce always coherent light has become ***,we present an always-coherent thresholdless laser based on superradiance by two-level atoms in a quantum superposition state with the same phase traversing a high-Q *** lasing was observed without the conventional lasing threshold around the unity photon number and the photon statistics remained near coherent even below *** coherence was improved by reducing the coupling constant as well as the excited-state amplitude in the superposition *** results pave a way toward always-coherent thresholdless lasers with more practical media such as quantum dots,nitrogen-vacancy centers and doped ions in crystals.

关键词： laser coherent lasing

Solid-state phase transformations toward a metal-organic framework of 7-connected Zn_(4)0 secondary building units

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Nano Research 2021年第2期14卷 411-416页

作者： Jaehui kim Junsu ha Jae Hwa Lee Hoi Ri Moon Department of Chemistry Ulsan National Institute of Science and Technology(UNIST) Ulsan 44919Republic of Korea

In the development of metal-organic frameworks(MOFs),secondary building units(SBUs)have been utilized as molecular modules for the construction of nanoporous materials with robust *** solvothermal synthetic conditions,dynamic changes in the metal coordination environments and ligand coordination modes of SBUs determine the resultant product ***,MOF phases with new topologies can also be achieved by post-synthetic treatment of as-synthesized MOFs via the introduction of acidic or basic moieties that cause the simultaneous cleavage/reformation of coordination bonds in the solid *** this sense,we studied the solid-state transformation of two ndc-based Zn-MOFs(ndc=1,4-naphthalene dicarboxylate)with different SBUs but the same pcu topology to another MOF with sev *** of the chosen MOFs with pcu nets is[Zn_(2)(ndc)_(2)(bpy)]_(n)(bpy=4,4,-bipyridine),(6C_(bpy)-MOF)consisting of a 6-connected pillared-paddlewheel SBU,and the other is IRMOF-7 composed of 6-connected Zn40(C 00)6 SBUs and *** post-structural modification,these pcu MOFs were converted into the same MOF with sev topology constructed from the uncommon 7-connected Zri_(4)O(COO)_(7)SBU(7C-MOF).The appropriate post-synthetic conditions for the transformation of each SBUs were systematically *** addition,the effect of the pillar molecules in the pillared-paddlewheel MOFs on the topology conversion was studied in terms of the linker basicity,which determines the inertness during the solid-state phase *** post-synthetic modification approach is expected to expand the available methods for designing and synthesizing MOFs with controlled topologies.

关键词： metal-organic framework secondary building units solid-state transform ation linker basicity ligand addition reaction

Combined treatment of phacoemulsification and single-port limited pars plana vitrectomy in acute angle-closure glaucoma

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International Journal of Ophthalmology(English edition) 2019年第6期12卷 974-979页

作者： ha Jeong Noh Seong Taeck kim Department of Ophthalmology Chosun University Hospital

AIM: To evaluate the efficacy of combined treatment of phacoemulsification(PE) and micro-incisional single-port transconjunctival limited pars plana vitrectomy(PPV) in acute angle-closure glaucoma(AACG).METHODS: A retrospective study included 26 patients who underwent PE diagnosed with AACG. Among them, 16 patients(16 eyes) underwent PE alone, 10 patients(10 eyes) underwent combined limited vitrectomy and PE. Then we compared intraocular pressure(IOP), anterior chamber angle, anterior chamber depth, central corneal thickness and corneal endothelial cell count before and after surgery, and effective PE time during cataract ***: Effective PE time was shorter in the combined surgery group than in the single surgery group(P=0.040). There was no statistically significant difference in IOP and best-corrected visual acuity between the two groups postoperatively. At 6 mo postoperatively, there was no difference in the anterior chamber angle, anterior chamber depth, and central corneal thickness between two groups, but corneal endothelial cell count was higher in the combined surgery group than in the single surgery group(P=0.046). No complication such as vitreoretinal disease, endophthalmitis, bullous keratopathy was ***: Combined micro-incisional single-port transconjunctival limited PPV and PE are more effective and safer than PE alone because of less operation time and fewer complications for management of AACG.

关键词： limited vitrectomy phacoemulsification acute angle-closure glaucoma

On the global existence of weak solutions for the Cucker-Smale-Navier-Stokes system with shear thickening

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Science China Mathematics 2018年第11期61卷 2033-2052页

作者： Seung-Yeal ha Hwa Kil kim Jae-Myoung kim Jinyeong Park Department of Mathematical Sciences and Research Institute of Mathematics Seoul National University Seoul 08826 Republic of Korea Korea Institute for Advanced Study Seoul 02455 Republic of Korea Department of Mathematics Education Hannam University Daejeon 34430 Republic of Korea Department of Mathematical Sciences Seoul National University Seoul 08826 Republic of Korea Department of Mathematics and Research Institute of Natural Sciences Hanyang University Seoul 04763 Republic of Korea

We study the large-time dynamics of Cucker-Smale(C-S)flocking particles interacting with nonNewtonian incompressible *** of particles and fluids were modeled using the kinetic Cucker-Smale equation for particles and non-Newtonian Navier-Stokes system for fluids,respectively and these two systems are coupled via the drag force,which is the main flocking(alignment)mechanism between particles and *** present a global existence theory for weak solutions to the coupled Cucker-Smale-Navier-Stokes system with shear *** also use a Lyapunov functional approach to show that sufficiently regular solutions approach flocking states exponentially fast in time.

关键词： emergence flocking Cucker-Smale model Navier-Stokes equation non-Newtonian fluid

Experimental Investigation of Flexible hawkmoth-like Wings on the Wing-wake Interaction in Hovering Flight

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Journal of Bionic Engineering 2018年第1期15卷 139-153页

作者： YeongGyun Ryu Jo Won Chang Joon Chung Dong-ha kim Department of Aerospace Engineering Ryerson University Toronto Ontario M5B 2K3 Canada Department of Aeronautical Science and Flight Operation Korea Aerospace University 76 Hanggongdaehak-ro Deogyang-gu Goyang-si Gyeonggi-do 10540 Republic of Korea Aerodynamics Group Korean Air R&D Center Daejeon Metropolitan City 34054 Republic of Korea

To study wing-wake interaction for various wing flexibilities, force measurements and digital particle image velocimetry were carried out on flapping hawkmoth-like wings in a water tank. Wing thickness was employed as a design variable for the wing flexi- bility distributions. Abrupt flap-down and phase delay in flexible wings influenced the behaviors of the Leading-Edge Vortex （LEV） and Trailing-Edge Vortex （TEV）, generated by the previous stroke. While the rigid wing exhibited a detached LEV at the end of the stroke, wing with specific flexibilities obtained attached LEVs. The attached LEVs induced a relatively rapid flow toward the wing surface as a result of encountering the TEV, and the flow caused a higher lift peak. On the other hand, the wings with larger wing deformations generated distinctive changes in LEV and TEV behaviors. The flap-down helped the TEV form closer to the wing surface, and it thus caused a downwash rather than wing-wake interaction. Furthermore, the most flexible wing had a newly-formed pair of LEVs above the wing during the wing reversal, thereby being not able to generate the wing-wake interaction. These results help to understand the different vortex structures generated by flexible wings during the wing reversal and the corresponding effects of wing-wake interaction.

关键词： hovering flight flexible hawkmoth wings wing-wake interaction Digital Particle Image Velocimetry (DPIV)

Variation in dynamic deformation behavior and resultant yield asymmetry of AZ80 alloy with extrusion temperature

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Journal of Materials Science & Technology 2020年第11期42卷 225-236页

作者： Sang-Hoon kim Sang Won Lee Byoung Gi Moon ha Sik kim Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu702701South Korea Implementation Research Division Korea Institute of Materials ScienceChangwon51508South Korea

In this work,variation in the dynamic recrystallization(DRX)and dynamic precipitation behavior of AZ80 alloy during extrusion due to changes in extrusion temperature was investigated,and the resultant microstructure and yield asymmetry were *** the extrusion temperature increases from 250℃to 350℃,the primary DRX mechanism changes from twin-induced DRX to discontinuous DRX,resulting in an increase in the DRX area fraction and un DRXed grain *** addition,as the extrusion temperature rises,Mg17Al12 precipitation during extrusion decreases sharply throughout the extruded *** reduction in the compressive yield strength(CYS)with increasing extrusion temperature is more pronounced than it is for the tensile yield strength(TYS),which ultimately increases the yield asymmetry of the extruded *** higher extrusion temperature has less of an influence on the TYS due to the promotion of certain hardening *** the other hand,the greater reduction in the CYS is attributed to the increased fraction and size of regions in which{1012}twins predominantly form and the lower amount of precipitates,which effectively facilitates{1012}twinning.

关键词： Magnesium alloys Extrusion Recrystallization Precipitation Yield asymmetry