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Clinical performance of presbyopia correction with a multifocal corneoscleral lens

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International Journal of Ophthalmology(English edition) 2021年第4期14卷 529-535页

作者： Woo Chan park chae hoon Kim Sang Wook Jin Department of Ophthalmology Dong-A University College of MedicineBusan 49201Republic of Korea

AIM:To assess the clinical performance of a multifocal corneoscleral lens for the presbyopia ***:A prospective clinical trial of the OnefitTM A multifocal corneoscleral lens was conducted with 40 participants with *** 4 wk of continuous wear of the corneoscleral lens,changes in the distance,intermediate,and near visual acuity(VA)were *** safety of the corneoscleral lens,central corneal thickness(CCT),corneal endothelial cell count,binocular stereopsis,tear film break-up time(BUT),corneal staining,corneal edema,corneal neovascularization(NV),and conjunctival hyperemia were *** addition,a subjective questionnaire addressing satisfaction(rated from 1 to 5 points)and discomfort(rated from 1 to 5 points)was ***:Forty participants were enrolled in this *** participants were excluded because of poor compliance with lens fitting(n=2)and loss to follow-up(n=4).The mean age of the participants was 53.0±4.9 *** 4 wk of continuous wear of the corneoscleral lens,the best corrected far,intermediate,and near VA was 0.08±0.11,0.10±0.12,and 0.10±0.12 log MAR,*** results were significant improvements over the baseline uncorrected VA(far:P=0.004;intermediate:P=0.004;near:P=0.002).CCT,corneal endothelial cell count,binocular stereopsis,BUT,corneal staining,corneal edema,corneal NV,and conjunctival hyperemia were not significantly different between baseline and after corneoscleral lens *** average satisfaction scores for fit sensation;corrected far,intermediate,and near VA;and ease of handling were 4.1,3.4,3.6,3.5,and 3.4,*** average discomfort scores for dryness,irritation,foreign body sensation,redness,fogging,and halo were 1.7,1.8,1.5,1.7,1.7,and 1.3,***:Far,intermediate,and near VA are improved in presbyopic patients with the multifocal corneoscleral lens compared to uncorrected baseline VA,without adverse ocular *** evidence supports the safety and effecti

关键词： presbyopia multifocal lens corneoscleral lens

Influences of ions and temperature on performance of carbon nano-particulates in supercapacitors with neutral aqueous electrolytes

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Particuology 2014年第4期12卷 9-17页

作者： Jung hoon chae George Zheng Chen Department of Chemical and Environmental Engineering and Energy and Sustainability Research DivisionFaculty of EngineeringUniversity of NottinghamNottinghamNG7 2RDUK

A commercial product of carbon nano-particles, Cabot MONACH 1300 pigment black （CMPB）, was studied for basic structural information and electrochemical performance in neutral aqueous electrolytes, aiming at applications in supercapacitors. As confirmed by SEM and HRTEM, the CMPB had a hierarchical struc- ture, containing basic 10 nm nano-spheres which combined into ca. 50 nm agglomerates which further aggregated into larger particles of micrometres. The capacitance of this commercial material was found to increase with decreasing the size of hydrous cation （Li＋→Na＋ → K＋）, instead of the cation crystal radius （K＋→ Na＋→Li＋） when coupled with the same anion （cl-）. In electrolytes with the same cation concentration （K＋）, changing the anion from the larger dianion （SO42 ） to the smaller monoanion （cl-） also increased the capacitance at high potential scan rates （〉50 mV/s）. Increasing electrolyte concentration produced expected effect, including raising the electrode capacitance, but lowering the equivalent series resistance （ESR）, charge transfer resistance （CTR）, and the diffusion resistance. At higher temperatures, the CMPB exhibited slightly higher capacitance, which does not agree with the Gouy-Chapman theory on electric double layer （EDL）. A hypothesis is proposed to account for the capacitance increase with temperature as a result of the CMPB opening up some micro-pores for more ions to access in response to the temperature increase.

关键词： Carbon nano-particlesSupercapacitorNeutral aqueous electrolytesIonic propertiesElectrochemistry

Electrochemically metal-doped reduced graphene oxide films:Properties and applications

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Journal of Materials Science & Technology 2020年第5期40卷 72-80页

作者： Myung-Sic chae Tae Ho Lee Kyung Rock Son Tae hoon park Kyo Seon Hwang Tae Geun Kim School of Electrical Engineering Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Department of Clinical Pharmacology and Therapeutics College of MedicineKyung Hee UniversitySeoul 02447South Korea

The fine control of doping levels in graphene materials such as reduced graphene oxide(RGO)is important to properly manipulate their ambipolar transport characteristics for various device ***,conventional doping methods involve complex chemical reactions,large-scale doping processes,and poor ***,a simple and controllable electrochemical doping treatment(EDT),performed via the conductive channels created at the RGO surface by the application of an electric field,is introduced to tailor the electrical properties of RGO films.X-ray photoelectron spectroscopy and Raman spectroscopy measurements are performed to detect the presence of Ni atoms in RGO films after the EDT(EDT-RGO).Then,EDT-RGO field-effect transistors(FETs)are fabricated with different doping areas(0 to 100%fractional area)on the RGO active channel to investigate the effect and selective-area doping capability of the *** to p-type doping compensation by the intercalated Ni atoms,the electron mobility of the EDT-RGO FET decreases from 1.40 to 0.12 cm2 V-1s-1 compared with that of the undoped RGO-FET,leading to the conversion from ambipolar to unipolar p-type transfer characteristics.

关键词： Reduced graphene oxide Electrochemical doping treatment Electrical breakdown process Field-effect transistor

Hepatocellular carcinoma in Budd-Chiari syndrome:A single center experience with long-term follow-up in South Korea

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World Journal of Gastroenterology 2012年第16期18卷 1946-1952页

作者： Hana park Jin Young Yoon Kyeong Hye park Do Young Kim Sang hoon Ahn Kwang-Hyub Han chae Yoon Chon Jun Yong park Department of Internal Medicine Yonsei University College of MedicineSeoul 120-752South Korea Institute of Gastroenterology Yonsei University College of MedicineSeoul 120-752South Korea Liver Cirrhosis Clinical Research Center Seoul 120-752South Korea Brain South Korea 21 Project for Medical Science Seoul 120-752South Korea

AIM:To evaluate long-term clinical course of BuddChiari syndrome(BCS) and predictive factors associated with the development of hepatocellular carcinoma(HCC) and ***:We analyzed 67 patients with BCS between June 1988 and May *** diagnosis of BCS was confirmed by hepatic venous outflow obstruction shown on abdominal ultrasound sonography,computed tomography,magnetic resonance imaging,or *** median follow-up period was 103 ± 156 [interquartile range(IQR)] ***:The median age of the patients was 47 ± 16(IQR) *** diagnosis,54 patients had cirrhosis,25(37.3%) Child-Pugh class A,23(34.3%) Child-Pugh class B,and six(9.0%) patients Child-Pugh class *** the follow-up period,HCC was developed in 17 patients,and the annual incidence of HCC in patients with BCS was 2.8%.Patients in HCC group(n = 17) had higher hepatic venous pressure gradient(HVPG) than those in non-HCC group(n = 50)(21 ± 12 mmHg vs 14 ± 7 mmHg,P = 0.019).The survival rate of BCS patients was 86.2% for 5 years,73.8% for 10 years,and 61.2% for 15 *** patients with BCS and HCC,survival was 79% for 5 years,43.1% for 10 years,and 21.5% for 15 ***:The incidence of HCC in patients with BCS was similar to that in patients with other etiologic cirrhosis in South *** HVPG is expected to provide additional information for predicting HCC development in BCS patients.

关键词： Budd-Chiari syndrome Hepatocellular carcinoma Prognosis

Design and Demonstration of a Locust-Like Jumping Mechanism for Small-Scale Robots

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Journal of Bionic Engineering 2012年第3期9卷 271-281页

作者： Quoc-Viet Nguyen hoon Cheol park Department of Advanced Technology Fusion Konkuk University Seoul 143-701 Republic of Korea

A jumping mechanism can be an efficient mode of motion for small robots to overcome large obstacles on the ground and rough terrain. In this paper, we present a 7 g prototype of locust-inspired jumping mechanism that uses springs, wire, reduction gears, and a motor as the actuation components. The leg structure and muscles of a locust or grasshopper were mimicked using springs and wire, springs for passive extensor muscles, and a wire as a flexor muscle. A small motor was used to slowly charge the spring through a lever and gear system, and a cam with a special profile was used as a clicking mechanism for quick release of elastic energy stored in the springs to create a sudden kick for a quick jump. Performance analysis and experiments were conducted for comparison and performance estimation of the jumping mechanism prototype. Our prototype could produce standing jumps over obstacles that were about 14 times its own size （approximate to 71 cm） and a jumping distance of 20 times its own size （approximate to 100 cm）.

关键词： biomimetics locust jumping mechanism passive tibia extensor muscle

Efficacy of switching to telbivudine plus adefovir in suboptimal responders to lamivudine plus adefovir

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World Journal of Gastroenterology 2013年第43期19卷 7671-7679页

作者： Hana park Jun Yong park Seung Up Kim Do Young Kim Kwang-Hyub Han chae Yoon Chon Sang hoon Ahn Department of Internal Medicine CHA Bundang Medical CenterCHA UniversitySeongnam-si 463-712South Korea Department of Internal Medicine Yonsei University College of MedicineSeoul 120-752South Korea Institute of Gastroenterology Yonsei University College of MedicineLiver Cirrhosis Clinical Research CenterSeoul 120-752South Korea Institute of Gastroenterology Yonsei University College of MedicineSeoul 120-752South Korea Liver Cirrhosis Clinical Research Center Seoul 120-752South Korea Brain Korea 21 Project for Medical Science Seoul 120-752South Korea

AIM:To examine the efficacy of telbivudine(LdT)+adefovir(ADV)vs continuation of lamivudine(LAM)+ADV in patients with LAM-resistant chronic hepatitis B(CHB)who show a suboptimal response to LAM+***:This was a randomized,active-control,open-label,single-center,parallel *** eligible patients were enrolled in this study in Severance Hospital,Yonsei University College of Medicine,Seoul,South Korea,between March 2010 and March *** Be antigen(HBeAg)-positive CHB patients whose serum hepatitis B virus(HBV)DNA remained detectable despite at least 6 mo of LAM+ADV therapy were *** patients were randomized to either switching to LdT(600 mg/d orally)plus ADV(10 mg/d orally)(LdT+ADV group)or to continuation with LAM(100 mg/d orally)plus ADV(10 mg/d orally)(LAM+ADV group),and were followed for 48 *** hundred and six patients completed the 48-wk treatment *** HBV DNA,HBeAg status,liver biochemistry and safety were monitored at baseline and week 12,24,36 and ***:The duration of prior LAM+ADV treatment was 18.3(LdT+ADV)and 14.9 mo(LAM+ADV),respectively(P=0.131).No difference was seen in baseline serum HBV DNA between the two groups[3.66(LdT+ADV)vs 3.76(LAM+ADV)log10IU/mL,P=0.729].At week 48,although there was no significant difference in the mean reduction of serum HBV DNA from baseline between LdT+ADV group and LAM+ADV group(-0.81 vs-0.47 log10IU/mL,P=0.167),more patients in the LdT+ADV group had undetectable HBV DNA levels compared to those in the LAM+ADV group(30.2%vs 11.5%,P=0.019).Three patients with LdT+ADV treatment and 2 patients with LAM+ADV treatment achieved HBeAg *** patients in both groups tolerated the treatment well without serious adverse *** proportion of patients with estimated glomerular filtration rate≥90 mL/min per 1.73 m2in the LdT+ADV group increased from 49.1%(26/53)at baseline to 58.5%(31/53)at week 48,while that in the LAM+ADV group decreased from 37.7%(20/53)at baseline to 30.2%(16/53)at

关键词： Chronic hepatitis B Antiviral resistance Suboptimal response Telbivudine Lamivudine

Characterization of focal liver masses using acoustic radiation force impulse elastography

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World Journal of Gastroenterology 2013年第2期19卷 219-226页

作者： Hana park Jun Yong park Do Young Kim Sang hoon Ahn chae Yoon Chon Kwang-Hyub Han Seung Up Kim Division of Gastroenterology Department of Internal MedicineCHA Bundang Medical CenterCHA UniversityGyeonggi-do 463-712South Korea Department of Internal Medicine Yonsei University College of MedicineSeoul 120-752South Korea

AIM:To investigate the diagnostic performance of acoustic radiation force impulse(ARFI) elastography for characterizing focal liver mass by quantifying their ***:This prospective study included 62 patients with a focal liver mass that was well visualized on conventional ultrasonography performed in our institution from February 2011 to November *** them,12 patients were excluded for ARFI measurement failure due to a lesion that was smaller than the region of the interest and at an inaccessible location(deeper than 8 cm)(n = 7) or poor compliance to hold their breath as required(n = 5).Finally,50 patients with valid ARFI measurements were *** a patient had multiple liver masses,only one mass of interest was *** masses were diagnosed by histological examination or clinical diagnostic *** ultrasonographic evaluation,stiffness,expressed as velocity,was checked 10 times per focal liver mass and the surrounding liver ***:After further excluding three masses that were non-diagnostic on biopsy,a total of 47 focal mass lesions were tested,including 39(83.0%) malignant masses [24 hepatocellular carcinomas(HCC),seven cholangiocellular carcinomas(CCC),and eight liver metastases] and eight(17.0%) benign masses(five hemangiomas and three focal nodular hyperplasias,FNH).Thirty-seven(74.0%) masses were confirmed by histological *** mean velocity was 2.48 m/s in HCCs,1.65 m/s in CCCs,2.35 m/s in metastases,1.83 m/s in hemangiomas,and 0.97 m/s in *** considerable overlap was still noted between malignant and benign masses,significant differences in ARFI values were observed between malignant and benign masses(mean 2.31 m/s vs 1.51 m/s,P = 0.047),as well as between HCCs and benign masses(mean 2.48 m/s vs 1.51 m/s,P = 0.006).The areas under the receiver operating characteristics curves(AUROC) for discriminating the malignant masses from benign masses was 0.724(95%CI,0.566-0.883,P = 0.048),and the AUROC

关键词： Acoustic radiation force impulse Focal liver mass Hepatocellular carcinoma Hemangioma Focal nodular hyperplasia Cholangiocellular carcinoma Liver metastasis

Generation of Control Moments in an Insect-like Tailless Flapping-wing Micro Air Vehicle by Changing the Stroke-plane Angle

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Journal of Bionic Engineering 2016年第3期13卷 449-457页

作者： Hoang Vu Phan hoon Cheol park Artificial Muscle Research Center Konkuk University Seoul 143-701 South Korea Deptment of Advanced Technology Fusion Konkuk University Seoul 143-701 South Korea

We propose a control moment generator to control the attitude of an insect-like tailless Flapping-wing Micro Air Vehicle （FW-MAV）, where the flapping wings simultaneously produce the flight force and control moments. The generator tilts the stroke plane of each wing independently to direct the resultant aerodynamic force in the desired direction to ultimately generate pitch and yaw moments. A roll moment is produced by an additional mechanism that shifts the trailing edge, which changes the wing rotation angles of the two flapping wings and produces an asymmetric thrust. Images of the flapping wings are captured with a high-speed camera and clearly show that the FW-MAV can independently change the stroke planes of its two wings. The measured force and moment data prove that the control moment generator produces reasonable pitch and yaw moments by tilting the stroke plane and realizes a roll moment by shifting the position of the trailing edge at the wing root.

关键词： insect-like Flapping-wing Micro Air Vehicle (FW-MAV) control mechanism stroke plane beetle flight

Influence of Center of Gravity Location on Flight Dynamic Stability in a Hovering Tailless FW-MAV: Lateral Motion

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Journal of Bionic Engineering 2020年第1期17卷 148-160页

作者： Loan Thi Kim Au hoon Cheol park Department of Smart Vehicle Engineering and Artificial Muscle Research Center Konkuk UniversitySeoul 05029Korea

This paper reports the effect of the Center of Gravity(CG)position on lateral flight dynamic stability of hovering KUBeetle,a tailless FW-MAV,providing further insights on the effects of asymmetries in body mass distribution and wing *** the current study,the standard linearized equations of motion were applied as in the previous work on longitudinal dynamic *** stability derivatives were acquired using the computational fluid dynamic methods via the commercial software of ANSYS *** exists a stable region for CG between 2.6%and 3.5%of the mean chord below the wing pivot point,in which the lateral motion of hovering KUBeetle is passively *** CG below the stable region,because of an unstable oscillatory mode,the lateral motion of the FW-MAV is unstable but can be stabilized using rolling rate *** CG above the stable region,because of a divergence mode,the system remains unstable even with the rolling rate *** with other works on an FW-MAV based on a quasi-steady aerodynamic model and on insect showed similar characteristics for flapping *** is also interesting to note that the asymmetries in body mass and wing kinematics can enlarge the stable region of the system by a non-zero Ixz which approaches the root square of√IxIz,a negative LrNp,and a positive Ix2(Ir+Np).Combining the current result with that of the previous work on longitudinal motion,the most beneficial region of the CG for full 6-DOF flight dynamic stability of hovering KUBeetle was suggested.

关键词： FW-MAV center of gravity flight dynamic stability lateral motion asymmetry computational fluid dynamics bioinspired flight