Crystallization of Local Anesthetics When Mixed With Corticosteroid Solutions

Hyeoncheol Hwang,Jihong Park,Won Kyung Lee,Woo Hyung Lee,이자호,Jin Joo Lee,Sun G. Chung,Chaiyoung Lim,Sang Jun Park,Keewon Kim 대한재활의학회 2016 Annals of Rehabilitation Medicine Vol.40 No.1

Objective To evaluate at which pH level various local anesthetics precipitate, and to confirm which combination of corticosteroid and local anesthetic crystallizes.Methods Each of ropivacaine-HCl, bupivacaine-HCl, and lidocaine-HCl was mixed with 4 different concentrations of NaOH solutions. Also, each of the three local anesthetics was mixed with the same volume of 3 corticosteroid solutions (triamcinolone acetonide, dexamethasone sodium phosphate, and betamethasone sodium phosphate). Precipitation of the local anesthetics (or not) was observed, by the naked eye and by microscope. The pH of each solution and the size of the precipitated crystal were measured.Results Alkalinized with NaOH to a certain value of pH, local anesthetics precipitated (ropivacaine pH 6.9, bupivacaine pH 7.7, and lidocaine pH 12.9). Precipitation was observed as a cloudy appearance by the naked eye and as the aggregation of small particles (<10 m) by microscope. The amount of particles and aggregation increased with increased pH. Mixed with betamethasone sodium phosphate, ropivacaine was precipitated in the form of numerous large crystals (>300 m, pH 7.5). Ropivacaine with dexamethasone sodium phosphate also precipitated, but it was only observable by microscope (a few crystals of 10–100 m, pH 7.0). Bupivacaine with betamethasone sodium phosphate formed precipitates of non-aggregated smaller particles (<10 m, pH 7.7). Lidocaine mixed with corticosteroids did not precipitate.Conclusion Ropivacaine and bupivacaine can precipitate by alkalinization at a physiological pH, and therefore also produce crystals at a physiological pH when they are mixed with betamethasone sodium phosphate. Thus, the potential risk should be noted for their use in interventions, such as epidural steroid injections.

The Overexpression of Aldehyde Dehydrogenase Improves Furfural Tolerance and Lipid Production of Yarrowia lipolytica from Lignocellulosic Biomass

Jiwon KIM,Hyeoncheol Francis SON,Sungmin HWANG,Youngsoon UM,Sung Ok HAN,Sun-Mi LEE 한국생물공학회 2022 한국생물공학회 학술대회 Vol.2022 No.9

TANK 모형의 매개변수 민감도 분석에 따른 최적화 프로그램 개발

맹승진 ( Seungjin Maeng ),김다예 ( Daye Kim ),윤현철 ( Hyeoncheol Yoon ),황주하 ( Juha Hwang ),김원범 ( Wonbeom Kim ) 한국농공학회 2020 한국농공학회 학술대회초록집 Vol.2020 No.-

본 연구에서는 우리나라의 농업용 저수지의 모의된 유입량을 TANK 모형에 의해 산정하고 관측된 유입량과 비교하였다. 관측유입량과 모의유입량간의 신뢰성을 높이기 위해 우선적으로 TANK 모형 매개변수의 민감도를 분석하였다. 민감도 분석을 위해 토지이용도, 유역면적, 유효저수량 등을 이용하여 대표 저수지를 선정하였다. 대표 저수지의 특정년을 대상으로 고수시와 저수시로 구분하여 매개변수 민감도 분석 결과 유입량이 고수시에는 A2, HA2, A1, A0 순으로, 저수시에는 HA2, A2, B1, B0 순으로 민감하게 반응하였다. 즉 고수시에는 1단 TANK 중심의 계수로 민감하였으며 저수시에는 1단 TANK 중심의 계수로 민감하게 나타났다. 고수시와 저수시를 모두 고려하면 매개변수가 A2, HA2, B1, B0순으로 민감하게 나타났다. 또한, 매개변수 민감도 분석 결과를 기반으로 190개의 저수지에 대한 매개변수 최적화를 실시하였다. 190개 저수지의 매개변수 초기값은 수자원장기종합계획(2011)에서 결정된 중권역별로 제시된 값으로 적용하였다. 즉 해당저수지가 1001중권역에 포함되어 있으며 수자원장기종합계획 1001 중권역에 해당하는 매개변수를 초기값으로 하였다. 저수지별로 TANK 모형의 매개변수 초기값을 기준으로 매개변수의 민감도 순(B1, B0, A0, HA1, A1, C1, C0, D1 순)으로 초기값을 기준하여 최소 -50%, 최대 50%로 하고 5% 간격으로 매개변수를 변화해 가면서 목적함수인 NSE(Nash-Sutcliffe Efficiency)와 체적비(Ratio Of Volume, ROV))가 1에 가깝게 산정되는 매개변수 군을 최종 매개변수로 결정하였다. TANK 모형의 매개변수 민감도 분석을 통한 매개변수 최적화 프로그램은 미계측 저수지를 대상으로 저수지 유역 특성이 유사한 저수지의 유입량 산정에 기여 할 수 있을 것으로 기대된다.

Effects of Hydrodilatation With Corticosteroid Injection and Biomechanical Properties in Patients With Adhesive Capsulitis After Breast Cancer Surgery

Chang Won Lee,In Soo Kim,Jeong-Gil Kim,Hyeoncheol Hwang,Il Young Jung,Shi-Uk Lee,Kwan-Sik Seo 대한재활의학회 2022 Annals of Rehabilitation Medicine Vol.46 No.4

Objective To compare the biomechanical properties of the glenohumeral joint capsule between adhesive capsulitis (AC) after breast cancer surgery and idiopathic AC and demonstrate the effects of hydrodilatation (HD) with corticosteroid injection for AC after breast cancer surgery.Methods Twenty-three prospective patients with AC after breast cancer surgery (BC group) and 44 retrospective patients with idiopathic AC without breast cancer (CON group) underwent HD with corticosteroid injection and home exercise training. We compared their biomechanical characteristics (capsular capacity, maximal pressure, and capsular stiffness). In the BC group, the passive range of motion (ROM) of the affected shoulder and a questionnaire (Shoulder Pain and Disability Index [SPADI]) were evaluated at baseline and 2 and 4 weeks after treatment.Results The BC group showed higher biomechanical characteristics (maximal pressure and capsular stiffness) than did the CON group. The mean maximal pressure and capsular stiffness were 519.67±120.90 mmHg and 19.69±10.58 mmHg/mL in the BC group and 424.78±104.42 mmHg and 11.55±7.77 mmHg/mL in the CON group (p=0.002 and p=0.001, respectively). And, the BC group showed significant improvements in all ROMs (abduction, flexion, and external rotation) and the SPADI pain and disability sub-scores following the treatment.Conclusion The glenohumeral joint capsular stiffness was greater in the patients with AC after breast cancer surgery than in those with idiopathic AC. HD with corticosteroid injection was effective in treating AC after breast cancer surgery.

Validation of Attitude and Heading Reference System and Microsoft Kinect for Continuous Measurement of Cervical Range of Motion Compared to the Optical Motion Capture System

Young Seop Song,Kyung Yong Yang,Kibum Youn,Chiyul Yoon,Jiwoon Yeom,Hyeoncheol Hwang,Jehee Lee,Keewon Kim 대한재활의학회 2016 Annals of Rehabilitation Medicine Vol.40 No.4

Objective To compare optical motion capture system (MoCap), attitude and heading reference system (AHRS) sensor, and Microsoft Kinect for the continuous measurement of cervical range of motion (ROM).Methods Fifteen healthy adult subjects were asked to sit in front of the Kinect camera with optical markers and AHRS sensors attached to the body in a room equipped with optical motion capture camera. Subjects were instructed to independently perform axial rotation followed by flexion/extension and lateral bending. Each movement was repeated 5 times while being measured simultaneously with 3 devices. Using the MoCap system as the gold standard, the validity of AHRS and Kinect for measurement of cervical ROM was assessed by calculating correlation coefficient and Bland–Altman plot with 95% limits of agreement (LoA). Results MoCap and ARHS showed fair agreement (95% LoA<10o), while MoCap and Kinect showed less favorable agreement (95% LoA>10o) for measuring ROM in all directions. Intraclass correlation coefficient (ICC) values between MoCap and AHRS in –40o to 40o range were excellent for flexion/extension and lateral bending (ICC>0.9). ICC values were also fair for axial rotation (ICC>0.8). ICC values between MoCap and Kinect system in –40o to 40o range were fair for all motions.Conclusion Our study showed feasibility of using AHRS to measure cervical ROM during continuous motion with an acceptable range of error. AHRS and Kinect system can also be used for continuous monitoring of flexion/extension and lateral bending in ordinary range.

트램사고 방지를 위한 사고유형 분석 및 교차로 제어방안에 대한 고찰

김유호(You-Ho Kim),이수환(Soo-Hwan Lee),김예지(Ye Ji Kim),황현철(Hyeoncheol Hwang) 대한전기학회 2015 전기학회논문지 P Vol.64 No.4

Korea"s first tram (so called "tram" ), which was commenced the operation on May 4, 1899 of late Joseon Dynasty and run until 1968, played a pivotal role of public transportation. However, tram as new transportation mean is being recognized as traffic congestion problem becomes issue due to geometric automobile increase and reckless urban plan after stoppage of tram service. Tram has an advantage of inexpensive construction cost and eco-friendly means compared to existing and city railway, carrying more passengers rather than existing bus, excellent connectivity of existing transportation because of easy accessible to destination in the city center. Therefore, tram, what is called "Green Rvolution of Public Transportation", has a dreaming of revival and in the process of pushing. We suggest the accident type which might break out in the early stage of tram introduction and preventive measures by surveying the accident cases of tram advanced country, and study the crossing control measures.