Effect of Total Hip Arthroplasty on Ipsilateral Lower Limb Alignment and Knee Joint Space Width: Minimum 5-Year Follow-up

Choi Yun Seong,Park Jung-Wee,Kim Tae Woo,Kang Kee Soo,Lee Young-Kyun,Koo Kyung-Hoi,Chang Chong Bum 대한의학회 2023 Journal of Korean medical science Vol.38 No.20

Background: This study aimed to 1) assess the effect of total hip arthroplasty (THA) on coronal limb alignment, namely, the hip–knee–ankle angle (HKA), 2) identify factors that determine changes in the HKA, and 3) determine whether alignment changes influence the knee joint space width. Methods: We retrospectively evaluated 266 limbs of patients who underwent THA. Three types of prostheses with neck shaft angles (NSAs) of 132°, 135°, and 138° were used. Several radiographic parameters were measured in the preoperative and final radiographs (at least 5 years after THA). A paired t-test was used to confirm the effect of THA on HKA change. Multiple regression analysis was performed to identify radiographic parameters related to HKA changes following THA and changes in knee joint space width. Subgroup analyses were performed to reveal the effect of NSA change on the HKA change, and the proportion of total knee arthroplasty usage and changes in radiographic parameters between maintained joint space and narrowed joint space groups were compared. Results: The preoperative mean HKA was 1.4° varus and increased to 2.7° varus after THA. This change was related to changes in the NSA, lateral distal femoral angle, and femoral bowing angle. In particular, in the group with a decrease in NSA of > 5°, the preoperative mean HKA was largely changed from 1.4° varus to 4.6° varus after THA. The prostheses with NSA of 132° and 135° also led to greater varus HKA changes than those with an NSA of 138°. Narrowing of the medial knee joint space was related to changes in the varus direction of the HKA, decrease in NSA, increase in femoral offset. Conclusion: A large reduction in NSA can lead to considerable varus limb alignment after THA, which can have adverse effects on the medial compartment of the ipsilateral knee.

Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

<P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

강대영,송규상,최정목,노승무,정경수,오정연,김진향,양준묵,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

가속도계를 이용한 재료의 영계수 측정방법

손창호(Sohn, Chang-Ho),박진호(Park, Jin-Ho),윤두병(Yoon, Doo-Byung),정의필(Chong, Ui-Pil),최영철(Choi, Young-Chul) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.11

For the description of the elastic properties of linear objects a convenient parameter is the ratio of the stress to the strain, a parameter called the Young's modulus of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Conventional method for estimating Young's modulus measured the ratio of stress to corresponding strain below the proportional limit of a material using a tensile testing machine. But the method needs precision specimens and expensive equipment. In this paper, we proposed method for estimating Young's modulus using accelerometer. The basic idea comes from that the wave velocity is different as the Young's modulus. To obtain Young's modulus, a group velocity is obtained. It is difficult to measure group velocity. This is because plate medium has a dispersive characteristics which has different wave speed as frequency. In this paper, we used Wigner-Ville distribution to measure group velocity. To verify the proposed method, steel and acryl plate experiments have been performed. Experimental results show that the proposed method is powerful for estimating Young's modulus.

Predictive Risk Assessment Using Cooperation Concept for Collision Avoidance of Side Crash in Autonomous Lane Change Systems

Hyunsoo Lee,Chang Mook Kang,Wonhee Kim,Woo Young Choi,Chung Choo Chung 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

We present an innovative approach to risk assessment using cooperation concept for collision avoidance of side crash for autonomous lane change system. The cooperation concept is proposed to check an available space in the target lane for lane change in a short period of the future. Before moving to the target lane, the ego vehicle needs to check whether the object vehicle is cooperative or not for the lane change. The object vehicles are indexed as cooperative driver (CD) or non-cooperative driver (NCD) through the conditions based on the relative longitudinal acceleration and the collision free time. If the object vehicle is CD, the ego vehicle moves toward the target lane within the original lane for the preparation of the lane change. The ego vehicle should keep its lateral position within the original lane until the situation for the lane change becomes safe. As soon as the risk assessment becomes safe, the lane change is performed. Therefore, lane change can be started in advance compared to the conventional methods. The proposed method was validated via computational simulation and experimental results.

老化過程에서 흰쥐 滑車神經의 軸索의 數 및 直徑의 變化

최영수,엄창섭,서영석 최신의학사 1987 最新醫學 Vol.30 No.8

Population Changes of Moths (Insecta: Lepidoptera) from Mt. Wolchul National Park, Jeollanam-do, Korea

Choi, Sei-Woong,Park, Marana,Chang, Young-Hyo The Ecological Society of Korea 2007 Journal of Ecology and Environment Vol.30 No.3

We investigated the moth fauna and monthly changes in moth populations at three sites - Dogapsa, Gyungpodae and Muwisa - in Mt. Wolchul National Park, Jeollanam-do, South Korea. From February to October, 2006, we collected a total of 1677 individuals comprising 348 species in 14 families. Monthly changes in the abundance of species and individuals showed an M-shaped pattern, with the highest peak in June and a second high peak in August. The diversity of the three dominant families (Noctuidae, Geometridae and Pyralidae) at the three sites varied, possibly due to differences in vegetation and other environmental factors. Diversity at Dogapsa was relatively higher than Gyungpodae and Muwisa, but, the fauna at Dogapsa more closely resembled Muwisa than Gyungpodae. 28 species occurred at the same time in all three sites, included the families Geometridae (14 species), Noctuidae (9 species), Pyralidae (2 species), Arctiidae (1 species), Nolidae (1 species), and Limacodidae (1 species). The present study provided baseline information about biodiversity and phenological patterns of moth abundance and permitted evaluation of moth biodiversity as a monitoring tool for vegetation structure and environmental change.

카드뮴폭로후 고환, 신장 및 간장내 카드뮴축적량과 조직손상의 변화

이영구,박정덕,최병선,홍연표,장임원 大韓産業醫學會 1994 대한직업환경의학회지 Vol.6 No.1

To assess the changes of cadmium deposit and histopathologic finding of testis, liver and kidney, different dose of cadmium (Cd) was administerd into male Sprague-Dawley rat(purchased from KIST, Korea Institute of Science and technology) by single intravenous injection. At 12, 24, 48, 168 and 672 hours after Cd injection, tissue cadmium concentration and histopathological change were examined. Cd exposed group showed lesser weight gain than the control. Renal Cd content tended to increase in time-dependent pattern, while hepatic and testicular Cd content tended to decrease. Mean of renal Cd content to hepatic Cd content (Cd K/Cd L) also progressively increased. These results suggest that Cd might be gradually transported to kidney from other organs. In testis and liver, degenerative changes appeared relatively in acute phase. These changes became more pronounced in testis, while less prominent in liver. In kidney, swelling of proximal tubluar cells and thickening of glomerular basement membrane appeared relatively later and these changes were progressively aggravated.

개에서 동소성 간이식술시의 대사 및 혈역학적 변화

이창준,홍순용,신근만,최영룡,이영주,문종선 대한마취과학회 1993 Korean Journal of Anesthesiology Vol.26 No.3

Skilled and experienced anestheia is of great importance for patients undergoing orthotopic liver transplantation, because of multiple preexisting medical problems in such patients as well as the intraoperative problems of rapid hemodynamic, metabolic, and coagulation changes. In this study, the intraoperative hemodynamic and laboratory data were analyzed in ten dogs that underwent an orthotopic liver transplantation procedure by veno-venous bypass using Biopump. Liver transplantation can be divided into three distinct periods: stage I, or preanhepatic stage, which begins with the induction of anesthesia and continues until cross clamping of portal vein and IVC; stage II, or anhepatic stage, which begins at the anhepatic time and continues until the donor liver is reperfused by the recipients circulating blood; and stage III, or postanhepatic stage, which begins at the time of reperfusion and continues until the end of surgical procedure. The hemodynamic changes at the time of IVC and portal vein cross clamping were decreases in CVP, PCWP, and pulmonary artery pressure in spite of using Biopump. The significant metabolic alternations during anhepatic stage were decrease in blood glucose levels and increase in blood lactate levels. The more significant hemodynamic changes occurred at the time of reperfusion. Systolic pressure decreased suddenly to 58±6 mmHg and cardiac output decreased to 1.08±0.1l L/min. However heart rate, pulmonary artery pressure, CVP, and PCWP did not change significantly. During stage III, hyperglycemia occurred quite frequently. Significant abnormal coagulation chages could not be found, probably because the dogs were healthy. In conclusion, during anhepatic stage, we have to compensate for alternations of fluid balance. At the time of reperfusion, we should prevent severe hemodynamic changes and treat them immediately if they occur. However, it seems that glucose administration is not necessary to the liver recipient during stage II because there is no significant hemodynamic depression e to hypoglycemia at this time and hyperglycemia occurs later

인덕터의 DC 바이어스 특성을 고려한 대용량 DC-DC 컨버터의 손실계산

조영창(Young-Chang Jo),최주엽(Ju-Yeop Choi),정승기(Seung-Ki Jung),최익(Ick Choy),송승호(Seung-Ho Song) 대한전기학회 2011 전기학회논문지 Vol.60 No.4

It is necessary to accurately predict converter losses for optimized design of a high-power DC-DC converter. The losses of switching devices and inductor among the elements of the converter take significantly greater proportion. The current ripple will be determined by the size of the inductance and this inductance value varies depending on the DC amount of inductor current. As the inductance changes according to load current, the change influences not only the inductor loss itself but also the total converter loss. In this paper, for more accurate design of a bi-directional DC-DC converter for 30㎾-class energy storage system, more accurate computational model is proposed considering inductance variation according to the load current change. The inductance changes using variable magnetic cores are verified and converter efficiency is tested through simulations and experiments.