• Title/Summary/Keyword: Improved materials

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Arthroscopic Ankle Arthrodesis Using Three Cannulated Screws (3개의 유관 나사를 이용한 관절경적 족근 관절 고정술)

  • Kim, Kyung-Tae;Lee, Song;Ko, Dong-Oh;Yang, Seung-Jin;Chun, Tae-Hwan;Yang, Jong-Hwa
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.3
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    • pp.249-253
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    • 2009
  • Purpose: We evaluated the clinical and radiographic results of arthroscopic ankle arthrodesis using 3 cannulated screws for the treatment of arthritis of ankle. Materials and Methods: From May 2006 to February 2009, 17 cases of arthritis of ankle were treated by ankle arthrodesis using 3 cannulated screws under arthroscopy. There were 8 male and 7 female and the average age was 62.2 years. We evaluated them clinically using AOFAS ankle-hindfoot functional scale, VAS pain score and patient’s satisfaction. For the radiographic evaluation, we checked them by simple AP, lateral and mortise view. The average follow-up period was 24.2 months. Results: The ankle-hindfoot functional scale was improved from an average of 47.4 points preoperatively to an average of 82.5 points at the last follow-up. The visual analogue scale pain score was decreased from an average of 8.6 to 2.4. Patient's satisfaction had favorable results with excellent in 7 cases(41.2%), good in 8 cases(47.0%), fair in 1 case(5.9%) and poor in1 case(5.9%). All ankles were successfully fused and the mean period of fusion was 9.1 weeks. Conclusion: Arthroscopic ankle arthrodesis using 3 cannulated screws was good modality of ankle arthrodesis with good clinical results and high union rate in the case of advanced ankle arthritis.

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Study of Factors Controlling Exposure Dose and Image Quality of C-arm in Operation Room according to Detector Size of It (Mainly L-Spine AP Study) (수술 중 C-Arm Neutral AP 검사 시 조절인자에 따른 피폭선량 및 화질비교(L-Spine AP검사를 기준으로))

  • CHOI, Sung-Hyun;JO, Hwang-Woo;Dong, Kyung-Rae;Chung, Woon-Kwan;Choi, Eun-Jin;Song, Ha-jin
    • Journal of Radiation Industry
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    • v.9 no.2
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    • pp.85-90
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    • 2015
  • Purpose: Time of operation has been reduced and accuracy of operation has been improved since C-arm, which offer real-time image of patient, was introduced in operation room. However, because of the contamination of patient, C-arm could not be used more appropriately. Therefore, this study is to know factors of controlling exposure dose, image quality and the exposed dose of health professional in operation room. Materials and methods: Height of Wilson frame (bed for operation) was fixed at 130 cm. Then, Model 76-2 Phantom, which was set by assembling manual of Fluke Company, was set on the bed. Head/Spine Fluoroscopy AEC mode was set for exposure condition. According to detector size of C-arm, the absorbed dose per min was measured in the 7 steps OFD (cm) from 10 cm to 40 cm (10, 15, 20, 25, 30, 35, 40 cm). In each step of OFD, the absorbed dose per min of same diameter of collimation was measured. Moreover, using Nero MAX Model 8000, exposure dose per min was measured according to 3 step of distance from detector (20 cm, 60 cm, 100 cm). Finally, resolution was measured by CDRH Disc Phantom and magnification of each OFD was measured by aluminum stick bar. Result: According to detector size of C-arm, difference of absorbed dose shows that the dose of 20 cm OFD is 1.750 times higher than the dose of 40 cm OFD. It means that the C-arm, which has smaller size of detector, shows the bigger difference of absorbed dose per min (p<0.05). In the difference of absorbed dose in the same step of OFD (from 20 cm to 40 cm), the absorbed dose of 9 inch detect or C-arm was 1.370 times higher than 12 inch' s (p<0.05). When OFD was set to 20 cm OFD, the absorbed dose of non-collimation case was approximately 0.816 times lower than the absorbed dose of collimation cases (p<0.05). When the distance was 20 cm from detector, exposed does includes first-ray and scatter-ray. When the distance was 60 cm and 100 cm from detector, exposed does includes just scatter-ray. So, there was the 2.200 times difference of absorbed does. Finally, when OFD was increased, spatial resolution was 4 to 5 step was increased. However, low contrast resolution was not relative. Moreover, there was 1.363 times difference of magnification (p<0.05). Conclusion: When C-Arm is used, avoiding contamination of patient is more important factor than reducing exposed dose of health professional in operation room. Just controlling exposure time is just way to reduce the exposed does of workers. However, in the case, non-probability influence could be occurred. Therefore, this study proved that the exposed dose will be reduced if the factors such as using small detector size of C-arm, setting OFD from 20 cm to 25 cm and non-collimating. Moreover, dose management of C-arm in the non-interesting area will be considered additionally.

Changes of Microbial Community Associated with Construction Method and Maintenance Practise on Soil Profile in Golf Courses (지반 조성과 관리방법에 따른 골프장 토양내 미생물 군집의 변화)

  • Moon, Kyung-Hee;Kim, Ki-Dong;Joo, Young-Kyoo
    • Asian Journal of Turfgrass Science
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    • v.23 no.2
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    • pp.219-228
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    • 2009
  • The construction procedures and artificial turf maintenance program on golf course definitely influence on the distortion of its environment. Soil microbial communities in soil profile were affected directly by those practises on turf areas. In Jeju island, the environmental impact assessment has been required to apply the first quality class granular activated carbon(GAC), which has a high absorbent character to agricultural chemicals, on the soil profiles of golf green system to reduce the pesticide leaching to ground water. This research was carried out to analyze the changes of microbial communities and chemical properties on soil profiles where GAC had been applied at the construction stage at two golf courses in Jeju. The changes of soil microbial population and chemical properties associated with construction methods of soil profile and agrochemical management program were analyzed by monthly at the surface and sub-soil profiles during April through October, 2007. The total numbers of bacteria and fungi, soil moisture content, soil physio-chemical properties were measured on greens and fairways of the both golf courses with different GAC treatment on the green and fairway soil profiles. The results showed that GAC had positive effects on the water holding capacity, pH and EC, however, it did not improved the holding capacity of available nutrients ${NO_3}^-,{NH_4}^+$, and phosphorus by its sorption phenomenon. In microbial count test, the total numbers of bacteria and fungi showed a great variation during sampling dates. That may directly relate to the agrochemical application, however, the ratio of total bacterial number versus total fungus number showed a constant value on a sub-soil of 15~30cm depth. Thus, the construction method of GAC in soil profile, and application of fertilizer and pesticide, both impacted on the changes of microbial population. It's means that the construction method of soil profile and turf management using agro-materials might greatly affect on the turfgrass culture and the environment of golf course.

Introduction on the Products and the Quality Management Plans for GOCI-II (천리안 해양위성 2호 산출물 및 품질관리 계획)

  • Lee, Sun-Ju;Lee, Kyeong-Sang;Han, Tae Hyun;Moon, Jeong-Eon;Bae, Sujung;Choi, Jong-kuk
    • Korean Journal of Remote Sensing
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    • v.37 no.5_2
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    • pp.1245-1257
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    • 2021
  • GOCI-II, succeeding the mission of GOCI, was launched in February 2020 and has been in regular operation since October 2020. Korea Institute of Ocean Science and Technology (KIOST) processes and produces in real time Level-1B and 26 Level-2 outputs, which then are provided by Korea Hydrographic and Oceanographic Agency (KHOA). We introduced current status of regular GOCI-II operation and showed future improvement. Basic GOCI-II products including chlorophyll-a, total suspended materials, and colored dissolved organic matter concentration, are induced by OC4 and YOC algorithms, which were described in detail. For the full disk (FD), imaging schedule was established considering solar zenith angle and sun glint during the in-orbital test, but improved by further considering satellite zenith angle. The number of slots satisfying the condition 'Best Ocean' significantly increased from 15 to 78. GOCI-II calibration requirements were presented based on that by European Space Agency (ESA) and candidate fixed locations for calibrating local observation area were. The quality management of FD uses research ships and overseas bases of KIOST, but it is necessary to establish an international calibration/validation network. These results are expected to enhance the understanding of users for output processing and help establish detailed plans for future quality management tasks.

The Therapeutic Effect of Postganglionic Nerve Block for Symptomatic Schmorl Nodule: A Retrospective Case Series (증후성 쉬모를 결절에 대한 신경절 이후 신경차단술의 치료 효과: 후향적 증례 분석)

  • Son, In Seok;Hwang, Suk Hyun;Lee, Suk Ha;Kang, Min Seok
    • Journal of Korean Society of Spine Surgery
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    • v.25 no.4
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    • pp.147-153
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    • 2018
  • Study Design: Retrospective case series. Objectives: We retrospectively evaluated the clinical efficacy of postganglionic nerve block in symptomatic Schmorl nodules (SNs). Summary of Literature Review: SNs are common lesions that are often asymptomatic. In certain cases, SNs have been reported to cause severe axial back pain, thereby considerably impacting patients' quality of life. No consensus currently exists on the treatment of symptomatic SNs. Materials and Methods: From October 2015 to October 2017, a total of 21 patients with symptomatic SNs diagnosed by magnetic resonance imaging (MRI) that did not respond to conservative treatment after 4 weeks were included in the study. All patients received postganglionic nerve block. We evaluated effective pain relief (improvement of back pain of more than 50% compared with before the intervention) and functional improvements, assessed by visual analogue scale (VAS) and Oswestry Disability Index scores obtained at 4 hours, 4 weeks, 8 weeks, 3 months, and 6 months after the procedure. Results: Symptomatic SNs were more common at the L2-3 level, and the lower end plate was more commonly involved than the upper end plate. Eighteen of the 21 patients (85.7%) showed effective pain relief, and no deterioration was observed within the followup period. Throughout the follow-up period, the VAS remained significantly improved compared to before the procedure (p<0.05). Complications were not reported in any cases. Conclusions: Postganglionic nerve block for symptomatic SNs that do not respond to conservative treatment is a non-invasive modality for pain relief.

Stem cell attached 3-dimentional printed polycarprolactone scaffold (줄기세포 탑재 3차원 프린팅 polycarprolactone 스캐폴드)

  • Hong, Gyusik;Cho, Jeong Hwan;Yun, Seokhwan;Choi, Eunjeong;An, Seongmin;Kim, Jung Seok;Lee, Jae Sam;Shim, Jin-hyung;Jin, Songwan;Yun, Won-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.618-626
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    • 2019
  • Stem cell therapy is not expected to bestow any therapeutic benefit because of the low engraftment rates after transplantation.Various cell-carrying scaffolds have been developed in order to overcome this problem. When the scaffold is formed by 3-dimensional (3D) printing, it is possible to create various shapes of scaffolds for specific regions of injury. At the same time, scaffolds provide stem cells as therapeutic-agents and mechanically support an injured region. PCL is not only cost effective, but it is also a widely used material for 3D printing. Therefore, rapid and economical technology development can be achieved when PCL is printed and used as a cell carrier. Yet PCL materials do not perform well as cell carriers, and only a few cells survive on the PCL surface. In this study, we tried to determine the conditions that maximize the cell-loading capacity on the PCL surface to overcome this issue. By applying a plasma treated condition and then collagen coating known to improve the cell loading capacity, it was confirmed that the 3% collagen coating after plasma treatment showed the best cell engraftment capacity during 72 hours after cell loading. By applying the spheroid cell culture method and scaffold structure change, which can affect the cell loading ability, the spheroid cell culture methods vastly improved cell engraftment, and the scaffold structure did not affect the cell engraftment properties. We will conduct further experiments using PCL material as a cell carrier and as based the excellent results of this study.

Mid-Term Results of Fixed Bearing Unicompartmental Knee Arthroplasty: Minimum 5-Year Follow-Up (고정형 슬관절 단일 구획 치환술의 중기 추시 결과: 최소 5년 추시)

  • Oh, Jeong Han;Joo, Il-Han;Kong, Dong-Yi;Choi, Choong-Hyeok
    • Journal of the Korean Orthopaedic Association
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    • v.53 no.6
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    • pp.498-504
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    • 2018
  • Purpose: To evaluate the clinical and radiological outcomes, and the complications of unicompartmental knee arthroplasty (UKA) using a fixed bearing prosthesis after 5-year follow-up. Materials and Methods: Twenty-six knees (25 patients) that underwent fixed bearing UKA between May 2003 and August 2011 were included. The subjects were 3 males (3 knees) and 22 females (23 knees), and the average age was 63.5 years. The preoperative diagnosis was osteoarthritis (23 knees) and osteonecrosis (3 knees). The mean follow-up duration was 67 months (from 60 to 149 months). The clinical evaluation included pre- and postoperative American knee society knee and function score, and range of motion. The radiology evaluation included standing antero-posterior, lateral view, and fluoroscopic film to analyze the postoperative alignment and osteolysis. Results: The mean American Knee Society knee score and function score were improved from 42.0 and 57.5 to 87.9 and 85.0, respectively (p<0.001). The mean preoperative and postoperative range of motion was $132.9^{\circ}$ and $132.5^{\circ}$, respectively. The mean femorotibial angle were varus $0.5^{\circ}$ preoperatively and valgus $2.2^{\circ}$ postoperatively. A radiolucent line was observed in 2 knees; one knee had a stable implant, while in the other knee, patellofemoral arthritis was identified during UKA. Diffuse pain of the knee joint with tenderness of the medial joint line was identified at the follow-up, so conversion to total knee arthroplasty was recommended. No other complications, such as osteolysis, infections, postoperative stiffness, and dislocation, were encountered. Conclusion: The midterm results of fixed bearing UKA were clinically and radiologically satisfactory.

Cementless Total Hip Arthroplasty Using Ceramic Femoral Head on Cross-Linked Ultra-High-Molecular Weight Polyethylene Liner in Patients Older than 65 Years: Minimum Five-Year Follow-Up Results (세라믹 대퇴 골두 및 교차결합 초고분자량 폴리에틸렌 라이너를 이용한 65세 이상 무시멘트형 인공 고관절 전치환술: 최소 5년 중기 추시 결과)

  • Yun, Ho Hyun;Cheong, Ji Young;Sim, Hyun Bo;Park, Jae Hong
    • Journal of the Korean Orthopaedic Association
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    • v.53 no.6
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    • pp.490-497
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    • 2018
  • Purpose: To evaluate the utility of ceramic-on-polyethylene articular bearing surface when cementless total hip arthroplasty is performed in patients older than 65 years through an analysis of the minimum five-year follow-up results using the ceramic femoral head and cross-linked polyethylene liner. Materials and Methods: From March 2010 to September 2012, 51 patients (56 hips) who were older than 65 years were enrolled in this retrospective study. The mean age at surgery was $70.9{\pm}5.1years$ old. A clinical assessment was analyzed using the Harris hip score. For the radiographic assessment, the cup inclination and anteversion, stem alignment, and wear amount were measured. The postoperative complications were also determined. Results: The mean Harris hip score was improved from preoperative 48 points to postoperative 87 points (p<0.05). The mean cup inclination was $40.9^{\circ}{\pm}6.4^{\circ}$ and the mean cup anteversion was $20.3^{\circ}{\pm}8.1^{\circ}$. The mean cup anteversion of the elevated liner-used group (16 cases) was $14.3^{\circ}{\pm}7.9^{\circ}$ and the mean cup anteversion of the neutral liner used group (40 cases) was $22.4^{\circ}{\pm}9.1^{\circ}$ (p<0.05). The mean stem alignment angle was $0^{\circ}$ (range, varus $4^{\circ}$-valgus $4^{\circ}$). The mean linear wear amount was $0.458{\pm}0.041mm$ and the average annual linear wear rate was $0.079{\pm}0.032mm/yr$. Six cases (10.7%) of intraoperative periprosthetic femoral fractures were encountered. Conclusion: Based on these results, the use of a ceramic-on-polyethylene articular bearing surface in elderly patients with cementless total hip arthroplasty is beneficial. On the other hand, careful effort is needed to prevent intraoperative periprosthetic femoral fractures.

Comparison of Doses of Single Scan PBS and Layered Rescanning PBS Using Moving Phantom in Proton Therapy (양성자 치료에서 Moving Phantom을 이용한 Single Scan PBS와 Layered Rescanning PBS의 선량비교)

  • Kim, Kyeong Tae;Kim, Seon Yeong;Kim, Dae Woong;Kim, Jae Won;Park, Ji Yeon;Jeon, Sang Min
    • The Journal of Korean Society for Radiation Therapy
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    • v.31 no.1
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    • pp.43-49
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    • 2019
  • Purpose : We apply the Layered Rescanning PBS designed to complement the Pencil Beam Scanning(PBS), which is vulnerable to moving organs with the Moving Phantom, and compare the homogeneity with the single scan PBS. Methods and materials: Matrix X (IBA, Belgium) and Moving Phantom (standard imaging, USA) were used. A dose of 200 cGy was measured in the AP direction on a hypothetical tumor $10{\times}10{\times}5cm$. The plan type was planned as 4 kinds of sinlge scan PBS, rescan number 4, 8, 12 times. Were measured three times for each types. During the measurement, the respiratory cycle of the Moving Phantom was generally set to 4 seconds per cycle, and the movement radius in the S-I direction was set to 2 cm. In addition, beam on time was measured. Results : The mean values of $D_{max}$ in the PTV were $246.47{\pm}18.8cGy$, $223.43{\pm}8.92cGy$, and $222.47{\pm}7.7cGy$, $213.9{\pm}6.11cGy$ and the mean values of $D_{min}$ were $165.53{\pm}4.32cGy$, $173.13{\pm}11.94cGy$, $184.13{\pm}8.04cGy$, $182.67{\pm}4.38cGy$ and the mean values of $D_{mean}$ $192.77{\pm}6.98cGy$, $196.7{\pm}4.01cGy$, $198.17{\pm}4.96cGy$, $195.77{\pm}3.15cGy$ respectively. As the number of rescanning increased, the Homogeneity Index converged to 1. The beam on time was measured as 2:15, 3:15, 4:30, 5:37 on average. In the measurement process, in the low dose layer of the MU, the problem was found that it was not rescanned as many times as the set number of rescan. Conclusions : In the treatment of tumors with long-term movements, the application of layered rescanning PBS showed a more uniform dose distribution than single scan PBS. And as the number of rescan increase, the distribution of homogeneity is uniform. Compared with single scan plan and 12 rescan plan, HI value was improved by 0.32. Further studies are expected to be applicable to patients who can not be treated with respiratory synchronous radiation therapy.

An investigation Of IntraFraction Motion Correction For Lung Stereotactic Body Radiation Therapy By Using IntraFraction Cone Beam Computed Tomography (폐암 환자의 정위적 체부 방사선 치료 시 IntraFraction CBCT를 이용한 치료 중 자세 오차 교정에 대한 고찰)

  • Song, Hyeong Seok;Cho, Kang Chul;Park, Hyo Kuk;Yoon, Jong Won;Cho, Jung Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.31 no.1
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    • pp.67-74
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    • 2019
  • Purpose: The purpose is to correct for position errors caused by long treatment times. By correcting the target motion that can occur during lung SBRT using IntraFraction CBCT. Methods and materials: We analyzed retrospectively the IFM data of 14 patients with two treatment arc in the treatment plan for lung cancer with stereotactic radiotherapy. An IntraFraction Motion was applied to the Arccheck phantom to acquire the Gamma index data. Results : IntraFraction Motion during the first treatment arc is in the left-right(LR), superiorinferior(SI), anterior-posterior(AP) directions were $0.16{\pm}0.05cm$, 0.72 cm(max error), $0.2{\pm}0.14cm$, 1.26 cm, $0.24{\pm}0.08cm$, 0.82 cm and rotational directions was $0.84{\pm}0.23^{\circ}$, $2.8^{\circ}$(pitch), $0.72{\pm}0.23^{\circ}$, $2.5^{\circ}$(yaw), $0.7{\pm}0.19^{\circ}$, $2^{\circ}$(roll). IntraFraction Motion during the second treatment arc is in the LR, SI, AP directions were $0.1{\pm}0.04cm$, 0.37 cm, $0.14{\pm}0.17cm$, 2 cm, $0.12{\pm}0.04cm$, 0.5 cm and rotational directions was $0.45{\pm}0.12^{\circ}$, $1.3^{\circ}$, $0.37{\pm}0.1^{\circ}$, $1^{\circ}$, $0.35{\pm}0.1^{\circ}$, $1.2^{\circ}$. Gamma index pass rates were $82.64{\pm}10.51%$, 48.4 %. Conclusions : In this study, we examined the validity of IntraFraction Motion correction in lung SBRT and the efficiency of IntraFraction CBCT. Due to the nature of SBRT treatment, IFM may increase due to the increased treatment time. It is believed that the increase in IFM with the increase in treatment time can be improved with the use of FFF Beam and additional position correction using CBCT during treatment.