• Radiation Oncology Journal
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• 제23권2호
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• pp.123-130
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• 2005

목적: 유방암 환자치료 과정에서 breast board를 이용한 방사선 치료시, 환자 위치 재현성을 향상시킬 수 있는 방법론을 개발하고, 효용성을 검증한다. 대상 및 방법: 환자와 breast board 사이에서 기존의 오목한 두개골 판 사용시 발생할 수 있는 오차를 개선하기 위해서, 두경부 지지대를 breast board에 장착할 수 있도록 개조한 장치를 개발하였다. 이 장치가 breast board에 장착된 상태에서 두부(頭部)의 위치를 측정할 수 있는 계측도구를 사용하여, 체중이 다른 2명의 자원자에 대해 각각 50회에 걸쳐 재현성을 검증하였다. breast board의 좌우 방향의 기울어짐을 방지하기 위하여서는, breast board 상하부에 지지대를 장착하여 높이에 맞게 아크릴 판을 삽입하여 좌우를 고정하는 계단형 좌우 고정장치와, breast board 측면에 홈으로 연결된 두 개의 알루미늄 지지대를 장착하여, 수평계로 보정된 높이를 고정시킬 수 있는 팔걸이형 좌우 고정장치를 개발하였다. 장치의 유무에 따라 좌우의 편중 하중에 대한 breast board의 좌우 높이(기준 위치) 변화를 수회 측정하여, 기울어짐의 전도를 수치적으로 환산함으로써 장치의 효용성을 검증하였다. 결과: Cranio-caudal 방향 오차에 대해서는 50 kg, 70 kg의 체중을 가진 2명의 자원자에 대하여 5단계(3 cm, 10 cm, 20 cm, 30 cm, 39 cm)의 breast board 높이에 따라 각각 10회씩, 기존의 오목한 두개골 판과 개선된 두경부지지대를 비교하여 실험을 수행한 결과, cranio-caudal 방향 위치의 표준편차가 평균 $55\%$ 이상 감소하였다. 계단형 좌우 고정장치의 효용성을 검토한 결과 50 kg, 70 kg 체중의 자원자에 대하여 각각 $73\%$, $85\%$ 이상의 기울기 감소 효과가 나타났고, 팔걸이형 좌우 고정장치에 대해서는 각각 $90\%$ 이상의 기울기가 감소한 것으로 나타났다. 결론: 모의 실험 결과, 개선된 두경부 지지대와 좌우 고정장치를 통해 cranio-caudal 방향 위치와 breast board의 기울기의 편차가 기존에 비해 현저하게 감소하였으므로, 임상적용시 환자 위치의 재현성 향상에 기여할 것으로 기대된다.

• 한국유기농업학회지
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• 제10권1호
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• pp.49-63
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• 2002

In order to supply 85% of total organic feed in ruminants and 80% in non-ruminants for organic animal production, nitrogen fixation ability of legume should be used in domestic roughages production. 50% of Europe organic farmer use intercropping legume in as green manure. This article is dealing with amount of biologically fixed nitrogen used by legumes and methods for estimating the transfer of biologically fixed N in rotation and separating the N benefit into fixed N and non-fixed N components are reviewed. Available data indicate that transfer amount of N to non legumes was from 50∼9.6(kg/ha) in legume-cereal rotations and proportion of legume N varied with seasons, 90% in summer, 50% in autumn. The important point in cropping system for legumes have to be included for organic forage production 6 year rotation is based on pasture system of 3 year pasture + 2 year annual(com, sudangrass), again pasture. Rye, barly and Italian ryegrass+legumes(vetch, crimson and pea) can be one of option in spring, com, soybean, sudangrass and Japanese bamyard millet would be seeded after spring harvest in the field. Farmer can make good use of rice paddy field as forge production potential area after harvesting rice. Italian, burly and rye+vetch and crimsonclover may be grown in autumn or spring time at the rice field.

• 한국초등과학교육학회지:초등과학교육
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• 제31권3호
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• pp.386-397
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• 2012

The purpose of this study was to find a way to improve the science textbook graph through analyzing teachers' interpretation process with eye movement tracking when they try to read the science textbook graph. Participants in this project were 10 elementary school teachers while bar graphs, line graphs, pie charts in 2007 revision science textbooks were used as materials. SMI (SensoMotoric Instruments)' iView X TM RED 120 Hz was used in order to collect eye movement data. Although subjects paid attention to the title of the graph at first, the consequence of the eye fixation was changed by the composition of the graph in case of the rest of areas. In particular, the flow of visual attention and fixation time were affected by the form and configuration of the graph. The diversity of graph construction caused confusion in interpreting graphs; the manner of presenting title, the difference of background colors, size of characters, the name of X-axis and Y-axis. Out results showed that the conformation of graphs as well as the presentation of each factor should be composed in accordance with the educational purpose for helping users to easier understanding.

• 미생물학회지
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• 제24권3호
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• pp.211-220
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• 1986

Nitrogen fixation (nif) genes of Rhizobium leguminosarum were transferred to nif Klebsiella pneumoniae and E. coli by conjugation after partial heat induction of $RP_4$ :: Mu cts in Rhizobium $R^+$ transconjugant, and the hybrid plasmids in the transconjugant strains were isolated and characterized. In order to transfer the nif genes from Rhizobium, the hybrid plasmid $RP_4$ :: Mu cts was transferred by conjugation from E. coil to the symbiotic nitrogen fixer, R. leguminosarum. After stabillity test, the $RP_4$ :: Mu cts in Rhixobium $R^+$ transconjugant was subjected to partial heat induction by culturing it statically at $38^{\circ}C$ for 16 hours, and then conjugated with the nif defective mutant strains of K. pneumoniae or nif mutant strains of E. coli having whole nif gene plasmid. Recombinant strains of K. pneumoniae, which could grow in a N-free medium and exhibit the nitrogenase activity were selected. However, in the case of E. coli, they could grow well in a NA medium containing antibiotices, but hardly frow in a N-free medium. The hybrid plasmids in these transconjugal strains were isolated by gel electrophoresis and compared their molecular sizes.

• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.491-497
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• 2014

PURPOSE. This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. MATERIALS AND METHODS. Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess the amount of settlement after abutment fixation, a 30-Ncm tightening torque was applied, then the change in length before and after tightening the abutment screw was measured, and the preload exerted was recorded. The compressive bending strength was measured under the ISO14801 conditions. In order to determine whether there were significant changes in settlement, preload, and compressive bending strength before and after abutment fixation depending on abutment materials, one-way ANOVA and Tukey's HSD post-hoc test was performed. RESULTS. Group TA exhibited the smallest mean change in the combined length of the implant and abutment before and after fixation, and no difference was observed between groups T3 and T4 (P>.05). Group TA exhibited the highest preload and compressive bending strength values, followed by T4, then T3 (P<.001). CONCLUSION. The abutment material can influence the stability of the interface in internal conical connection type implant systems. The strength of the abutment material was inversely correlated with settlement, and positively correlated with compressive bending strength. Preload was inversely proportional to the frictional coefficient of the abutment material.

• Hip & pelvis
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• 제35권3호
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• pp.175-182
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• 2023

Purpose: This study aims to compare patients in whom fixation failure occurred via cut-out (CO) or cut-through (CT) in order to determine patient factors and radiographic parameters that may be predictive of each mechanism. Materials and Methods: This retrospective cohort study includes 18 patients with intertrochanteric (IT) hip fractures (AO/OTA classification 31A1.3) who underwent treatment using a single lag screw design intramedullary nail in whom fixation failure occurred within one year. All patients were reviewed for demographics and radiographic parameters including tip-to-apex distance (TAD), posteromedial calcar continuity, neck-shaft angle, lateral wall thickness, and others. Patients were grouped into cohorts based on the mechanism of failure, either lag screw CO or CT, and a comparison was performed. Results: No differences in demographics, injury details, fracture classifications, or radiographic parameters were observed between CO/CT cohorts. Of note, a similar rate of post-reduction TAD>25 mm (P=0.936) was observed between groups. A higher rate of DEXA (dual energy X-ray absorptiometry) confirmed osteoporosis (25.0% vs. 60.0%) was observed in the CT group, but without significance. Conclusion: The mechanism of CT failure during intramedullary nail fixation of an IT fracture did not show an association with clinical data including patient demographics, reduction accuracy, or radiographic parameters. As reported in previous biomechanical studies, the main predictive factor for patients in whom early failure might occur via the CT effect mechanism may be related to bone quality; however, conduct of larger studies will be required in order to determine whether there is a difference in bone quality.

• 대한족부족관절학회지
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• 제19권3호
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• pp.97-101
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• 2015

Purpose: The purpose of this study was to analyze the clinical results of application of bioabsorbable screws in hallux valgus surgery using modified Mau osteotomy. Materials and Methods: We retrospectively reviewed medical records of 25 patients. Operations were performed between May 2013 and January 2014. We performed 33 modified Mau osteotomies and fixed using bioabsorbable screws. Mean age of patients was 52 years (range 19 to 71). Mean follow up duration was 13.2 months (range 12.3 to 18.9). The clinical evaluations included pain visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS) score, and satisfaction score. Weight bearing anteroposterior radiographs were taken for measurement of hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA). All radiographs were evaluated in order to detect complications related to bioabsorbable screws such as osteolysis, cyst formation, and fixation failure. Results: The mean pre- and postoperative pain VAS scores were 4.0 and 1.7 (p<0.05). The mean AOFAS score improved from 52.6 to 82.8 (p<0.05). Preoperative HVA and IMA were 31.2 and 13.9, respectively. Postoperative HVA and IMA were 5.2 and 6.2 (p<0.05). The DMAA increased from 7.8 to 9.9 (p<0.05). There was one case of superficial wound infection and one loss of correction, and no case of osteolysis, cystic formation around the screw, or deep infection. All patients showed union without fixation failure. Conclusion: The clinical and radiological evaluation of this study demonstrates reliable results without fixation failure or allergic reaction. The use of bioabsorbable screw appears not to be inferior to metal screw fixation in hallux valgus surgery.

• Journal of Korean Neurosurgical Society
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• 제45권4호
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• pp.219-223
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• 2009

Objective : Functional magnetic resonance imaging (fMRI) is frequently used to localize language areas in a non-invasive manner. Various paradigms for presurgical localization of language areas have been developed, but a systematic quantitative evaluation of the efficiency of those paradigms has not been performed. In the present study, the authors analyzed different language paradigms to see which paradigm is most efficient in localizing frontal language areas. Methods : Five men and five women with no neurological deficits participated (mean age, 24 years) in this study. All volunteers were right-handed. Each subject performed 4 tasks, including fixation (Fix), sentence reading (SRI. pseudoword reading (PR), and word generation (WG). Fixation and pseudoword reading were used as contrasts. The functional area was defined as the area(s) with a t-value of more than 3.92 in fMRI with different tasks. To apply an anatomical constraint, we used a brain atlas mapping system, which is available in AFNI, to define the anatomical frontal language area. The numbers of voxels in overlapped area between anatomical and functional area were individually counted in the frontal expressive language area. Results : Of the various combinations, the word generation task was most effective in delineating the frontal expressive language area when fixation was used as a contrast (p<0.05). The sensitivity of this test for localizing Broca's area was 81 % and specificity was 70%. Conclusion : Word generation versus fixation could effectively and reliably delineate the frontal language area. A customized effective paradigm should be analyzed in order to evaluate various language functions.

• 한국안전학회지
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• 제32권5호
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• pp.41-46
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• 2017

The coefficient of derailment and the rate of wheel load reduction were used as the index of train running safety that was directly affected the train derailment safety. In aspects of track, the train running safety depends on the complex interaction between wheel and rail, and the track-vehicle conditions (i.e., the curvature, cant, track system, vehicle speed and the operation conditions, etc). In this study, the relationship between the train running safety and the track curvature and vehicle speed for direct fixation concrete tracks currently employed in Korean light rapid transit was assessed by performing field tests using actual vehicles running along the service lines. The measured dynamic wheel load, lateral wheel load and lateral displacement of rail head were measured for same train running on four tested tracks under real conditions, which included curved and tangent tracks placed on the tunnel and bridge, thus increasing the train speed by approximately maximum design speed of each test site. Therefore, the measured dynamic track response was applied to the running safety analysis in order to evaluate the coefficient of derailment, the rate of wheel load reduction and the track gauge widening at each test site, and compare with the corresponding Korean train running safety standard. As the results, the lateral track response of direct fixation concrete track appeared to increase with the decreased track curvature; therefore, it was inferred that the track curvature directly affected the train running safety.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.499-503
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• 2007

Introduction: In orthognathic surgery, internal fixation has been usually done with titanium plates and screws. Recently, Biodegradable plates and screws have been frequently used but the reports of long term results of postoperative stability are rare, especially after maxillary reposition in orthognathic surgery. Objective: In order to clarify the clinical utility of self-reinforced bioresorbable poly-70L/30DL-Lactide miniplates & screws in maxillary fixation after LeFort I osteotomy, this study examined the postsurgical changes in maxilla and complications of biodegradable plates and screws. Study design: Nineteen patients who had undergone maxillary internal fixation using biodegradable plates and screws were evaluated radiographically and clinically. A comparison study of the changes in maxilla position after surgery in all 19 patients was performed with 1-week, 1-month, 3-months, 6-months and/or 1-year postoperative lateral cephalograms by tracing. Complication of the biodegradable plates and screws was evaluated by follow-up roentgenograms and clinical observation. And one-way ANOVA test was used for statistical analysis. Results: The position of the maxillary bone was stable after surgery and was not changed significantly from 1 week to 1 year after operation. And we could not find any complication of biodegradable plates and screws. Conclusions: Internal fixation of the maxilla after LeFort I osteotomy using self-reinforced biodegradable plates and screws is a reliable method for maintaining postoperative position of the maxilla after LeFort I osteotomy.