• Title/Summary/Keyword: CT data

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Development of Finite Element Ductile Tearing Simulation Model Considering Strain Rate Effect (변형률 속도를 고려한 유한요소 기반 연성 찢김 해석 기법 개발)

  • Nam, Hyun Suk;Kim, Ji Soo;Kim, Jin Weon;Kim, Yun Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.2
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    • pp.167-173
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    • 2016
  • This paper proposes ductile failure simulation under high strain rate conditions using finite element (FE) analyses. In order to simulate a cracked component under a high strain rate condition, this paper applies the stress-modified fracture strain model combined with the Johnson/Cook model. The stress-modified fracture strain model determines the incremental damage in terms of stress triaxiality (${\sigma}_m/{\sigma}_e$) and fracture strain (${\varepsilon}_f$) for a dimple fracture using the tensile test results. To validate the stress-modified fracture strain model under dynamic loading conditions, the parameters are calibrated using the tensile test results under various strain rates and the fracture toughness test results under quasi-static conditions. The calibrated damage model predicts the CT test results under a high strain rate. The simulated results were then compared with the experimental data.

Development of Multi-Body Dynamics Simulator for Bio-Mimetic Motion in Lizard Robot Design (도마뱀 로봇 설계를 위한 생체운동 모사 다물체 동역학 시뮬레이터 개발)

  • Park, Yong-Ik;Seo, Bong Cheol;Kim, Sung-Soo;Shin, Hocheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.6
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    • pp.585-592
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    • 2014
  • In this study, a multibody simulator was developed to analyze the bio-mimetic motion of a lizard robot design. A RecurDyn multibody dynamics model of a lizard was created using a micro-computerized tomography scan and motion capture data. The bio-mimetic motion simulator consisted of a trajectory generator, an inverse kinematics module, and an inverse dynamics module, which were used for various walking motion analyses of the developed lizard model. The trajectory generation module produces spinal movements and gait trajectories based on the lizard's speed. Using the joint angle history from an inverse kinematic analysis, an inverse dynamic analysis can be carried out, and the required joint torques can be obtained for the lizard robot design. In order to investigate the effectiveness of the developed simulator, the required joint torques of the model were calculated using the simulator.

Clinical Studies of Sweet Bee Venom to The Effect of Abdominal Fat Accumulation (Sweet BV가 복부비만에 미치는 영향)

  • Lim, Chung-San;Park, Won-Pil;Jang, Seong-Bong;Choi, Young-Chon;Kim, Kwan-Soo;Kwon, Ki-Rok;Lee, Hee-Choon
    • Journal of Pharmacopuncture
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    • v.11 no.2
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    • pp.33-40
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    • 2008
  • Objective The purpose of this study was to investigate the effects of Sweet Bee Venom to the abdominal fat accumulation clinically. Methods The 20 healthy women volunteers who showed the notice of this study by the home page of Sangji University were treated with Sweet Bee Venom(SBV) during twenty times. To investigate the effects of Sweet Bee Venom of the abdominal fat accumulation, abdominal CT, LFT, Thermography, BMI, Inbody 3.0 etc. were performed during clinical trials. And statistical analysis was carried out the data of 10 volunteers who performed all the schedule of this study. Results Following results were obtained from the clinical studies Sweet Bee Venom showed the effect of decreased the body weight, thickness of abdominal skin and fat layer, BMI, and increased abdominal heat, but they are not showed statistical significant. Conclusions These results suggest that treatment Sweet Bee Venom on the abdomen was effective to decrease fat tissue but for the treatment of obesity was performed with right diet program and exercise.

Clinical Application of 3-D Compensator in Head and Neck Cancer (두경부암 환자 치료시 3차원 보상체의 임상 적용에 대한 고찰)

  • Hong, Dong-Ki;Lee, Jeong-Woo;Lee, Koo-Hyun;Park, Kwang-Ho;Kim, Jeong-Man
    • The Journal of Korean Society for Radiation Therapy
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    • v.9 no.1
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    • pp.64-70
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    • 1997
  • The goal of radiation treatment planning is to deliver the dose to the patient within $5\%$ of that prescribed. We have often encountered the situation that the area which have not only several irregular contours but also tissue heterogeneities should be treated. With conventional devices such as wedges, missing tissue compensator. there are some limitations to achieve the uniform dose distribution in treatment volume. The use of CT simulator, 3-D planning system, computer-controlled milling machine enables it to deliver the dose uniformally. This report includes the whole procedure which have patient data acquisition 3D planning, computer-controlled milling, performance verification of 3D compensator, and TLD evaluation. We applied it for the treatment of head and heck cancer only. In Spite of the irregular contour and different electron density of tessue, we have achieved the uniformity of the dose distribution within ${\pm}3\%$ relatively. Although there are some problems which are not only verification of performance but uncertainties of using the new treatment device, we believe that the improvement of dosimetry will eliminate the uncertainties of that application. so the other lesions besides head and neck can will be ale to use the 3D compensator to achieve the dose uniformity

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Evaluation of reference genes for RT-qPCR study in abalone Haliotis discus hannai during heavy metal overload stress

  • Lee, Sang Yoon;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.19 no.4
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    • pp.21.1-21.11
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    • 2016
  • Background: The evaluation of suitable reference genes as normalization controls is a prerequisite requirement for launching quantitative reverse transcription-PCR (RT-qPCR)-based expression study. In order to select the stable reference genes in abalone Haliotis discus hannai tissues (gill and hepatopancreas) under heavy metal exposure conditions (Cu, Zn, and Cd), 12 potential candidate housekeeping genes were subjected to expression stability based on the comprehensive ranking while integrating four different statistical algorithms (geNorm, NormFinder, BestKeeper, and ${\Delta}CT$ method). Results: Expression stability in the gill subset was determined as RPL7 > RPL8 > ACTB > RPL3 > PPIB > RPL7A > EF1A > RPL4 > GAPDH > RPL5 > UBE2 > B-TU. On the other hand, the ranking in the subset for hepatopancreas was RPL7 > RPL3 > RPL8 > ACTB > RPL4 > EF1A > RPL5 > RPL7A > B-TU > UBE2 > PPIB > GAPDH. The pairwise variation assessed by the geNorm program indicates that two reference genes could be sufficient for accurate normalization in both gill and hepatopancreas subsets. Overall, both gill and hepatopancreas subsets recommended ribosomal protein genes (particularly RPL7) as stable references, whereas traditional housekeepers such as ${\beta}-tubulin$ (B-TU) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were ranked as unstable genes. The validation of reference gene selection was confirmed with the quantitative assay of MT transcripts. Conclusions: The present analysis showed the importance of validating reference genes with multiple algorithmic approaches to select genes that are truly stable. Our results indicate that expression stability of a given reference gene could not always have consensus across tissue types. The data from this study could be a good guide for the future design of RT-qPCR studies with respect to metal regulation/detoxification and other related physiologies in this abalone species.

A Study on Quality Improvement of Medical Equipments (의료기기 QI 활동 개선방안에 대한 연구)

  • Kang, Hun-Hee;Juh, Ra-Hyeong;Kim, Jong-Soon;Kim, Seo-Hwak;Huh, Soo-Jin
    • Quality Improvement in Health Care
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    • v.5 no.2
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    • pp.190-201
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    • 1998
  • Background : Medical equipments take a very important role in diagnosis and treatment of disease in modern medicine and effective maintenance of the equipments is a necessary to provide a good health care to the public. After developing a new QC program for effective maintenance of medical equipments and practicing it for a year, we report the results of the new program. Methods : The maintenance data of 9 equipments in 8 categories including a CT Scanner were analyzed with regard to the parts responsible for most frequent failure and cause of the failure. After learning the most frequent failure part and cause of the failure, we developed a new QC program that emphasizes preventive maintenance of the most frequent failure part. We compared the number of failure per year and active rate of each equipment before and after the adoption of the new QC program. Results : The average number of failure per year per equipment was 20.7 before and it decreased by 43% to 11.9 after adoption of the new QC program. The average active rate of the equipments was 92.6% before and it increased by 3.2% to 95.8% after adoption of the new program. Conclusions : The practice of the new QC program appears very useful as it decreased the failure rate and increased the active rate of the equipments.

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Expression of Vascular Endothelial Growth Factor in Astrocytic Tumors - Correlation to Peritumoral Brain Edema and Microvasculature - (성상세포종양에서 혈관내피증식인자의 발현 - 종양주변부 부종 및 미세혈관과의 상관관계 -)

  • Kim, Tae Young;Park, Jong Tae;Moon, Seong Keun;Han, Weon Cheol
    • Journal of Korean Neurosurgical Society
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    • v.29 no.10
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    • pp.1303-1308
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    • 2000
  • Objectives : It has been known that vascular endothelial growth factor(VEGF), as an endothelial cell-specific mitogen, induces angiogenesis, and possesses vascular permeability and procoagulant properties. Peritumoral brain edema(PTBE) is a common accompaniment of malignant gliomas. It results from microvascular extravasation of plasma and proteins through the interendothelial spaces. The correlation between pathological grading, PTBE, neovascularization, and the expression of VEGF were analyzed in 31 patients with astrocytic tumors. Methods : Astrocytic tumor samples(8 astrocytomas, 14 anaplastic astrocytomas, and 9 glioblastomas) from 31 patients( 21 males and 10 females : average age $37{\pm}24$ years) who underwent surgery were examined retrospectively for the expression of VEGF and CD31(microvasculature) immunohistochemically. The extent of PTBE was examined by using preoperative CT or MRI as an edema index(EI). In addition to VEGF and CD31, several causative factors including tumor size, histologic type were compared with EI. Results : Only one of 8 astrocytomas, and majority of high grade(21 of 23 anaplastic astrocytomas and glioblastomas) tumors demonstrated PTBE(p<0.05). The majority of high grade tumors showed higher expression of VEGF (p<0.01). High grade tumors showed even higher CD31 expression(p<0.05), however, there was no close correlation between expression of VEGF and CD31. The EI was increased significantly, just as VEGF(p<0.01), but CD31 expression was not correlated with high EI. Conclusion : These data suggest that VEGF expression is closely correlated with PTBE and histological grading in astrocytic tumors. Microvasculature(CD31) in tumors is highly correlated with histological grading, however, shows no correlation with the expression of VEGF and PTBE.

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Association of Genetic Polymorphisms at 1q22 but not 10q23 with Gastric Cancer in a Southern Chinese Population

  • Yang, Xue-Xi;Li, Fen-Xia;Zhou, Cui-Ping;Hu, Ni-Ya;Wu, Ying-Shong;Li, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2519-2522
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    • 2012
  • Objective: Data from a recent genome-wide association studiesy of gastric cancer (GC) and oesophageal squamous cell carcinoma in Chinese living in the Taihang Mountains of north-central China suggest that 1q22 and 10q23 are susceptibility-associated regions for GC. However, this has not been confirmed in southern Chinese populations. The aim of this study was to investigate whether these polymorphisms at 1q22 and 10q23 are associated with the risk of GC in a southern Chinese population. Methods: We selected seven top significant associated single nucleotide polymorphisms (SNPs) at 1q22 and 10q23 and conducted a population-based case-control study in a southern Chinese population. Genotypes were determined using MassARRAYTM system (Sequenome, San Diego, CA). Results: Two SNPs at 1q22, rs4072037 and rs4460629, were significantly associated with a reduced risk of GC, best fitting the dominant genetic model. Logistic regression models adjusted for age and sex showed that rs4072037 AG and GG (OR=0.64, P=0.017, compared with AA) and rs4460629 CT and TT (OR=0.54, P=0.0016, compared with TT) significantly reduced the risk of GC. However, no significant results for the five SNPs at 10q23 were obtained in this study. Conclusion: These outcomes indicate that 1q22 is associated with GC susceptibility in this southern Chinese population, while an association for the locus at 10q23 was not confirmed.

Modeling of Influential Predictors of Gastric Cancer Incidence Rates in Golestan Province, North Iran

  • Behnampour, Nasser;Hajizadeh, Ebrahim;Zayeri, Farid;Semnani, Shahriar
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1111-1117
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    • 2014
  • Golestan province has a reputation for relatively high incidence rates of gastric cancer in Iran. Along with dietary, lifestyle and environmental influential factors, soil selenium and high levels of pesticide used may exert influence in this region. The present study was designed for modeling the influential predictors on incidence of gastric cancer in Golestan. All registered cases of gastric cancer from March 2009 to March 2010 (49 females and 107 males) were investigated. Data were gathered by both check list and researcher made questionnaire (demographic, clinical and lifestyle characteristics) and analysed using logistic regression. Mean (${\pm}SD$) age at diagnosis was $62.9{\pm}13.8$ years. CIR and ASR of gastric cancer showed 9.16 and 13.9 per 100,000 people, respectively. Based on univariate logistic regression, a history of smoking (OR= 2.076), unwashed hands after defecation (OR= 2.612), history of cancer in relatives (OR= 2.473), history of gastric cancer in first-degree relatives (OR= 2.278), numbers of gastric cancers in first-degree relatives (OR= 2.078), history of X-ray and dye exposure (OR= 2.395), history of CT scan encounter (OR= 2.915), improper food habits (OR= 3.320), specific eating behavior (OR= 0.740), consumption of probable high risk foods (OR= 2.942), charred flesh (OR= 1.945), and animal fat (OR= 2.716) were confirmed as a risk factors. Changes in lifestyle may be expected to increase gastric cancer incidence dramatically in the near future. Therefore, appropriate educational interventions should be designed and implemented by competent authorities.

Diagnosis and Therapy of Primary Hepatic Neuroendocrine Carcinoma: Clinical Analysis of 10 Cases

  • Wang, Li-Ming;An, Song-Lin;Wu, Jian-Xiong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2541-2546
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    • 2014
  • Background: Primary hepatic neuroendocrine carcinoma (PHNEC) is rarer than extrahepatic gastrointestinal neuroendocrine carcinoma (NEC). It is difficult to make a correct diagnosis and poses a challenge for management. Materials and Methods: Ten PHNEC patients were admitted to our hospital from June 2006 to June 2011. Laboratory tests and imaging scans were performed for diagnosis and exclusion of extrahepatic NEC. All patients were AFP - and CA199-. Seven patients had solid tumors with cystic changes on ultrasonography, CT and/or MRI. For the initial treatment, four patients received combined-therapy and six monotherapy. Considering overall treatment, six patients received combined-therapy and four patients monotherapy. Staging criteria of primary hepatocellular carcinoma (PHC, AJCC 7th edition) were used to differentiate the stage of all patients: 3 patients were stage I, 2 stageII, 4 patients stageIII and 1 stageIV. All patients were followed up and clinical data were gathered. Results: The median follow-up duration was 38.5 months. The 1-year, 2-year, 3-year and 6-year disease-free survival was 80.0%, 46.2% and 46.2% and 0% respectively. The overall survival rates were 100%, 67.1%, 67.1% and 33.6% respectively. Patients in early-stages (I/II) had similar disease-free and overall survival as those in advanced-stages (III/IV). Patients with monotherapy had significant shorter disease-free and overall survival than the patients with combination-therapy. Conclusions: PHNEC has a unique specificity during its occurrence and development. The staging criteria of PHC might not be suitable for the PHENT. More convenient and effective features need to be found in imaging and laboratory detection. Surgical resection, TACE, chemotherapy and radiofrequency ablation should be performed in combination and actively for patients with PHNEC or recurrence to get the best effectiveness; they might extend the disease-free and overall survival.