• 제목/요약/키워드: anatomical properties

검색결과 130건 처리시간 0.023초

무치악에 대한 최소 임플란트의 구조물의 3차원 유한요소 해석 (The 3-Dimensional Finite Element Analysis of Minimum Implant Structure for Edentulous Jaw)

  • 장인식
    • 한국정밀공학회지
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    • 제25권2호
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    • pp.148-155
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    • 2008
  • The aim of the study is to interpret the distribution of occlusal force by 3-dimensional finite element analysis of ISP(Implant Supported Prosthesis) supported by minimum number of implant to restore the edentulous patients. For this study, the Astra Tech implant system is used. Geometric modeling for 6 and 4 fixture ISP group is performed with respect to the bone, implant and one piece superstructure, respectively. Implants are arbitrarily placed according to the anatomical limit of lower jaw and for the favorable distribution of occlusal force, which is applied at the end of cantilever extension of ISP with 30mm. Element type is tetrahedral for finite element model and the typical mechanical properties, Young's modulus and Poisson's ratio of each material, cortical, cancellous bone and implant material are utilized for the finite element analysis. From this study, we can see the distribution of equivalent stress equal to real situation and speculate the difference in the stress distribution in the whole model and at each implant fixture, From the analysis, the area of maximum stress is distributed on distal contact area between bone and fixture in the crestal bone. The maximum stress is 53MPa at the 0.2mm area from the bone-implant interface in the maximum side for 300N load condition for 4 fixture case, which is slightly less than the stress calculated from allowable strain. This stress has not been deduced to directly cause the loss of crestal bone around implant fixture, but the stress can be much reduced as the old peoples may have lower chewing force. Thus, clinical trial may be performed with this treatment protocol to use 4 fixtured ISP for old patients.

확장된 SSD에 기인한 Electron beam의 Output 및 특성 변화에 관한 연구 (A Study on clinical Considerations caused by inevitably Extended SSD for Electron beam therapy)

  • 이정우;김정만
    • 대한방사선치료학회지
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    • 제8권1호
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    • pp.29-35
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    • 1996
  • We are often faced with the clinical situations that is inevitably extended SSD for electron beam therapy due to anatomical restriction or applicator structure. But there are some difficulties in accurately predicting output and properties. In electron beam treatment , unlike photon beam the decrease in output for extended SSD does not follow inverse-square law accurately because of a loss of side scatter equilibrium, which is particularly significant for small cone size and low energies. The purpose of our study is to analyze the output in changing with the energy, cone size, air gap beyond the standard SSD and to compare inverse-square law factor derived from calculated effective SSD, mominal SSD with measured output factor. In addition, we have analyzed the change of PDD for several cones with different SSDs which range from 100cm to 120cm with 5cm step and with different energies(6MeV, 9MeV, 12MeV, 16MeV, 20MeV). In accordance with our study, an extended SSD produces a significant change in beam output, negligible change in depth dose which range from 100cm to 120cm SSDs. In order to deliver the more accurate dose to the neoplastic tissue, first of all we recommend inverse-square law using the table of effective SSDs with cone sizes and energies respectively or simply to create a table of extended SSD air gap correction factor. The second we need to have an insight into some change of dose distribution including PPD, penumbra caused by extended SSD for electron beam therapy.

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Role of Catheter's Position for Final Results in Intrathecal Drug Delivery. Analysis Based on CSF Dynamics and Specific Drugs Profiles

  • De Andres, Jose;Perotti, Luciano;Villanueva, Vicente;Asensio Samper, Juan Marcos;Fabregat-Cid, Gustavo
    • The Korean Journal of Pain
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    • 제26권4호
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    • pp.336-346
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    • 2013
  • Intrathecal drug delivery is an effective and safe option for the treatment of chronic pathology refractory to conventional pain therapies. Typical intrathecal administered drugs are opioids, baclofen, local anesthetics and adjuvant medications. Although knowledge about mechanisms of action of intrathecal drugs are every day more clear many doubt remain respect the correct location of intrathecal catheter in order to achieve the best therapeutic result. We analyze the factors that can affect drug distribution within the cerebrospinal fluid. Three categories of variables were identified: drug features, cerebrospinal fluid (CSF) dynamics and patients features. First category includes physicochemical properties and pharmacological features of intrathecal administered drugs with special attention to drug lipophilicity. In the second category, the variables in CSF flow, are considered that can modify the drug distribution within the CSF with special attention to the new theories of liquoral circulation. Last category try to explain inter-individual difference in baclofen response with difference that are specific for each patients such as the anatomical area to treat, patient posture or reaction to inflammatory stimulus. We conclude that a comprehensive evaluation of the patients, including imaging techniques to study the anatomy and physiology of intrathecal environment and CSF dynamics, could become essential in the future to the purpose of optimize the clinical outcome of intrathecal therapy.

Reconstruction of Vegetation During $9^{th}$ Century in Southern Korea: Anatomical and Dendrochronological Analysis of Waterlogged Woods Excavated at Cheonghea-jin Fort

  • Han, Sang-Hyo;Park, Won-Kyu;Kim, Yo-Jung;Jung, Suk-Bae
    • 한국제4기학회지
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    • 제17권2호
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    • pp.117-122
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    • 2003
  • This study is conducted to examine the woods that were excavated at Jangdo Island. The Jangdo site is located in a small island some 180 meters away from the main island of Wando, Jeollanam-do in southern Korea. This site is known as Cheong-Hea Jin fort for the marine King Jang Bogo during the early 9$^{th}$ century. Total of 101 specimens were collected in three groups; small-size piles, log fences (Mok-check) and logs from a well. The species of the group of piles consisted of Quercus spp. (43%), Pinus densiflora (29%), Pinus koraiensis (5%), Alnus japonica (3%), Fraxinus spp. (3%), Styrax obassia (3%), Juglans spp. (2%), Zelkova serrata (2%), Platycarya strobilacea (2%), Celtis spp. (2%), Torreya nucifera (2%), Quercus myrsinaefolia (2%), and Cinnamomum spp. (2%). The species of Mok-check and logs from the well were identified as all Pinus densiflora. The species composition indicated that the climate around A. D. 9th-10th century in southern Korea was similar to the present.. The wooden fences were also examined for tree-ring analysis. The ages of woods were 50∼60 years. We made two site chronologies. The chronologies indicated that southeastern and southwestern fences were repaired frequently. The results could not give the absolute dates due to lack of reference chronologies in this period.

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

  • 김태영;박종태;문성근;한원철
    • Journal of Korean Neurosurgical Society
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    • 제29권10호
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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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측두근-근막피판을 이용한 악관절 강직증의 외과적 재건 (INTERPOSITIONAL ARTHROPLASTY OF TEMPOROMANDIBULAR JOINT ANKYLOSIS WITH TEMPORALIS MYOFASCIAL FLAP)

  • 남정순;이용규;권대근;김종배
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제26권5호
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    • pp.544-549
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    • 2000
  • 악관절 강직증의 치료는 기술적 어려움과 높은 재발율로 인해 난관에 부딪히고 있다. 악관절 강직증은 골절제와 이종, 동종, 자가 물질을 이용한 악관절 재건술로 치료를 해왔다. 측두근-근막피판은 그것의 해부학적, 지리적, 기능적 성질로 인해 우수한 간치 이식물질로 여겨지고 있다. 본 연구는 전이개 절개, 근돌기 절제술과 병행한 아홉개의 악관절(다섯명의 환자)강직의 치료에서 측두근-근막피판의 효율성에 대해 알아 보았다. 그 결과 측두근-근막 피판은 이상적인 간치 이식물질의 기준을 만족하는 자가물질로 여겨지며 disc의 생리적 기능을 수행하는것으로 사료된다. 그러나, 이러한 우수한 기능적 결과에도 불구하고 술후 약간의 전치부 개교경향은 또다른 문제점으로 남아있다.

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증기 및 여러 가지 건조방법으로 처리된 잣나무 변재의 섬유방향 액체투과율 비교 (Comparison of Longitudinal Liquid Permeability of Pinus koraiensis Sapwood Treated by Steaming and Various Drying Methods)

  • 강호양
    • Journal of the Korean Wood Science and Technology
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    • 제33권6호통권134호
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    • pp.17-24
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    • 2005
  • 두께 30 mm 잣나무 판재를 증기와 4가지 건조방법으로 처리하였다. 처리된 판재의 변재에서 시편을 떼어내어 Darcy 법칙을 이용한 간단한 방법으로 섬유방향 비투과율을 비교하였다. 잣나무 변재의 섬유방향 수분이동기작을 조사하기 위해 시편을 알코올과 아세톤 추출한 후에 비투과율을 또 측정하였다. 측정된 비투과율은 측정시간에 따라 급격히 감소하는 것이 관찰되었다. 이는 Darcy 법칙에 어긋나는 것으로 음압에 의해 공기방울이 발생하여 이동통로를 막기 때문으로 설명할 수 있다. 처리방법에 따라 미추출 시편의 평균 비투과율은 다르게 나타났으며 용매추출에 의한 비투과율 변화도 처리방법에 따라 달리 나타났다. 처리방법에 따라 수지구내 잔류수지의 성질이 달라지기 때문으로 생각된다. 수지구내 잔류수지 형상을 SEM 사진으로 관찰하였다.

실시간 피부 변형 제어를 위한 근육 변형 모델 (Muscle Deformation Model for Real-Time Skin Deformation Control)

  • 진정환;김종혁;최정주
    • 한국컴퓨터그래픽스학회논문지
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    • 제16권3호
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    • pp.21-30
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    • 2010
  • 본 논문에서는 실제 근육의 해부학적 특징에 근거한 모델을 설계하고, 근육의 모양이 골격의 움직임에 따라서 변화하는 실시간 시뮬레이션 기법을 제시한다. 근육 모델은 골격 혹은 다른 근육의 양 끝 점에 부착되는 위치와 방위에 따라서 부피가 유지되도록 변형된다. 근육 변형의 결과는 간단한 스키닝을 통해서 실제 피부 변형의 결과로 이어져 관찰된다. 실제 인체와 유사하게 모델링된 다관절 캐릭터의 수행 성능을 제시한다. 실험적 결과에 따르면 수십개의 모델링된 근육을 골격 운동에 따라서 실시간에 변형할 수 있다. 따라서 빠른 수행속도에 일정한 품질을 요구하는 게임 등과 같은 실시간 제어 환경에 등장하는 다관절 캐릭터를 제어하는데 효과적으로 사용될 수 있다.

진주 가산리 우물지에서 출토된 동물뼈 유물의 해부학적 분류 (Anatomical classification of animal bone relics excavated from the well area of Gasan-ri in Jinju)

  • 최종혁;이시준;김종섭;원청길
    • 대한수의학회지
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    • 제61권4호
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    • pp.39.1-39.6
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    • 2021
  • The classification of the bone pieces excavated from Gasan-ri archaeological site 1 in Jinju, presumed to be relics was investigated macroscopically. The remains of the animal bone were 3 classes (Mammalia, Aves, Amphibia), 5 orders (Carnivora, Artiodactyla, Galliformer, Rodentia, Salientia), and 6 species (Sus scrofa, Cervidae sp., Nyctereutes procyonides, Phasianidae, Rattus norvegicus caraco, Rana nigromaculata). The total weight of the animal bone remains was 1,002.80 g, with the identified bones comprising 975.30 g and an identification rate of 97.26%. A total of 447 animal bone fragments were identified, including 204 bone pieces of S. scrofa (468.00 g, 47.99%), 102 bone pieces of Cervidae sp. (453.79 g, 46.53%), 68 bone pieces of R. nigromaculata (4.69 g, 0.48%), 59 bone pieces of N. procyonides (47.14 g, 4.83%), 9 bone pieces of Phasianidae (0.98 g, 0.10%), and 5 bone pieces of Rattus norvegicus caraco (0.70 g, 0.07%). The bone pieces of the animal relics consisted of 81 skull (18.12%), 161 axial skeleton (36.02%), 64 forelimb (14.32%), and 141 hindlimb (31.54%) fragments. The archaeological significance of the animal bones excavated in this investigation was that wild boars and deer were presumed to have been mainly used animals in the Gasan-ri area of Jinju during the Three Kingdoms period.

Review of potential spermatogenic and aphrodisiac effects of the Ferula genus

  • Seyyed Majid Bagheri;Amir Shieh;Jalil Alizadeh Ghalenoei;Maryam Yadegari;Nasrin Alborzi
    • Clinical and Experimental Reproductive Medicine
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    • 제50권3호
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    • pp.143-153
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    • 2023
  • Objective: Men's sexual health plays an important role in male fertility and childbearing, as it is associated with factors such as sexual desire, healthy spermatogenesis, and erectile function. In various cultures, medicinal plants have been utilized to address male sexual issues, including infertility and erectile dysfunction. Despite recent advancements in medical science for treating male impotence, some men opt for herbal supplements as an alternative, given that numerous herbs have the potential to enhance male sexual performance. The Apiaceae family is one of the oldest plant families used for medicinal purposes. Ferula, a genus within this family, comprises approximately 170 different species worldwide. Members of this genus possess numerous therapeutic properties due to the presence of various compounds. This article aims to explore the potential impacts of Ferula plants on the male reproductive system. Methods: This review article was prepared by searching for terms including Ferula and "aphrodisiac," Ferula and "spermatogenesis," and Ferula and "male reproductive system." Relevant information was gathered through electronic databases, including ISI Web of Knowledge, PubMed, and Google Scholar. Results: The findings indicated that relatively comprehensive studies have been conducted in this area, revealing that certain Ferula species have been employed in folk medicine to boost fertility and libido. Recent research has corroborated these effects. Conclusion: It is hoped that new aphrodisiac compounds with fewer side effects can be isolated from Ferula plants in the future.