• Applied Microscopy
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• 제15권1호
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• pp.71-85
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• 1985

The ultrastructure on the dorsal vessel of 5-day-old cabbage butterfly, Pieris rapae L., was carried out using the transmission and scanning electron microscope. The results are as follows. 1) The aorta. The aorta is simple tubular type and consists of the inner and outer membrane of the myocardium and thick myocardium is located between them. However the inner membrane with $0.26{\mu}m$ thickness and outer membrane with $0.08{\mu}m$ are composed of fibrous materials, the former is composed of low and high densed fibrous materials and the latter appears homogeneous layer. The myocardium consists of typical striated muscles. The sarcomere with $1.6{\mu}m$ length and in cross section, each thick filaments are surrounded by $7{\sim}8$ thin filaments. The intercalated disc is joining the end of the two muscle cells, desmosomes and septate junctions are appeared between the neighboring muscle cells. 2) The heart. The heart composing of myocardium enclosed by its inner and outer membrane as the aorta has a series of well formed segmental chamber. The arrangement of myofilaments, cell adhensions and membrane elements are observed as same as at the aorta. The inner membrane of the heart is deeply invaginated into the myocardium than the outer membrane and a lot of well developed mitochondria with rod shape are aggregated in the folds. The longitudinally and transversely oriented tubule system formed by invagnation of the sarcolemma into the muscle bundle is built up dyad with the sarcoplasmic reticulum as the aorta. The slit is formed by deeply invagination of the inner membrane of myocadium toward the muscle layer and then the inner and outer membrane of myocardium are fused. Therefore, the ostium is formed between the myocardium and situated at the lateral side of the myocardium.

• Applied Microscopy
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• 제41권4호
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• pp.257-263
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• 2011

지중해담치 소화맹낭의 해부학적 구조와 미세구조를 광학 및 전자현미경을 이용하여 기재하였다. 소화맹낭은 황갈색으로 위를 둘러싸고 위치하며, 일차소관으로 위와 연결되어 있었다. 소화맹낭은 다수의 소화선세관들로 구성되며, 각각의 소화선세관은 단층 상피층으로 호염기성세포와 소화세포들로 이루어져 있었다. 호염기성세포는 원주형이며, 세포질에는 잘 발달된 조면소포체, 관상의 미토콘드리아, 골지체 및 전자밀도가 높고 막을 가진 분비과립들을 함유하고 있었다. 소화세포는 원주형이며, 자유면에는 섬모와 미세융모가 발달되어 있었다. 세포질 상부에서는 음소포, 활성 용해소체 및 미토콘드리아가 관찰되었다. 본 연구에서 이러한 결과는 소화선세관의 호염기성세포와 소화세포는 각각 세포외 소화와 세포내 소화에 적당하게 분화되었음을 의미한다.

• Steel and Composite Structures
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• 제19권5호
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• pp.1115-1144
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• 2015

Current climate conditions along with advances in technology make further design and verification methods for structural strength and reliability of wind turbine towers imperative. Along with the growing interest for "green" energy, the wind energy sector has been developed tremendously the past decades. To this end, the improvement of wind turbine towers in terms of structural detailing and performance result in more efficient, durable and robust structures that facilitate their wider application, thus leading to energy harvesting increase. The wind tower industry is set to expand to greater heights than before and tapered steel towers with a circular cross-section are widely used as more capable of carrying heavier loads. The present study focuses on the improvement of the structural response of steel wind turbine towers, by means of internal stiffening. A thorough investigation of the contribution of stiffening rings to the overall structural behavior of the tower is being carried out. These stiffening rings are placed along the tower height to reduce local buckling phenomena, thus increasing the buckling strength of steel wind energy towers and leading the structure to a behavior closer to the one provided by the beam theory. Additionally to ring stiffeners, vertical stiffening schemes are studied to eliminate the presence of short wavelength buckles due to bending. For the purposes of this research, finite element analysis is applied in order to describe and predict in an accurate way the structural response of a model tower stiffened by internal stiffeners. Moreover, a parametric study is being performed in order to investigate the effect of the stiffeners' number to the functionality of the aforementioned stiffening systems and the improved structural behavior of the overall wind converter.

• 한국구조물진단유지관리공학회 논문집
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• 제18권6호
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• pp.21-29
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• 2014

본 연구에서는 모노파일지지구조의 고성능 그라우트연결부의 부착거동을 다루고 있다. 강관파일 연결부의 일체화를 위하여 섬유보강 고성능 그라우트를 개발하였으며, 재령 7일 압축강도 125MPa와 직인장강도 7.5MPa를 나타내었다. 축하중을 받는 상태에서의 그라우트의 부착거동을 평가하기 위하여 강관파일에 그라우트를 충진하여 부착실험을 수행하였으며, 그 결과를 기존의 설계기준과 분석하였다. 실험변수는 섬유혼입율 (0%, 0.5% and 0.9%), 섬유의 형상비 (60 and 80)와 전단키의 높이와 간격의 비 (0.013 and 0.056)로 선정하였다. 실험결과 최대부착강도는 30.8MPa로 관찰되었으며, 섬유 혼입율보다는 전단키의 높이와 간격의 비가 부착강도에 영향을 미치는 것으로 분석되었다.

• 한국항해항만학회지
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• 제27권1호
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• pp.63-70
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• 2003

초대형 부유식 구조무？ 상부구조는 육상 구조물과는 달리 파량하중의 영향을 받기 때문에 하부부체의 변형에 의해서 상부구조물에는 부가 모멘트가 크게 발생한다. 이와 같은 부가모멘트의 저감을 위하여 보-기둥 접합부에 반강접의 도입에 관한 연구는 시작단계이며 반강접의 비선형 거동을 고려한 상부구조물의 연구는 초기단계이다. 본 논문에서는 초대형 부유식 구조물의 상부구조물에 정적하중과 진폭의 크기가 다른 파랑하중이 동시에 작용할 경우 강접 골조와 부분적으로 반강접 접합부가 사용된 세 가지 접합부 종류에 대한 2차 탄성해석을 수행하였다. 접합부는 웨브에 더블 앵글을 가진 상하 앵글(TSD) 접합과 확장 엔드 플레이트 접합 그리고 각형강관 외다이아프램 접합부를 적용하였으며 중고층 구조물에 파랑하중이 작용할 경우 반강접 접합부의 위치에 따른 모멘트와 수평변위의 응답특성에 대하여 연구하였다.

• Applied Microscopy
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• 제34권2호
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• pp.83-93
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• 2004

붉은쏨뱅이의 피부 상피층은 다층상피층으로 지지세포, 선세포, 과립세포 그리고 mitochodria-rich cell들로 구성된다. 상피층은 지지세포의 형태와 구조에 따라 표면층, 중간층 및 기저층으로 구분할 수 있다. 점액세포들은 단세포선으로 상피의 표면층과 중간층에 분포하며, 산성의 비황화 뮤코다당류로 구성된 점액을 가진다. 곤봉상세포는 세포질에 잘 발달된 중심공포, 조면소포체 및 골지체를 가진다. 과립세포는 표면층에 존재하며, 전자밀도가 높은 과립을 가진다. mitochodria-rich cell의 주변부 세포질에는 미세섬유 다발이 발달되어 있으며, 수질부에는 다수의 관상 미토콘드리아를 가진다. 색소세포는 세포질에 존재하는 함유물의 전자밀도에 따라 세 종류로 구분할 수 있다.

• Parasites, Hosts and Diseases
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• 제44권2호
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• pp.151-156
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• 2006

A case of breast sparganosis was confirmed by surgical excision of a worm (fragmented into 5 pieces) in a 59-year-old Korean woman suffering from a palpable mass in the left breast. Mammography and ultrasonography characteristically revealed the presence of several well-defined, isodense and hypoechoic tubular masses, in the upper quadrant of the left breast, each mass consisting of a continuous cord- or worm-like structure. During surgery, a long segment of an actively moving sparganum of Spirometra sp. and 4 small fragments of the same worm, giving a total length of 20.3 cm, were extracted from the upper outer quadrant of the left breast and the axillary region. The infection source remains unclear, because the patient denied ingesting any snake or frog meat or drinking untreated water.

• Clinical and Experimental Reproductive Medicine
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• 제48권3호
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• pp.229-235
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• 2021

Objective: In this study, the effects of Lactobacillus acidophilus on testosterone (TES), follicle-stimulating hormone (FSH), luteinizing hormone (LH), androgen-binding protein (ABP), factor-associated apoptosis (FAS), and total cholesterol (TC), as well as histopathological changes, were investigated in male rats fed a high-cholesterol diet. Methods: The study included three groups. The control (C) group was fed standard-diet for 8 weeks. The hypercholesterolemia (HC) group was fed a 2% cholesterol-diet for 8 weeks. The therapeutic group (HCL) was fed a 2% cholesterol-diet for 8 weeks and administered L. acidophilus for the last 4 weeks. FSH, TES, and FAS levels in testicular tissue were determined using an enzyme-linked immunosorbent assay (ELISA), while another sample was examined histopathologically. LH and ABP levels were determined using ELISA, and serum TC levels were assessed via an autoanalyzer. Results: In the HC group, the TC levels were significantly higher and the LH levels were lower (p<0.05) than in the C group. The ABP levels were lower (p>0.05). In the HCL group, the LH and ABP levels were higher (p>0.05) and the TC level significantly lower (p<0.05) than in the HC group. The TES and FSH levels were lower, and the FAS levels were higher, in the HC than in the C group (p<0.05). In the HCL group, levels of all three resembled control levels. Histologically, in the testicular tissue of the HC group, the cells in the tubular wall exhibited atrophy, vacuolization, and reduced wall structure integrity. However, in the HCL group, these deteriorations were largely reversed. Conclusion: Supplementary dietary administration of an L. acidophilus to hypercholesterolemic male rats positively impacted testicular tissue and male fertility hormone levels.

• 대한의용생체공학회:의공학회지
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• 제44권1호
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• pp.85-91
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• 2023

Stress urinary incontinence (SUI) occurs when abdominal pressure increases, such as sneezing, exercising, and laughing. Surgical and non-surgical treatments are the common methods of SUI treatment; however, the conventional treatments still require continuous and invasive treatment. Laser have been used to treat SUI, but excessive temperature increase often causes thermal burn on urethra tissue. Therefore, the optimal conditions must be considered to minimize the thermal damage for the laser treatment. The current study investigated the feasibility of the laser irradiation condition for SUI treatment using non-ablative 980 nm laser from a safety perspective through numerical simulations. COMSOL Multiphysics was used to analyze the numerical simulation model. The Pennes bioheat equation with the Beer's law was used to confirm spatio-temporal temperature distributions, and Arrhenius equation defined the thermal damage caused by the laser-induced heat. Ex vivo porcine urethral tissue was tested to validate the extent of both temperature distribution and thermal damage. The temperature distribution was symmetrical and uniformly observed in the urethra tissue. A muscle layer had a higher temperature (28.3 ℃) than mucosal (23.4 ℃) and submucosal layers (25.5 ℃). MT staining revealed no heat-induced collagen and muscle damage. Both control and treated groups showed the equivalent thickness and area of the urethral mucosal layer. Therefore, the proposed numerical simulation can predict the appropriate irradiation condition (20 W for 15 s) for the SUI treatment with minimal temperature-induced tissue.

• 한국염색가공학회지
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• 제34권4호
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• pp.284-301
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• 2022

The limitations of food production caused by global warming, consumption of soil fertility, and land shortage have demanded the development of alternative foods. Their market has been increasing, and in particular, there is an urgent need for an alternative meat. Among them, the non-slaughtered cell-cultured meat that can be manufactured in the laboratory, that is, cultured meat, is in the spotlight, which can solve the problem of meat consumption while including the advantages of meat. It is classified into minced cultured meat and structured one with a structure similar to that of real meat. The latter is currently facing limitations related scaffolds, cells, and the multiplicative problems, and many attempts are being made to solve them. The complex problem is related to secure texture and taste as well as structural similarity to actual meat. To solve the problems, it is necessary to lay emphasis on cells, there are fat cells and vascular cells, and the most fundamental cells, muscle cells. These are the main cells that control the texture and nutrients of meat, and unlike other cells, they grow in the form of fibers. A myofibril (also known as a muscle fibril) is a basic rod-like organelle of a muscle cell, which is a quantitatively major component of meat, and one of the tissues that maintain the appearance of the body and bones. In this review article, we focused on the growth of muscle cells into long, tubular cells known as muscle fibers using the fabricated fibrous scaffold, and reviewed not only research results for muscle tissue engineering but also various results in the related fields for the last five years.