Characterizing Cutaneous Elastic Fibers by Eosin Fluorescence Detected by Fluorescence Microscopy

( Young Soo Heo ),( Hae Jun Song ) 대한피부과학회 2010 Annals of Dermatology Vol.23 No.1

Background: Though elastic fibers are as important as collagen fibers in interpretation of the histopathologic findings, it is impossible to observe them on the hematoxylin & eosin (H&E) stained specimen. Objective: Characterizing eosin fluorescence emitted by elastic fibers in H&E stained specimens. Methods: Normal skin tissue sections were stained in 4 different ways (unstained, hematoxylin only, eosin only, H&E) and observed under a fluorescence microscope using a FITC filter set. Fluorescent findings of 30 H&E-stained specimens showing abnormal dermal findings were compared with bright field findings of Miller`s elastic stained specimen. Results: Strong eosin fluorescence was related to the differential binding property of eosin with elastic fibers. Hematoxylin stain quenched excessive eosin fluorescence from other tissue components and contributed to better contrast. Fluorescence microscopy of H&E-stained sections was found to be especially useful in observing mature elastic fibers in the reticular dermis. In 74% of the specimens, eosin fluorescence findings of elastic fibers in reticular dermis matched well with that of specimens with elastic fiber special stain. Conclusion: Analysis of skin elastic fibers by fluorescence microscopy is a useful and complementary method to reveal hidden elastic fibers in H&E-stained specimens. (Ann Dermatol 23(1) 44~52, 2011)

Distribution of elastic fibers in the head and neck: a histological study using late-stage human fetuses

Hideaki Kinoshita,Takashi Umezawa,Yuya Omine,Masaaki Kasahara,José,Francisco Rodrí,guez-Vá,zquez,Gen Murakami,Shinichi Abe 대한해부학회 2013 Anatomy & Cell Biology Vol.46 No.1

There is little or no information about the distribution of elastic fibers in the human fetal head. We examined this issue in 15 late-stage fetuses (crown-rump length, 220–320 mm) using aldehyde-fuchsin and elastica-Masson staining, and we used the arterial wall elastic laminae and external ear cartilages as positive staining controls. The posterior pharyngeal wall, as well as the ligaments connecting the laryngeal cartilages, contained abundant elastic fibers. In contrast with the sphenomandibular ligament and the temporomandibular joint disk, in which elastic fibers were partly present, the discomalleolar ligament and the fascial structures around the pterygoid muscles did not have any elastic fibers. In addition, the posterior marginal fascia of the prestyloid space did contain such fibers. Notably, in the middle ear, elastic fibers accumulated along the tendons of the tensor tympani and stapedius muscles and in the joint capsules of the ear ossicle articulations. Elastic fibers were not seen in any other muscle tendons or vertebral facet capsules in the head and neck. Despite being composed of smooth muscle, the orbitalis muscle did not contain any elastic fibers. The elastic fibers in the sphenomandibular ligament seemed to correspond to an intermediate step of development between Meckel’s cartilage and the final ligament. Overall, there seemed to be a mini-version of elastic fiber distribution compared to that in adults and a different specific developmental pattern of connective tissues. The latter morphology might be a result of an adaptation to hypoxic conditions during development.

Characterizing Cutaneous Elastic Fibers by Eosin Fluorescence Detected by Fluorescence Microscopy

Young Soo Heo,송해준 대한피부과학회 2011 Annals of Dermatology Vol.23 No.1

Background: Though elastic fibers are as important as collagen fibers in interpretation of the histopathologic findings, it is impossible to observe them on the hematoxylin & eosin (H&E) stained specimen. Objective: Characterizing eosin fluorescence emitted by elastic fibers in H&E stained specimens. Methods: Normal skin tissue sections were stained in 4 different ways (unstained, hematoxylin only,eosin only, H&E) and observed under a fluorescence microscope using a FITC filter set. Fluorescent findings of 30H&E-stained specimens showing abnormal dermal findings were compared with bright field findings of Miller’s elastic stained specimen. Results: Strong eosin fluorescence was related to the differential binding property of eosin with elastic fibers. Hematoxylin stain quenched excessive eosin fluorescence from other tissue components and contributed to better contrast. Fluorescence microscopy of H&E-stained sections was found to be especially useful in observing mature elastic fibers in the reticular dermis. In 74% of the specimens, eosin fluorescence findings of elastic fibers in reticular dermis matched well with that of specimens with elastic fiber special stain. Conclusion: Analysis of skin elastic fibers by fluorescence microscopy is a useful and complementary method to reveal hidden elastic fibers in H&Estained specimens. (Ann Dermatol 23(1) 44∼52, 2011)

The estimation of age from elastic fibers in the tunica media of the aortic wall in a thai population: a preliminary study using aorta image analysis

Pornhatai Komutrattananont,Patison Palee,Sukon Prasitwattanaseree,Pasuk Mahakkanukrauh 대한해부학회 2020 Anatomy & Cell Biology Vol.53 No.3

Image analysis has an increasing role in the identification of individuals in forensic application. Beside the bones, microstructural of arteries can be used in age estimation study. Aorta is the largest elastic artery which consists of many elastic fibers. Elastin in arterial wall highly resist to chemical and physical influence. The purposes of the study were to quantify elastic fibers in tunica media in each location of the aorta and examine the correlation between elastic fibers and age by using image analysis program. A total of 36 human aortas were dissected in 4 locations. The aortas were obtained from cadavers with an age range of 20 to 90 years. Specimens were stained with Elastic Van Gieson staining. Histological images were investigated about elastic fibers using light microscope with cellSens program and aorta image analysis was used for the evaluation of data. The results showed that the mean percentage density of elastic fibers in the ascending aorta and the aortic arch increased. However, the mean percentage density of elastic fibers decreased in the 31 to 40 years age group in the thoracic aorta and the abdominal aorta and decreased in each location of aorta continuously until 81 to 90 years. The abdominal aorta showed the highest correlation with age (r=0.732) followed by the thoracic aorta, the aortic arch and the ascending aorta, respectively. Changes in the percentage density of elastic fibers in the tunica media of the aortic wall can be used to add information to age estimation for identification purposes.

경화부종에서 영상분석을 이용한 교원섬유와 탄력섬유의 비율에 대한 연구

문경원 ( Kyoung Won Moon ),김소영 ( So Young Kim ),최유원 ( Yoo Won Choi ),명기범 ( Ki Bum Myung ),최혜영 ( Hae Young Choi ) 대한피부과학회 2006 大韓皮膚科學會誌 Vol.44 No.9

Background: Scleredema is a rare connective tissue disorder, characterized by hard and thick skin. It is well known that collagen synthesis is increased in scleredema skin, but there has been no study on the change of elastic fibers. Objective: The purpose of this study was to compare the changes of collagen and elastic fibers in scleredema and normal skin. Methods: We retrospectively evaluated the biopsy specimens of 10 patients diagnosed with scleredema. The control group was selected by matching each scleredema case with same site and similar ages from the biopsy specimens which showed normal dermis. A computerized image analysis system was used to measure the fraction of collagen and elastic fibers and calculate the ratio of elastic fibers to collagen fibers in each group. Results: The skin of scleredema was found to have a significant increase in the percentage of collagen fibers in the dermis compared to the control group. On the other hand, the percentage of elastic fibers was significantly decreased in the scleredema group (p<0.05). Conclusion: In contrast to scleroderma which shows an increase in dermal elastic tissue and collagen fibers, we concluded that there is a decrease of elastic fibers in scleredema and that the pathogenesis and molecular involvement are different in the two diseases. we also found that the computerized image analysis system was a useful tool in the measurement of connective tissue components. (Korean J Dermatol 2006;44(9):1072~1077)

Effects of fiber aspect ratio evaluated by elastic analysis indiscontinuous composites

김홍건 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.3

An elastic stress analysis to investigate the effects of fiber aspect ratio in short fiber reinforced discontinuous composite materials has been done for different fiber volume fractions. In order to examine the elastic internal behavior, an evaluation of the load bearing capacity of discontinuous reinforcements is needed in advance. Accordingly, analytical derivation of composite mechanics has been carried out to predict fiber stresses and fiber/matrix interfacial shear stresses in discontinuous composites. The model is based on the theoretical development of conventional shear lag theory developed by Cox. However, the major shortcoming of the Cox model is due to the calculation without normal stress transfer from the end of fibers. In order to overcome the shortcoming, both of the normal and shear stress transfer mechanisms between the fiber and the matrix are accounted for with the stress concentration effects as well as material and geometrical properties. Results of predicted stresses concerning the various fiber aspect ratios are described by using the present model that is the closed form solution and compared with the Cox model and Taya model. It is found that the effect of fiber aspect ratio is significant to composite strengthening through load transfer from the matrix to the fiber, whereas the effect of fiber volume fraction is not so sensitive, relatively. It is also found that the present model has the capability to correctly predict the values of fiber stresses and fiber/matrix interfacial shear stresses.

INVESTIGATION OF A STRESS FIELD EVALUATED BY ELASTIC-PLASTIC ANALYSIS IN DISCONTINUOUS COMPOSITES

Kim, H.G. The Korean Society of Automotive Engineers 2007 International journal of automotive technology Vol.8 No.4

A closed form solution of a composite mechanics system is performed for the investigation of elastic-plastic behavior in order to predict fiber stresses, fiber/matrix interfacial shear stresses, and matrix yielding behavior in short fiber reinforced metal matrix composites. The model is based on a theoretical development that considers the stress concentration between fiber ends and the propagation of matrix plasticity and is compared with the results of a conventional shear lag model as well as a modified shear lag model. For the region of matrix plasticity, slip mechanisms between the fiber and matrix which normally occur at the interface are taken into account for the derivation. Results of predicted stresses for the small-scale yielding as well as the large-scale yielding in the matrix are compared with other theories. The effects of fiber aspect ratio are also evaluated for the internal elastic-plastic stress field. It is found that the incorporation of strong fibers results in substantial improvements in composite strength relative to the fiber/matrix interfacial shear stresses, but can produce earlier matrix yielding because of intensified stress concentration effects. It is also found that the present model can be applied to investigate the stress transfer mechanism between the elastic fiber and the elastic-plastic matrix, such as in short fiber reinforced metal matrix composites.

횡하중을 받는 SiC/Ti-15-3 MMC 복합재 계면영역에서의 탄소성 응력장분포거동(Ⅰ)

강지웅,김상태,권오헌 한국안전학회 2004 한국안전학회지 Vol.19 No.4

Unidirectional fiber-metal matrix composites have superior mechanical properties along the longitudinal direction. However, the applicability of continuous fiber reinforced MMCs is somewhat limited due to their relatively poor transverse properties. Therefore, the transverse properties of MMCs are significantly influenced by the properties of the fiber/matrix interface. In this study, the interfacial stress states of transversely loaded unidirectional fiber reinforced metal matrix composites investigated by using elastic-plastic finite element analysis. Different fiber volume fractions (5-60%) were studied numerically. The interface was treated as three thin layer (with different properties) with a finite thickness between the fiber and the matrix. The fiber is modeled as transversely isotropic linear-elastic, and the matrix as isotropic elastic-plastic material. The analyses were based on a two-dimensional generalized plane strain model of a cross-section of an unidirectional composite by the ANSYS finite element analysis code.

Mechanical Properties of Wool Fiber in the Stretch Breaking Process

Kwak, Seung-A,Lee, Jun-Young,Lee, Dae-Hoon,Jeon, Boong-Soo The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.1

Short wool fibers obtained by the stretch breaking process can be blended with cotton fibers and processed in a cotton spinning system, which has a high production rate. For the structural property of the wool fiber after stretch breaking, the diameter and length of the wool fiber were measured as a function of time. The diameter of the broken fibers was finer than the diameter of untreated fibers. The fiber diameter at the break point was the finest and was more irregular than the original fiber. The broken fiber showed mechanical properties of increased modulus, decreased breaking strain, and increased breaking strength.

Mechanical properties of coconut fiber-reinforced coral concrete

Cunpeng Liu,Fatimah De'nan,Qian Mo,Yi Xiao,Yanwen Wang 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.90 No.2

This study examined the changes in the mechanical properties of coral concrete under different coconut fiber admixtures. To accomplish this goal, the compressive strength, splitting tensile strength, flexural strength and elastic modulus properties of coral concrete blocks reinforced with coconut fibers were measured. The results showed that the addition of coconut fiber had little effect on the cube and axial compressive strengths. With increasing coconut fiber content, the flexural strength and splitting tensile strength of the concrete changed substantially, first by increasing and then by decreasing, with maximum increases of 36.0% and 12.8%, respectively; additionally, the addition of coconut fibers resulted in a failure type with some ductility. When the coconut fiber-reinforced coral concrete was 7 days old, it reached approximately 74% of its maximum strength. The addition of coconut fiber did not affect the early strength of the coral concrete mixed with seawater. When the amount of coconut fiber was no more than 3 kg/m3, the resulting concrete elastic modulus decreased only slightly from that of a similar concrete without coconut fiber, and the maximum decrease was 5.4%. The optimal dose of coconut fiber was 3 kg/m3 in this study.