• Applied Microscopy
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• v.22 no.1
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• pp.128-142
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• 1992

Ultrastructure of the poison secreting organ in the spiders, Agelena limbata Thorell and Nephila clavata L. Koch were studied using scanning and transmission electron microscopes. The venom glands located its secretory sac portion in cephalothorax and excretory duct in the fang of chelicera are one pair of simple alveolar glands composed of three kinds of basic tissues-outer spiral musculature, middle myoepithelium and inner glandular epithelium. The muscle cells of the venom gland junctioned with the motor nerve endings at neuromuscular contact area are composed of smooth muscle fibers, whereas the myoepithelial cells between the musculature and inner glandular epithelium have compact collagenous fibers within the cytoplasm. The glandular epithelial cells which arranged along the concentrical location are subdivided into basal light cells and apical dark cells according to electron densities of their cytoplasms.

• Earthquakes and Structures
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• v.16 no.4
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• pp.455-468
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• 2019

The behavior of pile-deck connections of pile-supported marginal wharfs subjected to earthquake loading is of key importance to ensure a good performance of this type of structures. Two precast-pretensioned pile-deck connections used in the construction of pile-supported marginal wharfs were tested under cyclic loading. The first is a connection with simple reinforcement details and light steel ratio developed for use where moderate pile-deck rotation demands are expected in the wharf. The second is specifically developed to sustain the large rotation, shear force and bending moment demands, as required for the shortest piles in a marginal wharf. Data obtained from the test program is used in the paper to calibrate an equivalent plastic hinge length that can be incorporated into nonlinear analysis models of these structures when prestressed pile-deck connections with duct embedded dowels are used.

• The Korean Journal of Zoology
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• v.31 no.2
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• pp.122-132
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• 1988

Ultrastructure of the cutaneous granular glands and production of their secretory granules in the water toad, Bufo steinegeri Schmidt, are studied with light and electron microscopes. Cutaneous granular glands of the water toad have gland cavity in dermis and gland duct in epidermis. Each gland cavity of the granular glands is consisted of 3 types of cells which are inner glandular epithelial cells, outermost myoepithelial cells and another kind of epithelial cells near the gland duct. Characteristically, cytoplasms of the glandular epitelial cells appeared multinucleated masses without differentiation into cells. Poisonous secretory graules excreated by the merocrine secretion are basicafly composed of 2 kinds of granules which are electron dense granules and electron lucent granules. These granules are fused each other and forming compounded structures. According to the granular size and differentiated levels, they are subdivided into 4 types of granules. Synthesis of these secretory granules is occurred at the smooth endoplasmic reticulums of the glandular epithelial cells and limiting membranes of these granules are also originated from these cell organelles.

• The Korean Journal of Zoology
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• v.23 no.4
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• pp.219-228
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• 1980

The ultrastructures of the granular glands in the asiatic land salamander (Hynobius leechi) skin were observed by means of electron microsope The results were as follows; 1. The granular gland of the asiatic land salamander skin consisted of a body of gland and a duct. The body of the granular gland consisted of the glandular epithelial cells and the myoepithelial cells. The duct of the granular gland consisted of the keratinocytes. 2. The glandular epithelial cells in the asiatic land salamander skin were divided into the dark cell and the light cells in accordance with the electron density of the cytoplasm. 3. The secretory granules of the granular glands were round or oval in form and were divided into the various granules, showing the secretory granules showing weak electron density had the parts showing strong electron density near the granular membrane. 4. It is supposed that showing the different electron densities of the granules in a glandular epithelial cell is due to different mature stages and to different level of water absorption, and the chemical components of the granules showing different electron densities are identical.

• Applied Microscopy
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• v.10 no.1_2
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• pp.77-86
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• 1980

The distribution of the secretory ducts, fine structures of the secretory epithelial cells, and the ingredients of the metaplasmic inclusions were studied at light and electron microscopical levels in seeds, stems, leaves, and roots of ginseng. The secretory ducts occurred in the hypocotyl of the embryo, in the cortex of the roots, and also both inside and outside of each vascular bundle in the stems and leaves. Especially, it is considered that the circular layers of the secretory ducts in roots may represent their ages. The epithelial cell has well developed nucleolus, mitochondria and smooth endoplasmic reticulum. Sudanophyl and osmiophilic inclusions were found in the epithelial cytoplasm and duct lumen. But these inclusions were not observed when extracted with pyridin or alcohol. In contrast to the lumen with red color, the epithelial cells were blue in color as stained with nile blue, suggesting that the former inclusions are neutral lipid while the latter are acidic lipid. The electron density of the cell inclusions was quite high as fixed with osmium tetroxide, indicating that most of these secretory materials seem to be unsaturated lipid. Therefore, since ginseng secretory ducts are closely associated with the lipid metabolism, it should be called lipid canal or lipid duct.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.257-265
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• 2000

Harderian glands are the unique organs in several mammals, which human and non-human primates do not have. We report the ultrastructural changes in the postnatal developmental periods of Harderian glands in Mongolian gerbil(Meriones unguiculatus). Male and female Mongolian gerbils were sacrificed on days 3, 10, 30 and 60 after birth and their Harderian glands were observed by transmission electron microscope. The obtained results were summarized as follows; 1. In 3-day-old Mongolian gerbils, Harderian gland was composed of one excretory duct and immature tubules which have two type cells, dark and light cells, identified electron-dense and electron-lucent respectively. 2. In 10-day-old Mongolian gerbils, small lipid vacuoles began to be found in the cytoplasm of the secretory cells of the Harderian gland. Mitochondria, Golgi apparatus, polysomes and slash were more abundant in the cytoplasm of dark cells than those of light cells. The arrangement of tubules in the gland was much more condensed than that of 3-day-old Mongolian gerbils. 3. In 30-day-old Mongolian gerbils, the secretory cells of the tubule were typically columnar in shape and there was one type cell in the tubule. Most of the columnar secretory cells contained various size vacuoles. 4. In 60-day-old Mongolian gerbils, the Harderian gland possessed the typical structural characteristics of adults. The mature glandular structures were more significant than those of 30-day-old animals.

• Parasites, Hosts and Diseases
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• v.57 no.3
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• pp.299-302
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• 2019

A clonorchiasis case in a captive leopard cat, Prionailurus bengalensis euptilurus, was confirmed by ultrasonographic findings and egg morphologies found in the bile juice sample in the Korea. The leopard cat was introduced from the wild habitat of Gyeongsangnam-do, to Cheongju Zoo in Cheongju-si, Chungcheongbuk-do, Korea in August 2014. Physical examinations were basically performed for quarantine and check-up health. The cat was comparatively good in health except anorexia. The cyst-like bile duct dilation and the increased echogenicity of gall bladder wall and hepatic parenchyma were observed by ultrasonography. Ultrasound-guided needle biopsy was conducted for collecting bile juice and the specimens were observed under light microscope. The numerous small trematode eggs were detected in the bile juice sample of the light microscopy. The eggs were $25-33(28{\pm}3){\mu}m$ by $18-22(20{\pm}1){\mu}m$ in size and showed typical characteristics of Clonorchis sinensis egg, i.e., a dominantly developed operculum, shoulder rim and dust-like wrinkles in surface. To treat the liver fluke infection, 20 mg/kg of praziquantel was orally administered only once to the case. Follow-up studies including fecal examinations were conducted during 2 years after treatment. But no more eggs were detected from the case. In the present study, we described the first clonorchiasis case of leopard cat, which was confirmed by ultrasonographic findings and egg morphologies from the bile juice sample in Korea.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1314-1321
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• 2010

The west express way which links south west area of the central city of Seoul has been notorious for extremely heavy traffics since its first opening in 1991(i.e. the average vehicle speed is less than 25km/h, a daily traffic is 112,000 and among them, more than 94% of the vehicles are the light vehicles). The city government recently initiated a new BTO(Build-Transfer-Operate) project as an alternative in releasing heavy traffic and a high construction cost. The proposed underground express road is the first double-level tunnel (i.e. a total length of road is 10,91km and the tunnel is 9.308km long) ever built in South Korea, while such tunnel system is not new worldwide as such A86 East tunnel in France, SMART tunnel in Malaysia, and Fuxing tunnel in China. This paper discusses major design issues regarding the internal structures such as deck slab, and secondary liner.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.3
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• pp.267-273
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• 2008

The circular cylinder pipes are used in the many industrial areas. In this paper, the acoustic wave propagation in the pipe containing a gas is researched. First of all, the theory for the coupled acoustic wave propagation in a pipe is investigated. Acoustic wave propagation in pipe can not be occurred independently between the wave of the fluid and the shell. It requires complicated analysis. However, as a special case, the coupled wave in a high density pipe containing a light density medium is corresponded closely to the uncoupled in-vacuo shell waves and to the rigid-walled duct fluid waves. The coincidence frequencies of acoustic and shell modes contribute to the predominant energy transmission. The coincidence frequency means the frequency corresponding to the coincidence of the wavenumber in both acoustic and shell. In this paper, it is assumed that the internal medium is much lighter than the pipe shell. After the uncoupled acoustic wave in the internal medium and uncoupled shell wave are considered, the coincidence frequencies are found. The analysis is successfully confirmed by the verification of the experiment using the real long steel pipe. This work verifies that the coupled wave characteristic of the shell and the fluid is occurred as predominant energy transmission at the coincidence frequencies.

• The Korean Journal of Malacology
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• v.26 no.1
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• pp.79-84
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• 2010

A morphological and ultrastructural study on the prostate of a land snail Nesiohelix samarangae was conducted. The prostate of Nesiohelix samarangae is a tubular gland connected with the large hermaphrodite duct. The lining of the prostate tubules possesses two distinct types of epithelial cells, one secretory and the other non-secretory. The secretory cells contained numerous secretory granules in various sizes and electron density. Most of the secretory granules showed light electron density but some of them showed heavy density. The ciliated cells were non-secreting cells situated only toward the lumen of the tubules and appeared as ordinary epithelial lining cells. The ciliated cells of the epithelium extensively interdigitate with each other and their apical surfaces had numerous cilia and microvilli. The bases of the ciliated cells did not reach the basal region of the secretory cells.