• Applied Microscopy
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• v.40 no.3
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• pp.155-162
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• 2010

Bone is a hierarchically structured composite material which has been well studied by the materials engineering community because of its unique structure and mechanical properties. Bone is a laminated organic-inorganic composite composed of primarily hydroxyapatite, collagen and water. The main mineral that gives bone's hardness is calcium phosphate, which is also known as hydroxyapatite. Light microscopy (LM) and transmission electron microscopy (TEM) were used to study the structure of femurs from chicken and rabbit. The elemental analysis was used to search variation in the distribution of calcium, potassium and oxygen in the femur. Current investigation focused on two structural scales: micro scale (arrangement of compact bone) and nano scale (collagen fibril and apatite crystals). At micro scale, distinct difference was found in microstructures of chicken femur and rabbit femur. At nano scale, we analyzed the shape and size of apatite crystals and the arrangement of collagen fibril. Consequently, femurs of chicken and rabbit had very similar chemical property and structures at nano scale despite of their different species.

• Applied Microscopy
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• v.32 no.3
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• pp.291-301
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• 2002

The present study was performed to compare the morphological differences of flight muscles among 3 species from insects (Xylocopa appendiculata circumvolans Smith, Davidins lunatus B. and Serrognathus platymelus castanicdor M.) by investigating ultrastructural observation and stereological analysis. Xylocopa appendiculata circumvolans Smith has the most flight hours. In addition, the number and arrangement of mitochondria and the structure of sarcomere were similar to those of vertebrates. However sarcomere structure of Davidins lunatus B. was irregular and the sarcomere length was longer than that of Xylocopa appendiculata circumvolans Smith. In Serrognathus platymelus castanicdor M. which has the least flight hours, the length of sarcomere appeared longer than that of Davidins lunatus B. In results of stereological analysis, Serrognathus platymelus castanicdor M. had the highest volume density of myofibrils in all species. The volume and numerical density of mitochondria and the volume density of sarcoplasmic reticulum were highest Xylocopa appendiculata circumvolans Smith and Davidins lunatus B. respectively. This study suggests that the flight hours and flight pattern by different ecological habitats may cause the morphological changes of flight muscle.

• Journal of radiological science and technology
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• v.29 no.1
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• pp.29-37
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• 2006

The breast cancer has the highest occurrence rate among the female cancers, and as the living style changes, the occurrence is increasing gradually. For the breast cancer test among women, who comprises up to 50% of the total population, the mammography is mainly used as the screening test, and the accuracy control is the most important aspect of the testing. Therefore this research divided the northern part of Kyeongsangbuk-do into 4 regions and investigated the accordance ratio of examination field and light examination field, the total focus using the optical density and compression rate, and the overall maintenance of mammography within the regions. The equipments of 11 hospitals were investigated, and the 7 hospitals passed the standard level of the accordance ratio of examination field. 6 hospitals passed the standard optical density, and 7 hospitals had the passing performance in the compression rate. Fibers, group of specks, and masses within the Mammographic Accreditation Phantom scored 10, being within the standard range. However, only 3 hospitals were equipped with private development processor and illumination. The result reflects the fact that the image quality of breast is not correctly being maintained. Moreover, only 27.27% satisfied all the three categories of compression fitting, accordance ratio of examination field, and phantom image evaluation at the same time. The accuracy control must be maintained more precisely for the accurate diagnosis of breast cancer.

• Applied Microscopy
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• v.32 no.4
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• pp.303-310
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• 2002

Spermatogenesis and sperm ultrastructure are investigated by means of light and transmission electron microscopy in the equilateral venus, Gomphina veneriformis which is dominant bivalve in the east coast of Korea. In the active spermatogenic season, testis consists of numerous spermatogenic follicles which is contains germ cells in the different developmental stage. The spermatogonia attached to spermatogenic follicle wall and has a large nucleus with electron-dense nucleolus. The spermatocytes are characterized by appearance of synaptonemal complex and well-developed Golgi complex. Nucleus of spermatid consists of numerous heterogeneous granules with high electron density. Karyoplasmic condensation, acrosome and flagellum formations are observed during spermiogenesis. Testicular matured sperms of sperm bundle consists of head, midpiece and tail. The head is about $8.5{\mu}m$ long and comprises a long nucleus and a bullet-like acrosome ($8.5{\mu}m$ in length). Acrosomal rod of microfilaments is observed in the lumen between nucleus and acrosome. The midpiece has four mitochondria. And tail has the typical '9+2' microtubule system.

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.154-159
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• 1992

Forniation ancl ~regcncration oi' conitlial pro1oplast of Pc, ti~i.rlli~in~~~ c~rr~~culo.hryupmel.- - czllulolytic Ihngus. were examined. By using Novozyme 134(1'!/0 w/c) as a cell wall lytic enzyme. the highest yield of protopl;~sts exceeding 501%, war obtained from the qwollen conidiosporcs preincubatrd in the minimal medium containing 2-tleoxy-D-glucose(2-UC;. 75 pglml) for 10-11 11. No protoplast were obtained horn dormant spores. The regeneration frequency of the protoplasts was 49.2'!11. which was higher than that of mycclium originated protoplast (4.6-17.X1X, . in 0.6 M MgS04. pH 5.6). 'l'lie best osmotic stahilizcr ror the isoaltion and regcueration of thc protoplast was 0.6 M iimmonium sulfatc and 0.6 M magnesiuni sulfhte. respectively. 'I'lie process of the protoplast isolaiton l'ro~n swollen cnnirliospore ancl regeneration ha\, ing two pattcrns from protoplast were obsen'etl through light microscope.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.9-13
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• 1998

Visual system of Korean Salamander(Hynobius leechi) was morphologically studied. Fertilized eggs in egg sacs were collected and were developed in sterile saline solution. Various sized larvae of 5-30mm in length were fixed. Specimens were paraffin sectioned and were observed under light microscope. In 5mm length larva, lens rudiment induced by optic cup was combined with sensory ectoderm. The shape of lens was changed as spherical in 12mm length larva, but the retinal layer did not differentiated into three layers. The differentiation of retinal layer was clear in 14-16mm length larva. The central region of lens fibers was degenerated. Iris and ciliary body were formed from the marginal zone of optic cup in 20mm length larva. Choroid was thicker in elder eye of 30mm length larva and cartilage developed at outer region of optic cup. The outer segment of photoreceptor cell layer grew longitudinally. Optic nerve was connected to the ventral part of brain through cartilage.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.2
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• pp.124-133
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• 2007

In our research, we focused on the FBG sensor system which is one of the fiber optic sensor system. The FBG sensor system is used for structural measurements. The problem of FBG sensor is very thin and weak. The methods that can protect FBG optical fiber sensor front outside forces such as the impacts are investigated. The FBG sensor embedded in the fiber reinforced composites which can replace the reinforcing steel bars in concretes can be applied to the concrete structures by embedding to the composite materials. The progresses in tensile strength of FBG sensor embedded in the reinforcing FRP bars in the concrete structures compare to plain FBGs were observed and the good long term durability is expected.

• Journal of Yeungnam Medical Science
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• v.5 no.2
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• pp.25-30
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• 1988

Soft-tissue expansion is a new surgical technique of providing donor tissue in modern reconstructive surgery. This technique provides a quantity of tissue of similar color, texture, and hair-bearing qualities for reconstruction of adjacent defects. It is known that the expanded skin shows several constant histologic changes including the increase in collagen fibers and vascularity within dermis, and thinning of subcutaneous tissue and dermis. In this study, the author observed serial histologic changes of rabbit skin induced by progressive tissue expansion upto excessive expansion of 6 times. The results are as follows : 1. Changes in the thickness of the epidermis was minimal until 3 times of expansion, but slight thinning was observed at excessive expansion state. 2. The thickness of the dermis was progressively decreased, and collagen fibers in the dermis was rapidly increased in early phase of expansion. 3. The vascularity in the dermis was also progressively increased. 4. The skin appendages showed no structural changes even in excessive expansion. 5. The panniculus carnosus showed no atrophic changes and the thickness was maintained in excessive expansion.

• Applied Microscopy
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• v.35 no.4
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• pp.42-54
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• 2005

This study described the spermatozoa of the discoglossidae Bombina orientalis using light, scanning and transmission electron microscopes. Sperm head possess a crescent or leaf shape, with a moderately flexible head, and with a sharp anterior and posterior tips. The nucleus are a thick cone shaped in the widest middle part of nucleus, and a slender anterior and posterior of nuclear tips. The chromatin is not completely compact, but irregularly imbricated such as roof. Some nuclear lacunae, irregular in shape, are scattered within the nucleus. No neck and middle piece were developed. The flagellum is composed of 9+2 axoneme, axial rod and undulating membrane. The mitochondria were distributed only in cytoplasmic membrane around the nucleus. In particular, the nuclear rod contains bundles of fibers, the rod penetrating from anterior portion to the middle of the nucleus, is extended roughly two-thirds of the nucleus such as eyelashes shaped.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.3
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• pp.261-268
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• 2001

An investigation on nondestructive evaluation of thermal stress-nduced damage in the composite laminates (3mm in thickness and $[+45_6/-45_6]_s$ lay-up angles) has been performed using the thermo-acoustic emission technique. Reduction of thermo-AE events due to repetitive thermal load cycles showed a Kaiser effect. An analysis of the thermo-AE behavior determined the stress free temperature of composite laminates. Fiber fracture and matrix cracks were observed using the optical microscopy, scanning electron microscopy and ultrasonic C-sean. Short-Time Fourier Transform of thermo-AE signals offered the time-frequency characteristics which might classily the thermo-AE as three different types to estimate the damage processes of the composites.