• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.265-271
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• 2021

The pattern of the tree's internal swelling depends on many causes. Since it is difficult to detect these various causes of swelling with a general method, if the state of swelling for a long time cannot be confirmed, serious damage to the trees may occur due to enlargement of the swelling area. In the method of acquiring a tree tomography image, an impulse passing through the tree is generated by tapping the sensor with a rubber mallet, and the moving speed is recorded. In this paper, to measure cracks, cavities, and swelling due to physical damage, we developed a 3D viewer that can know the internal state of a tree using a tree cross-section image acquired from Arbotom to determine the degree of swelling inside the tree. Based on this, we tried to present data that can be referred to when surgical operation of trees is required. In order to acquire a tomographic image of a tree, 6 sensors were attached to the three Yangpala and Maple trees, and a 1 m-long tree was measured using the Arbotom program, and a 3D image was implemented through the 3D Viewer created using MATLAB. In addition to simply acquiring images, the cross-sectional length and volume of the tree were measured. In the actually produced 3D Viewer, the length of the part where the swelling of the maple tree occurred was 33.12 cm, and the swelling of the yangpala tree was measured as 21.41 cm. The volume of the maple tree was measured to be 78.832 ㎤. As a result of comparing the cross-sectional image of the Arbotom and the 3D image, the same result as the real aspect of the tree was obtained, so it can be judged that the reliability of the manufactured software is also secured, and data to be applied to the surgical tree operation through the created Viewer is provided. It is believed that the damage will be minimized.

• The Korean Journal of Malacology
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• v.17 no.1
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• pp.45-55
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• 2001

Gametogenes, reproductive cycle, first sexual maturity(biological minimum size), sex ratio and larval development of the marsh clam Corbicula japonica were investigated monthly by histological observations. Samples were collected in brackish water of Gokgang stream, Kyungsangbuk-Do, Korea, from August 1997 to July 1998. Sexuality of Corbicula japonica is dioecious and the species are an oviparous clam. The gonads are irregularly arranged from the sub-region of mid-intestinal gland in visceral cavity to reticular connective tissue of foot. The ovary is composed of a number of ovarian sac which are branched arborescent. Oogonia actively proliferate along the germinal epithelium of ovarian sac, in which young oocytes are growing. The testis is composed of a number of testicular tubules, and the epithelium of the tubule has function of germinal epithelium, along which spermatogonia actively proliferate. A great number of undifferentiated mesenchymal tissue and eosinophilic granular cells are abundantly distributed between developing oocytes and spermatocytes in the early developmental stages. With the further development of the ovary and testis these tissue and cells gradually disappear. Then the undifferentiated mesenchymal tissue and eosinophilic granular cells are considered to be related to the growing of the oocytes and spermatocytes. The spawning period is from July to September, and the main spawning occur between July and August when seawater temperatures reach above 22$^{\circ}C$. The reproductive cycle of this species can be divided into five successive stages; early active (February to April), late active (May to July), ripe (June to September), partially spawned (July to September), degenerative (September to October) and resting stage (October to February). Percentages of first sexual maturity of female and male clams ranging in length from 10 mm to 12 mm are over 50% and 100% for clams over 16.0 mm in shell length. Fertilized eggs or Corbicula japonica were 80-90 ${\mu}{\textrm}{m}$ in diameter. In the early embryonic development of C. japonica, the appearance of polar body, trochophore and D-shaped veliger were observed around 40 min., 27 hours and 4 days after spawning, respectively, at a water temperature of 26.5-28.$0^{\circ}C$. The size of larvae of early umbo stage was about 185-210 ${\mu}{\textrm}{m}$ in shell length, 160-180 ${\mu}{\textrm}{m}$ in shell height around 7 days after fertilization. The correlation of relative growth between the culture day (D) and shell length (SL) was expressed by the following simple formula from D-shaped veliger to metamorphosing stage; SL = 13.300D + 209.36($r^2$= 0.9078).

• Applied Microscopy
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• v.30 no.2
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• pp.213-232
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• 2000

The development of the knee joint was studied by electron microscopy in human fetuses ranging from 20 mm to 260 mm crown-rump length ($7\sim30$ weeks of gestational age). The appearance of the primordium of the meniscus and cruciate ligament was conspicuous as the mesenchymal cells , preceeding that of joint space at 30 mm fetus. The primitive joint cavity was first seen in the interzone from the 40 mm fetus and its intermediate layer proceeded developing as a narrow cleft which was closely incorporated with two chondrogenic layers. Poorly differentiated mesenchymal cells of the meniscus at 40 mm fetus containing predominantly free ribosomes differentiated into fibroblasts at 60 mm fetus. By 100 mm fetus, the fibroblast in inner zone of the meniscus presented as oval profiles with a short cell processes, whereas middle and peripheral zones presented as elongated cells. Differentiation of the synovial membrane coincided with clarification of the joint cavity When dilatation of the synovial cavity occurred, the two types of synovial cells were identified at 60 mm fetus. By 100 mm fetus a majority of the intimal cells were B-type. B-type cells were clearly distinguishable from A-type cells by their content of extensive rough endoplasmic reticula and well developed Golgi complexes. In contrast, A-type cells had numerous filopodia, pinocytotic vesicles, lysosomes and large vacuoles. At 260 mm fetus the B-type cells were also a majority of intimal cells. At 260 mm fetus the inner zone of the meniscus was filled with parallel oriented fascicles of collagenous fibers and oval fibroblasts. The middle zone was constituted of parallel and radially arranged fibers and fibroblasts. The outer zone was populated by elongated fibroblasts encircled by crossed collagenous fibers with the blood vessels. At 30 mm fetus the fibroblasts of the cruciate ligament contained rough endoplasmic reticula and mitochondria. Collagen fibrils were noted within narrow cytoplasmic processes which were continued with the extracellular space. Collagen fibrils of ligament were filled in the bulk of extracellular space at 100 mm fetus. By $150\sim260mm$ fetus, the cruciate ligaments were constituted of longitudinally oriented bundle of collagen fibrils with irregular rows of round cells between.

• Applied Microscopy
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• v.31 no.4
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• pp.333-345
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• 2001

The mature sperms of three species of cephalopods (Octopus minar, Octopus ocellatus, Todarodes pacificus) were observed by electron microscopy. The results obtained are as follows: The sperm lengths of Octopus minor and Octopus ocellatus of octopods are long and they are about $390{\mu}m$ and $125\sim130{\mu}m$, respectively, but the sperm length of Todarodes pacificus is short and about $35{\mu}m$. The sperm of Octopus minor has a helical acrosome and a head bent a little like a banana while Octopus ocellatus of octopod has a twisted acrosome and a long rod-shaped head. A number of horizontal stripes are observed as a periodic structure in their subacrosome cavities and dense plugs are formed in the cavities of their heads. On the other hand, the acrosome of Todarodes pacificus is circular cap-shaped, and its head is long and oval. It is notable that two small cavities were observed in its basal acrosome. Juxtanuclear acrosomal materials of high electron density filled the subacrosomal cavity. In the middle piece of mature sperms of Octopus minor and Octopus ocellatus, the mitochondria form the mitochondrial sleeve, but the numbers of mitochondria differ between the species so that they are $11\sim12$ and $8\sim9$, respectively. Meanwhile, in the middle piece of mature sperms of Todarodes pacificus, the mitochondria are separated from the axoneme, forming a mitochondrial spur in which $10\sim13$ mitochondria and some electron dense materials concentrate. The axoneme of Octopus minor, Octopus ocellatus and Todarodes pacificus are of 9+2 type in common, surrounded by 9 coarse fibres. A number of glycogen were observed only in the axoneme of Todarodes pacificus. The coarse fibres were found as far as the main piece of sperm tail in Octopks minor and Todarodes pacificus, while to the end piece of sperm tail in Octopus ocellatus.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.109-121
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• 2010

The bioleaching experiment under $42^{\circ}C$ was effectively carried out to leach the more valuable element ions from the pyrite in the Gangyang mine waste. Bacteria can survive at this temperature, as indigenous acidophilic bacteria were collected in the Hatchobaru acidic hot spring, in Japan. To enhance the bacterial activity, yeast extract was added to the pyrite-leaching medium. The indigenous acidophilic bacteria appeared to be rod-shaped in the growth-medium which contained elemental sulfur and yeast extract. The rod-shaped bacteria ($0.7\times2.6\;{\mu}m$, $0.6\times7\;{\mu}m$, $0.8\times5\;{\mu}m$ and $0.7\times8.4\;{\mu}m$) were attached to the pyrite surface. The colonies of the rod-shaped bacteria were selectively attached to the surroundings of a hexagonal cavity and the inner wall of the hexagonal cavity, which developed on a pyrite surface. Filament-shaped bacteria ranging from $4.92\;{\mu}m$ to $10.0\;{\mu}m$ in length were subsequently attached to the surrounding cracks and inner wall of the cracks on the pyrite surface. In the XRD analysis, the intensity of (111), (311), (222) and (320) plane on the bacteria pyrite sample relatively decreased in plane on the control pyrite sample, whereas the intensity of (200), (210) and (211) increased in these samples. The microbiological leaching content of Fe ions was found to be 3.4 times higher than that of the chemical leaching content. As for the Zn, microbiological leaching content, it was 2 times higher than the chemical leaching content. The results of XRD analysis for the bioleaching of pyrite indicated that the indigenous acidophilic bacteria are selectively attacked on the pyrite specific plane. It is expected that the more valuable element ions can be leached out from the mine waste, if the temperature is increased in future bioleaching experiments.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.123-131
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• 1982

The purpose of this study was to observe the responses of the remaining pulp tissue after pulpotomy upon the several kinds of $Ca(OH)_2$ products and the responses of periapical tissue upon some root canal filling materials after extirpation. For pulpotomy, the class V cavities were prepared on the premolars, molars and upper canines, and the pulp was amputated. Each drug was placed over the amputated tissue and cavity was sealed with zinc oxide eugenol cement. The drugs which were used for the study were Dycal (Caulk Co. U.S.A.), Cavitec (Kerr Co. U.S.A.), Calvital, Nobudyne and Neodyne (Neo Dental Chemical Products). For extirpation, the endodontic cavities were prepared on the lingual surfaces of anterior teeth, and the pulp tissues were extirpated as routine method. After enlarging, irrigation, and measuring of root length by taking X-ray, each root canal filling material was filled in the canal with gutta percha cone, and endodontic cavity was sealed with zinc oxide eugenol cement. Zinc oxide eugenol, $Ca(OH)_2$ (Eli Lilly Co. U.S.A.) and Vitapex (Neo Dental Chemical Products) were used as root canal filling materials. Animals were sacrificed after 1, 3 and 6 weeks following the operation. The teeth were decalcified in formic acid, sectioned and stained with hematoxylin eosin. Microscopic examination revealed as follows. 1. Dycal: The dentin bridge formation was observed at the 3rd week after pulpotomy. Inflammatory conditions which were infiltration of inflammatory cells and dilatation of blood vessels were kept in remaining pulp tissue at the 6th week. 2. Calvital: The dentin bridge was observed at the 1st week after pulpotomy. As the time clasped, the pulp tended to be the fibrous degeneration. 3. Cavitec, Nobudyne and Neodyne: In the case of Cavitec and Nobudyne, the incompleted and irregular dentin bridge was observed at the 6th week, and in Neodyne, was observed at the 3rd week. The severe inflammatory changes were seen in the remaining pulp tissue. As the time clasped, the fibrous degeneration tended to spread in the remaining pulp tissue. 4. $Ca(OH)_2$: Osteocementum was formed at the 3rd week, the matrix of cementum and dentin were resorted, and infiltration of lymphocytes was seen in periapical tissue when $Ca(OH)_2$ was used as canal-filling materials. S. ZOE and Vitapex The cementum like substance was seen in periapical portion at the 1st week, when ZOE and Vitapex were used as root canal filling materials. As the time elapsed, the matrix of cementum and dentin tended to be resorted. At the 6th week, the inflammatory condition of periapical tissue was continued in the case of ZOE, but was reduced in the case of Vitapex.

• Molecules and Cells
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• v.40 no.4
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• pp.299-306
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• 2017

The transcriptional activator AphB has been implicated in acid resistance and pathogenesis in the food borne pathogens Vibrio vulnificus and Vibrio cholerae. To date, the full-length AphB crystal structure of V. cholerae has been determined and characterized by a tetrameric assembly of AphB consisting of a DNA binding domain and a regulatory domain (RD). Although acidic pH and low oxygen tension might be involved in the activation of AphB, it remains unknown which ligand or stimulus activates AphB at the molecular level. In this study, we determine the crystal structure of the AphB RD from V. vulnificus under aerobic conditions without modification at the conserved cysteine residue of the RD, even in the presence of the oxidizing agent cumene hydroperoxide. A cysteine to serine amino acid residue mutant RD protein further confirmed that the cysteine residue is not involved in sensing oxidative stress in vitro. Interestingly, an unidentified small molecule was observed in the inter-subdomain cavity in the RD when the crystal was incubated with cumene hydroperoxide molecules, suggesting a new ligand-binding site. In addition, we confirmed the role of AphB in acid tolerance by observing an aphB-dependent increase in cadC transcript level when V. vulnificus was exposed to acidic pH. Our study contributes to the understanding of the AphB molecular mechanism in the process of recognizing the host environment.

• Applied Microscopy
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• v.24 no.3
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• pp.1-9
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• 1994

Pardosa astrigera possessed eight eyes arranged in three rows on the frontal carapace. A pair of small anterior lateral eyes (ALE) flanked each side by an anterior median eyes (AME) lay along the anterior margin that was situated on the anterior row of clypeus. The anterior lateral eye was composed of cornea, vitreous body, and retina. Cornea was made up mainly of exocuticle lining the cuticle. Lens in anterior lateral eye was biconvex type which bulged into the cavity of the eyecup. Outer and inner central region of lens were approximately spherical with radius of curvature $5.6{\mu}m$ and $12.5{\mu}m$, respectly. Vitreous body formed a layer between the cuticular lens and retina. They formed biconcave shape. Retina of the anterior lateral eyes was composed of three types of cells: visual cells, glia cells, and pigment cells. The visual cells were unipolar neuron, as were the receptor of the posterior lateral eye. But cell body was unique to the anterior lateral eyes. They were giant cell, relatively a few in number, and under the layer of vitreous bodies. Each visual cell healed rhabdomeres for a short stretch beneath the cell body. Rhabdomes were irregulary pattern in retina and electron dense pigment granules scattered between the rhabdomes. Glia cell situated at the cell body of visual cell and glia cell process reached to rhabdomere portion. Below the rhabdome, tapetum were about $30{\mu}m$ distance from lens, which composed of 4-5 layers. It was about $25{\mu}m$ length that intermediate segment of distal portion of visual cell. Electron dense pigment granules between the intermediate segment were observed.

• Development and Reproduction
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• v.12 no.3
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• pp.215-220
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• 2008

Sex differentiation process of the spotted Black Bullhead, Pseudobagrus koreanus, was investigated using fish samples of different age after hatching. The primordial germ cells appeared separately under air bladder in 1-day larva (total length: $6.63{\sim}6.95\;mm$). The primordial gonad with a genital ridge developed in 5-day prelarva ($7.50{\sim}9.36\;mm$). The ovarian differentiation started in about 25-day juvenile ($11.58{\sim}13.21\;mm$). The somatic tissues enlongated in the tip of one end of undifferentiated gonad and fused each other. Thus a small ovarian cavity appeared. The testicular differentiation was initiated in 30-day juvenile ($12.19{\sim}13.72\;mm$). The rudiment of sperm duct was appeared in the lower part of the undifferentiated gonad. In 50-day juvenile ($16.28{\sim}17.06\;mm$), the ovary started to fill with peri-nucleolus oocytes, and the spermatogonia started to develop. In 250-day juvenile ($35.49{\sim}51.12\;mm$), the ovary became bigger and filled with oocytes, and the number of spermatogonia started to increase. Considering these results, the spotted Black Bullhead could be a differentiated type in sex differentiation and gonochorism in sexuality.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.508-517
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• 2004

We described a near-field scanning microwave microscope which uses a high-quality dielectric resonator with a tunable screw. The operating frequency is f=4.5 5GHz. The probe tip is mounted in a cylindrical resonant cavity coupled to a dielectric resonator We developed a hybrid tip combining a reduced length of the tapered part with a small apex. In order to understand the function of the probe, we fabricated three different tips using a conventional chemical etching technique and observed three different NSMM images for patterened Cr films on glass substrates. We measured the reflection coefficient of different metal thin film samples with the same thickness of 300m and compared with theoretical impedance respectly. By tuning the tunable screw coming through the top cover, we could improve sensitivity, signal-to-noise ratio, and spatial resolution to better than $1{\mu}m$. To demonstrate the ability of local microwave characterization, the surface resistance of metallic thin films has been mapped.