• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.75-82
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• 1992

The surface ultrastructure of Heterephyes nocens (Trematoda: Heterophyidae) was studied by scanning electron microscopy(SEM), The adult worms were recovered from experimentally infected cats and from a naturally infected patient. They were leaf-like, ventrally concave, and ovoid or lyriform in shape. Ciliated knob-like sensory papillae (type I) were observed in single or grouped forms on and around the oral sucker, whereas non-ciliated round swellings (type II papillae) were seen on the lip of the ventral sucker, The tegumental spines around the oral sucker were 5∼9 pointed, whereas those between the two suckers were 12∼17 pointed. yentrolaterally, three groups of 5∼6 type I papillae were located between the oral and ventral suckers, with single ones alternating between them. The genital sucker was protruded or depressed, depending on the contraction state of the nukes, and the gonotyl spine number ranged 50∼60. The number of tip points of tegumental spines was decreased posteriorly; finally they became 1∼3 pointed. On the dorsal surface, 4 groups of 4∼5 type I papillae were symmetrically located on both lateral sides, and the shape and distribution of tegumental spines were similar to those of the ventral surface. Although the tegumental ultrastructure of H. nocens was generally similar to those of other heterophyids, the genital sucker morphology including the number of gonotyl spines and/or the distribution pattern of tegumental spines and sensory papillae were suggested to be the characteristic features of H. necens.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.834-850
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• 2011

In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

• Animal cells and systems
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• v.8 no.2
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• pp.71-75
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• 2004

A study on marine sponges was conducted by SCUBA diving at Ulleungdo Island, Korea, from July 2001 to August 2003. Two species, Mycale (Naviculina) ulleugensis and Mycale (N.) neunggulensis, are new to science. Mycale (N.) ulleugensis n. sp. seems close to M. chungae based on the shape of spicules, but differs in the size of megascleres and sigmas, Mycale (N.) neunggulensis n. sp. seems close to M. flagellifer Vacelet and Vasseur in the type and size of spicules, but differs in the shape of naviculichela. Naviculichela I of M. flagellifer has a spine on the upper part of the felix.

• Animal cells and systems
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• v.2 no.3
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• pp.323-331
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• 1998

Three new marine heterotardigrades, Archechiniscus symbalanus, and Styraconyx craticuliformis of the family Halechiniscidae and Echiniscoides andamanensis of the family Echiniscoididae, are reported on the basis of the specimens sieved from intertidal barnacles in the Thai coast of the Andaman Sea. Archechinisos symbalanus n. sp. is related to Archehiniscus minutus Grimaldi De Zio and D'Addabbo Gallo, but discernible from it by possessing median cirrus, stylet sheath, sensory spine of leg l, prominent basal processes on all leg pairs, and S-shaped seminal receptacles. Styraconyx craticuliformis n. sp. is similar to S. craticulus (Pollock) in bearing the grid-like dorsal cuticle, but distinguished from it by the shape of claws and cirrophore of primary clava. Ediniscoides andamanensis n. sp. is rebated to Echiniscoides pollocki Hallas and Kristensen and E. sigismundi sigismundi (M. Schultze) in sharing the same patterns of sensory leg appendages and the claw configuration of 8-8-8-7, but characterized by the shape of cirri, pharyngeal apparatus and female gonopore.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.74-82
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• 2020

Dragonet fish (Callionymidae), living in benthic upper 900 m of all subtropical, tropical and temperate oceans, comprises 200 species in 20 genera worldwide, of which 18 species in 6 genera occur in Korea. Although dragonet fish plays an important role in linking between top predators and lower trophic levels, there are only few studies about their early life history. Herein, we present molecular and morphological data on larvae and juveniles of Bathycallionymus kaianus (Günther, 1880) collected from the Korean waters. During 2016 to 2018, one preflexion larvae [2.69 in total length (TL)], three flexion larvae (3.65 and 4.77 mm TL), six postflexion larvae (6.07 and 7.94 mm TL), and three juveniles (10.81 and 12.26 mm TL) were collected in the East Sea, Korea Strait, and Jeju Island using Bongo net. Of them, 13 individuals were identified through molecular markers (COI or 16S rRNA) and morphologically described. The larvae of B. kaianus are well distinguished from other species of Callionymidae in melanophore distribution, body shape and development of preopercular spine. It was very similar to larvae of two Repomucenus species, R. valenciennei and R. virgis, but was clearly distinguished in melanophore distribution, preopercular spine development, and head shape.

• Fibers and Polymers
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• v.4 no.2
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• pp.89-96
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• 2003

A vertebral cage is a hollow medical device which is used in spine forgery. By implanting the cage into the spine column, it is possible to restore disc and relieve pressure on the nerve roots. Most cages have been made of titanium alloys but they detract the biocompatibility. Currently PEEK (polyether ether ketone) if applied to various implants because it has good properties like heat resistance, chemical resistance, strength, and especially biocompatibility. A new shape of vertebral cage is designed and injection molding of PEEK is considered for production. Before injection molding of the cage, it is needed to evaluate process conditions and properties of the final product. Variables affecting the shrinkage of the cage are considered, e.g., injection time, packing pressure, mold temperature, and melt temperature. By using the numerical simula-tion program, MOLDFLOW, several cases are studied. Data files obtained by MOLDFLOW analysis are used for stress anal-ysis with ABAQUS, and shrinkage and residual stress fields are predicted. With these results, optimum process conditions are determined.

• Animal Systematics, Evolution and Diversity
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• v.13 no.2
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• pp.93-102
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• 1997

Two new marine tardigrade species, Batillipes longispinosus n. sp. and B. orientalis n. sp. are described on the basis of the specimens collected from the intertidal or shallow sublittoral sands of South Korea. Both the present species are characteristic in the absence of any caudal appendage throughout their life span, and bearing the long clava or cephalic appendages with the long spinous process on the femur of legs IV. B. longispinosus n. sp. most resembles B. tuvernatis Pollock, but is easily distinguished from it by the flattened caudal region and prominently developed spine of legs IV. B. orientalis n. sp. is much related to B. roscoffensis Kristensen, in having the wing-formed lateral body prohection between legs III and legs IV, the papillae on the head region, and the smooth caudal region, but discernible from it in the general body shape and the relatively longer spine of legs IV.

• Animal cells and systems
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• v.13 no.3
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• pp.323-329
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• 2009

We analyzed partial sequences of cytochrome b (cyt-b), a mitochondrial DNA (mtDNA) gene, to determine the genetic relationships between six horsehead fish species: Branchiostegus japonicus, Branchiostegus albus, Branchiostegus auratus, Branchiostegus argentatus, Branchiostegus wardi, and an unidentified Branchiostegus species. The specimens were collected in Korea, China, Japan, and Vietnam. We compared their molecular phylogenetic relationships inferred from mtDNA cyt-b sequences with an osteological analysis. The unidentified species, B. sp., was similar to B. albus in terms of the lack of triangular silver-white dot at the posterior region of eyes (vs. large one present in B. japonicus), but was also similar to B. japonicus in terms of the presence of a straight-shaped first hemal spine (vs. a curve-shaped hemal spine in B. albus). Analysis of the mtDNA cyt-b sequences indicated that the smallest estimated sequence divergence was between the B. japonicus and B. sp. (0.70-0.94%), whereas the largest difference was between B. auratus and B. argentatus (23.06-23.36%). Both the maximum parsimony and maximum likelihood trees showed that the B. sp. was closely clustered with B. japonicus, and that B. auratus was most distant from the other species. When comparing the osteological characters, UPGMA tree showed that the B. japonicus and B. sp. were the most closely clustered species, and B. auratus was the most distantly clustered fish relative to the other species. The shape of the nasal, otolith and first hemal spine was informative for distinguishing B. auratus from the other species. These osteological differences were consistent with the differences in mtDNA.

• Fisheries and Aquatic Sciences
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• v.21 no.12
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• pp.37.1-37.10
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• 2018

The larvae and juveniles of Porocottus leptosomus belonging to the family Cottidae were collected (n = 95, 3.9-16.5 mm in body length, BL) from Busan, Korea, in March 2015. The larvae and juvenile were identified using DNA barcoding as P. leptosomus, and their morphological description was presented in detail. The yolk-sac larvae (3.9-5.6 mm BL) body was slightly compressed, the head was large, the eye was round and large, and the anus was before the middle of the body. The preflexion larvae (5.2-10.0 mm BL) body length drastically increased; caudal fin rays began to occur. The flexion larvae (9.4-11.8 mm BL) notochord flexion started; dorsal, pectoral, and anal fin rays began to occur; pelvic fin buds are seen; they possessed a pair of parietal spine; and a pair of supraocular cirri was first to develop. At 12 mm BL, the notochord was completely flexed. The larva stage (3.9-12.6 mm SL) had the stellate melanophores in the head, isthmus, gut, and tail (along to the ventral midline). During the juvenile stage (11.4-16.5 mm BL), melanophores covered the head and began to form five black bands on the side of the body. The larvae of P. leptosomus spent pelagic life, but moved to the bottom during the juvenile stage. The larvae and juveniles of P. leptosomus differ from other cottid larval fishes by body shape, melanophore head pattern, and spine development. P. leptosomus can be distinguished from Porocottus allisi by morphological development and the occurrence of larval fish: preopercular spine development, melanophore pattern, and caudal fin development.

• Korea-Australia Rheology Journal
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• v.12 no.2
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• pp.107-117
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• 2000

Prediction of the product shape in sheet casting process is performed from the numerical simulation. A three-dimensional finite element method is used to investigate the flow behavior and to examine the effects of processing conditions on the sheet produced. Effects of inertia, gravity, surface tension and non-Newtonian viscosity on the thickness profile of the sheet are considered since the edge bead and the flow patterns in the chill roll region have great influence on the quality of the products. In the numerical simulation with free surface flows, the spine method is adopted to update the free surface, and the force-free boundary condition is imposed along the take-up plane to avoid severe singularity problems existing at the take-up plane. From the numerical results of steady isothermal flows of a generalized Newtonian fluid, it is shown that the draw ratio plays a major role in predicting the shape of the final sheet produced and the surface tension has considerable effect on the bead thickness ratio and the bead width fraction, while shear-thinning and/or tension-thickening viscosity affect the degree of neck-in.