• Applied Microscopy
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• v.40 no.1
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• pp.37-45
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• 2010

Captured wild specimens of the big white-toothed shrew, Crocidura lasiura were classified into three age classes by tooth wear and height of molars, and seasonal variations of breeding and reproductive organs were examined. Juveniles had not tooth wear in molars and height of the third molars were lower than the first and second molars, and had only non-breeding condition. Young adults had little tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear in molars, young adults and old adults had breeding or non-breeding condition according to the season. On the basis of histological examination, seasonal variations of breeding were confirmed that breeding condition of young and old adult males were continued from early February to early October although the breeding activity was the highest in April, that of females were continued from the end of March to October, males reached sexual maturity earlier than females. Whereas the breeding condition seems to cease for non-breeding season because of the deficiency of food resources, soil invertebrates. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules that were filled with numerous germ cells, and expanded caudal epididymides with a vast number of spermatozoa, and were more than 10.0 g in the body weight and 0.03 g in the testis and epididymis weight. The females of the breeding season were pregnant condition with 4~6 litters or had the Graafian follicles and the corpus lutea in the ovary, and were more than 9.6 g in the body weight.

• Applied Microscopy
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• v.40 no.3
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• pp.125-132
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• 2010

Captured specimens of the lesser white-toothed shrew, Crocidura suaveolens were classified into three age classes by tooth wear and seasonal variations of reproductive organs were investigated. Molars of juveniles had not tooth wear and the height of the third molars were lower than the first and second molars, young adults had smooth tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear and the third molars also reached to the first and second molars. On the basis of histological examination, seasonal variation of breeding was confirmed that breeding season of adult males was from early February to early October, having a peak of the breeding in April and July, and non-breeding season was from in the middle of October to late January. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules filling with numerous germ cells and expanded caudal epididymides with a vast number of spermatozoa, Young and old adult males of the non-breeding season had the small testes with the extremely slender seminiferous tubules filling with only spermatogonia and the reduced caudal epididymides without spermatozoa. Males weighing more than 3.9 g in the body weight and 0.013 g in the testis and epididymis weight reached sexual maturation in breeding season, and the females weighing more than 3.8 g in body weight of the breeding season were pregnant condition having 5~6 litters or had the Graafian follicles and the corpus lutea in the ovary.

• Archives of design research
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• v.16 no.3
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• pp.81-90
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• 2003

The purpose of the study is to propose a new way of classification for products and to forecast the future of products through the physical factor and the mental factor as human natures. For the purpose of the study, the research was carried out in three ways. Firstly, the study considered the evolutional process of products through human natures. At this stage, the study defined that the physical ability and the mental ability of human are the cores of the product's evolution. Secondly, for understanding human evolution, the study set up two types of future humans . Finally, the study classified products by the physical factor and the mental factor as human natures with the aspect of embryology. As the results, the study illustrated two different species of products and their futures.

• Journal of Korean Neurosurgical Society
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• v.63 no.3
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• pp.327-337
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• 2020

Junctional neurulation represents the most recent adjunct to the well-known sequential embryological processes of primary and secondary neurulation. While its exact molecular processes, occurring at the end of primary and the beginning of secondary neurulation, are still being actively investigated, its pathological counterpart -junctional neural tube defect (JNTD)- had been described in 2017 based on three patients whose well-formed secondary neural tube, the conus, is widely separated from its corresponding primary neural tube and functionally disconnected from corticospinal control from above. Several other cases conforming to this bizarre neural tube arrangement have since appeared in the literature, reinforcing the validity of this entity. The cardinal clinical, neuroimaging, and electrophysiological features of JNTD, and the hypothesis of its embryogenetic mechanism, form part of this review.

• Journal of Korean Neurosurgical Society
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• v.63 no.3
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• pp.272-278
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• 2020

Compared to any other decade, the last two decades have been the most dynamic period in terms of advances in the knowledge on spinal dysraphism. Among the several factors of rapid advancement, such as embryology during secondary neurulation and intraoperative neurophysiological monitoring, there is no doubt that Professor Dachling Pang stood high amidst the period. I review here the last two decades from my personal point of view on what has been achieved in the field of spinal dysraphism, focusing on occult tethered cord syndrome, lumbosacral lipomatous malformation, terminal myelocystocele, retained medullary cord, limited dorsal myeloschisis and junctional neural tube defect. There are still many issues to revise, add and extend. Profound knowledge of basic science is critical, as well as refined clinical analysis. I expect that young scholars who follow the footsteps of precedent giants will shed bright light on this topic in the future.

• Journal of applied mathematics & informatics
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• v.6 no.3
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• pp.835-850
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• 1999

The present paper deals with the problem of nonselective harvesting in a partly infected prey and predator system in which both the susceptible prey and the predator follow the law of logistic growth and some preys avoid predation by hiding. The dynamical behaviour of the system has been studied in both the local and global sense. The optimal policy of exploitation has been derived by using Pontraygin's maximal principle. Numerical analysis and computer simulation of the results have been performed to investigate the golbal properties of the system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1110-1116
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• 2002

The skin(皮膚) separates epidermis(皮) and dermis(膚) in Oriental medicine. epidermis and hair come from ectoderm as dermis comes from mesoderm in embryology. Epidermis and hair belong to the Metal(金) and dermis belongs to the Earth(土) in Oriental medicine. The lung is related to the skin and hair. The skin surface is nourished by the essence from the lung, and the. lung has the function of sending wei-qi(衛氣.: defensive Energy) to the skin surface to guarantee body resistance. The skin takes nourishment from blood(血) and express by qi(氣). The supply of nutrients to the lung and skin relies on the function of the spleen, pancreas and subcutis. Flaming of the heart fire may scorch the essence of the lung-metal, inducing dermatosis.

• Applied Microscopy
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• v.17 no.1
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• pp.1-15
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• 1987

Testes from the allied rock wallaby(Petrogale assimilus) have been examined by the electron microscopy in thin sections in order to examine spermiogenesis and structure of spermatozoa. The spermiogenesis can be divided into nine stages: early Golgi, late Golgi, collapsing, nuclear protrusion, condensation and flattening, nuclear shaping, rotation, nuclear ring contraction, and maturation. The acrosome has been abruptly formed following the collapse of expanded acrosomal vesicle without the cap stage described in the eutheria. The flatly condensed nucleus rotates obliquely to the axis of the axial filament complex and the folded acrosome covers the anterior third of the dorsal nuclear surface forming a wide subacrosormal space as the nuclear ring has contracted. The Sertoli cell reaction and spur are prominent during the nuclear protrusion and rotation stages. A mature spermatozoon has S-shape head which has an extended part reaching to the vicinity of the middle piece.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.600-605
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• 1998

춘천지역에서 포획한 한국 야생랫드(시궁쥐)에서 Capillaria hepatica에 자연감염된 예를 보고한다. Capillaria hepatica의 충란이 포획된 68마리의 랫드중 17마리에서 발견되었다. Capillaria에 감염된 랫드의 간장은 충란과 함께 림프구, 단핵구, 호산구의 침윤이 관찰되었고 심한 괴사소견을 보였다. 또한 섬유화, 출혈 hemosiderin의 침착이 뚜렷하게 관찰되었다. 최근 국내에서 자연에서 채집된 랫드의 Capillaria hepatica의 감염을 보고한 자료가 없는 것으로 미루어 Capillaria hepatica의 숙주감염을 파악하는 자료로 활용될 수 있을 것이다.

• The Korean Journal of Zoology
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• v.20 no.3
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• pp.149-157
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• 1977

At present over 3 dozen mutant genes have been recognized in the Mexican axolotl. These genes, all recessives, are categorized in 5 groups according to the nature of their effects and the developmental stage at which their phenotype is predominately expressed. They are genes affecting the oogenesis (maternal-effect genes), genes affecting the size of the nucleolus, genes affecting the development of specific tissues and organs, genes exert lethal effects on all cells or tissues (autonomous lethals), and genes affecting pigment cells. This report describes briefly the phenotypes and some of the current research applications of those genes.