• Applied Microscopy
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• v.30 no.2
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• pp.205-212
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• 2000

Present study was performed to observe the surface ultrastructures of Stictadora furcatum (Trematoda: Heterophyidae). Adult worms were recovered from the cat experimentally infected with metacercariae, and were prepared for scanning electron microscopy. The body was leaf-like and ventrally concave. The oral sucker armed with prominent tegumental spines on the inner surface, and it's lips were obscure. Sensory papillae (type I) in single or grouped forms symmetrically arranged around the oral sucker. The ventrogenital opening retained protruding gonotyl spines and sperms discharged from the genital pore . The body surface was covered with scale-like multipointed tegumental spines. The density and digitated point of spines were gradually decreased toward the posterior end of the body. The digitated points of spines on the anterior portion were 9-12, on the middle were 7-8 and 5-6, and on the posterior were 2-3 and peg-like. Although the tegumental ultrastructure of S. fuscatum was generally similar to those of other heterophyid flukes , the oral sucker with tegumental spines on the inner surface and without obvious lips, and the ventrogenital opening with protruding gonotyl spines were suggested to be the characteristic features.

• Journal of Sericultural and Entomological Science
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• v.7
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• pp.39-42
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• 1967

The author studied on the eggs laying order of silkworm eggs which was laid by double copulation. The results can be summarized as follows; 1. Fertilized eggs were not laid in order like the copulating order. Author supposes that the sperms of the first copulated moth and second's moth were mixed in the receptaculum seminis. 2. Intensity of fertilization was mainly affected by silkworm races and copulating order, but some other factors may be acted on the double copulation.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.173-177
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• 1989

Defective or inadequate semen quality, usually presenting as low sperm count or poor sperm motility , is recognizable by semen analysis. However, the ability of spermatozoa to fertilize an ovum is not determined used in various experiments. In this study, hamster oocyte sperm penetration assay was used to determine the fertilizing capacity of sperms in 20 subjects which divided into two groups, group A with 10 normal fertile men, and group B with 10 infertile men. The % penetration in group A and group B were 61% and 35% respectively, which showed statistically not significant but fertilization index was significantly different between group A(FI=2.24) and group B(FI=O.05). Additionally it seemed that the percentage of sperm penetraton was influenced more by the motility of spermatozoa than by the number.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.83.1-83.1
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• 2004

• Journal of Plant Biology
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• v.35 no.4
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• pp.339-358
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• 1992

The bark morphology and anatomy of six species in Korean gymnosperms were examined with light and scanning electron microscopes. The species were Thuja orientalis (Cupressaceae), Ginkgo biloba (Ginkgoaceae), Cyeas revoluta (Cycadaceae), Pinus koraiensis (pinaceae), Taxus cuspidata (Taxaceae), Cryptomeria japoniea (Taxodiaceae). We described the bark features such as surface colour, thickness, depth of inner and outer bark. presense or absence and features of expansion tissue of ray, composition of periderm, and component cells of secondary phloem. The comparison with these features showed significant differences among all six species. Furthermore. it was suggested that sclereids types and sieve area shapes in sieve cells might be useful to the comparative morphological studies of gymnosperms.sperms.

• Biomedical Science Letters
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• v.11 no.3
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• pp.333-336
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• 2005

Environmental endocrine disruptors are very toxic to the animals including humans. They are hormone-like acting chemicals which can be found in our normal daily life. We have examined the toxic effect of bisphenol A and if lactic acid bacteria could suppress this toxic effect. Thirty rats were divided into three groups (control, bisphenol A treated, bisphenol A and lactic acid bacteria treated). Treatments were carried out at an interval of 12 hours for each group. Control group showed normal and clear morphology of tissues. Cells were fine in their shape and color, and density was high enough for the normal function. However, bisphenol A treated group was abnormally destructed in cell morphology. In the testis, sperms were totally destructed. When treated with lactic acid bacteria together, the toxic effect of bisphenol A was clearly decreased. This study indicated that bisphenol A was toxic in any concentration especially for the liver and testis, however, lactic acid bacteria could suppress the toxic effects of bisphenol A.

• Journal of Plant Biology
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• v.36 no.3
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• pp.241-249
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• 1993

The pattern of RNA synthesis during male gametogenesis of Brassica napus was studied using 3H-uridine autoradiography. No incorporation of isotope occurred in the newly released microspore and the nonvacuolate, furrowed microspore. Peak incorporation of label during male gametogenesis occurred in the uninucleate, furrowed microspores showing various degrees of vacuolation. In this microspore stage, silver grains were localized in the nucleus and cytoplasm. Moderate incorporation of the isotope occurred in the nulceus of the vacuolated microspore. After the microspore mitosis, isotope incorporation occurred predominantly in the nucleus of the vegetative cell with little or no incorporation in the generative cell. In tricellular pollen, no incorporation of isotope was observed in both the vegetative nucleus and the sperms. Silver grains almost completely disappeared from tricellular mature pollen grains ready to germinate.

• Journal of Veterinary Clinics
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• v.14 no.2
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• pp.297-300
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• 1997

Artificial insemination with frozen canine semen using vaginal endoscope was performed in a two years old Golden Retriever to investigate the feasibility of this technique. The bitch was in her second estrus. Blood progesterone concentration was evaluated every two days to decide the timing of insemination since vaginal bleeding was observed. Insemination was performed twice in 48 hours interval on the fourth and sixth posterior to LH surge, respectively. The volume of frozen semen injected was 1.5 ml $(1{\times}10^{8}$ sperms/1ml of semen). The bitch was pregnant and she whelped a female pup on sixty one days after first insemination.

• Journal of Aquaculture
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• v.12 no.1
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• pp.1-5
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• 1999

To obtain fundamental data for sperm cryopreservation in river puffer (Takifugu obscurus), the proper conditions of cryopreservation were investigated. In the sperm cryopreservation of river puffer, marine fish Rinser's solution (MFRS) was found to be good diluent and dimethyl sulfoxide (DMSO) was proved to be superior to glycerol as a cryoprotectant. The highest fertilization rate was achieved when river puffer sperms were cryopreserved with MFRS adding 5％ DMSO.

• Journal of Radiation Protection and Research
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• v.32 no.4
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• pp.184-189
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• 2007

In order to investigate the enhancement effects of low dose radiation on biological activation, this study applied low dose X-ray to the whole body of male rats to find out whether hormesis is induced in male germ cells. Total 36 Sprague-Dawley(SD) rats as experimental animal were subdivided into 6 groups(in 6 rats per group) such as control, 10 mGy, 20 mGy, 50 mGy, 100 mGy and 200 mGy radiation group All the groups showed slightly increasing number of sperms per 0.1g semen ($14.216{\times}10^6,\;13.901{\times}10^6,\;14.153{\times}10^6,\;13.831{\times}10^6,\;14.137{\times}10^6,\;14.677{\times}10^6$ respectively), and the motility of sperms amounted to 50.9%, 49.5%, 55.1%, 54.3%, 48.0% and 52.2% respectively. Particularly, compared to the control, the other 5 groups showed higher male hormone level, and the microscopic observations of testicle tissues showed no vacuolization in seminiferous tubules and testis cells. In the results of this experiment, no harmful effect was observed on Sprague-Dawley (SD) rats for which the dose of radiation was controlled as regulated legally by the Ministry of Science and Technology and the Ministry of Health and Welfare. However, as these results were obtained from a limited number of animals, we cannot maintain that the same effect will be observed in the human body. Therefore, there should be further research on the effect on other animals and ultimately on the human body.