• Development and Reproduction
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• v.24 no.3
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• pp.167-176
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• 2020

The fat pad defined as the epididymal fat is located at the head part of the epididymis. However, another fat mass is present near the caudal epididymis, named tail epididymal fat. The present research was focused to determine the expression of adipocyte-associated molecules in the mouse tail epididymal fat at different postnatal ages, including 2, 5, 8, and 12 months of age. The quantitative real-time PCR analysis showed continuous increases of expression levels of delta like non-canonical Notch ligand 1, leptin, and resistin as postnatally aged. The transcript level of peroxisome proliferator-activated receptor gamma was the highest at 5 months of age, remaining at a steady level until 12 months of age. Expression levels of fatty acid binding protein 4, leptin, and adiponectin were significantly increased until 8 months of age, persisting the level at 12 months of age. The transcript level of fatty acid synthase was significantly increased at 8 months of age, without a further change of the level at 12 months of age. These findings exhibited the expression of adipocyte-associated genes which were also detected at the ordinary epididymal fat pad. However, expression patterns of these genes in the tail epididymal fat are different with those in the distal and proximal epididymal fat, suggesting distinct characteristics and/or functions of the tail epididymal fat.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.524-527
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• 1992

Synechococcus sp. cyanophage was isolated from Baekwoon reservoir located in KyonggiDo. The cyanophage was purified by employing ultrafiltration. differential centrifugation. and sucrose density gradient centrifugation. Electron microscopic observation indicated that the sizes of its isometric head and contractile tail are 89 nm and] II nm. respectively. which means that the isolated cyanophage is included in the group. Myoviridae. The cyanophage maintained the stability of more than 50 percent from $20^{\circ}C$ to $40^{\circ}C$ and from pH 5 to 8. and had the maximal infectivity at $30^{\circ}C$ and pH 9 implying its ecological significance.

• Journal of Photoscience
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• v.2 no.2
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• pp.95-98
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• 1995

The photodimers with cyclobutane rings and C$_2$ symmetry, derived from coumarin (syn, head to tail and anti, head to head) have been calculated by PM3-UHF-CI and Molecular Mechanics force field. The photocycloaddition to coumarin and 5,7-dimethoxycoumarin(DMC) dimers were deduced to be formed by their preferable frontier orbital interactions and via more stable cycloaddition by the C$_3$, C$_4$ bond. These results are consistent with the coumarin dimer model that the theoretical C$_4$-photocyclodimer of coumarin is predicted much more than the experimental C$_4$-photocyclodimer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.2
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• pp.133-138
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• 2001

We studied the optical properties of poly(3-hexylthiophene) for applying to the emitting material of organic electro luminescent device. The infrared spectrum and NMR of synthesized polymer gave good evidence for the conjugation of 3-hexylthiophene monomer unit. We confirmed that poly(3-hexylthiophene) contains the HT(head-to-tail)-HT(head-to-Tail) linkage larger than 65% based on NMR analysis. FTIR and raman spectroscopy show that poly(3-hexylthiophene) has two main vibration levels which have an energy about 0.18eV and 0.36eV. Electronic absorption spectra shifted to the shorter wavelength with increasing temperature, which is related to a conformational transition of the polymer. Photoluminescence spectrum generated at low temperature(10K) is separated at 669nm, 733nm and 812nm that it's because of phonon energy generated from the lattice vibration.

• Applied Microscopy
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• v.27 no.3
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• pp.309-320
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• 1997

The spermatogenesis of korean leech, Whitmania edentula was observed, using both light and electron microscopes. The spermatogonium and maturing spermatozoon are connected with long cytoplasmic process to the cytophore, which supplys nutrition to the germ cells and supports synchronous maturity. The truck of korean leech is divided into three regions; a long ladder-shaped acrosome and head, long middle piece and long tail. Long head region twists to the dextral helix, and nuclei are surrounded with microtubules (manchette).The nebenkern formed with long mitochondrion exists in the middle pieces, and a long tail of Whitmania edentula ($9\times2+1$ axoneme) differs from the $9\times2+2$ axoneme of Rhynchobdellae. The late cytophore is mostly formed with crystalloid matter and a number of lysosomes, and matured spermatozooms are engulfed into the late cytophore.

• Applied Microscopy
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• v.12 no.1
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• pp.69-73
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• 1982

The phages of Bacillus subtilis SNU 816 were observed by electron microscope with their host. The results are as follows; The phage had hexagonal head, contractile tail sheath and base plate with six tail fibers. During the lysis of bacteria due to attack of phage, dissolution of flagella were initiated from distal end of flagella.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1443-1449
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• 2013

Automatic detection of vehicles in front is an integral component of many advanced driver-assistance system, such as collision mitigation, automatic cruise control, and automatic head-lamp dimming. Regardless day and night, tail-lights play an important role in vehicle detecting and status recognizing of driving in front. However, some drivers do not know the status of the tail-lights of vehicles. Thus, it is required for drivers to inform status of tail-lights automatically. In this paper, a recognition method of status of tail-lights based on video processing and recognition technology is proposed. Background estimation, optical flow and Euclidean distance is used to detect vehicles entering tollgate. Then saliency map is used to detect tail-lights and recognize their status in the Lab color coordinates. As results of experiments of using tollgate videos, it is shown that the proposed method can be used to inform status of tail-lights.

• Bulletin of the Korean Chemical Society
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• v.13 no.6
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• pp.684-688
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• 1992

Three photocyclodimers of 5,7-dimethoxycoumarin (DMC) were isolated and characterized from the photolysis of DMC in acetonitrile. The configuration of the dimers was found to be anti head-to-head, syn head-to-head and syn head-to-tail, respectively. The number and the ratio of the products are solvent dependent. The anti head-to-head dimer is favored in nonpolar solvents and the preference decreases as the solvent polarity increases giving almost 100${\%}$ syn dimers and less than 1${\%}$ anti dimer from methanol solution. The overall yields of dimers also increase with the solvent polarity. From sensitization and quenching experiments, anti dimer was found to be formed via excited singlet state while syn dimers were formed via both excited singlet and triplet states.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.449-454
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• 1992

Eight healthy Holstein bulls, 4-6 years old were used to study the effect of season of the year on the incidence of the morphologically abnormal spermatozoa. Semen was collected twice a week by A. V. over one-year period. The percentage of total abnormal spermatozoa was $14.1{\pm}0.5$. Ejaculates collected during hot summer season had significantly higher incidence of abnormal spermatozoa than those collected during winter time. Warm spring had moderate semen abnormality. In addition to its effect on the total number of morphologically abnormal spermatozoa, season affected significantly the primary as well as the secondary types of abnormalities. The differences between incidence of primary and secondary types of abnormalities were not significant for all seasons and seasons pooled together. The ratio between the total forms of abnormality in the head, mid-piece and tail of spermatozoa was as 1:1.5:1. Head and mid-piece had defected more during summer compared with both winter and spring. There was no variation in tail abnormalities due to season. The significant effect of season on head was observed by large, pyriform, free and detached heads, while that on mid-piece was by swollen, coiled mid-pieces and protoplasmic droplets.

• Applied Microscopy
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• v.29 no.4
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• pp.427-435
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• 1999

Spermatogenesis and fine structure of the spermatozoon of the marbled sole, Limanda yokohamae were examined by means of the scanning and transmission electron microscopy. The process of spermatogenesis of the marbled tole is similar to that of other teleost with external fertilization. During the spermiogenesis, chromatin that has been became fine]y granular progressively condenses into many large globules and that homogeneously condensed in the spermatozoan head. A spermatozoon consists of head and tail, and the acrosome is absent. The cytoplasmic collar contained eight mitochondria is observed in the posterior part of the head. The well -developed axonemal lateral fins are observed in the tail. In the TEM observation, the cross section of the axial filament shows '9+2' axonemal structure of microtubules, and the numerous vesicles are observed in the cytoplasm.