• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권2호
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• pp.316-322
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• 1996

불소의 유전물질에 대한 독성효과는 현재까지 논란의 대상이되고 있으며, 서로 상반된 연구 결과들이 보고되고 있다. 저자는 불소의 세포 유전학적 효과를 규명하고자 실험실 내에서 배양된 편평상피암 세포주에 염화불소를 처리하여 세포독성 검사와 염색체이상 검사를 시행하여 다음과 같은 결론을 얻었다. 1. 염화불소의 농도와 처리시간에 비례하여 세포성장이 현저히 감소하므로 염화불소는 편평상피암 세포주에 독성을 가진다. 2. 염화불소의 농도가 증가할수록 염색체이상 발현빈도가 현저히 높게 나타나므로 염화불소는 편평상피암 세포주에서 DNA 손상을 야기할 수 있다. 염색체 이상의 형태는 chromatid break가 가장 많이 나타났다.

• 한국안광학회지
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• 제9권2호
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• pp.269-280
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• 2004

본 논문에서는 몇 개의 근축(paraxial) 모형안들과 정밀(finite) 모형안들을 선택하여 모형안의 자이델 수차를 이용하여 안구에 대한 광학적 특성을 살펴보았다. 즉, 구경조리개인 홍채를 수정체의 전면에 고정시킨 후 자이델 계수를 통하여 각 면의 수차 분포와 비구면도가 모형안 성능에 어떤 영향을 주는가를 조사하였다. 또한 조절 휴지 상태와 조절 상태로 구분하여 분석함으로서 조절 시 변화되는 광학적 특성도 함께 조사하였다.

• Journal of Astronomy and Space Sciences
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• 제29권1호
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• pp.79-84
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• 2012

After a visit by Peter Waddell from the University of Strathclyde, Glasgow, UK in 1991, Robert H. Koch launched a program at the University of Pennsylvania to build lightweight pneumatic membrane mirrors, initially for balloon flight observations where weight is at a premium. Mirror cells were fabricated from sizes 0.18 m to 1.77 m, and experiments conducted to characterize the mirror figure and stability. Most of the work stopped after Prof. Koch's retirement in 1996 until 2006 when the authors expressed an interest in building an array of medium-aperture portable telescopes. The program restarted in earnest at Gravic, Inc. in Malvern, PA in 2008 with Koch using his extensive observational astronomy experience to guide the fabrication of a fully operational 1.07 m membrane mirror telescope with an optical tube assembly weighing under 45 Kg. Residual wavefront aberrations remediation resulted in Koch and the authors investigating membrane tensioning techniques with different cell designs, active secondary wavefront correction, photometric algorithms for aberrated images, and the use of additional lightweight mirror substrates from the Alt-Az Initiative Group, such as foamed glass. The best result for the lightweight mirrors was a point spread function spot size of several arc seconds. A lightweight 1.6 m cast aluminum cell alt-az telescope was subsequently designed by Koch and the authors for prime focus use.

• 한국환경성돌연변이발암원학회지
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• 제22권2호
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• pp.90-96
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• 2002

Benzene is a widespread human carcinogen, inducing leukemia and hematotoxicity. Exposure to benzene metabolites has been shown to cause genetic damage, including aneusomy and chromosome aberrations. Fluorescence in situ hybridization(FISH) procedure was used to determine if the benzene metabolite, 1, 2, 4-benzenetriol(BT), hydroquinone(HQ) and trans, trans-muconic acid(t,t-MA) induced specific chromosomal change in HL-60 cells. Treatment with BT, HQ and t,t-MA resulted in the induction of monosomy 8 and 21 in HL-60 cells in a dose-dependent manner. All of these metabolites also induced trisomy 8 and 21, but no correlation between frequencies of trisomy and concentration was found. Translocations between chromosome 8 and another unidentified chromosome ［t(8:\ulcorner)］, and between chromosome 21 and another unidentified chromosome ［t(8:21)］ were found. However, translocation between chromosome 8 and 21 ［t(8:21)］ was not found. Results indicate that the benzene metabolites, BT, HQ and t,t-MA, induce chromosome specific numerical and structural aberrations, and the fluorescence in situ hybridization (FISH) approach may be a useful and powerful technique for detection of aneuploidy.

• 한국지역사회생활과학회지
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• 제26권4호
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• pp.633-645
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• 2015

This study investigates the genotoxicity of crude antifungal compounds produced by Lactobacillus plantarum AF1 (L.plantarum AF1) and Lactobacillus plantarum HD1 (L. plantarum HD1) isolated from kimchi. The genetic toxicity of crude antifungal compounds was evaluated in bacterial reverse mutation in Salmonella and Escherichia spp., chromosome aberrations in Chinese hamster lung cells, and micronucleous formations in mice. In bacterial reversion assays with Salmonella Typhimurium TA98, TA100, TA1535, TA1537, and WP2uvrA, crude antifungal compounds did not increase the number of revertant colonies in both the absence and presence of the 59 metabolic activation system. In the chromosome aberration test with Chinese hamster lung cells, crude antifungal compounds showed no increase in the frequency of chromosome aberrations in the short-period test with/without the S9 mix or in the continuos test. In the in vivo mouse micronucleus assay, crude antifungal compounds showed no increase in the frequency of polychromatic erythrocytes with micronuclei. The results show that crude antifungal compounds produced by L. plantarum AF1 and L. plantarum HD1 did not induce any genotoxicity.

• Toxicological Research
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• 제11권2호
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• pp.261-266
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• 1995

Age-related change in the frequency of spontaneous sister chromatid exchange (SCE) and chromosornal aberrations were investigated in bone marrow cells of accelerated senescence-resistant mice (SAM R1) and senescence accelerated ones (SAM P1). And the effect of chronic treatment of ginseng extract (Panax ginseng C.A. Meyer) on these chromosomal abnormalities was tested in SAM P1. SCE frequency in the cells was progressively increased with age in both mice, but it was consistently higher in SAM P1 than in SAM R1 at all corresponding age. Chromosomal aberrations were, however, not significantly changed with age except that it was slightly increased in only aged SAM P1. Interestingly, the rate of these genetic instabilities in SAM P1 was remarkably retarded by long-term administration of ginseng water extract (0.05% in drinking water). These results suggest that frequency of spontaneous SCE in bone marrow cells increase in parallel with senescence of the mice, and SAM P1 is in the condition of being more exposed than SAM R1 to DNA damaging factors. These also indicate that long-term treatment of ginseng may reduce the genetic damage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1422-1425
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• 2003

In the design of optical system, important variables of optical system (including indices, shapes, spaces, stops. etc.) must manipulate in order to balance out offensive aberration. In this paper, it carried out a basic study on the design of micro optical system usable for the acquaintance of visual information in the particular conditions such as capsule type endoscopes. In this study, specification for design of optical system selected voluntarily and the basic design of optical system carried out by using the ray tracing method on the assumption that ideal lenses without aberrations. In the designed optical system, the optimization including aberration correction and the performance evaluation of optical system carried out by using the CODE-V. The final designed optical system consists of seven sheets of lenses. Also the results of performance evaluation. the micro optical system combined with aspherical lenses was confirmed to have improved optical performance as compared with the micro optical system consisted of spherical lenses.

• 대한구순구개열학회지
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• 제8권1호
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• pp.23-29
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• 2005

The facial cleft and duplicated maxilla are lire congenital anomaly. After Rushton and Walker had reported a unilateral facial cleft with excess tooth and bone formation in 1937, few authors described similar cases. The etiology of this anomaly is not well understood, but considered embryologically as a neurocristopathy. A neurocristopathy is defined as a condition arising from aberrations in early migration, growth and differentiation of neural crest cells. This aberrations result in facial malformation such as facial clefts and loss or duplication of facial structures. We experienced a male newborn baby with bilateral facial cleft and duplicated maxilla. The cleft was surgically corrected when he was 5 months old. The function and appearance of lip are improved. Duplicated maxilla will be surgically removed. We report this case with review of literatures.

• Reproductive and Developmental Biology
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• 제30권4호
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• pp.263-270
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• 2006

The Chinese Hamster Ovarian cells CHO-K1 are one of the most extensively used cells for the evaluation of gene expression and toxicology. However, these cells are frequently used for biomedical research without consideration of their cytogenetic characteristics. Therefore, we carried out to investigate the karyologic profiles, the frequency and type of chromosome aberration, and the distribution of telomeric DNA on chromosomes of the CHO-K1 cells. The GTG banding and fluorescence in situ hybridization on CHO-K1 cells were performed to characterize the karyotype and the distribution of telomeric DNA The present study revealed that the chromosome modal number of CHO-K1 cells was 2n=20; eight chromosomes appeared to be identical with those of the normal Chinese hamster, whereas the remaining 12 chromosomes were shown to be translocated, deleted, inversed, or rearranged from Chinese hamster chromosomes. The telomeric DNA on CHO-K1 chromosomes was intensively distributed at the centromeres rather than the ends of chromosomes. In addition, three chromosomes had interstitial telomeres and one marker chromosome entirely consisted of telomeric DNAs. The frequency and type of chromosome aberrations in CHO-K1 cells were examined. Of the 822 metaphase spreads, 68 (8.3%) cells resulted in chromosome aberrations of which the chromosome breakage was the most frequently occurred.

• 한국정밀공학회지
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• 제27권2호
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• pp.50-59
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• 2010

In this paper, two kind of free-form progressive addition lenses (PALs) were designed with Zernike polynomial surface and anatomically accurate finite presbyopic schematic eyes which have aspheric cornea, aspheric GRIN crystalline lens, aspheric retina, and Gaussian apodization factor. Geometrical and diffraction MTFs were used for the optimization process in sequence. 5th orders of Zernike polynomials were used for the evaluation of progression zones of the two examples. The target MTF was set as 0.22 at 100 lp/mm which satisfies the standard visual resolution. These examples were fabricated with a CNC diamond turning machine controlled by slow tool servo (STS). After polishing process, the wavefront aberrations were measured with a laser interferometer on the ten test points across the progression zones and then compared with three current commercially available PALs on the optical performance. Astigmatic aberrations of the examples are very lower than the three selected PALs and have more increased stabilized progressive intermediate zones and near zones. It is expected to give better clear and comfortable distance, intermediate and near visions than other conventional PALs and to improve the adaptability of presbyopic patients to PALs.