• 천문학논총
• /
• 제19권1호
• /
• pp.71-76
• /
• 2004

We have developed a tool for measuring optical aberrations of telescope. We adopt curvature sensing technique and use the least square method for finding the amplitudes of the Zernike polynomials. This tool runs under the PC Linux system and the PC windows system with Linux emulators such as Cygwin. The program for UNIX system is used for optical alignment of 1.8M optical telescope at the Bohyunsan Optical Astronomical Observatory (BOAO) and the PC based program is used for the Korea Astronomy Observatory (KAO) wide field telescope (named NEOPAT-3). Our tool is found to be efficient for precise measurement of the optical aberrations of telescopes.

• 한국식품영양과학회지
• /
• 제21권4호
• /
• pp.454-459
• /
• 1992

수종의 Aspergillus속 및 Penicillium속 균이 생산하는 진균대사 산물인 kojic acid가 독성분해 활성제의 첨가유무에 관계없이 Chinese hamster 난소세포에 염색체 변이를 일으키는 것이 확인되었다. Kojic acid 처리량의 증가에 따라 염색체 변이 또한 증가되었다. Kojlc acid의 잠재독성에 관한 본 실험결과에 기초해 이는 일종의 변이 유기체로 추정되며 현재로는 식품첨가제로서의 사용에 문제가 있는 것으로 사료된다.

• 한국광학회지
• /
• 제12권5호
• /
• pp.418-424
• /
• 2001

수차가 적고 넓은 시야각에 걸쳐 높은 회절효율을 보이는 홀로그래픽 HMD 소자를 설계, 제작하였다. 적은 수차를 갖는 홀로그래픽 광학소자를 설계하기 위하여 recursive 설계 방법이 사용되었다. 적은 수차뿐만 아니라 넓은 FOV에 걸쳐 높은 회절효율을 갖도록 하기 위해 매개 홀로그램을 사용하였으며, 이를 이용해 수차가 보정된 홀로그램의 격자 함수를 최종적인 홀로그램에 전송하였다. 제작된 최종의 HMD용 홀로그래픽 광학소자의 수차는 보정 전보다 10배 가량 향상되었으며 FOV는 $\pm$$10^{\circ}$를 나타내었다.

• Current Optics and Photonics
• /
• 제5권6호
• /
• pp.660-671
• /
• 2021

We present a novel optical system for an augmented reality head-up display (AR HUD) with two virtual images at different conjugates by employing a confocal off-axis two-mirror and introducing the horopter circle. For a far virtual image with large asymmetrical aberrations, we initially obtain an off-axis two-mirror system corrected for these aberrations and compensated for the down angle by configuring its parameters to satisfy the confocal and Scheimpflug conditions, respectively. In addition, this system is designed to reduce the biocular parallax by matching Petzval surface into the longitudinal horopter circle in a near virtual image. This design approach enables us to easily balance the residual aberrations and biocular parallax when configuring the optical system with two different conjugates, which results in an AR HUD available for near and far virtual images together.

• 한국환경보건학회지
• /
• 제22권4호
• /
• pp.77-81
• /
• 1996

The present experiment was carried out to examine the mechanism of cytotoxicity of Chromium in CHO cells. Chromium induced chromosomal aberrations in a dose-dependent manner. The most frequent type of aberration was chromatid deletions and chromosome type exchanges were also observed. Ultrafiltrates of culture media from CHO cells treated with Chromium induced sister chromatid exchanges(SCE) in CHO cells and Chromium induced lipid peroxidation. It was suggested that indirect effect through formation of clastogenic factor(CF) as well as direct effect on DNA might contribute to the cytotoxicity of Chromium.

• Toxicological Research
• /
• 제5권1호
• /
• pp.27-35
• /
• 1989

When acetaminophen (25mM) was introduced into the perfused rat liver, the hepatic O2 uptake was rapidly inhibited first and then later slow-down. The rapid inhibition was found to be due to mitochondrial blockade, whereas the so-called slow inhibition" was associated with microcirulatory aberrations as evidenced by inhomogneous staining of the liver tissue by trypan blue infusion (0.1%). NaCN (0.5mM) also caused rapid and slow respiratory inhibitions, giving heterogeneous trypan blue staining.ning.

• 한국동물학회지
• /
• 제23권3호
• /
• pp.115-123
• /
• 1980

DNA 회복합성과 염색체이상과의 연관성여부를 추구하기 위하여 CHO 세포를 재료로 MNNG의 농도와 처리후 시간경과에 따른 절제회복율을 조사하고 이들 염색체 이상율과 비교하여 다음과 같은 결과를 얻었따. 1. MNNG에 의한 절제회복율은 $0.5 \\times 10^-5M$에서 $0.5 \\times 10^-5M$까지 농도의 증가에 따른 절제회복율의 증가를 보인다. 또 $1 \\times 10^-5M$ 처리후 0시간째는 절제회복율의 최고치를 보이다가 그후 점자 감소하여 24시간에는 0시간의 66%정도 나타난다. 2. MNNG에 의한 염색체이상은 $1 \\times 10^-5M$ 처리후 6시간에 최대치를 보이며 이상형의 대부분은 염색분체 절단을 나타낸다. 그러나 시간이 경과함에 따라 염색체분체절단은 감소하고 염색분체교환은 증가하여 24시간에는 두종류의 이상율이 비슷하게 이른다. 3. MNNG 처리후 시간경과에 따른 절제회복율은 전체이상율과 대체로 일치한다. 그러나 염색분체교환 또는 염색분체절단과는 어떤 비례관계도 보이지 않는다. 따라서 이같은 결과들은 MNNG에 의한 DNA 상해 및 그 회복은 염색체의 회복 현상과는 연관성이 없음을 암시하는 것이다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권2호
• /
• pp.651-658
• /
• 2013

Uterine leiomyomas (UL) are extremely common neoplasms in women of reproductive age, and are associated with a variety of characteristic choromosomal aberrations (CAs). The p53 gene has been reported to play a crucial role in suppressing the growth of a variety of cancer cells. Therefore, the present study investigated the effects of CAs and the p53 gene on ULs. We performed cytogenetic analysis by G-banding in 10 cases undergoing myomectomy or hysterectomy. Fluorescence in situ hybridization (FISH) with a p53 gene probe was also used on interphase nuclei to screen for deletions. In patients, CAs were found in 23.4% of 500 cells analysed, significantly more frequent than in the control group (p<0.001). In the patients, 76% of the abnormalities were structural aberrations (deletions, translocations and breaks), and only 24% were numerical. Deletions were the most common structural aberration observed in CAs. Among these CAs, specific changes in five loci 1q11, 1q42, 2p23, 5q31 and Xp22 have been found in our patients and these changes were not reported previously in UL. The chromosome breaks were more frequent in cases, from high to low, 1, 2, 6, 9, 3, 5, 10 and 12. Chromosome 22, X, 3, 17 and 18 aneuploidy was observed to be the most frequent among all numerical aberrations. We observed a low frequency of p53 losses (2-11%) in our cases. The increased incidence of autosomal deletions, translocations, chromatid breaks and aneuploidy, could contribute to the progression of the disease along with other chromosomal alterations.

• 동의생리병리학회지
• /
• 제34권6호
• /
• pp.355-361
• /
• 2020

This study was designed to assess the toxicity of capsaicin-containing (CP) pharmacopunture using an in vitro chromosomal aberrations in Chinese hamster lung (CHL/IU) cells. In order to determine the high dose level in the main study of this study, a dose range finding study was conducted first. The high dose was selected at 10.0% of CP pharmacopuncture extract, and then diluted sequentially to produce lower dose levels of 5.00, 2.50, 1.25, 0.625 and 0.313% by applying a geometric ratio of 2. As a result, the cytotoxicity and precipitation of the CP pharmacopuncture as a test substance were not evident at any dose level during short-time treatment with and without metabolic activation and continuous treatment without metabolic activation. Therefore, the dose levels for this study were chosen as 10.0, 5.0, and 2.5%., and the treatment volume was 1.3 mL. In addition, negative and positive controls were set. In main study, the frequency of cells with chromosome aberrations in CP treated groups was less than 5% in short-time treatment with and without metabolic activation and continuous treatment without metabolic activation. In addition, there was no statistically significant difference when compared to the negative control group. The frequency of cells with structural chromosomal aberrations in the positive control group was more than 10% compared to the negative control group, and it increased statistically significantly. In conclusion, under the conditions of this study, CP pharmacopuncture did not show the possibility of causing chromosome aberrations.

• 한국정밀공학회지
• /
• 제31권7호
• /
• pp.605-613
• /
• 2014

Scanning white-light interferometry is an important measurement option for many surfaces. However, serious profile measurement errors can be present when measuring free-form surfaces being highly curved or tilted. When the object surface slope is not zero, the object and reference rays are no longer common path and optical aberrations impact the measurement. Aberrations mainly occur at the beam splitter in the interference objective and from misalignment in the optical system. Both effects distort the white-light interference signal when the surface slope is not zero. In this paper, we describe a modified version of white-light interferometry for eliminating these measurement errors and improving the accuracy of white-light interferometry. Moreover, we report systematic errors that are caused by optical aberrations when the object is not flat, and compare our proposed method with the conventional processing algorithm using the random ball test.