• Toxicological Research
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• 제30권3호
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• pp.211-220
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• 2014

Resveratrol has received considerable attention as a polyphenol with various biological effects such as anti-inflammatory, anti-oxidant, anti-mutagenic, anti-carcinogenic, and cardioprotective properties. As part of the overall safety assessment of HS-1793, a novel resveratrol analogue free from the restriction of metabolic instability and the high dose requirement of resveratrol, we assessed genotoxicity in three in vitro assays: a bacterial mutation assay, a comet assay, and a chromosomal aberration assay. In the bacterial reverse mutation assay, HS-1793 did not increase revertant colony numbers in S. typhimurium strains (TA98, TA100, TA1535 and TA1537) or an E. coli strain (WP2 uvrA) regardless of metabolic activation. HS-1793 showed no evidence of genotoxic activity such as DNA damage on L5178Y $Tk^{+/-}$ mouse lymphoma cells with or without the S9 mix in the in vitro comet assay. No statistically significant differences in the incidence of chromosomal aberrations following HS-1793 treatment was observed on Chinese hamster lung cells exposed with or without the S9 mix. These results provide additional evidence that HS-1793 is non-genotoxic at the dose tested in three standard tests and further supports the generally recognized as safe determination of HS-1793 during early drug development.

• Laboratory Medicine Online
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• 제7권2호
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• pp.83-87
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• 2017

Pseudohypoparathyroidism (PHP) is a rare disorder caused by genetic and epigenetic aberrations in the GNAS complex locus resulting in impaired expression of stimulatory G protein ($Gs{\alpha}$). PHP type Ib (PHP-Ib) is characterized by hypocalcemia and hyperphosphatemia due to renal resistance to the parathyroid hormone, and is distinguished from PHP-Ia by the absence of osteodystrophic features. An 11-yr-old boy presented with poor oral intake and cramping lower limb pain after physical activity. Laboratory studies revealed hypocalcemia, hyperphosphatemia, and increased parathyroid hormone levels. The GNAS complex locus was evaluated using the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay. Gain of methylation in the NESP55 domain and loss of methylation in the antisense (AS) transcript, XL, and A/B domains in the maternal allele were observed. Consequently, we present a case of PHP-Ib diagnosed using MS-MLPA.

• 한국광학회지
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• 제14권3호
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• pp.236-243
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• 2003

본 논문에서는 구면수차와 Stiles-Crowford 효과를 고려하여 인간의 눈을 모델링한 정밀모형안과 등가인 렌즈모듈 모형안의 설계에 관하여 논의하였고, 렌즈모듈 모형안을 적용한 Head Mounted Display(HMD)용 광학계를 설계 및 평가하였다. HMD용 광학계에서 요구되는 소형화, 고성능 및 고해상도 등의 필수조건들을 만족시키기 위해 회절광학소자와 비구면을 이용하여 색수차와 단색수차를 보정하였다. SVGA급 480,000화소를 갖는 0.47 인치 micro-display, 플라스틱 hybrid 렌즈, 그리고 렌즈모듈 모형안으로 HMD용 광학계를 구성하였다. 설계된 광학계의 초점거리는 31.25 mm, FOV는 24H$\times$18V$\times$30D degrees, 그리고 전장길이는 59.1 mm이다. 결과적으로, 사용자가 편안함을 느낄 수 있는 HMD에 유용한 광학계를 얻었다.

• Journal of the Optical Society of Korea
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• 제17권4호
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• pp.336-343
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• 2013

Recently various types of driver assistance systems have been used for automobiles. In 2008, the U.S Congress passed a law which required that most cars be equipped with devices to warn objects behind the vehicle. Because of that, market of rear view cameras is expected to rise dramatically. Therefore many suppliers try to provide a wide angle camera for car makers. But a high distortion is caused by the wide angle might result in lower image quality. In order to improve the image quality, normally we use an algorithm to correct a distortion. Though we can improve the distorted image by correction algorithm, we must pay more cost to use it. In this paper, we propose a new optical system reducing a distortion in contrast to a conventional lens without cost. In other words, we can see only an area of interest. That is similar to reducing a field of view. Using a new optical system, we can get a less distorted image. In order to view an area of interest, we introduce an off axis optical system having refractive surfaces and reflective surfaces. In this paper, we describe the results of design and, evaluation of an off axis wide angle compact imaging system. In comparison to conventional wide angle lens, we can get the improvement of MTF, distortion, and lateral color aberrations. And we also can reduce a total cost because we don't need the outer apparatus or bracket to mount on the car.

• 한국광학회지
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• 제28권5호
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• pp.187-193
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• 2017

본 연구는 중등물리교사임용시험의 광학 문항 분석을 통해 광학 교육에의 시사점을 탐색하고 중등물리교사임용시험의 개선방안을 제시하는 것을 목적으로 한다. 이를 위해 2002학년도부터 2017학년도까지 16년간 실시된 중등물리교사임용시험에 출제된 38개의 광학문항을 분석하였다. 주요 연구 결과는 다음과 같다. 첫째, 광학 문항은 물리내용학 영역 중에서는 약 10.8% 비율로 출제되어 가장 출제빈도가 낮은 영역이었다. 둘째, 스넬의 법칙, 렌즈의 상, 간섭 등 특정 영역에 대해서 많은 문제가 출제되었으며, 광학기기 및 수차 등에서는 거의 출제되지 않았다. 셋째, 다른 영역에 비해 광학 내용 문항들은 비교적 쉬운 문항들로 출제되었으며, 일상생활 상황보다 실험실 상황의 문제가 더 많이 출제되었다. 추가로 평가 내용 요소별 문항 분석을 통해 물리교사임용시험과 중등물리예비교사교육에의 시사점을 논의하였다.

• 한국광학회지
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• 제28권5호
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• pp.241-249
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• 2017

본 논문에서는 $7.7{\mu}m$에서 $12.8{\mu}m$ 파장 대역에 적용 가능한 비냉각 열상장비 광학계를 설계 및 분석 하였다. 최적화 과정을 통하여 설계된 원적외선 광학계의 유효초점거리는 5.44 mm를 가지며, 4면의 비구면과 2면의 회절면을 포함하였다. 광학계의 F/수는 F/1.2로 설정하였고, 시야각은 $90^{\circ}{\times}67.5^{\circ}$가 되도록 하였다. 회절면이 적용된 hybrid 렌즈를 이용하여 보다 효율적으로 고차 수차가 보정되도록 하였고, 이때 발생되는 회절 특성은 scalar 회절 효율을 이용하여 평가하였다. 또한 hybrid 렌즈에서 발생되는 회절 현상에 의한 통합 회절효율을 예측하고 배경잡음에 의한 MTF 저하를 고려하였다. 원적외선 광학계의 온도 변화에 따른 보상은 광학식 비열화를 이용하여 광학계의 MTF 성능이 초점 심도 내에서 유지되도록 하였다. 결론적으로 비냉각 열상장비에 효율적으로 적용 가능한 광학설계 결과를 얻었다.

• Journal of Genetic Medicine
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• 제16권1호
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• pp.10-14
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• 2019

Purpose: The aim of this study was to investigate the clinicopathological features of premature ovarian insufficiency (POI) associated with chromosomal abnormalities. Materials and Methods: This was a retrospective study of POI patients with chromosomal abnormalities diagnosed between January 2009 and December 2017. The definition of POI is based on hypergonadotropinism of 40 or greater in follicle stimulating hormone (FSH) measurements at age 40 years or less. FSH was measured twice at least 4 weeks apart. Karyotyping using peripheral blood for chromosomal testing was conducted in all patients diagnosed with POI. We analyzed the clinical characteristics and genetic causes of patients who were diagnosed with POI. Results: Forty patients were diagnosed with POI including 9 (22.5%) with identified chromosomal abnormalities. The mean age at diagnosis was $23.1{\pm}7.8years$ (ranging between 14 and 39). Three patients did not experience menarche. The presenting complaints were short stature in one case, one case of amenorrhea with ambiguous external genitals, one case of infertility, and six related to menstruation such as oligomenorrhea or irregular rhythm. Turner syndrome was diagnosed in four cases, Xq deletion in one case, trisomy X in two cases, and 46,XY disorder of sexual development in two other patients. Conclusion: Patients diagnosed with POI carrying the same type of chromosomal abnormality manifest different phenotypes. The management protocol also needs to be changed depending on the diagnosis. A karyotype is indicated for accurate diagnosis and proper management of POI in patients, with or without stigmata of chromosomal abnormalities.

• Clinical and Experimental Reproductive Medicine
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• 제46권1호
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• pp.22-29
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• 2019

Objective: As paternal age increases, the quality of sperm decreases due to increased DNA fragmentation and aneuploidy. Higher levels of structural chromosomal aberrations in the gametes ultimately decrease both the morphologic quality of embryos and the pregnancy rate. In this study, we investigated whether paternal age affected the euploidy rate. Methods: This study was performed using the medical records of patients who underwent in vitro fertilization (IVF) procedures with preimplantation genetic screening (PGS) from January 2016 to August 2017 at a single center. Based on their morphological grade, embryos were categorized as good- or poor-quality blastocysts. The effects of paternal age were elucidated by adjusting for maternal age. Results: Among the 571 total blastocysts, 219 euploid blastocysts were analyzed by PGS (38.4%). When the study population was divided into four groups according to both maternal and paternal age, significant differences were only noted between groups that differed by maternal age (group 1 vs. 3, p= 0.031; group 2 vs. 4, p= 0.027). Further analysis revealed no significant differences in the euploidy rate among the groups according to the morphological grade of the embryos. Conclusion: Paternal age did not have a significant impact on euploidy rates when PGS was performed. An additional study with a larger sample size is needed to clarify the effects of advanced paternal age on IVF outcomes.

• 한국광학회지
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• 제33권6호
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• pp.275-286
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• 2022

광학설계 과정의 첫 단계에서 근축 광선이 만족하는 Gauss 방정식에 대한 해를 구할 수 있는 재귀적 수치 계산법을 도출하였다. 설계 사양으로 렌즈 모듈의 굴절력, 렌즈 제1 주요면으로의 입사각과 제2 주요면으로부터의 출사각이 주어지면 렌즈의 주요면 사이의 거리를 선택한 후, 재귀적 수치 계산법을 적용하여 렌즈의 두께, 렌즈 앞면의 곡률 반경과 뒷면의 곡률 반경을 구할 수 있다. 즉, 설계 사양을 만족하는 두께가 다른 여러 등가렌즈를 얻을 수 있다. 모듈이 2개 이상의 렌즈로 구성되는 경우에도 렌즈의 개수를 하나씩 증가하면서 렌즈의 주요면 사이의 거리를 설계 사양에 맞추어 선택한 후 각 렌즈의 두께와 곡률 반경을 결정할 수 있다.

• Clinical and Experimental Reproductive Medicine
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• 제49권3호
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• pp.210-214
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• 2022

Objective: Platelet-rich plasma (PRP) therapy has received a considerable attention as an adjunct to fertility treatments, especially in women with very low ovarian reserve and premature ovarian insufficiency. Although recent studies have demonstrated that PRP led to improvements in folliculogenesis and biomarkers of ovarian reserve, the effect of intraovarian PRP administration on embryo genetics has not been studied. Methods: We report a pilot study of patients who had preimplantation genetic testing for aneuploidy (PGT-A) before and then within 3 months following PRP administration. Twelve infertile women with at least one prior failed in vitro fertilization (IVF) cycle underwent ovarian stimulation (cycle 1) with a gentle stimulation protocol and PGT-A performed at the blastocyst stage. Following cycle 1, autologous intraovarian PRP administration was performed. Within 3 months following PRP administration, the patients underwent cycle 2 and produced blastocysts for PGT-A. The percentage of euploid embryos between both cycles was compared. Results: The mean age of all participants was 40.08±1.46 years, and their mean body mass index was 26.18±1.18 kg/m². The number of good-quality embryos formed at the blastocyst stage was similar between cycle 1 and cycle 2 (3.08±0.88 vs. 2.17±0.49, respectively; p=0.11). Among all patients in cycle 1, 3 of 37 embryos were euploid (8.11%) while in cycle 2, 11 out of 28 embryos were euploid (39.28%, p=0.002). Three clinical pregnancies were noted among this patient group. Conclusion: This novel study is the first to present an improvement in the embryo euploidy rate following intraovarian PRP application in infertile women with prior failed IVF cycles. The growth factors present in PRP may exhibit a local paracrine effect that could improve meiotic aberrations in human oocytes and thus improve euploidy rates. Whether PRP improves live birth rates and lowers miscarriage rates remains to be determined in large trials.