• Title/Summary/Keyword: Cornea

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Screening for Antioxidizing and Tyrosinase-inhibitory Activities of the Extracts of Marine Algae from Busan Coastal Area (부산 연안 해조류 추출물의 항산화 활성 및 Tyrosinase 저해 활성 스크리닝)

  • Seo, Young-Wan;Yoo, Jong-Su
    • Ocean and Polar Research
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    • v.25 no.1
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    • pp.129-132
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    • 2003
  • The crude extracts of marine algae were screened for tyrosinase-inhibitory and radical scavenging effects. Among the samples tested, Symphyocladia latiuscula and Gloiopeltis furcata were found to be the most effective in DPPH radical scavenging test while Gigatina tenella, Sargassum thunbergii, and Sargassum sp. were moderately active. For the inhibition against mushroom tyrosinase, Symphyocladia latiuscula and Sargassum confusum showed the strongest inhibition. Codium adhaerens, Corallina pilulifera, Carpopeltis cornea, Halymenia acuminata, Hizikia fuziformis, Porphyra suborbiculata, and Enteromorpha linza exhibited mild inhibitory potency.

Ocular Filariasis in Canine Anterior Chamber (개 전안방 안구사상충증)

  • 김기홍;엄혜윤;나기정;양만표
    • Journal of Veterinary Clinics
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    • v.16 no.2
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    • pp.506-508
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    • 1999
  • An one-year-old, female pointer dog with conjunctival hyperemia, corneal opaque and ocular pain in right eye was referred to Veterinary Medical Teaching Hospital, Chungbuk National University. In the ophthalmic examination the worm was observed in anterior chamber, The heart worm antigen test was positive. A modified Knott's test was negative. The values of complete blood count and serum chemistry (TP, BUN, creatinine, AST, ALT, ALP, albumin, globuline) showed normal ranges. Any abnormality was not detected in the heart using a thoracic radiography and cardiac sonography. Therefore, this dog was diagnosed as ocular filariasis. The worm was removed by surgical incision through a limbus of cornea. The closure of limbal incision was sutured in a simple interrupted suture pattern with 6-0 silk and the eye was reinflated with sterile saline solution. Antibiotics and dexamethasone ophthalmic solution were applied to right eye every 24 hours for 7 days. To prevent latent filariasis, ivermectin was also administered on day 14 of operation. The heart worm antigen test on day 60 was negative. The dog was successfully cured.

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Optical-effect Analysis of Nanoscale Collagen Fibers

  • Lee, Myoung-Hee;Kim, Young Chul
    • Current Optics and Photonics
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    • v.4 no.2
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    • pp.141-147
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    • 2020
  • To understand the cause of the high light transmittance of the human eye, the optical effects of the collagen fibers of the stroma layer, which constitute the majority of the cornea, were analyzed. These collagen fibers, approximately 20 nm in diameter, have a regular arrangement. Accordingly, the optical properties of the collagen fibers and the fiber layer were analyzed by simulation. A standing wave was formed in the incident space by the overlapping incident light and the light reflected by the plate. In addition, it was confirmed that when the collagen fibers are arranged in a layer, the light transmittance periodically changes, depending on the number of fiber layers. The standing wave was formed in the incident space, and the light's intensity distribution was changed by the nanoscale collagen fibers in the section with the collagen layer, which affected the transmittance. To explain this phenomenon, the collagen fiber was defined as a second light source, and an attempt was made to describe the simulation results in terms of overlap of the incident light with the light emitted from the collagen fiber.

First Report of the Mantid Shrimp Faughnia formosae (Stomatopoda: Parasquillidae) from Korea

  • Hwang, Hee-Seung;Lee, Sang-Kyu;Kim, Mijin;Kim, Won
    • Animal Systematics, Evolution and Diversity
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    • v.29 no.3
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    • pp.245-248
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    • 2013
  • The stomatopods are aggressive predatory marine crustaceans, which are mainly found in tropical and subtropical regions. Among these, a parasquillid stomatopod, Faughnia formosae Manning and Chan, 1997, collected from Jeju Island, is reported for the first time in Korea. The family is easily distinguished from other families by the presence of an asymmetrically bilobed cornea, stout propodus on the raptorial claw, and three primary spines of the uropodal protopod. In the paper, detailed descriptions and illustrations of this species are provided alongside a photograph. A key to the species of Korean mantis shrimp is also presented. As a result of this study, four species of stomatopods including this species are now recorded in Korean fauna.

Successful Surgical Treatments of Scleral Rupture with Hyphema in a Young Cat (어린 고양이에서 발생한 안구내출혈을 동반한 공막 파열의 수술적 치료)

  • Park, Youngwoo;Jung, Yechan;Lim, Jae Hyun
    • Journal of Veterinary Clinics
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    • v.32 no.1
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    • pp.127-129
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    • 2015
  • A 3-month-old, female Persian cat was presented with sclera mass. The mass was detected after cat's squeals during the playing with a dog before 2 days. On ophthalmic examination, a $2{\times}5mm$ dark purple colored raised mass was observed 1 mm behind the limbus in the right eye. Anterior chamber was filled with blood and epithelial defect was detected at 2 o'clock in the right central cornea. After general anesthesia, resection of the protruded iris was performed with iris scissors and bipolar cautery. Ruptured sclera and conjunctiva were closed with simple interrupted and simple continuous suture, respectively. Also, irrigation and aspiration (I/A) of the anterior chamber was performed to remove blood clot with bimanual I/A handpiece in the right eye. Four months after the surgery, the right eye was recovered completely and menace response was positive in spite of the retinal lesions.

Successful Surgical Treatment of Feline Acute Bullous Keratopathy and Corneal Perforation with a Conjunctival Hood Graft

  • Kim, Joon Young;Jeong, Soon-Wuk
    • Journal of Veterinary Clinics
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    • v.34 no.3
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    • pp.204-207
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    • 2017
  • We report the successful treatment of feline acute bullous keratopathy (FABK) and corneal perforation with a conjunctival hood graft. Two cats with FABK and corneal perforation had severe corneal edema with large central bullae. Their corneas were thinned and perforated. Conjunctival hood grafts were performed. All corneas recovered after 3-4 weeks. The grafts were then removed from the cornea using superficial keratectomy and no ocular irritation was observed. One month later, the corneas had recovered, although there was very mild fibrosis. The cats had normal vision without any corneal problems at this time. Conjunctival hood graft was thus useful for the treatment of severe FABK and allowed the cats to maintain vision.

Anti-Spoofing Method for Iris Recognition by Combining the Optical and Textural Features of Human Eye

  • Lee, Eui Chul;Son, Sung Hoon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.9
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    • pp.2424-2441
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    • 2012
  • In this paper, we propose a fake iris detection method that combines the optical and textural features of the human eye. To extract the optical features, we used dual Purkinje images that were generated on the anterior cornea and the posterior lens surfaces based on an analytic model of the human eye's optical structure. To extract the textural features, we measured the amount of change in a given iris pattern (based on wavelet decomposition) with regard to the direction of illumination. This method performs the following two procedures over previous researches. First, in order to obtain the optical and textural features simultaneously, we used five illuminators. Second, in order to improve fake iris detection performance, we used a SVM (Support Vector Machine) to combine the optical and textural features. Through combining the features, problems of single feature based previous works could be solved. Experimental results showed that the EER (Equal Error Rate) was 0.133%.

A Measurement Algorithm for the Cornea Curvature in Automatic Refracto-Keratometer (자동 시각 굴절력 곡률계의 각막 곡률 측정 알고리즘)

  • Sung, Won;Park, Jong-Won
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10d
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    • pp.517-519
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    • 2002
  • 본 논문은 자동 시각 굴절력 곡률계의 전자 부문에 연동될 곡률 측정 알고리즘을 소개한다. 만약 자동화된 시스템이 광학계로부터 나오는 영상을 이용하여 내부 처리를 거친 후 정확 시각 측정치를 검사자에게 알려줄 수 있다면 잘못 측정되는 측정 횟수를 크게 줄일 수 있을 것이다. 본 연구는 형태학적 필터링(morphological filtering)과 그레이-레벨의 신호 강조(signal enhance) 기술들을 이용하여 자동시각 굴절력 곡률계에 연동될 각막 곡률 측정 알고리즘을 개발하였다. 알고리즘에서는 광학계로부터 도출된 링 모양 광원의 화상을 처리하기 위해서 새로운 방법을 사용하는 대신에 굴절력 측정을 위해서 6개의 점으로 구성된 화상을 처리하는 방식으로 변형 적용시킨다. 이 때 링의 띠를 6개의 덩어리점으로 변형하는 과정만을 제외하면 굴절력 화상을 처리하는 방식과 같게 된다. 이는 알고리즘의 간결화와 측정 시간을 줄이는 효과를 얻게 된다. 그리하여 본 각막 곡률 측정 알고리즘은 정한 측정 값 도출이 어려운 시각 영상에 적용되어 효과적으로 오차를 줄임으로써 보다 효율적인 시각 측정을 가능하게 하였다.

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Mutation Effects on FAS1 Domain 4 Related to Protein Aggregation by Molecular Dynamics Simulations and Solvation Free Energy Analysis

  • Cho, Sunhee;Ham, Sihyun
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.70-75
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    • 2015
  • Fasciclin 1 (FAS1) is an extracellular protein whose aggregation in cornea leads to visual impairment. While a number of FAS1 mutants have been studied that exhibit enhanced/decreased aggregation propensity, no structural information has been provided so far that is associated with distinct aggregation potential. In this study, we have investigated the structural and thermodynamic characteristics of the wild-type FAS1 and its two mutants, R555Q and R555W, by using molecular dynamics simulations and three-dimensional reference interaction site model (3D-RISM) theory. We find that the hydrophobic solvent accessible surface area increases due to hydrophobic core repacking in the C-terminus caused by the mutation. We also find that the solvation free energy of the mutants increases due to the enhanced non-native H-bonding. These structural and thermodynamic changes upon mutation contribute to understand the aggregation of these mutants.

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The Vectorization of EOG for Man-Machine Interfacing (Man-Machine Interfacing을 위한 EOG의 벡터화)

  • Park, Jong-Hwan;Cheon, Woo-Young;Park, Hyung-Jun
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.604-606
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    • 1998
  • As a basic study for Man-Machine interfacing technics, this paper purposed the vertorization of EOG(electrooculogram) that is generated by eye movement. EOG is electric potential difference between the positive potential of cornea and the negative potential of retina. The magnitude and the polarity are depend on the direction of eye movement and degree of gaze angle. In order to vectorize EOG, EOG signal is measured about vertical and horizontal movement of eyes. This vectorization of EOG is expected to help Man-Machine Interfacing technics and development of other useful equipment.

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