• Title/Summary/Keyword: Focal

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Design of Imaging Optical System with 24mm Focal length for MWIR (MWIR용 24mm 초점거리를 가지는 결상광학계의 설계)

  • Lee, Sang-Kil;Lee, Dong-Hee
    • Journal of the Korea Convergence Society
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    • v.9 no.6
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    • pp.203-207
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    • 2018
  • This paper deals with the design and development of a lens system capable of imaging an infrared image of $3{\sim}5{\mu}m$ wavelength bands with a focal length of 24mm and good atmospheric transmission characteristics. The design used CodeV, a commercial design program, and the optimization is carried out with weighting to eliminate chromatic aberration, spherical aberration and distortion. The designed lens system consists of two lenses consisting of Si and Ge. Each lens has an aspherical surface on one side. And this optical system has the resolution of the characteristics that the MTF value is 0.40 at the line width of 29lp/mm and the MTF value is 0.25 at the line width of 20lp/mm. This optical system is considered to have the capability to be applied to the thermal imaging camera for MWIR using the $206{\times}156$ array infrared detector of $25{\mu}m$ pixels and the $320{\times}240$ array infrared detector of $17{\mu}m$ pixels.

The Role of SPICA/FPC in the SPICA System

  • Jeong, Woong-Seob;Matsumoto, Toshio;Lee, Dae-Hee;Pyo, Jeong-Hyun;Park, Sung-Joon;Moon, Bong-Kon;Ree, Chang-Hee;Park, Young-Sik;Han, Won-Yong;Lee, Hyung-Mok;Im, Myung-Shin;SPICA/FPC Team, SPICA/FPC Team
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.64.2-64.2
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    • 2012
  • The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) project is a next-generation infrared space telescope optimized for mid- and far-infrared observation with a cryogenically cooled 3m-class telescope. It will achieve the high resolution as well as the unprecedented sensitivity from mid to far-infrared range. The FPC (Focal Plane Camera) is a Korean-led near-infrared instrument as an international collaboration. The FPC-S and FPC-G are responsible for the scientific observation in the near-infrared and the fine guiding, respectively. The FPC-G will significantly reduce the alignement and random pointing error through the observation of guiding stars in the focal plane. We analyzed the pointing requirement from the focal plane instruments. The feasibility study was performed to achieve the requirements. Here, we present the role of SPICA/FPC as a fine guiding camera.

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Neuroprotection of Dexmedetomidine against Cerebral Ischemia-Reperfusion Injury in Rats: Involved in Inhibition of NF-κB and Inflammation Response

  • Wang, Lijun;Liu, Haiyan;Zhang, Ligong;Wang, Gongming;Zhang, Mengyuan;Yu, Yonghui
    • Biomolecules & Therapeutics
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    • v.25 no.4
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    • pp.383-389
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    • 2017
  • Dexmedetomidine is an ${\alpha}2$-adrenergic receptor agonist that exhibits a protective effect on ischemia-reperfusion injury of the heart, kidney, and other organs. In the present study, we examined the neuroprotective action and potential mechanisms of dexmedetomidine against ischemia-reperfusion induced cerebral injury. Transient focal cerebral ischemia-reperfusion injury was induced in Sprague-Dawley rats by middle cerebral artery occlusion. After the ischemic insult, animals then received intravenous dexmedetomidine of $1{\mu}g/kg$ load dose, followed by $0.05{\mu}g/kg/min$ infusion for 2 h. After 24 h of reperfusion, neurological function, brain edema, and the morphology of the hippocampal CA1 region were evaluated. The levels and mRNA expressions of interleukin-$1{\beta}$, interleukin-6 and tumor nevrosis factor-${\alpha}$ as well as the protein expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-${\kappa}Bp65$, inhibitor of ${\kappa}B{\alpha}$ and phosphorylated of ${\kappa}B{\alpha}$ in hippocampus were assessed. We found that dexmedetomidine reduced focal cerebral ischemia-reperfusion injury in rats by inhibiting the expression and release of inflammatory cytokines and mediators. Inhibition of the nuclear factor-${\kappa}B$ pathway may be a mechanism underlying the neuroprotective action of dexmedetomidine against focal cerebral I/R injury.

Podocytopathy and Morphologic Changes in Focal Segmental Glomerulosclerosis (초점분절사구체경화증에서 발세포병증과 형태 변화)

  • Jeong, Hyeon Joo
    • Childhood Kidney Diseases
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    • v.17 no.1
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    • pp.13-18
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    • 2013
  • Podocytopathy is glomerular lesions characterized by podocyte injury. It is observed in various glomerular diseases, but minimal change disease and focal segmental glomerulosclerosis (FSGS) are the prototypes. In this review, morphologic features of podocyte injury and subtypes of FSGS will be reviewed briefly. Effacement of podocyte foot processes is the most common feature of podocyte injury. As podocytic injury progresses, intracytoplasmic vacuoles, subpodocytic cyst, detachment of podocytes from the glomerular basement membrane and apoptosis develop. Glomerular capillary loops in epithelium-denuded area undergo capillary collapse. Synechia and hyalinosis may accompany this lesion. To manifest segmental sclerosis, podocyte loss above a threshold level may be required. Injured podocytes can injure neighboring intact podocytes, and thereby spread injury within the same lobule. FSGS can be categorized into five subtypes by morphologic characteristics; not otherwise specified (NOS), perihilar, cellular, tip, and collapsing types. Each subtype has been reported to show different clinical courses and associated conditions, but there are controversies on its significance. With recent progress in the discovery of genetic abnormalities causing FSGS and plasma permeability factors, we expect to unravel pathophysiology of FSGS and to understand histological sequences leading to FSGS in near future.

A Case of Cockayne Syndrome with Focal Segmental Glomerulosclerosis (국소성 분절성 사구체 경화증(FSGS)을 동반한 Cockayne 증후군 1례)

  • Shin, Hye-Kyung;Kim, Gun-Ha;Yim, Hyung-Eun;Hong, Young-Sook;Lee, Joo-Won;Won, Nam-Hee;Yoo, Kee-Hwan
    • Childhood Kidney Diseases
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    • v.11 no.1
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    • pp.100-105
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    • 2007
  • Cockayne syndrome is a rare autosomal recessive disorder characterized by cachectic dwafism, mental retardation, loss of facial subcutaneous adipose tissue, microcephaly and photosensitive dermatitis. It is associated with renal abnormalities characterized by hyalinization of glomeruli, atrophy of tubules and interstitial fibrosis. To our knowledge, this is the first report of a case of Cockayne syndrome with FSGS in Korea. A 7-year old boy was admitted for evaluation of hypertension and proteinuria, which were detected 2 month ago. He was followed for short stature(<3 percentile), mental retardation(IQ 55), strabismus and dental caries since 3 years ago. He also showed microcephaly, a bird-like face and relatively large hands and feet. Laboratory findings showed decreased creatinine clearance($C_{Cr}$ 76.1 mL/min/$1.73m^2$) and proteinuria(1,548 mg/day). Renal biopsy demonstrated focal segmental glomerulosclerosis of the hilar type with large hyaline deposits, moderate tubular atrophy and interstitial fibrosis. His cardinal features, mental retardation, and renal biopsy findings were consistent with Cockayne syndrome. We report here a very rare case of Cockayne syndrome with FSGS presenting with proteinuria and hypertension.

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A Study on Adaptable Non-contact Shape Inspection System (적응형 비접촉 형상 검사에 관한 연구)

  • Kang, Young-June;Park, Nak-Gyu;Lee, Dong-Hwan
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.2
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    • pp.74-80
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    • 2005
  • A new dimension measuring method for the measurement of diameter of an object has been developed using laser triangulation. The 3D data of an object was calculated from the 2 dimensional image information obtained by the laser stripe using the laser triangulation. The system that use existing theory can measure the diameter of hole not only in a normal plane but also ill an incline plane. However, in the existing theory, since the lens with fixed feral length was used, the area of measurement was fixed. The simplest way to solve this problem is to change distance between a CCD camera and object. Other way is to use a zoom lens having variable focal length. In this paper, the zoom lens with variable focal length was used. Therefore, we ran experiment with magnification that is optimized according to size of object using zoom lens with variable focal length.

Effects of Onion Vinegar on the Cerebral Blood Flow and the Safety Examination (양파식초가 뇌혈류 및 안전성에 미치는 영향)

  • Choi, Chan Hun;Kim, Kyung Yoon;Jeong, Woo Sik;Jeon, Byung Guan;Jung, Jae Gon;Jung, Jong Gil;Lee, Sang Young;Jeong, Hyun Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.5
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    • pp.657-664
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    • 2012
  • The aim of this study is to investigate the effects of onion vinegar on the cerebral blood flow by measuring the changes of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) and by observing the recovery of focal ischemic brain injury in rats. Rats are divided into thee groups depending on the medication; control group (no medication), 8.8-OV group (vinegar using 8.8 brix onion medication), 14.6-OV group (vinegar using 14.6 brix onion medication). The medication of onion vinegar significantly increased rCBF but decreased MABP. This result suggests that onion vinegar significantly increased rCBF by dilating arterial diameter. In addition, focal ischemic brain injury is induced in rats by middle cerebral arterial occlusion. The recovery from focal ischemic brain injury is more significantly improved in the groups using onion vinegar compared to the control group. The amount of recovery is measured by the GAP-43 and the medication of onion vinegar significantly increased GAP-43. This result suggests that onion vinegar is effective on the nerve regeneration. After the medication, the change of body weight, outcomes of renal and liver function test, and outcomes of CBC are analysed for safety examination. There are no statistical differences among control group and all experimental groups in the body weight, renal and liver function test, and CBC. In conclusion, these results suggest that onion vinegar can increase rCBF in normal state, and improve the stability of rCBF in ischemic state.

Botulinum A toxin for the treatment of focal hyperhidrosis -5 cases- (국소화 다한증에 대해 보툴리늄 독소를 이용한 치료 -5례보고-)

  • Lee, Song-Am;Kim, Kwang-Taik;Park, Sung-Min;Chung, Bong-Kyu;Sun, Kyung;Kim, Hyoung-Mook;Lee, IIn-Sung
    • Journal of Chest Surgery
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    • v.33 no.3
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    • pp.268-272
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    • 2000
  • Thoracic sympathicotomy has been used safely and successfully to treat essential hyperhidrosis. However, it has been difficult to treat compansatory hyperhidrosis after thoracic sympathicotomy and focal hyperhidrosis. The sweat glands were innervated by post-ganglionic sympathetic fibers with acetylcholic serving as the transmitter. Botulinum A toxin has been reported to block neuro-transmission at the cholinergic autonomic nerve terminals. Prospecting its effect for the sweat gland, we treated 5 patients with focal hyperhidrosis with botulinum A toxin. Three patients received bilateral thoracic sympathectomy (1 case) and sympathicotomy(2 case) via VAT. The hyperhidrosis area was marked with betadine and was subdivided into squares of 2$\times$2 cm(4$\textrm{cm}^2$) each. Botulinum A toxin was injected intracutaneously in a dosage of 2.5U/0.1ml(100U/4ml) /4$\textrm{cm}^2$. A total dose of 100U of Botulinum A toxin was injected into the affected sites. Subjective assessment of sweat production by the patients using a visual analogue scale showed a 20~70% improvement. During the follow-up period, no toxic effects were observed.

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Effects of Polygoni Multiflori Radix on Cerebral Ischemia of Hyperlipidemic Rats. (하수오가 고지혈증 흰쥐의 허혈성 뇌손상에 미치는 영향)

  • Lee Young-Hyo;Lee Won-Chul
    • The Journal of Korean Medicine
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    • v.26 no.3 s.63
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    • pp.146-161
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    • 2005
  • Objectives : This study investigated neuroprotective effects of Polygoni Multiflori Radix on cerebral ischemia of hyperlipidemic rats. Methods : Effects of Polygoni Multiflori Radix were evaluated with changes of infarct size after He focal cerebral ischemia induced by the middle cerebral artery occlusion, changes of pyramidal neurons and expressions of Bax and Bcl-2 apoptosis regulating factors after global cerebral ischemia, and changes of serum lipid revels after cerebral ischemia. Results & Conclusions : Results obtained were as follows; 1. Polygoni Multiflori Radix did net reduce the focal cerebral infarct size induced by the middle cerebral artery occlusion under both hyperlipidemic and normal-lipid conditions. 2. Polygoni Multiflori Radix significantly reduced the increase of neuronal cell death in CAl region of hippocampus induced by the global cerebral ischemia under both hyperlipidemic and normal-lipid conditions. 3. Polygoni Multiflori Radix significantly reduced the increase of Bax expression in the CAl region of the hippocampus induced by global cerebral ischemia under both hyperlipidemic and normal-lipid conditions. 4. Polygoni Multiflori Radix significantly increased Bc1-2 expression in the CA1 region of the hippocampus after global cerebral ischemia under normal-lipid condition, but was not effective on that under hyperlipidemic condition. 5. Polygoni Multiflori Radix was not effective on serum total-cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride levels under normal-lipid conditions, irrespective of focal cerebral infarct or global cerebral ischemia. 6. Polygoni Multiflori Radix significantly reduced the increase of serum total-cholesterol and triglyceride levels, and increased serum LDL-cholesterol level under hyperlipidemic conditions, irrespective of foc31 cerebral infarct or global cerebral ischemia.

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Neuroprotective Effects of Quetiapine on Neuronal Apoptosis Following Experimental Transient Focal Cerebral Ischemia in Rats

  • Yilmaz, Muhammet Bahadir;Tonge, Mehmet;Emmez, Hakan;Kaymaz, Figen;Kaymaz, Memduh
    • Journal of Korean Neurosurgical Society
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    • v.54 no.1
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    • pp.1-7
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    • 2013
  • Objective : This study was undertaken in the belief that the atypical antipsychotic drug quetiapine could prevent apoptosis in the penumbra region following ischemia, taking into account findings that show 5-hydroxytryptamine-2 receptor blockers can prevent apoptosis. Methods : We created 5 groups, each containing 6 animals. Nothing was done on the K-I group used for comparisons with the other groups to make sure adequate ischemia had been achieved. The K-II group was sacrificed on the 1st day after transient focal cerebral ischemia and the K-III group on the 3rd day. The D-I group was administered quetiapine following ischemia and sacrificed on the 1st day while the D-II group was administered quetiapine every day following the ischemia and sacrificed on the 3rd day. The samples were stained with the immunochemical TUNEL method and the number of apoptotic cells were counted. Results : There was a significant difference between the first and third day control groups (K-II/K-III : p=0.004) and this indicates that apoptotic cell death increases with time. This increase was not encountered in the drug groups (D-I/D-II : p=1.00). Statistical analysis of immunohistochemical data revealed that quetiapine decreased the apoptotic cell death that normally increased with time. Conclusion : Quetiapine is already in clinical use and is a safe drug, in contrast to many substances that are used to prevent ischemia and are not normally used clinically. Our results and the literature data indicate that quetiapine could help both as a neuronal protector and to resolve neuropsychiatric problems caused by the ischemia in cerebral ischemia cases.