• 지구물리와물리탐사
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• 제21권2호
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• pp.125-131
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• 2018

2017년 11월 15일 포항지진(규모 5.4)은 깊이효과로 경주지진(규모 5.8) 보다 피해가 더 컸으나, 정확한 깊이가 확증되지 않고 있다. 진원 깊이를 진원재결정을 통하여 역산한 결과, 대부분의 모델의 진원 깊이가 얕은 표층으로 도출된 반면, 지각구조가 가장 근접한 모델은 6.0 ~ 11.5 km 구간의 깊이로 산출되었다. 지온분석에서는 7.5 km 근방에서 $300^{\circ}C$의 온도가 관찰되어 지진유발층의 사례에 입각한 포항지진의 진원은 근접한 모델로 얻어진 7 km 근방인 것으로 추정되어진다.

• 한국지구과학회지
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• 제27권3호
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• pp.341-347
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• 2006

2001년부터 2005년까지 한반도 남서부에서 발생한 7개 미소지진에 대한 진원 기구해를 분석하였다. 진원 기구해를 구하기 위하여 P파 초동극성과 SH/P 진폭비 자료를 이용한 격자탐색을 수행하였다. 분석 결과, 대부분의 지진들이 일부 역단층 성분을 포함하는 주향이동 단층 운동과 관계된 것으로 해석된다. 전체적으로 한반도 남서부 지역의 지진원에서 단층 운동을 일으키는 주 압축 응력 방향은 ENE-WSW 또는 NE-SW 방향인 것으로 해석되며, 이 결과는 남한 내의 주요 지진에 대하여 알려진 주 응력장의 방향과 유사하다.

• Journal of Trauma and Injury
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• 제32권2호
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• pp.115-117
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• 2019

Although hemothorax and pneumothorax are common complications seen in rib fractures, focal extrapleural hematoma is quite rare. We report a 63-year-old female patient that developed large focal extrapleural hematoma after falling off a second floor veranda. The patient had sustained 3, 4, 5th costal cartilage rib fractures and a sternum fracture. She had developed suspected empyema with loculations with small amount of hemothorax. She underwent a planned early decortication/adhesiolysis by video assisted thoracoscopic surgery at the 12th post-trauma day due to failed drainage. Unexpectedly, she had no adhesions or any significant retained hematoma mimicking a mass, but was found with the focal extrapleural chest wall hematoma. She was discharged on postoperative 46th day for other reasons and is doing fine today.

• 지구물리와물리탐사
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• 제15권2호
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• pp.85-91
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• 2012

고유감쇠 분리를 위한 다중지연시간창(MLTW) 해석은 진원의 방사 형태에 크게 의존하여 제 1차 시간창의 분산이 매우 크다. 이를 보완하기 위하여 진원의 방위각에 따라 고르게 분포하는 많은 자료를 사용하여야 한다. 만일 진원함수를 알고 있는 자료를 이용하면 이용하면 이러한 오차를 줄이게 되어 적은 자료 및 방위각 분포에 상관없는 자료연구가 가능할 수 있다. Yoshimoto(2000)의 DSMC에 진원구조를 계산하는 알고리즘을 결합하여 MLTW 해석을 시도하였다. 진원함수를 고려한 MLTW법에서 같은 단층면해를 이용해야 하는 제약으로 최소자승을 이용할 수 있는 자료 수가 극히 제한된다. 따라서 진원구조 계산 알고리즘을 기존 다량의 자료를 이용하는 역산 방법에 적용하는 것이 불가능하다는 것을 확인하였다. 즉, 제1차 시간창의 분산이 줄어든 대신 완곡한 이론곡선을 구하기에는 자료가 턱없이 부족함을 확인하였다. 자료를 더 확보해야 한다는 일반적인 해결책 이외에, 새로운 제약조건을 부과하기 위한 연구가 필요할 것으로 사료된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.369-369
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• 2016

A nanostructure composite is a highly suitable substance for photoacoustic ultrasound generation. This allows an input laser beam (typically, nanosecond pulse duration) to be efficiently converted to an ultrasonic output with tens-of-MHz frequency. This type of energy converter has been demonstrated by using a carbon nanotube (CNT)-polydimethylsiloxane (PDMS) composite film that exhibit high optical absorption, rapid heat transition, and mechanical durability, all of which are necessary properties for high-amplitude ultrasound generation. In order to develop the CNT-PDMS composite film, a high-temperature chemical vapor deposition (HTCVD) method has been commonly used so far to grow CNT and then produce a CNT-PDMS composite structure. Here, instead of the complex HTCVD, we use a mixed solution of hydrophobic multi-walled CNT and dimethylformamid (DMF) and fabricate a solution-processed CNT-PDMS composite film over a spherically concave substrate, i.e. a focal energy converter. As the solution process can be applied over a large area, we could easily fabricate the focal transmitter that focuses the photoacoustic output at the moment of generation from the CNT-PDMS composite layer. With this method, we developed photoacoustic energy converters with a large diameter (>25 mm) and a long focal length (several cm). The lens performance was characterized in terms of output pressure amplitude for an incident pulsed laser energy and focal spot dimension in both lateral and axial. Due to the long focal length, we expect that the new lens can be applied for long-range ultrasonic treatment, e.g. biomedical therapy.

• Nutrition Research and Practice
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• 제4권3호
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• pp.196-202
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• 2010

To investigate the neuroprotective effects of bovine colostrums (BC), we evaluate the ability of consuming BC after focal brain ischemia/reperfusion injury rat model to reduce serum cytokine levels and infarct volume, and improve neurological outcome. Sprague-Dawley rats were randomly divided into 4 groups; one sham operation and three experimental groups. In the experimental groups, MCA occlusion (2 h) and subsequent reperfusion (O/R) were induced with regional cerebral blood flow monitoring. One hour after MCAO/R and once daily during the experiment, the experimental group received BC while the other groups received 0.9% saline or low fat milk (LFM) orally. Seven days later, serum pro-inflammatory cytokine (IL-$1{\beta}$, IL-6, and TNF-${\alpha}$) and anti-inflammatory cytokine (IL-10) levels were assessed. Also, the infarct volume was assessed by using a computerized image analysis system. Behavioral function was also assessed using a modified neurologic severity score and corner turn test during the experiment. Rats receiving BC after focal brain I/R showed a significant reduction (-26%/-22%) in infarct volume compared to LFM/saline rats, respectively (P < 0.05). Serum IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ levels were decreased significantly in rats receiving BC compared to LFM/saline rats (P < 0.05). In behavioral tests, daily BC intake showed consistent and significant improvement of neurological deficits for 7 days after MCAO/R. BC ingestion after focal brain ischemia/reperfusion injury may prevent brain injury by reducing serum pro-inflammatory cytokine levels and brain infarct volume in a rat model.

• 한국식품영양학회지
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• 제29권6호
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• pp.923-929
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• 2016

The purpose of this study was to evaluate the protective effect of $PineXol^{(R)}$ on $H_2O_2$-induced cell death in SK-N-MC cells, and in early stage focal ischemia rodent model. SK-N-MC cells were pre-treated with $200{\mu}M$ $H_2O_2$ or various concentrations of $PineXol^{(R)}$ (10, 30, and 50 pg/mL) for 24 h, and then exposed to $H_2O_2$ for 3 h. Cell death was assessed by the CCK-8 assay, reactive oxygen species (ROS) assay, and lactate and dehydrogenase (LDH) release assay. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) expressions were also analyzed by western blotting. Focal ischemia rodent model was used as the in vivo model, and different concentrations of $PineXol^{(R)}$ (1, 10, and 100 mg/kg) were administered. One week after administration, reduction of infarct volume was analyzed by TTC staining. Cell viability of $H_2O_2$-treated SK-N-MC cells significantly increased by pre-treatment of $PineXol^{(R)}$ (p<0.05). $PineXol^{(R)}$ pre-treatment also induced significant decrease of ROS and LDH expressions. However, $PineXol^{(R)}$ did not affect the infarct volume. These results suggest that $PineXol^{(R)}$ has significant neuroprotective effect in vitro, but statistical significance was not confirmed in the in vivo focal ischemia model.

• 천문학회보
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• 제35권1호
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• pp.36.2-36.2
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• 2010

The CQUEAN (Camera for QUasars in EArly uNiverse) is an optical CCD camera optimized for observation of high redshift objects. It is going to be attached to the cassegrain focus of 2.1m telescope at McDonald Observatory, USA. We are making a focal reducer for CQUEAN to secure a larger field of view. The focal reducer is composed of four spherical lens, and it reduces the focal length of telescope by one third. We designed the lens configuration, performed tolerance analysis, and estimated the optical performance with ZEMAX. The differences in optical performace with/without filters were also investigated. The result from ZEMAX shows that the system has ample margin of errors for median seeing of 1.2" at McDonald observatory. Even with aberration and alignment tolerance, the performance is better than the original requirement. The lenses are now being made, and the lens barrel and an adapter for assembly of the Andor CCD camera and the filter wheel is now under designing process. We expect that the manufacturing of the focal reducer system as well as its optical test will be finished by April 2010.

• 대한의생명과학회지
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• 제11권3호
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• pp.355-363
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• 2005

This study aimed to investigate the cerebroprotective effect of vascular endothelial growth factor (VEGF) on permanent focal cerebral ischemia in Sprague-Dawley rats. Right middle cerebral artery (MCA) was occluded for 6 and 24 hours by an intraluminal monofilament technique. An open cranial window was made on the right parietal bone for determination of continuous changes in regional cerebral blood flow (rCBF) by laser-Doppler flowmetry. The infarct size was morphometrically determined using the 2,3,5-triphenyltetrazolium chloride technique. Brain edema was determined by measuring brain water content. In normal rats, rCBF was significantly increased by intravenous infusion of VEGF for 10 minutes. The VEGF-induced increase in rCBF was significantly inhibited by pretreatment with suramin, a heparin-binding growth factor inhibitor as well as $N^{\omega}-nitro-L-arginine$, a nitric oxide synthase inhibitor. In focal cerebral ischemic rats, the amplitude of decrease in rCBF during ischemic period was significantly less in VEGF-treated group, compared with that in vehicle-treated group. The cerebral infarct size was reduced by VEGF in a dose-dependent manner. The brain edema formation was dose-dependently reduced by VEGF in 24-hour MCA occlusion group but not in 6-hour MCA occlusion group. It is suggested that VEGF not only improves the rCBF during cerebral ischemic period but also reduces the brain edema formation, and thereby exert a protective effect on focal cerebral ischemia in rats.

• Macromolecular Research
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• 제12권5호
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• pp.528-533
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• 2004

We have prepared amide dendrons having alkyl peripheral units and various focal moieties through a convergent synthetic approach. The amphiphilic properties, due to hydrophilic amide branches and the hydrophobic peripheral units, provide an opportunity for the amide dendrons to self-organize in water. The dendritic architecture itself is also one of the critical factors in the self-organization of the amide dendrons in water. In particular, function-alization was performed at the focal point to elucidate the relationship between the focal functionality and the self-organized structures of the dendritic building blocks in the aqueous phase. The dendron having a short poly(ethylene glycol) monomethyl ether (MeO-PEG) unit (M$\_$n/ =750) as the focal moiety formed a vesicular organization in water. As the size of the hydrophilic focal MeO-PEG increased to M$\_$n/ =2,000 and 5,000, the self-organized structures became rod-type and spherical micelles, respectively. Our observation of multiple morphologies for amide dendrons is in good agreement with previous reports that indicated that the micellar structures changed from vesicles to rod-types and then to spheres upon increasing the size of the hydrophilic moiety of the amphiphiles.