• Investigative Magnetic Resonance Imaging
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• 제23권3호
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• pp.202-209
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• 2019

Purpose: To investigate the temperature-based differences of cortical bone ultrashort echo time MRI (UTE-MRI) biomarkers between body and room temperatures. Investigations of ex vivo UTE-MRI techniques were performed mostly at room temperature however, it is noted that the MRI properties of cortical bone may differ in vivo due to the higher temperature which exists as a condition in the live body. Materials and Methods: Cortical bone specimens from fourteen donors ($63{\pm}21$ years old, 6 females and 8 males) were scanned on a 3T clinical scanner at body and room temperatures to perform T1, $T2^*$, inversion recovery UTE (IR-UTE) $T2^*$ measurements, and two-pool magnetization transfer (MT) modeling. Results: Single-component $T2^*$, $IR-T2^*$, short and long component $T2^*s$ from bi-component analysis, and T1 showed significantly higher values while the noted macromolecular fraction (MMF) from MT modeling showed significantly lower values at body temperature, as compared with room temperature. However, it is noted that the short component fraction (Frac1) showed higher values at body temperature. Conclusion: This study highlights the need for careful consideration of the temperature effects on MRI measurements, before extending a conclusion from ex vivo studies on cortical bone specimens to clinical in vivo studies. It is noted that the increased relaxation times at higher temperature was most likely due to an increased molecular motion. The T1 increase for the studied human bone specimens was noted as being significantly higher than the previously reported values for bovine cortical bone. The prevailing discipline notes that the increased relaxation times of the bound water likely resulted in a lower signal loss during data acquisition, which led to the incidence of a higher Frac1 at body temperature.

• Animal cells and systems
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• 제3권2호
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• pp.103-113
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• 1999

Many in-depth reviews related to regulations of prolactin secretion are available. We will, therefore, focus on controversial aspects using personal opinion in this review. The neuroendocrine control of prolactin secretion from the anterior pituitary gland involves multiple factors including prolactin-release inhibiting factor (PIF) and prolactin releasing factor (PRF). The PIF exerts a tonic inhibitory control in the physiological conditions. The PIF should be able to effectively inhibit prolactin release or a lifetime, but the inhibitory action of dopamine cannot be sustained for a long period of time. Perifusion of a high concentration of dopamine (l ,000 nM) could not sustain inhibitory action on prolactin release but when a small amount of ascorbic acid (0.1 mM) is added in a low concentration of dopamine (3 nM) solution, prolactin release was inhibited for a long period. Ascorbate is essential for dopamine action to inhibit prolactin release. We have, therefore, concluded that the PIF is dopamine plus ascorbate. The major transduction system for dopamine to inhibit prolactin release is the adenylyl cyclase system. Dopamine decreases cyclic AMP concentration by inhibiting adenylyl cyclase, and cyclic AMP stimulates prolactin release. However, the inhibitory mechanism of dopamine on prolactin release is much more complex than simple inhibition of CAMP production. The dopamine not only inhibits cyclic AMP synthesis but also inhibits prolactin release by acting on a link(s) after the CAMP event in a chain reaction for inhibiting prolactin release. Low concentrations of dopamine stimulate prolactin release. Lactotropes are made of several different subtypes of cells and several different dopamine receptors are found in pituitary. The inhibitory and stimulatory actions induced by dopamine can be generated by different subtype of receptors. The GH$_4$ZR$_7$ cells express only the short isoform (D$_{2s}$) of the dopamine receptor, as a result of transfecting the D$_{2s}$ receptors into GH$_4$C$_1$ cells which do not express any dopamine receptors. When dopamine stimulates or inhibits prolactin release in GH$_4$ZR$_7$ cells, it is clear that the dopamine should act on dopamine D$_{2s}$ receptors since there is no other dopamine receptor in the GH$_4$ZR$_7$. Dopamine is able to stimulate prolactin release in a relatively low concentration while it inhibits in a high concentration in GH$_4$ZR$_7$. These observations indicate that the dopamine D$_2$ receptor can activate stimulatory and/or inhibitory transduction system depending upon dopamine concentrations.

• 한국자기학회지
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• 제17권3호
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• pp.124-127
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• 2007

비정질 $Co_{70.5}Fe_{4.5}Si_{15}B_{10}$층을 갖는 자기터널접합(magnetic tunneling junctions; MTJ)를 연구하였다. 비정질 자유층이 MTJ의 스위칭 특성에 미치는 영향을 중점적으로 이해하기 위하여 기존의 사용된 CoFe 그리고 NiFe층들을 대신하여 비정질 강자성체 CoFeSiB을 사용하였다. CoFeSiB은 CoFe과 NiFe보다 각각 낮은 포화자기장($M_s:\;560\;emu/cm^3$)과 높은 자기이방성 상수($K_u:\;0.2800\;erg/cm^3$)를 갖는다. CoFeSiB층들의 사이에 1.0 nm Ru층 삽입시 $-0.003\;erg/cm^3$ 교환결합에너지($J_{ex}$)를 나타내었다. $Si-SiO_2-Ta$ 45/Ru 9.5/IrMn 10/CoFe 7/$AlO_x$/CoFeSiB 7 또는 CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60(in nm) MTJ 구조의 터널접합에 대하여 실험 및 시뮬레이션 결과를 통하여 낮은 $J_{ex}$에 기인하는 스위칭 자기장(switching field; $H_{sw}$)의 시료 크기 의존성이 나타나는 것을 알 수 있었다. CoFeSiB 합성형 반강자성 구조는 micrometer뿐만 아니라 submicrometer 시료 크기영역에서도 보자력($H_c$)의 감소와 민감도를 증가 시킴으로써 자기 스위칭 특성에 유리한 것으로 확인 되었다.

• 대한통합의학회지
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• 제7권2호
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• pp.1-10
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• 2019

Purpose : To investigate the relationship between breathing pattern disorder and joint position error (JPE) in patients with chronic low back pain (CLBP). Methods : Thirty nine patients with CLBP participated. End-tidal $CO_2$ and respiration rate (RR) were measured using a capnography. Breathing-hold time (BHT) and Nijmegen Questionnaire (NQ) were investigated. Thoracic excursion was measured with a cloth tape measurement technique. Joint position error were measured using a small laser point mounted on a lightweight headband. they were asked to relocate the head, after the neck movement on the horizontal plane. Pearson 's test was used for correlation analysis between respiratory variables and JPE in patients with CLBP. Independent t-test was used to verify the difference between thoracic and diaphragm breathing pattern in patients with CLBP. The significance level was set at 0.05. Results : There was a significant correlation between JPE (LR) and JPE (RR, EX) (r=.639, r=.813) (p<.001) and a low negative correlation with end-tidal $CO_2$ (r=-.357) (p<.05). There was a significant correlation between RR and JPE (EX) (r=.750) (p<.001). There was a low correlation between JPE (EX) and NQ (r=.333) (p<.05). There was a somewhat high negative correlation between NQ and thoracic excursion (r=-.528) (p<.001). There was a somewhat high negative correlation between thoracic excursion and JPE (LR, RR, EX) (r=-.470, r=-.484, r=-.602) (p<.001). There were no significant differences in the RR, BHT, NQ, and thoracic excursion between the thoracic and diaphragmatic breathing (p>.05). There was a significant difference in the JPE (EX), end - tidal $CO_2$, and VAS values between the thoracic and diaphragm breathing (p<.05). Conclusion : There was a correlation between JPE (EX) and NQ in patients with CLBP, and correlation between thoracic excursion and JPE (LR, RR, EX) and NQ. There was a significant difference in the JPE (EX), end-tidal $CO_2$ level, and VAS value in the comparison of thoracic breathing and diaphragm breathing. The results showed that breathing patterns and JPE were related to each other.

• 식물분류학회지
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• 제41권2호
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• pp.113-118
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• 2011

한국산 금방망이속(Senecio L.) 및 근연속인 국화방망이속(Sinosenecio B. Nord.), 솜방망이속 (Tephroseris (Rchb.) Rchb.)에 속하는 8분류군을 대상으로 체세포 염색체수를 조사하였다. 체세포 염색체수는 2n = 40, 2n = 44인 종류와 2n = 48인 종류로 구분되었으며, 2n = 40인 분류군은 쑥방망이(Senecio argunensis Turcz.), 금방망이(S. nemorensis L.), 개쑥갓(S. vulgaris L.), 산솜방망이(Tephroseris flammea (DC.) Holub)이었다. 2n = 44인 분류군은 바위솜나물(T. phaeantha (Nakai) C. Jeffrey & Y.L. Chen)이었으며, 2n = 48인 분류군은 국화방망이(Sinosenecio koreanus (Kom.) B. Nord.), 솜방망이(T. kirilowii (Turcz. ex DC.) Holub), 물솜방망이(T. pierotii (Miq.) Holub.)로서, 이중 국화방망이와 산솜방망이, 바위솜나물은 기존의 연구 결과와 차이를 보였다.

• 대한의용생체공학회:의공학회지
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• 제27권2호
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• pp.53-58
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• 2006

In this study, transverse relaxation time (T2) measurement and the evaluation of the characteristics of the spectral peak related to stomach tissue metabolites were performed using ex vivo proton magnetic resonance spectroscopic imaging (MRSI) at 1.5-T MRI/S instruments. Thirty-two gastric tissues resected from 12 patients during gastric cancer surgery, of which 19 were normal tissue and 13 were cancerous tissue, were used to measure the $T_2$ of the magnetic resonance spectroscopy (MRS) peaks. The volume of interest data results from the MRSI measurements were extracted from the proper muscle (MUS) layer and the composite mucosa/submucosa (MC/SMC) layer and were statistically analyzed. MR spectra were acquired using the chemical shift imaging (CSI) point resolved spectroscopy (CSI-PRESS) technique with the parameters of pulse repetition time (TR) and echo times (TE) TR/(TE1,TE2)=1500 msec/(35 msec, 144 msec), matrix $size=24{\times}24$, NA=1, and voxel $size=2.2{\times}2.2{\times}4mm^3$. In conclusion, the measured $T_2$ of the metabolite peaks, such as choline (3.21ppm) and lipid (1.33ppm), were significantly decreased (p<0.01 and p<0.05, respectively) in the cancerous stomach tissue.

• 재활치료과학
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• 제9권1호
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• pp.7-23
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• 2020

목적 : 본 연구는 뇌졸중 환자의 상지기능 회복에 대한 경두개 직류자극(transcranial Direct Current Stimulation; tDCS)의 효과를 살펴본 연구를 분석하는 데 목적이 있다. 연구 방법 : 2009년부터 2018년 현재까지 국내외 학술지에 게재된 논문들을 NDSL과 RISS를 통해 검색하였다. 선정기준과 배제기준을 통해 총 14개의 실험연구 논문이 선정되었다. 이를 PEDro 척도를 사용하여 질적 평가를 시행하고, 이 중 12개 논문에 대해서 Comprehensive Meta Analysis 3.0 프로그램을 사용하여 메타분석을 실시하였다. 결과 : 본 연구에서 고찰한 문헌 14편은 모두 국외 학술지에 게재된 문헌들이었다. 메타분석을 실시한 결과 효과 크기는 상지 근력 0.19로 '작은 효과크기', 상지 움직임 0.49로 '보통 효과크기'를 보였다. 상지 움직임의 효과크기는 통계적으로 유의한 변화가 있던 것으로 분석되었다(p<0.05). 또한 양극(anode) 모드는 '큰 효과크기'를. 음극(cathode) 모드는 '보통 효과크기'를 보였으며, 양극 모드의 효과크기만 통계적으로 유의하였다(p<0.05). 결론 : 본 연구 결과를 통하여 상지기능이 제한된 뇌졸중 환자에게 tDCS는 유용한 재활 기법이 될 수 있다는 것을 확인하였다. 이는 국내 임상가들에게 뇌졸중 환자를 위한 새로운 재활 기법의 기초자료를 제시하고, 효과적인 중재를 계획하는 데 도움이 될 것이다.

• 대한본초학회지
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• 제23권2호
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• pp.213-223
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• 2008

Objectives : This study was performed to prove the hypotensive effect of 70% MeOH extracts from Scrophularia buergeriana (SB) on rat's femoral artery. Methods : We observed hypotensive effect of SB on rat's femoral artery. Scrophularia buergeriana Miquel, S. kakudensis, S. koraiensis and S. ningpoenesis Hemsl. were used by the RFLP method and sequence analysis of ITS regions, in order to compare and discriminate. Results : SB 70% MeOH Ex., Water fraction, 40% MeOH fraction, 100% MeOH fraction didn't show significantly hypotensive effect. 20% fraction of SB 70% MeOH Ex. showed significantly hypotensive effect. The size of ITS region on Scrophularia sp. is 589${\sim}$590bp and amount of G+C is 59.3% to 59.7%, and it showed the similar of ITS parts on Scrophularia sp. Conclusions : We concluded that SB Ex. have hypotensive activity, and it's more efficient when separated. And Scrophularia sp. showed the similar of DNA analysis.

• 전기학회논문지P
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• 제66권4호
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• pp.252-257
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• 2017

In this paper for developing and implementing the HD level triple streaming hybrid security camera which output the three type of video outputs(HD-SDI, EX-SDI, Analog). We design the hardware and program the firmware supporting the main and sub functions. We use MN34229PL as image sensor, EN778, EN331 as image processor, KA909A as reset, iris, day&night function part, A3901SEJTR-T as zoom/focus control part. We request the performance test of developed security camera at the broadcasting and communication fusion testing department of TTA (Telecommunication Technology Association). We can get the three outputs (HD-SDI, EX-SDI, Analog) from the developed security camera, get the world best level at the jitter and eye pattern amplitude value and exceed the world best level at the signal/noise ratio, and minium illumination, power consumption part. The HD level triple streaming hybrid security camera in this paper will be widely used at the security camera because of the better performance and function.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2319-2344
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• 2010

Accumulated deficits resulting from managing the Korean Railroad and debts from the construction of the KTX (Korea Train Express which is a high-speed rail system) have left the Korean Railroad faced with great troubles. Since it changed into a public corporation Korail on January 1st, 2005, the Korea Railroad has been making unceasing efforts to overcome the troubles and improve its management. However, even these efforts haven't worked in the face of the improved conditions of other transportation methods such as better networks of land roads and air ways. The Korea Railroad had its revenue from its railway transportation limited, and has tried to expand its business to non-transportational areas. In some metropolitan cities, the Korea Railroad made investments in real estate by constructing station buildings based on private money. Yet, in small and medium size cities, the Korea Railroad has little particular strategic projects for business development. Recently certain small and medium size regional cities began to plan on business developments for the ex-railway land, and some small towns have developed real estate on the ex-railway land. Nevertheless, there have been no systematic case studies to classify these real estate developments.