• Journal of Acupuncture Research
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• 제26권2호
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• pp.59-70
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• 2009

Objectives : Although CTTH is one of the most common symptom in primary headache, the mechanism and treatment is not definite. The purpose of this study is to research about clinical characteristic and roentgenographic finding of the cervical spine in CTTH to determine relationship between the cervical spine and headache. Methods : This study was carried out on 93 patients with CTTH. By roentgenographic finding, they were classified into four groups - HNP, Spondylosis, Sprain, Normal. Then the HNP group was divided again into two groups - singer type and multiple type. Results: 1. Among 93 patients with CTTH, 69(74.19%) patients had abnormal cervical spine by roentgenographic finding. 2. There were HNP, spondylosis, sprain in abnormal roentgenographic finding. And a great majority of the patients were diagnosed as cervical sprain. 3. There were no significant difference between four groups on sex, weight, height, blood pressure, pulse, respiratory rate. But on ages, the HNP group showed the highest average while the sprain group showed the lowest. 4. The patients in HNP group had more frequent, severe pain, longer onset and higher onset-age than those of the other three group. 5. The patients in Multiple-type HNP group had severe pain, longer pain-duration, longer onset, more pre-symptoms and younger onset-age than those of the Single-type HNP group. Conclusions : A great majority of the patients with CTTH had abnormal cervical spines. Also, we found out that the worse the grade of HNP, heavier the level of headache.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.249-249
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• 2009

We have grown large area BSTO($(Ba_{1-x}Sr_x)TiO_3$) thin films (x=0.4) on 2 inch diameter MgO (001) single crystal substrates using a pulse laser deposition(PLD) system. Substrate temperature and oxygen pressure in the deposition chamber, and the laser optics for ablating a target have been controlled to obtain the uniform thickness and preferred orientation of the films. Results of x-ray diffraction and rocking curve analysis revealed that the BSTO films were grown on MgO substrates with a preferred orientation (002), and the full width half maximum of the rocking curve was measured to be 0.86 degree at optimum condition. Roughness of the films have been measured to be $3.42{\AA}$ rms by using atomic force microscopy. We have successfully deposited the large area BSTO thin films of $4000{\AA}$ thickness on 50 mm diameter MgO substrates.

• The Korean Journal of Physiology and Pharmacology
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• 제2권6호
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• pp.733-742
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• 1998

Background: We have previously reported that not only cGMP but also 8-Br-cGMP or 8-pCPT-cGMP, specific and potent stimulators of cGMP-dependent protein kinase (cGMP-PK), increased basal L-type calcium current $(I_{Ca})$ in rabbit ventricular myocytes. Our findings in rabbit ventricular myocytes were entirely different from the earlier findings in different species, suggesting that the activation of cGMP-PK is involved in the facilitation of $I_{Ca}}$ by cGMP. However, there is no direct evidence that cGMP-PK can stimulate $I_{Ca}}$ in rabbit ventricular myocytes. In this report, we focused on the direct effect of cGMP-PK on $I_{Ca}}$ in rabbit ventricular myocytes. Methods and Results: We isolated single ventricular myocytes of rabbit hearts by using enzymatic dissociation. Regulation of $I_{Ca}}$ by cGMP-PK was investigated in rabbit ventricular myocytes using whole-cell voltage clamp method. $I_{Ca}}$ was elicited by a depolarizing pulse to +10 mV from a holding potential of -40 mV. Extracellular 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate (8-pCPT-cGMP), potent stimulator of cGMP-dependent protein kinase (cGMP-PK), increased basal $I_{Ca}}$. cGMP-PK also increased basal $I_{Ca}}$. The stimulation of basal $I_{Ca}}$ by cGMP-PK required both 8-Br-cGMP in low concentration and intracellular ATP to be present. The stimulation of basal $I_{Ca}}$ by cGMP-PK was blocked by heat inactivation of the cGMP-PK and by bath application of 8-(4-chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer (Rp-pCPT-cGMP), a phosphodiesterase-resistant cGMP-PK inhibitor. When $I_{Ca}}$ was increased by internal application of cGMP-PK, IBMX resulted in an additional stimulation of $I_{Ca}}$. In the presence of cGMP-PK, already increased $I_{Ca}}$ was potentiated by bath application of isoprenaline or forskolin or intracellular application of cAMP. Conclusions: We present evidence that cGMP-PK stimulated basal $I_{Ca}}$ by a direct phosphorylation of L-type calcium channel or associated regulatory protein in rabbit ventricular myocytes.

• 생명과학회지
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• 제14권6호
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• pp.1023-1027
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• 2004

본 연구는 출아형 효모 Saccharomyces cerevisiae에서 자외선의 상해 시 이를 정상으로 회복시키는 절제회복(excision repair) 유전자로 알려진 RADS의 특성 규명을 위하여 균류 Coprinus cinereus에서 이와 유사한 유전자를 분리하였다. RADS 유사 유전자를 분리하기 위하여 균류 C. cinereus의 염색체 DNA를 전기영동하여 분리한 다음 효모 RADS DNA를 probe로 하여 이와 hybridization하였다. 이 결과 RADS유사 유전자는 3.4kb의 insert DNA를 갖고 있었다. 또한 Southern hybridization으로 이 유사 유전자는 fungus C. cinereus의 염색체에 존재함을 확인하였다. 분리한 RADS 유사 유전자의 전사체 크기는 2.8kb 였으며, 자외선의 상해시 전혀 자외선에 대한 유도성이 없음을 Northern hybridization으로 확인하였다. 또한 유사유전자 부분을 삭제하였을 때 이 부분이 없는 세포는 전혀 생존을 못하였다. 이 결과 분리한 RADS 유사유전자는 세포의 생존에 필수적인 유전자임을 알 수 있었다.

• International Journal of Automotive Technology
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• 제8권4호
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• pp.437-444
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• 2007

This paper experimentally investigates the effects of oxygen-enriched air (OEA) on the running behaviors of an LPG SI engine during both start/warm-up (SW) and hot idling (HI) stages. The experiments were performed on an air-cooled, single-cylinder, 4-stroke, LPG SI engine with an electronic fuel injection system and an electrically-heated oxygen sensor. OEA containing 23% and 25% oxygen (by volume) was supplied for the experiments. The throttle position was fixed at that of idle condition. A fueling strategy was used as following: the fuel injection pulse width (FIPW) in the first cycle of injection was set 5.05 ms, and 2.6 ms in the subsequent cycles till the achieving of closed-loop control. In closed-loop mode, the FIPW was adjusted by the ECU in terms of the oxygen sensor feedback. Instantaneous engine speed, cylinder pressure, engine-out time-resolved HC, CO and NOx emissions and excess air coefficient (EAC) were measured and compared to the intake air baseline (ambient air, 21% oxygen). The results show that during SW stage, with the increase in the oxygen concentration in the intake air, the EAC of the mixture is much closer to the stoichiometric one and more oxygen is made available for oxidation, which results in evidently-improved combustion. The ignition in the first firing cycle starts earlier and peak pressure and maximum heat release rate both notably increase. The maximum engine speed is elevated and HC and CO emissions are reduced considerably. The percent reductions in HC emissions are about 48% and 68% in CO emissions about 52% and 78%; with 23% and 25% OEA, respectively, compared to ambient air. During HI stage, with OEA, the fuel amount per cycle increases due to closed-loop control, the engine speed rises, and speed stability is improved. The HC emissions notably decrease: about 60% and 80% with 23% and 25% OEA, respectively, compared to ambient air. The CO emissions remain at the same low level as with ambient air. During both SW and HI stages, intake air oxygen enrichment causes the delay of spark timing and the increased NOx emissions.

• Childhood Kidney Diseases
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• 제19권2호
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• pp.98-104
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• 2015

Objective: To find out clinical features and long-term outcomes of idiopathic childhood nephrotic syndrome(NS) patients with late steroid resistance(LSR)/late steroid sensitiveness(LSS). Patients and Methods: A retrospective chart review was performed on 480 patients diagnosed with idiopathic childhood NS at Asan Medical Center Children's Hospital from 1990 to 2013. Twenty-four patients whose responsiveness to steroids changed over a minimum 2 year follow-up period (2-17.5 years) were investigated. All patients had undergone a renal biopsy. Results: Among 480 nephrotic children, 428 (89%) were sensitive to the first steroid course. Of those who initially responded, 11 (2.5%) developed resistance to steroid therapy after relapses. LSR mostly developed between 1 month and 1 year after the initial episode. Six patients showed a minimal change and five showed focal segmental glomerulosclerosis (FSGS). Nine (82%) responded to cyclosporine or methylprednisolone pulse therapy. Of these, two had no further relapse, whereas the other seven experienced several relapses that ranged in length from 1.1 to 13.9 years. Three of the nine who initially responded to immunosuppression went on to experience several changes in steroid responsiveness. Two (18%) with resistance to immunosuppressants, including steroids, eventually progressed to end stage renal disease. Among the 52 patients (11%) who were initially steroid resistant, 13 (23%) were converted to steroid sensitive at relapses. Among these, 9 showed minimal change and 4 showed FSGS. Two had no further relapse and the other 11 responded to steroids on subsequent relapses ranging in length from 1.3 to 9.4 years. All these patients have had no further changes in steroid responsiveness with normal renal function. Conclusions: In this study, 2.5% of initial steroid responders and 25% of initial steroid non-responders changed their responsiveness to steroids at subsequent relapses. Eighteen percent of LSR patients developed end stage renal disease. All of the LSS patients showed preserved normal renal function. Responsiveness to immunosuppressants seemed to be the most important factor determining longterm outcomes in LSR/LSS patients.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.17-22
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• 2011

This study was designed to determine the effect of electric field strength, duration and fusion buffer in fusion parameters on the rate of membrane fusion between the somatic cell and cytoplast for Korean cattle (HanWoo) somatic cell nuclear transfer (SCNT) procedure. Following electrofusion, effect of 5 or $10\;{\mu}M$ $Ca^{2+}$-ionophore of activation treatment on subsequent development was also evaluated. Cell fusion rates were significantly increased from 23.1% at 20 V/mm to 59.7% at 26 V/mm and 52.9% at 27 V/mm (p<0.05). Due to higher cytoplasmic membrane rupture or cellular lysis, overall efficiency was decreased when the strength was increased to 30 V/mm (18.5%) and 40 V/mm (6.3%) and the fusion rate was also decreased when the strength was at 25 V/mm or below. The optimal duration of electric stimulation was significantly higher in $25\;{\mu}s$ than 20 and $30\;{\mu}s$ (18.5% versus 9.3% and 6.3%, respectively, p<0.05). Two nonelectrolyte fusion buffers, Zimmermann's (0.28 M sucrose) and 0.28 M mannitol solution for cell fusion, were used for donor cell and ooplast fusion and the fusion rate was significantly higher in Zimmermann's cell fusion buffer than in 0.28 M mannitol (91.1% versus 48.4%, respectively, p<0.05). The cleavage and blastocyst formation rates of SCNT bovine embryos activated by $5\;{\mu}M$ $Ca^{2+}$-ionophore was significantly higher than the rates of the embryos activated with $10\;{\mu}M$ of $Ca^{2+}$-ionophore (70.0% versus 42.9% and 22.5% versus 14.3%, respectively; p<0.05). This result is the reverse to that of parthenotes which shows significantly higher cleavage and blastocyst rates in $10\;{\mu}M$ $Ca^{2+}$-ionophore than $5\;{\mu}M$ counterpart (65.6% versus 40.3% and 19.5% versus 9.7%, respectively; p<0.05). In conclusion, SCNT couplet fusion by single pulse of 26 V/mm for $25\;{\mu}s$ in Zimmermann's fusion buffer followed by artificial activation with $5\;{\mu}M$ $Ca^{2+}$-ionophore are suggested as optimal fusion and activation methods in Korean cattle SCNT protocol.

• The Korean Journal of Pain
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• 제12권2호
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• pp.177-182
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• 1999

Background: Clonidine, an ${\alpha}_2$ adrenergic agonist blocks nerve conduction. However, in our previous experiment we found that adrenaline neither blocks nerve conduction by itself nor augment nerve conduction blockade by lidocaine near clinical concentrations. Possible explanations are: 1) there may be antagonism between some of adrenergic receptors, 2) clonidine may block nerve conduction via non-adrenergic mechanism. The purpose of this study is to obtain dose-response curves of several different forms of adrenergic receptor agonist to see the relative potencies of each adrenergic receptors to block nerve conduction. Methods: Recordings of compound action potentials of A-fiber components (A-CAPs) were obtained from isolated sciatic nerves of adult male Sprague-Dawley rats. Nerve sheath of the sciatic nerve was removed and desheathed nerve bundle was mounted on a recording chamber. Single pulse stimuli (0.5 msec, supramaximal stimuli) were repeatedly applied (2Hz) to one end of the nerve and recordings of A-CAPs were made on the other end of the nerve. Dose-response curves of epinephrine, phenylephrine, isoproterenol, clonidine were obtained. Results: $ED_{50}$ of each adrenergic agonist was: $4.51\times10^{-2}$ M for epinephrine; phenylephrine, $7.74\times10^{-2}$ M; isoproterenol, $9.61\times10^{-2}$ M; clonidine, $1.57\times10^{-3}$ M. Conclusion: This study showed that only clonidine, ${\alpha}_2$ adrenergic agonist, showed some nerve blocking action while other adrenergic agonists showed similar poor degree of nerve blockade. This data suggest that non-effectiveness of epinephrine in blocking nerve conduction is not from the antagonism between adrenergic receptors.

• 한국통신학회논문지
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• 제24권6B호
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• pp.1134-1141
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• 1999

본 논문에서는 광 코드분할 다중접속(optical code division multiple access)시스템을 구현하고 그 구현된 시스템의 성능을 분석한다. 구현된 OCDMA 시스템에서 송신단은 레이저 다이오드를 이용하여 데이터를 광 펄스로 변환하며, 4단의 지연단으로 구성한 인코더를 이용하여 펄스 열로 확산한다. 수신단에서는 인코더의 지연선 구조와 동일한 구조의 디코더에서 펄스를 지연시킨 후 결합하여 수신된 신호를 복원한다. 성능분석에 있어서는, 먼저 단일 사용자 및 다중 사용자 환경 하에서 광 CDMA 신호의 auto-correlation과 cross-correlation을 분석하고, 실험을 통해 시뮬레이션 결과를 검증하였다. 또한 광섬유 지연선의 단 수 및 코드 길이 등 시스템의 성능에 영향을 미치는 파라메타를 컴퓨터 시뮬레이션을 통해 분석하였다. 실험 결과는 인코더와 디코더의 지연선 구조가 동일한 경우 펄스 열의 중앙에서 피크값의 펄스가 발생하는 auto-correlation 특성에 의해 데이터를 복원할 수 있었고, 지연선 구조가 동일하지 않은 경우 cross-correlation 특성에 의해 데이터를 복원할 수 없었다. 성능 분석 결과는 코드 길이가 감소하거나, 지연단위의 단 수를 증 $]$쳔갭\ulcorner비트 에러 확률이 감소하지만 요구되는 레이저 광원의 펄스폭이 점차로 감소하므로 시스템 구현이 어렵게 된다. 이러한 실험 및 분석 결과를 이용하면 CDMA 기술을 광 통신 네트워크로 적용할 수 있다.

• Investigative Magnetic Resonance Imaging
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• 제1권1호
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• pp.142-147
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• 1997

목적: 호흡정지 간 자기공영상에서 국소 간 병변을 발견함에 있어 동위상(inphase) 방식과 역위상(opposed-phase) 방식의 fast multiplanar spoiled gradient recalled(FMPSPGR) 영상간의 효율성을 비교하고자 하였다. 대상 및 방법: 다른 검사를 통해 국소 간 병변이 발견되었거나 의심되었던 45명의 환자의 78개의 병변에 대한 고속경사에코대열의 동위상과 역위상 영상을 비교하였다. 병변 발견률을 평가하기 위해 세 명의 사전 정보 없는 판독의가 독립적으로 영상을 검토하였다. 간의 신호대잡음비, 병변과 간의 대조대잡음비 및 간과 비장 간 대조대잡음비를 비교하였다. 세 명의 동의에 의해 어느 대열에서 영상의 질이 더 나은지 결정하였다. 결과: 역위상 영상에서 판독의 1, 2, 3이 각각 61(78%), 61(78%), 및 63(89%)개의 병변을 정확히 발견하였다. 동위상 영상에서 각 판독의가 66(85%), 65(83%) 및 65(93%)개의 병변을 발견하였다. 두 영상을 조합하였을 때, 71(91%), 69(88%) 및 76(97%)개의 병변이 각각 발견되었다. 간세포암이 증례에서 간-병변간 대조대잡음비는 역위상 영상에서 더 컸으나(p<0.05), 다른 병변에서의 의미 있는 차이는 보이지 않았다. 간-비장간 대조잡음비는 역위상 영상에서 높았으나(p<0.1), 간의 신호대잡음비는 동위상 영상에서 더 높았다. 결론: 국소적 간 병변을 놓치지 않고 발견 하기 위새서는 동위상 영상과 역위상 영상을 모두 이용하는 것이 바람직하다.