• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.85-85
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• 2010

Graphene, the building block of graphite, is one of the most promising materials due to their fascinating electronic transport properties. The pseudo-two-dimensional sp2 bonding in graphene layers yields one of the most effective solid lubricants. In this poster, we present the correlation between electrical and nanomechanical properties of graphene layer grown on Cu/Ni substrate with CVD (Chemical Vapor Deposition) method. The electrical (current and conductance) and nanomechanical (adhesion and friction) properties have been investigated by the combined apparatus of friction force microscopy/conductive probe atomic force microscopy (AFM). The experiment was carried out in a RHK AFM operating in ultrahigh vacuum using cantilevers with a conductive TiN coating. The current was measured as a function of the applied load between the AFM tip and the graphene layer. The contact area has been obtained with the continuum mechanical models. We will discuss the influence of mechanical deformation on the electrical transport mechanism on graphene layers.

• 대한정형외과 초음파학회지
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• 제7권1호
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• pp.28-32
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• 2014

목적: 슬관절 이하 부위의 정형외과적 수술을 위해 좌골 신경 차단 술기가 흔히 시행되고 있다. 좌골 신경 분지는 해부학적 차이가 있어 통상적인 신경 차단은 불완전한 신경 차단을 유발한다. 본 연구는 마취의 성공율을 개선하기 위하여 한국 여성에서 좌골 신경 분지 위치를 초음파를 이용해 확인하였다. 대상 및 방법: 한국 여성 33명을 대상으로 하였으며 체중, 키를 측정하였다. 초음파 측정을 위해 M-Turbo ultrasound system (SonoSite,Bothell, WA,USA) 13-6 MHz, 38 mm high frequency linear array transducer를 사용하였다. 복와위 자세에서 슬와 주름부터 분지부까지의 거리, 분지부에서 피부부터 신경까지의 깊이를 cm 단위로 측정하여 체중과 키와의 상관관계를 확인하였다. 측정은 한 명의 전문의에 의해 측정되었다. 통계는 SAS version 9.3를 사용하여 multiple linear regression 방법으로 분석하였다. 결과: 33명 여성의 평균 나이는 53세(34~71세), 평균 체중 59.7(50~77.1 kg), 평균 키 157.4(145~173.9 cm), 평균 BMI 24.1(18.4-28.9)였다. 슬와 주름에서 좌골 신경 분지부까지의 평균 거리는 5.7(4.5~7.5 cm)이였으며, 분지부에서 피부부터 신경까지의 평균 깊이는 2.4(1.8~3.2 cm)였으며, 통계적 분석 결과에서 거리와 키 조사 p-value 0.55, 거리와 몸무게 조사 p-value 0.34, 깊이와 키 조사 p-value 0.5, 깊이와 몸무게 조사 p-value 0.036 이였다. 결론: 한국 여성의 좌골 신경 분지 위치는 차이가 있었으며, 특히 몸무게에 따른 깊이 변화는 의미가 있었다. 한국 여성에서 좌골 신경 차단 술기를 시행할 때 평균 거리, 깊이를 생각하고 몸무게를 고려한다면 성공율이 증가할 것으로 생각되며, 슬와 주름 7.5 cm 상방에서 시행할 것을 추천하다.

• 식물조직배양학회지
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• 제25권5호
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• pp.341-346
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• 1998

색소유전자의 전이를 통하여 새로운 색소발현체계를 가진 품종을 육종하기 위한 기초연구로 stock (Matthiola incana R. Br.)의 꽃봉오리로부터 cDNA-library를 합성하였고 screening을 통하여 anthocyanin 합성경로의 중요효소의 하나인 DFR (dihydroflavonol 4-reductase) 유전자를 분리하였다. 염기서열분석을 수행하여 분리유전자의 크기가 1450bp 이며 이중 coding region은 1029 bp 임을 확인하였다. 이미 밝혀진 다른 식물체의 DFR 유전자와 서로 염기서열의 일치성을 비교해 본 결과 외자엽식물인 옥수수와 보리와는 각각 61%를 보였으며, 쌍자엽식물인 페튜니아, 금어초, 거베라, 과꽃 그리고 카네이션 등 과는 66%-67%의 일치성을 나타내었다. 아울러 염기서열의 G/C 함량분석을 통하여 쌍자엽식물의 G/C 함량은 외자엽식물의 그것에 비해 매우 낮은 수치를 나타내었다. 분리유전자의 발현을 확인하기 위하여 인위적으로 기내에서의 전사와 해석을 수행한 결과 42-44 kd 크기의 단백질을 확인하였다. Southern blot 분석의 결과 DFR 유전자는 stock의 genome에 다른 대부분의 식물체와 유사하게 한 개가 존재하며 야생종과 돌연변이종의 stock을 분리 DFR 유전자를 probe 로 Northern blot 분석을 수행하여 돌연변이종인 lineK17b가 DFR 돌연변이임을 확인하였다.

• Journal of Radiation Protection and Research
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• 제29권4호
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• pp.243-249
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• 2004

본 연구는 소핵분석과 염색체 1번 및 4번의 DNA probe를 이용한 FISH 기법을 병행하여 방사선에 의한 소핵과 이수성에 관여하는 각 염색체의 감수성을 평가하고자 하였다. 방사선 선량에 따라 소핵의 빈도는 증가하였으며 염색체 1번과 4번의 이수성도 대조군, 1 Gy 및 2 Gy 에서 각각 2000개의 BN세포 당 9개, 47개 및 71개로 유의하게 증가하였다. 염색체 1번의 이수성 빈도는 4번에 비해 높게 관찰되었다. 염색체 1번 및 4번을 포함하는 소핵도 방사선의 선량에 따라 증가하였으며, 소핵내 염색체 1번의 포함빈도가 4번보다 높게 관찰되었다. 또한 방사선에 의한 소핵 중 낮은 빈도의 염색체 signal를 포함하는 소핵이 관찰됨으로써 방사선에 의한 소핵은 대부분 절단에 의한 것임을 확인할 수 있었다. 따라서 본 연구 결과 방사선은 이수성을 유도하며 이에 염색체가 다르게 관여할 수 있음을 보여준다.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.73-73
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• 2002

Nuclear transfer (NT) techniques have advanced in the last years, and cloned animals have been produced by using somatic cells in several species including pig. However, it is difficult that the nuclear transfer porcine embryos development to blastocyst stage overcoming the cell block in vitro. Abnormal segregation of chromosomes in nuclear transferred embryos on genome activation stage bring about embryo degeneration, abnormal blastocyst, delayed and low embryo development. Thus, we are evaluated that the correlations of the frequency of embryo developmental rates and chromosome aberration in NT and In viかo fertilization (IVF) derived embryo. We are used for ear-skin-fibroblast cell in NT. If only karyotyping of embryonic cells are chromosomally abnormal, they may difficultly remain undetected. Then, we evaluate the chromosome aberrations, fluorescent in situ hybridization (FISH) with porcine chromosome 1 submetacentric specific DNA probe were excuted. In normal diploid cell nucleus, two hybridization signal was detected. In contrast, abnormal cell figured one or three over signals. The developmental rates of NT and IVF embryos were 55% vs 63%, 32% vs 33% and 13% vs 17% in 2 cell, 8 cell and blastocyst, respectively. When looking at the types of chromosome aberration, the detection of aneuploidy at Day 3 on the embryo culture. The percentage of chromosome aneuploidy of NT and IVF at 4-cell stage 40.0%, 31.3%, respectively. This result indicate that chromosomal abnormalities are associated with low developmental rate in porcine NT embryo. It is also suggest that abnormal porcine embryos produced by NT associated with lower implantation rate, increase abortion rate and production of abnormal fetuses.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.182-182
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• 1999

The chemisorption effect of CO on the Ni/Cu(001) surface was investigated using LEED(Low Energy Electron Diffraction) and EELS(Electron Energy Loss Spectrscopy0 under the UHV conditions. after mounting the Cu(001) single crystal in the UHV chamber (base pressure 1$\times$10-10Torr), a clean surface was obtained after a few cycles of repeated Ar+ ion sputtering and annealing at about 40$0^{\circ}C$. The epitaxial thin Ni films were formed on the Cu(001) by evaporation from 99.999% Ni block. The pseudomorphic growth and the orderness of the thin Ni films were monitored by c(2$^{\circ}C$2) LEED pattern. CO adlayers on Ni epitaxial thin films were prepared by dosing pure CO has through a leak valve. After CO adsorpton at room temperature, two pairs of peaks were observed by EELS, whose relative intensities are changed as the film thickness is varied and time is elapsed. These two pair of peaks are likely related to different bonding sites (-top and bridge sites) of C-Ni as well as C-O vibration. Experimental results and qualitative interpretation of the spectra wille be discussed. The possibility of using EELS in combination with probe species (CO) to investigate the nature of thin film growth is mentioned. We will report the experimental result of O2 dosage on Ni film and interaction of CO and O2.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권1호
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• pp.40-43
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• 2000

Pyrrolidinedithiocarbamate (PDTC) and N-Acetylcysteine (NAC) are metal and nonmetal-chelating antioxidant which can induce rat and human smooth muscle cell death. When the smooth muscle cells from mouse aorta (MASMC) that we successfully cultured recently was exposed to PDTC and NAC in a normal serum state, the cells were induced to death by these compounds. However, PDTC did not induce the cell death in a serum depleted medium. This data suggests that certain factors in the serum may mediate the cytotoxic effect of PDTC. The metal chelator, Ca-EDTA blocked PDTC-induced cell death, but Cu-, Fe-, and Zn-EDTA did not block the PDTC-induced cell death. This data indicated that copper, iron, and zinc in the serum may lead to the cytotoxic effect of PDTC. Investigation of the intracellular zinc level in PDTC-induced smooth muscle cell death using the zinc probe dye N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide shows that only the muscle-containing layers of the arteries have higher level of zinc. As expected, PDTC increased the intracellular fluorescence level of the zinc. In agreement with these results, the addition of an exogenous metal, zinc, induced the vascular aortic smooth muscle cell death which led to an increased intracellular zinc level. We concluded that PDTC induced mouse aortic smooth muscle cell death required not only zinc level but also intracellular copper and iron level. The mechanism of this antioxidant to induce vascular smooth muscle cell death may provide a new strategy to prevent their proliferation in arteriosclerotic lesions.

• 한국압력기기공학회 논문집
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• 제6권2호
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• pp.20-27
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• 2010

In order to prevent the corrosion of component contacted primary water designed alloy 600 material in the nuclear power plant. But the primary water stress corrosion cracking(PWSCC) of alloy 600 and weld area occurs continuously due to the residual stress. The leakage accident resulted from PWSCC in the drain nozzle of the steam generator of domestic power plants. Heater sleeves of the pressurizer are welded with alloy 600 weld material and therefore exposed to the primary water environment. PWSCC occurred in heater sleeve material and weld area of many foreign power plants. The current issue of domestic nuclear power plants are consequently concentrated to PWSCC of similar material. In order to improve the detection and the sizing of the PWSCC in the welding sleeve of the pressurizer, the automatic UT system and multi-directions probe sets have been developed. The experimental studies have been performed using the mock-up block containing artificial reflectors(ID connected EDM notch) and semi-artificial cracks made from thermal fatigue. The automatic UT System is applied in the detection and the length sizing of the ID/OD on the tube and the J-groove weld area of the artificial reflectors and results of the detection and the sizing are compared respectively. Also, the developed automatic UT system is successfully accomplished to inspect the heater sleeve and the J-groove weld area on the pressurizer for the detection of PWSCC.

• Clinical Pain
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• 제18권2호
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• pp.65-69
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• 2019

Objective: This study aims to evaluate the efficacy of high-voltage microcurrent therapy in patients with herniated lumbar disc (HLD) presenting radicular or back pain. Method: This is a retrospective study with 33 patients who are complaining pain with HLD findings on magnetic resonance image. Microcurrent therapy was applied to leg or paralumbar area. Treatment was conducted for seven minutes with 250~1000 uA intensity as high as the patients could tolerate via stimulating probe with roller type and the frequency was 60 Hz with a sine wave pulse. The visual analogue scale (VAS) was measured just before and after the treatment. Results: The degree of pain reduction (△VAS) was 1.6 points after treatment on average. The △VAS according to the diagnosis, stenosis, dermatome area, medication, pain site and caudal epidural block was not statistically significant. However, the △VAS according to the number of treatments (< 3, ≥ 3 times) showed a statistically significant difference (p=0.04). Conclusion: High-voltage microcurrent therapy may help reduce lumbar or lumbosacral radiating pain after the procedure. The effect was better when microcurrent was applied three times or more. This result suggests that the microcurrent would have cumulative effect on reducing radicular or back pain in patients with HLD.

• 생물정신의학
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• 제4권2호
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• pp.198-210
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• 1997

To examine the double-faced thymoleptic(antidepressant and antimanic) effects of risperidone in mood disorders, this article reviews the psychotropic-induced mania, thymoleptic effects of antipsychotics, therapeutic effects of risperidone and risperidone(RIS)-induced mania(RIM) in mood disorders, risk factors of RIM, possible neurochemical mechanism of these thymoleptic effects, pathophysiological and clinical significance of thymoleptic effects, and suggestive clinical guideline of RIS in mood disorders. RIS appeared effective for bipolar disorder at a lower dose than that recommended for schizophrenia, especially in the cases of maintenance of mood stabilizers, and gradual titration from low doses. Manic induction/exacerbation can occur by chance during RIS treatment in mood disorders, schizoaffective disorders, and schizophrenias. The possible risk factors for RIM are refractory mood disorder, especially in bipolar I disorder with poor initial response ; refractory schizoaffective disorders, especially in bipolar type with poor initial response ; refractory chronic schizophrenias, especially with initial responses ; psychotic features ; higher initial doses ; rapid titration ; combined therapy with antidepressants in refractory depression ; and RIS monotherapy in mania/hypomania. RIS is a drug that preferentially block 5-HT2 receptors. The effects of low dose are due mainly to the blockade of 5-HT2 receptors. There are more gradual increase in D2 blockade with increasing dose and this D2 blocking properties become apparent at higher doses. This may be related to a modulation of dopaminergic transmission by 5-HT2 antagonism at lower doses with the direct action of RIS on DA receptors coming into play at higher dose. The serotonergic antagonistic effect may be important for its effects on depressive symptoms. This, together with adequate blo-ckade of D2 receptors, may not necessarily lead to destabilization of mood disorder, but rather to more therapeutic effects. Therefore, this dose-receptor affinity relationship with both antidepressant and antimanic effects according to treatment duration can explain a continuum of antidepressant effect, antimanic effect, behavioral stimulation, and manic/hypomanic induction/exacerbation. It was the recognition of a useful psychiatric side effects by a thoughtful observer with fertile minds that led to their ultimate utilization as psychotropic drugs, i.e., phenothiazine, MAOI, TCA, and lithium. And, in vivo pharmacological challenge by novel psychotropics, as a neurochemical probe, with more specific actions is a useful tool to select pharmacologically homogeneous subgroup of the same phenotypical(clinical) condition, to further study the unknown underlying pathogenesis of various mental illnesses. Finally, RIS may be a useful alternative or adjunctive drug for patients with mood disorders without psychotic features or refractory to treatment with standard antipsychotic drugs. The more conservative doses(tirated slowly from 1-3 mg/d) of RIS, and maintenance of mood stabilizer in the cases with risk factors of RIM are recommended in mood disorder.