• 한국임상수의학회지
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• 제19권1호
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• pp.80-85
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• 2002

This study was performed to investigate the freezomg condition especially focused on extender composition to achieve good post-thaw viability and motility of canine sperm. Semen were collected from 6 male dogs which had been proved to be fertile in the past and were treated for freezing. Equex-STM paste was contained in both the 1st(3%) and the 2nd(7%) diluent and the 2nd diluent was added to the 1st diluent following glycerol equilibration for an hour and a half. To investigate the effect of Equex-STM paste in the extender on post-thaw canine sperm characteristics, the post-thaw viability, motility, and HOS(Hypoosmotic swelling) values were evaluated according to the different composition of extender with or without Equex-STM paste, thawing conditions, and different thawing media added to thawed semen. 1. Canine sperm removed from seminal plasma and frozen )n Sweden extender containing Equex showed higher post-thaw viability, motility, and HOS values than those frozen in the extender containing Equex-STM paste with seminal plasma and those frozen in the extender without Equex and seminal plasma. 2. Canine sperm frozen in Sweden extender containing Equex-STM paste with 5% glycerol showed higher post-thaw viability, motility, and HOS values than those frozen with 3%, 8% glycerol or 5% DMSO. 3. The canine semen frozen in Sweden extender with 5% glycerol and Equex-STM paste showed higher viability, motility, and HOS values when thawed at $70^{\circ}C$ for 8 seconds than when thawed at $37.5^{\circ}C$ for 1 min and at $18-20^{\circ}C$ for 5 min. 4. TFC (tris -fructose-citrate) and PB S (phosphate buffered saline) medium added immediately to thawed canine semen brought better viability, motility, and HOS values for the sperm than those semen added with TGC(tris-glucose-citrate) and no medium. These results indicated that Equex-STM paste in Sweden extender for freezing the canine sperm which were removed from seminal plasma brought good post-thaw viability and motility of canine sperm. Also of the freezing conditions of canine sperm with the same extender containing Equex, the concentration of 5% glycerol, the thawing condition at $70^{\circ}C$ for 8 sec, and TFC and PBS medium added to the thawed semen brought better post-thaw viability and motility of canine sperm than the other conditions used in this study.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1822-1828
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• 2004

Electrochemical, in situ electrochemical scanning tunneling microscope (EC-STM), and attenuated total reflectance-FTIR (ATR-FTIR) spectroscopic methods were employed to investigate the preparation of atomically flat Si(111)-H surface in ammonium fluoride solutions. Electrochemical properties of atomically flat Si(111)-H surface were characterized by anodic oxidation and cathodic hydrogen evolution with the open circuit potential (OCP) of ca. -0.4 V in concentrated ammonium fluoride solutions. As soon as the natural oxide-covered Si(111) electrode was immersed in fluoride solutions, OCP quickly shifted to near -1 V, which was more negative than the flat band potential of silicon surface, indicating that the surface silicon oxide had to be dissolved into the solution. OCP changed to become less negative as the oxide layer was being removed from the silicon surface. In situ EC-STM data showed that the surface was changed from the initial oxidecovered silicon to atomically rough hydrogen-terminated surface and then to atomically flat hydrogenterminated surface as the OCP moved toward less negative potentials. The atomically flat Si(111)-H structure was confirmed by in situ EC-STM and ATR-FTIR data. The dependence of atomically flat Si(111)-H terrace on mis-cut angle was investigated by STM, and the results agreed with those anticipated by calculation. Further, the stability of Si(111)-H was checked by STM in ambient laboratory conditions.

• 콘크리트학회논문집
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• 제13권2호
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• pp.130-138
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• 2001

본 논문은 변환각 트러스 모델(TATM)에 의한 철근콘크리트 보의 전단거동 예측에 관한 연구이다. TATM은 주응력면에 대한 응력과 변형률을 균열면에서의 응력과 변형률로 변환시킴으로써 콘크리트 균열면에 대한 응력-변형률 관계를 구한다. 제안된 해석 방법은 고정각 연화트러스 모델(FA-STM)을 간략화시켰으며 그 적용 한계 또한 제거하였다. 변환각 트러스 모델을 이용하여 철근콘크리트 보의 전단강도와 전단변형률을 예측하였다. 제안된 해석 방법의 검증을 위하여, TATM에 의한 해석결과는 총 40개 철근콘크리트 보의 전단 실험결과에 대하여 FA-STM과 RA-STM의 해석결과와 비교되었다. TATM에 의한 해석결과는 실험결과에 대하여 모멘트 효과를 고려하지 않은 상태에서 평균 0.80, 표준편차 0.105, 변동계수 0.132로 비교적 만족스러운 결과를 보였다.

• 생명과학회지
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• 제18권11호
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• pp.1507-1512
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• 2008

오랜 기간 동안의 연구에도 불구하고 사람에 특이적으로 장티푸스를 유발하는 S. typhi는 실험동물을 대상으로 하는 감염모델이 확립되어 있지 않기 때문에 S. typhi의 병원성 유발기작에 관한 정보는 부족하다. S. typhi Ty2 균주는 최소배지에서 시스테인의 영양요구성을 지닌다. 본 연구에서는 시스테인 영양요구성이, S. typhi Ty2 균주가 실험동물에서 균체형성을 하는데 어떤 영향을 미치는지를 조사하기 위해 시스테인 영양요구성을 상보할 수 있는 유전자를 찾고자 하였다. S. typhimurium의 genomic library로 형질전환된 S. typhi 균들 중 시스테인을 함유하지 않은 최소배지에서 생육을 하는 3개의 형질전환 균주를 선별하였으며, 이들 중 2개는 S. typhi의 시스테인 영양요구성을 아주 약하게 상보하였고 하나는 명확하게 시스테인의 영양요구성을 상보하였다. 이 클론에 포함되어져 있는 3개의 ORF의 시스테인 영양요구성을 분석한 결과, STM1490을 가진 클론이 S. typhi의 시스테인 영양요구성을 상보하였다. 비록 S. typhi에도 STM1490에 해당하는 유전자가 존재하지만 S. typhimurium의 STM1490에 해당하는 ORF와 비교하였을 때 2개의 아미노산 잔기가 서로 달랐다. 이들의 차이가 시스테인 영양요구성을 보이는 것은 아닌지 확인하기 위해 Overlapping PCR을 통해 S. typhimurium의 STM1490 아미노산(H229Y, C246W)을 치환하였다. 아미노산을 바꾼 돌연변이체도 역시 시스테인 영양요구성을 상보할 수 있어서 아미노산의 차이는 아닌 것을 확인되었으므로 그 외의 다른 인자들이 영양요구성에 관여하는 것으로 추정되었고 후속연구에서 그인자를 찾을 수 있을 것으로 생각된다.

• 한국진공학회지
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• 제15권2호
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• pp.139-144
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• 2006

Scanning tunneling microscopy (STM)를 이용하여 Si(111)$4{\times}1$-In 표면에의 수소원자 흡착의 영향을 고찰하였다. STM 이미지에서 수소원자는 $4{\times}1$-In chain의 한 쪽 줄에 있는 두개의 연속된 밝은 부분 사이에 위치한다. 이 H 원자는 두 줄의 zigzag subchain 중의 한 쪽에만 선택적으로 흡착되는 경향성을 보이며 이는 수소원자의 흡착에 표면 밑의 구조가 영향을 미침을 시사한다. 표면에 흡착된 수소원자는 흡착위치 주위의 국소적 변형 뿐 만 아니라 chain 방향으로 멀리 떨어진 곳에도 영향을 미쳐서 STM 이미지에 두 배 주기의 modulation이 나타나게 한다. 수소흡착에 의해 유도되는 두 배 주기의 modulation은 기존에 보고된 Na 원자 흡착에 의해 유도되는 상과 다름을 확인하였다.

• 대한정형도수물리치료학회지
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• 제26권1호
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• pp.37-46
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• 2020

Background: The present study aimed to investigate the immediate effects of Soft Tissue Mobilization (STM) before Mobilization with Movement (MWM) on ankle ROM, pennation angle, balance in stroke patients. Methods: A total of 22 subjects were randomly assigned to one of two groups: the experimental group and the control group. The experimental group received intervention STM before MWM. STM was applied for one minute, MWM was applied one set of six times, in a total 3 sets. The passive ankle joint range of motion (ROM) was measured using a goniometer, the pennation angle was measured using RUSI, and the balance was measured using Timed Up & Go Test. Results: The ROM of the ankle dorsi-flexion, muscle tissue (pennation angle) and balance were significantly increased. Conclusion: In this study, it was confirmed that the ankle dorsi-flexion ROM, pennation angle of the medial gastrocnemius muscle, and balance were significantly improved in the group where STM was performed before the MWM intervention. Therefore, the physiotherapists should consider these results in their intervention. If MWM is applied to stroke patients, applying STM first is a better intervention.

• 한국전기전자재료학회논문지
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• 제18권7호
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• pp.622-627
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• 2005

In this study, electrical properties of self-assembled dipyridinium dithioacetate molecule onto the Au(111) substrate is observed using Scanning Tunneling Microscopy(STM) by vortical structure of STM probe. At first, the Au(111) substrate is cleaned by piranha solution$(H_2SO_4:H_2O_2\;=\;3:1)$. Subsequently, 1 mM/ml of dipyridinium dithioacetate molecule is self-assembled onto the Au(111) surface. Using STM, the images of dipyridinium dithioacetate molecule which is self-assembled onto the Au(111) substrate, can be observed. In addition, the electrical properties(I-V) of dipyridinium dithioacetate can also be examined by using Scanning Tunneling Spectroscopy(STS). From the results of the measurement of the current-voltage(I-V), the property of Negative Differential Resistance(NDR) that shows the decreases of current according to the increases of voltage is observed. We found the NDR voltage of the dipyridinium dithioacetate is -1.42 V(negative region) and 1.30 V(positive region), respectively.

• 한국구조물진단유지관리공학회 논문집
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• 제4권2호
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• pp.113-129
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• 2000

This study evaluates the behavior and strength of an anchorage zone of the prestressed concrete box girder bridge on the Kyungboo highway railroad using the 2D SUB-3D STM approach and a linear elastic finite element analysis. The 2D SUB-3D STM approach utilizes several two-dimensional sub strut-tie models that represent the compressive and tensile stress flows of each projected plane of the three-dimensional structural concrete in the selection of a three dimensional strut-tie model, evaluation of the effective strengths of the concrete struts, and verification of the geometric compatibility condition and bearing capacity of the critical nodal zones in the selected three-dimensional strut-tie model. The finite element analysis uses an 8-node brick element and the longitudinal prestressing force is considered as the equivalent nodal force. Analysis results show that the 2D SUB-3D STM approach and linear elastic finite element method can be effectively applied to the analysis and design of three-dimensional structural concrete including a prestressed concrete box girder anchorage zone.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.595-600
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• 2000

The shear strength and strain of reinforced concrete beams are predicted by using the Transformated-Angle Truss-Model. This proposed analytical method simplified the fixed-angle softened-truss model (FA-STM) and removed the limitation of applicability of the FA-STM. The results of the proposed method for reinforced concrete beams were compared to those of the FA-STM.

• 한국진공학회지
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• 제3권4호
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• pp.377-381
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• 1994

초고진공(UHV) Scanning Tummeling Microscopy(STM)을 제작하였다. 8인치 프란지에 부착한 STM은 초고진공에서 시료의 통전가열이 가능하며 다른 표면 측정방법의 적용과시료처리가 용이하다. 외부로부터 초고진공을 깨지 않고 시료와 tip의 도입이 가능하며 tip을 가열할 수 있다. 완성된 장치로 Si(111)-7$\times$7 구조의 STM상을 얻었다.