• 제목/요약/키워드: Columbia

검색결과 666건 처리시간 0.027초

Staurosporine Induced Apoptosis Rapidly Downregulates TDP-43 in Glioma Cells

  • Nan, Yi-Nan;Zhu, Jing-Yan;Tan, Yan;Zhang, Qi;Jia, William;Hua, Qian
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3575-3579
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    • 2014
  • TDP-43 is a ubiquitously expressed DNA/RNA binding protein that has recently attracted attention for its involvement in neurodegenerative diseases. While TDP-43 has been found to participate in various important cellular activities including stress and apoptosis, little is known about its role in cancer cells. Here we report that staurosporine (STS) induced apoptosis in U87 glioma cells is associated with rapid downregulation of TDP-43 at both mRNA and protein levels. The latter is dependent on activation of caspase 3. More importantly, we have shown that knockdown of TDP-43 by specific siRNA dramatically enhanced cytotoxicity of STS. These results suggest that normal level of TDP-43 may be protective for cancer cells under apoptotic insult.

웨스턴 레드시더 큰 정각재(正角材)의 고주파 진공 건조 특성 (Drying Characteristics of Large Western Redcedar Timber During Radio Frequency/Vacuum Drying)

  • 정희석;스티브로스 아브라미디스;리핑 카이
    • Journal of the Korean Wood Science and Technology
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    • 제26권3호
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    • pp.1-8
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    • 1998
  • Western redcedar timber, 26 by 26cm in cross section and by 200cm long, was dried in a laboratory radio-frequency/vacuum kiln under 65torr of ambient pressure and a fixed frequency of 6.78MHz for the potential rapidly dry large timber. All process data were collected and saved in a computer through a data acquisition system. The temperature in the middle of timber was higher than temperature at the quarter point of timber length and thickness. Temperature gradients developed in the longitudinal and transverse direction of timber. The pressure in the middle of timber was higher than pressure at the quarter point of timber length. The pressure in the middle of timber was lower in the early stage of drying, and higher in the latter stage of drying than pressure at the quarter point of timber thickness. Power density was very highest during heating period and then gradually decreased. The drying curve was approximately linear and the total drying time was 27 hours from an initial moisture content(MC) of 48.6 percent to a final Me of 19.2 percent with only a few mild internal checks in the middle location of timber.

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Growth of Nanocrystalline Graphite on Sapphire by Solid Carbon Source Molecular Beam Epitaxy

  • Jerng, S.K.;Yu, D.S.;Kim, Y.S.;Ryou, Jung-A;Hong, Suk-Lyun;Kim, C.;Yoon, S.;Efetov, D.K.;Kim, P.;Chun, S.H.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.51-51
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    • 2011
  • We have grown nanocrystalline graphite on sapphire substrate by using solid carbon source molecular beam epitaxy. Changes of structure from amorphous carbon to nanocrystalline graphite controlled by the growth temperature have been investigated by Raman spectroscopy. Raman spectra show D, G, and 2D peaks, whose intensities vary on the growth temperature. Atomic force microscopy reveals that the surface is very flat. Sapphire substrates of different cutting direction produce similar results. Simulations suggest that the interaction between carbon and oxygen causes disorders. Electrical transport measurements exhibit a Dirac-like peak, including a carrier type change by an external gate voltage bias.

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Shrimp (Pandalopsis dispar) waste hydrolysate as a source of novel β-secretase inhibitors

  • Li-Chan, Eunice C.Y.;Cheung, Imelda W.Y.;Byun, Hee-Guk
    • Fisheries and Aquatic Sciences
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    • 제19권2호
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    • pp.11.1-11.7
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    • 2016
  • In this study, purified peptides from shrimp waste hydrolysates (SWHs) were examined for their inhibitory effects against ${\beta}$-secretase. During consecutive purification using a Sephadex G-25 column chromatography and high performance liquid chromatography on a C18 column, a potent ${\beta}$-secretase inhibitory peptide Asp-Val-Leu-Phe-His (629 Da) was isolated and identified from SWH24 by Q-TOF MS/MS and the $IC_{50}$ value was determined to be $92.70{\mu}M$. The ${\beta}$-secretase inhibition patterns of the purified peptides were found to be competitive. Among synthesized ${\beta}$-secretase inhibitory peptides, Leu-Phe-His had higher ${\beta}$-secretase inhibitory activity than the others. The result of this study suggests that the ${\beta}$-secretase inhibitory peptide derived from SWH24 could be potential candidates to develop nutraceuticals and pharmaceuticals.

An Investigation on Models of Making-hypothesis Process by Analysis of Formulating Hypotheses on Repetition Hypothesis Activities in Middle School Students

  • Kim, Young-Shin;Germann, Paul J.
    • 한국과학교육학회지
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    • 제24권4호
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    • pp.731-747
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    • 2004
  • The scientific inquiry enterprise consists of formulating hypotheses, testing hypotheses, evaluating evidence, and revising hypothesis. Scientific inquiry in the science classrooms requires students' background experience and knowledge with the phenomenon in order to ask appropriate questions, identify and define variables operationally, formulate hypotheses, and design clear and complete experiment. The ability to test hypotheses has been postulated to play a central role in cognitive processes. The purpose of this study was to analyze what the change of the quantity and quality of the hypothesis, the rejecting or accepting of the hypothesis, and the use results in the repetitional hypothesis activity experiments. To examine the problems, this study analyzed 5 classes which were designed and administered to 16 students of the 7th grade. The results of this study showed that students preferred the engineering method to scientific method and the quality of a second hypothesis got low. The quality of the hypothesis came to be higher through a repetitional hypothesis and the number of hypothesis was reduced. The results of the experiments did not play central roles in revising hypotheses and accepting or rejecting hypothesis.

Numerical simulation on structural behavior of UHPFRC beams with steel and GFRP bars

  • Yoo, Doo-Yeol;Banthia, Nemkumar
    • Computers and Concrete
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    • 제16권5호
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    • pp.759-774
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    • 2015
  • This study simulates the flexural behavior of ultra-high-performance fiber-reinforced concrete (UHPFRC) beams reinforced with steel and glass fiber-reinforced polymer (GFRP) rebars. For this, micromechanics-based modeling was first carried out on the basis of single fiber pullout models considering inclination angle. Two different tension-softening curves (TSCs) with the assumptions of 2-dimensional (2-D) and 3-dimensional (3-D) random fiber orientations were obtained from the micromechanics-based modeling, and linear elastic compressive and tensile models before the occurrence of cracks were obtained from the mechanical tests and rule of mixture. Finite element analysis incorporating smeared crack model was used due to the multiple cracking behaviors of structural UHPFRC beams, and the characteristic length of two times the element width (or two times the average crack spacing at the peak load) was suggested as a result of parametric study. Analytical results showed that the assumption of 2-D random fiber orientation is appropriate to a non-reinforced UHPFRC beam, whereas the assumption of 3-D random fiber orientation is suitable for UHPFRC beams reinforced with steel and GFRP rebars due to disorder of fiber alignment from the internal reinforcements. The micromechanics-based finite element analysis also well predicted the serviceability deflections of UHPFRC beams with GFRP rebars and hybrid reinforcements.

The first record of Rhabdocoela, Alcha sinensis, Wang & Hu, 2019 (Platyhelminthes: Polycystididae) from Korea

  • Kim, Kimi;Van Steenkiste, Niels W.L.;Leander, Brian S.;Jung, Jongwoo
    • Journal of Species Research
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    • 제9권3호
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    • pp.269-272
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    • 2020
  • In this study, a species of Rhabdocoela is reported from Korea for the first time. The kalyptorhynch Alcha sinensis Wang & Hu, 2019, was collected from the intertidal zone of Anmyeon Island. Compared to the original study on A. sinensis and previous studies on A. evelinae, we provide additional detail of these two species through pictures of the stylet and a improved description of the prostate stylet type III, which is composed of a bowtie-shaped base and two pairs of heteromorphic plates with fringed or serrated edges. Two plates are also provided with a rounded "blade". Also, we discuss the importance of the prostate stylet type III as a diagnostic character. After a thorough comparison of the descriptions of A. evelinae Marcus, 1949, and A. sinensis, we conclude that the Korean specimens belong to the latter species. Finally, we discuss the difficulties of interpreting diagnostic characters of the small and complex prostate stylet type III within the genus Alcha.

유니버설 디자인 관점에서 본 미국노인들의 주거실태 및 요구 - 미조리주 콜럼비아 재가노인들을 대상으로 - (The Survey on Residential Conditions and the Needs based on Universal Interior Design Features of the Elderly in U.S.A. - Focused on the Elderly Who Want to Age in Place in Columbia Missouri -)

  • 박정아
    • 한국생활과학회지
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    • 제19권6호
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    • pp.1127-1137
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    • 2010
  • This study explored ways of changing a detached house which has older residents to a universal design home. This study investigated the residential conditions based on the universal design features and the need of universal design for aging in place. For this study, 153 residents who were living in single detached houses in Columbia, MO, were surveyed using written questionnaires and interviews. Primary findings of residential conditions were showed according to each spaces such as entrance, interior hallway, master bedroom, bathroom and kitchen. The major results are as follows: 1)It was confirmed that major spaces for daily living such as a bedroom, bathroom, kitchen and laundry facilities needed to be on the ground floor. 2)The most dangerous spaces in house were stairs to the upper or lower floors and the bathroom, 3)The need for modification based on universal design were high in order to facilitate aging in place. 4) Finally, elderly people in their seventies had especially strong needs through modification compared to the elderly people in their sixties who had plans to relocate.

Cutter-workpiece engagement determination for general milling using triangle mesh modeling

  • Gong, Xun;Feng, Hsi-Yung
    • Journal of Computational Design and Engineering
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    • 제3권2호
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    • pp.151-160
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    • 2016
  • Cutter-workpiece engagement (CWE) is the instantaneous contact geometry between the cutter and the in-process workpiece during machining. It plays an important role in machining process simulation and directly affects the calculation of the predicted cutting forces and torques. The difficulty and challenge of CWE determination come from the complexity due to the changing geometry of in-process workpiece and the curved tool path of cutter movement, especially for multi-axis milling. This paper presents a new method to determine the CWE for general milling processes. To fulfill the requirement of generality, which means for any cutter type, any in-process workpiece shape, and any tool path even with self-intersections, all the associated geometries are to be modeled as triangle meshes. The involved triangle-to-triangle intersection calculations are carried out by an effective method in order to realize the multiple subtraction Boolean operations between the tool and the workpiece mesh models and to determine the CWE. The presented method has been validated by a series of case studies of increasing machining complexity to demonstrate its applicability to general milling processes.

Principal Component and Multiple Regression Analysis for Steel Fiber Reinforced Concrete (SFRC) Beams

  • Islam, Mohammad S.;Alam, Shahria
    • International Journal of Concrete Structures and Materials
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    • 제7권4호
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    • pp.303-317
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    • 2013
  • This study evaluates the shear strength of steel fiber reinforced concrete (SFRC) beams from a database, which consists of extensive experimental results of 222 SFRC beams having no stirrups. In order to predict the analytical shear strength of the SFRC beams more precisely, the selected beams were sorted into six different groups based on their ultimate concrete strength (low strength with $f_c^{\prime}$ <50 MPa and high strength with $f_c^{\prime}$ <50 MPa), span-depth ratio (shallow beam with $a/d{\geq}2.5 $and deep beam with a/d<2.5) and steel fiber shape (plain, crimped and hooked). Principal component and multiple regression analyses were performed to determine the most feasible model in predicting the shear strength of SFRC beams. A variety of statistical analyses were conducted, and compared with those of the existing equations in estimating the shear strength of SFRC beams. The results showed that the recommended empirical equations were best suited to assess the shear strength of SFRC beams more accurately as compared to those obtained by the previously developed models.