• Title/Summary/Keyword: Molecular size

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Radiolabeled single-domain antibody for tumor receptor imaging

  • Moon, Yeajin;Lee, Ju Young;Ryoo, Woonseok;Seo, Seung-Yong
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.6 no.1
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    • pp.39-45
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    • 2020
  • Recently, single-domain antibodies (sdAb) are bioengineered for molecular imaging applications. Single-domain antibody, obtained from naturally occurring antibodies in camelid species and cartilaginous fish is the smallest fully functional antigen-binding antibody fragments of heavy-chain. Since their discovery, they have been investigated extensively in clinical therapeutics, monitoring and diagnostics. Their small size is important advantage for high solubility, high stability, fast blood clearance and rapid targeting. This review article summarizes the recent status of this new antibody to visualize, diagnose or inhibit specific targets of cancer.

Effects of Dietary Fructan on Cecal Enzyme Activities in Rats

  • Kang, Soon-Ah;Chun, Uck-Han;Jang, Ki-Hyo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.6
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    • pp.582-586
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    • 2005
  • In this Study, we have attempted to determine the effects of dietary fructose polymers (fructan), high molecular-weight ${\beta}-(2,6)-linked$ levan, and low-molecular-weight ${\beta}-(2,1)-linked$ inulin, on two intestinal enzymes $({\beta}-glucuronidase\;and\;{\beta}-glucosidase)$. As a preliminary experiment, when intestinal microflora were cultured in anaerobic media harboring levan or its oligosaccharides, bacterial cell growth was observed in the levanoligosaccharide-supplemented media, but not in the levan-supplemented media, indicating that levan's size is important for the utilization by intestinal bacteria of levan as an energy Source. In our animal study, the intake of a levan-rich diet was determined to significantly attenuate the activity of the harmful enzyme $({\beta}-glucuronidase$, but d id not affect the activity of ${\beta}-glucosidase$.

Multiscale simulation based on kriging based finite element method

  • Sommanawat, Wichain;Kanok-Nukulchai, Worsak
    • Interaction and multiscale mechanics
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    • v.2 no.4
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    • pp.353-374
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    • 2009
  • A new seamless multiscale simulation was developed for coupling the continuum model with its molecular dynamics. Kriging-based Finite Element Method (K-FEM) is employed to model the continuum base of the entire domain, while the molecular dynamics (MD) is confined in a localized domain of interest. In the coupling zone, where the MD domain overlaps the continuum model, the overall Hamiltonian is postulated by contributions from the continuum and the molecular overlays, based on a quartic spline scaling parameter. The displacement compatibility in this coupling zone is then enforced by the Lagrange multiplier technique. A multiple-time-step velocity Verlet algorithm is adopted for its time integration. The validation of the present method is reported through numerical tests of one dimensional atomic lattice. The results reveal that at the continuum/MD interface, the commonly reported spurious waves in the literature are effectively eliminated in this study. In addition, the smoothness of the transition from MD to the continuum can be significantly improved by either increasing the size of the coupling zone or expanding the nodal domain of influence associated with K-FEM.

Dynamic Motion of Polyelectrolyte in a Composite Membrane: II. Molecular Study (막에서 전하고분자의 동적 현상 II. 미시적 연구)

  • Park, Young;Lim, Hwa A.
    • Membrane Journal
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    • v.4 no.2
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    • pp.96-105
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    • 1994
  • Theoretical model for membrane transport of large polye!ectroiyte is presented. When the electric field is applied, the molecular conformation quickly orients in the field direction showing overshooting orientation. the predicted dependence of overshoot time and orientation upon field intensity and molecular size aids to understand the dynamic motion of molecules in membrane transport. The dynamics of the overshoot is associated with self-trapping conformations of molecule. The understanding of these effects supports evidences for the electrophoretic filtration of polydectrolyte in the polymeric membrane. This paper shows one example for molecular study in the theoretical review paper of membrane transport.

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A Method for Determining Molecular Weights of Block Copolymers by Gel Permeation Chromatography

  • Sohn, Jeong-In;Ree, Tai-Kyue
    • Bulletin of the Korean Chemical Society
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    • v.5 no.4
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    • pp.140-145
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    • 1984
  • A theory is given for determining the molecular weights of block copolymers from the experimental elution volume in GPC. Interaction effect between a sample of block copolymer and a column packing material as well as the size effect are separately considered for the first time applying the partial exclusion mechanism proposed by Dawkins. The molecular weight determination shows 6${\%}$ standard-deviation from the molecular weights measured by an osmometric method for eight block copolymers, which is much more improved result than other methods, e.g., the universal plot method (13 ${\%}$) and the Runyon's method (12 ${\%}$). The reason which explains the better result is that our theory takes into account the interaction effect correctly.

A Study on the Microcutting for Configuration of Tools using Molecular Dynamics (분자동역학을 이용한 공구형상에 따른 미소절삭현상에 관한 연구)

  • Moon, Chan-Hong;Kim, Jeong-Du
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.4
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    • pp.135-142
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    • 1995
  • Recently, the analysis of microcutting with submicrometer depth of cut is tried to get a more high quality surface product, but to get a valuable result another method instead of conventional finite element method must be considered because finite element method is impossible for a very small focused region and mesh size. As the alternative method, Molecular Dynamics or Statics is suggested and accepted in the field of microcutting, indentation and crack propagation. In this paper using Molecular Dynamics simulation, the phenomena of microcutting with subnanometer chip thickness is studied and the cutting mechanism for tool edge configuration is evaluated. As the result of simulation the atomistic chip formation is achieved.

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A Study on the Boundary Layer Thickness at a Liquid-Vapor Interface (기액계면의 경계층 두께에 관한 연구)

  • Choi, Soon-Ho;Song, Chi-Sung;Choi, Hyun-Kyu;Lee, Jung-Hye;Kim, Kyung-Kun
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1086-1091
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    • 2004
  • The boundary layer is a very important characteristic of a liquid-vapor interface since it governs the heat and mass transfer phenomena across an interface. However, the thickness of a boundary layer is generally micro- or nano-sized, which requires highly accurate measurement devices and, consequently, costs the related experiments very high and time-consuming. Due to these size dependent limitations, the experiments related with a nano-scaled size have suffered from the errors and the reliability of the obtained data. This study is performed to grasp the characteristics of a liquid-vapor interface, by using a molecular dynamics method. The simulation results were compared with other studies if possible. Although other studies reported that there existed a temperature discontinuity over an interface when the system was reduced to micro- or nano-sized, we confirmed that there was no such a temperature discontinuity.

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Continuum Model considering Surface Effect for Thin film (박막구조해석을 위한 표면효과를 고려하는 연속체 모델)

  • Choi, Jin-Bok;Jung, Kwang-Sub;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.527-531
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    • 2007
  • The classical continuum theory-based thin film model is independent of their size and the surface effect can be ignored. But the surface to bulk ratio becomes very large in nano-size structures such as nano film, nano wire and nano beam. In this case, surface effect plays an important role and its contribution of the surface effect must be considered. Molecular dynamics simulation has been a conventional way to analyze these ultra-thin structures but structures in the range between submicro and micro are difficult to analyze by classical molecular dynamics due to the restriction of computing resources and time. Therefore, in present study, the continuum-based method is considered to predict the overall physical and mechanical properties of the structures in nano-scale, especially, for the thin-film. The proposed continuum based-thin plate finite element is efficient and reliable for the prediction of nano-scale film behavior.

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Isolation and Characterization of Aquatic Humic Acid and Fulvic Acid (수질계의 Humic Acid와 Fulvic Acid의 분리 및 특성)

  • Rhee, Dong Seok
    • Analytical Science and Technology
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    • v.15 no.1
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    • pp.36-42
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    • 2002
  • The dissolved organic carbon extracted from groundwater is separated into humic acid and fulvic acid. They are characterized for their chemical composition, spectroscopic characteristics using UV/VIS, IR and solid state $^{13}C-NMR$ spectroscopy, proton exchange capacity and molecular size distribution. The results are comparable with the literature data. The study explains that the aquatic humic and fulvic acid in this experiment are site-specipic and polydisperse natural organic matter with considerable proton exchange capacity.

Numerical Study on the Sub-Voxel Tracking Using Micro-Beads in a 3.0 T MRI (3.0 T MRI 환경에서 마이크로비드를 이용한 서브복셀 추적에 관한 수치해석적 연구)

  • Han, Byung-Hee;Lee, Soo-Yeol
    • Journal of Biomedical Engineering Research
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    • v.28 no.1
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    • pp.102-107
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    • 2007
  • In molecular imaging studies via magnetic resonance imaging, in vivo cell tracking is an important issue for the observation of cell therapy or disease behavior. High resolution imaging and longitudinal study are necessary to track the cell movement. Since the field inhomogeneity extends over several voxels, we have performed the numerical analysis using the sub-voxel method dividing a voxel of MR image into several elements and the information about the field inhomogeneity distribution around the micro-beads. We imbedded ferrite-composite micro-beads with the size of $20-150{\mu}m$ in the subject substituted for cells to induce local field distortion. In the phantom imaging with the isotropic voxel size of $200{\mu}m^3$, we could confirm the feasibility of sub-voxel tracking in a 3.0 T MRI.