• Title/Summary/Keyword: Cross-reaction

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Recombinant Interferon-${\alpha}$ Cross-linked with Thymosin ${\alpha}$1 is Biologically Active

  • Jeong, Jee-Yeong;Chung, Hye-Shin
    • BMB Reports
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    • v.29 no.4
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    • pp.365-371
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    • 1996
  • Partially reduced interferon-a ($IFN-{\alpha}$) was cross-linked with thymosin ${\alpha}1$ ($T{\alpha}1$) using sulfo-succinimidyl (4-iodoacetyl) amino benzoate (SIAB), a bifunctional cross-linking reagent. The partially reduced $IFN-{\alpha}$ optimal for the cross-linking reaction was obtained by incubating native $IFN-{\alpha}$ with 0.5 mM DTT at $30^{\circ}C$ for 60~100 min. $T{\alpha}1$ was activated by incubating with sulfo-SIAB at $37^{\circ}C$ for 30 min to produce $T{\alpha}1-IAB$. The $T{\alpha}1-IFN-{\alpha}$ cross-linking was achieved by the reaction of the partially reduced $IFN-{\alpha}$ with $T{\alpha}1-IAB$. This cross-linking was between the sulfhydryl group of Cys1 in $IFN-{\alpha}$ and the N-terminal amino group of $T{\alpha}1$ through acetyl amino benzoate as a spacer. The immunological activity of the cross-linked molecule showed the same extent as that of $T{\alpha}1$, and most of the antiviral activity was retained compared to that of the partially reduced $IFN-{\alpha}$.

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Coriolis Coupling Influence on the H+LiH Reaction

  • Zhai, Hongsheng;Li, Wenliang;Liu, Yufang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.151-157
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    • 2014
  • We have reported the reaction probability, integral reaction cross section, and rate constant for the title system calculated with the aid of a time-dependent wave packet approach. The ab initio potential energy surface (PES) of Prudente et al. (Chem. Phys. Lett. 2009, 474, 18) is employed for the purpose. The calculations are carried out over the collision energy range of 0.05-1.4 eV for the two reaction channels of H + LiH ${\rightarrow}$ Li + $H_2$ and $H_b$ + $LiH_a$ ${\rightarrow}$ $LiH_b$ + $H_a$. The Coriolis coupling (CC) effect are taken into account. The importance of including the Coriolis coupling quantum scattering calculations are revealed by the comparison between the Coriolis coupling and the centrifugal sudden (CS) approximation calculations.

Studies on the Classification of Aspergillus spp. by Fluorence Antibody Reaction (형광항체반응(螢光抗體反應)에 의(依)한 Aspergillus spp.의 분류(分類)에 관(關)한 연구(硏究))

  • Moon, Hi-Joo;Kim, Sung-Kon;Lee, Bae-Ham
    • The Korean Journal of Mycology
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    • v.1 no.2
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    • pp.9-14
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    • 1973
  • Author investigated fluorence antibody reaction for the antigenic relationships between Asp niger group, Asp flavus and Asp parasiticus which was indicated as follows: 1. It was concluded that there are complete differences in the antigenic properties each other because it has not cross reaction, therefore identification of strains will be simpley classified. 2. A complete cross reaction between Asp flavus and Asp parasitic us in the Asp flavus groups existed, accordingly this reaction could not identified the strain and classified between Asp. flavus and Asp. parasiticus. 3. This experiment also followed with the separated each strains from the origin (Meju, Nuruk, ATCC, NRRL), but there no differences. From the above results, this method could be classified between Asp flavus group and Asp niger group in the genus Aspergillus, but classification of Asp. flavus and Asp. parasiticus should hardely conclude with this method.

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Preparation of Hyaluronic Acid Microspheres with Enhanced Physical Stability by Double Cross-link or Alginate (이중 가교제 또는 알긴산에 의해 물리적인 안정성이 향상된 히알루론산 마이크로입자의 제조)

  • Kim, Dong-Hwan;Song, Chung-Kil;Balakrishnan, Prabagar;Park, Chun-Geon;Choi, Ae-Jin;Chung, Suk-Jae;Shim, Chang-Koo;Kim, Dae-Duk
    • YAKHAK HOEJI
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    • v.55 no.1
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    • pp.69-74
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    • 2011
  • Hyaluronic acid (HA) is a natural polymer consisting of disaccharide units of D-glucuronic acid and N-acetyl-D-glucosamine. It has a great potential and success in cosmetic and biomedical applications. However, native HA is highly soluble and easily metabolized by enzymes such as hyaluronidase. Thus, various studies have been reported on modifying the physicochemical properties of HA, while maintaining its biocompatibility. For controlled drug delivery, many trials for fabricating HA microspheres were achieved under chemical reaction. The HA microspheres fabricated to improve the physical stability of HA using adipic acid dihydrazide (ADH) by cross-linking reaction has been reported earlier, however it lacks the desired physical stability and rapidly decomposes by swelling or enzymes. Therefore, we prepared double cross-linked HA microspheres (DC-HA microspheres) and alginate containing HA microspheres (AC-HA microspheres) to enhance its physicochemical properties. DC-HA microspheres were prepared using trisodium trimetaphosphate (STMP) under crosslinking reaction after ADH cross-linking reaction. AC-HA microspheres were prepared by adding alginate as a networking polymer. These microspheres were characterized by morphology, particle size, zeta potential, stability against hyaluronidase. Results showed that the DC-HA and AC-HA microspheres are more stable than that of HA microspheres.

Impact of molybdenum cross sections on FHR analysis

  • Ramey, Kyle M.;Margulis, Marat;Read, Nathaniel;Shwageraus, Eugene;Petrovic, Bojan
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.817-825
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    • 2022
  • A recent benchmarking effort, under the auspices of the Organization for Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA), has been made to evaluate the current state of modeling and simulation tools available to model fluoride salt-cooled high temperature reactors (FHRs). The FHR benchmarking effort considered in this work consists of several cases evaluating the neutronic parameters of a 2D prismatic FHR fuel assembly model using the participants' choice of simulation tools. Benchmark participants blindly submitted results for comparison with overall good agreement, except for some which significantly differed on cases utilizing a molybdenum-bearing control rod. Participants utilizing more recently updated explicit isotopic cross sections had consistent results, whereas those using elemental molybdenum cross sections observed reactivity differences on the order of thousands of pcm relative to their peers. Through a series of supporting tests, the authors attribute the differences as being nuclear data driven from using older legacy elemental molybdenum cross sections. Quantitative analysis is conducted on the control rod to identify spectral, reaction rate, and cross section phenomena responsible for the observed differences. Results confirm the observed differences are attributable to the use of elemental cross sections which overestimate the reaction rates in strong resonance channels.

Some Calculated (p,α) Cross-Sections Using the Alpha Particle Knock-On and Triton Pick-Up Reaction Mechanisms: An Optimisation of the Single-Step Feshbache-Kermane-Koonin (FKK) Theory

  • Olise, Felix S.;Ajala, Afis;Olaniyi, Hezekiah B.
    • Nuclear Engineering and Technology
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    • v.48 no.2
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    • pp.482-494
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    • 2016
  • The Feshbache-Kermane-Koonin (FKK) multi-step direct (MSD) theory of pre-equilibrium reactions has been used to compute the single-step cross-sections for some (p,${\alpha}$) reactions using the knock-on and pick-up reaction mechanisms at two incident proton energies. For the knock-on mechanism, the reaction was assumed to have taken place by the direct ejection of a preformed alpha cluster in a shell-model state of the target. But the reaction was assumed to have taken place by the pick-up of a preformed triton cluster (also bound in a shell-model state of the target core) by the incident proton for the pick-up mechanism. The Yukawa forms of potential were used for the proton-alpha (for the knock-on process) and proton-triton (for the pick-up process) interaction and several parameter sets for the proton and alpha-particle optical potentials. The calculated cross-sections for both mechanisms gave satisfactory fits to the experimental data. Furthermore, it has been shown that some combinations of the calculated distorted wave Born approximation cross-sections for the two reaction mechanisms in the FKK MSD theory are able to give better fits to the experimental data, especially in terms of range of agreement. In addition, the theory has been observed to be valid over a wider range of energy.

Rovibrational Energy Transitions and Coupled Chemical Reaction Modeling of H+H2 and He+H2 in DSMC

  • Kim, Jae Gang
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.3
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    • pp.347-359
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    • 2015
  • A method of describing the rovibrational energy transitions and coupled chemical reactions in the direct simulation Monte Carlo (DSMC) calculations is constructed for $H(^2S)+H_2(X^1{\Sigma}_g)$ and $He(^1S)+H_2(X^1{\Sigma}_g)$. First, the state-specific total cross sections for each rovibrational states are proposed to describe the state-resolved elastic collisions. The state-resolved method is constructed to describe the rotational-vibrational-translational (RVT) energy transitions and coupled chemical reactions by these state-specific total cross sections and the rovibrational state-to-state transition cross sections of bound-bound and bound-free transitions. The RVT energy transitions and coupled chemical reactions are calculated by the state-resolved method in various heat bath conditions without relying on a macroscopic properties and phenomenological models of the DSMC. In nonequilibrium heat bath calculations, the state-resolved method are validated with those of the master equation calculations and the existing shock-tube experimental data. In bound-free transitions, the parameters of the existing chemical reaction models of the DSMC are proposed through the calibrations in the thermochemical nonequilibrium conditions. When the bound-free transition component of the state-resolved method is replaced by the existing chemical reaction models, the same agreement can be obtained except total collision energy model.

Temperature-dependent studies on catalytic hydrosilation of polyalkylsiloxane using NMR

  • Sul, Hyewon;Lee, Tae Hee;Lim, Eunsoo;Rho, Yecheol;Kim, Chong-Hyeak;Kim, Jeongkwon
    • Analytical Science and Technology
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    • v.30 no.4
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    • pp.213-219
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    • 2017
  • Polyalkylsiloxane has been spotlighted in pressure-sensitive adhesive (PSA) application due to excellent physical properties and good biocompatibility. Thermal behaviour of polyalkylsiloxane mixtures, such as thermal stability and heat flow, were studied using TG-DTA during catalytic hydrosilation. To understand reaction kinetics of cross-linking, catalytic hydrosilation of polyalkylsiloxane was monitored using variable temperature nuclear magnetic resonance (VT-NMR) as increased temperature. The formation of cross-linking bond $Si-CH_2-CH_2-Si$ was directly observed using distortionless enhanced by polarization transfer (DEPT) technique. Successfully polyalkylsiloxane PSA samples exhibited excellent adhesion properties by cross-linking reaction.

Theoretical study of cross sections of proton-induced reactions on cobalt

  • Yigit, Mustafa
    • Nuclear Engineering and Technology
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    • v.50 no.3
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    • pp.411-415
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    • 2018
  • Nuclear fusion may be among the strongest sustainable ways to replace fossil fuels because it does not contribute to acid rain or global warming. In this context, activated cobalt materials in corrosion products for fusion energy are significant in determination of dose levels during maintenance after a coolant leak in a nuclear fusion reactor. Therefore, cross-section studies on cobalt material are very important for fusion reactor design. In this article, the excitation functions of some nuclear reaction channels induced by proton particles on $^{59}Co$ structural material were predicted using different models. The nuclear level densities were calculated using different choices of available level density models in ALICE/ASH code. Finally, the newly calculated cross sections for the investigated nuclear reactions are compared with the experimental values and TENDL data based on TALYS nuclear code.