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1.
Kang Il Yoo Ji Yeong Jeon Su Jeong Ryu Giri Nam Hyewon Youn Eun Young Choi 《Experimental & molecular medicine》2015,47(2):e140
In allogeneic transplantation, including the B6 anti-BALB.B settings, H60 and H4 are two representative dominant minor histocompatibility antigens that induce strong CD8 T-cell responses. With different distribution patterns, H60 expression is restricted to hematopoietic cells, whereas H4 is ubiquitously expressed. H60-specific CD8 T-cell response has been known to be dominant in most cases of B6 anti-BALB.B allo-responses, except in the case of skin transplantation. To understand the mechanism underlying the subdominance of H60 during allogeneic skin transplantation, we investigated the dynamics of the H60-specific CD8 T cells in B6 mice transplanted with allogeneic BALB.B tail skin. Unexpectedly, longitudinal bioluminescence imaging and flow cytometric analyses revealed that H60-specific CD8 T cells were not always subdominant to H4-specific cells but instead showed a brief dominance before the H4 response became predominant. H60-specific CD8 T cells could expand in the draining lymph node and migrate to the BALB.B allografts, indicating their active participation in the anti-BALB.B allo-response. Enhancing the frequencies of H60-reactive CD8 T cells prior to skin transplantation reversed the immune hierarchy between H60 and H4. Additionally, H60 became predominant when antigen presentation was limited to the direct pathway. However, when antigen presentation was restricted to the indirect pathway, the expansion of H60-specific CD8 T cells was limited, whereas H4-specific CD8 T cells expanded significantly, suggesting that the temporary immunodominance and eventual subdominance of H60 could be due to their reliance on the direct antigen presentation pathway. These results enhance our understanding of the immunodominance phenomenon following allogeneic tissue transplantation. 相似文献
2.
A least‐squares meshfree method based on the first‐order velocity–pressure–vorticity formulation for two‐dimensional incompressible Navier–Stokes problem is presented. The convective term is linearized by successive substitution or Newton's method. The discretization of all governing equations is implemented by the least‐squares method. Equal‐order moving least‐squares approximation is employed with Gauss quadrature in the background cells. The boundary conditions are enforced by the penalty method. The matrix‐free element‐by‐element Jacobi preconditioned conjugate method is applied to solve the discretized linear systems. Cavity flow for steady Navier–Stokes problem and the flow over a square obstacle for time‐dependent Navier–Stokes problem are investigated for the presented least‐squares meshfree method. The effects of inaccurate integration on the accuracy of the solution are investigated. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
3.
We herein report that PtCl4 has proven to be a hydroarylation catalyst with an efficiency and substrate scope superior to previously known methods. This catalyst demonstrated consistent performance with arene-yne substrates of diverse structural features, including propargyl ethers, propargylamines, and alkynoate esters, providing good to excellent yields of the 6-endo products (chromenes, dihydroquinolines, and coumarins). In contrast, Pt(II), Pd(II), and Ga(III) salts were shown to be sensitive to the substitution on the alkyne moiety. PtCl4 is compatible with both terminal and disubstituted alkynes, as well as with various functionalities on the arene ring, including methyl, methoxyl, hydroxyl, protected amine, and halide. 相似文献
4.
The viscoelastic behavior of carbon-black-filled rubber under small oscillatory loads superimposed on large static deformation
is dealt with. In this class of problems, as the strain amplitudes of the load increase, the dynamic stiffness decreases,
and this phenomenon is known as the Payne effect. Besides the effects of the static deformation and the frequencies of the
superimposed dynamic load, the Payne effect is considered in this study. Influence factors are introduced in this model in
order to consider the influence of static predeformation, the dynamic-strain-dependent properties, and frequency-dependent
properties. For simplicity, separation of the three dominant variables, frequency, prestatic deformation, and dynamic amplitude
of strain, is assumed. The Kraus model is used for describing the Payne effect. Dynamic tension tests are executed to obtain
the model parameters and also for the verification of the proposed model. The suggested constitutive equation shows reasonable
agreement with test data. 相似文献
5.
6.
Kang YK Rubtsov IV Iovine PM Chen J Therien MJ 《Journal of the American Chemical Society》2002,124(28):8275-8279
The electron-transfer (ET) dynamics of a series of unusually rigid pi-stacked porphyrin-quinone (P-Q) systems, in which sub-van der Waals interplanar distances separate juxtaposed porphyryl, aromatic bridge, and quinonyl components of these assemblies, are reported. The photoinduced charge separation (CS) and thermal charge recombination (CR) ET reactions of [5-[8'-(2',5'-benzoquinonyl)-1'-naphthyl]-10,20-diphenylporphinato]zinc(II) (1a-Zn), [5-[8'-(4'-[8'"-(2'"',5'"'-benzoquinonyl)-1'"-naphthyl]-1'-phenyl)-1'-naphthyl]-10,20-diphenylporphinato]zinc(II) (2a-Zn), and [5-(8'-[4'-(8'"-[4'"'-(8'"-[2'"',5'"'-benzoquinonyl]-1'"-naphthyl)-1'"'-phenyl]-1'"-naphthyl)-1'-phenyl]-1'-naphthyl)-10,20-diphenylporphinato]zinc(II) (3a-Zn) in CH(2)Cl(2) were investigated by pump-probe transient absorption spectroscopy. Analyses of these data show that the phenomenological ET distance dependence (beta) for both the CS and CR reactions in these systems is soft (beta(CS) = 0.43 A(-1); beta(CR) = 0.35 +/- 0.16 A(-1)). This work demonstrates that simple aromatic building blocks such as benzene, which are characterized by highly stabilized filled molecular orbitals and large HOMO-LUMO gaps, can provide substantial D-A electronic coupling when organized within a pi-stacked structural motif that features a modest degree of arene-arene interplanar compression. 相似文献
7.
Seo YJ Jeon MH Lee JH Lee YJ Youn HJ Ko JH Lee JH 《Experimental & molecular medicine》2005,37(6):624-630
Bis (Bag-3, CAIR), a Bcl-2-interacting protein, promotes the anti-apoptotic activity of Bcl-2 and increased levels of Bis have been observed in several disease models. The involvement of Bcl-2 and some Bcl-2-binding proteins in differentiation has recently been reported. However, the relevance of Bis to cellular differentiation remains unknown. The findings herein show that Bis expression is up-regulated during the differentiation of HL-60 cells. To investigate the effect of Bis expression on differentiation, we established Bis-overexpressing HL-60 cells (HL-60-bis). HL-60-bis cells have a low nuclear: cytoplasmic ratio and indented nucleus in Wright- Giemsa staining, and an increased expression of CD11b in immunofluorescence study, indicating the promotion of differentiation. The overexpression of Bis also resulted in a retarded cell growth rate, accompanied by the accumulation of HL-60 cells at the G0/G1 phase of the cell cycle, which was sustained during the differentiation process. Western blot analysis revealed that the expression of p27, a representative inducer of cell cycle arrest at the G1 phase, was increased 2.5-fold in HL-60-bis cells compared to HL-60-neo cells. These results suggest that the Bis induced growth inhibition of HL-60 cells promotes G0/G1 phase arrest via up-regulation of p27, which seems to be a prerequisite for differentiation. Further studies will be required to define the exact roles of Bis on cellular differentiation more precisely. 相似文献
8.
A one-step chromatographic method capable of separating all isomers of polyethylene glycol (PEG)-growth hormone-releasing factor (GRF) (1-29) conjugates was developed. The unmodified GRF (1-29) and seven different isomers of PEG-GRF (1-29) conjugates were separated by using a simple reversed-phase HPLC method depending on the differences of hydrophobicity due to the number and site of PEG attachment. The PEGylation sites of all isomers of PEG-GRF (1-29) conjugates were identified by determining the molecular masses of the Lys-C digested fragments with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This study is a first report for the separation of all PEG-conjugate isomers and would be useful for further studies to find the promising conjugate by evaluating biological activity and stability of each isomer. 相似文献
9.
Park JI Lee WR Bae SS Kim YJ Yoo KH Cheon J Kim S 《The journal of physical chemistry. B》2005,109(27):13119-13123
In this paper, we describe an easy and reliable method for the production of patterned monolayers of Co nanoparticles. A two-dimensional monolayer of Co nanoparticles is fabricated by spreading a nanoparticle solution over an air-water interface and then transferring it to a hydrophobic substrate by using the Langmuir-Blodgett (LB) method. Transmission electron microscopy (TEM) was used to show that, with increasing surface pressure, the Co nanoparticles become well-organized into a Langmuir monolayer with a hexagonal close-packed structure. By controlling the pH of the subphase, it was found that a monolayer of Co nanoparticles with long-range order could be obtained. Further, by transferring the Langmuir monolayer onto a poly(dimethoxysilane) (PDMS) mold, the selective micropatterning of the Co nanoparticles could be achieved on a patterned electronic circuit. The electronic transport properties of the Co nanoparticles showed the ohmic I-V curve. 相似文献
10.
Ha PS Youn HJ Jung HS Hong KS Park YH Ko KH 《Journal of colloid and interface science》2000,223(1):16-20
The effect of alcohol washing on the anatase-rutile transition of precipitated titanium oxide was investigated using X-ray powder diffraction, Fourier-transform IR spectroscopy, and thermogravimetry. Alcohol (butanol) rinsing accelerated the anatase-rutile transition of precipitated titanium oxide powder so that the onset temperature of transition decreased drastically from 800 degrees C for water-washed powder to 550 degrees C for alcohol-rinsed powder. Alternation of transition kinetics and mechanisms by rinsing media could be confirmed from the analysis of temperature and time dependence of rutile content. The attributability of the chemical state of anatase after crystallization, which contained H(2)O, OH, and organic residues, to the change of transition kinetics with alcohol rinsing will be discussed. Two mechanisms, the effect of residual organics and/or H(2)O(OH), could be suggested on the basis of analysis of the difference between chemical states of water-washed anatase and alcohol-rinsed powder. Copyright 2000 Academic Press. 相似文献