1,217 research outputs found

    Retinal S-antigen Th1 cell epitope mapping in patients with Behcet's disease

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    Background - Retinal S-antigen (S-Ag) is a most characterized autoantigen of autoimmune uveitis. The recognized immunodominant epitope of human S-Ag in patients with uveitis has not been identified. In this study, we selected certain patients with active uveitis to map the Th1 cell epitope spectrum of human S-Ag in Behcet's disease(BD). Methods - Blood samples were taken from eight active BD patients who showed an immune response to 40 mixed overlapping peptides spanning the entire sequence of human S-Ag. Peripheral blood mononuclear cells were isolated and stimulated with single S-Ag peptide at 5 mu g/ml or 20 mu g/ml. Single-cell immune responses were measured by IFN-gamma ELIspot assay. Results - BD patients heterogeneously responded to the S-Ag peptides at two concentrations. In general, the responses to 5 mu g/ml peptides were slightly stronger than those to 20 mu g/ml peptides, while the maximum SFC frequency to single peptide at the two concentrations was similar. Several peptides including P31, P35 and P40 induced a prominent response, with the frequency of S-Ag specific cells being about 0.007%. Significant reactivity pattern shift was noted in patients with different disease courses. Conclusions - Certain active BD patients have S-Ag specific Th1 cells with a low frequency. The S-Ag epitope specificity between patients is highly heterogeneous, and varies with the uveitis cours

    Splenic CD8(+) T cells secrete TGF-beta 1 to exert suppression in mice with anterior chamber-associated immune deviation

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    Background CD8(+) regulatory T cells (Treg) have been considered to be involved in a model of ocular-induced tolerance, known as anterior chamber-associated immune deviation (ACAID). The mechanisms of suppression by CD8(+) T cells in ACAID remain only poorly understood. TGF-beta 1 is considered as an inhibitory cytokine for immunosuppression in some models. The production of TGF-beta 1 by CD8(+) T cells in ACAID, and whether CD8+ T cells exert suppression through TGF-beta 1, is unknown. Methods The suppressive effect of CD8(+) T cells in ACAID mice was determined by a local adoptive transfer (LAT) assay. The production of TGF-beta 1 by CD8(+) T cells was measured by enzyme-linked immunosorbent assay (ELISA). Anti-TGF-beta 1 antibodies were used in the LAT assay to test if they could block the inhibitory effect of CD8(+) T cells. Results CD8(+) T cells from ACAID mice were shown to block the delayed-type hypersensitivity (DTH) response in an antigen-specific manner in a LAT assay. These CD8+ T cells secreted TGF-beta 1, and their suppression could partially be blocked by anti-TGF-beta 1 antibodies. Conclusions Our study confirms that CD8+ T cells from ACAID mice possess inhibitory properties. This population exerts part of its suppressive function via the production of TGF-beta 1

    Chiral Baryon Fields in the QCD Sum Rule

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    We study the structure of local baryon fields using the method of QCD sum rule. We only consider the single baryon fields and calculate their operator product expansions. We find that the octet baryon fields belonging to the chiral representations [(3,3*)+(3*,3)] and [(8,1)+(1,8)] and the decuplet baryon fields belonging to the chiral representations [(3,6)+(6,3)] lead to the baryon masses which are consistent with the experimental data of ground baryon masses. We also calculate their decay constants, check our normalizations for baryon fields in PRD81:054002(2010) and find that they are well-defined.Comment: 12 pages, 6 figure, 1 table, accepted by EPJ

    Quantum Ferromagnetism and Phase Transitions in Double-Layer Quantum Hall Systems

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    Double layer quantum Hall systems have interesting properties associated with interlayer correlations. At ν=1/m\nu =1/m where mm is an odd integer they exhibit spontaneous symmetry breaking equivalent to that of spin 1/21/2 easy-plane ferromagnets, with the layer degree of freedom playing the role of spin. We explore the rich variety of quantum and finite temperature phase transitions in these systems. In particular, we show that a magnetic field oriented parallel to the layers induces a highly collective commensurate-incommensurate phase transition in the magnetic order.Comment: 4 pages, REVTEX 3.0, IUCM93-013, 1 FIGURE, hardcopy available from: [email protected]

    Collective Modes of Soliton-Lattice States in Double-Quantum-Well Systems

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    In strong perpendicular magnetic fields double-quantum-well systems can sometimes occur in unusual broken symmetry states which have interwell phase coherence in the absence of interwell hopping. When hopping is present in such systems and the magnetic field is tilted away from the normal to the quantum well planes, a related soliton-lattice state can occur which has kinks in the dependence of the relative phase between electrons in opposite layers on the coordinate perpendicular to the in-plane component of the magnetic field. In this article we evaluate the collective modes of this soliton-lattice state in the generalized random-phase aproximation. We find that, in addition to the Goldstone modes associated with the broken translational symmetry of the soliton-lattice state, higher energy collective modes occur which are closely related to the Goldstone modes present in the spontaneously phase-coherent state. We study the evolution of these collective modes as a function of the strength of the in-plane magnetic field and comment on the possibility of using the in-plane field to generate a finite wave probe of the spontaneously phase-coherent state.Comment: REVTEX, 37 pages (text) and 15 uuencoded postscript figure

    EGAM Induced by Energetic-electrons and Nonlinear Interactions among EGAM, BAEs and Tearing Modes in a Toroidal Plasma

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    In this letter, it is reported that the first experimental results are associated with the GAM induced by energetic electrons (eEGAM) in HL-2A Ohmic plasma. The energetic-electrons are generated by parallel electric fields during magnetic reconnection associated with tearing mode (TM). The eEGAM localizes in the core plasma, i.e. in the vicinity of q=2 surface, and is very different from one excited by the drift-wave turbulence in the edge plasma. The analysis indicated that the eEGAM is provided with the magnetic components, whose intensities depend on the poloidal angles, and its mode numbers are jm/nj=2/0. Further, there exist intense nonlinear interactions among eEGAM, BAEs and strong tearing modes (TMs). These new findings shed light on the underlying physics mechanism for the excitation of the low frequency (LF) Alfv\'enic and acoustic uctuations.Comment: 5 pages,4 figure

    Degradación de algunos compuestos volátiles de aceites de onagra bajo un proceso UV/TiO2

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    Off-flavor is one of the limiting factors in the quality and commercial acceptability of evening primrose oil (EPO). The results of this study demonstrated that ultraviolet light irradiated with titanium dioxide (UV/TiO2) was able to effectively reduce odorous aldehyde concentrations, which would produce undesired flavors. Specifically, reductions in the E-2-Decenal, 1-octen-3-ol and hexanoic acid in EPO reached 50, 75.2 and 61.4% after a UV/TiO2 process of 5 min, respectively. The odor active values (OAV) and hierarchical cluster analysis (HCA) showed that the result of the 5 min group was similar to that of the original oil. In addition, the physicochemical characteristics of EPO after processing did not change significantly. The result of the aroma profile analysis was consistent with the OAV and HCA results. Therefore, it has been concluded that 5 min UV/TiO2 treatment could degrade some volatile compounds and provide a potential deodorization method for industry.El mal sabor es uno de los factores limitantes de la calidad y aceptabilidad comercial del aceite de onagra (EPO). Los resultados de este estudio demostraron que la luz ultravioleta irradiada con dióxido de titanio (UV/TiO2) fue capaz de reducir eficazmente las concentraciones de aldehídos volátiles, que darían olores no deseados. En concreto, la reducción del E-2-Decenal, 1-octen-3-ol y el ácido hexanoico en EPO alcanzó el 50%, 75,2% y 61,4% respectivamente tras un proceso UV/TiO2 de 5 min. Los valores de olor activo (OAV) y el análisis de conglomerados jerárquicos (HCA) mostraron que el resultado del grupo de 5 min fue similar al del aceite original. Además, las características fisicoquímicas del EPO después del procesamiento no cambiaron significativamente. El resultado del análisis del perfil de aroma fue consistente con nuestro resultado de OAV y HCA. Por lo tanto, se ha llegado a la conclusión de que el tratamiento con UV/TiO2 durante 5 min podría degradar algunos compuestos volátiles y proporcionar un método de desodorización potencial para la industria

    The σ\sigma pole in J/ψωπ+πJ/\psi \to \omega \pi^+ \pi^-

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    Using a sample of 58 million J/ψJ/\psi events recorded in the BESII detector, the decay J/ψωπ+πJ/\psi \to \omega \pi^+ \pi^- is studied. There are conspicuous ωf2(1270)\omega f_2(1270) and b1(1235)πb_1(1235)\pi signals. At low ππ\pi \pi mass, a large broad peak due to the σ\sigma is observed, and its pole position is determined to be (541±39)(541 \pm 39) - ii (252±42)(252 \pm 42) MeV from the mean of six analyses. The errors are dominated by the systematic errors.Comment: 15 pages, 6 figures, submitted to PL
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