291 research outputs found
Beating in electronic transport through quantum dot based devices
Electronic transport through a two-level system driven by external electric
field and coupled to (magnetic or non-magnetic) electron reservoirs is
considered theoretically. The basic transport characteristics such as current
and tunnel magnetoresistance (TMR) are calculated in the weak coupling
approximation by the use of rate equation connected with Green function
formalism and slave-boson approach. The time dependent phenomenon is considered
in the gradient expansion approximation. The results show that coherent beats
pattern can be observed both in current and TMR. The proposed system consisting
of two quantum dots attached to external leads, in which the dots' levels can
be tuned independently, can be realized experimentally to test this well known
physical phenomenon. Finally, we also indicate possible practical applications
of such device.Comment: 9 pages, 9 figure
HLA-Associated viral mutations are common in human immunodeficiency virus type 1 elite controllers
Elite controllers (EC) of human immunodeficiency virus type 1 (HTV-1) maintain viremia below the limit of detection without antiretroviral treatment. Virus-specific cytotoxic CD8+ T lymphocytes are believed to play a crucial role in viral containment, but the degree of immune imprinting and compensatory mutations in EC is unclear. We obtained plasma gag, pol, and nef sequences from HLA-diverse subjects and found that 30 to 40% of the predefined HLA-associated polymorphic sites show evidence of immune selection pressure in EC., compared to approximately 50% of the sites in chronic progressors. These data indicate ongoing viral replication and escape from cytotoxic T lymphocytes are present even in strictly controlled HTV-1 infection
A viral CTL escape mutation leading to immunoglobulin-like transcript 4-mediated functional inhibition of myelomonocytic cells
Viral mutational escape can reduce or abrogate recognition by the T cell receptor (TCR) of virus-specific CD8+ T cells. However, very little is known about the impact of cytotoxic T lymphocyte (CTL) epitope mutations on interactions between peptide–major histocompatibility complex (MHC) class I complexes and MHC class I receptors expressed on other cell types. Here, we analyzed a variant of the immunodominant human leukocyte antigen (HLA)-B2705–restricted HIV-1 Gag KK10 epitope (KRWIILGLNK) with an L to M amino acid substitution at position 6 (L6M), which arises as a CTL escape variant after primary infection but is sufficiently immunogenic to elicit a secondary, de novo HIV-1–specific CD8+ T cell response with an alternative TCR repertoire in chronic infection. In addition to altering recognition by HIV-1–specific CD8+ T cells, the HLA-B2705–KK10 L6M complex also exhibits substantially increased binding to the immunoglobulin-like transcript (ILT) receptor 4, an inhibitory MHC class I–specific receptor expressed on myelomonocytic cells. Binding of the B2705–KK10 L6M complex to ILT4 leads to a tolerogenic phenotype of myelomonocytic cells with lower surface expression of dendritic cell (DC) maturation markers and co-stimulatory molecules. These data suggest a link between CTL-driven mutational escape, altered recognition by innate MHC class I receptors on myelomonocytic cells, and functional impairment of DCs, and thus provide important new insight into biological consequences of viral sequence diversificatio
HLA-Cw*0102-restricted HIV-1 p24 epitope variants can modulate the binding of the inhibitory KIR2DL2 receptor and primary NK cell function
50 Tbit/s Massively ParallelWDMTransmission in C and L Band Using Interleaved Cavity-Soliton Kerr Combs
Interleaving two soliton Kerr combs we generate 179 carriers for WDM transmission and demonstrate transmission of a data stream of 50 Tbit/s over 75 km. This is the highest data rate achieved with a chip-scale comb source
OA03-06 LB. Unique stimulatory properties of myeloid dendritic cells in individuals with "elite" HIV-1 control
OA031-04. Impairment of HIV-1-specific CD8+ T cell function by soluble epithelial adhesion molecules
Identification of overlapping HLA class I-restricted cytotoxic T cell epitopes in a conserved region of the human immunodeficiency virus type 1 envelope glycoprotein: definition of minimum epitopes and analysis of the effects of sequence variation.
A high dimensional immune monitoring model of HIV-specific CD8 T cell responses accurately identifies subjects achieving spontaneous control of viral replication
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