2,754 research outputs found
Immune evasion of the CD1d/NKT cell axis
Many reviews on the CD1d/NKT cell axis focus on the ability of CD1d-restricted NKT cells to serve as effector cells in a variety of disorders, be they infectious diseases, cancer or autoimmunity. In contrast, here, we discuss the ways that viruses, bacteria and tumor cells can evade the CD1d/NKT cell axis. As a result, these disease states have a better chance to establish a foothold and potentially cause problems for the subsequent adaptive immune response, as the host tries to rid itself of infections or tumors
A Potent CD1d-binding Glycolipid for iNKT-Cell-based Therapy Against Human Breast Cancer
Background/Aim: Invariant natural killer T-cells (iNKT) stimulated by CD1d-binding glycolipids have been shown to exert antitumor effects by a number of studies in a mouse model. Breast cancer is a devastating disease, with different types of breast cancer recurring locally or distant as metastatic/advanced disease following initial treatment. The aim of this study was to examine the tumoricidal effect of a CD1d-binding glycolipid, called 7DW8-5, against a highly invasive human breast cancer cell line both in vitro and in vivo. Materials and Methods: Parental MDA-MB-231 cells and MDA-MB-231 cells transduced with human CD1d were labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE), followed by loading with glycolipids. After co-culturing with human iNKT cells, the cells were permeabilized and stained with Alexa Flour 647-conjugated antibody to active caspase-3, and analyzed using a BD LSR II. For the in vivo tumoricidal effect, MDA-MB-231 cells transduced with human CD1d and luciferase genes were injected into the mammary fat pad of female NOD/SCID/IL2rγnull (NSG) mice, followed by the injection of human iNKT cells with or without 7DW8-5, and the levels of luminescence were analyzed with whole-body imaging. Results: Human iNKT cells could kill CD1d-expressing human breast cancer cells in vitro in the presence of 7DW8-5, but not α-GalCer. As for in vivo, the adoptive transfer of human iNKT cells into tumor-challenged NSG mice significantly inhibited the growth of CD1d+ MDA-MB-231 human breast cancer cells in the presence of 7DW8-5. Conclusion: CD1d-binding, glycolipid-based iNKT-cell therapy is suggested as a potent and effective treatment against breast cancer in humans
A very high speed lossless compression/decompression chip set
A chip is described that will perform lossless compression and decompression using the Rice Algorithm. The chip set is designed to compress and decompress source data in real time for many applications. The encoder is designed to code at 20 M samples/second at MIL specifications. That corresponds to 280 Mbits/second at maximum quantization or approximately 500 Mbits/second under nominal conditions. The decoder is designed to decode at 10 M samples/second at industrial specifications. A wide range of quantization levels is allowed (4...14 bits) and both nearest neighbor prediction and external prediction are supported. When the pre and post processors are bypassed, the chip set performs high speed entropy coding and decoding. This frees the chip set from being tied to one modeling technique or specific application. Both the encoder and decoder are being fabricated in a 1.0 micron CMOS process that has been tested to survive 1 megarad of total radiation dosage. The CMOS chips are small, only 5 mm on a side, and both are estimated to consume less than 1/4 of a Watt of power while operating at maximum frequency
Deconvoluting Reversal Modes in Exchange Biased Nanodots
Ensemble-averaged exchange bias in arrays of Fe/FeF2 nanodots has been
deconvoluted into local, microscopic, bias separately experienced by nanodots
going through different reversal modes. The relative fraction of dots in each
mode can be modified by exchange bias. Single domain dots exhibit a simple loop
shift, while vortex state dots have asymmetric shifts in the vortex nucleation
and annihilation fields, manifesting local incomplete domain walls in these
nanodots as magnetic vortices with tilted cores.Comment: 17 pages, 3 figures. Phys. Rev. B in pres
The application of Nano-silica gel in sealing well micro-annuli and cement channeling
The possibility for hydrocarbon fluids to migrate through debonded
micro-annuli wells is a major concern in the petroleum industry. With effective
permeability of 0.1-1.0 mD, the existence of channels in a cement annulus with
apertures of 10-300 micrometer constitutes a major threat. Squeeze cement is
typically difficult to repair channels-leakage with small apertures; hence, a
low-viscosity sealer that can be inserted into these channels while producing a
long-term resilient seal is sought. A novel application using nano-silica
sealants could be the key to seal these channels. In the construction and
sealing of hydrocarbon wells, cementing is a critical phase. Cement is prone to
cracking during the life cycle of a well because of the changes in downhole
conditions. The usage of micro-sized cross-linked nano-silica gel as a sealant
material to minimize damaged cement sheaths is investigated in this study.
Fluid leakage through channels in the cement was investigated using an
experimental system. With a diameter of 0.05 inches, the impact of the cement
channel size was explored. The sealing efficiency increased from 86 percent to
95 percent when the nano-silica concentration of the sealing gel increased from
13 percent to 25 percent. This demonstrates that the concentration of
nano-silica in the sealing gel affects the gel's ability to seal against fluid
flow. This research proposes a new way for improving cement zonal isolation and
thereby lowering the impact of cement failure in the oil and gas industry.Comment: 10 page
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