2,248 research outputs found
L-Tetrahydropalamatine: A Potential New Medication for the Treatment of Cocaine Addiction
Levo-tetrahydropalmatine (l-THP) is an active constituent of herbal preparations containing plant species of the genera Stephania and Corydalis and has been approved and used in China for a number of clinical indications under the drug name Rotundine. The pharmacological profile of l-THP, which includes antagonism of dopamine D1 and D2 receptors and actions at dopamine D3, α adrenergic and serotonin receptors, suggests that it may have utility for treating cocaine addiction. In this review, we provide an overview of the pharmacological properties of l-THP and the evidence supporting its development as an anti-addiction medication. The results of preclinical work demonstrating that l-THP attenuates cocaine’s reinforcing/rewarding effects and reinstatement in rat models of cocaine relapse are summarized, and the outcomes of studies demonstrating efficacy in human addicts are described. Finally, an overview of the safety profile of l-THP is provided and challenges associated with US FDA approval of l-THP are discussed
Dilations for Systems of Imprimitivity acting on Banach Spaces
Motivated by a general dilation theory for operator-valued measures, framings
and bounded linear maps on operator algebras, we consider the dilation theory
of the above objects with special structures. We show that every
operator-valued system of imprimitivity has a dilation to a probability
spectral system of imprimitivity acting on a Banach space. This completely
generalizes a well-kown result which states that every frame representation of
a countable group on a Hilbert space is unitarily equivalent to a
subrepresentation of the left regular representation of the group. The dilated
space in general can not be taken as a Hilbert space. However, it can be taken
as a Hilbert space for positive operator valued systems of imprimitivity. We
also prove that isometric group representation induced framings on a Banach
space can be dilated to unconditional bases with the same structure for a
larger Banach space This extends several known results on the dilations of
frames induced by unitary group representations on Hilbert spaces.Comment: 21 page
Dilations of frames, operator valued measures and bounded linear maps
We will give an outline of the main results in our recent AMS Memoir, and
include some new results, exposition and open problems. In that memoir we
developed a general dilation theory for operator valued measures acting on
Banach spaces where operator-valued measures (or maps) are not necessarily
completely bounded. The main results state that any operator-valued measure,
not necessarily completely bounded, always has a dilation to a
projection-valued measure acting on a Banach space, and every bounded linear
map, again not necessarily completely bounded, on a Banach algebra has a
bounded homomorphism dilation acting on a Banach space. Here the dilation space
often needs to be a Banach space even if the underlying space is a Hilbert
space, and the projections are idempotents that are not necessarily
self-adjoint. These results lead to some new connections between frame theory
and operator algebras, and some of them can be considered as part of the
investigation about "noncommutative" frame theory.Comment: Contemporary Mathematics, 21 pages. arXiv admin note: substantial
text overlap with arXiv:1110.583
Large-Scale MIMO Detection for 3GPP LTE: Algorithms and FPGA Implementations
Large-scale (or massive) multiple-input multiple-output (MIMO) is expected to
be one of the key technologies in next-generation multi-user cellular systems,
based on the upcoming 3GPP LTE Release 12 standard, for example. In this work,
we propose - to the best of our knowledge - the first VLSI design enabling
high-throughput data detection in single-carrier frequency-division multiple
access (SC-FDMA)-based large-scale MIMO systems. We propose a new approximate
matrix inversion algorithm relying on a Neumann series expansion, which
substantially reduces the complexity of linear data detection. We analyze the
associated error, and we compare its performance and complexity to those of an
exact linear detector. We present corresponding VLSI architectures, which
perform exact and approximate soft-output detection for large-scale MIMO
systems with various antenna/user configurations. Reference implementation
results for a Xilinx Virtex-7 XC7VX980T FPGA show that our designs are able to
achieve more than 600 Mb/s for a 128 antenna, 8 user 3GPP LTE-based large-scale
MIMO system. We finally provide a performance/complexity trade-off comparison
using the presented FPGA designs, which reveals that the detector circuit of
choice is determined by the ratio between BS antennas and users, as well as the
desired error-rate performance.Comment: To appear in the IEEE Journal of Selected Topics in Signal Processin
Chloroquine supplementation increases the cytotoxic effect of curcumin against Her2/neu overexpressing breast cancer cells in vitro and in vivo in nude mice while counteracts it in immune competent mice
Autophagy is usually a pro-survival mechanism in cancer cells, especially in the course of chemotherapy, thus autophagy inhibition may enhance the chemotherapy-mediated anti-cancer effect. However, since autophagy is strongly involved in the immunogenicity of cell death by promoting ATP release, its inhibition may reduce the immune response against tumors, negatively influencing the overall outcome of chemotherapy. In this study, we evaluated the in vitro and in vivo anti-cancer effect of curcumin (CUR) against Her2/neu overexpressing breast cancer cells (TUBO) in the presence or in the absence of the autophagy inhibitor chloroquine (CQ). We found that TUBO cell death induced by CUR was increased in vitro by CQ and slightly in vivo in nude mice. Conversely, CQ counteracted the Cur cytotoxic effect in immune competent mice, as demonstrated by the lack of in vivo tumor regression and the reduction of overall mice survival as compared with CUR-treated mice. Immunohistochemistry analysis revealed the presence of a remarkable FoxP3 T cell infiltrate within the tumors in CUR/CQ treated mice and a reduction of T cytotoxic cells, as compared with single CUR treatment. These findings suggest that autophagy is important to elicit anti-tumor immune response and that autophagy inhibition by CQ reduces such response also by recruiting T regulatory (Treg) cells in the tumor microenvironment that may be pro-tumorigenic and might counteract CUR-mediated anti-cancer effects
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