941 research outputs found
Beam Management for Millimeter Wave Beamspace MU-MIMO Systems
Millimeter wave (mmWave) communication has attracted increasing attention as
a promising technology for 5G networks. One of the key architectural features
of mmWave is the use of massive antenna arrays at both the transmitter and the
receiver sides. Therefore, by employing directional beamforming (BF), both
mmWave base stations (MBSs) and mmWave users (MUEs) are capable of supporting
multi-beam simultaneous transmissions. However, most researches have only
considered a single beam, which means that they do not make full potential of
mmWave. In this context, in order to improve the performance of short-range
indoor mmWave networks with multiple reflections, we investigate the challenges
and potential solutions of downlink multi-user multi-beam transmission, which
can be described as a high-dimensional (i.e., beamspace) multi-user
multiple-input multiple-output (MU-MIMO) technique, including multi-user BF
training, simultaneous users' grouping, and multi-user multibeam power
allocation. Furthermore, we present the theoretical and numerical results to
demonstrate that beamspace MU-MIMO compared with single beam transmission can
largely improve the rate performance of mmWave systems.Comment: The sixth IEEE/CIC International Conference on Communications in
China (ICCC2017
4-Amino-3-(4-pyridyl)-1,2,4-triazole-5(4H)-thione
In the title molecule, C7H7N5S, the pyridyl and triazole rings form a dihedral angle of 20.07 (6)°. Intermolecular N—H⋯N hydrogen bonds link the molecules into chains extended in the direction [10]. Further stability is provided by π⋯π stacking interactions, indicated by short distances between the centroids of triazole rings [3.480 (5) Å] and pyridyl rings [3.574 (5) Å] of neighbouring molecules
A chalcone derivative reactivates latent HIV-1 transcription through activating P-TEFb and promoting Tat-SEC interaction on viral promoter.
The principal barrier to the eradication of HIV/AIDS is the existence of latent viral reservoirs. One strategy to overcome this barrier is to use latency-reversing agents (LRAs) to reactivate the latent proviruses, which can then be eliminated by effective anti-retroviral therapy. Although a number of LRAs have been found to reactivate latent HIV, they have not been used clinically due to high toxicity and poor efficacy. In this study, we report the identification of a chalcone analogue called Amt-87 that can significantly reactivate the transcription of latent HIV provirses and act synergistically with known LRAs such as prostratin and JQ1 to reverse latency. Amt-87 works by activating the human transcriptional elongation factor P-TEFb, a CDK9-cyclin T1 heterodimer that is part of the super elongation complex (SEC) used by the viral encoded Tat protein to activate HIV transcription. Amt-87 does so by promoting the phosphorylation of CDK9 at the T-loop, liberating P-TEFb from the inactive 7SK snRNP, and inducing the formation of the Tat-SEC complex at the viral promoter. Together, our data reveal chalcones as a promising category of compounds that should be further explored to identify effective LRAs for targeted reversal of HIV latency
Controlling atomic spin-mixing via multiphoton transitions in a cavity
We propose to control spin-mixing dynamics in a gas of spinor atoms, via the
combination of two off-resonant Raman transition pathways, enabled by a common
cavity mode and a bichromatic pump laser. The mixing rate, which is
proportional to the synthesized spin-exchange interaction strength, and the
effective atomic quadratic Zeeman shift (QZS), can both be tuned by changing
the pump laser parameters. Quench and driving dynamics of the atomic collective
spin are shown to be controllable on a faster time scale than in existing
experiments based on inherent spin-exchange collision interactions. The results
we present open a promising avenue for exploring spin-mixing physics of atomic
ensembles accessible in current experiments.Comment: 4.5pages with appendices, 3 figure
Association of ABCC2 and CDDP-Resistance in Two Sublines Resistant to CDDP Derived from a Human Nasopharyngeal Carcinoma Cell Line
Cisplatin (CDDP) is one of the most active drugs to treat nasopharyngeal carcinoma (NPC) patients. To further understand the mechanisms of CDDP-resistance in NPC, two CDDP-resistant sublines (CNE2-CDDP and CNE2-CDDP-5Fu) derived from parental NPC cell line CNE2 were established. It was found that at the IC50 level, the resistance of CNE2-CDDP and CNE2-CDDP-5Fu against CDDP was 2.63-fold and 5.35-fold stronger than that of parental CNE2, respectively. Of the four ABC transporters (ABCB1, ABCC1, ABCC2 and ABCG2) related to MDR, only ABCC2 was found to be elevated both in CDDP-resistant sublines, with ABCC2 located in nucleus of CNE2-CDDP-5Fu but not in CNE2-CDDP and parental CNE2. Further research showed that compared to untreated CNE2, the intracellular levels of CDDP were decreased by 2.03-fold in CNE2-CDDP and 2.78-fold in CNE2-CDDP-5Fu. After treatment with PSC833, a modulator of MDR associated transporters including ABCC2, the intracellular level of CDDP was increased in CDDP-resistant sublines, and the resistance to CDDP was partially reversed from 2.63-fold to 1.62-fold in CNE2-CDDP and from 5.35-fold to 4.62-fold in CNE2-CDDP-5Fu. These data indicate that ABCC2 may play an important role in NPC resistant to CDDP
Ethyl (E)-3-anilino-2-cyano-3-mercaptoacrylate
In the title compound, C12H12N2O2S, there are S—H⋯N and N—H⋯O hydrogen-bond interactions. The N—H⋯O hydrogen bond is bifurcated, with the hydrogen being simultaneously donated to two equivalent O atoms, forming one intra- and one intermolecular N—H⋯O bond with an R
1
2(4) motif. The motif of the S—H⋯N hydrogen bond is R
2
2(12)
Prognostic implications of plasma fibrinogen and serum Creactive protein levels in non-small cell lung cancer resection and survival
Purpose: To investigate the prognostic implications of plasma fibrinogen and serum C-reactive protein (CRP) levels in tumour resection and survival following successful tumour resection in patients with nonsmall cell lung cancer (NSCLC).Methods: One hundred and fifty-three NSCLC patients who underwent surgical resection at a tertiary care hospital from January 2006 through December 2010 were enrolled. Pre-operative serum CRP and plasma fibrinogen levels were measured. The levels of these biomarkers correlated with tumour size and pathologic TNM stage. The possibility of complete resection and associated findings are reported.Results: Plasma fibrinogen (r = 0.381, p = 0.002) and serum CRP (r = 0.471, p < 0.001) levels were positively associated with tumour diameter. Increased levels of these biomarkers were significantly associated with sex, smoking status, histological type, tumour stage, and clinical stage. Partial tumour resection occurred in 28 % (27/95) of patients with an increased plasma fibrinogen level compared to 10 % (6/58) with a normal fibrinogen level (p = 0.008), and in 30 % (29/97) of patients with an increased serum CRP level compared to 11 % (6/56) with a normal CRP level (p = 0.006). Patients with elevated CRP and fibrinogen concentrations demonstrated higher susceptibility to disease advancement andsurvival compared to patients with normal fibrinogen and CRP levels.Conclusion: Pre-operative functional concentrations of serum CRP and plasma fibrinogen could serve as indicators of tumour resectability wherein a high tumour resection rate is possible in patients with favourable pre-operative levels of these biomarkers. Increased concentrations of serum CRP and plasma fibrinogen are associated with poor overall survival and progression-free survival.Key words: Plasma fibrinogen, serum C-reactive protein, biomarker, non-small cell lung cance
Broadband multi-wavelength study of LHAASO detected AGN
Recently, the Large High Altitude Air Shower Observatory (LHAASO)
collaboration presents the first catalog of -ray sources using 508 days
LHAASO data from March 2021 to September 2022. This catalog contains five
active galactic nuclei (AGNs), of which four are blazars and one is a
liner-type AGN. In this work, we establish averaged multi-wavelength SEDs by
combining data from -Large Area Telescope, , , and
with the same period as the LHAASO detection. In general, these five AGNs are
found in low states at all wavelengths. To study the multi-wavelength
properties of these AGNs, several jet emission models, including the one-zone
leptonic model, the one-zone leptonic and hadronuclear () model, the
one-zone proton-synchrotron model, and the spine-layer model are applied to
reproduce their averaged SEDs, respectively. We find that the one-zone leptonic
model can reproduce most of the SEDs, except for the high-energy tail of LHAASO
spectra. To improve the fitting, emission from interactions is favoured in
the framework of one-zone model. The spine-layer model, which can be treated as
a multi-zone scenario, also can provide good spectra fits. The influence of
different extragalactic background light models on fitting LHAASO energy
spectrum is also discussed.Comment: 22 pages, 10 figures, submitted to ApJS. Suggestions, comments or
feedback will be appreciate
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