2,750 research outputs found
Asymptotic distributions of the signal-to-interference ratios of LMMSE detection in multiuser communications
Let ,
where are independent and identically distributed
random variables with and . Let
, and
\beta_k=p_k{\mathbf{s}}_k^T({\mathb
f{S}}_k{\mathbf{P}}_k{\mathbf{S}}_k^T+\sigma^2{\mathbf{I}})^{-1}{\math
bf{s}}_k, where and the is referred to as the
signal-to-interference ratio (SIR) of user with linear minimum mean-square
error (LMMSE) detection in wireless communications. The joint distribution of
the SIRs for a finite number of users and the empirical distribution of all
users' SIRs are both investigated in this paper when and tend to
infinity with the limit of their ratio being positive constant. Moreover, the
sum of the SIRs of all users, after subtracting a proper value, is shown to
have a Gaussian limit.Comment: Published at http://dx.doi.org/10.1214/105051606000000718 in the
Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute
of Mathematical Statistics (http://www.imstat.org
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
6-Mercaptopurine attenuates tumor necrosis factor-α production in microglia through Nur77-mediated transrepression and PI3K/Akt/mTOR signaling-mediated translational regulation
Physical interaction between Nur77 and p65. BV-2 cells were pretreated with 6-MP (50 μM) for 16 h followed by exposure to LPS (100 ng/ml) for 60 min. Nuclear extracts were harvested for immunoprecipitation (IP) experiments using anti-Nur77 and anti-p65 antibodies. Immunoblot (IB) analyses of the immunoprecipitates were performed using these antibodies. The immunoblots are representative of three independent experiments. (TIF 280 kb
Multidetector CT Findings of a Congenital Coronary Sinus Anomaly: a Report of Two Cases
Congenital coronary sinus anomalies are extremely rare, and they have received relatively little attention. This is probably due to the lack of both clinical symptoms and significant cardiac functional disturbance. We present two cases of a coronary sinus anomaly and briefly review the literature. Recognizing and being familiar with the variations of a congenital coronary sinus anomaly in congenital heart disease may avoid a misinterpretation of cardiac catheterization findings and the troublesome disruption of coronary sinus blood return during the surgical management of cardiac lesions
Preparation of FeO(OH) Modified with Polyethylene Glycol and Its Catalytic Activity on the Reduction of Nitrobenzene with Hydrazine Hydrate
Iron oxyhydroxide was prepared by dropping ammonia water to Fe(NO3)3.9H2O dispersed in polyethylene glycol (PEG) 1000. The catalyst was characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy and laser particle size analyzer. The results showed the catalyst modified with polyethylene glycol was amorphous. The addition of PEG during the preparation make the particle size of the catalyst was smaller and more uniform. The catalytic performance was tested in the reduction of nitroarenes to corresponding amines with hydrazine hydrate, and the catalyst showed excellent activity and stability.
Moxibustion treatment modulates the gut microbiota and immune function in a dextran sulphate sodium-induced colitis rat model
AIM:
To investigate the effect and mechanism of moxibustion in rats with ulcerative colitis.
METHODS:
A rat colitis model was established by administering 4% dextran sulphate sodium solution. Seventy male rats were randomly divided into seven groups: Healthy controls (HC), ulcerative colitis model group (UC), UC with 7 d of moxibustion (UC-7), UC with 14 d of moxibustion (UC-14), UC with mesalazine gavage (UC-W), HC with 7 d of moxibustion (HC-7), HC with 14 d of moxibustion (HC-14). Moxibustion was applied to the bilateral Tianshu (ST25). Gut microbiome profiling was conducted by 16S rRNA amplicon sequencing, and PCR and ELISA determined the expression of inflammatory cytokines in colon mucosa and serum, respectively.
RESULTS:
Moxibustion treatment restored the colonic mucosa and decreased submucosal inflammatory cell infiltration in colitis rats. Rats treated with moxibustion and mesalazine had significantly lower levels of the dominant phyla Proteobacteria and the genera Saccharibacteria, Sphingomonas and Barnesiella than colitis rats, and they could restore the microbiome to levels similar to those observed in healthy rats. UC rats had reduced alpha diversity, which could be alleviated by moxibustion therapy, and UC-7 had a higher alpha diversity than UC-14. This finding suggests that short-term (7 d) but no longer term (14 d) moxibustion treatment may significantly affect the gut microbiome. The potential bacterial functions affected by moxibustion may be ascorbate and aldarate metabolism, and amino acid metabolism. Compared with HC group, the levels of the cytokines interleukin-12 (IL-12) (P < 0.05) and IL-6, IL-17, IL-23, interferon-γ, lipopolysaccharide, IgA, tumour necrosis factor-α and its receptors 1 (TNFR1) and TNFR2 (P < 0.01) were all increased, whereas anti-inflammatory cytokine IL-2 and IL-10 (P < 0.01) and transforming growth factor-β (P < 0.05) were decreased in UC rats. These changes were reversed by moxibustion.
CONCLUSION:
Our findings suggest that moxibustion exerts its therapeutic effect by repairing mucosal tissue damage and modulating the gut microbiome and intestinal mucosal immunity
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