2,228 research outputs found

    Periodic Radio Variability in NRAO 530: Phase Dispersion Minimization Analysis

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    In this paper, a periodicity analysis of the radio light curves of the blazar NRAO 530 at 14.5, 8.0, and 4.8 GHz is presented employing an improved Phase Dispersion Minimization (PDM) technique. The result, which shows two persistent periodic components of 6 \sim 6 and 10 \sim 10 years at all three frequencies, is consistent with the results obtained with the Lomb-Scargle periodogram and weighted wavelet Z-transform algorithms. The reliability of the derived periodicities is confirmed by the Monte Carlo numerical simulations which show a high statistical confidence. (Quasi-)Periodic fluctuations of the radio luminosity of NRAO 530 might be associated with the oscillations of the accretion disk triggered by hydrodynamic instabilities of the accreted flow. \keywords{methods: statistical -- galaxies: active -- galaxies: quasar: individual: NRAO 530}Comment: 8 pages, 5 figures, accepted by RA

    A Model Of Inflationary Cosmology Without Singularity

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    In this letter, we propose a model of inflationary cosmology with a bounce preceded and study its primordial curvature perturbations. Our model gives rise to a primordial power spectrum with a feature of oscillation on large scales compared with the nearly scale-invariant spectrum generated by the traditional slow rolling inflation model. We will show this effect changes the Cosmic Microwave Background (CMB) temperature power spectrum and the Large Scale Structure (LSS) matter power spectrum. And further with a detailed simulation we will point out this signal is detectable to the forthcoming observations, such as PLANCK and LAMOST.Comment: 4 pages, 4 figure

    Corrections to electroweak precision observables from mixings of an exotic vector boson in light of the CDF WW-mass anomaly

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    We enumerate various effective couplings that contribute to the mixings between an exotic vector boson ZZ^{\prime} and the neutral electroweak vector bosons. The miscellaneous mixing patterns can be evaluated perturbatively. The effective oblique parameters SS^{\prime}, TT^{\prime}, and UU^{\prime} are calculated to compare with the electroweak precision test results. With the contributions to the non-negligible UU^{\prime} parameter from the ϵB,W\epsilon_{B,W} parameters and the aid of some other parameters to cancel the negative TT^{\prime}, the recent CDF WW-mass anomaly can therefore be explained.Comment: S, T, U parameters are changed to the effective S', T', U'. Further detailed discussions about the parameter definitions and the corresponding effective operators are elaborated in the appendix. Figures are update

    Using corneal topography design personalized cataract surgery programs

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    AIM:To investigate how to design personalized cataract surgery programs to achieve surgical correction of preoperative corneal astigmatism with surgical astigmatism under the guidance of corneal topography, improve postoperative visual quality and reduce the cost of treatment. <p>METHODS: Totally 202 cases(226 eyes)cataract patients were divided into randomized treatment group and individualized treatment group. According to the method and location of the incision, randomized treatment group were divided into 8 groups. Surgical astigmatism after different incision were calculated with the use of preoperative and postoperative corneal astigmatism through vector analysis method. Individualized treatment groups were designed personably for surgical method with reference of every surgically induced astigmatism, the surgical method chooses the type of surgical incision based on close link between preoperative corneal astigmatism and surgically induced astigmatism, and the incision was located in the steep meridian. The postoperative corneal astigmatism of individualized treatment group was observed. <p>RESULTS: Postoperative corneal astigmatism of individualized treatment group were lower than that of 3.0mm clear corneal tunnel incision in the randomized treatment group, there were statistically significance difference, while with 3.0mm sclera tunnel incision group there were no statistically significance difference. After 55.8% of patients with the use of individualized surgical plan could undergo the operation of extracapsular cataract extraction with relatively low cost and rigid intraocular lens implantation, the per capita cost of treatment could be reduced. <p>CONCLUSION: Personalized cataract surgery programs are designed to achieve surgical correction of preoperative corneal astigmatism under the use of corneal topography, improve postoperative visual quality and reduce the cost of treatment

    Efficacy and safety of guselkumab for the treatment of patients with moderate-to-severe plaque psoriasis: A metaanalysis of randomized clinical trials

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    Purpose: To conduct a systematic analysis on data from randomized controlled trials (RCTs) on different doses of guselkumab, and provide high-quality evidence for its use in the treatment of patients with moderate-to-severe plaque psoriasis (PsO). Methods: Related studies were searched using online search engines including MEDLINE, PubMed, and central registry of Cochrane controlled trials from January 2001 to October 2017. Only randomized, placebo-controlled, double-blind clinical trials involving guselkumab- and placebo-treated PsO subjects were included. Results: Five eligible double-blind, randomized, and placebo-controlled trials involving patients with moderate-to-severe PsO subjects treated with guselkumab were included. Compared with the placebo groups, the proportion of patients with improvements in Psoriasis Area and Severity Index (PASI) 75 (RR= 12.14; 95% CI= 9.11-16.16; p &lt; 0.001); PASI 90 (RR= 23.26; 95% CI =14.57-37.13; p &lt; 0.001), and PASI 100 (RR = 37.66; 95% CI = 15.81-89.69; p &lt; 0.001) were significantly higher than those in guselkumab-treated groups. Furthermore, the guselkumab-treated groups showed significant decreases in Physician’s Global Assessment (PGA) score (RR = 10.46; 95% CI = 7.96-13.83; p &lt; 0.001) and the Dermatology Life Quality Index (DLQI) score (SMD = -1.3; 95% CL = -1.4 to -1.19; p &lt; 0.001), when compared with the placebo groups. However, there were no significant differences in adverse events (AEs) (RR = 1.01; 95% CL = 0.93-1.11; p &gt; 0.05); severe adverse events (SAEs) (RR = 1.32; 95% CI =0.69-2.54; p &gt; 0.05) and study discontinuations (RR = 0.79; 95% CI = 0.42-1.48; p &gt; 0.05) between the two groups. Conclusion: This meta-analysis summarizes available evidence for the use of guselkumab in psoriasis. The results suggest that guselkumab is superior to placebo in moderate-to-severe psoriasis, and is welltolerated, effective, and safe in improving the severity of disease and quality of life. Keywords: Guselkumab, Effectiveness, Safety, Plaque psoriasis, Meta-analysis, Quality of lif

    7-Piperazinethylchrysin inhibits melanoma cell proliferation by targeting Mek 1/2 kinase activity

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    Purpose: To investigate the growth-inhibitory effect of 7-piperazinethylchrysin (PEC) on melanoma cell lines.Methods: Cell viability was analyzed by trypan blue exclusion assays and the cell cycle by flow cytometry using ModFit LT software. Specifically, cells were stained with propidium iodide (0.5 mg/mL) supplemented with RNase A (50 mg/mL), and analyzed using flow cytometry and ModFit LT software.Results: In A375 and B16F10 cell cultures, proliferation was reduced to 79 and 72 %, respectively, on treatment with 30 μM PEC. PEC increased the proportion of A375 cells in G1/G0 phase to 71.23 %, versus 42.76 % in untreated cells. In B16F10 and A375 cells, treatment with PEC caused the inhibition of Mek 1/2 kinase activity and suppressed Erk 1/2 phosphorylation. The level of cAMP-response element binding protein was increased by PEC. The expression of microphthalmia-linked transcription factor was also increased by PEC treatment. Marked enhancement was observed in the level of tyrosinase in melanoma cells on treatment with PEC. Analysis of PBG-D expression showed a marked increase in B16F10 and A375 cells on the addition of PEC to cell cultures at 72 h. The level of PBG D expression was increased by 9- and 8.5-fold in B16F10 and A375 cells, respectively, on incubation with 30 μM PEC. The addition of a Mek 1/2 inhibitor (U0126) to the cultures promoted PEC-mediated growth inhibition.Conclusion: PEC inhibited melanoma cell proliferation, apparently by blocking the cell cycle at G0/G1 and downregulating the Ras/Raf/Mek/Erk pathway.Keywords: Tyrosinase, Kinase, Microphthalmia, Phosphorylation, 7-Piperazinethylchrysi

    Molecular simulation and spectroscopic studies on the interaction between perfluorohexadecanoic acid and human serum albumin

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    185-192In the present study, the interaction between Perfluorohexadecanoic acid (PFHxDA) and human serum albumin (HAS) was studied by fluorescence spectroscopy, molecular docking, dynamic simulation and circular dichroism (CD). The interaction character and the effect on human serum albumin conformation were measured by simulating the physiological condition (pH= 7.4). Experiments and simulation results revealed that PFHxDA molecules and HSA have regular fluorescence quenching, and the quenching mechanism is static quenching and non-radiative energy transfer. Thermodynamic analysis revealed the binding behavior was mainly governed by hydrophobic forces. Specific binding site experiments showed that the binding site of PFHxDA was a site I of HSA. The results from the CD spectrum demonstrated that PFHxDA changed the molecular conformation of HSA, which is consistent with the results obtained by molecular docking and dynamic simulation

    Molecular simulation and spectroscopic studies on the interaction between perfluorohexadecanoic acid and human serum albumin

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    In the present study, the interaction between Perfluorohexadecanoic acid (PFHxDA) and human serum albumin (HAS) was studied by fluorescence spectroscopy, molecular docking, dynamic simulation and circular dichroism (CD). The interaction character and the effect on human serum albumin conformation were measured by simulating the physiological condition (pH= 7.4). Experiments and simulation results revealed that PFHxDA molecules and HSA have regular fluorescence quenching, and the quenching mechanism is static quenching and non-radiative energy transfer. Thermodynamic analysis revealed the binding behavior was mainly governed by hydrophobic forces. Specific binding site experiments showed that the binding site of PFHxDA was a site I of HSA. The results from the CD spectrum demonstrated that PFHxDA changed the molecular conformation of HSA, which is consistent with the results obtained by molecular docking and dynamic simulation
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