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Abstract-We consider channel/subspace tracking systems for temporally correlated millimeter wave (e.g., E-band) multipleinput multiple-output (MIMO) channels. Our focus is given to the tracking algorithm in the non-line-of-sight (NLoS) environment, where the transmitter and the receiver are equipped with hybrid analog/digital precoder and combiner, respectively. In the absence of straightforward time-correlated channel model in the millimeter wave MIMO literature, we present a temporal MIMO channel evolution model for NLoS millimeter wave scenarios. Considering that conventional MIMO channel tracking algorithms in microwave bands are not directly applicable, we propose a new channel tracking technique based on sequentially updating the precoder and combiner. Numerical results demonstrate the superior channel tracking ability of the proposed technique over independent sounding approach in the presented channel model and the spatial channel model (SCM) adopted in 3GPP specification.

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IntroductionIncreasing evidence suggests that beta-blocker use might be associated with reduced mortality in prostate cancer patients. To provide a quantitative assessment of this association, we pooled data available to examine the association between beta-blocker use and mortality of prostate cancer.MethodsWe identified studies by a literature search of MEDLINE (from 1 January 1966) and EMBASE (from 1 January 1974), through 10 September 2014, and by searching the reference lists of pertinent articles. Two authors independently screened and reviewed the eligibility of each study. The primary outcomes were prostate cancer-specific mortality and all-cause mortality.ResultsA total of four studies including 16,825 patients were included in this meta-analysis. Analysis of all studies showed that beta-blocker use was associated with reduced prostate cancer-specific mortality (hazard ratio =0.85, 95% confidence interval =0.77–0.94), without any heterogeneity between studies (Q=3.59, I 2=16.5%, P=0.309). However, we observed no association with all-cause mortality (hazard ratio =0.97, 95% confidence interval =0.90–1.04). There was also no evidence of the presence of significant heterogeneity between the four studies (Q=2.48, I 2=0.0%, P=0.480).ConclusionThese findings indicate that beta-blocker use was associated with reduced cancer-specific mortality among prostate cancer patients taking beta-blockers.

Epoxy-clay nanocomposites were prepared by the dispersion of an organically modified layered clay in an epoxy resin (diglycidyl ether of bisphenol A) and curing in the presence of methyl tetrahydro acid anhydride at 80 -160°C. The nanometer-scale dispersion of layered clay within the crosslinked epoxy-resin matrix was confirmed by X-ray diffraction and transmission electron microscopy, and the basal spacing of the silicate layer was greater than 100 -150 Å. Experiments indicated that the hydroxyethyl groups of the alkyl ammonium ions, which were located in the galleries of organically modified clay, participated in the curing reaction and were directly linked to the epoxy-resin matrix network. Experimental results showed that the properties of epoxy were improved, evidently because of the loading of organically modified clay. The impact strength and tensile strength of the nanocomposites increased by 87.8 and 20.9%, respectively, when 3 wt % organic clay was loaded, and this demonstrated that the composites were toughened and strengthened. The thermal-decomposition and heat-distortion temperatures were heightened in comparison with those of pure epoxy resin, and so were the dynamic mechanical properties, including the storage modulus and glass-transition temperature. Moreover, experiments showed that most properties of the composites were ameliorated with low clay contents.

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