Development of Hydrophilic Polyacrylamide Gel-Based Condensing Reagents Comprised of Chlorotriazine.

Hydrophilic polyacrylamide gel-based triazine-type condensing reagents, PAG-Trz-Cl, have been developed. PAG-Trz-Cls were synthesized using a chlorotriazine with an acrylamide moiety, acrylamide, and N,N'-methylenebisacrylamide via both precipitation and solution polymerization. Because PAG-Trz-Cls adequately swell in aqueous media, the amidation between polar carboxylic acids and amines afforded the corresponding amides in good yields.

Particle Dark Matter Searches Outside the Local Group.

If dark matter (DM) is composed by particles which are nongravitationally coupled to ordinary matter, their annihilations or decays in cosmic structures can result in detectable radiation. We show that the most powerful technique to detect a particle DM signal outside the Local Group is to study the angular cross-correlation of nongravitational signals with low-redshift gravitational probes. This method allows us to enhance the signal to noise from the regions of the Universe where the DM-induced emission is preferentially generated. We demonstrate the power of this approach by focusing on GeV-TeV DM and on the recent cross-correlation analysis between the 2MASS galaxy catalogue and the Fermi-LAT γ-ray maps. We show that this technique is more sensitive than other extragalactic γ-ray probes, such as the energy spectrum and angular autocorrelation of the extragalactic background, and emission from clusters of galaxies. Intriguingly, we find that the measured cross-correlation can be well fitted by a DM component, with a thermal annihilation cross section and mass between 10 and 100 GeV, depending on the small-scale DM properties and γ-ray production mechanism. This solicits further data collection and dedicated analyses.

Evidence for bouncing evolution before inflation after BICEP2.

The BICEP2 Collaboration reports a detection of primordial cosmic microwave background (CMB) B mode with a tensor-to-scalar ratio r = 0.20(-0.05)(+0.07) (68% C.L.). However, this result disagrees with the recent Planck limit r < 0.11 (95% C.L.) on constraining inflation models. In this Letter we consider an inflationary cosmology with a preceding nonsingular bounce, which gives rise to observable signatures on primordial perturbations. One interesting phenomenon is that both the primordial scalar and tensor modes can have a step feature on their power spectra, which nicely cancels the tensor excess power on the CMB temperature power spectrum. By performing a global analysis, we obtain the 68% C.L. constraints on the parameters of the model from the Planck+WP and BICEP2 data together: the jump scale log(10)(k(B)/Mpc(-1)) = -2.4 ± 0.2 and the spectrum amplitude ratio of bounce to inflation r(B) ≡ P(m)/A(s) = 0.71 ± 0.09. Our result reveals that the bounce inflation scenario can simultaneously explain the Planck and BICEP2 observations better than the standard cold dark matter model with a cosmological constant, and can be verified by future CMB polarization measurements.

Correlation between osteoporosis and degeneration of intervertebral discs in aging rats.

This study examined the correlation between osteoporosis and the degeneration of intervertebral discs. Sprague-Dawley rats were maintained up to 22 or 28 months. The femoral bone, tibial bone and lumbar vertebra were histologically studied and the expression of collagen type II and X in intervertebral discs was immunohistochemiscally determined. Several indices for the degeneration of intervertebral discs and osteoporosis and the correlation among them were then analyzed. Close correlations were found among the indices for the degeneration of intervertebral discs, including the relative area of the vascular bud, the ratio of the uncalcified and the calcified layers, the expression of collagen type II and X. The correlation with collagen type X was negative. There existed positive correlations among the indices for osteoporosis, including the thickness ratio of cortical bone, the relative area of bone trabecula, the density of femoral and vertebral body bones, and the maximum stress and strain on bone. Analysis on the relationship of osteoporosis and the disease on disc showed that the indices of osteoporosis were negatively correlated with the indices of the degeneration of intervertebral discs but the expression of collagen type X was positively correlated, with the density of vertebral body bones having the strongest dependence on collagen type X. The maximum stress and strain bore no correlation with the degeneration of intervertebral discs. These results suggest that osteoporosis was negatively correlated with the degeneration of intervertebral discs.

Correlation between Osteoporosis and Degeneration of Intervertebral Discs in Aging Rats / 华中科技大学学报（医学）（英德文版）

This study examined the correlation between osteoporosis and the degeneration of intervertebral discs.Sprague-Dawley rats were maintained up to 22 or 28 months.The femoral bone,tibial bone and lumbar vertebra were histologically studied and the expression of collagen type Ⅱ and X in intervertebral discs was immunohistochemiscally determined.Several indices for the degeneration of intervertebral discs and osteoporosis and the correlation among them were then analyzed.Close correlations were found among the indices for the degeneration of intervertebral discs,including the relative area of the vascular bud,the ratio of the uncalcified and the calcified layers,the expression of collagen type Ⅱ and X.The correlation with collagen type X was negative.There existed positive correlations among the indices for osteoporosis,including the thickness ratio of cortical bone,the relative area of bone trabecula,the density of femoral and vertebral body bones,and the maximum stress and strain on bone.Analysis on the relationship of osteoporosis and the disease on disc showed that the indices of osteoporosis were negatively correlated with the indices of the degeneration of intervertebral discs but the expression of collagen type X was positively correlated,with the density of vertebral body bones having the strongest dependence on collagen type X.The maximum stress and strain bore no correlation with the degeneration of intervertebral discs.These results suggest that osteoporosis was negatively correlated with the degeneration of intervertebral discs.

Searching for CPT violation with cosmic microwave background data from WMAP and BOOMERANG.

We search for signatures of Lorentz and violations in the cosmic microwave background (CMB) temperature and polarization anisotropies by using the Wilkinson Microwave Anisotropy Probe (WMAP) and the 2003 flight of BOOMERANG (B03) data. We note that if the Lorentz and symmetries are broken by a Chern-Simons term in the effective Lagrangian, which couples the dual electromagnetic field strength tensor to an external four-vector, the polarization vectors of propagating CMB photons will get rotated. Using the WMAP data alone, one could put an interesting constraint on the size of such a term. Combined with the B03 data, we found that a nonzero rotation angle of the photons is mildly favored: [Formula: See Text].