Next-to-Leading order approximation of polarized valon and parton distributions

Polarized parton distributions and structure functions of the nucleon are analyzed in the improved valon model. The valon representation provides a model to represent hadrons in terms of quarks, providing a unified description of bound state and scattering properties of hadrons. Polarized valon distributions are seen to play an important role in describing the spin dependence of parton distributions in the leading order (LO) and next-to-leading order (NLO) approximations. In the polarized case, a convolution integral is derived in the framework of the valon model. The Polarized valon distribution in a proton and the polarized parton distributions inside the valon are necessary to obtain the polarized parton distributions in a proton. Bernstein polynomial averages are used to extract the unknown parameters of the polarized valon distributions by fitting to the available experimental data. The predictions for the NLO calculations of the polarized parton distributions and proton structure functions are compared with the LO approximation. It is shown that the results of the calculations for the proton structure function, $xg_1^p$, and its first moment, $\Gamma_{1}^p$, are in good agreement with the experimental data for a range of values of $Q^{2}$. Finally the spin contribution of the valons to the proton is calculated.Comment: 22 pages, 7 figures. Published in Journal of High Energy Physics (JHEP

Disorder in DNA-Linked Gold Nanoparticle Assemblies

We report experimental observations on the effect of disorder on the phase behavior of DNA-linked nanoparticle assemblies. Variation in DNA linker lengths results in different melting temperatures of the DNA-linked nanoparticle assemblies. We observed an unusual trend of a non-monotonic ``zigzag'' pattern in the melting temperature as a function of DNAlinker length. Linker DNA resulting in unequal DNA duplex lengths introduces disorder and lowers the melting temperature of the nanoparticle system. Comparison with free DNA thermodynamics shows that such an anomalous zigzag pattern does not exist for free DNA duplex melting, which suggests that the disorder introduced by unequal DNA duplex lengths results in this unusual collective behavior of DNA-linked nanoparticle assemblies.Comment: 4 pages, 4 figures, Phys.Rev.Lett. (2005), to appea

A novel microassay for the quantitation of the sulfated glycosaminoglycan content of histological sections: its application to determine the effects of Diacerhein on cartilage in an ovine model of osteoarthritis

AbstractObjective A new micro-histological method of assessing the sulfated glycosaminoglycan (S-GAG) content in unstained histological sections of articular cartilage was developed and used to study the effects of orally administered Diacerhein (DIA) on joint cartilage in an ovine model of osteoarthritis (OA).Methods Twenty adult, age-matched Merino wethers were subjected to bilateral lateral meniscectomy, while 10 served as non-operated controls (NOC groups). Half of the operated sheep (N=10) remained untreated (MEN groups), while the other 10 animals were given DIA (25mg/kg orally) daily for 3 months, then 50mg/kg daily for a further 6 months (DIA groups). Five animals each of the DIA, MEN and NOC groups, respectively, were sacrificed at 3 months post-operatively, and the remainder 6 months later. For the present study only one knee joint of each animal was used for histological processing. The tissues studied were from the lateral femoral condyles (LFC) and lateral tibial plateaux (LTP). Each of these joint regions was further subdivided into inner (I), middle (M), and outer (O) zones. Unstained histological sections from these AC regions and zones were then analysed for S-GAG content using the following procedure. Images of each section of 6μm thickness were acquired using a flatbed scanner and the area determined with an image analysis software program. The sections were then transferred to wells of a microtiter plate, digested with papain and the S-GAG content quantitated using a modification of the 1,9-dimethylmethylene blue dye binding assay. The data was represented as μg S-GAG/mm3of each tissue section. These data were also compared with toluidine blue stained sections from the same paraffin blocks.Results The results obtained showed that the area of histological sections could be very accurately determined by computer assisted image analysis using a 10mm×10mm calibration grid. Cartilage sections of areas ranging from 1mm2up to 25mm2were analysed for S-GAG content with this simple technique. There was a linear relationship between section thickness (2–10μm) and S-GAG content per unit area (R2=0.993). Sections of 6μm thickness were found to be optimal. S-GAG analyses of serial sections from tibial and femoral articular cartilage (I, M and O zones) revealed an average coefficient of variation of 7.0±2.3% (range 4.9–10.2%) confirming the accuracy and reproducibility of this assay method. A separate experiment showed that no significant losses of S-GAG occurred during the histological sample processing.The different regions and zones of the knee joint AC in the six experimental groups revealed variable levels of S-GAG which did not necessarily correlate with the histochemical distribution of toluidine blue staining. The major S-GAG changes occurred in the middle (lesion zone) and outer zones (hypertrophic zone) of both the LFC and LTP of the MEN groups. In the lesion (M) zone the S-GAG content was reduced while in the O zone levels were increased at both 3 and 6 months post-surgery. In animals receiving Diacerhein S-GAG levels in the M zone were lower than or equivalent to those of non-drug treated OA or non-operated controls for both joint regions at 3 and 6 months. While the hypertrophic response in the outer zone of the LFC, as assessed by S-GAG content, was enhanced by drug treatment, the cartilage of the outer zones of the LTP was not affected by drug treatment.Conclusion The results of this study have demonstrated that the S-GAG (and therefore proteoglycan [PG]) content in different cartilage zones of OA joints can be readily quantitated by direct biochemical analysis of unstained histological sections. By this means subtle changes in PG distribution in different cartilage zones, which were not evident using traditional histochemical staining methods, could be readily detected

Laser-based three-dimensional manufacturing technologies for rechargeable batteries.

Laser three-dimensional (3D) manufacturing technologies have gained substantial attention to fabricate 3D structured electrochemical rechargeable batteries. Laser 3D manufacturing techniques offer excellent 3D microstructure controllability, good design flexibility, process simplicity, and high energy and cost efficiencies, which are beneficial for rechargeable battery cell manufacturing. In this review, notable progress in development of the rechargeable battery cells via laser 3D manufacturing techniques is introduced and discussed. The basic concepts and remarkable achievements of four representative laser 3D manufacturing techniques such as selective laser sintering (or melting) techniques, direct laser writing for graphene-based electrodes, laser-induced forward transfer technique and laser ablation subtractive manufacturing are highlighted. Finally, major challenges and prospects of the laser 3D manufacturing technologies for battery cell manufacturing will be provided

Seasonal Gradient Patterns of Polycyclic Aromatic Hydrocarbons and Particulate Matter Concentrations near a Highway

Close proximity to roadways has been associated with higher exposure to traffic-related air pollutants. However, analyses of the effects of season and meteorological parameters on horizontal gradient patterns of traffic-generated air pollutants still need to be elucidated. Our objectives were to: (1) determine effects of season on horizontal gradient patterns of polycyclic aromatic hydrocarbons (PAHs), total suspended particles (TSP), and PM2.5 near a heavily trafficked highway; and (2) examine the effect of day-of-the-week variations (weekday versus weekend) associated with traffic counts on measured airborne-contaminant levels. PAHs (Σ8PAHs [MW 228–278]; gas + particulate), TSP and PM2.5 were monitored at nominal distances (50, 100, and 150 m) from the New Jersey Turnpike every 6 days for periods of 24 h, between September 2007 and September 2008. Seasonal variations in the horizontal gradient patterns of Σ8PAHs were observed. In the summer, Σ8PAHs declined significantly between 50–100 m from the highway (23% decrease), but not between the furthermost distances (100–150 m). An inverse pattern was observed in the winter: Σ8PAHs declined between 100–150 m (26% decrease), but not between the closest distances. Σ8PAHs and TSP, but not PM2.5, concentrations measured on weekends were 12–37% lower than those on weekdays, respectively, corresponding to lower diesel traffic volume. This study suggests that people living in the close proximity to highways may be exposed to varying levels of Σ8PAHs, TSP, and PM2.5 depending on distance to highway, season, and day-of-the-week variations

Peptide Mimicrying Between SARS Coronavirus Spike Protein and Human Proteins Reacts with SARS Patient Serum

Molecular mimicry, defined as similar structures shared by molecules from dissimilar genes or proteins, is a general strategy used by pathogens to infect host cells. Severe acute respiratory syndrome (SARS) is a new human respiratory infectious disease caused by SARS coronavirus (SARS-CoV). The spike (S) protein of SARS-CoV plays an important role in the virus entry into a cell. In this study, eleven synthetic peptides from the S protein were selected based on its sequence homology with human proteins. Two of the peptides D07 (residues 927–937) and D08 (residues 942–951) were recognized by the sera of SARS patients. Murine hyperimmune sera against these peptides bound to proteins of human lung epithelial cells A549. Another peptide D10 (residues 490–502) stimulated A549 to proliferate and secrete IL-8. The present results suggest that the selected S protein regions, which share sequence homology with human proteins, may play important roles in SARS-CoV infection

Disorder-Induced Depinning Transition

The competition in the pinning of a directed polymer by a columnar pin and a background of random point impurities is investigated systematically using the renormalization group method. With the aid of the mapping to the noisy-Burgers' equation and the use of the mode-coupling method, the directed polymer is shown to be marginally localized to an arbitrary weak columnar pin in 1+1 dimensions. This weak localization effect is attributed to the existence of large scale, nearly degenerate optimal paths of the randomly pinned directed polymer. The critical behavior of the depinning transition above 1+1 dimensions is obtained via an $\epsilon$-expansion.Comment: 47 pages in revtex; postscript files of 6 figures include

Azimuthal distributions of radial momentum and velocity in relativistic heavy ion collisions

Azimuthal distributions of radial (transverse) momentum, mean radial momentum, and mean radial velocity of final state particles are suggested for relativistic heavy ion collisions. Using transport model AMPT with string melting, these distributions for Au + Au collisions at 200 GeV are presented and studied. It is demonstrated that the distribution of total radial momentum is more sensitive to the anisotropic expansion, as the anisotropies of final state particles and their associated transverse momentums are both counted in the measure. The mean radial velocity distribution is compared with the radial {\deg}ow velocity. The thermal motion contributes an isotropic constant to mean radial velocity