Compared with

conventional polystyrene, the synthesized copolymers exhibited a higher refractive index and a higher thermal stability both under nitrogen and air atmospheres at elevated temperature, and the visible-light transmittance of the copolymers decreased slightly. With increasing ratio of compound 1 to styrene in the copolymers, the onset decomposition temperature and the char yield both increased gradually. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 3137-3144, 2011″
“The Keller-Segel system has been widely proposed as a model for bacterial waves driven by chemotactic processes. Current experiments on Escherichia coli have shown the precise structure of traveling pulses. We present here an alternative mathematical selleck chemical description

of traveling pulses at the macroscopic scale. This modeling task is complemented with numerical simulations in accordance with the experimental observations. Our model is derived from an accurate kinetic description of the mesoscopic run-and-tumble process performed by bacteria. This can account for recent experimental observations with E. coli. Qualitative agreements include the asymmetry of the pulse and transition in the collective behaviour (clustered motion versus dispersion). In addition, we can capture quantitatively the traveling speed of the pulse as well as its characteristic length. This work opens several experimental and theoretical perspectives since coefficients at the macroscopic level are derived from considerations

at the cellular scale. For instance, the particular response of a single cell to chemical cues turns this website selleck chemicals llc out to have a strong effect on collective motion. Furthermore, the bottom-up scaling allows us to perform preliminary mathematical analysis and write efficient numerical schemes. This model is intended as a predictive tool for the investigation of bacterial collective motion.”
“Although morphine is often the best option for treating acute and chronic severe pain, its analgesic activity can be blocked in situations in which there are elevated levels of chemokines. Indeed, recently we have shown that elevated brain levels of the chemokine stromal cell-derived growth factor-1alpha (SDF-1 alpha/CXCL12, the ligand of the HIV co-receptor CXCR4) diminish the antinociceptive effect of morphine. The purpose of the present study was to investigate whether such an effect is restricted to morphine or extends to other opioid medications such as buprenorphine. A sterilized stainless-steel C313G guide cannula was implanted into the periaqueductal grey (PAG), a brain region critical to the processing of pain signals, and a primary site of action of many analgesic compounds. The cold-water (-3 degrees C) tail-flick test (CWT) was used to measure antinociception. Rats were pretreated with SDF-1 alpha/CXCL12 administered into the PAG.