“
“We study the linear and nonlinear optical response of intersubband transitions in a semiconductor quantum well. We describe the coupling of the quantum well structure with the electromagnetic field by using the nonlinear density matrix equations, in the two-subband approximation. We provide proper approximate analytical solutions to these equations that are used for the closed-form determination of the optical susceptibilities X((1)), X((3),) and X((5).) We also explore the dependence of X((1)), X((3),) and X((5)) on the electron sheet density for a specific double GaAs/AlGaAs quantum well. (C) 2010 American Institute of Physics. [doi:

10.1063/1.3457855]“
“Polyurethane (PU) based on castor oil and hexamethylene diisocyanate (HDI) was synthesized by a two-step method in the presence of dibutyltin dilaurate DAPT (DBTDL) as catalyst. The PU obtained was blended

with various Smad inhibitor amounts of cellulose fibers extracted from alfa stems to prepare composite materials. The influence of cellulose fibers on the thermal and mechanical properties of different composites was demonstrated by means of several characterization techniques, such as thermomechanical, structural, and morphological analyses. The hydrogen bonding interaction and the possible formation of urethane links between PU and hydroxyl groups of cellulose provide a good fiber-matrix interface. The infrared absorption vibration of the N-H bond, which is 3336 cm(-1) for pure PU, in fact shifts to 3319 cm(-1) for a composite containing 25% of cellulose. Moreover, the variation of glass transition temperature, T(g), versus cellulose content is linear, for example, T(g) of pure PU

and of a composite containing 40% of cellulose is -35 and -24 degrees C, respectively. Furthermore, the mechanical properties rise steadily up to 20 wt % of fibers and decrease beyond this value. The novelty of this article lies in the selleckchem fact that over 95% of starting materials used are obtained from agro-resource. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 902-909, 2010″
“Serotonin receptor (5-HTR) agonists that target 5-HT(4(a))R and 5-HT(1A)R can reverse mu-opioid receptor (mu-OR)-evoked respiratory depression. Here, we have tested whether such rescuing by serotonin agonists also applies to the cardiovascular system. In working heart-brainstem preparations in situ, we have recorded phrenic nerve activity, thoracic sympathetic chain activity (SCA), vascular resistance and heart rate (HR) and in conscious rats, diaphragmatic electromyogram, arterial blood pressure (BP) and HR via radio-telemetry. In addition, the distribution of 5-HT(4(a))R and 5-HT(1A)R in ponto-medullary cardiorespiratory networks was identified using histochemistry. Systemic administration of the mu-OR agonist fentanyl in situ decreased HR, vascular resistance, SCA and phrenic nerve activity.