Fluorescence quenching of poly(methylphenylsilane) in solution

The solution, electron-transfer fluorescence quenching of a typical aromatic polysilane[poly(methylphenylsilane)] by a series of electronic deficient aromatic monomers is described. The rate of fluorescence quenching is a function of the reduction potential of the quencher, and only very fast processes can be observed, due to the short polymer fluorescence lifetime. The measurement of quenching rate constants, which are considerably larger than diffusion control, suggests that extensive energy migration occurs in the polymer. Although the fluorescence quenching at low quencher concentrations follows Stern-Volmer kinetics, at high concentrations, contributions from static quenching are apparent. Strong fluorescence quenching can either accelerate or inhibit photodegradation, depending on the structure of the quencher.     

A Nonlinear Device to Suppress Strong Interfering Signals with Arbitrary Angle Modulation in Spread-Spectrum Receivers

A device which can be used to suppress strong constantenvelope interfering signals at the input of spread-spectrum receivers is described and analyzed. Unlike similar circuits known from literature, this device is not restricted to the suppression of narrow-band jamming signals; it can also cope with broad-band interfering signals bearing any kind of angle modulation. The theoretical results are confirmed by measurements.     

Experimental investigation of ESD design window for fully depleted SOI N-MOSFETs

In this article, the impact in FDSOI technology, of ground plane and buried oxide (BOX) size on the robustness and on the NMOS triggering voltage (Vt1) is shown. We show experimentally that firstly thin BOX devices are more robust than thick BOX devices and secondly with a higher Vt1, thin BOX device purposes a larger range to trigger ESD network and to optimize design.     

Natural convection in shear‐thinning yield stress fluids in a square enclosure

The influence of viscoplastic rheological features on the Rayleigh‐Bénard convection is investigated by numerical means in order to compare with first experimental results given by Darbouli et al. The fluid is modeled by a regularized Herschel‐Bulkley law which is often used to fit numerous pasty fluids. Natural convection in a two‐dimensional square cavity heated from below is considered. Critical values of Oldroyd number Od and yield number Y are provided. Numerical results highlight a stabilizing effect of the yield stress as well as a destabilizing effect of increasing shear‐thinning coefficient n as the increase in n enhances the heat transfer in the range of our calculations. Unyielded regions are located in the square corners of the cavity and in the cavity where convection occurs. The unyielded zones size increases with the increase in Od and can invade all the cavity for sufficiently large values of Od. © 2015 American Institute of Chemical Engineers AIChE J, 62: 1347–1355, 2016     

The Body's Response to Deliberate Implants: Phagocytic Cell Responses to Large Substrata Vs. Small Particles

It is important to characterize possible inflammatory responses to small particles, and to separate clearly these effects from responses to larger objects nearby. This research used a chemiluminescent assay, scanning electron micrographs, and energy dispersive X-ray spectra to monitor inflammation-related reactive oxygen intermediate (ROI) production and morphological alterations of human monocyte-derived macrophages interacting with the walls of apolar and polar polystyrene cuvettes, in the absence and presence of small particles of surface-characterized Teflon?, polyethylene, Co-Cr-Mo alloy, titanium and alumina. The two types of polystyrene substrata represent the “bacterial” (as produced) and “tissue culture” (gas-plasma-treated [GPT]) materials widely used in biological testing and tissue culture. Monocyte-derived macrophage spreading during contact with the higher-surface-energy, more polar substratum suppressed “oxidative bursts” to lower levels than expressed from rounded cells in contact with the lower-energy, apolar substratum. Particulate matter engulfed by both rounded and spread cells did not significantly enhance ROI production beyond levels observed for no-particle controls during the one-hour exposure time. Biocompatibility of some implants might be related to cell-spreading-induced suppression of ROI production, improving the tissue integration of GPT implants.     

Discovery of a New Class of Non‐imidazole Oxazoline‐Based Histamine H3 Receptor (H3R) Inverse Agonists

H ₃ R inverse agonists based on an aminopropoxy‐phenyloxazoline framework constitute highly valuable druglike lead compounds that display efficacy in a mouse model of recognition memory.