We investigated the possibility of controlling thin film buckling patterns by varying the substrate curvature and the stress induced therein upon cooling. The numerical and experimental studies are based on a spherical Ag core/SiO(2) shell system. For Ag substrates with a relatively larger curvature, the dentlike triangular buckling pattern comes out when the film nominal stress exceeds a critical value. With increasing film stress and/or substrate radius, the labyrinthlike buckling pattern takes over. Both the buckling wavelength and the critical stress increase with the substrate radius.

Fluorescent quantum dots (QDs) have great potential for in vivo biomedical imaging and diagnostic applications. However, these nanoparticles are composed of heavy metals and are very small in diameter, and their possible toxicity must therefore be considered. As yet, no studies have reported the transfer of QDs between mother and fetus. The transfer of CdTe/CdS QDs of different sizes and dosages, and with different outer capping materials, from pregnant mice to fetuses is investigated. It is shown that QDs may be transferred from female mice to their fetuses across the placental barrier. Smaller QDs are more easily transferred than larger QDs and the number of QDs transferred increases with increasing dosage. Capping with an inorganic silica shell or organic polyethylene glycol reduces QD transfer but does not eliminate it. These results suggest that the clinical utility of QDs could be limited in pregnant women.

The proinflammatory and lipopolysaccharide (LPS)-inducible cytokine tumor necrosis factor ␣ (TNF␣) has been shown to enhance primary sensory nociceptive signaling. However, the precise cellular sites of TNF␣ and TNF receptor synthesis are still a matter of controversy. Therefore, we differentiated the neuronal and non-neuronal sites of TNF␣, TNFR1, and TNFR2 mRNA synthesis in dorsal root ganglion (DRG) of control rats and evaluated how their expression is altered under systemic challenge with LPS. In situ hybridization (ISH), RT-PCR analysis of laser-microdissected cells, and immunocytochemistry revealed absence of TNF␣ from DRG neurons and LPS-induced expression of TNF␣ exclusively in a subpopulation of non-neuronal DRG cells. Using RT-PCR and Northern blotting TNFR1 and TNFR2 mRNAs were found to be constitutively expressed and increased after LPS. TNFR1 mRNA was expressed in virtually all neurons and in non-neuronal cells with increased levels after LPS in both. TNFR2 was exclusively expressed and regulated in nonneuronal cells. RT-PCR analysis of microdissected DRG neurons and of the sensory neuronal cell line F11 confirmed the neuronal expression of TNFR1 and excluded that of TNFR2. Double ISH revealed varying levels of TNFR1 mRNA in virtually all DRG neurons including putative nociceptive neurons coding for calcitonin gene-related peptide, substance P, or vanilloid receptor 1. Taken together, we provide evidence that non-neuronally synthesized TNF␣ may directly act on primary afferent neurons via TNFR1 but not TNFR2. This is likely to be relevant under conditions of inflammatory pain and infections accompanied by widespread TNF␣ synthesis and release and may drive sickness behavior.

Atmospheric pressure plasma jet ͑APPJ͒ can protrude several centers into the ambient air; therefore it holds remarkable promise for many innovative applications. The mechanism underlying this nonthermal discharge, however, remains unsettled that it has been often taken as resulting from dielectric barrier discharge or vaguely referred as streamerlike. We generated APPJ by using a quartz capillary tube with three distinct electrode configurations: conventional double dielectric electrodes for making dielectric barrier discharges, single dielectric electrode, and single bare metal electrode attached to the tube orifice. The jets generated by using the double dielectric electrodes were found consisting of three distinct parts and of different origins. The plasma jet starting from the active electrodes is essentially the propagation of streamers induced by corona discharge. With one single electrode, plasma jets can be generated in both downstream and upstream directions simultaneously; and more importantly at a significantly reduced voltage ͑peak-to-peak value from 3.6 kV on, at 17 kHz͒, this is particularly the case with the bare metal electrode configuration which also helps promote the jet velocity. The typical jet velocity at 10 4 m / s, the occurrence of a second streamer observed in the optical emission as well as the voltage and/or gas flow dependence of jet length can be reasonably accounted for by a streamer mechanism. These results may help steer the research into the underlying physics and will also facilitate a safer and more flexible implementation of this marvelous cold plasma source.