Studies of thermal transition behavior in plasticized poly(vinyl butyral-co-vinyl alcohol) with solid-state NMR and thermal analysis techniques

Samples of plasticized poly(vinyl butyral-co-vinyl alcohol) (PVB) are found to exhibit multiple thermal transitions as observed by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). Arrhenius plots using DSC and DMA data suggest that two of the transitions are glass-type ones. Variable temperature solid-state ¹³C-NMR experiments show a temperature-dependent line-broadening pattern for all PVB backbone carbons with maximum broadening at 55°C or at about 50°C above the second-order-type transitions α₁ and α₂ as measured by DSC. Using Arrhenius plots, the NMR transition is found to best correlate with α₁, which is consistent with glass transition behavior. The solid-state NMR spectra also show that vinyl alcohol tacticity remains unresolved up to a temperature of about 95°C, beyond which line narrowing begins to occur. High-temperature thermal transitions are also observed by DSC and DMA, which suggest that the onset of motion involving vinyl alcohol sequences may be responsible for these transitions.     

Assessment of psychological outcomes and quality of life in the rheumatic diseases

OBJECTIVES: To report our experience with temporalis myofascial flaps (TMF), describe the healing process of uncovered flaps in the mouth, and the histology of the repaired mucosa in the long term. DESIGN: Prospective clinical and histological study. SUBJECTS: 36 patients who received a TMF over a 6.5 year period for serial assessment of the oral healing, 24 patients whose scars over the reconstructed area were assessed clinically, and 11 whose repaired mucosa was assessed histologically. MAIN OUTCOME MEASURES: To follow the clinical process of oral healing of the TMF and describe the repaired mucosa healed over the flap. RESULTS: The uncovered TMF in the mouth healed gradually starting with an acute inflammatory phase, going through chronic inflammatory and proliferative phases with eventual epithelialisation of the oral mucosa. There were no major complications. The healed mucosa showed mild scarring in 70% of cases and the repaired mucosa had characteristic histological features that were distinct from the normal mucosa. CONCLUSION: The TMF is an extremely reliable and versatile flap for maxillofacial reconstruction which heals gradually with eventual coverage by mildly scarred repaired mucosa.     

Wavelength-tolerant optical access architectures featuringN-dimensional addressing and cascaded arrayed waveguide gratings

This paper describes two- and three-stage wavelength routed optical access networks, which offer wavelength tolerance by using coarse passband-flattened arrayed waveguide grating routers. An N-dimensional addressing strategy enables 6912 customers to be bidirectionally accessed with multi-Gb/s data using only 24 wavelengths and 1.6 nm spacing. These architectures are designed to map onto standard access network topologies, allowing elegant upgradability from legacy passive optical network (PON) infrastructures at low cost     

Olfactory-visual associative learning in monkeys depends on intrahemispheric olfactory-visual interaction.

Three Cynomolgus monkeys (Macaca fasicularis) learned a series of food-visual conditional discrimination problems. In each problem, 1 of 2 possible food items was presented at the beginning of each trial and acted as an instruction cue as to which of 2 visually distinct stimulus objects the monkey must displace on that trial to obtain a further food reward. Following surgical disconnection of olfactory-visual intrahemispheric interaction, the monkeys were unable to use olfactory properties of the food items to guide visual choices. These results show both that olfactory differences between foodstuffs are a powerful olfactory stimulus, which can enter into cross-modal association with visual stimuli, and that this association depends on an intrahemispheric pathway of olfactory-visual interaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Place conditioning in a three- or four-choice apparatus: Role of stimulus novelty in drug-induced place conditioning.

Examined in a series of 4 experiments the suggestion (M. T. Scoles and S. Siegel, 1986) that drug-induced place preference conditioning may be due to interference with habituation. In each experiment, rats had the opportunity to select among a drug-paired chamber, a saline-paired chamber, and a novel (or relatively novel) chamber. The drugs included the positively reinforcing drugs amphetamine, apomorphine, morphine, and nicotine and the aversive drug lithium chloride. The rats preferred chambers that were paired with amphetamine, apomorphine, and morphine more than chambers that were novel; however, they also consistently preferred novel chambers to familiar saline-paired chambers. There was no evidence of place conditioning with nicotine. The drug-induced place preference, but not the novelty preference, occurred after a single conditioning trial in a 3-choice apparatus but not a 4-choice apparatus. Lithium chloride established a place aversion after 1–3 conditioning trials. Measures of activity revealed that the rats were least active while in their most preferred chamber and most active while in their least preferred chamber. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overview of the Mars Pathfinder mission and assessment of landing site predictions

Chemical analyses returned by Mars Pathfinder indicate that some rocks may be high in silica, implying differentiated parent materials. Rounded pebbles and cobbles and a possible conglomerate suggest fluvial processes that imply liquid water in equilibrium with the atmosphere and thus a warmer and wetter past. The moment of inertia indicates a central metallic core of 1300 to 2000 kilometers in radius. Composite airborne dust particles appear magnetized by freeze-dried maghemite stain or cement that may have been leached from crustal materials by an active hydrologic cycle. Remote-sensing data at a scale of generally greater than approximately 1 kilometer and an Earth analog correctly predicted a rocky plain safe for landing and roving with a variety of rocks deposited by catastrophic floods that are relatively dust-free.