Long‐Range Nanoparticle Surface‐Energy‐Transfer Ruler for Monitoring Photothermal Therapy Response

A recent gold nanotechnology‐driven approach opens up a new possibility for the destruction of cancer cells through photothermal therapy. Ultimately, photothermal therapy may enter into clinical therapy and, as a result, there is an urgent need for techniques to monitor the tumor response to therapy. Driven by this need, a nanoparticle surface‐energy‐transfer (NSET) approach to monitor the photothermal therapy process by measuring a simple fluorescence intensity change is reported. The fluorescence intensity change is due to the light‐controlled photothermal release of single‐stranded DNA/RNA via dehybridization during the therapy process. Time‐dependent results show that just by measuring the fluorescence intensity change, the photothermal therapy response during the therapy process can be monitored. The possible mechanism and operating principle of the NSET assay are discussed. Ultimately, this NSET assay could have enormous potential applications in rapid, on‐site monitoring of the photothermal therapy process, which is critical to providing effective treatment of cancer and multidrug‐resistant bacterial infections.     

Navigating gendered labor and local food: A tale of working mothers in Vermont

Over the past several decades, the state of Vermont has become a national leader in the local food movement. Located along the banks of Lake Champlain, Chittenden County is a hub for the local food movement and innovative food security efforts. This article presents qualitative data from a collaborative research project examining the multiple ways that Chittenden County residents access, prepare, and share food. Following the model of “critical case studies,” I focus in on the narratives of six working mothers from diverse cultural backgrounds to examine the work of these mothers related to accessing, preparing, and sharing food and how this work is shaped by intersections of cultural identity and gendered obligations. I argue that narratives of food and family are a meaningful site for examining the lived dimensions of local food systems and shared values related to food that are culturally familiar and embedded in social relationships.     

Tape casting of strontium and cobalt doped lanthanum chromite suspensions

Lanthanum chromite (LaCrO₃) is currently the most widely studied material as interconnector layers for solid oxide fuel cells (SOFC). The complexity of microstructures and geometries of SOFC devices, which are usually built-up by lamination of the different constitutive layers, make it necessary a precise control of processing parameters to achieve the desired combination of properties. Much effort has been devoted to the processing of electrodes and electrolytes but the other layers, such as that of interconnecting material, have received scarce attention. This work deals with the preparation and optimisation of the rheological behaviour of concentrated suspensions of Sr- and Co-doped LaCrO₃ and the subsequent tape casting to produce homogeneous thin sheets to be used in the SOFC stack.The starting powder was produced by combustion synthesis from the corresponding nitrates and urea as a fuel, and had a final composition of La_0.80Sr_0.20Cr_0.92Co_0.08O₃. These powders were dispersed in ethanol with commercial copolymers (Hypermer, KD6) to solids loading of up to 58 wt%. The binding system (BS) consisted of a mixture of a binder, polyvinyl butyral-co-vinyl alcohol-co-vinyl acetate (PVA-PVAc), and two plasticizers, polyethyleneglycol (PEG400) and benzylbutylphthalate (BBP). The effect of the binding system content and the binder-to-plasticizer ratio on the tape casting performance and the characteristics of the green and the sintered tapes, were studied, as well as the influence of the casting parameters (casting speed and blades height).     

Adsorption of methyl mercaptan on activated carbons

Activated carbons of different origins were studied as methyl mercaptan adsorbents in wet, dry, and oxidizing conditions. The materials were characterized using adsorption of nitrogen, Boehm titration, and thermal analysis. Investigation was focused on the feasibility of the removal of methyl mercaptan on activated carbons and on the role of surface chemistry and porosity in the adsorption/oxidation processes. The results showed relatively high capacities of carbons for removal of CH3SH. The amount adsorbed depends on the surface features. Methyl mercaptan, in general, is oxidized to disulfides, which, depending on the chemistry of the carbon surface, can be converted to sulfonic acid due to the presence of water and active radicals.     

Application of Ozone and Advanced Oxidation Processes to the Treatment of Lye-Wastewaters from the Table Olives Industry

An important fraction of wastewaters generated in the black table olives industry results from the treatment of the olives with sodium hydroxide for debittering and darkening of the fruit. These lye-wastewaters are characterized by a high presence of organic compounds, mainly phenols and polyphenols. The decomposition of that organic content was studied by means of several chemical treatments: ozonation alone and combined with hydrogen peroxide or UV radiation, as well as UV radiation alone and combined with hydrogen peroxide. The degradation levels and the effect of the additional presence of H₂O₂ and UV radiation on the organic matter removal were established for these processes. An approximate kinetic study was conducted, which led to the evaluation of the rate constants for the organic matter reduction. In a second phase, non-pretreated lye-wastewaters and preozonated wastewaters were degraded biologically by means of aerobic microorganisms. The evolution of the organic matter and the biomass were followed. It was demonstrated that the pretreatment with ozone significantly enhances the efficiency of the aerobic process, increasing both the substrate removal level and the degradation rate. This enhancement is probably due to the elimination of most of the toxic phenolic compounds and the increase of the biodegradability in the ozonation pretreatment.     

Optical properties of the synthetic nanocomposites SiO2/CdS/poly(styrene-co-maleic anhydride) and SiO2/CdS/poly(styrene-co-maleimide)

Hybrid materials consisting of SiO2/CdS particles dispersed in poly(styrene-co-maleic anhydride) and poly(styrene-co-maleimide) have been synthesized and characterized. The polymer nanocomposites were synthesised in situ in the presence of previously prepared inorganic fillers (SiO2/CdS). The nanocomposites were synthesized with the use of as-prepared or surface-modified SiO2/CdS fillers. For both types of nanocomposites, the optical properties were evaluated and the observation of size quantization effects in the optical spectra is discussed. In this context, the influence of the inorganic fillers and polymer matrices on the optical properties of the final nanocomposites was investigated.     

Stopped flow kinetic-spectrophotometric determination of Diquat in waters

Using the measures of initial reaction rate, a kinetic-photometric method is developed that uses the reaction of Diquat with H2O2 in basic medium. The reaction rate is very high and therefore the stopped-flow mixing technique is required in order to make kinetic measurements. The reaction rate is obtained in 20 s after the reactants are mixed and it allows the simple application of the method proposed to the routine analyses. The sensitivity of the method is very high being the detection limit 0.44 microgmL(-1) and the application range between 1 and 16 microgmL(-1). The time of measure per sample is 90s. The proposed kinetic-photometric method has been applied to the direct determination of this compound in river water, in the water of laundry of the olives, and in a commercial product. The results are very acceptable.     

Sex-Specific Differences in Olfactory Sensitivity for Putative Human Pheromones in Nonhuman Primates.

In humans, the volatile C19-steroids androsta-4,16-dien-3-one (AND) and estra-1,3,5(10),16-tetraen-3-ol (EST) have been shown to modulate autonomic nervous system responses, and to cause hypothalamic activation in a gender-specific manner. Using two conditioning paradigms, the authors here show that pigtail macaques and squirrel monkeys of both sexes were able to detect AND and EST at concentrations in the micromolar and mM range, respectively. Male and female spider monkeys, in contrast, differed markedly in their sensitivity to these two odorous steroids, with males not showing any behavioral responses to the highest concentrations of AND tested and females not responding to the highest concentrations of EST. These data provide the first examples of sex-specific bimodal distributions of olfactory sensitivity in a nonhuman primate species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Iterative solution of algebraic matrix Riccati equations in open loop Nash games

In this note we study a fixed point iteration approach to solve algebraic Riccati equations as they appear in general two player Nash differential games on an infinite time horizon, where the information structure is of open loop type. We obtain conditions for existence and uniqueness of non‐negative solutions. The performance of the numerical algorithm is shown in an example. Copyright © 2005 John Wiley & Sons, Ltd.     

Pulsed Laser Deposition of Zr1-xCexO2 and Ce1-xLaxO2-x/2 for Buffer Layers and Insulating Barrier in Oxide Heterostructures

We have studied the pulsed laser deposition (PLD) of Zr_1-xCexO₂ and Ce_1-xLa_xO₂-x/2 initially to grow buffer layers for perovskite films deposited on Si, LaAlO₃, SrTiO₃ and MgO and then to produce tunneling barriers for cuprate or manganite heterostructures. On (1 0 0) Si, the deposition of Zr_1-xCexO₂ (x = 0.12) produces a smooth epitaxial layer (R _RMS = 0.25/1m²), which allows the further deposition of high quality YBa₂Cu₃O₇ (Tc 88 K) and La_0.7Sr_0.3MnO₃ films. On the other hand, the use of Ce_1-xLa_xO_2-x/2 (0 x 0.4) makes it possible to match the YBa₂Cu₃O₇ and La_0.7Sr_0.3MnO₃ layers to various substrates. The buffer layers are epitaxially grown with a 45° rotation of the in-plane axes with respect to those of the substrate, and the smoothness is high (R _RMS = 0.25/1m²). In the case of an ultra-thin barrier (2.5 nm) of Ce_1-xLa_xO_2-x/2 sandwiched in a La_0.7Sr_0.3MnO₃, the out-of-plane mismatch of 2 induces distortions at the interface steps, which propagate into the topmost La_0.7Sr_0.3MnO₃ layer. This is in contrast to the case of SrTiO₃ barriers where an ideal crystal continuity in the growth direction is observed.