Photothermal liquid release from arrayed Au nanorod/hydrogel composites for chemical stimulation

Controlled photothermal actuation of liquid release is presented using periodically arrayed hydrogel columns in a macroporous silicon membrane. Thermo-responsive hydrogel is mixed with Gold (Au) nanorods, and surface plasmon-induced local heating by near-infrared (NIR) light is utilized as an actuation method. We adopted theoretical modeling, which treats the hydrogel as a poro-viscoelastic medium to understand the mechanical and liquid transport properties of the hydrogel. To demonstrate the feasibility of the liquid release control using NIR light, we first characterized the temperature response of Au nanorod embedded hydrogel in the silicon membrane using its optical transmission behavior to confirm the successful device fabrication. Next, the liquid release characteristics from the structure were studied using fluorescent imaging of fluorescein dye solution while pulsed NIR light was illuminated on the structure. We successfully demonstrate that the liquid release can be controlled using remote NIR illumination from the presented structure. Considering the periodically arrayed configuration with high spatial resolution, this will have a potential prospect for optically-addressable chemical release systems, which benefit retina prosthesis interfaces.

Reusable Water Bottles: Release of Inorganic Elements, Phthalates, and Bisphenol A in a “Real Use” Simulation Experiment

Reusable water bottles are growing in popularity; thus, possible chemical release from the internal surface into water should be carefully considered to control related health risks. We experimentally evaluated the release into deionized water of 40 elements, six phthalates, and bisphenol-A for 20 different reusable bottles by simulating the use in real world scenario. The 20 bottles, identified as those most purchased in Italy, were made of various materials (stainless steel, aluminum, plastic, and silicone). The experiment was carried out for four consecutive weeks in duplicate for each type of bottle. Our results showed the release, to various extents, of inorganic elements from all 20 bottles, while the release of phthalates and bisphenol-A was never found. The elements most frequently released were Al, Sr, Mo, and Cr, while the highest concentrations were for Ca, K, Mg, and Na; the release of toxic elements (such as Pb, Cd, Ni, Sb) also occurred. The comparison of our results with regulatory limits on drinking water quality revealed no exceeding values except for Al. However, these releases represent a further intake, and the related risks cannot be neglected, especially for highly susceptible populations. Thus, it is essential to correctly inform consumers both with dedicated interventions and exhaustive labelling.

Enhanced Immunoprecipitation Techniques for the Identification of RNA Binding Protein Partners: CRD-BP interactions in mammary epithelial cells

RNA binding proteins (RBPs) regulate expression of large cohorts of RNA species to affect programmatic changes in cellular phenotypes. In order to describe the function of RBPs within a cell, it is key to identify their mRNA binding partners. This is often done by cross-linking nucleic acids to RBPs, followed by chemical release of the nucleic acid fragments for analysis. However, this methodology is lengthy, involves complex processing leading to extraordinary losses, requires large amounts of starting materials, and is prone to artifacts due to the labile nature of mRNA. To evaluate potential alternative technologies, we tested "exclusion-based" purification of immunoprecipitates (oil-based IFAST™ or air-based SLIDE™), and report here that these methods can efficiently, rapidly and specifically isolate RBP-RNA complexes with minimal handling. The analysis starts with >100x less material than for techniques that include cross-linking. Depending on the specific antibody used, 50-100% of starting protein is retrieved, allowing the assay of endogenous levels of RBP instead of tagged and over-expressed ectopic proteins. Isolated protein and nucleic acid components are purified and analyzed using standard techniques to provide a comprehensive portrait of RBP complexes. Using exclusion-based techniques, we show that the mRNA binding partners for CRD-BP/IMP1/IGF2BP1/ZBP1 in cultured mammary epithelial cells are enriched in mRNAs important for de-toxifying superoxides (glutathione metabolic enzymes) and other mRNAs encoding mitochondrial proteins.

Vesicular Release Dynamics are Altered by Interaction between Chemical Cargo and Vesicle Membrane Lipids

We used liposomes loaded with different monoamines, dopamine (DA) and serotonin (5-HT), to simulate vesicular release and to monitor the dynamics of chemical release from isolated vesicles during vesicle impact electrochemical cytometry (VIEC). The release of DA from liposomes presents a longer release time compared to 5-HT. Modelling the release time showed that DA filled vesicles had a higher percentage of events where the time for the peak fall was better fit to a double exponential (DblExp) decay function, suggesting multiple kinetic steps in the release. By fitting to a desorption-release model, where the transmitters adsorbed to the vesicle membrane, the dissociation rates of DA and 5-HT from liposome membrane were estimated. DA has a lower desorption rate constant, which leads to slower DA release than that observed for 5-HT, whereas there is little difference in pore size. The alteration of vesicular release dynamics due to the interaction between chemical cargo and vesicle membrane lipids provides an important mechanism to regulate vesicular release in chemical and physiological processes. It is highly possible that this introduces a fundamental chemical regulation difference between transmitters during exocytosis.

Vesicular Release Dynamics are Altered by Interaction between Chemical Cargo and Vesicle Membrane Lipids

We used liposomes loaded with different monoamines, dopamine (DA) and serotonin (5-HT), to simulate vesicular release and to monitor the dynamics of chemical release from isolated vesicles during vesicle impact electrochemical cytometry (VIEC). The release of DA from liposomes presents a longer release time compared to 5-HT. Modelling the release time showed that DA filled vesicles had a higher percentage of events where the time for the peak fall was better fit to a double exponential (DblExp) decay function, suggesting multiple kinetic steps in the release. By fitting to a desorption-release model, where the transmitters adsorbed to the vesicle membrane, the dissociation rates of DA and 5-HT from liposome membrane were estimated. DA has a lower desorption rate constant, which leads to slower DA release than that observed for 5-HT, whereas there is little difference in pore size. The alteration of vesicular release dynamics due to the interaction between chemical cargo and vesicle membrane lipids provides an important mechanism to regulate vesicular release in chemical and physiological processes. It is highly possible that this introduces a fundamental chemical regulation difference between transmitters during exocytosis.

Simultaneous estimation of simvstatin and piperine in its formulation by UV spectrophotometric method

The active ingredient, called piperine, is present in black pepper. The ions are very small so they are easily consumed by the tissue and nervous system, causing the chemical release within the brain. Piperine has been shown to help ease gastrointestinal ailments, help with vomiting, and has the ability to help with inflammation of the body. This explains to us how simvastatin can help expedite piperine in the body. The new, clear, effective, quick, accurate ultraviolet spectrophotometric method has to be validated and developed for the study of simvastatin and piperine in bulk and poly-herbal formulations. Data from validation experiments was tested using methodological techniques. Since processing at a wavelength of 285nm, the standard solution appeared to have a far higher absorbance than at other wavelengths. Normal simvastatin and piperine have been measured in varying amounts, and they make spectrums of overlays. In Beer Law, the concentration (C) of a solvent is plotted against the absorbance (A) from a calibration curve, as a result. A linearity range of between 14and 39μg/mL was observed. The sample was tested by prorating the standard deviation and standard error of the approximate means with the sample size, demonstrating the accuracy and the precision of the methods used in the analysis. Based on the experimental findings, it can be easily inferred that for UV spectrometry estimation of simvastatin and piperine from pharmaceutical intravenous liquid formulation, the proposed method is very simple, fast, accurate, precise, economical and reproducible.

Potential impacts of shale and tight gas developments on unconfined aquifers – a chemical screening framework

The Geological and Bioregional Assessment Program examines the potential impacts of shale, tight and deep coal gas development on water and the environment. A key part of the project was quantifying the potential for a decline in the water quality of unconfined aquifers due to unintentional chemical release at the soil surface. To assess this hazard, a quantitative analysis of chemical migration pathways was undertaken, which involved the estimation of contaminant attenuation by dilution and dispersion in soil and groundwater. This provided a conservative screening approach to identify areas for further analysis. Attenuation calculations involved one-dimensional advection-dispersion (AD) simulations through the unsaturated zone, and three-dimensional AD solute transport within the surficial aquifers. Dilution factor (DF) relationships for the combined effect of attenuation in the unsaturated and saturated zone were used to construct spatial maps of the potential for impact on aquifer properties after accidental chemical spills. A higher DF (therefore lower consequence of the surface contamination) was associated with deeper unsaturated zones characterized by heavier soils near the surface, and lower ground water velocities due to lower hydraulic conductivity and/or hydraulic gradient in the saturated zone. The framework was applied across the Cooper Basin and Beetaloo Sub-basin and resulted in two types of maps. The first identified areas being more susceptible to contamination if soil remediation does not occur within a 10-year period. The second map shows the spatially variable combined DFs for a ground water receptor, which may be used to develop site-specific management plans and mitigation measures.

Waterborne, non-fluorinated and durable anti-icing superhydrophobic coatings based on diatomaceous earth

Superhydrophobic coatings have a great potential for anti-icing compared with conventional techniques (e.g., thermally melting, chemical release and mechanical vibration), but suffer from short water freezing time, environmentally unfriendness and...