Expression Pattern of Purinergic Signaling Components in Colorectal Cancer Cells and Differential Cellular Outcomes Induced by Extracellular ATP and Adenosine

The purine nucleotide adenosine triphosphate (ATP) is known for its fundamental role in cellular bioenergetics. However, in the last decades, different works have described emerging functions for ATP, such as that of a danger signaling molecule acting in the extracellular space on both tumor and stromal compartments. Beside its role in immune cell signaling, several studies have shown that high concentrations of extracellular ATP can directly or indirectly act on cancer cells. Accordingly, it has been reported that purinergic receptors are widely expressed in tumor cells. However, their expression pattern is often associated with contradictory cellular outcomes. In this work, we first investigated gene expression profiles through “RNA-Sequencing” (RNA Seq) technology in four colorectal cancer (CRC) cell lines (HT29, LS513, LS174T, HCT116). Our results demonstrate that CRC cells mostly express the A2B, P2X4, P2Y1, P2Y2 and P2Y11 purinergic receptors. Among these, the P2Y1 and P2Y2 coding genes are markedly overexpressed in all CRC cells compared to the HCEC-1CT normal-like colonic cells. We then explored the cellular outcomes induced by extracellular ATP and adenosine. Our results show that in terms of cell death induction extracellular ATP is consistently more active than adenosine against CRC, while neither compound affected normal-like colonic cell survival. Intriguingly, while for the P2Y2 receptor pharmacological inhibition completely abolished the rise in cytoplasmic Ca²⁺ observed after ATP exposure in all CRC cell lines, Ca²⁺ mobilization only impacted the cellular outcome for HT29. In contrast, non-selective phosphodiesterase inhibition completely abolished the effects of extracellular ATP on CRC cells, suggesting that cAMP and/or cGMP levels might determine cellular outcome. Altogether, our study provides novel insights into the characterization of purinergic signaling in CRC.     

Chicken fat dry fractionation: Effects of temperature and time on crystallization,filtration and fraction properties

A surface response experimental design was used to quantify the effects of the final cooling temperature and the residence time at this temperature on the filtration characteristics of the crystal suspension and the quality of the fractions during chicken fat dry fractionation. The crystal morphology was monitored to gain insight into the observed effects. Temperature affected crystallization and the characteristics of the olein and stearin fractions. The crystals became fragmented as the residence time increased, thus leading to a decrease in the filterability of the crystal suspension and an increase in the proportion of the entrained liquid phase. The residence time only affected the quality of the stearin fraction. This time effect was noted at high cooling temperatures in the investigated experimental domain. At low temperatures, increasing the residence time enhanced crystal growth and increased the extent of unsaturation of both fractions without modifying the filtration features.     

New 2-Methyl-13-Icosenoic Acid from the Temperate Calcisponge <Emphasis Type="Italic">Leuconia johnstoni</Emphasis>

The fatty acid composition of the temperate calcareous marine sponge Leuconia johnstoni Carter 1871 (Calcaronea, Calcarea) was characterized for the first time in specimens collected off the Brittany coast of France over four years from October 2005 to September 2008. Forty-one fatty acids (FA) with chain lengths ranging from C₁₄ to C₂₂ were identified as fatty methyl esters (FAME) and N-acyl pyrrolidide (NAP) derivatives by gas chromatography–mass spectrometry (GC–MS). Twenty-two saturated fatty acids (SFA) were identified accounting for 52.1–59.0% of the total FA and dimethylacetals (DMA). In addition, among the SFA, we noticed the presence of numerous methyl-branched iso and anteiso FA, suggesting a large number of associated bacteria within L. johnstoni. Thirteen monounsaturated fatty acids (MUFA, 28.0–36.0% of total FA + DMA) were also identified as well as six polyunsaturated fatty acids (PUFA, 4.0–8.2%). A noticeable DMA was detected at a high level, particularly in September 2008 (11.8%), indicating the presence of plasmalogens in this sponge species. This calcareous sponge lacked the non-methylene-interrupted FA (NMI FA) with a Δ5,9 system typical of siliceous Demosponges and Hexactinellids. The occurrence of the unusual 8,13-octadecadienoic acid was reported for the first time as a minor PUFA in a calcareous sponge. The major FA, representing 20–25% of this sponge FA, was identified as the new 2-methyl-13-icosenoic acid from mass spectra of its methyl ester and its corresponding N-acyl pyrrolidide derivatives as well as a dimethyl disulfide adduct.     

Statistical study of the influence of building architectural properties on scattered fields in urban environment

Statistical studies on the reflection coefficient of concrete–glass building facades are conducted using a fast and an accurate method based on the Green’s functions. The variation of different architectural parameters, such as concrete permitting and distribution, size and type of windows, are studied. The influence of selected parameters on the total reflection coefficient of the building is quantified for different incidence and observation angles as well as in different diffraction zones.     

Interpenetrating polymer networks derived from silylated soybean oil and polydimethylsiloxane

A series of interpenetrating polymer networks (IPNs) was prepared using various concentrations of silylated soybean oil and polydimethylsiloxane (PDMS) that were cross linked with inorganic silicates. This series of IPNs was prepared from emulsions of silylated soybean oil and PDMS together with colloidal silica and dioctyltin dilaurate catalyst at pH 10. Under these conditions, water soluble silicates reacted with silanols in the oil phase and formed intraparticle siloxane cross links. Upon casting films and evaporation of the water, additional interparticle cross linking were obtained between the coagulating particles to produce entangled networks of soybean oil and PDMS that were further reinforced by fine silica particles. The morphology revealed intimate mixing of the two immiscible components. The mechanical properties depended on the ratio of the soft, flexible PDMS phase and the rigid, brittle cross linked silylated soybean oil phase. These IPNs can be used as high release liners, low friction materials, or as a general protective coating. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2479–2486, 2013     

Effect of Clay Modification on the Mechanism of Local Deformations in PA6 Nanocomposites

PA nanocomposites are prepared from clays organophilized with a phosphonium and an ammonium salt, and sodium montmorillonite is used as reference. The analysis of mechanical and micromechanical properties of the composites reveal that several micromechanical deformation processes occur in the PA/MMT composites. The matrix cavitates at relatively small stress. Processes related to non‐exfoliated clay structural units are initiated at larger stresses. Sound is emitted mainly by the fracture of particles, but debonding may also occur. The plastic deformation of the matrix dominates at larger stresses and deformations. The various local deformations are independent of each other and composite properties are not determined by silicate related processes but by the deformation of the matrix.

     

Synthesis and Pharmacological Evaluation of a series of the Agomelatine Analogues as Melatonin MT1/MT2 Agonist and 5‐HT2C Antagonist

Agomelatine is a naphthalenic analogue of melatonin that is in clinical use for the treatment of major depressive disorders. Interestingly, while agomelatine exhibits potent affinity for melatonin receptors, it binds with only moderate affinity to the serotonin 5‐HT_2C receptor. Optimization of agomelatine toward this target could further potentiate its clinical efficacy. To explore this hypothesis and to access derivatives in which a key point of agomelatine metabolism is blocked, a series of naphthalenic derivatives was designed and synthesized as novel analogues of agomelatine. Most of the prepared compounds exhibited good binding affinity at the melatonin MT₁ and MT₂ receptor subtypes. Two compounds, an acetamide and an acrylamide derivative, exhibited good binding affinities at both the human melatonin (MT) receptors and the serotonin 5‐HT_2C receptor subtype, with pK_i values of 7.96 and 7.95 against MT₁, 7.86 and 8.68 against MT2, and 6.64 and 6.44 against 5‐HT_2C, respectively.     

Renewable biocomposites of dimer fatty acid-based polyamides with cellulose fibres: Thermal,physical and mechanical properties

Dimer fatty acid-based polyamides (DAPA) are reinforced with cellulose fibres (CF) from 5 to 20 wt.%. Thermal, morphological, dynamic mechanical and mechanical properties of the corresponding biocomposites (DAPAC) are investigated. They exhibit a high increase in glass transition temperature (T_g) and a decrease in the crystallisation temperature and crystallinity degree. This can be attributed to carbonyl (DAPA) and hydroxyl (CP) groups’ interactions. These hydrogen bonds reduce the polymer mobility. For instance, the dynamic mechanical spectra of these biocomposites reveal an increase in the stiffness and higher thermal–mechanical stability. Morphological observations reveal a moderate interfacial adhesion between the fibres and the matrix. With the increase of the fibre content, tensile tests show a high increase in Young modulus and yield stress, and a decrease of elongation at break. Predicted modulus results based on micromechanical models, Voigt and Reuss bounds and Halpin–Tsai approaches, are compared with the experimental values. They show that the Halpin–Tsai model can be used to quantify the mechanical properties for DAPA/CF biocomposites.     

Field Study of the Ability of Two Grassed Bioretention Cells to Reduce Storm-Water Runoff Pollution

Two grassed bioretention cells including internal storage zones (ISZs) were monitored for 16?months in central North Carolina. Each cell had a surface area of 106?m2 and fill media depths were 0.75 and 1.05?m for the north (North) and the south (South) cells, respectively. Asphalt parking lot inflow and outflows were analyzed for nitrogen and phosphorus forms and fecal coliform (FC). Outflow volumes and peak flows for individual storms were generally less than those of inflow. Overall, except for NO2,3–N, effluent nitrogen species event mean concentrations (EMCs) and loads were significantly (α = 0.05) lower than those of the inflow, and nitrogen species load reductions ranged from 47 to 88%. Apart from fall and winter, during which a longer hydraulic contact time seemed to be needed, the ISZs appeared to improve denitrification. Total phosphorus (TP) and OPO4-P EMCs were significantly lower than those of the inlet. Reductions were 58% (South) and 63% (North) for TP and 78% (North) and 74% (South) for OPO4–P. There was no significant difference in TP and OPO4–P loads between the inlet and the two outlets. Moreover, effluent concentrations for both phosphorus species were low, relative to other studies. The best nutrient EMC and load reductions occurred during the warm and humid seasons. When considering effluent concentrations in addition to removal rates, the grassed cells showed promising results for FC and nutrient pollution abatement when compared to conventionally vegetated bioretention (trees, shrubs, and mulch) previously studied in North Carolina.     

Optimization of the spark plasma sintering processing parameters affecting the properties of polyimide

The present study deals with the optimization of polyimide (PI) mechanical properties, obtained by Spark Plasma Sintering (SPS), by using a method combining Design of Experiments (DOE) with physical, structural, and mechanical characterizations. The effects of SPS parameters such as temperature, pressure, dwell time, and cooling rate on the density, mechanical properties, and structure of PI were investigated. The experimental results revealed that the mechanical properties of the material were optimized by raising the sintering temperature up to 350°C. The optimized SPS processing parameters were a temperature of 350°C, a pressure of 40 MPa, and a dwell time of 5 min. Under these conditions, a relative density of 99.6% was reached within only a few minutes. The corresponding mechanical properties consisted of Young's modulus of 3.43 GPa, a Shore D hardness of 87.3, and a compressive strength of 738 MPa for a maximum compressive strain of 61.8%. Moreover, when working at 320°C and at 100 MPa, an increase in the dwell time was necessary to enhance the properties. Contrary to the other parameters, the cooling rate appeared to be a non‐significant parameter. Finally, correlations between the PI structure and the mechanical properties were made to demonstrate the densification mechanisms. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41542.