Effect of substitution by Ni in MgAl2O4 spinel for biogas dry reforming

Mesoporous nanocrystalline Mg_1-xNi_xAl₂O₄ (x = 0.10, 0.13, 0.17 and 0.20) with large surface area were synthesized via a simple one-step sol-gel method using nonprecious metals. The prepared Mg_1-xNi_xAl₂O₄ catalysts exhibit good catalytic performance towards methane and carbon dioxide dry reforming reaction. The catalysts were evaluated by various techniques, including XRD, BET, TPR, TPO, EPR, Chemisorption, SEM and TEM. All the Ni incorporated MgAl₂O₄ samples possessed high BET area (296–305 m² g^?1) and pore volume (0.47–0.56 cm³ g^?1) with small pore size (6.4–7.4 nm) in meso region after calcination at 700 °C. The TPR results suggested strong interaction effect in NiMg and the reducibility property of the catalysts improved with the increase of nickel doping. Mg_0.8Ni_0.2Al₂O₄ exhibited the highest activity for biogas dry reforming with 72.6% CH₄ and 80.7% CO₂ conversion at 700 °C. Electron paramagnetic resonance (EPR) results indicated that the incorporation of Ni in MgAl₂O₄ spinel lattice led to the lattice distortion and formed oxygen vacancies which are a benefit for the dry reforming reaction.     

Magnetic nanobiosorbent (MG‐Chi/Fe3O4) for dispersive solid‐phase extraction of Cu(II), Pb(II), and Cd(II) followed by flame atomic absorption spectrometry determination

Trace amounts of Cu (II), Pb (II), and Cd (II) in a wastewater sample were preconcentrated with a novel cross‐linked magnetic chitosan modified with a new synthesised methionine‐glutaraldehyde Schiff''s base (MG‐Chi/Fe₃O₄) as a dispersive solid‐phase extraction (DSPE) adsorbent. The adsorbed metal ions were then eluted with a specific volume of suitable solution and determined by flame atomic absorption spectrometry (FAAS). Various parameters affecting the extraction efficiency of the metal ions were investigated and optimised, including pH, amount of adsorbent, extraction time, type and volume rate of eluent, elution time, sample volume, and effect of interfering ions. The adsorption kinetics are more consistent with the pseudo‐second order model. The results were statistically interpreted and the analytical performance of the proposed method was found to have preconcentration factors of 55, 60, and 50 μg L⁻¹ for Cu(II), Pb(II), and Cd(II), respectively, limits of detection were 0.22, 0.24, and 0.10 μg L⁻¹ for Cu(II), Pb(II), and Cd(II), respectively, with a relative standard deviation (1.5%‐2.8 %), and the liner range was 5–1000 for Cu(II) and Pb(II) and 2.5–1000 for Cd(II). It was concluded that this method was suitable for successful simultaneous determination of Cu(II), Pb(II), and Cd(II) in industrial wastewater samples.     

Layer-by-layer self-assembly of collagen and chitosan biomolecules on polyurethane films

Polyurethane (PU) films used in wound dressing applications often have appropriate properties. Still, surface modification is necessary to increase the biocompatibility. In this research, the surface of the PU films was modified with collagen and chitosan biomolecules through layer by layer (LbL) self-assembly process. The PU films were synthesized from castor oil and hexamethylene diisocyanate. Then, they were treated with low-pressure nitrogen plasma to graft with poly(acrylic acid). Before performing the LbL process, the surfaces of the PU films were modified using three different reagents, including (A) NaOH solution, (B) EDC/NHS solution, or (C) hexamethylene diamine. Then, the collagen and chitosan deposited in three and five layers on the surface. The images of FESEM, confocal microscopy, and AFM showed that the best performance of the LbL deposition process was after the surface modification with hexamethylenediamine (HMDA). The MTT assay showed that the presence of these biomolecules had boosted the proliferation of fibroblast cells. Increasing the number of the deposited layer from three to five, decreased the cell viability and antibacterial activity of the films. The obtained results propose the modification with HMDA and the deposition of three layers of collagen and chitosan on the PU films to improve its biocompatibility.     

Potent CCR3 Receptor Antagonist,SB328437, Suppresses Colonic Eosinophil Chemotaxis and Inflammation in the Winnie Murine Model of Spontaneous Chronic Colitis

Eosinophils and their regulatory molecules have been associated with chronic intestinal inflammation and gastrointestinal dysfunctions; eosinophil accumulation in the gut is prominent in inflammatory bowel disease (IBD). The chemokine receptor CCR3 plays a pivotal role in local and systemic recruitment and activation of eosinophils. In this study, we targeted CCR3-ligand interactions with a potent CCR3 receptor antagonist, SB328437, to alleviate eosinophil-associated immunological responses in the Winnie model of spontaneous chronic colitis. Winnie and C57BL/6 mice were treated with SB328437 or vehicle. Clinical and histopathological parameters of chronic colitis were assessed. Flow cytometry was performed to discern changes in colonic, splenic, circulatory, and bone marrow-derived leukocytes. Changes to the serum levels of eosinophil-associated chemokines and cytokines were measured using BioPlex. Inhibition of CCR3 receptors with SB328437 attenuated disease activity and gross morphological damage to the inflamed intestines and reduced eosinophils and their regulatory molecules in the inflamed colon and circulation. SB328437 had no effect on eosinophils and their progenitor cells in the spleen and bone marrow. This study demonstrates that targeting eosinophils via the CCR3 axis has anti-inflammatory effects in the inflamed intestine, and also contributes to understanding the role of eosinophils as potential end-point targets for IBD treatment.     

Physicochemical modification of hydroxylated polymers to develop thermosensitive double network hydrogels

Due to the unique biophysicochemical characteristics of synthesized superhydrophilic poly[N-[tris(hydroxymethyl)methyl] acrylamide] (PTHMMA) and poly(vinyl alcohol) (PVA), in this study, we investigated the preparation of physically and chemically crosslinked thermosensitive double network (DN) hydrogels with superior mechanical properties. The effect of the combination of PTHMMA with PVA was further explored experimentally and theoretically. Moreover, adjusting the lower critical solution temperature (LCST) of PTHMMA/PVA DN hydrogels in the phosphate buffer was achieved by chemical alteration and crosslinking of water-soluble polymers. Changing the composition and the extent of ether/acetal linkages altered the LCST based on hydrophilic/hydrophobic composition, which decreased the complexity of adjusting hydrogels' temperature sensitivity. PTHMMA-comprising hydrogels were found to have non-Fickian and super case ΙΙ transport characters. Moreover, the construction of shrunken PVA at high temperature was tailored by introducing PTHMMA into the network to permit a relaxed drug release of indomethacin (IND) at 37°C and pH 7.4. Finally, the tensile strength, the equilibrium water content, thermo-sensitivity, and cell viability behaviors suggest that these materials can be tailored for potential applications as biomaterials.     

Current Understanding of the Relationship between Blood Donor Variability and Blood Component Quality

While differences among donors has long challenged meeting quality standards for the production of blood components for transfusion, only recently has the molecular basis for many of these differences become understood. This review article will examine our current understanding of the molecular differences that impact the quality of red blood cells (RBC), platelets, and plasma components. Factors affecting RBC quality include cytoskeletal elements and membrane proteins associated with the oxidative response as well as known enzyme polymorphisms and hemoglobin variants. Donor age and health status may also be important. Platelet quality is impacted by variables that are less well understood, but that include platelet storage sensitive metabolic parameters, responsiveness to agonists accumulating in storage containers and factors affecting the maintenance of pH. An increased understanding of these variables can be used to improve the quality of blood components for transfusion by using donor management algorithms based on a donors individual molecular and genetic profile.     

Low-pressure plasma surface modification of polyurethane films with chitosan and collagen biomolecules

Polyurethane (PU) was synthesized using castor oil and a trade grade of hexamethylene diisocyanate, and then PU films were prepared for wound dressing applications. The PU films were then plasma treated with the low-pressure nitrogen plasma to functionalize with peroxide and hydroperoxide groups in order to attach with acrylic acid monomers. Therefore, the polyacrylic acid polymer branches were formed on the film surfaces. Carboxylic acid groups were activated by N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride/N-hydroxysuccinimide and bonded with chitosan and collagen biomolecules. Untreated, nitrogen plasma treated, polyacrylic acid grafted, and finally chitosan and collagen-immobilized PU films were characterized by several tests. The tests included the attenuated total reflectance Fourier transform infrared spectroscopy, static contact angle, atomic force microscopy, scanning electron microscopy, fibroblast L929 cell culture, and antibacterial activity assay to evaluate their in vitro cytocompatibility. The results confirmed that chitosan and collagen were immobilized successfully on the PU surfaces. The chitosan-immobilized PU and collagen-immobilized PU improved the adhesion and proliferation of fibroblast cells compared to untreated PU films. The chitosan-modified PU films exhibit the best antibacterial properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47567.     

Inheritance Pattern of Fiber Related Traits under Normal and Hypoxia Conditions in Cotton (Gossypium Hirsutum L.)

An 8 × 8 diallel crossing system was employed in F₁ generation of cotton to study the inheritance pattern of fiber related traits like micronaire, strength and maturity under normal and hypoxia conditions. Analysis of variance revealed significant variation (P < 0.01) for all the traits under both environments. The regression coefficient b deviated significantly from zero but not from unity for all studies traits allowed further analysis of the data. The additive component (D) was significant for all the traits and more than the values of dominance components H₁ and H₂ in case of fiber strength under both conditions and for fiber uniformity under normal conditions thus showing the preponderance of additive genetic effects. For micronaire non-additive effects were predominant under both environments. Estimates of narrow sense heritability for micronaire were 38.6% under normal and 49.5% for hypoxia, 79 and 80% for fiber strength and for fiber uniformity the estimates were 79% under normal conditions and 63% under hypoxia conditions. Predominance of additive genetic effects, high heritability along with partial dominance for fiber strength under both conditions and for fiber uniformity under normal conditions is indicative of early generation selection but for micronaire under both conditions selection may be practiced in later generations.     

Preparation of high surface area activated carbon from corn by chemical activation using potassium hydroxide

Activated carbons were prepared through chemical activation of corn cob precursor, using potassium hydroxide as the chemical agent. The effect of different parameters, such as particle size, method of mixing, chemical/corn ratio, activation time and activation temperature, on weight loss and BET surface area of the produced activated carbons were discussed. The porosity of the activated carbons was evaluated through nitrogen adsorption. The storage capacity of the activated carbon was evaluated using natural gas. Under the experimental conditions investigated, the optimal conditions for production of high surface area carbons by chemical activation were identified. The results were compared with commercial activated carbons from coal.