Influence of induced magnetic field on the peristaltic flow of nanofluid

This article investigates the effects of an induced magnetic field on the mixed convection peristaltic motion of nanofluid in a vertical channel. Transport equations involve the combined effects of Brownian motion and thermophoretic diffusion of nanoparticles. Analysis has been addressed subject to long wavelength and low Reynolds number assumptions. Explicit expressions of stream function, magnetic force function, temperature and nanoparticles concentration are developed. Analytic expressions are validated with the obtained numerical solutions. Peristaltic pumping rate is found to increase upon increasing the strengths of electric and magnetic fields and the buoyancy force due to temperature gradient. Moreover temperature rises and nanoparticles concentration decreases with an intensification in the Brownian motion effect.     

A T‐shaped selenenyl halide

The title selenenyl halide complex, 3‐iodo‐2‐phenyl‐3H‐3‐selenaindazole, C₁₂H₉IN₂Se, has an almost planar conformation and a nearly ideal T‐shape for the Se(INC) moiety [Se—I 2.8122 (12), Se—C 1.881 (7) and Se—N2 2.051 (6) Å; C—Se—N 79.6 (3), C—Se—I 96.8 (2) and N—Se—I 176.17 (17)°]. This arrangement, together with the two selenium lone pairs, leads to a distorted trigonal‐bipyrimidal geometry about the Se atom. Intermolecular interactions are largely limited to stacking forces.     

Thermal degradation of ammonium polymethacrylate and polymethacrylamide

The degradation of ammonium polymethacrylate and polymethacrylamide has been studied by a combination of thermal analysis methods (TVA and TG) and examination of volatile and involatile products by infrared analysis. It is shown that total reaction comprises an initial cyclization and further fragmentation of the modified chain at higher temperatures to yield gaseous volatiles. The partially degraded NH₄PMA contains anhydride ring and cyclic imide structures in the chain. Quantitative comparison of yields of isocyanic acid and carbon dioxide has shown that imidization is the major reaction and anhydride formation is of less importance. The mechanisms of the various reactions are discussed.     

Cyanobacteria as Natural Therapeutics and Pharmaceutical Potential: Role in Antitumor Activity and as Nanovectors

Cyanobacteria (blue-green microalgae) are ubiquitous, Gram-negative photoautotrophic prokaryotes. They are considered as one of the most efficient sources of bioactive secondary metabolites. More than 50% of cyanobacteria are cultivated on commercial platforms to extract bioactive compounds, which have bene shown to possess anticancer activity. The chemically diverse natural compounds or their analogues induce cytotoxicity and potentially kill a variety of cancer cells via the induction of apoptosis, or altering the activation of cell signaling, involving especially the protein kinase-C family members, cell cycle arrest, mitochondrial dysfunctions and oxidative damage. These therapeutic properties enable their use in the pharma and healthcare sectors for the betterment of future generations. This review provides a baseline overview of the anti-cancerous cyanobacterial bioactive compounds, along with recently introduced nanomaterials that could be used for the development of new anticancer drugs to build a healthy future for mankind.     

Graphene Nanosheets Decorated with Copper Oxide Nanoparticles for the Photodegradation of Methylene Blue

Textile industries extensively use colorants, such as methylene blue, and if disposed off untreated, they contaminate the effluent streams, causing a severe impact on the environment and aquatic life. Photocatalytic degradation has been found as an inevitable approach to treat them. Herein, we decorated the copper oxide nanoparticles on graphene nanosheets during the reflux process. The resultant copper oxide/graphene nanocomposites were analyzed for structural and functional attributes. It was observed that on increasing the copper oxide contents, the z-average size of the resultant nanocomposites decreased. The X-ray diffraction analysis demonstrated the crystalline nature of the nanocomposite. The surface morphology of the copper oxide nanoparticles appeared to be spherical and that of the copper oxide/graphene composite somehow wrinkled. The infrared analysis indicated successful intercalation of precursors in the nanocomposite. The bandgap of copper oxide/graphene nanocomposites varied in the range of 1.03-1.30 eV, which indicated their effective photocatalytic activity. The results demonstrated that after 120 min of exposure, the methylene blue removal efficiency reached 94.0%, 92.2%, and 89.4%(mass fraction) on the copper oxide/graphene nanocomposite at copper oxide nanoparticles to graphene nanosheets ratios of 1:1, 1.5:1, and 2:1 (mass ratio), respectively. The photodegradation performance of the prepared nano-catalyst was found satisfactory even after five cycles.     

Identification of Human Kinin-Forming Enzyme Inhibitors from Medicinal Herbs

The goal of this study was to assess the pharmacological effects of black tea (Camellia sinensis var. assamica) water extract on human kinin-forming enzymes in vitro. Tea is a highly consumed beverage in the world. Factor XII (FXII, Hageman factor)-independent- and -dependent activation of prekallikrein to kallikrein leads to the liberation of bradykinin (BK) from high-molecular-weight kininogen (HK). The excessive BK production causes vascular endothelial and nonvascular smooth muscle cell permeability, leading to angioedema. The prevalence of angiotensin-converting enzyme inhibitor (ACEI)-induced angioedema appears to be through BK. Both histamine and BK are potent inflammatory mediators. However, the treatments for histamine-mediated angioedema are unsuitable for BK-mediated angioedema. We hypothesized that long-term consumption of tea would reduce bradykinin-dependent processes within the systemic and pulmonary vasculature, independent of the anti-inflammatory actions of polyphenols. A purified fraction of the black tea water extract inhibited both kallikrein and activated FXII. The black tea water extracts inhibited factor XII-induced cell migration and inhibited the production of kallikrein on the endothelial cell line. We compared the inhibitory effects of the black tea water extract and twenty-three well-known anti-inflammatory medicinal herbs, in inhibiting both kallikrein and FXII. Surprisingly, arjunglucoside II specifically inhibited the activated factor XII (FXIIa), but not the kallikrein and the activated factor XI. Taken together, the black tea water extract exerts its anti-inflammatory effects, in part, by inhibiting kallikrein and activated FXII, which are part of the plasma kallikrein–kinin system (KKS), and by decreasing BK production. The inhibition of kallikrein and activated FXII represents a unique polyphenol-independent anti-inflammatory mechanism of action for the black tea.     

Fabrication and characterization of nanocrystalline Al,Co:ZnO thin films by a sol–gel dip coating

The consequence of annealing on the micro-structural and electrochemical characteristics of Al doped CoZnO thin films deposited by sol–gel dip coating technique are studied. X-ray diffraction indicates that films have a hexagonal wurtzite structure oriented towards the (100). Optical properties of films are recorded by transmission curves utilising a UV–VIS spectrophotometer. The investigation of the optical transmission spectra indicates that the band gap of the films decrease from 3.99 eV to minimum 3.83 eV upon annealing. All films show room temperature ferromagnetism whose magnetization increases with annealing. Dip coated films possess polycrystalline nanosized grains with porous morphology.