Mass cultivation of various algal species and their evaluation as a potential candidate for lipid production

Microalgae have been proposed as a promising source for biodiesel production. Focusing on algal strains for biodiesel production, efforts should be made to search new strains. Experiments were carried out to investigate the effects of growth parameters (nutrients, pH, light, aeration and temperature) and the oil percentage of eight algal strains (Chlorella sp., Cladophora sp., Hydrodictylium sp., Oedogonium sp., Oscillatoria sp., Spirogyra sp., Stigeocolonium sp., Ulothrix sp.). Results show that 6.5–7.5 is the optimum pH for the growth of all algal species. Temperature showed a greater variation (25°40°C). Ulothrix sp. gave more biomass productivity and is the most suitable strain for biodiesel production due to higher oil percentage (62%). Least biomass production was observed for Stigeocolonium sp. and least oil content was obtained from Hydrodictylium sp. It was observed that among these eight algal strains for biodiesel production, Ulothrix and Chlorella are the most promising algae species.     

N-acetyl-D-glucosamine kinase interacts with dynein light-chain roadblock type 1 at Golgi outposts in neuronal dendritic branch points

N-acetylglucosamine kinase (GlcNAc kinase or NAGK) is a ubiquitously expressed enzyme in mammalian cells. Recent studies have shown that NAGK has an essential structural, non-enzymatic role in the upregulation of dendritogenesis. In this study, we conducted yeast two-hybrid screening to search for NAGK-binding proteins and found a specific interaction between NAGK and dynein light-chain roadblock type 1 (DYNLRB1). Immunocytochemistry (ICC) on hippocampal neurons using antibodies against NAGK and DYNLRB1 or dynein heavy chain showed some colocalization, which was increased by treating the live cells with a crosslinker. A proximity ligation assay (PLA) of NAGK-dynein followed by tubulin ICC showed the localization of PLA signals on microtubule fibers at dendritic branch points. NAGK-dynein PLA combined with Golgi ICC showed the colocalization of PLA signals with somal Golgi facing the apical dendrite and with Golgi outposts in dendritic branch points and distensions. NAGK-Golgi PLA followed by tubulin or DYNLRB1 ICC showed that PLA signals colocalize with DYNLRB1 at dendritic branch points and at somal Golgi, indicating a tripartite interaction between NAGK, dynein and Golgi. Finally, the ectopic introduction of a small peptide derived from the C-terminal amino acids 74–96 of DYNLRB1 resulted in the stunting of hippocampal neuron dendrites in culture. Our data indicate that the NAGK-dynein-Golgi tripartite interaction at dendritic branch points functions to regulate dendritic growth and/or branching.     

Graphene oxide‐induced polymerization and crystallization to produce highly conductive polyaniline/graphene oxide composite

Graphene oxide (GO)–polyaniline (PANI) composite is synthesized by in situ polymerization of aniline in the presence of GO as oxidant, resulting in highly crystalline and conductive composite. Fourier transform infrared spectrum confirms aniline polymerization in the presence of GO without using conventional oxidants. Scanning electron microscopic images show the formation of PANI nanofibers attached to GO sheets. X‐ray diffraction (XRD) patterns indicate the presence of highly crystalline PANI. The sharp peaks in XRD pattern suggest GO sheets not only play an important role in the polymerization of aniline but also in inducing highly crystalline phase of PANI in the final composite. Electrical conductivity of doped GO–PANI composite is 582.73 S m^?1, compared with 20.3 S m^?1 for GO–PANI obtained by ammonium persulfate assisted polymerization. The higher conductivity appears to be the result of higher crystallinity and/or chemical grafting of PANI to GO, which creates common conjugated paths between GO and PANI. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1545–1554     

Cosmography of Generalized Ghost Dark Energy Model in f(G) Gravity

Journal of Experimental and Theoretical Physics - This paper is devoted to construction of generalized ghost dark energy f(G) model by using correspondence scheme for both interacting and...     

Nanocomposite Coatings Based on Modified Graphene Oxide and Polydimethylsiloxane: Characterization and Thermal Properties

Russian Journal of Applied Chemistry - Graphene oxide as a derivative of graphite has been noticed as a high efficient material and its application in nanocomposite coatings is surprisingly...     

Relationship of nanostructure and thermo-chemical response/thermal ablation of carbon aerogels

In this work, the interfacial mass balance relations combined with the non-parametric kinetic (NPK) analysis results were used for evaluating the thermo-chemical ablation process and oxidation mechanism of carbon aerogels with various porous structure. It was found that the two-parameter model of Nomen–Sempereis was able to describe the kinetics of the oxidation reaction and to reveal the structure-dependent contribution of two main processes with chemical and physical nature. The porosity of the carbon aerogel, rather than the other microstructural features, was realized more effective on the rate of ablation.     

Olive-Derived Triterpenes Suppress SARS COV-2 Main Protease: A Promising Scaffold for Future Therapeutics

SARS CoV-2 pandemic is still considered a global health disaster, and newly emerged variants keep growing. A number of promising vaccines have been recently developed as a protective measure; however, cost-effective treatments are also of great importance to support this critical situation. Previously, betulinic acid has shown promising antiviral activity against SARS CoV via targeting its main protease. Herein, we investigated the inhibitory potential of this compound together with three other triterpene congeners (i.e., ursolic acid, maslinic acid, and betulin) derived from olive leaves against the viral main protease (M^pro) of the currently widespread SARS CoV-2. Interestingly, betulinic, ursolic, and maslinic acids showed significant inhibitory activity (IC₅₀ = 3.22–14.55 µM), while betulin was far less active (IC₅₀ = 89.67 µM). A comprehensive in-silico analysis (i.e., ensemble docking, molecular dynamic simulation, and binding-free energy calculation) was then performed to describe the binding mode of these compounds with the enzyme catalytic active site and determine the main essential structural features required for their inhibitory activity. Results presented in this communication indicated that this class of compounds could be considered as a promising lead scaffold for developing cost-effective anti-SARS CoV-2 therapeutics.     

Stability of Gorenstein categories

We show that an iteration of the procedure used to define theGorenstein projective modules over a commutative ring R yieldsexactly the Gorenstein projective modules. Specifically, givenan exact sequence of Gorenstein projective R-modules

such that the complexes Hom_R(G, H) and Hom_R(H,G) are exact for each Gorenstein projective R-module H, themodule Coker() is Gorensteinprojective. The proof of this result hinges upon our analysisof Gorenstein subcategories of abelian categories.     

Chitosan–iron oxide nanobiocomposite based immunosensor for ochratoxin-A

The rabbit immunoglobulin antibodies (IgGs) have been immobilized onto nanobiocomposite film of chitosan (CH)–iron oxide (Fe₃O₄₎ nanoparticles prepared onto indium–tin oxide (ITO) electrode for detection of ochratoxin-A (OTA). Excellent film forming ability and availability of –NH₂ group in CH and affinity of surface charged Fe₃O₄ nanoparticles for oxygen support the immobilization of IgGs. Differential pulse voltammettry (DPV) studies indicate that Fe₃O₄ nanoparticles provide increased electroactive surface area for loading of IgGs and improved electron transport between IgGs and electrode. IgGs/CH–Fe₃O₄ nanobiocomposite/ITO immunoelectrode exhibits improved characteristics such as low detection limit (0.5 ng dL⁻¹), fast response time (18 s) and high sensitivity (36 μA/ng dL⁻¹ cm⁻²) with respect to IgGs/CH/ITO immunoelectrode.     

Fiber Optic Excitation of Silicon Microspheres in Amorphous and Crystalline Fluids

ABSTRACT

This study investigates the optical resonance spectra of free-standing monolithic single crystal silicon microspheres immersed in various amorphous fluids, such as air, water, ethylene glycol, and 4-Cyano-4’-pentylbiphenyl nematic liquid crystal. For the various amorphous fluids, morphology-dependent resonances with quality factors on the order of 10⁵ are observed at 1428 nm. The mode spacing is always on the order of 0.23 nm. The immersion in various amorphous fluids affects the spectral response of the silicon microsphere and heralds this technique for use in novel optofluidics applications. Even though the nematic liquid crystal is a highly birefringent, scattering, and high-index optical medium, morphology-dependent resonances with quality factors on the order of 10⁵ are observed at 1300 nm in the elastic scattering spectra of the silicon microsphere, realizing a liquid-crystal-on-silicon geometry. The relative refractive index and the size parameter of the silicon microsphere are the parameters that affect the resonance structure. The more 4-Cyano-4’-pentylbiphenyl interacting with the silicon microsphere, the lower the quality factor of the resonances is. The more 4-Cyano-4’-pentylbiphenyl is interacting with the silicon microsphere, the lower the mode spacing Δλ of the resonances is. The silicon microspheres wetted with nematic liquid crystal can be used for optically addressed liquid-crystal-on-silicon displays, light valve applications, or reconfigurable optical networks.