Photodetachment Spectrum of Hydrogen Negative Ion Near a Partially Reflecting Spherical Surface

Photodetachment of negative ions near surfaces is of great interest in view of its fundamental significance and technological applications. We reinvestigate the dynamics of photoelectrons in H^? photodetachment near a partially reflecting spherical surface by the semiclassical closed-orbit theory. Reflection parameter R and curvature K is used to observe inelastic and spherical effects of the surface, respectively. The classical action is evaluated from the photodetached electron trajectories incident normally at the surface, arising simultaneously from the source and its image. The derived analytical formula of photodetachment cross section correctly recovers the results of reflective spherical surface published recently based on theoretical imaging method.     

Enhanced Protein Adsorption,Cell Attachment,and Neural Differentiation with the Help of Amine Functionalized Polycaprolactone Scaffolds

Today, neurodegenerative diseases are very common among people. As a result, researchers are investigating methods for treatment of these diseases. One therapeutic approach is differentiating stem cells into neural cells to replace damaged areas of the brain. Cell attachment is the first, necessary step for the process of differentiation. Hence, we tried to enhance cell adhesion and proliferation of bone marrow stem cells on poly(?-caprolactone) (PCL) scaffolds through modifying this substrate with amine functional groups. The presence of amine groups was confirmed by Fourier transform infrared spectrometry (FTIR). Protein adsorption was measured at 280 nm via UV-spectrometry. The proliferation of differentiated neurons was assessed by 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (a dye) and cresyl violet staining. Finally, the morphology of differentiated neurons was shown by scanning electron microscopy (SEM). Results showed that amine modification of PCL scaffolds enhanced protein absorption and, consequently, cell adhesion and proliferation.     

Sorption of silver ion from aqueous solutions using conducting electroactive polymers

In this research polypyrrole (PPy) and polyaniline (PAni) conducting polymers which were synthesized chemically on the surface of wood sawdust (SD). These electroactive polymers as coated form on sawdust then were used for sorption or removal of silver ion from aqueous solutions under simple open circuit conditions. The effects of some important parameters such as pH, initial concentration, sorbent dosage, and contact time on uptake of silver ion were also investigated in this research. The experiments were carried out using both batch and column systems at room temperature. The treatments of the data were carried out using both Freundlich and Langmuir adsorption isotherms. In order to find out the possibility of the regeneration and reuse of the exhausted adsorbent, desorption studies were also performed. It was found that conducting electroactive polymers such as PPy or PAni are efficient sorbents for removal of the silver ions from aqueous solutions. Sorption/desorption processes can be simply carried out with pH control with satisfactory performance. Recovery percentage observed for PAni/SD in column study was more than PPy/SD and SD, under the same operational conditions.     

Improved extraction method for the determination of iron, copper, and nickel in new varieties of sunflower oil by atomic absorption spectroscopy

A simple and fast procedure is proposed for the extraction of iron (Fe), copper (Cu), and nickel (Ni) in 16 varieties of sunflower seed oil samples using an ultrasonic bath. The experimental parameters of the ultrasonic-assisted extraction (UAE) method were optimized to improve the sensitivity and detect the metals at trace levels in minimum time. Conventional wet acid digestion method was used for comparative purposes. The optimum recovery of all 3 metals was obtained by UAE for 7 min, while the separation of aqueous and organic phases after extraction using centrifugation (UAE-2) required 3 min, as compared to the conventional equilibration method (UAE-1) that required 90 min. The respective recoveries of Cu, Fe, and Ni obtained with UAE-2 were in the range of 95.8-97.5, 93.5-98.3, and 95.6-98.2%, respectively, for different varieties of sunflower oil samples. Accuracy was determined by the standard addition method. Under the optimum operating conditions, the limits of detection obtained from the standard addition curves were 21.7, 20.4, and 35.6 ng/mL for Fe, Cu, and Ni, respectively. The fact that all varieties of sunflower oil contain significant amounts of Fe, Cu, and Ni indicates the deterioration of sunflower oil quality immediately after extraction from seeds, which poses a threat to oil quality and human health.     

Exact solutions of some nonlinear systems of partial differential equations by using the first integral method

In recent years, many approaches have been utilized for finding the exact solutions of nonlinear systems of partial differential equations. In this paper, the first integral method introduced by Feng is adopted for solving some important nonlinear systems of partial differential equations, including, KdV, Kaup–Boussinesq and Wu–Zhang systems, analytically. By means of this method, some exact solutions for these systems of equations are formally obtained. The results obtained confirm that the proposed method is an efficient technique for analytic treatment of a wide variety of nonlinear systems of partial differential equations.     

A novel, one-pot, solvent-, and catalyst-free synthesis of 2-aryl/alkyl-4(3H)-quinazolinones

A novel and one-pot synthesis of 2-aryl/alkyl-4(3H)-quinazolinones is described. The in situ prepared amidoximes from the reaction between nitriles and hydroxylamine are condensed with anthranilic acids under solvent- and catalyst-free conditions to produce the title compounds in excellent yields.     

Mann type iterative methods for finding a common solution of split feasibility and fixed point problems

The purpose of this paper is to study and analyze three different kinds of Mann type iterative methods for finding a common element of the solution set ?? of the split feasibility problem and the set Fix(S) of fixed points of a nonexpansive mapping S in the setting of infinite-dimensional Hilbert spaces. By combining Mann??s iterative method and the extragradient method, we first propose Mann type extragradient-like algorithm for finding an element of the set ${{{\rm Fix}}(S) \cap \Gamma}$ ; moreover, we derive the weak convergence of the proposed algorithm under appropriate conditions. Second, we combine Mann??s iterative method and the viscosity approximation method to introduce Mann type viscosity algorithm for finding an element of the ${{{\rm Fix}}(S)\cap \Gamma}$ ; moreover, we derive the strong convergence of the sequences generated by the proposed algorithm to an element of set ${{{\rm Fix}}(S) \cap \Gamma}$ under mild conditions. Finally, by combining Mann??s iterative method and the relaxed CQ method, we introduce Mann type relaxed CQ algorithm for finding an element of the set ${{{\rm Fix}}(S)\cap \Gamma}$ . We also establish a weak convergence result for the sequences generated by the proposed Mann type relaxed CQ algorithm under appropriate assumptions.     

Explicit analytical expressions for the critical buckling stresses in a monolayer graphene sheet based on nonlocal elasticity

Explicit expressions are given to study the biaxial buckling of monolayer graphene sheets. Based upon the continuum mechanics, a plate model is adopted in which the small length scale effect is incorporated into the governing equation through the nonlocal elasticity theory of Eringen. By employing the Galerkin method, analytical expressions are derived which allow quick and accurate calculation of the critical buckling loads of monolayer graphene sheets with various boundary conditions from the static deflection under a uniformly distributed load. The effectiveness of the present study is assessed by molecular dynamics simulations as a benchmark of good accuracy.     

Doxorubicin-Conjugated Zinc Oxide Nanoparticles,Biogenically Synthesised Using a Fungus Aspergillus niger,Exhibit High Therapeutic Efficacy against Lung Cancer Cells

This study reports the therapeutic effectiveness of doxorubicin-conjugated zinc oxide nanoparticles against lung cancer cell line. The zinc oxide nanoparticles (ZnONPs) were first synthesised using a fungus, isolated from air with an extraordinary capability to survive in very high concentrations of zinc salt. Molecular analysis based on 18S rRNA gene sequencing led to its identification as Aspergillus niger with the NCBI accession no. {"type":"entrez-nucleotide","attrs":{"text":"OL636020","term_id":"2155690654"}}OL636020. The fungus was found to produce ZnONPs via the reduction of zinc ions from zinc sulphate. The ZnONPs were characterised by various biophysical techniques. ZnONPs were further bioconjugated with the anti-cancer drug doxorubicin (DOX), which was further confirmed by different physical techniques. Furthermore, we examined the cytotoxic efficacy of Doxorubicin-bioconjugated-ZnONPs (DOX-ZnONPs) against lung cancer A549 cells in comparison to ZnONPs and DOX alone. The cytotoxicity caused due to ZnONPs, DOX and DOX-ZnONPs in lung cancer A549 cells was assessed by MTT assay. DOX-ZnONPs strongly inhibited the proliferation of A549 with IC50 value of 0.34 μg/mL, which is lower than IC50 of DOX alone (0.56 μg/mL). Moreover, DOX-ZnONPs treated cells also showed increased nuclear condensation, enhanced ROS generation in cytosol and reduced mitochondrial membrane potential. To investigate the induction of apoptosis, caspase-3 activity was measured in all the treated groups. Conclusively, results of our study have established that DOX-ZnONPs have strong therapeutic efficacy to inhibit the growth of lung cancer cells in comparison to DOX alone. Our study also offers substantial evidence for the biogenically synthesised zinc oxide nanoparticle as a promising candidate for a drug delivery system.