Best Proximity Points and Fixed Points Results for Noncyclic and Cyclic Fisher Quasi-contractions

In this article, in the setting of metric spaces we introduce the notions of noncyclic and cyclic Fisher quasi-contraction mappings. We establish the existence of an optimal pair of fixed points for a noncyclic Fisher quasi-contraction mapping and iterative algorithms are furnished to determine such optimal pair of fixed points. For a cyclic Fisher quasi-contraction mapping, we also study the existence of best proximity points. Presented results extend and improve some recent results in the literature.     

Substituted Quinolinones,Part 11: Efficient Synthesis of Different 3‐(4‐Arylidene and Hetarylidene‐5‐oxopyrazolin‐3‐yl) quinolin‐2‐ones

Several 3‐(4‐arylidene and hetarylidene‐5‐oxopyrazolin‐3‐yl)quinolin‐2‐ones 6–26 were synthesized in an efficient methodology utilizing both pyrazolinylquinolinone 2 and its chromenylmethylene derivative 10. Compound 2 was derivatized by Knoevenagel condensation with different carbonyl compounds. Nucleophilic ring opening–ring closure (RORC) of the compound 10 furnished the desired 4‐methylenepyarzolinone bearing novel five‐, six‐, and seven‐membered heterocycles, in good yields.     

Novel Synthesis of Some New Pyridazine and Pyridazino[4,5-d]pyridazine Derivatives

Phenacyl-malononitrile derivatives 1a and b react with dimethylformamide dimethylacetal (DMFDMA) in refluxing toluene to afford the enaminones 2a and b respectively. Compounds 2a and 2b react with the hydrazine hydrate 3a and phenyl hydrazine 3b in refluxing ethanol to afford the pyridazine derivatives 5a–d, presumably via the intermediates 4. Compounds 5a–d, react with hydrazine hydrate 3a to afford the pyridazino[4,5-d]pyridazines 6a–d respectively. The pyridazines 5a and b and the pyridazino[4,5-d] pyridazines 6a and b could be oxidized into the full aromatic systems 7a and b and 8a and b respectively. Compounds 7a and b react also with hydrazine hydrate 3a to afford 8a and b respectively.

KAl(SO4)2 · 12H2O as a Recyclable Lewis Acid Catalyst for Synthesis of Some Amidoalkyl Naphthols Under Solvent-Free Conditions

A general and practical one-pot synthesis of amidoalkyl naphthols derivatives using KAl(SO₄)₂ · 12H₂O as catalyst is described. This method provides several advantages such as short reaction times, good yields, and simple workup procedure.     

The Kinetics of Oxidation of L-Tryptophan by Water-Soluble Colloidal Manganese Dioxide

The kinetics of the oxidation of L-tryptophan by water-soluble colloidal MnO₂ (prepared from potassium permanganate and sodium thiosulfate solutions) has been carried out in aqueous perchloric acid medium at different temperatures. Monitoring the disappearance of the MnO₂ spectrophotometrically at 390 nm was used to follow the kinetics. The first-order kinetics with respect to [L-tryptophan] at low concentrations shifted to zero-order at higher concentrations. The reaction followed first-order with respect to [MnO₂] but fractional-order with respect to [HClO₄]. Adding trapping agents enhanced the rate of the reaction. The Arrhenius and Eyring equations were found valid for the reaction between 35°C and 55°C and different activation parameters (E_a, ΔH^#, ΔS^#) have been evaluated. On the basis of various observations and product characterization a plausible mechanism has been envisaged for the reaction taking place at the colloid surface. The results suggest formation of an adsorption complex between L-tryptophan and MnO₂. The complex decomposes in a rate-determining step, leading to the formation of free radical, which again reacts with the colloidal MnO₂ in a subsequent fast step to yield products. Freundlich isotherm is used to explain the adsorption of L-tryptophan on the colloidal MnO₂.     

Szeged index, edge Szeged index, and semi-star trees

A semi-star tree is a star tree whose some edges may be replaced by paths of length more than one. In this paper we present some increasing and decreasing transformations for Szeged index of the semi-star trees. Then we introduce palm semi-star tree and uniform semi-star tree and show that they are extremal with respect to the Szeged index and edge Szeged index. In addition, we investigate the relation between the Szeged index and edge Szeged index for all trees.     

Chemical characterization and therapeutic properties of Achillea biebersteinii leaf aqueous extract synthesized copper nanoparticles against methamphetamine-induced cell death in PC12: A study in the nanotechnology and neurology fields

Recently, scientist have used metallic nanoparticles for synthesizing many new drugs in the field of neurology. One of the metals used in the metallic nanoparticles is copper. The role of Achillea biebersteinii in increasing the physiological activities of central nervous system in Iranian traditional medicine is well known. In this study fresh leaves of A. biebersteinii were used for the biosynthesis of copper nanoparticles. We also assessed the effect of copper nanoparticles on methamphetamine-induced cell death in the PC12 cell line. The nanoparticles were analyzed by Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, and ultraviolet–visible spectroscopy. A 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging experiment was carried out to assess the antioxidant properties of Cu(NO₃)₂, A. biebersteinii, and CuNPs. The DPPH test revealed similar antioxidant activities for A. biebersteinii, CuNPs, and butylated hydroxytoluene. In the cellular and molecular part of the present study, the Trypan blue test was performed to assess cell viability. The terminal deoxynucleotidyl transferase 2′-Deoxyuridine, 5′-Triphosphate (dUTP) nick end labeling test clarified the DNA fragmentation and apoptosis occurrence. The Griess reaction was used to measure nitric oxide production and caspase-3 activity was evaluated by spectrophotometry. The obtained results were fed into SPSS-22 software and analyzed by one-way ANOVA, followed by Tukey's post hoc test (p ≤ 0.01). The results indicate that both doses of CuNPs had cell death-suppressing effects on nerve cells. In particular, both doses of CuNPs significantly (p ≤ 0.01) increased cell viability and NO production, and decreased cell cytotoxicity, cell death index, and caspase-3 activity near the normal. According to these results, it seems that CuNPs could be administrated as a neuroprotective supplement or drug for the treatment of central nervous system disorders in clinical trials.     

Differential Nonlinear Absorption of an Elliptically Polarized Femtosecond Vortex Beam in Tellurite Glass

Optics and Spectroscopy - We present differential nonlinear absorption of an elliptically polarized femtosecond laser vortex beam carrying an angular momentum of $$ell = - 1$$ in tellurite glass....     

Improving catalytic converter performance by controlling the structural and redox properties of Zr-doped CeO2 nanorods supported Pd catalysts

Research on Chemical Intermediates - The work herein introduces a facile and novel synthesis procedure for producing Zr-doped CeO2 nanorod catalysts applicable for upgrading the car catalytic...     

Preparation,characterization, and evaluation of cytotoxicity,antioxidant, cutaneous wound healing,antibacterial, and antifungal effects of gold nanoparticles using the aqueous extract of Falcaria vulgaris leaves

The new age drugs are nanoparticles of metals, which can combat conditions like wounds and fight human pathogens like bacteria. The aim of the experiment was preparation, characterization, and assessment of cytotoxicity, antioxidant, cutaneous wound healing, antibacterial, and antifungal potentials of gold nanoparticles using the aqueous extract of Falcaria vulgaris leaves (AuNPs@F. vulgaris) under in vitro and in vivo condition. These nanoparticles were characterized by FT‐IR, UV, XRD, FE‐SEM, TEM, and AFM. The synthesized AuNPs@F. vulgaris had great cell viability dose‐dependently (Investigating the effect of the nanoparticles on HUVEC cell line) and indicated these nanoparticles were nontoxic. DPPH free radical scavenging test was done to evaluate the antioxidant potentials, which showed similar antioxidant potentials for AuNPs@F. vulgaris and butylated hydroxytoluene. In part of cutaneous wound healing effect of F. vulgaris, after creating the cutaneous wound, the rats were randomly divided into six groups: untreated control, treatment with Eucerin basal ointment, treatment with 3% tetracycline ointment, treatment with 0.2% HAuCl₄ × H₂O ointment, treatment with 0.2% F. vulgaris ointment, and treatment with 0.2% AuNPs@F. vulgaris ointment. These groups were treated for 10 days. Use of AuNPs@F. vulgaris ointment in the treatment groups substantially decreased (p ≤ 0.01) the wound area, total cells, neutrophil, and lymphocyte and remarkably raised (p ≤ 0.01) the wound contracture, hydroxyl proline, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate compared to other groups. In antimicrobial part, MIC, MBC, and MFC were specified by macro‐broth dilution assay. AuNPs@F. vulgaris revealed higher antibacterial and antifungal properties than many standard antibiotics (p ≤ 0.01). Also, AuNPs@F. vulgaris prevented the growth of all bacteria at 2‐8 mg/ml concentrations and removed them at 2‐16 mg/ml concentrations (p ≤ 0.01). In case of antifungal potentials of AuNPs@F. vulgaris, they inhibited the growth of all fungi at 2‐4 mg/ml concentrations and destroyed them at 2‐8 mg/ml concentrations (p ≤ 0.01). In conclusion, synthesized AuNPs@F. vulgaris revealed non‐cytotoxicity, antioxidant, cutaneous wound healing, antibacterial, and antifungal activities.