Best proximity point theorems: exposition of a significant non-linear programming problem

The primary goal of this work is to address the non-linear programming problem of globally minimizing the real valued function x → d(x, Tx) where T is presumed to be a non-self mapping that is a generalized proximal contraction in the setting of a metric space. Indeed, an iterative algorithm is presented to determine a solution of the preceding non-linear programming problem that focuses on global optimization. As a sequel, one can compute optimal approximate solutions to some fixed point equations and optimal solutions to some unconstrained non-linear programming problems.     

A facile synthesis of novel 5‐substituted pyridine 2 carboxamide derivatives and their biological evaluation and 3D QSAR studies

A variety of novel 5‐substituted pyridine 2 carboxamides were designed and synthesized using both normal and solvent‐free microwave (MW) irradiation techniques. The results revealed that MW protocol proceeded smoothly under mild reaction conditions in short reaction times, thus avoiding the use of toxic organic solvents. Structural elucidation of the synthesized compounds was carried out on the basis of various spectroscopic methods, such as ¹H NMR, ¹³C NMR, LCMS, and IR. The synthesized compounds were evaluated for their in vitro antimicrobial activity (MIC) using the agar disk diffusion method. Among the various synthetic compounds, compound 3b showed higher potential activity against Escherichia coli than the other compounds. The order of activity against E. coli of the studied compounds is 3b > 3e > 3g > 3h > 3d > 3c > 3a > 3f . Additionally, 2D and 3D structural features of the synthesized derivatives were recognized by the 3D‐QSAR model. This validated model exhibited good internal (r², 0.924) and external prediction (r²pred, 0.851) correlation. The results of QSAR studies concluded that Alog P, the number of hydrogen bond acceptors, and the number of rotatable bonds were necessary features for the activity of the pyridine carboxamide derivatives.     

Spectroscopic investigations on cometary molecules CO, CH and CH

The experimental potential energy curves for the electronic ground states of molecules like CO⁺, CH and CH⁺ observed in comets are constructed by using the Rydberg-Klein-Rees method as modified by Vanderslice et al. The ground state dissociation energies are determined by curve fitting technique using the five parameter Hulburt-Hirschfelder (H-H) function. The estimated dissociation energies are 8.33±0.19, 3.48±0.903 and for CO⁺, CH and CH⁺, respectively. These values are in good agreement with the literature values. Estimated dissociation energies of CO⁺, CH and CH⁺ are used in the relation given by Gaydon and ionization potentials are evaluated for CO and CH molecules. The estimated ionization potentials are 14.03 and , respectively for CO and CH. The Franck-Condon factors and r-centroids for the band system of - of CO⁺ molecule have been calculated employing an approximate analytical methods of Jarmain and Fraser. The absence of the bands in this system is explained.     

Optical and dielectric properties of PVP based composite polymer electrolyte films

Solid polymer electrolyte films were prepared by adding Al₂O₃ particles to poly(vinylpyrrolidone)-MgCl₂ ? 6H₂O salt using solution cast technique. Various analytical techniques have been applied to characterize the prepared polymer films such as XRD, SEM, UV–Vis spectroscopy and AC conductivity. The structural analysis of pure poly(vinylpyrrolidone) complexed with MgCl₂ ? 6H₂O salt showed orthorhombic lattice structure indicating its semi-crystalline nature. SEM analysis reveals the heterogeneous phase of nanocomposite polymer electrolyte systems. The conductivity of Al2O3 doped poly(vinylpyrrolidone) based solid polymer electrolyte was found to be 1.22 × 10^–6 S/cm at room temperature for 85: 15 weight composition. Electrochemical cell has been fabricated with the configuration Mg⁺/(PVP + MgCl₂ ? 6H₂O + Al₂O₃)/(I₂ + C + electrolyte) and its discharge characteristics were studied for a constant load of 100 kΩ. Various cell parameters such as open-circuit voltage, short circuit current, energy density and power density were calculated for the prepared samples.     

Synthesis,spectral characterization and bioactivity evaluation of novel α-aminophosphonates

A facile synthesis of novel α-aminophosphonates 5a-j was accomplished by condensation of imines (3a-j) with diethyl phosphite (4) in ethanol at 50–60°C using easily recoverable and reusable catalyst, tetramethyl guanidine (TMG) via pudovik reaction in high yields. All the title compounds were characterized by spectral and elemental analysis. They were further screened for their abilities towards in vitro antibacterial, antifungal and antioxidant activities. The compounds 5g, 5d, 5f exhibited good antibacterial and antifungal activities compared to the standard bactericide, Penicillin and fungicide, Griseofulvin, respectively. The compounds 5h, 5i, 5g, and 5c exhibited good antioxidant activity compared to the standard ascorbic acid.     

Well-Orientation Strategy Biosynthesis of Cefuroxime-Silver Nanoantibiotic for Reinforced Biodentine™ and Its Dental Application against Streptococcus mutans

Dental caries results from the bacterial pathogen Streptococcus mutans (S. mutans) and is the maximum critical reason for caries formation. Consequently, the present study aims to evaluate the antibacterial activity of a newly synthesized nanoantibiotic–Biodentine formulation. The silver nanoparticles (ROE-AgNPs) were biosynthesized from the usage of Rosmarinus officinalis L. extract (ROE) and conjugated with cefuroxime to form Cefuroxime-ROE-AgNPs. Using Biodentine™ (BIOD), five groups of dental materials were prepared, in which Group A included conventional BIOD, Group B included BIOD with ROE-AgNPs, Groups C and D included BIOD with Cefuroxime-ROE-AgNPs at concentrations of 0.5% and 1.5% cefuroxime, respectively, and Group E included BIOD with 1.5% cefuroxime. The synthesized ROE-AgNPs or Cefuroxime-ROE-AgNPs were characterized for conjugating efficiency, morphology, particle size, and in vitro release. Minimum inhibitory concentration (MIC) of the cefuroxime, ROE-AgNPs, and Cefuroxime-ROE-AgNPs were additionally evaluated against cefuroxime resistant S. mutans, which furthered antibacterial efficacy of the five groups of dental materials. The UV-Visible spectrum showed the ROE-AgNPs or Cefuroxime-ROE-AgNPs peaks and their formation displayed through transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern, and Fourier transforms infrared (FTIR) analysis. The end result of Cefuroxime-ROE-AgNPs showed conjugating efficiency up to 79%. Cefuroxime-ROE-AgNPs displayed the highest antibacterial efficacy against S. mutans as compared to cefuroxime or ROE-AgNPs alone. Moreover, the MIC of ROE-AgNPs and Cefuroxime-ROE-AgNPs was detected against S. mutans to be 25 and 8.5 μg/mL, respectively. Consequently, Cefuroxime-ROE-AgNPs displayed that a decrease in the MIC reached to more than three-fold less than MIC of ROE-AgNPs on the tested strain. Moreover, Cefuroxime-ROE-AgNPs/BIOD was employed as a novel dental material that showed maximum antimicrobial activity. Groups C and D of novel materials showed inhibitory zones of 19 and 26 mm, respectively, against S. mutans and showed high antimicrobial rates of 85.78% and 91.17%, respectively. These data reinforce the utility of conjugating cefuroxime with ROE-AgNPs to retrieve its efficiency against resistant S. mutant. Moreover, the nanoantibiotic delivered an advantageous antibacterial effect to BIOD, and this may open the door for future conjugation therapy of dental materials against bacteria that cause dental caries.     

New Charge Transfer Complexes of K+-Channel-Blocker Drug (Amifampridine; AMFP) for Sensitive Detection; Solution Investigations and DFT Studies

UV–Vis spectroscopy was used to investigate two new charge transfer (CT) complexes formed between the K⁺-channel-blocker amifampridine (AMFP) drug and the two π-acceptors 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and tetracyanoethylene (TCNE) in different solvents. The molecular composition of the new CT complexes was estimated using the continuous variations method and found to be 1:1 for both complexes. The formed CT complexes’ electronic spectra data were further employed for calculating the formation constants (K_CT), molar extinction coefficients (ε_CT), and physical parameters at various temperatures, and the results demonstrated the high stability of both complexes. In addition, sensitive spectrophotometric methods for quantifying AMFP in its pure form were proposed and statistically validated. Furthermore, DFT calculations were used to predict the molecular structures of AMFP–DDQ and AMFP–TCNE complexes in CHCl₃. TD-DFT calculations were also used to predict the electronic spectra of both complexes. A CT-based transition band (exp. 399 and 417 nm) for the AMFP–TCNE complex was calculated at 411.5 nm (f = 0.105, HOMO-1 → LUMO). The two absorption bands at 459 nm (calc. 426.9 nm, f = 0.054) and 584 nm (calc. 628.1 nm, f = 0.111) of the AMFP–DDQ complex were theoretically assigned to HOMO-1 → LUMO and HOMO → LUMO excitations, respectively.     

Entropy generation of tangent hyperbolic nanofluid flow over a circular cylinder in the presence of nonlinear Boussinesq approximation: a non-similar solution

Journal of Thermal Analysis and Calorimetry - The analysis of entropy generation has received notable attention in the study of nanofluids because the prime objective of nanofluids is to admit high...