Effects of ultrasound on growth, bioconversion of isoflavones and probiotic properties of parent and subsequent passages of Lactobacillus fermentum BT 8633 in biotin-supplemented soymilk

This study aimed to evaluate the effects of ultrasound on Lactobacillus fermentum BT 8633 in parent and subsequent passages based on their growth and isoflavone bioconversion activities in biotin-supplemented soymilk. The treated cells were also assessed for impact of ultrasound on probiotic properties. The growth of ultrasonicated parent cells increased (P < 0.05) by 3.23-9.14% compared to that of the control during fermentation in biotin-soymilk. This was also associated with enhanced intracellular and extracellular (8.4-17.0% and 16.7-49.2%, respectively; P < 0.05) β-glucosidase specific activity, leading to increased bioconversion of isoflavones glucosides to aglycones during fermentation in biotin-soymilk compared to that of the control (P < 0.05). Such traits may be credited to the reversible permeabilized membrane of ultrasonicated parent cells that have facilitated the transport of molecules across the membrane. The growing characteristics of first, second and third passage of treated cells in biotin-soymilk were similar (P > 0.05) to that of the control, where their growth, enzyme and isoflavone bioconversion activities (P > 0.05) were comparable. This may be attributed to the temporary permeabilization in the membrane of treated cells. Ultrasound affected probiotic properties of parent L. fermentum, by reducing tolerance ability towards acid (pH 2) and bile; lowering inhibitory activities against selected pathogens and reducing adhesion ability compared to that of the control (P < 0.05). The first, second and third passage of treated cells did not exhibit such traits, with the exception of their bile tolerance ability which was inherited to the first passage (P < 0.05). Our results suggested that ultrasound could be used to increase bioactivity of biotin-soymilk via fermentation by probiotic L. fermentum FTDC 8633 for the development of functional food.     

Appraisal of radioactivity and associated radiation hazards in sand samples of four rivers of Punjab province, Pakistan

Natural and anthropogenic radioactivity of sand and water samples collected from the four big rivers of Punjab province, Pakistan, was measured using a high-purity germanium detector coupled with a high resolution multichannel analyser. The average concentration of the naturally occurring radionuclides (226)Ra, (232)Th and (40)K in all the sand samples from the rivers Jhelum, Chenab, Ravi and Indus was found to be 22±0.6, 36±1 and 287±10 Bq kg (-1), respectively, while the concentration of the anthropogenic radionuclide (137)Cs was found to be below the minimum detectable activity, i.e. ~1.2 Bq?kg (-1). All the sand samples have Ra(eq) concentrations lower than the limit of 370 Bq kg (-1). Indoor (H (in)) and outdoor (H (out)) radiation hazard indices were calculated for the samples to assess the radiation hazards arising due to the use of this sand in construction, and were found to be less than unity in the study area. Calculated values of the absorbed dose rate were less than the typical world average value of 59 nGy h (-1), and the annual effective dose rate was also less than the typical world value of 70 μSv, except in the Indus river, in which it is slightly higher then the world average. Results show that the measured values are comparable with other global radioactivity measurements. None of the studied riverbeds was considered a radiological hazard, and their sand can be safely used in construction.     

Stability and Neimark–Sacker bifurcation of a ratio‐dependence predator–prey model

In this paper, stability and bifurcation of a two‐dimensional ratio‐dependence predator–prey model has been studied in the close first quadrant . It is proved that the model undergoes a period‐doubling bifurcation in a small neighborhood of a boundary equilibrium and moreover, Neimark–Sacker bifurcation occurs at a unique positive equilibrium. We study the Neimark–Sacker bifurcation at unique positive equilibrium by choosing b as a bifurcation parameter. Some numerical simulations are presented to illustrate theocratical results. Copyright © 2017 John Wiley & Sons, Ltd.     

Computing topological indices of Sudoku graphs

In QSAR/QSPR study, physico-chemical properties and topological indices such as Randi?, atom-bond connectivity (ABC) and geometric-arithmetic (GA) index are used to predict the bioactivity of chemical compounds. A topological index is actually designed by transforming a chemical structure into a numeric number. These topological indices correlate certain physico-chemical properties like boiling point, stability, strain energy etc. of chemical compounds. Graph theory has found a considerable use in this area of research. The topological indices of certain interconnection networks were studied recently by Imran et al. (Appl Math Comput 244:936–951, 2014). In this paper, we extend this study to \(n\times n\) Sudoku graphs and derive analytical closed results of general Randi? index \(R_{\alpha }(G)\) for different values of “\(\alpha \)” for Sudoku (SK). We also compute the general Randi?, first Zagreb, ABC, GA, \(ABC_{4}\) and \(GA_{5}\) indices and give closed formulae of these indices for Sudoku graphs.     

Theoretical and experimental investigations of complexation with BF3.Et2O effects on electronic structures,energies and photophysical properties of Anil and tetraphenyl (hydroxyl) imidazol

The novel compounds (E)‐2‐(((4‐hydroxyphenyl)imino)methyl)phenol, Tetraphenyl (hydroxyl) imidazole and their corresponding Boron difluoride complexes were synthesized and characterized by spectroscopic techniques. Density functional theory calculations at B3LYP‐D3/6–311++G (d, p) level of theory were performed for the geometric parameters. The MEP surface studies were used to understand the behavior of molecules in terms of charge transfer and to determine how these molecules interact. We used the GIAO and the B3LYP‐D3 with a 6–311++ G (d, p) basis set to simulate the (¹H‐NMR and ¹⁹F‐NMR) and the IR spectra, respectively. The corresponding calculated results are in good agreement with the experimental data. The stability of the molecule arising from hyperconjugation interaction and charge delocalization were analyzed using NBO analysis. FMOs revealed the occurrence of charge transfer within the molecule. The complexation using BF₃.Et₂O was also found to have remarkable effects on the electrochemical properties of the studied molecules, where (b) and (d) present lower chemical stability, higher reactivity and higher polarizability than (a) and (c), respectively. Moreover, the energy gap of (a) and (c) decreased after complexation using BF₃.Et₂O, indicating the reliability of the electrochemical evaluation of LUMO and HOMO energy levels. These values are the factors explaining the possible charge transfer interaction within the molecule. The absorption and emission spectra of the model compound were also simulated and compared to experimental observations in the DMF solvent. The results of DFT calculations supported the structural and spectroscopic data and confirmed the structure modification of frontier molecular orbitals for BF₂ complexes as well as tunable potentials and energy levels.     

The gas-phase on-line production of vanadium oxytrihalides, VOX3 and their identification by infrared spectroscopy

A new route has been devised, leading to the production of VOX₃ molecules where X=F, Br and I by an on-line process using vanadium oxytrichloride, VOCl₃ as a starting compound passed over the following heated salts NaF, KBr and KI at 375, 700 and 550°C, respectively. The products have been characterized by the IR spectra of their vapors. The low resolution gas phase on-line Fourier transform infrared spectra reported for the first time show strong bands with PQR type structure, centered at 1058, 1035, 1030 and 1025 cm⁻¹ assigned to the ν₁(a₁), the O=V stretching fundamental mode of VOF₃, VOCl₃, VOBr₃ and VOI₃, respectively.     

Laser processing for bio-microfluidics applications (part I)

This paper reviews applications of laser-based techniques to the fabrication of microfluidic devices for biochips and addresses some of the challenges associated with the manufacture of these devices. Special emphasis is placed on the use of lasers for the rapid prototyping and production of biochips in particular for applications in which silicon is not the preferred material base. Part I of this review addresses applications and devices using UV lasers for laser ablation and surface treatment of microchannels, in particular in polymers.     

Platform for Highly Sensitive Alkaline Phosphatase‐Based Immunosensors Using 1‐Naphthyl Phosphate and an Avidin‐Modified Indium Tin Oxide Electrode

We report a versatile platform for highly sensitive alkaline phosphatase (ALP)‐based electrochemical biosensors that uses an avidin‐modified indium tin oxide (ITO) electrode as a sensing electrode and 1‐naphthyl phosphate (NPP) as an ALP substrate. Almost no electrocatalytic activity of NPP and good electrocatalytic activity of 1‐naphthol (ALP product) on the ITO electrodes allow a high signal‐to‐background ratio. The effective surface covering of avidin on the ITO electrodes allows very low levels of nonspecific binding of proteins to the sensing electrodes. The platform technology is used to detect mouse IgG with a detection limit of 1.0 pg/mL.