Quality standardization of herbal medicines of Spondias dulcis Parkinson using analytical and microbiological analysis

Journal of Thermal Analysis and Calorimetry - The solid–liquid phase equilibrium for binary system of 2,4,6-trimethylphenol (TMP) and 2,5-dimethylphenol (DMP) was built by differential...     

Low power laser radiation at 685 nm stimulates stem-cell proliferation rate in Dugesia tigrina during regeneration

Today’s scientific interest in tissue engineering for organ transplantations and regeneration from stem cells, allied with recent observations on biostimulation of tissues and cells by laser radiation, stands as a strong motivation for the present work, in which we examine the effects of the low power laser radiation onto planarians under regenerative process. To investigate those effects, a number of 60 amputated worms were divided in three study groups: a control group and two other groups submitted to daily 1 and 3 min long laser treatment sections at 910 W/m² power density. A 685 nm diode laser with 35 mW optical power was used. Samples were sent to histological analysis at the 4th, the 7th and the 15th days after amputation. A remarkable increase in stem cells counts for the fourth day of regeneration was observed when the regenerating worms was stimulated by the laser radiation. Our findings encourage further research works on the influence of optical radiation onto stem cells and tissue regeneration.     

Monte Carlo calculation of resonance self-shielding factors for epithermal neutron spectra

In this work, the resonance self-shielding factor is calculated by means of the Monte Carlo technique for different materials (Au, Co, Mn), geometries (circular foils and wires) and incidence of neutrons (isotropic field and collimated beam). The results are compared with the values obtained by other authors.     

Kinetic study of the gas‐phase reaction of the nitrate radical with methyl‐substituted thiophenes

The gas‐phase reactions of the NO₃ radical with 2‐methylthiophene, 3‐methylthiophene, and 2,5‐dimethylthiophene have been studied, using relative and absolute methods at 298 K. Determination of relative rate was performed using Teflon collapsible bag as the reaction chamber and gas chromatography as the analytical tool. For the absolute method, experiments were carried out using fast‐flow‐discharge technique with detection of NO₃ by laser‐induced fluorescence. The temperature dependence was studied by the absolute technique for the reactions of NO₃ with 2‐methylthiophene and 3‐methylthiophene in the range 263–335 K. The proposed Arrhenius expressions for the reaction of the nitrate radical with 2‐methylthiophene and 3‐methylthiophene are k = (4 ± 2) × 10^?16 exp[?(2200 ± 100)/T]] cm³ molecule^?1 s^?1 and k = (3 ± 2) × 10^?15 exp[?(1700 ± 200)/T]] cm³ molecule^?1 s^?1, respectively. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 286–293, 2003     

Numerical treatment of realistic boundary conditions for the eddy current problem in an electrode via Lagrange multipliers

This paper deals with the finite element solution of the eddy current problem in a bounded conducting domain, crossed by an electric current and subject to boundary conditions appropriate from a physical point of view. Two different cases are considered depending on the boundary data: input current density flux or input current intensities. The analysis of the former is an intermediate step for the latter, which is more realistic in actual applications. Weak formulations in terms of the magnetic field are studied, the boundary conditions being imposed by means of appropriate Lagrange multipliers. The resulting mixed formulations are analyzed depending on the regularity of the boundary data. Finite element methods are introduced in each case and error estimates are proved. Finally, some numerical results to assess the effectiveness of the methods are reported.