Mutagenicity and Safety Evaluation of Water Extract of Coriander sativum Leaves

ABSTRACT:  Coriander has been used as a spice and medicinal plant for centuries. Several studies have described its biological properties and some reports have indicated its pharmacological actions in some human pathology. However, data on its toxicity and metabolism are limited or null, and no research has been conducted with mammalian cells. The purpose of this study was to evaluate the mutagenicity and safety of  Coriandrum sativum  extract. The mutagenic effects of  C. sativum  extract were evaluated by Ames test. Mutagenicity was present when the  C. sativum  extract was used in high concentrations in both tested strains ( Salmonella typhimurium  TA97 and TA102). Our research showed that  C. sativum  extract reduced the cell survival of human cell lines (WRL-68 and 293Q cells) by inducing apoptosis and necrosis in the cases where extract concentration was the highest. The  C. sativum  extract altered the cell cycle; it increased the G1 phase of hepatic cells and reduced the G2+M phase in both cell lines in a dose-response manner. These results showed correlation with a reduction in the mitotic index. The extract also induced severe malformations during embryonic development. Exposure of chicken embryos to the  C. sativum  extract resulted in a dose-dependent increase of anomalies. Present results show that  C. sativum  extract reduced the axial skeleton and affected the neural tube, the somites, the cardiovascular structures, and the eye. According to the present results, the  C. sativum  aqueous extract cannot be considered safe. These results indicate that some significant adverse effects of  C. sativum  extract could be observed  in vivo .     

A study on wear evaluation of railway wheels based on multibody dynamics and wear computation

The wear evolution of railway wheels is a very important issue in railway engineering. In the past, the reprofiling intervals of railway vehicle steel wheels have been scheduled according to designers’ experience. Today, more reliable and accurate tools in predicting wheel wear evolution and wheelset lifetime can be used in order to achieve economical and safety benefits. In this work, a computational tool that is able to predict the evolution of the wheel profiles for a given railway system, as a function of the distance run, is presented. The strategy adopted consists of using a commercial multibody software to study the railway dynamic problem and a purpose-built code for managing its pre- and post-processing data in order to compute the wear. The tool is applied here to realistic operation scenarios in order to assess the effect of some service conditions on the wheel wear progression.     

Combinatorial Multicomponent Access to Natural‐Products‐Inspired Peptidomimetics: Discovery of Selective Inhibitors of Microbial Metallo‐aminopeptidases

The development of selective inhibitors of microbial metallo‐aminopeptidases is an important goal in the pursuit of antimicrobials for therapeutic applications. Herein, we disclose a combinatorial approach relying on two Ugi reactions for the generation of peptidomimetics inspired by natural metallo‐aminopeptidase inhibitors. The library was screened for inhibitory activity against the neutral metallo‐aminopeptidase of Escherichia coli (ePepN) and the porcine kidney cortex metallo‐aminopeptidase (pAPN), which was used as a model of the M1‐aminopeptidases of mammals. Six compounds showed typical dose–response inhibition profiles toward recombinant ePepN, with two of them being very potent and highly selective for ePepN over pAPN. Another compound showed moderate ePepN inhibition but total selectivity for this bacterial enzyme over its mammalian orthologue at concentrations of physiological relevance. This strategy proved to be useful for the identification of lead compounds for further optimization and development.     

Assessment of process parameters on the production of diglycerides rich in omega-3 fatty acids through the enzymatic glycerolysis of fish oil

The main objective of this work is to present new experimental information concerning the effect of relevant process parameters related to the production of diglycerides by enzymatic glycerolysis of fish oil. Reaction products can be applied as ingredients in food industry, joining the emulsifying properties of partial glycerides along with the nutritional benefits attributed to the omega-3 fatty acids. From preliminary reactions, conversion was higher for a solvent- and surfactant-free system but the long time to reach appreciable amounts of diglycerides may be a drawback for practical purposes. To overcome this problem, the addition of tert-butanol revealed to be relevant, leading to high diglycerides contents in short times. The system containing Tween 65 led to the highest amount of diglycerides. This study described the feasibility of enzymatic synthesis of diglycerides rich in EPA and DHA in short reaction times as well by using a more environmentally friendly process.     

Glass transition temperature measured at high frequencies by piezoelectric excitation

As the temperature of a polymer melt or rubber is lowered, a point known as the glass transition temperature, T_g, is reached where polymeric materials undergo a marked change in properties associated with the virtual cessation of local molecular motion. In fact, as the thermal energy reduces, the distance between macromolecules, and consequently the specific volume of the sample, diminishes. However, this change is not abrupt, that is, the glass transition is not a rigorous phase transition from the thermodynamical point of view. Effectively, it depends not only on the polymeric structure but also on the heating rate, the measuring method, etc. Since there is a copious literature referring to traditional methods employed to measure T_g, this work will only present them as a frame to compare them with the experimental procedure we used. The determination of T_g is based on the change of the real component of the dynamic modulus with temperature. This modulus is measured at high frequencies on exciting the sample with a piezoelectric crystal attached to it. Glass transition temperatures of several glassy polymers are determined. These results are compared with values measured through other methods. Finally, the advantages of our procedure are discussed.     

Rough Surfaces Profiles and Speckle Patterns Analysis by Hurst Exponent Method

In this work, a conventional surface roughness comparator is used to perform an analysis of different textures. The Hurst exponent method for the characterization of optical profiles and speckle digital patterns obtained from the comparator was used. By implementation of a simple experimental setup with minimum alignment, information about specific points on the comparator for different roughness was obtained. The processing and analysis of optical signals and images obtained by reflection allowed calculation of Hurst coefficients, revealing a relation between surface roughness, optical profiles and speckle patterns. The setup simplicity and Hurst analysis suggest their combined application on surface metrology.     

Wind turbine angular frequency analysis by means of computer vision techniques

The turbine synchronization phenomenon is of great interest in order to estimate the flicker produced by a wind farm. This paper proposes an initial approach to analyze the appearance of this phenomenon by the use of various image processing techniques: a method to automatically calculate the angular frequency of an unknown number of wind turbines from a video. The recorded video images were obtained at the Manzanal wind farm, province of León (Spain).