A Review on Application of Microextraction Techniques for Analysis of Chemical Compounds and Metal Ions in Foodstuffs

Foodstuffs analysis is very important due to population growth and increasing consumer demand for safety and nutritional excellence. The Analysis of different compounds in foodstuffs is so difficult without using sample preparation techniques. Traditional techniques require large amounts of toxic organic solvents. As a result, they are not only expensive but also environmentally unfriendly and they generate a considerable amount of waste. Nowadays efforts are being focused on development of microextraction techniques. Different microextraction techniques such as solid phase microextraction (SPME), stir bar sorptive extraction (SBSE), and liquid phase microextraction (LPME) have found an important place in sample preparation because of their inherent advantages over the conventional procedures. In particular, they have been applied with successfully for the analysis of food samples despite their complexity. The review discusses different microextraction approaches used in analysis of chemical compounds and metal ions in foodstuffs. It summarizes the application of microextraction techniques in food analysis in details as possible

The Potential Applicability of Melatonin as an Immunosuppressive Agent for COVID-19: Review

COVID-19 is an emerging pathogen that has recently caused a global pandemic. It is an RNA virus that causes a respiratory tract infection. The pathogenesis of this virus involves an over aggressive immune reaction leading to inflammation and in certain cases acute respiratory distress syndrome (ARDS) and various neurological manifestations. Melatonin, a mitochondrially targeted antioxidant with anti-inflammatory properties, is being tested in trials as a potential adjuvant therapeutic agent that can help reduce oxidative stress damage caused by viral infections as well as optimizing the innate immune response. In addition, melatonin is an extremely safe drug and reports show its usefulness in treating other respiratory viral infections. The role of melatonin as an adjuvant in managing COVID-19 cases as well as the delirious states that are often encountered in these patients is being discussed

Authoritative subspecies diagnosis tool for European honey bees based on ancestryinformative SNPs

Background With numerous endemic subspecies representing four of its five evolutionary lineages, Europe holds a large fraction of Apis mellifera genetic diversity. This diversity and the natural distribution range have been altered by anthropogenic factors. The conservation of this natural heritage relies on the availability of accurate tools for subspecies diagnosis. Based on pool-sequence data from 2145 worker bees representing 22 populations sampled across Europe, we employed two highly discriminative approaches (PCA and F-ST) to select the most informative SNPs for ancestry inference. Results Using a supervised machine learning (ML) approach and a set of 3896 genotyped individuals, we could show that the 4094 selected single nucleotide polymorphisms (SNPs) provide an accurate prediction of ancestry inference in European honey bees. The best ML model was Linear Support Vector Classifier (Linear SVC) which correctly assigned most individuals to one of the 14 subspecies or different genetic origins with a mean accuracy of 96.2% +/- 0.8 SD. A total of 3.8% of test individuals were misclassified, most probably due to limited differentiation between the subspecies caused by close geographical proximity, or human interference of genetic integrity of reference subspecies, or a combination thereof. Conclusions The diagnostic tool presented here will contribute to a sustainable conservation and support breeding activities in order to preserve the genetic heritage of European honey bees.The SmartBees project was funded by the European Commission under its FP7 KBBE programme (2013.1.3-02, SmartBees Grant Agreement number 613960) https://ec.europa.eu/research/fp7.MP was supported by a Basque Government grant (IT1233-19). The funders provided the financial support to the research, but had no role in the design of the study, analysis, interpretations of data and in writing the manuscript

A novel bidirectional DC–DC converter with high voltage conversion ratio and capability of cancelling input current ripple

Abstract This paper proposes a novel bidirectional DC–DC converter with high voltage conversion ratio and capability of cancelling input current ripple. The proposed converter uses two coupled inductors and switched‐capacitor circuit to increase the voltage conversion ratio. The input current ripple at low voltage side can be eliminated for a pre‐selected duty cycle by adjusting special values of magnetizing inductances of coupled inductors. The input current is divided into two paths of the primary winding of coupled inductors that causes the decrease in the current stresses of switches. The proposed converter has five switches that consist the internal diodes of switches to bring about bidirectional power flow and have boost and buck operations. Here, the proposed topology is analysed in all operating modes and the current and voltage stresses of switches, input current ripple cancelling condition and voltage conversion ratio are calculated. Finally, the accuracy performance of the proposed converter is reconfirmed through EMTDC/PSCAD simulation and experimental results for boost operations

Porcine SLITRK1: Molecular cloning and characterization

The membrane protein SLITRK1 functions as a developmentally regulated stimulator of neurite outgrowth and variants in this gene have been implicated in Tourette syndrome. In the current study we have cloned and characterized the porcine SLITRK1 gene. The genomic organization of SLITRK1 lacks introns, as does its human and mouse counterparts. RT-PCR cloning revealed two SLITRK1 transcripts: a full-length mRNA and a transcript variant that results in a truncated protein. The encoded SLITRK1 protein, consisting of 695 amino acids, displays a very high homology to human SLITRK1 (99%). The porcine SLITRK1 gene is expressed exclusively in brain tissues

Antibacterial Effect of Juglans Regia Bark against Oral Pathologic Bacteria

Background. In this study antimicrobial effect of ethanolic and aqueous extracts of Juglans regia bark in Iran was evaluated on four different oral bacteria, Streptococcus mutans, Streptococcus salivarius, Streptococcus sanguis, and Staphylococcus aureus. Methods. Aqueous and ethanol extracts of Juglans regia bark were prepared by using disk diffusion technique and Minimal Inhibitory Concentration (MIC) methods. Tetracycline 30 μg and Erythromycin 15 μg were used as positive control and water as negative control in disk diffusion and MIC methods. Data were analyzed by ANOVA test. Results. The results showed that S. sanguis and S. mutans were the most sensitive and the most resistant bacteria against ethanolic and aqueous extracts, respectively. Ethanolic extract had significant antibacterial effect against all tested bacteria. Aqueous extract did not show antibacterial effect on S. mutans, in contrast to ethanolic extract. Aqueous extract had significantly antibacterial effect against Staphylococcus aureus, S. salivarius, and S. sanguis compared to control (P<0.0001), but it did not show effect on S. mutans when compared with Erythromycin. According to the obtained MIC values, ethanol extract of Juglans regia bark had the lowest rate. Conclusion. The results may provide the basis for using natural antimicrobial substance for oral hygiene prophylaxis purposes