Search results for " Detection"
showing 10 items of 1676 documents
Development of an Analytical Assay for Electrochemical Detection and Quantification of Protein-Bound 3-Nitrotyrosine in Biological Samples and Compar…
2020
Reactive oxygen and nitrogen species (RONS) cause oxidative damage, which is associated with endothelial dysfunction and cardiovascular disease, but may also contribute to redox signaling. Therefore, their precise detection is important for the evaluation of disease mechanisms. Here, we compared three different methods for the detection of 3-nitrotyrosine (3-NT), a marker of nitro-oxidative stress, in biological samples. Nitrated proteins were generated by incubation with peroxynitrite or 3-morpholino sydnonimine (Sin-1) and subjected to total hydrolysis using pronase, a mixture of different proteases. The 3-NT was then separated by high performance liquid chromatography (HPLC) and quantifi…
External Influences on Invertebrate Brain Histamine and Related Compounds via an Automated Derivatization Method for Capillary Electrophoresis.
2017
8 pages; International audience; Histamine has been shown to modulate visual system and photic behavior in arthropods. However, few methods are available for the direct quantification of histamine and its precursor and metabolites in arthropod brain. In this work, a method for the separation of histamine, its precursor histidine, and its metabolite N-methyl-histamine from brain extracts of a freshwater crustacean has been developed using capillary electrophoresis with laser-induced fluorescence detection. Molecules were tagged on their primary amine function with naphthalene-2,3-dicarboxaldehyde, but derivatized histamine and N-methyl-histamine exhibited poor stability in contrast to deriva…
Taking up the cudgels for the traditional reactive oxygen and nitrogen species detection assays and their use in the cardiovascular system
2017
Reactive oxygen and nitrogen species (RONS such as H2O2, nitric oxide) confer redox regulation of essential cellular functions (e.g. differentiation, proliferation, migration, apoptosis), initiate and catalyze adaptive stress responses. In contrast, excessive formation of RONS caused by impaired break-down by cellular antioxidant systems and/or insufficient repair of the resulting oxidative damage of biomolecules may lead to appreciable impairment of cellular function and in the worst case to cell death, organ dysfunction and severe disease phenotypes of the entire organism. Therefore, the knowledge of the severity of oxidative stress and tissue specific localization is of great biological …
MycoKey Round Table Discussions of Future Directions in Research on Chemical Detection Methods, Genetics and Biodiversity of Mycotoxins
2018
MycoKey, an EU-funded Horizon 2020 project, includes a series of “Roundtable Discussions” to gather information on trending research areas in the field of mycotoxicology. This paper includes summaries of the Roundtable Discussions on Chemical Detection and Monitoring of mycotoxins and on the role of genetics and biodiversity in mycotoxin production. Discussions were managed by using the nominal group discussion technique, which generates numerous ideas and provides a ranking for those identified as the most important. Four questions were posed for each research area, as well as two questions that were common to both discussions. Test kits, usually antibody based, were one major focus of the…
Validation and implementation of a commercial real-time PCR assay for direct detection of Candida auris from surveillance samples.
2021
Background Rapid and reliable laboratory methods are required for detecting the nosocomial yeast Candida auris. AurisID® (Olm Diagnostics, England) is a real-time PCR assay approved for detecting C. auris in fungal cultures as well as directly from blood samples, involving a nucleic acid extraction as a prior step. Objectives The purpose of this study is to validate the AurisID® kit for direct detection of C. auris from surveillance samples without prior DNA extraction and to analyze the results of implementing this methodology to our daily laboratory routine protocol for C. auris surveillance studies. Methods Our PCR method using the AurisID® kit was compared with our routine protocol, con…
Fast UPLC/PDA determination of squalene in Sicilian P.D.O. pistachio from Bronte: Optimization of oil extraction method and analytical characterizati…
2017
Abstract A fast reversed-phase UPLC method was developed for squalene determination in Sicilian pistachio samples that entry in the European register of the products with P.D.O. In the present study the SPE procedure was optimized for the squalene extraction prior to the UPLC/PDA analysis. The precision of the full analytical procedure was satisfactory and the mean recoveries were 92.8 ± 0.3% and 96.6 ± 0.1% for 25 and 50 mg L−1 level of addition, respectively. Selected chromatographic conditions allowed a very fast squalene determination; in fact it was well separated in ∼0.54 min with good resolution. Squalene was detected in all the pistachio samples analyzed and the levels ranged from 5…
Gene-based and semantic structure of the Gene Ontology as a complex network
2012
The last decade has seen the advent and consolidation of ontology based tools for the identification and biological interpretation of classes of genes, such as the Gene Ontology. The information accumulated time-by-time and included in the GO is encoded in the definition of terms and in the setting up of semantic relations amongst terms. This approach might be usefully complemented by a bottom-up approach based on the knowledge of relationships amongst genes. To this end, we investigate the Gene Ontology from a complex network perspective. We consider the semantic network of terms naturally associated with the semantic relationships provided by the Gene Ontology consortium and a gene-based …
A heuristic, iterative algorithm for change-point detection in abrupt change models
2017
Change-point detection in abrupt change models is a very challenging research topic in many fields of both methodological and applied Statistics. Due to strong irregularities, discontinuity and non-smootheness, likelihood based procedures are awkward; for instance, usual optimization methods do not work, and grid search algorithms represent the most used approach for estimation. In this paper a heuristic, iterative algorithm for approximate maximum likelihood estimation is introduced for change-point detection in piecewise constant regression models. The algorithm is based on iterative fitting of simple linear models, and appears to extend easily to more general frameworks, such as models i…
A widely used sampling device in colorectal cancer screening programmes allows for large-scale microbiome studies.
2018
We read with interest the article by Passamonti et al ,1 reporting the performance of two different faecal immunochemical tests (FITs) highlighting the importance of standardisation and validation of screening methodologies. Conventionally, laboratory-based FIT is the preferred approach in testing for occult blood in faeces, which includes colorectal cancer screening programmes.2–4 The potential of preserving stable faecal samples in a widely used FIT buffer for microbiome research would enable prospective microbiome studies in generally healthy subjects undergoing colorectal cancer screening. For this purpose, we evaluated faecal sample stability in the commonly used OC-Sensor (Eiken Chemi…
Observation of elastic anisotropy in strained optical nanofibers using Brillouin spectroscopy
2019
Optical nanofibers (ONFs) are excellent nanophotonic platforms for many applications such as optical sensing, quantum photonics, and nonlinear optics, due to both tight optical confinement and their evanescent field. From an acoustic viewpoint, it has recently been reported the observation of a new class of Brillouin acoustic resonances in optical nanofibers, including hybrid shear/longitudinal acoustic waves (HAWs) and surface acoustic waves (SAWs) [1–2]. It has been later shown that, under axial tensile strain, the Brillouin frequency shifts (BFS) of these elastic resonances are fundamentally different from that of standard optical fibers [3]. This is principally due to the hybrid nature …