Search results for " Analytical"
showing 10 items of 1453 documents
Recent advances on application of peptide nucleic acids as a bioreceptor in biosensors development
2019
Abstract The analogs of DNA are unique biomedical tools that are broadly utilized to develop different types of biosensors. Peptide nucleic acids (PNA) are an individual and notable class of nucleic acid analogs due to their unique, novel physicochemical and biochemical characteristics, stability and resistance to nuclease and protease enzymes, significant interactions with complementary strands and remarkable hybridization attributes. Therefore, they are employed in the preparation and fabrication of various types of functional biosensors. In other words, immobilization of PNA as an appropriate diagnostic probe on the surface of electrochemical and optical converters lead to the fabricatio…
Characterizing physicochemical, nutritional and quality attributes of wholegrain Oryza sativa L. subjected to high intensity ultrasound-stimulated pr…
2020
Abstract When ultrasonic stimulation is applied to plant seeds it may promote the development of new adaptive characteristics during germination, thus providing an alternative to regulate nutritional and physicochemical attributes of germinated seeds. However, there is rather limited information concerning high-intensity ultrasound (HIU) effects on the germination process of crop seeds as foodstuff. This investigation aimed at examining the effects of a novel processing pattern, which coupled HIU stimulation (28 kHz, 17.83 W cm−2) to a pre-germination stage, on the physicochemical, nutritional and quality changes of wholegrain brown rice (WBR; Oryza sativa L.). Results suggested that HIU st…
Zero- to Ultralow-Field NMR Spectroscopy of Small Biomolecules.
2021
Nuclear magnetic resonance (NMR) spectroscopy is a well-established analytical technique used to study chemicals and their transformations. However, high-field NMR spectroscopy necessitates advanced infrastructure, and even cryogen-free benchtop NMR spectrometers cannot be readily assembled from commercially available components. We demonstrate construction of a portable zero-field NMR spectrometer employing a commercially available magnetometer and investigate its applications in analytical chemistry. In particular, J-spectra of small representative biomolecules [13C]-formic acid, [1-13C]-glycine, [2,3-13C]-fumarate, and [1-13C]-d-glucose were acquired, and an approach relying on the prese…
Analysis of the metabolic switch induced by the spirulina peptide SP6 in high fat diet ApoE-/-mice model: A direct infusion FT-ICR-MS based approach
2021
Atherosclerosis, dyslipidemia and hypertension are comorbid diseases often found in combination. Among different pharmacological approaches the employment of natural multifunctional peptides is an attractive option as side therapy. Mass spectrometry-based metabolomics provide valuable information on metabolic changes and can be useful to elucidate peptide pharmacodynamics. In this this work we performed a preliminary investigation on the potential effect of a recently characterized Spirulina platensis peptide named SP6 (GIVAGDVTPI) on the modulation of metabolism in a high fat diet ApoE-/- mice atherosclerotic model. A direct infusion Fourier transform ion cyclotron resonance mass spectrome…
Temporal fatty acid profiles of human decomposition fluid in soil
2017
Abstract We studied the changes in concentration and relative abundance of human-derived fatty acids (FAs) in soil over a period of one year. The study is based on analysis of soil underneath a human body that lay on the soil surface for 18 days before it was discovered. Soil samples were taken when the body was removed, and also 358 days later. Large amounts of the total FA concentration at the start of the measurement period were still present one year after the removal of the body. The FA profile suggested that extensive saturated FA reduction occurred during the first 18 days after deposition. 10-Hydroxystearic acid and FA salts, which are characteristic of adipocere, were abundant in a…
Study of silica-structured materials as sorbents for organophosphorus pesticides determination in environmental water samples
2018
Abstract A novel sorbent based on a UVM-7 mesoporous silica doped with Ti has been synthesized and used for solid-phase extraction of several organophosphorus pesticides in environmental water samples followed by gas chromatography coupled to a nitrogen-phosphorus selective detector. Thus, mesoporous silica materials doped with Ti and Fe as well as immobilized cyclodextrin silica-based supports were prepared and morphologically characterized by several techniques such as transmission electronic microscopy, nitrogen adsorption-desorption and X-ray diffraction. These sorbents were comparatively evaluated, and Ti25-UVM-7 material was selected as the best solid phase. After optimization of extr…
Study of the factors influencing the bioaccessibility of 10 elements from chocolate drink powder
2016
Abstract A risk/benefit assessment of chocolate drink powder has been conducted by evaluating the total contents and the bioaccessibilities of Al, Ba, Cd, Cr, Cu, Fe, Mg, Mn, P and Zn. The bioaccessibility was studied considering the type of sample (traditional, light, diet and organic) and the different factors that may affect it, including physical-chemical parameters of the human digestive process (gastric pH, concentration of bile salts and presence of lipase) and the presence of dietary components (phytate, pectin, cellulose and tannin). The bioaccessibility varied greatly according to the sample type, being greater in the diet and organic samples, and on the element being considered (…
Carbon nanostructures incorporated on methacrylate monoliths for separation of small molecules by nano-liquid chromatography
2018
Abstract Carbon nanostructures have been incorporated to polymethacrylate monoliths to develop novel stationary phases with enhanced separation performance in nano-liquid chromatography (nano-LC). Two incorporation approaches of these nanomaterials in monoliths were investigated. Single-walled carbon nanohorns (SWNHs) were first incorporated to the polymerization mixture, followed by UV initiation. The resulting stationary phases with embedded SWNHs led to an increase in the separation performance of analytes compared to the parent monolith. Alternatively, a two-step photo-grafting approach was also adopted to attach the carbon nanoparticles onto the polymer monolith surface. The effect of …
Zearalenone presence in wheat field samples from Romania
2016
Deep eutectic solvents vs ionic liquids: Similarities and differences
2020
Abstract Deep eutectic solvents (DES) were introduced as an alternative to ionic liquids (IL) to overcome the drawbacks of IL solvents. However, some authors consider them to be a subclass of ILs. In contrast, other authors emphasize that these are by their nature independent, different groups of substances. Thus, the question arises: Which solvent group should DESs belong to? Maybe a new class should be added to the existing ones. The aim of this work is to attract the attention of researchers using DES in their studies to the need for a proper use of terms.