Search results for "010401 analytical chemistry"
showing 10 items of 1284 documents
Effects of ultrasound and high pressure on physicochemical properties and HMF formation in Turkish honey types
2018
Abstract In industrial production, thermal processing of honey at 50 °C commonly induces liquefaction, i.e. it reduces the crystal count and viscosity and delays any subsequent crystallization. Unfortunately, thermal treatment can generate toxic 5-hydroxymethylfurfural (HMF), thereby resulting in quality reduction. Considering this, the present work aims at evaluating the influence of (two) processing technologies as alternatives to thermal processing of honey, namely high hydrostatic pressure (HHP; P = 220–330 MPa, T = 50/60 °C, t = 23/106 min), and ultrasound processing (US; at 24 kHz). The quality parameters evaluated for honey included liquefaction time, HMF content, diastase number, co…
Effect of buffer nature and concentration on the chromatographic performance of basic compounds in the absence and presence of 1-hexyl-3-methylimidaz…
2019
Abstract In reversed-phase liquid chromatography, the performance for basic compounds is affected by the interaction of the protonated (cationic) species with the anionic free silanols on the alkyl-bonded stationary phases. Using aqueous-organic mobile phases in the absence of additives, the retention may be too high, and the peaks be broad and asymmetric. The performance is improved by addition to the mobile phase of ionic liquids, from which 1-hexyl-3-methylimidazolium chloride ([C6MIm][Cl]) has especially good characteristics. A recent report has also revealed that the use of the phosphate system as buffer, at varying concentration and pH, may have a significant role in the chromatograph…
A review of sustainable and intensified techniques for extraction of food and natural products
2020
International audience; This review presents innovative extraction techniques and their role in promoting sustainable ingredients forthe food, cosmetic and pharmaceutical industries. These techniques (such as microwave, ultrasound, pulseelectricfield, instant controlled pressure drop, sub- and super-criticalfluid processing, extrusion, mechano-chemistry, high pressure, and ohmic, UV and IR heating) use or produce less solvent, energy, and hazards.This review will provide the necessary theoretical background and some details about green extractiontechniques, their mechanisms, some applications, and environmental impacts. We will pay special attentionto the strategies and present them as succ…
Quando bisogna discostarsi dalle linee guida? I casi problematici nella prassi odontoiatrica
2018
Obiettivi Delineare vantaggi e limiti delle linee guida e dei riferimenti alle buone pratiche nella valutazione della condotta professionale dell’odontoiatra. Definire tipologie di pazienti e contesti operativi nei quali esse non risultano applicabili. Quest’obiettivo è coerente con i recenti sviluppi giurisprudenziali della Corte di Cassazione a Sezioni Unite del dicembre 2017 in tema di colpa e responsabilità dei sanitari. Materiali e metodi Si analizzano i riferimenti contenuti nella Legge 24/2017; quindi, in riferimento alla metodologia della responsabilità medico/odontoiatrica, si individuano i contesti della pratica clinica nei quali è più opportuno cercare di sviluppare buone pratich…
Development of biosensors for detection of alpha-fetoprotein: As a major biomarker for hepatocellular carcinoma
2020
Abstract Alpha-fetoprotein as a multifunctional glycoprotein with a dual regulatory role in cancer and fetal activities is belonging to an albuminoid gene family. Due to important biological activities of alpha-fetoprotein in the adjustment of cancer, the level of this biomarker, majorly in liver carcinomas, abnormally is elevated. Also, the probability of high-risk or low-risk patients for chromosomal abnormalities can be identified by the serum level of alpha-fetoprotein. The detection of biomarkers possesses an important role in prognosis and early diagnosis of cancer and other diseases. So, the development of accurate and sensitive methods for measurement of alpha-fetoprotein is of grea…
Lateral flow assays towards point-of-care cancer detection: A review of current progress and future trends
2020
Abstract Cancer is one of the main causes of mortality and morbidity worldwide. However, its early non-invasive detection via quantification of appropriate biomarkers can significantly reduce mortality, enhance survival, and save treatment costs. Lateral flow test strips (LFTS) are nowadays considered as the most attractive point-of-care devices for healthcare applications. However, the quantification of cancer biomarkers in body fluids suffers from some challenges including i) the necessity for multiplex analysis, ii) the development of sensitive detection systems, iii) to overcome the analysis of complex samples, at the same time, it should keep the quality assurance criteria for an accur…
DTMC modeling for performance evaluation of DW-MAC in wireless sensor networks
2016
Synchronized duty cycling (DC) aligns sensor nodes to wake up at the same time in order to reduce idle listening for medium access control (MAC) in wireless sensor networks (WSNs). Demand wakeup MAC (DW-MAC) is a popular synchronous DC MAC protocol which allows nodes to compete and transmit multiple packets in one operational cycle. This multiple packet transmission (MPT) feature makes DW-MAC more energy efficient when comparing with other existing single time competition based protocols such as sensor MAC (S-MAC). In the literature, no analytical model exists to evaluate the performance of DW-MAC. In this paper, we develop two associated discrete time Markov chain (DTMC) models and incorpo…
Recent advances in the application of innovative food processing technologies for mycotoxins and pesticide reduction in foods
2020
Abstract Background Agricultural products are a vital component of the human diet. However, these products can be contaminated by health-threatening pesticides and mycotoxins due to improper farming and storage practices. Besides, pesticide pollution can be also regarded as environmental pollution and pesticide reduction is among the Sustainable Development Goals (SDGs). While these hazardous chemicals are stable during several traditional food processing, innovative food processing technologies, including high-pressure processing (HPP), pulsed electric fields (PEF), cold plasma (CP), supercritical carbon dioxide (SC-CO2), and ultrasound (USN) processing, have been found to have good potent…
Influence of Innovative Processing on γ-Aminobutyric Acid (GABA) Contents in Plant Food Materials
2017
Over the last several decades, γ-aminobutyric acid (GABA) has attracted much attention due to its diverse physiological implications in plants, animals, and microorganisms. GABA naturally occurs in plant materials and its concentrations may vary considerably, from traces up to μmol/g (dry basis) depending on plant matrix, germination stage, and processing conditions, among other factors. However, due to its important biological activities, considerable interest has been shown by both food and pharmaceutical industries to improve its concentration in plants. Natural and conventional treatments such as mechanical and cold stimulation, anoxia, germination, enzyme treatment, adding exogenous gl…
Low-Cost Sensor Based on SDR Platforms for TETRA Signals Monitoring
2021
The paper presents the design and implementation of an electromagnetic field monitoring sensor for the measurement of the Terrestrial Truncked Radio (TETRA) signals using low-cost software defined radio (SDR) platforms. The sensor includes: an SDR platform, a Global Positioning System (GPS) module and a hardware control module. Several SDR platforms having different resolutions of the analog–digital converters were tested in the first phase. The control module was implemented in two variants: a fixed one, using a laptop, and a mobile one, using a Raspberry Pi. The tests demonstrate the following achieved performances: instantaneous acquisition band of 5.12 MHz