Chemical Sensor for Haemodialysis Application

Abstract The water used to supply a haemodialysis center requires particular mode of treatment in order to achieve the best technical, economic and therapeutic distribution. Dialysis patients come in contact weekly with a large amount of water through the dialysis apparatus. It is therefore essential that this solution has a high quality and purity in terms of proper electrolyte composition, low concentration or absence of organic and inorganic chemical pollutants, low concentration or absence of bacteria, yeasts, fungi and endotoxins. The chemical and microbiological quality of water intended for medical and biomedical treatments, such as haemodialysis, is generally defined on the basis of a plurality of international reference standards (ASTM International standards D1193 and D5196; International Pharmacopoeia and European Pharmacopoeia CAP / NCCLS 1988). In this work the authors have designed an electrochemical device used to characterize pure and ultrapure water for biomedical applications (Patent: TO2014A000765). The results obtained show a good ability of the device in the discrimination of different bacteria and of their concentration (CFU); Pseudomonas and E-coli have been here tested

Innovative IAQ organic sensor

An innovative organic sensor for the monitoring of indoor air quality is described. For office buildings and schools the main requirements are: temperature, RH %, O-2 and CO2 concentrations. Moreover low O2 and high CO2 concentrations can be hazardous. There are a lot of sensors based on different principal transducers that are able to detect very low concentrations of CO2, O-2, and RH%.The system is based on a resistive interdigital sensor based on an organic sensing material, anthocyanin. Anthocyanins are natural pigments widely distributed in nature: they are produced by plants as secondary metabolites responsible for the pigmentation of many flowers, fruits and vegetables. In this work authors show the possibility to use this innovative organic sensor to monitor indoor air quality by measuring O2 concentration shifts with respect to a standard of 20% (20.000 ppm) and the critical CO2 concentration value of about 5% (5000 ppm) which is comparable with OSHA (Occupational Safety & Health Administration) standard in an eight-hour time-weighted average (TWA). (C) 2014 Published by Elsevier Ltd

Evaluation of a multisensorial system for a rapid preliminary screening of the olive oil chemical compounds in an industrial process

In this study, a sensory system, named BIONOTE, based on gas and liquid analyses was used to analyse the headspace of olive oil samples obtained at the end of the extraction process for a preliminary screening of the volatile and phenolic compounds. Olive oil samples were obtained using different olive paste conditioning systems, including microwave and megasound machines at different processing time. The same olives batch was used for the entire test. BIONOTE showed the ability toon-commediscriminate between 64 virgin olive oils originated from different technologies or by using different process parameters, as demonstrated by the partial least square discriminant analysis (PLS-DA) models calculated. The percentage of correct classification in different conditions are in a range from 92.19% to 100%. In addition, the research shown that the multisensorial system can provide a preliminary estimation of some volatile and phenolic compounds concentrations detected by laboratory analysis. Data analysis has been performed using multivariate data analysis techniques: PLS-DA cross validation via leave one out criterion. Future perspectives are to further develop BIONOTE in order to increase the number of detected chemical compounds and finally to include the mathematical models obtained in the BIONOTE microcontroller for a rapid chemical characterization of olive oil in the mill

A sensor which can be varied in humidity sensitivity: a first experience paving the way to new chemical sensors?

During last decades, a number of different sensors have been developing for different analytics to detect. A key aspect of those sensors is that each of them results with a fixed particular sensitivity. Consequently, at occurrence, it is necessary to use a plurality of sensors to arrange measures with different levels of sensitivity. This work intends to investigate the possibility to obtain different sensitivity, in particular with respect to humidity, from one sensor only. To this aim we investigated the resistive flex sensor, which has been already used for other applications but, as far as we know, never investigated for its potential properties as a chemical sensor. Results demonstrated how the resistive flex sensor behaves with different sensitivity values and different sensitivity curves for different bend conditions. Copyright © 2018 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved

Resonant directly coupled inductors-capacitors ladder network shows a new, interesting property useful for application in the sensor field, down to micrometric dimensions

The study of ladder networks made by sequences of directly coupled inductor⁻capacitor single cells has led us to discover a new property, which may be of certain interest in the sensor field. In the case of n cells, the n-frequencies vector characterizing each node may allow for the identification of that capacitor (sensor), which has experienced a variation of its nominal value. This localization is possible independently from the observable node of the ladder network as proven by the application of the following multivariate data analysis techniques: principal component analysis and partial least square discriminant analysis. This property can be applied on a large scale down to micrometric dimensions in agreement with the technologic ability to shrink the capacitive sensor dimensions

Methodological pipeline for monitoring post-harvest quality of leafy vegetables

Abstract Plants are primary source of nutrients for humans. However, the nutritional value of vegetables tends to decrease once organ and tissue sinks are detached from the plant. Minimal processing of leafy vegetables involves cutting and washing before packaging and storage. These processing procedures result in stressful conditions and post-harvest disorders senescence-related can also occur. The aim of this work is to define a methodological pipeline to evaluate the “quality” changes of fresh cut leafy vegetables over their shelf-life. At this purpose, intra-species variability has been investigated considering two varieties of Lactuca sativa (var. longifolia and capitata), showing different susceptibility to browning. Since browning mainly depends on phenol oxidation, redox parameters as well as the activity of the enzymes involved in phenol biosynthesis and oxidation have been monitored over storage time. At the same time, the metabolic changes of the lettuce leaves have been estimated as response patterns to chemical sensors. The obtained sensor outputs were predictive of browning-related biological features in a cultivar-dependent manner. The integration of the results obtained by this multivariate methodological approach allowed the identification of the most appropriate quality markers in lettuce leaves from different varieties. This methodological pipeline is proposed for the identification and subsequent monitoring of post-harvest quality of leafy vegetables

An investigation on e-nose platform relevance to respiratory diseases

The e-nose platform here presented gather up 190 sensors belonging to four different e-nose technologies. This platform is used in the context of a European project (U-Biopred) measuring exhaled breath samples collected from patients affected by mild or severe asthma. Sensor responses are investigated asking which disease can be diagnosed on the basis of sensor correlation with specific clinical parameters

An electrochemical sensor for monitoring biogenic amines in anchovies as quality and safety index

In this paper an electrochemical sensor for the monitoring of anchovy's shelf life is presented. The device has been developed addressing three user needs critical in food application: fast response, high reproducibility and ease of use. The system is composed of an electronic interface optimized with a low noise architecture coupled with a non-functionalized commercial screen printed electrode (SPE). The stability of the measuring process is ensured by the electronic feedback, and the interactions with the solutions are not mediated by a sensing material. The sensor has been calibrated against different concentration levels of seven specific biogenic amines (BAs) associated with the degradation of anchovies: β-phenylethylamine (β-PEA), putrescine (PUT), cadaverine (CAD), histamine (HIS), tyramine (TYR), spermine (SPM) and spermidine (SPD). This proof-of-concept experiment evidenced the potentialities of this technology both in BAs quantification and in monitoring anchovy's spoilage. The results obtained have been compared with LC-UV as standard laboratory instrument. After a first calibration step with standard BAs, the sensor has been tested in the monitoring of anchovy's samples stored for ten days at a temperature of 2 ± 1 °C. Sensors’ responses followed samples evolution against time in accordance with LC-UV results. Further developments are requested to set up a standard method for the industrial application of the sensor, but rapidity, low-cost and the ease of use account for its relevance as device to be used on field

Is there a risk for the astronauts' hearing in a microgravity environment? the Acoustic Diagnostics experiment on board the ISS

Acoustic Diagnostics is an experiment dedicated to monitoring the hearing function of the astronauts on board the International Space Station (ISS). The Italian Space Agency (ASI) provides access to the ISS as a laboratory in space to the Italian research community, through agreements between ASI and NASA for its use and between ASI and the European Space Agency (ESA) for the "BEYOND" mission, and via the Italian participation to the ISS as a member state of ESA. The main aim of the "Acoustic Diagnostics" experiment on board the space station ISS is investigating possible dysfunction of the human auditory system related to long-term missions on board the station. Some astronauts reported indeed mild hearing damage after long-term permanence in orbit. Probable hazard sources might be noise and micro-gravity, which affects intracranial fluid pressure. Before and after the mission, the astronauts will be subjected to full audiological examination, including pure tone audiometry, ABR, tuning and time-resolution measurements, impedance measurements, and otoacoustic emission (OAE) tests, which are a particularly sensitive tool for the early detection of mild hearing loss. The OAE test employed will be the measurement of distortion product otoacoustic emissions (DPOAEs) monitored during the flight, as a function of their permanence, in at least three in-flight sessions. OAE-based measurements are objective, non-invasive, and fast tests. The particular technology used for this type of tests on board will allow measurements relatively unaffected by the high noise levels of the ISS environment, and special precautions will be used to limit the EMI disturbances. High reproducibility of the measurements is guaranteed thanks to the forward-pressure calibration using the Thevenin methodology and a substantial (10dB) SNR increase will be provided by a customized time-frequency filtering procedure based on the wavelet transform