1,720,967 research outputs found
Edible film coating to extend the shelf-life of fresh-cut kiwi
Full text linkIn this work, a novel coating strategy able to prolonge the shelf-life of fresh-cut kiwi is proposed and the effectiveness of the procedure was evaluated over a period of 15 days in order to propose innovative minimally processed fruits as ready-to-eat. Chitosan and carboxymethyl cellulose were compared as coating material while a number of pretreatments were tested in order to assess the most performing strategy leading to the most stable product. The complete characterization of the Volatile Organic Compounds (VOCs) was achieved by Solide Phase Micro Extraction associated to gaschromatography and mass spectrometry (SPME-GC/MS) and correlated to the weight losses occurring with the increase of aging. The obtained results suggested that the involvement of carboxymethyl cellulose and ascorbic acid on pretreated fresh-cut kiwi, permitted to extend the shelf-life of the fruit until 15 days during storage at 4°
Innovative miniaturized approach by MicroNIR and chemometrics for the monitoring of the occupational exposure of workers
Full text linkInnovative preparation strategies for nanomaterial functionalization were proposed to provide novel tool to be used as drug delivery vectors for biomedical applications. In particular, three different carbon nanotubes were considered in this study such as the very small CNTs, the carboxylated CNTs (CNT-COOH) and the buckypapers and two polymers were used to study the functionalization. Different preparation procedures were investigated by thermogravimetric analysis (TGA), including the selection of the most performing polymer to be linked to the nanomaterial between PEI and PAMAM, the percentage of the polymer and the time of suspension. To simultaneously evaluate all these variables, an experimental design was planned and the recorded data were processed by chemometrics to identify the preparing procedure providing new nanomaterials able to conjugate microRNAs and to transfect efficiently endothelial cells
The detection of cannabinoids in veterinary feeds by microNIR/chemometrics: A new analytical platform
No full textIn this work, the capabilities of a novel miniaturized and portable microNIR spectrometer were investigated in order to propose a practical and intelligible test allowing the rapid and easy screening of cannabinoids in veterinary feeds. In order to develop a predictive model that could identify and simultaneously quantify the residual amounts of cannabinoids, specimens from popular veterinary feeds were considered and spiked with increasing amounts of cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), and cannabigerol (CBG). Partial least squares discriminant analysis (PLS-DA) and partial least squares regression (PLSr) were applied for the simultaneous detection and quantification of cannabinoids. The results demonstrated that the microNIR/chemometric platform could statistically identify the presence of CBD, THC and CBG in the simulated samples containing cannabinoids from 0.001 to 0.01%w/w, with the accuracy and sensitivity of the official reference methods actually proposed. The method was checked against false positive and true positive responses, and the results proved to be those required for confirmatory analyses, permitting to provide a fast and accurate method for monitoring cannabinoids in veterinary feeds
TGA/Chemometrics addressing innovative preparation strategies for functionalized carbon nanotubes
Full text linkIn this work, functionalized carbon nanotubes (CNTs) using two polyamine polymers, polyethyleneimine (PEI) and polyamidoamine dendrimer (PAMAM), were investigated by thermal analysis in order to address preparation strategies to obtain low cytotoxic compounds with the ability to conjugate microRNAs and, at the same time, to transfect efficiently endothelial cells. Thermogravimetric analysis (TGA) was coupled to chemometrics as a novel analytical strategy to characterize functionalized CNTs from different preparation conditions. In particular, two starting materials were considered: very small CNTs and carboxylated CNTs (CNT-COOH) in order to examine the affinity with polymers. Chemometrics permitted to compare results from TGA and to investigate the effect of a number of factors affecting the synthesis of coated nanotubes including a different amount of involved polymer and the time required for the suspension for a satisfactory and reproducible preparation procedure. The results demonstrated the effectiveness of TGA as a tool able to address synthesis of coated CNTs to be employed as efficient drug delivery vectors in biomedical applications. (C) 2020 Xi'an Jiaotong University. Production and hosting by Elsevier B.V
Development of a "single-click" analytical platform for the detection of cannabinoids in hemp seed oil
No full textIn this work, an innovative screening platform is developed and validated for the on site detection of cannabinoids in hemp seed oil, for food safety control of commercial products. The novelty of this completely automated tool consists of a miniaturized NIR spectrometer operating in a wireless mode that permits processing samples in a rapid and accurate way and to obtain in a single click the early detection of a residual amount of cannabinoids in oil, including cannabidiol (CBD), the psychoactive Δ9-tetrahydrocannabinol (THC) and the Δ9-tetrahydrocannabinolic acid (THCA). Simulated samples were realized to instruct the platform and prediction models were developed by chemometric analysis of the NIR spectra using partial least square regression algorithms. Once calibrated, the platform was used to predict samples acquired in the market and on websites. Validation of the system was achieved by comparing results with those obtained from GC-MS analyses and a good correlation was observed
MicroNIR/Chemometrics: a new analytical platform for fast and accurate detection of Δ9-Tetrahydrocannabinol (THC) in oral fluids
No full textBackground: Δ9-Tetrahydrocannabinol (THC) is already considered one of the most addictive substances since an increasing number of consumers/abusers of THC and THC based products are observed worldwide. In this work, the capabilities of a novel miniaturized and portable MicroNIR spectrometer were investigated in order to propose a practical and intelligible test allowing the rapid and easy screening of Δ9-Tetrahydrocannabinol (THC) oral fluids without any pretreatment. Methods: Specimens from volunteers were collected in order to consider any sources of variability in the spectral response and spiked with increasing amount of THC in order to realize predictive models to be used in real cases. Partial Least Square-Discriminant Analysis (PLS-DA) and Partial Least Square regression (PLSr) for the simultaneously detection and quantification of THC, were applied to baseline corrected spectra pre-treated by first derivative transform. Results: Results demonstrated that MicroNIR/Chemometric platform is statistically able to identify THC abuse in simulated oral fluid samples containing THC from 10 to 100 ng/ml, with a precision and a sensitivity of about 1.51% and 0.1% respectively. Conclusions: The coupling MicroNIR/Chemometrics permits to simplify THC abuse monitoring for roadside drug testing or workplace surveillance and provides the rapid interpretation of results, as once the model is assessed, it can be used to process real samples in a “click-on” device
TGA/Chemometric Test Is Able to Detect the Presence of a Rare Hemoglobin Variant Hb Bibba
Full text linkIn this study the TGA/Chemometric test was applied for diagnosis of a case of congenital hemolytic anemia for which the common first level diagnostic tests were not able to find the erythrocyte congenital defect. A 6 years old girl presented chronic hemolytic anemia characterized by hyperbilirubinemia, increased spleen, negative Coombs tests, normal hemoglobin values, decreased mean corpuscular volume (MCV), increased red cell distribution width (RDW), reticulocytes and lactate dehydrogenase (LDH), and altered erythrocyte morphology (ovalocytes, spherocytes, and rare schizocytes). The diagnostic protocols for differential diagnosis of hereditary hemolytic anemia were carried out by the investigation of the congenital hemolytic anemias due to defects of membrane proteins and the most common erythrocyte enzymes, but no defect was found. The TGA/Chemometric test was applied and the PLS-DA model of prediction was used to process results. The thermogravimetric profile of the patient was very distinct from those of healthy subjects and comparable with those of thalassemia patients. The classification model applied to the patient identified a chronic hemolytic anemia due to a hemoglobin defect and the molecular characterization confirmed the TGA/Chemometrics results, demonstrating the presence of a very rare hemoglobin variant Hb Bibba (α2136(H19)Leu → Proβ2). In conclusion the TGA/Chemometric test proved to be a promising tool for the screening of the hemoglobin defects, in a short time and at low cost, of this case of congenital hemolytic anemia of difficult diagnosis. This method results particularly suitable in pediatric patients as it requires small sample volumes and is able to characterize patients subjected to transfusion
Thermal behavior, morphology and antibacterial properties study of silica/quercetin nanocomposite materials prepared by sol–gel route
No full textThe sol–gel process was used to synthesize four organic/inorganic hybrid materials by entrapping different amounts of quercetin (Q), namely 5, 10, 15 and 20 mass%, in a silica (S) matrix. A detailed characterization focused on revealing the nature of the bonds between the inorganic and organic components was performed by Fourier transform infrared (FTIR) spectroscopy. Silica/quercetin (SQ) hybrid materials showed an increase in the mass loss percentages of the first decomposition step with increasing the amount of Q, thus suggesting the incorporation of Q in the hybrid materials and a stabilization of the structure by hydrogen bonds. The morphology of the SQ hybrids investigated by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS) confirmed a regular size distribution of the particles and a homogeneous distribution of quercetin in the silica matrix in the suitable expected ratio. Furthermore, the SEM images confirmed the absence of contaminants during the sol–gel synthesis. Finally, the antibacterial properties of the SQ hybrid materials were tested using four (two Gram-positive and two Gram-negative) bacteria strains. The results demonstrated that they can be proposed as valuable antibacterial agents against Escherichia coli and Pseudomonas aeruginosa as Gram-negative bacteria and Staphylococcus aureus and Enterococcus faecalis as Gram-positive for amounts above 50 mg
Innovative screening test for the early detection of sickle cell anemia
No full textIn this study, the capability of thermogravimetry in conjuction with a multivariate statistical analysis, was investigated for the screening of Sickle Cell Anemia (SCA), a hereditary disorder of hemoglobin characterized by severe hemolytic anemia with different severe clinical manifestations. SCA results from a mutation in the sixth codon of the beta globin gene, which results in the substitution of glutamic acid for valine and leads to the production of an altered form of hemoglobin, hemoglobin S (HbS). People with this disorder have atypical hemoglobin molecules which tend to aggregate together and form filaments inside the red blood cells. These deformed red blood cells called half-moon or sickle, are rigid and unable to flow inside the small vessels, creating occlusions of the small circulation. Systematic screening for SCA is not a common practice, and diagnosis is usually made when a severe complication occurs. An early and rapid diagnosis is important for patients in order to prevent and treat the painful episodes that can occur when sickled red blood cells, which are stiff and inflexible, get stuck in small blood vessels. A novel test was developed using whole blood samples from patients with congenital defects and analyzed by the TG7 thermobalance (PerkinElmer) without any pretreatment. The resulting TG and DTG curves of blood samples were compared to those typical of healthy individuals and results demonstrated a different thermal behaviour of the anemic patients with respect to healthy individuals as result of the different amounts of water content and corpuscular fraction. The multivariate statistical analysis performed by chemometrics allowed a quick identification of differences between the two population and provided a model of prediction in patients with heterogeneous congenital hematological disorders. The predictive ability of the model was tested by processing patient affected by SCA and with a confirmed diagnosis obtained by the molecular analysis. The model provided for a sensitivity and an accuracy of a 100% and an error of prediction of about 0.1%
An Innovative Multilevel Test for Hemoglobinopathies. TGA/Chemometrics Simultaneously Identifies and Classifies Sickle Cell Disease From Thalassemia
Full text linkIntroduction: Hemoglobinopathies are the most common genetic disorder wordlwide and because of migrations are become an emerging global health problem. Screening programmes for Sickle cell disease and Thalassemia have been implemented in some countries, but are not a common practice, due to a lack in the accuracy of the methods and to the costs of the analyses. Objectives: The objective of this study was the application of the thermogravimetry coupled to chemometrics as new screening method to perform an early diagnosis of thalassemia and sickle cell disease. Methods: Whole blood samples (30 μL) from sickle cell anemia and thalassemia patients were analyzed using the thermobalance TG7 and the resulting curves were compared with those of healthy individuals. A chemometric approach based on Principal Components Analysis (PCA) was exploited to enhance correlation between thermogravimetric profiles and a model of prediction by Partial Least Square Discriminant Analysis (PLS-DA) was developed and validated. Results: The characteristic profile of the blood sample thermal decomposition and the first derivative of the TG curve showed that patients were clearly distinguished from healthy individuals as a result of different amounts of water and corpuscular fraction of blood. The chemometric approach based on PCA allowed a quick identification of differences between healthy subjects and patients and also between thalassemic and sickle cell anemia subjects. Chemometric tools (PLS-DA) were used to validate a model of prediction to process the thermogravimetric curves and to obtain in 1 h an accurate diagnosis. The TGA/Chemometric test permitted to perform first level test for hemoglobinopathies with the same accuracy of confirmatory analyses obtained by the molecular investigation. Conclusions: A screening test based on the coupling of thermogravimetry and chemometrics was optimized for the differential diagnosis of hemoglobinopathies. The novel test is able to simultaneously perform a simple and fast diagnosis of sickle cell anemia or thalassemia, in a single analysis of few microliters of non-pretreated whole blood at low cost, and with high accuracy. Moreover this method results particularly suitable in pediatric patients as it requires small sample volumes and is able to characterize also transfused patients
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