Search results for "liquid"
showing 10 items of 4351 documents
Long-term stability study of clofarabine injection concentrate and diluted clofarabine infusion solutions
2011
Purpose: The aim of this study was to investigate the physicochemical stability of clofarabine (CAFdA) injection concentrate and ready-to-use CAFdA infusion solutions over a prolonged period of 28 days. Methods: To determine the stability of CAFdA infusion solutions, the injection concentrate (Evoltra®, 1 mg/mL, Genzyme) was diluted either with 0.9% sodium chloride or 5% glucose infusion solution. The resulting concentrations of 0.2 mg/mL or 0.6 mg/mL, respectively, were chosen to represent the lower and upper limit of the ordinary concentration range. Test solutions were stored under refrigeration (2–8°C) or at room temperature either light protected or exposed to light. CAFdA concentrati…
Enzymatic, physicochemical, nutritional and phytochemical profile changes of apple (Golden Delicious L.) juice under supercritical carbon dioxide and…
2018
The impact of supercritical carbon dioxide (SCCD) (10-60 MPa/45 °C/30 min) and subsequent 10 weeks storage at 4 °C on polyphenol oxidase (PPO), peroxidase (POD) activities, phenolic profile, vitamin C, sugars, physicochemical properties of cloudy apple juices was investigated. No significant changes in sugars and total polyphenols were observed, whereas significant degradation (≈28%) of vitamin C and individual polyphenols (≈18%) was noted after SCCD treatment. After 4 weeks storage only 34% of vitamin C was retained and no vitamin C was detected after this time. Ten weeks of storage caused hydrolysis of sucrose in 15%, whereas degradation of individual polyphenols ranged from 43 to 50% dep…
Selective labelling of melittin with a fluorescent dansylcadaverine probe using guinea-pig liver transglutaminase
1991
Abstract Melittin, a C-terminal peptide, incorporated the fluorescent probe monodansylcadaverine (DNC) when catalysed by guinea-pig liver transglutaminase and Ca2+, as determined by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). A 1:1 adduct DNC-melittin was identified in which a single glutamine residue out of two, i.e. Gln25, acts as acyl donor. Incubation of melittin with transglutaminase in the absence of DNC originated high molecular mass complexes indicative that the peptide lysine residue can act as an acyl acceptor. The DNC-melittin was about 3 times more active in the lysis of red cell membranes than native melittin. Fluorescence study of the lab…
Hydrothermal Synthesis of Ionic Liquid [Bmim]OH-Modified TiO2 Nanoparticles with Enhanced Photocatalytic Activity under Visible Light
2010
TiO(2) nanocomposites modified with the ionic liquid [Bmim]OH are synthesized by a hydrothermal procedure. X-ray diffraction, Zeta-potential measurement, TEM, thermogravimetric analysis, photoluminescence, UV/Vis, FTIR, and X-ray photoelectron spectroscopy are used to characterize the TiO(2) nanocomposites. The TiO(2) nanocomposites consist of pure anatase particles of about 10 nm. The modification of [Bmim]OH on the surface of the TiO(2) particles extends the TiO(2) absorption edge to the visible-light region. The electrochemical redox potentials indicated that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of [Bmim]OH match well with the valen…
Occurrence of mycotoxins in refrigerated pizza dough and risk assessment of exposure for the Spanish population.
2016
Mycotoxins are toxic metabolites produced by filamentous fungi, as Aspergillus, Penicillium and Fusarium. The first objective of this research was to study the presence of mycotoxins in 60 samples of refrigerated pizza dough, by extraction with methanol and determination by liquid chromatography associated with tandem mass spectrometry (LC-MS/MS). Then, the estimated dietary intakes (EDIs) of these mycotoxins, among the Spanish population, was calculated and the health risk assessment was performed, comparing the EDIs data with the tolerable daily intake values (TDIs). The mycotoxins detected in the analyzed samples were aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), zearale…
Infant exposure of perfluorinated compounds: Levels in breast milk and commercial baby food
2010
In this study, an analytical method to determine six previous termperfluorinatednext term compounds (PFCs) based on alkaline digestion and solid phase extraction (SPE) followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS) was validated for the analysis of human breast milk, milk previous terminfantnext term formulas and cereals baby food. The average recoveries of the different matrices were in general higher than 70% with a relative standard deviation (RSD) lower than 21% and method limits of detection (MLOD) ranging from 1.2 to 362 ng/L for the different compounds and matrices. The method was applied to investigate the occurrence of PFCs in 20 sample…
Occurrence of fumonisins B1 and B2 in broa, typical Portuguese maize bread
2007
Fumonisin B1 (FB1) and fumonisin B2 (FB2) are mycotoxins mainly produced by Fusarium verticillioides, and Fusarium proliferatum, fungi species most commonly isolated from maize. The natural occurrence of FB1 and FB2 in broa, typical Portuguese maize bread, was evaluated in 30 samples. Twenty five were found positive with levels ranging from 142 to 550 [mu]g kg- 1. The limit established by the European regulations was exceeded by 27% of the samples. The tolerable daily intake for fumonisin B1, and B2, alone or in combination, for all of the analysed samples, was lower than 2 [mu]g kg- 1 body weight per day established by the European Commission. http://www.sciencedirect.com/science/article/B…
Dietary intake of ochratoxin A from conventional and organic bread
2006
Ochratoxin A (OTA) was extracted from 100 bread samples by using accelerated solvent extraction (ASE) and analyzed with liquid chromatography coupled with fluorescence detection. The presence of OTA was confirmed by methyl-ester derivatization. Bread samples were bought from different bakeries and supermarkets, 74 of non-organic and 26 of organic bread. The incidence of OTA varied between 20.3% and 23.0% for non-organic and organic bread, respectively. The highest values were obtained with non-organic versus organic products, five samples exceeded the European maximum permitted limit of OTA (3 ng/g) for this product. Estimated daily intake of OTA in this study was 1.6 ng/kg b.w./day. This v…
Determination of Fungi and Multi-Class Mycotoxins in Camelia sinensis and Herbal Teas and Dietary Exposure Assessment
2020
In this paper, a study of fungal and multi-mycotoxin contamination in 140 Camellia sinensis and 26 herbal teas marketed in Latvia is discussed. The analysis was performed using two-dimensional liquid chromatography with time-of-flight mass spectrometry (2D-LC-TOF-MS) and MALDI-TOF-MS. In total, 87% of the tea samples tested positive for 32 fungal species belonging to 17 genera, with the total enumeration of moulds ranging between 1.00 ×
Tuneable multicoloured patterns from photonic cross-communication between cholesteric liquid crystal droplets
2014
Monodisperse droplets of planar-aligned cholesteric (N*) liquid crystal exhibit an intriguing capacity for photonic cross-communication, giving rise to colourful patterns that depend sensitively on the N* pitch, droplet positions and illuminated area. The phenomenon results from a combination of omnidirectional selective reflection of N* droplets—which thus act as spherically symmetric self-assembled photonic crystals—and total internal reflection at the continuous phase surface. We outline how the unique optical properties can be employed in numerous applications.