Search results for "High Pressure"
showing 10 items of 894 documents
High-pressure electrical transport measurements on p-type GaSe and InSe
2006
We performed high-pressure Hall effect and resistivity measurements in p-type GaSe and InSe up to 12 GPa. The pressure behaviour of the transport parameters shows dramatic differences between both materials. In GaSe, the hole concentration and mobility increase moderately and continuously. In InSe, the hole mobility raises rapidly and the hole concentration increases abruptly near 0.8 GPa. The observed results are attributed to the different pressure evolution of the valence-band structure in each material. In InSe a carrier-type inversion is also detected near 4.5 GPa.
Analysis of protein composition of red wine in comparison with rosé and white wines by electrophoresis and high-pressure liquid chromatography-mass s…
2009
Wine proteins not only influence wine stability but are also being discussed as potential allergens. Proteins from red, rose, and white wines were enriched by dialysis and lyophilization followed by separation by SDS-PAGE. Significant differences were detected in the protein compositions of the analyzed wine varieties, and the major protein bands were identified by mass spectrometry after in-gel digestion with trypsin. In German Portugieser red wine, a total of 121 tryptic peptides were identified, which were attributed to 12 grape proteins and 6 proteins derived from yeast. Among the identified constituents are several proteins considered to influence wine stability and previously describe…
Multiresidue analysis of organic pollutants by in-tube solid phase microextraction coupled to ultra-high performance liquid chromatography-electrospr…
2013
In this work, in-tube solid phase microextraction (IT-SPME) coupling with ultra-high-pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) multiresidue analytical method has been proposed for the first time for on-line enrichment of 9 analytes included in Water Frame Directive 2000/60/EC (WFD). The device was equipped with a GC TRB-5 capillary column, used as pre-concentration loop, and two conventional six-port injection valves. Water sample and desorption solvent volumes were tested. The optimum conditions were 4mL of processed sample followed by elution with 40μL of methanol. The analytes were detected with a mass spectrometer after being ionized positively using an elect…
Analysis of carbamate and phenylurea pesticide residues in fruit juices by solid-phase microextraction and liquid chromatography–mass spectrometry
2007
A new analysis method to detect carbamates and phenylurea pesticide residues in fruit juices was developed using solid-phase microextraction (SPME) coupled with liquid chromatography-single quadrupole mass spectrometry (LC/MS) and liquid chromatography-quadrupole ion trap mass spectrometry (LC/QIT-MS). The pesticide residues present in watery matrices as fruit juices were extracted using three types of fibers: 50-microm Carbowax/templated resin (CW/TPR), 60-mum poly(dimethylsiloxane)/divinylbenzene (PDMS/DVB) and 85-microm polyacrylate. The different extraction conditions were evaluated choosing as the best parameters 90 min (time), 20 degrees C (temperature) and 1 ml (volume). After extrac…
Prenatal exposure to mixtures of xenoestrogens and repetitive element DNA methylation changes in human placenta
2014
BACKGROUND: Prenatal exposure to endocrine disrupting compounds (EDCs) has previously shown to alter epigenetic marks. OBJECTIVES: In this work we explore whether prenatal exposure to mixtures of xenoestrogens has the potential to alter the placenta epigenome, by studying DNA methylation in retrotransposons as a surrogate of global DNA methylation. METHODS: The biomarker total effective xenoestrogen burden (TEXB) was measured in 192 placentas from participants in the longitudinal INMA Project. DNA methylation was quantitatively assessed by bisulfite pyrosequencing on 10 different retrotransposons including 3 different long interspersed nuclear elements (LINEs), 4 short interspersed nuclear …
Effects of high pressure processing and biopreservation on the inactivation and the germination of spores of Bacillus and Clostridium
2018
Bacterial endospores are one of the most resistant life form on earth. Their capacity to survive to decontamination processes and their potential pathogenicity represent a real problem for the food industry. Currently, the only way to prevent their development in foods is the application of thermal treatments or the use of preservatives. However, these two methods have negative impacts on the nutritional properties of foods and on the consumers’ health. High hydrostatic pressure (HP) is a non-thermal process widely used for commercial pasteurization of foods. However, this process has a very low effect on spores and has therefore to be combined with other decontamination processes to enhanc…
Incorporation and metabolism of trans 20∶5 in endothelial cells. Effect on prostacyclin synthesis
2000
To study the ability of long-chain trans fatty acids (FA) to be incorporated and metabolized into endothelial cells, bovine aortic endothelial cells were incubated with medium enriched eicosapentaenoic acid (EPA) bound to albumin (M2) or one of its geometrical isomers: 20:5 5c,8c,11t,14c,17c (M3), 20:5 5c,8c,11c,14c,17t (M4), or 20:5 5c,8c,11t,14c,17t (M5). After 48 h of incubation, supernatant and cells were harvested and their lipids were analyzed, including prostacyclin synthesis. EPA and 22:5n-3 of endothelial cells incubated with M2 were, respectively, three and two times higher than in control cells (incubated in M1, without any fatty acid added), whereas 22:6n-3 increased only in the…
International Conference on Functional Materials and Nanotechnologies (FM&NT2012)
2012
The International Conference Functional Materials and Nanotechnologies (FMN ferroics; multiscale and multiphenomenal material modeling and simulation 2. Nanotechnologies including progressive methods, technologies and design for investigation of nanoparticles, nanostructures, nanocomposites, thin films and coatings; 3. Energy including perspective materials and technologies for renewable and hydrogen energy, fuel cells, photovoltaics and developing diverse energy systems. A special section devoted to Organic Materials was organized to commemorate a long-time organizer of the FM&NT conference series, Dr. habil. phys, academician Inta Muzikante who passed away on 15 February 2012. The number …
Bioconcentration, metabolism and toxicity of substituted anilines in the zebrafish (Brachydanio rerio).
1991
The LC50 (96 h) values and the bioconcentration factors (BCF) for nine anilines (aniline; 2-, 3-, 4-chloroaniline; 2-, 3-, 4-nitroaniline; 2,4- and 3,4-dichloroaniline) in the zebrafish (Brachydanio rerio) were determined. Biotransformation products of anilines in the zebrafish were analyzed by HPLC. The aim of the investigations was to find relationships between accumulation/elimination/metabolism and toxicity on the one hand and between chemical structure and biotransformation on the other. We found a good correlation of log BCF and of log Pow with log LC50. This concurs with the assumption that the internal dose determines the toxicological effect. All anilines investigated, with the exc…
Determination of mono-, di- and trinitronaphthalenes in soil samples contaminated by explosives.
2004
We investigated the extraction of eight mono-, di- and trinitronaphthalenes from soil samples by ultrasonic, respectively, soxhlet extraction. Sonication was the more convenient procedure with a usually higher repeatability than the soxhlet method. All extracts were analysed by high-performance liquid chromatography with diode array detection. These methods were used to determine the concentration of nitronaphthalenes in five soil samples polluted by explosives. The most abundant contaminants were 1,5- and 1,8-dinitronaphthalene as well as 1,3,5-, 1,3,8- and 1,4,5-trinitronaphthalene. In all samples the sum of trinitronaphthalenes exceeded the sum of mono- and dinitronaphthalenes. It is rec…