Search results for "Reference"
showing 10 items of 2491 documents
Determination of trace elements in gluten-free food for celiac people by ICP-MS
2014
Abstract This paper is the first analytical approach to the study of twenty heavy metals in the gluten-free foods for celiac people. Only the ICP-MS technique was used. One of the advantages about the use of ICP-MS for this characterization is the high sensitivity that improved the limits of quantification levels for some elements that are present at low quantities in some samples. The concentration values of As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn in seventeen gluten-free food samples are reported. The highest arsenic and molybdenum levels were measured in Rice noodle from China (0.088 and 0.47 mg kg − 1 , respectively). The highest concentrations of some metal…
Prognostic and Predictive Significance of Pharmacogenetic Analysis in Patients with Carcinomas of Unknown Primary (CAUP)
2012
ABSTRACT Purpose To investigate the prognostic/predictive significance of the expression of BRCA1, ERCC1, RRM1, TOPO-I, TOPO-IIa, TOPO-IIb, TXR1 TYMS and HIF1a mRNA in patients with Carcinomas of Unknown Primary (CaUP). Material and methods Ninety-three patients with CaUP and available tumoral samples diagnosed in three institutions were included in the study. The mRNA levels of the target genes were determined by quantitative real-time PCR from microdissected cells derived from patients' tumoral specimens. β-actin and PGK1 were used as reference genes. Results Successful amplification of at least one gene was achieved in all samples. BRCA1, ERCC1, HIF1a and TXR1 were amplified in all sampl…
Poly-Victimization in Polish Adolescents: Risk Factors and the Moderating Role of Coping.
2018
This study aimed to investigate the prevalence of poly-victimization in Polish adolescents and assess factors associated with poly-victimization risk across different ecological levels. This study further examined whether coping styles could moderate the impact of poly-victimization on emotional well-being. Participants were 454 adolescents, aged between 13 and 19 years, from an urban region of Poland. Adolescents completed self-report measures assessing community, school, and family risks, along with a peer nomination task measuring social preference. Teachers also completed a measure assessing adolescent problem behaviors. Findings revealed that the majority of the sample (70%) experience…
Tobacco plants detect a decrease of environmental genotoxicity in Toulouse (France).
2003
Tobacco plants, heterozygous for two independent loci involved in the chlorophyll parenchyma differentiation, allow the genotoxic effects of the atmosphere of the industrial estate South of Toulouse to be estimated. Somatic spots of green cellular colonies on yellow-green background, were counted to calculate the cellular rates of reversion. Two experiments were carried out in 1981, and in 1997. A general decrease of genotoxic effects was observed. These observations were interpreted as being due to a general decrease of the air pollution evaluated by the development of the concentrations of three toxic gases before and after the implementation of cleanup devices. The results obtained demon…
Microscale synthesis of phosphatidyl-[3H]choline from 1,2-diacylglycerol. Assessment of isomerization by reversed-phase high-performance liquid chrom…
1995
The synthesis of rac-1-palmitoyl-2-oleoylglycero-3-phospho-[3H]choline of high specific activity was carried out on a microscale by making 7 mumol of rac-1-palmitoyl-2-oleoylglycerol react first with an equimolar amount of POCl3 and then of [3H]choline. After purification by thin-layer chromatography and normal-phase high-performance liquid chromatography and normal-phase high-performance liquid chromatography (HPLC), the yield of the synthesis of [3H]phosphatidylcholine (120 microCi/mumol) was 22%. rac-1-Palmitoyl-2-oleoylglycerol was purified before use by reversed-phase HPLC under conditions which were nonisomerizing and allowed the separation of 1,2- and 1,3-isomers of diacylglycerol. E…
Determination of pyrethroid pesticide residues in fatty materials by solid-matrix dispersion partition, followed by mini-column size-exclusion chroma…
1999
The method studied uses a combination of a solid-matrix dispersion partition (SMDP) followed by high-performance size-exclusion chromatography on a minicolumn (HPmSEC) of 7.8 mm I.D. for the separation of pyrethroid (PYR) residues from fatty material. The solid-matrix dispersion extraction is carried out by absorbing a fat solution onto an Extrelut-3 cartridge (filled with a macroporous diatomaceous material) and extracting the PYR residues with acetonitrile. Up to 1 g of fatty material can be extracted with 15 ml acetonitrile. The small amount (mean +/- S.D. = 12.4 +/- 5.9 mg) of fatty material which is eluted into the acetonitrile is further removed by HPmSEC. PYR pesticide residues are c…
Determination of organochlorine pesticide residues in honey from the central zone of Portugal and the Valencian community of Spain
2004
In this study nine organochlorine pesticide residues ([alpha]-, [beta]-, and [gamma]-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), aldrin, p,p'-DDE, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in forty nine samples of honey collected from markets of Portugal and Spain during 2001 and 2002, respectively, were evaluated. For this evaluation, three analytical procedures were studied. The analytical procedure, based on LLE extraction with ethyl acetate followed by gas chromatography-electron-capture detection (GC-ECD) for quantification, and mass spectrometry (GC-MS) for confirmation, has been selected. Recoveries of spiked samples ranged from 68%, for [beta]-HCH, and 126% for p,p'-DDT, for forti…
Application of point-to-point matching algorithms for background correction in on-line liquid chromatography–Fourier transform infrared spectrometry …
2009
A new background correction method for the on-line coupling of gradient liquid chromatography and Fourier transform infrared spectrometry has been developed. It is based on the use of a point-to-point matching algorithm that compares the absorption spectra of the sample data set with those of a previously recorded reference data set in order to select an appropriate reference spectrum. The spectral range used for the point-to-point comparison is selected with minimal user-interaction, thus facilitating considerably the application of the whole method. The background correction method has been successfully tested on a chromatographic separation of four nitrophenols running acetonitrile (0.08…
Processing of Generator-Produced 68Ga for Medical Application
2007
The (68)Ge/(68)Ga generator provides an excellent source of positron-emitting (68)Ga. However, newly available "ionic" (68)Ge/(68)Ga radionuclide generators are not necessarily optimized for the synthesis of (68)Ga-labeled radiopharmaceuticals. The eluates have rather large volumes, a high concentration of H(+) (pH of 1), a breakthrough of (68)Ge, increasing with time or frequency of use, and impurities such as stable Zn(II) generated by the decay of (68)Ga, Ti(IV) as a constituent of the column material, and Fe(III) as a general impurity.We have developed an efficient route for the processing of generator-derived (68)Ga eluates, including the labeling and purification of biomolecules. Prec…
Univariate method for background correction in liquid chromatography–Fourier transform infrared spectrometry
2007
An univariate method is proposed for background correction in on-line gradient liquid chromatography-Fourier transform infrared (LC-FTIR) spectrometry using acetonitrile:water as mobile phase components. The method is based on the calculation of the ratio of absorbances (AR) at two characteristic wavenumbers for each spectrum. This parameter is subsequently used to locate the most appropriated eluent spectrum within a reference spectra matrix (RSM) to be subtracted from each spectrum included in the sample chromatogram. To correct minor changes in eluent spectra intensity during the elution of analytes, a correction factor (Kf), defined as the ratio of the absorbance of the sample and the s…