Search results for " Limit"
showing 10 items of 1716 documents
Predicting unit plot soil loss in Sicily, south Italy
2008
Predicting soil loss is necessary to establish soil conservation measures. Variability of soil and hydrological parameters complicates mathematical simulation of soil erosion processes. Methods for predicting unit plot soil loss in Sicily were developed by using 5 years of data from replicated plots. At first, the variability of the soil water content, runoff, and unit plot soil loss values collected at fixed dates or after an erosive event was investigated. The applicability of the Universal Soil Loss Equation (USLE) was then tested. Finally, a method to predict event soil loss was developed. Measurement variability decreased as the mean increased above a threshold value but it was low als…
A gated material as immunosensor for in-tissue detection of IDH1-R132H mutation in gliomas
2021
[EN] A nanodevice consisted on nanoporous anodic alumina (NAA) supports functionalized with specific and selective antibody-based gatekeepers for the detection of IDH1-R132H mutant enzyme is here reported. Molecular profile and tissue mutations of the tumours (such as IDH1/IDH2 mutations in gliomas) are a great source of information that already make a difference in terms of prognosis and prediction of response to combined therapy. However, standardized methodologies to determine this mutation are time-consuming and cannot provide information before or during surgical intervention, which significantly limits their utility in terms of intraoperative decisionmaking. To solve this limitation, …
Fluorogenic Sensing of Carcinogenic Bisphenol A using Aptamer-Capped Mesoporous Silica Nanoparticles
2017
[EN] Mesoporous silica nanoparticles loaded with rhodamine B and capped with a bisphenol A aptamer were used for the selective and sensitive detection of this lethal chemical. The pores of the nanoparticles are selectively opened in the presence of bisphenol A (through its selective coordination with the aptamer) with subsequent rhodamine B delivery. With this capped material a limit of detection as low as 3.5 mu m of bisphenol A was measured.
Multi‐residue extraction to determine organic pollutants in mussel hemolymph
2021
This study assesses the extraction of eleven pharmaceuticals, five pesticides, five perfluoroalkyl substances, and two illicit drugs in hemolymph from (Mytilus Galloprovincialis). Four extraction procedures using Phree™ Phospholipid Removal cartridges were tested using different volumes of methanol (400 and 600 μL) and acetonitrile (300 and 450 μL). The pollutants were determined by high-performance liquid chromatography–tandem mass spectrometry. The use of methanol gave several problems during the extraction procedure, such as longer times and sample loss. Three methods (acetonitrile 300 and 450 μL; and methanol 600 μL) were validated. Recoveries at three concentration levels (5, 50, and 1…
Automated Determination of Paroxetine and Its Main Metabolite by Column Switching and On-Line High-Performance Liquid Chromatography
1994
An automated column-switching method coupled to isocratic high-performance liquid chromatography has been developed for simultaneous determination of blood levels of paroxetine and its nonconjugated main metabolite BRL 36610. The lower limits of detection were 9-15 nmol/L (3-5 ng/ml) and linearity between drug concentration and detector response was found for 0-1,500 nmol/L (0-500 ng/ml). The method could be applied to the analysis of serum samples obtained from depressed patients who were treated with daily oral doses of 20 or 40 mg of paroxetine. After the 20-mg dose, the mean blood level of paroxetine was 69 nM (23 ng/ml), whereas the metabolite BRL 36610 was detectable in only one of 5 …
Hapten Synthesis and Polyclonal Antibody-Based Immunoassay Development for the Analysis of Forchlorfenuron in Kiwifruit
2010
High-affinity polyclonal antibodies directed against the synthetic cytokinin forchlorfenuron (CPPU) were produced from three immunizing haptens with equivalent spacer arms located at different positions. A competitive immunoassay was developed with a limit of detection in buffer of 12.42 +/- 3.06 ng/L. In addition, the ability of the produced antibodies to recognize a set of synthetic CPPU analogues was studied. It was evidenced that the linker position had a strong impact on the specificity of the generated polyclonals, which were more sensitive to changes at moieties of the target analyte located furthest from the derivatization site of the immunogen. Finally, matrix effects of gold and g…
Carbonyl metallo immuno assay: a new application for Fourier transform infrared spectroscopy
2000
Abstract We describe here the development of a new, non-isotopic immunological assay termed CMIA (carbonyl metallo immunoassay) that uses metal carbonyl complexes as tracers and Fourier transform infrared spectroscopy (FT-IR) as the detection method. This assay is based on the particular spectral features of these complexes, which show very strong absorption bands in the 1800–2200 cm −1 spectral range where proteins and organic molecules do not absorb. In Section 1 , the optimisation of the quantitative detection of these tracers is detailed. In Section 2 , the implementation of mono-CMIA is described, including the CMIA assays of three antiepileptic drugs (carbamazepine, phenobarbital, phe…
Hapten synthesis, monoclonal antibody generation, and development of competitive immunoassays for the analysis of picoxystrobin in beer.
2010
Abstract This paper describes the original synthesis of a functionalized derivative of the fungicide picoxystrobin and the generation of the first reported monoclonal antibodies against this strobilurin pesticide. The synthetic hapten was prepared by total synthesis from commercial chemicals and incorporating the spacer arm through a carbon–carbon single bond. Also, to obtain the immunogen, an uncommon hapten activation strategy based on N,N′-disuccinimidyl carbonate was employed, affording high activation yields and clean and reproducible coupling results. With these immunoreagents, two enzyme-linked immunosorbent assays (ELISAs) were developed: a competitive one-step assay using the antib…
Designing solid optical sensors for in situ passive discrimination of volatile amines based on a new one-step hydrophilic PDMS preparation
2016
Abstract We reported an optimal material for embedding chemoresponsive dyes based on modified commercial PDMS. A new approach to impart hydrophilicity to H-PDMS in an unique step was developed by addition of tetraethyl orthosilicate (TEOS) and in absence of basic or acid aqueous mixtures or hydroxyl-compounds during the PDMS coating process. This incorporation significantly enhances the performance of PDMS-based devices for sensing applications. New colorimetric sensors for passive detection and in situ discrimination of volatile amines have been obtained. The limit of detection achieved was 1.5 mg m −3 for both, dimethylamine and methylamine, suitable to control real working atmospheres. T…
Molte Palermo. Temi
2019
Nel tema delle incompiute idee di città possibili si riconoscerà il paradigma connotativo dello stesso divenire di Palermo, lungo un percorso millenario di processi di trasformazione nessuno dei quali portato a compimento, in virtù di quel valore distintivo di exemplum che non necessita di ulteriori e conclusive dimostrazioni. Il corso della storia, del resto, ha imposto a Palermo il ciclico riproporsi di destini interrotti. Tale si rilevò l’invenzione della città capitale, quella della “quadratura geometrica e della croce di strade” sovrimpressa a quella archetipica e fondativa della Pan-ormos scambiatrice. E l’incompiutezza sarà il tratto distintivo della città dei rettifili stradali otto…