Search results for "imprint"
showing 10 items of 194 documents
Determination of phenolic compounds in surface waters using high-performance liquid chromatography and molecularly imprinted solid-phase extraction
2021
An effective and reliable analytical method based on molecularly imprinted solid-phase extraction (MI-SPE) and high-performance liquid chromatography with photodiode array detector was developed to simultaneously determine four phenolic compounds: bisphenol A, 2-phenylphenol, tert-octylphenol and nonylphenol. A molecularly imprinted polymer that can selectively recognize bisphenol A and alkylphenols was developed. A bulk polymerization method using bisphenol A as a template, acrylamide as functional monomer, ethylene glycol dimethacrylate as the cross-linking agent, acetonitrile as porogenic solvent and 1,1’-azobis(cyclohexanecarbonitrile) as initiator was applied. This polymer was applied …
Development of an improved method for trace analysis of quinolones in eggs of laying hens and wildlife species using molecularly imprinted polymers.
2012
A sensitive, selective, and efficient method was developed for simultaneous determination of 11 fluoroquinolones (FQs), ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, flumequine, marbofloxacin, norfloxacin, ofloxacin, oxolinic acid, pipemidic acid, and sarafloxacin, in eggs by molecularly imprinted polymer (MIP) and column liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Samples were diluted with 50 mM sodium dihydrogen phosphate at pH 7.4, followed by purification with a commercial MIP (SupelMIP SPE-Fluoroquinolones). Recoveries for the 11 quinolones were in the range of 90-106% with intra- and interday relative standard deviation ranging from …
Impact of assisted reproductive technologies on the regulation of imprinted genes and transposable elements in Human blood cord and placenta
2018
It is estimated that more than five million children have been born by Assisted Reproductive Technologies (ART) worldwide, representing up to 4% of all births. As around 10% of reproductive-aged couples are currently infertile, providing them with treatment options is a public health issue. However, the safety of these techniques has not been fully demonstrated. Notably, the rate of placenta-related adverse pregnancy outcomes could be increased after ART. Moreover, adverse perinatal outcomes, a higher risk of major malformations and imprinting disorders have also been reported in children born following ART. These issues combined raise the question of a potential ART-induced epigenetic vuln…
Multivariate Assessment of Procedures for Molecularly Imprinted Polymer Synthesis for Pesticides Determination in Environmental and Agricultural Samp…
2021
In the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application of molecularly imprinted polymers (MIPs) is gaining greater popularity. It is mainly related to their physicochemical properties, sorption capacity and selectivity, thermo-mechanical resistance, as well as a wide range of polymerization techniques allowing to obta…
Sperm imprinting integrity in seminoma patients?
2018
IF 4.990; International audience; BackgroundTesticular germ cell tumor such as seminoma is strongly associated with male reproductive problems commonly associated with the alteration of sperm parameters as described in testicular dysgenesis syndrome. Interestingly, numerous studies have reported that the precursor of germ cell cancer, germ cell neoplasia in situ (GCNIS), present similarities to fetal gonocytes, specifically characterized by global DNA hypomethylation particularly on imprinting sequences. These disorders may have a common origin derived from perturbations of embryonal programming during fetal development. Presently, there is no available information concerning the sperm DNA …
ADHD and DAT1: Further evidence of paternal over-transmission of risk alleles and haplotype
2010
Contains fulltext : 87259.pdf (Publisher’s version ) (Closed access) We [Hawi et al. (2005); Am J Hum Genet 77:958-965] reported paternal over-transmission of risk alleles in some ADHD-associated genes. This was particularly clear in the case of the DAT1 3'-UTR VNTR. In the current investigation, we analyzed three new sample comprising of 1,248 ADHD nuclear families to examine the allelic over-transmission of DAT1 in ADHD. The IMAGE sample, the largest of the three-replication samples, provides strong support for a parent of origin effect for allele 6 and the 10 repeat allele (intron 8 and 3'-UTR VNTR, respectively) of DAT1. In addition, a similar pattern of over-transmission of paternal ri…
Methylation status of VTRNA2-1/nc886 is stable across populations, monozygotic twin pairs and in majority of tissues.
2022
Aims & methods: The aim of this study was to characterize the methylation level of a polymorphically imprinted gene, VTRNA2-1/nc886, in human populations and somatic tissues.48 datasets, consisting of more than 30 tissues and >30,000 individuals, were used. Results: nc886 methylation status is associated with twin status and ethnic background, but the variation between populations is limited. Monozygotic twin pairs present concordant methylation, whereas similar to 30% of dizygotic twin pairs present discordant methylation in the nc886 locus. The methylation levels of nc886 are uniform across somatic tissues, except in cerebellum and skeletal muscle. Conclusion: The nc886 imprint may be est…
Molecularly imprinted polymer solid phase extraction of fungicides from wine samples
2014
In order to preconcentrate iprodione fungicide in white wine samples, molecularly imprinted polymers (MIPs) specific for iprodione were synthesized using two polymerization approaches: precipitation (MIPp) and bulk polymerization (MIPb). A comparison of the performance of the MIPs and the corresponding non-imprinted polymers (NIPs) was conducted in batch studies. In this case, the MIPp revealed better recognition properties toward iprodione in wine samples than the MIPb. The MIPp and MIPb were then used as sorbents on solid phase extraction cartridges (MISPEp and MISPEb consecutively) in order to pre-concentrate iprodione from white wine samples. The optimization of the MISPE elution step w…
La naissance des préférences alimentaires
2012
Pourquoi certains enfants adorent les cornichons alors que d’autres détestent le fromage ? Pourquoi sont-ils si attirés vers le sucré ? Pourquoi certains deviennent difficiles à partir de 2 ans ? Quand doit commencer l’éducation alimentaire ? Comment éveiller le goût des enfants et les accompagner vers l’offre de la table familiale ? Quel est le poids des expériences précoces ? Que faire lorsque les courgettes restent dans l’assiette ? Ces questions viennent souvent aux parents des jeunes enfants, qui sont parfois perplexes quant à l’attitude à adopter. Elles sont aussi abordées de manière plus systématique par les chercheurs. Cet exposé montrera quand et comment les préférences alimentaire…