Search results for "amina"
showing 10 items of 2711 documents
Valoración de los niveles materno-fetales de 25-OH Vitamina D y grado de mineralización ósea del recién nacido
2018
Introducción: La Vitamina D (VD) se obtiene mayoritariamente de la síntesis endógena cutánea tras exposición solar y, en menor medida, del aporte dietético. Su función fundamental es asegurar unos niveles séricos adecuados de calcio y fósforo que permitan una adecuada mineralización ósea. Su déficit durante la edad pediátrica causa raquitismo y podría afectar a la adquisición del pico de masa ósea durante la pubertad, lo que ha motivado diversas recomendaciones para su suplementación. Pero hasta la fecha se desconoce qué efecto pueden tener los niveles bajos de 25(OH)VD o calcidiol de las embarazadas sobre la mineralización del esqueleto fetal. Objetivo Principal: Conocer si existe relación…
Universal method to determine acidic licit and illicit drugs and personal care products in water by liquid chromatography quadrupole time-of-flight
2016
Graphical abstract
Stereoselective Synthesis and Pharmacological Evaluation of 2,4-Bridged Piperidine Derivatives Designed to Activate the κ-Opioid Receptor
2021
L‐Aspartate as a high‐quality nitrogen source in Escherichia coli : Regulation of L‐aspartase by the nitrogen regulatory system and interaction of L‐…
2020
Escherichia coli uses the C4-dicarboxylate transporter DcuA for L-aspartate/fumarate antiport, which results in the exploitation of L-aspartate for fumarate respiration under anaerobic conditions and for nitrogen assimilation under aerobic and anaerobic conditions. L-Aspartate represents a high-quality nitrogen source for assimilation. Nitrogen assimilation from L-aspartate required DcuA, and aspartase AspA to release ammonia. Ammonia is able to provide by established pathways the complete set of intracellular precursors (ammonia, L-aspartate, L-glutamate, and L-glutamine) for synthesizing amino acids, nucleotides, and amino sugars. AspA was regulated by a central regulator of nitrogen meta…
Evaluation of Mycotoxin Residues on Ready-to-Eat Food by Chromatographic Methods Coupled to Mass Spectrometry in Tandem
2018
Simultaneous determination of twenty-seven mycotoxins in ready-to-eat food samples using &ldquo
Mycotoxins and their consequences in aquaculture: A review
2016
Fish consumption has been increasing worldwide, mainly due to the availability, access and price in relation to other kinds of meat consumption, such as beef, pork, and poultry. Consequently, some concerns begin to emerge, primarily regarding the quality of fish available in the market. Residues could be present in any product of animal origin causing economic losses and putting into a risk human and animal health. Food contamination by mycotoxins is a risk to human and animal health, and it is responsible for significant economic losses. It's very difficult to prove that a disease is a mycotoxicosis, and even when mycotoxins are detected, it is not easy to show that they are the etiologica…
Sterigmatocystin: Occurrence, toxicity and molecular mechanisms of action – A review
2020
The mycotoxin sterigmatocystin (STE) is produced mainly by Aspergillus fungi. It has been reported to occur in grains and grain-based products, cheese, coffee, spices and beer. The STE is a known biogenic precursor of aflatoxin B1, sharing with it several structural and biological similarities. The STE has been shown to be hepatotoxic and nephrotoxic in animals and it has been classified as possible human carcinogen (group 2B) by IARC. The STE has been reported to cause a marked decrease in cell proliferation in different mammalian cells. Data available on literature suggest that the cellular mechanisms underlying STE-induced toxicity include the induction of oxidative stress, mitochondrial…
Method optimization to measure polybrominated diphenyl ether (PBDE) concentrations in soils of Bratislava, Slovakia.
2010
We modified an analytical method to determine polybrominated diphenyl ethers (PBDEs) in urban soils of Bratislava (Slovakia). Gel permeation chromatography (GPC) introduced as a clean-up step for soil extracts substantially reduced matrix enhancements when PBDEs were measured with gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS). The resulting method proved to be accurate, precise, and showed low detection limits. The sum of 15 PBDE concentrations in surface horizons of Bratislava soils ranged from 87 to 627 pg g(-1). PBDE concentrations were mostly higher in surface than deeper horizons probably because of atmospheric deposition and lack of substantial vertical…
Window-Based Energy Selecting X-ray Imaging and Charge Sharing in Cadmium Zinc Telluride Linear Array Detectors for Contaminant Detection
2023
The spectroscopic and imaging performance of energy-resolved photon counting detectors, based on new sub-millimetre boron oxide encapsulated vertical Bridgman cadmium zinc telluride linear arrays, are presented in this work. The activities are in the framework of the AVATAR X project, planning the development of X-ray scanners for contaminant detection in food industry. The detectors, characterized by high spatial (250 µm) and energy (<3 keV) resolution, allow spectral X-ray imaging with interesting image quality improvements. The effects of charge sharing and energy-resolved techniques on contrast-to-noise ratio (CNR) enhancements are investigated. The benefits of a new energy-resolved …
Rośliny naczyniowe jako bioindykatory stanu środowiska
2017
Dzięki coraz nowocześniejszym i powszechniej stosowanym metodom bioindykacji można dokonać precyzyjnej i stosunkowo wydajnej oceny stanu środowiska naturalnego oraz zmian w nim zachodzących.Wymiernym sposobem monitoringu przyrody są obserwacje reakcji żywych organizmów. Badania przeprowadza się głównie z użyciem stenobiontów, czyli taksonów o małej tolerancji na zmienność warunków środowiska. Grupę roślin oraz zwierząt wykorzystywanych w badaniach bioindykacyjnych nazywa się wskaźnikowymi.Bioindykacja znajduje zastosowanie w geologii poszukiwawczej do odnajdywania miejsc z możliwością pozyskania cennych kruszców oraz w ochronie środowiska do monitoringu stanu jego zanieczyszczenia. Na podst…