Search results for "FATE"
showing 10 items of 765 documents
Analytical method, pattern and sources of polycyclic aromatic hydrocarbons (PAHs) in the stone of the Temples of Agrigento (Italy)
2009
Abstract This study shows the extraction and analytical conditions for the determination of polycyclic aromatic hydrocarbons (PAHs) in the stone of archaeological and historical interest. The aim of this research was to determine the concentrations, distribution and the main sources of PAHs present in the surface layer of stone of the Temples of Agrigento. Together with PAHs, we analyzed sulphates and nitrates since it has been demonstrated that these are very destructive salts that play an important role in the deterioration of stones. Total PAHs at different sites of the Valley of Temples at Agrigento varied from 18 to 84 μg/kg. Analyses were performed by GC–MS. The relative abundance of …
Releasing rates of inorganic ions in lichens monitored by capillary zone electrophoresis as indicators of atmospheric pollution
2000
Abstract The releasing rates of inorganic ions in lichens when a thallus sample is sonicated under water, were studied. Ramalina farinacea samples taken from two locations exposed to atmospheric pollution sources at Els Ports (Castellon, Spain), and from three control locations, were used. Samples without visual symptoms of injuries were sonicated from 3 to 6 successive 10-min periods while renewing the water layer in between. Experiments with successive 2-min-sonication periods were also performed. The extracts were analysed by capillary zone electrophoresis, and K + , NH 4 + , Na + , Ca 2+ , Mg 2+ , Cl − , SO 4 2− and NO 3 − were detected. The apparently undamaged lichens sampled at locat…
Multicompartment Micelles with Adjustable Poly(ethylene glycol) Shell for Efficient in Vivo Photodynamic Therapy
2014
We describe the preparation of well-defined multicompartment micelles from polybutadiene-block-poly(1-methyl-2-vinyl pyridinium methyl sulfate)-block-poly(methacrylic acid) (BVqMAA) triblock terpolymers and their use as advanced drug delivery systems for photodynamic therapy (PDT). A porphyrazine derivative was incorporated into the hydrophobic core during self-assembly and served as a model drug and fluorescent probe at the same time. The initial micellar corona is formed by negatively charged PMAA and could be gradually changed to poly(ethylene glycol) (PEG) in a controlled fashion through interpolyelectrolyte complex formation of PMAA with positively charged poly(ethylene glycol)-block-p…
The apparently anomalous effects of surfactants on interfacial tension in the IBA/water system near its upper critical solution temperature
2016
We studied the effect of anionic, cationic, and nonionic surfactants on the interfacial tension between the two phases of the isobutyric acid/water system using spinning drop tensiometry. It has been found that interfacial tension decreases with increasing concentration of the surfactant in the case of sodium dodecyl sulfate (SDS) and of dodecyltrimethylammonium chloride (DTAC). However, in the case of Triton X-100 an increase of surfactant concentration leads to an increase of the interfacial tension. Such results are consistent with the upper critical solution temperature (UCST) in the presence of these surfactants: the UCST decreases with increasing SDS and DTAC concentrations while it i…
Synthesis of Polymer Colloids Using Polymerizable Surfactants
2001
A series of new anionic surfactants were prepared by reacting a polymerizable alcohol with either maleic or succinic anhydride, as well as sulfosuccinic anhydride, resulting in either bireactive or monoreactive surfactants, either carboxylated or sulfonated. The synthesis presented and the critical micelle concentration (CMC) determined. These compounds were engaged in the emulsion polymerization of styrene in batch and also in semi-batch seeded copolymerization producing core-shell latexes. The core was a polystyrene seed prepared using sodium dodecyl sulfate (SDS), thoroughly purified through ion exchange resins. The seed was then swollen overnight with a small amount of a 1 : 1 mixture o…
A Comparative Study of Poly(Azure A) Film-Modified Disposable Electrodes for Electrocatalytic Oxidation of H₂O₂: Effect of Doping Anion.
2018
In the present paper, poly(azure A) (PAA) films were electrosynthetized in the presence of different doping anions on disposable screen-printed carbon electrodes (SPCEs). The anions used included inorganic monoatomic (chloride and fluoride), inorganic polyatomic (nitrate and sulfate) and organic polyatomic (dodecyl sulfate, DS) species. The coated electrodes thus obtained were characterized by electrochemical techniques and SEM. They showed improved electrocatalytic activities towards hydrogen peroxide oxidation compared to that of a bare SPCE. In particular, the insertion of DS anions inside PAA films provided a special sensitivity to the electrocatalysis of H2O2, which endowed these elect…
Absorption-partition relationships for true homologous series of xenobiotics as a possible approach to study mechanisms of surfactants in absorption.…
1992
Abstract This paper — the latest in this series of reports — deals with the effects of the anionic surfactant sodium lauryl sulfate on the colonic absorption of acidic xenobiotics (phenylalkylcarboxylic acids), as compared with those exerted by the nonionic polysorbate 80. The effects of these surfactants are qualitatively identical but quantitatively different. Thus, the increase in polarity of the colonic absorbant membrane is greater with lauryl sulfate, whereas micellar solubilization is much higher with polysorbate. As for the rest (i.e. the elimination of the stagnant aqueous diffusion layer as a limiting step for absorption), the two surfactants behave in a similar way. The biopharma…
Cell fate regulation upon DNA damage : p53 Serine 46 kinases pave the cell death road
2019
Mild and massive DNA damage are differentially integrated into the cellular signaling networks and, in consequence, provoke different cell fate decisions. After mild damage, the tumor suppressor p53 directs the cellular response to cell cycle arrest, DNA repair, and cell survival, whereas upon severe damage, p53 drives the cell death response. One posttranslational modification of p53, phosphorylation at Serine 46, selectively occurs after severe DNA damage and is envisioned as a marker of the cell death response. However, the molecular mechanism of action of the p53 Ser46 phospho-isomer, the molecular timing of this phosphorylation event, and its activating effects on apoptosis and ferropt…
Role Of S-Nitrosylation In The Extrinsic Apoptotic Signalling Pathway In Cancer.
2015
One of the key features of tumour cells is the acquisition of resistance to apoptosis. Thus, determining therapeutic strategies that circumvent apoptotic resistance and result in tumor regression is a challenge. One strategy to induce apoptosis is to activate death receptor signalling pathways. Members of the Tumor Necrosis Factor TNF-family death receptors ligand (TRAIL, FasL and TNF-α) can originate from immune and non-immune cells. Death receptors, engaged by cognate ligands, can initiate multiple signaling pathways, which can generate diverse outcomes, including non-apoptosis-related signal. Knowledge on the molecular mechanisms (that determine death or survival of tumour cells) followi…
Cell cycle independent role of Cyclin E during neural cell fate specification in Drosophila is mediated by its regulation of Prospero function
2009
AbstractDuring development, neural progenitor cells or neuroblasts generate a great intra- and inter-segmental diversity of neuronal and glial cell types in the nervous system. In thoracic segments of the embryonic central nervous system of Drosophila, the neuroblast NB6-4t undergoes an asymmetric first division to generate a neuronal and a glial sublineage, while abdominal NB6-4a divides once symmetrically to generate only 2 glial cells. We had earlier reported a critical function for the G1 cyclin, CyclinE (CycE) in regulating asymmetric cell division in NB6-4t. Here we show that (i) this function of CycE is independent of its role in cell cycle regulation and (ii) the two functions are m…