Search results for "Propionic acid"
showing 10 items of 21 documents
Modelling the effect of temperature, pH, water activity, and organic acids on the germination time of Penicillium camemberti and Penicillium roquefor…
2017
International audience; In this study, the influence of environmental factors on the germination time of Penicillium camemberti and Penicillium roqueforti conidia was evaluated. To do so, the effects of i/temperature, pH, water activity, and ii/organic acids were determined using models based on i/cardinal values, and ii/minimum inhibitory concentration (MIC) respectively. Cardinal values for germination of conidia were not observed to be species dependent. Minimum temperatures were estimated to be below the freezing point, with an optimum of 26.9 degrees C, and a maximum of 33.5 degrees C. For both species, minimal and optimal a(w) values were found to be 0.83 and 0.99, respectively, while…
ChemInform Abstract: Microwave-Assisted Organocatalytic Enantioselective Intramolecular Aza-Michael Reaction with α,β-Unsaturated Ketones.
2012
The combination of an epi-hydroquinine catalyst and pentafluoropropionic acid accelerates the process.
Biomonitoring of glyphosate and AMPA in the urine of Spanish lactating mothers
2021
The objectives of this study were to evaluate the urinary levels of Glyphosate (Gly) and its metabolite aminomethylphosphonic acid (AMPA) in Spanish breastfeeding mothers (n = 97), to identify the main predictors of exposure and to perform a risk assessment. Urine samples were analyzed using a method based on solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS) determination. The developed method showed limits of quantification of 0.1 μg/L for both analytes. The detection frequencies (DFs) were 54% for Gly and 60% for AMPA, with geometric means (GMs) of 0.12 μg/L and 0.14 μg/L, respectively. In the statistical analysis, no relationship was found between the u…
Controllable Nonspecific Protein Adsorption by Charged Hyperbranched Polyglycerol Thin Films
2015
Antifouling thin films derived from charged hyperbranched polyglycerol (hbPG) layers were fabricated and evaluated. The anionic hbPG (a-hbPG) monolayers and cationic hbPG/anionic hbPG (c/a-hbPG) bilayers were adsorbed on the underlying self-assembled monolayers (SAMs) of cysteamine and 3-mercaptopropionic acid (3-MPA) by electrostatic interaction, respectively, and their procession was monitored by surface plasmon resonance spectroscopy (SPR). The adsorption of bovine serum albumin (BSA) and fibrinogen on the premade a-hbPG and c/a-hbPG thin films was measured and the capability of these thin films to resist nonspecific protein adsorption was evaluated by SPR as well. It is observed that th…
Brain-Derived Neurotrophic Factor But Not Forced Arm Use Improves Long-Term Outcome After Photothrombotic Stroke and Transiently Upregulates Binding …
2008
Background and Purpose— Both application of neurotrophic factors like brain-derived neurotrophic factor (BDNF) and constraint-induced movement therapy like forced arm use have been shown to potentially improve outcome after stroke. The aim of the present study was to check whether postischemic long-term outcome correlates to specific modifications in the abundance of various neurotransmitter receptors. Methods— Adult male Wistar rats were subjected to photothrombotic ischemia and assigned to various treatment groups (n=5 each) with end points at 3 and 6 weeks: (1) ischemic control (saline); (2) BDNF (ischemia, 20 μg BDNF); (3) forced arm use (ischemia, saline, and ipsilateral plaster cast …
Differential effect of beta-N-oxalylamino-L-alanine, the Lathyrus sativus neurotoxin, and (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate …
2000
We studied the effect of beta-oxalylamino-L-alanine, a glutamate analog present in Lathyrus sativus seeds and implicated in the etiopathogenesis of neurolathyrism, and (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate on the extracellular levels of aspartate, glutamate and taurine in the primary motor cortex of freely moving rats. We found that while both neurotoxins increase the level of aspartate and glutamate, only (+/-)-alpha(-amino-3-hydroxy-5-methylisoxazole-4-propionate is able to modulate the level of taurine. GYKI-52466, a non-competitive non-NMDA antagonist, inhibited beta-oxalylamino-L-alanine-induced increase of aspartate, but not that of glutamate. Conversely, this ant…
Effects of excitatory amino acids and neuropeptide Y on the discharge activity of suprachiasmatic neurons in rat brain slices
1997
Effects of L-glutamate, AMPA, NMDA and NPY on the discharge activity of neurons located in the ventral subdivision of the suprachiasmatic nucleus were examined in submerged coronal slices of the rat hypothalamus. All substances were bath applied. Application of L-glutamate (14 neurons examined) induced an excitatory response in 8 suprachiasmatic neurons (+248.9 +/- 122.24%, mean +/- S.E.M.; P0.001). A biphasic response, i.e. an initial transient excitation (+54.3 +/- 8.21%; P0.001) succeeded by an inhibition (-66.2 +/- 9.31%; P0.001), was observed in 6 neurons. Application of AMPA (36 neurons examined) resulted in an excitation of 31 neurons (+209.2 +/- 58.58%; P0.0001). Application of NMDA…
Pharmacological activity of C10-substituted analogs of the high-affinity kainate receptor agonist dysiherbaine
2009
Kainate receptor antagonists have potential as therapeutic agents in a number of neuropathologies. Synthetic modification of the convulsant marine toxin neodysiherbaine A (NDH) previously yielded molecules with a diverse set of pharmacological actions on kainate receptors. Here we characterize three new synthetic analogs of NDH that contain substituents at the C10 position in the pyran ring of the marine toxin. The analogs exhibited high-affinity binding to the GluK1 (GluR5) subunit and lower affinity binding to GluK2 (GluR6) and GluK3 (GluR7) subunits in radioligand displacement assays with recombinant kainate and AMPA receptors. As well, the natural toxin NDH exhibited approximately 100-f…
Reduced presynaptic efficiency of excitatory synaptic transmission impairs LTP in the visual cortex of BDNF-heterozygous mice
2006
The neurotrophin brain-derived neurotrophic factor (BDNF) plays an important role in neuronal survival, axonal and dendritic growth and synapse formation. BDNF has also been reported to mediate visual cortex plasticity. Here we studied the cellular mechanisms of BDNF-mediated changes in synaptic plasticity, excitatory synaptic transmission and long-term potentiation (LTP) in the visual cortex of heterozygous BDNF-knockout mice (BDNF(+/-)). Patch-clamp recordings in slices showed an approximately 50% reduction in the frequency of miniature excitatory postsynaptic currents (mEPSCs) compared to wild-type animals, in the absence of changes in mEPSC amplitudes. A presynaptic impairment of excita…
Dendritic Ih selectively blocks temporal summation of unsynchronized distal inputs in CA1 pyramidal neurons.
2004
The active dendritic conductances shape the input-output properties of many principal neurons in different brain regions, and the various ways in which they regulate neuronal excitability need to be investigated to better understand their functional consequences. Using a realistic model of a hippocampal CA1 pyramidal neuron, we show a major role for the hyperpolarization-activated current, I-h, in regulating the spike probability of a neuron when independent synaptic inputs are activated with different degrees of synchronization and at different distances from the soma. The results allowed us to make the experimentally testable prediction that the I-h in these neurons is needed to reduce ne…