Search results for "Ammonium compounds"
showing 10 items of 104 documents
Ammonium acts systemically while nitrate exerts an additional local effect on Medicago truncatula nodules
2020
National audience; Symbiotic nitrogen fixation (SNF) has a high energetic cost for legume plants; legumes thus reduce SNF when soil N is available. The present study aimed to increase our understanding regarding the impacts of the two principal forms of available N in soils (ammonium and nitrate) on SNF. We continuously measured the SNF of Medicago truncatula under controlled conditions. This permitted nodule sampling for comparative transcriptome profiling at points connected to the nodules' reaction following ammonium or nitrate applications. The N component of both ions systemically induced a rhythmic pattern of SNF, while the activity in control plants remained constant. This rhythmic a…
A meta-analysis on the ecological effects of aquaculture on the water column: dissolved nutrients
2007
Environmental effects of aquaculture loadings have often been reviewed descriptively, and thus have not provided quantitative estimates of the overall response in the water column. Meta-analytical reviewing techniques allow the contextualisation of quantitative effects in the domain of current literature. In the present paper, more than 50 peer-reviewed articles were analysed and about 425 study cases used to test whether worldwide cultivations have a differential effect on dissolved nutrient levels. Meta-analysis feasibility depends on obtaining an estimate of the effect size from every study and the most common measure of effect size (Hedges’ d) is the difference between means of controls…
Hybrid Biopolymer and Lipid Nanoparticles with Improved Transfection Efficacy for mRNA
2020
Cells 9(9), 2034 (1-19) (2020). doi:10.3390/cells9092034
NO donors. Part 16: investigations on structure-activity relationships of organic mononitrates reveal 2-nitrooxyethylammoniumnitrate as a high potent…
2007
The vasoactive properties of 14 organic mononitrates were investigated in vitro using PGF(2alpha)-precontracted porcine pulmonary arteries. A surprisingly wide range of vasorelaxant potencies was observed (pD(2): 3.36-7.50). Activities showed to be highly sensitive to the molecular structure and the substituents at the molecular carrier of the nitrate group. A correlation between lipophilicity and vasorelaxant potency could not be recognized. 2-Nitrooxyethylammoniumnitrate (1) was found to be slightly superior to the high potency trinitrate GTN.
Distribution of betalain pigments in red blood cells after consumption of cactus pear fruits and increased resistance of the cells to ex vivo induced…
2005
Betalain pigments are bioavailable phytochemicals recently acknowledged as natural radical scavengers. This work, which extends previous research on the postabsorbitive fate of dietary betalains, investigated the distribution of betanin and indicaxanthin in red blood cells (RBCs) isolated from healthy volunteers (n = 8), before and during the 1-8 h interval after a cactus pear fruit meal, and the potential antioxidative activity of the pigments in these cells. A peak concentration of indicaxanthin (1.03 +/- 0.2 microM) was observed in RBCs isolated at 3 h after fruit feeding, whereas the concentration at 5 h was about half, and even smaller amounts were measured at 8 h. Indicaxanthin was no…
Absorption, excretion, and distribution of dietary antioxidant betalains in LDLs: potential health effects of betalains in humans
2004
Background: Betalains were recently identified as natural antioxidants. However, little is known about their bioavailability from dietary sources. Objective: The objective was to evaluate the bioavailability of betalains from dietary sources. Design: The plasma kinetics and urinary excretion of betalains were studied in healthy volunteers (n 8) after a single ingestion of 500 g cactus pear fruit pulp, which provided 28 and 16 mg indicaxanthin and betanin, respectively. The incorporation of betalains in LDL and the resistance of the particles to ex vivo–induced oxidation was also researched. Results: Betanin and indicaxanthin reached their maximum plasma concentrations 3 h after the fruit me…
Surfactant effect on the physicochemical characteristics of cationic solid lipid nanoparticles
2016
Solid lipid nanoparticles (SLNs) may be considered as a new approach for therapeutics for many diseases. In addition to drug delivery, their use as non-viral vectors for gene delivery can be obtained by including cationic lipids, which provide a positive surface potential that favors binding to the nucleic acids as DNA, siRNA, miRNA, etc. In fact, the addition of cationic surfactants is indispensable for obtaining nanoparticles with surface positive charge. In this study, three different cationic lipids (dioctadecyl dimethyl ammonium bromide, cetyltrimethyl ammonium bromide, cetylpyridinium chloride) and Brij 76 as nonionic surfactant were employed to formulate Precirol ATO 5 based cSLN usi…
From attraction to repulsion : anion–π interactions between bromide and fluorinated phenyl groups
2011
Anion–π interactions in crystals of fluorobenzyl ammonium salts depend on the degree of fluorination at the aromatics.
Self-assembly of 3,5-bis(ethoxycarbonyl)pyrazolate anions and ammonium cations of β-phenylethylamine or homoveratrylamine into hetero-double-stranded…
2009
Hydrogen-bonded double-stranded hetero-helices are formed when reacting sodium 3,5-bis(ethoxycarbonyl)pyrazolate with beta-phenethylammonium or homoveratrylammonium chloride, in which one of the strands is defined by the ammonium cations and the other one by the pyrazolate anions.
CH-Directed Anion-π Interactions in the Crystals of Pentafluorobenzyl-Substituted Ammonium and Pyridinium Salts
2010
Simple pentafluorobenzyl-substituted ammonium and pyridinium salts with different anions can be easily obtained by treatment of the parent amine or pyridine with the respective pentafluorobenzyl halide. Hexafluorophosphate is introduced as the anion by salt metathesis. In the case of the ammonium salt 4, water co-crystallisation seems to suppress effective anion-pi interactions of bromide with the electron-deficient aromatic system, whereas with salts 5 and 6 such interactions are observed despite the presence of water. However, due to asymmetric hydrogen-bonding interactions with ammonium side chains, the anion of 5 is located close to the rim of the pentafluorophenyl group (eta(1) interac…