Search results for "Nitrite"
showing 7 items of 227 documents
KOSMOS 2017 Peru Side Experiment: nutrients, phytoplankton abundances, enzyme rates, photophysiology
2022
This data was collected during an short-term incubation experiment in March 2017 that investigated the response of a surface plankton community to upwelling. This experiment was carried in the framework of the SFB754-funded KOSMOS mesocosm study that took place in La Punta, Callao, Peru between February-April 2017. A total of six different treatments were used to disentangle chemical and biological characteristics of deep water that influence surface plankton blooms: 2 different deep water sources with different nutrient concentrations; 3 treatments to distinguish the effects of inorganic nutrients, organic nutrients and deep water microbial populations. Measured variables include inorganic…
Discharge management in fresh and brackish water RAS: Combined phosphorus removal by organic flocculants and nitrogen removal in woodchip reactors
2020
The current study combined P and N removal using organic flocculant chemicals and woodchip bioreactors in both freshwater and brackish water (7 ppm) recirculating aquaculture systems (RAS). The use of carbon (C) containing flocculant chemicals in the process was hypothesized to further stimulate C-demanding N removal (denitrification) in bioreactors. The trial of combined P and N removal consisted of four treatments: freshwater and brackish water RAS with and without the addition of supernatant from flocculation process to the woodchip reactor. Duplicate woodchip reactors were used per treatment and the trial was run for six weeks. 56 % and 49 % of P was removed from fresh and brackish slud…
Nitrate and nitrite in the diet: How to assess their benefit and risk for human health
2015
Nitrate is a natural constituent of the human diet and an approved food additive. It can be partially converted to nitrogen monoxide, which induces vasodilation and thereby decreases blood pressure. This effect is associated with a reduced risk regarding cardiovascular disease, myocardial infarction, and stroke. Moreover, dietary nitrate has been associated with beneficial effects in patients with gastric ulcer, renal failure, or metabolic syndrome. Recent studies indicate that such beneficial health effects due to dietary nitrate may be achievable at intake levels resulting from the daily consumption of nitrate-rich vegetables. N-nitroso compounds are endogenously formed in humans. However…
Analysis of nitrite and nitrate in foodstuffs-Method development, ocurrence, regulation, metrological aspects and exposure
2017
La presencia y la inocuidad de los nitritos y nitratos son un tema controvertido. El nitrito es un aditivo autorizado considerado como un ingrediente importante para la preservación de productos cárnicos. Nitrato es un componente natural de la dieta humana que, sin embargo, despierta preocupación por su supuesta potencial nocividad relacionada con cianosis, carcinogénesis y contaminación ambiental. Por lo tanto, determinaciones confiables de nitrito/nitrato son necesarias por tres razones principales: a) vigilar el cumplimiento de las regulaciones actuales sobre aditivos y contaminantes, b) determinar el contenido de nitrito/nitrato in alimentos, dietas y agua potables y c) estudiar el comp…
Slāpekļa oksīda metabolītu koncentrācija pacientiem ar 1.tipa cukura diabētu
2017
Pamatojums: pētījumos ar 1. tipa diabēta pacientiem tika konstatēta palielināta nitrīta koncentrācija plazmā. Literatūrā nav atrodami dati par nitrīta koncentrāciju 1. tipa diabēta pacientu siekalās. Mērķi: noteikt nitrīta koncentrāciju 1. tipa diabēta pacientu siekalās un tās korelāciju ar slāpekļa oksīda (NO), tā metabolītu nitrātjona (NO3) un nitrītjona (NO2) koncentrāciju asinīs, kā arī blakusslimībām un dzīvesveida faktoriem. Matriāli un metodes: pētījumam tika uzaicināti 44 pacienti no LatDiane kohortas. Dati par diabēta anamnēzi, diētu, fizisko aktivitāti un citiem dzīvesveida faktoriem tika savākti ar anketas palīdzību. 5 ml siekalu tika savākti turpmākai NO2 koncentrācijas analīzei…
Trapping and Reactivity of a Molecular Aluminium Oxide Ion
2019
Aluminium oxides constitute an important class of inorganic compound that are widely exploited in the chemical industry as catalysts and catalyst supports. Due to the tendency for such systems to aggregate via Al‐O‐Al bridges, the synthesis of well‐defined, soluble, molecular models for these materials is challenging. Here we show that reactions of the potassium aluminyl complex K 2 [( NON )Al] 2 ( NON = 4,5‐bis(2,6‐diiso‐propylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene) with CO 2 , PhNCO and N 2 O all proceed via a common aluminium oxide intermediate. This highly reactive species can be trapped by coordination of a THF molecule as the anionic oxide complex [( NON )AlO(THF)] ‐ , which …
Protein tyrosine nitration and thiol oxidation by peroxynitrite-strategies to prevent these oxidative modifications.
2013
The reaction product of nitric oxide and superoxide, peroxynitrite, is a potent biological oxidant. The most important oxidative protein modifications described for peroxynitrite are cysteine-thiol oxidation and tyrosine nitration. We have previously demonstrated that intrinsic heme-thiolate (P450)-dependent enzymatic catalysis increases the nitration of tyrosine 430 in prostacyclin synthase and results in loss of activity which contributes to endothelial dysfunction. We here report the sensitive peroxynitrite-dependent nitration of an over-expressed and partially purified human prostacyclin synthase (3.3 μM) with an EC50 value of 5 μM. Microsomal thiols in these preparations effectively co…