Liberation Of Nitrogen Research Articles

Lewis-Acid-Catalyzed Oxa-Michael Addition to Give α-Diazo-β-alkoxy Carbonyls and Tetrahydro-3H-furo[3,4-c]pyrazoles.

The conjugate addition of alcohols to vinyl diazonium ions formed via Zn(OTf)2-catalysis gives α-diazo-β-alkoxy carbonyls. The diazo group is retained in this reaction, and this process is an efficient way to couple a reactive partner to the diazo fragment. As an example, we disclose that addition of allyl alcohols provides tetrahydro-3H-furo[3,4-c]pyrazoles via an addition/cycloaddition sequence. This two-step sequence provides good yields and good diastereoselectivity of these sterically hindered pyrazoline scaffolds with up to three quaternary centers and four stereogenic centers. These products can be elaborated to cyclopropane-fused tetrahydrofurans upon liberation of nitrogen. The reaction conditions are mild, operationally simple, and avoid the use of expensive transition metal catalysts.

The influence of plastic pollution and ocean change on detrital decomposition

Plastic pollution and ocean change have mostly been assessed separately, missing potential interactions that either enhance or reduce future impacts on ecosystem processes. Here, we used manipulative experiments with outdoor mesocosms to test hypotheses about the interactive effects of plastic pollution, ocean warming and acidification on macrophyte detrital decomposition. These experiments focused on detritus from kelp, Ecklonia radiata, and eelgrass, Zostera muelleri, and included crossed treatments of (i) no, low and high plastic pollution, (ii) current/future ocean temperatures, and (iii) ambient/future ocean partial pressure of carbon dioxide (pCO2). High levels of plastic pollution significantly reduced the decomposition rate of kelp and eelgrass by approximately 27% and 36% in comparison to controls respectively. Plastic pollution also significantly slowed the nitrogen liberation from seagrass and kelp detritus. Higher seawater temperatures significantly increased the decomposition rate of kelp and eelgrass by 12% and 5% over current conditions, respectively. Higher seawater temperatures were also found to reduce the nitrogen liberation in eelgrass. In contrast, ocean acidification did not significantly influence the rate of macrophyte decomposition or nutrient liberation. Overall, our results show how detrital processes might respond to increasing plastic pollution and ocean temperatures, which has implications for detrital-driven secondary productivity, nutrient dynamics and carbon cycling.

Concurrent Formation of N-H Imines and Carbonyl Compounds by Ruthenium-Catalyzed C-C Bond Cleavage of β-Hydroxy Azides.

A commercial cyclopentadienylrutenium dicarbonyl dimer ([CpRu(CO)2]2) efficiently catalyzes the formation of N-H imines and carbonyl compounds simultaneously from β-hydroxy azides via C-C bond cleavage under visible light. Density functional theory calculations for the cleavage reaction support the mechanism involving chelation of alkoxy azide species and liberation of nitrogen as the driving force. The synthetic utility of the reaction was demonstrated by a new amine synthesis promoted by chemoselective allylation of imine and synthesis of isoquinoline.

Gas Liberation in the High-Temperature Isothermal Holding of Coke Residues

The dynamics of nitrogen, hydrogen, and carbon-monoxide liberation in the isothermal holding of coke residues from G, Zh, KO, KS, and T coal at 1000°C is studied in experiments after heating at 10°C/min. The gas liberation in isothermal holding continues throughout the experiment (2 h). The rate of gas liberation declines exponentially in the course of holding. The rates of H2 and CO emission are related to the clinkering properties of the coal (the plastic-layer thickness) on the basis of a second-order polynomial; for the rate of nitrogen liberation, this relationship is linear. In isothermal holding, the mass loss of the coke residue may be 0.60–1.00% after 60 min and 0.85–1.38% after 120 min. The corresponding gas yields are 25–30 and 35–42 m3/t of coke. The gas consists of 76.8–93.0 vol % hydrogen, 1.9–11.7 vol % nitrogen, and 4.1–14.9 vol % carbon monoxide.

Assessment of iron-modified calcite/zeolite mixture as a capping material to control sedimentary phosphorus and nitrogen liberation.

Calcite/zeolite mixture (CZ) can be used to construct a capping layer for the simultaneous management of phosphorus (P) and nitrogen (N) liberation from sediments into the overlying water (OVER-water). However, its control efficiency of sedimentary P release still needs to be improved. To address this issue, an iron-modified CZ (Fe-CZ) was synthesized, characterized, and employed as a capping material to simultaneously prevent P and N release from sediments into OVER-water. Batch and microcosm incubation experiments were performed to study the efficiency and mechanism for the control of P and N release from sediments by capping Fe-CZ. Results showed that sediment capping with Fe-CZ resulted in the significant reduction of soluble reactive P (SRP) and ammonium-N (NH3-N) in OVER-water, with reduction rates of 77.8-99.7% and 54.0-96.7%, respectively. Furthermore, the Fe-CZ capping layer decreased the SRP concentration in the pore water (PORE-water) at depth of 0-30mm and reduced the concentration of PORE-water NH3-N at depth of 0-50mm. Moreover, the Fe-CZ capping layer gave rise to the great decrement of the concentration of the labile P measured by DGT (diffusive gradient in thin films) technology (P-DGT) in the profile of OVER-water and sediment. Additionally, the Fe-CZ capping resulted in the reduction of redox-sensitive P (P-BD) in the 0-50mm sediment and caused the transformation of P-BD to calcium-bound P (P-HCl) and residual P (P-RES) in the 0-10mm sediment as well as to P-RES in the 10-20mm sediment. Results of this work indicate that the Fe-CZ capping has a high potential for the simultaneous management of P and N release from sediments, and the decrease of the contents of sediment P-DGT, sediment P-BD, PORE-water SRP and PORE-water NH3-N as well as the conversion of mobile P to more stable P in the top sediment should have a significant role in the simultaneous interception of sedimentary P and N liberation into OVER-water by the Fe-CZ capping.

Light emitting diode (LED) photobiomodulation therapy on murine macrophage exposed to Bothropstoxin-I and Bothropstoxin-II myotoxins

The light-emitting diode (LED) is considered a therapeutic tool due to its anti-inflammatory, analgesic, and wound-healing effects, which occur through angiogenesis, decrease in IL-1β and IL-6 secretion, and acceleration of the cicatricial process. Snakebites are an important public health problem in tropical regions of the world. LED treatment is a therapeutic tool associated with serum therapy used to minimize the local effects of snakebites, including decrease in creatine kinase (CK) and lactate dehydrogenase (LDH) concentrations, myonecrosis, and inflammatory and haemorrhagic responses. In this study, we analysed the photobiomodulation effect of LED on the activation of murine macrophages induced by BthTX-I or BthTX-II isolated from Bothrops jararacussu venom. Photobiomodulation caused an increase in mitochondrial metabolism and a considerable decrease in cytotoxicity in murine macrophages. Moreover, it induced a decrease in reactive oxygen species and nitrogen liberation. However, photobiomodulation caused an increase in macrophage phagocytic capacity and lipid droplet formation. The results of this study corroborated with those of others in an unprecedented way and provide a better understanding of the mechanism of action of photobiomodulation, besides offering a coadjuvant action treatment for the local effects of snakebites, not achieved with serum therapy alone.

Synthesis of 2-Naphthylacetylene Selenides from 4-(2-Naphthyl)-1,2,3-selenadiazole

4-(2-Naphthyl)-1,2,3-selenadiazole under the action of bases eagerly decomposes with liberation of nitrogen to form potassium 2-(2-naphthyl)ethyneselenolate. By further treatment of the reaction mixture with the excess of alkyl halide the corresponding methyl- and butyl-2-(2-naphthyl)-1-ethynyl selenides were obtained. In the absence of alkyl halides treating with the potassium hydroxide ethanol solution yields 4-(2- naphthyl)-2-[1-(2-naphthyl)-2-[1-(2-naphthyl)methylidenee]-1,3-diselenol.

Ectomycorrhizal fungi and the enzymatic liberation of nitrogen from soil organic matter: why evolutionary history matters.

Contents Summary 68 I. Introduction 68 II. Have ECM fungi retained genes with lignocellulolytic potential from saprotrophic ancestors? 69 III. Are genes with saprotrophic function expressed by ECM fungi when in symbiosis? 71 IV. Do transcribed enzymes operate to obtain N from SOM? 71 V. Is the organic N derived from SOM transferred to the plant host? 71 VI. Concluding remarks 72 Acknowledgements 72 References 72 SUMMARY: The view that ectomycorrhizal (ECM) fungi commonly participate in the enzymatic liberation of nitrogen (N) from soil organic matter (SOM) has recently been invoked as a key mechanism governing the biogeochemical cycles of forest ecosystems. Here, we provide evidence that not all evolutionary lineages of ECM have retained the genetic potential to produce extracellular enzymes that degrade SOM, calling into question the ubiquity of the proposed mechanism. Further, we discuss several untested conditions that must be empirically validated before it is certain that any lineage of ECM fungi actively expresses extracellular enzymes in order to degrade SOM and transfer N contained therein to its host plant.

Thiadiazole ring opening in the derivatives of 2-substituted 5-(1,2,3-thiadiazol-4-yl)-3-furoic acid under the action of bases

Transformations of the derivatives of 2-substituted 5-(1,2,3-thiadiazol-4-yl)-3-furoic acid under the action of bases has been studied. In the presence of potassium tert-butylate in THF, the studied compounds decompose with the cleavage of the thiadiazole ring, liberation of nitrogen, and formation of labile acetylene thiolates. In the presence of methyl iodide, these salts form stable 2-methylthioethynylfurans. Under the action of sodium ethylate in ethanol, thiadiazole ring of ethyl [2-methyl-5-(1,2,3-thiadiazol-4-yl)]-3-furoate is split to form the corresponding sodium acetylene thiolate. Under the action of ethanol, two molecules of this salt give bis(furyl)dithiafulvene. In the DMF–potassium carbonate system, acetylene thiolates react with primary and secondary amines giving thioamides of (4-ethoxycarbonyl-5-methylfur-2-yl)acetic acid. Treating of ethyl 2-methyland 2-N-morpholinomethyl-5-(1,2,3-thiadiazol-4-yl)-3-furoates with hydrazine hydrate leads to hydrazinolysis of the ester group and cleavage of thiadiazole ring resulting in the formation of hydrazides of 4-hydrazinocarbonylfur-2-ylacetic acid. In the case of ethyl 2-acetoxymethyl- and 2-(4-nitrophenoxy)methyl-5-(1,2,3-thiadiazol-4-yl)-3-furoates, thiadiazole ring is retained and exclusively hydrazinolysis of the ester groups is observed.

Contribution of yeast and base wine supplementation to sparkling wine composition.

The differential characteristic of sparkling wine is the formation of foam, which is dependent, among other factors, on yeast autolysis, aging and oenological practices. In this study, we analyzed the effects of yeast strain, nutrient supplementation to the base wine and aging process on the sparkling wine composition and its foamability. We determined that the addition of inorganic nitrogen promoted nitrogen liberation to the extracellular medium, while the addition of inactive dry yeast to the base wine caused an increase in the polysaccharide concentration and foaming properties of the sparkling wine. The use of synthetic and natural base wines allowed us to discriminate that the differences in high-molecular-weight polysaccharides and oligosaccharides could be attributed to the yeast cells and that the higher nitrogen content in the natural wine could be due to external proteolysis. The practices of nitrogen addition and supplementation of inactive dry yeast could modulate the main characteristics of the sparkling wine and be a critical element for the design of this kind of wine. © 2016 Society of Chemical Industry.

INVESTIGATION INTO ETCHING OF COPPER IN HYDRAZINE

Etching of copper with hydrazine is considered. It is shown that the informative parameter of the etching end is stopping the liberation of nitrogen. The advantage of using hydrazine compared with acids is to facilitate the design of pickle baths.

Synthesis and some reactions of derivatives of 5-(1,2,3-thiadiazol-4-yl)furan-2-carboxylic and 3-[5-(1,2,3-thiadiazol-4-yl)fur-2-yl]acrylic acids

Alkyl 5-(1,2,3-thiadiazol-4-yl)furan-2-furoate and 3-[5-(1,2,3-thiadiazol-4-yl)fur-2-yl]acrylate were synthesized via cyclization of carbethoxyhydrazones of acetyl derivatives of furan-2-carboxylic and 3-(2-furyl)-acrylic acids under the conditions of the Hurd-Mori reaction. Corresponding acids, acid chlorides, amides, furoyl hydrazide and acryloyl azide were prepared. It was shown that in all above-mentioned substances furylthiadiazole fragment is thermally stable. Treating of methyl 5-(1,2,3-thiadiazol-4-yl)furan-2-furoate with morpholine in the presence of potassium hydroxide leads to the cleavage of thiadiazole ring with the liberation of nitrogen and the formation of [5-(methoxycarbonyl)fur-2-yl]acetic acid morpholide.

N-rich fluid inclusions in octahedrally-grown diamond

Nitrogen is generally considered a trace component in the Earth's mantle. Mantle volatiles sampled from mid-ocean ridge basalts or preserved as fluid inclusions in xenoliths are dominated by CO2, with only traces of nitrogen. Here we describe CO2–N2 fluid inclusions with 40 mol% N2 and silicate melt inclusions with ∼0.1 wt% dissolved N2 in mantle-derived diamonds from 3 different cratons. The diamonds are octahedrally-grown, which is the most common growth habit and rarely reported to contain fluid inclusions. The inclusions have C/N ratios <1, more than two orders of magnitude below typical mantle values. We propose that nitrogen can become concentrated to high degrees by processes related to diamond growth. A growing diamond does not readily consume the nitrogen available, suggesting incompatible behaviour. Residual N2 from this process represents a concentrated nitrogen flux escaping the convecting mantle. Hidden nitrogen fluxes like this might be significant in counteracting the large apparent net influx by subduction. Based on nitrogen and carbon speciation in the inclusions, we propose that redox processes control the liberation of nitrogen from the convecting mantle, by the oxidation of NH+4 in silicates to mobile N2, concurrent with a parallel oxidation process releasing carbonate melt from the asthenosphere. Isotopic fractionation accompanying changes in nitrogen speciation could help account for the apparent isotopic mismatch between surficial and mantle nitrogen.

ChemInform Abstract: Synthesis of Benzo[b]furan‐2‐thioles from 4‐(2‐Hydroxyaryl)‐1,2,3‐thiadiazoles.

AbstractA new method for the synthesis of benzo[b]furan‐2‐thiols is developed using the base‐mediated decomposition of title o‐hydroxyaryl‐thiadiazoles, which is accompanied by liberation of nitrogen, and subsequent recyclization.

Optimization of wort production from rice malt using enzymes and barley malt

Commercially, rice malt has never been successfully used in brewing because of its low free α-amino nitrogen (FAN) content. This study was designed to optimise rice malt replacement for barley malt in wort production and to improve FAN by adding α-amylase and protease. The response surface methodology (RSM) through face central composite design (CCD) was selected to examine the effects of the four independent variables at three levels: germination time (X 1 ), rice malt ratio (X 2 ), α-amylase (X 3 ) addition, and protease (X 4 ) addition. The rice malt ratio influenced the adjusted wort yield (AWY); 75% rice malt gave the maximum AWY. The addition of protease increased the amount of wort FAN due to the improvement in amino nitrogen liberation. Moreover, the germination time of rice had the most impact on wort FAN. On the 1st and 3rd days of germination of the rice malt, the FAN was 18.76 and 44.70 mg/100 g malt, respectively; on the 5th day, the FAN was 118.45 mg/100 g malt. The optimisation process for wort production using the addition of enzymes and rice malt was successfully accomplished. The rice malt ratio was increased up to 90% (w/w) using the five-day germinated rice malt, α-amylase and protease at 0.40 g/100 g malt. Key words : Response surface methodology (RSM), rice malt, wort production.

Synthesis of benzo[b]furan-2-thioles from 4-(2-hydroxyaryl)-1,2,3-thiadiazoles

4-(2-Hydroxyaryl)-1,2,3-thiadiazoles treated with bases decompose with nitrogen liberation and the formation of benzo[b]furan-2-thiolates. On acidifying the thiolates benzo[b]furan-2-thiols were obtained. 4-(4- and -5-Benzyloxy-2-hydroxyphenyl)-1,2,3-thiadiazoles formed analogously the corresponding benzo[b]furan-2-thiolates whose acidifying afforded polymeric compounds.

Systematics of pyrolytic N2 and CH4 release from peat and coals of different thermal maturity

Open system non-isothermal (programmed) pyrolysis with a constant heating rate of 0.5 °C/min up to a final temperature of 1200 °C was used to study the liberation of molecular nitrogen (N2) and methane (CH4) from organic-rich sedimentary matter of different thermal maturity. The sample set analysed comprised peats, lignites, bituminous coals and anthracites. Temperature ranges, shapes and intensities of pyrolytic peaks in the CH4 and N2 pyrograms are sensitive indicators of the chemical composition of the sedimentary organic matter and may serve as characteristic fingerprints of organofacies and depositional environment. Within the coalification sequence, an increase in total organic carbon (TOC)-normalized methane yields was observed from peat to medium volatile bituminous coal, followed by a distinct decrease for the anthracites. The onset of methane and nitrogen liberation temperatures shifted towards higher temperatures with increasing rank, reflecting the increase in thermal stability of the residual organic matter. A systematic temperature shift was also observed for the methane generation maximum (peak). The N2 pyrograms exhibit bimodal generation curves (two maxima) up to the bituminous coal rank, while essentially only one single high-temperature N2 generation maximum persists at the anthracite level. This is attributed to a predominance of nitrogen-containing moieties (e.g. pyridinic and pyrrolic) of high thermal stability. The N2 pyrograms of the lignites show a higher degree of complexity, indicating a substantial variability in nitrogen-containing compound groups. Characteristic N2 spikes were found in the Miocene lignites of the Lower Rhine Basin, similar to those observed previously in Greek lignites. The origin of these “anomalies” and their relation to depositional environment and diagenesis still remains unknown.

Uso de clinoptilolita como un vehículo de fertilizantes nitrogenados en un suelo de la región Pampeana de Argentina

G. Millan, F. Agosto, M. Vazquez, L. Botto, L. Lombardi, and L. Juan. 2008. Use of clinoptilolite as a carrier for nitrogen fertilizers in soils of the Pampean regions of Argentina. Cien. Inv. Agr. 35(3):293-302. The properties of clinoptilolite related to cationic exchange and ionic selectivity have motivated us to study its application for agronomic purposes. The high potential of the clinoptilolite has been demonstrated as a vehicle for nitrogen fertilizers, with the aims of decreasing negative impacts on the environment and increasing fertilizer effi ciency. The objective of this study was to evaluate the effects of an exchanged form, clinoptiloliteNH 4 , and an occluded form, clinoptilolite-urea, of nitrogen fertilizer relative to commercial urea on dry matter and the nitrogen uptake effi ciency of Lolium multifl orum under controlled conditions. Lolium multifl orum, sowed in a sandy loam soil, was fertilized with 0, 60, 120, and 180 kg·ha -1 of nitrogen. Yield increased considerably and nitrogen uptake effi ciency was enhanced when clinoptilolite-NH 4 was used, possibly due to its ability to retain and slowly liberate NH 4 + ions. This effect produces time differences in nitrogen disponibility in relation to urea, making the nitrogen available for a longer time for the plant. The clinoptilolite-urea treatments reduced yields signifi cantly in comparison with urea applications only at the lowest dose. In addition, the nitrogen uptake effi ciency was always lower than the other treatments. This behavior is related to the fact that nitrogen liberation dynamics of the occluded form are much slower than for the ionic one.

Influence of autochthonous Argentine goat lactobacillus in ripening of slurry cheese models

Three indigenous lactobacilli isolated from autochthonous Argentinean goat cheeses were evaluated in models of ripening of semihard goat cheeses made under microbiologically controlled conditions. Batches A, B and C were manufactured with single strain of Lactobacillus plantarum ETC17, Lactobacillus rhamnosus ETC14 and Lactobacillus casei ETC19, respectively. Lactobacilli counts showed higher values on batch C until ripening on day 18. Chemical composition did not show differences between batches. Batch C showed a higher decrease in pH on day 1, higher liberation of nitrogen water‐soluble cheese extracts and higher free amino acids content up to day 18. Amino acid distribution was analysed by studying the main components.

Ultrasonication-assisted surface functionalization of double-walled carbon nanotubes with azobis-type radical initiators

This paper reports the development of a facile approach for the functionalization of double-walled carbon nanotubes (DWNTs) with azobis-type radical initiators under combined thermal and sonic conditions. The thermal decomposition of azobis-type radical initiators generates free radicals of the alkyl group terminated with various chemically active sites along with the liberation of nitrogen. These radicals are capable of opening the π-bonds of DWNTs, and the generation of chemically active sites on their surface. With the assistance of ultrasonication they can effectively separate DWNT bundles for radical addition and therefore significantly shorten the reaction time.