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K R Hartop, M J Sullivan, G Giannopoulos, A J Gates, P L Bond, Z Yuan, T A Clarke, G Rowley, D J Richardson
Nitrite, in equilibrium with free nitrous acid (FNA), can inhibit both aerobic and anaerobic growth of microbial communities through bactericidal activities that have considerable potential for control of microbial growth in a range of water systems. There has been much focus on the effect of nitrite/FNA on anaerobic metabolism and so, to enhance understanding of the metabolic impact of nitrite/FNA on aerobic metabolism, a study was undertaken with a model denitrifying bacterium Paracoccus denitrificans PD1222...
February 7, 2017: Water Research
Han Gao, Miaomiao Liu, James S Griffin, Longcheng Xu, Da Xiang, Yaniv D Scherson, Wen-Tso Liu, George F Wells
Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) is a promising emerging bioprocess for wastewater treatment that enables direct energy recovery from nitrogen (N) in three steps: (1) ammonium oxidation to nitrite; (2) denitrification of nitrite to nitrous oxide (N2O); and (3) N2O conversion to N2 with energy generation. However, CANDO does not currently target phosphorus (P) removal. Here, we demonstrate that denitrifying polyphosphate accumulating organism (PAO) enrichment cultures are capable of catalyzing simultaneous biological N and P removal coupled to N2O generation in a 2nd generation CANDO process, CANDO+P...
February 17, 2017: Environmental Science & Technology
Wei Qin, Kelley A Meinhardt, James W Moffett, Allan H Devol, E Virginia Armbrust, Anitra E Ingalls, David A Stahl
Recent studies point to the importance of oxygen (O2 ) in controlling the distribution and activity of marine ammonia-oxidizing archaea (AOA), one of the most abundant prokaryotes in the ocean. The AOA are associated with regions of low O2 tension in oceanic oxygen minimum zones (OMZs), and O2 availability is suggested to influence their production of the ozone-depleting greenhouse gas nitrous oxide (N2 O). We show that marine AOA available in pure culture sustain high ammonia oxidation activity at low μM O2 concentrations, characteristic of suboxic regions of OMZs (<10 µM O2 ), and that atmospheric concentrations of O2 may inhibit the growth of some environmental populations...
February 17, 2017: Environmental Microbiology Reports
Stephen Wilson, Elizabeth S Gosnell
PURPOSE: The purpose of this study was to survey the membership of the American Academy of Pediatric Dentistry (AAPD) and determine the current status of nitrous oxide (N2O) utilization in their dental practices while also comparing the findings to a similar survey completed 20 years ago. METHODS: A 55-item questionnaire on the use of N2O was sent to the AAPD membership. RESULTS: The total number of respondents was 1,632 (26 percent). Sixty-two percent are board-certified, 97 percent use N2O in their office, 18 percent indicated greater than 80 percent of their patient pool required N2O versus six percent in 1996...
October 15, 2016: Pediatric Dentistry
Marc S Lener, Bashkim Kadriu, Carlos A Zarate
Clinical and preclinical studies suggest that dysfunction of the glutamatergic system is implicated in mood disorders such as major depressive disorder and bipolar depression. In clinical studies of individuals with major depressive disorder and bipolar depression, rapid reductions in depressive symptoms have been observed in response to subanesthetic-dose ketamine, an agent whose mechanism of action involves the modulation of glutamatergic signaling. The findings from these studies have prompted the repurposing and/or development of other glutamatergic modulators for antidepressant efficacy, both as monotherapy or as an adjunct to conventional monoaminergic antidepressants...
February 14, 2017: Drugs
Fabrizio Sabba, Cristian Picioreanu, Joshua P Boltz, Robert Nerenberg
Wastewater treatment plants can be significant sources of nitrous oxide (N2O), a potent greenhouse gas. While our understanding of N2O emissions from suspended-growth processes has advanced significantly, less is known about emissions from biofilm processes. Biofilms may behave differently due to their substrate gradients and microbial stratification. In this study, we used mathematical modeling to explore the mechanisms of N2O emissions from nitrifying and denitrifying biofilms. Our ammonia-oxidizing bacteria biofilm model suggests that N2O emissions from biofilm can be significantly greater than from suspended-growth systems...
February 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Longqi Lang, Mathieu Pocquet, Bing-Jie Ni, Zhiguo Yuan, Mathieu Spérandio
The aim of this work is to compare the capability of two recently proposed two-pathway models for predicting nitrous oxide (N2O) production by ammonia-oxidizing bacteria (AOB) for varying ranges of dissolved oxygen (DO) and nitrite. The first model includes the electron carriers whereas the second model is based on direct coupling of electron donors and acceptors. Simulations are confronted to extensive sets of experiments (43 batches) from different studies with three different microbial systems. Despite their different mathematical structures, both models could well and similarly describe the combined effect of DO and nitrite on N2O production rate and emission factor...
February 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Yusuke Toya, Toshiko Itagaki, Kazuaki Wagatsuma
We investigated a simultaneous internal standard method in flame atomic absorption spectrometry (FAAS), in order to better the analytical precision of 3d-transition metals contained in steel materials. For this purpose, a new spectrometer system for FAAS, comprising a bright xenon lamp as the primary radiation source and a high-resolution Echelle monochromator, was employed to measure several absorption lines at a wavelength width of ca. 0.3 nm at the same time, which enables the absorbances of an analytical line and also an internal standard line to be estimated...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
J Hoeffe, E Doyon Trottier, B Bailey, D Shellshear, M Lagacé, C Sutter, G Grimard, R Cook, F E Babl
INTRODUCTION: Procedural sedation and analgesia (PSA) are frequently used for fracture reduction in pediatric emergency departments (ED). Combining intranasal (IN) fentanyl with inhalation of nitrous oxide (N2O) allow for short recovery time and obviates painful and time-consuming IV access insertions. METHODS: We performed a bicentric, prospective, observational cohort study. Patients aged 4-18years were included if they received combined PSA with IN fentanyl and N2O for the reduction of mildly/moderately displaced fracture or of dislocation...
January 5, 2017: American Journal of Emergency Medicine
Girish P Joshi, John H Pennant, Henrik Kehlet
No abstract text is available yet for this article.
February 8, 2017: Anesthesia and Analgesia
Young Ju Won, Byung Gun Lim, Gwi Eun Yeo, Min Ki Lee, Dong Kyu Lee, Heezoo Kim, Il Ok Lee, Myoung Hoon Kong
BACKGROUND: The effectiveness of surgical pleth index (SPI) for managing nociception-antinociception balance during general anesthesia with vasodilators, including nicardipine has not been demonstrated. We aimed to compare the time course during surgery in SPI values in patients receiving nicardipine or remifentanil infusion during thyroidectomy. METHODS: Forty patients undergoing thyroidectomy were randomly assigned to receive nicardipine (group N; n = 19) or remifentanil (group R; n = 21) along with induction (propofol, fentanyl, and rocuronium) and maintenance (50% desflurane/nitrous oxide in oxygen) anesthesia (goal bispectral index [BIS] ∼50)...
February 2017: Medicine (Baltimore)
E W Duncan, C J Dell, P J A Kleinman, D B Beegle
Trade-offs associated with surface application or injection of manure pose important environmental and agronomic concerns. Manure injection can conserve nitrogen (N) by decreasing ammonia (NH) volatilization. However, the injection band also creates conditions that potentially favor nitrous oxide (NO) production: an abundant organic substrate-promoting microbial activity, anaerobic conditions favoring denitrification, and large local concentrations of N. We assessed differences in NH volatilization and NO emissions with broadcast application versus shallow disk injection of dairy slurry during the 2011 to 2013 growing seasons on a well-drained silt loam that received average manure-N application rates of 180 kg N ha via injection or 200 kg N ha via broadcast...
January 2017: Journal of Environmental Quality
Annemiek Buizert, Ruby Sharma, Hille Koppen
Here we describe a case of subacute combined spinal cord degeneration caused by nitrous oxide (N2O, laughing gas) use. Because of its euphoric effects, the use of N2O has become increasingly popular in recent years. Unfortunately, the use of N2O leads to inactivation of vitamin B12. Vitamin B12 plays an essential role in the synthesis and maintenance of myelin, a fatty substance that surrounds nerve cells and is crucial for their functioning. Deficiency of vitamin B12 could typically result in degeneration of posterior and lateral columns of the spinal cord...
February 3, 2017: Journal of Addiction Medicine
Akihiko Terada, Sho Sugawara, Keisuke Hojo, Yuki Takeuchi, Shohei Riya, Willie F Harper, Tomoko Yamamoto, Megumi Kuroiwa, Kazuo Isobe, Chie Katsuyama, Yuichi Suwa, Keisuke Koba, Masaaki Hosomi
The goal of this study was to elucidate the mechanisms of N2O production from a bioreactor for partial nitrification (PN). Ammonia-oxidizing bacteria (AOB) enriched from a sequencing batch reactor (SBR) were subjected to N2O production pathway tests. The N2O pathway test was initiated by supplying an inorganic medium to ensure an initial NH4(+)-N concentration of 160 mg-N/L, followed by (15)NO2(-) (20 mg-N/L) and dual (15)NH2OH (each 17 mg-N/L) spikings to quantify isotopologs of gaseous N2O ((44)N2O, (45)N2O, and (46)N2O)...
February 6, 2017: Environmental Science & Technology
George S Bause
Laughing-gas showman G.Q. Colton franchised dental extraction under 100% nitrous oxide in many large American cities before popularizing the practice with French Imperial Court dentist T.W. Evans in France and then England. Chicago dentist Z. Rogers helped surgeon E. Andrews oxygenate nitrous oxide, with neither man changing significantly the clinical practices of others. London's F.W. Hewitt and Pittsburgh's S.J. Hayes oxygenated anesthetics with greater clinical impact. By 1920, E.I. McKesson had publicized his practice of secondary saturation with bursts of 100% nitrous oxide to relax musculature in anesthetized patients...
January 2017: Journal of Anesthesia History
John H Krystal, Ismene L Petrakis, Stephanie O'Malley, Suchitra Krishnan-Sarin, Godfrey Pearlson, Gihyun Yoon
No abstract text is available yet for this article.
January 31, 2017: International Journal of Neuropsychopharmacology
Jianqiang Zhao, Jinna Wu, Xiaoling Li, Sha Wang, Bo Hu, Xiaoqian Ding
Microbial fuel cells (MFCs) have attracted much attention due to their ability to generate electricity while treating wastewater. The performance of a double-chamber MFC with simultaneous nitrification and denitrification (SND) in the cathode for treating synthetic high concentration ammonia wastewater was investigated at different dissolved oxygen (DO) concentrations and high temperatures. The results showed that electrode denitrification and traditional heterotrophic denitrification co-existed in the cathode chamber...
2017: Frontiers in Microbiology
Yizhen Zhou, Yuanyuan Zhang, Di Tian, Yujing Mu
Crop straw returning has become a prevailing cultivation practice in the vast area of the North China Plain (NCP), while few investigations about its influence on nitrous oxide (N2O) emission have been conducted. In this study, N2O emissions from an agricultural field in the NCP with and without straw returning were comparably investigated by using static chambers in two consecutive maize-wheat growing seasons from June 2010 to June 2012. Compared with the NP treatment (compound nitrogen fertilizer only), the cumulative N2O emission from the SP treatment (compound nitrogen fertilizer plus straw) increased about 150% during the maize season in 2010, but decreased by about 35% during the maize season in 2011...
January 30, 2017: Science of the Total Environment
Anna Jurado, Alberto V Borges, Serge Brouyère
This work reviews the concentrations, the dynamics and the emissions of nitrous oxide (N2O) in groundwater. N2O is an important greenhouse gas (GHG) and the primary stratospheric ozone depleting substance. The major anthropogenic source that contributes to N2O generation in aquifers is agriculture because the use of fertilizers has led to the widespread groundwater contamination by inorganic nitrogen (N) (mainly nitrate, NO3(-)). Once in the aquifer, this inorganic N is transported and affected by several geochemical processes that produce and consume N2O...
January 30, 2017: Science of the Total Environment
Muzaffer Colakoglu, Ozgur Ozkaya, Gorkem Aybars Balci, Bulent Yapicioglu
It is important to verify the old findings of Cumming (1972) and Goldberg and Shephard (1980) who showed that stroke volume (SV) may be higher during recovery rather than during exercise, in order to organize the number of intervals throughout training sessions. The purpose of this study was to re-evaluate individual SV responses to various upright cycling exercises using the nitrous-oxide rebreathing method. Nine moderate to well-trained male athletes volunteered to take part in the study (maximal O2 uptake (VO2max): 60...
December 1, 2016: Journal of Human Kinetics
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