Database : MEDLINE
Search on : nitrogen [Words]
References found : 309021 [refine]
Displaying: 1 .. 10   in format [Detailed]

page 1 of 30903 go to page                         

  1 / 309021 MEDLINE  
              next record last record
select
to print
Photocopy
Full text

[PMID]: 29524912
[Au] Autor:Vandekerckhove TGL; Kobayashi K; Janda J; Van Nevel S; Vlaeminck SE
[Ad] Address:Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
[Ti] Title:Sulfur-based denitrification treating regeneration water from ion exchange at high performance and low cost.
[So] Source:Bioresour Technol;257:266-273, 2018 Feb 13.
[Is] ISSN:1873-2976
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:Autotrophic denitrification with sulfur is an underexplored alternative to heterotrophic denitrification to remove nitrate from wastewater poor in organics. The application on ion exchange regeneration water (19.4-32.1 mS cm ) is novel. Three fixed bed reactors were tested at 15 C for >4 months, inoculated with activated sludge from sewage treatment. All were fast in start-up (<10 days) with high performance (94  2% removal efficiency). pH control with NaOH rendered higher nitrate removal rates than limestone addition to the bed (211  13 vs. 102  13 mg N L d ), related to higher pH (6.64 vs. 6.24) and sulfur surface area. Bacterial communities were strongly enriched in Sulfurimonas (63-67%) and Thiobacillus (24-26%). In an economic comparison, sulfur-based denitrification (5.3 kg N) was 15% cheaper than methanol-based denitrification (6.22 kg N) and both treatments were opex dominated (85.9 vs. 86.5%). Overall, the technological and economic feasibility should boost further implementation of sulfurotrophic denitrification.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  2 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524902
[Au] Autor:Zhu S; Xia L; Wu J; Chen S; Chen F; Zeng F; Chen X; Chen C; Xia Y; Zhao X; Zhang J
[Ad] Address:Department of Epidemiology and Biostatistics, School of Public Health, Sichuan University, Chengdu 610044, China.
[Ti] Title:Ambient air pollutants are associated with newly diagnosed tuberculosis: A time-series study in Chengdu, China.
[So] Source:Sci Total Environ;631-632:47-55, 2018 Mar 07.
[Is] ISSN:1879-1026
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:Although a few studies have analyzed the associations between ambient air pollutants and the development of tuberculosis (TB), most have been conducted in the core countries with inconsistent results. In this study, we used a distributed lag non-linear model to investigate the associations between the newly diagnosed TB cases and daily exposure to particulate matter with an aerodynamic diameter of <10m (PM ), nitrogen dioxide (NO ), and sulfur dioxide (SO ) in Chengdu, a severely polluted city. There were 36,108 newly diagnosed active TB cases from January 1, 2010 to December 31, 2015 in Chengdu. In a single-pollutant model, the cumulative relative risk of active TB cases was 1.06 [lag of 0 to 21days, 95% confidence interval (CI): 1.01-1.11] for each 10g/m increase in PM above the threshold of 70g/m ; 1.06 (lag of 0 to 2days, 95% CI: 1.03-1.09) for each 10g/m increase in NO above the threshold of 40g/m ; and 1.07 (lag of 0 to 2days, 95% CI: 1.02-1.12) for each 10g/m increase in SO above the threshold of 60g/m . Meanwhile, we found a positive association in males after exposure to a 10g/m increase in SO above the threshold of 60g/m at a lag of 0 to 2days. Exposure to PM , NO , and SO was associated with an increment in the incidence of active TB cases.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  3 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524900
[Au] Autor:Krantzberg G; Hartley P
[Ad] Address:McMaster University, Canada. Electronic address: krantz@mcmaster.ca.
[Ti] Title:Feasible policy development and implementation for the destruction of endocrine disruptors in wastewater.
[So] Source:Sci Total Environ;631-632:246-251, 2018 Mar 07.
[Is] ISSN:1879-1026
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:Endocrine disruptors when introduced to waterways have many adverse health effects on wildlife and humans. These health effects vary from neurological, immune, carcinogenic and reproductive disorders. Currently, there are few wastewater treatment facilities that are purposefully treating endocrine disruptors as part of the normal wastewater treatment process. Current literature has shown that endocrine disruptors can be treated using conventional methods. These conventional methods are centered around the denitrification process, which is rarely adopted in Canada. This paper investigates the current wastewater effluent regulations and guidelines in Canada, Ontario and the European Union. The research identifies a policy strategy that would include denitrification in the wastewater treatment process to help eliminate endocrine disruptors and acutely toxic nitrogen based compounds. Our emphasis here is on action possible in the Province of Ontario Canada, give the context of the Great Lakes basin and the potential for early action to stimulate other jurisdictions to follow. Our recommendations while aimed at one jurisdiction, have broad application globally.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  4 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524896
[Au] Autor:Pathak D; Whitehead PG; Futter MN; Sinha R
[Ad] Address:Department of Earth Sciences, Indian Institute of Technology Kanpur, Kanpur 208016, India.
[Ti] Title:Water quality assessment and catchment-scale nutrient flux modeling in the Ramganga River Basin in north India: An application of INCA model.
[So] Source:Sci Total Environ;631-632:201-215, 2018 Mar 07.
[Is] ISSN:1879-1026
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:The present study analyzes the water quality characteristics of the Ramganga (a major tributary of the Ganga river) using long-term (1991-2009) monthly data and applies the Integrated Catchment Model of Nitrogen (INCA-N) and Phosphorus (INCA-P) to the catchment. The models were calibrated and validated using discharge (1993-2011), phosphate (1993-2010) and nitrate (2007-2010) concentrations. The model results were assessed based on Pearson's correlation, Nash-Sutcliffe and Percentage bias statistics along with a visual inspection of the outputs. The seasonal variation study shows high nutrient concentrations in the pre-monsoon season compared to the other seasons. High nutrient concentrations in the low flows period pose a serious threat to aquatic life of the river although the concentrations are lowered during high flows because of the dilution effect. The hydrological model is satisfactorily calibrated with R and NS values ranging between 0.6-0.8 and 0.4-0.8, respectively. INCA-N and INCA-P successfully capture the seasonal trend of nutrient concentrations with R >0.5 and PBIAS within 17% for the monthly averages. Although, high concentrations are detected in the low flows period, around 50% of the nutrient load is transported by the monsoonal high flows. The downstream catchments are characterized by high nutrient transport through high flows where additional nutrient supply from industries and agricultural practices also prevail. The seasonal nitrate (R : 0.88-0.94) and phosphate (R : 0.62-0.95) loads in the catchment are calculated using model results and ratio estimator load calculation technique. On average, around 548tonnes of phosphorus (as phosphate) and 77,051tonnes of nitrogen (as nitrate) are estimated to be exported annually from the Ramganga River to the Ganga. Overall, the model has been able to successfully reproduce the catchment dynamics in terms of seasonal variation and broad-scale spatial variability of nutrient fluxes in the Ramganga catchment.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  5 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524893
[Au] Autor:Hao Z; Yin Y; Wang J; Cao D; Liu J
[Ad] Address:State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
[Ti] Title:Formation of organobromine and organoiodine compounds by engineered TiO nanoparticle-induced photohalogenation of dissolved organic matter in environmental waters.
[So] Source:Sci Total Environ;631-632:158-168, 2018 Mar 07.
[Is] ISSN:1879-1026
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:There are increasing concerns about the adverse effects of released engineered nanoparticles and photochemically formed organohalogen compounds (OHCs) on human health and the environment. Herein, we report that titanium dioxide nanoparticles (TiO NPs) can photocatalytically halogenate dissolved organic matter (DOM) to form a large number of organobromine compounds (OBCs) and organoiodine compounds (OICs), as characterized by negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry. Compared with no OHCs produced in control samples in darkness and/or without TiO NPs under sunlight irradiation, various OBCs and OICs were detected in freshwater and seawater under sunlight irradiation for 12h and 24h even in the presence of 1mgL TiO NPs, indicating the photocatalytic roles TiO NPs played in DOM halogenation. Furthermore, TiO NPs could result in the photodegradation of newly formed OHCs, as evidenced by the intensity and the number of some OHCs decreased with reaction time. In addition, many TiO NP-induced OBCs contained two or three bromine atoms, and/or nitrogen and sulfur elements, belonging to lignin-like, tannin-like, unsaturated hydrocarbon and aliphatic compounds. While the OICs were primarily contained one iodine, and very few consisted of nitrogen and sulfur elements, most were lignin-like and tannin-like compounds. Finally, the OBCs in freshwater were found to be formed mainly via a substitution reaction or addition reaction and were accompanied by other reactions such as photooxidation, while the OBCs in seawater and OICs were formed primarily via substitution reactions. Given the abundance of produced OHCs and their toxicity, our findings call for further studies on the exact structure and toxicity of the formed OHCs, taking account the TiO NP-induced DOM photohalogenation in aquatic environments during the evaluation of the environmental effects of engineered TiO NPs.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  6 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524888
[Au] Autor:Li S; Zheng X; Liu C; Yao Z; Zhang W; Han S
[Ad] Address:State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China.
[Ti] Title:Influences of observation method, season, soil depth, land use and management practice on soil dissolvable organic carbon concentrations: A meta-analysis.
[So] Source:Sci Total Environ;631-632:105-114, 2018 Mar 07.
[Is] ISSN:1879-1026
[Cp] Country of publication:Netherlands
[La] Language:eng
[Ab] Abstract:Quantifications of soil dissolvable organic carbon concentrations, together with other relevant variables, are needed to understand the carbon biogeochemistry of terrestrial ecosystems. Soil dissolvable organic carbon can generally be grouped into two incomparable categories. One is soil extractable organic carbon (EOC), which is measured by extracting with an aqueous extractant (distilled water or a salt solution). The other is soil dissolved organic carbon (DOC), which is measured by sampling soil water using tension-free lysimeters or tension samplers. The influences of observation methods, natural factors and management practices on the measured concentrations, which ranged from 2.5-3970 (mean: 69) mg kg of EOC and 0.4-200 (mean: 12) mg L of DOC, were investigated through a meta-analysis. The observation methods (e.g., extractant, extractant-to-soil ratio and pre-treatment) had significant effects on EOC concentrations. The most significant divergence (approximately 109%) occurred especially at the extractant of potassium sulfate (K SO ) solutions compared to distilled water. As EOC concentrations were significantly different (approximately 47%) between non-cultivated and cultivated soils, they were more suitable than DOC concentrations for assessing the influence of land use on soil dissolvable organic carbon levels. While season did not significantly affect EOC concentrations, DOC concentrations showed significant differences (approximately 50%) in summer and autumn compared to spring. For management practices, applications of crop residues and nitrogen fertilizers showed positive effects (approximately 23% to 91%) on soil EOC concentrations, while tillage displayed negative effects (approximately -17%), compared to no straw, no nitrogen fertilizer and no tillage. Compared to no nitrogen, applications of synthetic nitrogen also appeared to significantly enhance DOC concentrations (approximately 32%). However, further studies are needed in the future to confirm/investigate the effects of ecosystem management practices using standardized EOC measurement protocols or more DOC cases of field experiments.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  7 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524858
[Au] Autor:Piazzoli A; Breider F; Aquillon CG; Antonelli M; von Gunten U
[Ad] Address:Politecnico di Milano, DICA - Environmental Section, Piazza Leonardo da Vinci 32, 20133 Milano, Italy; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fdrale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
[Ti] Title:Specific and total N-nitrosamines formation potentials of nitrogenous micropollutants during chloramination.
[So] Source:Water Res;135:311-321, 2018 Feb 10.
[Is] ISSN:1879-2448
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:N-nitrosamines are a group of potent human carcinogens that can be formed during oxidative treatment of drinking water and wastewater. Many tertiary and quaternary amines present in consumer products (e.g., pharmaceuticals, personal care and household products) are known to be N-nitrosodimethylamine (NDMA) precursors during chloramination, but the formation of other N-nitrosamines has been rarely studied. This study investigates the specific and total N-nitrosamine (TONO) formation potential (FP) of various precursors from nitrogen-containing micropollutants (chlorhexidine, metformin, benzalkonium chloride and cetyltrimethylammonium chloride) and tertiary and quaternary model amines (trimethyl amine, N,N-dimethylbutyl amine, N,N-dimethylbenzyl amine and tetramethyl ammonium). All the studied nitrogenous micropollutants displayed quantifiable TONO FP, with molar yields in the range 0.04-11.92%. However, the observed TONO pools constituted mostly of uncharacterized species, not included in US-EPA 8270 N-nitrosamines standard mix. Only the quaternary ammonium compound benzalkonium chloride showed quantifiable NDMA FP (0.56% molar yield), however, explaining only a minor fraction of the observed TONO FP. The studied model amines showed molar NDMA yields from 0.10% (trimethyl amine) to 5.05% (N,N-dimethylbenzyl amine), very similar to the molar TONO yields. The comparison of the FPs of micropollutants and model compounds showed that the presence of electron donating functional groups (such as a benzyl group) in tertiary and quaternary amine precursors leads to a higher formation of NDMA and uncharacterized N-nitrosamines, respectively. LC-qTOF screening of a list of proposed N-nitrosamine structures has enabled to identify a novel N-nitrosamine (N-nitroso-N-methyldodecylamine) from the chloramination of benzalkonium chloride. This finding supports the hypothesis that different functional groups in quaternary amines can act as leaving groups during chloramination and form differing N-nitrosamine structures at significant yield. Molar TONO yields determined for micropollutants were finally validated under experimental conditions closer to real water matrices, confirming their representativeness also for lower concentration ranges.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  8 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524817
[Au] Autor:Ly QV; Hur J
[Ad] Address:Department of Environment & Energy, Sejong University, Seoul 05006, South Korea; Sustainable Management of Natural Resources and Environment Research Group, Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Viet Nam.
[Ti] Title:Further insight into the roles of the chemical composition of dissolved organic matter (DOM) on ultrafiltration membranes as revealed by multiple advanced DOM characterization tools.
[So] Source:Chemosphere;201:168-177, 2018 Mar 01.
[Is] ISSN:1879-1298
[Cp] Country of publication:England
[La] Language:eng
[Ab] Abstract:This study assessed the relative contributions of different constitutes in dissolved organic matter (DOM) with two different sources (i.e., urban river and effluent) to membrane fouling on three types of ultrafiltration (UF) membranes via excitation emission matrix - parallel factor analysis (EEM-PARAFAC), size exclusion chromatography (SEC), and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Two polyethersulfone membranes with different pore sizes and one regenerated cellulose membrane were used as representative hydrophobic (HPO) and hydrophilic (HPI) UF membranes, respectively. Although size exclusion effect was found to be the most prevailing rejection mechanism, the behaviors of individual fluorescent components (one tryptophan-like, one microbial-humic-like, and terrestrial humic-like) and different size fractions upon the UF filtration revealed that chemical interactions (e.g., hydrophobic interactions and hydrogen bonding) between DOM and membrane might play important roles in UF membrane fouling, especially for small sized DOM molecules. Based on the molecular level composition determined by FT-ICR-MS, the CHOS formula group showed a greater removal tendency toward the HPO membrane, while the CHONS group was prone to be removed by the HPI membrane. The changes in the overall molecular composition of DOM upon UF filtration were highly dependent on the sources of DOM. The molecules of more acidic nature tended to remain in the permeate of effluent DOM, while the river DOM was shifted into more nitrogen-enriched composition after filtration. Regardless of the DOM sources, the HPO membrane with a smaller pore size led to the most pronounced changes in the molecular composition of DOM.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  9 / 309021 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 29524757
[Au] Autor:Wittmann JJ; Can TV; Eckardt M; Harneit W; Griffin RG; Corzilius B
[Ad] Address:Institute for Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt am Main, Germany.
[Ti] Title:High-precision measurement of the electron spin g factor of trapped atomic nitrogen in the endohedral fullerene N@C .
[So] Source:J Magn Reson;290:12-17, 2018 Mar 06.
[Is] ISSN:1096-0856
[Cp] Country of publication:United States
[La] Language:eng
[Ab] Abstract:The electronic g factor carries highly useful information about the electronic structure of a paramagnetic species, such as spin-orbit coupling and dia- or paramagnetic (de-)shielding due to local fields of surrounding electron pairs. However, in many cases, a near "spin-only" case is observed, in particular for light elements, necessitating accurate and precise measurement of the g factors. Such measurement is typically impeded by a "chicken and egg situation": internal or external reference standards are used for relative comparison of electron paramagnetic resonance (EPR) Larmor frequencies. However, the g factor of the standard itself usually is subject to a significant uncertainty which directly limits the precision and/or accuracy of the sought after sample g factor. Here, we apply an EPR reference-free approach for determining the g factor of atomic nitrogen trapped within the endohedral fullerene C :N@C in its polycrystalline state by measuring the H NMR resonance frequency of dispersing toluene at room temperature. We found a value of g=2.00204(4) with a finally reached relative precision of ∼20 ppm. This accurate measurement allows us to directly compare the electronic properties of N@C to those found in atomic nitrogen in the gas phase or trapped in other solid matrices at liquid helium temperature. We conclude that spin-orbit coupling in N@C at room temperature is very similar in magnitude and of same sign as found in other inert solid matrices and that interactions between the quartet spin system and the C molecular orbitals are thus negligible.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher

  10 / 309021 MEDLINE  
              first record previous record
select
to print
Photocopy
Full text

[PMID]: 29524728
[Au] Autor:Han T; Tian K; Pan H; Liu Y; Xu F; Li Z; Uchita T; Gao M; Hua H; Li D
[Ad] Address:Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, and School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, PR China.
[Ti] Title:Novel hybrids of brefeldin A and nitrogen mustards with improved antiproliferative selectivity: Design, synthesis and antitumor biological evaluation.
[So] Source:Eur J Med Chem;150:53-63, 2018 Mar 01.
[Is] ISSN:1768-3254
[Cp] Country of publication:France
[La] Language:eng
[Ab] Abstract:A series of novel conjugates of brefeldin A (11a-c, 12a-c and 13a-c) were obtained by introducing a variety of nitrogen mustards at 4-OH or 7-OH position to explore more efficacious and less toxic antitumor agents. The antiproliferative activities were tested against three cancer cell lines (HL-60, PC-3 and Bel-7402) and one multidrug resistant cell line Bel-7402/5-FU. Among them, compound 11a was the strongest derivative with IC values of 4.48, 9.37, 0.2 and 0.84 M, respectively, and more potent than nitrogen mustards. Though the antiproliferative potency was weaker than the lead compound brefeldin A, 11a displayed lower toxicity than brefeldin A (IC < 0.001 M) with an IC of 9.74 M against normal human liver L-O2 cells, showing good selectivity between normal and malignant liver cells. The mechanism studies confirmed that 11a could induce apoptosis, arrest cell cycle at the G1 phase and lead to mitochondrial dysfunction in Bel-7402 cells at submicromolar concentrations. Furthermore, 11a induced the intrinsic apoptotic mitochondrial pathway in Bel-7402 cells, evidenced by the enhanced expression of the pro-apoptotic protein Bax, cyto-c and p53, and the reduced expression of the anti-apoptotic protein Bcl-2. The caspase-9 and -3 levels were also up-regulated.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1803
[Cu] Class update date: 180310
[Lr] Last revision date:180310
[St] Status:Publisher


page 1 of 30903 go to page                         
   


Refine the search
  Database : MEDLINE Advanced form   

    Search in field  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/PAHO/WHO - Latin American and Caribbean Center on Health Sciences Information