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Journal of Environmental Quality 2001Methane (CH4) flux from soil to the atmosphere is the result of two microbial processes, methanogenesis and CH4 oxidation. Land use may have a profound impact on the...
Methane (CH4) flux from soil to the atmosphere is the result of two microbial processes, methanogenesis and CH4 oxidation. Land use may have a profound impact on the relative activities of these groups of organisms. In this study, the CH4 production and consumption potentials of soils from agricultural and nonagricultural ecosystems were assessed in laboratory incubations. Methane production potentials of most soils were low and in the range of 0.02 to 0.35 nmol CH4 g soil(-1) h(-1); however, soils from two of the agricultural sites that experience periodic water saturation had CH4 production potentials from 100 to 300 nmol CH4 g soil(-1) h(-1). The high methanogenic potential suggests that CH4 consumers may not be wholly dependent on atmospheric CH4 for their survival and maintenance. The prairie soils exhibited the highest CH4 oxidation under ambient atmospheric CH4 concentrations, and CH4 oxidation activity was markedly enhanced in incubations with an atmosphere enriched in CH4. This stimulated CH4 oxidation activity was generally greater in the agricultural soils as compared with the forest and prairie soils. Methane oxidation appeared to be related to soil nitrogen status. Under ambient atmospheric CH4 concentrations, CH4 oxidation was negatively related to soil mineral N (NO2- + NO3- + NH4+) concentration. However, a positive relationship between soil mineral N status and CH4 oxidation activity was observed in incubations with atmospheres enriched in CH4. This pattern suggests that the agricultural lands contain different populations of CH4 oxidizers than the natural systems.
Topics: Agriculture; Ecosystem; Environmental Monitoring; Methane; Nitrogen; Oxidation-Reduction; Population Dynamics; Soil Microbiology; Volatilization
PubMed: 11789994
DOI: 10.2134/jeq2001.1896 -
Bioorganic & Medicinal Chemistry Feb 2017A novel synthetic approach to bis(indolyl)methanes has been established. Our one-pot synthetic strategy based on two consecutive hetero-Diels-Alder cycloaddition...
A novel synthetic approach to bis(indolyl)methanes has been established. Our one-pot synthetic strategy based on two consecutive hetero-Diels-Alder cycloaddition reactions of electrophilic conjugated nitrosoalkenes with indoles was extended to a range of new 1-hydroxyiminomethyl-bis(indolyl)methanes. Furthermore, a similar and broad range approach was applied to the synthesis of previously unknown 1-hydrazonomethyl-bis(indolyl)methanes. The biological evaluation of the new bis(indolyl)methanes as anti-cancer agents was investigated.
Topics: Antineoplastic Agents; Cell Line; Cell Proliferation; Cell Survival; Cycloaddition Reaction; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Indoles; Methane; Molecular Structure; Stereoisomerism; Structure-Activity Relationship
PubMed: 28062194
DOI: 10.1016/j.bmc.2016.12.028 -
The Science of the Total Environment Feb 2023Mercury decontamination from water requires highly effective and efficient methods for maintaining public health and environmental protection. Herein, based on the...
Mercury decontamination from water requires highly effective and efficient methods for maintaining public health and environmental protection. Herein, based on the coordination theory between functional groups and metal ions, we proposed phenylic carboxyl group-based poly(pyrrole methane)s (PPDCBAs) as highly efficient mercury removal materials for environmental remediation applications. It was found that PPDCBAs can efficiently adsorb and remove mercury(II) from aqueous solutions by functionalizing the molecular structure with phenylic carboxyl groups. Among the as-prepared PPDCBAs, poly[pyrrole-2, 5-diyl (4-carboxybenzylidane)] (PPD4CBA) with the carboxyl group at the para position can not only adsorb mercury over 1400 mg⋅g but also achieve a 92.5 % mercury(II) uptake within 100 min by a very low dosage of 0.1 g⋅L. In addition, PPDCBAs exhibited excellent adsorption selectivity for mercury(II) compared with copper(II), cadmium(II), zinc(II) and lead(II). Furthermore, as determined by Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) and the density functional theory (DFT) calculation, the mercury removal was found to be mainly dependent on the high density of chelating sites, the phenylic carboxyl moieties, which helped us to realize an ultra-trace amount mercury removal (from 10.8 μg⋅L to 0.6-0.8 μg⋅L) for meeting drinking water standard requirements (1.0 μg⋅L).
Topics: Mercury; Adsorption; Polymers; Spectroscopy, Fourier Transform Infrared; Pyrroles; Methane; Water Pollutants, Chemical; Hydrogen-Ion Concentration; Chelating Agents; Water; Kinetics
PubMed: 36328257
DOI: 10.1016/j.scitotenv.2022.159870 -
Environmental Science & Technology Apr 2022Efficient conversion of CO-rich gas to methane (CH) provides an effective energy solution by taking advantage of existing natural gas infrastructures. However,...
Efficient conversion of CO-rich gas to methane (CH) provides an effective energy solution by taking advantage of existing natural gas infrastructures. However, traditional chemical and biological conversions face different challenges. Herein, an innovative biophotoelectrochemistry (BPEC) system using -CdS as a biohybrid catalyst was successfully employed for CO methanation. Compared with CO-fed BPEC, BPEC-CO significantly extended the CH producing time by 1.7-fold and exhibited a higher CH yield by 9.5-fold under light irradiation. This superior conversion of CO resulted from the fact that CO could serve as an effective quencher of reactive species along with the photoelectron production. In addition, CO was used as a carbon source either directly or indirectly via the produced CO for . Such a process improved the redox activities of membrane-bound proteins for BPEC methanogenesis. These results were consistent with the transcriptomic analyses, in which the genes for the putative CO oxidation and CO reduction pathways in were highly expressed, while the gene expression for reactive oxygen species detoxification remained relatively stable under light irradiation. This study has provided the first proof-of-concept evidence for sustainable CO methanation under a mild condition in the self-replicating BPEC system.
Topics: Carbon Dioxide; Catalysis; Methane; Natural Gas; Oxidation-Reduction
PubMed: 35290037
DOI: 10.1021/acs.est.1c08340 -
PloS One 2019Imidazolium salts are shown to catalyze the rapid room temperature reaction of indoles or naphthol with aldehydes to provide bis(indolyl)methanes or bis(naphthol)methane...
Imidazolium salts are shown to catalyze the rapid room temperature reaction of indoles or naphthol with aldehydes to provide bis(indolyl)methanes or bis(naphthol)methane in excellent yields and the reaction proceeds optimally in dichloromethane with no base additives. The reaction exhibits a broad substrate tolerance and occurs through nucleophilic activation of the indoles and naphthols through a cation-π interaction.
Topics: Catalysis; Imidazoles; Methane; Proton Magnetic Resonance Spectroscopy; Salts
PubMed: 31022274
DOI: 10.1371/journal.pone.0216008 -
Bioengineered Dec 2019The rise in intermittent renewable electricity production presents a global requirement for energy storage. Biological hydrogen methanation (BHM) facilitates wind and... (Review)
Review
The rise in intermittent renewable electricity production presents a global requirement for energy storage. Biological hydrogen methanation (BHM) facilitates wind and solar energy through the storage of otherwise curtailed or constrained electricity in the form of the gaseous energy vector biomethane. Biological methanation in the circular economy involves the reaction of hydrogen - produced during electrolysis - with carbon dioxide in biogas to produce methane (4H + CO = CH + 2H), typically increasing the methane output of the biogas system by 70%. In this paper, several BHM systems were researched and a compilation of such systems was synthesized, facilitating comparison of key parameters such as methane evolution rate (MER) and retention time. Increased retention times were suggested to be related to less efficient systems with long travel paths for gases through reactors. A significant lack of information on gas-liquid transfer co-efficient was identified.
Topics: Biofuels; Bioreactors; Biotechnology; Carbon Dioxide; Hydrogen; Methane; Renewable Energy
PubMed: 31679461
DOI: 10.1080/21655979.2019.1684607 -
Methods in Enzymology 2011
Topics: Carbon Cycle; Methane; Microbiology
PubMed: 21402206
DOI: 10.1016/B978-0-12-385112-3.00017-2 -
ChemistryOpen Jan 2023The indole moiety is an important N-heterocycle found in natural products, and a key structural component of many value-added chemicals including pharmaceuticals. In...
The indole moiety is an important N-heterocycle found in natural products, and a key structural component of many value-added chemicals including pharmaceuticals. In particular, bis(3-indolyl)methanes (BIMs) are an important subgroup of indoles, composed of two indole units. Herein, we report the development of a simple method to access BIMs derivatives in yields of up to 77 % by exploiting a tBuOK-mediated coupling reaction of indoles and benzyl alcohols.
Topics: Methane; Butanols; Indoles
PubMed: 36650736
DOI: 10.1002/open.202200265 -
Ecotoxicology and Environmental Safety Dec 2020The widespread existence of microplastics in wastewater has caused great concern. As the exposure time of microplastics in the environment increases, the microplastic...
The widespread existence of microplastics in wastewater has caused great concern. As the exposure time of microplastics in the environment increases, the microplastic leaching solution (i.e.,chemical additives) may be released into the environment causing toxic effects. In this study, the effect of polystyrene (PS) microplastics on the anaerobic digestion system was investigated. The results showed that the exposure to 80 nm and 5 μm polystyrene microplastics with the concentrations of 0.2 g/L or lower did not significantly affect the cumulative methane production (P ≥ 0.05). On the other hand, 80 nm and 5 μm PS microplastic level of 0.25 g/L led to a decrease in methane production by 19.3% (P = 2 × 10) and 17.9% (P = 4 × 10), respectively. The 80 nm PS nanoplastics therefore had slightly higher inhibition capacity on methane production than 5 μm PS microplastics. The pH of all groups remained stable at 6.7-7.5. Volatile fatty acids (VFAs) concentration and ammonium-nitrogen concentration had no obvious relationship to PS micro and nanoplastics addition. Further investigation showed that PS micro and nanoplastics concentration of 0.25 g/L or higher could inhibit acidification and methanation stage of anaerobic digestion. However, the main negative influence of PS micro and nanoplastics on methane production was due to the severe inhibition on the methanization stage.
Topics: Anaerobiosis; Methane; Microplastics; Plastics; Polystyrenes; Waste Disposal, Fluid; Wastewater
PubMed: 32827962
DOI: 10.1016/j.ecoenv.2020.111095 -
Chemical Society Reviews Jan 2013The discovery of cisplatin's antitumor activity in 1969 prompted the search for novel metal-containing complexes as potential anticancer drugs. Among these novel... (Review)
Review
The discovery of cisplatin's antitumor activity in 1969 prompted the search for novel metal-containing complexes as potential anticancer drugs. Among these novel complexes, metal N-heterocyclic carbene (NHC) complexes have recently gained considerable attention because they perfectly fit prerequisites for efficient drug design and fast optimization. Moreover, most of them have shown higher cytotoxicity than cisplatin. This review describes the advances that have been achieved in using transition metal (Ag, Au, Pt, Pd, Cu, Ni, and Ru) complexes containing NHC ligands as antitumor agents. Their modes of action at the cellular lever are further discussed. All these initial achievements clearly demonstrate the great potential of metal-NHC complexes as antitumor agents.
Topics: Animals; Antineoplastic Agents; Coordination Complexes; Humans; Methane; Models, Molecular; Neoplasms; Transition Elements
PubMed: 23147001
DOI: 10.1039/c2cs35314h