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Sample records for hydrogen sulfide formation

  1. Hydrogen Sulfide Inhibits Amyloid Formation

    PubMed Central

    2015-01-01

    Amyloid fibrils are large aggregates of misfolded proteins, which are often associated with various neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and vascular dementia. The amount of hydrogen sulfide (H2S) is known to be significantly reduced in the brain tissue of people diagnosed with Alzheimer’s disease relative to that of healthy individuals. These findings prompted us to investigate the effects of H2S on the formation of amyloids in vitro using a model fibrillogenic protein hen egg white lysozyme (HEWL). HEWL forms typical β-sheet rich fibrils during the course of 70 min at low pH and high temperatures. The addition of H2S completely inhibits the formation of β-sheet and amyloid fibrils, as revealed by deep UV resonance Raman (DUVRR) spectroscopy and ThT fluorescence. Nonresonance Raman spectroscopy shows that disulfide bonds undergo significant rearrangements in the presence of H2S. Raman bands corresponding to disulfide (RSSR) vibrational modes in the 550–500 cm–1 spectral range decrease in intensity and are accompanied by the appearance of a new 490 cm–1 band assigned to the trisulfide group (RSSSR) based on the comparison with model compounds. The formation of RSSSR was proven further using a reaction with TCEP reduction agent and LC-MS analysis of the products. Intrinsic tryptophan fluorescence study shows a strong denaturation of HEWL containing trisulfide bonds. The presented evidence indicates that H2S causes the formation of trisulfide bridges, which destabilizes HEWL structure, preventing protein fibrillation. As a result, small spherical aggregates of unordered protein form, which exhibit no cytotoxicity by contrast with HEWL fibrils. PMID:25545790

  2. Hydrogen sulfide

    Integrated Risk Information System (IRIS)

    Hydrogen sulfide ; 7783 - 06 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  3. Hydrogen sulfide is a novel gasotransmitter with pivotal role in regulating lateral root formation in plants

    PubMed Central

    Li, Yan-Jun; Shi, Zhi-Qi; Gan, Li-Jun; Chen, Jian

    2014-01-01

    Hydrogen sulfide (H2S), the third gasotransmitter after nitric oxide (NO) and carbon monoxide (CO), is a critical neuromodulator in the pathogenesis of various diseases from neurodegenerative diseases to diabetes or heart failure. The crosstalk between NO and H2S has been well established in mammalian physiology. In planta, NO is demonstrated to regulate lateral root formation by acting downstream of auxin. The recent reports revealed that H2S is a novel inducer of lateral root (LR) formation by stimulating the expression of cell cycle regulatory genes (CCRGs), acting similarly with NO, CO, and IAA. Interestingly, during the initiation of lateral root primordia, IAA is a potent inducer of endogenous H2S and CO, which is produced by L-cysteine desulfhydrase (LCD) and heme oxygenase-1 (HO-1), respectively. The increasing evidences suggest that H2S-promoted LR growth is dependent on the endogenous production of CO. In addition, our results indicate that the H2S signaling in the regulation of LR formation can be associated to NO and Ca2+. In this addendum, we advanced a proposed schematic model for H2S-mediated signaling pathway of plant LR development. PMID:24832131

  4. Auxin-induced hydrogen sulfide generation is involved in lateral root formation in tomato.

    PubMed

    Fang, Tao; Cao, Zeyu; Li, Jiale; Shen, Wenbiao; Huang, Liqin

    2014-03-01

    Similar to auxin, hydrogen sulfide (H2S), mainly produced by l-cysteine desulfhydrase (DES; EC 4.4.1.1) in plants, could induce lateral root formation. The objective of this study was to test whether H2S is also involved in auxin-induced lateral root development in tomato (Solanum lycopersicum L.) seedlings. We observed that auxin depletion-induced down-regulation of transcripts of SlDES1, decreased DES activity and endogenous H2S contents, and the inhibition of lateral root formation were rescued by sodium hydrosulfide (NaHS, an H2S donor). However, No additive effects were observed when naphthalene acetic acid (NAA) was co-treated with NaHS (lower than 10 mM) in the induction of lateral root formation. Subsequent work revealed that a treatment with NAA or NaHS could simultaneously induce transcripts of SlDES1, DES activity and endogenous H2S contents, and thereafter the stimulation of lateral root formation. It was further confirmed that H2S or HS(-), not the other sulfur-containing components derived from NaHS, was attributed to the stimulative action. The inhibition of lateral root formation and decreased of H2S metabolism caused by an H2S scavenger hypotaurine (HT) were reversed by NaHS, but not NAA. Molecular evidence revealed that both NaHS- or NAA-induced modulation of some cell cycle regulatory genes, including the up-regulation of SlCDKA;1, SlCYCA2;1, together with simultaneous down-regulation of SlKRP2, were differentially reversed by HT pretreatment. To summarize, above results clearly suggested that H2S might, at least partially, act as a downstream component of auxin signaling to trigger lateral root formation.

  5. Geothermal hydrogen sulfide removal

    SciTech Connect

    Urban, P.

    1981-04-01

    UOP Sulfox technology successfully removed 500 ppM hydrogen sulfide from simulated mixed phase geothermal waters. The Sulfox process involves air oxidation of hydrogen sulfide using a fixed catalyst bed. The catalyst activity remained stable throughout the life of the program. The product stream composition was selected by controlling pH; low pH favored elemental sulfur, while high pH favored water soluble sulfate and thiosulfate. Operation with liquid water present assured full catalytic activity. Dissolved salts reduced catalyst activity somewhat. Application of Sulfox technology to geothermal waters resulted in a straightforward process. There were no requirements for auxiliary processes such as a chemical plant. Application of the process to various types of geothermal waters is discussed and plans for a field test pilot plant and a schedule for commercialization are outlined.

  6. Formation of Hydrogen Sulfide in Wine: Interactions between Copper and Sulfur Dioxide.

    PubMed

    Bekker, Marlize Z; Smith, Mark E; Smith, Paul A; Wilkes, Eric N

    2016-01-01

    The combined synergistic effects of copper (Cu(2+)) and sulfur dioxide (SO₂) on the formation of hydrogen sulfide (H₂S) in Verdelho and Shiraz wine samples post-bottling was studied over a 12-month period. The combined treatment of Cu(2+) and SO₂ significantly increased H₂S formation in Verdelho wines samples that were not previously treated with either Cu(2+) or SO₂. The formation of H₂S produced through Cu(2+) mediated reactions was likely either: (a) directly through the interaction of SO₂ with either Cu(2+) or H₂S; or (b) indirectly through the interaction of SO₂ with other wine matrix compounds. To gain better understanding of the mechanisms responsible for the significant increases in H₂S concentration in the Verdelho samples, the interaction between Cu(2+) and SO₂ was studied in a model wine matrix with and without the presence of a representative thiol quenching compound (4-methylbenzoquinone, 4MBQ). In these model studies, the importance of naturally occurring wine compounds and wine additives, such as quinones, SO₂, and metal ions, in modulating the formation of H₂S post-bottling was demonstrated. When present in equimolar concentrations a 1:1 ratio of H₂S- and SO₂-catechol adducts were produced. At wine relevant concentrations, however, only SO₂-adducts were produced, reinforcing that the competition reactions of sulfur nucleophiles, such as H₂S and SO₂, with wine matrix compounds play a critical role in modulating final H₂S concentrations in wines. PMID:27626394

  7. Homolytic cleavage of both heme-bound hydrogen peroxide and hydrogen sulfide leads to the formation of sulfheme

    DOE PAGES

    Arbelo-Lopez, Hector D.; Simakov, Nikolay A.; Smith, Jeremy C.; Lopez-Garriga, Juan; Wymore, Troy

    2016-06-29

    Many heme-containing proteins with a histidine in the distal E7 (HisE7) position can form sulfheme in the presence of hydrogen sulfide (H2S) and a reactive oxygen species such as hydrogen peroxide. For reasons unknown, sulfheme derivatives are formed specifically on solvent-excluded heme pyrrole B. Sulfhemes severely decrease the oxygen-binding affinity in hemoglobin (Hb) and myoglobin (Mb). Here, use of hybrid quantum mechanical/molecular mechanical methods has permitted characterization of the entire process of sulfheme formation in the HisE7 mutant of hemoglobin I (HbI) from Lucina pectinata. This process includes a mechanism for H2S to enter the solvent-excluded active site through amore » hydrophobic channel to ultimately form a hydrogen bond with H2O2 bound to Fe(III). Proton transfer from H2O2 to His64 to form compound (Cpd) 0, followed by hydrogen transfer from H2S to the Fe(III) H2O2 complex, results in homolytic cleavage of the O–O and S–H bonds to form a reactive thiyl radical (HS*), ferryl heme Cpd II, and a water molecule. Subsequently, the addition of HS to Cpd II, followed by three proton transfer reactions, results in the formation of a three-membered ring ferric sulfheme that avoids migration of the radical to the protein matrix, in contrast to that in other peroxidative reactions. The transformation of this three-membered episulfide ring structure to the five-membered thiochlorin ring structure occurs through a significant potential energy barrier, although both structures are nearly isoenergetic. Both three- and five-membered ring structures reveal longer NB–Fe(III) bonds compared with other pyrrole nitrogen–Fe(III) bonds, which would lead to decreased oxygen binding. Altogether, these results are in agreement with a wide range of experimental data and provide fertile ground for further investigations of sulfheme formation in other heme proteins and additional effects of H2S on cell signaling and reactivity.« less

  8. Homolytic Cleavage of Both Heme-Bound Hydrogen Peroxide and Hydrogen Sulfide Leads to the Formation of Sulfheme.

    PubMed

    Arbelo-Lopez, Hector D; Simakov, Nikolay A; Smith, Jeremy C; Lopez-Garriga, Juan; Wymore, Troy

    2016-08-01

    Many heme-containing proteins with a histidine in the distal E7 (HisE7) position can form sulfheme in the presence of hydrogen sulfide (H2S) and a reactive oxygen species such as hydrogen peroxide. For reasons unknown, sulfheme derivatives are formed specifically on solvent-excluded heme pyrrole B. Sulfhemes severely decrease the oxygen-binding affinity in hemoglobin (Hb) and myoglobin (Mb). Here, use of hybrid quantum mechanical/molecular mechanical methods has permitted characterization of the entire process of sulfheme formation in the HisE7 mutant of hemoglobin I (HbI) from Lucina pectinata. This process includes a mechanism for H2S to enter the solvent-excluded active site through a hydrophobic channel to ultimately form a hydrogen bond with H2O2 bound to Fe(III). Proton transfer from H2O2 to His64 to form compound (Cpd) 0, followed by hydrogen transfer from H2S to the Fe(III)-H2O2 complex, results in homolytic cleavage of the O-O and S-H bonds to form a reactive thiyl radical (HS(•)), ferryl heme Cpd II, and a water molecule. Subsequently, the addition of HS(•) to Cpd II, followed by three proton transfer reactions, results in the formation of a three-membered ring ferric sulfheme that avoids migration of the radical to the protein matrix, in contrast to that in other peroxidative reactions. The transformation of this three-membered episulfide ring structure to the five-membered thiochlorin ring structure occurs through a significant potential energy barrier, although both structures are nearly isoenergetic. Both three- and five-membered ring structures reveal longer NB-Fe(III) bonds compared with other pyrrole nitrogen-Fe(III) bonds, which would lead to decreased oxygen binding. Overall, these results are in agreement with a wide range of experimental data and provide fertile ground for further investigations of sulfheme formation in other heme proteins and additional effects of H2S on cell signaling and reactivity.

  9. Homolytic Cleavage of Both Heme-Bound Hydrogen Peroxide and Hydrogen Sulfide Leads to the Formation of Sulfheme.

    PubMed

    Arbelo-Lopez, Hector D; Simakov, Nikolay A; Smith, Jeremy C; Lopez-Garriga, Juan; Wymore, Troy

    2016-08-01

    Many heme-containing proteins with a histidine in the distal E7 (HisE7) position can form sulfheme in the presence of hydrogen sulfide (H2S) and a reactive oxygen species such as hydrogen peroxide. For reasons unknown, sulfheme derivatives are formed specifically on solvent-excluded heme pyrrole B. Sulfhemes severely decrease the oxygen-binding affinity in hemoglobin (Hb) and myoglobin (Mb). Here, use of hybrid quantum mechanical/molecular mechanical methods has permitted characterization of the entire process of sulfheme formation in the HisE7 mutant of hemoglobin I (HbI) from Lucina pectinata. This process includes a mechanism for H2S to enter the solvent-excluded active site through a hydrophobic channel to ultimately form a hydrogen bond with H2O2 bound to Fe(III). Proton transfer from H2O2 to His64 to form compound (Cpd) 0, followed by hydrogen transfer from H2S to the Fe(III)-H2O2 complex, results in homolytic cleavage of the O-O and S-H bonds to form a reactive thiyl radical (HS(•)), ferryl heme Cpd II, and a water molecule. Subsequently, the addition of HS(•) to Cpd II, followed by three proton transfer reactions, results in the formation of a three-membered ring ferric sulfheme that avoids migration of the radical to the protein matrix, in contrast to that in other peroxidative reactions. The transformation of this three-membered episulfide ring structure to the five-membered thiochlorin ring structure occurs through a significant potential energy barrier, although both structures are nearly isoenergetic. Both three- and five-membered ring structures reveal longer NB-Fe(III) bonds compared with other pyrrole nitrogen-Fe(III) bonds, which would lead to decreased oxygen binding. Overall, these results are in agreement with a wide range of experimental data and provide fertile ground for further investigations of sulfheme formation in other heme proteins and additional effects of H2S on cell signaling and reactivity. PMID:27357070

  10. Hydrogen sulfide intoxication.

    PubMed

    Guidotti, Tee L

    2015-01-01

    Hydrogen sulfide (H2S) is a hazard primarily in the oil and gas industry, agriculture, sewage and animal waste handling, construction (asphalt operations and disturbing marshy terrain), and other settings where organic material decomposes under reducing conditions, and in geothermal operations. It is an insoluble gas, heavier than air, with a very low odor threshold and high toxicity, driven by concentration more than duration of exposure. Toxicity presents in a unique, reliable, and characteristic toxidrome consisting, in ascending order of exposure, of mucosal irritation, especially of the eye ("gas eye"), olfactory paralysis (not to be confused with olfactory fatigue), sudden but reversible loss of consciousness ("knockdown"), pulmonary edema (with an unusually favorable prognosis), and death (probably with apnea contributing). The risk of chronic neurcognitive changes is controversial, with the best evidence at high exposure levels and after knockdowns, which are frequently accompanied by head injury or oxygen deprivation. Treatment cannot be initiated promptly in the prehospital phase, and currently rests primarily on supportive care, hyperbaric oxygen, and nitrite administration. The mechanism of action for sublethal neurotoxicity and knockdown is clearly not inhibition of cytochrome oxidase c, as generally assumed, although this may play a role in overwhelming exposures. High levels of endogenous sulfide are found in the brain, presumably relating to the function of hydrogen sulfide as a gaseous neurotransmitter and immunomodulator. Prevention requires control of exposure and rigorous training to stop doomed rescue attempts attempted without self-contained breathing apparatus, especially in confined spaces, and in sudden release in the oil and gas sector, which result in multiple avoidable deaths. PMID:26563786

  11. Studying inhibition of calcium oxalate stone formation: an in vitro approach for screening hydrogen sulfide and its metabolites

    PubMed Central

    Vaitheeswari, S.; Sriram, R.; Brindha, P.; Kurian, Gino A.

    2015-01-01

    ABSTRACT Purpose: Calcium oxalate urolithiasis is one of the most common urinary tract diseases and is of high prevalence. The present study proposes to evaluate the antilithiatic property of hydrogen sulfide and its metabolites like thiosulfate & sulfate in an in vitro model. Materials and Methods: The antilithiatic activity of sodium hydrogen sulfide (NaSH), sodium thiosulfate (Na2S2O3) and sodium sulfate (Na2SO4) on the kinetics of calcium oxalate crystal formation was investigated both in physiological buffer and in urine from normal and recurrent stone forming volunteers. The stones were characterized by optical and spectroscopic techniques. Results: The stones were characterized to be monoclinic, prismatic and bipyramidal habit which is of calcium monohydrate and dihydrate nature. The FTIR displayed fingerprint corresponding to calcium oxalate in the control while in NaSH treated, S=O vibrations were visible in the spectrum. The order of percentage inhibition was NaSH>Na2S2O3>Na2SO4. Conclusion: Our study indicates that sodium hydrogen sulfide and its metabolite thiosulfate are inhibitors of calcium oxalate stone agglomeration which makes them unstable both in physiological buffer and in urine. This effect is attributed to pH changes and complexing of calcium by S2O3 2-and SO4 2- moiety produced by the test compounds. PMID:26200543

  12. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... black lettering as follows: Letter height Wording 12 inches Danger. Poisonous Gas. Hydrogen Sulfide. 7... well-control techniques to prevent formation fracturing in an open hole within the pressure limits of... designed consistent with the anticipated depth, conditions of the hole, and reservoir environment to...

  13. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... black lettering as follows: Letter height Wording 12 inches Danger. Poisonous Gas. Hydrogen Sulfide. 7... well-control techniques to prevent formation fracturing in an open hole within the pressure limits of... designed consistent with the anticipated depth, conditions of the hole, and reservoir environment to...

  14. Nitric oxide-releasing flurbiprofen reduces formation of proinflammatory hydrogen sulfide in lipopolysaccharide-treated rat

    PubMed Central

    Anuar, Farhana; Whiteman, Matthew; Siau, Jia Ling; Kwong, Shing Erl; Bhatia, Madhav; Moore, Philip K

    2006-01-01

    The biosynthesis of both nitric oxide (NO) and hydrogen sulfide (H2S) is increased in lipopolysaccharide (LPS)-injected mice and rats but their interaction in these models is not known. In this study we examined the effect of the NO donor, nitroflurbiprofen (and the parent molecule flurbiprofen) on NO and H2S metabolism in tissues from LPS-pretreated rats. Administration of LPS (10 mg kg−1, i.p.; 6 h) resulted in an increase (P<0.05) in plasma TNF-α, IL-1β and nitrate/nitrite (NOx) concentrations, liver H2S synthesis (from added cysteine), CSE mRNA, inducible nitric oxide synthase (iNOS), myeloperoxidase (MPO) activity (marker for neutrophil infiltration) and nuclear factor-kappa B (NF-κB) activation. Nitroflurbiprofen (3–30 mg kg−1, i.p.) administration resulted in a dose-dependent inhibition of the LPS-mediated increase in plasma TNF-α, IL-1β and NOx concentration, liver H2S synthesis (55.00±0.95 nmole mg protein−1, c.f. 62.38±0.47 nmole mg protein−1, n=5, P<0.05), CSE mRNA, iNOS, MPO activity and NF-κB activation. Flurbiprofen (21 mg kg−1, i.p.) was without effect. These results show for the first time that nitroflurbiprofen downregulates the biosynthesis of proinflammatory H2S and suggest that such an effect may contribute to the augmented anti-inflammatory activity of this compound. These data also highlight the existence of ‘crosstalk' between NO and H2S in this model of endotoxic shock. PMID:16491094

  15. Thermochemical hydrogen production via a cycle using barium and sulfur - Reaction between barium sulfide and water

    NASA Technical Reports Server (NTRS)

    Ota, K.; Conger, W. L.

    1977-01-01

    The reaction between barium sulfide and water, a reaction found in several sulfur based thermochemical cycles, was investigated kinetically at 653-866 C. Gaseous products were hydrogen and hydrogen sulfide. The rate determining step for hydrogen formation was a surface reaction between barium sulfide and water. An expression was derived for the rate of hydrogen formation.

  16. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    DOEpatents

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  17. In Site Bioimaging of Hydrogen Sulfide Uncovers Its Pivotal Role in Regulating Nitric Oxide-Induced Lateral Root Formation

    PubMed Central

    Xian, Ming; Zhou, Li-Gang; Han, Fengxiang X.; Gan, Li-Jun; Shi, Zhi-Qi

    2014-01-01

    Hydrogen sulfide (H2S) is an important gasotransmitter in mammals. Despite physiological changes induced by exogenous H2S donor NaHS to plants, whether and how H2S works as a true cellular signal in plants need to be examined. A self-developed specific fluorescent probe (WSP-1) was applied to track endogenous H2S in tomato (Solanum lycopersicum) roots in site. Bioimaging combined with pharmacological and biochemical approaches were used to investigate the cross-talk among H2S, nitric oxide (NO), and Ca2+ in regulating lateral root formation. Endogenous H2S accumulation was clearly associated with primordium initiation and lateral root emergence. NO donor SNP stimulated the generation of endogenous H2S and the expression of the gene coding for the enzyme responsible for endogenous H2S synthesis. Scavenging H2S or inhibiting H2S synthesis partially blocked SNP-induced lateral root formation and the expression of lateral root-related genes. The stimulatory effect of SNP on Ca2+ accumulation and CaM1 (calmodulin 1) expression could be abolished by inhibiting H2S synthesis. Ca2+ chelator or Ca2+ channel blocker attenuated NaHS-induced lateral root formation. Our study confirmed the role of H2S as a cellular signal in plants being a mediator between NO and Ca2+ in regulating lateral root formation. PMID:24587333

  18. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250.604... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  19. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250.504... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  20. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250.808... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of...

  1. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  2. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.604 Section 250.604...-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined...

  3. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.504 Section 250.504...-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined...

  4. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  5. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  6. Hydrogen Sulfide as a Gasotransmitter

    PubMed Central

    Gadalla, Moataz M.; Snyder, Solomon H.

    2010-01-01

    Nitric oxide (NO) and carbon monoxide (CO) are well established as messenger molecules throughout the body, gasotransmitters, based on striking alterations in mice lacking the appropriate biosynthetic enzymes. Hydrogen sulfide (H2S) is even more chemically reactive, but till recently there was little definitive evidence for its physiologic formation. Cystathionine β-synthase (CBS, EC 4.2.1.22), and Cystathionine γ-lyase (CSE; EC 4.4.1.1), also known as cytathionase, can generate H2S from cyst(e)ine. Very recent studies with mice lacking these enzymes have established that CSE is responsible for H2S formation in the periphery, while in the brain CBS is the biosynthetic enzyme. Endothelial-derived relaxing factor (EDRF) activity is reduced 80% in the mesenteric artery of mice with deletion of CSE, establishing H2S as a major physiologic EDRF. H2S appears to signal predominantly by S-sulfhydrating cysteines in its target proteins, analogous to S-nitrosylation by NO. Whereas S-nitrosylation typically inhibits enzymes, S-sulfhydration activates them. S-nitrosylation basally affects 1–2% of its target proteins, while 10–25% of H2S target proteins are S-sulfhydrated. In summary, H2S appears to be a physiologic gasotransmitter of comparable importance to NO and CO. PMID:20067586

  7. Hydrogen attack - Influence of hydrogen sulfide. [on carbon steel

    NASA Technical Reports Server (NTRS)

    Eliezer, D.; Nelson, H. G.

    1978-01-01

    An experimental study is conducted on 12.5-mm-thick SAE 1020 steel (plain carbon steel) plate to assess hydrogen attack at room temperature after specimen exposure at 525 C to hydrogen and a blend of hydrogen sulfide and hydrogen at a pressure of 3.5 MN/sq m for exposure times up to 240 hr. The results are discussed in terms of tensile properties, fissure formation, and surface scales. It is shown that hydrogen attack from a high-purity hydrogen environment is severe, with the formation of numerous methane fissures and bubbles along with a significant reduction in the room-temperature tensile yield and ultimate strengths. However, no hydrogen attack is observed in the hydrogen/hydrogen sulfide blend environment, i.e. no fissure or bubble formation occurred and the room-temperature tensile properties remained unchanged. It is suggested that the observed porous discontinuous scale of FeS acts as a barrier to hydrogen entry, thus reducing its effective equilibrium solubility in the iron lattice. Therefore, hydrogen attack should not occur in pressure-vessel steels used in many coal gasification processes.

  8. Hydrogen Sulfide Oxidation by Myoglobin.

    PubMed

    Bostelaar, Trever; Vitvitsky, Victor; Kumutima, Jacques; Lewis, Brianne E; Yadav, Pramod K; Brunold, Thomas C; Filipovic, Milos; Lehnert, Nicolai; Stemmler, Timothy L; Banerjee, Ruma

    2016-07-13

    Enzymes in the sulfur network generate the signaling molecule, hydrogen sulfide (H2S), from the amino acids cysteine and homocysteine. Since it is toxic at elevated concentrations, cells are equipped to clear H2S. A canonical sulfide oxidation pathway operates in mitochondria, converting H2S to thiosulfate and sulfate. We have recently discovered the ability of ferric hemoglobin to oxidize sulfide to thiosulfate and iron-bound hydropolysulfides. In this study, we report that myoglobin exhibits a similar capacity for sulfide oxidation. We have trapped and characterized iron-bound sulfur intermediates using cryo-mass spectrometry and X-ray absorption spectroscopy. Further support for the postulated intermediates in the chemically challenging conversion of H2S to thiosulfate and iron-bound catenated sulfur products is provided by EPR and resonance Raman spectroscopy in addition to density functional theory computational results. We speculate that the unusual sensitivity of skeletal muscle cytochrome c oxidase to sulfide poisoning in ethylmalonic encephalopathy, resulting from the deficiency in a mitochondrial sulfide oxidation enzyme, might be due to the concentration of H2S by myoglobin in this tissue. PMID:27310035

  9. Redetermination of piperidinium hydrogen sulfide structure

    NASA Technical Reports Server (NTRS)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    The presence of adventitious water in a reaction between dicyclopentamethylene thiuram-disulfide (C5H10NCS2)(sub 2) and a picoline solution of tricyclopentadienyl indium(III) (C5H5)(sub 3). It resulted in the formation of piperidinium hydrogen sulfide (C5H13NS). The piperidinium hydrogen sulfide produced in this way was unambiguously characterized by X-ray crystallography. The structure determination showed that the piperidinium hydrogen sulfide crystal (MW = 119.23 g/mol) has an orthorhombic (Pbcm) unit cell whose parameters are: a = 9.818(2), b = 7.3720(1), c = 9.754(1) A, V = 706.0(3) A(exp 3), Z=4. D(sub chi) = 1.122 g cm(exp -3), Mo K(alpha) (lamda = 0.71073), mu= 3.36 cm(exp -1), F(000) = 264.0, T =293 K, R = 0.036 for 343 reflections with F(sub O)(sup 2) greater than 3 sigma (F(sub O)(sup 2)) and 65 variables. The compound consists of (C5H10NH2)(+) cations and (SH)(-) anions with both species residing on crystallographic mirror planes. N-H -- S hydrogen bonding contributes to the interconnection of neighboring piperidinium components of the compound.

  10. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  11. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.504 Section 250.504... § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  12. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  13. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.504 Section 250.504... § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  14. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  15. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.504 Section 250.504... § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  16. Pediatric Cystic Fibrosis Sputum Can Be Chemically Dynamic, Anoxic, and Extremely Reduced Due to Hydrogen Sulfide Formation

    PubMed Central

    Cowley, Elise S.; Kopf, Sebastian H.; LaRiviere, Alejandro

    2015-01-01

    ABSTRACT Severe and persistent bacterial lung infections characterize cystic fibrosis (CF). While several studies have documented the microbial diversity within CF lung mucus, we know much less about the inorganic chemistry that constrains microbial metabolic processes and their distribution. We hypothesized that sputum is chemically heterogeneous both within and between patients. To test this, we measured microprofiles of oxygen and sulfide concentrations as well as pH and oxidation-reduction potentials in 48 sputum samples from 22 pediatric patients with CF. Inorganic ions were measured in 20 samples from 12 patients. In all cases, oxygen was depleted within the first few millimeters below the sputum-air interface. Apart from this steep oxycline, anoxia dominated the sputum environment. Different sputum samples exhibited a broad range of redox conditions, with either oxidizing (16 mV to 355 mV) or reducing (−300 to −107 mV) potentials. The majority of reduced samples contained hydrogen sulfide and had a low pH (2.9 to 6.5). Sulfide concentrations increased at a rate of 0.30 µM H2S/min. Nitrous oxide was detected in only one sample that also contained sulfide. Microenvironmental variability was observed both within a single patient over time and between patients. Modeling oxygen dynamics within CF mucus plugs indicates that anoxic zones vary as a function of bacterial load and mucus thickness and can occupy a significant portion of the mucus volume. Thus, aerobic respiration accounts only partially for pathogen survival in CF sputum, motivating research to identify mechanisms of survival under conditions that span fluctuating redox states, including sulfidic environments. PMID:26220964

  17. [Activity of hydrogen sulfide production enzymes in kidneys of rats].

    PubMed

    Mel'nyk, A V; Pentiuk, O O

    2009-01-01

    An experimental research of activity and kinetic descriptions of enzymes participating in formation of hydrogen sulfide in the kidney of rats has been carried out. It was established that cystein, homocystein and thiosulphate are the basic substrates for hydrogen sulfide synthesis. The higest activity for hydrogen sulfide production belongs to thiosulfate-dithiolsulfurtransferase and cysteine aminotransferase, less activity is characteristic of cystathionine beta-synthase and cystathio-nine gamma-lyase. The highest affinity to substrate is registered for thiosulfate-dithiolsulfurtransferase and cystathionine gamma-lyase. It is discovered that the substrate inhibition is typical of all hydrogen sulfide formation enzymes, although this characteristic is the most expressed thiosulfat-dithiolsulfurtransferase. PMID:20387629

  18. Ammonia and hydrogen sulfide removal using biochar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  19. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE... Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain...

  20. Hydrogen sulfide pollution in wastewater treatment facilities

    SciTech Connect

    AlDhowalia, K.H. )

    1987-01-01

    The hydrogen sulfide (H{sub 2}S) found in wastewater collection systems and wastewater treatment facilities results from the bacterial reduction of the sulfate ion (SO{sub 4}). Hydrogen sulfide is a gas that occurs both in the sewer atmosphere and as a dissolved gas in the wastewater. When raw wastewater first enters the wastewater treatment facility by gravity most of the hydrogen sulfide is in the gaseous phase and will escape into the atmosphere at the inlet structures. Also some of the dissolved hydrogen sulfide will be released at points of turbulance such as at drops in flow, flumes, or aeration chambers. Several factors can cause excessive hydrogen sulfide concentrations in a sewerage system. These include septic sewage, long flow times in the sewerage system, high temperatures, flat sewer grades, and poor ventilation. These factors are discussed in this paper.

  1. [Hydrogen sulfide and penile erection].

    PubMed

    Huang, Yi-Ming; Cheng, Yong; Jiang, Rui

    2012-09-01

    Hydrogen sulfide (H2S) is the third type of active endogenous gaseous signal molecule following nitric oxide (NO) and carbon monoxide (CO). In mammalians, H2S is mainly synthesized by two proteases, cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CSE). H2S plays an essential function of physiological regulation in vivo, and promotes penile erection by acting on the ATP-sensitive potassium channels to relax the vascular smooth muscle as well as by the synergistic effect with testosterone and NO to relax the corpus cavernosum smooth muscle (CCSM). At present, the selective phosphodiesterase type 5 (PDE5) inhibitor is mainly used for the treatment of erectile dysfunction (ED), but some ED patients fail to respond. Therefore, further studies on the mechanism of H2S regulating penile erection may provide a new way for the management of erectile dysfunction.

  2. The Role of Amines, Hydrogen Sulfide and Carbon Dioxide in the Formation of Prebiotic Macromolecules Surrounded by Membranes

    NASA Astrophysics Data System (ADS)

    Rajen, Gaurav

    2016-04-01

    Amphiphilic compounds are known to self-assemble into membranous structures when exposed to alternate dry and wet conditions. This paper presents a model of how such structures could form near hydrothermal vents while containing macromolecules such as amino acids. The formation of amino acids near deep ocean hydrothermal vents as precursors for the origins of life is problematic as amino acids degrade from thermal energy. In the model proposed here, amino acids would degrade into amines (near hydrothermal vents). Amines have an affinity to interact with carbon dioxide (CO2) and hydrogen sulfide (H2S), form weak heat-unstable salts, and then through exposure to thermal energy release the acid gases and regenerate back to amines. Amines carrying and releasing H2S and CO2 would help other macromolecules form along with amino acids within protected cell-like structures; the cyclical release and recapture of acid gases would subsequently help the amino acids form bonds; further thermal action would degrade some of the amines into polymers that provide more strength and rigidity to the membrane walls; and also enable escaping gases to form tubes within the surrounding membranes for inlet and outlet of chemicals. Consider that liquids and gases are undergoing thermal convection inside a porous medium, and the convecting liquids contain some amines. Consider now that an amine weak salt carrying H2S and another carrying CO2 is inside a vesicle that formed through self-assembly. As this vesicle moves around in the thermal convection cell it will come close to the heat source and release the H2S and CO2 inside the vesicle. As the vesicle moves away from the heat source, the gases would be reabsorbed into the amines. This process would create stability and a repeating set of reactions, reactants, and products forming and reforming - cyclical stability is a key criterion for more complex reactions to occur. Some of the amines present would reform into an amino acid (as occurs

  3. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, John B. L.; Gorski, Anthony J.; Daniels, Edward J.

    1993-01-01

    A process for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  4. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, J.B.L.; Gorski, A.J.; Daniels, E.J.

    1993-05-18

    A process is described for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is [dis]associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  5. Ridding Groundwater of Hydrogen Sulfide. Part 1.

    ERIC Educational Resources Information Center

    Lochrane, Thomas G.

    1979-01-01

    This article is the first in a series reviewing the problems associated with hydrogen sulfide in drinking water sources. Discussion centers on identification of a cost-effective balance between aeration and chlorination treatment operations. (AS)

  6. Determination of Hydrogen Sulfide in Fermentation Broths Containing SO21

    PubMed Central

    Acree, T. E.; Sonoff, Elisabeth P.; Splittstoesser, D. F.

    1971-01-01

    A procedure for the determination of hydrogen sulfide in fermentation broths containing up to 100 μg of SO2 per ml is described. The method involves the sparging of H2S from the broth into a cadmium hydroxide absorption solution, the formation of methylene blue from the absorbed sulfide, and the measuring of this color spectrophotometrically. The use of cadmium hydroxide instead of zinc acetate, the common absorbent, substantially reduced the interference of SO2 with the analysis. PMID:5111300

  7. Hydrogen sulfide and translational medicine

    PubMed Central

    Guo, Wei; Cheng, Ze-yu; Zhu, Yi-zhun

    2013-01-01

    Hydrogen sulfide (H2S) along with carbon monoxide and nitric oxide is an important signaling molecule that has undergone large numbers of fundamental investigations. H2S is involved in various physiological activities associated with the regulation of homeostasis, vascular contractility, pro- and anti-inflammatory activities, as well as pro- and anti-apoptotic activities etc. However, the actions of H2S are influenced by its concentration, reaction time, and cell/disease types. Therefore, H2S is a signaling molecule without definite effect. The use of existing H2S donors is limited because of the instant release and short lifetime of H2S. Thus, translational medicine involving the sustained and controlled release of H2S is of great value for both scientific and clinical uses. H2S donation can be manipulated by different ways, including where H2S is given, how H2S is donated, or the specific structures of H2S-releasing drugs and H2S donor molecules. This review briefly summarizes recent progress in research on the physiological and pathological functions of H2S and H2S-releasing drugs, and suggests hope for future investigations. PMID:24096643

  8. Hydrogen Sulfide and Urogenital Tract.

    PubMed

    di Villa Bianca, Roberta d'Emmanuele; Cirino, Giuseppe; Sorrentino, Raffaella

    2015-01-01

    In this chapter the role played by H2S in the physiopathology of urogenital tract revising animal and human data available in the current relevant literature is discussed. H2S pathway has been demonstrated to be involved in the mechanism underlying penile erection in human and experimental animal. Both cystathionine-β synthase (CBS) and cystathionine-γ lyase (CSE) are expressed in the human corpus cavernosum and exogenous H2S relaxes isolated human corpus cavernosum strips in an endothelium-independent manner. Hydrogen sulfide pathway also accounts for the direct vasodilatory effect operated by testosterone on isolated vessels. Convincing evidence suggests that H2S can influence the cGMP pathway by inhibiting the phosphodiesterase 5 (PDE-5) activity. All these findings taken together suggest an important role for the H2S pathway in human corpus cavernosum homeostasis. However, H2S effect is not confined to human corpus cavernosum but also plays an important role in human bladder. Human bladder expresses mainly CBS and generates in vitro detectable amount of H2S. In addition the bladder relaxant effect of the PDE-5 inhibitor sildenafil involves H2S as mediator. In conclusion the H2S pathway is not only involved in penile erection but also plays a role in bladder homeostasis. In addition the finding that it involved in the mechanism of action of PDE-5 inhibitors strongly suggests that modulation of this pathway can represent a therapeutic target for the treatment of erectile dysfunction and bladder diseases. PMID:26162831

  9. Estimation of bacterial hydrogen sulfide production in vitro.

    PubMed

    Basic, Amina; Blomqvist, Susanne; Carlén, Anette; Dahlén, Gunnar

    2015-01-01

    Oral bacterial hydrogen sulfide (H2S) production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways. PMID:26130377

  10. Estimation of bacterial hydrogen sulfide production in vitro

    PubMed Central

    Basic, Amina; Blomqvist, Susanne; Carlén, Anette; Dahlén, Gunnar

    2015-01-01

    Oral bacterial hydrogen sulfide (H2S) production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways. PMID:26130377

  11. Hydrogen and sulfur production from hydrogen sulfide wastes

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.

    1993-03-01

    A new hydrogen sulfide waste-treatment process that uses microwave plasma-chemical technology is currently under development in the Soviet Union and in the United States. Whereas the present waste treatment process only recovers sulfur at best, this novel process recovers both hydrogen and sulfur. The plasma process involves dissociating hydrogen sulfide in a ``nonequilibrium`` plasma in a microwave or radio-frequency reactor. After the dissociation process, sulfur is condensed and sold just as is currently done. The remaining gases are purified and separated into streams containing the product hydrogen, the hydrogen sulfide to be recycled to the plasma reactor, and the process purge containing carbon dioxide and water. This process has particular implications for the petroleum refining industry, in which hydrogen is a widely used reagent and must be produced from increasingly scarce hydrocarbon resources. The modular nature of the new process may also offer economic advantages over small-scale waste treatment technologies widely used in the natural-gas industry. Laboratory-scale experiments with pure hydrogen sulfide indicate that conversions exceeding 90% are possible with appropriate reactor design and that the energy required to dissociate hydrogen sulfide is low enough for the plasma process to be economically competitive. In addition, the experiments show that typical refinery acid-gas streams are compatible with the plasma process and that all by-products can be treated with existing technology.

  12. Hydrogen and sulfur production from hydrogen sulfide wastes

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.

    1993-01-01

    A new hydrogen sulfide waste-treatment process that uses microwave plasma-chemical technology is currently under development in the Soviet Union and in the United States. Whereas the present waste treatment process only recovers sulfur at best, this novel process recovers both hydrogen and sulfur. The plasma process involves dissociating hydrogen sulfide in a nonequilibrium'' plasma in a microwave or radio-frequency reactor. After the dissociation process, sulfur is condensed and sold just as is currently done. The remaining gases are purified and separated into streams containing the product hydrogen, the hydrogen sulfide to be recycled to the plasma reactor, and the process purge containing carbon dioxide and water. This process has particular implications for the petroleum refining industry, in which hydrogen is a widely used reagent and must be produced from increasingly scarce hydrocarbon resources. The modular nature of the new process may also offer economic advantages over small-scale waste treatment technologies widely used in the natural-gas industry. Laboratory-scale experiments with pure hydrogen sulfide indicate that conversions exceeding 90% are possible with appropriate reactor design and that the energy required to dissociate hydrogen sulfide is low enough for the plasma process to be economically competitive. In addition, the experiments show that typical refinery acid-gas streams are compatible with the plasma process and that all by-products can be treated with existing technology.

  13. Formation of Dimethyl Sulfide and Methanethiol in Anoxic Freshwater Sediments

    PubMed Central

    Lomans, B. P.; Smolders, A.; Intven, L. M.; Pol, A.; Op, De; Van Der Drift, C.

    1997-01-01

    Concentrations of volatile organic sulfur compounds (VOSC) were measured in water and sediment columns of ditches in a minerotrophic peatland in The Netherlands. VOSC, with methanethiol (4 to 40 nM) as the major compound, appeared to be mainly of sediment origin. Both VOSC and hydrogen sulfide concentrations decreased dramatically towards the water surface. High methanethiol and high dimethyl sulfide concentrations in the sediment and just above the sediment surface coincided with high concentrations of hydrogen sulfide (correlation factors, r = 0.91 and r = 0.81, respectively). Production and degradation of VOSC were studied in 32 sediment slurries collected from various freshwater systems in The Netherlands. Maximal endogenous methanethiol production rates of the sediments tested (up to 1.44 (mu)mol per liter of sediment slurry (middot) day(sup-1)) were determined after inhibition of methanogenic and sulfate-reducing populations in order to stop VOSC degradation. These experiments showed that the production and degradation of VOSC in sediments are well balanced. Statistical analysis revealed multiple relationships of methanethiol production rates with the combination of methane production rates (indicative of total anaerobic mineralization) and hydrogen sulfide concentrations (r = 0.90) or with the combination of methane production rates and the sulfate/iron ratios in the sediment (r = 0.82). These findings and the observed stimulation of methanethiol formation in sediment slurry incubations in which the hydrogen sulfide concentrations were artificially increased provided strong evidence that the anaerobic methylation of hydrogen sulfide is the main mechanism for VOSC formation in most freshwater systems. Methoxylated aromatic compounds are likely a major source of methyl groups for this methylation of hydrogen sulfide, since they are important degradation products of the abundant biopolymer lignin. Increased sulfate concentrations in several freshwater

  14. Microbial control of hydrogen sulfide production

    SciTech Connect

    Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J.

    1995-12-31

    A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

  15. Comparison of Hydrogen Sulfide Analysis Techniques

    ERIC Educational Resources Information Center

    Bethea, Robert M.

    1973-01-01

    A summary and critique of common methods of hydrogen sulfide analysis is presented. Procedures described are: reflectance from silver plates and lead acetate-coated tiles, lead acetate and mercuric chloride paper tapes, sodium nitroprusside and methylene blue wet chemical methods, infrared spectrophotometry, and gas chromatography. (BL)

  16. Mechanisms of hydrogen sulfide removal with steel making slag.

    PubMed

    Kim, Kyunghoi; Asaoka, Satoshi; Yamamoto, Tamiji; Hayakawa, Shinjiro; Takeda, Kazuhiko; Katayama, Misaki; Onoue, Takasumi

    2012-09-18

    In the present study, we experimentally investigated the removal of hydrogen sulfide using steel-making slag (SMS) and clarified the mechanism of hydrogen sulfide removal with the SMS. The results proved that SMS is able to remove hydrogen sulfide dissolved in water, and the maximum removal amount of hydrogen sulfide per unit weight of the SMS for 8 days was estimated to be 37.5 mg S/g. The removal processes of hydrogen sulfide were not only adsorption onto the SMS, but oxidation and precipitation as sulfur. The chemical forms of sulfide adsorbed onto the SMS were estimated to be sulfur and manganese sulfide in the ratio of 81% and 19%, respectively. It is demonstrated here that the SMS is a promising material to remediate organically enriched coastal sediments in terms of removal of hydrogen sulfide. Furthermore, using SMS is expected to contribute to development of a recycling-oriented society.

  17. Utilization of hydrogen sulfide from acidic gases produced in treatment with amines

    SciTech Connect

    Lunin, A.F.; Hussein, A.H.; Burdeinaya, T.N.

    1994-07-01

    Treatment with amines is the basic method for removing hydrogen sulfide from gases. When such treatment is used, there is a problem in utilizing the acidic regeneration gases, which consist of carbon dioxide, hydrogen sulfide, and C{sub 1}-C{sub 4} hydrocarbons. If the concentration of hydrogen sulfide in these gases is below 20%, it is best removed by direct oxidation by oxygen to form sulfur or sulfur dioxide, over solid or liquid catalysts. Here we are reporting on an investigation of the activity and selectivity of commercial oxide catalysts in this reaction. Commercial catalysts were used in the direct oxidation of gas containing hydrogen sulfide (2-4% hydrogen sulfide, 1-4% C{sub 1}-C{sub 4} hydrocarbons, remainder carbon dioxide) in a laboratory flow unit with a fixed bed of catalyst. The compositions of the feed and the reaction products were determined by gas-liquid chromatography. The oxidation of hydrogen sulfide may proceed with the formation of either sulfur dioxide or sulfur. Catalyst activity was rated on the basis of the total conversion of hydrogen sulfide, the percentage conversions to elemental sulfur and sulfur dioxide, and the selectivity for the formation of elemental sulfur. The catalyst activities were investigated at temperatures of 170-270{degrees}C, space velocity of feed 300 h{sup -1}, hydrogen sulfide concentration 2-4%, and O{sub 2}: H{sub 2}S ratio 1.

  18. Method for direct production of carbon disulfide and hydrogen from hydrocarbons and hydrogen sulfide feedstock

    SciTech Connect

    Miao, Frank Q.; Erekson, Erek James

    1998-12-01

    A method for converting hydrocarbons and hydrogen sulfide to carbon disulfide and hydrogen is provided comprising contacting the hydrocarbons and hydrogen sulfide to a bi-functional catalyst residing in a controlled atmosphere for a time and at a temperature sufficient to produce carbon disulfide and hydrogen. Also provided is a catalyst for converting carbon sulfides and hydrogen sulfides to gasoline range hydrocarbons comprising a mixture containing a zeolite catalyst and a hydrogenating catalyst.

  19. Hydrogen sulfide determines HNO-induced stimulation of trigeminal afferents.

    PubMed

    Wild, Vanessa; Messlinger, Karl; Fischer, Michael J M

    2015-08-18

    Endogenous NO and hydrogen sulfide form HNO, which causes CGRP release via TRPA1 channel activation in sensory nerves. In the present study, stimulation of intact trigeminal afferent neuron preparations with NO donors, Na2S or both was analyzed by measuring CGRP release as an index of mass activation. Combined stimulation was able to activate all parts of the trigeminal system and acted synergistic compared to stimulation with both substances alone. To investigate the contribution of both substances, we varied their ratio and tracked intracellular calcium in isolated neurons. Our results demonstrate that hydrogen sulfide is the rate-limiting factor for HNO formation. CGRP has a key role in migraine pathophysiology and HNO formation at all sites of the trigeminal system should be considered for this novel means of activation.

  20. Hydrogen sulfide prodrugs—a review

    PubMed Central

    Zheng, Yueqin; Ji, Xingyue; Ji, Kaili; Wang, Binghe

    2015-01-01

    Hydrogen sulfide (H2S) is recognized as one of three gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications. PMID:26579468

  1. Adsorption of hydrogen sulfide on montmorillonites modified with iron.

    PubMed

    Nguyen-Thanh, Danh; Block, Karin; Bandosz, Teresa J

    2005-04-01

    Sodium-rich montmorillonite was modified with iron in order to introduce active centers for hydrogen sulfide adsorption. In the first modification, interlayer sodium cations were exchanged with iron. In another modification, iron oxocations were introduced to the clay surface. The most elaborated modification was based on doping of iron within the interlayer space of aluminum-pillared clay. The modified clay samples were tested as hydrogen sulfide adsorbents. Iron-doped samples showed a significant improvement in the capacity for H2S removal, despite of a noticeable decrease in microporosity compared to the initial pillared clay. The smallest capacity was obtained for the clay modified with iron oxocations. Variations in adsorption capacity are likely due to differences in the chemistry of iron species, degree of their dispersion on the surface, and accessibility of small pores for H2S molecule. The results suggest that on the surface of iron-modified clay hydrogen sulfide reacts with Fe(+3) forming sulfides or it is catalytically oxidized to SO2 on iron (hydro)oxides. Subsequent oxidation may lead to sulfate formation.

  2. Structure of 4-methylpyridinium Hydrogen Sulfide

    NASA Technical Reports Server (NTRS)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Martuch, Robert A.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    4-Methylpyridinium hydrogen sulfide, (C6H7NH)HS, M(sub r) = 127.21, consists of C6H7NH(+) cations and HS(-) anions. Z = 2 for the crystal with monoclinic space group Cm (#8), dimensions of a = 8.679(2) A, b = 7.964(1) A, and c = 4.860(2) A, an angle beta of 101.10(2) degrees, and a volume of V = 329.6(3) A(exp 3). R = 0.039 and R(sub w) = 0.048 for 385 reflections with F(sub o)(exp 2) greater than 3 sigma(F(sub o)(exp 2)) and 59 variables. Both the C6H7NH(+) cation and the HS(-) anion lie on crystallographic mirror planes with the N,S, two carbon atoms, and two hydrogen atoms positioned in the planes. The hydrogen atom of the HS(-) anion was not located.

  3. The Determination of Hydrogen Sulfide in Stack Gases, Iodometric Titration After Sulfite Removal.

    ERIC Educational Resources Information Center

    Robles, E. G.

    The determination of hydrogen sulfide in effluents from coal-fired furnaces and incinerators is complicated by the presence of sulfur oxides (which form acids). Organic compounds also may interfere with or prevent the formation of the cadmium sulfide precipitate or give false positive results because of reaction with iodine. The report presents a…

  4. High temperature regenerable hydrogen sulfide removal agents

    DOEpatents

    Copeland, Robert J.

    1993-01-01

    A system for high temperature desulfurization of coal-derived gases using regenerable sorbents. One sorbent is stannic oxide (tin oxide, SnO.sub.2), the other sorbent is a metal oxide or mixed metal oxide such as zinc ferrite (ZnFe.sub.2 O.sub.4). Certain otherwise undesirable by-products, including hydrogen sulfide (H.sub.2 S) and sulfur dioxide (SO.sub.2) are reused by the system, and elemental sulfur is produced in the regeneration reaction. A system for refabricating the sorbent pellets is also described.

  5. Nickel sulfide hollow whisker formation

    SciTech Connect

    Holcomb, G.R.; Cramer, S.D.

    1997-02-01

    Hollow, high-aspect-ratio nickel sulfide whiskers were formed during aqueous corrosion experiments at 250 C by the US Department of Energy. The whiskers grew radially from Teflon thread at the waterline in acidic sodium sulfate solutions containing chloride additions. The hollow morphology is consistent with that reported for the mineral millerite found in nature in hematite cavities. The data suggest that iron and chloride impurities are necessary for the observed whisker structure. Hollow nickel sulfide whiskers were observed only in high-temperature corrosion experiments conducted on stainless steels; they were not observed in similar experiments on nickel-base alloys.

  6. Amorphous molybdenum sulfides as hydrogen evolution catalysts.

    PubMed

    Morales-Guio, Carlos G; Hu, Xile

    2014-08-19

    Providing energy for a population projected to reach 9 billion people within the middle of this century is one of the most pressing societal issues. Burning fossil fuels at a rate and scale that satisfy our near-term demand will irreversibly damage the living environment. Among the various sources of alternative and CO2-emission-free energies, the sun is the only source that is capable of providing enough energy for the whole world. Sunlight energy, however, is intermittent and requires an efficient storage mechanism. Sunlight-driven water splitting to make hydrogen is widely considered as one of the most attractive methods for solar energy storage. Water splitting needs a hydrogen evolution catalyst to accelerate the rate of hydrogen production and to lower the energy loss in this process. Precious metals such as Pt are superior catalysts, but they are too expensive and scarce for large-scale applications. In this Account, we summarize our recent research on the preparation, characterization, and application of amorphous molybdenum sulfide catalysts for the hydrogen evolution reaction. The catalysts can be synthesized by electrochemical deposition under ambient conditions from readily available and inexpensive precursors. The catalytic activity is among the highest for nonprecious catalysts. For example, at a loading of 0.2 mg/cm(2), the optimal catalyst delivers a current density of 10 mA/cm(2) at an overpotential of 160 mV. The growth mechanism of the electrochemically deposited film catalysts was revealed by an electrochemical quartz microcrystal balance study. While different electrochemical deposition methods produce films with different initial compositions, the active catalysts are the same and are identified as a "MoS(2+x)" species. The activity of the film catalysts can be further promoted by divalent Fe, Co, and Ni ions, and the origins of the promotional effects have been probed. Highly active amorphous molybdenum sulfide particles can also be prepared

  7. Microaeration for hydrogen sulfide removal in UASB reactor.

    PubMed

    Krayzelova, Lucie; Bartacek, Jan; Kolesarova, Nina; Jenicek, Pavel

    2014-11-01

    The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge. PMID:25270045

  8. Hydrogen sulfide: physiological properties and therapeutic potential in ischaemia.

    PubMed

    Bos, Eelke M; van Goor, Harry; Joles, Jaap A; Whiteman, Matthew; Leuvenink, Henri G D

    2015-03-01

    Hydrogen sulfide (H2 S) has become a molecule of high interest in recent years, and it is now recognized as the third gasotransmitter in addition to nitric oxide and carbon monoxide. In this review, we discuss the recent literature on the physiology of endogenous and exogenous H2 S, focusing upon the protective effects of hydrogen sulfide in models of hypoxia and ischaemia.

  9. Protection of steel from hydrogen sulfide corrosion by bactericides

    SciTech Connect

    Abbasov, V.M.; Mamedov, I.A.; Abdullaev, E.Sh.

    1995-03-01

    Modern effective inhibitors, Araz-1 and INFKh-4, are recommended for preventing the corrosion of oilfield equipment affected by hydrogen sulfide and sulfate-reducing bacteria. Both inhibitors have undergone full-scale field tests and have shown highly effective inhibition of corrosion in two-phase hydrocarbon-electrolyte media saturated with hydrogen sulfide.

  10. Hydrogen Production from Hydrogen Sulfide in IGCC Power Plants

    SciTech Connect

    Elias Stefanakos; Burton Krakow; Jonathan Mbah

    2007-07-31

    IGCC power plants are the cleanest coal-based power generation facilities in the world. Technical improvements are needed to help make them cost competitive. Sulfur recovery is one procedure in which improvement is possible. This project has developed and demonstrated an electrochemical process that could provide such an improvement. IGCC power plants now in operation extract the sulfur from the synthesis gas as hydrogen sulfide. In this project H{sub 2}S has been electrolyzed to yield sulfur and hydrogen (instead of sulfur and water as is the present practice). The value of the byproduct hydrogen makes this process more cost effective. The electrolysis has exploited some recent developments in solid state electrolytes. The proof of principal for the project concept has been accomplished.

  11. Signaling of hydrogen sulfide and polysulfides.

    PubMed

    Kimura, Hideo

    2015-02-10

    It has been almost two decades since the first demonstration of hydrogen sulfide (H2S) as a physiological mediator of cognitive function and vascular tone. H2S is physiologically important because it protects various organs from ischemia-reperfusion injury besides regulating inflammation, oxygen sensing, cell growth, and senescence. The production, metabolism, and regulation of H2S have been studied extensively. H2S modulates target proteins through sulfhydration (or sulfuration) or by the reduction of cysteine disulfide bonds. A large number of novel H2S-donating compounds are being developed owing to the therapeutic potential of H2S. Recently, polysulfides, rather than H2S, have been identified as molecules that sulfhydrate (or sulfurate) their target proteins.

  12. Chemical Foundations of Hydrogen Sulfide Biology

    PubMed Central

    Li, Qian; Lancaster, Jack R.

    2013-01-01

    Following nitric oxide (nitrogen monoxide) and carbon monoxide, hydrogen sulfide (or its newer systematic name sulfane, H2S) became the third small molecule that can be both toxic and beneficial depending on the concentration. In spite of its impressive therapeutic potential, the underlying mechanisms for its beneficial effects remain unclear. Any novel mechanism has to obey fundamental chemical principles. H2S chemistry was studied long before its biological relevance was discovered, however, with a few exceptions, these past works have received relatively little attention in the path of exploring the mechanistic conundrum of H2S biological functions. This review calls attention to the basic physical and chemical properties of H2S, focuses on the chemistry between H2S and its three potential biological targets: oxidants, metals and thiol derivatives, discusses the applications of these basics into H2S biology and methodology, and introduces the standard terminology to this youthful field. PMID:23850631

  13. Hydrogen sulfide and polysulfides as signaling molecules

    PubMed Central

    KIMURA, Hideo

    2015-01-01

    Hydrogen sulfide (H2S) is a familiar toxic gas that smells of rotten eggs. After the identification of endogenous H2S in the mammalian brain two decades ago, studies of this molecule uncovered physiological roles in processes such as neuromodulation, vascular tone regulation, cytoprotection against oxidative stress, angiogenesis, anti-inflammation, and oxygen sensing. Enzymes that produce H2S, such as cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase have been studied intensively and well characterized. Polysulfides, which have a higher number of inner sulfur atoms than that in H2S, were recently identified as potential signaling molecules that can activate ion channels, transcription factors, and tumor suppressors with greater potency than that of H2S. This article focuses on our contribution to the discovery of these molecules and their metabolic pathways and mechanisms of action. PMID:25864468

  14. Optimization of the superconducting phase of hydrogen sulfide

    SciTech Connect

    Degtyarenko, N. N.; Masur, E. A.

    2015-12-15

    The electron and phonon spectra, as well as the densities of electron and phonon states of the SH{sub 3} phase and the stable orthorhombic structure of hydrogen sulfide SH{sub 2}, are calculated for the pressure interval 100–225 GPa. It is found that the I4/mmm phase can be responsible for the superconducting properties of metallic hydrogen sulfide along with the SH{sub 3} phase. Sequential stages for obtaining and conservation of the SH{sub 2} phase are proposed. The properties of two (SH{sub 2} and SH{sub 3}) superconducting phases of hydrogen sulfide are compared.

  15. Biogenesis of reactive sulfur species for signaling by hydrogen sulfide oxidation pathways

    PubMed Central

    Mishanina, Tatiana V; Libiad, Marouane; Banerjee, Ruma

    2016-01-01

    The chemical species involved in H2S signaling remain elusive despite the profound and pleiotropic physiological effects elicited by this molecule. The dominant candidate mechanism for sulfide signaling is persulfidation of target proteins. However, the relatively poor reactivity of H2S toward oxidized thiols, such as disulfides, the low concentration of disulfides in the reducing milieu of the cell and the low steady-state concentration of H2S raise questions about the plausibility of persulfide formation via reaction between an oxidized thiol and a sulfide anion or a reduced thiol and oxidized hydrogen disulfide. In contrast, sulfide oxidation pathways, considered to be primarily mechanisms for disposing of excess sulfide, generate a series of reactive sulfur species, including persulfides, polysulfides and thiosulfate, that could modify target proteins. We posit that sulfide oxidation pathways mediate sulfide signaling and that sulfurtransferases ensure target specificity. PMID:26083070

  16. NEAR-CONTINUOUS MEASUREMENT OF HYDROGEN SULFIDE AND CARBONYL SULFIDE BY AN AUTOMATIC GAS CHROMATOGRAPH

    EPA Science Inventory

    An automatic gas chromatograph with a flame photometric detector that samples and analyzes hydrogen sulfide and carbonyl sulfide at 30-s intervals is described. Temperature programming was used to elute trace amounts of carbon disulfide present in each injection from a Supelpak-S...

  17. The hydrogen sulfide metabolite trimethylsulfonium is found in human urine

    NASA Astrophysics Data System (ADS)

    Lajin, Bassam; Francesconi, Kevin A.

    2016-06-01

    Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-QQQ), and applied the method to establish the urinary levels of TMS in a group of human volunteers. The measured urinary levels of TMS were in the nanomolar range, which is commensurate with the steady-state tissue concentrations of hydrogen sulfide previously reported in the literature. The developed method can be used in future studies for the quantification of urinary TMS as a potential biomarker for hydrogen sulfide body pools.

  18. An Experiment in Autotrophic Fermentation: Microbial Oxidation of Hydrogen Sulfide.

    ERIC Educational Resources Information Center

    Sublette, Kerry L.

    1989-01-01

    Described is an experiment which uses an autotrophic bacterium to anaerobically oxidize hydrogen sulfide to sulfate in a batch-stirred tank reactor. Discusses background information, experimental procedure, and sample results of this activity. (CW)

  19. The hydrogen sulfide metabolite trimethylsulfonium is found in human urine

    PubMed Central

    Lajin, Bassam; Francesconi, Kevin A.

    2016-01-01

    Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-QQQ), and applied the method to establish the urinary levels of TMS in a group of human volunteers. The measured urinary levels of TMS were in the nanomolar range, which is commensurate with the steady-state tissue concentrations of hydrogen sulfide previously reported in the literature. The developed method can be used in future studies for the quantification of urinary TMS as a potential biomarker for hydrogen sulfide body pools. PMID:27247020

  20. Detection of interstellar hydrogen sulfide in cold, dark clouds.

    PubMed

    Minh, Y C; Irvine, W M; Ziurys, L M

    1989-10-01

    We have detected interstellar hydrogen sulfide (H2S) toward the cold, dark clouds L134N and TMC 1. We derive total column densities of approximately 2.6 x 10(13) cm-2 and approximately 7.0 x 10(12) cm-2 at the SO peak of L134N and at the NH3 peak of TMC 1, respectively. Since the expected gas phase reactions leading to the formation of H2S are thought to be endothermic, grain surface reactions may play a major role in the synthesis of this species in cold, dark clouds. If the carbon abundance is high and grain surface reactions are the dominant formation route, H2CS would be expected to form instead of H2S, and the abundances of H2CS have been observed to be high where those of H2S are low in L134N and TMC 1.

  1. Hydrogen Sulfide and Cellular Redox Homeostasis

    PubMed Central

    Xie, Zhi-Zhong; Liu, Yang; Bian, Jin-Song

    2016-01-01

    Intracellular redox imbalance is mainly caused by overproduction of reactive oxygen species (ROS) or weakness of the natural antioxidant defense system. It is involved in the pathophysiology of a wide array of human diseases. Hydrogen sulfide (H2S) is now recognized as the third “gasotransmitters” and proved to exert a wide range of physiological and cytoprotective functions in the biological systems. Among these functions, the role of H2S in oxidative stress has been one of the main focuses over years. However, the underlying mechanisms for the antioxidant effect of H2S are still poorly comprehended. This review presents an overview of the current understanding of H2S specially focusing on the new understanding and mechanisms of the antioxidant effects of H2S based on recent reports. Both inhibition of ROS generation and stimulation of antioxidants are discussed. H2S-induced S-sulfhydration of key proteins (e.g., p66Shc and Keap1) is also one of the focuses of this review. PMID:26881033

  2. Enamel surface changes caused by hydrogen sulfide

    PubMed Central

    Yamaguchi, Takao; Hanabusa, Masao; Hosoya, Noriyasu; Chiba, Toshie; Yoshida, Takumasa; Morito, Akiyuki

    2015-01-01

    Background: Volatile sulfur compounds (VSCs) produced inside the mouth are a well-known cause of halitosis. Recent studies have suggested that VSCs modify the pathology of periodontitis by encouraging the migration of bacterial toxins associated with increased permeability of gingival epithelia, and enhancing the production of matrix metalloproteinases in gingival connective tissue. Nonetheless, the effects on the enamel of direct exposure to VSCs within the oral cavity remain unclear. In the present study, we observed the effects of VSCs in the form of hydrogen sulfide (H2S) on enamel surfaces and determined their effects on restorations. Materials and Methods: Extracted human tooth and bovine tooth samples were divided into the H2S experimental side and the control side. We observed the effects of H2S on enamel surfaces using electron microscopy and conducted a shear test. Results: We found that exposure to H2S obscured the enamel surface's crystal structure. The surface also exhibited coarseness and reticular changes. Shear testing did not reveal any differences in bond strength. Conclusions: Our findings suggested that H2S occurring inside the mouth causes changes to the crystal structure of the enamel surface that can lead to tooth wear, but that it does not diminish the effects of dental bonding in adhesive restorations. PMID:26752833

  3. Signaling Molecules: Hydrogen Sulfide and Polysulfide

    PubMed Central

    2015-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has been recognized as a signaling molecule as well as a cytoprotectant. It modulates neurotransmission, regulates vascular tone, and protects various tissues and organs, including neurons, the heart, and kidneys, from oxidative stress and ischemia-reperfusion injury. H2S is produced from l-cysteine by cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase. Recent Advances: In addition to these enzymes, we recently identified a novel pathway to produce H2S from d-cysteine, which involves d-amino acid oxidase (DAO) along with 3MST. These enzymes are localized in the cytoplasm, mitochondria, and peroxisomes. However, some enzymes translocate to organelles under specific conditions. Moreover, H2S-derived potential signaling molecules such as polysulfides and HSNO have been identified. Critical Issues: The physiological stimulations, which trigger the production of H2S and its derivatives and maintain their local levels, remain unclear. Future Directions: Understanding the regulation of the H2S production and H2S-derived signaling molecules and the specific stimuli that induce their release will provide new insights into the biology of H2S and therapeutic development in diseases involving these substances. Antioxid. Redox Signal. 22, 362–376. PMID:24800864

  4. Hydrogen Sulfide Signaling in the Gastrointestinal Tract

    PubMed Central

    2014-01-01

    Abstract Significance: The current literature regarding the effects of the gaseous signal molecule hydrogen sulfide (H2S) in the gastrointestinal system is reviewed. Bacterial, host and pharmaceutical-derived H2S are all considered and presented according to the physiological or pathophysiological effects of the gaseous signal molecule. These subjects include the toxicology of intestinal H2S with emphasis on bacterial-derived H2S, especially from sulfate-reducing bacteria, the role of endogenous and exogenous H2S in intestinal inflammation, and the roles of H2S in gastrointestinal motility, secretion and nociception. Recent Advances: While its pro- and anti-inflammatory, smooth muscle relaxant, prosecretory, and pro- and antinociceptive actions continue to remain the major effects of H2S in this system; recent findings have expanded the potential molecular targets for H2S in the gastrointestinal tract. Critical Issues: Numerous discrepancies remain in the literature, and definitive molecular targets in this system have not been supported by the use of competitive antagonism. Future Directions: Future work will hopefully resolve discrepancies in the literature and identify molecular targets and mechanisms of action for H2S. It is clear from the current literature that the long-appreciated relationship between H2S and the gastrointestinal tract continues to be strong as we endeavor to unravel its mysteries. Antioxid. Redox Signal. 20, 818–830. PMID:23582008

  5. Production and Physiological Effects of Hydrogen Sulfide

    PubMed Central

    2014-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has been recognized as a physiological mediator with a variety of functions. It regulates synaptic transmission, vascular tone, inflammation, transcription, and angiogenesis; protects cells from oxidative stress and ischemia-reperfusion injury; and promotes healing of ulcers. Recent Advances: In addition to cystathionine β-synthase and cystathionine γ-lyase, 3-mercaptopyruvate sulfurtransferase along with cysteine aminotransferase was recently demonstrated to produce H2S. Even in bacteria, H2S produced by these enzymes functions as a defense against antibiotics, suggesting that the cytoprotective effect of H2S is a universal defense mechanism in organisms from bacteria to mammals. Critical Issues: The functional form of H2S—undissociated H2S gas, dissociated HS ion, or some other form of sulfur—has not been identified. Future Directions: The regulation of H2S production by three enzymes may lead to the identification of the physiological signals that are required to release H2S. The identification of the physiological functions of other forms of sulfur may also help understand the biological significance of H2S. Antioxid. Redox Signal. 20, 783–793. PMID:23581969

  6. Control of microbially generated hydrogen sulfide in produced waters

    SciTech Connect

    Burger, E.D.; Vance, I.; Gammack, G.F.; Duncan, S.E.

    1995-12-31

    Production of hydrogen sulfide in produced waters due to the activity of sulfate-reducing bacteria (SRB) is a potentially serious problem. The hydrogen sulfide is not only a safety and environmental concern, it also contributes to corrosion, solids formation, a reduction in produced oil and gas values, and limitations on water discharge. Waters produced from seawater-flooded reservoirs typically contain all of the nutrients required to support SRB metabolism. Surface processing facilities provide a favorable environment in which SRB flourish, converting water-borne nutrients into biomass and H{sub 2}S. This paper will present results from a field trial in which a new technology for the biochemical control of SRB metabolism was successfully applied. A slip stream of water downstream of separators on a produced water handling facility was routed through a bioreactor in a side-steam device where microbial growth was allowed to develop fully. This slip stream was then treated with slug doses of two forms of a proprietary, nonbiocidal metabolic modifier. Results indicated that H{sub 2}S production was halted almost immediately and that the residual effect of the treatment lasted for well over one week.

  7. Hydrogen sulfide production from subgingival plaque samples.

    PubMed

    Basic, A; Dahlén, G

    2015-10-01

    Periodontitis is a polymicrobial anaerobe infection. Little is known about the dysbiotic microbiota and the role of bacterial metabolites in the disease process. It is suggested that the production of certain waste products in the proteolytic metabolism may work as markers for disease severity. Hydrogen sulfide (H2S) is a gas produced by degradation of proteins in the subgingival pocket. It is highly toxic and believed to have pro-inflammatory properties. We aimed to study H2S production from subgingival plaque samples in relation to disease severity in subjects with natural development of the disease, using a colorimetric method based on bismuth precipitation. In remote areas of northern Thailand, adults with poor oral hygiene habits and a natural development of periodontal disease were examined for their oral health status. H2S production was measured with the bismuth method and subgingival plaque samples were analyzed for the presence of 20 bacterial species with the checkerboard DNA-DNA hybridization technique. In total, 43 subjects were examined (age 40-60 years, mean PI 95 ± 6.6%). Fifty-six percent had moderate periodontal breakdown (CAL > 3 < 7 mm) and 35% had severe periodontal breakdown (CAL > 7 mm) on at least one site. Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis and Fusobacterium nucleatum were frequently detected. H2S production could not be correlated to periodontal disease severity (PPD or CAL at sampled sites) or to a specific bacterial composition. Site 21 had statistically lower production of H2S (p = 0.02) compared to 16 and 46. Betel nut chewers had statistically significant lower H2S production (p = 0.01) than non-chewers. Rapid detection and estimation of subgingival H2S production capacity was easily and reliably tested by the colorimetric bismuth sulfide precipitation method. H2S may be a valuable clinical marker for degradation of proteins in the subgingival pocket. PMID:25280920

  8. Formation of hydrogen sulfide from cysteine in Saccharomyces cerevisiae BY4742: genome wide screen reveals a central role of the vacuole.

    PubMed

    Winter, Gal; Cordente, Antonio G; Curtin, Chris

    2014-01-01

    Discoveries on the toxic effects of cysteine accumulation and, particularly, recent findings on the many physiological roles of one of the products of cysteine catabolism, hydrogen sulfide (H2S), are highlighting the importance of this amino acid and sulfur metabolism in a range of cellular activities. It is also highlighting how little we know about this critical part of cellular metabolism. In the work described here, a genome-wide screen using a deletion collection of Saccharomyces cerevisiae revealed a surprising set of genes associated with this process. In addition, the yeast vacuole, not previously associated with cysteine catabolism, emerged as an important compartment for cysteine degradation. Most prominent among the vacuole-related mutants were those involved in vacuole acidification; we identified each of the eight subunits of a vacuole acidification sub-complex (V1 of the yeast V-ATPase) as essential for cysteine degradation. Other functions identified included translation, RNA processing, folate-derived one-carbon metabolism, and mitochondrial iron-sulfur homeostasis. This work identified for the first time cellular factors affecting the fundamental process of cysteine catabolism. Results obtained significantly contribute to the understanding of this process and may provide insight into the underlying cause of cysteine accumulation and H2S generation in eukaryotes. PMID:25517415

  9. Formation of Hydrogen Sulfide from Cysteine in Saccharomyces cerevisiae BY4742: Genome Wide Screen Reveals a Central Role of the Vacuole

    PubMed Central

    Winter, Gal; Cordente, Antonio G.; Curtin, Chris

    2014-01-01

    Discoveries on the toxic effects of cysteine accumulation and, particularly, recent findings on the many physiological roles of one of the products of cysteine catabolism, hydrogen sulfide (H2S), are highlighting the importance of this amino acid and sulfur metabolism in a range of cellular activities. It is also highlighting how little we know about this critical part of cellular metabolism. In the work described here, a genome-wide screen using a deletion collection of Saccharomyces cerevisiae revealed a surprising set of genes associated with this process. In addition, the yeast vacuole, not previously associated with cysteine catabolism, emerged as an important compartment for cysteine degradation. Most prominent among the vacuole-related mutants were those involved in vacuole acidification; we identified each of the eight subunits of a vacuole acidification sub-complex (V1 of the yeast V-ATPase) as essential for cysteine degradation. Other functions identified included translation, RNA processing, folate-derived one-carbon metabolism, and mitochondrial iron-sulfur homeostasis. This work identified for the first time cellular factors affecting the fundamental process of cysteine catabolism. Results obtained significantly contribute to the understanding of this process and may provide insight into the underlying cause of cysteine accumulation and H2S generation in eukaryotes. PMID:25517415

  10. Formation of hydrogen sulfide from cysteine in Saccharomyces cerevisiae BY4742: genome wide screen reveals a central role of the vacuole.

    PubMed

    Winter, Gal; Cordente, Antonio G; Curtin, Chris

    2014-01-01

    Discoveries on the toxic effects of cysteine accumulation and, particularly, recent findings on the many physiological roles of one of the products of cysteine catabolism, hydrogen sulfide (H2S), are highlighting the importance of this amino acid and sulfur metabolism in a range of cellular activities. It is also highlighting how little we know about this critical part of cellular metabolism. In the work described here, a genome-wide screen using a deletion collection of Saccharomyces cerevisiae revealed a surprising set of genes associated with this process. In addition, the yeast vacuole, not previously associated with cysteine catabolism, emerged as an important compartment for cysteine degradation. Most prominent among the vacuole-related mutants were those involved in vacuole acidification; we identified each of the eight subunits of a vacuole acidification sub-complex (V1 of the yeast V-ATPase) as essential for cysteine degradation. Other functions identified included translation, RNA processing, folate-derived one-carbon metabolism, and mitochondrial iron-sulfur homeostasis. This work identified for the first time cellular factors affecting the fundamental process of cysteine catabolism. Results obtained significantly contribute to the understanding of this process and may provide insight into the underlying cause of cysteine accumulation and H2S generation in eukaryotes.

  11. Hydrogen sulfide in the mammalian cardiovascular system.

    PubMed

    Liu, Yi-Hong; Lu, Ming; Hu, Li-Fang; Wong, Peter T-H; Webb, George D; Bian, Jin-Song

    2012-07-01

    For more than a century, hydrogen sulfide (H(2)S) has been regarded as a toxic gas. This review surveys the growing recognition of the role of H(2)S as an endogenous signaling molecule in mammals, with emphasis on its physiological and pathological pathways in the cardiovascular system. In biological fluids, H(2)S gas is a weak acid that exists as about 15% H(2)S, 85% HS(-), and a trace of S(2-). Here, we use "H(2)S" to refer to this mixture. H(2)S has been found to influence heart contractile functions and may serve as a cardioprotectant for treating ischemic heart diseases and heart failure. Alterations of the endogenous H(2)S level have been found in animal models with various pathological conditions such as myocardial ischemia, spontaneous hypertension, and hypoxic pulmonary hypertension. In the vascular system, H(2)S exerts biphasic regulation of a vascular tone with varying effects based on its concentration and in the presence of nitric oxide. Over the past decade, several H(2)S-releasing compounds (NaHS, Na(2)S, GYY4137, etc.) have been utilized to test the effect of exogenous H(2)S under different physiological and pathological situations in vivo and in vitro. H(2)S has been found to promote angiogenesis and to protect against atherosclerosis and hypertension, while excess H(2)S may promote inflammation in septic or hemorrhagic shock. H(2)S-releasing compounds and inhibitors of H(2)S synthesis hold promise in alleviating specific disease conditions. This comprehensive review covers in detail the effects of H(2)S on the cardiovascular system, especially in disease situations, and also the various underlying mechanisms.

  12. Hydrogen Sulfide as an Oxygen Sensor

    PubMed Central

    2015-01-01

    Abstract Significance Although oxygen (O2)-sensing cells and tissues have been known for decades, the identity of the O2-sensing mechanism has remained elusive. Evidence is accumulating that O2-dependent metabolism of hydrogen sulfide (H2S) is this enigmatic O2 sensor. Recent Advances The elucidation of biochemical pathways involved in H2S synthesis and metabolism have shown that reciprocal H2S/O2 interactions have been inexorably linked throughout eukaryotic evolution; there are multiple foci by which O2 controls H2S inactivation, and the effects of H2S on downstream signaling events are consistent with those activated by hypoxia. H2S-mediated O2 sensing has been demonstrated in a variety of O2-sensing tissues in vertebrate cardiovascular and respiratory systems, including smooth muscle in systemic and respiratory blood vessels and airways, carotid body, adrenal medulla, and other peripheral as well as central chemoreceptors. Critical Issues Information is now needed on the intracellular location and stoichometry of these signaling processes and how and which downstream effectors are activated by H2S and its metabolites. Future Directions Development of specific inhibitors of H2S metabolism and effector activation as well as cellular organelle-targeted compounds that release H2S in a time- or environmentally controlled way will not only enhance our understanding of this signaling process but also provide direction for future therapeutic applications. Antioxid. Redox Signal. 22, 377–397. “Nothing in Biology Makes Sense Except in the Light of Evolution” —Theodosius Dobzhansky (29) PMID:24801248

  13. Hydrogen sulfide at high pressure: change in stoichiometry

    NASA Astrophysics Data System (ADS)

    Goncharov, Alexander; Lobanov, Sergey; Kruglov, Ivan; Zhao, Xiao-Miao; Chen, Xiao-Jia; Oganov, Artem; Konopkova, Zuzana; Prakapenka, Vitali

    Hydrogen sulfide (H2S) was studied by x-ray synchrotron diffraction (XRD) and Raman spectroscopy up to 144 GPa at 180-295 K. We find that H2S compound become unstable with respect to formation of new compounds with different composition including pure S, H3S and HS2 depending on the thermodynamic P-T path. These results are supported by our quantum-mechanical variable-composition evolutionary simulations that show the stability of the above mentioned compounds at elevated pressures. The stability of H3S at high pressures, which we find a strong experimental and theoretical confirmation here, suggests that it is this material which is responsible for high-temperature superconducting properties reported previously. We thank DARPA, NSF, ISSP (Hefei, China), Government of Russian Federation, and Foreign Talents Introduction and Academic Exchange Program. Use of the Advanced Photon Source was supported by the U. S. Department of Energy Office of Science.

  14. Hydrogen sulfide at high pressure: Change in stoichiometry

    NASA Astrophysics Data System (ADS)

    Goncharov, Alexander F.; Lobanov, Sergey S.; Kruglov, Ivan; Zhao, Xiao-Miao; Chen, Xiao-Jia; Oganov, Artem R.; Konôpková, Zuzana; Prakapenka, Vitali B.

    2016-05-01

    Hydrogen sulfide (H2S ) was studied by x-ray synchrotron diffraction and Raman spectroscopy up to 150 GPa at 180-295 K and by quantum-mechanical variable-composition evolutionary simulations. The experiments show that H2S becomes unstable with respect to formation of compounds with different structure and composition, including Cccm and a body-centered cubic like (R 3 m or I m -3 m ) H3S , the latter one predicted previously to show a record-high superconducting transition temperature, a Tc of 203 K. These experiments provide experimental ground for understanding of this record-high Tc. The experimental results are supported by theoretical structure searches that suggest the stability of H3S , H4S3 , H5S8 , H3S5 , and H S2 compounds that have not been reported previously at elevated pressures.

  15. Micro-aeration for hydrogen sulfide removal from biogas

    NASA Astrophysics Data System (ADS)

    Duangmanee, Thanapong

    The presence of sulfur compounds (e.g. protein, sulfate, thiosulfate, sulfite, etc.) in the feed stream generates highly corrosive and odorous hydrogen sulfide during anaerobic digestion. The high sulfide level in the biogas stream is not only poisonous to many novel metal catalysts employed in thermo-catalytic processes but also reduces the quality of methane to produce renewable energy. This study used an innovative, low-maintenance, low-cost biological sulfide removal technology to remove sulfides simultaneously from both gas and liquid phase. ORP (Oxidation-Reduction-Potential) was used as the controlling parameter to precisely regulate air injection to the sulfide oxidizing unit (SOU). The microaeration technique provided just enough oxygen to partially oxidize sulfides to elemental sulfur without inhibiting methanogenesis. The SOU was equipped with a diffuser at the bottom for the dispersion of sulfide-laden biogas and injected air throughout the column. The SOU can be operated as a standalone unit or coupled with an anaerobic digester to simultaneously remove sulfide from the biogas and effluent. The integrated system was capable of reducing hydrogen sulfide in biogas from 2,450 to less than 2 ppmV with minimal sulfate production at the highest available sulfide loading rate of 0.24 kg/m3-day. More than 98% of sulfide removed was recovered as elemental sulfur. However, the standalone SOU was able to operate at high hydrogen sulfide loading of 1.46 kg/m 3-day at inlet sulfide concentration of 3000 ppmV and reduce the off-gas hydrogen sulfide concentrations to less than 10 ppmV. The experiment also revealed that the ORP controlled aeration was sensitive enough to prevent oxygen overdosing (dampening effect) during unexpected surges of aeration. Using generalized linear regression, a model predicting output H2S concentration based on input H2S concentrations, SOU medium heights, and biogas flow rates, was derived. With 95% confidence, output H2S concentration

  16. Hydrogen evolution from water through metal sulfide reactions

    NASA Astrophysics Data System (ADS)

    Saha, Arjun; Raghavachari, Krishnan

    2013-11-01

    Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M2SX- (M = Mo and W, X = 4-6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo2S4- isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W2S4- and M2S5- isomers. In all the lowest energy H2 elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H2 elimination step involve a thiol (-SH) and a hydroxyl (-OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M2S4- and M2S5- clusters with water to liberate H2 are exothermic and involve modest free energy barriers. However, the reaction of water with M2S6- is highly endothermic with a considerable barrier due to saturation of the local bonding environment.

  17. Hydrogen evolution from water through metal sulfide reactions.

    PubMed

    Saha, Arjun; Raghavachari, Krishnan

    2013-11-28

    Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M2S(X)(-) (M = Mo and W, X = 4-6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo2S4(-) isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W2S4(-) and M2S5(-) isomers. In all the lowest energy H2 elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H2 elimination step involve a thiol (-SH) and a hydroxyl (-OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M2S4(-) and M2S5(-) clusters with water to liberate H2 are exothermic and involve modest free energy barriers. However, the reaction of water with M2S6(-) is highly endothermic with a considerable barrier due to saturation of the local bonding environment.

  18. Hydrogen sulfide release from dairy manure storages containing gypsum bedding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recycled gypsum products can provide a cost-effective bedding alternative for dairy producers. Manufacturers report reduced odors, moisture and bacteria in the stall environment when compared to traditional bedding. Gypsum provides a sulfate source that can be converted to hydrogen sulfide under ana...

  19. Biology and therapeutic potential of hydrogen sulfide and hydrogen sulfide-releasing chimeras

    PubMed Central

    Kashfi, Khosrow; Olson, Kenneth R.

    2012-01-01

    Hydrogen sulfide, H2S, is a colorless gas with a strong odor that until recently was only considered to be a toxic environmental pollutant with little or no physiological significance. However, the past few years have demonstrated its role in many biological systems and it is becoming increasingly clear that H2S is likely to join nitric oxide (NO) and carbon monoxide (CO) as a major player in mammalian biology. In this review, we have provided an overview of the chemistry and biology of H2S and have summarized the chemistry and biological activity of some natural and synthetic H2S-donating compounds. The naturally occurring compounds discussed include, garlic, sulforaphane, erucin, and iberin. The synthetic H2S donors reviewed include, GYY4137; cysteine analogs; S-propyl cysteine, S-allyl cysteine, S-propargyl cysteine, and N-acetyl cysteine. Dithiolethione and its NSAID and other chimeras such as, L-DOPA, sildenafil, aspirin, diclofenac, naproxen, ibuprofen, indomethacin, and mesalamine have also been reviewed in detail. The newly reported NOSH-aspirin that releases both NO and H2S has also been discussed. PMID:23103569

  20. Non-oxidative removal of hydrogen sulfide from gaseous, petrochemical, and other streams

    SciTech Connect

    Bricker, J.C.; Imai, T.

    1991-07-23

    This patent describes a method of reducing the hydrogen sulfide level in streams containing hydrogen sulfide at concentrations from about 2 ppm up to about 1,000 ppm. It comprises reacting the hydrogen sulfide with an unsaturated hydrocarbon in the presence of an acidic solid catalyst selected from the group consisting of polymeric sulfonic acid resins, solid polyphosphoric acid, supported sulfuric acid, supported boric acid, silica-aluminas, clays, faujasite, mordenite, and L, omega, X or Y zeolites at mercaptan-forming concentrations, and recovering a stream having a reduced hydrogen sulfide concentration and containing no more than 5 ppm hydrogen sulfide.

  1. Plasma-chemical conversion of hydrogen sulfide into hydrogen and sulfur

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.; Daniels, E.J.

    1993-09-01

    A waste-treatment process that recovers both hydrogen and sulfur from hydrogen-sulfide-contaminated industrial wastes is being developed to replace the Claus technology, which recovers only sulfur. The proposed process is based on research reported in the Soviet technical literature and uses microwave (or radio-frequency) energy to initiate plasma-chemical reactions that dissociate hydrogen sulfide into elemental hydrogen and sulfur. In the plasma-chemical process, the gaseous stream would be purified and separated into streams containing the product hydrogen, hydrogen sulfide for recycle to the plasma reactor, and the process purge containing carbon dioxide and water. Since unconverted hydrogen sulfide is recycled to the plasma reactor, the plasma-chemical process has the potential for sulfur recoveries in excess of 99% without the additional tail-gas clean-up processes associated with the Claus technology. Laboratory experiments with pure hydrogen sulfide have confirmed that conversions of over 90% per pass are possible. Experiments with impurities typical of petroleum refinery and natural gas production acid gases have demonstrated that these impurities are compatible with the plasma dissociation process and do not appear to create new waste-treatment problems. Other experiments show that the cyclonic-flow pattern hypothesized by the Russian theoretical analysis of the plasma-chemical process can substantially decrease energy requirements for hydrogen sulfide dissociation while increasing conversion. This process has several advantages over the current Claus-plus-tail-gas-cleanup technology. The primary advantage is the potential for recovering hydrogen more cheaply than the direct production of hydrogen. The difference could amount to an energy savings of 40 {times} 10{sup 15} to 70 {times} 10{sup 15} J/yr in the refining industry, for an annual savings of $500 million to $1,000 million.

  2. Reaction of Hydrogen Sulfide with Oxygen in the Presence ofSulfite

    SciTech Connect

    Weres, Oleh; Tsao, Leon

    1983-01-01

    Commonly, abatement of hydrogen sulfide emissions from a geothermal powerplant requires that hydrogen sulfide dissolved in the cooling water be eliminated by chemical reaction. Oxidation by atmospheric oxygen is the preferred reaction, but requires a suitable catalyst. Nickel is the most potent and thereby cheapest catalyst for this purpose. One Mg/L nickel in the cooling water would allow 99% removal of hydrogen sulfide to be attained. A major drawback of catalytic air oxidation is that colloidal sulfur is a major reaction product; this causes rapid sludge accumulation and deposition of sulfur scale. The authors studied the kinetics and product distribution of the reaction of hydrogen sulfide with oxygen, catalyzed by nickel. Adding sodium sulfite to the solution completely suppresses formation of colloidal sulfur by converting it to thiosulfate. The oxidation reaction is an autocatalytic, free radical chain reaction. A rate expression for this reaction and a detailed reaction mechanism were developed. Nickel catalyzes the chain initiation step, and polysulfidoradical ions propagate the chains. Several complexes of iron and cobalt were also studied. Iron citrate and iron N-hydroxyEDT are the most effective iron based catalysts. Uncomplexed cobalt is as effective as nickel, but forms a precipitate of cobalt oxysulfide and is too expensive for practical use.

  3. Reaction of hydrogen sulfide with oxygen in the presence of sulfite

    SciTech Connect

    Weres, O.; Tsao, L.

    1983-01-14

    Commonly, abatement of hydrogen sulfide emission from a geothermal powerplant requires that hydrogen sulfide dissolved in the cooling water be eliminated by chemical reaction. Oxidation by atmospheric oxygen is the preferred reaction, but requires a suitable catalyst. Nickel is the most potent and thereby cheapest catalyst for this purpose. One mg/L nickel in the cooling water would allow 99% removal of hydrogen sulfide to be attained. A major drawback of catalytic air oxidation is that colloidal sulfur is a major reaction product; this causes rapid sludge accumulation and deposition of sulfur scale. We studied the kinetics and product distribution of the reaction of hydrogen sulfide with oxygen, catalyzed by nickel. Adding sodium sulfite to the solution completely suppresses formation of colloidal sulfur by converting it to thiosulfate. The oxidation reaction is an autocatalytic, free radical chain reaction. A rate expression for this reaction and a detailed reaction mechanism were developed. Nickel catalyzes the chain initiation step, and polysulfidoradical ions propagate the chains. Several complexes of iron and cobalt were also studied. Iron citrate and iron N-hydroxyEDTA are the most effective iron based catalysts. Uncomplexed cobalt is as effective as nickel, but forms a precipitate of cobalt oxysulfide and is too expensive for practical use. 33 figures, 9 tables.

  4. MODELING OF SYNGAS REACTIONS AND HYDROGEN GENERATION OVER SULFIDES

    SciTech Connect

    Kamil Klier; Jeffery A. Spirko; Michael L. Neiman

    2004-10-01

    The objective of the research is to analyze pathways of reactions of hydrogen with oxides of carbon over sulfides, and to predict which characteristics of the sulfide catalyst (nature of metal, defect structure) give rise to the lowest barriers toward oxygenated hydrocarbon product. Reversal of these pathways entails the generation of hydrogen, which is also proposed for study. During this study, adsorption reactions of H atoms and H{sub 2} molecules with MoS{sub 2}, both in molecular and solid form, have been modeled using high-level density functional theory. The relative stabilities of pure MoS{sub 2} edges were calculated and small clusters exhibiting properties of the edges were modeled. The results were finalized and published in the journal ''Surface Science''. Hydrogen adsorption energies on both the edges and the clusters were calculated, and the thermodynamics of hydrogen adsorption on both systems were evaluated. The adsorption locations and vibrational frequencies were also determined. These additional results were published in a second paper in ''Surface Science''. Most recently, the bonding and effect of alkali and transition metal ions was investigated on the MoS{sub 2} clusters. Potassium atoms bind to the clusters and increase the binding of hydrogen to the clusters while reducing the activation barriers for hydrogen adsorption. Silver attaches to the Mo7S14 cluster and donates its odd electron to the nearby Mo atoms and should have a similar effect to hydrogen as potassium does.

  5. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination

    PubMed Central

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions. PMID:27446159

  6. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination.

    PubMed

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions.

  7. Hydrogenation properties of ruthenium sulfide clusters in acidic zeolites

    SciTech Connect

    Breysse, M.; Cattenot, M.; Kougionas, V.

    1997-06-01

    Catalysts of ruthenium sulfide, dispersed in a series of Y zeolites with various acidic properties, were prepared by ion exchange and subsequent sulfidation. The activities for the reactions of hydrogenation of tetralin and toluene, carried out in the presence of H{sub 2}S (1.9%), vary widely according to the nature of the zeolites. Ruthenium sulfide catalysts are much more active when using acidic zeolite, HY and HYd (dealuminated), and a partially potassium-exchanged KHYd sample, than when using the KY support. The acidic properties of the sulfided RuY catalysts were determined in situ using infrared spectroscopy and the conversion of isooctane. Both methods gave similar rankings of catalyst acidity. The electronic properties of the ruthenium sulfide phase were examined by means of the infrared study of the adsorption of CO. A low-frequency shift of 15 cm{sup -1} was observed for CO adsorbed on RuKY by reference to CO adsorbed on all other samples. The increase in activity for the hydrogenation of aromatics is related to the electron- deficient character of the sulfide particles in the acidic zeolites; as has been proposed, in the literature, for metal catalysts. A superimposed influence of the acidic sites on the adsorption of the aromatic molecule may also occur which could explain the amplitude of the effect (difference of activity between the most and less active catalysts {approximately}200 times) and the variations of activity observed within the series of the acidic catalysts. 33 refs., 10 figs., 7 tabs.

  8. Formation, stability, and reactivity studies of neutral iron sulfide clusters

    NASA Astrophysics Data System (ADS)

    Yin, Shi; Wang, Zhechen; Bernstein, Elliot

    2014-03-01

    Different methods are used to generate neutral iron sulfide clusters to study their formation, stability, and reactivity, employing a time of flight mass spectrometer (TOFMS) with VUV (118 nm) radiation single photon ionization (SPI). Neutral FemSn (m = 1-4, n = 1-6), and hydrogen containing FemSnHx (x >0, n > m) clusters are generated by the reaction of seeded H2S in a helium carrier gas with laser ablated iron metal within a supersonic nozzle. The observed strong signal of association products Fe2S2(SH)0,1 M (M = CO, C2H4, C3H6) suggest that the Fe2S2(SH)0,1 clusters have the high activity for interactions with these small molecules. In order to avoid the effect for reactivity from hydrogen containing clusters, pure FemSnclusters are generated through laser ablation of a mixed iron/sulfur target in the presence of a pure helium carrier gas. (FeS)m (m = 1-4) is observed to be the most stable series. Reaction of CO and H2 on neutral (FeS)1,2clusters is farther investigated both experimentally and theoretically. A size dependent reactivity of iron sulfide clusters toward CO is characterized. The reaction FeS + CO --> Fe + OCS is found for the FeS cluster. Products Fe2S 213COH2 and Fe2S 213COH4 are identified for reactions of 13CO and H2 on Fe2S2 clusters: this suggests that the Fe2S2 cluster has a high catalytic activity for hydrogenation reactions of CO to form formaldehyde and methanol. DFT calculations are performed to explore the potential energy surfaces for the two reactions: Fe2S2 + CO + 2H2 --> Fe2S2 + CH3OH; and Fe2S2 + CO + H2 --> Fe2S2 + CH2O.

  9. Health assessment document for hydrogen sulfide: review draft

    SciTech Connect

    Ammann, H.M.; Bradow, F.; Fennell, D.; Griffin, R.; Kearney, B.

    1986-08-01

    Hydrogen sulfide is a highly toxic gas which is immediately lethal in concentrations greater than 2000 ppm. The toxic end-point is due to anoxia to brain and heart tissues which results from its interaction with the celluar enzyme cytochrome oxidase. Inhibition of the enzyme halts oxidative metabolism which is the primary energy source for cells. A second toxic end-point is the irritative effect of hydrogen sulfide on mucous membranes, particularly edema at sublethal doses (250 to 500 ppm) in which sufficient exposure occurs before conciousness is lost. Recovered victims of exposure report neurologic symptoms such as headache, fatigue, irritability, vertigo, and loss of libido. Long-term effects are similar to those caused by anoxia due to other toxic agents like CO, and probably are not due to specific H/sub 2/S effects. H/sub 2/S is not a cumulative poison. No mutagenic, carcinogenic, reproductive, or teratogenic effects have been reported in the literature.

  10. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices.

    PubMed

    Tangerman, Albert

    2009-10-15

    This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (-SH) group and appear in the free gaseous form, in the acid-labile form and in the dithiothreitol-labile form. Dimethyl sulfide is a neutral molecule and exists only in the free form. The foul odor of these sulfur volatiles is a striking characteristic and plays a major role in bad breath, feces and flatus. Because sulfur is a biologically active element, the biological significance of the sulfur volatiles are also highlighted. Despite its highly toxic properties, hydrogen sulfide has been lately recommended to become the third gasotransmitter, next to nitric oxide and carbon monoxide, based on high concentration found in healthy tissues, such as blood and brain. However, there is much doubt about the reliability of the assay methods used. Many artifacts in the sulfide assays exist. The methods to detect the various forms of hydrogen sulfide are critically reviewed and compared with findings of our group. Recent findings that free gaseous hydrogen sulfide is absent in whole blood urged the need to revisit its role as a blood-borne signaling molecule.

  11. Chromium(VI) reduction by hydrogen sulfide in aqueous media: stoichiometry and kinetics.

    PubMed

    Kim, C; Zhou, Q; Deng, B; Thornton, E C; Xu, H

    2001-06-01

    The objective of this work was to investigate the reaction stoichiometry, kinetics, and mechanism for Cr(VI) reduction by hydrogen sulfide in the aqueous phase. Batch experiments with excess [Cr(VI)] over [H2S]T indicated that the molar amount of sulfide required for the reduction of 1 M Cr(VI) was 1.5, suggesting the following stoichiometry: 2CrO4(2-) + 3H2S + 4H+-->2Cr(OH)3(s) + 3S(s) + 2H2O. Further study with transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) confirmed that chromium hydroxide and elemental sulfur were the stable products. The kinetics of Cr(VI) reduction by hydrogen sulfide was measured under various initial concentrations of Cr(VI) and sulfide as well as pH values controlled by HEPES, phosphate, and borate buffers. Results showed that the overall reaction was second-order, i.e., first-order with respect to Cr(VI) and first-order to sulfide. The reaction rate increased as pH was decreased, and the pH dependence correlated well with the fraction of fully protonated sulfide (H2S) in the pH range of 6.5-10. The nature of buffers did not influence the reaction rate significantly in the homogeneous system. The reaction kinetics could be interpreted by a three-step mechanism: formation of an inner-sphere chromate-sulfide intermediate complex ((H2O4CrVIS)2-), intramolecular electron transfer to form Cr(IV) species, and subsequent fast reactions leading to Cr(III).

  12. Method of removing hydrogen sulfide from gases utilizing a zinc oxide sorbent and regenerating the sorbent

    DOEpatents

    Jalan, Vinod M.; Frost, David G.

    1984-01-01

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500.degree. C. to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent.

  13. Hydrogen evolution from water through metal sulfide reactions

    SciTech Connect

    Saha, Arjun; Raghavachari, Krishnan

    2013-11-28

    Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M{sub 2}S{sub X}{sup −} (M = Mo and W, X = 4–6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo{sub 2}S{sub 4}{sup −} isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W{sub 2}S{sub 4}{sup −} and M{sub 2}S{sub 5}{sup −} isomers. In all the lowest energy H{sub 2} elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H{sub 2} elimination step involve a thiol (–SH) and a hydroxyl (–OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M{sub 2}S{sub 4}{sup −} and M{sub 2}S{sub 5}{sup −} clusters with water to liberate H{sub 2} are exothermic and involve modest free energy barriers. However, the reaction of water with M{sub 2}S{sub 6}{sup −} is highly endothermic with a considerable

  14. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... signs? Each sign must be a high-visibility yellow color with black lettering as follows: Letter height... techniques to prevent formation fracturing in an open hole within the pressure limits of the well equipment... anticipated depth, conditions of the hole, and reservoir environment to be encountered. You must...

  15. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... signs? Each sign must be a high-visibility yellow color with black lettering as follows: Letter height... techniques to prevent formation fracturing in an open hole within the pressure limits of the well equipment... anticipated depth, conditions of the hole, and reservoir environment to be encountered. You must...

  16. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... signs? Each sign must be a high-visibility yellow color with black lettering as follows: Letter height... techniques to prevent formation fracturing in an open hole within the pressure limits of the well equipment... anticipated depth, conditions of the hole, and reservoir environment to be encountered. You must...

  17. Atomic layer deposition of aluminum sulfide thin films using trimethylaluminum and hydrogen sulfide

    SciTech Connect

    Sinha, Soumyadeep; Sarkar, Shaibal K.; Mahuli, Neha

    2015-01-15

    Sequential exposures of trimethylaluminum and hydrogen sulfide are used to deposit aluminum sulfide thin films by atomic layer deposition (ALD) in the temperature ranging from 100 to 200 °C. Growth rate of 1.3 Å per ALD cycle is achieved by in-situ quartz crystal microbalance measurements. It is found that the growth rate per ALD cycle is highly dependent on the purging time between the two precursors. Increased purge time results in higher growth rate. Surface limited chemistry during each ALD half cycle is studied by in-situ Fourier transformed infrared vibration spectroscopy. Time of flight secondary ion-mass spectroscopy measurement is used to confirm elemental composition of the deposited films.

  18. Modeling of hydrogen sulfide oxidation in concrete corrosion products from sewer pipes.

    PubMed

    Jensen, Henriette Stokbro; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2009-04-01

    Abiotic and biotic oxidation of hydrogen sulfide related to concrete corrosion was studied in corrosion products originating from a sewer manhole. The concrete corrosion products were suspended in an acidic solution, mimicking the conditions in the pore water of corroded concrete. The removal of hydrogen sulfide and dissolved oxygen was measured in parallel in the suspension, upon which the suspension was sterilized and the measurement repeated. The results revealed the biotic oxidation to be fast compared with the abiotic oxidation. The stoichiometry of the hydrogen sulfide oxidation was evaluated using the ratio between oxygen and hydrogen sulfide uptake. The ratio for the biotic oxidation pointed in the direction of elemental sulfur being formed as an intermediate in the oxidation of hydrogen sulfide to sulfuric acid. The experimental results were applied to suggest a hypothesis and a mathematical model describing the hydrogen sulfide oxidation pathway in a matrix of corroded concrete. PMID:19445325

  19. Modeling of hydrogen sulfide oxidation in concrete corrosion products from sewer pipes.

    PubMed

    Jensen, Henriette Stokbro; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2009-04-01

    Abiotic and biotic oxidation of hydrogen sulfide related to concrete corrosion was studied in corrosion products originating from a sewer manhole. The concrete corrosion products were suspended in an acidic solution, mimicking the conditions in the pore water of corroded concrete. The removal of hydrogen sulfide and dissolved oxygen was measured in parallel in the suspension, upon which the suspension was sterilized and the measurement repeated. The results revealed the biotic oxidation to be fast compared with the abiotic oxidation. The stoichiometry of the hydrogen sulfide oxidation was evaluated using the ratio between oxygen and hydrogen sulfide uptake. The ratio for the biotic oxidation pointed in the direction of elemental sulfur being formed as an intermediate in the oxidation of hydrogen sulfide to sulfuric acid. The experimental results were applied to suggest a hypothesis and a mathematical model describing the hydrogen sulfide oxidation pathway in a matrix of corroded concrete.

  20. Effect of hydrogen sulfide on phosphorus lability in lake sediments amended with drinking water treatment residuals.

    PubMed

    Wang, Changhui; Liu, Juanfeng; Pei, Yuansheng

    2013-05-01

    The use of drinking water treatment residuals (WTRs) to immobilize P in sediments is a novel approach for lake restoration. However, the lability of P in WTRs-amended sediments may vary with many factors, e.g., hydrogen sulfide content. Earlier works in our laboratory have demonstrated that WTRs are effective sorbents for hydrogen sulfide in water. Thus, we hypothesized that the lability of P in WTRs-amended sediments would not be increased by hydrogen sulfide. The results of this work suggested that this hypothesis was tenable. Compared to the raw sediments, the amended sediments had significantly lower P desorption potential in the presence of hydrogen sulfide at different times, pH and concentrations. Moreover, the amended sediments were also better able to adsorb hydrogen sulfide. In the amended sediments, the P, which was easily desorbed due to the effect of hydrogen sulfide, was transformed into the Fe/Al bound P.

  1. Utilization of Hyperbaric Oxygen Therapy and Induced Hypothermia After Hydrogen Sulfide Exposure

    PubMed Central

    Asif, Mir J.; Exline, Matthew C.

    2013-01-01

    Hydrogen sulfide is a toxic gas produced as a byproduct of organic waste and many industrial processes. Hydrogen sulfide exposure symptoms may vary from mild (dizziness, headaches, nausea) to severe lactic acidosis via its inhibition of oxidative phosphorylation, leading to cardiac arrhythmias and death. Treatment is generally supportive. We report the case of a patient presenting with cardiac arrest secondary to hydrogen sulfide exposure treated with both hyperbaric oxygen therapy and therapeutic hypothermia with great improvement in neurologic function. PMID:22004989

  2. Hydrogen Sulfide Induced Carbon Dioxide Activation by Metal-Free Dual Catalysis.

    PubMed

    Kumar, Manoj; Francisco, Joseph S

    2016-03-18

    The role of metal free dual catalysis in the hydrogen sulfide (H2S)-induced activation of carbon dioxide (CO2) and subsequent decomposition of resulting monothiolcarbonic acid in the gas phase has been explored. The results suggest that substituted amines and monocarboxylic type organic or inorganic acids via dual activation mechanisms promote both activation and decomposition reactions, implying that the judicious selection of a dual catalyst is crucial to the efficient C-S bond formation via CO2 activation. Considering that our results also suggest a new mechanism for the formation of carbonyl sulfide from CO2 and H2S, these new insights may help in better understanding the coupling between the carbon and sulfur cycles in the atmospheres of Earth and Venus.

  3. Abundances of hydrogen sulfide in star-forming regions.

    PubMed

    Minh, Y C; Ziurys, L M; Irvine, W M; McGonagle, D

    1991-01-01

    Interstellar hydrogen sulfide (H2S) and its isotopic variant H2 34S have been observed toward several star-forming regions via their 1(10)-1(01) transitions at 2 mm, using the FCRAO telescope. In sources where both isotopic species H2S and H2 34S were observed, column densities of approximately 10(16) cm-2 were measured. Column density lower limits of approximately 10(14) cm-2 for H2S were found for other sources, where only the main isotopic line was observed. The fractional abundances of H2S relative to molecular hydrogen appear to be enhanced by at least an order of magnitude relative to quiescent cloud values (approximately 10(-9)) for many of the observed sources. Such enhancement toward star-forming clouds suggests that some process involving elevated temperature aids in producing this species; this could be gas-phase reactions, grain-related processes, or both.

  4. Hydrogen Sulfide Emissions from Sow Farm Lagoons across Climates Zones.

    PubMed

    Grant, Richard H; Boehm, Matthew T; Lawrence, Alfred J; Heber, Albert J

    2013-11-01

    Hydrogen sulfide (HS) emissions were measured periodically over the course of 2 yr at three sow waste lagoons representing humid mesothermal (North Carolina, NC), humid microthermal (Indiana, IN), and semiarid (Oklahoma, OK) climates. Emissions were determined using a backward Lagrangian stochastic model in conjunction with line-sampled HS concentrations and measured turbulence. The median annual sow-specific (area-specific) lagoon emissions at the OK farm were approximately 1.6 g head [hd] d (5880 µg m s), whereas those at the IN and NC sow farms were 0.035 g hd d (130 µg m s), and 0.041 g hd d (260 µg m s), respectively. Hydrogen sulfide emissions generally increased with wind speed. The daily HS emissions from the OK lagoon were greatest during the first half of the year and decreased as the year progressed. Emissions were episodic at the NC and IN lagoons. The generally low emissions at the NC and IN lagoons were probably a result of significant populations of purple sulfur bacteria maintained in the humid mesothermal and humid microthermal climates. Most of the large HS emission events at the NC and IN lagoons appeared to be a result of either precipitation events or liquid pump-out events. The high emissions at the OK lagoon in a semiarid climate were largely a result of high wind speeds enhancing both lagoon and air boundary layer mixing. The climate (air temperature, winds, and precipitation) appeared to influence the HS emissions from lagoons.

  5. Catalysts for the selective oxidation of hydrogen sulfide to sulfur

    DOEpatents

    Srinivas, Girish; Bai, Chuansheng

    2000-08-08

    This invention provides catalysts for the oxidation of hydrogen sulfide. In particular, the invention provides catalysts for the partial oxidation of hydrogen sulfide to elemental sulfur and water. The catalytically active component of the catalyst comprises a mixture of metal oxides containing titanium oxide and one or more metal oxides which can be selected from the group of metal oxides or mixtures of metal oxides of transition metals or lanthanide metals. Preferred metal oxides for combination with TiO.sub.2 in the catalysts of this invention include oxides of V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Catalysts which comprise a homogeneous mixture of titanium oxide and niobium (Nb) oxide are also provided. A preferred method for preparing the precursor homogenous mixture of metal hydroxides is by coprecipitation of titanium hydroxide with one or more other selected metal hydroxides. Catalysts of this invention have improved activity and/or selectivity for elemental sulfur production. Further improvements of activity and/or selectivity can be obtained by introducing relatively low amounts (up to about 5 mol %)of a promoter metal oxide (preferably of metals other than titanium and that of the selected second metal oxide) into the homogeneous metal/titanium oxide catalysts of this invention.

  6. Growth kinetics of hydrogen sulfide oxidizing bacteria in corroded concrete from sewers.

    PubMed

    Jensen, Henriette Stokbro; Lens, Piet N L; Nielsen, Jeppe L; Bester, Kai; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2011-05-30

    Hydrogen sulfide oxidation by microbes present on concrete surfaces of sewer pipes is a key process in sewer corrosion. The growth of aerobic sulfur oxidizing bacteria from corroded concrete surfaces was studied in a batch reactor. Samples of corrosion products, containing sulfur oxidizing bacteria, were suspended in aqueous solution at pH similar to that of corroded concrete. Hydrogen sulfide was supplied to the reactor to provide the source of reduced sulfur. The removal of hydrogen sulfide and oxygen was monitored. The utilization rates of both hydrogen sulfide and oxygen suggested exponential bacterial growth with median growth rates of 1.25 d(-1) and 1.33 d(-1) as determined from the utilization rates of hydrogen sulfide and oxygen, respectively. Elemental sulfur was found to be the immediate product of the hydrogen sulfide oxidation. When exponential growth had been achieved, the addition of hydrogen sulfide was terminated leading to elemental sulfur oxidation. The ratio of consumed sulfur to consumed oxygen suggested that sulfuric acid was the ultimate oxidation product. To the knowledge of the authors, this is the first study to determine the growth rate of bacteria involved in concrete corrosion with hydrogen sulfide as source of reduced sulfur. PMID:21440988

  7. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must... Contents of Exploration Plans (ep) § 250.215 What hydrogen sulfide (H2S) information must accompany the...

  8. Growth kinetics of hydrogen sulfide oxidizing bacteria in corroded concrete from sewers.

    PubMed

    Jensen, Henriette Stokbro; Lens, Piet N L; Nielsen, Jeppe L; Bester, Kai; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2011-05-30

    Hydrogen sulfide oxidation by microbes present on concrete surfaces of sewer pipes is a key process in sewer corrosion. The growth of aerobic sulfur oxidizing bacteria from corroded concrete surfaces was studied in a batch reactor. Samples of corrosion products, containing sulfur oxidizing bacteria, were suspended in aqueous solution at pH similar to that of corroded concrete. Hydrogen sulfide was supplied to the reactor to provide the source of reduced sulfur. The removal of hydrogen sulfide and oxygen was monitored. The utilization rates of both hydrogen sulfide and oxygen suggested exponential bacterial growth with median growth rates of 1.25 d(-1) and 1.33 d(-1) as determined from the utilization rates of hydrogen sulfide and oxygen, respectively. Elemental sulfur was found to be the immediate product of the hydrogen sulfide oxidation. When exponential growth had been achieved, the addition of hydrogen sulfide was terminated leading to elemental sulfur oxidation. The ratio of consumed sulfur to consumed oxygen suggested that sulfuric acid was the ultimate oxidation product. To the knowledge of the authors, this is the first study to determine the growth rate of bacteria involved in concrete corrosion with hydrogen sulfide as source of reduced sulfur.

  9. Giant hydrogen sulfide plume in the oxygen minimum zone off Peru supports chemolithoautotrophy.

    PubMed

    Schunck, Harald; Lavik, Gaute; Desai, Dhwani K; Großkopf, Tobias; Kalvelage, Tim; Löscher, Carolin R; Paulmier, Aurélien; Contreras, Sergio; Siegel, Herbert; Holtappels, Moritz; Rosenstiel, Philip; Schilhabel, Markus B; Graco, Michelle; Schmitz, Ruth A; Kuypers, Marcel M M; Laroche, Julie

    2013-01-01

    In Eastern Boundary Upwelling Systems nutrient-rich waters are transported to the ocean surface, fuelling high photoautotrophic primary production. Subsequent heterotrophic decomposition of the produced biomass increases the oxygen-depletion at intermediate water depths, which can result in the formation of oxygen minimum zones (OMZ). OMZs can sporadically accumulate hydrogen sulfide (H2S), which is toxic to most multicellular organisms and has been implicated in massive fish kills. During a cruise to the OMZ off Peru in January 2009 we found a sulfidic plume in continental shelf waters, covering an area >5500 km(2), which contained ∼2.2×10(4) tons of H2S. This was the first time that H2S was measured in the Peruvian OMZ and with ∼440 km(3) the largest plume ever reported for oceanic waters. We assessed the phylogenetic and functional diversity of the inhabiting microbial community by high-throughput sequencing of DNA and RNA, while its metabolic activity was determined with rate measurements of carbon fixation and nitrogen transformation processes. The waters were dominated by several distinct γ-, δ- and ε-proteobacterial taxa associated with either sulfur oxidation or sulfate reduction. Our results suggest that these chemolithoautotrophic bacteria utilized several oxidants (oxygen, nitrate, nitrite, nitric oxide and nitrous oxide) to detoxify the sulfidic waters well below the oxic surface. The chemolithoautotrophic activity at our sampling site led to high rates of dark carbon fixation. Assuming that these chemolithoautotrophic rates were maintained throughout the sulfidic waters, they could be representing as much as ∼30% of the photoautotrophic carbon fixation. Postulated changes such as eutrophication and global warming, which lead to an expansion and intensification of OMZs, might also increase the frequency of sulfidic waters. We suggest that the chemolithoautotrophically fixed carbon may be involved in a negative feedback loop that could fuel

  10. Giant Hydrogen Sulfide Plume in the Oxygen Minimum Zone off Peru Supports Chemolithoautotrophy

    PubMed Central

    Großkopf, Tobias; Kalvelage, Tim; Löscher, Carolin R.; Paulmier, Aurélien; Contreras, Sergio; Siegel, Herbert; Holtappels, Moritz; Rosenstiel, Philip; Schilhabel, Markus B.; Graco, Michelle; Schmitz, Ruth A.; Kuypers, Marcel M. M.; LaRoche, Julie

    2013-01-01

    In Eastern Boundary Upwelling Systems nutrient-rich waters are transported to the ocean surface, fuelling high photoautotrophic primary production. Subsequent heterotrophic decomposition of the produced biomass increases the oxygen-depletion at intermediate water depths, which can result in the formation of oxygen minimum zones (OMZ). OMZs can sporadically accumulate hydrogen sulfide (H2S), which is toxic to most multicellular organisms and has been implicated in massive fish kills. During a cruise to the OMZ off Peru in January 2009 we found a sulfidic plume in continental shelf waters, covering an area >5500 km2, which contained ∼2.2×104 tons of H2S. This was the first time that H2S was measured in the Peruvian OMZ and with ∼440 km3 the largest plume ever reported for oceanic waters. We assessed the phylogenetic and functional diversity of the inhabiting microbial community by high-throughput sequencing of DNA and RNA, while its metabolic activity was determined with rate measurements of carbon fixation and nitrogen transformation processes. The waters were dominated by several distinct γ-, δ- and ε-proteobacterial taxa associated with either sulfur oxidation or sulfate reduction. Our results suggest that these chemolithoautotrophic bacteria utilized several oxidants (oxygen, nitrate, nitrite, nitric oxide and nitrous oxide) to detoxify the sulfidic waters well below the oxic surface. The chemolithoautotrophic activity at our sampling site led to high rates of dark carbon fixation. Assuming that these chemolithoautotrophic rates were maintained throughout the sulfidic waters, they could be representing as much as ∼30% of the photoautotrophic carbon fixation. Postulated changes such as eutrophication and global warming, which lead to an expansion and intensification of OMZs, might also increase the frequency of sulfidic waters. We suggest that the chemolithoautotrophically fixed carbon may be involved in a negative feedback loop that could fuel further

  11. Hydrogen sulfide intervention in focal cerebral ischemia/reperfusion injury in rats.

    PubMed

    Li, Xin-Juan; Li, Chao-Kun; Wei, Lin-Yu; Lu, Na; Wang, Guo-Hong; Zhao, Hong-Gang; Li, Dong-Liang

    2015-06-01

    The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors.

  12. Hydrogen sulfide intervention in focal cerebral ischemia/reperfusion injury in rats

    PubMed Central

    Li, Xin-juan; Li, Chao-kun; Wei, Lin-yu; Lu, Na; Wang, Guo-hong; Zhao, Hong-gang; Li, Dong-liang

    2015-01-01

    The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors. PMID:26199610

  13. Catalytic oxidation of aqueous hydrogen sulfide in the presence of sulfite

    SciTech Connect

    Weres, O.; Tsao, L.; Chhatre, R.M.

    1985-06-01

    Nickel sulfate catalyzes the reaction of hydrogen sulfide with oxygen in aqueous solution. This reaction was studied, and an empirical rate expression and a reaction mechanism were deduced. The rate of oxidation is independent of oxygen concentration and pH over the range investigated. The reaction rate is one half order in nickel, and it changes from second to first order in sulfide with increasing concentration. The oxidation reaction is an autocatalytic, free radical chain reaction. Nickel catalyzes the chain initiation step, and polysulfido radical ions propagate the chains. Colloidal sulfur is a major, frequently undesirable reaction product. Sodium sulfite suppresses formation of colloidal sulfur by converting it to thiosulfate. Cobalt is an equally potent catalyst, but a colloidal dispersion of cobalt oxysulfide is produced. Iron compounds are much weaker catalysts; iron citrate and iron HEDTA (n-hydroxyethylenediaminetriacetic acid) were among those tested. 24 references, 15 figures, 3 tables.

  14. An intercomparison of aircraft instrumentation for tropospheric measurements of carbonyl sulfide, hydrogen sulfide, and carbon disulfide

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Davis, Douglas D.; Thornton, Donald C.; Johnson, James E.; Bandy, Alan R.; Saltzman, Eric S.; Andreae, Meinrat O.; Barrick, John D.

    1993-01-01

    This paper reports results of NASA's Chemical Instrumentation and Test Evaluation (CITE 3) during which airborne measurements for carbonyl sulfide (COS), hydrogen sulfide (H2S), and carbon disulfide (CS2) were intercompared. Instrumentation included a gas chromatograph using flame photometric detection (COS, H2S, and CS2), a gas chromatograph using mass spectrometric detection (COS) and CS2), a gas chromatograph using fluorination and subsequent SF6 detection via electron capture (COS and CS2), and the Natusch technique (H2S). The measurements were made over the Atlantic Ocean east of North and South America during flights from NASA's Wallops Flight Center, Virginia, and Natal, Brazil, in August/September 1989. Most of the intercomparisons for H2S and CS2 were at mixing ratios less than 25 pptv and less than 10 pptv, respectively, with a maximum mixing ratio of about 100 pptv and 50 pptv, respectively. Carbonyl sulfide intercomparisons were at mixing ratios between 400 and 600 pptv. Measurements were intercompared from data bases constructed from time periods of simultaneous or overlapping measurements. Agreement among the COS techniques averaged about 5%, and individual measurements were generally within 10%. For H2S and at mixing ratio greater than 25 pptv, the instruments agreed on average to about 15%. At mixing ratios less than 25 pptv the agreement was about 5 pptv. For CS2 (mixing ratios less than 50 pptv), two techniques agreed on average to about 4 pptv, and the third exhibited a bias (relative to the other two) that varied in the range of 3-7 pptv. CS2 mixing ratios over the ocean east of Natal as measured by the gas chromatograph-mass spectrometer technique were only a few pptv and were below the detection limits of the other two techniques. The CITE 3 data are used to estimate the current uncertainty associated with aircraft measurements of COS, H2S, and CS2 in the remote troposphere.

  15. Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

    1991-01-01

    Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

  16. Carbonyl sulfide removal with compost and wood chip biofilters, and in the presence of hydrogen sulfide.

    PubMed

    Sattler, Melanie L; Garrepalli, Divya R; Nawal, Chandraprakash S

    2009-12-01

    Carbonyl sulfide (COS) is an odor-causing compound and hazardous air pollutant emitted frequently from wastewater treatment facilities and chemical and primary metals industries. This study examined the effectiveness of biofiltration in removing COS. Specific objectives were to compare COS removal efficiency for various biofilter media; to determine whether hydrogen sulfide (H2S), which is frequently produced along with COS under anaerobic conditions, adversely impacts COS removal; and to determine the maximum elimination capacity of COS for use in biofilter design. Three laboratory-scale polyvinyl chloride biofilter columns were filled with up to 28 in. of biofilter media (aged compost, fresh compost, wood chips, or a compost/wood chip mixture). Inlet COS ranged from 5 to 46 parts per million (ppm) (0.10-9.0 g/m3 hr). Compost and the compost/wood chip mixture produced higher COS removal efficiencies than wood chips alone. The compost and compost/wood chip mixture had a shorter stabilization times compared with wood chips alone. Fresh versus aged compost did not impact COS removal efficiency. The presence of H2S did not adversely impact COS removal for the concentration ratios tested. The maximum elimination capacity is at least 9 g/m3 hr for COS with compost media.

  17. Carbonyl sulfide removal with compost and wood chip biofilters, and in the presence of hydrogen sulfide.

    PubMed

    Sattler, Melanie L; Garrepalli, Divya R; Nawal, Chandraprakash S

    2009-12-01

    Carbonyl sulfide (COS) is an odor-causing compound and hazardous air pollutant emitted frequently from wastewater treatment facilities and chemical and primary metals industries. This study examined the effectiveness of biofiltration in removing COS. Specific objectives were to compare COS removal efficiency for various biofilter media; to determine whether hydrogen sulfide (H2S), which is frequently produced along with COS under anaerobic conditions, adversely impacts COS removal; and to determine the maximum elimination capacity of COS for use in biofilter design. Three laboratory-scale polyvinyl chloride biofilter columns were filled with up to 28 in. of biofilter media (aged compost, fresh compost, wood chips, or a compost/wood chip mixture). Inlet COS ranged from 5 to 46 parts per million (ppm) (0.10-9.0 g/m3 hr). Compost and the compost/wood chip mixture produced higher COS removal efficiencies than wood chips alone. The compost and compost/wood chip mixture had a shorter stabilization times compared with wood chips alone. Fresh versus aged compost did not impact COS removal efficiency. The presence of H2S did not adversely impact COS removal for the concentration ratios tested. The maximum elimination capacity is at least 9 g/m3 hr for COS with compost media. PMID:20066911

  18. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs.

    PubMed

    Klatt, Judith M; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    2015-09-01

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2 S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2 S: (i) H2 S accelerated the recovery of photosynthesis after prolonged exposure to darkness and anoxia. We suggest that this is possibly due to regulatory effects of H2 S on photosystem I components and/or on the Calvin cycle. (ii) H2 S concentrations of up to 210 μM temporarily enhanced the photosynthetic rates at low irradiance. Modelling showed that this enhancement is plausibly based on changes in the light-harvesting efficiency. (iii) Above a certain light-dependent concentration threshold H2 S also acted as an inhibitor. Intriguingly, this inhibition was not instant but occurred only after a specific time interval that decreased with increasing light intensity. That photosynthesis is most sensitive to inhibition at high light intensities suggests that H2 S inactivates an intermediate of the oxygen evolving complex that accumulates with increasing light intensity. We discuss the implications of these three effects of H2 S in the context of cyanobacterial photosynthesis under conditions with diurnally fluctuating light and H2 S concentrations, such as those occurring in microbial mats and biofilms.

  19. Analytical measurement of discrete hydrogen sulfide pools in biological specimens.

    PubMed

    Shen, Xinggui; Peter, Elvis A; Bir, Shyamal; Wang, Rui; Kevil, Christopher G

    Hydrogen sulfide (H₂S) is a ubiquitous gaseous signaling molecule that plays a vital role in numerous cellular functions and has become the focus of many research endeavors, including pharmacotherapeutic manipulation. Among the challenges facing the field is the accurate measurement of biologically active H₂S. We have recently reported that the typically used methylene blue method and its associated results are invalid and do not measure bona fide H₂S. The complexity of analytical H₂S measurement reflects the fact that hydrogen sulfide is a volatile gas and exists in the body in various forms, including a free form, an acid-labile pool, and bound as sulfane sulfur. Here we describe a new protocol to discretely measure specific H₂S pools using the monobromobimane method coupled with RP-HPLC. This new protocol involves selective liberation, trapping, and derivatization of H₂S. Acid-labile H₂S is released by incubating the sample in an acidic solution (pH 2.6) of 100 mM phosphate buffer with 0.1mM diethylenetriaminepentaacetic acid (DTPA), in an enclosed system to contain volatilized H₂S. Volatilized H₂S is then trapped in 100 mM Tris-HCl (pH 9.5, 0.1 mM DTPA) and then reacted with excess monobromobimane. In a separate aliquot, the contribution of the bound sulfane sulfur pool was measured by incubating the sample with 1 mM TCEP (tris(2-carboxyethyl)phosphine hydrochloride), a reducing agent, to reduce disulfide bonds, in 100 mM phosphate buffer (pH 2.6, 0.1 mM DTPA), and H₂S measurement was performed in a manner analogous to the one described above. The acid-labile pool was determined by subtracting the free hydrogen sulfide value from the value obtained by the acid-liberation protocol. The bound sulfane sulfur pool was determined by subtracting the H₂S measurement from the acid-liberation protocol alone compared to that of TCEP plus acidic conditions. In summary, our new method allows very sensitive and accurate measurement of the three primary

  20. High temperature hydrogen sulfide removal with tin oxide

    SciTech Connect

    Karpuk, M.E.; Copeland, R.J.; Feinberg, D.; Wickham, D.; Windecker, B.; Yu, J.

    1993-09-01

    The system is based on the absorption of hydrogen sulfide (H{sub 2}S) by stannic (tin) oxide. Two sorbents are required, the first sorbent is tin oxide and the second sorbent is a zinc oxide based material (i.e., zinc ferrite or zinc titanate) which is regenerated by air producing SO{sub 2}. TDA`s process carries out a modified Claus reaction to reduce the SO{sub 2} from the second sorbent generation to elemental sulfur. In this case the sulfided stannic oxide forms stannous sulfide (SnS) which reduces the SO{sub 2}. The absorption by SnO{sub 2} could remove over 90% of the H{sub 2}S from typical coal gas streams, but we use zinc ferrite (or zinc titanate), (a) to reduce H{sub 2}S to less than 20 ppM and (b) as a source of SO{sub 2} in regeneration. Due to stoichiometry of regeneration we want to remove half of the H{sub 2}S by SnO{sub 2} and the remainder by the second sorbent. The reactions with stannic oxide minimize the heat released during H{sub 2}S removal and regeneration. The absorption by SnO{sub 2} is slightly endothermic and cools the gas stream by less that 5{degrees}F (2.8{degrees}C) during absorption. Regeneration with SO{sub 2} is exothermic but releases only 11% of the heat that is liberated in regenerating the ZnO. For a nominal 6.5:1 steam to air the regeneration of ZnO increases the temperature by {approx_equal}400{degrees}F. The regeneration of SnO{sub 2} increases the temperature by less than 50{degrees}F (28{degrees}C) in the same gas flow.

  1. Understanding hydrogen sulfide storage: probing conditions for sulfide release from hydrodisulfides.

    PubMed

    Bailey, T Spencer; Zakharov, Lev N; Pluth, Michael D

    2014-07-30

    Hydrogen sulfide (H2S) is an important biological signaling agent that exerts action on numerous (patho)physiological processes. Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides. Despite the importance of hydrodisulfides in H2S storage and signaling, little is known about the physical properties or chemical reactivity of these compounds. We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases. Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool. PMID:25010540

  2. Process for removal of hydrogen sulfide from gas streams

    SciTech Connect

    Hansford, R.C.; Hass, R.H.

    1981-01-06

    A process for the removal of H/sub 2/S from a feed gas, and the production of sulfur therefrom, is effected by oxidation with oxygen and/or SO/sub 2/ at temperatures between 250* and 450* F. The oxidation is conducted in the presence of an extremely stable oxidation catalyst comprising an oxide and/or sulfide of vanadium supported on a non-alkaline porous refractory oxide. Sulfur deposition and consequent catalyst deactivation are prevented by maintaining the partial pressure of free sulfur in the oxidation reactor below that necessary for condensation. H/sub 2/, CO, and light hydrocarbons present in the feed gas are not oxidized. Typical uses of the process include the removal of H/sub 2/S and the production of sulfur from sour natural gases or gases obtained from the gasification of coal. Feed gases which contain SO/sub 2/ and H/sub 2/S in mole ratios greater than 5, or which contain other gaseous sulfur compounds such as CO, CS/sub 2/, SO/sub 3/ and mercaptans, can be desulfurized by hydrogenating all of such sulfur components to H/sub 2/S and subsequently removing the H/sub 2/S from the hydrogenated feed gas by the oxidation process of the invention. This hydrogenation-oxidation combination is especially contemplated for the desulfurization of claus tail gases and stack gas effluents.

  3. Process for removal of hydrogen sulfide from gas streams

    SciTech Connect

    Hansford, R.C.; Hass, R.H.

    1982-01-19

    A process for the removal of H2S from a feed gas, and the production of sulfur therefrom, is effected by oxidation with oxygen and/or SO2 at temperatures between 250 and 450/sup 0/F. The oxidation is conducted in the presence of an extremely stable oxidation catalyst comprising an oxide and/or sulfide of vanadium supported on a non-alkaline porous refractory oxide. Sulfur deposition and consequent catalyst deactivation are prevented by maintaining the partial pressure of free sulfur in the oxidation reactor below that necessary for condensation. H2, CO, and light hydrocarbons present in the feed gas are not oxidized. Typical uses of the process include the removal of H2S and the production of sulfur from sour natural gases or gases obtained from the gasification of coal. Feed gases which contain SO2 and H2S in mole ratios greater than 5, or which contain other gaseous sulfur compounds such as CO CS2, SO3 and mercaptans, can be desulfurized by hydrogenating all of such sulfur components to H2S and subsequently removing the H2S from the hydrogenated feed gas by the oxidation process of the invention. This hydrogenation-oxidation combination is especially contemplated for the desulfurization of claus tail gases and stack gas effluents.

  4. Endogenous hydrogen sulfide is involved in the pathogenesis of atherosclerosis

    SciTech Connect

    Qiao, Wang; Chaoshu, Tang; Hongfang, Jin; Junbao, Du

    2010-05-28

    Atherosclerosis is a chronic, complex, and progressive pathological process in large and medium sized arteries. The exact mechanism of this process remains unclear. Hydrogen sulfide (H{sub 2}S), a novel gasotransmitter, was confirmed as playing a major role in the pathogenesis of many cardiovascular diseases. It plays a role in vascular smooth muscle cell (VSMC) proliferation and apoptosis, participates in the progress of hyperhomocysteinemia (HHCY), inhibits atherogenic modification of LDL, interferes with vascular calcification, intervenes with platelet function, and there are interactions between H{sub 2}S and inflammatory processes. The role of H{sub 2}S in atherosclerotic pathogenesis highlights the mysteries of atherosclerosis and inspires the search for innovative therapeutic strategies. Here, we review the studies to date that have considered the role of H{sub 2}S in atherosclerosis.

  5. Protein-based nanobiosensor for direct detection of hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Omidi, Meisam; Amoabediny, Ghasem; Yazdian, Fatemeh; Habibi-Rezaei, M.

    2015-01-01

    The chemically modified cytochrome c from equine heart, EC (232-700-9), was immobilized onto gold nanoparticles in order to develop a specific biosensing system for monitoring hydrogen sulfide down to the micromolar level, by means of a localized surface plasmon resonance spectroscopy. The sensing mechanism is based on the cytochrome-c conformational changes in the presence of H2S which alter the dielectric properties of the gold nanoparticles and the surface plasmon resonance peak undergoes a redshift. According to the experiments, it is revealed that H2S can be detected at a concentration of 4.0 μ \\text{M} (1.3 \\text{ppb}) by the fabricated biosensor. This simple, quantitative and sensitive sensing platform provides a rapid and convenient detection for H2S at concentrations far below the hazardous limit.

  6. Role of Hydrogen Sulfide in Ischemia-Reperfusion Injury

    PubMed Central

    Wu, Dongdong; Wang, Jun; Li, Hui; Xue, Mengzhou; Ji, Ailing; Li, Yanzhang

    2015-01-01

    Ischemia-reperfusion (I/R) injury is one of the major causes of high morbidity, disability, and mortality in the world. I/R injury remains a complicated and unresolved situation in clinical practice, especially in the field of solid organ transplantation. Hydrogen sulfide (H2S) is the third gaseous signaling molecule and plays a broad range of physiological and pathophysiological roles in mammals. H2S could protect against I/R injury in many organs and tissues, such as heart, liver, kidney, brain, intestine, stomach, hind-limb, lung, and retina. The goal of this review is to highlight recent findings regarding the role of H2S in I/R injury. In this review, we present the production and metabolism of H2S and further discuss the effect and mechanism of H2S in I/R injury. PMID:26064416

  7. Hydrogen Sulfide, Oxidative Stress and Periodontal Diseases: A Concise Review

    PubMed Central

    Greabu, Maria; Totan, Alexandra; Miricescu, Daniela; Radulescu, Radu; Virlan, Justina; Calenic, Bogdan

    2016-01-01

    In the past years, biomedical research has recognized hydrogen sulfide (H2S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gastransmitter with paramount roles in health and disease. Current research focuses on several aspects of H2S biology such as the biochemical pathways that generate the compound and its functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present work addresses the knowledge we have to date on H2S production and its biological roles in the general human environment with a special focus on the oral cavity and its involvement in the initiation and development of periodontal diseases. PMID:26805896

  8. Hydrogen Sulfide, Oxidative Stress and Periodontal Diseases: A Concise Review.

    PubMed

    Greabu, Maria; Totan, Alexandra; Miricescu, Daniela; Radulescu, Radu; Virlan, Justina; Calenic, Bogdan

    2016-01-01

    In the past years, biomedical research has recognized hydrogen sulfide (H₂S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gastransmitter with paramount roles in health and disease. Current research focuses on several aspects of H₂S biology such as the biochemical pathways that generate the compound and its functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present work addresses the knowledge we have to date on H₂S production and its biological roles in the general human environment with a special focus on the oral cavity and its involvement in the initiation and development of periodontal diseases. PMID:26805896

  9. Release and control of hydrogen sulfide during sludge thermal drying

    SciTech Connect

    Weng, Huanxin; Dai, Zhixin; Ji, Zhongqiang; Gao, Caixia; Liu, Chongxuan

    2015-04-15

    The release of hydrogen sulfide (H2S) during sludge drying is a major environmental problem because of its toxicity to human health. A series of experiments were performed to investigate the mechanisms and factors controlling the H2S release. Results of this study show that: 1) the biomass and activity of sulfate-reducing bacteria (SRB) in sludge were the major factors controlling the amount of H2S release, 2) the sludge drying temperature had an important effect on both the extent and the timing of H2S release from the sludge, and 3) decreasing sludge pH increased the H2S release. Based on the findings from this study, a new system that integrates sludge drying and H2S gas treatment was developed to reduce the amount of H2S released from sludge treatments.

  10. Observation of superconductivity in hydrogen sulfide from nuclear resonant scattering.

    PubMed

    Troyan, Ivan; Gavriliuk, Alexander; Rüffer, Rudolf; Chumakov, Alexander; Mironovich, Anna; Lyubutin, Igor; Perekalin, Dmitry; Drozdov, Alexander P; Eremets, Mikhail I

    2016-03-18

    High-temperature superconductivity remains a focus of experimental and theoretical research. Hydrogen sulfide (H2S) has been reported to be superconducting at high pressures and with a high transition temperature. We report on the direct observation of the expulsion of the magnetic field in H2S compressed to 153 gigapascals. A thin (119)Sn film placed inside the H2S sample was used as a sensor of the magnetic field. The magnetic field on the (119)Sn sensor was monitored by nuclear resonance scattering of synchrotron radiation. Our results demonstrate that an external static magnetic field of about 0.7 tesla is expelled from the volume of (119)Sn foil as a result of the shielding by the H2S sample at temperatures between 4.7 K and approximately 140 K, revealing a superconducting state of H2S. PMID:26989248

  11. Sulfur as a Signaling Nutrient Through Hydrogen Sulfide

    PubMed Central

    Kabil, Omer; Vitvitsky, Victor; Banerjee, Ruma

    2015-01-01

    Hydrogen sulfide (H2S) has emerged as an important signaling molecule with beneficial effects on various cellular processes affecting, for example, cardiovascular and neurological functions. The physiological importance of H2S is motivating efforts to develop strategies for modulating its levels. However, advancement in the field of H2S-based therapeutics is hampered by fundamental gaps in our knowledge of how H2S is regulated, its mechanism of action, and its molecular targets. This review provides an overview of sulfur metabolism; describes recent progress that has shed light on the mechanism of H2S as a signaling molecule; and examines nutritional regulation of sulfur metabolism, which pertains to health and disease. PMID:25033061

  12. Recent advances in fluorescent probes for monitoring of hydrogen sulfide.

    PubMed

    Duan, Cun-Xian; Liu, Yu-Guo

    2013-01-01

    Hydrogen sulfide (H₂S), known for its unpleasant rotten egg smell and its high toxicity, has recently emerged as an important mediator of human physiological and pathological processes, such as the regulation of cell growth, cardiovascular protection, the stimulation of angiogenesis, gastric mucosal injury and Alzheimer's disease. Due to its significant actions in the physiology, H₂S has attracted the abundant concern of numerous researchers in the cutting edge of chemistry, biology and medicine. Recently, several fluorescent probes have been developed for detecting and elucidating the role played by H₂S in biological systems. This review highlights recent advances that have been made on the mechanism and applications of fluorescent probes for the detection of H₂S, demonstrating a new field in which remarkable improvements have been accomplished over the last two years.

  13. Hydrogen Sulfide Chemical Biology: Pathophysiological roles and detection

    PubMed Central

    Kolluru, Gopi K; Shen, Xinggui; Bir, Shyamal C.; Kevil, Christopher G.

    2014-01-01

    Hydrogen sulfide (H2S) is the most recent endogenous gasotransmitter that has been reported to serve many physiological and pathological functions in different tissues. Studies over the past decade have revealed that H2S can be synthesized through numerous pathways and its bioavailability regulated through its conversion into different biochemical forms. H2S exerts its biological effects in various manners including redox regulation of protein and small molecular weight thiols, polysulfides, thiosulfate/sulfite, iron-sulfur cluster proteins, and anti-oxidant properties that affect multiple cellular and molecular responses. However, precise measurement of H2S bioavailability and its associated biochemical and pathophysiological roles remains less well understood. In this review, we discuss recent understanding of H2S chemical biology, its relationship to tissue pathophysiological responses and possible therapeutic uses. PMID:23850632

  14. Hydrogen sulfide removal from sediment and water in box culverts/storm drains by iron-based granules.

    PubMed

    Sun, J L; Shang, C; Kikkert, G A

    2013-01-01

    A renewable granular iron-based technology for hydrogen sulfide removal from sediment and water in box culverts and storm drains is discussed. Iron granules, including granular ferric hydroxide (GFH), granular ferric oxide (GFO) and rusted waste iron crusts (RWIC) embedded in the sediment phase removed aqueous hydrogen sulfide formed from sedimentary biological sulfate reduction. The exhausted iron granules were exposed to dissolved oxygen and this regeneration process recovered the sulfide removal capacities of the granules. The recovery is likely attributable to the oxidation of the ferrous iron precipitates film and the formation of new reactive ferric iron surface sites on the iron granules and sand particles. GFH and RWIC showed larger sulfide removal capacities in the sediment phase than GFO, likely due to the less ordered crystal structures on their surfaces. This study demonstrates that the iron granules are able to remove hydrogen sulfide from sediment and water in box culverts and storm drains and they have the potential to be regenerated and reused by contacting with dissolved oxygen.

  15. Hydrogen sulfide removal from sediment and water in box culverts/storm drains by iron-based granules.

    PubMed

    Sun, J L; Shang, C; Kikkert, G A

    2013-01-01

    A renewable granular iron-based technology for hydrogen sulfide removal from sediment and water in box culverts and storm drains is discussed. Iron granules, including granular ferric hydroxide (GFH), granular ferric oxide (GFO) and rusted waste iron crusts (RWIC) embedded in the sediment phase removed aqueous hydrogen sulfide formed from sedimentary biological sulfate reduction. The exhausted iron granules were exposed to dissolved oxygen and this regeneration process recovered the sulfide removal capacities of the granules. The recovery is likely attributable to the oxidation of the ferrous iron precipitates film and the formation of new reactive ferric iron surface sites on the iron granules and sand particles. GFH and RWIC showed larger sulfide removal capacities in the sediment phase than GFO, likely due to the less ordered crystal structures on their surfaces. This study demonstrates that the iron granules are able to remove hydrogen sulfide from sediment and water in box culverts and storm drains and they have the potential to be regenerated and reused by contacting with dissolved oxygen. PMID:24355850

  16. Low-level hydrogen sulfide and central nervous system dysfunction.

    PubMed

    Kilburn, Kaye H; Thrasher, Jack D; Gray, Michael R

    2010-08-01

    Forty-nine adults living in Lovington, Tatum, and Artesia, the sour gas/oil sector of Southeastern New Mexico, were tested for neurobehavioral impairment. Contributing hydrogen sulfide were (1) an anaerobic sewage plant; (2) two oil refineries; (3) natural gas/oil wells and (4) a cheese-manufacturing plant and its waste lagoons. Comparisons were to unexposed Wickenburg, Arizona, adults. Neurobehavioral functions were measured in 26 Lovington adults including 23 people from Tatum and Artesia, New Mexico, and 42 unexposed Arizona people. Participants completed questionnaires including chemical exposures, symptom frequencies and the Profile of Mood States. Measurements included balance, reaction time, color discrimination, blink reflex, visual fields, grip strength, hearing, vibration, problem solving, verbal recall, long-term memory, peg placement, trail making and fingertip number writing errors (FTNWE). Average numbers of abnormalities and test scores were adjusted for age, gender, educational level, height and weight, expressed as percent predicted (% pred) and compared by analysis of variance (ANOVA). Ages and educational attainment of the three groups were not statistically significantly different (ssd). Mean values of Lovington residents were ssd from the unexposed Arizona people for simple and choice reaction times, balance with eyes open and closed, visual field score, hearing and grip strength. Culture Fair, digit symbol substitution, vocabulary, verbal recall, peg placement, trail making A and B, FTNWE, information, picture completion and similarities were also ssd. The Lovington adults who averaged 11.8 abnormalities were ssd from, Tatum-Artesia adults who had 3.6 and from unexposed subjects with 2.0. Multiple source community hydrogen sulfide exposures impaired neurobehavioral functions.

  17. The effects of varying humidity on copper sulfide film formation.

    SciTech Connect

    Mayer, Thomas Michael; Missert, Nancy A.; Barbour, John Charles; Sullivan, John Patrick; Copeland, Robert Guild; Campin, Michael J.

    2004-02-01

    Detailed experiments involving extensive high resolution transmission electron microscopy (TEM) revealed significant microstructural differences between Cu sulfides formed at low and high relative humidity (RH). It was known from prior experiments that the sulfide grows linearly with time at low RH up to a sulfide thickness approaching or exceeding one micron, while the sulfide initially grows linearly with time at high RH then becomes sub-linear at a sulfide thickness less than about 0.2 microns, with the sulfidation rate eventually approaching zero. TEM measurements of the Cu2S morphology revealed that the Cu2S formed at low RH has large sized grains (75 to greater than 150 nm) that are columnar in structure with sharp, abrupt grain boundaries. In contrast, the Cu2S formed at high RH has small equiaxed grains of 20 to 50 nm in size. Importantly, the small grains formed at high RH have highly disordered grain boundaries with a high concentration of nano-voids. Two-dimensional diffusion modeling was performed to determine whether the existence of localized source terms at the Cu/Cu2S interface could be responsible for the suppression of Cu sulfidation at long times at high RH. The models indicated that the existence of static localized source terms would not predict the complete suppression of growth that was observed. Instead, the models suggest that the diffusion of Cu through Cu2S becomes restricted during Cu2S formation at high RH. The leading speculation is that the extensive voiding that exists at grain boundaries in this material greatly reduces the flux of Cu between grains, leading to a reduction in the rate of sulfide film formation. These experiments provide an approach for adding microstructural information to Cu sulfidation rate computer models. In addition to the microstructural studies, new micro-patterned test structures were developed in this LDRD to offer insight into the point defect structure of Cu2S and to permit measurement of surface reaction

  18. Structural effects of naphthalimide-based fluorescent sensor for hydrogen sulfide and imaging in live zebrafish

    NASA Astrophysics Data System (ADS)

    Choi, Seon-Ae; Park, Chul Soon; Kwon, Oh Seok; Giong, Hoi-Khoanh; Lee, Jeong-Soo; Ha, Tai Hwan; Lee, Chang-Soo

    2016-05-01

    Hydrogen sulfide (H2S) is an important biological messenger, but few biologically-compatible methods are available for its detection in aqueous solution. Herein, we report a highly water-soluble naphthalimide-based fluorescent probe (L1), which is a highly versatile building unit that absorbs and emits at long wavelengths and is selective for hydrogen sulfide over cysteine, glutathione, and other reactive sulfur, nitrogen, and oxygen species in aqueous solution. We describe turn-on fluorescent probes based on azide group reduction on the fluorogenic ‘naphthalene’ moiety to fluorescent amines and intracellular hydrogen sulfide detection without the use of an organic solvent. L1 and L2 were synthetically modified to functional groups with comparable solubility on the N-imide site, showing a marked change in turn-on fluorescent intensity in response to hydrogen sulfide in both PBS buffer and living cells. The probes were readily employed to assess intracellular hydrogen sulfide level changes by imaging endogenous hydrogen sulfide signal in RAW264.7 cells incubated with L1 and L2. Expanding the use of L1 to complex and heterogeneous biological settings, we successfully visualized hydrogen sulfide detection in the yolk, brain and spinal cord of living zebrafish embryos, thereby providing a powerful approach for live imaging for investigating chemical signaling in complex multicellular systems.

  19. Structural effects of naphthalimide-based fluorescent sensor for hydrogen sulfide and imaging in live zebrafish

    PubMed Central

    Choi, Seon-Ae; Park, Chul Soon; Kwon, Oh Seok; Giong, Hoi-Khoanh; Lee, Jeong-Soo; Ha, Tai Hwan; Lee, Chang-Soo

    2016-01-01

    Hydrogen sulfide (H2S) is an important biological messenger, but few biologically-compatible methods are available for its detection in aqueous solution. Herein, we report a highly water-soluble naphthalimide-based fluorescent probe (L1), which is a highly versatile building unit that absorbs and emits at long wavelengths and is selective for hydrogen sulfide over cysteine, glutathione, and other reactive sulfur, nitrogen, and oxygen species in aqueous solution. We describe turn-on fluorescent probes based on azide group reduction on the fluorogenic ‘naphthalene’ moiety to fluorescent amines and intracellular hydrogen sulfide detection without the use of an organic solvent. L1 and L2 were synthetically modified to functional groups with comparable solubility on the N-imide site, showing a marked change in turn-on fluorescent intensity in response to hydrogen sulfide in both PBS buffer and living cells. The probes were readily employed to assess intracellular hydrogen sulfide level changes by imaging endogenous hydrogen sulfide signal in RAW264.7 cells incubated with L1 and L2. Expanding the use of L1 to complex and heterogeneous biological settings, we successfully visualized hydrogen sulfide detection in the yolk, brain and spinal cord of living zebrafish embryos, thereby providing a powerful approach for live imaging for investigating chemical signaling in complex multicellular systems. PMID:27188400

  20. Metal-organic frameworks for the storage and delivery of biologically active hydrogen sulfide

    SciTech Connect

    Allan, Phoebe K; Wheatley, Paul S; Aldous, David; Mohideen, M Infas; Tang, Chiu; Hriljac, Joseph A; Megson, Ian L; Chapman, Karena W; De Weireld, Guy; Vaesen, Sebastian; Morris, Russell E

    2012-04-02

    Hydrogen sulfide is an extremely toxic gas that is also of great interest for biological applications when delivered in the correct amount and at the desired rate. Here we show that the highly porous metal-organic frameworks with the CPO-27 structure can bind the hydrogen sulfide relatively strongly, allowing the storage of the gas for at least several months. Delivered gas is biologically active in preliminary vasodilation studies of porcine arteries, and the structure of the hydrogen sulfide molecules inside the framework has been elucidated using a combination of powder X-ray diffraction and pair distribution function analysis.

  1. Mitigation of hydrogen sulfide emissions in The Geysers KGRA

    SciTech Connect

    Buell, R.

    1981-07-01

    Violations of the ambient air quality standard (AAQS) for hydrogen sulfide (H/sub 2/S) are currently being experienced in The Geysers KGRA and could significantly increase in the future. Attainment and maintenance of the H/sub 2/S AAQS is a potential constraint to optimum development of this resource. The availability of reliable H/sub 2/S controls and the development of a validated air dispersion model are critical to alleviating this constraint. The purpose of this report is to assess the performance capabilities for state-of-the-art controls, to identify potential cost-effective alternative controls, and to identify the California Energy Commission (CEC) staff's efforts to develop a validated air dispersion model. Currently available controls (Stretford, Hydrogen Peroxide, and EIC) are capable of abating H/sub 2/S emissions from a proposed facility to five lbs/hr. Alternative controls, such as condensate stripping and condensate pH control, appear to be promising, cost-effective control options.

  2. Methods for producing hydrogen (BI) sulfide and/or removing metals

    DOEpatents

    Truex, Michael J [Richland, WA; Peyton, Brent M [Pullman, WA; Toth, James J [Kennewick, WA

    2002-05-14

    The present invention is a process wherein sulfide production by bacteria is efficiently turned on and off, using pH adjustment. The adjustment of pH impacts sulfide production by bacteria by altering the relative amounts of H.sub.2 S and HS-- in solution and thereby control the inhibition of the bacterial metabolism that produces sulfide. This process can be used to make a bioreactor produce sulfide "on-demand" so that the production of sulfide can be matched to its use as a metal precipitation reagent. The present invention is of significance because it enables the use of a biological reactor, a cost effective sulfide production system, by making the biological reactor produce hydrogen sulfide "on demand", and therefore responsive to production schedules, waste stream generation rate, and health and safety requirements/goals.

  3. Hydrogen sulfide as an oxygen sensor in trout gill chemoreceptors.

    PubMed

    Olson, Kenneth R; Healy, Michael J; Qin, Zhaohong; Skovgaard, Nini; Vulesevic, Branka; Duff, Douglas W; Whitfield, Nathan L; Yang, Guangdong; Wang, Rui; Perry, Steve F

    2008-08-01

    O2 chemoreceptors elicit cardiorespiratory reflexes in all vertebrates, but consensus on O2-sensing signal transduction mechanism(s) is lacking. We recently proposed that hydrogen sulfide (H2S) metabolism is involved in O2 sensing in vascular smooth muscle. Here, we examined the possibility that H2S is an O2 sensor in trout chemoreceptors where the first pair of gills is a primary site of aquatic O2 sensing and the homolog of the mammalian carotid body. Intrabuccal injection of H2S in unanesthetized trout produced a dose-dependent bradycardia and increased ventilatory frequency and amplitude similar to the hypoxic response. Removal of the first, but not second, pair of gills significantly inhibited H2S-mediated bradycardia, consistent with the loss of aquatic chemoreceptors. mRNA for H2S-synthesizing enzymes, cystathionine beta-synthase and cystathionine gamma-lyase, was present in branchial tissue. Homogenized gills produced H2S enzymatically, and H2S production was inhibited by O2, whereas mitochondrial H2S consumption was O2 dependent. Ambient hypoxia did not affect plasma H2S in unanesthetized trout, but produced a PO2-dependent increase in a sulfide moiety suggestive of increased H2S production. In isolated zebrafish neuroepithelial cells, the putative chemoreceptive cells of fish, both hypoxia and H2S, produced a similar approximately 10-mV depolarization. These studies are consistent with H2S involvement in O2 sensing/signal transduction pathway(s) in chemoreceptive cells, as previously demonstrated in vascular smooth muscle. This novel mechanism, whereby H2S concentration ([H2S]) is governed by the balance between constitutive production and oxidation, tightly couples tissue [H2S] to PO2 and may provide an exquisitely sensitive, yet simple, O2 sensor in a variety of tissues.

  4. No facilitator required for membrane transport of hydrogen sulfide

    PubMed Central

    Mathai, John C.; Missner, Andreas; Kügler, Philipp; Saparov, Sapar M.; Zeidel, Mark L.; Lee, John K.; Pohl, Peter

    2009-01-01

    Hydrogen sulfide (H2S) has emerged as a new and important member in the group of gaseous signaling molecules. However, the molecular transport mechanism has not yet been identified. Because of structural similarities with H2O, it was hypothesized that aquaporins may facilitate H2S transport across cell membranes. We tested this hypothesis by reconstituting the archeal aquaporin AfAQP from sulfide reducing bacteria Archaeoglobus fulgidus into planar membranes and by monitoring the resulting facilitation of osmotic water flow and H2S flux. To measure H2O and H2S fluxes, respectively, sodium ion dilution and buffer acidification by proton release (H2S ⇆ H+ + HS−) were recorded in the immediate membrane vicinity. Both sodium ion concentration and pH were measured by scanning ion-selective microelectrodes. A lower limit of lipid bilayer permeability to H2S, PM,H2S ≥ 0.5 ± 0.4 cm/s was calculated by numerically solving the complete system of differential reaction diffusion equations and fitting the theoretical pH distribution to experimental pH profiles. Even though reconstitution of AfAQP significantly increased water permeability through planar lipid bilayers, PM,H2S remained unchanged. These results indicate that lipid membranes may well act as a barrier to water transport although they do not oppose a significant resistance to H2S diffusion. The fact that cholesterol and sphingomyelin reconstitution did not turn these membranes into an H2S barrier indicates that H2S transport through epithelial barriers, endothelial barriers, and membrane rafts also occurs by simple diffusion and does not require facilitation by membrane channels. PMID:19805349

  5. Impact of fermentation rate changes on potential hydrogen sulfide concentrations in wine.

    PubMed

    Butzke, Christian E; Park, Seung Kook

    2011-05-01

    The correlation between alcoholic fermentation rate, measured as carbon dioxide (CO2) evolution, and the rate of hydrogen sulfide (H2S) formation during wine production was investigated. Both rates and the resulting concentration peaks in fermentor headspace H2S were directly impacted by yeast assimilable nitrogenous compounds in the grape juice. A series of model fermentations was conducted in temperature-controlled and stirred fermentors using a complex model juice with defined concentrations of ammonium ions and/or amino acids. The fermentation rate was measured indirectly by noting the weight loss of the fermentor; H2S was quantitatively trapped in realtime using a pre-calibrated H2S detection tube which was inserted into a fermentor gas relief port. Evolution rates for CO2 and H2S as well as the relative ratios between them were calculated. These fermentations confirmed that total sulfide formation was strongly yeast strain-dependent, and high concentrations of yeast assimilable nitrogen did not necessarily protect against elevated H2S formation. High initial concentrations of ammonium ions via addition of diammonium phosphate (DAP) caused a higher evolution of H2S when compared with a non-supplemented but nondeficient juice. It was observed that the excess availability of a certain yeast assimilable amino acid, arginine, could result in a more sustained CO2 production rate throughout the wine fermentation. The contribution of yeast assimilable amino acids from conventional commercial yeast foods to lowering of the H2S formation was marginal. PMID:21617350

  6. Temperature-programmed sulfiding of precursor cobalt oxide genesis of highly active sites on sulfided cobalt catalyst for hydrogenation and isomerization

    SciTech Connect

    Inamura, Kazuhiro; Takyu, Toshiyuki ); Okamoto, Yasuaki; Nagata, Kozo; Imanaka, Toshinobu )

    1992-02-01

    It was found that the method of sulfidation of cobalt oxide strongly affects the catalytic activities and selectivities of the resultant cobalt sulfide catalyst, as well as the calcination temperature of the cobalt oxide. When cobalt oxide was sulfided at 673 K by a temperature-programmed sulfiding method (a heating rate of 6 K/min), catalytic activities for the hydrogenation of butadiene and the isomerization of 1-butene were considerably enhanced compared with those for cobalt sulfide prepared by isothermal sulfidation at 673 K. Results of temperature-programmed sulfiding (TPS), temperature-programmed reduction (TPR), and X-ray diffraction (XRD) suggest that the catalysts showing high catalytic activities after sulfidation are partially sulfided at 673 K and consist of the unsulfided cobalt core phases (CoO or metallic Co). The sulfidation property of precursor cobalt oxides has been studied using TPS, simulating the sulfidation process of the cobalt sulfide catalysts. Two distinctly different kinds of sulfidation process are estimated by TPS measurements of the cobalt oxides. The calcination temperature of the precursor cobalt oxides strongly affects the sulfidation paths. They are differentiated in terms of the presence of a metallic Co intermediate. The relationship of the mechanism of sulfidation of the cobalt oxides to the generation of highly active sites is discussed.

  7. Hyperbaric oxygen therapy in the management of two cases of hydrogen sulfide toxicity from liquid manure.

    PubMed

    Belley, Richard; Bernard, Nicolas; Côté, Mario; Paquet, Francois; Poitras, Julien

    2005-07-01

    Hydrogen sulfide is a potent lethal gas. Supportive care, nitrite therapy and hyperbaric oxygen are the treatment modalities reported in the literature in cases of hydrogen sulfide exposure. We describe an industrial exposure in which 6 workers inhaled high concentrations of hydrogen sulfide when they entered a closed spreader tank partially filled with liquid swine manure. Five of the 6 lost consciousness, and 2 were agitated and poorly responsive on arrival to the emergency department despite having already received high-flow oxygen for nearly 1 hour. These 2 patients received nitrite therapy followed by orotracheal intubation and hyperbaric oxygen. All patients were discharged home without sequelae after short stays in hospital. The emergency management of hydrogen sulfide exposure is briefly reviewed.

  8. Novel Composite Hydrogen-Permeable Membranes for Nonthermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect

    Morris Argyle; John Ackerman; Suresh Muknahallipatna; Jerry Hamann; Stanislaw Legowski; Gui-Bing Zhao; Sanil John; Ji-Jun Zhang; Linna Wang

    2007-09-30

    The goal of this experimental project was to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a nonthermal plasma and to recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), but it was not achieved at the moderate pressure conditions used in this study. However, H{sub 2}S was successfully decomposed at energy efficiencies higher than any other reports for the high H{sub 2}S concentration and moderate pressures (corresponding to high reactor throughputs) used in this study.

  9. Hydrogen sulfide scavengers market assessment. Topical report, June 16-December 15, 1995

    SciTech Connect

    Houston, C.W.

    1996-03-01

    The report objective was to establish the dollar market size for removing low level concentrations of hydrogen sulfide from natural gas using commercially available scavengers, identify the key players, and determine significant trends in the industry. The study established the oilfield and refinery markets for the treating of natural gas, with hydrogen sulfide scavengers. The total North American market is estimated to be worth $172 million in 1995. Natural gas stream or vapor phase treating represents 85 percent of the total market.

  10. Evaluation of thiosulfate as a substitute for hydrogen sulfide in sour corrosion fatigue studies

    NASA Astrophysics Data System (ADS)

    Kappes, Mariano Alberto

    This work evaluates the possibility of replacing hydrogen sulfide (H 2S) with thiosulfate anion (S2O32- ) in sour corrosion fatigue studies. H2S increases the corrosion fatigue crack growth rate (FCGR) and can be present in carbon steel risers and flowlines used in off-shore oil production. Corrosion tests with gaseous H2S require special facilities with safety features, because H2S is a toxic and flammable gas. The possibility of replacing H2S with S2O32-, a non-toxic anion, for studying stress corrosion cracking of stainless and carbon steels in H2S solutions was first proposed by Tsujikawa et al. ( Tsujikawa et al., Corrosion, 1993. 49(5): p. 409-419). In this dissertation, Tsujikawa work will be extended to sour corrosion fatigue of carbon steels. H2S testing is often conducted in deareated condition to avoid oxygen reaction with sulfide that yields sulfur and to mimic oil production conditions. Nitrogen deareation was also adopted in S2O3 2- testing, and gas exiting the cell was forced through a sodium hydroxide trap. Measurements of the sulfide content of this trap were used to estimate the partial pressure of H2S in nitrogen, and Henry's law was used to estimate the content of H2S in the solution in the cell. H2S was produced by a redox reaction of S2O 32-, which required electrons from carbon steel corrosion. This reaction is spontaneous at the open circuit potential of steel. Therefore, H2S concentration was expected to be maximum at the steel surface, and this concentration was estimated by a mass balance analysis. Carbon steel specimens exposed to S2O32- containing solutions developed a film on their surface, composed by iron sulfide and cementite. The film was not passivating and a good conductor of electrons. Hydrogen permeation experiments proved that this film controls the rate of hydrogen absorption of steels exposed to thiosulfate containing solutions. The absorption of hydrogen in S2O3 2- solutions was compared with the absorption of hydrogen in

  11. Epithelial Electrolyte Transport Physiology and the Gasotransmitter Hydrogen Sulfide

    PubMed Central

    Pouokam, Ervice; Althaus, Mike

    2016-01-01

    Hydrogen sulfide (H2S) is a well-known environmental chemical threat with an unpleasant smell of rotten eggs. Aside from the established toxic effects of high-dose H2S, research over the past decade revealed that cells endogenously produce small amounts of H2S with physiological functions. H2S has therefore been classified as a “gasotransmitter.” A major challenge for cells and tissues is the maintenance of low physiological concentrations of H2S in order to prevent potential toxicity. Epithelia of the respiratory and gastrointestinal tract are especially faced with this problem, since these barriers are predominantly exposed to exogenous H2S from environmental sources or sulfur-metabolising microbiota. In this paper, we review the cellular mechanisms by which epithelial cells maintain physiological, endogenous H2S concentrations. Furthermore, we suggest a concept by which epithelia use their electrolyte and liquid transport machinery as defence mechanisms in order to eliminate exogenous sources for potentially harmful H2S concentrations. PMID:26904165

  12. PROVISIONAL ADVISORY LEVELS (PALs) FOR HYDROGEN SULFIDE (H2S)

    SciTech Connect

    Marshall, Thomas C; Dorman, David; Gardner, Donald; Adeshina, Femi; Ross, Robert Hord

    2009-01-01

    Application of PAL protocols was performed for hydrogen sulfide (H2S) as experimental data permitted. The data base includes human experimental studies, worker exposure evaluations, as well as case studies on acute and repeated exposure. The data base of animal studies is substantial covering multiple species and addressing acute, repeated, and subchronic exposure scenarios. PAL estimates were approved by the Expert Consultation Panel for Provisional Advisory Levels in November 2006. No reliable data were found on oral exposure, making it impractical to estimate PALs for drinking water. Since H2S exists as a gas, partitioning to air is likely to occur with an environmental release. H2S inhalation PAL values for 24 hr exposure are: PAL 1 = 1.2 ppm; PAL 2 = 7.0 ppm; and PAL 3 = 27 ppm; the 30-d and 90-d inhalation exposure values are: PAL 1 = 0.85 ppm and PAL 2 = 3.0 ppm. PAL 3 values for 30-d and 90-d are not recommended due to insufficient data. Long-term data were insufficient to estimate 2-year inhalation PALs.

  13. Physiological Importance of Hydrogen Sulfide: Emerging Potent Neuroprotector and Neuromodulator

    PubMed Central

    Chung, Hyung-Joo

    2016-01-01

    Hydrogen sulfide (H2S) is an emerging neuromodulator that is considered to be a gasotransmitter similar to nitrogen oxide (NO) and carbon monoxide (CO). H2S exerts universal cytoprotective effects and acts as a defense mechanism in organisms ranging from bacteria to mammals. It is produced by the enzymes cystathionine β-synthase (CBS), cystathionine ϒ-lyase (CSE), 3-mercaptopyruvate sulfurtransferase (MST), and D-amino acid oxidase (DAO), which are also involved in tissue-specific biochemical pathways for H2S production in the human body. H2S exerts a wide range of pathological and physiological functions in the human body, from endocrine system and cellular longevity to hepatic protection and kidney function. Previous studies have shown that H2S plays important roles in peripheral nerve regeneration and degeneration and has significant value during Schwann cell dedifferentiation and proliferation but it is also associated with axonal degradation and the remyelination of Schwann cells. To date, physiological and toxic levels of H2S in the human body remain unclear and most of the mechanisms of action underlying the effects of H2S have yet to be fully elucidated. The primary purpose of this review was to provide an overview of the role of H2S in the human body and to describe its beneficial effects. PMID:27413423

  14. Discoveries of hydrogen sulfide as a novel cardiovascular therapeutic.

    PubMed

    Barr, Larry A; Calvert, John W

    2014-01-01

    Hydrogen sulfide (H2S) is an endogenously produced gaseous signaling molecule that elicits a number of cytoprotective effects in mammalian species. H2S was originally considered toxic at elevated levels, but 15 years ago the labile molecule was discovered in mammalian tissue and termed a gasotransmitter, thus opening the door for research aimed towards understanding its physiologic nature. Since then, novel findings have depicted the beneficial aspects of H2S therapy, such as vasodilation, antioxidant upregulation, inflammation inhibition, and activation of anti-apoptotic pathways. These cytoprotective alterations effectively treat multiple forms of cardiac injury at the preclinical level of research. The field has progressed towards instituting novel H2S donors that prove more effective at activating the subsequent cardioprotective enhancements over longer time periods. As more findings explore the efficacy of H2S, research focused on detection of sulfhydrated targets is on the rise. Understanding the molecular mechanisms that stem from H2S treatment may lead the field towards powerful therapeutics in the clinical setting. This review will discuss the cytoprotective and cardioprotective effects of H2S therapy, provide analysis on the molecular alterations that lead to these enhancements, and explore recently developed therapeutics that may bring this gasotransmitter into the clinic in the near future.

  15. Hydrogen Sulfide Donor GYY4137 Protects against Myocardial Fibrosis

    PubMed Central

    Meng, Guoliang; Zhu, Jinbiao; Xiao, Yujiao; Huang, Zhengrong; Zhang, Yuqing; Tang, Xin; Xie, Liping; Chen, Yu; Shao, Yongfeng; Ferro, Albert; Wang, Rui; Moore, Philip K.; Ji, Yong

    2015-01-01

    Hydrogen sulfide (H2S) is a gasotransmitter which regulates multiple cardiovascular functions. However, the precise roles of H2S in modulating myocardial fibrosis in vivo and cardiac fibroblast proliferation in vitro remain unclear. We investigated the effect of GYY4137, a slow-releasing H2S donor, on myocardial fibrosis. Spontaneously hypertensive rats (SHR) were administrated with GYY4137 by intraperitoneal injection daily for 4 weeks. GYY4137 decreased systolic blood pressure and inhibited myocardial fibrosis in SHR as evidenced by improved cardiac collagen volume fraction (CVF) in the left ventricle (LV), ratio of perivascular collagen area (PVCA) to lumen area (LA) in perivascular regions, reduced hydroxyproline concentration, collagen I and III mRNA expression, and cross-linked collagen. GYY4137 also inhibited angiotensin II- (Ang II-) induced neonatal rat cardiac fibroblast proliferation, reduced the number of fibroblasts in S phase, decreased collagen I and III mRNA expression and protein synthesis, attenuated oxidative stress, and suppressed α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1) expression as well as Smad2 phosphorylation. These results indicate that GYY4137 improves myocardial fibrosis perhaps by a mechanism involving inhibition of oxidative stress, blockade of the TGF-β1/Smad2 signaling pathway, and decrease in α-SMA expression in cardiac fibroblasts. PMID:26078813

  16. Hydrogen sulfide induced disruption of Na+ homeostasis in the cortex.

    PubMed

    Chao, Dongman; He, Xiaozhou; Yang, Yilin; Balboni, Gianfranco; Salvadori, Severo; Kim, Dong H; Xia, Ying

    2012-07-01

    Maintenance of ionic balance is essential for neuronal functioning. Hydrogen sulfide (H(2)S), a known toxic environmental gaseous pollutant, has been recently recognized as a gasotransmitter involved in numerous biological processes and is believed to play an important role in the neural activities under both physiological and pathological conditions. However, it is unclear if it plays any role in maintenance of ionic homeostasis in the brain under physiological/pathophysiological conditions. Here, we report by directly measuring Na(+) activity using Na(+) selective electrodes in mouse cortical slices that H(2)S donor sodium hydrosulfide (NaHS) increased Na(+) influx in a concentration-dependent manner. This effect could be partially blocked by either Na(+) channel blocker or N-methyl-D-aspartate receptor (NMDAR) blocker alone or almost completely abolished by coapplication of both blockers but not by non-NMDAR blocker. These data suggest that increased H(2)S in pathophysiological conditions, e.g., hypoxia/ischemia, potentially causes a disruption of ionic homeostasis by massive Na(+) influx through Na(+) channels and NMDARs, thus injuring neural functions. Activation of delta-opioid receptors (DOR), which reduces Na(+) currents/influx in normoxia, had no effect on H(2)S-induced Na(+) influx, suggesting that H(2)S-induced disruption of Na(+) homeostasis is resistant to DOR regulation and may play a major role in neuronal injury in pathophysiological conditions, e.g., hypoxia/ischemia.

  17. Hydrogen Sulfide: A Therapeutic Candidate for Fibrotic Disease?

    PubMed Central

    Song, Kai; Li, Qian; Yin, Xiao-Ya; Lu, Ying; Liu, Chun-Feng; Hu, Li-Fang

    2015-01-01

    Fibrotic diseases including chronic kidney disease, liver cirrhosis, idiopathic pulmonary fibrosis, and chronic disease account for 45% mortality in the developed countries and pose a great threat to the global health. Many great targets and molecules have been reported to be involved in the initiation and/or progression of fibrosis, among which inflammation and oxidative stress are well-recognized modulation targets. Hydrogen sulfide (H2S) is the third gasotransmitter with potent properties in inhibiting inflammation and oxidative stress in various organs. Recent evidence suggests that plasma H2S level is decreased in various animal models of fibrotic diseases and supplement of exogenous H2S is able to ameliorate fibrosis in the kidney, lung, liver, and heart. This leads us to propose that modulation of H2S production may represent a promising therapeutic venue for the treatment of a variety of fibrotic diseases. Here, we summarize and discuss the current data on the role and underlying mechanisms of H2S in fibrosis diseases related to heart, liver, kidney, and other organs. PMID:26078807

  18. Physiological Importance of Hydrogen Sulfide: Emerging Potent Neuroprotector and Neuromodulator.

    PubMed

    Panthi, Sandesh; Chung, Hyung-Joo; Jung, Junyang; Jeong, Na Young

    2016-01-01

    Hydrogen sulfide (H2S) is an emerging neuromodulator that is considered to be a gasotransmitter similar to nitrogen oxide (NO) and carbon monoxide (CO). H2S exerts universal cytoprotective effects and acts as a defense mechanism in organisms ranging from bacteria to mammals. It is produced by the enzymes cystathionine β-synthase (CBS), cystathionine ϒ-lyase (CSE), 3-mercaptopyruvate sulfurtransferase (MST), and D-amino acid oxidase (DAO), which are also involved in tissue-specific biochemical pathways for H2S production in the human body. H2S exerts a wide range of pathological and physiological functions in the human body, from endocrine system and cellular longevity to hepatic protection and kidney function. Previous studies have shown that H2S plays important roles in peripheral nerve regeneration and degeneration and has significant value during Schwann cell dedifferentiation and proliferation but it is also associated with axonal degradation and the remyelination of Schwann cells. To date, physiological and toxic levels of H2S in the human body remain unclear and most of the mechanisms of action underlying the effects of H2S have yet to be fully elucidated. The primary purpose of this review was to provide an overview of the role of H2S in the human body and to describe its beneficial effects. PMID:27413423

  19. An inhibitory enzyme electrode for hydrogen sulfide detection.

    PubMed

    poor, Neda Zia Mottalebi; Baniasadi, Ladan; Omidi, Maysam; Amoabediny, Ghasem; Yazdian, Fatemeh; Attar, Hossein; Heydarzadeh, Ali; Zarami, Ashraf Sadat Hatamian; Sheikhha, Mohammad Hassan

    2014-09-01

    An enzymatic biosensing system has been developed to study the capability of ascorbate oxidase (AOx), EC (1.10.3.3), in hydrogen sulfide (H2S) detection, based on the inhibition of AOx activity. The immobilization parameters including glutaraldehyde (GA) concentration and pH were optimized using experimental design. The optimized values of GA concentration and pH were found to be 12.5% (w/w) and 7, respectively, where the enzymatic reaction reached the steady-state level within 55 s. A linear relationship was observed between the decrease in the oxygen concentration and H2S concentration, where H2S concentration is in the range of 1-15 mg/L. Moreover, to investigate the selectivity of the biosensor, a certain H2S concentration (9 mg/L) was used against different ions. The results indicated that Fe(3+) and SO4(-2) ions had no significant (11% error) effect on the H2S detection. The operational stability of the biosensing system was determined in terms of response to H2S concentration, at optimal working conditions. The enzyme electrode could retain 73% of its original sensitivity after this period, which has made it possible for the system to measure H2S with concentrations as low as 0.5 mg/L.

  20. Hydrogen Sulfide in Physiology and Diseases of the Digestive Tract

    PubMed Central

    Singh, Sudha B.; Lin, Henry C.

    2015-01-01

    Hydrogen sulfide (H2S) is a Janus-faced molecule. On one hand, several toxic functions have been attributed to H2S and exposure to high levels of this gas is extremely hazardous to health. On the other hand, H2S delivery based clinical therapies are being developed to combat inflammation, visceral pain, oxidative stress related tissue injury, thrombosis and cancer. Since its discovery, H2S has been found to have pleiotropic effects on physiology and health. H2S is a gasotransmitter that exerts its effect on different systems, such as gastrointestinal, neuronal, cardiovascular, respiratory, renal, and hepatic systems. In the gastrointestinal tract, in addition to H2S production by mammalian cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE), H2S is also generated by the metabolic activity of resident gut microbes, mainly by colonic Sulfate-Reducing Bacteria (SRB) via a dissimilatory sulfate reduction (DSR) pathway. In the gut, H2S regulates functions such as inflammation, ischemia/ reperfusion injury and motility. H2S derived from gut microbes has been found to be associated with gastrointestinal disorders such as ulcerative colitis, Crohn’s disease and irritable bowel syndrome. This underscores the importance of gut microbes and their production of H2S on host physiology and pathophysiology.

  1. Hydrogen Sulfide as Endothelial Derived Hyperpolarizing Factor Sulfhydrates Potassium Channels

    PubMed Central

    Mustafa, Asif K.; Sikka, Gautam; Gazi, Sadia K.; Steppan, Jochen; Jung, Sung M.; Bhunia, Anil K.; Barodka, Viachaslau M.; Gazi, Farah K.; Barrow, Roxanne K.; Wang, Rui; Amzel, L. Mario; Berkowitz, Dan E.; Snyder, Solomon H.

    2011-01-01

    Rationale Nitric oxide, the classic endothelial derived relaxing factor (EDRF), acts via cyclic GMP and calcium without notably affecting membrane potential. A major component of EDRF activity derives from hyperpolarization and is termed endothelial derived hyperpolarizing factor (EDHF). Hydrogen sulfide (H2S) is a prominent EDRF, since mice lacking its biosynthetic enzyme, cystathionine γ-lyase (CSE), display pronounced hypertension with deficient vasorelaxant responses to acetylcholine. Objective The purpose of this study is to determine if H2S is a major physiologic EDHF. Methods and Results We now show that H2S is a major EDHF, as in blood vessels of CSE deleted mice hyperpolarization is virtually abolished. H2S acts by covalently modifying (sulfhydrating) the ATP-sensitive potassium channel, as mutating the site of sulfhydration prevents H2S-elicited hyperpolarization. The endothelial intermediate conductance (IKCa) and small conductance (SKCa) potassium channels mediate in part the effects of H2S, as selective IKCa and SKCa channel inhibitors, charybdotoxin and apamin, inhibit glibenclamide insensitive H2S induced vasorelaxation. Conclusions H2S is a major EDHF that causes vascular endothelial and smooth muscle cell hyperpolarization and vasorelaxation by activating the ATP-sensitive, intermediate conductance and small conductance potassium channels through cysteine S-sulfhydration. As EDHF activity is a principal determinant of vasorelaxation in numerous vascular beds, drugs influencing H2S biosynthesis offer therapeutic potential. PMID:21980127

  2. Biochemistry and therapeutic potential of hydrogen sulfide - reality or fantasy?

    PubMed

    Brodek, Paulina; Olas, Beata

    2016-01-01

    Hydrogen sulfide (H2S) is a signaling gasotransmitter, involved in different physiological and pathological processes. H2S regulates apoptosis, the cell cycle and oxidative stress. H2S exerts powerful effects on smooth muscle cells, endothelial cells, inflammatory cells, endoplasmic reticulum, mitochondria and nuclear transcription factors. H2S is known to be produced from L-cysteine, D-cysteine and L-homocysteine in the body. Four enzymes - cystathionine-b synthase (CBS), mercaptopyruvate sulfurtransferase (3-MST), cystathionine-γ lyase (CSE) and cysteine aminotransferase (CAT) - are involved in H2S synthesis. The biosynthetic pathway for the production of H2S from D-cysteine involves 3-MST and D-amino acid oxidase (DAO). The therapeutic potential of H2S is not clear. However, recently results have demonstrated that H2S has protective action for ischemic heart disease or hypertension, and protects against ischemia of the brain. This review summarizes the negative and the positive roles of H2S in various biological systems, for example the cardiovascular system and nervous system. We also discuss the function of classical, therapeutic and natural (for example garlic) donors of H2S in pre-clinical and clinical studies. PMID:27516569

  3. Hydrogen Sulfide in Physiology and Diseases of the Digestive Tract

    PubMed Central

    Singh, Sudha B.; Lin, Henry C.

    2015-01-01

    Hydrogen sulfide (H2S) is a Janus-faced molecule. On one hand, several toxic functions have been attributed to H2S and exposure to high levels of this gas is extremely hazardous to health. On the other hand, H2S delivery based clinical therapies are being developed to combat inflammation, visceral pain, oxidative stress related tissue injury, thrombosis and cancer. Since its discovery, H2S has been found to have pleiotropic effects on physiology and health. H2S is a gasotransmitter that exerts its effect on different systems, such as gastrointestinal, neuronal, cardiovascular, respiratory, renal, and hepatic systems. In the gastrointestinal tract, in addition to H2S production by mammalian cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE), H2S is also generated by the metabolic activity of resident gut microbes, mainly by colonic Sulfate-Reducing Bacteria (SRB) via a dissimilatory sulfate reduction (DSR) pathway. In the gut, H2S regulates functions such as inflammation, ischemia/ reperfusion injury and motility. H2S derived from gut microbes has been found to be associated with gastrointestinal disorders such as ulcerative colitis, Crohn’s disease and irritable bowel syndrome. This underscores the importance of gut microbes and their production of H2S on host physiology and pathophysiology. PMID:27682122

  4. Hydrogen Sulfide as a Potential Therapeutic Target in Fibrosis

    PubMed Central

    Zhang, Shufang; Pan, Chuli; Zhou, Feifei; Yuan, Zhi; Wang, Huiying; Cui, Wei; Zhang, Gensheng

    2015-01-01

    Hydrogen sulfide (H2S), produced endogenously by the activation of two major H2S-generating enzymes (cystathionine β-synthase and cystathionine γ-lyase), plays important regulatory roles in different physiologic and pathologic conditions. The abnormal metabolism of H2S is associated with fibrosis pathogenesis, causing damage in structure and function of different organs. A number of in vivo and in vitro studies have shown that both endogenous H2S level and the expressions of H2S-generating enzymes in plasma and tissues are significantly downregulated during fibrosis. Supplement with exogenous H2S mitigates the severity of fibrosis in various experimental animal models. The protective role of H2S in the development of fibrosis is primarily attributed to its antioxidation, antiapoptosis, anti-inflammation, proangiogenesis, and inhibition of fibroblasts activities. Future studies might focus on the potential to intervene fibrosis by targeting the pathway of endogenous H2S-producing enzymes and H2S itself. PMID:26078809

  5. Role of hydrogen sulfide in the physiology of penile erection.

    PubMed

    Qiu, Xuefeng; Villalta, Jackie; Lin, Guiting; Lue, Tom F

    2012-01-01

    Hydrogen sulfide (H(2)S), which is a well-known toxic gas, has recently been recognized as a biological messenger that plays an important role in physiological and pathophysiological conditions. Relatively high levels of H(2)S have been discovered in mammalian tissues. It is mainly synthesized by 2 enzymes, including cystathionine β-synthase and cystathionine γ-lysase, which utilize L-cysteine as substrate to produce H(2)S. H(2)S has been demonstrated to exhibit potent vasodilator activity both in vitro and in vivo by relaxing vascular smooth muscle. Recently, H(2)S has been discovered in penile tissue with smooth muscle relaxant effects. Furthermore, other effects of H(2)S could play a role in the physiology of erection. Understanding H(2)S in the physiology of erection might provide alternative erectile dysfunction strategies for those patients with poor or no response to type 5 phosphodiesterase inhibitors. This review intends to present the H(2)S pathway in penile tissue and the potential role of H(2)S in the physiology of erections.

  6. Solutions to a combined problem of excessive hydrogen sulfide in biogas and struvite scaling.

    PubMed

    Charles, W; Cord-Ruwisch, R; Ho, G; Costa, M; Spencer, P

    2006-01-01

    The Woodman Point Wastewater Treatment Plant (WWTP) in Western Australia has experienced two separate problems causing avoidable maintenance costs: the build-up of massive struvite (MgNH4PO4. 6H2O) scaling downstream of the anaerobic digester and the formation of hydrogen sulfide (H2S) levels in the digester gas to levels that compromised gas engine operation and caused high operating costs on the gas scrubber. As both problems hang together with a chemical imbalance in the anaerobic digester, we decided to investigate whether both problems could be (feasibly and economically) addressed by a common solution (such as dosing of iron solutions to precipitate both sulfide and phosphate), or by using separate approaches. Laboratory results showed that, the hydrogen sulfide emission in digesters could be effectively and economically controlled by the addition of iron dosing. Slightly higher than the theoretical value of 1.5 mol of FeCl3 was required to precipitate 1 mol of dissolved sulfide inside the digester. Due to the high concentration of PO4(3-) in the digested sludge liquor, significantly higher iron is required for struvite precipitation. Iron dosing did not appear an economic solution for struvite control via iron phosphate formation. By taking advantage of the natural tendency of struvite formation in the digester liquid, it is possible to reduce the risk of struvite precipitation in and around the sludge-dewatering centrifuge by increasing the pH to precipitate struvite out before passing through the centrifuge. However, as the Mg2+/PO4(3-) molar ratio in digested sludge was low, by increasing the pH alone (using NaOH) the precipitation of PO4(3-) was limited by the amount of cations (Ca2+ and Mg2+) available in the sludge. Although this would reduce struvite precipitation in the centrifuge, it could not significantly reduce PO4(3-) recycling back to the plant. For long-term operation, maximum PO4(3-) reduction should be the ultimate aim to minimise PO4

  7. Mitochondrial adaptations to utilize hydrogen sulfide for energy and signaling.

    PubMed

    Olson, Kenneth R

    2012-10-01

    Sulfur is a versatile molecule with oxidation states ranging from -2 to +6. From the beginning, sulfur has been inexorably entwined with the evolution of organisms. Reduced sulfur, prevalent in the prebiotic Earth and supplied from interstellar sources, was an integral component of early life as it could provide energy through oxidization, even in a weakly oxidizing environment, and it spontaneously reacted with iron to form iron-sulfur clusters that became the earliest biological catalysts and structural components of cells. The ability to cycle sulfur between reduced and oxidized states may have been key in the great endosymbiotic event that incorporated a sulfide-oxidizing α-protobacteria into a host sulfide-reducing Archea, resulting in the eukaryotic cell. As eukaryotes slowly adapted from a sulfidic and anoxic (euxinic) world to one that was highly oxidizing, numerous mechanisms developed to deal with increasing oxidants; namely, oxygen, and decreasing sulfide. Because there is rarely any reduced sulfur in the present-day environment, sulfur was historically ignored by biologists, except for an occasional report of sulfide toxicity. Twenty-five years ago, it became evident that the organisms in sulfide-rich environments could synthesize ATP from sulfide, 10 years later came the realization that animals might use sulfide as a signaling molecule, and only within the last 4 years did it become apparent that even mammals could derive energy from sulfide generated in the gastrointestinal tract. It has also become evident that, even in the present-day oxic environment, cells can exploit the redox chemistry of sulfide, most notably as a physiological transducer of oxygen availability. This review will examine how the legacy of sulfide metabolism has shaped natural selection and how some of these ancient biochemical pathways are still employed by modern-day eukaryotes. PMID:22430869

  8. Characteristics of the interaction of azulene with water and hydrogen sulfide: A computational study.

    PubMed

    Cabaleiro-Lago, Enrique M; Rodríguez-Otero, Jesús; Peña-Gallego, Angeles

    2008-08-28

    A computational study was carried out for studying the characteristics of the interaction between azulene and water or hydrogen sulfide. In azulene...water complex the water molecule is located with both hydrogen atoms pointing toward the aromatic cloud but displaced to the five-membered ring. Hydrogen sulfide adopts a similar arrangement but located roughly over the central C-C bond of azulene. Calculations show that hydrogen sulfide interacts with azulene more strongly (-4.19 kcal/mol) than water (-3.76 kcal/mol), although this is only revealed at the highest levels of calculation. The nature of the interaction is electrostatic and dispersive in the same percentage for water cluster, whereas for hydrogen sulfide dispersion is the dominant contribution. Clusters containing two water molecules are controlled by the possibility of establishing an O-H...O hydrogen bond. As a consequence, the most stable structure corresponds to the interaction between a water dimer and azulene, with an interaction energy amounting to -11.77 kcal/mol. Hydrogen sulfide interaction is stronger with azulene than with itself, so structures with S-H...S contact and others, where H(2)S only interacts with azulene, present similar interaction energies (-8.02 kcal/mol for the most stable one).

  9. Crossed-beam reaction of carbon atoms with sulfur containing molecules. I. Chemical dynamics of thioformyl (HCS X2A') formation from reaction of C(3Pj) with hydrogen sulfide, H2S(X1A1)

    NASA Astrophysics Data System (ADS)

    Kaiser, R. I.; Ochsenfeld, C.; Head-Gordon, M.; Lee, Y. T.

    1999-02-01

    The reaction between ground state carbon atoms, C(3Pj), and hydrogen sulfide, H2S(X1A1), was studied at four average collision energies between 16.7 and 42.8 kJ mol-1 using the crossed molecular beam technique. The reaction dynamics were deducted from time-of-flight spectra and from laboratory angular distributions combined with ab initio calculations. These data suggest that the reaction proceeds through an addition of C(3Pj) to the sulfur atom to form a triplet CSH2 van der Waals complex. Successive H atom migration on the triplet or singlet surface forms a thiohydroxycarbene intermediate, HCSH, which decomposes through a tight exit transition state to HCS(X2A')+H(2S1/2). At lower collision energies, a weak L-L' coupling leads to isotropic center-of-mass angular distributions. As the collision energy rises, the angular distributions show increasing forward scattering thereby documenting that the reaction goes through an osculating HCSH complex. Identification of the HCS isomer under single collision conditions is a potential one-step pathway by which to form organo-sulfur molecules in interstellar environments during the collision of the comet Shoemaker-Levy 9 with Jupiter, and in combustion flames of sulfur containing fuels.

  10. A Single Fluorescent Probe to Visualize Hydrogen Sulfide and Hydrogen Polysulfides with Different Fluorescence Signals.

    PubMed

    Chen, Wei; Pacheco, Armando; Takano, Yoko; Day, Jacob J; Hanaoka, Kenjiro; Xian, Ming

    2016-08-16

    Hydrogen sulfide (H2 S) and hydrogen polysulfides (H2 Sn , n>1) are endogenous regulators of many physiological processes. In order to better understand the symbiotic relationship and cellular cross-talk between H2 S and H2 Sn , it is highly desirable to develop single fluorescent probes which enable dual-channel discrimination between H2 S and H2 Sn . Herein, we report the rational design, synthesis, and evaluation of the first dual-detection fluorescent probe DDP-1 that can visualize H2 S and H2 Sn with different fluorescence signals. The probe showed high selectivity and sensitivity to H2 S and H2 Sn in aqueous media and in cells. PMID:27410794

  11. Modeling of the occurrence of hydrogen sulfide in coal seams

    SciTech Connect

    Gillies, A.D.S.; Kizil, M.S.; Wu, H.W.; Harvey, T.J.M.

    1999-07-01

    Hydrogen Sulfide (H{sub 2}S) has been encountered within a number of Bowen Basin collieries, Central Queensland, Australia. High concentration occurrence during mining of a longwall panel raises a number of potential problems, which demand greater understanding to allow efficient mining while maintaining safe and healthy environmental conditions. Longwall panels at Mine A and Mine B have recently mined through H{sub 2}S zones. The high H{sub 2}S zone mined through at Mine A was wide and covering the whole length of the face comparing to the narrow H{sub 2}S zone which was cutting the panel at 45{degree} at Mine B. Longwall panels had been sampled for H{sub 2}S in pre-mining phases with vertical and inseam exploration boreholes and rib sampling of gateroad development headings. During mining face coal samples were collected in an intensive program and tested in a drum tumbler to determine an indicated seam concentration level through contouring that could be used to calculate the concentrations of H{sub 2}S liberated to the atmosphere. Data were analyzed to determine a geostatistical method, which would best represent the indicated seam concentration level from the given data and the block dimension of the data set. This study discusses the different sampling methods used, selection of the most suitable geostatistical method and the impact of grid size on results of data analysis. Some general observations are made correlating indicated seam H{sub 2}S concentrations from production face sampling with both predictions made from exploration and liberation rates during mining of the longwall panel.

  12. The Role of Hydrogen Sulfide in Renal System

    PubMed Central

    Cao, Xu; Bian, Jin-Song

    2016-01-01

    Hydrogen sulfide has gained recognition as the third gaseous signaling molecule after nitric oxide and carbon monoxide. This review surveys the emerging role of H2S in mammalian renal system, with emphasis on both renal physiology and diseases. H2S is produced redundantly by four pathways in kidney, indicating the abundance of this gaseous molecule in the organ. In physiological conditions, H2S was found to regulate the excretory function of the kidney possibly by the inhibitory effect on sodium transporters on renal tubular cells. Likewise, it also influences the release of renin from juxtaglomerular cells and thereby modulates blood pressure. A possible role of H2S as an oxygen sensor has also been discussed, especially at renal medulla. Alternation of H2S level has been implicated in various pathological conditions such as renal ischemia/reperfusion, obstructive nephropathy, diabetic nephropathy, and hypertensive nephropathy. Moreover, H2S donors exhibit broad beneficial effects in renal diseases although a few conflicts need to be resolved. Further research reveals that multiple mechanisms are underlying the protective effects of H2S, including anti-inflammation, anti-oxidation, and anti-apoptosis. In the review, several research directions are also proposed including the role of mitochondrial H2S in renal diseases, H2S delivery to kidney by targeting D-amino acid oxidase/3-mercaptopyruvate sulfurtransferase (DAO/3-MST) pathway, effect of drug-like H2S donors in kidney diseases and understanding the molecular mechanism of H2S. The completion of the studies in these directions will not only improves our understanding of renal H2S functions but may also be critical to translate H2S to be a new therapy for renal diseases. PMID:27803669

  13. Role of hydrogen sulfide in skeletal muscle biology and metabolism

    PubMed Central

    Veeranki, Sudhakar; Tyagi, Suresh C.

    2014-01-01

    Hydrogen sulfide (H2S) is a novel endogenous gaseous signal transducer (gasotransmittor). Its emerging role in multiple facets of inter- and intra-cellular signaling as a metabolic, inflammatory, neuro and vascular modulator has been increasingly realized. Although H2S is known for its effects as an anti-hypertensive, anti-inflammatory and anti-oxidant molecule, the relevance of these effects in skeletal muscle biology during health and during metabolic syndromes is unclear. H2S has been implicated in vascular relaxation and vessel tone enhancement, which might lead to mitigation of vascular complications caused by the metabolic syndromes. Metabolic complications may also lead to mitochondrial remodeling by interfering with fusion and fission, therefore, leading to mitochondrial mitophagy and skeletal muscle myopathy. Mitochondrial protection by H2S enhancing treatments may mitigate deterioration of muscle function during metabolic syndromes. In addition, H2S might upregulate uncoupling proteins and might also cause browning of white fat, resulting in suppression of imbalanced cytokine signaling caused by abnormal fat accumulation. Likewise, as a source for H+ ions, it has the potential to augment anaerobic ATP synthesis. However, there is a need for studies to test these putative H2S benefits in different patho-physiological scenarios before its full-fledged usage as a therapeutic molecule. The present review highlights current knowledge with regard to exogenous and endogenous H2S roles in skeletal muscle biology, metabolism, exercise physiology and related metabolic disorders, such as diabetes and obesity, and also provides future directions. PMID:25461301

  14. Hydrogen sulfide improves neural function in rats following cardiopulmonary resuscitation

    PubMed Central

    LIN, JI-YAN; ZHANG, MIN-WEI; WANG, JIN-GAO; LI, HUI; WEI, HONG-YAN; LIU, RONG; DAI, GANG; LIAO, XIAO-XING

    2016-01-01

    The alleviation of brain injury is a key issue following cardiopulmonary resuscitation (CPR). Hydrogen sulfide (H2S) is hypothesized to be involved in the pathophysiological process of ischemia-reperfusion injury, and exerts a protective effect on neurons. The aim of the present study was to investigate the effects of H2S on neural functions following cardiac arrest (CA) in rats. A total of 60 rats were allocated at random into three groups. CA was induced to establish the model and CPR was performed after 6 min. Subsequently, sodium hydrosulfide (NaHS), hydroxylamine or saline was administered to the rats. Serum levels of H2S, neuron-specific enolase (NSE) and S100β were determined following CPR. In addition, neurological deficit scoring (NDS), the beam walking test (BWT), prehensile traction test and Morris water maze experiment were conducted. Neuronal apoptosis rates were detected in the hippocampal region following sacrifice. After CPR, as the H2S levels increased or decreased, the serum NSE and S100β concentrations decreased or increased, respectively (P<0.0w. The NDS results of the NaHS group were improved compared with those of the hydroxylamine group at 24 h after CPR (P<0.05). In the Morris water maze experiment, BWT and prehensile traction test the animals in the NaHS group performed best and rats in the hydroxylamine group performed worst. At day 7, the apoptotic index and the expression of caspase-3 were reduced in the hippocampal CA1 region, while the expression of Bcl-2 increased in the NaHS group; and results of the hydroxylamine group were in contrast. Therefore, the results of the present study indicate that H2S is able to improve neural function in rats following CPR. PMID:26893650

  15. Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide

    PubMed Central

    Fiedler, Nancy; Kipen, Howard; Ohman-Strickland, Pamela; Zhang, Junfeng; Weisel, Clifford; Laumbach, Robert; Kelly-McNeil, Kathie; Olejeme, Kelechi; Lioy, Paul

    2008-01-01

    Background Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S). Objectives We hypothesized a dose–response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures. Methods In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (± SD) = 24.7 ± 4.2; mean years of education = 16.5 ± 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period. Results Dose–response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No dose–response effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition. Conclusions Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures. PMID:18197303

  16. Intermittent control procedures for the Geysers hydrogen sulfide emission abatement

    SciTech Connect

    Buick, B.D.; Mooney, M.L.

    1984-01-01

    Pacific Gas and Electric Company (PG and E) operates the world's largest geothermal steam electric power generation facility, currently about 1.140 megawatts (Mw). This facility is located about 80 miles north of San Francisco, California and is within a region referred to as the Known Geothermal Resource Area (KGRA). Pollutants resulting from this method of electric power generation are due to impurities in the geothermal steam. A major contaminate in the steam is hydrogen sulfide (H/sub 2/S), a regulated pollutant in California. The ambient air quality standard (AAQS) for this pollutant in California is 0.03 parts per million (ppM) averaged over one hour. H/sub 2/S is an invisible, unpleasant smelling gas present in varying concentrations in the geothermal steam. Its odor has been compared to the smell of rotten eggs. Since PG and E is increasingly relying on this source of electrical power generation, it has committed millions of dollars to the development, testing, acquisition, and installation of abatement equipment to reduce H/sub 2/S emissions during the past ten years. In order to reduce the number of exceeds of the AAQS during this developmental period, a predictive model was needed for interim abatement purposes. Most of the high hourly H/sub 2/S values occur with meteorological conditions having poor ventilation resulting from a combination of low wind speed and reduced mixing layer depths. This weather condition is most common during the months of June through October in California. A predictive model was developed from three years of hourly H/sub 2/S measurements of 0.03 ppM or greater in populated areas downwind of the generation facility and from observations of associated meteorological data.

  17. Hydrogen Sulfide Maintains Mitochondrial DNA Replication via Demethylation of TFAM

    PubMed Central

    Li, Shuangshuang

    2015-01-01

    Abstract Aims: Hydrogen sulfide (H2S) exerts a wide range of actions in the body, especially in the modulation of mitochondrial functions. The normal replication of mitochondrial DNA (mtDNA) is critical for cellular energy metabolism and mitochondrial biogenesis. The aim of this study was to investigate whether H2S affects mtDNA replication and the underlying mechanisms. We hypothesize that H2S maintains mtDNA copy number via inhibition of Dnmt3a transcription and TFAM promoter methylation. Results: Here, we demonstrated that deficiency of cystathionine gamma-lyase (CSE), a major H2S-producing enzyme, reduces mtDNA copy number and mitochondrial contents, and it inhibits the expressions of mitochondrial transcription factor A (TFAM) and mitochondrial marker genes in both smooth muscle cells and aorta tissues from mice. Supply of exogenous H2S stimulated mtDNA copy number and strengthened the expressions of TFAM and mitochondrial marker genes. TFAM knockdown diminished H2S-enhanced mtDNA copy number. In addition, CSE deficiency induced the expression of DNA methyltransferase 3a (Dnmt3a) and TFAM promoter DNA methylation, and H2S repressed Dnmt3a expression, resulting in TFAM promoter demethylation. We further found that H2S S-sulfhydrates transcription repressor interferon regulatory factor 1 (IRF-1) and enhances the binding of IRF-1 with Dnmt3a promoter after reduced Dnmt3a transcription. H2S had little effects on the expression of Dnmt1 and Dnmt3b as well as on ten-eleven translocation methylcytosine dioxygenase 1, 2, and 3. Innovation: A sufficient level of H2S is able to inhibit TFAM promoter methylation and maintain mtDNA copy number. Conclusion: CSE/H2S system contributes to mtDNA replication and cellular bioenergetics and provides a novel therapeutic avenue for cardiovascular diseases. Antioxid. Redox Signal. 23, 630–642. PMID:25758951

  18. The Role of Water for Photodecomposition of Aqueous Hydrogen Sulfide Using Stratified Photocatalyst—Experimental Part

    NASA Astrophysics Data System (ADS)

    Arai, Takeo; Matsumoto, Takatoshi; Sakima, Shuhei; Shinoda, Kozo; Nagashima, Umpei; Tohji, Kazuyuki

    2006-05-01

    Splitting of hydrogen sulfide using sunlight is a useful reaction to produce hydrogen. Alkaline sulfide solution, which is prepared by dissolving hydrogen sulfide into alkaline water, is selected as the reaction medium of photocatalytic hydrogen generation reaction. In this system, the photocatalytic reaction is assumed to occur as follows: 2H2O + 2e- → H2 + 2OH- (1) 2S2- + 2h+ → S22- (2) However, as the reaction progresses white solids precipitate in the reaction medium. Furthermore, the HPLC analysis suggested that the ratio between the consumption of sulfide ion and the amount of hydrogen generation was about 3:2, which is not stoichiometric. Thus, in this paper, we characterized the white solid precipitate and tried to optimize the solution condition to prevent the precipitation of the same. From our study, the white solid precipitate was confirmed as sulfur derived from the oxidation of the disulfide ion. It was confirmed that the addition of sulfite ions prevented the oxidation of disulfide ions, which causes the precipitation. In the absence of sulfite ions and for sufide ion concentration less than 0.1M, the precipitation of sulfur occurs in a very short reaction time. On the other hand the hydrogen evolution rate retarded when the sulfide ion concentration is higher than 0.1M. This was due to the degradation of the stratified CdS particles. Thus, the optimal concentration of Na2S solution was determined to be around 0.1M.

  19. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must... CONTINENTAL SHELF Plans and Information Contents of Exploration Plans (ep) § 250.215 What hydrogen...

  20. Direct chlorination process for geothermal power plant off-gas - hydrogen sulfide abatement

    SciTech Connect

    Sims, A.V.

    1983-06-01

    The Direct Chlorination Process removes hydrogen sulfide from geothermal off-gases by reacting hydrogen sulfide with chlorine in the gas phase. Hydrogen chloride and elemental sulfur are formed by this reaction. The Direct Chlorination Process has been successfully demonstrated by an on-site operation of a pilot plant at the 3 M We HPG-A geothermal power plant in the Puna District on the island of Hawaii. Over 99.5 percent hydrogen sulfide removal was achieved in a single reaction stage. Chlorine gas did not escape the pilot plant, even when 90 percent excess chlorine gas was used. Because of the higher cost of chemicals and the restricted markets in Hawaii, the economic viability of this process in Hawaii is questionable.

  1. Direct chlorination process for geothermal power plant off-gas - hydrogen sulfide abatement

    SciTech Connect

    Sims, A.V.

    1983-06-01

    The Direct Chlorination Process removes hydrogen sulfide from geothermal off-gases by reacting hydrogen sulfide with chlorine in the gas phase. Hydrogen chloride and elemental sulfur are formed by this reaction. The Direct Chlorination Process has been successfully demonstrated by an on-site operation of a pilot plant at the 3 M We HPG-A geothermal power plant in the Puna District on the island of Hawaii. Over 99.5 percent hydrogen sulfide removal was achieved in a single reaction state. Chlorine gas did not escape the pilot plant, even when 90 percent excess chlorine gas was used. A preliminary economic evaluation of the Direct Chlorination Process indicates that it is very competitive with the Stretford Process. Compared to the Stretford Process, the Direct Chlorination Process requires about one-third the initial capital investment and about one-fourth the net daily expenditure.

  2. Mobile measurement of methane and hydrogen sulfide at natural gas production site fence lines in the Texas Barnett Shale.

    PubMed

    Eapi, Gautam R; Sabnis, Madhu S; Sattler, Melanie L

    2014-08-01

    Production of natural gas from shale formations is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past, which has generated considerable interest in potential environmental impacts. This study focused on the Barnett Shale Fort Worth Basin in Texas, which saw the number of gas-producing wells grow from 726 in 2001 to 15,870 in 2011. This study aimed to measure fence line concentrations of methane and hydrogen sulfide at natural gas production sites (wells, liquid storage tanks, and associated equipment) in the four core counties of the Barnett Shale (Denton, Johnson, Tarrant, and Wise). A mobile measurement survey was conducted in the vicinity of 4788 wells near 401 lease sites, representing 35% of gas production volume, 31% of wells, and 38% of condensate production volume in the four-county core area. Methane and hydrogen sulfide concentrations were measured using a Picarro G2204 cavity ring-down spectrometer (CRDS). Since the research team did not have access to lease site interiors, measurements were made by driving on roads on the exterior of the lease sites. Over 150 hr of data were collected from March to July 2012. During two sets of drive-by measurements, it was found that 66 sites (16.5%) had methane concentrations > 3 parts per million (ppm) just beyond the fence line. Thirty-two lease sites (8.0%) had hydrogen sulfide concentrations > 4.7 parts per billion (ppb) (odor recognition threshold) just beyond the fence line. Measured concentrations generally did not correlate well with site characteristics (natural gas production volume, number of wells, or condensate production). t tests showed that for two counties, methane concentrations for dry sites were higher than those for wet sites. Follow-up study is recommended to provide more information at sites identified with high levels of methane and hydrogen sulfide. Implications: Information regarding air emissions from shale gas

  3. Mobile measurement of methane and hydrogen sulfide at natural gas production site fence lines in the Texas Barnett Shale.

    PubMed

    Eapi, Gautam R; Sabnis, Madhu S; Sattler, Melanie L

    2014-08-01

    Production of natural gas from shale formations is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past, which has generated considerable interest in potential environmental impacts. This study focused on the Barnett Shale Fort Worth Basin in Texas, which saw the number of gas-producing wells grow from 726 in 2001 to 15,870 in 2011. This study aimed to measure fence line concentrations of methane and hydrogen sulfide at natural gas production sites (wells, liquid storage tanks, and associated equipment) in the four core counties of the Barnett Shale (Denton, Johnson, Tarrant, and Wise). A mobile measurement survey was conducted in the vicinity of 4788 wells near 401 lease sites, representing 35% of gas production volume, 31% of wells, and 38% of condensate production volume in the four-county core area. Methane and hydrogen sulfide concentrations were measured using a Picarro G2204 cavity ring-down spectrometer (CRDS). Since the research team did not have access to lease site interiors, measurements were made by driving on roads on the exterior of the lease sites. Over 150 hr of data were collected from March to July 2012. During two sets of drive-by measurements, it was found that 66 sites (16.5%) had methane concentrations > 3 parts per million (ppm) just beyond the fence line. Thirty-two lease sites (8.0%) had hydrogen sulfide concentrations > 4.7 parts per billion (ppb) (odor recognition threshold) just beyond the fence line. Measured concentrations generally did not correlate well with site characteristics (natural gas production volume, number of wells, or condensate production). t tests showed that for two counties, methane concentrations for dry sites were higher than those for wet sites. Follow-up study is recommended to provide more information at sites identified with high levels of methane and hydrogen sulfide. Implications: Information regarding air emissions from shale gas

  4. Distributed fiber optic chemical sensor for hydrogen sulfide and chlorine detection

    NASA Astrophysics Data System (ADS)

    Mukamal, Harold; Cordero, Steven R.; Ruiz, David; Beshay, Manal; Lieberman, Robert A.

    2005-11-01

    Fiber optic sensors having their entire length as the sensing elements for chlorine or hydrogen sulfide are reported here. The chlorine fiber consists of a silica core and a chlorine-sensitive cladding, and the hydrogen sulfide fiber has a hydrogen sulfide sensitive cladding. Upon exposure to the corresponding challenge gas, the cladding very rapidly changes color resulting in attenuation of the light throughput of the fiber. A one-meter portion of the chlorine sensor fiber responds to 10 ppm chlorine in 20 seconds and to 1 ppm in several minutes. The attenuation after 10 minutes of exposure is very high, and is dependant on both chlorine concentration and fiber length. A ten-meter portion of the hydrogen sulfide sensor fiber responds to 100 ppm hydrogen sulfide in 30 seconds and to 10 ppm in 1 minute. The high sensitivity suggests that the propagating modes of the light interact strongly with the cladding, and that these interactions are massively increased (Beers Law) due to the extended sensor length. This approach will supersede the current method of having a collection of point-detectors to cover large areas.

  5. Protective effects of hydrogen sulfide anions against acetaminophen-induced hepatotoxicity in mice.

    PubMed

    Ishii, Isao; Kamata, Shotaro; Hagiya, Yoshifumi; Abiko, Yumi; Kasahara, Tadashi; Kumagai, Yoshito

    2015-12-01

    The key mechanism for hepatotoxicity resulting from acetaminophen (APAP) overdose is cytochrome P450-dependent formation of N-acetyl-p-benzoquinone imine (NAPQI), a potent electrophilic metabolite that forms protein adducts. The fundamental roles of glutathione in the effective conjugation/clearance of NAPQI have been established, giving a molecular basis for the clinical use of N-acetylcysteine as a sole antidote. Recent evidence from in vitro experiments suggested that sulfide anions (S(2-)) to yield hydrogen sulfide anions (HS(-)) under physiological pH could effectively react with NAPQI. This study evaluated the protective roles of HS(-) against APAP-induced hepatotoxicity in mice. We utilized cystathionine γ-lyase-deficient (Cth(-/-)) mice that are highly sensitive to acetaminophen toxicity. Intraperitoneal injection of acetaminophen (150 mg/kg) into Cth(-/-) mice resulted in highly elevated levels of serum alanine/aspartate aminotransferases and lactate dehydrogenase associated with marked increases in oncotic hepatocytes; all of which were significantly inhibited by intraperitoneal preadministration of sodium hydrosulfide (NaHS). NaHS preadministration significantly suppressed APAP-induced serum malondialdehyde level increases without abrogating APAP-induced rapid depletion of hepatic glutathione. These results suggest that exogenous HS(-) protects hepatocytes by directly scavenging reactive NAPQI rather than by increasing cystine uptake and thereby elevating intracellular glutathione levels, which provides a novel therapeutic approach against acute APAP poisoning. PMID:26558465

  6. Protective effects of hydrogen sulfide anions against acetaminophen-induced hepatotoxicity in mice.

    PubMed

    Ishii, Isao; Kamata, Shotaro; Hagiya, Yoshifumi; Abiko, Yumi; Kasahara, Tadashi; Kumagai, Yoshito

    2015-12-01

    The key mechanism for hepatotoxicity resulting from acetaminophen (APAP) overdose is cytochrome P450-dependent formation of N-acetyl-p-benzoquinone imine (NAPQI), a potent electrophilic metabolite that forms protein adducts. The fundamental roles of glutathione in the effective conjugation/clearance of NAPQI have been established, giving a molecular basis for the clinical use of N-acetylcysteine as a sole antidote. Recent evidence from in vitro experiments suggested that sulfide anions (S(2-)) to yield hydrogen sulfide anions (HS(-)) under physiological pH could effectively react with NAPQI. This study evaluated the protective roles of HS(-) against APAP-induced hepatotoxicity in mice. We utilized cystathionine γ-lyase-deficient (Cth(-/-)) mice that are highly sensitive to acetaminophen toxicity. Intraperitoneal injection of acetaminophen (150 mg/kg) into Cth(-/-) mice resulted in highly elevated levels of serum alanine/aspartate aminotransferases and lactate dehydrogenase associated with marked increases in oncotic hepatocytes; all of which were significantly inhibited by intraperitoneal preadministration of sodium hydrosulfide (NaHS). NaHS preadministration significantly suppressed APAP-induced serum malondialdehyde level increases without abrogating APAP-induced rapid depletion of hepatic glutathione. These results suggest that exogenous HS(-) protects hepatocytes by directly scavenging reactive NAPQI rather than by increasing cystine uptake and thereby elevating intracellular glutathione levels, which provides a novel therapeutic approach against acute APAP poisoning.

  7. Conversion of ammonia into hydrogen and nitrogen by reaction with a sulfided catalyst

    DOEpatents

    Matthews, Charles W.

    1977-01-01

    A method is provided for removing ammonia from the sour water stream of a coal gasification process. The basic steps comprise stripping the ammonia from the sour water; heating the stripped ammonia to a temperature from between 400.degree. to 1,000.degree. F; passing the gaseous ammonia through a reactor containing a sulfided catalyst to produce elemental hydrogen and nitrogen; and scrubbing the reaction product to obtain an ammonia-free gas. The residual equilibrium ammonia produced by the reactor is recycled into the stripper. The ammonia-free gas may be advantageously treated in a Claus process to recover elemental sulfur. Iron sulfide or cobalt molybdenum sulfide catalysts are used.

  8. Sulfur transformations at the hydrogen sulfide/oxygen interface in stratified waters and in cyanobacterial mats

    NASA Technical Reports Server (NTRS)

    Cohen, Y.

    1985-01-01

    Stratified water bodies allow the development of several microbial plates along the water column. The microbial plates develop in relation to nutrient availability, light penetration, and the distribution of oxygen and sulfide. Sulfide is initially produced in the sediment by sulfate-reducing bacteria. It diffuses along the water column creating a zone of hydrogen sulfide/oxygen interface. In the chemocline of Solar Lake oxygen and sulfide coexist in a 0 to 10 cm layer that moves up and down during a diurnal cycle. The microbial plate at the chemocline is exposed to oxygen and hydrogen sulfide, alternating on a diurnal basis. The cyanobacteria occupying the interface switch from anoxygenic photosynthesis in the morning to oxygenic photosynthesis during the rest of the day which results in a temporal build up of elemental sulfur during the day and disappears at night due to both oxidation to thiosulfate and sulfate by thiobacilli, and reduction to hydrogen sulfide by Desulfuromonas sp. and anaerobically respiring cyanobacteria. Sulfate reduction was enhanced in the light at the surface of the cyanobacterial mats. Microsulfate reduction measurements showed enhanced activity of sulfate reduction even under high oxygen concentrations of 300 to 800 micrometer. Apparent aerobic SO sub 4 reduction activity is explained by the co-occurrence of H sub 2. The physiology of this apparent sulfate reduction activity is studied.

  9. Red soil as a regenerable sorbent for high temperature removal of hydrogen sulfide from coal gas.

    PubMed

    Ko, Tzu-Hsing; Chu, Hsin; Lin, Hsiao-Ping; Peng, Ching-Yu

    2006-08-25

    In this study, hydrogen sulfide (H(2)S) was removed from coal gas by red soil under high temperature in a fixed-bed reactor. Red soil powders were collected from the northern, center and southern of Taiwan. They were characterized by XRPD, porosity analysis and DCB chemical analysis. Results show that the greater sulfur content of LP red soils is attributed to the higher free iron oxides and suitable sulfidation temperature is around 773K. High temperature has a negative effect for use red soil as a desulfurization sorbent due to thermodynamic limitation in a reduction atmosphere. During 10 cycles of regeneration, after the first cycle the red soil remained stable with a breakthrough time between 31 and 36 min. Hydrogen adversely affects sulfidation reaction, whereas CO exhibits a positive effect due to a water-shift reaction. COS was formed during the sulfidation stage and this was attributed to the reaction of H(2)S and CO. Results of XRPD indicated that, hematite is the dominant active species in fresh red soil and iron sulfide (FeS) is a product of the reaction between hematite and hydrogen sulfide in red soils. The spinel phase FeAl(2)O(4) was found during regeneration, moreover, the amount of free iron oxides decreased after regeneration indicating the some of the free iron oxide formed a spinel phase, further reducting the overall desulfurization efficiency.

  10. Methanol and hydrogen sulfide in comet P/Halley

    NASA Technical Reports Server (NTRS)

    Eberhardt, P.; Meier, R.; Krankowsky, D.; Hodges, R. R.

    1994-01-01

    The Neutral Mass Spectrometer on the Giotto spacecraft measured the gas and ion composition in the coma of comet P/Halley. A detailed model of the ion chemistry inside the contact surface located at 4660 km is used to interpret the measured ion desnity profiles in the 32 to 35 amu/e mass range. The masses 33 and 35 amu/e are dominated by the protonated methanol and hydrogen sulfide ions CH3OH2(+) and H3S(+). Both profiles are essentially compatible with CH3OH and H2S originating from the nucleus only. The production rates relative to water are Y(CH3OH) = Q(CH3OH)/Q(H2O) = 1.7% and Y(H2S) = 0.41%. Our Y(CH3OH) agrees well with a determination from IR spectra obtained about 6 weeks after the Giotto encounter with P/Halley. In 7 other comets IR and microwave observations give Y(CH3OH) values between about 0.7 and 6%, indicating that the methanol abundance shows a strong variability from comet to comet. In three other comets Y(H2S) values between 0.2 and 0.5% have been reported. In addition to H2S(+), only ions containing minor isotopes of H, C, O and S contribute to mass 34 amu/e (e.g. (34)S(+), (13)CH3OH2(+), CH4DO(+)). These contributions can be calculated from the measured densities of the ions containing the major isotopes and the H2S(+) contribution from the measured H3S(+) density. From mass 34 amu/e we can also derive an upper limit of 1% for the abundance of deuterated methanol. This limit is at most marginally compatible with a direct interstellar origin of the CH3OH in P/Halley as the measured interstellar abundance of deuterated methanol is 1 to 6%.

  11. Thermodynamics of Complex Sulfide Inclusion Formation in Ca-Treated Al-Killed Structural Steel

    NASA Astrophysics Data System (ADS)

    Guo, Yin-tao; He, Sheng-ping; Chen, Gu-jun; Wang, Qian

    2016-08-01

    Controlling the morphology of the sulfide inclusion is of vital importance in enhancing the properties of structural steel. Long strip-shaped sulfides in hot-rolled steel can spherize when, instead of the inclusion of pure single-phase MnS, the guest is a complex sulfide, such as an oxide-sulfide duplex and a solid-solution sulfide particle. In this study, the inclusions in a commercial rolled structural steel were investigated. Spherical and elongated oxide-sulfide duplex as well as single-phase (Mn,Ca)S solid solution inclusions were observed in the steel. A thermodynamic equilibrium between the oxide and sulfide inclusions was proposed to understand the oxide-sulfide duplex inclusion formation. Based on the equilibrium solidification principle, thermodynamic discussions on inclusion precipitation during the solidification process were performed for both general and resulfurized structural steel. The predicted results of the present study agreed well with the experimental ones.

  12. Removal of hydrogen sulfide from waste treatment plant biogas using the apollo scrubber

    SciTech Connect

    Smith, J.W.; Burrowes, P.A.; Gupta, A.; Walton, P.S.; Meffe, S.

    1996-12-31

    The removal of hydrogen sulfide and other sulphur compounds from anaerobic digester gas streams prior to their use as fuel for boilers, stationary engines, and cogeneration units minimizes corrosion problems and reduces sulfur emission loadings. A research program at the Department of Chemical Engineering and Applied Chemistry, University of Toronto in the 1980`s demonstrated the use of a modified flotation cell for the absorption of hydrogen sulfide from a gas stream and its catalytic oxidation to sulfur. The essence of the technology was a proprietary gas liquid contactor which provided very high mass transfer rates at the interface. A bench scale contactor developed at the university achieved hydrogen sulfide removal efficiencies of over 99.9% at atmospheric pressure. A demonstration unit for digester gas scrubbing applications was designed, fabricated, and then installed and evaluated at the Metropolitan Toronto Works Department - Main Treatment Plant (MTP).

  13. Computational study of the interaction of indole-like molecules with water and hydrogen sulfide.

    PubMed

    Cabaleiro-Lago, Enrique M; Rodríguez-Otero, Jesús; Peña-Gallego, Ángeles

    2011-10-01

    The characteristics of the interaction between water and hydrogen sulfide with indole and a series of analogs obtained by substituting the NH group of indole by different heteroatoms have been studied by means of ab initio calculations. In all cases, minima were found corresponding to structures where water and hydrogen sulfide interact by means of X-H···π contacts. The interaction energies for all these π complexes are quite similar, spanning from -13.5 to -18.8 kJ/mol, and exhibiting the stability sequence NH > CH(2) ≈ PH > Se ≈ S > O, for both water and hydrogen sulfide. Though interaction energies are similar, hydrogen sulfide complexes are slightly favored over their water counterparts when interacting with the π cloud. σ-Type complexes were also considered for the systems studied, but only in the case of water complexes this kind of complexes is relevant. Only for complexes formed by water and indole, a significantly more stable σ-type complex was found with an interaction energy amounting to -23.6 kJ/mol. Oxygen and phosphorous derivatives also form σ-type complexes of similar stability as that observed for π ones. Despite the similar interaction energies exhibited by complexes with water and hydrogen sulfide, the nature of the interaction is very different. For π complexes with water the main contributions to the interaction energy are electrostatic and dispersive contributing with similar amounts, though slightly more from electrostatics. On the contrary, in hydrogen sulfide complexes dispersion is by far the main stabilizing contribution. For the σ-type complexes, the interaction is clearly dominated by the electrostatic contribution, especially in the indole-water complex.

  14. Organic silicon compounds anf hydrogen sulfide removal from biogas by mineral and adsorbent

    NASA Astrophysics Data System (ADS)

    Choi, J.

    2015-12-01

    Biogas utilized for energy production needs to be free from organic silicon compounds and hydrogen sulfide , as their burning has damaging effects on utilities and humans; organic silicon compounds and hydrogen sulfide can be found in biogas produced from biomass wastes, due to their massive industrial use in synthetic product,such as cosmetics, detergents and paints.Siloxanes and hydrogen sulfide removal from biogas can be carried out by various methods (Ajhar et al., 2010); aim of the present work is to find a single practical andeconomic way to drastically and simultaneously reduce both hydrogen sulfide and the siloxanes concentration to less than 1 ppm. Some commercial activated carbons previously selected (Monteleoneet al., 2011) as being effective in hydrogen sulfide up taking have been tested in an adsorption measurement apparatus, by flowing both hydrogen sulphide and volatile siloxane (Decamethycyclopentasiloxane or D5) in a nitrogen stream,typically 25-300 ppm D5 over N2, through an clay minerals, Fe oxides and Silica; the adsorption process was analyzed by varying some experimental parameters (concentration, grain size, bed height). The best silica shows an adsorption capacity of 0.2 g D5 per gram of silica. The next thermo gravimetric analysis (TGA) confirms the capacity data obtained experimentally by the breakthrough curve tests.The capacity results depend on D5 and hydrogen sulphide concentrations. A regenerative silica process is then carried out byheating the silica bed up to 200 ° C and flushing out the adsorbed D5 and hydrogen sulphide samples in a nitrogen stream in athree step heating procedure up to 200 ° C. The adsorption capacity is observed to degrade after cyclingthe samples through several adsorption-desorption cycles.

  15. Chirped laser dispersion spectroscopy for laser-based hydrogen sulfide detection in open-path conditions.

    PubMed

    Nikodem, Michał

    2016-05-16

    In this paper the design and characterization of a near-IR Chirped Laser Dispersion Spectroscopy (CLaDS)-based setup for hydrogen sulfide (H2S) detection is reported. This system can be implemented for open-path sensing also in standoff configuration. Target transition selection, system noise and detection limit are discussed and characterized. Furthermore, the cross-interference with other molecules is analyzed. CLaDS-based detection is shown to be highly immune to background carbon dioxide changes, which is a critical issue in accurate open-path sensing of hydrogen sulfide.

  16. Importance of Hydrogen Sulfide, Thiosulfate, and Methylmercaptan for Growth of Thiobacilli during Simulation of Concrete Corrosion.

    PubMed

    Sand, W

    1987-07-01

    Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments. At 9 months after inoculation with thiobacilli, concrete blocks were severely corroded. The sulfur compounds hydrogen sulfide, thiosulfate, and methylmercaptan were tested for their corrosive action. With hydrogen sulfide, severe corrosion was noted. The flora was dominated by Thiobacillus thiooxidans. Thiosulfate led to medium corrosion and a dominance of Thiobacillus neapolitanus and Thiobacillus intermedius. Methylmercaptan resulted in negligible corrosion. A flora of heterotrophs and fungi grew on the blocks. This result implies that methylmercaptan cannot be degraded by thiobacilli. PMID:16347391

  17. Importance of Hydrogen Sulfide, Thiosulfate, and Methylmercaptan for Growth of Thiobacilli during Simulation of Concrete Corrosion.

    PubMed

    Sand, W

    1987-07-01

    Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments. At 9 months after inoculation with thiobacilli, concrete blocks were severely corroded. The sulfur compounds hydrogen sulfide, thiosulfate, and methylmercaptan were tested for their corrosive action. With hydrogen sulfide, severe corrosion was noted. The flora was dominated by Thiobacillus thiooxidans. Thiosulfate led to medium corrosion and a dominance of Thiobacillus neapolitanus and Thiobacillus intermedius. Methylmercaptan resulted in negligible corrosion. A flora of heterotrophs and fungi grew on the blocks. This result implies that methylmercaptan cannot be degraded by thiobacilli.

  18. Importance of hydrogen sulfide, thiosulfate, and methylmercaptan for growth of thiobacilli during simulation of concrete corrosion

    SciTech Connect

    Sand, W.

    1987-07-01

    Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments. At 9 months after inoculation with thiobacilli, concrete blocks were severely corroded. The sulfur compounds hydrogen sulfide, thiosulfate, and methylmercaptan were tested for their corrosive action. With hydrogen sulfide, severe corrosion was noted. The flora was dominated by Thiobacillus thiooxidans. Thiosulfate led to medium corrosion and a dominance of Thiobacillus neapolitanus and Thiobacillus intermedius. Methylmercaptan resulted in negligible corrosion. A flora of heterotrophs and fungi grew on the blocks. This result implies that methylmercaptan cannot be degraded by thiobacilli.

  19. Hydrogen sulfide in plants: from dissipation of excess sulfur to signaling molecule.

    PubMed

    Calderwood, Alexander; Kopriva, Stanislav

    2014-09-15

    Sulfur is essential in all organisms for the synthesis of amino acids cysteine and methionine and as an active component of numerous co-factors and prosthetic groups. However, only plants, algae, fungi, and some prokaryotes are capable of using the abundant inorganic source of sulfur, sulfate. Plants take sulfate up, reduce it, and assimilate into organic compounds with cysteine being the first product of the pathway and a donor of reduced sulfur for synthesis of other S-containing compounds. Cysteine is formed in a reaction between sulfide, derived from reduction of sulfite and an activated amino acid acceptor, O-acetylserine. Sulfide is thus an important intermediate in sulfur metabolism, but numerous other functions in plants has been revealed. Hydrogen sulfide can serve as an alternative source of sulfur for plants, which may be significant in anaerobic conditions of waterlogged soils. On the other hand, emissions of hydrogen sulfide have been detected from many plant species. Since the amount of H2S discharged correlated with sulfate supply to the plants, the emissions were considered a mechanism for dissipation of excess sulfur. Significant hydrogen sulfide emissions were also observed in plants infected with pathogens, particularly with fungi. H2S thus seems to be part of the widely discussed sulfur-induced-resistance/sulfur-enhanced-defense. Recently, however, more evidence has emerged for a role for H2S in regulation and signaling. Sulfide stabilizes the cysteine synthase complex, increasing so the synthesis of its acceptor O-acetylserine. H2S has been implicating in regulation of plant stress response, particularly draught stress. There are more and more examples of processes regulated by H2S in plants being discovered, and hydrogen sulfide is emerging as an important signaling molecule, similar to its role in the animal and human world. How similar the functions, and homeostasis of H2S are in these diverse organisms, however, remains to be elucidated.

  20. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... analysis must be consistent with the EPA's risk management plan methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must... Documents (docd) § 250.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?...

  1. 75 FR 19319 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting; Extension of Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ... requirements for hydrogen sulfide (75 FR 8889). B. Why and for How Long Is EPA Extending the Comment Period... Number (CAS No.) 7783-06-4) (75 FR 8889). The purpose of today's action is to inform interested parties... AGENCY 40 CFR Part 372 RIN 2025-AA27 Hydrogen Sulfide; Community Right-to-Know Toxic Chemical...

  2. Hydrogen sulfide releasing capacity of natural isothiocyanates: is it a reliable explanation for the multiple biological effects of Brassicaceae?

    PubMed

    Citi, Valentina; Martelli, Alma; Testai, Lara; Marino, Alice; Breschi, Maria C; Calderone, Vincenzo

    2014-06-01

    Hydrogen sulfide is an endogenous pleiotropic gasotransmitter, which mediates important physiological effects in the human body. Accordingly, an impaired production of endogenous hydrogen sulfide contributes to the pathogenesis of important disorders. To date, exogenous compounds, acting as hydrogen sulfide-releasing agents, are viewed as promising pharmacotherapeutic agents. In a recent report, the hydrogen sulfide-releasing properties of some synthetic aryl isothiocyanate derivatives have been reported, indicating that the isothiocyanate function can be viewed as a suitable slow hydrogen sulfide-releasing moiety, endowed with the pharmacological potential typical of this gasotransmitter. Many isothiocyanate derivatives (deriving from a myrosinase-mediated transformation of glucosinolates) are well-known secondary metabolites of plants belonging to the family Brassicaceae, a large botanical family comprising many edible species. The phytotherapeutic and nutraceutic usefulness of Brassicaceae in the prevention of important human diseases, such as cancer, neurodegenerative processes and cardiovascular diseases has been widely discussed in the scientific literature. Although these effects have been largely attributed to isothiocyanates, the exact mechanism of action is still unknown. In this experimental work, we aimed to investigate the possible hydrogen sulfide-releasing capacity of some important natural isothiocyanates, studying it in vitro by amperometric detection. Some of the tested natural isothiocyanates exhibited significant hydrogen sulfide release, leading us to hypothesize that hydrogen sulfide may be, at least in part, a relevant player accounting for several biological effects of Brassicaceae.

  3. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... analysis must be consistent with the EPA's risk management plan methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must... Development Operations Coordination Documents (docd) § 250.245 What hydrogen sulfide (H2S) information...

  4. Hydrogen sulfide production and volatilization in a polymictic eutrophic saline lake, Salton Sea, California.

    PubMed

    Reese, Brandi Kiel; Anderson, Michael A; Amrhein, Christopher

    2008-11-15

    The Salton Sea is a large shallow saline lake located in southern California that is noted for high sulfate concentrations, substantial algal productivity, and very warm water column temperatures. These conditions are well-suited for sulfide production, and sulfide has been implicated in summer fish kills, although no studies have been conducted to specifically understand hydrogen sulfide production and volatilization there. Despite polymictic mixing patterns and relatively short accumulation periods, the amount of sulfide produced is comparable to meromictic lakes. Sulfide levels in the Salton Sea reached concentrations of 1.2 mmol L(-1) of total free sulfide in the hypolimnion and 5.6 mmol L(-1) in the sediment pore water. Strong winds in late July mixed H2S into the surface water, where it depleted the entire water column of dissolved oxygen and reached a concentration of 0.1 mmol L(-1). Sulfide concentrations exceeded the toxicity threshold of tilapia (Oreochromis mossambicus) and combined with strong anoxia throughout the water column, resulted in a massive fish kill. The mixing of sulfide into the surface waters also increased atmospheric H2S concentrations, reaching 1.0 micromol m(-3). The flux of sulfide from the sediment into the water column was estimated to range from 2-3 mmol m(-2) day(-1) during the winter and up to 8 mmol m(-2) day(-1) during the summer. Application of the two-layer model for volatilization indicates that up to 19 mmol m(-2) day(-1) volatilized from the surface during the mixing event. We estimate that as much as 3400 Mg year(-1) or approximately 26% of sulfide that diffused into the water column from the deepest sediments may have been volatilized to the atmosphere. PMID:18760446

  5. Estimation of hydrogen sulfide removal efficiency with granulated coal ash applied to eutrophic marine sediment using a simplified simulation model.

    PubMed

    Asaoka, Satoshi; Yamamoto, Tamiji; Yamamoto, Hironori; Okamura, Hideo; Hino, Kazutoshi; Nakamoto, Kenji; Saito, Tadashi

    2015-05-15

    Hydrogen sulfide generated in eutrophic marine sediment is harmful for living organisms. It is therefore necessary to remove hydrogen sulfide from the sediment to restore benthic ecosystems. Previous studies revealed that granulated coal ash, which is a by-product of coal thermal electric power stations, could remove and oxidize hydrogen sulfide. In this study, we propose a simplified simulation model to estimate the hydrogen sulfide removal efficiency of granulated coal ash. Hydrogen sulfide concentrations in eutrophic marine sediment pore water with and without the application of granulated coal ash were calculated by the proposed model, and the outputs were compared with semi-field or field observation data. The model outputs reproduced the observed data well. Using the proposed model outputs, we suggest an optimum application dosage of granulated coal ash for remediating eutrophic marine sediment.

  6. Nickel sulfide formation at low temperature: initial precipitates, solubility and transformation products

    EPA Science Inventory

    The formation of nickel sulfides has been examined experimentally over the temperature range from 25 to 60°C. At all conditions studied, hexagonal (α-NiS) was the initial precipitate from solution containing Ni2+ and dissolved sulfide. The formation of millerite (β- NiS, rhombo...

  7. Design of an atomic layer deposition reactor for hydrogen sulfide compatibility

    NASA Astrophysics Data System (ADS)

    Dasgupta, Neil P.; Mack, James F.; Langston, Michael C.; Bousetta, Al; Prinz, Fritz B.

    2010-04-01

    A customized atomic layer deposition (ALD) reactor was designed with components compatible with hydrogen sulfide (H2S) chemistry. H2S is used as a reactant for the ALD of metal sulfides. The use of H2S in an ALD reactor requires special attention to safety issues due to its highly toxic, flammable, and corrosive nature. The reactor was designed with respect to materials compatibility of all wetted components with H2S. A customized safety interlock system was developed to shut down the system in the event of toxic gas leakage, power outage, loss of building ventilation or compressed air pressure. ALD of lead sulfide (PbS) and zinc sulfide (ZnS) were demonstrated with no chemical contamination or detectable release of H2S.

  8. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    PubMed

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5.

  9. Kinetics and mechanisms of iron sulfide reductions in hydrogen and in carbon monoxide

    USGS Publications Warehouse

    Wiltowski, T.; Hinckley, C.C.; Smith, Gerard V.; Nishizawa, T.; Saporoschenko, Mykola; Shiley, R.H.; Webster, J.R.

    1987-01-01

    The reduction of iron sulfides by hydrogen and by carbon monoxide has been studied using plug flow and thermogravimetric methods. The reactions were studied in the 523-723??K temperature range and were found to be first-order processes. Plug flow studies were used to correlate reaction rates between pyrite and the gases as a function of the surface area of the pyrite. The rate of H2S formation increases with the surface area of the pyrite sample. The results of thermogravimetric experiments indicate that the reactions consist of several steps. Rate constants for the pyrite reduction by H2 and by CO were obtained. The activation energies increased with degree of reduction. Values of Ea were 113.2 (step I) and 122.5 kJ/mole (step II) for pyrite reduction with CO and 99.4 (step I), 122.4 (step II), 125.2 (step III), and 142.6 kJ/mole (step IV) for pyrite reduction with hydrogen. ?? 1987.

  10. [Regulation of sulfates, hydrogen sulfide and heavy metals in technogenic reservoirs by sulfate-reducing bacteria].

    PubMed

    Hudz', S P; Peretiatko, T B; Moroz, O M; Hnatush, S O; Klym, I R

    2011-01-01

    Sulfate-reducing bacteria Desulfovibrio desulfuricans Ya-11 in the presence of sulfates and organic compounds in the medium reduce sulfates to hydrogen sulfide (dissimilatory sulfate reduction). Heavy metals in concentration over 2 mM inhibit this process. Pb2+, Zn2+, Ni2+, Co2+, Fe2+ and Cd2+ ions in concentration 1-1.5 mM display insignificant inhibiting effect on sulfate reduction process, and metals precipitate in the form of sulfides. At concentrations of heavy metals 2-3 mM one can observe a decrease of sulfates reduction intensity, and a percent of metals binding does not exceed 72%. Obtained results give reason to confirm, that sulfate-reducing bacteria play an important role in regulation of the level of sulfates, hydrogen sulfide and heavy metals in reservoirs and they may be used for purification of water environment from these compounds.

  11. Assessment of Hydrogen Sulfide Minimum Detection Limits of an Open Path Tunable Diode Laser

    EPA Science Inventory

    During June 2007, U.S. EPA conducted a feasibility study to determine whether the EPA OTM 10 measurement approach, also known as radial plume mapping (RPM), was feasible. A Boreal open-path tunable diode laser (OP-TDL) to collect path-integrated hydrogen sulfide measurements alon...

  12. Hydrogen sulfide and nonmethane hydrocarbon emissions from broiler houses in the Southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogen sulfide (H2S) and nonmethane hydrocarbon (NMHC) emissions from two mechanically ventilated commercial broiler houses located in the Southeastern United States were continuously monitored over 12 flocks during the one-year period of 2006-2007 as a joint effort between Iowa State University a...

  13. 75 FR 8889 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ... toxic chemicals as part of a 1993 final rule (December 1, 1993, 58 FR 63500). Hydrogen sulfide was... Federal Register of February 4, 1987 (52 FR 3479) to provide guidance regarding the recommended content... Federal Register of May 23, 1991 (56 FR 23703) regarding the recommended content of petitions to...

  14. 76 FR 69136 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... required by 1 CFR 21.1, regarding the lifted stay of hydrogen sulfide reporting requirements. In FR Doc... a document on August 22, 1994 (59 FR 43048) imposing stays on the reporting requirements for... Register of October 17, 2011 (76 FR 64022) should have lifted the Administrative Stay of the...

  15. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR HYDROGEN SULFIDE (EXTERNAL REVIEW DRAFT)

    EPA Science Inventory

    Hydrogen sulfide (H2S) is a colorless gas with a strong odor of rotten eggs. Its primary uses include the production of elemental sulfur and sulfuric acid, the manufacture of heavy water and other chemicals. Occupational exposure occurs primarily from its presence in petroleum, n...

  16. Genetically Anchored Fluorescent Probes for Subcellular Specific Imaging of Hydrogen Sulfide

    PubMed Central

    Jiang, Xiqian; Sizovs, Antons; Wang, Meng C.; Provost, Christopher R.; Huang, Jia

    2016-01-01

    Imaging hydrogen sulfide (H2S) at the subcellular resolution will greatly improve the understanding of functions of this signaling molecule. Taking advantage of the protein labeling technologies, we report a general strategy for the development of organelle specific H2S probes, which enables sub-cellular H2S imaging essentially in any organelles of interest. PMID:26806071

  17. 40 CFR 721.10445 - 2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propen-1-ol, reaction products with... Significant New Uses for Specific Chemical Substances § 721.10445 2-Propen-1-ol, reaction products with...) The chemical substance identified as 2-propen-1-ol, reaction products with hydrogen sulfide,...

  18. 40 CFR 721.10445 - 2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propen-1-ol, reaction products with... Significant New Uses for Specific Chemical Substances § 721.10445 2-Propen-1-ol, reaction products with...) The chemical substance identified as 2-propen-1-ol, reaction products with hydrogen sulfide,...

  19. CHROMATOGRAPHIC SEPARATION AND IDENTIFICATION OF PRODUCTS FROM THE REACTION OF DIMETHYLARSINIC ACID WITH HYDROGEN SULFIDE

    EPA Science Inventory

    The reaction of dimethylarsinic acid (DMAV) with hydrogen sulfide (H2S) is of biological significance and may be implicated in the overall toxicity and carcinogenicity of arsenic. The course of the reaction in aqueous phase was monitored and an initial product, dimethylthioarsin...

  20. Protective effect of hydrogen sulfide on renal injury in the experimental unilateral ureteral obstruction

    PubMed Central

    Dursun, Murat; Otunctemur, Alper; Ozbek, Emin; Sahin, Suleyman; Besiroglu, Huseyin; Ozsoy, Ozgur Doga; Cekmen, Mustafa; Somay, Adnan; Ozbay, Nurver

    2015-01-01

    ABSTRACT Introduction/Objective: Ureteral obstruction is a common pathology and causes kidney fibrosis and dysfunction at late period. In this present study, we investigated the antifibrotic and antiinflammatory effects of hydrogen sulfide on kidney damage after unilateral ureteral obstruction (UUO) in rats. Materials and Methods: 24 rats were divided into four groups. Group 1 was control, group 2 was sham, group 3 included rats with UUO and group 4 rats with UUO which were given sodium hydrogen sulfide (NaHS)-exogenous donor of hydrogen sulfide (intraperitoneally 56μmoL/kg/day). After 14 days, rats were killed and their kidneys were taken and blood analysis was performed. Tubular necrosis, mononuclear cell infiltration and interstitial fibrosis were determined histopathologically in a part of the kidneys; nitric oxide (NO), malondialdehyde (MDA) and reduced glutathione (GSH) levels were determined in the other part of the kidneys. Urea-creatinine levels were investigated by blood analysis. Statistical analyses were made by the Chi-square test and one-way analysis of variance (ANOVA). Results: There was no significantly difference for urea-creatinine levels among groups. Pathologically, there was serious tubular necrosis and fibrosis in group 3 and there was significantly decreasing of tubular necrosis and fibrosis in group 4 (p<0.005). Also, there was significantly increase of NO and MDA levels and decrease of GSH levels in group 3 compared to other groups (p<0.005). Conclusions: hydrogen sulfide prevents kidney damage with antioxidant and antiinflammatory effect. PMID:26742979

  1. VERIFICATION OF AMBIENT MONITORING TECHNOLOGIES FOR AMMONIA AND HYDROGEN SULFIDE AT ANIMAL FEEDING OPERATIONS

    EPA Science Inventory

    The increasing concentration of livestock agriculture into animal feeding operations (AFOs) has raised concerns about the environmental and potential health impact of the emissions from AFOs into the atmosphere. Gaseous ammonia (NH3) and hydrogen sulfide (H2...

  2. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect

    K. C. Kwon

    2006-09-30

    syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash or carbon coats, and catalytic metals, to develop a catalytic regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. To achieve the above-mentioned objectives using a monolithic catalyst reactor, experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 40-560 seconds at 120-150 C to evaluate effects of reaction temperatures, total pressure, space time, and catalyst regeneration on conversion of hydrogen sulfide into elemental sulfur and formation of COS. Simulated coal gas mixtures consist of 3,600-4,000-ppmv hydrogen sulfide, 1,800-2,000 ppmv sulfur dioxide, 23-27 v% hydrogen, 36-41 v% CO, 10-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to the reactor are 30-180 SCCM. The temperature of the reactor is controlled in an oven at 120-150 C. The pressure of the reactor is maintained at 40

  3. [Regulation of hydrogen sulfide level by acidophobic bacteria of Thiobacillus genus in technogenic reservoirs of sulfur mining regions].

    PubMed

    Moroz, O M

    2010-01-01

    An increase of acidophobic thione bacteria quantity in Rozdil and Yavoriv reservoirs of sulfur mining regions during 2005-2009 years, which correlates with a decrease of hydrogen sulfide content in water surface layers, was shown. The ability of acidophobic bacteria of Thiobacillus genus, isolated from "Yavorivske" lake, to oxidize effectively hydrogen sulfide added into Beijerinck medium instead of thiosulfate, was discovered. It was established, that hydrogen sulfide oxidizing efficiency by Thiobacillus sp. Yav-8, Yav-11 and Yav-14 strains is the highest (78.48-84.56%) when its content in cultivation medium was increased twice: to 2584 mg/l. An increase of sulfur quantity in sodium sulfide form from to six times as compared with its standard content in sodium thiosulfate form in the Beijerinck medium does not lead to the increase of hydrogen sulfide oxidizing efficiency by cells.

  4. Cystathionine β-synthase-derived hydrogen sulfide is involved in human malignant hyperthermia.

    PubMed

    Vellecco, Valentina; Mancini, Antonio; Ianaro, Angela; Calderone, Vincenzo; Attanasio, Chiara; Cantalupo, Anna; Andria, Barbara; Savoia, Gennaro; Panza, Elisabetta; Di Martino, Antonietta; Cirino, Giuseppe; Bucci, Mariarosaria

    2016-01-01

    Hydrogen sulfide is an endogenous gasotransmitter and its mechanism of action involves activation of ATP-sensitive K(+) channels and phosphodiesterase inhibition. As both mechanisms are potentially involved in malignant hyperthermia (MH), in the present study we addressed the involvement of the L-cysteine/hydrogen sulfide pathway in MH. Skeletal muscle biopsies obtained from 25 MH-susceptible (MHS) and 56 MH-negative (MHN) individuals have been used to perform the in vitro contracture test (IVCT). Quantitative real-time PCR (qPCR) and Western blotting studies have also been performed. Hydrogen sulfide levels are measured in both tissue samples and plasma. In MHS biopsies an increase in cystathionine β-synthase (CBS) occurs, as both mRNA and protein expression compared with MHN biopsies. Hydrogen sulfide biosynthesis is increased in MHS biopsies (0.128±0.12 compared with 0.943±0.13 nmol/mg of protein per min for MHN and MHS biopsies, respectively; P<0.01). Addition of sodium hydrosulfide (NaHS) to MHS samples evokes a response similar, in the IVCT, to that elicited by either caffeine or halothane. Incubation of MHN biopsies with NaHS, before caffeine or halothane challenge, switches an MHN to an MHS response. In conclusion we demonstrate the involvement of the L-cysteine/hydrogen sulfide pathway in MH, giving new insight into MH molecular mechanisms. This finding has potential implications for clinical care and could help to define less invasive diagnostic procedures. PMID:26460077

  5. Use of AERMOD to Determine a Hydrogen Sulfide Emission Factor for Swine Operations by Inverse Modeling.

    PubMed

    O'Shaughnessy, Patrick T; Altmaier, Ralph

    2011-08-01

    This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 µg/m(2)-s was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10(-7) µg/yr-m(2)-kg was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1M kg), concentrations 0.5 km from the CAFO were 35 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels.

  6. Use of AERMOD to determine a hydrogen sulfide emission factor for swine operations by inverse modeling

    NASA Astrophysics Data System (ADS)

    O'Shaughnessy, Patrick T.; Altmaier, Ralph

    2011-09-01

    This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 μg m -2 s -1 was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10 -7 μg yr -1 m -2 kg -1 was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1 M kg), concentrations within 0.5 km from the CAFO exceeded 25 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels.

  7. Cystathionine β-synthase-derived hydrogen sulfide is involved in human malignant hyperthermia.

    PubMed

    Vellecco, Valentina; Mancini, Antonio; Ianaro, Angela; Calderone, Vincenzo; Attanasio, Chiara; Cantalupo, Anna; Andria, Barbara; Savoia, Gennaro; Panza, Elisabetta; Di Martino, Antonietta; Cirino, Giuseppe; Bucci, Mariarosaria

    2016-01-01

    Hydrogen sulfide is an endogenous gasotransmitter and its mechanism of action involves activation of ATP-sensitive K(+) channels and phosphodiesterase inhibition. As both mechanisms are potentially involved in malignant hyperthermia (MH), in the present study we addressed the involvement of the L-cysteine/hydrogen sulfide pathway in MH. Skeletal muscle biopsies obtained from 25 MH-susceptible (MHS) and 56 MH-negative (MHN) individuals have been used to perform the in vitro contracture test (IVCT). Quantitative real-time PCR (qPCR) and Western blotting studies have also been performed. Hydrogen sulfide levels are measured in both tissue samples and plasma. In MHS biopsies an increase in cystathionine β-synthase (CBS) occurs, as both mRNA and protein expression compared with MHN biopsies. Hydrogen sulfide biosynthesis is increased in MHS biopsies (0.128±0.12 compared with 0.943±0.13 nmol/mg of protein per min for MHN and MHS biopsies, respectively; P<0.01). Addition of sodium hydrosulfide (NaHS) to MHS samples evokes a response similar, in the IVCT, to that elicited by either caffeine or halothane. Incubation of MHN biopsies with NaHS, before caffeine or halothane challenge, switches an MHN to an MHS response. In conclusion we demonstrate the involvement of the L-cysteine/hydrogen sulfide pathway in MH, giving new insight into MH molecular mechanisms. This finding has potential implications for clinical care and could help to define less invasive diagnostic procedures.

  8. Use of AERMOD to Determine a Hydrogen Sulfide Emission Factor for Swine Operations by Inverse Modeling.

    PubMed

    O'Shaughnessy, Patrick T; Altmaier, Ralph

    2011-08-01

    This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 µg/m(2)-s was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10(-7) µg/yr-m(2)-kg was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1M kg), concentrations 0.5 km from the CAFO were 35 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels. PMID:21804761

  9. Use of AERMOD to Determine a Hydrogen Sulfide Emission Factor for Swine Operations by Inverse Modeling

    PubMed Central

    O’Shaughnessy, Patrick T.; Altmaier, Ralph

    2011-01-01

    This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 µg/m2-s was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10−7 µg/yr-m2-kg was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1M kg), concentrations 0.5 km from the CAFO were 35 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels. PMID:21804761

  10. Reaction Mechanisms of Metals with Hydrogen Sulfide and Thiols in Model Wine. Part 1: Copper-Catalyzed Oxidation.

    PubMed

    Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

    2016-05-25

    Sulfidic off-odors as a result of hydrogen sulfide (H2S) and low-molecular-weight thiols are commonly encountered in wine production. These odors are usually removed by the process of Cu(II) fining, a process that remains poorly understood. The present study aims to elucidate the underlying mechanisms by which Cu(II) interacts with H2S and thiol compounds (RSH) under wine-like conditions. Copper complex formation was monitored along with H2S, thiol, oxygen, and acetaldehyde concentrations after the addition of Cu(II) (50 or 100 μM) to air-saturated model wine solutions containing H2S, cysteine, 6-sulfanylhexan-1-ol, or 3-sulfanylhexan-1-ol (300 μM each). The presence of H2S and thiols in excess to Cu(II) led to the rapid formation of ∼1.4:1 H2S/Cu and ∼2:1 thiol/Cu complexes, resulting in the oxidation of H2S and thiols and reduction of Cu(II) to Cu(I), which reacted with oxygen. H2S was observed to initially oxidize rather than form insoluble copper sulfide. The proposed reaction mechanisms provide insight into the extent to which H2S can be selectively removed in the presence of thiols in wine. PMID:27133282

  11. The Role of Hydrogen Sulfide in Evolution and the Evolution of Hydrogen Sulfide in Metabolism and Signaling.

    PubMed

    Olson, Kenneth R; Straub, Karl D

    2016-01-01

    The chemical versatility of sulfur and its abundance in the prebiotic Earth as reduced sulfide (H2S) implicate this molecule in the origin of life 3.8 billion years ago and also as a major source of energy in the first seven-eighths of evolution. The tremendous increase in ambient oxygen ∼ 600 million years ago brought an end to H2S as an energy source, and H2S-dependent animals either became extinct, retreated to isolated sulfide niches, or adapted. The first 3 billion years of molecular tinkering were not lost, however, and much of this biochemical armamentarium easily adapted to an oxic environment where it contributes to metabolism and signaling even in humans. This review examines the role of H2S in evolution and the evolution of H2S metabolism and signaling. PMID:26674552

  12. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect

    K.C. Kwon

    2009-09-30

    of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash coat, and catalytic metals, to develop a regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor. The task of developing kinetic rate equations and modeling the direct oxidation process to assist in the design of large-scale plants will be abandoned since formulation of catalysts suitable for the removal of H{sub 2}S and COS is being in progress. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 46-570 seconds under reaction conditions to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases and evaluate their capabilities in reducing hydrogen sulfide and COS in coal gases. Simulated coal gas mixtures consist of 3,200-4,000-ppmv hydrogen sulfide, 1,600-20,000-ppmv sulfur dioxide, 18-27 v% hydrogen, 29-41 v% CO, 8-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of simulated coal gas mixtures to the reactor are 30 - 180 cm{sup 3}/min at 1 atm and 25 C (SCCM). The temperature of the reactor is controlled in

  13. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect

    K. C. Kwon

    2007-09-30

    of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash or carbon coats, and catalytic metals, to develop a catalytic regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 130-156 seconds at 120-140 C to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases, evaluate removal capabilities of hydrogen sulfide and COS from coal gases with formulated catalysts, and develop an economic regeneration method of deactivated catalysts. Simulated coal gas mixtures consist of 3,300-3,800-ppmv hydrogen sulfide, 1,600-1,900 ppmv sulfur dioxide, 18-21 v% hydrogen, 29-34 v% CO, 8-10 v% CO{sub 2}, 5-18 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to the reactor are 114-132 SCCM. The temperature of the reactor is controlled in an oven at 120-140 C. The pressure of the reactor is maintained

  14. Formation of selenide, sulfide or mixed selenide-sulfide films on metal or metal coated substrates

    DOEpatents

    Eser, Erten; Fields, Shannon

    2012-05-01

    A process and composition for preventing cracking in composite structures comprising a metal coated substrate and a selenide, sulfide or mixed selenide sulfide film. Specifically, cracking is prevented in the coating of molybdenum coated substrates upon which a copper, indium-gallium diselenide (CIGS) film is deposited. Cracking is inhibited by adding a Se passivating amount of oxygen to the Mo and limiting the amount of Se deposited on the Mo coating.

  15. Electrochemical polishing of hydrogen sulfide from coal synthesis gas

    SciTech Connect

    Gleason, E.F.; Winnick, J.

    1995-11-01

    An advanced process has been developed for the separation of H{sub 2}S from coal gasification product streams through an electrochemical membrane. This technology is developed for use in coal gasification facilities providing fuel for cogeneration coal fired electrical power facilities and Molten Carbonate Fuel Cell electrical power facilities. H{sub 2}S is removed from the syn-gas by reduction to the sulfide ion and H at the cathode. The sulfide ion migrates to the anode through a molten salt electrolyte suspended in an inert ceramic matrix. Once at the anode it is oxidized to elemental sulfur and swept away for condensation in an inert gas stream. The syn-gas is enriched with the H{sub 2}. Order-of-magnitude reductions in H{sub 2}S have been repeatably recorded (100 ppm to 10 ppm H{sub 2}S) on a single pass through the cell. This process allows removal of H{sub 2}S without cooling the gas stream and with negligible pressure loss through the separator. Since there are no absorbents used, there is no absorption/regeneration step as with conventional technology. Elemental sulfur is produced as a by-product directly, so there is no need for a Claus process for sulfur recovery. This makes the process economically attractive since it is much less equipment intensive than conventional technology.

  16. In situ AFM observations of Ca-Mg carbonate crystallization catalyzed by dissolved sulfide: Implications for sedimentary dolomite formation

    NASA Astrophysics Data System (ADS)

    Zhang, Fangfu; Yan, Chao; Teng, H. Henry; Roden, Eric E.; Xu, Huifang

    2013-03-01

    It has been observed that the metabolism of sulfate-reducing bacteria can overcome the energy barrier to Mg2+ incorporation into growing Ca-Mg carbonates and enhance dolomite precipitation, although the role of SRB in dolomite formation is still under debate. In this study, we presented in situ AFM observations of Ca-Mg carbonate {1 0 4} surface growing from supersaturated solutions. Our data showed that not only can Mg2+ modify the morphology of the polygonal growth hillocks and impede step growth, but it can also inhibit 1-D step nucleation, resulting in the inability for spirals to continue their vertical growth. However, in the presence of dissolved sulfide, both the 1-D step nucleation and step growth which had been retarded by Mg2+ ions were significantly enhanced. For example, in the presence as low as 0.13 mM dissolved sulfide, the step velocity can be increased by more than 9 times compared to that in contact with solutions containing Mg2+ ions but no dissolved sulfide. The Ca-Mg carbonate growth hillock in contact with dissolved sulfide-bearing growth solutions eventually developed a micromosaic-like structure. Based on our observations, we propose that the overall catalytic effect of dissolved sulfide may be twofold, one to stabilize the critical nuclei during 1-D step nucleation by the adsorption of dissolved sulfide on Ca-Mg carbonate surfaces and two to facilitate the dehydration of surface Mg2+-water complexes during growth. We hypothesize that dissolved sulfide may adsorb on crystal faces through hydrogen bonding between the H in HS-/H2S and the O in calcite CO32- to weaken the rigid Mg2+ hydration shell, resulting in an elevated activation entropy for particle attachment and hence a larger kinetic coefficient for step growth. Together with previous studies on disorder dolomite precipitation induced by dissolved sulfide, we demonstrate the catalysis role of dissolved sulfide in sedimentary dolomite formation associate with SRB, which may shed new

  17. High temperature hydrogen sulfide removal with tin oxide

    SciTech Connect

    Copeland, R.J.; Feinberg, D.; Wickham, D.; Windecker, B.; Yu, J.

    1993-06-01

    This Phase II SBIR contract is developing a sorbent and process which removes H{sub 2}S from hot gasified coal and generates sulfur during regeneration of the sorbent. The process can be used with any type of reactor (e.g., fixed or moving bed) and any gasifier (e.g., KRW or Texaco) and shows lower costs that competing H{sub 2}S removal processes. TDA Research`s (TDA) process uses a regenerable stannic oxide-based (SnO{sub 2}) sorbent as the first sorbent and zinc ferrite (or zinc titanate) as a second sorbent to remove H{sub 2}S to very low concentrations. The process converts the sulfides from both sorbents to elemental sulfur, a commercial product which is easy to store and transport. The object of this phase is to develop chemically active, high sulfur loadings, and durable stannic oxide sorbents and to demonstrate the process at the bench scale.

  18. Control of hydrogen sulfide production in oil fields by managing microbial communities through nitrate or nitrite addition

    NASA Astrophysics Data System (ADS)

    Hubert, Casey R. J.

    Nitrate or nitrite injection into oil reservoirs during water flooding has the potential to control biological souring, the production of hydrogen sulfide (H2S) by sulfate-reducing bacteria (SRB). Souring control is essential because sulfide is toxic, sulfide precipitates can plug reservoir formations, souring lowers crude oil value, and SRB induce corrosion. Nitrate and nitrite can stimulate heterotrophic nitrate- or nitrite-reducing bacteria (hNRB) and nitrate- or nitrite-reducing, sulfide oxidizing bacteria (NRSOB). Nitrite also inhibits SRB activity by blocking the sulfate reduction pathway. Continuous up-flow packed-bed bioreactors were inoculated with produced water from the Coleville oil field to establish sulfide-producing biofilms similar to those found in sour reservoirs. Nitrate or nitrite addition to bioreactors indicated that the dose required for hNRB or NR-SOB to control souring depended on the concentration of oil organics. Either mechanism mediates the net removal of oil organics (lactate) with nitrate or nitrite, with lower doses of nitrate required due to its greater oxidative power. Microbial community analysis by reverse sample genome probing (RSGP) revealed that NR-SOB mediated sulfide removal at low nitrate or nitrite concentrations when lactate was still available to SRB and the redox potential was low. At high nitrate doses hNRB oxidized lactate directly, produced nitrite and maintained a high redox potential, thus excluding SRB activity. Facultatively chemolithotrophic Campylobacter sp. strains were isolated from the bioreactors and incorporated into RSGP analyses, revealing their dominance in both NR-SOB- and hNRB-containing communities. The metabolic flexibility of these strains may confer a competitive advantage over obligate chemolithotrophs like Thiomicrospira sp. strain CVO or hNRB that do not have NR-SOB activity like newly isolated Thauera sp. and Rhodobacter sp. strains. A single high dose of nitrite resulted in immediate

  19. Visible-light-enhanced interactions of hydrogen sulfide with composites of zinc (oxy)hydroxide with graphite oxide and graphene.

    PubMed

    Seredych, Mykola; Mabayoje, Oluwaniyi; Bandosz, Teresa J

    2012-01-17

    Composites of zinc(oxy)hydroxide-graphite oxide and of zinc(oxy)hydroxide-graphene were used as adsorbents of hydrogen sulfide under ambient conditions. The initial and exhausted samples were characterized by XRD, FTIR, potentiometric titration, EDX, thermal analysis, and nitrogen adsorption. An increase in the amount of H(2)S adsorbed/oxidized on their surfaces in comparison with that of pure Zn(OH)(2) is linked to the structure of the composite, the relative number of terminal hydroxyls, and the kind of graphene-based phase used. Although terminal groups are activated by a photochemical process, the graphite oxide component owing to the chemical bonds with the zinc(oxy)hydroxide phase and conductive properties helps in electron transfer, leading to more efficient oxygen activation via the formation of superoxide ions. Elemental sulfur, zinc sulfide, sulfite, and sulfate are formed on the surface. The formation of sulfur compounds on the surface of zinc(oxy)hydroxide during the course of the breakthrough experiments and thus Zn(OH)(2)-ZnS heterojunctions can also contribute to the increased surface activity of our materials. The results show the superiority of graphite oxide in the formation of composites owing to its active surface chemistry and the possibility of interface bond formation, leading to an increase in the number of electron-transfer reactions.

  20. Direct Chlorination Process for geothermal power plant off-gas - hydrogen sulfide abatement

    SciTech Connect

    Sims, A.V.

    1983-06-01

    The Direct Chlorination Process removes hydrogen sulfide from geothermal off-gases by reacting hydrogen sulfide with chlorine in the gas phase. Hydrogen chloride and elemental sulfur are formed by this reaction. The Direct Chlorination Process has been successfully demonstrated by an on-site operation of a pilot plant at the 3 M We HPG-A geothermal power plant in the Puna District on the island of Hawaii. Over 99.5% hydrogen sulfide removal was achieved in a single reaction stage. Chlorine gas did not escape the pilot plant, even when 90% excess chlorine gas was used. A preliminary economic evaluation of the Direct Chlorination Process indicates that it is very competitive with the Stretford Process Compared to the Stretford Process, the Direct Chlorination process requires about one-third the initial capital investment and about one-fourth the net daily expenditure. Because of the higher cost of chemicals and the restricted markets in Hawaii, the economic viability of this process in Hawaii is questionable.

  1. Involvement of ERK in NMDA receptor-independent cortical neurotoxicity of hydrogen sulfide

    SciTech Connect

    Kurokawa, Yuko; Sekiguchi, Fumiko; Kubo, Satoko; Yamasaki, Yoshiko; Matsuda, Sachi; Okamoto, Yukari; Sekimoto, Teruki; Fukatsu, Anna; Nishikawa, Hiroyuki; Kume, Toshiaki; Fukushima, Nobuyuki; Akaike, Akinori; Kawabata, Atsufumi

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Hydrogen sulfide causes NMDA receptor-independent neurotoxicity in mouse fetal cortical neurons. Black-Right-Pointing-Pointer Activation of ERK mediates the toxicity of hydrogen sulfide. Black-Right-Pointing-Pointer Apoptotic mechanisms are involved in the hydrogen-induced cell death. -- Abstract: Hydrogen sulfide (H{sub 2}S), a gasotransmitter, exerts both neurotoxicity and neuroprotection, and targets multiple molecules including NMDA receptors, T-type calcium channels and NO synthase (NOS) that might affect neuronal viability. Here, we determined and characterized effects of NaHS, an H{sub 2}S donor, on cell viability in the primary cultures of mouse fetal cortical neurons. NaHS caused neuronal death, as assessed by LDH release and trypan blue staining, but did not significantly reduce the glutamate toxicity. The neurotoxicity of NaHS was resistant to inhibitors of NMDA receptors, T-type calcium channels and NOS, and was blocked by inhibitors of MEK, but not JNK, p38 MAP kinase, PKC and Src. NaHS caused prompt phosphorylation of ERK and upregulation of Bad, followed by translocation of Bax to mitochondria and release of mitochondrial cytochrome c, leading to the nuclear condensation/fragmentation. These effects of NaHS were suppressed by the MEK inhibitor. Our data suggest that the NMDA receptor-independent neurotoxicity of H{sub 2}S involves activation of the MEK/ERK pathway and some apoptotic mechanisms.

  2. Highly sensitive hydrogen sulfide (H₂S) gas sensors from viral-templated nanocrystalline gold nanowires.

    PubMed

    Moon, Chung Hee; Zhang, Miluo; Myung, Nosang V; Haberer, Elaine D

    2014-04-01

    A facile, site-specific viral-templated assembly method was used to fabricate sensitive hydrogen sulfide (H2S) gas sensors at room temperature. A gold-binding M13 bacteriophage served to organize gold nanoparticles into linear arrays which were used as seeds for subsequent nanowire formation through electroless deposition. Nanowire widths and densities within the sensors were modified by electroless deposition time and phage concentration, respectively, to tune device resistance. Chemiresistive H2S gas sensors with superior room temperature sensing performance were produced with sensitivity of 654%/ppm(v), theoretical lowest detection limit of 2 ppb(v), and 70% recovery within 9 min for 0.025 ppm(v). The role of the viral template and associated gold-binding peptide was elucidated by removing organics using a short O₂ plasma treatment followed by an ethanol dip. The template and gold-binding peptide were crucial to electrical and sensor performance. Without surface organics, the resistance fell by several orders of magnitude, the sensitivity dropped by more than a factor of 100 to 6%/ppm(v), the lower limit of detection increased, and no recovery was detected with dry air flow. Viral templates provide a novel, alternative fabrication route for highly sensitive, nanostructured H2S gas sensors.

  3. Penning ionization electron spectroscopy of hydrogen sulfide by metastable helium and neon atoms.

    PubMed

    Falcinelli, Stefano; Candori, Pietro; Bettoni, Marta; Pirani, Fernando; Vecchiocattivi, Franco

    2014-08-21

    The dynamics of the Penning ionization of hydrogen sulfide molecules by collision with helium and metastable neon atoms, occurring in the thermal energy range, has been studied by analyzing the energy spectra of the emitted electrons obtained in our laboratory in a crossed beam experiment. These spectra are compared with the photoelectron spectra measured by using He(I) and Ne(I) photons under the same experimental conditions. In this way we obtained the negative energy shifts for the formation of H2S(+) ions in the first three accessible electronic states by He*(2(3,1)S1,0) and Ne*((3)P2,0) Penning ionization collisions: the 2b1 (X̃(2)B1) fundamental one, the first 5a1 (Ã(2)A1), and the second 2b2 (B̃(2)B2) excited states, respectively. The recorded energy shifts indicate that in the case of He* and Ne*-H2S the autoionization dynamics depends on the features of the collision complex and is mainly driven by an effective global attraction that comes from a balance among several non covalent intermolecular interaction components. This suggests that the Penning ionization should take place, in a specific range of intermolecular distances, as we have already observed in the case of Penning ionization of water molecules [Brunetti, B. G.; Candori, P.; Falcinelli, S.; Pirani, F.; Vecchiocattivi, F. J. Chem. Phys. 2013, 139, 164305-1-164305-8].

  4. Hydrogen sulfide lowers proliferation and induces protective autophagy in colon epithelial cells.

    PubMed

    Wu, Ya C; Wang, Xiao J; Yu, Le; Chan, Francis K L; Cheng, Alfred S L; Yu, Jun; Sung, Joseph J Y; Wu, William K K; Cho, Chi H

    2012-01-01

    Hydrogen sulfide (H(2)S) is a gaseous bacterial metabolite that reaches high levels in the large intestine. In the present study, the effect of H(2)S on the proliferation of normal and cancerous colon epithelial cells was investigated. An immortalized colon epithelial cell line (YAMC) and a panel of colon cancer cell lines (HT-29, SW1116, HCT116) were exposed to H(2)S at concentrations similar to those found in the human colon. H(2)S inhibited normal and cancerous colon epithelial cell proliferation as measured by MTT assay. The anti-mitogenic effect of H(2)S was accompanied by G(1)-phase cell cycle arrest and the induction of the cyclin-dependent kinase inhibitor p21(Cip). Moreover, exposure to H(2)S led to features characteristic of autophagy, including increased formation of LC3B(+) autophagic vacuoles and acidic vesicular organelles as determined by immunofluorescence and acridine orange staining, respectively. Abolition of autophagy by RNA interference targeting Vps34 or Atg7 enhanced the anti-proliferative effect of H(2)S. Further mechanistic investigation revealed that H(2)S stimulated the phosphorylation of AMP-activated protein kinase (AMPK) and inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and S6 kinase. Inhibition of AMPK significantly reversed H(2)S-induced autophagy and inhibition of cell proliferation. Collectively, we demonstrate that H(2)S inhibits colon epithelial cell proliferation and induces protective autophagy via the AMPK pathway. PMID:22679478

  5. Highly sensitive hydrogen sulfide (H2 S) gas sensors from viral-templated nanocrystalline gold nanowires

    NASA Astrophysics Data System (ADS)

    Moon, Chung Hee; Zhang, Miluo; Myung, Nosang V.; Haberer, Elaine D.

    2014-04-01

    A facile, site-specific viral-templated assembly method was used to fabricate sensitive hydrogen sulfide (H2S) gas sensors at room temperature. A gold-binding M13 bacteriophage served to organize gold nanoparticles into linear arrays which were used as seeds for subsequent nanowire formation through electroless deposition. Nanowire widths and densities within the sensors were modified by electroless deposition time and phage concentration, respectively, to tune device resistance. Chemiresistive H2S gas sensors with superior room temperature sensing performance were produced with sensitivity of 654%/ppmv, theoretical lowest detection limit of 2 ppbv, and 70% recovery within 9 min for 0.025 ppmv. The role of the viral template and associated gold-binding peptide was elucidated by removing organics using a short O2 plasma treatment followed by an ethanol dip. The template and gold-binding peptide were crucial to electrical and sensor performance. Without surface organics, the resistance fell by several orders of magnitude, the sensitivity dropped by more than a factor of 100 to 6%/ppmv, the lower limit of detection increased, and no recovery was detected with dry air flow. Viral templates provide a novel, alternative fabrication route for highly sensitive, nanostructured H2S gas sensors.

  6. [Hydrogen sulfide as a biologically active mediator in the cardiovascular system].

    PubMed

    Bełtowski, Jerzy

    2004-07-19

    Recent studies suggest that apart from nitric oxide (NO) and carbon monoxide (CO), hydrogen sulfide (H2S) is another inorganic gaseous mediator in the cardiovascular system. H2S is synthesized from L-cysteine by either cystathionine beta-synthase (CBS) or cystathionin gamma--lyase (CSE), both using pyridoxal 5'-phosphate (vitamin B6) as a cofactor. CBS is the main H2S-producing enzyme in the brain and CSE is involved in H2S formation in the cardiovascular system. H2S induces hypotension in vivo and vasodilation vitro by opening KATP channels in vascular smooth muscle cells. Chronic administration of CSE inhibitor induces arterial hypertension in the rat. In addition, decreased H2S generation has been demonstrated in the vasculature of spontaneously hypertensive rat, in experimental hypertension induced by NO synthase blockade, and in hypoxia-induced pulmonary hypertension, and administration of exogenous H2S donor has significant therapeutic effects in these models. Deficiency of H2S may contribute to atherogenesis in some patients with hyperhomocysteinemia, in whom the metabolism of homocysteine to cysteine and H2S is compromised by vitamin B6 deficiency. Reduced H2S production in the brain was observed in patients with Alzheimer's disease. On the other hand, excess of H2S may lead to mental retardation in patients with Down's syndrome and may be involved in the pathogenesis of hypotension associated with septic shock.

  7. Hydrogen sulfide: A novel nephroprotectant against cisplatin-induced renal toxicity.

    PubMed

    Dugbartey, George J; Bouma, Hjalmar R; Lobb, Ian; Sener, Alp

    2016-07-01

    Cisplatin is a potent chemotherapeutic agent for the treatment of various solid-organ cancers. However, a plethora of evidence indicates that nephrotoxicity is a major side effect of cisplatin therapy. While the antineoplastic action of cisplatin is due to formation of cisplatin-DNA cross-links, which damage rapidly dividing cancer cells upon binding to DNA, its nephrotoxic effect results from metabolic conversion of cisplatin into a nephrotoxin and production of reactive oxygen species, causing oxidative stress leading to renal tissue injury and potentially, kidney failure. Despite therapeutic targets in several pre-clinical and clinical studies, there is still incomplete protection against cisplatin-induced nephrotoxicity. Hydrogen sulfide (H2S), the third discovered gasotransmitter next to nitric oxide and carbon monoxide, has recently been identified in several in vitro and in vivo studies to possess specific antioxidant, anti-inflammatory and anti-apoptotic properties that modulate several pathogenic pathways involved in cisplatin-induced nephrotoxicity. The current article reviews the molecular mechanisms underlying cisplatin-induced nephrotoxicity and displays recent findings in the H2S field that could disrupt such mechanisms to ameliorate cisplatin-induced renal injury.

  8. Missing Lead and High 3He/4He in Ancient Sulfides Associated with Continental Crust Formation

    PubMed Central

    Huang, Shichun; Lee, Cin-Ty A.; Yin, Qing-Zhu

    2014-01-01

    Major terrestrial reservoirs have Pb isotopes more radiogenic than the bulk silicate Earth. This requires a missing unradiogenic Pb reservoir, which has been argued to reside in the lower continental crust or dissolved in the core. Chalcophile element studies indicate that continent formation requires the formation of sulfide-bearing mafic cumulates in arcs. Because Pb, but not U, partitions into sulfides, we show that continent formation must have simultaneously generated time-integrated unradiogenic Pb reservoirs composed of sulfide-bearing cumulates, now recycled back into the mantle or stored deep in the continental lithosphere. The generation of such cumulates could also lead to coupled He-Pb isotopic systematics because 4He is also produced during U-Th-Pb decay. Here, we show that He may be soluble in sulfide melts, such that sulfide-bearing cumulates would be enriched in both Pb and He relative to U and Th, “freezing” in He and Pb isotopes of the ambient mantle at the time of sulfide formation. This implies that ancient sulfide-bearing cumulates would be characterized by unradiogenic Pb and He isotopes (high-3He/4He). These primitive signatures are usually attributed to primordial, undifferentiated mantle, but in this case, they are the very imprint of mantle differentiation via continent formation. PMID:24937103

  9. What do we really know about the role of microorganisms in iron sulfide mineral formation?

    NASA Astrophysics Data System (ADS)

    Picard, Aude; Gartman, Amy; Girguis, Peter

    2016-06-01

    Iron sulfide mineralization in low-temperature systems is a result of biotic and abiotic processes, though the delineation between these two modes of formation is not always straightforward. Here we review the role of microorganisms in the precipitation of extracellular iron sulfide minerals. We summarize the evidence that links sulfur-metabolizing microorganisms and sulfide minerals in nature and we present a critical overview of laboratory-based studies of the nucleation and growth of iron sulfide minerals in microbial cultures. We discuss whether biologically derived minerals are distinguishable from abiotic minerals, possessing attributes that are uniquely diagnostic of biomineralization. These inquiries have revealed the need for additional thorough, mechanistic and high-resolution studies to understand microbially mediated formation of a variety of sulfide minerals across a range of natural environments.

  10. Hydrogen sulfide replacement therapy protects the vascular endothelium in hyperglycemia by preserving mitochondrial function

    PubMed Central

    Suzuki, Kunihiro; Olah, Gabor; Modis, Katalin; Coletta, Ciro; Kulp, Gabriella; Gerö, Domokos; Szoleczky, Petra; Chang, Tuanjie; Zhou, Zongmin; Wu, Lingyun; Wang, Rui; Papapetropoulos, Andreas; Szabo, Csaba

    2011-01-01

    The goal of the present studies was to investigate the role of changes in hydrogen sulfide (H2S) homeostasis in the pathogenesis of hyperglycemic endothelial dysfunction. Exposure of bEnd3 microvascular endothelial cells to elevated extracellular glucose (in vitro “hyperglycemia”) induced the mitochondrial formation of reactive oxygen species (ROS), which resulted in an increased consumption of endogenous and exogenous H2S. Replacement of H2S or overexpression of the H2S-producing enzyme cystathionine-γ-lyase (CSE) attenuated the hyperglycemia-induced enhancement of ROS formation, attenuated nuclear DNA injury, reduced the activation of the nuclear enzyme poly(ADP-ribose) polymerase, and improved cellular viability. In vitro hyperglycemia resulted in a switch from oxidative phosphorylation to glycolysis, an effect that was partially corrected by H2S supplementation. Exposure of isolated vascular rings to high glucose in vitro induced an impairment of endothelium-dependent relaxations, which was prevented by CSE overexpression or H2S supplementation. siRNA silencing of CSE exacerbated ROS production in hyperglycemic endothelial cells. Vascular rings from CSE−/− mice exhibited an accelerated impairment of endothelium-dependent relaxations in response to in vitro hyperglycemia, compared with wild-type controls. Streptozotocin-induced diabetes in rats resulted in a decrease in the circulating level of H2S; replacement of H2S protected from the development of endothelial dysfunction ex vivo. In conclusion, endogenously produced H2S protects against the development of hyperglycemia-induced endothelial dysfunction. We hypothesize that, in hyperglycemic endothelial cells, mitochondrial ROS production and increased H2S catabolism form a positive feed-forward cycle. H2S replacement protects against these alterations, resulting in reduced ROS formation, improved endothelial metabolic state, and maintenance of normal endothelial function. PMID:21808008

  11. Hydrogen sulfide replacement therapy protects the vascular endothelium in hyperglycemia by preserving mitochondrial function.

    PubMed

    Suzuki, Kunihiro; Olah, Gabor; Modis, Katalin; Coletta, Ciro; Kulp, Gabriella; Gerö, Domokos; Szoleczky, Petra; Chang, Tuanjie; Zhou, Zongmin; Wu, Lingyun; Wang, Rui; Papapetropoulos, Andreas; Szabo, Csaba

    2011-08-16

    The goal of the present studies was to investigate the role of changes in hydrogen sulfide (H(2)S) homeostasis in the pathogenesis of hyperglycemic endothelial dysfunction. Exposure of bEnd3 microvascular endothelial cells to elevated extracellular glucose (in vitro "hyperglycemia") induced the mitochondrial formation of reactive oxygen species (ROS), which resulted in an increased consumption of endogenous and exogenous H(2)S. Replacement of H(2)S or overexpression of the H(2)S-producing enzyme cystathionine-γ-lyase (CSE) attenuated the hyperglycemia-induced enhancement of ROS formation, attenuated nuclear DNA injury, reduced the activation of the nuclear enzyme poly(ADP-ribose) polymerase, and improved cellular viability. In vitro hyperglycemia resulted in a switch from oxidative phosphorylation to glycolysis, an effect that was partially corrected by H(2)S supplementation. Exposure of isolated vascular rings to high glucose in vitro induced an impairment of endothelium-dependent relaxations, which was prevented by CSE overexpression or H(2)S supplementation. siRNA silencing of CSE exacerbated ROS production in hyperglycemic endothelial cells. Vascular rings from CSE(-/-) mice exhibited an accelerated impairment of endothelium-dependent relaxations in response to in vitro hyperglycemia, compared with wild-type controls. Streptozotocin-induced diabetes in rats resulted in a decrease in the circulating level of H(2)S; replacement of H(2)S protected from the development of endothelial dysfunction ex vivo. In conclusion, endogenously produced H(2)S protects against the development of hyperglycemia-induced endothelial dysfunction. We hypothesize that, in hyperglycemic endothelial cells, mitochondrial ROS production and increased H(2)S catabolism form a positive feed-forward cycle. H(2)S replacement protects against these alterations, resulting in reduced ROS formation, improved endothelial metabolic state, and maintenance of normal endothelial function.

  12. Hydrogen sulfide replacement therapy protects the vascular endothelium in hyperglycemia by preserving mitochondrial function.

    PubMed

    Suzuki, Kunihiro; Olah, Gabor; Modis, Katalin; Coletta, Ciro; Kulp, Gabriella; Gerö, Domokos; Szoleczky, Petra; Chang, Tuanjie; Zhou, Zongmin; Wu, Lingyun; Wang, Rui; Papapetropoulos, Andreas; Szabo, Csaba

    2011-08-16

    The goal of the present studies was to investigate the role of changes in hydrogen sulfide (H(2)S) homeostasis in the pathogenesis of hyperglycemic endothelial dysfunction. Exposure of bEnd3 microvascular endothelial cells to elevated extracellular glucose (in vitro "hyperglycemia") induced the mitochondrial formation of reactive oxygen species (ROS), which resulted in an increased consumption of endogenous and exogenous H(2)S. Replacement of H(2)S or overexpression of the H(2)S-producing enzyme cystathionine-γ-lyase (CSE) attenuated the hyperglycemia-induced enhancement of ROS formation, attenuated nuclear DNA injury, reduced the activation of the nuclear enzyme poly(ADP-ribose) polymerase, and improved cellular viability. In vitro hyperglycemia resulted in a switch from oxidative phosphorylation to glycolysis, an effect that was partially corrected by H(2)S supplementation. Exposure of isolated vascular rings to high glucose in vitro induced an impairment of endothelium-dependent relaxations, which was prevented by CSE overexpression or H(2)S supplementation. siRNA silencing of CSE exacerbated ROS production in hyperglycemic endothelial cells. Vascular rings from CSE(-/-) mice exhibited an accelerated impairment of endothelium-dependent relaxations in response to in vitro hyperglycemia, compared with wild-type controls. Streptozotocin-induced diabetes in rats resulted in a decrease in the circulating level of H(2)S; replacement of H(2)S protected from the development of endothelial dysfunction ex vivo. In conclusion, endogenously produced H(2)S protects against the development of hyperglycemia-induced endothelial dysfunction. We hypothesize that, in hyperglycemic endothelial cells, mitochondrial ROS production and increased H(2)S catabolism form a positive feed-forward cycle. H(2)S replacement protects against these alterations, resulting in reduced ROS formation, improved endothelial metabolic state, and maintenance of normal endothelial function. PMID:21808008

  13. Bioconversion of High Concentrations of Hydrogen Sulfide to Elemental Sulfur in Airlift Bioreactor

    PubMed Central

    Abdel-Monaem Zytoon, Mohamed; Ahmad AlZahrani, Abdulraheem; Hamed Noweir, Madbuli; Ahmed El-Marakby, Fadia

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m−3 h−1 were achieved in the airlift bioreactor under investigation at a pH range 6.5–8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0–8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8–8.5. PMID:25147857

  14. Quantum hydrogen-bond symmetrization in the superconducting hydrogen sulfide system.

    PubMed

    Errea, Ion; Calandra, Matteo; Pickard, Chris J; Nelson, Joseph R; Needs, Richard J; Li, Yinwei; Liu, Hanyu; Zhang, Yunwei; Ma, Yanming; Mauri, Francesco

    2016-04-01

    The quantum nature of the proton can crucially affect the structural and physical properties of hydrogen compounds. For example, in the high-pressure phases of H2O, quantum proton fluctuations lead to symmetrization of the hydrogen bond and reduce the boundary between asymmetric and symmetric structures in the phase diagram by 30 gigapascals (ref. 3). Here we show that an analogous quantum symmetrization occurs in the recently discovered sulfur hydride superconductor with a superconducting transition temperature Tc of 203 kelvin at 155 gigapascals--the highest Tc reported for any superconductor so far. Superconductivity occurs via the formation of a compound with chemical formula H3S (sulfur trihydride) with sulfur atoms arranged on a body-centred cubic lattice. If the hydrogen atoms are treated as classical particles, then for pressures greater than about 175 gigapascals they are predicted to sit exactly halfway between two sulfur atoms in a structure with Im3m symmetry. At lower pressures, the hydrogen atoms move to an off-centre position, forming a short H-S covalent bond and a longer H···S hydrogen bond in a structure with R3m symmetry. X-ray diffraction experiments confirm the H3S stoichiometry and the sulfur lattice sites, but were unable to discriminate between the two phases. Ab initio density-functional-theory calculations show that quantum nuclear motion lowers the symmetrization pressure by 72 gigapascals for H3S and by 60 gigapascals for D3S. Consequently, we predict that the Im3m phase dominates the pressure range within which the high Tc was measured. The observed pressure dependence of Tc is accurately reproduced in our calculations for the phase, but not for the R3m phase. Therefore, the quantum nature of the proton fundamentally changes the superconducting phase diagram of H3S.

  15. Quantum hydrogen-bond symmetrization in the superconducting hydrogen sulfide system

    NASA Astrophysics Data System (ADS)

    Errea, Ion; Calandra, Matteo; Pickard, Chris J.; Nelson, Joseph R.; Needs, Richard J.; Li, Yinwei; Liu, Hanyu; Zhang, Yunwei; Ma, Yanming; Mauri, Francesco

    2016-04-01

    The quantum nature of the proton can crucially affect the structural and physical properties of hydrogen compounds. For example, in the high-pressure phases of H2O, quantum proton fluctuations lead to symmetrization of the hydrogen bond and reduce the boundary between asymmetric and symmetric structures in the phase diagram by 30 gigapascals (ref. 3). Here we show that an analogous quantum symmetrization occurs in the recently discovered sulfur hydride superconductor with a superconducting transition temperature Tc of 203 kelvin at 155 gigapascals—the highest Tc reported for any superconductor so far. Superconductivity occurs via the formation of a compound with chemical formula H3S (sulfur trihydride) with sulfur atoms arranged on a body-centred cubic lattice. If the hydrogen atoms are treated as classical particles, then for pressures greater than about 175 gigapascals they are predicted to sit exactly halfway between two sulfur atoms in a structure with symmetry. At lower pressures, the hydrogen atoms move to an off-centre position, forming a short H-S covalent bond and a longer H···S hydrogen bond in a structure with R3m symmetry. X-ray diffraction experiments confirm the H3S stoichiometry and the sulfur lattice sites, but were unable to discriminate between the two phases. Ab initio density-functional-theory calculations show that quantum nuclear motion lowers the symmetrization pressure by 72 gigapascals for H3S and by 60 gigapascals for D3S. Consequently, we predict that the phase dominates the pressure range within which the high Tc was measured. The observed pressure dependence of Tc is accurately reproduced in our calculations for the phase, but not for the R3m phase. Therefore, the quantum nature of the proton fundamentally changes the superconducting phase diagram of H3S.

  16. Quantum hydrogen-bond symmetrization in the superconducting hydrogen sulfide system

    NASA Astrophysics Data System (ADS)

    Errea, Ion; Calandra, Matteo; Pickard, Chris J.; Nelson, Joseph R.; Needs, Richard J.; Li, Yinwei; Liu, Hanyu; Zhang, Yunwei; Ma, Yanming; Mauri, Francesco

    2016-04-01

    The quantum nature of the proton can crucially affect the structural and physical properties of hydrogen compounds. For example, in the high-pressure phases of H2O, quantum proton fluctuations lead to symmetrization of the hydrogen bond and reduce the boundary between asymmetric and symmetric structures in the phase diagram by 30 gigapascals (ref. 3). Here we show that an analogous quantum symmetrization occurs in the recently discovered sulfur hydride superconductor with a superconducting transition temperature Tc of 203 kelvin at 155 gigapascals—the highest Tc reported for any superconductor so far. Superconductivity occurs via the formation of a compound with chemical formula H3S (sulfur trihydride) with sulfur atoms arranged on a body-centred cubic lattice. If the hydrogen atoms are treated as classical particles, then for pressures greater than about 175 gigapascals they are predicted to sit exactly halfway between two sulfur atoms in a structure with symmetry. At lower pressures, the hydrogen atoms move to an off-centre position, forming a short H–S covalent bond and a longer H···S hydrogen bond in a structure with R3m symmetry. X-ray diffraction experiments confirm the H3S stoichiometry and the sulfur lattice sites, but were unable to discriminate between the two phases. Ab initio density-functional-theory calculations show that quantum nuclear motion lowers the symmetrization pressure by 72 gigapascals for H3S and by 60 gigapascals for D3S. Consequently, we predict that the phase dominates the pressure range within which the high Tc was measured. The observed pressure dependence of Tc is accurately reproduced in our calculations for the phase, but not for the R3m phase. Therefore, the quantum nature of the proton fundamentally changes the superconducting phase diagram of H3S.

  17. Quantum hydrogen-bond symmetrization in the superconducting hydrogen sulfide system.

    PubMed

    Errea, Ion; Calandra, Matteo; Pickard, Chris J; Nelson, Joseph R; Needs, Richard J; Li, Yinwei; Liu, Hanyu; Zhang, Yunwei; Ma, Yanming; Mauri, Francesco

    2016-04-01

    The quantum nature of the proton can crucially affect the structural and physical properties of hydrogen compounds. For example, in the high-pressure phases of H2O, quantum proton fluctuations lead to symmetrization of the hydrogen bond and reduce the boundary between asymmetric and symmetric structures in the phase diagram by 30 gigapascals (ref. 3). Here we show that an analogous quantum symmetrization occurs in the recently discovered sulfur hydride superconductor with a superconducting transition temperature Tc of 203 kelvin at 155 gigapascals--the highest Tc reported for any superconductor so far. Superconductivity occurs via the formation of a compound with chemical formula H3S (sulfur trihydride) with sulfur atoms arranged on a body-centred cubic lattice. If the hydrogen atoms are treated as classical particles, then for pressures greater than about 175 gigapascals they are predicted to sit exactly halfway between two sulfur atoms in a structure with Im3m symmetry. At lower pressures, the hydrogen atoms move to an off-centre position, forming a short H-S covalent bond and a longer H···S hydrogen bond in a structure with R3m symmetry. X-ray diffraction experiments confirm the H3S stoichiometry and the sulfur lattice sites, but were unable to discriminate between the two phases. Ab initio density-functional-theory calculations show that quantum nuclear motion lowers the symmetrization pressure by 72 gigapascals for H3S and by 60 gigapascals for D3S. Consequently, we predict that the Im3m phase dominates the pressure range within which the high Tc was measured. The observed pressure dependence of Tc is accurately reproduced in our calculations for the phase, but not for the R3m phase. Therefore, the quantum nature of the proton fundamentally changes the superconducting phase diagram of H3S. PMID:27018657

  18. Elevated corrosion rates and hydrogen sulfide in homes with 'Chinese Drywall'.

    PubMed

    Allen, Joseph G; MacIntosh, David L; Saltzman, Lori E; Baker, Brian J; Matheson, Joanna M; Recht, Joel R; Minegishi, Taeko; Fragala, Matt A; Myatt, Theodore A; Spengler, John D; Stewart, James H; McCarthy, John F

    2012-06-01

    In December 2008, the U.S. Consumer Product Safety Commission (CPSC) began receiving reports about odors, corrosion, and health concerns related to drywall originating from China. In response, a detailed environmental health and engineering evaluation was conducted of 41 complaint and 10 non-complaint homes in the Southeast U.S. Each home investigation included characterization of: 1) drywall composition; 2) indoor and outdoor air quality; 3) temperature, moisture, and building ventilation; and 4) copper and silver corrosion rates. Complaint homes had significantly higher hydrogen sulfide concentrations (mean 0.82 vs. sulfide and silver sulfide corrosion compared to non-complaint homes (Cu(2)S: 476 vs. <32 Å/30 d, p<0.01; Ag(2)S: 1472 vs. 389 Å/30 d, p<0.01). The abundance of carbonate and strontium in drywall was also elevated in complaint homes, and appears to be useful objective marker of problematic drywall in homes that meet other screening criteria (e.g., constructed or renovated in 2006-2007, reports of malodor and accelerated corrosion). This research provides empirical evidence of the direct association between homes constructed with 'Chinese Drywall' in 2006-2007 and elevated corrosion rates and hydrogen sulfide concentrations in indoor air.

  19. Hydrogen sulfide attenuates ferric chloride-induced arterial thrombosis in rats.

    PubMed

    Qin, Yi-Ren; You, Shou-Jiang; Zhang, Yan; Li, Qian; Wang, Xian-Hui; Wang, Fen; Hu, Li-Fang; Liu, Chun-Feng

    2016-06-01

    Hydrogen sulfide (H2S) is a novel gaseous transmitter, regulating a multitude of biological processes in the cardiovascular and other systems. However, it remains unclear whether it exerts any effect on arterial thrombosis. In this study, we examined the effect of H2S on ferric chloride (FeCl3)-induced thrombosis in the rat common carotid artery (CCA). The results revealed a decrease of the H2S-producing enzyme cystathionine γ-lyase (CSE) expression and H2S production that persisted until 48 h after FeCl3 application. Intriguingly, administration with NaHS at appropriate regimen reduced the thrombus formation and enhanced the blood flow, accompanied with the alleviation of CSE and CD31 downregulation, and endothelial cell apoptosis in the rat CCA following FeCl3 application. Moreover, the antithrombotic effect of H2S was also observed in Rose Bengal photochemical model in which the development of thrombosis is contributed by oxidative injury to the endothelium. The in vitro study demonstrated that the mRNA and protein expression of CSE, as well as H2S production, was decreased in hydrogen peroxide (H2O2)-treated endothelial cells. Exogenous supplement of NaHS and CSE overexpression consistently alleviated the increase of cleaved caspase-3 and endothelial cell damage caused by H2O2. Taken together, our findings suggest that endogenous H2S generation in the endothelium may be impaired during arterial thrombosis and that modulation of H2S, either exogenous supplement or boost of endogenous production, may become a potential venue for arterial thrombosis therapy.

  20. Microbial Formation of Dimethyl Sulfide in Anoxic Sphagnum Peat

    PubMed Central

    Kiene, R. P.; Hines, M. E.

    1995-01-01

    Peat bogs dominated by Sphagnum spp. have relatively high areal rates of dimethyl sulfide (DMS) emission to the atmosphere. DMS was produced in anoxic slurries of Sphagnum peat with a linear time course and with an average rate of 40.4 (range, 22.0 to 68.6) nmol per liter of slurry (middot) day(sup-1) observed in nine batches of slurry. Methanethiol (MeSH) was produced at roughly similar rates over the typical 4- to 8-day incubations. DMS and MeSH production in these acidic (pH 4.2 to 4.6) peats were biological, as they were stopped completely by autoclaving and inhibited strongly by addition of antibiotics and 500 (mu)M chloroform. Endogenous DMS production may be due to the degradation of S-methyl-methionine, dimethyl sulfoxide, or methoxyaromatic compounds (e.g., syringic acid), each of which stimulated DMS formation when added at 5 to 10 (mu)M concentrations. However, on the basis of the high rates of thiol (MeSH and ethanethiol) methylation activity that we observed and the availability of endogenous MeSH, we suggest that methylation of MeSH is the major pathway leading to DMS formation in anaerobic peat. Solid-phase adsorption of MeSH plays a key role in its availability for biomethylation reactions. Additions of acetate (1.5 mM) or compounds which could cause acetate to accumulate (e.g., glucose, alanine, and 2-bromoethanesulfonate) suppressed DMS formation. It is likely that acetogenic bacteria are involved in DMS formation, but our data are insufficient to allow firm conclusions about the metabolic pathways or organisms involved. Our observations are the first which point to the methylation of MeSH as the major mechanism for endogenous DMS production in any environment. The rates of net DMS production observed are sufficient to explain the relatively high fluxes of DMS emitted to the atmosphere from Sphagnum sp.-dominated wetlands. PMID:16535080

  1. Efficient new process for the desulfurization of mixtures of air and hydrogen sulfide via a dielectric barrier discharge plasma

    NASA Astrophysics Data System (ADS)

    Dahle, S.

    2015-10-01

    The efficient removal of hydrogen sulfide, H2S, from streams of H2S in air via a dielectric barrier discharge (DBD) plasma has been investigated using a quadrupole mass spectrometer. A suitable plasma device with a reservoir for storing sorbent powder of various kinds within the plasma region was constructed. Plasma treatments of gas streams with high concentrations of hydrogen sulfide in air yielded a removal of more than 98% of the initial hydrogen sulfide and a deposition of sulfur at the surface of the dielectric, while small amounts of sulfur dioxide were generated. The presence of calcium carbonate within the plasma region of the DBD device resulted in the removal of over 99% of the initial hydrogen sulfide content and the removal of 98% of the initial sulfur dioxide impurities from the gas mixture.

  2. Acidification and sulfide formation control during reductive dechlorination of 1,2-dichloroethane in groundwater: Effectiveness and mechanistic study.

    PubMed

    Wang, S Y; Chen, S C; Lin, Y C; Kuo, Y C; Chen, J Y; Kao, C M

    2016-10-01

    To enhance the reductive dechlorination of 1,2-dichloroethane (DCA) in groundwater, substrate injection may be required. However, substrate biodegradation causes groundwater acidification and sulfide production, which inhibits the bacteria responsible for DCA dechlorination and results in an odor problem. In the microcosm study, the effectiveness of the addition of ferrous sulfate (FS), desulfurization slag (DS), and nanoscale zero-valent iron (nZVI) on acidification and sulfide control was studied during reductive dechlorination of DCA, and the emulsified substrate (ES) was used as the substrate. Up to 94% of the sulfide was removed with FS and DS addition (0.25 wt%) (initial DCA concentration = 13.5 mg/L). FS and DS amendments resulted in the formation of a metal sulfide, which reduced the hydrogen sulfide concentration as well as the subsequent odor problem. Approximately 96% of the DCA was degraded under reductive dechlorination with nZVI or DS addition using ES as the substrate. In microcosms with nZVI or DS addition, the sulfide concentration was reduced to less than 15 μg/L. Acidification can be controlled via hydroxide ions production after nZVI oxidation and reaction of free CaO (released from DS) with water, which enhanced DCA dechlorination. The quantitative polymerase chain reaction results confirmed that the microcosms with nZVI added had the highest Dehalococcoides population (up to 2.5 × 10(8) gene copies/g soil) due to effective acidification control. The α-elimination mechanism was the main abiotic process, and reductive dechlorination dominated by Dehalococcides was the biotic mechanism that resulted in DCA removal. More than 22 bacterial species were detected, and dechlorinating bacteria existed in soils under alkaline and acidic conditions. PMID:27376861

  3. Acidification and sulfide formation control during reductive dechlorination of 1,2-dichloroethane in groundwater: Effectiveness and mechanistic study.

    PubMed

    Wang, S Y; Chen, S C; Lin, Y C; Kuo, Y C; Chen, J Y; Kao, C M

    2016-10-01

    To enhance the reductive dechlorination of 1,2-dichloroethane (DCA) in groundwater, substrate injection may be required. However, substrate biodegradation causes groundwater acidification and sulfide production, which inhibits the bacteria responsible for DCA dechlorination and results in an odor problem. In the microcosm study, the effectiveness of the addition of ferrous sulfate (FS), desulfurization slag (DS), and nanoscale zero-valent iron (nZVI) on acidification and sulfide control was studied during reductive dechlorination of DCA, and the emulsified substrate (ES) was used as the substrate. Up to 94% of the sulfide was removed with FS and DS addition (0.25 wt%) (initial DCA concentration = 13.5 mg/L). FS and DS amendments resulted in the formation of a metal sulfide, which reduced the hydrogen sulfide concentration as well as the subsequent odor problem. Approximately 96% of the DCA was degraded under reductive dechlorination with nZVI or DS addition using ES as the substrate. In microcosms with nZVI or DS addition, the sulfide concentration was reduced to less than 15 μg/L. Acidification can be controlled via hydroxide ions production after nZVI oxidation and reaction of free CaO (released from DS) with water, which enhanced DCA dechlorination. The quantitative polymerase chain reaction results confirmed that the microcosms with nZVI added had the highest Dehalococcoides population (up to 2.5 × 10(8) gene copies/g soil) due to effective acidification control. The α-elimination mechanism was the main abiotic process, and reductive dechlorination dominated by Dehalococcides was the biotic mechanism that resulted in DCA removal. More than 22 bacterial species were detected, and dechlorinating bacteria existed in soils under alkaline and acidic conditions.

  4. Use of sulfur-oxidizing bacteria as recognition elements in hydrogen sulfide biosensing system.

    PubMed

    Janfada, Behdokht; Yazdian, Fatemeh; Amoabediny, Ghassem; Rahaie, Mahdi

    2015-01-01

    Four sulfur-oxidizing bacteria (Thiobacillus thioparus, Acidithiobacillus thiooxidans PTCC1717, Acidithiobacillus ferrooxidans PTCC1646, and Acidithiobacillus ferrooxidans PTCC1647) were used as biorecognition elements in a hydrogen sulfide biosensing system. All the experiments were performed in 0.1 M phosphate buffer solution containing 1-20 ppm H2S with optimum pH and temperature for each species. Although H2 S was applied to the biosensing system, the dissolved O2 content decreased. Dissolved O2 consumed by cells in both free and immobilized forms was measured using a dissolved oxygen sensor. Free bacterial cells exhibit fast response (<200 Sec). Immobilization of the cells on polyvinyl alcohol was optimized using an analytical software. Immobilized A. ferrooxidans and A. thiooxidans retained more than 50% of activity after 30 days of immobilization. According to the data, A. thiooxidans and A. ferrooxidans are appropriate species for hydrogen sulfide biosensor.

  5. Factors contributing to the ability of acrolein to scavenge corrosive hydrogen sulfide

    SciTech Connect

    Kissel, C.L.; Brady, J.L.; Gottry, N.; Meshishnek, M.J.; Preus, M.W.

    1985-10-01

    Acrolein can function under a variety of conditions as an effective hydrogen sulfide scavenger in oilfield waterflood systems. The scavenging ability is maximized in waters having a pH range of 6 through 8, a total dissolved solids level below 1%, and temperatures less than 149/sup 0/F (65/sup 0/C). At least 4 ppm acrolein is necessary to achieve sufficient reaction of each original 1 ppm hydrogen sulfide. This reaction requires about 2 to 20 minutes, depending on the nature of the system. Although sand, garnet, or diatomaceous earth filters do not affect the scavenging ability of acrolein, charcoal filters, large tanks, long pipelines, high-temperature Wemcos, and reboilers can produce diminished effects. Further diminished effects also can be produced when incompatible chemicals are used concurrently with acrolein. Some application techniques that can lessen or eliminate these adverse conditions are presented.

  6. Factors contributing to the ability of Acrolein to scavenge corrosive hydrogen sulfide

    SciTech Connect

    Kissel, C.L.; Brady, J.L.; Clifton, N.; Meshishnek, M.J.; Preus, M.W.

    1983-03-01

    Acrolein can function under a variety of conditions as an effective hydrogen sulfide scavenger in oil field water flood systems. The scavenging ability is maximized in waters having a pH range of 6-8, a total dissolved solids level below 1 percent, and temperatures less than 65/sup 0/C. At least 4 ppm acrolein is necessary to achieve sufficient reaction of each original 1 ppm hydrogen sulfide. This reaction requires about 2-20 minutes, depending on the nature of the system. Although sand, garnet, or diatomaceous earth filters do not affect the scavenging ability of acrolein, charcoal filters, large tanks, long pipelines, high temperature Wemcos, and reboilers can produce diminished effects. Further diminished effects can also be produced when incompatible chemicals are used concurrently with acrolein. Some application techniques are presented which can lessen or eliminate these adverse conditions.

  7. Selective Catalytic Oxidation of Hydrogen Sulfide on Activated Carbons Impregnated with Sodium Hydroxide

    SciTech Connect

    Schwartz, Viviane; Baskova, Svetlana; Armstrong, Timothy R.

    2009-01-01

    Two activated carbons of different origin were impregnated with the solution of sodium hydroxide (NaOH) of various concentrations up to 10 wt %, and the effect of impregnation on the catalytic performance of the carbons was evaluated. The catalytic activity was analyzed in terms of the capacity of carbons for hydrogen sulfide (H2S) conversion and removal from hydrogen-rich fuel streams and the emission times of H2S and the products of its oxidation [e.g., sulfur dioxide (SO2) and carbonyl sulfide (COS)]. The results of impregnation showed a significant improvement in the catalytic activity of both carbons proportional to the amount of NaOH introduced. NaOH introduces hydroxyl groups (OH-) on the surface of the activated carbon that increase its surface reactivity and its interaction with sulfur-containing compounds.

  8. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    SciTech Connect

    Siriwardane, R.V.

    1995-12-31

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are presented in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (Drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  9. Spin- and angle-resolved spectroscopy of S 2p photoionization in the hydrogen sulfide molecule

    SciTech Connect

    Turri, G.; Snell, G.; Canton, S.E.; Bilodeau, R.C.; Langer, B.; Martins, M.; Kukk, E.; Cherepkov, N.; Bozek, J.D.; Kilcoyne, A.L.; Berrah, N.

    2004-08-01

    Angle- and spin-resolved photoelectron spectroscopy with circularly and linearly polarized synchrotron radiation were used to study the electronic structure of the hydrogen sulfide molecule. A strong effect of the molecular environment appears in the spin-resolved measurements and, although less clearly, in the angular distribution of the sulfur 2p photoelectrons. The anisotropy and spin parameters of the three main spectral components have been obtained. The validity of simple atomic models in explaining the results is discussed.

  10. Aqueous process for recovering sulfur from hydrogen sulfide-bearing gas

    SciTech Connect

    Basu, Arunabha

    2015-05-05

    A process for recovering sulfur from a hydrogen sulfide-bearing gas utilizes an aqueous reaction medium, a temperature of about 110-150.degree. C., and a high enough pressure to maintain the aqueous reaction medium in a liquid state. The process reduces material and equipment costs and addresses the environmental disadvantages associated with known processes that rely on high boiling point organic solvents.

  11. Effect of nitrogen supplementation and Saccharomyces species on hydrogen sulfide and other volatile sulfur compounds in shiraz fermentation and wine.

    PubMed

    Ugliano, Maurizio; Fedrizzi, Bruno; Siebert, Tracey; Travis, Brooke; Magno, Franco; Versini, Giuseppe; Henschke, Paul A

    2009-06-10

    A Shiraz must with low yeast assimilable nitrogen (YAN) was supplemented with two increasing concentrations of diammonium phosphate (DAP) and fermented with one Saccharomyces cerevisiae and one Saccharomyces bayanus strain, with maceration on grape skins. Hydrogen sulfide (H(2)S) was monitored throughout fermentation, and a total of 16 volatile sulfur compounds (VSCs) were quantified in the finished wines. For the S. cerevisiae yeast strain, addition of DAP to a final YAN of 250 or 400 mg/L resulted in an increased formation of H(2)S compared to nonsupplemented fermentations (100 mg/L YAN). For this yeast, DAP-supplemented fermentations also showed prolonged formation of H(2)S into the later stage of fermentation, which was associated with increased H(2)S in the final wines. The S. bayanus strain showed a different H(2)S production profile, in which production was inversely correlated to initial YAN. No correlation was found between total H(2)S produced by either yeast during fermentation and H(2)S concentration in the final wines. For both yeasts, DAP supplementation yielded higher concentrations of organic VSCs in the finished wines, including sulfides, disulfides, mercaptans, and mercaptoesters. PCA analysis indicated that nitrogen supplementation before fermentation determined a much clearer distinction between the VSC profiles of the two yeasts compared to nonsupplemented fermentations. These results raise questions concerning the widespread use of DAP in the management of low YAN fermentations with respect to the formation of reductive characters in wine. PMID:19391591

  12. Single Membrane Reactor Configuration for Separation of Hydrogen, Carbon Dioxide and Hydrogen Sulfide

    SciTech Connect

    Micheal Roberts; Robert Zabransky; Shain Doong; Jerry Lin

    2008-05-31

    The objective of the project was to develop a novel complementary membrane reactor process that can consolidate two or more downstream unit operations of a coal gasification system into a single module for production of a pure stream of hydrogen and a pure stream of carbon dioxide. The overall goals were to achieve higher hydrogen production efficiencies, lower capital costs and a smaller overall footprint than what could be achieved by utilizing separate components for each required unit process/operation in conventional coal-to-hydrogen systems. Specifically, this project was to develop a novel membrane reactor process that combines hydrogen sulfide removal, hydrogen separation, carbon dioxide separation and water-gas shift reaction into a single membrane configuration. The carbon monoxide conversion of the water-gas-shift reaction from the coal-derived syngas stream is enhanced by the complementary use of two membranes within a single reactor to separate hydrogen and carbon dioxide. Consequently, hydrogen production efficiency is increased. The single membrane reactor configuration produces a pure H{sub 2} product and a pure CO{sub 2} permeate stream that is ready for sequestration. This project focused on developing a new class of CO{sub 2}-selective membranes for this new process concept. Several approaches to make CO{sub 2}-selective membranes for high-temperature applications have been tested. Membrane disks using the technique of powder pressing and high temperature sintering were successfully fabricated. The powders were either metal oxide or metal carbonate materials. Experiments on CO{sub 2} permeation testing were also performed in the temperature range of 790 to 940 C for the metal carbonate membrane disks. However, no CO{sub 2} permeation rate could be measured, probably due to very slow CO{sub 2} diffusion in the solid state carbonates. To improve the permeation of CO{sub 2}, one approach is to make membranes containing liquid or molten carbonates

  13. Study of the interaction between water and hydrogen sulfide with polycyclic aromatic hydrocarbons.

    PubMed

    Cabaleiro-Lago, Enrique M; Carrazana-García, Jorge A; Rodríguez-Otero, Jesús

    2009-06-21

    A computational study has been carried out for determining the characteristics of the interaction between one water and hydrogen sulfide molecule with a series of polycyclic aromatic hydrocarbons of increasing size, namely, benzene, anthracene, triphenylene, coronene, circumcoronene, and dicircumcoronene. Potential energy curves were calculated for structures where H(2)X (X=O,S) molecule is located over the central six-membered ring with its hydrogen atoms pointing toward to (mode A) or away from (mode B) the hydrocarbon. The accuracy of different methods has been tested against the results of coupled cluster calculations extrapolated to basis set limit for the smaller hydrocarbons. The spin component scaled MP2 (SCS-MP2) method and a density functional theory method empirically corrected for dispersion (DFT-D) reproduce fairly well the results of high level calculations and therefore were employed for studying the larger systems, though DFT-D seems to underestimate the interaction in hydrogen sulfide clusters. Water complexes in mode A have interaction energies that hardly change with the size of the hydrocarbon due to compensation between the increase in the correlation contribution to the interaction energy and the increase in the repulsive character of the Hartree-Fock energy. For all the other clusters studied, there is a continuous increase in the intensity of the interaction as the size of the hydrocarbon increases, suggesting already converged values for circumcoronene. The interaction energy for water clusters extrapolated to an infinite number of carbon atoms amounts to -13.0 and -15.8 kJ/mol with SCS-MP2 and DFT-D, respectively. Hydrogen sulfide interacts more strongly than water with the hydrocarbons studied, leading to a limiting value of -21.7 kJ/mol with the SCS-MP2 method. Also, complexes in mode B are less stable than the corresponding A structures, with interaction energies amounting to -8.2 and -18.2 kJ/mol for water and hydrogen sulfide

  14. State-of-the-art hydrogen sulfide control for geothermal energy systems: 1979

    SciTech Connect

    Stephens, F.B.; Hill, J.H.; Phelps, P.L. Jr.

    1980-03-01

    Existing state-of-the-art technologies for removal of hydrogen sulfide are discussed along with a comparative assessment of their efficiencies, reliabilities and costs. Other related topics include the characteristics of vapor-dominated and liquid-dominated resources, energy conversion systems, and the sources of hydrogen sulfide emissions. It is indicated that upstream control technologies are preferred over downsteam technologies primarily because upstream removal of hydrogen sulfide inherently controls all downstream emissions including steam-stacking. Two upstream processes for vapor-dominated resources appear promising; the copper sulfate (EIC) process, and the steam converter (Coury) process combined with an off-gas abatement system such as a Stretford unit. For liquid-dominated systems that produce steam, the process where the non-condensible gases are scrubbed with spent geothermal fluid appears to be promising. An efficient downstream technology is the Stretford process for non-condensible gas removal. In this case, partitioning in the surface condenser will determine the overall abatement efficiency. Recommendations for future environmental control technology programs are included.

  15. Water vapor inhibits hydrogen sulfide detection in pulsed fluorescence sulfur monitors

    NASA Astrophysics Data System (ADS)

    Bluhme, Anders B.; Ingemar, Jonas L.; Meusinger, Carl; Johnson, Matthew S.

    2016-06-01

    The Thermo Scientific 450 Hydrogen Sulfide-Sulfur Dioxide Analyzer measures both hydrogen sulfide (H2S) and sulfur dioxide (SO2). Sulfur dioxide is measured by pulsed fluorescence, while H2S is converted to SO2 with a molybdenum catalyst prior to detection. The 450 is widely used to measure ambient concentrations, e.g., for emissions monitoring and pollution control. An air stream with a constant H2S concentration was generated and the output of the analyzer recorded as a function of relative humidity (RH). The analyzer underreported H2S as soon as the relative humidity was increased. The fraction of undetected H2S increased from 8.3 at 5.3 % RH (294 K) to over 34 % at RH > 80 %. Hydrogen sulfide mole fractions of 573, 1142, and 5145 ppb were tested. The findings indicate that previous results obtained with instruments using similar catalysts should be re-evaluated to correct for interference from water vapor. It is suspected that water decreases the efficiency of the converter unit and thereby reduces the measured H2S concentration.

  16. Protective effect of hydrogen sulfide on hyperbaric hyperoxia-induced lung injury in a rat model.

    PubMed

    Liu, Wenwu; Liu, Kehuan; Ma, Chunqing; Yu, Jiangang; Peng, Zhaoyun; Huang, Guoyang; Cai, Zhiyu; Li, Runping; Xu, Weigang; Sun, Xuejun; Liu, Kan; Zheng, Juan

    2014-01-01

    Hyperbaric oxygen therapy is one of the most widely used clinical interventions to counteract insufficient pulmonary oxygen delivery in patients with severe lung injury. However, prolonged exposure to hyperoxia leads to inflammation and acute lung injury. This study aimed to investigate the protective effect of hydrogen sulfide on hyperbaric hyperoxia-induced lung injury. Rats were intraperitoneally treated with sodium hydrosulphide (NaHS) at 28 μmol/kg immediately before hyperoxia exposure and then exposed to pure oxygen at 2.5 atmospheres absolute (atm abs) with continuous ventilation for six hours, Immediately after hyperoxia exposure, rats were sacrificed via anesthesia. The bronchoalveolar lavage fluid (BALF) was harvested for the detection of protein concentration and IL-1 content, and the lungs were collected for HE staining, TUNEL staining and detection of wet/dry weight ratio. Our results showed hyperbaric hyperoixa exposure could significantly damage the lung (HE staining), increase the protein and IL-13 in the BALF, elevate the wet/dry Weight ratio and raise the TUNEL positive cells. However, pre-treatment with hydrogen sulfide improved the lung morphology, reduced the TUNEL positive cells and attenuated the lung inflammation (reduction in IL-13 of BALF and HE staining). Taken together, our findings indicate that hydrogen sulfide pretreatment may exert protective effects on hyperbaric hyperoxia-induced lung injury.

  17. Proceedings of the Hydrogen Sulfide Health Research and Risk Assessment Symposium October 31-November 2, 2000.

    PubMed

    Woodall, George M; Smith, Roy L; Granville, Geoff C

    2005-10-01

    The Hydrogen Sulfide Health Research and Risk Assessment Symposium came about for several reasons: (1) increased interest by the U.S. Environmental Protection Agency (EPA) and several state agencies in regulating hydrogen sulfide (H2S); (2) uncertainty about ambient exposure to H2S; (3) confusion and disagreement in the literature about possible health effects at low-level exposures; and (4) presentation of results of a series of recent animal bioassays. The American Petroleum Institute (API) proposed this symposium and the EPA became an early co-sponsor, with the Chemical Industry Institute of Toxicology (CIIT) and the American Forest & Paper Association (AF&PA) contributing expertise and funding assistance. The topics covered in this symposium included Animal Research, Human Research, Mode-of-Action and Dosimetry Issues, Environmental Exposure and Monitoring, Assessment and Regulatory Issues, and closed with a panel discussion. The overall goals of the symposium were to: gather together experts in H2S health effects research and individuals from governmental agencies charged with protecting the public health, provide a venue for reporting of recent research findings, identify gaps in the current information, and outline new research directions and promote research collaboration. During the course of the symposium, presenters provided comprehensive reviews of the state of knowledge for each topic. Several new research proposals discussed at the symposium have subsequently been initiated. This report provides a summary of the talks, poster presentations, and panel discussions that occurred at the Hydrogen Sulfide Health and Risk Assessment Symposium. PMID:16033755

  18. Effect of Surface Characteristics of Wood-Based Activated Carbons on Adsorption of Hydrogen Sulfide.

    PubMed

    Adib; Bagreev; Bandosz

    1999-06-15

    Three wood-based commercial activated carbons supplied by Westvaco were studied as adsorbents of hydrogen sulfide. The initial materials were characterized using sorption of nitrogen, Boehm titration, potentiometric titration, water sorption, thermal analysis, and temperature-programmed desorption. The breakthrough tests were done at low concentrations of H2S in the input gas to simulate conditions in water pollution control plants where carbon beds are used as odor adsorbents. In spite of apparent general similarities in the origin of the materials, method of activation, surface chemistry, and porosity, significant differences in their performance as hydrogen sulfide adsorbents were observed. Results show that the combined effect of the presence of pores large enough to accommodate surface functional groups and small enough to have the film of water at relatively low pressure contributes to oxidation of hydrogen sulfide. Moreover, there are features of activated carbon surfaces such as local environment of acidic/basic groups along with the presence of alkali metals which are important to the oxidation process. Copyright 1999 Academic Press.

  19. Arsenic Sulfide Nanowire Formation on Fused Quartz Surfaces

    SciTech Connect

    Olmstead, J.; Riley, B.J.; Johnson, B.R.; Sundaram, S.K.

    2005-01-01

    Arsenic sulfide (AsxSy) nanowires were synthesized by an evaporation-condensation process in evacuated fused quartz ampoules. During the deposition process, a thin, colored film of AsxSy was deposited along the upper, cooler portion of the ampoule. The ampoule was sectioned and the deposited film analyzed using scanning electron microscopy (SEM) to characterize and semi-quantitatively evaluate the microstructural features of the deposited film. A variety of microstructures were observed that ranged from a continuous thin film (warmer portion of the ampoule), to isolated micron- and nano-scale droplets (in the intermediate portion), as well as nanowires (colder portion of the ampoule). Experiments were conducted to evaluate the effects of ampoule cleaning methods (e.g. modify surface chemistry) and quantity of source material on nanowire formation. The evolution of these microstructures in the thin film was determined to be a function of initial pressure, substrate temperature, substrate surface treatment, and initial volume of As2S3 glass. In a set of two experiments where the initial pressure, substrate thermal gradient, and surface treatment were the same, the initial quantity of As2S3 glass per internal ampoule volume was doubled from one test to the other. The results showed that AsxSy nanowires were only formed in the test with the greater initial quantity of As2S3 per internal ampoule volume. The growth data for variation in diameter (e.g. nanowire or droplet) as a function of substrate temperature was fit to an exponential trendline with the form y = Aekx, where y is the structure diameter, A = 1.25×10-3, k = 3.96×10-2, and x is the temperature with correlation coefficient, R2 = 0.979, indicating a thermally-activated process.

  20. Cobalt (hydr)oxide/graphite oxide composites: importance of surface chemical heterogeneity for reactive adsorption of hydrogen sulfide.

    PubMed

    Mabayoje, Oluwaniyi; Seredych, Mykola; Bandosz, Teresa J

    2012-07-15

    Composites of cobalt (hydr)oxide and graphite oxide (GO) were obtained and evaluated as adsorbents of hydrogen sulfide at ambient conditions. The surface properties of the initial and exhausted samples were studied by FTIR, TEM, SEM/EDX, XRD, adsorption of nitrogen, potentiometric titration, and thermal analysis. The results obtained show a significant improvement in their adsorption capacities compared to parent compounds. The importance of the OH groups of cobalt (hydr)oxide/GO composites and new interface chemistry for the adsorption of hydrogen sulfide on these materials is revealed. The oxygen activation by the carbonaceous component resulted in formation of sulfites. Water enhanced the removal process. This is the result of the basic environment promoting dissociation of H(2)S and acid-base reactions. Finally, the differences in the performance of the materials with different mass ratios of GO were linked to the availability of active sites on the surface of the adsorbents, dispersion of these sites, their chemical heterogeneity, and location in the pore system.

  1. Enhanced reactive adsorption of hydrogen sulfide on the composites of graphene/graphite oxide with copper (hydr)oxychlorides.

    PubMed

    Mabayoje, Oluwaniyi; Seredych, Mykola; Bandosz, Teresa J

    2012-06-27

    Composites of copper (hydr)oxychlorides with graphite oxide or graphene were synthesized and used as adsorbents of hydrogen sulfide at dynamic conditions at ambient temperatures. The materials were extensively characterized before and after adsorption in order to link their performance to the surface features. X-ray diffraction, FTIR, thermal analysis, TEM, SEM/EDX, and adsorption of nitrogen were used. It was found that the composite with graphene has the most favorable surface features enhancing reactive adsorption of hydrogen sulfide. The presence of moisture in the H2S stream has a positive effect on the removal process owing to the dissociation process. H2S is retained on the surface via a direct replacement of OH groups and via acid-base reactions with the copper (hydr)oxide. Highly dispersed reduced copper species on the surface of the composite with graphene enhance activation of oxygen and cause formation of sulfites and sulfates. Higher conductivity of the graphene phase than that of graphite oxide helps in electron transfer in redox reactions.

  2. First-principles demonstration of superconductivity at 280 K in hydrogen sulfide with low phosphorus substitution

    NASA Astrophysics Data System (ADS)

    Ge, Yanfeng; Zhang, Fan; Yao, Yugui

    2016-06-01

    Recently, BCS superconductivity at 203 K has been observed in a highly compressed hydrogen sulfide. We use first-principles calculations to systematically examine the effects of partially substituting chalcogen atoms on the superconductivity of hydrogen chalcogenides under high pressures. We find detailed trends of how the critical temperature changes upon increasing the V-, VI- or VII-substitution rate. These trends highlight the key roles played by low atomic mass and metallized covalent bonds. In particular, a possible record high critical temperature of 280 K is predicted in stable H3S0.925P0.075 with the I m 3 ¯m structure under 250 GPa.

  3. Contribution of dissolved sulfates and sulfites in hydrogen sulfide emission from stagnant water bodies in Sri Lanka.

    PubMed

    Kularatne, K I A; Dissanayake, D P; Mahanama, K R R

    2003-08-01

    Accumulation of sulfur-containing compounds and their bacterial mediated reductions have led to the emission of pungent odors from stagnant water bodies. This study is focused on the contribution of inorganic sulfur compounds in the emission of hydrogen sulfide. The measured dissolved oxygen levels have demonstrated good negative correlations with the dissolved sulfide levels implying the oxygen deficiency is the key for the reduction of sulfate ion and sulfite ion to sulfide ion. Particularly, the dissolved molar fractions of sulfide from the total dissolved sulfur compounds (sulfates, sulfites and sulfides) have a very good correlation with the dissolved oxygen for the stagnant water bodies except the artificially aerated prawn farms. For the stagnant water bodies with significant correlations, linear regressions are reported for them to be utilized in estimating one component of the regression from the measurement of the other. The measured data were further utilized to estimate the levels of hydrogen sulfide gas. The pH of the water bodies has confined much of the dissolved sulfides in the form of bisulfide ion and they can be easily escaped to the atmosphere upon acidification due to industrial discharges and/or acidic precipitations. The estimated levels of hydrogen sulfide just above the water surface were plotted for the most polluted stagnant water body in Sri Lanka for the pH range of 5-10 and temperature range of 25-35 degrees C.

  4. The possible role of hydrogen sulfide as a modulator of hemostatic parameters of plasma.

    PubMed

    Olas, Beata; Kontek, Bogdan

    2014-09-01

    Hydrogen sulfide (H2S) is a well known toxic gas at high levels. However, at physiological levels, H2S may play a role in the pathogenesis of various cardiovascular diseases. The objective was to study the effects of exogenous H2S on the hemostatic parameters (coagulation and fibrinolytic activity) of human plasma. Human plasma was incubated (5, 15 and 30 min) with NaHS as a H2S donor at the final concentration of 0.01-100 μM. Hemostatic factors, such as maximum velocity of clot formation, fibrin lysis half-time, the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) were estimated. Moreover, the aim of our study was to establish the influence of NaHS (10 μM; 5, 15 and 30 min) on the clot formation using the purified fibrinogen. We demonstrated that coagulation/fibrinolytic properties of human plasma incubated with NaHS were changed. APPT, PT and TT of plasma treated with NaHS at tested concentrations--0.01-100 μM were prolonged. We observed that NaHS (0.01-100 μM) reduced fibrin polymerization in whole plasma and 10 μM NaHS also reduced polymerization of purified fibrinogen. In the presence of NaHS (at the low tested concentration--1 μM) the decrease was about 18% (in plasma, p<0.05). Our experiments also showed that NaHS (0.01-100 μM) stimulated the fibrin lysis in whole plasma. However, the time-dependent (5, 15 and 30 min) reduction of fibrin/fibrinogen polymerization and stimulation of fibrin lysis by NaHS (10 μM) was not observed. In conclusion, the present study demonstrates the anticoagulant properties of exogenous H2S in vitro.

  5. Pathophysiological Concepts in Multiple Sclerosis and the Therapeutic Effects of Hydrogen Sulfide

    PubMed Central

    2016-01-01

    Introduction: Multiple sclerosis (MS) is generally known as a manageable but not yet curable autoimmune disease affecting central nervous system. A potential therapeutic approach should possess several properties: Prevent immune system from damaging the brain and spinal cord, promote differentiation of oligodendrocyte progenitor cells (OPCs) into mature oligodendrocytes to produce myelin, prevent the formation of fibronectin aggregates by astrocytes to inhibit scar formation, and enhance function of healthy endothelial cells (ECs). Methods: To determine if an increase in sulfur contents through H2S, a potent antioxidant known to induce protective autophagy in cells, could provide the above desired outcomes, peripheral blood mononuclear cells (PBMNCs), OCPs, astrocytes, and ECs were treated with NaHS (50 μM) in vitro. Results: Transmigration assay using EC monolayer showed that serotonin increased migration of PBMNC while pretreatment of EC with NaHS inhibited the migration induced by serotonin treatment. NaHS upregulated proteins involved in immune system response and downregulated PBMNCs- and EC-related adhesion molecules (LFA-1 and VCAM-1). Furthermore, it had a cell expansion inducing effect, altering EC morphology. The effects of NaHS on OPCs and astrocytes were studied compared to mTOR inhibitor rapamycin. In NaHS treated astrocytes the induced fibronectin production was partially inhibited while rapamycin almost fully inhibited fibronectin production. NaHS slowed but did not inhibit the differentiation of OCPs or the production of myelin compared to rapamycin. Conclusion: The in vitro results point to the potential therapeutic application of hydrogen sulfide releasing molecules or health-promoting sulfur compounds in MS. PMID:27303607

  6. Reasons for high-temperature superconductivity in the electron–phonon system of hydrogen sulfide

    SciTech Connect

    Degtyarenko, N. N.; Mazur, E. A.

    2015-08-15

    We have calculated the electron and phonon spectra, as well as the densities of the electron and phonon states, of the stable orthorhombic structure of hydrogen sulfide SH{sub 2} in the pressure interval 100–180 GPa. It is found that at a pressure of 175 GPa, a set of parallel planes of hydrogen atoms is formed due to a structural modification of the unit cell under pressure with complete accumulation of all hydrogen atoms in these planes. As a result, the electronic properties of the system become quasi-two-dimensional. We have also analyzed the collective synphase and antiphase vibrations of hydrogen atoms in these planes, leading to the occurrence of two high-energy peaks in the phonon density of states.

  7. Electrochemical separation and concentration of hydrogen sulfide from gas mixtures

    DOEpatents

    Winnick, Jack; Sather, Norman F.; Huang, Hann S.

    1984-10-30

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  8. ELECTROCHEMICAL SEPARATION AND CONCENTRATION OF HYDROGEN SULFIDE FROM GAS MIXTURES

    DOEpatents

    Winnick, Jack; Sather, Norman F.; Huang, Hann S.

    1984-10-30

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  9. Plasma-chemical treatment of hydrogen sulfide in natural gas processing. Final report, May 1991--December 1992

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.

    1993-05-01

    A new process for the treatment of hydrogen sulfide waste that uses microwave plasma-chemical technology has been under development in Russia and the United States. Whereas the present waste-treatment technology, at best, only recovers sulfur, this novel process recovers both hydrogen and sulfur by dissociating hydrogen sulfide in a plasma by means of a microwave or radio-frequency reactor. A research project has been undertaken to determine the suitability of the plasma process in natural gas processing applications. The experiments tested acid-gas compositions with 30--65% carbon dioxide, 0--7% water, and 0--0.2% of a standard mixture of pipeline gas. The balance gas in all cases was hydrogen sulfide. The reactor pressure for the experiments was 50 torr, and the microwave power was 1.0 kW. Conversions of hydrogen sulfide ranged from 80 to 100%, while 35--50% of the carbon dioxide was converted to carbon monoxide. This conversion of carbon dioxide resulted in a loss of hydrogen production and an energy loss from a hydrogen sulfide waste-treatment perspective. Tests of a direct natural gas treatment concept showed that hydrocarbon losses were unacceptably high; consequently, the concept would not be economically viable.

  10. Replacive sulfide formation in anhydrite chimneys from the Pacmanus hydrothermal field, Papua New Guinea

    NASA Astrophysics Data System (ADS)

    Los, Catharina; Bach, Wolfgang; Plümper, Oliver

    2016-04-01

    Hydrothermal flow within the oceanic crust is an important process for the exchange of energy and mass between the lithosphere, hydrosphere and biosphere. Infiltrated seawater heats up and interacts with wall rock, causing mineral replacement reactions. These play a large role in the formation of ore deposits; at the discharge zone, a hot, acidic and metal-rich potential ore fluid exits the crust. It mixes with seawater and forms chimneys, built up of sulfate minerals such as anhydrite (CaSO4), which are subsequently replaced by sulfide minerals. Sulfide formation is related to fluid pathways, defined by cracks and pores in the sulfate chimney. Over time, these systems might develop into massive sulfide deposits. The big question is then: how is sulfate-sulfide replacement related to the evolution of rock porosity? To address this question, sulfide-bearing anhydrite chimneys from the Pacmanus hydrothermal field (Manus Basin, Papua New Guinea) were studied using X-ray tomography, EMPA, FIB-SEM and -TEM. The apparently massive anhydrite turns out highly porous on the micro scale, with sulfide minerals in anhydrite cleavage planes and along grain boundaries. The size of the sulfide grains relates to the pores they grew into, suggesting a tight coupling between dissolution (porosity generation) and growth of replacive minerals. Some of the sulfide grains are hollow and apparently used the dissolving anhydrite as a substrate to start growth in a pore. Another mode of sulfide development is aggregates of euhedral pyrite cores surrounded by colloform chalcopyrite. This occurrence implies that fluid pathways have remained open for some time to allow several stages of precipitation during fluid evolution. To start the replacement and to keep it going, porosity generation is crucial. Our samples show that dissolution of anhydrite occurred along pathways where fluid could enter, such as cleavage planes and grain boundaries. It appears that fluids ascending within the inner

  11. Competition for Dimethyl Sulfide and Hydrogen Sulfide by Methylophaga sulfidovorans and Thiobacillus thioparus T5 in Continuous Cultures

    PubMed Central

    De Zwart, J.; Sluis, J.; Kuenen, J. G.

    1997-01-01

    Pure and mixed cultures of Methylophaga sulfidovorans and Thiobacillus thioparus T5 were grown in continuous cultures on either dimethyl sulfide, dimethyl sulfide and H(inf2)S, or H(inf2)S and methanol. In pure cultures, M. sulfidovorans showed a lower affinity for sulfide than T. thioparus T5. Mixed cultures, grown on dimethyl sulfide, showed coexistence of both species. M. sulfidovorans fully converted dimethyl sulfide to thiosulfate, which was subsequently further oxidized to sulfate by T. thioparus T5. Mixed cultures supplied with sulfide and methanol showed that nearly all the sulfide was used by T. thioparus T5, as expected on the basis of the affinities for sulfide. The sulfide in mixed cultures supplied with dimethyl sulfide and H(inf2)S, however, was used by both bacteria. This result may be explained by the fact that the H(inf2)S-oxidizing capacity of M. sulfidovorans remains fully induced by intracellular H(inf2)S originating from dimethyl sulfide metabolism. PMID:16535680

  12. Hydrogen sulfide (H2S) releasing agents: chemistry and biological applications.

    PubMed

    Zhao, Yu; Biggs, Tyler D; Xian, Ming

    2014-10-14

    Hydrogen sulfide (H2S) is a newly recognized signaling molecule with very potent cytoprotective actions. The fields of H2S physiology and pharmacology have been rapidly growing in recent years, but a number of fundamental issues must be addressed to advance our understanding of the biology and clinical potential of H2S in the future. Hydrogen sulfide releasing agents (also known as H2S donors) have been widely used in these fields. These compounds are not only useful research tools, but also potential therapeutic agents. It is therefore important to study the chemistry and pharmacology of exogenous H2S and to be aware of the limitations associated with the choice of donors used to generate H2S in vitro and in vivo. In this review we summarized the developments and limitations of currently available donors including H2S gas, sulfide salts, garlic-derived sulfur compounds, Lawesson's reagent/analogs, 1,2-dithiole-3-thiones, thiol-activated donors, photo-caged donors, and thioamino acids. Some biological applications of these donors were also discussed.

  13. Hydrogen Sulfide (H2S) Releasing Agents: Chemistry and Biological Applications

    PubMed Central

    Zhao, Yu; Biggs, Tyler D.

    2014-01-01

    Hydrogen sulfide (H2S) is a newly recognized signaling molecule with very potent cytoprotective actions. The fields of H2S physiology and pharmacology have been rapidly growing in recent years, but a number of fundamental issues must be addressed to advance our understanding of the biology and clinical potential of H2S in the future. Hydrogen sulfide releasing agents (also known as H2S donors) have been widely used in the field. These compounds are not only useful research tools, but also potential therapeutic agents. It is therefore important to study the chemistry and pharmacology of exogenous H2S and to be aware of the limitations associated with the choice of donors used to generate H2S in vitro and in vivo. In this review we summarized the developments and limitations of current available donors including H2S gas, sulfide salts, garlic-derived sulfur compounds, Lawesson’s reagent/analogs, 1,2-dithiole-3-thiones, thiol-activated donors, photo-caged donors, and thioamino acids. Some biological applications of these donors were also discussed. PMID:25019301

  14. Formation of nanocolloidal metacinnabar in mercury-DOM-sulfide systems

    USGS Publications Warehouse

    Gerbig, C.A.; Kim, C.S.; Stegemeier, J.P.; Ryan, J.N.; Aiken, G.R.

    2011-01-01

    Direct determination of mercury (Hg) speciation in sulfide-containing environments is confounded by low mercury concentrations and poor analytical sensitivity. Here we report the results of experiments designed to assess mercury speciation at environmentally relevant ratios of mercury to dissolved organic matter (DOM) (i.e., <4 nmol Hg (mg DOM)-1) by combining solid phase extraction using C18 resin with extended X-ray absorption fine structure (EXAFS) spectroscopy. Aqueous Hg(II) and a DOM isolate were equilibrated in the presence and absence of 100 ??M total sulfide. In the absence of sulfide, mercury adsorption to the resin increased as the Hg:DOM ratio decreased and as the strength of Hg-DOM binding increased. EXAFS analysis indicated that in the absence of sulfide, mercury bonds with an average of 2.4 ?? 0.2 sulfur atoms with a bond length typical of mercury-organic thiol ligands (2.35 ??). In the presence of sulfide, mercury showed greater affinity for the C18 resin, and its chromatographic behavior was independent of Hg:DOM ratio. EXAFS analysis showed mercury-sulfur bonds with a longer interatomic distance (2.51-2.53 ??) similar to the mercury-sulfur bond distance in metacinnabar (2.53 ??) regardless of the Hg:DOM ratio. For all samples containing sulfide, the sulfur coordination number was below the ideal four-coordinate structure of metacinnabar. At a low Hg:DOM ratio where strong binding DOM sites may control mercury speciation (1.9 nmol mg -1) mercury was coordinated by 2.3 ?? 0.2 sulfur atoms, and the coordination number rose with increasing Hg:DOM ratio. The less-than-ideal coordination numbers indicate metacinnabar-like species on the nanometer scale, and the positive correlation between Hg:DOM ratio and sulfur coordination number suggests progressively increasing particle size or crystalline order with increasing abundance of mercury with respect to DOM. In DOM-containing sulfidic systems nanocolloidal metacinnabar-like species may form, and these

  15. Formation of nanocolloidal metacinnabar in mercury-DOM-sulfide systems

    USGS Publications Warehouse

    Gerbig, Chase A.; Kim, Christopher S.; Stegemeier, John P.; Ryan, Joseph N.; Aiken, George R.

    2011-01-01

    Direct determination of mercury (Hg) speciation in sulfide-containing environments is confounded by low mercury concentrations and poor analytical sensitivity. Here we report the results of experiments designed to assess mercury speciation at environmentally relevant ratios of mercury to dissolved organic matter (DOM) (i.e., -1) by combining solid phase extraction using C18 resin with extended X-ray absorption fine structure (EXAFS) spectroscopy. Aqueous Hg(II) and a DOM isolate were equilibrated in the presence and absence of 100 μM total sulfide. In the absence of sulfide, mercury adsorption to the resin increased as the Hg:DOM ratio decreased and as the strength of Hg-DOM binding increased. EXAFS analysis indicated that in the absence of sulfide, mercury bonds with an average of 2.4 ± 0.2 sulfur atoms with a bond length typical of mercury-organic thiol ligands (2.35 Å). In the presence of sulfide, mercury showed greater affinity for the C18 resin, and its chromatographic behavior was independent of Hg:DOM ratio. EXAFS analysis showed mercury–sulfur bonds with a longer interatomic distance (2.51–2.53 Å) similar to the mercury–sulfur bond distance in metacinnabar (2.53 Å) regardless of the Hg:DOM ratio. For all samples containing sulfide, the sulfur coordination number was below the ideal four-coordinate structure of metacinnabar. At a low Hg:DOM ratio where strong binding DOM sites may control mercury speciation (1.9 nmol mg-1) mercury was coordinated by 2.3 ± 0.2 sulfur atoms, and the coordination number rose with increasing Hg:DOM ratio. The less-than-ideal coordination numbers indicate metacinnabar-like species on the nanometer scale, and the positive correlation between Hg:DOM ratio and sulfur coordination number suggests progressively increasing particle size or crystalline order with increasing abundance of mercury with respect to DOM. In DOM-containing sulfidic systems nanocolloidal metacinnabar-like species may form, and these species need to

  16. Endogenous hydrogen sulfide regulates leukocyte trafficking in cecal ligation and puncture-induced sepsis.

    PubMed

    Zhang, Huili; Zhi, Liang; Moochhala, Shabbir M; Moore, Philip Keith; Bhatia, Madhav

    2007-10-01

    Hydrogen sulfide (H(2)S) is recognized increasingly as a proinflammatory mediator in various inflammatory conditions. Here, we have investigated the role of H(2)S in regulating expression of some endothelial adhesion molecules and recruitment of leukocytes to inflamed sites in sepsis. Male Swiss mice were subjected to cecal ligation and puncture (CLP)-induced sepsis and treated with saline (i.p.), DL-propargylglycine (PAG; 50 mg/kg, i.p.), an inhibitor of H(2)S formation or NaHS (10 mg/kg, i.p.), an H(2)S donor. PAG was administered 1 h before or after the induction of sepsis, and NaHS was given at the same time of CLP. Using intravital microcopy, we found that in sepsis, prophylactic and therapeutic administration of PAG reduced leukocyte rolling and adherence significantly in mesenteric venules coupled with decreased mRNA and protein levels of adhesion molecules (ICAM-1, P-selectin, and E-selectin) in lung and liver. In contrast, injection of NaHS up-regulated leukocyte rolling and attachment significantly, as well as tissue levels of adhesion molecules in sepsis. Conversely, normal mice were given NaHS (10 mg/kg, i.p.) to induce lung inflammation, with or without NF-kappaB inhibitor BAY 11-7082 pretreatment. NaHS treatment enhanced the level of adhesion molecules and neutrophil infiltration in lung. These alterations were reversed by pretreatment with BAY 11-7082. Moreover, expression of CXCR2 in neutrophils obtained from H(2)S-treated mice was up-regulated significantly, leading to an obvious elevation in MIP-2-directed migration of neutrophils. Therefore, H(2)S acts as an important endogenous regulator of leukocyte activation and trafficking during an inflammatory response.

  17. The hydrogen sulfide emissions abatement program at the Geysers Geothermal Power Plant

    NASA Technical Reports Server (NTRS)

    Allen, G. W.; Mccluer, H. K.

    1974-01-01

    The scope of the hydrogen sulfide (H2S) abatement program at The Geysers Geothermal Power Plant and the measures currently under way to reduce these emissions are discussed. The Geysers steam averages 223 ppm H2S by weight and after passing through the turbines leaves the plant both through the gas ejector system and by air-stripping in the cooling towers. The sulfide dissolved in the cooling water is controlled by the use of an oxidation catalyst such as an iron salt. The H2S in the low Btu ejector off gases may be burned to sulfur dioxide and scrubbed directly into the circulating water and reinjected into the steam field with the excess condensate. Details are included concerning the disposal of the impure sulfur, design requirements for retrofitting existing plants and modified plant operating procedures. Discussion of future research aimed at improving the H2S abatement system is also included.

  18. Formation of nickel sulfide nanoframes from metal-organic frameworks with enhanced pseudocapacitive and electrocatalytic properties.

    PubMed

    Yu, Xin-Yao; Yu, Le; Wu, Hao Bin; Lou, Xiong Wen David

    2015-04-27

    Nanoframe-like hollow structures with unique three-dimensional (3D) open architecture hold great promise for various applications. Current research efforts mainly focus on frame-like noble metals and metal oxides. However, metal sulfides with frame-like nanostructures have been rarely reported. Starting from metal-organic frameworks (MOFs), we demonstrate a novel structure-induced anisotropic chemical etching/anion exchange method to transform Ni-Co Prussian blue analogue (PBA) nanocubes into NiS nanoframes with tunable size. The reaction between Ni-Co PBA nanocube templates and Na2 S in solution leads to the formation of well-defined NiS nanoframes. The different reactivity between the edges and the plane surface of the Ni-Co PBA nanocubes is found to be the key factor for the formation of NiS nanoframes. Benefitting from their structural merits including 3D open structure, small size of primary nanoparticles, high specific surface area, and good structural robustness, the as-derived NiS nanoframes manifest excellent electrochemical performance for electrochemical capacitors and hydrogen evolution reaction in alkaline electrolyte.

  19. Formation of nickel sulfide nanoframes from metal-organic frameworks with enhanced pseudocapacitive and electrocatalytic properties.

    PubMed

    Yu, Xin-Yao; Yu, Le; Wu, Hao Bin; Lou, Xiong Wen David

    2015-04-27

    Nanoframe-like hollow structures with unique three-dimensional (3D) open architecture hold great promise for various applications. Current research efforts mainly focus on frame-like noble metals and metal oxides. However, metal sulfides with frame-like nanostructures have been rarely reported. Starting from metal-organic frameworks (MOFs), we demonstrate a novel structure-induced anisotropic chemical etching/anion exchange method to transform Ni-Co Prussian blue analogue (PBA) nanocubes into NiS nanoframes with tunable size. The reaction between Ni-Co PBA nanocube templates and Na2 S in solution leads to the formation of well-defined NiS nanoframes. The different reactivity between the edges and the plane surface of the Ni-Co PBA nanocubes is found to be the key factor for the formation of NiS nanoframes. Benefitting from their structural merits including 3D open structure, small size of primary nanoparticles, high specific surface area, and good structural robustness, the as-derived NiS nanoframes manifest excellent electrochemical performance for electrochemical capacitors and hydrogen evolution reaction in alkaline electrolyte. PMID:25702684

  20. Influences of salinity and temperature on the stable isotopic composition of methane and hydrogen sulfide trapped in pressure-vessel hydrates

    NASA Astrophysics Data System (ADS)

    Carvajal-Ortiz, Humberto; Pratt, Lisa M.

    2013-10-01

    The stable isotopic composition of carbon (δ13CCH4) and hydrogen (δ2HCH4) in methane and sulfur (δ34SH2S) in hydrogen sulfide can be used to infer the source of volatile molecules encaged in gas hydrates. Differentiation of methane and hydrogen sulfide from microbial and thermal origins provides valuable information for hydrocarbon exploration and for climatic models assessing the role of gas hydrates during climate change. In astrobiological studies, δ13CCH4, δ2HCH4, and δ34SH2S values will be critical in deciphering the origin of methane and hydrogen sulfide molecules if gas hydrates are detected within the cryosphere of Mars or associated with ice-covered oceans on Europa or Enceladus. It is challenging, however, to apply isotope systematics to hydrate-forming systems due to complex influences on nucleation and decomposition under varying conditions of salinity, pressure, and temperature. Few laboratory studies have evaluated the effect of hydrate formation, on isotopic composition of free, encaged, and dissolved gas molecules. In this study, pressure-vessel hydrates were nucleated under conditions inferred for marine continental margins and terrestrial permafrost: low temperatures, moderate pressures, saturation of methane and/or hydrogen sulfide saturation, and varying concentration of sodium chloride (NaCl) and magnesium sulfate heptahydrate (MgSO4·7H2O). Methane experiments show less than 1‰ differences in values of δ13CCH4 between free and encaged molecules and up to 6.5‰ variations in values of δ2HCH4 between free and encaged molecules. In hydrogen-sulfide hydrates, δ34SH2S values show less than 4‰ differences between free and encaged molecules, but up to 14‰ differences between dissolved and free molecules and between dissolved and encaged molecules. Results presented here indicate that shifts found for free and encaged values of δ13CCH4 and δ2HCH4 are small and do not complicate interpretation of gas provenance. Conversely, in hydrate

  1. Effects of hydrogen sulfide exposure on lung mitochondrial respiratory chain enzymes in rats.

    PubMed

    Khan, A A; Schuler, M M; Prior, M G; Yong, S; Coppock, R W; Florence, L Z; Lillie, L E

    1990-05-01

    Fischer-344 rats were exposed for 4 hr to various concentrations of hydrogen sulfide (H2S) gas and killed either immediately or at 1, 24, or 48 hr after exposure. Mitochondrial fractions from lung tissues were assayed for the activities of respiratory chain enzymes. Exposure of rats to a low concentration (10 ppm) of H2S caused no significant changes in the activities of lung mitochondrial enzymes. However, exposure to sublethal concentrations of H2S (50-400 ppm) produced marked and highly significant depressions in the activities of cytochrome c oxidase and succinate oxidase complexes of the respiratory chain. The inhibition of cytochrome c oxidase activity in lungs was most severe (greater than 90%) in rats that died from acute exposure to greater than 500 ppm H2S. In rats exposed to 200 and 400 ppm H2S, a marked recovery in cytochrome c oxidase activity of lungs was observed at 24 and 48 hr postexposure. Studies in vitro with rat lung mitochondria showed that low concentrations of sulfide also caused a similar and selective inhibition of cytochrome c oxidase activity. This effect was reversed upon removal of sulfide either by washing or by oxidation with methemoglobin. The nature of sulfide inhibition of cytochrome c oxidase was noncompetitive with respect to ferrocytochrome c. Because the activities of NADH-cytochrome c reductase and succinate-cytochrome c reductase were not significantly altered by H2S exposure and in vitro treatments with low concentrations of sulfide, it is concluded that under physiological conditions H2S would block the respiratory chain primarily by inhibiting cytochrome c oxidase. Such a biochemical impairment would lead to functional (histotoxic) hypoxia in the lung tissues.

  2. Mechanisms Underlying Adaptation to Life in Hydrogen Sulfide-Rich Environments.

    PubMed

    Kelley, Joanna L; Arias-Rodriguez, Lenin; Patacsil Martin, Dorrelyn; Yee, Muh-Ching; Bustamante, Carlos D; Tobler, Michael

    2016-06-01

    Hydrogen sulfide (H2S) is a potent toxicant interfering with oxidative phosphorylation in mitochondria and creating extreme environmental conditions in aquatic ecosystems. The mechanistic basis of adaptation to perpetual exposure to H2S remains poorly understood. We investigated evolutionarily independent lineages of livebearing fishes that have colonized and adapted to springs rich in H2S and compared their genome-wide gene expression patterns with closely related lineages from adjacent, nonsulfidic streams. Significant differences in gene expression were uncovered between all sulfidic and nonsulfidic population pairs. Variation in the number of differentially expressed genes among population pairs corresponded to differences in divergence times and rates of gene flow, which is consistent with neutral drift driving a substantial portion of gene expression variation among populations. Accordingly, there was little evidence for convergent evolution shaping large-scale gene expression patterns among independent sulfide spring populations. Nonetheless, we identified a small number of genes that was consistently differentially expressed in the same direction in all sulfidic and nonsulfidic population pairs. Functional annotation of shared differentially expressed genes indicated upregulation of genes associated with enzymatic H2S detoxification and transport of oxidized sulfur species, oxidative phosphorylation, energy metabolism, and pathways involved in responses to oxidative stress. Overall, our results suggest that modification of processes associated with H2S detoxification and toxicity likely complement each other to mediate elevated H2S tolerance in sulfide spring fishes. Our analyses allow for the development of novel hypotheses about biochemical and physiological mechanisms of adaptation to extreme environments.

  3. Metallic Iron-Nickel Sulfide Ultrathin Nanosheets As a Highly Active Electrocatalyst for Hydrogen Evolution Reaction in Acidic Media.

    PubMed

    Long, Xia; Li, Guixia; Wang, Zilong; Zhu, HouYu; Zhang, Teng; Xiao, Shuang; Guo, Wenyue; Yang, Shihe

    2015-09-23

    We report on the synthesis of iron-nickel sulfide (INS) ultrathin nanosheets by topotactic conversion from a hydroxide precursor. The INS nanosheets exhibit excellent activity and stability in strong acidic solutions as a hydrogen evolution reaction (HER) catalyst, lending an attractive alternative to the Pt catalyst. The metallic α-INS nanosheets show an even lower overpotential of 105 mV at 10 mA/cm(2) and a smaller Tafel slope of 40 mV/dec. With the help of DFT calculations, the high specific surface area, facile ion transport and charge transfer, abundant electrochemical active sites, suitable H(+) adsorption, and H2 formation kinetics and energetics are proposed to contribute to the high activity of the INS ultrathin nanosheets toward HER.

  4. Metallic Iron-Nickel Sulfide Ultrathin Nanosheets As a Highly Active Electrocatalyst for Hydrogen Evolution Reaction in Acidic Media.

    PubMed

    Long, Xia; Li, Guixia; Wang, Zilong; Zhu, HouYu; Zhang, Teng; Xiao, Shuang; Guo, Wenyue; Yang, Shihe

    2015-09-23

    We report on the synthesis of iron-nickel sulfide (INS) ultrathin nanosheets by topotactic conversion from a hydroxide precursor. The INS nanosheets exhibit excellent activity and stability in strong acidic solutions as a hydrogen evolution reaction (HER) catalyst, lending an attractive alternative to the Pt catalyst. The metallic α-INS nanosheets show an even lower overpotential of 105 mV at 10 mA/cm(2) and a smaller Tafel slope of 40 mV/dec. With the help of DFT calculations, the high specific surface area, facile ion transport and charge transfer, abundant electrochemical active sites, suitable H(+) adsorption, and H2 formation kinetics and energetics are proposed to contribute to the high activity of the INS ultrathin nanosheets toward HER. PMID:26338434

  5. A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes.

    PubMed

    Sun, Mei; Sun, Wenjie; Barlaz, Morton A

    2016-05-01

    Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H2S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H2S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H2S produced by different types of sulfur-containing wastes in a relatively fast (30days) and inexpensive (125mL serum bottles) batch assay. This study confirmed the toxic effect of H2S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H2S by base adsorption was effective for mitigating inhibition. H2S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8mLH2S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H2S yield. A 60day incubation in selected samples resulted in 39-86% additional sulfide production. H2S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H2S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating the importance of assays to estimate the microbial sulfide production

  6. Hydrogen sulfide inhibits the translational expression of hypoxia-inducible factor-1α

    PubMed Central

    Wu, Bo; Teng, Huajian; Yang, Guangdong; Wu, Lingyun; Wang, Rui

    2012-01-01

    BACKGROUND AND PURPOSE The accumulation of hypoxia-inducible factor-1α (HIF-1α) is under the influence of hydrogen sulfide (H2S), which regulates hypoxia responses. The regulation of HIF-1α accumulation by H2S has been shown, but the mechanisms for this effect are largely elusive and controversial. This study aimed at addressing the controversial mechanisms for and the functional importance of the interaction of H2S and HIF-1α protein. EXPERIMENTAL APPROACH HIF-1α protein levels and HIF-1α transcriptional activity were detected by Western blotting and luciferase assay. The mechanisms for H2S-regulated HIF-1α protein levels were determined using short interfering RNA transfection, co-immunoprecipitation and 7-methyl-GTP sepharose 4B pull-down assay. Angiogenic activity was evaluated using tube formation assay in EA.hy926 cells. KEY RESULTS The accumulation of HIF-1α protein under hypoxia (1% O2) or hypoxia-mimetic conditions was reversed by sodium hydrosulfide (NaHS). This effect of NaHS was not altered after blocking the ubiquitin-proteasomal pathway for HIF-1α degradation; however, blockade of protein translation with cycloheximide abolished the effect of NaHS on the half-life of HIF-1α protein. Knockdown of eukaryotic translation initiation factor 2α (eIF2α) suppressed the effect of NaHS on HIF-1α protein accumulation under hypoxia. NaHS inhibited the expression of VEGF under hypoxia. It also decreased in vitro capillary tube formation and cell proliferation of EA.hy926 cells under hypoxia, but stimulated the tube formation under normoxia. CONCLUSIONS AND IMPLICATIONS H2S suppresses HIF-1α translation by enhancing eIF2α phosphorylation under hypoxia. The interaction of H2S and HIF-1α inhibits the angiogenic activity of vascular endothelial cells under hypoxia through the down-regulation of VEGF. PMID:22831549

  7. Spectroscopic investigations into the binding of hydrogen sulfide to synthetic picket-fence porphyrins.

    PubMed

    Hartle, Matthew D; Prell, James S; Pluth, Michael D

    2016-03-21

    The reversible binding of hydrogen sulfide (H2S) to hemeprotein sites has been attributed to several factors, likely working in concert, including the protected binding pocket environment, proximal hydrogen bond interactions, and iron ligation environment. To investigate the importance of a sterically-constrained, protected environment on sulfide reactivity with heme centers, we report here the reactivity of H2S and HS(-) with the picket-fence porphyrin system. Our results indicate that the picket-fence porphyrin does not bind H2S in the ferric or ferrous state. By contrast, reaction of the ferric scaffold with HS(-) results in reduction to the ferrous species, followed by ligation of one equivalent of HS(-), as evidenced by UV-vis, NMR spectroscopy and mass spectrometry studies. Measurement of the HS(-) binding affinities in the picket-fence or tetraphenyl porphyrin systems revealed identical binding. Taken together, these results suggest that the protected, sterically-constrained binding pocket alone is not the primary contributor for stabilization of ferric H2S/HS(-) species in model systems, but that other interactions, such as hydrogen bonding, must play a critical role in facilitation of reversible interactions in ferric hemes. PMID:26869340

  8. A systematic review of occupational exposure to hydrogen sulfide in livestock operations.

    PubMed

    Guarrasi, Justene; Trask, Catherine; Kirychuk, Shelley

    2015-01-01

    This systematic review summarizes the current state of knowledge in hydrogen sulfide (H2S) concentrations within intensive livestock operations. The review was undertaken to better understand H2S concentrations in intensive livestock operations, in relation to the American Conference of Governmental Industrial Hygienists (ACGIH) limit reduction to a 1 ppm time-weighted average (TWA). Several online academic databases were searched using two conceptual groups of search terms: "livestock" and "hydrogen sulfide." Industry gray literature was additionally identified via targeted searches of online agriculture-specific Web sites. Title, abstract, and full-text screening were performed to select articles reporting H2S measurements made within livestock facilities. Forty-five articles were included in this review. The bulk (70%) of articles described swine operations, whereas the remaining represented poultry and dairy operations. Although 14% of the articles described task-based monitoring of H2S, the majority of articles (86%) involved only area monitoring. Weighted means from all three livestock types were below 1 ppm, although swine operations displayed a wider range of exposure (from 0 to 97 ppm). Despite most mean task-based exposures being close to 1 ppm, the peak concentrations measurements may be higher during power washing (97 ppm) and miscellaneous tasks (11.4 ppm). This review provides a novel overview of H2S levels in intensive livestock operations, including information on task-based measurements. The review highlights numerous influences that produce a wide variability of H2S levels in intensive livestock operations. The review also highlights the need for research focused on personal monitoring of daily worker exposures to hydrogen sulfide in intensive livestock operations. PMID:25906281

  9. Hydrogen sulfide and sodium nitroprusside compete to activate/deactivate MMPs in bone tissue homogenates

    PubMed Central

    Vacek, Thomas P; Qipshidze, Natia; Tyagi, Suresh C

    2013-01-01

    Background Bone microvascular remodeling is the primary predictor of bone structure and function. Remodeling by its very nature implies synthesis and degradation of the extracellular matrix. Normally, 50% of total protein in the vessel wall is elastin. During remodeling, elastin is degraded by specialized matrix metalloproteinases (MMPs). Because the turnover of elastin is 1000-fold slower than that of collagen, most of the elastin is replaced by stiffer collagen. Stiffer vessels impose pressure on the aortic valve, causing regurgitation and increased pulse pressure. On the other hand, high MMP activity will cause vascular dilatation, leading to aneurysm. Therefore, balanced constitutive remodeling is necessary for adequate bone structure and function. Interestingly, collagen-degrading MMPs are involved in various pathological conditions, including osteoporosis, osteoarthritis, and cardiovascular disease. Sodium nitroprusside is a nitric oxide donor that could potentially alter MMP activity via vasodilation in vivo, but can also produce peroxynitrite, which activates MMPs by combining with superoxide. Moreover, hydrogen sulfide is a known antioxidant as well as a vasodilator, and is also speculated to contribute directly to MMP activity. We hypothesized that hydrogen sulfide reduced activity of MMP in ex vivo bone tissue homogenates and that sodium nitroprusside would increase MMP activity in vitro. Methods We surgically removed the tibia and femur from anesthetized mice, and prepared bone tissue homogenates using a mortar and pestle, measured the protein concentration with a spectrophotometer, and detected MMP activity using gelatin gel zymography. Results Our data showed increased MMP activity at a sodium nitroprusside concentration of 1 μM, and MMP activity increased exponentially. There was a decrease in MMP activity with increasing hydrogen sulfide, beginning at 16 μM (P < 0.01) and continuing to 40 μM. Moreover, sodium nitroprusside 3 μM was able to

  10. Release of hydrogen sulfide by asteroid impacts in Black Sea and risks for inland human population.

    PubMed

    Badescu, Viorel

    2007-10-01

    The hydrogen sulfide rich waters of the Black Sea pose a potential danger for the surrounding land regions. The impact of an asteroid may cause a catastrophic poisonous gas release in the atmosphere. Some effects of this last phenomenon on the Eastern Black Sea coastal regions are evaluated in this article. Two simple models are proposed to describe the generation of the H(2)S cloud. The initial diameter of the cloud depends on asteroid size. The initial thickness of the cloud depends, in addition, on sea depth at impact location. The wind speed plays an important role in H(2)S cloud dynamics. At 10 m/s wind-speed the cloud margins may be seen at about 150 km from impact location in about 3.2 h. The maximum distance traveled by the hydrogen sulfide cloud increases by increasing the asteroid size and wind speed. The influence of the impact position on the distance traveled by hydrogen sulfide clouds is rather weak, as far as the seawater depth does not change significantly. Two values are considered when referring to the effect of hydrogen sulfide concentrations on humans: the lower concentration limit of 19.88 ppm (which corresponds to fatigue, loss of appetite, headache, irritability, poor memory, dizziness) and the upper concentration limit of 497 ppm (which corresponds to death after single exposures). The land surface area covered by the H(2)S cloud generated by a 1000 m size asteroid during the run-in ranges between about 6080 and 11,520 km(2). This may affect between 145,000 and 276,000 people. When a 250 m size asteroid is considered, the covered land surface area ranges between about 840 and 1,890 km(2) and between 20,000 and 45,000 people may be affected. In case of a 70 m size asteroid, the cloud covers up to 105 km(2) of land during the run-in. This may affect about 2500 people. These are moderate estimates. They do not include the urban population and may be 10 times underestimated for some particular wind directions. General recommendations to diminish

  11. Hydrogen sulfide and PKG in ischemia-reperfusion injury: sources, signaling, accelerators and brakes

    PubMed Central

    Andreadou, Ioanna; Iliodromitis, Efstathios K.; Szabo, Csaba; Papapetropoulos, Andreas

    2015-01-01

    Over the past decade, hydrogen sulfide has emerged as an important cardioprotective molecule with potential for clinical applications. Although several pathways have been proposed to mediate the beneficial effects of H2S, the NO and cGMP axis has attracted significant attention. Recent evidence has suggested that cGMP-dependent protein kinase can lie both downstream and upstream of H2S. The current literature on this topic is reviewed and data from recent studies are integrated to propose a unifying model. PMID:26318600

  12. Hydrogen sulfide-based therapeutics: exploiting a unique but ubiquitous gasotransmitter.

    PubMed

    Wallace, John L; Wang, Rui

    2015-05-01

    Hydrogen sulfide (H2S) has become recognized as an important signalling molecule throughout the body, contributing to many physiological and pathological processes. In recent years, improved methods for measuring H2S levels and the availability of a wider range of H2S donors and more selective inhibitors of H2S synthesis have helped to more accurately identify the many biological effects of this highly reactive gaseous mediator. Animal studies of several H2S-releasing drugs have demonstrated considerable promise for the safe treatment of a wide range of disorders. Several such drugs are now in clinical trials.

  13. Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors

    SciTech Connect

    Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

    2014-10-14

    A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.

  14. Hydrogen Formation by Proton Impact on Positronium

    SciTech Connect

    Merrison, J.; Bluhme, H.; Chevallier, J.; Deutch, B.; Hvelplund, P.; Jo Knudsen, H.; Poulsen, M.; Charlton, M.

    1997-04-01

    Hydrogen formation has been observed following proton impact on positronium. This is the first observation of charge exchange involving a positronium target. The cross section for hydrogen formation has been experimentally determined at proton energies of 11.3, 13.3, and 15.8keV. Values of {sigma}{sub H}=26({plus_minus}9), 7.8({plus_minus}2.3), and 7.6({plus_minus}4.4){times}10{sup -16}cm{sup 2} were obtained, in reasonable agreement with recent calculations. {copyright} {ital 1997} {ital The American Physical Society}

  15. Effect of hydrogen sulfide on aqueous corrosion of commercially pure Al 99.5

    SciTech Connect

    Bjoergum, A.; Sigurdsson, H.; Nisancioglu, K.

    1995-08-01

    Recently, there has been interest in the use of aluminum alloys as possible alternatives to carbon steel for handling oilfield products, such as brines with dissolved carbon dioxide (CO{sub 2}) and H{sub 2}S. The effect of hydrogen sulfide on the corrosion behavior of commercially pure aluminum (DIN Al 99.5 [AA 1050A]) in chloride solutions containing carbon dioxide, bicarbonate, and copper ions at 30 C and 80 C was investigated using natural immersion corrosion tests, cathodic polarization, and scanning electron microscopy. The highest corrosion rates were observed in solutions containing Cu{sup 2+} but with no H{sub 2}S content because of copper deposition on the metal surface. Significant pitting occurred at 80 C. With H{sub 2}S in the solution, pitting corrosion was eliminated by removal of Cu{sup 2+} and other deleterious heavy-metal ion impurities form the solution in the form of insoluble sulfides. If H{sub 2}S was introduced after the copper deposited on the aluminum surface, no inhibiting effect was detected at 30 C, but a degree of inhibition still was observed at 80 C, presumably because the deposited copper was converted more effectively into copper sulfide at the higher temperature.

  16. Effect of inoculum and sulfide type on simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry and microbial mechanism.

    PubMed

    Wang, Lan; Wei, Benping; Chen, Ziai; Deng, Liangwei; Song, Li; Wang, Shuang; Zheng, Dan; Liu, Yi; Pu, Xiaodong; Zhang, Yunhong

    2015-12-01

    Four reactors were initiated to study the effect of inoculum and sulfide type on the simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry (Ssu-Nir) process. Anaerobic sludge, aerobic sludge, and water were used as inocula, and Na2S and biogas were used as a sulfide substrate, respectively. Additionally, 454 pyrosequencing of the 16S rRNA gene was used to explore the bacterial diversity. The results showed that sulfur-oxidizing bacteria (Thiobacillus, 42.2-84.4 %) were dominant in Ssu-Nir process and led to the excellent performance. Aerobic sludge was more suitable for inoculation of the Ssu-Nir process because it is better for rapidly enriching dominant sulfur-oxidizing bacteria (Thiobacillus, 54.4 %), denitrifying sulfur-oxidizing bacteria (40.0 %) and denitrifiers (23.9 %). Lower S(2-) removal efficiency (72.6 %) and NO3 (-) removal efficiency (<90 %) of the Ssu-Nir process were obtained using biogas as a sulfide substrate than when Na2S was used. For the Ssu-Nir process with biogas as the sulfide substrate, limiting H2S absorption caused a high relative abundance of sulfur-oxidizing bacteria, Thiobacillus (84.8 %) and Thiobacillus sayanicus (39.6 %), which in turn led to low relative abundance of denitrifiers (1.6 %) and denitrifying sulfur-oxidizing bacteria (24.4 %), low NO3 (-) removal efficiency, and eventually poor performance. PMID:26286512

  17. Effect of inoculum and sulfide type on simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry and microbial mechanism.

    PubMed

    Wang, Lan; Wei, Benping; Chen, Ziai; Deng, Liangwei; Song, Li; Wang, Shuang; Zheng, Dan; Liu, Yi; Pu, Xiaodong; Zhang, Yunhong

    2015-12-01

    Four reactors were initiated to study the effect of inoculum and sulfide type on the simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry (Ssu-Nir) process. Anaerobic sludge, aerobic sludge, and water were used as inocula, and Na2S and biogas were used as a sulfide substrate, respectively. Additionally, 454 pyrosequencing of the 16S rRNA gene was used to explore the bacterial diversity. The results showed that sulfur-oxidizing bacteria (Thiobacillus, 42.2-84.4 %) were dominant in Ssu-Nir process and led to the excellent performance. Aerobic sludge was more suitable for inoculation of the Ssu-Nir process because it is better for rapidly enriching dominant sulfur-oxidizing bacteria (Thiobacillus, 54.4 %), denitrifying sulfur-oxidizing bacteria (40.0 %) and denitrifiers (23.9 %). Lower S(2-) removal efficiency (72.6 %) and NO3 (-) removal efficiency (<90 %) of the Ssu-Nir process were obtained using biogas as a sulfide substrate than when Na2S was used. For the Ssu-Nir process with biogas as the sulfide substrate, limiting H2S absorption caused a high relative abundance of sulfur-oxidizing bacteria, Thiobacillus (84.8 %) and Thiobacillus sayanicus (39.6 %), which in turn led to low relative abundance of denitrifiers (1.6 %) and denitrifying sulfur-oxidizing bacteria (24.4 %), low NO3 (-) removal efficiency, and eventually poor performance.

  18. Formation of Molecular Hydrogen in the ISM

    NASA Astrophysics Data System (ADS)

    Vidali, Gianfranco; Pirronello, V.; Biham, O.

    2008-05-01

    The ubiquitous presence of molecular hydrogen in very different environments of the interstellar medium (from diffuse to dark clouds and photodissociating regions) poses considerable challenges in explaining its formation. In these environments, it is believed that molecular hydrogen forms on dust grains, but the understanding of the actual processes and rates leading to its formation is unsatisfactory. I'll describe the type of information that can be extracted from carefully designed experiments and how experimentally determined physical parameters are used in theoretical calculations to yield molecular hydrogen formation rates in actual ISM environments. Our most recent investigation on the recombination reaction of hydrogen atoms on amorphous silicates1,2 reveals the importance of understanding and quantifying the basic physical-chemical processes at grain surfaces. This work was supported by NASA through NASA NNG06GD84G, and NSF AST-0507405 (G.V.), by the Israel Science Foundation and the Adler Foundation for Space Research (Ofer Biham), and by the Italian Ministry for University and Scientific Research through Grant 21043088 (Valerio Pirronello) 1. H.B.Perets, A.Lederhendler, O.Biham, G.Vidali, L. Li, S.Swords, E.Congiu, J. Roser, G.Manico', J.R.Brucato, V.Pirronello: "Molecular Hydrogen Formation on Amorphous Silicates Under Interstellar Conditions" Ap.J. 661, L163 (2007). 2. G.Vidali, V.Pirronello, L.Li, J.Roser, G.Manico', H.Mehl, A.Lederhendler, H.B.Perets, J.R.Brucato, and O.Biham: "Analysis of Molecular Hydrogen Formation on Low Temperature Surfaces in Temperature Programmed Desorption Experiments", J.Phys.Chem. A, 111, 12611 (2007).

  19. Dissolved sulfide-catalyzed precipitation of disordered dolomite: Implications for the formation mechanism of sedimentary dolomite

    NASA Astrophysics Data System (ADS)

    Zhang, Fangfu; Xu, Huifang; Konishi, Hiromi; Kemp, Joshua M.; Roden, Eric E.; Shen, Zhizhang

    2012-11-01

    Dolomite is a common mineral in the rock record. However, the rarity of modern dolomite and the notorious difficulty in synthesizing dolomite abiotically under normal Earth-surface conditions result in the long-standing “dolomite problem” in sedimentary geology. Some modern dolomites are associated with sediments where microbial sulfate reduction is active; however, the role of sulfate-reducing bacteria in dolomite formation is still under debate. In this study, we tested the effect of dissolved sulfide on the precipitation of Ca-Mg carbonates, which has been never explored before although dissolved sulfide is one of the major products of microbial sulfate reduction. Our results demonstrated that dissolved sulfide with a concentration of as low as several millimoles can enhance the Mg2+ incorporation into the calcitic structure, and promote the crystallization of high magnesian calcite and disordered dolomite. We also conducted seeded precipitation in experimental solutions containing dissolved sulfide, which showed that calcite seeds can inhibit the precipitation of aragonite and monohydrocalcite (CaCO3·H2O), and induce more Mg2+ incorporation. We propose that accumulated dissolved sulfide in pore waters in organic-rich sediments may trigger the precipitation of disordered dolomite which can be considered as a precursor of some sedimentary dolomite. Our adsorption experiments revealed a strong adsorption of dissolved sulfide onto calcite faces. We suggest that adsorbed dissolved sulfide can lower the energy barrier to the dehydration of Mg2+-water complexes on the growing carbonate surfaces. This study sheds new light on understanding the role of sulfate-reducing bacteria in dolomite formation and the formation mechanism of sedimentary dolomite.

  20. A metal sulfide photocatalyst composed of ubiquitous elements for solar hydrogen production.

    PubMed

    Shiga, Y; Umezawa, N; Srinivasan, N; Koyasu, S; Sakai, E; Miyauchi, M

    2016-06-14

    A visible-light-sensitive tin sulfide photocatalyst was designed based on a ubiquitous element strategy and density functional theory (DFT) calculations. Computational analysis suggested that tin monosulfide (SnS) would be more efficient than SnS2 as a photocathode for hydrogen production because of the low ionization potential and weak ionic character of SnS. To test this experimentally, nanoparticles of SnS were loaded onto a mesoporous electrode using a wet chemical method, and the bandgap of the synthesized SnS quantum dots was found to be tunable by adjusting the number of successive ionic layer adsorption and reaction (SILAR) cycles, which controls the magnitude of the quantum confinement effect. Efficient hydrogen production was achieved when the bandgap of SnS was wider than that of the bulk form.

  1. Tungsten sulfide enhancing solar-driven hydrogen production from silicon nanowires.

    PubMed

    Huang, Zhipeng; Wang, Chifang; Chen, Zhibo; Meng, Hua; Lv, Cuncai; Chen, Zhongzhong; Han, Ruqu; Zhang, Chi

    2014-07-01

    Tungsten sulfides, including WS2 (crystalline) and WS3 (amorphous), were introduced to silicon nanowires, and both can promote the photoelectrochemical hydrogen production of silicon nanowires. In addition, more enhancement of energy conversion efficiency can be achieved by the loading of WS3, in comparison with loading of WS2. Polarization curves of WS3 and WS2 suggest that WS3 has higher catalytic activity in the hydrogen evolution reaction than WS2, affording higher energy conversion efficiency in silicon nanowires decorated with WS3. The higher electrocatalytic activity of WS3 correlates with the amorphous structure of WS3 and larger surface area of WS3, which result in more active sites in comparison with crystalline WS2.

  2. Physiological Implications of Hydrogen Sulfide in Plants: Pleasant Exploration behind Its Unpleasant Odour

    PubMed Central

    Jin, Zhuping

    2015-01-01

    Recently, overwhelming evidence has proven that hydrogen sulfide (H2S), which was identified as a gasotransmitter in animals, plays important roles in diverse physiological processes in plants as well. With the discovery and systematic classification of the enzymes producing H2S in vivo, a better understanding of the mechanisms by which H2S influences plant responses to various stimuli was reached. There are many functions of H2S, including the modulation of defense responses and plant growth and development, as well as the regulation of senescence and maturation. Additionally, mounting evidence indicates that H2S signaling interacts with plant hormones, hydrogen peroxide, nitric oxide, carbon monoxide, and other molecules in signaling pathways. PMID:26078806

  3. Measurement, analysis, and modeling of hydrogen sulfide emissions from a swine facility in North Carolina

    NASA Astrophysics Data System (ADS)

    Blunden, Jessica

    Annual global source contributions of sulfur compounds to the natural atmospheric environment are estimated to be 142 x 106 tons. Although not quantified, volatilization from animal wastes may be an important source of gaseous reduced sulfur compounds. Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive "rotten egg" odor. Once released into the atmosphere, H 2S is oxidized and the eventual byproduct, sulfuric acid, may combine with other atmospheric constituents to form aerosol products such as ammonium bisulfate and ammonium sulfate. In recent years, confined animal feeding operations (CAFOs) have increased in size, resulting in more geographically concentrated areas of animals and, subsequently, animal waste. In North Carolina and across the southeastern United States anaerobic waste treatment lagoons are traditionally used to store and treat hog excreta at commercial hog farms. Currently, no state regulations exist for H2S gaseous emissions from animal production facilities in North Carolina and the amount of H2S being emitted into the atmosphere from these potential sources is widely unknown. In response to the need for data, this research initiative has been undertaken in an effort to quantify emissions of H2S from swine CAFOs. An experimental study was conducted at a commercial swine farm in eastern North Carolina to measure hydrogen sulfide emissions from a hog housing unit utilizing a mechanical fan ventilation system and from an on-site waste storage treatment lagoon. A dynamic flow-through chamber system was employed to make lagoon flux measurements. Semi-continuous measurements were made over a one-year period (2004-2005) for a few days during each of the four predominant seasons in order to assess diurnal and temporal variability in emissions. Fan rpm from the barn was continuously measured and flow rates were calculated in order to accurately assess gaseous emissions from the system

  4. Application of bacteriophages to reduce biofilms formed by hydrogen sulfide producing bacteria on surfaces in a rendering plant.

    PubMed

    Gong, Chao; Jiang, Xiuping

    2015-08-01

    Hydrogen sulfide producing bacteria (SPB) in raw animal by-products are likely to grow and form biofilms in the rendering processing environments, resulting in the release of harmful hydrogen sulfide (H2S) gas. The objective of this study was to reduce SPB biofilms formed on different surfaces typically found in rendering plants by applying a bacteriophage cocktail. Using a 96-well microplate method, we determined that 3 SPB strains of Citrobacter freundii and Hafnia alvei are strong biofilm formers. Application of 9 bacteriophages (10(7) PFU/mL) from families of Siphoviridae and Myoviridae resulted in a 33%-70% reduction of biofilm formation by each SPB strain. On stainless steel and plastic templates, phage treatment (10(8) PFU/mL) reduced the attached cells of a mixed SPB culture (no biofilm) by 2.3 and 2.7 log CFU/cm(2) within 6 h at 30 °C, respectively, as compared with 2 and 1.5 log CFU/cm(2) reductions of SPB biofilms within 6 h at 30 °C. Phage treatment was also applied to indigenous SPB biofilms formed on the environmental surface, stainless steel, high-density polyethylene plastic, and rubber templates in a rendering plant. With phage treatment (10(9) PFU/mL), SPB biofilms were reduced by 0.7-1.4, 0.3-0.6, and 0.2-0.6 log CFU/cm(2) in spring, summer, and fall trials, respectively. Our study demonstrated that bacteriophages could effectively reduce the selected SPB strains either attached to or in formed biofilms on various surfaces and could to some extent reduce the indigenous SPB biofilms on the surfaces in the rendering environment. PMID:26102989

  5. Application of bacteriophages to reduce biofilms formed by hydrogen sulfide producing bacteria on surfaces in a rendering plant.

    PubMed

    Gong, Chao; Jiang, Xiuping

    2015-08-01

    Hydrogen sulfide producing bacteria (SPB) in raw animal by-products are likely to grow and form biofilms in the rendering processing environments, resulting in the release of harmful hydrogen sulfide (H2S) gas. The objective of this study was to reduce SPB biofilms formed on different surfaces typically found in rendering plants by applying a bacteriophage cocktail. Using a 96-well microplate method, we determined that 3 SPB strains of Citrobacter freundii and Hafnia alvei are strong biofilm formers. Application of 9 bacteriophages (10(7) PFU/mL) from families of Siphoviridae and Myoviridae resulted in a 33%-70% reduction of biofilm formation by each SPB strain. On stainless steel and plastic templates, phage treatment (10(8) PFU/mL) reduced the attached cells of a mixed SPB culture (no biofilm) by 2.3 and 2.7 log CFU/cm(2) within 6 h at 30 °C, respectively, as compared with 2 and 1.5 log CFU/cm(2) reductions of SPB biofilms within 6 h at 30 °C. Phage treatment was also applied to indigenous SPB biofilms formed on the environmental surface, stainless steel, high-density polyethylene plastic, and rubber templates in a rendering plant. With phage treatment (10(9) PFU/mL), SPB biofilms were reduced by 0.7-1.4, 0.3-0.6, and 0.2-0.6 log CFU/cm(2) in spring, summer, and fall trials, respectively. Our study demonstrated that bacteriophages could effectively reduce the selected SPB strains either attached to or in formed biofilms on various surfaces and could to some extent reduce the indigenous SPB biofilms on the surfaces in the rendering environment.

  6. Analysis of Japanese Articles about Suicides Involving Charcoal Burning or Hydrogen Sulfide Gas

    PubMed Central

    Nabeshima, Yoshihiro; Onozuka, Daisuke; Kitazono, Takanari; Hagihara, Akihito

    2016-01-01

    It is well known that certain types of media reports about suicide can result in imitative suicides. In the last two decades, Japan has experienced two suicide epidemics and the subsequent excessive media coverage of these events. However, the quality of the media suicide reports has yet to be evaluated in terms of the guidelines for media suicide coverage. Thus, the present study analyzed Japanese newspaper articles (n = 4007) on suicides by charcoal burning or hydrogen sulfide gas between 11 February 2003 and 13 March 2010. The suicide reports were evaluated in terms of the extent to which they conformed to the suicide reporting guidelines. The mean violation scores were 3.06 (±0.7) for all articles, 3.2 (±0.8) for articles about suicide by charcoal burning, and 2.9 (±0.7) for articles about suicide by hydrogen sulfide (p < 0.001). With the exception of not following several recommendations, newspaper articles about suicide have improved in quality, as defined by the recommendations for media suicide coverage. To prevent imitative suicides based on media suicide reports, individuals in the media should try not to report suicide methods and to make attempts to report the poor condition of suicide survivors. PMID:27754453

  7. Effects of bamboo salt and its component, hydrogen sulfide, on enhancing immunity.

    PubMed

    Kim, Na-Rae; Nam, Sun-Young; Ryu, Ka-Jung; Kim, Hyung-Min; Jeong, Hyun-Ja

    2016-08-01

    Korean bamboo salt (BS) is known to have therapeutic effects in the treatment of diseases, including viral disease, dental plaque, diabetes, circulatory organ disorders, cancer and inflammatory disorders. However, the effect of BS on immune functions remains to be elucidated. The present study was designed to determine the immune‑enhancing effect of BS and its component, hydrogen sulfide, using RAW264.7 macrophages and a forced swimming test (FST) animal model. BS and sodium hydrosulfide (NaSH), a hydrogen sulfide donor, significantly increased the levels of tumor necrosis factor (TNF)‑α through the activation of nuclear factor‑κB in the RAW 264.7 cells. In an in vivo experiment, BS and NaSH were administered orally once a day for 28 days. After the 28 days, the immobility times in the FST were significantly decreased in the BS and NaSH‑fed groups, compared with the control group. In addition, BS and NaSH induced significant increases in the levels of interferon‑γ, interleukin‑2 and TNF‑α, compared with the control group. Taken together, these results indicated that BS and NaSH may improve immune function. PMID:27315400

  8. Carbon dioxide and hydrogen sulfide associations with regional bacterial diversity patterns in microbially induced concrete corrosion.

    PubMed

    Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

    2014-07-01

    The microbial communities associated with deteriorating concrete corrosion fronts were characterized in 35 samples taken from wastewater collection and treatment systems in ten utilities. Bacterial communities were described using Illumina MiSeq sequencing of the V1V2 region of the small subunit ribosomal ribonucleic acid (SSU-rRNA) gene recovered from fresh corrosion products. Headspace gas concentrations (hydrogen sulfide, carbon dioxide, and methane), pore water pH, moisture content, and select mineralogy were tested for correlation to community outcomes and corrosion extent using pairwise linear regressions and canonical correspondence analysis. Corroding concrete was most commonly characterized by moisture contents greater than 10%, pore water pH below one, and limited richness (<10 taxa). Bacterial community composition was not correlated to geographic location when considered independently from other environmental factors. Corrosion was most severe in sites with high levels of hydrogen sulfide (>100 ppm) and carbon dioxide (>1%) gases, conditions which also were associated with low diversity biofilms dominated by members of the acidophilic sulfur-oxidizer genus Acidithiobacillus. PMID:24842376

  9. Hydrogen sulfide donor sodium hydrosulfide-improved heat tolerance in maize and involvement of proline.

    PubMed

    Li, Zhong-Guang; Ding, Xiao-Jiao; Du, Pei-Fang

    2013-05-15

    Hydrogen sulfide (H2S) has long been considered as a phytotoxin, but nowadays as a cell signal molecule involved in growth, development, and the acquisition of stress tolerance in higher plants. In the present study, hydrogen sulfide donor, sodium hydrosulfide (NaHS), pretreatment markedly improved germination percentage of seeds and survival percentage of seedlings of maize under heat stress, and alleviated an increase in electrolyte leakage of roots, a decrease in tissue vitality and an accumulation of malondialdehyde (MDA) in coleoptiles of maize seedlings. In addition, pretreatment of NaHS could improve the activity of Δ(1)-pyrroline-5-carboxylate synthetase (P5CS) and lower proline dehydrogenase (ProDH) activity, which in turn induced accumulation of endogenous proline in maize seedlings. Also, application of proline could enhance endogenous proline content, followed by mitigated accumulation of MDA and increased survival percentage of maize seedlings under heat stress. These results suggest that sodium hydrosulfide pretreatment could improve heat tolerance of maize and the acquisition of this heat tolerance may be involved in proline.

  10. Effects of bamboo salt and its component, hydrogen sulfide, on enhancing immunity.

    PubMed

    Kim, Na-Rae; Nam, Sun-Young; Ryu, Ka-Jung; Kim, Hyung-Min; Jeong, Hyun-Ja

    2016-08-01

    Korean bamboo salt (BS) is known to have therapeutic effects in the treatment of diseases, including viral disease, dental plaque, diabetes, circulatory organ disorders, cancer and inflammatory disorders. However, the effect of BS on immune functions remains to be elucidated. The present study was designed to determine the immune‑enhancing effect of BS and its component, hydrogen sulfide, using RAW264.7 macrophages and a forced swimming test (FST) animal model. BS and sodium hydrosulfide (NaSH), a hydrogen sulfide donor, significantly increased the levels of tumor necrosis factor (TNF)‑α through the activation of nuclear factor‑κB in the RAW 264.7 cells. In an in vivo experiment, BS and NaSH were administered orally once a day for 28 days. After the 28 days, the immobility times in the FST were significantly decreased in the BS and NaSH‑fed groups, compared with the control group. In addition, BS and NaSH induced significant increases in the levels of interferon‑γ, interleukin‑2 and TNF‑α, compared with the control group. Taken together, these results indicated that BS and NaSH may improve immune function.

  11. Carbon dioxide and hydrogen sulfide associations with regional bacterial diversity patterns in microbially induced concrete corrosion.

    PubMed

    Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

    2014-07-01

    The microbial communities associated with deteriorating concrete corrosion fronts were characterized in 35 samples taken from wastewater collection and treatment systems in ten utilities. Bacterial communities were described using Illumina MiSeq sequencing of the V1V2 region of the small subunit ribosomal ribonucleic acid (SSU-rRNA) gene recovered from fresh corrosion products. Headspace gas concentrations (hydrogen sulfide, carbon dioxide, and methane), pore water pH, moisture content, and select mineralogy were tested for correlation to community outcomes and corrosion extent using pairwise linear regressions and canonical correspondence analysis. Corroding concrete was most commonly characterized by moisture contents greater than 10%, pore water pH below one, and limited richness (<10 taxa). Bacterial community composition was not correlated to geographic location when considered independently from other environmental factors. Corrosion was most severe in sites with high levels of hydrogen sulfide (>100 ppm) and carbon dioxide (>1%) gases, conditions which also were associated with low diversity biofilms dominated by members of the acidophilic sulfur-oxidizer genus Acidithiobacillus.

  12. Stable Isotope Measurements of Carbon Dioxide, Methane, and Hydrogen Sulfide Gas Using Frequency Modulation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Nowak-Lovato, K.

    2014-12-01

    Seepage from enhanced oil recovery, carbon storage, and natural gas sites can emit trace gases such as carbon dioxide, methane, and hydrogen sulfide. Trace gas emission at these locations demonstrate unique light stable isotope signatures that provide information to enable source identification of the material. Light stable isotope detection through surface monitoring, offers the ability to distinguish between trace gases emitted from sources such as, biological (fertilizers and wastes), mineral (coal or seams), or liquid organic systems (oil and gas reservoirs). To make light stable isotope measurements, we employ the ultra-sensitive technique, frequency modulation spectroscopy (FMS). FMS is an absorption technique with sensitivity enhancements approximately 100-1000x more than standard absorption spectroscopy with the advantage of providing stable isotope signature information. We have developed an integrated in situ (point source) system that measures carbon dioxide, methane and hydrogen sulfide with isotopic resolution and enhanced sensitivity. The in situ instrument involves the continuous collection of air and records the stable isotope ratio for the gas being detected. We have included in-line flask collection points to obtain gas samples for validation of isotopic concentrations using our in-house isotope ratio mass spectroscopy (IRMS). We present calibration curves for each species addressed above to demonstrate the sensitivity and accuracy of the system. We also show field deployment data demonstrating the capabilities of the system in making live dynamic measurements from an active source.

  13. Glutathione-garlic sulfur conjugates: slow hydrogen sulfide releasing agents for therapeutic applications.

    PubMed

    Bhuiyan, Ashif Iqbal; Papajani, Vilma Toska; Paci, Maurizio; Melino, Sonia

    2015-01-01

    Natural organosulfur compounds (OSCs) from Allium sativum L. display antioxidant and chemo-sensitization properties, including the in vitro inhibition of tumor cell proliferation through the induction of apoptosis. Garlic water- and oil-soluble allyl sulfur compounds show distinct properties and the capability to inhibit the proliferation of tumor cells. In the present study, we optimized a new protocol for the extraction of water-soluble compounds from garlic at low temperatures and the production of glutathionyl-OSC conjugates during the extraction. Spontaneously, Cys/GSH-mixed-disulfide conjugates are produced by in vivo metabolism of OSCs and represent active molecules able to affect cellular metabolism. Water-soluble extracts, with (GSGaWS) or without (GaWS) glutathione conjugates, were here produced and tested for their ability to release hydrogen sulfide (H2S), also in the presence of reductants and of thiosulfate:cyanide sulfurtransferase (TST) enzyme. Thus, the TST catalysis of the H2S-release from garlic OSCs and their conjugates has been investigated by molecular in vitro experiments. The antiproliferative properties of these extracts on the human T-cell lymphoma cell line, HuT 78, were observed and related to histone hyperacetylation and downregulation of GAPDH expression. Altogether, the results presented here pave the way for the production of a GSGaWS as new, slowly-releasing hydrogen sulfide extract for potential therapeutic applications. PMID:25608858

  14. Electrochemical behavior of silver sulfide

    SciTech Connect

    Drouven, B.U.E.

    1982-01-01

    The electrochemical behavior of silver sulfide in sulfuric acid as well as in nitric acid was studied using electrodes made from synthetic silver sulfide. The primary techniques used were potentiostatic, potentiodynamic, galvanostatic and corrosion cell experiments. The cathodic reaction of silver sulfide produces silver and hydrogen sulfide. This reaction mechanism is a sequential two step charge transfer involving a single electron in each step. Silver ions are produced from silver sulfide upon applying an anodic potential. The dissolution rate of silver sulfide can be so high that the formation of silver sulfate occurs which partially covers the silver sulfide surface and inhibits a further rate increase. The sulfur from the silver sulfide will be oxidized at low overpotentials to elemental sulfur; at high overpotentials, the oxidation to sulfate or bisulfate is observed. The results suggest that the catalysis of chalcopyrite by the addition of silver ions is caused by the formation and subsequent dissolution of silver sulfide leaving a porous layer behind. The understanding of the reaction mechanism of silver sulfide dissolution and its optimization will significantly improve the economic evaluation of industrial processes using the catalyzed leaching of chalcopyrite. The present knowledge of the catalysis indicates that other ions may be substituted for silver ions which would increase the feasibility of hydrometallurgical processes.

  15. Occurrence and distribution of color and hydrogen sulfide in water of the principal artesian aquifers in the Valdosta area, Georgia

    USGS Publications Warehouse

    Krause, Richard E.

    1976-01-01

    Hydrogen sulfide and color occur in objectionable amounts in ground water from the principal artesian aquifer in the Valdosta , Ga., area. Generally, water from wells south of Valdosta is high in hydrogen sulfide; water from wells north of the city is high in color. Water with high sulfate is likely to be a problem in wells deeper than about 540 ft. Heavy pumpage concentrated in a small area may cause high-sulfate water to migrate vertically upward into shallower wells. (Woodard-USGS)

  16. Hydrogen sulfide removal from coal gas by the metal-ferrite sorbents made from the heavy metal wastewater sludge.

    PubMed

    Tseng, Ting Ke; Chang, Han Ching; Chu, Hsin; Chen, Hung Ta

    2008-12-30

    The metal-ferrite (chromium-ferrite and zinc-ferrite) sorbents made from the heavy metal wastewater sludge have been developed for the hydrogen sulfide removal from coal gas. The high temperature absorption of hydrogen sulfide from coal gas with the metal-ferrite sorbent in a fixed bed reactor was conducted in this study. The metal-ferrite powders were the products of the ferrite process for the heavy metal wastewater treatment. The porosity analysis results show that the number of micropores of the sorbents after sulfidation and regeneration process decreases and the average pore size increases due to the acute endothermic and exothermic reactions during the sulfidation-regeneration process. The FeS, ZnS, and MnS peaks are observed on the sulfided sorbents, and the chromium extraction of the CFR6 can fulfill the emission standard of Taiwan EPA. The suitable sulfidation temperature range for chromium-ferrite sorbent is at 500-600 degrees C. In addition, effects of various concentrations of H2 and CO were also conducted in the present work at different temperatures. By increasing the H2 concentration, the sulfur sorption capacity of the sorbent decreases and an adverse result is observed in the case of increasing CO concentration. This can be explained via water-shift reaction.

  17. Water formation by surface O3 hydrogenation.

    PubMed

    Romanzin, C; Ioppolo, S; Cuppen, H M; van Dishoeck, E F; Linnartz, H

    2011-02-28

    Three solid state formation routes have been proposed in the past to explain the observed abundance of water in space: the hydrogenation reaction channels of atomic oxygen (O + H), molecular oxygen (O(2) + H), and ozone (O(3) + H). New data are presented here for the third scheme with a focus on the reactions O(3) + H, OH + H and OH + H(2), which were difficult to quantify in previous studies. A comprehensive set of H/D-atom addition experiments is presented for astronomically relevant temperatures. Starting from the hydrogenation/deuteration of solid O(3) ice, we find experimental evidence for H(2)O/D(2)O (and H(2)O(2)/D(2)O(2)) ice formation using reflection absorption infrared spectroscopy. The temperature and H/D-atom flux dependence are studied and this provides information on the mobility of ozone within the ice and possible isotope effects in the reaction scheme. The experiments show that the O(3) + H channel takes place through stages that interact with the O and O(2) hydrogenation reaction schemes. It is also found that the reaction OH + H(2) (OH + H), as an intermediate step, plays a prominent (less efficient) role. The main conclusion is that solid O(3) hydrogenation offers a potential reaction channel for the formation of water in space. Moreover, the nondetection of solid ozone in dense molecular clouds is consistent with the astrophysical picture in which O(3) + H is an efficient process under interstellar conditions.

  18. Hydrogen Sulfide-Mediated Polyamines and Sugar Changes Are Involved in Hydrogen Sulfide-Induced Drought Tolerance in Spinacia oleracea Seedlings

    PubMed Central

    Chen, Juan; Shang, Yu-Ting; Wang, Wen-Hua; Chen, Xi-Yan; He, En-Ming; Zheng, Hai-Lei; Shangguan, Zhouping

    2016-01-01

    Hydrogen sulfide (H2S) is a newly appreciated participant in physiological and biochemical regulation in plants. However, whether H2S is involved in the regulation of plant responses to drought stress remains unclear. Here, the role of H2S in the regulation of drought stress response in Spinacia oleracea seedlings is reported. First, drought stress dramatically decreased the relative water content (RWC) of leaves, photosynthesis, and the efficiency of PSII. Moreover, drought caused the accumulation of ROS and increased the MDA content. However, the application of NaHS counteracted the drought-induced changes in these parameters. Second, NaHS application increased the water and osmotic potential of leaves. Additionally, osmoprotectants such as proline and glycinebetaine (GB) content were altered by NaHS application under drought conditions, suggesting that osmoprotectant contributes to H2S-induced drought resistance. Third, the levels of soluble sugars and polyamines (PAs) were increased differentially by NaHS application in S. oleracea seedlings. Moreover, several genes related to PA and soluble sugar biosynthesis, as well as betaine aldehyde dehydrogenase (SoBADH), choline monooxygenase (SoCMO), and aquaporin (SoPIP1;2), were up-regulated by H2S under drought stress. These results suggest that H2S contributes to drought tolerance in S. oleracea through its effect on the biosynthesis of PAs and soluble sugars. Additionally, GB and trehalose also play key roles in enhancing S. oleracea drought resistance. PMID:27540388

  19. Hydrogen Sulfide-Mediated Polyamines and Sugar Changes Are Involved in Hydrogen Sulfide-Induced Drought Tolerance in Spinacia oleracea Seedlings.

    PubMed

    Chen, Juan; Shang, Yu-Ting; Wang, Wen-Hua; Chen, Xi-Yan; He, En-Ming; Zheng, Hai-Lei; Shangguan, Zhouping

    2016-01-01

    Hydrogen sulfide (H2S) is a newly appreciated participant in physiological and biochemical regulation in plants. However, whether H2S is involved in the regulation of plant responses to drought stress remains unclear. Here, the role of H2S in the regulation of drought stress response in Spinacia oleracea seedlings is reported. First, drought stress dramatically decreased the relative water content (RWC) of leaves, photosynthesis, and the efficiency of PSII. Moreover, drought caused the accumulation of ROS and increased the MDA content. However, the application of NaHS counteracted the drought-induced changes in these parameters. Second, NaHS application increased the water and osmotic potential of leaves. Additionally, osmoprotectants such as proline and glycinebetaine (GB) content were altered by NaHS application under drought conditions, suggesting that osmoprotectant contributes to H2S-induced drought resistance. Third, the levels of soluble sugars and polyamines (PAs) were increased differentially by NaHS application in S. oleracea seedlings. Moreover, several genes related to PA and soluble sugar biosynthesis, as well as betaine aldehyde dehydrogenase (SoBADH), choline monooxygenase (SoCMO), and aquaporin (SoPIP1;2), were up-regulated by H2S under drought stress. These results suggest that H2S contributes to drought tolerance in S. oleracea through its effect on the biosynthesis of PAs and soluble sugars. Additionally, GB and trehalose also play key roles in enhancing S. oleracea drought resistance. PMID:27540388

  20. Hydrogen Sulfide-Mediated Polyamines and Sugar Changes Are Involved in Hydrogen Sulfide-Induced Drought Tolerance in Spinacia oleracea Seedlings.

    PubMed

    Chen, Juan; Shang, Yu-Ting; Wang, Wen-Hua; Chen, Xi-Yan; He, En-Ming; Zheng, Hai-Lei; Shangguan, Zhouping

    2016-01-01

    Hydrogen sulfide (H2S) is a newly appreciated participant in physiological and biochemical regulation in plants. However, whether H2S is involved in the regulation of plant responses to drought stress remains unclear. Here, the role of H2S in the regulation of drought stress response in Spinacia oleracea seedlings is reported. First, drought stress dramatically decreased the relative water content (RWC) of leaves, photosynthesis, and the efficiency of PSII. Moreover, drought caused the accumulation of ROS and increased the MDA content. However, the application of NaHS counteracted the drought-induced changes in these parameters. Second, NaHS application increased the water and osmotic potential of leaves. Additionally, osmoprotectants such as proline and glycinebetaine (GB) content were altered by NaHS application under drought conditions, suggesting that osmoprotectant contributes to H2S-induced drought resistance. Third, the levels of soluble sugars and polyamines (PAs) were increased differentially by NaHS application in S. oleracea seedlings. Moreover, several genes related to PA and soluble sugar biosynthesis, as well as betaine aldehyde dehydrogenase (SoBADH), choline monooxygenase (SoCMO), and aquaporin (SoPIP1;2), were up-regulated by H2S under drought stress. These results suggest that H2S contributes to drought tolerance in S. oleracea through its effect on the biosynthesis of PAs and soluble sugars. Additionally, GB and trehalose also play key roles in enhancing S. oleracea drought resistance.

  1. Sodium tetraborate decahydrate treatment reduces hydrogen sulfide emissions and the sulfate reducing bacteria population of swine manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The emission of odorous and toxic gases from stored livestock manure is well documented, and poses a serious health risk to farmers and livestock. Hydrogen sulfide emissions have been sharply rising with more intensive livestock production and are of particular concern due to its acute toxicity. Num...

  2. Inhibitory Effects of Condensed Tannins on Sulfate-Reducing Bacteria Populations and Hydrogen Sulfide Production from Swine Manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Odorous compounds and emissions associated with consolidated storage of swine manure are produced as a result of anaerobic microbial digestion of materials present in the manure. Hydrogen sulfide (H2S) is one such offensive and toxic odorant that can reach hazardous levels during manure storage and...

  3. 40 CFR 60.5408 - What is an optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine. (b... leveling bottle. (c) Reagents. (1) Iodine stock solution, 0.1N. Weight 12.7 g iodine, and 20 to 25 g cp potassium iodide for each liter of solution. Dissolve KI in as little water as necessary; dissolve iodine...

  4. 40 CFR 60.5408 - What is an optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine. (b... leveling bottle. (c) Reagents. (1) Iodine stock solution, 0.1N. Weight 12.7 g iodine, and 20 to 25 g cp potassium iodide for each liter of solution. Dissolve KI in as little water as necessary; dissolve iodine...

  5. Combined borax and tannin treatment of stored dairy manure to reduce bacterial populations and hydrogen sulfide emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Anaerobic digestion of organic residues in stored livestock manure is associated with the production of odors and emissions. Hydrogen sulfide (H2S) is one such emission that can reach hazardous levels during manure storage and handling, posing a risk to both farmers and livestock. New te...

  6. Borax and Octabor Treatment of Stored Swine Manure: Reduction in Hydrogen Sulfide Emissions and Phytotoxicity to Agronomic Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gaseous emissions from stored manure have become environmental and health issues for humans and animals as the livestock industry becomes specialized and concentrated. Of particular concern is hydrogen sulfide, which is being targeted for regulatory control in concentrated animal farm operations. ...

  7. Borax and octabor treatment of stored swine manure to reduce sulfate reducing bacteria and hydrogen sulfide emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Odorous gas emissions from stored swine manure are becoming serious environmental and health issues as the livestock industry becomes more specialized, concentrated, and industrialized. These nuisance gasses include hydrogen sulfide (H2S), ammonia, and methane, which are produced as a result of ana...

  8. Investigation of the active sites of rhodium sulfide for hydrogen evolution/oxidation using carbon monoxide as a probe.

    PubMed

    Singh, Nirala; Upham, David C; Liu, Ru-Fen; Burk, Jonathan; Economou, Nick; Buratto, Steven; Metiu, Horia; McFarland, Eric W

    2014-05-20

    Carbon monoxide (CO) was observed to decrease the activity for hydrogen evolution, hydrogen oxidation, and H2-D2 exchange on rhodium sulfide, platinum, and rhodium metal. The temperature at which the CO was desorbed from the catalyst surface (detected by recovery in the H2-D2 exchange activity of the catalyst) was used as a descriptor for the CO binding energy to the active site. The differences in the CO desorption temperature between the different catalysts showed that the rhodium sulfide active site is not metallic rhodium. Using density functional theory, the binding energy of CO to the Rh sites in rhodium sulfide is found comparable to the binding energy on Pt. Coupled with experiment this supports the proposition that rhodium rather than sulfur atoms in the rhodium sulfide are the active site for the hydrogen reaction. This would indicate the active sites for hydrogen evolution/oxidation as well as oxygen reduction (determined by other groups using X-ray absorption spectroscopy) may be the same.

  9. Gas phase recovery of hydrogen sulfide contaminated polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Kakati, Biraj Kumar; Kucernak, Anthony R. J.

    2014-04-01

    The effect of hydrogen sulfide (H2S) on the anode of a polymer electrolyte membrane fuel cell (PEMFC) and the gas phase recovery of the contaminated PEMFC using ozone (O3) were studied. Experiments were performed on fuel cell electrodes both in an aqueous electrolyte and within an operating fuel cell. The ex-situ analyses of a fresh electrode; a H2S contaminated electrode (23 μmolH2S cm-2); and the contaminated electrode cleaned with O3 shows that all sulfide can be removed within 900 s at room temperature. Online gas analysis of the recovery process confirms the recovery time required as around 720 s. Similarly, performance studies of an H2S contaminated PEMFC shows that complete rejuvenation occurs following 600-900 s O3 treatment at room temperature. The cleaning process involves both electrochemical oxidation (facilitated by the high equilibrium potential of the O3 reduction process) and direct chemical oxidation of the contaminant. The O3 cleaning process is more efficient than the external polarization of the single cell at 1.6 V. Application of O3 at room temperature limits the amount of carbon corrosion. Room temperature O3 treatment of poisoned fuel cell stacks may offer an efficient and quick remediation method to recover otherwise inoperable systems.

  10. Hydrogen sulfide and reduced-sulfur gases adversely affect neurophysiological functions.

    PubMed

    Kilburn, K H; Warshaw, R H

    1995-01-01

    Hydrogen sulfide (H2S) above 50 parts per million (ppm) causes unconsciousness and death. Lower doses of H2S and related gases have been regarded as innocuous, but the effects of prolonged exposure have not been studied. This study was designed to determine whether people exposed to sulfide gases as a result of working at or living downwind from the processing of "sour" crude oil demonstrate persistent neurobehavioral dysfunction. Thirteen former workers and 22 neighbors of a refinery complained of headaches, nausea, vomiting, depression, personality changes, nosebleeds, and breathing difficulties. Their neurobehavioral functions and a profile of mood states (POMS) were compared to 32 controls, matched for age and educational level. The exposed subjects' mean values were statistically significantly abnormal compared to controls for two-choice reaction time, balance (as speed of sway), color discrimination, digit symbol, trail-making A and B, and immediate recall of a story. Their POMS scores were much higher than those of controls. Visual recall was significantly impaired in neighbors, but not in exworkers. It was concluded that neurophysiological abnormalities were associated with exposure to reduced sulfur gases, including H2S from crude oil desulfurization.

  11. Coordination polymer structure and revisited hydrogen evolution catalytic mechanism for amorphous molybdenum sulfide

    NASA Astrophysics Data System (ADS)

    Tran, Phong D.; Tran, Thu V.; Orio, Maylis; Torelli, Stephane; Truong, Quang Duc; Nayuki, Keiichiro; Sasaki, Yoshikazu; Chiam, Sing Yang; Yi, Ren; Honma, Itaru; Barber, James; Artero, Vincent

    2016-06-01

    Molybdenum sulfides are very attractive noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER) from water. The atomic structure and identity of the catalytically active sites have been well established for crystalline molybdenum disulfide (c-MoS2) but not for amorphous molybdenum sulfide (a-MoSx), which exhibits significantly higher HER activity compared to its crystalline counterpart. Here we show that HER-active a-MoSx, prepared either as nanoparticles or as films, is a molecular-based coordination polymer consisting of discrete [Mo3S13]2- building blocks. Of the three terminal disulfide (S22-) ligands within these clusters, two are shared to form the polymer chain. The third one remains free and generates molybdenum hydride moieties as the active site under H2 evolution conditions. Such a molecular structure therefore provides a basis for revisiting the mechanism of a-MoSx catalytic activity, as well as explaining some of its special properties such as reductive activation and corrosion. Our findings open up new avenues for the rational optimization of this HER electrocatalyst as an alternative to platinum.

  12. Hydrogen Sulfide Signaling Axis as a Target for Prostate Cancer Therapeutics

    PubMed Central

    Liu, Mingzhe; Wu, Lingyun; Montaut, Sabine; Yang, Guangdong

    2016-01-01

    Hydrogen sulfide (H2S) was originally considered toxic at elevated levels; however just in the past decade H2S has been proposed to be an important gasotransmitter with various physiological and pathophysiological roles in the body. H2S can be generated endogenously from L-cysteine by multiple enzymes, including cystathionine gamma-lyase, cystathionine beta-synthase, and 3-mercaptopyruvate sulfurtransferase in combination with cysteine aminotransferase. Prostate cancer is a major health concern and no effective treatment for prostate cancers is available. H2S has been shown to inhibit cell survival of androgen-independent, androgen-dependent, and antiandrogen-resistant prostate cancer cells through different mechanisms. Various H2S-releasing compounds, including sulfide salts, diallyl disulfide, diallyl trisulfide, sulforaphane, and other polysulfides, also have been shown to inhibit prostate cancer growth and metastasis. The expression of H2S-producing enzyme was reduced in both human prostate cancer tissues and prostate cancer cells. Androgen receptor (AR) signaling is indispensable for the development of castration resistant prostate cancer, and H2S was shown to inhibit AR transactivation and contributes to antiandrogen-resistant status. In this review, we summarized the current knowledge of H2S signaling in prostate cancer and described the molecular alterations, which may bring this gasotransmitter into the clinic in the near future for developing novel pharmacological and therapeutic interventions for prostate cancer. PMID:27019751

  13. Molecular Dynamics Simulations of Small Clusters and Liquid Hydrogen Sulfide at Different Thermodynamic Conditions.

    PubMed

    Albertí, M; Amat, A; Aguilar, A; Pirani, F

    2016-07-14

    A new force field for the intermolecular H2S-H2S interaction has been used to study the most relevant properties of the hydrogen sulfide system from gaseous to liquid phases by means of molecular dynamics (MD) simulations. In order to check the validity of the interaction formulation, ab initio CCSD(T)/aug-cc-pVTZ calculations, including the counterpoise correction on the H2S, (H2S)2, and (H2S)3 structures optimized at the MP2/aug-cc-pVDZ level, have been performed. The (H2S)2,3 systems have been characterized by performing NVE MD simulations at decreasing values of the temperature, while the liquid sulfide behavior has been investigated considering a NpT ensemble of 512 molecules at several thermodynamic states, defined by different pressure and temperature values. Additional calculations using an ensemble of 2197 molecules at two different temperatures have been performed to investigate the liquid/vapor interface of the system. The S-S, S-H, and H-H radial distribution functions and the coordination number, calculated at the same conditions used in X-ray and neutron diffraction experiments, and the evaluated thermodynamic and structural properties have been compared successfully with experimental data, thus confirming the reliability of the force field formulation and of the MD predictions.

  14. Coordination polymer structure and revisited hydrogen evolution catalytic mechanism for amorphous molybdenum sulfide.

    PubMed

    Tran, Phong D; Tran, Thu V; Orio, Maylis; Torelli, Stephane; Truong, Quang Duc; Nayuki, Keiichiro; Sasaki, Yoshikazu; Chiam, Sing Yang; Yi, Ren; Honma, Itaru; Barber, James; Artero, Vincent

    2016-06-01

    Molybdenum sulfides are very attractive noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER) from water. The atomic structure and identity of the catalytically active sites have been well established for crystalline molybdenum disulfide (c-MoS2) but not for amorphous molybdenum sulfide (a-MoSx), which exhibits significantly higher HER activity compared to its crystalline counterpart. Here we show that HER-active a-MoSx, prepared either as nanoparticles or as films, is a molecular-based coordination polymer consisting of discrete [Mo3S13](2-) building blocks. Of the three terminal disulfide (S2(2-)) ligands within these clusters, two are shared to form the polymer chain. The third one remains free and generates molybdenum hydride moieties as the active site under H2 evolution conditions. Such a molecular structure therefore provides a basis for revisiting the mechanism of a-MoSx catalytic activity, as well as explaining some of its special properties such as reductive activation and corrosion. Our findings open up new avenues for the rational optimization of this HER electrocatalyst as an alternative to platinum. PMID:26974410

  15. Electrically Conducting Polymer-Copper Sulphide Composite Films, Preparation by Treatment of Polymer-Copper (2) Acetate Composites with Hydrogen Sulfide

    NASA Technical Reports Server (NTRS)

    Yamamoto, Takakazu; Kamigaki, Takahira; Kubota, Etsuo

    1988-01-01

    Polymer copper sulfide composite films were prepared by treatment of polymer poly(vinyl chloride), poly(acrylonitrile), copolymer of vinyl chloride and vinyl acetate (90:10), and ABS resin copper (2) acetate composites with hydrogen sulfide. The films showed electrical conductivity higher than 0.015 S/cm when they contained more than 20 wt percent of copper sulfide. A poly(acrylonitrile)-copper sulfide composite film containing 40 to 50 wt percent of copper sulfide showed electrical conductivity of 10 to 150.0 S/cm and had relatively high mechanical strength to be used in practical purposes.

  16. Method of recovering elemental sulfur from reactive gases containing sulfur dioxide and hydrogen sulfide

    SciTech Connect

    Thomsen, A.

    1981-12-01

    Reactive gases containing sulfur dioxide and hydrogen sulfide, e.g. reaction gases of the claus process, are passed through a catalyst stage having an inlet side and an outlet side for the gas mixture to produce elemental sulfur and water. According to the invention the gases are cooled between the inlet and discharge sides by heat-exchanger means to a temperature not less than the activation temperature for the reaction and preferably not less than the temperature at which the gases are initially introduced into the catalyst body. The heat exchanger means can be provided in gaps between catalyst beds and/or within the catalyst beds of the body of catalyst.

  17. Reaction-based fluorescent probes for selective imaging of hydrogen sulfide in living cells.

    PubMed

    Lippert, Alexander R; New, Elizabeth J; Chang, Christopher J

    2011-07-01

    Hydrogen sulfide (H(2)S) is emerging as an important mediator of human physiology and pathology but remains difficult to study, in large part because of the lack of methods for selective monitoring of this small signaling molecule in live biological specimens. We now report a pair of new reaction-based fluorescent probes for selective imaging of H(2)S in living cells that exploit the H(2)S-mediated reduction of azides to fluorescent amines. Sulfidefluor-1 (SF1) and Sulfidefluor-2 (SF2) respond to H(2)S by a turn-on fluorescence signal enhancement and display high selectivity for H(2)S over other biologically relevant reactive sulfur, oxygen, and nitrogen species. In addition, SF1 and SF2 can be used to detect H(2)S in both water and live cells, providing a potentially powerful approach for probing H(2)S chemistry in biological systems.

  18. An Anticancer Role of Hydrogen Sulfide in Human Gastric Cancer Cells

    PubMed Central

    Qi, Qi; Yang, Jianqiang; Sun, Dongsheng; Li, Chunfeng; Xue, Yingwei; Jiang, Qiuying; Tian, Ye; Xu, Changqing; Wang, Rui

    2015-01-01

    Hydrogen sulfide (H2S) can be synthesized in mammalian cells by cystathionine γ-lyase (CSE) and/or cystathionine β-synthase (CBS). Both CSE and CBS are expressed in rat gastric tissues but their role in human gastric neoplasia has been unclear. The aims of the present study were to detect CSE and CBS proteins in human gastric cancer and determine the effect of exogenous NaHS on the proliferation of gastric cancer cells. We found that both CSE and CBS proteins were expressed in human gastric cancer cells and upregulated in human gastric carcinoma mucosa compared with those in noncancerous gastric samples. NaHS induced apoptosis of gastric cancer cells by regulating apoptosis related proteins. Also, NaHS inhibited cancer cell migration and invasion. An antigastric cancer role of H2S is thus indicated. PMID:26078811

  19. Hydrogen Sulfide Regulates Inward-Rectifying K+ Channels in Conjunction with Stomatal Closure1[OPEN

    PubMed Central

    Papanatsiou, Maria; Scuffi, Denisse; Blatt, Michael R.; García-Mata, Carlos

    2015-01-01

    Hydrogen sulfide (H2S) is the third biological gasotransmitter, and in animals, it affects many physiological processes by modulating ion channels. H2S has been reported to protect plants from oxidative stress in diverse physiological responses. H2S closes stomata, but the underlying mechanism remains elusive. Here, we report the selective inactivation of current carried by inward-rectifying K+ channels of tobacco (Nicotiana tabacum) guard cells and show its close parallel with stomatal closure evoked by submicromolar concentrations of H2S. Experiments to scavenge H2S suggested an effect that is separable from that of abscisic acid, which is associated with water stress. Thus, H2S seems to define a unique and unresolved signaling pathway that selectively targets inward-rectifying K+ channels. PMID:25770153

  20. Adsorption of hydrogen sulfide onto activated carbon fibers: effect of pore structure and surface chemistry.

    PubMed

    Feng, Wenguo; Kwon, Seokjoon; Borguet, Eric; Vidic, Radisav

    2005-12-15

    To understand the nature of H2S adsorption onto carbon surfaces under dry and anoxic conditions, the effects of carbon pore structure and surface chemistry were studied using activated carbon fibers (ACFs) with different pore structures and surface areas. Surface pretreatments, including oxidation and heattreatment, were conducted before adsorption/desorption tests in a fixed-bed reactor. Raw ACFs with higher surface area showed greater adsorption and retention of sulfur, and heat treatment further enhanced adsorption and retention of sulfur. The retained amount of hydrogen sulfide correlated well with the amount of basic functional groups on the carbon surface, while the desorbed amount reflected the effect of pore structure. Temperature-programmed desorption (TPD) and thermal gravimetric analysis (TGA) showed that the retained sulfurous compounds were strongly bonded to the carbon surface. In addition, surface chemistry of the sorbent might determine the predominant form of adsorbate on the surface. PMID:16475362

  1. Homocysteine in renovascular complications: hydrogen sulfide is a modulator and plausible anaerobic ATP generator

    PubMed Central

    Sen, Utpal; Pushpakumar, Sathnur B.; Amin, Matthew A.; Tyagi, Suresh C.

    2014-01-01

    Homocysteine (Hcy) is a non-protein amino acid derived from dietary methionine. High levels of Hcy, known as hyperhomocysteinemia (HHcy) is known to cause vascular complications. In the mammalian tissue, Hcy is metabolized by transsulfuration enzymes to produce hydrogen sulfide (H2S). H2S, a pungent smelling gas was previously known for its toxic effects in the central nervous system, recent studies however has revealed protective effects in a variety of diseases including hypertension, diabetes, inflammation, atherosclerosis, and renal disease progression and failure. Interestingly, under stress conditions including hypoxia, H2S can reduce metabolic demand and also act as a substrate for ATP production. This review highlights some of the recent advances in H2S research as a potential therapeutic agent targeting renovascular diseases associated with HHcy. PMID:24963795

  2. Intravital Microscopic Methods to Evaluate Anti-inflammatory Effects and Signaling Mechanisms Evoked by Hydrogen Sulfide

    PubMed Central

    Zuidema, Mozow Y.; Korthuis, Ronald J.

    2016-01-01

    Hydrogen sulfide (H2S) is an endogenous gaseous signaling molecule with potent anti-inflammatory properties. Exogenous application of H2S donors, administered either acutely during an inflammatory response or as an antecedent preconditioning intervention that invokes the activation of anti-inflammatory cell survival programs, effectively limits leukocyte rolling, adhesion and emigration, generation of reactive oxygen species, chemokine and cell adhesion molecule expression, endothelial barrier disruption,capillary perfusion deficits, and parenchymal cell dysfunction and injury. This chapter focuses on intravital microscopic methods that can be used to assess the anti-inflammatory effects exerted by H2S, as well as to explore the cellular signaling mechanisms by which this gaseous molecule limits the aforementioned inflammatory responses. Recent advances include use of intravital multiphoton microscopy and optical biosensor technology to explore signaling mechanisms in vivo. PMID:25747477

  3. Effect of partial charge parametrization on the fluid phase behavior of hydrogen sulfide.

    PubMed

    Kamath, Ganesh; Lubna, Nusrat; Potoff, Jeffrey J

    2005-09-22

    The effect of partial charge parametrization on the fluid phase behavior of hydrogen sulfide is investigated with grand canonical histogram reweighting Monte Carlo simulations. Four potential models, based on a Lennard-Jones + point charge functional form, are developed. It is shown that Lennard-Jones parameters can be tuned such that partial charges for the sulfur atom in the range -0.40 < q(s) < -0.252 will lead to an accurate reproduction of experimental vapor-liquid equilibria. Each of the parameter sets developed in this work are used to predict the pressure composition behavior H2S-n-pentane at 377.6 K. While the mixture calculation provides a means of reducing the number of candidate parameter sets, multiple parameter sets were found to yield an excellent reproduction of both the pure component and mixture phase behavior.

  4. A Hypothesis: Hydrogen Sulfide Might Be Neuroprotective against Subarachnoid Hemorrhage Induced Brain Injury

    PubMed Central

    Yu, Yong-Peng; Chi, Xiang-Lin; Liu, Li-Jun

    2014-01-01

    Gases such as nitric oxide (NO) and carbon monoxide (CO) play important roles both in normal physiology and in disease. Recent studies have shown that hydrogen sulfide (H2S) protects neurons against oxidative stress and ischemia-reperfusion injury and attenuates lipopolysaccharides (LPS) induced neuroinflammation in microglia, exhibiting anti-inflammatory and antiapoptotic activities. The gas H2S is emerging as a novel regulator of important physiologic functions such as arterial diameter, blood flow, and leukocyte adhesion. It has been known that multiple factors, including oxidative stress, free radicals, and neuronal nitric oxide synthesis as well as abnormal inflammatory responses, are involved in the mechanism underlying the brain injury after subarachnoid hemorrhage (SAH). Based on the multiple physiologic functions of H2S, we speculate that it might be a promising, effective, and specific therapy for brain injury after SAH. PMID:24707204

  5. Homocysteine in renovascular complications: hydrogen sulfide is a modulator and plausible anaerobic ATP generator.

    PubMed

    Sen, Utpal; Pushpakumar, Sathnur B; Amin, Matthew A; Tyagi, Suresh C

    2014-09-15

    Homocysteine (Hcy) is a non-protein amino acid derived from dietary methionine. High levels of Hcy, known as hyperhomocysteinemia (HHcy) is known to cause vascular complications. In the mammalian tissue, Hcy is metabolized by transsulfuration enzymes to produce hydrogen sulfide (H2S). H2S, a pungent smelling gas was previously known for its toxic effects in the central nervous system, recent studies however has revealed protective effects in a variety of diseases including hypertension, diabetes, inflammation, atherosclerosis, and renal disease progression and failure. Interestingly, under stress conditions including hypoxia, H2S can reduce metabolic demand and also act as a substrate for ATP production. This review highlights some of the recent advances in H2S research as a potential therapeutic agent targeting renovascular diseases associated with HHcy.

  6. Systematization of published spectral data on deuterated isotopologues of hydrogen sulfide molecule

    NASA Astrophysics Data System (ADS)

    Voronina, S. S.; Naumenko, O. V.; Polovtseva, E. R.; Fazliev, A. Z.

    2014-11-01

    The report presents a description of properties of published data on spectral lines parameters of deuterated isotopologues of hydrogen sulfide - HDS, HD34S, D2S, D2 34S. Properties values characterizing data quality are calculated taking into account the validity criteria and credit estimation according to publishing criteria. Formalized criteria of data check based on the constraints and selection rules known from the vibrational-rotational theory, as well as an expert evaluation are utilized for validation of the original experimental transitions and energy levels. The consistent and accurate set of the vibration - rotation (VR) energy levels is derived based on the cleaned transitions. Published vibrational-rotational transitions and energy levels of considered molecules as well as the knowledge base are available in the Internet in W@DIS information system (IS).

  7. Adsorption of hydrogen sulfide onto activated carbon fibers: effect of pore structure and surface chemistry.

    PubMed

    Feng, Wenguo; Kwon, Seokjoon; Borguet, Eric; Vidic, Radisav

    2005-12-15

    To understand the nature of H2S adsorption onto carbon surfaces under dry and anoxic conditions, the effects of carbon pore structure and surface chemistry were studied using activated carbon fibers (ACFs) with different pore structures and surface areas. Surface pretreatments, including oxidation and heattreatment, were conducted before adsorption/desorption tests in a fixed-bed reactor. Raw ACFs with higher surface area showed greater adsorption and retention of sulfur, and heat treatment further enhanced adsorption and retention of sulfur. The retained amount of hydrogen sulfide correlated well with the amount of basic functional groups on the carbon surface, while the desorbed amount reflected the effect of pore structure. Temperature-programmed desorption (TPD) and thermal gravimetric analysis (TGA) showed that the retained sulfurous compounds were strongly bonded to the carbon surface. In addition, surface chemistry of the sorbent might determine the predominant form of adsorbate on the surface.

  8. Exposure to low levels of hydrogen sulfide elevates circulating glucose in maternal rats

    SciTech Connect

    Hayden, L.J.; Goeden, H.; Roth, S.H. )

    1990-09-01

    Although the lethal effect of hydrogen sulfide (H{sub 2}S) has long been known, the results of exposure to low levels of H{sub 2}S have not been well documented. Rat dams and pups were exposed to low levels of H{sub 2}S (less than or equal to 75 ppm) from d 1 of gestation until d 21 postpartum and analyzed for changes in circulating enzymatic activity and metabolites. Blood glucose was significantly elevated in maternal blood on d 21 postpartum at all exposure levels. This increase in glucose was accompanied by a possible decrease in serum triglyceride in the pups and in the dams on d 21 postpartum. There was no evidence of alterations in serum alkaline phosphatase, lactate dehydrogenase, or serum glutamate oxaloacetate transaminase.

  9. Effects of a hydrogen sulfide donor on spontaneous contractile activity of rat stomach and jejunum.

    PubMed

    Shafigullin, M Y; Zefirov, R A; Sabirullina, G I; Zefirov, A L; Sitdikova, G F

    2014-07-01

    We studied the effect of sodium hydrosulfite (NaHS), a donor of hydrogen sulfide (H2S), on spontaneous contractive activity of isolated preparations of rat stomach and jejunum under isometric conditions. NaHS in concentrations of 10-200 μM reduced the amplitude, tonic tension, and frequency of contractions of the preparations. Blockade of K(+) channels with a non-specific antagonist tetraethylammonium (10 mM) increased contraction amplitude in the stomach strip and jejunum segment. The effects of NaHS on all parameters of contractile activity of the stomach and jejunum were fully preserved against the background of tetraethylammonium application. These data suggest that H2S in physiologically relevant concentrations inhibited spontaneous contractile activity of smooth muscle cells in rat stomach and jejunum by reducing the amplitude and frequency of contractions and decreased tonic tension without affecting the function of voltage- and calcium-dependent K(+) channels.

  10. Effective Hydrogen Generation from the Hydrogen Sulfide Solution by using Stratified Type Photocatalyst

    SciTech Connect

    Takahashi, H.; Yokoyama, S.; Baba, Y.; Hayashi, T.; Tohji, K.

    2008-02-25

    Stratified type photocatalyst with the extremely higher photocatalytic activities can be synthesized by using the chemical reaction between the Na{sub 2}S solution and Cd(OH){sub 2} precursors. This type of photocatalyst has the specific morphology which constructed by the nano-sized and capsule like formed structure, and the metal concentration was gradually changed in its wall. The 'charge gradient' was formed at the metal sulfide and oxide/hydroxide junction in the wall, which favored for the separation of the photo excited electron-hole pair. Consequently, stratified type photocatalyst shows the high catalytic activity than the usual nano CdS particles. By the addition of sulfur compound into the bio reactor contained the sulfur reducing bacteria, the H{sub 2}S gas concentration can increased to about 1000 times enlarge than the usual condition. Therefore, we can conclude that the enhancement of the H{sub 2}S gas evolved from the bio reactor was successfully achievement, and we don't need to afraid the shortage risk of H{sub 2}S supply. These H{sub 2}S gas concentration can enlarged to 80% by using A type zeorite. Especially, Ca-A type zeorite is considered as the suitable material.

  11. Contribution of cysteine aminotransferase and mercaptopyruvate sulfurtransferase to hydrogen sulfide production in peripheral neurons.

    PubMed

    Miyamoto, Ryo; Otsuguro, Ken-Ichi; Yamaguchi, Soichiro; Ito, Shigeo

    2014-07-01

    Hydrogen sulfide (H2 S) is a gaseous neuromodulator produced from L-cysteine. H2 S is generated by three distinct enzymatic pathways mediated by cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS), and mercaptopyruvate sulfurtransferase (MPST) coupled with cysteine aminotransferase (CAT). This study investigated the relative contributions of these three pathways to H2 S production in PC12 cells (rat pheochromocytoma-derived cells) and the rat dorsal root ganglion. CBS, CAT, and MPST, but not CSE, were expressed in the cells and tissues, and appreciable amounts of H2 S were produced from L-cysteine in the presence of α-ketoglutarate, together with dithiothreitol. The production of H2 S was inhibited by a CAT inhibitor (aminooxyacetic acid), competitive CAT substrates (L-aspartate and oxaloacetate), and RNA interference (RNAi) against MPST. Immunocytochemistry revealed a mitochondrial localization of MPST in PC12 cells and dorsal root ganglion neurons, and the amount of H2 S produced by CAT/MPST at pH 8.0, a physiological mitochondrial matrix pH, was comparable to that produced by CSE and CBS in the liver and the brain, respectively. Furthermore, H2 S production was markedly increased by alkalization. These results indicate that CAT and MPST are primarily responsible for H2 S production in peripheral neurons, and that the regulation of mitochondrial metabolism may influence neuronal H2 S generation. In the peripheral nervous system, hydrogen sulfide (H2 S) has been implicated in neurogenic pain or hyperalgesia. This study provides evidence that H2 S is synthesized in peripheral neurons through two mitochondrial enzymes, cysteine aminotransferase (CAT) and mercaptopyruvate sulfurtransferase (MPST). We propose that mitochondrial metabolism plays key roles in the physiology and pathophysiology of the peripheral nervous system via regulation of neuronal H2 S production. PMID:24611772

  12. Application of bacteriophages specific to hydrogen sulfide-producing bacteria in raw poultry by-products.

    PubMed

    Gong, Chao; Liu, Xiaohua; Jiang, Xiuping

    2014-03-01

    Hydrogen sulfide-producing bacteria (SPB) can spoil raw animal materials and release harmful hydrogen sulfide (H2S) gas. The objective of this study was to apply a SPB-specific bacteriophage cocktail to control H2S production by SPB in different raw poultry by-products in the laboratory (20, 30, and 37°C) and greenhouse (average temperature 29 to 31°C, humidity 34.8 to 59.8%, and light intensity 604.8 Wm(2)) by simulating transportation and a rendering facility. The amount of H2S production was determined using either test strips impregnated with lead acetate or a H2S monitor. In the laboratory, phage treatment applied to fresh chicken meat inoculated with SPB, spoiled chicken meat, chicken guts, and chicken feathers reduced H2S production by approximately 25 to 69% at temperatures from 20 to 37°C. In the greenhouse, phage treatment achieved approximately a 30 to 85% reduction of H2S yield in chicken offal and feathers. Among all phage treatments, multiplicity of infection (MOI) of 100 exhibited the highest inhibitory activities against SPB on H2S production. Several factors such as initial SPB level, temperature, and MOI affect lytic activities of bacteriophages. Our study demonstrated that the phage cocktail is effective to reduce the production of H2S by SPB significantly in raw animal materials. This biological control method can control SPB in raw poultry by-products at ambient temperatures, leading to a safer working environment and high quality product with less nutrient degradation for the rendering industry.

  13. Reduction of ferrylmyoglobin by hydrogen sulfide. Kinetics in relation to meat greening.

    PubMed

    Libardi, Silvia H; Pindstrup, Helene; Cardoso, Daniel R; Skibsted, Leif H

    2013-03-20

    The hypervalent meat pigment ferrylmyoglobin, MbFe(IV)═O, characteristic for oxidatively stressed meat and known to initiate protein cross-linking, was found to be reduced by hydrogen sulfide to yield sulfmyoglobin. Horse heart myoglobin, void of cysteine, was used to avoid possible interference from protein thiols. For aqueous solution, the reactions were found to be second-order, and an apparent acid catalysis could be quantitatively accounted for in terms of a fast reaction between protonated ferrylmyoglobin, MbFe(IV)═O,H(+), and hydrogen sulfide, H2S (k2 = (2.5 ± 0.1) × 10(6) L mol(-1) s(-1) for 25.0 °C, ionic strengh 0.067, dominating for pH < 4), and a slow reaction between MbFe(IV)═O and HS(-) (k2 = (1.0 ± 0.7) × 10(4) L mol(-1) s(-1) for 25.0 °C, ionic strengh 0.067, dominating for pH > 7). For meat pH, a reaction via the transition state {MbFe(IV)═O···H···HS}([symbol: see text]) contributed significantly, and this reaction appeared almost independent of temperature with an apparent energy of activation of 2.1 ± 0.7 kJ mol(-1) at pH 7.4, as a result of compensation among activation energies and temperature influence on pKa values explaining low temperature greening of meat.

  14. Design of a sorbent to enhance reactive adsorption of hydrogen sulfide.

    PubMed

    Wang, Long-Jiang; Fan, Hui-Ling; Shangguan, Ju; Croiset, Eric; Chen, Zhongwei; Wang, Hui; Mi, Jie

    2014-12-10

    A series of novel zinc oxide-silica composites with three-dimensionally ordered macropores (3DOM) structure were synthesized via colloidal crystal template method and used as sorbents for hydrogen sulfide (H2S) removal at room temperature for the first time. The performances of the prepared sorbents were evaluated by dynamic breakthrough testing. The materials were characterized before and after adsorption using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the composite with 3DOM structure exhibited remarkable desulfurization performance at room temperature and the enhancement of reactive adsorption of hydrogen sulfide was attributed to the unique structure features of 3DOM composites; high surface areas, nanocrystalline ZnO and the well-ordered interconnected macroporous with abundant mesopores. The introduction of silica could be conducive to support the 3DOM structure and the high dispersion of zinc oxide. Moisture in the H2S stream plays a crucial role in the removal process. The effects of Zn/Si ratio and the calcination temperature of 3DOM composites on H2S removal were studied. It demonstrated that the highest content of ZnO could reach up to 73 wt % and the optimum calcination temperature was 500 °C. The multiple adsorption/regeneration cycles showed that the 3DOM ZnO-SiO2 sorbent is stable and the sulfur capacity can still reach 67.4% of that of the fresh sorbent at the fifth cycle. These results indicate that 3DOM ZnO-SiO2 composites will be a promising sorbent for H2S removal at room temperature.

  15. Selectivity of layered double hydroxides and their derivative mixed metal oxides as sorbents of hydrogen sulfide.

    PubMed

    Othman, Mohamed A; Zahid, Waleed M; Abasaeed, Ahmed E

    2013-06-15

    In the context of finding high efficient sorbent materials for removing hydrogen sulfide (H2S) from air stream, a screening study was performed to find the best combination of metals for the synthesis of layered double hydroxides (LDHs) and their derivative mixed metal oxides. Based on selectivity of 998 natural mineral species of sulfur-containing compounds, Cu(2+), Ni(2+) and Zn(2+) were selected as divalent metals, and Fe(3+), Al(3+) and Cr(3+) as trivalent metals to synthesis the LDHs sorbents. 10 LDHs materials and their calcined mixed metal oxides, Ni(0.66)Al(0.34), Cu(0.35)Ni(0.32)Al(0.33), Zn(0.66)Al(0.34), Cu(0.36)Zn(0.32)Al(0.32), Ni(0.64)Fe(0.36), Cu(0.35)Ni(0.31)Fe(0.34), Ni(0.66)Cr(0.34), Cu(0.35)Ni(0.31)Cr(0.34), Zn(0.66)Cr(0.34), Cu(0.33)Zn(0.32)Cr(0.35) were synthesized, characterized chemically and physically, and then tested using breakthrough test to determine their sulfur uptake. Ni(0.64)Fe(0.36) mixed metal oxides was found to have the best uptake of hydrogen sulfide (136 mg H₂S/g). Regeneration of spent Ni(0.64)Fe(0.36) mixed metal oxides was studied using two different mixture solutions, NaCl/NaOH and acetate-buffer/NaCl/NaOH. The latter mixture successfully desorbed the sulfur from the Ni0.64Fe0.36 sorbent for 2 cycles of regeneration/sorption.

  16. Delivery of Hydrogen Sulfide by Ultrasound Targeted Microbubble Destruction Attenuates Myocardial Ischemia-reperfusion Injury.

    PubMed

    Chen, Gangbin; Yang, Li; Zhong, Lintao; Kutty, Shelby; Wang, Yuegang; Cui, Kai; Xiu, Jiancheng; Cao, Shiping; Huang, Qiaobing; Liao, Wangjun; Liao, Yulin; Wu, Juefei; Zhang, Wenzhu; Bin, Jianping

    2016-01-01

    Hydrogen sulfide (H2S) is an attractive agent for myocardial ischemia-reperfusion injury, however, systemic delivery of H2S may cause unwanted side effects. Ultrasound targeted microbubble destruction has become a promising tool for organ specific delivery of bioactive substance. We hypothesized that delivery of H2S by ultrasound targeted microbubble destruction attenuates myocardial ischemia-reperfusion injury and could avoid unwanted side effects. We prepared microbubbles carrying hydrogen sulfide (hs-MB) with different H2S/C3F8 ratios (4/0, 3/1, 2/2, 1/3, 0/4) and determined the optimal ratio. Release of H2S triggered by ultrasound was investigated. The cardioprotective effect of ultrasound targeted hs-MB destruction was investigated in a rodent model of myocardial ischemia-reperfusion injury. The H2S/C3F8 ratio of 2/2 was found to be an optimal ratio to prepare stable hs-MB with higher H2S loading capability. Ultrasound targeted hs-MB destruction triggered H2S release and increased the concentration of H2S in the myocardium and lung. Ultrasound targeted hs-MB destruction limited myocardial infarct size, preserved left ventricular function and had no influence on haemodynamics and respiratory. This cardioprotective effect was associated with alleviation of apoptosis and oxidative stress. Delivery of H2S to the myocardium by ultrasound targeted hs-MB destruction attenuates myocardial ischemia-reperfusion injury and may avoid unwanted side effects. PMID:27469291

  17. Delivery of Hydrogen Sulfide by Ultrasound Targeted Microbubble Destruction Attenuates Myocardial Ischemia-reperfusion Injury

    PubMed Central

    Chen, Gangbin; Yang, Li; Zhong, Lintao; Kutty, Shelby; Wang, Yuegang; Cui, Kai; Xiu, Jiancheng; Cao, Shiping; Huang, Qiaobing; Liao, Wangjun; Liao, Yulin; Wu, Juefei; Zhang, Wenzhu; Bin, Jianping

    2016-01-01

    Hydrogen sulfide (H2S) is an attractive agent for myocardial ischemia-reperfusion injury, however, systemic delivery of H2S may cause unwanted side effects. Ultrasound targeted microbubble destruction has become a promising tool for organ specific delivery of bioactive substance. We hypothesized that delivery of H2S by ultrasound targeted microbubble destruction attenuates myocardial ischemia-reperfusion injury and could avoid unwanted side effects. We prepared microbubbles carrying hydrogen sulfide (hs-MB) with different H2S/C3F8 ratios (4/0, 3/1, 2/2, 1/3, 0/4) and determined the optimal ratio. Release of H2S triggered by ultrasound was investigated. The cardioprotective effect of ultrasound targeted hs-MB destruction was investigated in a rodent model of myocardial ischemia-reperfusion injury. The H2S/C3F8 ratio of 2/2 was found to be an optimal ratio to prepare stable hs-MB with higher H2S loading capability. Ultrasound targeted hs-MB destruction triggered H2S release and increased the concentration of H2S in the myocardium and lung. Ultrasound targeted hs-MB destruction limited myocardial infarct size, preserved left ventricular function and had no influence on haemodynamics and respiratory. This cardioprotective effect was associated with alleviation of apoptosis and oxidative stress. Delivery of H2S to the myocardium by ultrasound targeted hs-MB destruction attenuates myocardial ischemia-reperfusion injury and may avoid unwanted side effects. PMID:27469291

  18. Hydrogen sulfide is essential for Schwann cell responses to peripheral nerve injury.

    PubMed

    Park, Byung Sun; Kim, Hyun-Wook; Rhyu, Im Joo; Park, Chan; Yeo, Seung Geun; Huh, Youngbuhm; Jeong, Na Young; Jung, Junyang

    2015-01-01

    Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from substances by three enzymes: cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (MST). In human tissues, these enzymes are involved in tissue-specific biochemical pathways for H2 S production. For example, CBS and cysteine aminotransferase/MST are present in the brain, but CSE is not. Thus, we examined the expression of H2 S production-related enzymes in peripheral nerves. Here, we found that CSE and MST/cysteine aminotransferase, but not CBS, were present in normal peripheral nerves. In addition, injured sciatic nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration (WD); however, CSE was not up-regulated in peripheral axons. Using an ex vivo sciatic nerve explant culture, we found that the inhibition of H2 S production broadly prevented the process of nerve degeneration, including myelin fragmentation, axonal degradation, Schwann cell dedifferentiation, and Schwann cell proliferation in vitro and in vivo. Thus, these results indicate that H2 S signaling is essential for Schwann cell responses to peripheral nerve injury. Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfur transferase (MST). Here, we found that CSE and MST/CAT were present in normal peripheral nerves. Injured static nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration, but CSE was not up-regulated in peripheral axons.

  19. Hydrogen Sulfide Decreases Reactive Oxygen in a Model of Lung Transplantation

    PubMed Central

    George, Timothy J.; Arnaoutakis, George J.; Beaty, Claude A.; Jandu, Simran K.; Santhanam, Lakshmi; Berkowitz, Dan E.; Shah, Ashish S.

    2012-01-01

    Objectives Ischemia-reperfusion injury(IRI) is a common complication following lung transplantation(LTx). IRI is thought to be mediated by reactive oxygen species(ROS). Hydrogen sulfide(H2S) is a novel agent that has been previously shown to scavenge ROS and slow metabolism. We evaluated the impact of infused H2S on the presence of ROS after reperfusion in an ex vivo model of LTx. Methods Heart-Lung blocks were recovered from New Zealand White rabbits(n=12) and cold stored in Perfadex solution for 18 hours. Following storage, the heart-lung blocks were reperfused ex vivo with donor rabbit blood. In the treatment group(n=7), a bolus of sodium hydrogen sulfide was added at the beginning of reperfusion(100ug/kg) and continuously infused throughout the two hour experiment(1mg/kg/hr). The vehicle group(n=5) received an equivalent volume of saline. Serial airway and pulmonary artery pressures were measured along with arterial and venous blood gases. Results Oxygenation and pulmonary artery pressures were similar between the two groups. However, treatment with H2S resulted in a dramatic reduction in the presence of ROS after 2 hours of reperfusion(4851 ± 2139 vs. 235 ± 462 RFU/mg protein, p=0.003). There was a trend toward increased levels of cGMP in the H2S treated group(3.08 ± 1.69 vs. 1.73 ± 1.41 fmol/mg tissue, p=0.23). Conclusions After prolonged ischemia, infusion of H2S during reperfusion is associated with a significant decrease in the presence of ROS, a suspected mediator of IRI. To our knowledge, this study represents the first reported therapeutic use of H2S in an experimental model of lung transplant. PMID:22464394

  20. Application of bacteriophages specific to hydrogen sulfide-producing bacteria in raw poultry by-products.

    PubMed

    Gong, Chao; Liu, Xiaohua; Jiang, Xiuping

    2014-03-01

    Hydrogen sulfide-producing bacteria (SPB) can spoil raw animal materials and release harmful hydrogen sulfide (H2S) gas. The objective of this study was to apply a SPB-specific bacteriophage cocktail to control H2S production by SPB in different raw poultry by-products in the laboratory (20, 30, and 37°C) and greenhouse (average temperature 29 to 31°C, humidity 34.8 to 59.8%, and light intensity 604.8 Wm(2)) by simulating transportation and a rendering facility. The amount of H2S production was determined using either test strips impregnated with lead acetate or a H2S monitor. In the laboratory, phage treatment applied to fresh chicken meat inoculated with SPB, spoiled chicken meat, chicken guts, and chicken feathers reduced H2S production by approximately 25 to 69% at temperatures from 20 to 37°C. In the greenhouse, phage treatment achieved approximately a 30 to 85% reduction of H2S yield in chicken offal and feathers. Among all phage treatments, multiplicity of infection (MOI) of 100 exhibited the highest inhibitory activities against SPB on H2S production. Several factors such as initial SPB level, temperature, and MOI affect lytic activities of bacteriophages. Our study demonstrated that the phage cocktail is effective to reduce the production of H2S by SPB significantly in raw animal materials. This biological control method can control SPB in raw poultry by-products at ambient temperatures, leading to a safer working environment and high quality product with less nutrient degradation for the rendering industry. PMID:24604865

  1. Physical solubility of hydrogen sulfide and carbon dioxide in alkanolamine solutions

    SciTech Connect

    Abu-Arabi, M.K.

    1988-01-01

    The study was undertaken to develop a method that would make direct measurements of acid gases, hydrogen sulfide and carbon dioxide, physical solubilities in aqueous alkanolamine solutions possible. Hydrogen sulfide and carbon dioxide physical solubilities in 20, 35, and 50% by weight diethanolamine aqueous solutions were measured. The solubility measurements were made at acid gas partial pressure up to 1000 psia and temperatures of 80, 150, 240 F. The solubility of nitrous oxide in water and in protonated diethanolamine solution was also determined at 80 F. A method that allows for direct measurements of acid gases physical solubilities has been developed. The method eliminates amines reactivity with acid gases by protonating the amines prior to their contact with acid gases. CO{sub 2} physical solubility in aqueous DEA solutions occurs mainly in the water portion of the solution. Therefore, the physical solubility of CO{sub 2} in an aqueous amine solution must be corrected based on the fraction of water in the solution. However, H{sub 2}S physical solubility in aqueous DEA solutions is the same as H{sub 2}S solubility in water. At any acid gas partial pressure, the physical solubility of H{sub 2}S is higher than that of CO{sub 2} for the same solution concentration and for the same temperature. This is also true for their solubilities is pure water. The ratio of CO{sub 2} to H{sub 2}S physical solubility to N{sub 2}O solubility in aqueous DEA solutions is not the same as their ratio in pure water.

  2. Amorphous Molybdenum Sulfide on Graphene-Carbon Nanotube Hybrids as Highly Active Hydrogen Evolution Reaction Catalysts.

    PubMed

    Pham, Kien-Cuong; Chang, Yung-Huang; McPhail, David S; Mattevi, Cecilia; Wee, Andrew T S; Chua, Daniel H C

    2016-03-01

    In this study, we report on the deposition of amorphous molybdenum sulfide (MoSx, with x ≈ 3) on a high specific surface area conductive support of Graphene-Carbon Nanotube hybrids (GCNT) as the Hydrogen Evolution Reaction (HER) catalysts. We found that the high surface area GCNT electrode could support the deposition of MoSx at much higher loadings compared with simple porous carbon paper or flat graphite paper. The morphological study showed that MoSx was successfully deposited on and was in good contact with the GCNT support. Other physical characterization techniques suggested the amorphous nature of the deposited MoSx. With a typical catalyst loading of 3 mg cm(-2), an overpotential of 141 mV was required to obtain a current density of 10 mA cm(-2). A Tafel slope of 41 mV decade(-1) was demonstrated. Both measures placed the MoSx-deposited GCNT electrode among the best performing molybdenum sulfide-based HER catalysts reported to date. The electrode showed a good stability with only a 25 mV increase in overpotential required for a current density of 10 mA cm(-2), after undergoing 500 potential sweeps with vigorous bubbling present. The current density obtained at -0.5 V vs SHE (Standard Hydrogen Electrode potential) decreased less than 10% after the stability test. The deposition of MoSx on high specific surface area conductive electrodes demonstrated to be an efficient method to maximize the catalytic performance toward HER. PMID:26864503

  3. Removal of hydrogen sulfide from hot fuel gas using an electrochemical membrane system

    NASA Astrophysics Data System (ADS)

    Burke, Adrian Alan

    Sulfur is a natural contaminant in nearly all fossil fuel supplies. When a fuel stream is gasified or reformed, the sulfur manifests itself in the form of hydrogen sulfide, H2S. Extraordinary effort is put forth to remove H2S to at least ppm levels before the fuel can be used for power generation. To compete with current methods, an electrochemical membrane system (EMS) is now being studied to remove H2S in one step at high temperature. This process offers continuous H2S removal at an estimated operating cost of $0.32/kg H2S removed and a capital cost that is roughly half that of a Claus plant with tail-gas clean-up. Other advantages are the considerable savings in energy and space compared to current methods. A bench scale set-up was constructed to test the cell performance at 600-700°C and 1 atm. The typical fuel stream inlet proportions were 34% CO, 22% CO2, 35% H2, 8% H2O, and 450-2000 ppm H2S. The fundamental transport restrictions for sulfur species in an electrochemical cell were examined. Temperature and membrane thickness were varied to examine how these parameters affect the maximum flux of H 2S removal. It was found that higher temperature allows more sulfide species to enter the electrolyte, thus increasing the sulfide flux across the membrane and raising the maximum flux of H2S removal. Also, membrane thickness was found to be a critical parameter in cell design. A thinner membrane decreases the distance that sulfide ions must travel to be oxidized at the anode. These results identify sulfide diffusion across the membrane as the rate-limiting step in H2S removal. The maximum H2S removal flux of 1.1 x 10-6 gmol H2S min-1 cm-2 (or 3.5 mA cm-2) was obtained at 650°C, with a membrane that was 0.9 mm thick, 36% porous, and had an estimated tortuosity of 3.6. Another focus of this thesis was to examine the stability of cathode materials in full cell trials. A major hurdle that remains in process scale-up is cathode selection, as the lifetime of the cell

  4. Hydrogen sulfide oxidation is coupled to oxidative phosphorylation in mitochondria of Solemya reidi

    SciTech Connect

    Powell, M.A.; Somero, G.N.

    1986-08-01

    Solemya reidi, a gutless clam found in sulfide-rich habitats, contains within its gills bacterial symbionts thought to oxidize sulfur compounds and provide a reduced carbon food source to the clam. However, the initial step or steps in sulfide oxidation occur in the animal tissue, and mitochondria isolated from both gill and symbiont-free foot tissue of the clam coupled the oxidation of sulfide to oxidative phosphorylation (adenosine triphosphate (ATP) synthesis). The ability of Solemya reidi to exploit directly the energy in sulfide for ATP synthesis is unprecedented, and suggests that sulfide-habitat animals that lack bacterial symbionts may also use sulfide as an inorganic energy source.

  5. Density functional theory studies of the adsorption of hydrogen sulfide on aluminum doped silicane.

    PubMed

    Sánchez-Ochoa, Francisco; Guerrero-Sánchez, Jonathan; Canto, Gabriel I; Cocoletzi, Gregorio H; Takeuchi, Noboru

    2013-08-01

    First principles total energy calculations have been performed to study the hydrogen sulfide (H2S) adsorption on silicane, an unusual one monolayer of Si(111) surface hydrogenated on both sides. The H2S adsorption may take place in dissociative or non-dissociative forms. Silicane has been considered as: (A) non-doped with a hydrogen vacancy, and doped in two main configurations; (B) with an aluminum replacing a hydrogen atom and (C-n; n = 1, 2, 3) with an aluminum replacing a silicon atom at a lattice site. In addition, three supercells; 4x4, 3x3 and 2x2 have been explored for both non-doped and doped silicane. The non-dissociative adsorption takes place in geometries (A), (C-1), (C-2) and (C-3) while the dissociative in (B). Adsorption energies of the dissociative case are larger than those corresponding to the non-dissociated cases. In the dissociative adsorption, the molecule is fragmented in a HS structure and a H atom which are bonded to the aluminum to form a H-S-Al-H structure. The presence of the doping produces some electronic changes as the periodicity varies. Calculations of the total density of states (DOS) indicate that in most cases the energy gap decreases as the periodicity changes from 4x4 to 2x2. The features of the total DOS are explained in terms of the partial DOS. The reported charge density plots explain quite well the chemisorptions and physisorptions of the molecule on silicane in agreement with adsorption energies.

  6. FORMATION OF MOLECULAR HYDROGEN FROM METHANE ICE

    SciTech Connect

    He Jiao; Gao Kun; Vidali, Gianfranco; Bennett, Chris J.; Kaiser, Ralf I.

    2010-10-01

    To study the formation of molecular hydrogen in the wake of the processing of interstellar ices by energetic cosmic-ray particles, we investigated the interaction of energetic electrons, as formed in the track of galactic cosmic-ray particles, with deuterated methane ices (CD{sub 4}) at 11 K. The energetic electrons mimic energy-transfer processes that occur in the track of the trajectories of energetic cosmic-ray particles; deuterated methane ice was utilized to discriminate the molecular deuterium (m/z = 4) formed during the radiation exposure from the residual molecular hydrogen gas (m/z = 2) released inside the ultrahigh vacuum scattering chamber from outgassing of the stainless steel material. The ices were characterized online and in situ using Fourier transform infrared spectroscopy, while the evolution of the molecular deuterium (D{sub 2}) into the gas phase was monitored using a mass spectrometer. A mass spectrometric signal proportional to the number density of the deuterium molecules generated inside the ice and released during the irradiation was analyzed kinetically using a set of coupled rate equations. From the fit to the experimental data, we obtain activation energies for the diffusion of atomic deuterium (E{sub 0} = 37 {+-} 1 meV), and for the desorption of atomic (E{sub 1} = 32 {+-} 1 meV) and molecular deuterium (E{sub 2} = 32 {+-} 1 meV). These energies are placed in context and then transferred to atomic and molecular hydrogen to yield astrophysically relevant data. The experimental yield of molecular deuterium is then used to calculate the formation rate of molecular hydrogen due to cosmic-ray interaction with ice-covered grains in dense clouds.

  7. Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect

    Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Guibling Zhao; Ji-Jun Zhang; Sanil John

    2005-10-01

    The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. A pulsed corona discharge (PCD) reactor has been fabricated and used to dissociate H{sub 2}S into hydrogen and sulfur. A nonthermal plasma cannot be produced in pure H{sub 2}S with our reactor geometry, even at discharge voltages of up to 30 kV, because of the high dielectric strength of pure H{sub 2}S ({approx}2.9 times higher than air). Therefore, H{sub 2}S was diluted in another gas with lower breakdown voltage (or dielectric strength). Breakdown voltages of H{sub 2}S in four balance gases (Ar, He, N{sub 2} and H{sub 2}) have been measured at different H{sub 2}S concentrations and pressures. Breakdown voltages are proportional to the partial pressure of H{sub 2}S and the balance gas. H{sub 2}S conversion and the reaction energy efficiency depend on the balance gas and H{sub 2}S inlet concentrations. With increasing H{sub 2}S concentrations, H{sub 2}S conversion initially increases, reaches a maximum, and then decreases. H{sub 2}S conversion in atomic balance gases, such as Ar and He, is more efficient than that in diatomic balance gases, such as N{sub 2} and H{sub 2}. These observations can be explained by the proposed reaction mechanism of H{sub 2}S dissociation in different balance gases. The results show that nonthermal plasmas are effective for dissociating H{sub 2}S into hydrogen and sulfur.

  8. Hydrogen sulfide releasing aspirin, ACS14, attenuates high glucose-induced increased methylglyoxal and oxidative stress in cultured vascular smooth muscle cells.

    PubMed

    Huang, Qian; Sparatore, Anna; Del Soldato, Piero; Wu, Lingyun; Desai, Kaushik

    2014-01-01

    Hydrogen sulfide is a gasotransmitter with vasodilatory and anti-inflammatory properties. Aspirin is an irreversible cyclooxygenase inhibitor anti-inflammatory drug. ACS14 is a novel synthetic hydrogen sulfide releasing aspirin which inhibits cyclooxygenase and has antioxidant effects. Methylglyoxal is a chemically active metabolite of glucose and fructose, and a major precursor of advanced glycation end products formation. Methylglyoxal is harmful when produced in excess. Plasma methylglyoxal levels are significantly elevated in diabetic patients. Our aim was to investigate the effects of ACS14 on methylglyoxal levels in cultured rat aortic vascular smooth muscle cells. We used cultured rat aortic vascular smooth muscle cells for the study. Methylglyoxal was measured by HPLC after derivatization, and nitrite+nitrate with an assay kit. Western blotting was used to determine NADPH oxidase 4 (NOX4) and inducible nitric oxide synthase (iNOS) protein expression. Dicholorofluorescein assay was used to measure oxidative stress. ACS14 significantly attenuated elevation of intracellular methylglyoxal levels caused by incubating cultured vascular smooth muscle cells with methylglyoxal (30 µM) and high glucose (25 mM). ACS14, but not aspirin, caused a significant attenuation of increase in nitrite+nitrate levels caused by methylglyoxal or high glucose. ACS14, aspirin, and sodium hydrogen sulfide (NaHS, a hydrogen sulfide donor), all attenuated the increase in oxidative stress caused by methylglyoxal and high glucose in cultured cells. ACS14 prevented the increase in NOX4 expression caused by incubating the cultured VSMCs with MG (30 µM). ACS14, aspirin and NaHS attenuated the increase in iNOS expression caused by high glucose (25 mM). In conclusion, ACS14 has the novel ability to attenuate an increase in methylglyoxal levels which in turn can reduce oxidative stress, decrease the formation of advanced glycation end products and prevent many of the known deleterious effects

  9. Mitigation of Hydrogen Sulfide Emissions in the Geysers KGRA (Staff Draft)

    SciTech Connect

    Buell, Richard

    1981-07-01

    Violations of the ambient air quality standard (AAQS) for hydrogen sulfide (H2S) are currently being experienced in The Geysers KGRA and could significantly increase in the future. Attainment and maintenance of the H2S AAQS is a potential constraint to optimum development of this resource. The availability of reliable H2S controls and the development of a validated air dispersion model are critical to alleviating this constraint. The purpose of this report is to assess the performance capabilities for state-of-the-art controls, to identify potential cost-effective alternative controls, and to identify the California Energy Commission (CEC) staffs efforts to develop a validated air dispersion model. Currently available controls (Stretford, Hydrogen Peroxide, and EIC) are capable of abating H2S emissions from a proposed facility to five lbs/hr. Alternative controls, such as condensate stripping and condensate pH control, appear to promising, cost-effective control option. The CEC staff is currently developing a validated air dispersion model for The Geysers KGRA. The CEC staff recommends investigation of retrofit control options for existing units, investigation of alternative control technologies, and dispersion analysis for optimum plant location in order to maximize the development potential of The Geysers KGRA. Energy cost studies suggest that the EIC process would be the most cost-effective for retrofits at The Geysers. (DJE-2005)

  10. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses

    PubMed Central

    Ni, Zhi-Jing; Hu, Kang-Di; Song, Chang-Bing; Ma, Run-Hui; Li, Zhi-Rong; Zheng, Ji-Lian; Fu, Liu-Hui

    2016-01-01

    Hydrogen sulfide (H2S) has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2∙−) in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX) and catalase (CAT) and decreased those of lipoxygenase (LOX) in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation. PMID:27594971

  11. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses

    PubMed Central

    Ni, Zhi-Jing; Hu, Kang-Di; Song, Chang-Bing; Ma, Run-Hui; Li, Zhi-Rong; Zheng, Ji-Lian; Fu, Liu-Hui

    2016-01-01

    Hydrogen sulfide (H2S) has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2∙−) in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX) and catalase (CAT) and decreased those of lipoxygenase (LOX) in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation.

  12. Development of the Transferable Potentials for Phase Equilibria Model for Hydrogen Sulfide.

    PubMed

    Shah, Mansi S; Tsapatsis, Michael; Siepmann, J Ilja

    2015-06-11

    The transferable potentials for phase equilibria force field is extended to hydrogen sulfide. The pure-component and binary vapor-liquid equilibria with methane and carbon dioxide and the liquid-phase relative permittivity are used for the parametrization of the Lennard-Jones (LJ) and Coulomb interactions, and models with three and four interaction sites are considered. For the three-site models, partial point charges are placed on the sites representing the three atoms, while the negative partial charge is moved to an off-atom site for the four-site models. The effect of molecular shape is probed using either only a single LJ interaction site on the sulfur atom or adding sites also on the hydrogen atoms. This procedure results in four distinct models, but only those with three LJ sites can accurately reproduce all properties considered for the parametrization. These two are further assessed for predictions of the liquid-phase structure, the lattice parameters and relative permittivity for the face-centered-cubic solid, and the triple point. An effective balance between LJ interactions and the dipolar and quadrupolar terms of the first-order electrostatic interactions is struck in order to obtain a four-site model that describes the condensed-phase properties and the phase equilibria with high accuracy. PMID:25981731

  13. Hydrogen sulfide prolongs postharvest shelf life of strawberry and plays an antioxidative role in fruits.

    PubMed

    Hu, Lan-Ying; Hu, Shu-Li; Wu, Jun; Li, Yan-Hong; Zheng, Ji-Lian; Wei, Zhao-Jun; Liu, Jian; Wang, Hui-Li; Liu, Yong-Sheng; Zhang, Hua

    2012-09-01

    Accumulating evidence shows that hydrogen sulfide (H(2)S) plays various physiological roles in plants, such as seed germination, root organogenesis, abiotic stress tolerance, and senescence of cut flowers. However, whether H(2)S participates in the regulation of ripening and senescence in postharvest fruits remains unknown. In the present study, the effect of H(2)S on postharvest shelf life and antioxidant metabolism in strawberry fruits was investigated. Fumigation with H(2)S gas released from the H(2)S donor NaHS prolonged postharvest shelf life of strawberry fruits in a dose-dependent manner. Strawberry fruits fumigated with various concentrations of H(2)S sustained significantly lower rot index, higher fruit firmness, and kept lower respiration intensity and polygalacturonase activities than controls. Further investigation showed that H(2)S treatment maintained higher activities of catalase, guaiacol peroxidase, ascorbate peroxidase, and glutathione reductase and lower activities of lipoxygenase relative to untreated controls. H(2)S also reduced malondialdehyde, hydrogen peroxide, and superoxide anion to levels below control fruits during storage. Moreover, H(2)S treatment maintained higher contents of reducing sugars, soluble proteins, free amino acid, and endogenous H(2)S in fruits. We interpret these data as indicating that H(2)S plays an antioxidative role in prolonging postharvest shelf life of strawberry fruits.

  14. Development of the Transferable Potentials for Phase Equilibria Model for Hydrogen Sulfide.

    PubMed

    Shah, Mansi S; Tsapatsis, Michael; Siepmann, J Ilja

    2015-06-11

    The transferable potentials for phase equilibria force field is extended to hydrogen sulfide. The pure-component and binary vapor-liquid equilibria with methane and carbon dioxide and the liquid-phase relative permittivity are used for the parametrization of the Lennard-Jones (LJ) and Coulomb interactions, and models with three and four interaction sites are considered. For the three-site models, partial point charges are placed on the sites representing the three atoms, while the negative partial charge is moved to an off-atom site for the four-site models. The effect of molecular shape is probed using either only a single LJ interaction site on the sulfur atom or adding sites also on the hydrogen atoms. This procedure results in four distinct models, but only those with three LJ sites can accurately reproduce all properties considered for the parametrization. These two are further assessed for predictions of the liquid-phase structure, the lattice parameters and relative permittivity for the face-centered-cubic solid, and the triple point. An effective balance between LJ interactions and the dipolar and quadrupolar terms of the first-order electrostatic interactions is struck in order to obtain a four-site model that describes the condensed-phase properties and the phase equilibria with high accuracy.

  15. Factors affecting activated carbon-based catalysts for selective hydrogen sulfide oxidation

    SciTech Connect

    Li, Huixing; Monnell, J.D.; Alvin, M.A.; Vidic, R.D.

    2008-09-01

    The primary product of coal gasification processes is synthesis gas (syngas), a mixture of CO, H2, CO2, H2O and a number of minor components. Among the most significant minor components in syngas is hydrogen sulfide (H2S). In addition to its adverse environmental impact, H2S poisons the catalysts and hydrogen purification membranes, and causes severe corrosion in gas turbines. Technologies that can remove H2S from syngas and related process streams are, therefore, of considerable practical interest. To meet this need, we work towards understanding the mechanism by which prospective H2S catalysts perform in simulated fuel gas conditions. Specifically, we show that for low-temperature gas clean-up (~1408C) using activated carbon fibers and water plays a significant role in H2S binding and helps to prolong the lifetime of the material. Basic surface functional groups were found to be imperative for significant conversion of H2S to daughter compounds, whereas metal oxides (La and Ce) did little to enhance this catalysis. We show that although thermal regeneration of the material is possible, the regenerated material has a substantially lower catalytic and sorption capacity.

  16. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses.

    PubMed

    Ni, Zhi-Jing; Hu, Kang-Di; Song, Chang-Bing; Ma, Run-Hui; Li, Zhi-Rong; Zheng, Ji-Lian; Fu, Liu-Hui; Wei, Zhao-Jun; Zhang, Hua

    2016-01-01

    Hydrogen sulfide (H2S) has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2 (∙-)) in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX) and catalase (CAT) and decreased those of lipoxygenase (LOX) in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation. PMID:27594971

  17. Regulation of mitochondrial bioenergetic function by hydrogen sulfide. Part I. Biochemical and physiological mechanisms.

    PubMed

    Szabo, Csaba; Ransy, Céline; Módis, Katalin; Andriamihaja, Mireille; Murghes, Baptiste; Coletta, Ciro; Olah, Gabor; Yanagi, Kazunori; Bouillaud, Frédéric

    2014-04-01

    Until recently, hydrogen sulfide (H2 S) was exclusively viewed a toxic gas and an environmental hazard, with its toxicity primarily attributed to the inhibition of mitochondrial Complex IV, resulting in a shutdown of mitochondrial electron transport and cellular ATP generation. Work over the last decade established multiple biological regulatory roles of H2 S, as an endogenous gaseous transmitter. H2 S is produced by cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). In striking contrast to its inhibitory effect on Complex IV, recent studies showed that at lower concentrations, H2 S serves as a stimulator of electron transport in mammalian cells, by acting as a mitochondrial electron donor. Endogenous H2 S, produced by mitochondrially localized 3-MST, supports basal, physiological cellular bioenergetic functions; the activity of this metabolic support declines with physiological aging. In specialized conditions (calcium overload in vascular smooth muscle, colon cancer cells), CSE and CBS can also associate with the mitochondria; H2 S produced by these enzymes, serves as an endogenous stimulator of cellular bioenergetics. The current article overviews the biochemical mechanisms underlying the stimulatory and inhibitory effects of H2 S on mitochondrial function and cellular bioenergetics and discusses the implication of these processes for normal cellular physiology. The relevance of H2 S biology is also discussed in the context of colonic epithelial cell physiology: colonocytes are exposed to high levels of sulfide produced by enteric bacteria, and serve as a metabolic barrier to limit their entry into the mammalian host, while, at the same time, utilizing it as a metabolic 'fuel'.

  18. Regulation of mitochondrial bioenergetic function by hydrogen sulfide. Part I. Biochemical and physiological mechanisms

    PubMed Central

    Szabo, Csaba; Ransy, Céline; Módis, Katalin; Andriamihaja, Mireille; Murghes, Baptiste; Coletta, Ciro; Olah, Gabor; Yanagi, Kazunori; Bouillaud, Frédéric

    2014-01-01

    Until recently, hydrogen sulfide (H2S) was exclusively viewed a toxic gas and an environmental hazard, with its toxicity primarily attributed to the inhibition of mitochondrial Complex IV, resulting in a shutdown of mitochondrial electron transport and cellular ATP generation. Work over the last decade established multiple biological regulatory roles of H2S, as an endogenous gaseous transmitter. H2S is produced by cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). In striking contrast to its inhibitory effect on Complex IV, recent studies showed that at lower concentrations, H2S serves as a stimulator of electron transport in mammalian cells, by acting as a mitochondrial electron donor. Endogenous H2S, produced by mitochondrially localized 3-MST, supports basal, physiological cellular bioenergetic functions; the activity of this metabolic support declines with physiological aging. In specialized conditions (calcium overload in vascular smooth muscle, colon cancer cells), CSE and CBS can also associate with the mitochondria; H2S produced by these enzymes, serves as an endogenous stimulator of cellular bioenergetics. The current article overviews the biochemical mechanisms underlying the stimulatory and inhibitory effects of H2S on mitochondrial function and cellular bioenergetics and discusses the implication of these processes for normal cellular physiology. The relevance of H2S biology is also discussed in the context of colonic epithelial cell physiology: colonocytes are exposed to high levels of sulfide produced by enteric bacteria, and serve as a metabolic barrier to limit their entry into the mammalian host, while, at the same time, utilizing it as a metabolic ‘fuel’. Linked Articles This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue-8 PMID:23991830

  19. Size-tunable copper nanocluster aggregates and their application in hydrogen sulfide sensing on paper-based devices

    NASA Astrophysics Data System (ADS)

    Chen, Po-Cheng; Li, Yu-Chi; Ma, Jia-Yin; Huang, Jia-Yu; Chen, Chien-Fu; Chang, Huan-Tsung

    2016-04-01

    Polystyrene sulfonate (PSS), a strong polyelectrolyte, was used to prepare red photoluminescent PSS-penicillamine (PA) copper (Cu) nanoclusters (NC) aggregates, which displayed high selectivity and sensitivity to the detection of hydrogen sulfide (H2S). The size of the PSS-PA-Cu NC aggregates could be readily controlled from 5.5 μm to 173 nm using different concentrations of PSS, which enabled better dispersity and higher sensitivity towards H2S. PSS-PA-Cu NC aggregates provided rapid H2S detection by using the strong Cu-S interaction to quench NC photoluminescence as a sensing mechanism. As a result, a detection limit of 650 nM, which is lower than the maximum level permitted in drinking water by the World Health Organization, was achieved for the analysis of H2S in spring-water samples. Moreover, highly dispersed PSS-PA-Cu NC aggregates could be incorporated into a plate-format paper-based analytical device which enables ultra-low sample volumes (5 μL) and feature shorter analysis times (30 min) compared to conventional solution-based methods. The advantages of low reagent consumption, rapid result readout, limited equipment, and long-term storage make this platform sensitive and simple enough to use without specialized training in resource constrained settings.

  20. Study and modeling of the evolution of gas-liquid partitioning of hydrogen sulfide in model solutions simulating winemaking fermentations.

    PubMed

    Mouret, Jean-Roch; Sablayrolles, Jean-Marie; Farines, Vincent

    2015-04-01

    The knowledge of gas-liquid partitioning of aroma compounds during winemaking fermentation could allow optimization of fermentation management, maximizing concentrations of positive markers of aroma and minimizing formation of molecules, such as hydrogen sulfide (H2S), responsible for defects. In this study, the effect of the main fermentation parameters on the gas-liquid partition coefficients (Ki) of H2S was assessed. The Ki for this highly volatile sulfur compound was measured in water by an original semistatic method developed in this work for the determination of gas-liquid partitioning. This novel method was validated and then used to determine the Ki of H2S in synthetic media simulating must, fermenting musts at various steps of the fermentation process, and wine. Ki values were found to be mainly dependent on the temperature but also varied with the composition of the medium, especially with the glucose concentration. Finally, a model was developed to quantify the gas-liquid partitioning of H2S in synthetic media simulating must to wine. This model allowed a very accurate prediction of the partition coefficient of H2S: the difference between observed and predicted values never exceeded 4%.

  1. Size-tunable copper nanocluster aggregates and their application in hydrogen sulfide sensing on paper-based devices

    PubMed Central

    Chen, Po-Cheng; Li, Yu-Chi; Ma, Jia-Yin; Huang, Jia-Yu; Chen, Chien-Fu; Chang, Huan-Tsung

    2016-01-01

    Polystyrene sulfonate (PSS), a strong polyelectrolyte, was used to prepare red photoluminescent PSS-penicillamine (PA) copper (Cu) nanoclusters (NC) aggregates, which displayed high selectivity and sensitivity to the detection of hydrogen sulfide (H2S). The size of the PSS-PA-Cu NC aggregates could be readily controlled from 5.5 μm to 173 nm using different concentrations of PSS, which enabled better dispersity and higher sensitivity towards H2S. PSS-PA-Cu NC aggregates provided rapid H2S detection by using the strong Cu-S interaction to quench NC photoluminescence as a sensing mechanism. As a result, a detection limit of 650 nM, which is lower than the maximum level permitted in drinking water by the World Health Organization, was achieved for the analysis of H2S in spring-water samples. Moreover, highly dispersed PSS-PA-Cu NC aggregates could be incorporated into a plate-format paper-based analytical device which enables ultra-low sample volumes (5 μL) and feature shorter analysis times (30 min) compared to conventional solution-based methods. The advantages of low reagent consumption, rapid result readout, limited equipment, and long-term storage make this platform sensitive and simple enough to use without specialized training in resource constrained settings. PMID:27113330

  2. NOVEL COMPOSITE HYDROGEN-PERMEABLE MEMBRANES FOR NON-THERMAL PLASMA REACTORS FOR THE DECOMPOSITION OF HYDROGEN SULFIDE

    SciTech Connect

    Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Ji-Jun Zhang; Guibing Zhao; Robyn J. Alcanzare; Linna Wang; Ovid A. Plumb

    2004-07-01

    The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. Experiments involving methane conversion reactions were conducted with a preliminary pulsed corona discharge reactor design in order to test and improve the reactor and membrane designs using a non-toxic reactant. This report details the direct methane conversion experiments to produce hydrogen, acetylene, and higher hydrocarbons utilizing a co-axial cylinder (CAC) corona discharge reactor, pulsed with a thyratron switch. The reactor was designed to accommodate relatively high flow rates (655 x 10{sup -6} m{sup 3}/s) representing a pilot scale easily converted to commercial scale. Parameters expected to influence methane conversion including pulse frequency, charge voltage, capacitance, residence time, and electrode material were investigated. Conversion, selectivity and energy consumption were measured or estimated. C{sub 2} and C{sub 3} hydrocarbon products were analyzed with a residual gas analyzer (RGA). In order to obtain quantitative results, the complex sample spectra were de-convoluted via a linear least squares method. Methane conversion as high as 51% was achieved. The products are typically 50%-60% acetylene, 20% propane, 10% ethane and ethylene, and 5% propylene. First Law thermodynamic energy efficiencies for the system (electrical and reactor) were estimated to range from 38% to 6%, with the highest efficiencies occurring at short residence time and low power input (low specific energy) where conversion is the lowest (less than 5%). The highest methane conversion of 51% occurred at a

  3. Operational overview of the NASA GTE/CITE 3 airborne instrument intercomparisons for sulfur dioxide, hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, and carbon disulfide

    NASA Technical Reports Server (NTRS)

    Hoell, James M., Jr.; Davis, Douglas D.; Gregory, Gerald L.; Mcneal, Robert J.; Bendura, Richard J.; Drewry, Joseph W.; Barrick, John D.; Kirchhoff, Volker W. J. H.; Motta, Adauto G.; Navarro, Roger L.

    1993-01-01

    This paper reports the overall experimental design and gives a brief overview of results from the third airborne Chemical Instrumentation Test and Evaluation (CITE 3) mission conducted as part of the National Aeronautics and Space Administration's Global Tropospheric Experiment. The primary objective of CITE 3 was to evaluate the capability of instrumentation for airborne measurements of ambient concentrations of SO2, H2S, CS, dimethyl sulfide, and carbonyl sulfide. Ancillary measurements augmented the intercomparison data in order to address the secondary objective of CITE 3 which was to address specific issues related to the budget and photochemistry of tropospheric sulfur species. The CITE 3 mission was conducted on NASA's Wallops Flight Center Electra aircraft and included a ground-based intercomparison of sulfur standards and intercomparison/sulfur science flights conducted from the NASA Wallops Flight Facility, Wallops Island, Virginia, followed by flights from Natal, Brazil. Including the transit flights, CITE 3 included 16 flights encompassing approximately 96 flight hours.

  4. Catalytic activity of metal oxides in hydrogen sulfide oxidation by oxygen and sulfur dioxide

    SciTech Connect

    Marshneva, V.I.; Mokrinskii, V.V.

    1989-02-01

    Separate investigations have been made of the catalytic activities of a wide range of oxides by groups I-VIII metals in the Claus reaction and oxidation of H/sub 2/S by oxygen. Only 9 of 21 oxides used in the Claus reaction exhibit stable activity. The remaining oxides are deactivated, mainly by absorbing H/sub 2/S and being converted into sulfides. There are similar tendencies in the changes of sulfur formation specific velocities in both processes in the series of stable oxides V/sub 2/O/sub 5/, TiO/sub 2/, Mn/sub 2/O/sub 3/, Al/sub 2/O/sub 3/, MgO, Cr/sub 2/O/sub 3/. Vanadium pentoxide is the most active catalyst in the total and partial oxidations of H/sub 2/S and the Claus reaction.

  5. Phase- and morphology-controlled synthesis of cobalt sulfide nanocrystals and comparison of their catalytic activities for hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Pan, Yuan; Liu, Yunqi; Liu, Chenguang

    2015-12-01

    Colalt sulfide nanocrystals (NCs), including dandelion-like Co9S8 and sphere-like Co3S4, have been synthesized via a thermal decomposition approach using cobalt acetylacetonate as the cobalt source, 1-dodecanethiol as the sulfur source and oleic acid or oleylamine as the high boiling organic solvent. It is found that the molar ratio of the Co:S precursor and the species of solvent play an important role in the control of phase and morphology of cobalt sulfide nanostructures. The phase structure and morphology of the as-synthesized nickel sulfide NCs are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), energy dispersive spectrum (EDS) mapping, X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption. Then we further compare the electrocatalytic activity and stability of as-synthesized cobalt sulfide NCs for hydrogen evolution reaction (HER). The results show that sphere-like Co3S4 exhibits better electrocatalytic activity than the dandelion-like Co9S8 NCs for HER, which can be attributed to the difference of phase structure and morphology. The sphere-like Co3S4 NCs have large surface area and high electrical conductivity, both are beneficial to enhance the catalytic activity. This study indicates that the crystalline phase structure and morphology of cobalt sulfide NCs are important for designing HER electrocatalysts with high efficiency and good stability.

  6. Evaluation of different techniques to control hydrogen sulfide and greenhouse gases from animal production systems

    NASA Astrophysics Data System (ADS)

    Gautam, Dhan Prasad

    The livestock manure management sector is one of the prime sources for the emission of greenhouse gases (GHGs) and other pollutant gases such as ammonia (NH3) and hydrogen sulfide (H2S), which may affect the human health, animal welfare, and the environment. So, worldwide investigations are going on to mitigate these gaseous emissions. The overall objective of this research was to investigate different approaches (dietary manipulation and nanotechnology) for mitigating the gaseous emissions from livestock manure system. A field study was conducted to investigate the effect of different levels of dietary proteins (12 and 16%) and fat levels (3 to 5.5%) fed to beef cattle on gaseous emission (methane-CH4, nitrous oxide-N2O, carbon dioxide-CO 2 and hydrogen sulfide-H2S) from the pen surface. To evaluate the effects of different nanoparticles (zinc oxide-nZnO; and zirconium-nZrO 2) on these gaseous emissions from livestock manure stored under anaerobic conditions, laboratory studies were conducted with different treatments (control, bare NPs, NPs entrapped alginate beads applying freely and keeping in bags, and used NPs entrapped alginate beads). Field studies showed no significant differences in the GHG and H2S emissions from the manure pen surface. Between nZnO and nZrO2, nZnO outperformed the nZrO2 in terms of gases production and concentration reduction from both swine and dairy liquid manure. Application of nZnO at a rate of 3 g L-1 showed up to 82, 78, 40 and 99% reduction on total gas production, CH 4, CO2 and H2S concentrations, respectively. The effectiveness of nZnO entrapped alginate (alginate-nZnO) beads was statistically lower than the bare nZnO, but both of them were very effective in reducing gas production and concentrations. These gaseous reductions were likely due to combination of microbial inhibition of microorganisms and chemical conversion during the treatment, which was confirmed by microbial plate count, SEM-EDS, and XPS analysis. However

  7. A comprehensive study on atomic layer deposition of molybdenum sulfide for electrochemical hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Kwon, Do Hyun; Jin, Zhenyu; Shin, Seokhee; Lee, Wook-Seong; Min, Yo-Sep

    2016-03-01

    Atomic layer deposition (ALD) has emerged as an efficient method to design and prepare catalysts with atomic precision. Here, we report a comprehensive study on ALD of molybdenum sulfide (MoSx) for an electrocatalytic hydrogen evolution reaction. By using molybdenum hexacarbonyl and dimethyldisulfide as the precursors of Mo and S, respectively, the MoSx catalysts are grown at 100 °C on porous carbon fiber papers (CFPs). The ALD process results in the growth of particle-like MoSx on the CFP due to the lack of adsorption sites, and its crystallographic structure is a mixture of amorphous and nano-crystalline phases. In order to unveil the intrinsic activity of the ALD-MoSx, the exchange current densities, Tafel slopes, and turnover frequencies of the catalysts grown under various ALD conditions have been investigated by considering the fractional surface coverage of MoSx on the CFP and catalytically-active surface area. In addition, the ALD-MoSx/CFP catalysts exhibit excellent catalytic stability due to the strong adhesion of MoSx on the CFP and the mixed phase.Atomic layer deposition (ALD) has emerged as an efficient method to design and prepare catalysts with atomic precision. Here, we report a comprehensive study on ALD of molybdenum sulfide (MoSx) for an electrocatalytic hydrogen evolution reaction. By using molybdenum hexacarbonyl and dimethyldisulfide as the precursors of Mo and S, respectively, the MoSx catalysts are grown at 100 °C on porous carbon fiber papers (CFPs). The ALD process results in the growth of particle-like MoSx on the CFP due to the lack of adsorption sites, and its crystallographic structure is a mixture of amorphous and nano-crystalline phases. In order to unveil the intrinsic activity of the ALD-MoSx, the exchange current densities, Tafel slopes, and turnover frequencies of the catalysts grown under various ALD conditions have been investigated by considering the fractional surface coverage of MoSx on the CFP and catalytically

  8. Suicide Fads: Frequency and Characteristics of Hydrogen Sulfide Suicides in the United States

    PubMed Central

    Reedy, Sarah Jane D.; Schwartz, Michael D.; Morgan, Brent W.

    2011-01-01

    Objective: To assess the frequency of hydrogen sulfide (H2S) suicides and describe the characteristics of victims in the United States (U.S.) since the technique became common in Japan in 2007. Methods: To ascertain the frequency of intentional H2S related deaths in the U.S. prior to the start of the Japanese trend in 2007, we searched the multiple-cause-of-death data from the National Vital Statistics System. To collect as much information about the victims as possible, we sent an email to the National Association of Medical Examiners (NAME) listserv asking for their cooperation in identifying cases of H2S suicide. To identify cases that were not voluntarily reported by medical examiners but were reported by the media, we conducted Google searches using the search terms: “hydrogen sulfide suicide,” “H2S suicide,” “detergent suicide,” “chemical suicide,” and “suicide fad.” We obtained all available autopsy reports and abstracted information, including the site of the incident, the presence of a note warning others about the toxic gas and the demographic characteristics of the victims. We contacted medical examiners who potentially had custody of the cases that were identified through media reports and requested autopsies of these victims. When unable to obtain the autopsies, we gathered information from the media reports. Results: Forty-five deaths from H2S exposure occurred in the U.S. from 1999 to 2007, all unintentional. Responses from the NAME listserv yielded autopsy reports for 11 victims, and Google searches revealed an additional 19 H2S suicides in the U.S. since 2008. Overall (n=30), two cases were identified during 2008, 10 in 2009, and 18 in 2010. The majority of victims were white males, less than 30-years-old, left a warning note, and were found in cars. There were five reports of injuries to first responders, but no secondary fatalities. Conclusion: H2S suicides are increasing in the U.S., and their incidence is probably

  9. Phosphorylation of BK channels modulates the sensitivity to hydrogen sulfide (H2S)

    PubMed Central

    Sitdikova, Guzel F.; Fuchs, Roman; Kainz, Verena; Weiger, Thomas M.; Hermann, Anton

    2014-01-01

    Introduction: Gases, such as nitric oxide (NO), carbon monoxide (CO), or hydrogen sulfide (H2S), termed gasotransmitters, play an increasingly important role in understanding of how electrical signaling of cells is modulated. H2S is well-known to act on various ion channels and receptors. In a previous study we reported that H2S increased calcium-activated potassium (BK) channel activity. Aims: The goal of the present study is to investigate the modulatory effect of BK channel phosphorylation on the action of H2S on the channel as well as to recalculate and determine the H2S concentrations in aqueous sodium hydrogen sulfide (NaHS) solutions. Methods: Single channel recordings of GH3, GH4, and GH4 STREX cells were used to analyze channel open probability, amplitude, and open dwell times. H2S was measured with an anion selective electrode. Results: The concentration of H2S produced from NaHS was recalculated taking pH, temperature salinity of the perfusate, and evaporation of H2S into account. The results indicate that from a concentration of 300 μM NaHS, only 11–13%, i.e., 34–41 μM is effective as H2S in solution. GH3, GH4, and GH4 STREX cells respond differently to phosphorylation. BK channel open probability (Po) of all cells lines used was increased by H2S in ATP-containing solutions. PKA prevented the action of H2S on channel Po in GH4 and GH4 STREX, but not in GH3 cells. H2S, high significantly increased Po of all PKG pretreated cells. In the presence of PKC, which lowers channel activity, H2S increased channel Po of GH4 and GH4 STREX, but not those of GH3 cells. H2S increased open dwell times of GH3 cells in the absence of ATP significantly. A significant increase of dwell times with H2S was also observed in the presence of okadaic acid. Conclusions: Our results suggest that phosphorylation by PKG primes the channels for H2S activation and indicate that channel phosphorylation plays an important role in the response to H2S. PMID:25429270

  10. New spectrophotometric methods for the determinations of hydrogen sulfide present in the samples of lake water, industrial effluents, tender coconut, sugarcane juice and egg

    NASA Astrophysics Data System (ADS)

    Shyla, B.; Nagendrappa, G.

    2012-10-01

    The new methods are working on the principle that iron(III) is reduced to iron(II) by hydrogen sulfide, catechol and p-toluidine the system 1/hydrogen sulfide the system 2, in acidic medium followed by the reduced iron forming complex with 1,10-phenanthroline with λmax 510 nm. The other two methods are based on redox reactions between electrolytically generated manganese(III) sulfate taken in excess and hydrogen sulfide followed by the unreacted oxidant oxidizing diphenylamine λmax 570 the system 3/barium diphenylamine sulphonate λmax 540 nm, the system 4. The increase/decrease in the color intensity of the dye products of the systems 1 and 2 or 3 and 4 are proportional to the concentration of hydrogen sulfide with its quantification range 0.035-1.40 μg ml-1/0.14-1.40 μg ml-1.

  11. New spectrophotometric methods for the determinations of hydrogen sulfide present in the samples of lake water, industrial effluents, tender coconut, sugarcane juice and egg.

    PubMed

    Shyla, B; Nagendrappa, G

    2012-10-01

    The new methods are working on the principle that iron(III) is reduced to iron(II) by hydrogen sulfide, catechol and p-toluidine the system 1/hydrogen sulfide the system 2, in acidic medium followed by the reduced iron forming complex with 1,10-phenanthroline with λ(max) 510 nm. The other two methods are based on redox reactions between electrolytically generated manganese(III) sulfate taken in excess and hydrogen sulfide followed by the unreacted oxidant oxidizing diphenylamine λ(max) 570 the system 3/barium diphenylamine sulphonate λ(max) 540 nm, the system 4. The increase/decrease in the color intensity of the dye products of the systems 1 and 2 or 3 and 4 are proportional to the concentration of hydrogen sulfide with its quantification range 0.035-1.40 μg ml(-1)/0.14-1.40 μg ml(-1).

  12. Influence of inhibitors on the corrosion cracking resistance of 65G steel wire in hydrogen sulfide solutions

    SciTech Connect

    Lubenskii, A.P.; Sokolova, T.I.

    1987-07-01

    Protection from hydrogen sulfide corrosion in the recovery and transport of natural gas is done with the use of inhibitors. In this paper the authors present results of an investigation into the resistance of steel to cracking under stress in aqueous solutions of hydrogen sulfide and calcium chloride in the presence of candidate inhibitors. Cold drawn wire of 65G steel was used. All the inhibitors were found to increase the resistance of steel to stress cracking but the degree of their influence on this form of corrosion failure varied. The decrease in their ability to retard stress corrosion cracking was found to be cause by chlorine anions and not by other factors such as the salting-out action of calcium chloride.

  13. Microbiological removal of hydrogen sulfide from biogas by means of a separate biofilter system: experience with technical operation.

    PubMed

    Schieder, D; Quicker, P; Schneider, R; Winter, H; Prechtl, S; Faulstich, M

    2003-01-01

    The "BIO-Sulfex" biofilter of ATZ-EVUS removes hydrogen sulfide from biogas in a biological way. Hydrogen sulfide causes massive problems during power generation from biogas in a power plant, e.g. corrosion of engines and heat exchangers, and thus causes frequent and therefore expensive engine oil changes. The BIO-Sulfex module is placed between the digester and the power-plant and warrants a cost-effective, reliable and fully biological desulfurization. In the cleaned gas concentrations of less than 100 ppm can be achieved. Power-plant manufacturers usually demand less than 500 or less than 200 ppm. At present, several plants with biogas flow rates between 20 and 350 m3/h are in operation.

  14. Sensitivity of Interfibrillar and Subsarcolemmal Mitochondria to Cobalt Chloride-induced Oxidative Stress and Hydrogen Sulfide Treatment.

    PubMed

    Ayswarya, A; Kurian, G A

    2016-01-01

    Oxidative stress plays a significant role not only in cardiovascular disease but also in non-communicable diseases, where it plays a significant role the mortality rate. Hydrogen sulfide, the biological gaseous signaling molecule that preserves mitochondria in its mode of action, is an effective cardioprotective drug. However, cardiac mitochondria comprise of two distinct populations, namely interfibrillar and subsarcolemmal mitochondria, which respond distinctly in cardiovascular disease. This study was designed to determine the direct impact of cobalt chloride-induced oxidative stress in isolated mitochondrial subpopulations with an intention to examine the efficacy of hydrogen sulfide in preserving interfibrillar and subsarcolemmal mitochondria functional activities when they were incubated as pretreated, co-treated and post-treated agent. Mitochondrial subpopulations were isolated from the heart of male Wistar rats and subjected to cobalt chloride treatment (500 μM) for 20 min, followed by incubation with 10 μM sodium hydrosulfide in three different ways (Pre, Co, and Post-cobalt chloride treatment). Mitochondrial oxidative stress was measured by the concentration of thiobarbituric acid reactive species, reduced glutathione and the activities of enzymes like superoxide dismutase, catalase and glutathione peroxidase. Mitochondrial membrane potential, swelling behavior and enzyme activities were measured to assess its function. The increased level of lipid peroxidation and the decreased level of reduced glutathione in cobalt chloride-induced group confirm the induction of oxidative stress and were more predominant in the subsarcolemmal mitochondria. Hydrogen sulfide treatment to interfibrillar and subsarcolemmal mitochondria preserved their functional activities, but the effect was prominent only with co-treated group. In conclusion, the present study demonstrated that subsarcolemmal mitochondria are more prone to oxidative stress and the co-treatment of the

  15. Concentrations of Bioaerosols, Odors and Hydrogen Sulfide Inside and Downwind from Two Types of Swine Livestock Operations

    PubMed Central

    Thorne, Peter S.; Ansley, Anne; Perry, Sarah Spencer

    2016-01-01

    Few data on in-barn and downwind concentrations of endotoxin, bioaerosols and odors from livestock facilities are available and no studies have compared conventional confinement operations to the more animal-friendly hoop operations. Hoops are open to the environment and use a composted bedding system rather than housing pigs on slatted floors over pits holding manure slurry as in conventional confinements. We assessed airborne toxicants upwind, in-barns and downwind and evaluated determinants of exposure. Inhalable particulate matter, endotoxin, odor threshold, hydrogen sulfide, culturable mesophilic bacteria, culturable fungi, and total airborne microbes along with wind speed, temperature, and humidity were measured at separate midsized livestock facilities (1 hoop, 1 confinement) in Central Iowa on ten occasions over two years. Significant differences in contaminants were observed between hoops and confinement buildings and across seasons for endotoxin, odors, airborne microorganisms, and hydrogen sulfide. For hoops and confinements, respectively, geometric mean in-barn concentrations were 3250 and 3100 EU/m3 for endotoxin; 1400 and 1910 μg/m3 for particulates; 19.6 and 146 ppb for hydrogen sulfide; 137 and 428 dilutions for odor threshold; and 3.0×106 and 1.5×106 organisms/m3 for total microbes. Endotoxin, odor, and culturable microorganisms exceeded recommended exposure limits. Reduced analysis of variance models for these contaminants demonstrated differences by barn type, season, number of pigs, and, in some cases, temperature and humidity. Both types of swine operations produced high airborne concentrations of endotoxin, odor, hydrogen sulfide, bacteria and fungi. Endotoxin and odors were found downwind at concentrations previously associated with adverse health effects. PMID:19177273

  16. Sensitivity of Interfibrillar and Subsarcolemmal Mitochondria to Cobalt Chloride-induced Oxidative Stress and Hydrogen Sulfide Treatment

    PubMed Central

    Ayswarya, A.; Kurian, G. A.

    2016-01-01

    Oxidative stress plays a significant role not only in cardiovascular disease but also in non-communicable diseases, where it plays a significant role the mortality rate. Hydrogen sulfide, the biological gaseous signaling molecule that preserves mitochondria in its mode of action, is an effective cardioprotective drug. However, cardiac mitochondria comprise of two distinct populations, namely interfibrillar and subsarcolemmal mitochondria, which respond distinctly in cardiovascular disease. This study was designed to determine the direct impact of cobalt chloride-induced oxidative stress in isolated mitochondrial subpopulations with an intention to examine the efficacy of hydrogen sulfide in preserving interfibrillar and subsarcolemmal mitochondria functional activities when they were incubated as pretreated, co-treated and post-treated agent. Mitochondrial subpopulations were isolated from the heart of male Wistar rats and subjected to cobalt chloride treatment (500 μM) for 20 min, followed by incubation with 10 μM sodium hydrosulfide in three different ways (Pre, Co, and Post-cobalt chloride treatment). Mitochondrial oxidative stress was measured by the concentration of thiobarbituric acid reactive species, reduced glutathione and the activities of enzymes like superoxide dismutase, catalase and glutathione peroxidase. Mitochondrial membrane potential, swelling behavior and enzyme activities were measured to assess its function. The increased level of lipid peroxidation and the decreased level of reduced glutathione in cobalt chloride-induced group confirm the induction of oxidative stress and were more predominant in the subsarcolemmal mitochondria. Hydrogen sulfide treatment to interfibrillar and subsarcolemmal mitochondria preserved their functional activities, but the effect was prominent only with co-treated group. In conclusion, the present study demonstrated that subsarcolemmal mitochondria are more prone to oxidative stress and the co-treatment of the

  17. Sensitivity of Interfibrillar and Subsarcolemmal Mitochondria to Cobalt Chloride-induced Oxidative Stress and Hydrogen Sulfide Treatment.

    PubMed

    Ayswarya, A; Kurian, G A

    2016-01-01

    Oxidative stress plays a significant role not only in cardiovascular disease but also in non-communicable diseases, where it plays a significant role the mortality rate. Hydrogen sulfide, the biological gaseous signaling molecule that preserves mitochondria in its mode of action, is an effective cardioprotective drug. However, cardiac mitochondria comprise of two distinct populations, namely interfibrillar and subsarcolemmal mitochondria, which respond distinctly in cardiovascular disease. This study was designed to determine the direct impact of cobalt chloride-induced oxidative stress in isolated mitochondrial subpopulations with an intention to examine the efficacy of hydrogen sulfide in preserving interfibrillar and subsarcolemmal mitochondria functional activities when they were incubated as pretreated, co-treated and post-treated agent. Mitochondrial subpopulations were isolated from the heart of male Wistar rats and subjected to cobalt chloride treatment (500 μM) for 20 min, followed by incubation with 10 μM sodium hydrosulfide in three different ways (Pre, Co, and Post-cobalt chloride treatment). Mitochondrial oxidative stress was measured by the concentration of thiobarbituric acid reactive species, reduced glutathione and the activities of enzymes like superoxide dismutase, catalase and glutathione peroxidase. Mitochondrial membrane potential, swelling behavior and enzyme activities were measured to assess its function. The increased level of lipid peroxidation and the decreased level of reduced glutathione in cobalt chloride-induced group confirm the induction of oxidative stress and were more predominant in the subsarcolemmal mitochondria. Hydrogen sulfide treatment to interfibrillar and subsarcolemmal mitochondria preserved their functional activities, but the effect was prominent only with co-treated group. In conclusion, the present study demonstrated that subsarcolemmal mitochondria are more prone to oxidative stress and the co-treatment of the

  18. Source Of Hydrogen Sulfide To Sulfidic Spring And Watershed Ecosystems In Northern Sierra De Chiapas, Mexico Based On Sulfur And Carbon Isotopes

    NASA Astrophysics Data System (ADS)

    Rosales Lagarde, L.; Boston, P. J.; Campbell, A.

    2013-12-01

    At least four watersheds in northern Sierra de Chiapas, Mexico are fed by conspicuous karst sulfide-rich springs. The toxic hydrogen sulfide (H2S) in these springs nurtures rich ecosystems including especially adapted microorganisms, invertebrates and fish. Sulfur and carbon isotopic analysis of various chemical species in the spring water are integrated within their hydrogeologic context to evaluate the hydrogen sulfide source. Constraining the H2S origin can also increase the understanding of this compound effect in the quality of the nearby hydrocarbon reservoirs, and the extent to which its oxidation to sulfuric acid increases carbonate dissolution and steel corrosion in surface structures. The SO42-/H2S ratio in the spring water varies from 70,000 to 2 meq/L thus sulfate is the dominant species in the groundwater system. This sulfate is mainly produced from anhydrite dissolution based on its isotopic signature. The Δ SO42--H2S range of 16 spring water samples (30-50 ‰) is similar to the values determined by Goldhaber & Kaplan (1975) and Canfield (2001) for low rates of bacterial sulfate reduction suggesting that this is the most important mechanism producing H2S. Although the carbon isotopes do not constrain the nature of the organic matter participating in this reaction, this material likely comes from depth, perhaps as hydrocarbons, due to the apparent stability of the system. The organic matter availability and reactivity probably control the progress of sulfate reduction. The subsurface environments identified in the area also have different sulfur isotopic values. The heavier residual sulfate isotopic value in the Northern brackish springs (δ34S SO42- ≥ 18 ‰) compared to the Southern springs (δ34S SO42- ~18 ‰) suggests sulfate reduction is particularly enhanced in the former, probably by contribution of organic matter associated with oil produced water. In comparison, the composition of the Southern aquifer is mainly influenced by halite

  19. Nonaqueous System of Iron-Based Ionic Liquid and DMF for the Oxidation of Hydrogen Sulfide and Regeneration by Electrolysis.

    PubMed

    Guo, Zhihui; Zhang, Tingting; Liu, Tiantian; Du, Jun; Jia, Bing; Gao, Shujing; Yu, Jiang

    2015-05-01

    To improve the hydrogen sulfide removal efficiency with the application of an iron-based imidazolium chloride ionic liquid (Fe(III)-IL) as desulfurizer, Fe(II) and N,N-dimethylformamide (DMF) are introduced to Fe(III)-IL to construct a new nonaqueous desulfurization system (Fe(III/II)-IL/DMF). Following desulfurization, the system can be regenerated using the controlled-potential electrolysis method. The addition of Fe(II) in Fe(III)-IL is beneficial for the hydrogen sulfide removal and the electrochemical regeneration of the desulfurizer. The addition of DMF in Fe(III/II)-IL does not change the structure of Fe(III/II)-IL but clearly decreases the acidity, increases the electrolytic current, and decreases the stability of the Fe-Cl bond in Fe(III/II)-IL. Fe(III/II)-IL/DMF can remove hydrogen sulfide and can be regenerated through an electrochemical method more efficiently than can Fe(III/II)-IL. After six cycles, the desulfurization efficiency remains higher than 98%, and the average conversion rate of Fe(II) is essentially unchanged. No sulfur peroxidation occurs, and the system remains stable. Therefore, this new nonaqueous system has considerable potential for removing H2S in pollution control applications.

  20. Oxidative stress suppresses the cellular bioenergetic effect of the 3-mercaptopyruvate sulfurtransferase/hydrogen sulfide pathway.

    PubMed

    Módis, Katalin; Asimakopoulou, Antonia; Coletta, Ciro; Papapetropoulos, Andreas; Szabo, Csaba

    2013-04-19

    Recent data show that lower concentrations of hydrogen sulfide (H2S), as well as endogenous, intramitochondrial production of H2S by the 3-mercaptopyruvate (3-MP)/3-mercaptopyruvate sulfurtransferase (3-MST) pathway serves as an electron donor and inorganic source of energy to support mitochondrial electron transport and ATP generation in mammalian cells by donating electrons to Complex II. The aim of our study was to investigate the role of oxidative stress on the activity of the 3-MP/3-MST/H2S pathway in vitro. Hydrogen peroxide (H2O2, 100-500 μM) caused a concentration-dependent decrease in the activity of recombinant mouse 3-MST enzyme. In mitochondria isolated from murine hepatoma cells, H2O2 (50-500 μM) caused a concentration-dependent decrease in production of H2S from 3-MP. In cultured murine hepatoma cells H2O2, (3-100 μM), did not result in overall cytotoxicity, but caused a partial decrease in basal oxygen consumption and respiratory reserve rapacity. The positive bioenergetic effect of 3-MP (100-300 nM) was completely abolished by pre-treatment of the cells with H2O2 (50 μM). The current findings demonstrate that oxidative stress inhibits 3-MST activity and interferes with the positive bioenergetic role of the 3-MP/3-MST/H2S pathway. These findings may have implications for the pathophysiology of various conditions associated with increased oxidative stress, such as various forms of critical illness, cardiovascular diseases, diabetes or physiological aging. PMID:23537657

  1. Bioenergetic relevance of hydrogen sulfide and the interplay between gasotransmitters at human cystathionine β-synthase.

    PubMed

    Vicente, João B; Malagrinò, Francesca; Arese, Marzia; Forte, Elena; Sarti, Paolo; Giuffrè, Alessandro

    2016-08-01

    Merely considered as a toxic gas in the past, hydrogen sulfide (H2S) is currently viewed as the third 'gasotransmitter' in addition to nitric oxide (NO) and carbon monoxide (CO), playing a key signalling role in human (patho)physiology. H2S can either act as a substrate or, similarly to CO and NO, an inhibitor of mitochondrial respiration, in the latter case by targeting cytochrome c oxidase (CcOX). The impact of H(2)S on mitochondrial energy metabolism crucially depends on the bioavailability of this gaseous molecule and its interplay with the other two gasotransmitters. The H(2)S-producing human enzyme cystathionine β-synthase (CBS), sustaining cellular bioenergetics in colorectal cancer cells, plays a role in the interplay between gasotransmitters. The enzyme was indeed recently shown to be negatively modulated by physiological concentrations of CO and NO, particularly in the presence of its allosteric activator S-adenosyl-l-methionine (AdoMet). These newly discovered regulatory mechanisms are herein reviewed. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:27039165

  2. Hydrogen Sulfide Improves Drought Tolerance in Arabidopsis thaliana by MicroRNA Expressions

    PubMed Central

    Yuan, Huihong; Liu, Zhiqiang; Jin, Zhuping; Zhang, Liping; Pei, Yanxi

    2013-01-01

    Hydrogen sulfide (H2S) is a gasotransmitter and plays an important role in many physiological processes in mammals. Studies of its functions in plants are attracting ever growing interest, for example, its ability to enhance drought resistance in Arabidopsis. A general role of microRNAs (miRNAs) in plant adaptive responses to drought stress has thereby increased our interest to delve into the possible interplay between H2S and miRNAs. Our results showed that treating wild type (WT) Arabidopsis seedlings with polyethylene glycol 8000 (PEG8000) to simulate drought stress caused an increase in production rate of endogenous H2S; and a significant transcriptional reformation of relevant miRNAs, which were also triggered by exogenous H2S in WT. When lcd mutants (with lower H2S production rate than WT) were treated with PEG8000, they showed lower levels of miRNA expression changes than WT. In addition, we detected significant changes in target gene expression of those miRNAs and the corresponding phenotypes in lcd, including less roots, retardation of leaf growth and development and greater superoxide dismutase (SOD) activity under drought stress. We thereby conclude that H2S can improve drought resistance through regulating drought associated miRNAs in Arabidopsis. PMID:24194857

  3. Hydrogen sulfide interacts with calcium signaling to enhance the chromium tolerance in Setaria italica.

    PubMed

    Fang, Huihui; Jing, Tao; Liu, Zhiqiang; Zhang, Liping; Jin, Zhuping; Pei, Yanxi

    2014-12-01

    The oscillation of intracellular calcium (Ca(2+)) concentration is a primary event in numerous biological processes in plants, including stress response. Hydrogen sulfide (H2S), an emerging gasotransmitter, was found to have positive effects in plants responding to chromium (Cr(6+)) stress through interacting with Ca(2+) signaling. While Ca(2+) resemblances H2S in mediating biotic and abiotic stresses, crosstalk between the two pathways remains unclear. In this study, Ca(2+) signaling interacted with H2S to produce a complex physiological response, which enhanced the Cr(6+) tolerance in foxtail millet (Setaria italica). Results indicate that Cr(6+) stress activated endogenous H2S synthesis as well as Ca(2+) signaling. Moreover, toxic symptoms caused by Cr(6+) stress were strongly moderated by 50μM H2S and 20mM Ca(2+). Conversely, treatments with H2S synthesis inhibitor and Ca(2+) chelators prior to Cr(6+)-exposure aggravated these toxic symptoms. Interestingly, Ca(2+) upregulated expression of two important factors in metal metabolism, MT3A and PCS, which participated in the biosynthesis of heavy metal chelators, in a H2S-dependent manner to cope with Cr(6+) stress. These findings also suggest that the H2S dependent pathway is a component of the Ca(2+) activating antioxidant system and H2S partially contributes Ca(2+)-activating antioxidant system.

  4. Anti-Cancer Activity of New Designer Hydrogen Sulfide-Donating Hybrids

    PubMed Central

    2014-01-01

    Abstract Significance: Hydrogen sulfide (H2S) is likely to join nitric oxide (NO) and carbon monoxide (CO) as the third gaseous transmitter, influencing an array of intracellular signaling cascades. Thus, H2S is implicated in numerous physiological processes and in the pathology of various diseases. Recent Advances: H2S-donating agents that liberate H2S slowly either alone or in combination with NO, the so-called NOSH compounds, are being synthesized, and these have been shown to have great potential against cancer. Critical Issues: An accurate determination of H2S levels is challenging. H2S and NO share many similar actions; do these similarities act to potentiate each other? Since many actions of H2S appear to be mediated through inhibition of inflammation and Nuclear factor kappa-light-chain-enhancer of activated B cells is a central player in this scenario, does S-nitrosylation of this transcription factor by NO affect its S-sulfhydration by H2S and vice versa? Future Directions: Deciphering the molecular targets of these novel hybrid agents and having genetically engineered animals should help us move toward targeted therapeutic applications. Human safety data with these new hybrids is essential. Antioxid. Redox Signal. 20, 831–846. PMID:23581880

  5. New catalysts active for the mild oxidation of hydrogen sulfide to sulfur

    SciTech Connect

    Laperdrix, E.; Costentin, G.; Guyen, N.N.; Saur, O.; Lavalley, J.C.

    1999-10-25

    Nickel iron phosphates were studied for the selective oxidation of hydrogen sulfide to sulfur. Nickel iron phosphate and Fe/Cr samples were more active than simple iron, chromium, and mixed iron-chromium oxides, which has been previously studied. Nickel iron phosphate catalyst prepared by solid-solid method with, consequently, a very low specific surface area was intrinsically active and selective to sulfur (conversion 17%, S{sub n} selectivity 97%); no rapid deactivation was observed. Even though higher specific surface area samples, prepared according to a solution method at various calcination temperatures, showed better performance (conversion 76%, S{sub n}selectivity {gt}90%), the specific activity depended on the crystallinity of the samples. The reaction is apparently structure sensitive. The structure of the catalytic material must facilitate electronic exchange, evidence by Moessbauer characterization. The establishment of the mixed valency Fe{sub 2+}/Fe{sup 3+} under catalytic feed was shown to be an essential factor in this reaction.

  6. Hydrogen sulfide alleviates hypoxia-induced root tip death in Pisum sativum.

    PubMed

    Cheng, Wei; Zhang, Liang; Jiao, Chengjin; Su, Miao; Yang, Tao; Zhou, Lina; Peng, Renyi; Wang, Ranran; Wang, Chongying

    2013-09-01

    Flooding of soils often results in hypoxic conditions surrounding plant roots, which is a harmful abiotic stress to crops. Hydrogen sulfide (H2S) is a highly diffusible, gaseous molecule that modulates cell signaling and is involved in hypoxia signaling in animal cells. However, there have been no previous studies of H2S in plant cells in response to hypoxia. The effects of H2S on hypoxia-induced root tip death were studied in pea (Pisum sativum) via analysis of endogenous H2S and reactive oxygen species (ROS) levels. The activities of key enzymes involved in antioxidative and H2S metabolic pathways were determined using spectrophotometric assays. Ethylene was measured by gas chromatography. We found that exogenous H2S pretreatment dramatically alleviated hypoxia-induced root tip death by protecting root tip cell membranes from ROS damage induced by hypoxia and by stimulating a quiescence strategy through inhibiting ethylene production. Conversely, root tip death induced by hypoxia was strongly enhanced by inhibition of the key enzymes responsible for endogenous H2S biosynthesis. Our results demonstrated that exogenous H2S pretreatment significantly alleviates hypoxia-induced root tip death in pea seedlings and, therefore, enhances the tolerance of the plant to hypoxic stress.

  7. Case report: Profound neurobehavioral deficits in an oil field worker overcome by hydrogen sulfide

    SciTech Connect

    Kilburn, K.H. )

    1993-11-01

    A 24-year-old oil well tester was rendered semiconscious by hydrogen sulfide (H2S). He received oxygen and was hospitalized but released in 30 minutes. The next day, nausea, vomiting, diarrhea, and incontinence of urine and stool led to rehospitalization. These problems and leg shaking, dizziness, sweating, trouble sleeping, and nightmares prevented his return to work. A physical examination, chest x-ray, and pulmonary function tests were normal 39 months after the episode but vibration sense was diminished. Two choice visual reaction times were delayed. Balance was highly abnormal (5 to 6 cm/sec) with eyes closed. Blink reflex latency was slow (R-1 17.5 msec versus normal 14.3 msec). Numbers written on finger tips were not recognized. Verbal and visual recall were impaired but overlearned memory was intact. Cognitive functions measured by Culture Fair, block design, and digit symbol were impaired. Perceptual motor was slow. Scores for confusion, tension-anxiety, depression, and fatigue were elevated and vigor was reduced. Forty-nine months after exposure his reaction time, sway speed, and color vision had not improved. His recall and his cognitive, constructional, and psychomotor speeds had improved but remained abnormal. These deficits are most likely due to H2S. Similar testing of other survivors is recommended.

  8. Hydrogen sulfide in renal physiology, disease and transplantation--the smell of renal protection.

    PubMed

    Koning, Anne M; Frenay, Anne-Roos S; Leuvenink, Henri G D; van Goor, Harry

    2015-04-30

    Hydrogen sulfide (H2S), the third gasotransmitter, next to nitric oxide and carbon monoxide, is a key mediator in physiology and disease. It is involved in homeostatic functions, such as blood pressure control, electrolyte balance and apoptosis, and regulates pathological mechanisms, including oxidative stress and inflammation. Besides, it is believed to serve as an oxygen sensor under ischemic conditions. The kidney plays a decisive role in many of these processes, indicating an interplay between H2S and renal (patho)physiology. In this review we focus on the (protective) functions of H2S in the kidney. We first discuss endogenous renal H2S production and signaling and elaborate on its regulatory functions in renal physiology. Next, we present data on the role of aberrant H2S levels in the onset and progression of renal disease and suggest the use of H2S metabolites as biomarkers. Finally, we describe that exogenous H2S can protect the kidney against various forms of injury and conclude that modulation of renal H2S levels holds promise for renal patients in the future.

  9. Hydrogen sulfide mediates the protection of dietary restriction against renal senescence in aged F344 rats.

    PubMed

    Wang, Wen-Juan; Cai, Guang-Yan; Ning, Yi-Chun; Cui, Jing; Hong, Quan; Bai, Xue-Yuan; Xu, Xiao-Meng; Bu, Ru; Sun, Xue-Feng; Chen, Xiang-Mei

    2016-07-26

    Renal aging is always accompanied by increased oxidative stress. Hydrogen sulfide (H2S) can be up-regulated by 50% dietary restriction (DR) for 7-day and can block mitochondrial oxidative stress. H2S production exerts a critical role in yeast, worm, and fruit fly models of DR-mediated longevity. In this study, we found that renal aging could be attenuated by 30% DR for 6-month (DR-6M) and life-long (DR-LL), but not for 6-week (DR-6W). The expressions of cystathionine-γ-lyase (CGL) and cystathionine-β- synthase (CBS) were improved by DR-6M and DR-LL. Endogenous H2S production shared the same trend with CBS and CGL, while glutathione (GSH) didn't. When comparing efficiencies of DR for different durations, more evident production of H2S was found in DR-6M and DR-LL than in DR-6W. Finally the level of oxidative stress was improved by DR-6M and DR-LL rather than by DR-6W. It concluded that aged rats had the ability to produce enough H2S on 30% DR interventions protecting against renal aging, and the effect of DR for long-term were more significant than that of DR for short-term.

  10. Hydrogen sulfide improves cardiomyocytes electrical remodeling post ischemia/reperfusion injury in rats.

    PubMed

    Sun, Ying-Gang; Wang, Xin-Yan; Chen, Xiu; Shen, Cheng-Xing; Li, Yi-Gang

    2015-01-01

    Hydrogen sulfide (H2S), produced by cystanthionine-γ-lysase (CSE) in the cardiovascular system, is an endogenous gaseous mediator exerting pronounced physiological effects as the third gasotransmitter in addition to nitric oxide (NO) and carbon monoxide (CO). Accumulating evidence indicated that H2S could mediate the cardioprotective effects in myocardial ischemia model. Ventricular arrhythmia is the most important risk factor for cardiac mortality and sudden death after acute myocardial infarction (AMI). The potential impact of H2S on cardiomyocytes electrical remodeling post ischemic insult is not fully explored now. Present study investigated the role of H2S on cardiomyocytes electrical remodeling in rats with ischemia/reperfusion injury. H2S concentration was reduced and arrhythmia score was increased in this model. CSE mRNA level was also upregulated in the ischemic myocardium. Exposure to exogenous NaHS reduced the action potential duration (APD), inhibited L-type Ca(2+) channels and activated K(ATP) channels in cardiomyocytes isolated from ischemic myocardium Exogenous H2S application improves electrical remodeling in cardiomyocytes isolated from ischemic myocardium. These results indicated that reduced H2S level might be linked to ischemia/reperfusion induced arrhythmias. PMID:25755736

  11. Hydrogen sulfide improves cardiomyocytes electrical remodeling post ischemia/reperfusion injury in rats

    PubMed Central

    Sun, Ying-Gang; Wang, Xin-Yan; Chen, Xiu; Shen, Cheng-Xing; Li, Yi-Gang

    2015-01-01

    Hydrogen sulfide (H2S), produced by cystanthionine-γ-lysase (CSE) in the cardiovascular system, is an endogenous gaseous mediator exerting pronounced physiological effects as the third gasotransmitter in addition to nitric oxide (NO) and carbon monoxide (CO). Accumulating evidence indicated that H2S could mediate the cardioprotective effects in myocardial ischemia model. Ventricular arrhythmia is the most important risk factor for cardiac mortality and sudden death after acute myocardial infarction (AMI). The potential impact of H2S on cardiomyocytes electrical remodeling post ischemic insult is not fully explored now. Present study investigated the role of H2S on cardiomyocytes electrical remodeling in rats with ischemia/reperfusion injury. H2S concentration was reduced and arrhythmia score was increased in this model. CSE mRNA level was also upregulated in the ischemic myocardium. Exposure to exogenous NaHS reduced the action potential duration (APD), inhibited L-type Ca2+ channels and activated KATP channels in cardiomyocytes isolated from ischemic myocardium Exogenous H2S application improves electrical remodeling in cardiomyocytes isolated from ischemic myocardium. These results indicated that reduced H2S level might be linked to ischemia/reperfusion induced arrhythmias. PMID:25755736

  12. Hydrogen Sulfide Detection Using a Gold Nanoparticle/Metalloprotein Based Probe

    NASA Astrophysics Data System (ADS)

    Meisam, Omidi; Gh., Amoabediny; Yazdian, F.; Habibi-Rezaei, M.

    2014-08-01

    We present a simple method for direct detection of hydrogen sulfide (H2S) in an aqueous solution. This method represents a novel biosensor based on metalloprotein cytochrome c (cyt c) with the localized surface plasmon resonance of gold nanoparticles (AuNPs). For this purpose, we develop a new approach based on attaching chemically-modified cyt c onto AuNPs. Here, by reacting H2S with protein heme center, its conformation changes in the locality of the heme moiety. The conformational changes occurring in the protein alter the spectral characteristics by changing the dielectric properties of AuNPs. The conformational changes of cyt c induced by the H2S interaction are characterized by the UV-visible absorption spectroscopy and the circular dichroism technique. The limit of the detection and sensitivity of the AuNPs/cyt c biosensor are evaluated by using UV-visible spectroscopy. According to the experiments, it is revealed that H2S can be detected at a concentration of 4.0 μM (1.3 ppb) by the fabricated AuNPs/cyt c biosensor. In addition, the sensor retains activity and gives reproducible results after storage in 4°C for 60 d. This simple and cost-effective sensing platform provides a rapid and convenient detection for H2S at concentrations far below the hazardous limit.

  13. A comprehensive study on atomic layer deposition of molybdenum sulfide for electrochemical hydrogen evolution.

    PubMed

    Kwon, Do Hyun; Jin, Zhenyu; Shin, Seokhee; Lee, Wook-Seong; Min, Yo-Sep

    2016-04-01

    Atomic layer deposition (ALD) has emerged as an efficient method to design and prepare catalysts with atomic precision. Here, we report a comprehensive study on ALD of molybdenum sulfide (MoSx) for an electrocatalytic hydrogen evolution reaction. By using molybdenum hexacarbonyl and dimethyldisulfide as the precursors of Mo and S, respectively, the MoSx catalysts are grown at 100 °C on porous carbon fiber papers (CFPs). The ALD process results in the growth of particle-like MoSx on the CFP due to the lack of adsorption sites, and its crystallographic structure is a mixture of amorphous and nano-crystalline phases. In order to unveil the intrinsic activity of the ALD-MoSx, the exchange current densities, Tafel slopes, and turnover frequencies of the catalysts grown under various ALD conditions have been investigated by considering the fractional surface coverage of MoSx on the CFP and catalytically-active surface area. In addition, the ALD-MoSx/CFP catalysts exhibit excellent catalytic stability due to the strong adhesion of MoSx on the CFP and the mixed phase. PMID:26973254

  14. Hydrogen sulfide inhibits enzymatic browning of fresh-cut lotus root slices by regulating phenolic metabolism.

    PubMed

    Sun, Ying; Zhang, Wei; Zeng, Tao; Nie, Qixing; Zhang, Fengying; Zhu, Liqin

    2015-06-15

    The effect of fumigation with hydrogen sulfide (H2S) gas on inhibiting enzymatic browning of fresh-cut lotus root slices was investigated. Browning degree, changes in color, total phenol content, superoxide anion production rate (O2(-)), H2O2 content, antioxidant capacities (DPPH radical scavenging ability, ABTS radical scavenging activity and the reducing power) and activities of the phenol metabolism-associated enzymes including phenylalanine ammonialyase (PAL), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) were evaluated. The results showed that treatment with 15 μl L(-1) H2S significantly inhibited the browning of fresh-cut lotus root slices (P<0.05), reduced significantly O2(-) production rate and H2O2 content, and enhanced antioxidant capacities (P<0.05). PPO and POD activities in the fresh-cut lotus root slices were also significantly inhibited by treatment with H2S (P<0.05). This study suggested that treatment with exogenous H2S could inhibit the browning of fresh-cut lotus root slices by enhancing antioxidant capacities to alleviate the oxidative damage.

  15. Operando spectroscopic analysis of an amorphous cobalt sulfide hydrogen evolution electrocatalyst.

    PubMed

    Kornienko, Nikolay; Resasco, Joaquin; Becknell, Nigel; Jiang, Chang-Ming; Liu, Yi-Sheng; Nie, Kaiqi; Sun, Xuhui; Guo, Jinghua; Leone, Stephen R; Yang, Peidong

    2015-06-17

    The generation of chemical fuel in the form of molecular H2 via the electrolysis of water is regarded to be a promising approach to convert incident solar power into an energy storage medium. Highly efficient and cost-effective catalysts are required to make such an approach practical on a large scale. Recently, a number of amorphous hydrogen evolution reaction (HER) catalysts have emerged that show promise in terms of scalability and reactivity, yet remain poorly understood. In this work, we utilize Raman spectroscopy and X-ray absorption spectroscopy (XAS) as a tool to elucidate the structure and function of an amorphous cobalt sulfide (CoSx) catalyst. Ex situ measurements reveal that the as-deposited CoSx catalyst is composed of small clusters in which the cobalt is surrounded by both sulfur and oxygen. Operando experiments, performed while the CoSx is catalyzing the HER, yield a molecular model in which cobalt is in an octahedral CoS2-like state where the cobalt center is predominantly surrounded by a first shell of sulfur atoms, which, in turn, are preferentially exposed to electrolyte relative to bulk CoS2. We surmise that these CoS2-like clusters form under cathodic polarization and expose a high density of catalytically active sulfur sites for the HER.

  16. Optical properties of copper oxide thin films as selective sensing principle for hydrogen sulfide detection

    NASA Astrophysics Data System (ADS)

    Kneer, Janosch; Boxberg, Manuel; Wöllenstein, Jürgen

    2013-05-01

    Semiconducting cuprous (Cu2O) and cupric oxide (CuO) have been subject to intense research efforts, mainly because of the materials' potential for photovoltaic applications and as doping material. In this work, the impact of hydrogen sulfide (H2S) exposure on thin film samples of CuO and Cu2O has been investigated, focusing on alterations in the optical properties. The materials composition was verified using Raman spectroscopy. The samples were exposed to well-defined dosages of H2S and the transmission and reflection characteristics in the expanded UV/Vis regime (350-1100 nm) were recorded. Cu2O films showed an explicit increase in transmissivity for the wavelength region l = 550-900 nm, besides a general decrease in reflectivity of all samples within the considered spectral range. Optical band gaps were determined using Tauc's plotting, revealing a shift in the slope of a2 of CuO after gas exposure. The observed effects can be exploited as sensing effect, which was examined in a thin film total-internal-reflection (TIR) set-up to transiently monitor surface-gas interactions, yielding reproducible changes in response to 20 min exposure to5 ppm H2S.

  17. The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential.

    PubMed

    Shen, Yaqi; Shen, Zhuqing; Luo, Shanshan; Guo, Wei; Zhu, Yi Zhun

    2015-01-01

    Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases. Therefore, insight into the molecular mechanisms underlying H2S action in the heart may promote the understanding of pathophysiology of cardiac diseases and lead to new therapeutic targets based on modulation of H2S production.

  18. Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis.

    PubMed

    Shi, Haitao; Ye, Tiantian; Han, Ning; Bian, Hongwu; Liu, Xiaodong; Chan, Zhulong

    2015-07-01

    Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NaHS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interestingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcriptionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors. PMID:25329496

  19. Hydrogen sulfide generation in simulated construction and demolition debris landfills: impact of waste composition.

    PubMed

    Yang, Kenton; Xu, Qiyong; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel; Booth, Matthew

    2006-08-01

    Hydrogen sulfide (H2S) generation in construction and demolition (C&D) debris landfills has been associated with the biodegradation of gypsum drywall. Laboratory research was conducted to observe H2S generation when drywall was codisposed with different C&D debris constituents. Two experiments were conducted using simulated landfill columns. Experiment 1 consisted of various combinations of drywall, wood, and concrete to determine the impact of different waste constituents and combinations on H2S generation. Experiment 2 was designed to examine the effect of concrete on H2S generation and migration. The results indicate that decaying drywall, even alone, leached enough sulfate ions and organic matter for sulfate-reducing bacteria (SRB) to generate large H2S concentrations as high as 63,000 ppmv. The codisposed wastes show some effect on H2S generation. At the end of experiment 1, the wood/drywall and drywall alone columns possessed H2S concentrations > 40,000 ppmv. Conversely, H2S concentrations were < 1 ppmv in those columns containing concrete. Concrete plays a role in decreasing H2S by increasing pH out of the range for SRB growth and by reacting with H2S. This study also showed that wood lowered H2S concentrations initially by decreasing leachate pH values. Based on the results, two possible control mechanisms to mitigate H2S generation in C&D debris landfills are suggested. PMID:16933645

  20. Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis.

    PubMed

    Shi, Haitao; Ye, Tiantian; Han, Ning; Bian, Hongwu; Liu, Xiaodong; Chan, Zhulong

    2015-07-01

    Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NaHS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interestingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcriptionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors.

  1. C. elegans Aging Is Modulated by Hydrogen Sulfide and the sulfhydrylase/cysteine Synthase cysl-2

    PubMed Central

    Qabazard, Bedoor; Ahmed, Samanza; Li, Ling; Arlt, Volker M.; Moore, Philip K.; Stürzenbaum, Stephen R.

    2013-01-01

    Exogenous hydrogen sulfide (H2S) administration and endogenous H2S metabolism were explored in the nematode C. elegans. Chronic treatment with a slow-releasing H2S donor, GYY4137, extended median survival by 17-23% and increased tolerance towards oxidative and endoplasmic reticulum (ER) stress. Also, cysl-2, a sulfhydrylase/cysteine synthase in C. elegans, was transcriptionally upregulated by GYY4137 treatment and the deletion of cysl-2 resulted in a significant reduction in lifespan which was partially recovered by the supplementation of GYY4137. Likewise, a mammalian cell culture system, GYY4137 was able to protect bovine aortic endothelial cells (BAECs) from oxidative stress and (H2O2)-induced cell death. Taken together, this provides further support that H2S exerts a protective function which is consistent with the longevity dividend theory. Overall, this study underlines the therapeutic potential of a slow-releasing H2S donor as regulators of the aging and cellular stress pathways. PMID:24260346

  2. The mechanism of hydrogen sulfide adsorption on fine rubber particle media (FRPM).

    PubMed

    Wang, Ning; Park, Jaeyoung; Ellis, Timothy G

    2013-09-15

    A commercial rubber waste product, fine rubber particle media (FRPM), was found to adsorb hydrogen sulfide (H₂S) at 0.12 mg H₂S/g FRPM of adsorption capacity. Since FRPM seems to be an attractive alternative to treat H₂S owing to its economic advantages as well as its physicochemical characteristics, several analyses were conducted to investigate fundamental information, surface properties, and breakthrough characteristics of FRPM as adsorbent. The physical properties of FRPM including composition and surface chemistry were investigated to compare its performance with commonly available commercial H₂S adsorbents such as activated carbon and assess the possible adsorption mechanism. The specific surface area of FRPM was less than 1% of activated carbon. FRPM does not have enough surface area supporting a pure physical adsorption of H₂S because it is particulate in nature with limited porosity. The adsorption of FRPM to remove H₂S was complex mechanism and involved a combination of zinc compounds and carbon black.

  3. Hydrogen sulfide improves left ventricular function in smoking rats via regulation of apoptosis and autophagy.

    PubMed

    Zhou, Xiang; An, Guoyin; Chen, Jianchang

    2014-06-01

    The present study was designed to investigate the protective effects of hydrogen sulfide (H2S) against cigarette smoking-induced left ventricular dysfunction in rats. Left ventricular structure and function were assessed using two-dimensional echocardiography. Cardiomyocyte apoptosis was determined by Annexin V/PI and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. Cardiac autophagy was evaluated by detection of autophagy-related protein expression and observation of autophagosomes. Our results indicated that administration of NaHS (a donor of H2S) could protect against smoking-induced left ventricular systolic dysfunction. H2S was found to exert anti-apoptotic effects in the myocardium of smoking rats by inhibiting JNK and P38 mitogen-activated protein kinases pathways and activating PI3K/Akt signaling. Moreover, H2S could also reduce smoking-induced autophagic cell death via regulation of AMPK/mTOR signaling pathway. In conclusion, our study demonstrates that H2S can improve left ventricular systolic function in smoking rats via regulation of apoptosis and autophagy.

  4. Interaction of Hydrogen Sulfide with Nitric Oxide in the Cardiovascular System

    PubMed Central

    Nagpure, B. V.; Bian, Jin-Song

    2016-01-01

    Historically acknowledged as toxic gases, hydrogen sulfide (H2S) and nitric oxide (NO) are now recognized as the predominant members of a new family of signaling molecules, “gasotransmitters” in mammals. While H2S is biosynthesized by three constitutively expressed enzymes (CBS, CSE, and 3-MST) from L-cysteine and homocysteine, NO is generated endogenously from L-arginine by the action of various isoforms of NOS. Both gases have been transpired as the key and independent regulators of many physiological functions in mammalian cardiovascular, nervous, gastrointestinal, respiratory, and immune systems. The analogy between these two gasotransmitters is evident not only from their paracrine mode of signaling, but also from the identical and/or shared signaling transduction pathways. With the plethora of research in the pathophysiological role of gasotransmitters in various systems, the existence of interplay between these gases is being widely accepted. Chemical interaction between NO and H2S may generate nitroxyl (HNO), which plays a specific effective role within the cardiovascular system. In this review article, we have attempted to provide current understanding of the individual and interactive roles of H2S and NO signaling in mammalian cardiovascular system, focusing particularly on heart contractility, cardioprotection, vascular tone, angiogenesis, and oxidative stress. PMID:26640616

  5. Superoxide Mediates Depressive Effects Induced by Hydrogen Sulfide in Rostral Ventrolateral Medulla of Spontaneously Hypertensive Rats

    PubMed Central

    Yu, Haiyun; Xu, Haiyan; Liu, Xiaoni; Zhang, Nana; He, Anqi; Yu, Jerry; Lu, Ning

    2015-01-01

    Hydrogen sulfide (H2S) plays a crucial role in the regulation of blood pressure and oxidative stress. In the present study, we tested the hypothesis that H2S exerts its cardiovascular effects by reducing oxidative stress via inhibition of NADPH oxidase activity in the rostral ventrolateral medulla (RVLM). We examined cell distributions of cystathionine-β-synthase (CBS) and effects of H2S on reactive oxygen species (ROS) and mean arterial blood pressure (MAP) in spontaneously hypertensive rats (SHRs). We found that CBS was expressed in neurons of the RVLM, and the expression was lower in SHRs than in Wistar-Kyoto rats. Microinjection of NaHS (H2S donor), S-adenosyl-l-methionine (SAM, a CBS agonist), or Apocynin (NADPH oxidase inhibitor) into the RVLM reduced the ROS level, NADPH oxidase activity, and MAP, whereas microinjection of hydroxylamine hydrochloride (HA, a CBS inhibitor) increased MAP. Furthermore, intracerebroventricular infusion of NaHS inhibited phosphorylation of p47phox, a key step of NADPH oxidase activation. Since decreasing ROS level in the RVLM reduces MAP and heart rate and increasing H2S reduces ROS production, we conclude that H2S exerts an antihypertensive effect via suppressing ROS production. H2S, as an antioxidant, may be a potential target for cardiovascular diseases. PMID:26078823

  6. Methylation reactions, the redox balance and atherothrombosis: the search for a link with hydrogen sulfide.

    PubMed

    Lupoli, Roberta; Di Minno, Alessandro; Spadarella, Gaia; Franchini, Massimo; Sorrentino, Raffaella; Cirino, Giuseppe; Di Minno, Giovanni

    2015-06-01

    It is now clear that homocysteine (Hcy) is irreversibly degraded to hydrogen sulfide (H(2)S), an endogenous gasotransmitter that causes in vivo platelet activation via upregulation of phospholipase A2 and downstream boost of the arachidonate cascade. This mechanism involves a transsulfuration pathway. Based on these new data, clinical and experimental models on the relationships between Hcy and folate pathways in vascular disease and information on the Hcy controversy have been reanalyzed in the present review. Most interventional trials focused on Hcy lowering by folate administration did not exclude patients routinely taking the arachidonate inhibitor aspirin. This may have influenced the results of some of these trials. It is also clear that nutritional intake of folate affects several enzymatic reactions of the methionine-Hcy cycle and associated one-carbon metabolism and, thereby, both methylation reactions and redox balance. Hence, it is conceivable that the abnormally high Hcy levels seen in pathologic states reflect a poorly elucidated perturbation of such reactions and of such balance. While it is unknown whether there is an interplay between H2S, methylation reactions, and redox balance, measuring the sole reduction of blood Hcy that follows folate administration may well be an oversimplified approach to a complex biologic perturbation. The need to investigate this complex framework is thoroughly discussed in this article.

  7. Bioenergetic relevance of hydrogen sulfide and the interplay between gasotransmitters at human cystathionine β-synthase.

    PubMed

    Vicente, João B; Malagrinò, Francesca; Arese, Marzia; Forte, Elena; Sarti, Paolo; Giuffrè, Alessandro

    2016-08-01

    Merely considered as a toxic gas in the past, hydrogen sulfide (H2S) is currently viewed as the third 'gasotransmitter' in addition to nitric oxide (NO) and carbon monoxide (CO), playing a key signalling role in human (patho)physiology. H2S can either act as a substrate or, similarly to CO and NO, an inhibitor of mitochondrial respiration, in the latter case by targeting cytochrome c oxidase (CcOX). The impact of H(2)S on mitochondrial energy metabolism crucially depends on the bioavailability of this gaseous molecule and its interplay with the other two gasotransmitters. The H(2)S-producing human enzyme cystathionine β-synthase (CBS), sustaining cellular bioenergetics in colorectal cancer cells, plays a role in the interplay between gasotransmitters. The enzyme was indeed recently shown to be negatively modulated by physiological concentrations of CO and NO, particularly in the presence of its allosteric activator S-adenosyl-l-methionine (AdoMet). These newly discovered regulatory mechanisms are herein reviewed. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.

  8. [THE INFLUENCE OF HYDROGEN SULFIDE ON COLLAGEN-INDUCED AGGREGATION OF HUMAN PLATELETS].

    PubMed

    Petrova, I V; Trubacheva, O A; Mangataeva, O S; Suslova, T E; Kovalev, I V; Gusakova, S V

    2015-10-01

    Study the impact of hydrogen sulfide on collagen-induced platelet aggregation from healthy donors and patients with type 2 diabetes. In healthy individuals, in contrast to patients with type 2 diabetes, NaHS significantly inhibited platelet aggregation. Activators of cAMP signaling (forskolin and phosphodiesterase inhibitor) significantly reduced platelet aggregation in both groups of examinees. NO-synthase inhibitors increased platelet aggregation in healthy volunteers, but not in patients with type 2 diabetes. The presence of H2S donor did not alter the extent of platelet aggregation at high concentrations of cAMP or decreased production of nitric oxide. It is assumed that the antiplatelet effect of H2S is not associated with the effect on the signal system, mediated cAMP or nitric oxide. Change H2S-dependent regulation of platelet aggregation in patients with type 2 diabetes is caused by disorders have been reported with this disease: the increase of intracellular calcium ion concentration, oxidative damage to proteins, hyperhomocysteinemia, glycosylation of key proteins involved in this process.

  9. Emergence of hydrogen sulfide as an endogenous gaseous signaling molecule in cardiovascular disease.

    PubMed

    Polhemus, David J; Lefer, David J

    2014-02-14

    Long recognized as a malodorous and highly toxic gas, recent experimental studies have revealed that hydrogen sulfide (H2S) is produced enzymatically in all mammalian species including man and exerts several critical actions to promote cardiovascular homeostasis and health. During the past 15 years, scientists have determined that H2S is produced by 3 endogenous enzymes and exerts powerful effects on endothelial cells, smooth muscle cells, inflammatory cells, mitochondria, endoplasmic reticulum, and nuclear transcription factors. These effects have been reported in multiple organ systems, and the majority of data clearly indicate that H2S produced by the endogenous enzymes exerts cytoprotective actions. Recent preclinical studies investigating cardiovascular diseases have demonstrated that the administration of physiological or pharmacological levels of H2S attenuates myocardial injury, protects blood vessels, limits inflammation, and regulates blood pressure. H2S has emerged as a critical cardiovascular signaling molecule similar to nitric oxide and carbon monoxide with a profound effect on the heart and circulation. Our improved understanding of how H2S elicits protective actions, coupled with the rapid development of novel H2S-releasing agents, has resulted in heightened enthusiasm for the clinical translation of this ephemeral gaseous molecule. This review will examine our current state of knowledge about the actions of H2S within the cardiovascular system with an emphasis on the therapeutic potential and molecular cross talk between H2S, nitric oxide, and carbon monoxide.

  10. Hydrogen Sulfide Delays LPS-Induced Preterm Birth in Mice via Anti-Inflammatory Pathways

    PubMed Central

    Liu, Weina; Xu, Chen; You, Xingji; Olson, David M.; Chemtob, Sylvain; Gao, Lu; Ni, Xin

    2016-01-01

    A major cause of preterm labor in pregnant women is intra-amniotic infection, which is mediated by an inflammatory process. Hydrogen sulfide (H2S), a gaseous transmitter, has been implicated to be involved in inflammatory responses. We sought to investigate whether H2S affects infectious preterm birth using the mouse model of lipopolysaccharides (LPS)-induced preterm birth. Administration of LPS at 0.4 mg/kg with two injections intraperitoneally (i.p.) on gestational day 14.5 induced preterm labor. LPS significantly increased leukocyte infiltration in uterus, stimulated the expression of pro-inflammatory cytokines interleukin 1β (IL-1β), IL-6, tumor necrosis factor α (TNF-α), CCL2 and CXCL15 in myometrium. Administration of NaHS (i.p.) delayed the onset of labor induced by LPS in a dose-dependent manner. NaHS prevented leukocyte infiltration into intrauterine tissues and inhibited the production of pro-inflammatory cytokines in myometrium and decreased the levels of these cytokines in maternal circulation. H2S also decreased LPS-activated extracellular signal-regulated kinase (ERK) 1/2/ nuclear factor (NF)-κB signaling pathways in myometrium. This study provides new in vivo evidence for the roles of H2S in attenuating inflammation, and a potential novel therapeutic strategy for infection-related preterm labor. PMID:27035826

  11. Regulation of mitochondrial bioenergetic function by hydrogen sulfide. Part II. Pathophysiological and therapeutic aspects.

    PubMed

    Módis, Katalin; Bos, Eelke M; Calzia, Enrico; van Goor, Harry; Coletta, Ciro; Papapetropoulos, Andreas; Hellmich, Mark R; Radermacher, Peter; Bouillaud, Frédéric; Szabo, Csaba

    2014-04-01

    Emerging work demonstrates the dual regulation of mitochondrial function by hydrogen sulfide (H2 S), including, at lower concentrations, a stimulatory effect as an electron donor, and, at higher concentrations, an inhibitory effect on cytochrome C oxidase. In the current article, we overview the pathophysiological and therapeutic aspects of these processes. During cellular hypoxia/acidosis, the inhibitory effect of H2 S on complex IV is enhanced, which may shift the balance of H2 S from protective to deleterious. Several pathophysiological conditions are associated with an overproduction of H2 S (e.g. sepsis), while in other disease states H2 S levels and H2 S bioavailability are reduced and its therapeutic replacement is warranted (e.g. diabetic vascular complications). Moreover, recent studies demonstrate that colorectal cancer cells up-regulate the H2 S-producing enzyme cystathionine β-synthase (CBS), and utilize its product, H2 S, as a metabolic fuel and tumour-cell survival factor; pharmacological CBS inhibition or genetic CBS silencing suppresses cancer cell bioenergetics and suppresses cell proliferation and cell chemotaxis. In the last chapter of the current article, we overview the field of H2 S-induced therapeutic 'suspended animation', a concept in which a temporary pharmacological reduction in cell metabolism is achieved, producing a decreased oxygen demand for the experimental therapy of critical illness and/or organ transplantation.

  12. Emersion in the mangrove forest fish Rivulus marmoratus: A unique response to hydrogen sulfide

    SciTech Connect

    Abel, D.C.; Koenig, C.C.; Davis, W.P.

    1987-01-01

    The mangrove forest fish Rivulus marmoratus (Cyprinodontidae) has frequently been observed out of water, a phenomenon generally attributed to habitat drying. The hypothesis that hydrogen sulfide, a substance characteristically found in their environment, can serve as a stimulus for emersion, is tested in this study. In the field R. marmoratus was found in water with low to moderate level of H{sub 2}S. In the laboratory, R marmora leaped from water contaminated with H{sub 2}S at ecologically relevant concentrations. Aquatic hypoxia did not induce emersion, but prey capture did. Oxygen consumption by both juveniles and adults decreased significantly in air. These results suggest that avoidance of H{sub 2}S and the ability to survive terrestrial conditions enable this species to permanently occupy an area of the forest unavailable to other fishes. Furthermore, because a variety of stimuli lead to emersion in R. marmoratus, terrestriality in this species is likely a generalized response to environmental stress as well as a means of exploiting terrestrial resources. 16 refs., 1 fig., 2 tabs.

  13. Hydrogen sulfide post-conditioning preserves interfibrillar mitochondria of rat heart during ischemia reperfusion injury.

    PubMed

    Banu, Shakila A; Ravindran, Sriram; Kurian, Gino A

    2016-07-01

    Cardiac mitochondrial dysfunction is considered to be the main manifestation in the pathology of ischemia reperfusion injury, and by restoring its functional activity, hydrogen sulfide (H2S), a novel endogenous gaseotransmitter renders cardioprotection. Given that interfibrillar (IFM) and subsarcolemmal (SSM) mitochondria are the two main types in the heart, the present study investigates the specific H2S-mediated action on IFM and SSM during ischemic reperfusion in the Langendorff rat heart model. Rats were randomly divided into five groups, namely normal, ischemic control, reperfusion control (I/R), ischemic post-conditioning (POC), and H2S post-conditioning (POC_H2S). In reperfusion control, cardiac contractility decreased, and lactate dehydrogenase, creatine kinase, and infracted size increased compared to both normal and ischemic group. In hearts post-conditioned with H2S and the classical method improved cardiac mechanical function and decreased cardiac markers in the perfusate and infarct size significantly. Both POC and POC_H2S exerts its cardioprotective effect of preserving the IFM, as evident by significant improvement in electron transport chain enzyme activities and mitochondrial respiration. The in vitro action of H2S on IFM and SSM from normal and I/R rat heart supports H2S and mediates cardioprotection via IFM preservation. Our study indicates that IFM play an important role in POC_H2S mediated cardioprotection from reperfusion injury. PMID:26951457

  14. Emerging Roles of Hydrogen Sulfide in Inflammatory and Neoplastic Colonic Diseases

    PubMed Central

    Guo, Fang-Fang; Yu, Ta-Chung; Hong, Jie; Fang, Jing-Yuan

    2016-01-01

    Hydrogen sulfide (H2S) is a toxic gas that has been recognized as an important mediator of many physiological processes, such as neurodegeneration, regulation of inflammation, blood pressure, and metabolism. In the human colon, H2S is produced by both endogenous enzymes and sulfate-reducing bacteria (SRB). H2S is involved in the physiological and pathophysiological conditions of the colon, such as inflammatory bowel disease (IBD) and colorectal cancer (CRC), which makes the pharmacological modulation of H2S production and metabolism a potential chemical target for the treatment of colonic diseases. However, the exact mechanisms and pathways by which H2S-mediates normal physiological function and disease in the colon are not fully understood. Besides, the production and release of H2S are modulated by both endogenous and exogenous factors. This review will discuss the production and storage of H2S, its biological roles and the emerging importance in physiology and pathology of IBD and CRC. PMID:27199771

  15. A Practical Look at the Chemistry and Biology of Hydrogen Sulfide

    PubMed Central

    2012-01-01

    Abstract Significance: Hydrogen sulfide (H2S) is garnering increasing interest as a biologically relevant signaling molecule. The effects of H2S have now been observed in virtually every organ system and numerous physiological processes. Recent Advances: These studies have not only opened a new field of “gasotransmitter” biology, they have also led to the development of synthetic H2S “donating” compounds with the potential to be parlayed into a variety of therapeutic applications. Critical Issues: Often lost in the exuberance of this new field is a critical examination or understanding of practical aspects of H2S chemistry and biology. This is especially notable in the areas of handling and measuring H2S, evaluating biosynthetic and metabolic pathways, and separating physiological from pharmacological responses. Future Directions: This brief review describes some of the pitfalls in H2S chemistry and biology that can lead or have already led to misleading or erroneous conclusions. The intent is to allow individuals entering or already in this burgeoning field to critically analyze the literature and to assist them in the design of future experiments. Antioxid. Redox Signal. 17, 32–44. PMID:22074253

  16. Peracute toxic effects of inhaled hydrogen sulfide and injected sodium hydrosulfide on the lungs of rats.

    PubMed

    Lopez, A; Prior, M G; Reiffenstein, R J; Goodwin, L R

    1989-02-01

    This study was designed to test whether intraperitoneally injected sodium hydrosulfide (NaHS) would mimic the pulmonary alterations induced by lethal peracute exposure to an atmosphere containing hydrogen sulfide. Groups of five Sprague-Dawley rats were exposed to an atmosphere of either 2317.6 +/- 547.3 mg m-3 H2S (H2S group) or no H2S (air group), or were injected intraperitoneally with a solution containing 30 mg kg-1 sodium hydrosulfide (NaHS group) or saline solution (vehicle control). Rats of the air and saline groups were killed by cervical dislocation. All rats exposed to H2S or injected with NaHS died within 3 min; however, only rats exposed to H2S showed severe respiratory distress in the agonic phase preceding death. In addition, rats in the H2S group had a notable discharge of serous fluid from the mouth and nostrils. At necropsy, all rats in the H2S group had gross and histologic evidence of pulmonary edema characterized by massive extravasation of eosinophilic fluid into the bronchoalveolar space. In contrast, the lungs of rats injected with NaHS or saline or exposed to air were unaffected. It was concluded that the edematogenic effect of H2S in the lungs cannot be reproduced by injection of NaHS. The severity of lung edema induced by a peracute exposure to H2S was extensive enough to account for death.

  17. Hydrogen sulfide ameliorates cardiovascular dysfunction induced by cecal ligation and puncture in rats.

    PubMed

    Abdelrahman, R S; El-Awady, M S; Nader, M A; Ammar, E M

    2015-10-01

    Hydrogen sulfide (H2S) is an endogenously produced gaseous messenger that participates in regulation of cardiovascular functions. This study evaluates the possible protective effect of H2S in cardiovascular dysfunction induced by cecal ligation and puncture (CLP) in rats. After 24 h of induction of CLP, heart rate (HR), mortality, cardiac and inflammation biomarkers (creatine kinase-MB (CK-MB) isozyme, cardiac troponin I (cTnI), C-reactive protein (CRP), and lactate dehydrogenase (LDH)), in vitro vascular reactivity, histopathological examination, and oxidative biomarkers (malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD)) were determined. CLP induced elevations in HR, mortality, serum CK-MB, cTnI, CRP, and LDH, in addition to impaired aortic contraction to potassium chloride and phenylephrine and relaxation to acetylcholine without affecting sodium nitroprusside responses. Moreover, CLP increased cardiac and aortic MDA and decreased SOD, without affecting GSH and caused a marked subserosal and interstitial inflammation in endocardium. Sodium hydrosulfide, but not the irreversible inhibitor of H2S synthesis dl-propargyl glycine, protected against CLP-induced changes in HR, mortality, cardiac and inflammatory biomarkers, oxidative stress, and myocardium histopathological changes without affecting vascular dysfunction. Our results confirm that H2S can attenuate CLP-induced cardiac, but not vascular, dysfunction possibly through its anti-inflammatory and antioxidant effects.

  18. Hydrogen sulfide protects against cognitive impairment induced by hepatic ischemia and reperfusion via attenuating neuroinflammation.

    PubMed

    Tu, Faping; Li, Jingdong; Wang, Ji; Li, Qiang; Chu, Weihua

    2016-03-01

    Previously, hepatic ischemia followed by reperfusion (hepatic I/R) has been found to cause cognitive impairment. Hydrogen sulfide (H2S) attenuates hepatectomy induced cognitive deficits and also protects against cognitive dysfunction induced by neurodegenerative diseases. In this study, we aim to determine whether sodium hydrosulfide (NaHS), a H2S donor, could alleviate hepatic I/R-induced cognitive impairment and the underlying mechanisms. Rats were injected intraperitoneally with NaHS (5 mg/kg/d) for 11 days. A segmental hepatic I/R model was established on the fourth day. Cognitive function, proinflammatory cytokines levels, and hippocampal ionized calcium-binding adaptor molecule 1 (Iba1) expression was analyzed. We found hepatic I/R increased proinflammatory cytokines levels in serum and hippocampus, up-regulated Iba1 expression, leading to cognitive impairment in rats. However, treatment with NaHS alleviated hepatic I/R induced these neuroinflammatory changes and effectively improved cognitive function. Thus, NaHS appears to protect against cognitive impairment in rats undergoing hepatic I/R by attenuating neuroinflammation in the hippocampus.

  19. Hydrogen sulfide prevents Abeta-induced neuronal apoptosis by attenuating mitochondrial translocation of PTEN.

    PubMed

    Cui, Weigang; Zhang, Yinghua; Yang, Chenxi; Sun, Yiyuan; Zhang, Min; Wang, Songtao

    2016-06-14

    Neuronal cell apoptosis is an important pathological change in Alzheimer's disease (AD). Hydrogen sulfide (H(2)S) is known to be a novel gaseous signaling molecule and a cytoprotectant in many diseases including AD. However, the molecular mechanism of the antiapoptosis activity of H(2)S in AD is not yet fully understood. The aim of the present study is to evaluate the inhibitory effects of H(2)S on Abeta (Aβ)-induced apoptosis and the molecular mechanisms underlying primary neuron cells. Our results showed that sodium hydrosulfide (NaHS), a donor of H(2)S, significantly ameliorated Aβ-induced cell apoptosis. NaHS also reversed the Aβ-induced translocation of the phosphatase and tensin homologs deleted on chromosome 10 (PTEN) from the cytosol to the mitochondria. Furthermore, H(2)S increased the level of p-AKT/AKT significantly. Interestingly, the antiapoptosis effects of H(2)S were blocked down by specific PI3K/AKT inhibitor wortmannin. In conclusion, these data indicate that H(2)S inhibits Aβ-induced neuronal apoptosis by attenuating mitochondrial translocation of PTEN and that activation of PI3K/AKT signaling pathway plays a critical role in H(2)S-mediated neuronal protection. Our findings provide a novel route into the molecular mechanisms of neuronal apoptosis in AD.

  20. Exogenous hydrogen sulfide promotes cell proliferation and differentiation by modulating autophagy in human keratinocytes.

    PubMed

    Xie, Xin; Dai, Hui; Zhuang, Binyu; Chai, Li; Xie, Yanguang; Li, Yuzhen

    2016-04-01

    The effects and the underlying mechanisms of hydrogen sulfide (H2S) on keratinocyte proliferation and differentiation are still less known. In the current study, we investigated the effects and the underlying mechanisms of exogenous H2S on keratinocyte proliferation and differentiation. Human keratinocytes (HaCaT cells) were treated with various concentrations (0.05, 0.25, 0.5 and 1 mM) of sodium hydrosulfide (NaHS, a donor of H2S) for 24 h. A CCK-8 assay was used to assess cell viability. Western blot analysis was performed to determine the expression levels of proteins associated with differentiation and autophagy. Transmission electron microscopy was performed to observe autophagic vacuoles, and flow cytometry was applied to evaluate apoptosis. NaHS promoted the viability, induced the differentiation, and enhanced autophagic activity in a dose-dependent manner in HaCaT cells but had no effect on cell apoptosis. Blockage of autophagy by ATG5 siRNA inhibited NaHS-induced cell proliferation and differentiation. The current study demonstrated that autophagy in response to exogenous H2S treatment promoted keratinocyte proliferation and differentiation. Our results provide additional insights into the potential role of autophagy in keratinocyte proliferation and differentiation.

  1. Hydrogen sulfide mediates the protection of dietary restriction against renal senescence in aged F344 rats.

    PubMed

    Wang, Wen-Juan; Cai, Guang-Yan; Ning, Yi-Chun; Cui, Jing; Hong, Quan; Bai, Xue-Yuan; Xu, Xiao-Meng; Bu, Ru; Sun, Xue-Feng; Chen, Xiang-Mei

    2016-01-01

    Renal aging is always accompanied by increased oxidative stress. Hydrogen sulfide (H2S) can be up-regulated by 50% dietary restriction (DR) for 7-day and can block mitochondrial oxidative stress. H2S production exerts a critical role in yeast, worm, and fruit fly models of DR-mediated longevity. In this study, we found that renal aging could be attenuated by 30% DR for 6-month (DR-6M) and life-long (DR-LL), but not for 6-week (DR-6W). The expressions of cystathionine-γ-lyase (CGL) and cystathionine-β- synthase (CBS) were improved by DR-6M and DR-LL. Endogenous H2S production shared the same trend with CBS and CGL, while glutathione (GSH) didn't. When comparing efficiencies of DR for different durations, more evident production of H2S was found in DR-6M and DR-LL than in DR-6W. Finally the level of oxidative stress was improved by DR-6M and DR-LL rather than by DR-6W. It concluded that aged rats had the ability to produce enough H2S on 30% DR interventions protecting against renal aging, and the effect of DR for long-term were more significant than that of DR for short-term. PMID:27456368

  2. Inhibition of hydrogen sulfide generation from disposed gypsum drywall using chemical inhibitors.

    PubMed

    Xu, Qiyong; Townsend, Timothy; Bitton, Gabriel

    2011-07-15

    Disposal of gypsum drywall in landfills has been demonstrated to elevate hydrogen sulfide (H(2)S) concentrations in landfill gas, a problem with respect to odor, worker safety, and deleterious effect on gas-to-energy systems. Since H(2)S production in landfills results from biological activity, the concept of inhibiting H(2)S production through the application of chemical agents to drywall during disposal was studied. Three possible inhibition agents - sodium molybdate (Na(2)MoO(4)), ferric chloride (FeCl(3)), and hydrated lime (Ca(OH)(2)) - were evaluated using flask and column experiments. All three agents inhibited H(2)S generation, with Na(2)MoO(4) reducing H(2)S generation by interrupting the biological sulfate reduction process and Ca(OH)(2) providing an unfavorable pH for biological growth. Although FeCl(3) was intended to provide an electron acceptor for a competing group of bacteria, the mechanism found responsible for inhibiting H(2)S production in the column experiment was a reduction in pH. Application of both Na(2)MoO(4) and FeCl(3) inhibited H(2)S generation over a long period (over 180 days), but the impact of Ca(OH)(2) decreased with time as the alkalinity it contributed was neutralized by the generated H(2)S. Practical application and potential environmental implications need additional exploration. PMID:21592650

  3. Comparative Proteomic Analysis of Differentially Expressed Proteins Induced by Hydrogen Sulfide in Spinacia oleracea Leaves

    PubMed Central

    Chen, Juan; Liu, Ting-Wu; Hu, Wen-Jun; Simon, Martin; Wang, Wen-Hua; Chen, Juan; Liu, Xiang; Zheng, Hai-Lei

    2014-01-01

    Hydrogen sulfide (H2S), as a potential gaseous messenger molecule, has been suggested to play important roles in a wide range of physiological processes in plants. The aim of present study was to investigate which set of proteins is involved in H2S-regulated metabolism or signaling pathways. Spinacia oleracea seedlings were treated with 100 µM NaHS, a donor of H2S. Changes in protein expression profiles were analyzed by 2-D gel electrophoresis coupled with MALDI-TOF MS. Over 1000 protein spots were reproducibly resolved, of which the abundance of 92 spots was changed by at least 2-fold (sixty-five were up-regulated, whereas 27 were down-regulated). These proteins were functionally divided into 9 groups, including energy production and photosynthesis, cell rescue, development and cell defense, substance metabolism, protein synthesis and folding, cellular signal transduction. Further, we found that these proteins were mainly localized in cell wall, plasma membrane, chloroplast, mitochondria, nucleus, peroxisome and cytosol. Our results demonstrate that H2S is involved in various cellular and physiological activities and has a distinct influence on photosynthesis, cell defense and cellular signal transduction in S. oleracea leaves. These findings provide new insights into proteomic responses in plants under physiological levels of H2S. PMID:25181351

  4. Interaction of Hydrogen Sulfide with Nitric Oxide in the Cardiovascular System.

    PubMed

    Nagpure, B V; Bian, Jin-Song

    2016-01-01

    Historically acknowledged as toxic gases, hydrogen sulfide (H2S) and nitric oxide (NO) are now recognized as the predominant members of a new family of signaling molecules, "gasotransmitters" in mammals. While H2S is biosynthesized by three constitutively expressed enzymes (CBS, CSE, and 3-MST) from L-cysteine and homocysteine, NO is generated endogenously from L-arginine by the action of various isoforms of NOS. Both gases have been transpired as the key and independent regulators of many physiological functions in mammalian cardiovascular, nervous, gastrointestinal, respiratory, and immune systems. The analogy between these two gasotransmitters is evident not only from their paracrine mode of signaling, but also from the identical and/or shared signaling transduction pathways. With the plethora of research in the pathophysiological role of gasotransmitters in various systems, the existence of interplay between these gases is being widely accepted. Chemical interaction between NO and H2S may generate nitroxyl (HNO), which plays a specific effective role within the cardiovascular system. In this review article, we have attempted to provide current understanding of the individual and interactive roles of H2S and NO signaling in mammalian cardiovascular system, focusing particularly on heart contractility, cardioprotection, vascular tone, angiogenesis, and oxidative stress.

  5. Analysis of some enzymes activities of hydrogen sulfide metabolism in plants.

    PubMed

    Li, Zhong-Guang

    2015-01-01

    Hydrogen sulfide (H2S) which is considered as a novel gasotransmitter after reactive oxygen species and nitric oxide in plants has dual character, that is, toxicity that inhibits cytochrome oxidase at high concentration and as signal molecule which is involved in plant growth, development, and the acquisition of tolerance to adverse environments such as extreme temperature, drought, salt, and heavy metal stress at low concentration. Therefore, H2S homeostasis is very important in plant cells. The level of H2S in plant cells is regulated by its synthetic and degradative enzymes, L-/D-cysteine desulfhydrase (L-/D-DES), sulfite reductase (SiR), and cyanoalanine synthase (CAS), which are responsible for H2S synthesis, while cysteine synthase (CS) takes charge of the degradation of H2S, but its reverse reaction also can produce H2S. Here, after crude enzyme is extracted from plant tissues, the activities of L-/D-DES, SiR, CAS, and CS are measured by spectrophotometry, the aim is to further understand homeostasis of H2S in plant cells and its potential mechanisms. PMID:25747484

  6. Endogenous generation of hydrogen sulfide and its regulation in Shewanella oneidensis

    PubMed Central

    Wu, Genfu; Li, Ning; Mao, Yinting; Zhou, Guangqi; Gao, Haichun

    2015-01-01

    Hydrogen sulfide (H2S) has been recognized as a physiological mediator with a variety of functions across all domains of life. In this study, mechanisms of endogenous H2S generation in Shewanella oneidensis were investigated. As a research model with highly diverse anaerobic respiratory pathways, the microorganism is able to produce H2S by respiring on a variety of sulfur-containing compounds with SirACD and PsrABC enzymatic complexes, as well as through cysteine degradation with three enzymes, MdeA, SO_1095, and SseA. We showed that the SirACD and PsrABC complexes, which are predominantly, if not exclusively, responsible for H2S generation via respiration of sulfur species, do not interplay with each other. Strikingly, a screen for regulators controlling endogenous H2S generation by transposon mutagenesis identified global regulator Crp to be essential to all H2S-generating processes. In contrast, Fnr and Arc, two other global regulators that have a role in respiration, are dispensable in regulating H2S generation via respiration of sulfur species. Interestingly, Arc is involved in the H2S generation through cysteine degradation by repressing expression of the mdeA gene. We further showed that expression of the sirA and psrABC operons is subjected to direct regulation of Crp, but the mechanisms underlying the requirement of Crp for H2S generation through cysteine degradation remain elusive. PMID:25972854

  7. Measurement and modeling of hydrogen sulfide lagoon emissions from a swine concentrated animal feeding operation.

    PubMed

    Rumsey, Ian C; Aneja, Viney P

    2014-01-01

    Hydrogen sulfide (H2S) emissions were determined from an anaerobic lagoon at a swine concentrated animal feeding operation (CAFO) in North Carolina. Measurements of H2S were made continuously from an anaerobic lagoon using a dynamic flow-through chamber for ∼ 1 week during each of the four seasonal periods from June 2007 through April 2008. H2S lagoon fluxes were highest in the summer with a flux of 3.81 ± 3.24 μg m(-2) min(-1) and lowest in the winter with a flux of 0.08 ± 0.09 μg m(-2) min(-1). An air-manure interface (A-MI) mass transfer model was developed to predict H2S manure emissions. The accuracy of the A-MI mass transfer model in predicting H2S manure emissions was comprehensively evaluated by comparing the model predicted emissions to the continuously measured lagoon emissions using data from all four seasonal periods. In comparison to this measurement data, the A-MI mass transfer model performed well in predicting H2S fluxes with a slope of 1.13 and an r(2) value of 0.60, and a mean bias value of 0.655 μg m(-2) min(-1). The A-MI mass transfer model also performed fairly well in predicting diurnal H2S lagoon flux trends. PMID:24387076

  8. Hydrogen sulfide inhibits enzymatic browning of fresh-cut lotus root slices by regulating phenolic metabolism.

    PubMed

    Sun, Ying; Zhang, Wei; Zeng, Tao; Nie, Qixing; Zhang, Fengying; Zhu, Liqin

    2015-06-15

    The effect of fumigation with hydrogen sulfide (H2S) gas on inhibiting enzymatic browning of fresh-cut lotus root slices was investigated. Browning degree, changes in color, total phenol content, superoxide anion production rate (O2(-)), H2O2 content, antioxidant capacities (DPPH radical scavenging ability, ABTS radical scavenging activity and the reducing power) and activities of the phenol metabolism-associated enzymes including phenylalanine ammonialyase (PAL), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) were evaluated. The results showed that treatment with 15 μl L(-1) H2S significantly inhibited the browning of fresh-cut lotus root slices (P<0.05), reduced significantly O2(-) production rate and H2O2 content, and enhanced antioxidant capacities (P<0.05). PPO and POD activities in the fresh-cut lotus root slices were also significantly inhibited by treatment with H2S (P<0.05). This study suggested that treatment with exogenous H2S could inhibit the browning of fresh-cut lotus root slices by enhancing antioxidant capacities to alleviate the oxidative damage. PMID:25660900

  9. Electrocatalytic Hydrogen Evolution from Molybdenum Sulfide-Polymer Composite Films on Carbon Electrodes.

    PubMed

    Lattach, Youssef; Deronzier, Alain; Moutet, Jean-Claude

    2015-07-29

    The design of more efficient catalytic electrodes remains an important objective for the development of water splitting electrolyzers. In this context a structured composite cathode material has been synthesized by electrodeposition of molybdenum sulfide (MoSx) into a poly(pyrrole-alkylammonium) matrix, previously coated onto carbon electrodes by oxidative electropolymerization of a pyrrole-alkylammonium monomer. The composite material showed an efficient electrocatalytic activity toward proton reduction and the hydrogen evolution reaction (HER). Data from Tafel plots have demonstrated that the electron transfer rate in the composite films is fast, in agreement with the high catalytic activity of this cathode material. Bulk electrolysis of acidic water at carbon foam electrodes modified with the composite have shown that the cathodes display a high catalytic activity and a reasonable operational stability, largely exceeding that of regular amorphous MoSx electrodeposited on naked carbon foam. The enhanced catalytic performances of the composite electrode material were attributed to the structuration of the composite, which led to a homogeneous distribution of the catalyst on the carbon foam network, as shown by SEM characterizations.

  10. Isolation and characterization of bacteriophages specific to hydrogen-sulfide-producing bacteria.

    PubMed

    Gong, Chao; Heringa, Spencer; Singh, Randhir; Kim, Jinkyung; Jiang, Xiuping

    2013-01-01

    The objectives of this study were to isolate and characterize bacteriophages specific to hydrogen-sulfide-producing bacteria (SPB) from raw animal materials, and to develop a SPB-specific bacteriophage cocktail for rendering application. Meat, chicken offal, and feather samples collected from local supermarkets and rendering processing plants were used to isolate SPB (n = 142). Bacteriophages (n = 52) specific to SPB were isolated and purified from the above samples using 18 of those isolated SPB strains as hosts. The host ranges of bacteriophages against 5 selected SPB strains (Escherichia coli, Citrobacter freundii, and Hafnia alvei) were determined. Electron microscopy observation of 9 phages selected for the phage cocktail revealed that 6 phages belonged to the family of Siphoviridae and 3 belonged to the Myoviridae family. Restriction enzyme digestion analysis with endonuclease DraI detected 6 distinguished patterns among the 9 phages. Phage treatment prevented the growth of SPB for up to 10 h with multiplicity of infection ratios of 1, 10, 100, and 1000 in tryptic soy broth at 30 °C, and extended the lag phase of SPB growth for 2 h at 22 °C with multiplicities of infection of 10, 100, and 1000. These results suggest that the selected bacteriophage cocktail has a high potential for phage application to control SPB in raw animal materials destined for the rendering process.

  11. Hydrogen sulfide protects against cognitive impairment induced by hepatic ischemia and reperfusion via attenuating neuroinflammation

    PubMed Central

    Tu, Faping; Li, Jingdong; Wang, Ji; Li, Qiang

    2016-01-01

    Previously, hepatic ischemia followed by reperfusion (hepatic I/R) has been found to cause cognitive impairment. Hydrogen sulfide (H2S) attenuates hepatectomy induced cognitive deficits and also protects against cognitive dysfunction induced by neurodegenerative diseases. In this study, we aim to determine whether sodium hydrosulfide (NaHS), a H2S donor, could alleviate hepatic I/R-induced cognitive impairment and the underlying mechanisms. Rats were injected intraperitoneally with NaHS (5 mg/kg/d) for 11 days. A segmental hepatic I/R model was established on the fourth day. Cognitive function, proinflammatory cytokines levels, and hippocampal ionized calcium-binding adaptor molecule 1 (Iba1) expression was analyzed. We found hepatic I/R increased proinflammatory cytokines levels in serum and hippocampus, up-regulated Iba1 expression, leading to cognitive impairment in rats. However, treatment with NaHS alleviated hepatic I/R induced these neuroinflammatory changes and effectively improved cognitive function. Thus, NaHS appears to protect against cognitive impairment in rats undergoing hepatic I/R by attenuating neuroinflammation in the hippocampus. PMID:26811101

  12. [A new "turn-on" fluorescent probe for visual detection of hydrogen sulfide].

    PubMed

    Liu, Chun-xia; Ma, Xing; Wei, Guo-hua; Du, Yu-guo

    2015-01-01

    Hydrogen sulfide (H2S) is one of the important parameters for characterizing water pollution. Therefore, fast and effective detection method is in great need. Fluorescence analysis method gains wide attention because of unparalleled advantages. A new colorimetric and fluorescent "turn-on" probe for H2S detection based on thiolysis by H2S was reported. 2-(2'-Hydroxyphenyl) benzimidazole (HBI), a kind of excited-state intramolecular proton transfer dye was chosen as the fluorophore because of large Stokes shift and high fluorescence quantum yield. It was found that the fluorescence intensity of testing system increased with the addition of H2S and accompanied with a color change from pale yellow to purple. The visual detection limit was 3 micromol x L(-1). The new fluorescent probe showed a good selectivity for H2S over other anions and a good fluorescence response in a relatively wide pH range. The response process was finished in five minutes with a 100-fold fluorescence enhancement. The probe provides a new method for the detection of H2S. PMID:25898685

  13. Hydrogen Sulfide Mitigates Kidney Injury in High Fat Diet-Induced Obese Mice

    PubMed Central

    Wu, Dongdong; Gao, Biao; Li, Mengling; Yao, Ling; Wang, Shuaiwei; Chen, Mingliang; Li, Hui; Ma, Chunyan

    2016-01-01

    Obesity is prevalent worldwide and is a major risk factor for the development and progression of kidney disease. Hydrogen sulfide (H2S) plays an important role in renal physiological and pathophysiological processes. However, whether H2S is able to mitigate kidney injury induced by obesity in mice remains unclear. In this study, we demonstrated that H2S significantly reduced the accumulation of lipids in the kidneys of high fat diet- (HFD-) induced obese mice. The results of hematoxylin and eosin, periodic acid-Schiff, and Masson's trichrome staining showed that H2S ameliorated the kidney structure, decreased the extent of interstitial injury, and reduced the degree of kidney fibrosis in HFD-induced obese mice. We found that H2S decreased the expression levels of tumor necrosis factor-α, interleukin- (IL-) 6, and monocyte chemoattractant protein-1 but increased the expression level of IL-10. Furthermore, H2S treatment decreased the protein expression of p50, p65, and p-p65 in the kidney of HFD-induced obese mice. In conclusion, H2S is able to mitigate renal injury in HFD-induced obese mice through the reduction of kidney inflammation by downregulating the expression of nuclear factor-kappa B. H2S or its releasing compounds may serve as a potential therapeutic molecule for obesity-induced kidney injury. PMID:27413418

  14. Genetic Targets of Hydrogen Sulfide in Ventilator-Induced Lung Injury – A Microarray Study

    PubMed Central

    Spassov, Sashko; Pfeifer, Dietmar; Strosing, Karl; Ryter, Stefan; Hummel, Matthias; Faller, Simone; Hoetzel, Alexander

    2014-01-01

    Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection. PMID:25025333

  15. An Antifungal Role of Hydrogen Sulfide on the Postharvest Pathogens Aspergillus niger and Penicillium italicum

    PubMed Central

    Li, Yan-Hong; Hu, Liang-Bin; Yan, Hong; Liu, Yong-Sheng; Zhang, Hua

    2014-01-01

    In this research, the antifungal role of hydrogen sulfide (H2S) on the postharvest pathogens Aspergillus niger and Penicillium italicum growing on fruits and under culture conditions on defined media was investigated. Our results show that H2S, released by sodium hydrosulfide (NaHS) effectively reduced the postharvest decay of fruits induced by A. niger and P. italicum. Furthermore, H2S inhibited spore germination, germ tube elongation, mycelial growth, and produced abnormal mycelial contractions when the fungi were grown on defined media in Petri plates. Further studies showed that H2S could cause an increase in intracellular reactive oxygen species (ROS) in A. niger. In accordance with this observation we show that enzyme activities and the expression of superoxide dismutase (SOD) and catalase (CAT) genes in A. niger treated with H2S were lower than those in control. Moreover, H2S also significantly inhibited the growth of Saccharomyces cerevisiae, Rhizopus oryzae, the human pathogen Candida albicans, and several food-borne bacteria. We also found that short time exposure of H2S showed a microbicidal role rather than just inhibiting the growth of microbes. Taken together, this study suggests the potential value of H2S in reducing postharvest loss and food spoilage caused by microbe propagation. PMID:25101960

  16. Emergence of Hydrogen Sulfide as an Endogenous Gaseous Signaling Molecule in Cardiovascular Disease

    PubMed Central

    Polhemus, David J.; Lefer, David J.

    2014-01-01

    Long recognized as a malodorous and highly toxic gas, recent experimental studies have revealed that hydrogen sulfide (H2S) is produced enzymatically in all mammalian species including man and exerts a number of critical actions to promote cardiovascular homeostasis and health. During the past 15 years, scientists have determined that H2S is produced by three endogenous enzymes and exerts powerful effects on endothelial cells, smooth muscle cells, inflammatory cells, mitochondria, endoplasmic reticulum, and nuclear transcription factors. These effects have been reported in multiple organ systems and the vast majority of data clearly indicate that H2S produced by the endogenous enzymes exerts cytoprotective actions. Recent preclinical studies investigating cardiovascular diseases have demonstrated that the administration of physiological or pharmacological levels of H2S attenuates myocardial injury, protects blood vessels, limits inflammation, and regulates blood pressure. H2S has emerged as a critical cardiovascular signaling molecule similar to nitric oxide (NO) and carbon monoxide (CO) with a profound impact on the heart and circulation (Figure 1). Our improved understanding of how H2S elicits protective actions, coupled with the very rapid development of novel H2S releasing agents, has resulted in heightened enthusiasm for the clinical translation of this ephemeral gaseous molecule. This review will examine our current state of knowledge regarding the actions of H2S within the cardiovascular system with an emphasis on the therapeutic potential and molecular crosstalk between H2S, NO, and CO. PMID:24526678

  17. The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential

    PubMed Central

    Shen, Yaqi; Shen, Zhuqing; Luo, Shanshan; Guo, Wei; Zhu, Yi Zhun

    2015-01-01

    Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases. Therefore, insight into the molecular mechanisms underlying H2S action in the heart may promote the understanding of pathophysiology of cardiac diseases and lead to new therapeutic targets based on modulation of H2S production. PMID:26078822

  18. Carbon Monoxide, Hydrogen Sulfide, and Nitric Oxide as Signaling Molecules in the Gastrointestinal Tract

    PubMed Central

    Farrugia, Gianrico; Szurszewski, Joseph H.

    2014-01-01

    Carbon monoxide (CO) and hydrogen sulfide (H2S) used to be thought of simply as lethal and (for H2S) smelly gaseous molecules; now they are known to have important signaling functions in the gastrointestinal tract. CO and H2S, which are produced in the gastrointestinal tract by different enzymes, regulate smooth muscle membrane potential and tone, transmit signals from enteric nerves and can regulate the immune system. The pathways that produce nitric oxide (NO) H2S and CO interact—each can inhibit and potentiate the level and activity of the other. However, there are significant differences between these molecules, such as in half-lives; CO is more stable and therefore able to have effects distal to the site of production, whereas NO and H2S are short lived and act only close to sites of production. We review their signaling functions in the luminal gastrointestinal tract and discuss how their pathways interact. We also describe other physiologic functions of CO and H2S and how they might be used as therapeutic agents. PMID:24798417

  19. Comparative proteomic analysis of differentially expressed proteins induced by hydrogen sulfide in Spinacia oleracea leaves.

    PubMed

    Chen, Juan; Liu, Ting-Wu; Hu, Wen-Jun; Simon, Martin; Wang, Wen-Hua; Chen, Juan; Liu, Xiang; Zheng, Hai-Lei

    2014-01-01

    Hydrogen sulfide (H2S), as a potential gaseous messenger molecule, has been suggested to play important roles in a wide range of physiological processes in plants. The aim of present study was to investigate which set of proteins is involved in H2S-regulated metabolism or signaling pathways. Spinacia oleracea seedlings were treated with 100 µM NaHS, a donor of H2S. Changes in protein expression profiles were analyzed by 2-D gel electrophoresis coupled with MALDI-TOF MS. Over 1000 protein spots were reproducibly resolved, of which the abundance of 92 spots was changed by at least 2-fold (sixty-five were up-regulated, whereas 27 were down-regulated). These proteins were functionally divided into 9 groups, including energy production and photosynthesis, cell rescue, development and cell defense, substance metabolism, protein synthesis and folding, cellular signal transduction. Further, we found that these proteins were mainly localized in cell wall, plasma membrane, chloroplast, mitochondria, nucleus, peroxisome and cytosol. Our results demonstrate that H2S is involved in various cellular and physiological activities and has a distinct influence on photosynthesis, cell defense and cellular signal transduction in S. oleracea leaves. These findings provide new insights into proteomic responses in plants under physiological levels of H2S.

  20. Hydrogen sulfide and the probabilities of inhalation through a tympanic membrane defect

    SciTech Connect

    Ronk, R.; White, M.K.

    1985-05-01

    The authors conclude that workers with tympanic membrane defects (perforated eardrums) should not be excluded from working in atmospheres containing concentrations of hydrogen sulfide (H/sub 2/S). Several existing requirements and recommendations exclude workers with perforated eardrums from working in or around H/sub 2/S. Such protective measures stem from the belief that H/sub 2/S can enter the body through the perforation in sufficient measure to compromise the wearer's respiratory protection. However, based on calculations of anticipated leakage of H/sub 2/S for a variety of eustachian tube conditions and in the absence of either medical literature or personal reports documenting H/sub 2/S poisoning due to eardrum perforation, the recommendation for excluding workers with such a condition from working in or around H/sub 2/S is not supported. The anatomy, physiology, and pathology of the eustachian tube are discussed, including the effects such devices as tympanomaxillary shunts might have on contaminant leakage. The National Institute for Occupational Safety and Health (NIOSH) criteria for respirator tests and sources of respirator leakage are examined and NIOSH recommendations for respiratory protection against H/sub 2/S are outlined.