Science.gov

Sample records for geothermal hydrogen sulfide

  1. Control of hydrogen sulfide emission from geothermal steam plants with hydrogen peroxide and sodium vanadate

    SciTech Connect

    Brown, R.A.; Hills, W.A.

    1982-11-30

    Removing hydrogen sulfide from geothermal steam condensate is described whereby the hydrogen sulfide that is present in the condensate from a geothermal steam plant is oxidized with a peroxygen compound such as hydrogen peroxide in the presence of catalytic quantities of sodium vanadate under neutral to alkaline conditions.

  2. Removing hydrogen sulfide from geothermal gases: hypochlorite process reduces hydrogen sulfide emissions to acceptable levels. NTIS tech note

    SciTech Connect

    Not Available

    1981-10-01

    This citation summarizes a one-page announcement of technology available for utilization. A hypochlorite process has been proposed as an alternative to other methods for the removal of hydrogen sulfide from the exhaust gases of geothermal powerplants. An electrolytically-generated sodium hypochlorite solution converts the hydrogen sulfide to water, salt, and sulfur. The hypochlorite process appears to be less expensive than competing processes for most of the cases studied. ...FOR ADDITIONAL INFORMATION: Detailed information about the technology described may be obtained by ordering the NTIS report, order number: DOE/ER/1092-T7, price code: PC A03.

  3. HYDROGEN SULFIDE EMISSIONS OF GEOTHERMAL DEVELOPMENT IN A THESIS SUBMITTED TO THE GLOBAL ENVIRONEMENTAL SCIENCE

    E-print Network

    Qiu, Bo

    i HYDROGEN SULFIDE EMISSIONS OF GEOTHERMAL DEVELOPMENT IN HAWAI`I A THESIS SUBMITTED Donald Thomas Eric DeCarlo #12; iv Abstract Geothermal energy is a renewable source of energy that has been developed worldwide and on the Island of Hawai'i. Future geothermal developments are proposed

  4. Analysis of hypochlorite process for removal of hydrogen sulfide from geothermal gases

    SciTech Connect

    Not Available

    1980-04-01

    Sodium hypochlorite reacts readily with hydrogen sulfide to convert the sulfide ion into free sulfur in a neutral or acid solution and to the sulfate ion in an alkaline solution. Sodium hypochlorite can be generated on site by processing geothermal brine in electrolytic cells. An investigation to determine if this reaction could be economically used to remove hydrogen sulfide from geothermal noncondensible gases is reported. Two processes, the LO-CAT Process and the Stretford Process, were selected for comparison with the hypochlorite process. Three geothermal reservoirs were considered for evaluation: Niland KGRA, Baca KGRA, and The Geysers KGRA. Because of the wide variation in the amount of hydrogen sulfide present at The Geysers, two different gas analyses were considered for treatment. Plants were designed to process the effluent noncondensible gases from a 10 MW/sub e/ geothermal power plant. The effluent gas from each plant was to contain a maximum hydrogen sulfide concentration of 35 ppb. Capital costs were estimated for each of the processes at each of the four sites selected. Operating costs were also calculated for each of the processes at each of the sites. The results of these studies are shown.

  5. 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.

  6. Hydrogen sulfide

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 03 / 005 www.epa.gov / iris TOXICOLOGICAL REVIEW OF HYDROGEN SULFIDE ( CAS No . 7783 - 06 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) June 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been revie

  7. 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.

  8. 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

  9. Hydrogen and bioenergetics in the Yellowstone geothermal ecosystem

    E-print Network

    #12;Hydrogen and bioenergetics in the Yellowstone geothermal ecosystem John R. Spear*, Jeffrey J in the presence of high concentrations of sulfide. geothermal springs phylogenetic study primary productivity

  10. Guidance Document Safe Handling of Sulfides and Hydrogen Sulfide

    E-print Network

    sulfide salts. Sulfide toxicity is comparable with that of cyanide. In the body sulfides can form complex and in procedures for use and disposal. Sulfides are toxic. Hydrogen sulfide is toxic and flammable. Hydrogen waste for disposal by EHS. Call EHS (ext. 3316) for assistance with any spill. First Aid: Inhalation

  11. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Hydrogen sulfide. 250.808 Section 250...Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in zones...

  12. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Hydrogen sulfide. 250.808 Section 250...Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in zones...

  13. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Hydrogen sulfide. 250.808 Section 250...Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in zones...

  14. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250...Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in zones...

  15. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.490 Section 250.490 ...CONTINENTAL SHELF Oil and Gas Drilling Operations Hydrogen Sulfide § 250.490 Hydrogen sulfide. (a) What precautions must I...

  16. Hydrogen sulfide and cancer

    PubMed Central

    Hellmich, Mark R.; Szabo, Csaba

    2015-01-01

    Recent studies revealed increased expression of various hydrogen sulfide (H2S) producing enzymes in cancer cells of various tissue types, and new roles of H2S in the pathophysiology of cancer have emerged. This is particularly evident in cancers of the colon and ovaries, where the malignant cells both overexpress cystathionine-?-synthase (CBS) and produce increased amounts of H2S, which enhances tumor growth and spread by (a) stimulating cellular bioenergetics, (b) activating proliferative, migratory, and invasive signaling pathways, and (c) enhancing tumor angiogenesis. Importantly, in preclinical models of these cancers, either pharmacological inhibition or genetic silencing of CBS was shown to be sufficient to suppress cancer cell bioenergetics in vitro, inhibit tumor growth and metastasis in vivo, and enhance the antitumor efficacy of front-line chemotherapeutic agents, providing a strong rationale for the development of CBS-targeted inhibitors as anticancer therapies. However, the observation that inhibition of H2S biosynthesis exerts anticancer effects is contradicted by other studies showing that increasing H2S with exogenous donors also exert antitumor actions. Herein, we present a brief review of the scientific literature documenting the function of H2S, H2S donors, and transsulfuration enzymes in cancers from various tissue types, and propose that the paradoxical actions of H2S can be resolved by considering the bell-shaped pharmacology of H2S, whereby lower (endogenous) H2S production tend to promote, while higher (generated from exogenously added H2S donors) tend to inhibit cancer cell proliferation. Finally, we suggest areas for future investigations to expand our knowledge of this nascent field. PMID:26162838

  17. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.490 Section 250.490... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Hydrogen Sulfide § 250.490 Hydrogen... black lettering as follows: Letter height Wording 12 inches Danger. Poisonous Gas. Hydrogen Sulfide....

  18. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.490 Section 250.490 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Hydrogen Sulfide § 250.490 Hydrogen sulfide. (a)...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Hydrogen sulfide. 250.808 Section...Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION...Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2 S) or in...

  11. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Hydrogen sulfide. 250.504 Section...Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION...Operations § 250.504 Hydrogen sulfide. When a well-completion...conducted in zones known to contain hydrogen sulfide (H2 S) or in...

  12. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Hydrogen sulfide. 250.604 Section...Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION...Operations § 250.604 Hydrogen sulfide. When a well-workover...conducted in zones known to contain hydrogen sulfide (H2 S) or in...

  13. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Hydrogen sulfide. 250.604 Section 250...Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  14. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Hydrogen sulfide. 250.504 Section 250...Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  15. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Hydrogen sulfide. 250.504 Section 250...Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  16. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Hydrogen sulfide. 250.504 Section 250...Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  17. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Hydrogen sulfide. 250.604 Section 250...Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  18. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Hydrogen sulfide. 250.604 Section 250...Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  19. 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...

  20. 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...

  1. 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...

  2. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250...Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  3. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250...Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion...is conducted in zones known to contain hydrogen sulfide (H2 S) or in zones...

  4. 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.

  5. Purification of hydrogen sulfide from oxygen

    NASA Astrophysics Data System (ADS)

    Kruglyakova, O. V.; Startsev, A. N.

    2015-08-01

    A technique for determining the concentration of oxygen in hydrogen sulfide is developed on passing the tested hydrogen sulfide through the stainless steel chips and determining the amount of solid sulfur formed over the catalyst's surface as a result of hydrogen sulfide oxidation by impurities of oxygen. A method for the deep purification of hydrogen sulfide of oxygen is developed. It is shown that under certain conditions, two chemical reactions for the conversion of hydrogen sulfide into two different modifications of sulfur (solid and gaseous) can proceed independently and simultaneously on the catalyst's surface.

  6. Demonstration of EIC's copper sulfate process for removal of hydrogen sulfide and other trace contaminants from geothermal steam at turbine inlet temperatures and pressures. Final report

    SciTech Connect

    Not Available

    1980-05-01

    The results obtained during the operation of an integrated, one-tenth commercial scale pilot plant using EIC's copper sulfate process for the removal of hydrogen sulfide and other contaminants from geothermal steam at turbine upstream conditions are discussed. The tests took place over a six month period at Pacific Gas and Electric Company's Unit No. 7 at The Geysers Power Plant. These tests were the final phase of a development effort which included the laboratory research and engineering design work which led to the design of the pilot plant. Broadly, the objectives of operating the pilot plant were to confirm the preliminary design criteria which had been developed, and provide data for their revisions, if appropriate, in a plant which contained all the elements of a commercial process using equipment of a size sufficient to provide valid scale-up data. The test campaign was carried out in four phases: water testing; open circuit, i.e., non integrated scrubbing, liquid-solid separation and regeneration testing; closed circuit short term; and closed circuit long term testing.

  7. Arsenic speciation in natural sulfidic geothermal waters

    NASA Astrophysics Data System (ADS)

    Keller, Nicole S.; Stefánsson, Andri; Sigfússon, Bergur

    2014-10-01

    The speciation of arsenic in natural sulfidic geothermal waters was studied using chemical analyses and thermodynamic aqueous speciation calculations. Samples were collected in three geothermal systems in Iceland, having contrasting H2S concentrations in the reservoir (high vs. low). The sampled waters contained 7-116 ppb As and <0.01-77.6 ppm H2S with pH of 8.56-9.60. The analytical setup used for the determination of arsenic species (Ion Chromatography-Hydride Generation Atomic Fluorescence Spectrometry, IC-HG-AFS) was field-deployed and the samples analyzed within ?5 min of sampling in order to prevent changes upon storage, which were shown to be considerable regardless of the sample storage method used. Nine aqueous arsenic species were detected, among others arsenite (HnAsO3n-3), thioarsenite (HnAsS3n-3), arsenate (HnAsO4n-3), monothioarsenate (HnAsSO3n-3), dithioarsenate (HnAsS2O2n-3), trithioarsenate (HnAsS3O) and tetrathioarsenate (HnAsS4n-3). The results of the measured aqueous arsenic speciation in the natural geothermal waters and comparison with thermodynamic calculations reveal that the predominant factors determining the species distribution are sulfide concentration and pH. In alkaline waters with low sulfide concentrations the predominant species are AsIII oxyanions. This can be seen in samples from a liquid-only well, tapping water that is H2S-poor and free of oxygen. At intermediate sulfide concentration AsIII and AsV thio species become important and predominate at high sulfide concentration, as seen in two-phase well waters, which have high H2S concentrations in the reservoir. Upon oxidation, for instance due to mixing of the reservoir fluid with oxygenated water upon ascent to the surface, AsV oxyanions form, as well as AsV thio complexes if the sulfide concentration is intermediate to high. This oxidation process can be seen in samples from hot springs in the Geysir geothermal area. While the thermodynamic modeling allows for a first-order estimation of the dominant species, discrepancies between the model results and the field data highlight the fact that for such dynamic chemical systems the exact speciation cannot be calculated, thus on-site and preferentially in-situ analysis is of crucial importance.

  8. 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...

  9. 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.

  10. Investigation of Hydrogen Sulfide Exposure and Lung Function, Asthma and Chronic Obstructive Pulmonary Disease in a Geothermal Area of New Zealand

    PubMed Central

    Bates, Michael N.; Crane, Julian; Balmes, John R.; Garrett, Nick

    2015-01-01

    Background Results have been conflicting whether long-term ambient hydrogen sulfide (H2S) affects lung function or is a risk factor for asthma or chronic obstructive pulmonary disease (COPD). Rotorua city, New Zealand, has the world’s largest population exposed to ambient H2S—from geothermal sources. Objectives We investigated associations of H2S with lung function, COPD and asthma in this population. Methods 1,204 of 1,639 study participants, aged 18–65 years during 2008–2010, provided satisfactory spirometry results. Residences, workplaces and schools over the last 30 years were geocoded. Exposures were estimated from data collected by summer and winter H2S monitoring networks across Rotorua. Four metrics for H2S exposure, representing both current and long-term (last 30 years) exposure, and also time-weighted average and peak exposures, were calculated. Departures from expected values for pre-bronchodilator lung function, calculated from prediction equations, were outcomes for linear regression models using quartiles of the H2S exposure metrics. Separate models examined participants with and without evidence of asthma or COPD, and never- and ever-smokers. Logistic regression was used to investigate associations of COPD (a post-bronchodilator FEV1/FVC < 70% of expected) and asthma (doctor-diagnosed or by FEV1 response to bronchodilator) with H2S exposure quartiles. Results None of the exposure metrics produced evidence of lung function decrement. The logistic regression analysis showed no evidence that long-term H2S exposure at Rotorua levels was associated with either increased COPD or asthma risk. Some results suggested that recent ambient H2S exposures were beneficially associated with lung function parameters. Conclusions The study found no evidence of reductions in lung function, or increased risk of COPD or asthma, from recent or long-term H2S exposure at the relatively high ambient concentrations found in Rotorua. Suggestions of improved lung function associated with recent ambient H2S exposures require confirmation in other studies. PMID:25822819

  11. 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)

  12. 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.

  13. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, John B. L. (Naperville, IL); Gorski, Anthony J. (Woodridge, IL); Daniels, Edward J. (Oak Lawn, IL)

    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.

  14. 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 ?-synthase (CBS, EC 4.2.1.22), and Cystathionine ?-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

  15. 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

  16. Hydrogen and Sulfur Production from Hydrogen Sulfide Wastes 

    E-print Network

    Harkness, J.; 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...

  17. 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)

  18. HYDROGEN SULFIDE -HIGH TEMPERATURE DRILLING CONTINGENCY PLAN

    E-print Network

    HYDROGEN SULFIDE - HIGH TEMPERATURE DRILLING CONTINGENCY PLAN OCEAN DRILLING PROGRAM TEXAS A&M UNIVERSITY Technical Note 16 Steven P. Howard Ocean Drilling Program Texas A&M University 1000 Discovery Drive College Station, TX 77845-9547 Daniel H. Reudelhuber Ocean Drilling Program Texas A&M University

  19. 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.

  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. 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.

  2. Selective removal of hydrogen sulfide from gases containing hydrogen sulfide and carbon dioxide using diethanolamine

    SciTech Connect

    Haimour, N.; Sandall, O.C.

    1983-01-01

    It is sometimes necessary to selectively remove hydrogen sulfide from gases containing carbon dioxide. This may be the case for example in the production of sulfur using the Claus process. When two gases are simultaneously absorbed into a solution containing a reactant with which each gas can react, the rate of absorption of each component is affected by the presence of the other gas. For the absorption of hydrogen sulfide into primary and secondary amines, the reaction which occurs can usually be considered to be instantaneous. An instantaneous reaction is diffusion-limited since the reaction occurs so rapidly that the liquid phase reactant and the absorbed gas cannot coexist in the same region of the liquid. For primary and secondary amines used for the gas treatment, the reaction with carbon dioxide is much slower than for hydrogen sulfide and can often be considered to be second order. In this work the simultaneous absorption of two gases into a liquid containing a reactant with which both gases can react is modeled using penetration theory. It is assumed that one gas reacts instantaneously and the other gas undergoes a second order reaction. Parameters used in the calculations are those available in the literature corresponding to the absorption of hydrogen sulfide and carbon dioxide in diethanolamine.

  3. High temperature regenerable hydrogen sulfide removal agents

    DOEpatents

    Copeland, Robert J. (Wheat Ridge, CO)

    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.

  4. 75 FR 8889 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ...FRL-9119-2] RIN 2025-AA27 Hydrogen Sulfide; Community Right-to-Know...release reporting requirements for hydrogen sulfide (Chemical Abstracts Service...Number (CAS No.) 7783-06-4). Hydrogen sulfide was added to the EPCRA...

  5. 76 FR 64022 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-17

    ...EPA-HQ-TRI-2009-0844; FRL-9463-5] RIN 2025-AA27 Hydrogen Sulfide; Community Right-to-Know...Lifting of Administrative Stay for Hydrogen Sulfide...chemical release reporting requirements for hydrogen sulfide (Chemical Abstracts...

  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 from simple wet-chemical routes. Electron transport is sometimes slow in the particle catalysts, and an impedance model has been established to identify this slow electron transport. Finally, the amorphous molybdenum sulfide film catalyst has been integrated onto a copper(I) oxide photocathode for photoelectrochemical hydrogen evolution. The conformal catalyst efficiently extracts the excited electrons to give an impressive photocurrent density of -5.7 mA/cm(2) at 0 V vs RHE. The catalyst also confers good stability. PMID:25065612

  7. 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.

  8. 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...

  9. Microbial oxidation of mixtures of methylmercaptan and hydrogen sulfide.

    PubMed

    Subramaniyan, A; Kolhatkar, R; Sublette, K L; Beitle, R

    1998-01-01

    Refinery spent-sulfidic caustic, containing only inorganic sulfides, has previously been shown to be amenable to biotreatment with Thiobacillus denitrificans strain F with complete oxidation of sulfides to sulfate. However, many spent caustics contain mercaptans that cannot be metabolized by this strict autotroph. An aerobic enrichment culture was developed from mixed Thiobacilli and activated sludge that was capable of simultaneous oxidation of inorganic sulfide and mercaptans using hydrogen sulfide (H2S) and methylmercaptan (MeSH) gas feeds used to simulate the inorganic and organic sulfur of a spent-sulfidic caustic. The enrichment culture was also capable of biotreatment of an actual mercaptan-containing, spent-sulfidic caustic but at lower rates than predicted by operation on MeSH and H2S fed to the culture in the gas phase, indicating that the caustic contained other inhibitory components. PMID:18576062

  10. 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

  11. 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)

  12. Organization of the Human Mitochondrial Hydrogen Sulfide Oxidation Pathway*?

    PubMed Central

    Libiad, Marouane; Yadav, Pramod Kumar; Vitvitsky, Victor; Martinov, Michael; Banerjee, Ruma

    2014-01-01

    Sulfide oxidation is expected to play an important role in cellular switching between low steady-state intracellular hydrogen sulfide levels and the higher concentrations where the physiological effects are elicited. Yet despite its significance, fundamental questions regarding how the sulfide oxidation pathway is wired remain unanswered, and competing proposals exist that diverge at the very first step catalyzed by sulfide quinone oxidoreductase (SQR). We demonstrate that, in addition to sulfite, glutathione functions as a persulfide acceptor for human SQR and that rhodanese preferentially synthesizes rather than utilizes thiosulfate. The kinetic behavior of these enzymes provides compelling evidence for the flow of sulfide via SQR to glutathione persulfide, which is then partitioned to thiosulfate or sulfite. Kinetic simulations at physiologically relevant metabolite concentrations provide additional support for the organizational logic of the sulfide oxidation pathway in which glutathione persulfide is the first intermediate formed. PMID:25225291

  13. 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.

  14. 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.

  15. Detection of thiol modifications by hydrogen sulfide.

    PubMed

    Williams, E; Pead, S; Whiteman, M; Wood, M E; Wilson, I D; Ladomery, M R; Teklic, T; Lisjak, M; Hancock, J T

    2015-01-01

    Hydrogen sulfide (H2S) is an important gasotransmitter in both animals and plants. Many physiological events, including responses to stress, have been suggested to involve H2S, at least in part. On the other hand, numerous responses have been reported following treatment with H2S, including changes in the levels of antioxidants and the activities of transcription factors. Therefore, it is important to understand and unravel the events that are taking place downstream of H2S in signaling pathways. H2S is known to interact with other reactive signaling molecules such as reactive oxygen species (ROS) and nitric oxide (NO). One of the mechanisms by which ROS and NO have effects in a cell is the modification of thiol groups on proteins, by oxidation or S-nitrosylation, respectively. Recently, it has been reported that H2S can also modify thiols. Here we report a method for the determination of thiol modifications on proteins following the treatment with biological samples with H2S donors. Here, the nematode Caenorhabditis elegans is used as a model system but this method can be used for samples from other animals or plants. PMID:25747483

  16. 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

  17. Hydrogen Sulfide in Biochemistry and Medicine

    PubMed Central

    Predmore, Benjamin Lee; Lefer, David Joseph

    2012-01-01

    Abstract Significance: An abundance of experimental evidence suggests that hydrogen sulfide (H2S) plays a prominent role in physiology and pathophysiology. Many targets exist for H2S therapy. The molecular targets of H2S include proteins, enzymes, transcription factors, and membrane ion channels. Recent Advances: Novel H2S precursors are being synthesized and discovered that are capable of releasing H2S in a slow and sustained manner. This presents a novel and advantageous approach to H2S therapy for treatment of chronic conditions associated with a decline in endogenous H2S, such as diabetes and cardiovascular disease. Critical Issues: While H2S is cytoprotective at physiological concentrations, it is not universally cytoprotective, as it appears to have pro-apoptotic actions in cancer cells and is well known to be toxic at supraphysiological concentrations. Many of the pleiotropic effects of H2S on health are associated with the inhibition of inflammation and upregulation of prosurvival pathways. The powerful anti-inflammatory, cytoprotective, immunomodulating, and trophic effects of H2S on the vast majority of normal cells seem to be mediated mainly by its actions as an extremely versatile direct and indirect antioxidant and free radical scavenger. While the overall effects of H2S on transformed (i.e., malignant) cells can be characterized as pro-oxidant and pro-apoptotic, they contrast sharply with the cytoprotective effects on most normal cells. Future Directions: H2S has become a molecule of great interest, and several slow-releasing H2S prodrugs are currently under development. We believe that additional agents regulating H2S bioavailability will be developed during the next 10 years. Antioxid. Redox Signal. 17, 119–140. PMID:22432697

  18. 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 ?g 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

  19. 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.

  20. Hydrogen sulfide measurement using sulfide dibimane: critical evaluation with electrospray ion trap mass spectrometry

    PubMed Central

    Shen, Xinggui; Chakraborty, Sourav; Dugas, Tammy R; Kevil, Christopher G

    2015-01-01

    Accurate measurement of hydrogen sulfide bioavailability remains a technical challenge due to numerous issues involving sample processing, detection methods used, and actual biochemical products measured. Our group and others have reported that reverse phase HPLC detection of sulfide dibimane (SDB) product from the reaction of H2S/HS? with monobromobimane allows for analytical detection of hydrogen sulfide bioavailability in free and other biochemical forms. However, it remains unclear whether possible interfering contaminants may contribute to HPLC SDB peak readings that may result in inaccurate measurements of bioavailable sulfide. In this study, we critically compared hydrogen sulfide dependent SDB detection using reverse phase HPLC (RP-HPLC) versus quantitative SRM electrospray ionization mass spectrometry (ESI/MS) to obtain greater clarity into the validity of the reverse phase HPLC method for analytical measurement of hydrogen sulfide. Using an LCQ-deca ion-trap mass spectrometer, SDB was identified by ESI/MS positive ion mode, and quantified by selected reaction monitoring (SRM) using hydrocortisone as an internal standard. Collision induced dissociation (CID) parameters were optimized at MS2 level for SDB and hydrocortisone. ESI/MS detection of SDB standard was found to be a log order more sensitive than RP-HPLC with a lower limit of 0.25 nM. Direct comparison of tissue and plasma SDB levels using RP-HPLC and ESI/MS methods revealed comparable sulfide levels in plasma, aorta, heart, lung and brain. Together, these data confirm the use of SDB as valid indicator of H2S bioavailability and highlights differences between analytical detection methods. PMID:24932544

  1. Hydrogen sulfide measurement using sulfide dibimane: critical evaluation with electrospray ion trap mass spectrometry.

    PubMed

    Shen, Xinggui; Chakraborty, Sourav; Dugas, Tammy R; Kevil, Christopher G

    2014-09-15

    Accurate measurement of hydrogen sulfide bioavailability remains a technical challenge due to numerous issues involving sample processing, detection methods used, and actual biochemical products measured. Our group and others have reported that reverse phase HPLC detection of sulfide dibimane (SDB) product from the reaction of H2S/HS(-) with monobromobimane allows for analytical detection of hydrogen sulfide bioavailability in free and other biochemical forms. However, it remains unclear whether possible interfering contaminants may contribute to HPLC SDB peak readings that may result in inaccurate measurements of bioavailable sulfide. In this study, we critically compared hydrogen sulfide dependent SDB detection using reverse phase HPLC (RP-HPLC) versus quantitative SRM electrospray ionization mass spectrometry (ESI/MS) to obtain greater clarity into the validity of the reverse phase HPLC method for analytical measurement of hydrogen sulfide. Using an LCQ-Deca ion-trap mass spectrometer, SDB was identified by ESI/MS positive ion mode, and quantified by selected reaction monitoring (SRM) using hydrocortisone as an internal standard. Collision induced dissociation (CID) parameters were optimized at MS2 level for SDB and hydrocortisone. ESI/MS detection of SDB standard was found to be a log order more sensitive than RP-HPLC with a lower limit of 0.25 nM. Direct comparison of tissue and plasma SDB levels using RP-HPLC and ESI/MS methods revealed comparable sulfide levels in plasma, aorta, heart, lung and brain. Together, these data confirm the use of SDB as valid indicator of H2S bioavailability and highlights differences between analytical detection methods. PMID:24932544

  2. 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 was affected by changes in liquid heights the most, followed by changes in flow rates. Feasibility studies for H2S removal from biogas by micro-aeration were conducted at the Ames Water Pollution Control Facility (AWPCF) by using different types of liquid media available at the plant, i.e. plant effluent, mixed liquor, and digester supernatant. From the experiment at AWPCF, it was found that operating pHs were affected by the amount of alkalinity in the liquid media and that the removal efficiencies were affected by the operating pH. Among all the liquid media tested, digester supernatant showed the greatest potential with more than 99% H2S removal at an operating pH of 7.0 and volumetric biogas flow rate of 21.6 m3/m 3-hr. By increasing trace metal contents and temperature of the medium, the hydrogen sulfide removal rate was greatly improved. The operating cost of the full-scale system was estimated to be approximately $2/kg-S-removed. In addition, it was also revealed that abiotic sulfide oxidation accounted for 95% of overall sulfide oxidation. This technology is expected to widen the use of biogas as a renewable fuel since the maintenance requirements of biogas handling equipment, the methane purification costs, and the emissions of SOx will dramatically be reduced. Importantly, the technology does not require inoculation of special bacteria, addition of nutrients and trace elements, or chemicals for pH control.

  3. Nature creates, adapts, protects and sustains life using hydrogen sulfide.

    PubMed

    Tabibzadeh, Siamak

    2016-01-01

    Life emerged on Earth in an anaerobic environment, bathed in noxious gases. Among these gases, the role of hydrogen sulfide is significant since this gas, was required as a building block of life, contributed to abiogenic generation of organic compounds that gave rise to life and drove adaptations of life throughout its entire evolutionary path. During evolution, hydrogen sulfide contributed to sustaining life in face of harsh environmental conditions. Modern cells still utilize hydrogen sulfide as a signaling molecule, in pro and anti-inflammatory responses, for acquisition of tolerance against damage, in directing repair responses, as a source of energy and in modifying their genetic makeup and function to acquire a phenotype reminiscent of early life forms. PMID:26709792

  4. Chronic Ambient Hydrogen Sulfide Exposure and Cognitive Function

    PubMed Central

    Reed, Bruce R.; Crane, Julian; Garrett, Nick; Woods, David L.; Bates, Michael N.

    2014-01-01

    Background Exposures to hydrogen sulfide gas (H2S) have been inconclusively linked to a variety of negative cognitive outcomes. We investigated possible effects on cognitive function in an urban population with chronic, low-level exposure to H2S. Methods Participants were 1,637 adults, aged 18-65 years from Rotorua city, New Zealand, exposed to ambient H2S from geothermal sources. Exposures at homes and workplaces were estimated from data collected by summer and winter H2S monitoring networks across Rotorua in 2010/11. Metrics for H2S exposure at the time of participation and for exposure over the last 30 years were calculated. H2S exposure was modeled both as continuous variables and as quartiles of exposure covering the range of 0 – 64 ppb (0-88 ?g/m3). Outcomes were neuropsychological tests measuring visual and verbal episodic memory, attention, fine motor skills, psychomotor speed and mood. Associations between cognition and measures of H2S exposure were investigated with multiple regression, while covarying demographics and factors known to be associated with cognitive performance. Results The consistent finding was of no association between H2S exposure and cognition. Quartiles of H2S exposure had a small association with simple reaction time: higher exposures were associated with faster response times. Similarly, for digit symbol, higher H2S exposures tended to be marginally associated with better performance. Conclusion The results provide evidence that chronic H2S exposure, at the ambient levels found in and around Rotorua, is not associated with impairment of cognitive function. PMID:24548790

  5. Polyaniline nanowires-gold nanoparticles hybrid network based chemiresistive hydrogen sulfide sensor

    E-print Network

    .1063/1.3070237 Hydrogen sulfide H2S is a toxic, corrosive, and inflam- mable gas produced in sewage, coal mines, oilPolyaniline nanowires-gold nanoparticles hybrid network based chemiresistive hydrogen sulfide for hydrogen sulfide detection and quantification using polyaniline nanowires-gold nanoparticles hybrid network

  6. 76 FR 69136 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ...EPA-HQ-TRI-2009-0844; FRL-9488-5] RIN 2025-AA27 Hydrogen Sulfide; Community Right-to-Know...Lifting of Administrative Stay for Hydrogen Sulfide; Correction...Stay of the reporting requirements for hydrogen sulfide. The Office of the Federal...

  7. Chromium(VI) Reduction by Hydrogen Sulfide in Aqueous

    E-print Network

    Deng, Baolin

    Chromium(VI) Reduction by Hydrogen Sulfide in Aqueous Media: Stoichiometry and Kinetics C H U L S U-ray spectroscopy (EDS) confirmed that chromium hydroxide and elemental sulfur were the stable products to accidental leakages and improper disposals associated with its wide- spread usage (1-3). Since some chromium

  8. DETERMINATION OF HYDROGEN SULFIDE IN REFINERY FUEL GASES

    EPA Science Inventory

    Several widely employed test methods for the iodimetric measurement of hydrogen sulfide in refinery fuel gases are shown to suffer from serious thiol interferences. An absorbing solution consisting of 0.16 M cadmium sulfate/sulfuric acid at pH 3.0 is shown to be effective for the...

  9. Adsorption of Hydrogen Sulfide onto Activated Carbon Fibers: Effect of

    E-print Network

    Borguet, Eric

    Adsorption of Hydrogen Sulfide onto Activated Carbon Fibers: Effect of Pore Structure and Surface chemistry were studied using activated carbon fibers (ACFs) with different pore structures and surface areas onto carbon surfaces under dry and anoxic conditions, the effects of carbon pore structure and surface

  10. HEALTH ASSESSMENT DOCUMENT FOR HYDROGEN SULFIDE, REVIEW DRAFT

    EPA Science Inventory

    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 halt...

  11. 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

  12. Synthesis of a photocontrollable hydrogen sulfide donor using ketoprofenate photocages.

    PubMed

    Fukushima, Naoki; Ieda, Naoya; Sasakura, Kiyoshi; Nagano, Tetsuo; Hanaoka, Kenjiro; Suzuki, Takayoshi; Miyata, Naoki; Nakagawa, Hidehiko

    2014-01-18

    We report the design, synthesis and application of a directly photocontrollable hydrogen sulfide (H2S) donor, which releases H2S proportionally to the intensity and duration of photoirradiation. Photocontrolled H2S release from this donor was also demonstrated in bovine serum. This H2S donor should be suitable for use in various biological systems. PMID:24280741

  13. 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

  14. Endogenously produced hydrogen sulfide is involved in porcine oocyte maturation in vitro.

    PubMed

    Nevoral, Jan; Žalmanová, Tereza; Zámostná, Kate?ina; Kott, Tomáš; Ku?erová-Chrpová, Veronika; Bodart, Jean-Francois; Gelaude, Armance; Procházka, Radek; Orsák, Matyáš; Šulc, Miloslav; Klein, Pavel; Dvo?áková, Markéta; Weingartová, Ivona; Víghová, Aurélia; Hošková, Kristýna; Krej?ová, Tereza; Jílek, František; Petr, Jaroslav

    2015-12-01

    Hydrogen sulfide, one of three known gasotransmitters, is involved in physiological processes, including reproductive functions. Oocyte maturation and surrounding cumulus cell expansion play an essential role in female reproduction and subsequent embryonic development. Although the positive effects of exogenous hydrogen sulfide on maturing oocytes are well known, the role of endogenous hydrogen sulfide, which is physiologically released by enzymes, has not yet been described in oocytes. In this study, we observed the presence of Cystathionine ?-Synthase (CBS), Cystathionine ?-Lyase (CTH) and 3-Mercaptopyruvate Sulfurtransferase (3-MPST), hydrogen sulfide-releasing enzymes, in porcine oocytes. Endogenous hydrogen sulfide production was detected in immature and matured oocytes as well as its requirement for meiotic maturation. Individual hydrogen sulfide-releasing enzymes seem to be capable of substituting for each other in hydrogen sulfide production. However, meiosis suppression by inhibition of all hydrogen sulfide-releasing enzymes is not irreversible and this effect is a result of M-Phase/Maturation Promoting Factor (MPF) and Mitogen-Activated Protein Kinase (MAPK) activity inhibition. Futhermore, cumulus expansion expressed by hyaluronic acid (HA) production is affected by the inhibition of hydrogen sulfide production. Moreover, quality changes of the expanded cumuli are indicated. These results demonstrate hydrogen sulfide involvement in oocyte maturation as well as cumulus expansion. As such, hydrogen sulfide appears to be an important cell messenger during mammalian oocyte meiosis and adequate cumulus expansion. PMID:26456342

  15. 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. PMID:26149232

  16. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... section have the following meanings: Facility means a vessel, a structure, or an artificial island used... wind directions, the wake effects caused by the facility and adjacent structure(s), and the height of... atomic hydrogen when H2S is present....

  17. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Definitions. Terms used in this section have the following meanings: Facility means a vessel, a structure, or... structure(s), and the height of all such facilities and structures. You must equip the flare outlet with an..., reinforcing pads) which can be invaded by atomic hydrogen when H2S is present....

  18. 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 barrier due to saturation of the local bonding environment.

  19. 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 Ĺ 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.

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

    PubMed

    Jensen, Henriette Stokbro; Nielsen, Asbjřrn 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

  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. Corrosion of concrete sewers--the kinetics of hydrogen sulfide oxidation.

    PubMed

    Vollertsen, Jes; Nielsen, Asbjřrn Haaning; Jensen, Henriette Stokbro; Wium-Andersen, Tove; Hvitved-Jacobsen, Thorkild

    2008-05-01

    Hydrogen sulfide absorption and oxidation by corroding concrete surfaces was quantified in a test rig consisting of 6 concrete pipes operated under sewer conditions. The test rig was placed in an underground sewer monitoring station with access to fresh wastewater. Hydrogen sulfide gas was injected into the pipe every 2nd hour to peak concentrations around 1000 ppm. After some months of operation, the hydrogen sulfide became rapidly oxidized by the corroding concrete surfaces. At hydrogen sulfide concentrations of 1000 ppm, oxidation rates as high as 1 mg S m(-2) s(-1) were observed. The oxidation process followed simple nth order kinetics with a process order of 0.45-0.75. Extrapolating the results to gravity sewer systems showed that hydrogen sulfide oxidation by corroding concrete is a fast process compared to the release of hydrogen sulfide from the bulk water, resulting in low gas concentrations compared with equilibrium. Balancing hydrogen sulfide release with hydrogen sulfide oxidation at steady state conditions demonstrated that significant corrosion rates--several millimeters of concrete per year--can potentially occur at hydrogen sulfide gas phase concentrations well below 5-10 ppm. The results obtained in the study advances the knowledge on prediction of sewer concrete corrosion and the extent of odor problems. PMID:18281080

  3. Micellar-mediated extractive spectrophotometric determination of hydrogen sulfide/sulfide through Prussian Blue reaction: application to environmental samples.

    PubMed

    Pandurangappa, Malingappa; Samrat, Devaramani

    2010-01-01

    A sensitive surfactant-mediated extractive spectrophotometric method has been developed, based on the reaction of ferric iron with sulfide to form ferrous iron and its subsequent reaction with ferricyanide to form Prussian Blue, to quantify trace levels of hydrogen sulfide/sulfide in environmental samples. The method obeys Beer's law in the concentration range 2-10 microg of sulfide in 25 mL of aqueous phase with molar absorptivity (epsilon) of 3.92 x 10(4) L mol(-1) cm(-1). The colored species has been extracted into isoamyl acetate in the presence of a cationic surfactant i.e. cetylpyridinium chloride, to enhance the sensitivity of the method with epsilon value 5.2 x 10(4) L mol(-1) cm(-1). The relative standard deviation has been found to be 0.69% for 10 determinations at 4 microg of sulfide and the limit of detection was 0.009 microg mL(-1). The interference from common anions and cations has been studied. The proposed method has been applied to the determination of residual hydrogen sulfide in the laboratory fume hood as well as ambient atmospheric hydrogen sulfide in the vicinity of open sewer lines after fixing the analyte in ionic form using suitable trapping medium. PMID:20065592

  4. Bioluminescence Probe for Detecting Hydrogen Sulfide in Vivo.

    PubMed

    Ke, Bowen; Wu, Wenxiao; Liu, Wei; Liang, Hong; Gong, Deying; Hu, Xiaotong; Li, Minyong

    2016-01-01

    Considering that hydrogen sulfide (H2S) is an endogenous signaling molecule involved in numerous biological processes, a method for monitoring H2S as a powerful tool for investigating its complicated functions and mechanisms is urgently demanded. Herein, a bioluminescent turn-on probe was reported based on caged strategy for the detection of H2S in vitro and in vivo. This probe will help us understand the intricate contribution of H2S to a variety of physiological and pathological processes. PMID:26634959

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

    DOEpatents

    Srinivas, Girish (Thornton, CO); Bai, Chuansheng (Baton Rouge, LA)

    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. A STUDY TO EVALUATE CARBON MONOXIDE AND HYDROGEN SULFIDE CONTINUOUS EMISSION MONITORS AT AN OIL REFINERY

    EPA Science Inventory

    An eleven month field evaluation was done on five hydrogen sulfide and four carbon monoxide monitors located at an oil refinery. The hydrogen sulfide monitors sampled a fuel gas feed line and the carbon monoxide monitors sampled the emissions from a fluid cat cracker (FCC). Two o...

  7. Survival of hydrogen sulfide oxidizing bacteria on corroded concrete surfaces of sewer systems.

    PubMed

    Jensen, H S; Nielsen, A H; Hvitved-Jacobsen, T; Vollertsen, J

    2008-01-01

    The activity of hydrogen sulfide oxidizing bacteria within corroded concrete from a sewer manhole was investigated. The bacteria were exposed to hydrogen sulfide starvation for up till 18 months, upon which their hydrogen sulfide oxidizing activity was measured. It was tested whether the observed reduction in biological activity was caused by a biological lag phase or by decay of the bacteria. The results showed that the bacterial activity declined with approximately 40% pr. month during the first two months of hydrogen sulfide starvation. After 2-3 months of starvation, the activity stabilized. Even after 6 months of starvation, exposure to hydrogen sulfide for 6 hours a day on three successive days could restore the bacteriological activity to about 80% of the initial activity. After 12 months of starvation, the activity could, however, not be restored, and after 18 months the biological activity approached zero. The long-term survival aspect of concrete corroding bacteria has implications for predicting hydrogen sulfide corrosion in sewer systems subject to irregular hydrogen sulfide loadings, e.g. as they occur in temperate climates where hydrogen sulfide often is a summer-problem only. PMID:18547922

  8. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must accompany... Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT...Exploration Plans (ep) § 250.215 What hydrogen sulfide (H2S) information must...

  9. 30 CFR 550.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Resources 2 2013-07-01 2013-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 550... Contents of Exploration Plans (ep) § 550.215 What hydrogen sulfide (H2 S) information must accompany the EP?...

  10. 30 CFR 550.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Resources 2 2014-07-01 2014-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 550... Contents of Exploration Plans (ep) § 550.215 What hydrogen sulfide (H2 S) information must accompany the EP?...

  11. 30 CFR 550.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Resources 2 2012-07-01 2012-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 550... Contents of Exploration Plans (ep) § 550.215 What hydrogen sulfide (H2 S) information must accompany the EP?...

  12. 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...

  13. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must accompany the EP? 250... Contents of Exploration Plans (ep) § 250.215 What hydrogen sulfide (H2S) information must accompany the EP? The...

  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. 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

  16. 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.

  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??M 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. PMID:25630511

  19. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment... procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel.... In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with...

  20. 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

    ...EPA-HQ-TRI-2009-0844; FRL-9137-7] RIN 2025-AA27 Hydrogen Sulfide; Community Right-to-Know...chemical release reporting requirements for hydrogen sulfide (Chemical Abstracts Service...manufacture, process, or otherwise use hydrogen sulfide. Potentially affected...

  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. 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 ? \\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.

  3. 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

  4. 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.

  5. 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

  6. 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

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

    SciTech Connect

    Qiao, Wang; Chaoshu, Tang; Key Laboratory of Molecular Cardiovascular Medicine, Ministry of Education ; 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.

  8. The metallization and superconductivity of dense hydrogen sulfide

    SciTech Connect

    Li, Yinwei Hao, Jian; Li, Yanling; Liu, Hanyu; Ma, Yanming

    2014-05-07

    Hydrogen sulfide (H{sub 2}S) is a prototype molecular system and a sister molecule of water (H{sub 2}O). The phase diagram of solid H{sub 2}S at high pressures remains largely unexplored arising from the challenges in dealing with the pressure-induced weakening of S–H bond and larger atomic core difference between H and S. Metallization is yet achieved for H{sub 2}O, but it was observed for H{sub 2}S above 96 GPa. However, the metallic structure of H{sub 2}S remains elusive, greatly impeding the understanding of its metallicity and the potential superconductivity. We have performed an extensive structural study on solid H{sub 2}S at pressure ranges of 10–200 GPa through an unbiased structure prediction method based on particle swarm optimization algorithm. Besides the findings of candidate structures for nonmetallic phases IV and V, we are able to establish stable metallic structures violating an earlier proposal of elemental decomposition into sulfur and hydrogen [R. Rousseau, M. Boero, M. Bernasconi, M. Parrinello, and K. Terakura, Phys. Rev. Lett. 85, 1254 (2000)]. Our study unravels a superconductive potential of metallic H{sub 2}S with an estimated maximal transition temperature of ?80 K at 160 GPa, higher than those predicted for most archetypal hydrogen-containing compounds (e.g., SiH{sub 4}, GeH{sub 4}, etc.)

  9. Hydrogen sulfide (H 2S) in urban ambient air

    NASA Astrophysics Data System (ADS)

    Kourtidis, K.; Kelesis, A.; Petrakakis, M.

    Despite indications of high hydrogen sulfide levels in some urban environments, only sparse measurements have been reported in the literature. Here we present one full year of hydrogen sulfide measurements in an urban traffic site in the city of Thessaloniki, Greece. In this 1-million-population city the H 2S concentrations were surprisingly high, with a mean annual concentration of 8 ?g m -3 and wintertime mean monthly concentrations up to 20 ?g m -3 (12.9 ppb). Daily mean concentrations in the winter were up to 30 ?g m -3 (19.3 ppb), while hourly concentrations were up to 54 ?g m -3 (34.8 ppb). During calm (wind velocity < 0.5 m s -1) conditions, mainly encountered during night-time hours, hourly values of H 2S were highly correlated with those of CO ( r2 = 0.75) and SO 2 ( r2 = 0.70), pointing to a common traffic source from catalytic converters. Annual mean concentrations are above the WHO recommendation for odor annoyance; hence, H 2S might play a role to the malodorous episodes that the city occasionally experiences. The high ambient H 2S levels might also be relevant to the implementation of preservation efforts for outdoor marble and limestone historical monuments that have been targeting SO 2 emissions as an atmospheric acidity source, since the measurements presented here suggest that about 19% of the annual sulfur (SO 2 + H 2S) emissions in Thessaloniki are in the form of H 2S.

  10. 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.

  11. 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.

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

    PubMed

    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

    2012-04-14

    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. PMID:22378060

  13. 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…

  14. 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

  15. Rate controlling processes for crack growth in hydrogen sulfide for an alsl 4340 steel

    NASA Astrophysics Data System (ADS)

    Lu, M.; Pao, P. S.; Weir, T. W.; Simmons, G. W.; Wei, R. P.

    1981-05-01

    Parallel fracture mechanics and surface chemistry studies were carried out to develop further understanding of environment assisted subcritical crack growth in high strength steels. The kinetics of crack growth for an AISI 4340 steel (tempered at 477 K) in high purity hydrogen sulfide have been determined as a function of pressure at room temperature and as a function of temperature at hydrogen sulfide pressures of 0.133 and 2.66 kPa. The kinetics for the reactions of hydrogen sulfide with this steel and the extent of reactions were also determined. Two rate controlling processes have been identified. At the lower pressure, the rate of crack growth varies according to T1/2 and is controlled by the rate of transport of hydrogen sulfide to the crack tip. At the higher pressure, crack growth is controlled by the rate of diffusion of hydrogen into the steel ahead of the crack tip and exhibits an apparent activation energy of about 5 kJ/mol. Embrittlement results from hydrogen that is produced by the reactions of hydrogen sulfide with the steel. These reactions are extremely rapid and are limited in extent, leading to the formation of one to two layers of “sulfide” on the fracture surfaces. The crack growth results are discussed in terms of measured reaction kinetics and published data on diffusion, and in relation to models for transport- and diffusion-controlled crack growth.

  16. EMERSION IN THE MANGROVE FOREST FISH 'RIVULUS MARMORATUS': A UNIQUE RESPONSE TO HYDROGEN SULFIDE

    EPA Science Inventory

    The mangrove forest fish Rivulus marmoratus (Cyprinodontidae) has frequently been observed out of water, a phenomenon generally attributed to habitat drying. The authors tested the hypothesis that hydrogen sulfide, a substance characteristically found in their environment, can se...

  17. Occupationally related hydrogen sulfide deaths in the United States from 1984 to 1994.

    PubMed

    Fuller, D C; Suruda, A J

    2000-09-01

    Alice Hamilton described fatal work injuries from acute hydrogen sulfide poisonings in 1925 in her book Industrial Poisons in the United States. There is no unique code for H2S poisoning in the International Classification of Diseases, 9th Revision; therefore, these deaths cannot be identified easily from vital records. We reviewed US Occupational Safety and Health Administration (OSHA) investigation records for the period 1984 to 1994 for mention of hazardous substance 1480 (hydrogen sulfide). There were 80 fatalities from hydrogen sulfide in 57 incidents, with 19 fatalities and 36 injuries among coworkers attempting to rescue fallen workers. Only 17% of the deaths were at workplaces covered by collective bargaining agreements. OSHA issued citations for violation of respiratory protection and confined space standards in 60% of the fatalities. The use of hydrogen sulfide detection equipment, air-supplied respirators, and confined space safety training would have prevented most of the fatalities. PMID:10998771

  18. 75 FR 8889 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ...EPA is announcing that it is considering whether to lift the Administrative Stay of the Emergency Planning and Community Right-to- Know Act (EPCRA) section 313 toxic chemical release reporting requirements for hydrogen sulfide (Chemical Abstracts Service Number (CAS No.) 7783-06-4). Hydrogen sulfide was added to the EPCRA section 313 list of toxic chemicals in a final rule published in the......

  19. Experimental Observations on the Biological Significance of Hydrogen Sulfide in Carotid Body Chemoreception.

    PubMed

    Gallego-Martin, T; Agapito, T; Ramirez, M; Olea, E; Yubero, S; Rocher, A; Gomez-Nińo, A; Obeso, A; Gonzalez, C

    2015-01-01

    The cascade of transduction of hypoxia and hypercapnia, the natural stimuli to chemoreceptor cells, is incompletely understood. A particular gap in that knowledge is the role played by second messengers, or in a most ample term, of modulators. A recently described modulator of chemoreceptor cell responses is the gaseous transmitter hydrogen sulfide, which has been proposed as a specific activator of the hypoxic responses in the carotid body, both at the level of the chemoreceptor cell response or at the level of the global output of the organ. Since sulfide behaves in this regard as cAMP, we explored the possibility that sulfide effects were mediated by the more classical messenger. Data indicate that exogenous and endogenous sulfide inhibits adenyl cyclase finding additionally that inhibition of adenylyl cyclase does not modify chemoreceptor cell responses elicited by sulfide. We have also observed that transient receptor potential cation channels A1 (TRPA1) are not regulated by sulfide in chemoreceptor cells. PMID:26303462

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

    PubMed

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

    2015-07-01

    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

  1. 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

  2. Biofiltration of hydrogen sulfide by Sulfolobus metallicus at high temperatures.

    PubMed

    Morales, M; Silva, J; Morales, P; Gentina, J C; Aroca, G

    2012-01-01

    Biofiltration of reduced sulfur compounds such as hydrogen sulfide has been mainly applied to emissions at mild temperatures (25 to 35 °C). However, an important number of industrial gaseous emission containing sulfur compounds, from diverse industrial sectors (petroleum refinery, cellulose production, smelting, rendering plants and food industries) are emitted at temperatures over 50 °C. Most of the studies on thermophilic systems report that a higher elimination capacity can be obtained at elevated temperature, allowing the design of smaller equipment for the same loading rate than that required for removing the same load under mesophilic conditions. A biotrickling filter inoculated with Sulfolobus metallicus, which operates at three different residence times, 60, 80 and 120 s, and two different temperatures (45 and 55 °C) for treating H(2)S is reported. The input loads of H(2)S were progressively increased from 0 to 100 gS/m(3). The aim of this study was to determine the capacity and ability of S. metallicus to oxidize H(2)S at high temperatures. The better removal capacity of H(2)S obtained was 37.1 ± 1.7 gS/m(3) h at 55 °C for a residence time of 120 s. The difference of the removal capacity of H(2)S between the two temperatures was 4 g/m(3) h on average of sulfur removal for the different residence times. PMID:22925869

  3. Hydrogen Sulfide Decomposition in Pulsed Corona Discharge Reactors

    NASA Astrophysics Data System (ADS)

    John, S.; Zhao, G. B.; Zhang, J. J.; Hamann, J. C.; Muknahallipatna, S. S.; Legowski, S.; Ackerman, J. F.; Argyle, M. D.

    2008-10-01

    Hydrogen sulfide (H2S) decomposition was carried out in each of four balance gases (Ar, He, N2 and H2) in a wire-in-tube pulsed corona discharge reactor. H2S conversion rates and H2S decomposition energy efficiencies depend on the balance gas and H2S concentrations. H2S conversion in monatomic balance gases, like Ar and He, is more efficient than in diatomic balance gases like N2 and H2. Low pulse forming capacitance, low charge voltage, and high pulse frequency operation produces the highest energy efficiency for H2S conversion at constant power. H2S conversion is more efficient in Ar-N2 gas mixture than in Ar or N2. These results can be explained by corona discharge observations, the electron attachment reactions of H2S and the proposed reaction mechanism of H2S dissociation. The results reveal the potential for energy efficient H2S decomposition in pulsed corona discharge reactors.

  4. New nitric oxide or hydrogen sulfide releasing aspirins.

    PubMed

    Lazzarato, Loretta; Chegaev, Konstantin; Marini, Elisabetta; Rolando, Barbara; Borretto, Emily; Guglielmo, Stefano; Joseph, Sony; Di Stilo, Antonella; Fruttero, Roberta; Gasco, Alberto

    2011-08-11

    A new series of (((R-oxy)carbonyl)oxy)methyl esters of aspirin (ASA), bearing nitric oxide (NO) or hydrogen sulfide (H(2)S) releasing groups, was synthesized, and the compounds were evaluated as new ASA co-drugs. All the products were quite stable in buffered solution at pH 1 and 7.4. Conversely, they were all rapidly metabolized, producing ASA and the NO/H(2)S releasing moiety used for their preparation. Consequent on ASA release, the compounds were capable of inhibiting collagen-induced platelet aggregation of human platelet-rich plasma (PRP). The simple NO/H(2)S donor substructures were able to relax contracted rat aorta strips, with a NO- and H(2)S-dependent mechanism, respectively, but they either did not trigger antiaggregatory activity or displayed antiplatelet potency markedly below that of the related co-drug. The new products might provide a safer and improved alternative to the use of ASA principally in its anti-inflammatory and antithrombotic applications. PMID:21688846

  5. Hydrogen sulfide anion regulates redox signaling via electrophile sulfhydration

    PubMed Central

    Nishida, Motohiro; Sawa, Tomohiro; Kitajima, Naoyuki; Ono, Katsuhiko; Inoue, Hirofumi; Ihara, Hideshi; Motohashi, Hozumi; Yamamoto, Masayuki; Suematsu, Makoto; Kurose, Hitoshi; van der Vliet, Albert; Freeman, Bruce A; Shibata, Takahiro; Uchida, Koji; Kumagai, Yoshito; Akaike, Takaaki

    2014-01-01

    An emerging aspect of redox signaling is the pathway mediated by electrophilic byproducts, such as nitrated cyclic nucleotide (for example, 8-nitroguanosine 3?,5?-cyclic monophosphate (8-nitro-cGMP)) and nitro or keto derivatives of unsaturated fatty acids, generated via reactions of inflammation-related enzymes, reactive oxygen species, nitric oxide and secondary products. Here we report that enzymatically generated hydrogen sulfide anion (HS?) regulates the metabolism and signaling actions of various electrophiles. HS? reacts with electrophiles, best represented by 8-nitro-cGMP, via direct sulfhydration and modulates cellular redox signaling. The relevance of this reaction is reinforced by the significant 8-nitro-cGMP formation in mouse cardiac tissue after myocardial infarction that is modulated by alterations in HS? biosynthesis. Cardiac HS?, in turn, suppresses electrophile-mediated H-Ras activation and cardiac cell senescence, contributing to the beneficial effects of HS? on myocardial infarction–associated heart failure. Thus, this study reveals HS?-induced electrophile sulfhydration as a unique mechanism for regulating electrophile-mediated redox signaling. PMID:22772154

  6. 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 ?-synthase and cystathionine ?-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

  7. [Hydrogen sulfide: A promising therapy in neuroprotection following cardiac arrest?].

    PubMed

    Sayouri, H; Boudier, A; Vigneron, C; Leroy, P; Le Tacon, S

    2015-11-01

    Each year, in France, the number of cardiac arrests is evaluated between 30,000 to 50,000. When a patient survives, he undergoes a post-resuscitation syndrome which can aggravate the injuries and for which nowadays, no medication is available. In some kinds of cardiac arrest, a hypothermia protocol can be applied with a need for monitoring because of the appearance of side effects. In this context, hydrogen sulfide, which is a gasotransmitter with numerous physiological and pharmacological properties, may be interesting. Indeed, its use could protect against oxidative, inflammatory and apoptotic troubles induced by the post-resuscitation syndrome. The implied biochemical mechanisms are adenosine triphosphate potassium channels activation and cytochrome c oxidase inhibition. This molecule can also induce a suspended animation state characterized by a metabolism decrease, which could give a delay for physicians to start a therapeutic monitoring. Thus, in spite of a modest and sometimes contradictory literature, this compound could become the first neuroprotective molecule in cardiac arrest. PMID:26033567

  8. Fatal accidental hydrogen sulfide poisoning: a domestic case.

    PubMed

    Sastre, Caroline; Baillif-Couniou, Valérie; Kintz, Pascal; Cirimele, Vincent; Bartoli, Christophe; Christia-Lotter, Marie-Amandine; Piercecchi-Marti, Marie-Dominique; Leonetti, Georges; Pelissier-Alicot, Anne-Laure

    2013-01-01

    Hydrogen sulfide (H(2)S) poisonings are classically reported in occupational settings. We describe an unusual domestic case of fatal acute poisoning by H(2)S inhalation. A mother and her infant daughter were found dead in the kitchen of their home. The emergency medical team described a strong smell of rotten eggs, suggesting acute H(2)S poisoning. Autopsies revealed only multiorgan congestion. H(2) S was measured in blood and lung tissue samples by gas chromatography/mass spectrometry. Body fluids were negative, but H(2) S was found in the lungs of both the mother and the child at concentrations of 1.46 and 1.92 mg/kg, respectively, concentrations described in the literature as potentially lethal. Expert surveys of the premises suggested a complex mechanism involving both defective maintenance of the pipes and drains of the building and faulty assembly of the sink siphon, which led to stagnation of waste water and formation of a pocket of H(2)S. PMID:23126240

  9. 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.

  10. J. Am. Chem. SOC.1994,116, 5379-5391 5379 Oxidation of Amines and Sulfides with Hydrogen Peroxide and

    E-print Network

    Schlegel, H. Bernhard

    J. Am. Chem. SOC.1994,116, 5379-5391 5379 Oxidation of Amines and Sulfides with Hydrogen Peroxide and Alkyl Hydrogen Peroxide. The Nature of the Oxygen-Transfer Step Robert D. Bach,' Ming-Der Su, and H sulfide by hydrogen peroxide and methyl hydroperoxide. Geometries of reactants, complexes, transition

  11. Generation of DNA-Damaging Reactive Oxygen Species via the Autoxidation of Hydrogen Sulfide under Physiologically Relevant

    E-print Network

    Gates, Kent. S.

    indicate that this process involved autoxidation of H2S to generate superoxide, hydrogen peroxide, andGeneration of DNA-Damaging Reactive Oxygen Species via the Autoxidation of Hydrogen Sulfide under States ABSTRACT: Hydrogen sulfide (H2S) has long been known for its toxic properties; however, in recent

  12. 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.

  13. Biofiltration for control of carbon disulfide and hydrogen sulfide vapors

    SciTech Connect

    Fucich, W.J.; Yang, Y.; Togna, A.P.; Alibeckoff, D.

    1997-12-31

    A full-scale biofiltration system has been installed to control carbon disulfide (CS{sub 2}) and hydrogen sulfide (H{sub 2}S) vapor emissions at Nylonge Corporation (Nylonge), a cellulose sponge manufacturing facility in Elyria, Ohio. Both CS{sub 2} and H{sub 2}S are toxic and odorous. In addition, the US Environmental Protection Agency (EPA) has classified CS{sub 2} as one of the 189 hazardous air pollutants listed under Title 3 of the 1990 Clean Air Act Amendments. Nylonge evaluated several technologies to control CS{sub 2} and H{sub 2}S vapor emissions. After careful consideration of both removal efficiency requirements and cost, Nylonge selected biological treatment as the best overall technology for their application. A biological based technology has been developed to effectively degrade CS{sub 2} and H{sub 2}S vapors. Biofiltration is a process that aerobically converts particular vapor phase compounds into CO{sub 2}, biomass, and water vapor. In this process, microorganisms, in the form of a moistened biofilm layer, immobilized on an organic packing material, such as compost, peat, wood chips, etc., are used to catalyze beneficial chemical reactions. As a contaminated vapor stream passes through the biofilter bed, the contaminants are transferred to the biofilm and are degraded by the microorganisms. This paper describes the CS{sub 2} and H{sub 2}S biofiltration process and the full-scale biofilter system installed at Nylonge`s facility. The system was started in October of 1995, and is designed to treat a 30,000 CFM exhaust stream contaminated with CS{sub 2} and H{sub 2}S vapors.

  14. Hydrogen sulfide promotes calcium uptake in larval zebrafish.

    PubMed

    Kwong, Raymond W M; Perry, Steve F

    2015-07-01

    Hydrogen sulfide (H2S) can act as a signaling molecule for various ion channels and/or transporters; however, little is known about its potential involvement in Ca(2+) balance. Using developing zebrafish (Danio rerio) as an in vivo model system, the present study demonstrated that acute exposure to H2S donors increased Ca(2+) influx at 4 days postfertilization, while chronic (3-day) exposure caused a rise in whole body Ca(2+) levels. The mRNA expression of Ca(2+)-transport-related genes was unaffected by H2S exposure, suggesting that posttranscriptional modifications were responsible for the altered rates of Ca(2+) uptake. Indeed, treatment of fish with the protein kinase A inhibitor H-89 abolished the H2S-mediated stimulation of Ca(2+) influx, suggesting that H2S increased Ca(2+) influx by activating cAMP-protein kinase A pathways. Cystathionine ?-synthase (CBS) and cystathionine ?-lyase (CSE) are two key enzymes in the endogenous synthesis of H2S. Using an antisense morpholino knockdown approach, we demonstrated that Ca(2+) influx was reduced in CBS isoform b (CBSb)- but not in CSE-deficient fish. Interestingly, the reduction in Ca(2+) influx in CBSb-deficient fish was observed only in fish that were acclimated to low-Ca(2+) water (i.e., 25 ?M Ca(2+); control: 250 ?M Ca(2+)). Similarly, mRNA expression of cbsb but not cse was increased in fish acclimated to low-Ca(2+) water. Results from whole-mount immunohistochemistry further revealed that CBSb was expressed in Na(+)-K(+)-ATPase-rich cells, which are implicated in Ca(2+) uptake in zebrafish larvae. Collectively, the present study suggests a novel role for H2S in promoting Ca(2+) influx, particularly in a low-Ca(2+) environment. PMID:25948733

  15. Hydrogen sulfide inhibits Na+ uptake in larval zebrafish, Danio rerio.

    PubMed

    Kumai, Yusuke; Porteus, Cosima S; Kwong, Raymond W M; Perry, Steve F

    2015-04-01

    The present study investigated the role of hydrogen sulfide (H2S) in regulating Na(+) uptake in larval zebrafish, Danio rerio. Waterborne treatment of larvae at 4 days post-fertilization (dpf) with Na2S or GYY-4137 (chemicals known to generate H2S) significantly reduced Na(+) uptake. Exposure of larvae to water enriched with NaCl (1 mM NaCl) caused a pronounced reduction in Na(+) uptake which was prevented by pharmacological inhibition of cystathionine ?-synthase (CBS) or cystathionine ?-lyase (CSE), two key enzymes involved in the endogenous synthesis of H2S. Furthermore, translational gene knockdown of CSE and CBSb significantly increased the basal rate of Na(+) uptake. Waterborne treatment with Na2S significantly decreased whole-body acid excretion and reduced Na(+) uptake in larval zebrafish preexposed to acidic (pH 4.0) water (a condition shown to promote Na(+) uptake via Na(+)-H(+)-exchanger 3b, NHE3b). However, Na2S did not affect Na(+) uptake in larvae depleted of NHE3b-containing ionocytes (HR cells) after knockdown of transcription factor glial cell missing 2 (gcm2) in which Na(+) uptake occurs predominantly via Na(+)-Cl(-) co-transporter (NCC)-containing cells. These observations suggest that Na(+) uptake via NHE3b, but not NCC, is regulated by H2S. Whole-mount immunohistochemistry demonstrated that ionocytes expressing NHE3b also express CSE. These data suggests a physiologically relevant role of H2S as a mechanism to lower Na(+) uptake in zebrafish larvae, probably through its inhibitory action on NHE3b. PMID:24939700

  16. Hydrogen sulfide is an endogenous stimulator of angiogenesis

    PubMed Central

    Papapetropoulos, Andreas; Pyriochou, Anastasia; Altaany, Zaid; Yang, Guangdong; Marazioti, Antonia; Zhou, Zongmin; Jeschke, Mark G.; Branski, Ludwik K.; Herndon, David N.; Wang, Rui; Szabó, Csaba

    2009-01-01

    The goal of the current study was to investigate the role of exogenous and endogenous hydrogen sulfide (H2S) on neovascularization and wound healing in vitro and in vivo. Incubation of endothelial cells (ECs) with H2S enhanced their angiogenic potential, evidenced by accelerated cell growth, migration, and capillary morphogenesis on Matrigel. Treatment of chicken chorioallantoic membranes (CAMS) with H2S increased vascular length. Exposure of ECs to H2S resulted in increased phosphorylation of Akt, ERK, and p38. The KATP channel blocker glibenclamide or the p38 inhibitor SB203580 abolished H2S-induced EC motility. Since glibenclamide inhibited H2S-triggered p38 phosphorylation, we propose that KATP channels lay upstream of p38 in this process. When CAMs were treated with H2S biosynthesis inhibitors dl-propylargylglycine or beta-cyano-L-alanine, a reduction in vessel length and branching was observed, indicating that H2S serves as an endogenous stimulator of the angiogenic response. Stimulation of ECs with vascular endothelial growth factor (VEGF) increased H2S release, while pharmacological inhibition of H2S production or KATP channels or silencing of cystathionine gamma-lyase (CSE) attenuated VEGF signaling and migration of ECs. These results implicate endothelial H2S synthesis in the pro-angiogenic action of VEGF. Aortic rings isolated from CSE knockout mice exhibited markedly reduced microvessel formation in response to VEGF when compared to wild-type littermates. Finally, in vivo, topical administration of H2S enhanced wound healing in a rat model, while wound healing was delayed in CSE?/? mice. We conclude that endogenous and exogenous H2S stimulates EC-related angiogenic properties through a KATP channel/MAPK pathway. PMID:19955410

  17. 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...

  18. Cold excitation and determination of hydrogen sulfide by dielectric barrier discharge molecular emission spectrometry.

    PubMed

    Wu, Zhongchen; Jiang, Jie; Li, Na

    2015-11-01

    A low-temperature microplasma generated in a dielectric barrier discharge (DBD) was used as a radiation source for the excitation of hydrogen sulfide and its determination by molecular emission spectrometry (MES). The excitation/emission chamber was enclosed to eliminate spectral interference from ambient air. The spectral emission lines of hydrogen sulfide were clearly discriminated from the background spectrum, and the emission line at 365.06nm was selected for parameter optimization and quantitative analysis. The S(2-) ions in aqueous samples were reacted with acid to generate hydrogen sulfide and then determined. The experimental parameters affecting the determination of hydrogen sulfide and S(2-) were optimized. The limits of detection were 1.4mgm(-3) for H2S and 11.2mgL(-1) for S(2-). The repeatability of the method was satisfactory, as the RSD values were 2.3% for H2S and 1.8% for S(2-). The enclosed DBD-MES system was demonstrated to be a useful tool for the determination of hydrogen sulfide in gas samples and S(2-) in aqueous samples. PMID:26452884

  19. Cystathionine ?-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 ?-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

  20. 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%.

  1. Imaging of living cells and zebrafish in vivo using a ratiometric fluorescent probe for hydrogen sulfide.

    PubMed

    Liu, Tianbao; Lin, Jie; Li, Zhen; Lin, Lin; Shen, Yuning; Zhu, Hailiang; Qian, Yong

    2015-10-12

    We have developed a novel colorimetric and ratiometric fluorescence probe for the selective and sensitive monitoring of hydrogen sulfide based on a dicyanoisophorone platform. An excellent linear relationship of fluorescence intensity ratio (I637/I558) (R(2) = 0.9867) versus hydrogen sulfide concentration in the range of 1-12 ?M was obtained. This probe exhibited a remarkable fluorescence response to hydrogen sulfide over other physiological thiols or biological species, which fluoresces in the red region with a large Stokes shift (172 nm). This probe was successfully utilized to monitor H2S under in vitro physiological conditions and for imaging H2S in living cells and living zebrafish in vivo. PMID:26401525

  2. 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).

  3. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco.

    PubMed

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild; Nielsen, Asbjřrn Haaning

    2015-11-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit with some uncertainty. It was concluded that the model could be applied for the purpose in mind. PMID:26564586

  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. 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...

  6. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must accompany... Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT...Documents (docd) § 250.245 What hydrogen sulfide (H2S) information must...

  7. 30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Resources 2 2013-07-01 2013-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...Operations Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2 S) information must accompany the DPP or...

  8. 30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Resources 2 2012-07-01 2012-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...Operations Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2 S) information must accompany the DPP or...

  9. 30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Resources 2 2014-07-01 2014-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...Operations Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2 S) information must accompany the DPP or...

  10. 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?...

  11. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...Operations Coordination Documents (docd) § 250.245 What hydrogen sulfide (H2S) information must accompany the DPP or...

  12. Geothermal hydrogen sulfide and health in Rotorua, New Zealand

    SciTech Connect

    Siegel, S.M.; Siegel, B.Z.

    1984-02-15

    Rotorua, New Zealand, lies inside a volcanic caldera. Natural steam is extensively used for space and water heating, and electric power generation. This report presents results of a preliminary reconnaissance survey of atmospheric H/sub 2/S levels in the area and attempts to relate these levels to health statistics in the region. 5 refs., 8 tabs. (ACR)

  13. 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. PMID:25818857

  14. 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

  15. Geothermal pipeline: Progress and development update from the geothermal progress monitor

    SciTech Connect

    1995-10-01

    This document is a Progress and Development Update from the Geothermal Progress Monitor. It contains brief descriptions of progress made on varying projects involving the use of geothermal resources or research about geothermal systems. This article describes the following projects: Conversion of waste water to geothermal energy in Northern California, Hydrogen sulfide study in Hawaii, a new program at the Cerro Prieto geothermal resource in Mexico, geothermal heating of a Nevadan school, development of a geothermal fluid standard, and the broadcasting of geothermal teleconferences.

  16. 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,...

  17. 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,...

  18. Removal of ammonia and hydrogen sulfide using biochar produced from pyrolyzing animal manures

    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. The emission of these gases can be substantially reduced using adsorption filters filled with biochar produced from pyrolysis of livestock residuals such as c...

  19. 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...

  20. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: HORIBA INSTRUMENTS,INC., APSA-360 AMBIENT HYDROGEN SULFIDE ANALYZER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this verification test was to evaluate the APSA-360’s performance in measuring gaseous hydrogen sulfide (H2S) in ambient air at an animal feeding operation (AFO). The verification test was conducted between April 25 and June 3, 2005, at a swine finishing farm near Ames, Iowa; the AP...

  1. PERGAMON Carbon 38 (2000) 17671774 High temperature hydrogen sulfide adsorption on activated

    E-print Network

    Cal, Mark P.

    2000-01-01

    PERGAMON Carbon 38 (2000) 1767­1774 High temperature hydrogen sulfide adsorption on activated of activated carbon sorbents were evaluated for removal of H S at high temperatures (400­6008C) in an2, gas pressure and sorbent regeneration. Adsorption experiments with a zinc-impregnated activated carbon

  2. PERGAMON Carbon 38 (2000) 17571765 High temperature hydrogen sulfide adsorption on activated

    E-print Network

    Cal, Mark P.

    2000-01-01

    PERGAMON Carbon 38 (2000) 1757­1765 High temperature hydrogen sulfide adsorption on activated types of activated carbon sorbents were evaluated for their ability to remove H S from a simulated coal gas stream2 at a temperature of 5508C. The ability of activated carbon to remove H S at elevated

  3. 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...

  4. Compensation effect and volcano curve in toluene hydrogenation catalyzed by transition metal sulfides.

    PubMed

    Guernalec, N; Geantet, C; Cseri, T; Vrinat, M; Toulhoat, H; Raybaud, P

    2010-09-28

    Within the framework of volcano curves, a kinetic study of toluene hydrogenation catalyzed by transition metal sulfides highlights the variation of the apparent kinetic parameters as a function of the ab initio sulfur-metal bond energy descriptor and sulfo-reductive reaction conditions. PMID:20424734

  5. 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...

  6. Creation of active sites by impregnation of carbon fibers: application to the fixation of hydrogen sulfide.

    PubMed

    Meljac, Laure; Perier-Camby, Laurent; Thomas, Gérard

    2004-06-01

    Activated carbon fibers, which exhibit high specific area and numerous active surface sites, constitute very powerful adsorbents and are widely used in filtration to eliminate pollutants from liquid or gaseous effluents. The fibers studied in this work are devoted to the filtration of gaseous effluent containing very small amounts (few vpm) of hydrogen sulfide. Preliminary experiments evidenced that these fibers weakly adsorb hydrogen sulfide. To improve their fixation capacity toward H(2)S the activated fibers are impregnated in an aqueous solution of potassium hydroxide. The impregnation treatment usually takes place before activation but in this work it occurs at room temperature after activation of the fibers. A further thermal treatment is performed to increase the efficiency of the system. The overall treatment leads to the creation of basic sites showing a great activity for H(2)S gas in the presence of water vapor. The mechanism has been established by a series of characterizations before, during, and after the different operation units. The KOH deposited after impregnation is carbonated into KHCO(3) at room temperature and then decomposed into K(2)CO(3) during the thermal treatment. K(2)CO(3) and H(2)S dissolve in a liquid aqueous solution formed on the fiber surface. Then carbonate ions and H(2)S molecules react together almost completely to yield HS(-) species. As a consequence the sorption capacities of hydrogen sulfide on the impregnated fibers are much higher, even for small hydrogen sulfide volume fractions. PMID:15120288

  7. 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...

  8. 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...

  9. 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...

  10. 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 ?g 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 ?g 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.

  11. 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

  12. Human Cystathionine-?-Synthase Phosphorylation on Serine227 Modulates Hydrogen Sulfide Production in Human Urothelium

    PubMed Central

    d’Emmanuele di Villa Bianca, Roberta; Donnarumm, Erminia; Russo, Annapina; Fusco, Ferdinando; Ianaro, Angela; Mirone, Vincenzo; Cirino, Giuseppe; Russo, Giulia; Sorrentino, Raffaella

    2015-01-01

    Urothelium, the epithelial lining the inner surface of human bladder, plays a key role in bladder physiology and pathology. It responds to chemical, mechanical and thermal stimuli by releasing several factors and mediators. Recently it has been shown that hydrogen sulfide contributes to human bladder homeostasis. Hydrogen sulfide is mainly produced in human bladder by the action of cystathionine-?-synthase. Here, we demonstrate that human cystathionine-?-synthase activity is regulated in a cGMP/PKG-dependent manner through phosphorylation at serine 227. Incubation of human urothelium or T24 cell line with 8-Bromo-cyclic-guanosine monophosphate (8-Br-cGMP) but not dibutyryl-cyclic-adenosine monophosphate (d-cAMP) causes an increase in hydrogen sulfide production. This result is congruous with the finding that PKG is robustly expressed but PKA only weakly present in human urothelium as well as in T24 cells. The cGMP/PKG-dependent phosphorylation elicited by 8-Br-cGMP is selectively reverted by KT5823, a specific PKG inhibitor. Moreover, the silencing of cystathionine-?-synthase in T24 cells leads to a marked decrease in hydrogen sulfide production either in basal condition or following 8-Br-cGMP challenge. In order to identify the phosphorylation site, recombinant mutant proteins of cystathionine-?-synthase in which Ser32, Ser227 or Ser525 was mutated in Ala were generated. The Ser227Ala mutant cystathionine-?-synthase shows a notable reduction in basal biosynthesis of hydrogen sulfide becoming unresponsive to the 8-Br-cGMP challenge. A specific antibody that recognizes the phosphorylated form of cystathionine-?-synthase has been produced and validated by using T24 cells and human urothelium. In conclusion, human cystathionine-?-synthase can be phosphorylated in a PKG-dependent manner at Ser227 leading to an increased catalytic activity. PMID:26368121

  13. 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

  14. 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

  15. Human sulfide:quinone oxidoreductase catalyzes the first step in hydrogen sulfide metabolism and produces a sulfane sulfur metabolite.

    PubMed

    Jackson, Michael R; Melideo, Scott L; Jorns, Marilyn Schuman

    2012-08-28

    Sulfide:quinone oxidoreductase (SQOR) is a membrane-bound enzyme that catalyzes the first step in the mitochondrial metabolism of H(2)S. Human SQOR is successfully expressed at low temperature in Escherichia coli by using an optimized synthetic gene and cold-adapted chaperonins. Recombinant SQOR contains noncovalently bound FAD and catalyzes the two-electron oxidation of H(2)S to S(0) (sulfane sulfur) using CoQ(1) as an electron acceptor. The prosthetic group is reduced upon anaerobic addition of H(2)S in a reaction that proceeds via a long-wavelength-absorbing intermediate (?(max) = 673 nm). Cyanide, sulfite, or sulfide can act as the sulfane sulfur acceptor in reactions that (i) exhibit pH optima at 8.5, 7.5, or 7.0, respectively, and (ii) produce thiocyanate, thiosulfate, or a putative sulfur analogue of hydrogen peroxide (H(2)S(2)), respectively. Importantly, thiosulfate is a known intermediate in the oxidation of H(2)S by intact animals and the major product formed in glutathione-depleted cells or mitochondria. Oxidation of H(2)S by SQOR with sulfite as the sulfane sulfur acceptor is rapid and highly efficient at physiological pH (k(cat)/K(m,H(2)S) = 2.9 × 10(7) M(-1) s(-1)). A similar efficiency is observed with cyanide, a clearly artificial acceptor, at pH 8.5, whereas a 100-fold lower value is seen with sulfide as the acceptor at pH 7.0. The latter reaction is unlikely to occur in healthy individuals but may become significant under certain pathological conditions. We propose that sulfite is the physiological acceptor of the sulfane sulfur and that the SQOR reaction is the predominant source of the thiosulfate produced during H(2)S oxidation by mammalian tissues. PMID:22852582

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

    DOEpatents

    Jalan, Vinod M. (Concord, MA); Frost, David G. (Maynard, MA)

    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.

  17. PRELIMINARY COST ESTIMATES OF POLLUTION CONTROL TECHNOLOGIES FOR GEOTHERMAL DEVELOPMENTS

    EPA Science Inventory

    This report provides preliminary cost estimates of air and water pollution control technologies for geothermal energy conversion facilities. Costs for solid waste disposal are also estimated. The technologies examined include those for control of hydrogen sulfide emissions and fo...

  18. Fluorescence chemosensors for hydrogen sulfide detection in biological systems.

    PubMed

    Guo, Zhi; Chen, Guiqiu; Zeng, Guangming; Li, Zhongwu; Chen, Anwei; Wang, Jiajia; Jiang, Longbo

    2015-03-21

    A comprehensive review of the development of H2S fluorescence-sensing strategies, including sensors based on chemical reactions and fluorescence resonance energy transfer (FRET), is presented. The advantages and disadvantages of fluorescence-sensing strategies are compared with those of traditional methods. Fluorescence chemosensors, especially those used in FRET sensing, are highly promising because of their low cost, technical simplicity, and their use in real-time sulfide imaging in living cells. Potential applications based on sulfate reduction to H2S, the relationship between sulfate-reducing bacteria activity and H2S yield, and real-time detection of sulfate-reducing bacteria activity using fluorescence sensors are described. The current challenges, such as low sensitivity and poor stability, are discussed. PMID:25529122

  19. 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.

  20. Process for purifying geothermal steam

    DOEpatents

    Li, Charles T. (Richland, WA)

    1980-01-01

    Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

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

    DOEpatents

    Siriwardane, R.V.

    1999-02-02

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared 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.

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

    DOEpatents

    Siriwardane, R.V.

    1997-12-30

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared 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.

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

    DOEpatents

    Siriwardane, Ranjani V. (Morgantown, WV)

    1999-01-01

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared 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.

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

    DOEpatents

    Siriwardane, Ranjani V. (Morgantown, WV)

    1997-01-01

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared 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.

  6. 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.

  7. Assessment of effects of chronic hydrogen sulfide poisoning on cytochrome P450 isoforms activity of rats by cocktail approach.

    PubMed

    Wang, Xianqin; Chen, Xiaole; Chen, Mengchun; Hu, Guoxin; Ma, Jianshe; Pan, Jianchun; Hu, Lufeng; Lin, Guanyang

    2013-01-01

    Hydrogen sulfide (H?S) is one of the neurotoxic gases with suffocating and irritating. Its main target organs of toxic effects are the central nervous system and respiratory system. Cocktail method was used to evaluate the influence of chronic hydrogen sulfide poisoning on the activities of cytochrome P450 (CYP450) isoforms CYP1A2, CYP2C9, CYP2B6 and CYP2D6, which were reflected by the changes of pharmacokinetic parameters of 4 specific probe drugs phenacetin, tolbutamide bupropion and metroprolol, respectively. The experimental rats were randomly divided into two groups, control group and chronic hydrogen sulfide poisoning group. The chronic hydrogen sulfide poisoning group rats were inhaled 20 ppm for 1 h twice a day for 40 d. The mixture of 4 probes was given to rats through sublingual veins and the blood samples were obtained at a series of time-points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by liquid chromatography-mass spectrometry (LC-MS). In the experiment for chronic hydrogen sulfide poisoning and control group, there was a statistically significant difference in the area under the plasma concentration-time curve from zero to infinity (AUC(0-?)), plasma clearance (CL) and maximum plasma concentration (C(max)) for phenacetin and bupropion, while there was no statistical pharmacokinetics difference for tolbutamide and metoprolol. Chronic hydrogen sulfide poisoning could induce the activity of CYP1A2 and CYP2B6 of rats. PMID:24088256

  8. Differential mechanisms underlying neuroprotection of hydrogen sulfide donors against oxidative stress.

    PubMed

    Jia, Jia; Xiao, Yunqi; Wang, Wei; Qing, Lina; Xu, Yinxiu; Song, Heng; Zhen, Xuechu; Ao, Guizhen; Alkayed, Nabil J; Cheng, Jian

    2013-06-01

    This study investigated whether slow-releasing organic hydrogen sulfide donors act through the same mechanisms as those of inorganic donors to protect neurons from oxidative stress. By inducing oxidative stress in a neuronal cell line HT22 with glutamate, we investigated the protective mechanisms of the organic donors: ADT-OH [5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione], the most widely used moiety for synthesizing slow-releasing hydrogen sulfide donors, and ADT, a methyl derivative of ADT-OH. The organic donors were more potent than the inorganic donor sodium hydrogensulfide (NaHS) in protecting HT22 cells against glutamate toxicity. Consistent with previous publications, NaHS partially restored glutamate-depleted glutathione (GSH) levels, protected HT22 from direct free radical damage induced by hydrogen peroxide (H2O2), and NaHS protection was abolished by a KATP channel blocker glibenclamide. However, neither ADT nor ADT-OH enhanced glutamate-depleted GSH levels or protected HT22 from H2O2-induced oxidative stress. Glibenclamide, which abolished NaHS neuroprotection against oxidative stress, did not block ADT and ADT-OH neuroprotection against glutamate-induced oxidative stress. Unexpectedly, we found that glutamate induced AMPK activation and that compound C, a well-established AMPK inhibitor, remarkably protected HT22 from glutamate-induced oxidative stress, suggesting that AMPK activation contributed to oxidative glutamate toxicity. Interestingly, all hydrogen sulfide donors, including NaHS, remarkably attenuated glutamate-induced AMPK activation. However, under oxidative glutamate toxicity, compound C only increased the viability of HT22 cells treated with NaHS, but did not further increase ADT and ADT-OH neuroprotection. Thus, suppressing AMPK activation likely contributed to ADT and ADT-OH neuroprotection. In conclusion, hydrogen sulfide donors acted through differential mechanisms to confer neuroprotection against oxidative toxicity and suppressing AMPK activation was a possible mechanism underlying neuroprotection of organic hydrogen sulfide donors against oxidative toxicity. PMID:23587562

  9. Fluorescence signaling of hydrogen sulfide in broad pH range using a copper complex based on BINOL-benzimidazole ligands.

    PubMed

    Sun, Mingtai; Yu, Huan; Li, Huihui; Xu, Hongda; Huang, Dejian; Wang, Suhua

    2015-04-20

    A weakly fluorescent complex derived from a binaphthol-benzimidazole ligand was designed and synthesized for hydrogen sulfide at different pH conditions. It was demonstrated that the probe showed the same reactivity to various hydrogen sulfide species in a broad range of pH values to generate highly fluorescent product through a displacement reaction mechanism, whereas the product's fluorescence spectrum exhibited a hypsochromic shift of ?73 nm (2393 cm(-1)) as pH increased from neutral to basic, which can be used for distinguishing the various species of hydrogen sulfide. This turn-on fluorescence probe was highly selective and sensitive to hydrogen sulfide with a detection limit of 0.11 ?M. It was then applied for evaluating the total content of sulfide (including hydrogen sulfide, hydrosulfide, and sulfide) as well as for the visual detection of gaseous H2S in air using a simple test paper strip. PMID:25839192

  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 ?-, ?- and ?-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 sulfate reduction and potentially stabilize the sulfidic OMZ waters. PMID:23990875

  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. 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. Several different types of dual-phase membranes were fabricated and tested for their CO{sub 2} permeation in reducing conditions without the presence of oxygen. Although the flux was quite low, on the order of 0.01-0.001 cc STP/cm{sup 2}/min, the selectivity of CO{sub 2}/He was almost infinite at temperatures of about 800 C. A different type of dual-phase membrane prepared by Arizona State University (ASU) was also tested at GTI for CO{sub 2} permeation. The measured CO{sub 2} fluxes were 0.015 and 0.02 cc STP/cm{sup 2}/min at 750 and 830 C, respectively. These fluxes were higher than the previous flux obtained ({approx}0.01 cc STP/cm{sup 2}/min) using the dual-phase membranes prepared by GTI. Further development in membrane development should be conducted to improve the CO{sub 2} flux. ASU has also focused on high temperature permeation/separation experiments to confirm the carbon dioxide separation capabilities of the dual-phase membranes with La{sup 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (LSCF6482) supports infiltrated with a Li/Na/K molten carbonate mixture (42.5/32.5/25.0 mole %). The permeation experiments indicated that the addition of O{sub 2} does improve the permeance of CO{sub 2} through the membrane. A simplified membrane reactor model was developed to evaluate the performance of the process. However, the simplified model did not allow the estimation of membrane transport area, an important parameter for evaluating the feasibility of the proposed membrane reactor technology. As a result, an improved model was developed. Results of the improved membrane reactor model show that the membrane shift reaction has promise as a means to simplify the production of a clean stream of hydrogen and a clean stream of carbon dioxide. The focus of additional development work should address the large area required for the CO{sub 2} membrane as identified in the modeling calculations. Also, a more detailed process flow diagram should be developed that includes integration of cooling and preheating feed streams as well as particulate removal so that stea

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

    DOEpatents

    Winnick, Jack (Atlanta, GA); Sather, Norman F. (Naperville, IL); Huang, Hann S. (Darian, IL)

    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.

  14. 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

  15. Hydrogen and Primary Productivity: Inference of Biogeochemistry from Phylogeny in a Geothermal Ecosystem

    E-print Network

    113 Hydrogen and Primary Productivity: Inference of Biogeochemistry from Phylogeny in a Geothermal 114 GEOTHERMAL BIOLOGY AND GEOCHEMISTRY IN YELLOWSTONE NATIONAL PARK ABSTRACT The geochemical energy sources for microbial primary productivity in the >70°C geothermal springs of Yellowstone National Park

  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. Removal of hydrogen sulfide using crushed oyster shell from pore water to remediate organically enriched coastal marine sediments.

    PubMed

    Asaoka, Satoshi; Yamamoto, Tamiji; Kondo, Shunsuke; Hayakawa, Shinjiro

    2009-09-01

    Hydrogen sulfide is highly toxic and fatal to benthic organisms as well as causing depletion of dissolved oxygen and generating blue tide in eutrophic coastal seas. The purposes of this study are to reveal adsorption characteristics of hydrogen sulfide onto crushed oyster shell, and to evaluate removal efficiency of hydrogen sulfide from pore water in organically enriched sediments using container experiment in order to develop a coastal sediment amendment. The crushed oyster shell was mainly composed of CaCO(3) with calcite and CaO crystal phase. The batch experiment showed removal kinetics of hydrogen sulfide can be expressed as the first order equation and Langmuir plot fitted well in describing the adsorption behavior with the adsorption maximum at 12 mg-S g(-1). The container experiments suggested the oyster shell adsorbs hydrogen sulfide in pore water effectively and reduces oxygen consumption in the overlying water. Furthermore, oxidation-reduction potential of the sediment was higher with addition of crushed oyster shell than the control without oyster shell. Thus, it is concluded that crushed oyster shell can be an effective amendment to remediate organically enriched sediments in eutrophic coastal seas. PMID:19394819

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

    DOEpatents

    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.

  19. 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

  20. 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 solutions saturated with different H2S partial pressures. The partial pressure was selected so that the concentration of H2S in the solution saturated with the gas would be the same as that reached in the surface of steel freely corroding in the thiosulfate solution. For solutions obtained by bubbling H2S, the rate of hydrogen absorption increased with the partial pressure of the gas, but the rate of hydrogen absorption reached a maximum at 10-3 M S2O3 2-, despite the surface concentration of H2S increased with the concentration of S2O32-. This effect was associated with the formation of thicker films, which inhibited the absorption of hydrogen. FCGR were evaluated at constant stress intensity factor range. Crack length was monitored in-situ by the direct current potential drop (DCPD) method. FCGR increased with the partial pressure of H2S in nitrogen. FCGR was controlled not only by the amount of hydrogen present in the steel, but also by inhibiting contributions like crack closure and crack tip blunting. FCGR in dilute thiosulfate solutions was near that measured in a solution saturated with a partial pressure of H2S equal to 0.56 kPa, in accord with hydrogen permeation results.

  1. 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. Temperature at the fan outlet and static pressure inside the barn were measured. Lagoon samples were collected daily and analyzed for sulfide content. Lagoon parameters, temperature and pH; and atmospheric environmental parameters, ambient temperature, relative humidity, wind speed and ambient hydrogen sulfide concentration were concurrently monitored on-site. The highest barn emissions were measured during the winter and appeared to be related to the age and weight of the animals housed inside the barn. (Abstract shortened by UMI.)

  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. Reaction-based epoxide fluorescent probe for in vivo visualization of hydrogen sulfide.

    PubMed

    Sathyadevi, Palanisamy; Chen, Yu-Jen; Wu, Shou-Cheng; Chen, Yen-Hao; Wang, Yun-Ming

    2015-06-15

    Hydrogen sulfide (H2S) has emerged as the most important biosynthetic gasotransmitters along with nitric oxide (NO) and carbon monoxide (CO). In this study, we report the design and the synthesis of a new epoxide fluorescent probe 7-glycidyloxy-9-(2-glycidyloxycarbonylphenyl)-2-xanthone (FEPO) for use in in vivo visualization of hydrogen sulfide. The probe employs a fluorescein as a fluorophore, and is equipped with an operating epoxide unit. FEPO functions via epoxide ring opening upon nucleophilic attack of H2S. This ring opening strategy may open a new avenue for the development of various H2S fluorescent sensors. FEPO showed high selectivity and high sensitivity for H2S. FEPO's cytotoxicity was tested using MTT (2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide) assay. Furthermore, the use of confocal imaging of H2S and in vivo imaging in live zebra fish demonstrated FEPO's potential biological applications. We anticipate that, owing to their ideal properties, probes of this type will find great uses in exploring the role of H2S in biology. PMID:25660659

  4. 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 ?(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. PMID:23523123

  5. 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

  6. 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.

  7. 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)

  8. 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

  9. 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. PMID:24773379

  10. AMMONIA AND HYDROGEN SULFIDE FLUX AND DRY DEPOSITION VELOCITY ESTIMATES USING VERTICAL GRADIENT METHOD AT A COMMERCIAL BEEF CATTLE FEEDLOT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia and hydrogen sulfide flux and dry deposition velocity were estimated using micrometeorological vertical gradient flux method at a commercial cattle feedyard of approximately 50,000 head of beef cattle and average 14.4 m2/head (150 ft2/head) stocking density. During summertime, NH3-N emission...

  11. 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. ...

  12. DECHLORINATION OF CHLOROPICRIN AND 1,3-DICHLOROPROPENE BY HYDROGEN SULFIDE SPECIES: REDOX AND NUCLEOPHILIC SUBSTITUTION REACTIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chlorinated fumigants chloropicrin and 1,3-dichloropropene (1,3-D) are extensively used in agricultural production for the control of soil-borne pests. Reaction of these two fumigants with hydrogen sulfide species (H2S and HS ) was examined in well-defined anoxic aqueous solutions. Chloropicrin ...

  13. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... volume, and store in glass-stoppered brown glass bottle. (2) Standard iodine solution, 1 ml=0.001771 g I... per cubic feet of gas. (3) Starch solution. Rub into a thin paste about one teaspoonful of wheat... dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a...

  14. 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

    ... concentrated KI solution, make up to proper volume, and store in glass-stoppered brown glass bottle. (2... grains, a 500 ml Tutwiler burette and more dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine....

  15. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... volume, and store in glass-stoppered brown glass bottle. (2) Standard iodine solution, 1 ml=0.001771 g I... per cubic feet of gas. (3) Starch solution. Rub into a thin paste about one teaspoonful of wheat... dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a...

  16. 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

    ... concentrated KI solution, make up to proper volume, and store in glass-stoppered brown glass bottle. (2... grains, a 500 ml Tutwiler burette and more dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine....

  17. 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...

  18. 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...

  19. 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...

  20. 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

    ... Number (CAS No.) 7783-06-4) (75 FR 8889). The purpose of today's action is to inform interested parties... requirements for hydrogen sulfide (75 FR 8889). B. Why and for How Long Is EPA Extending the Comment Period..., 212231, 212234, 212299 (correspond to SIC 10, Metal Mining (except 1011, 1081, and 1094)); or...

  1. 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).

  2. Hydrogen Sulfide, the Next Potent Preventive and Therapeutic Agent in Aging and Age-Associated Diseases

    PubMed Central

    Zhang, Yuan; Tang, Zhi-Han; Ren, Zhong; Qu, Shun-Lin; Liu, Mi-Hua; Liu, Lu-Shan

    2013-01-01

    Hydrogen sulfide (H2S) is the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide. It is physiologically generated by cystathionine-?-lyase, cystathionine-?-synthase, and 3-mercaptopyruvate sulfurtransferase. H2S has been gaining increasing attention as an important endogenous signaling molecule because of its significant effects on the cardiovascular and nervous systems. Substantial evidence shows that H2S is involved in aging by inhibiting free-radical reactions, activating SIRT1, and probably interacting with the age-related gene Klotho. Moreover, H2S has been shown to have therapeutic potential in age-associated diseases. This article provides an overview of the physiological functions and effects of H2S in aging and age-associated diseases, and proposes the potential health and therapeutic benefits of H2S. PMID:23297346

  3. Hydrogen sulfide and ammonia removal on activated carbon fiber cloth-supported metal oxides.

    PubMed

    Le Leuch, L M; Subrenat, A; Le Cloirec, P

    2005-11-01

    The present investigation attempts to provide mechanisms for the influence of metal catalysts on carbon supports in odorous gas removal. For this purpose, an activated carbon fiber cloth (ACFC) was subjected to successive metal impregnation to modify its surface properties and so increase its treatment capacity. The carbon fiber cloth adsorbent was prepared by classical incipient wetness impregnation followed by calcination in order to obtain metal oxide phases. Different impregnation parameters (type of metal, level of impregnation, calcination temperature) in the removal of hydrogen sulfide and ammonia were studied. Adsorption kinetics and capacities were carried out in a batch reactor at room temperature. It was found that removal activity depended on metal loading as well as on the order of the metal addition and calcination phase. The capacity of ACFC-supported metal oxides to adsorb both pollutants showed great improvement compared to the virgin adsorbent. PMID:16335599

  4. Kinetics of the reaction of hydrogen sulfide and sulfur dioxide in organic solvents

    SciTech Connect

    Neumann, D.W.; Lynn, S.

    1986-01-01

    Calorimetry was used to study the kinetics of the irreversible reaction between hydrogen sulfide and sulfur dioxide in mixtures of N,N-dimethylaniline (DMA) and diethylene glycol monomethyl ether (DGM) and of DMA and triethylene glycol dimethyl ether (triglyne). The reaction was found to be first order in both H/sub 2/S and SO/sub 2/ in the presence of DMA. The approximate heat of reaction is 28 kcal/mol of sulfur dioxide. The addition of DMA accelerates the reaction by an order of magnitude over that obtained in the glycol ethers alone. Rate constants are in the range of 1-20 L/(mol s). Hydroxylated species such as water, methanol, and other alcohols increase the rate still more dramatically when added to the DMA/ether mixtures. The results of these experiments show some of the effects of solvent composition on the kinetics of the reaction.

  5. 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

  6. Sensitive absorption measurements of hydrogen sulfide at 1.578 ?m using wavelength modulation spectroscopy

    NASA Astrophysics Data System (ADS)

    Xia, Hua; Dong, Feng-Zhong; Wu, Bian; Zhang, Zhi-Rong; Pang, Tao; Sun, Peng-Shuai; Cui, Xiao-Juan; Han, Luo; Wang, Yu

    2015-03-01

    Sensitive detection of hydrogen sulfide (H2S) has been performed by means of wavelength modulation spectroscopy (WMS) near 1.578 ?m. With the scan amplitude and the stability of the background baseline taken into account, the response time is 4 s for a 0.8 L multi-pass cell with a 56.7 m effective optical path length. Moreover, the linearity has been tested in the 0-50 ppmv range. The detection limit achievable by the Allan variance is 224 ppb within 24 s under room temperature and ambient pressure conditions. This tunable diode laser absorption spectroscopy (TDLAS) system for H2S detection has the feasibility of real-time online monitoring in many applications. Project supported by the Special Fund for Basic Research on Scientific Instruments of the Chinese Academy of Sciences (Grant No. YZ201315) and the National Natural Science Foundation of China (Grant Nos. 11204320, 41405034, and 11204319).

  7. Doubly differential and integral cross sections for electron elastic scattering by hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Aouchiche, H.; Medegga, F.; Champion, C.

    2014-08-01

    Theoretical doubly differential and integral cross sections for elastic scattering of electrons by hydrogen sulfide vapor are here reported for impact energies ranging from 10 eV to 10 keV. The calculations are carried out within the partial-wave formalism by means of a spherical complex optical potential model taking into account a static contribution deduced from a single-center Hartree-Fock target description as well as correlation-polarization and exchange effects. The results clearly point out the role played by the exchange and the correlation-polarization in particular at low incident energies and around the observed minima. Both doubly differential and integral cross sections are finally compared with a large set of experimental data and a satisfactory agreement is observed.

  8. Hydrogenation reactions of ethylene on neutral vanadium sulfide clusters: experimental and theoretical studies.

    PubMed

    Yin, Shi; Xie, Yan; Bernstein, Elliot R

    2011-09-22

    The reactions of C(2)H(4) with H(2) on neutral vanadium sulfide clusters in a fast flow reactor are investigated by time-of-flight mass spectrometry employing 118 nm (10.5 eV) single photon ionization. The experimental products of these reactions are V(m)S(n)C(2)H(x) (m=1, n=1-3; m=2, n=1-5, and x=4-6). Observation of these products indicates that these V(m)S(n) clusters have high catalytic activity for hydrogenation reactions of C(2)H(4). Density functional theory calculations at the BPW91/TZVP level are carried out to explore the geometric and electronic structures of the V(m)S(n) clusters and to determine reaction intermediates and transition states, as well as reaction mechanisms. All reactions are estimated as overall barrierless or with only a small barrier (0.1 eV), and are thermodynamically favorable processes at room temperature. The ethylene molecule is predicted to connect with active V atoms through its ?-orbital or form a ?-bond with active V atoms of catalytic V(m)S(n) clusters. The S atoms bonding with active V atoms play an important role in the dissociation of the H(2) molecule; H atoms transfer to the C(2)H(4) (one after another) following breaking of the H-H bond. A catalytic cycle for C(2)H(4) hydrogenation reactions on a vanadium sulfide catalyst surface is suggested based on our experimental and theoretical investigations. PMID:21838236

  9. Hydrogen Sulfide in the RVLM and PVN has No Effect on Cardiovascular Regulation

    PubMed Central

    Streeter, Eloise; Al-Magableh, Mohammad; Hart, Joanne Louise; Badoer, Emilio

    2011-01-01

    Hydrogen sulfide (H2S) is now recognized as an important signaling molecule and has been shown to have vasodilator and cardio-protectant effects. More recently it has been suggested that H2S may also act within the brain to reduce blood pressure (BP). In the present study we have demonstrated the presence of the H2S-producing enzyme, cystathionine-?-synthase (CBS) in the rostral ventrolateral medulla (RVLM), and the hypothalamic paraventricular nucleus (PVN), brain regions with key cardiovascular regulatory functions. The cardiovascular role of H2S was investigated by determining the BP, heart rate (HR), and lumbar sympathetic nerve activity (LSNA) responses elicited by a H2S donor sodium hydrogen sulfide (NaHS) or inhibitors of CBS, microinjected into the RVLM and PVN. In anesthetized Wistar Kyoto rats bilateral microinjections of NaHS (0.2–2000?pmol/side) into the RVLM did not significantly affect BP, HR, or LSNA, compared to vehicle. Similarly, when the CBS inhibitors, amino-oxyacetate (AOA; 0.1–1.0?nmol/side) or hydroxylamine (HA; 0.2–2.0?nmol/side), were administered into the RVLM, there were no significant effects on the cardiovascular variables compared to vehicle. Microinjections into the PVN of NaHS, HA, and AOA had no consistent significant effects on BP, HR, or LSNA compared to vehicle. We also investigated the cardiovascular responses to NaHS microinjected into the RVLM and PVN in spontaneously hypertensive rats. Again, there were no significant effects on BP, HR, and LSNA. Together, these results suggest that H2S in the RVLM and PVN does not have a major role in cardiovascular regulation. PMID:21941511

  10. Hydrogen sulfide-induced dual vascular effect involves arachidonic acid cascade in rat mesenteric arterial bed.

    PubMed

    d'Emmanuele di Villa Bianca, Roberta; Sorrentino, Rosalinda; Coletta, Ciro; Mitidieri, Emma; Rossi, Antonietta; Vellecco, Valentina; Pinto, Aldo; Cirino, Giuseppe; Sorrentino, Raffaella

    2011-04-01

    Hydrogen sulfide (H(2)S), a novel gaseous transmitter, is considered a physiological regulator of vascular homeostasis. Recent evidence suggests H(2)S as an endothelium-hyperpolarizing factor (EDHF) candidate. To address this issue, we evaluated the vascular effect of sodium hydrogen sulfide (NaHS), an H(2)S donor, on the rat mesenteric arterial bed. NaHS concentration-response curve was performed on preconstricted mesenteric arterial bed. To assess the contribution of EDHF, we performed a pharmacologic dissection using indomethacin, N(G)-nitro-l-arginine methyl ester (l-NAME), or apamin and charybdotoxin as cyclooxygenase, nitric-oxide synthase, and calcium-dependent potassium channel inhibitors, respectively. In another set of experiments, we used 4-(4-octadecylphenyl)-4-oxobutenoic acid, baicalein, or proadifen as phospholipase A(2) (PLA(2)), lipoxygenase, and cytochrome P450 inhibitors, respectively. Finally, an immunofluorescence study was performed to support the involvement of PLA(2) in mesenteric artery challenged by NaHS. NaHS promoted a dual vascular effect (i.e., vasoconstriction and vasodilation). l-NAME or baicalein administration affected neither NaHS-mediated vasodilation nor vasoconstriction, whereas apamin and charybdotoxin significantly inhibited NaHS-induced relaxation. Pretreatment with PLA(2) inhibitor abolished both the contracting and the relaxant effect, whereas P450 cytochrome blocker significantly reduced NaHS-mediated relaxation. The immunofluorescence study showed that NaHS caused a migration of cytosolic PLA(2) close to the nucleus, which implicates activation of this enzyme. Our data indicate that H(2)S could activate PLA(2), which in turn releases arachidonic acid leading, initially, to vasoconstriction followed by vasodilation mediated by cytochrome P450-derived metabolites. Because EDHF has been presumed to be a cytochrome P450 derivative of the arachidonic acid, our results suggest that H(2)S acts through EHDF release. PMID:21228064

  11. Hydrogen Peroxide Cycling in Acidic Geothermal Environments and Potential Implications for Oxidative Stress

    NASA Astrophysics Data System (ADS)

    Mesle, M.; Beam, J.; Jay, Z.; Bodle, B.; Bogenschutz, E.; Inskeep, W.

    2014-12-01

    Hydrogen peroxide (H2O2) may be produced in natural waters via photochemical reactions between dissolved oxygen, organic carbon and light. Other reactive oxygen species (ROS) such as superoxide and hydroxyl radicals are potentially formed in environments with high concentrations of ferrous iron (Fe(II), ~10-100 ?M) by reaction between H2O2 and Fe(II) (i.e., Fenton chemistry). Thermophilic archaea and bacteria inhabiting acidic iron-oxide mats have defense mechanisms against both extracellular and intracellular peroxide, such as peroxiredoxins (which can degrade H2O2) and against other ROS, such as superoxide dismutases. Biological cycling of H2O2 is not well understood in geothermal ecosystems, and geochemical measurements combined with molecular investigations will contribute to our understanding of microbial response to oxidative stress. We measured H2O2 and other dissolved compounds (Fe(II), Fe(III), H2S, O2), as well as photon flux, pH and temperature, over time in surface geothermal waters of several acidic springs in Norris Geyser Basin, Yellowstone National Park, WY (Beowulf Spring and One Hundred Spring Plain). Iron-oxide mats were sampled in Beowulf Spring for on-going analysis of metatranscriptomes and RT-qPCR assays of specific stress-response gene transcription (e.g., superoxide dismutases, peroxiredoxins, thioredoxins, and peroxidases). In situ analyses show that H2O2 concentrations are lowest in the source waters of sulfidic systems (ca. 1 ?M), and increase by two-fold in oxygenated waters corresponding to Fe(III)-oxide mat formation (ca. 2 - 3 ?M). Channel transects confirm increases in H2O2 as a function of oxygenation (distance). The temporal dynamics of H2O2, O2, Fe(II), and H2S in Beowulf geothermal waters were also measured during a diel cycle, and increases in H2O2 were observed during peak photon flux. These results suggest that photochemical reactions may contribute to changes in H2O2. We hypothesize that increases in H2O2 and O2 concentrations in iron-oxidizing habitats will induce higher transcription rates of genes responsible for H2O2 degradation and O2 respiration. Subsequent measurements of additional ROS and analysis of transcript data will provide broader insight on the interactions and metabolic response within iron mat communities under oxidative stress.

  12. 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.

  13. Sulfide chemiluminescence detection

    DOEpatents

    Spurlin, Stanford R. (Ames, IA); Yeung, Edward S. (Ames, IA)

    1985-01-01

    A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

  14. Sulfide chemiluminescence detection

    DOEpatents

    Spurlin, S.R.; Yeung, E.S.

    1985-11-26

    A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

  15. 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. PMID:22871304

  16. 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

  17. 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.

  18. 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.

  19. 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 production is important given the recent increase in number of wells in various regions in the United States. Methane, the primary natural gas constituent, is a greenhouse gas; hydrogen sulfide, which can be present in gas condensate, is an odor-causing compound. This study surveyed wells representing one-third of the natural gas production volume in the Texas Barnett Shale and identified the percent of sites that warrant further study due to their fence line methane and hydrogen sulfide concentrations. PMID:25185395

  20. Sulfur isotopic evidence of large release of hydrogen sulfide during P-T transition

    NASA Astrophysics Data System (ADS)

    Rai, V. K.; Mane, P.; Shukla, A. D.; Jackson, T. L.; Thiemens, M. H.

    2011-12-01

    The Permo-Triassic mass extinction is the most devastating event in the history of life on Earth and occurred circa 251 Ma ago. The exact cause of extinction remains uncertain. In order to understand the cause of extinction, we studied the sulfur isotopes and redox sensitive elements from the P-T section of Spiti valley of Himalaya, India. In Spiti valley, 1-10 cm of ferruginous band of sediments separates the Permian shale from Triassic limestone. Analyses of redox sensitive elements such as As, Mo, As, Ni, Sb, Th, Mn and Fe show clear evidence of anoxia or euxinia. The total sulfur content of overlying Triassic limestones varies from 0.1 to 0.25% with ?34S values between -17.7 to -6.4 %. The underlying shales contains 0.2 to 0.4 wt% of sulfur with ?34S of sulfate ranging from -16 to -19.8 %. Whereas sulfate content from the boundary are an order of magnitude higher and varies from 1% to 2.5 wt % with ?34S ranging between -13 to -15.4 %. Both above and below the extinction boundary, the ?34S of pyrites are in general lighter than their sulfate counterpart and this most likely results from bacterial reduction of sulfate. The trend is reversed at the boundary where the pyrites are much heavier than sulfate. We believe that this heavy sulfur isotope composition is due to preferential loss of light sulfur isotope during hydrogen sulfide loss to atmosphere. This occurred when chemocline which separates sulfidic deep water from sulfate rich (oxygenated) water abruptly moved upward to the surface. This migration emits copious amounts of H2S to the atmosphere which may be an associated cause for the extinction.

  1. 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 ?-lyase (CSE), cystathionine ?-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

  2. 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 ?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 ?max 570 the system 3/barium diphenylamine sulphonate ?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 ?g ml-1/0.14-1.40 ?g ml-1.

  3. 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 ?(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 ?(max) 570 the system 3/barium diphenylamine sulphonate ?(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 ?g ml(-1)/0.14-1.40 ?g ml(-1). PMID:22889607

  4. 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 ? 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 (?34S SO42- ? 18 ‰) compared to the Southern springs (?34S 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 dissolution. Fresh water from the Local environment percolates into the Northern and the Southern environments. Mixing between these three aquifers may enhance bacterial sulfate reduction, thus increasing the H2S concentration in the sulfidic springs. The integration of the geochemical attributes and the aquatic communities at each watershed will produce a more comprehensive view of these spring ecosystems and their temporal and spatial evolution.

  5. 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 ?M NaHS, only 11–13%, i.e., 34–41 ?M 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

  6. 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. PMID:14531443

  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; 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 residence time of 18.8 s with a flow rate of 39.4 x 10{sup -6} m{sup 3}/s (5 ft{sup 3}/h) and a specific energy of 13,000 J/l using niobium and platinum coated stainless steel tubes as cathodes. Under these conditions, the First Law efficiency for the system was 8%. Under similar reaction conditions, methane conversions were {approx}50% higher with niobium and platinum coated stainless steel cathodes than with a stainless steel cathode.

  8. Drilling and operating oil, gas, and geothermal wells in an H/sub 2/S environment

    SciTech Connect

    Dosch, M.W.; Hodgson, S.F.

    1981-01-01

    The following subjects are covered: facts about hydrogen sulfides; drilling and operating oil, gas, and geothermal wells; detection devices and protective equipment; hazard levels and safety procedures; first aid; and H/sub 2/S in California oil, gas, and geothermal fields. (MHR)

  9. A gas chromatography-mass spectrometry based study on serum metabolomics in rats chronically poisoned with hydrogen sulfide.

    PubMed

    Deng, Mingjie; Zhang, Meiling; Huang, Xueli; Ma, Jianshe; Hu, Lufeng; Lin, Guanyang; Wang, Xianqin

    2015-05-01

    Hydrogen sulfide poisoning is a common occupational hazard, whose mortality and incidence rates are first and second, respectively, among occupational poisoning incidents in China. The main target organs of its toxicity are in the central nervous system and respiratory system. However, there are currently no specific direct tests that can be used to diagnose poisoned patients. In this study, we developed a serum metabonomic method using orthogonal partial least squares-discriminate analysis (OPLS-DA), based on gas chromatography-mass spectrometry (GC/MS) to evaluate the effect of chronic poisoning by hydrogen sulfide in rats. The OPLS-DA data demonstrated that the model group (n = 60) differed significantly from the control group (n = 30), suggesting that the metabolic profiles of the two groups are markedly different. Alterations in the levels of some metabolites such as citrate, galactose, lactate, mannose, inositol, urea, phosphate, alanine and valine were detected by OPLS-DA analysis. We observed changes in metabolic pathways including lipid metabolism, energy metabolism and amino metabolism in the model group. Our results indicate that GC/MS-based metabonomic methods may provide novel detection means for chronic hydrogen sulfide poisoning. PMID:25882152

  10. Microbial control of the production of hydrogen sulfide by sulfate-reducing bacteria.

    PubMed

    Montgomery, A D; McLnerney, M J; Sublette, K L

    1990-03-01

    A sulfide-resistant ctrain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium or in Berea sandstone cores. 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. These data suggest that strain F would be effective in controlling sulfide production in oil reservoirs and other environments. PMID:18592547

  11. A highly selective on-off-on responsive lanthanide(iii) based probe for recognition of copper and hydrogen sulfide.

    PubMed

    Yip, Yuk-Wang; Law, Ga-Lai; Wong, Wing-Tak

    2016-01-01

    The development of a europium(iii) based probe () for the detection of Cu(ii) ions and hydrogen sulphide is presented. With the addition of Cu(ii) ions, displayed the greatest quenching among the other cations examined. The binding constant was 74?026 ± 2899 M(-1). Once combined with Cu(ii) ions, demonstrated high specificity for hydrogen sulfide compared to other organic and inorganic sulfur compounds. exhibited an on-off-on type luminescence change with the alternate addition of Cu(ii) ions and H2S along with reversible forming-separating of the complex. PMID:26584271

  12. 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

  13. Hydrogen Sulfide Deactivates Common Nitrobenzofurazan-Based Fluorescent Thiol Labeling Reagents

    PubMed Central

    2015-01-01

    Sulfhydryl-containing compounds, including thiols and hydrogen sulfide (H2S), play important but differential roles in biological structure and function. One major challenge in separating the biological roles of thiols and H2S is developing tools to effectively separate the reactivity of these sulfhydryl-containing compounds. To address this challenge, we report the differential responses of common electrophilic fluorescent thiol labeling reagents, including nitrobenzofurazan-based scaffolds, maleimides, alkylating agents, and electrophilic aldehydes, toward cysteine and H2S. Although H2S reacted with all of the investigated scaffolds, the photophysical response to each scaffold was significantly different. Maleimide-based, alkylating, and aldehydic thiol labeling reagents provided a diminished fluorescence response when treated with H2S. By contrast, nitrobenzofurazan-based labeling reagents were deactivated by H2S addition. Furthermore, the addition of H2S to thiol-activated nitrobenzofurazan-based reagents reduced the fluorescence signal, thus establishing the incompatibility of nitrobenzofurazan-based thiol labeling reagents in the presence of H2S. Taken together, these studies highlight the differential reactivity of thiols and H2S toward common thiol-labeling reagents and suggest that sufficient care must be taken when labeling or measuring thiols in cellular environments that produce H2S due to the potential for both false-positive and eroded responses. PMID:24852143

  14. Effects of hydrogen sulfide on high glucose-induced glomerular podocyte injury in mice

    PubMed Central

    Liu, Ye; Zhao, Huichen; Qiang, Ye; Qian, Guanfang; Lu, Shengxia; Chen, Jicui; Wang, Xiangdong; Guan, Qingbo; Liu, Yuantao; Fu, Yuqin

    2015-01-01

    The aim of this study was to assess the effects of hydrogen sulfide on high glucose-induced mouse podocyte (MPC) injury and the underlying mechanisms. Mouse podocytes were randomly divided into 4 groups, including high glucose (HG), normal glucose (NG), normal glucose + DL-propargylglycine (PPG), and high glucose + NaHS (HG + NaHS) groups for treatment. Then, ZO-2, nephrin, ?-catenin, and cystathionine ?-lyase (CSE) protein expression levels were determined by western blot. We found that high glucose significantly reduced nephrin, ZO-2, and CSE expression levels (P<0.05), and overtly elevated ?-catenin amounts (P<0.05), in a time-dependent manner. Likewise, PPG at different concentrations in normal glucose resulted in significantly lower CSE, ZO-2, and nephrin levels (P<0.05), and increased ?-catenin amounts (P<0.05). Interestingly, significantly increased ZO-2 and nephrin levels, and overtly reduced ?-catenin amounts were observed in the HG + NaHS group compared with HG treated cells (P<0.01). Compared with NG treated cells, decreased ZO-2 and nephrin levels and higher ?-catenin amounts were obtained in the HG + NaHS group. In conclusion,CSE downregulation contributes to hyperglycemia induced podocyte injury, which is alleviated by exogenous H2S possibly through ZO-2 upregulation and the subsequent suppression of Wnt/?-catenin pathway. PMID:26261567

  15. Ratiometric two-photon fluorescent probes for mitochondrial hydrogen sulfide in living cells.

    PubMed

    Liu, Xiu-Ling; Du, Xiao-Jiao; Dai, Chun-Guang; Song, Qin-Hua

    2014-10-17

    Hydrogen sulfide (H2S) is an important signaling molecule with diverse biological roles. Various fluorescent probes for H2S with biological application have been developed. However, two-photon ratiometric imaging of mitochondrial H2S is scarce. In this paper, we report two ratiometric two-photon probes, AcHS-1 and AcHS-2, which employ 4-amino-1,8-naphthalimide as the fluorophore and 4-azidobenzyl carbamate as the H2S response site. These probes exhibit high selectivity toward H2S over biothiols and other reactive species, low detection limits of 50-85 nM, low cytotoxicity, and high stability under physiological conditions. Furthermore, through cell imaging with one-photon and two-photon microscopy, MCF-7 cells incubated with two probes show a marked change in emission color from blue to green in response to H2S. Cell images costraining with a mitochondrial dye reveal that AcHS-2 is a mitochondria-specific two-photon probe for H2S. These results show that AcHS-2 may find useful applications in biological research such as tracking mitochondrial H2S in living biological specimens. PMID:25254293

  16. 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 ?l 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

  17. 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

  18. Performance of biotrickling filters for hydrogen sulfide removal under starvation and shock loads conditions*

    PubMed Central

    Zhang, Lan-he; Meng, Xiu-li; Wang, Ying; Liu, Li-dan

    2009-01-01

    In the industrial operation of biotrickling filters for hydrogen sulfide (H2S) removal, shock loads or starvation was common due to process variations or equipment malfunctions. In this study, effects of starvation and shock loads on the performance of biotrickling filters for H2S removal were investigated. Four experiments were conducted to evaluate the changes of biomass and viable bacteria numbers in the biotrickling filters during a 24-d starvation. Compared to biomass, viable bacteria numbers decreased significantly during the starvation, especially when airflow was maintained in the absence of spray liquid. During the subsequent re-acclimation, all the bioreactors could resume high removal efficiencies within 4 d regardless of the previous starvation conditions. The results show that the re-acclimation time, in the case of biotrickling filters for H2S removal, is mainly controlled by viable H2S oxidizing bacteria numbers. On the other hand, the biotrickling filters can protect against shock loads in inlet fluctuating H2S concentration after resuming normal operation. When the biotrickling filters were supplied with H2S at an input of lower than 1700 mg/m3, their removal efficiencies were nearly 98% regardless of previous H2S input. PMID:19650198

  19. Design and performance characterization strategy using modeling for biofiltration control of odorous hydrogen sulfide.

    PubMed

    Martin, Ronald W; Mihelcic, James R; Crittenden, John C

    2004-07-01

    Biofilter, dynamic modeling software characterizing contaminant removal via biofiltration, was used in the preliminary design of a biofilter to treat odorous hydrogen sulfide (H2S). Steady-state model simulations were run to generate performance plots for various influent concentrations, loadings, residence times, media sizes, and temperatures. Although elimination capacity and removal efficiency frequently are used to characterize biofilter performance, effluent concentration can be used to characterize performance when treating to a target effluent concentration. Model simulations illustrate that, at a given temperature, a biofilter cannot reduce H2S emissions below a minimum value, no matter how large the biofilter or how long the residence time. However, a higher biofilter temperature results in lower effluent H2S concentrations. Because dynamic model simulations show that shock loading can significantly increase the effluent concentration above values predicted by the steady-state model simulations, it is recommended that, to consistently meet treatment objectives, dynamic feed conditions should be considered. This study illustrates that modeling can serve as a valuable tool in the design and performance optimization of biofilters. PMID:15303296

  20. 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.

  1. Hydrogen sulfide-releasing naproxen suppresses colon cancer cell growth and inhibits NF-?B signaling

    PubMed Central

    Kodela, Ravinder; Nath, Niharika; Chattopadhyay, Mitali; Nesbitt, Diandra E; Velázquez-Martínez, Carlos A; Kashfi, Khosrow

    2015-01-01

    Colorectal cancer (CRC) is the second leading cause of death due to cancer and the third most common cancer in men and women in the USA. Nuclear factor kappa B (NF-?B) is known to be activated in CRC and is strongly implicated in its development and progression. Therefore, activated NF-?B constitutes a bona fide target for drug development in this type of malignancy. Many epidemiological and interventional studies have established nonsteroidal anti-inflammatory drugs (NSAIDs) as a viable chemopreventive strategy against CRC. Our previous studies have shown that several novel hydrogen sulfide-releasing NSAIDs are promising anticancer agents and are safer derivatives of NSAIDs. In this study, we examined the growth inhibitory effect of a novel H2S-releasing naproxen (HS-NAP), which has a repertoire as a cardiovascular-safe NSAID, for its effects on cell proliferation, cell cycle phase transitions, and apoptosis using HT-29 human colon cancer cells. We also investigated its effect as a chemo-preventive agent in a xenograft mouse model. HS-NAP suppressed the growth of HT-29 cells by induction of G0/G1 arrest and apoptosis and downregulated NF-?B. Tumor xenografts in mice were significantly reduced in volume. The decrease in tumor mass was associated with a reduction of cell proliferation, induction of apoptosis, and decreases in NF-?B levels in vivo. Therefore, HS-NAP demonstrates strong anticancer potential in CRC. PMID:26346117

  2. 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

  3. High-pressure hydrogen sulfide from first principles: a strongly anharmonic phonon-mediated superconductor.

    PubMed

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

    2015-04-17

    We use first-principles calculations to study structural, vibrational, and superconducting properties of H_{2}S at pressures P?200??GPa. The inclusion of zero-point energy leads to two different possible dissociations of H2S, namely 3H2S?2H3S+S and 5H2S?3H3S+HS2, where both H3S and HS2 are metallic. For H3S, we perform nonperturbative calculations of anharmonic effects within the self-consistent harmonic approximation and show that the harmonic approximation strongly overestimates the electron-phonon interaction (??2.64 at 200 GPa) and Tc. Anharmonicity hardens H?S bond-stretching modes and softens H?S bond-bending modes. As a result, the electron-phonon coupling is suppressed by 30% (??1.84 at 200 GPa). Moreover, while at the harmonic level Tc decreases with increasing pressure, the inclusion of anharmonicity leads to a Tc that is almost independent of pressure. High-pressure hydrogen sulfide is a strongly anharmonic superconductor. PMID:25933334

  4. 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.

  5. Effects of hydrogen sulfide on myocardial fibrosis in diabetic rats: Changes in matrix metalloproteinases parameters.

    PubMed

    Xiao, Ting; Zeng, Ou; Luo, Jian; Wu, Zhixiong; Li, Fang; Yang, Jun

    2015-08-17

    In order to explore the effects of hydrogen sulfide (H2S) on myocardial fibrosis in diabetic rats and its underlying mechanisms, intraperitoneal injections of streptozotocin were used to establish the diabetes models and sodium hydrosulfide (NaHS) was used as an exogenous donor of H2S. Eight weeks later, Van Gieson staining was used to observe pathological changes, and basic hydrolysis methods were adopted to measure hydroxyproline content, while Western Blot was used to determine the expression of MMP2, MMP7, MMP11, MMP13, MMP16, TIMP1 and TGF?1.The results showed that significant myocardial fibrosis, decreased TIMP1 and MMP2 expression and increased MMP7, MMP11, MMP13, MMP16 expressions occurred in diabetic group, but all these changes were significantly reversed in diabetic rats after NaHS treatment. This suggests that H2S could attenuate cardiac fibrosis induced by diabetes and its mechanisms may be related to its modulation of MMPs/TIMPs expression and regulation of TGF?1. PMID:26405980

  6. 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.

  7. Removal of hydrogen sulfide by immobilized Thiobacillus thioparus in a biotrickling filter packed with polyurethane foam.

    PubMed

    Ramírez, Martín; Gómez, José Manuel; Aroca, Germán; Cantero, Domingo

    2009-11-01

    In the work described here, a biotrickling filter with Thiobacillus thioparus (ATCC 23645) immobilized on polyurethane foam is proposed for the removal of hydrogen sulfide contained in air. The effect of surface velocity of the recirculation medium (5.9-1.2 m/h), sulfate concentration inhibition (3.0-10.7 g/L), pH (6.0-8.2), empty bed residence time (EBRT) (150-11 s) for constant loads of 11.5 and 2.9 g S/m(3)/h, and pressure drop of the system were investigated. The total amount of biomass immobilized on the carrier was 8.2+/-1.3x10(10) cells/g. The optimal values of the operating variables were: pH between 7.0 and 7.5, surface velocity of 5.9 m/h and sulfate concentration below 5 g/L. The critical EC value was 14.9 g S/m(3)/h (removal efficiency of 99.8%) and the EC(max) was 55.0 g S/m(3)/h (removal efficiency of 79.8%) for an EBRT of 150 s. For loads of 2.89+/-0.05 and 11.5+/-0.1 g S/m(3)/h, the removal efficiency was higher than 99% for an EBRT over 90 s. PMID:19501506

  8. Effectiveness and mechanisms of hydrogen sulfide adsorption by camphor-derived biochar.

    PubMed

    Shang, Guofeng; Shen, Guoqing; Wang, Tingting; Chen, Qin

    2012-08-01

    The characteristics and mechanisms of hydrogen sulfide (H2S) adsorption on a biochar through pyrolysis at various temperatures (100 to 500 degrees C) were investigated. The biochar used in the current study was derived from the camphor tree (Cinnamomum camphora). The samples were ground and sieved to produceparticle sizes of 0.4 mm to 1.25 mm, 0.3 mm to 0.4 mm, and <0.3 mm. The H2S breakthrough capacity was measured using a laboratory-designed test. The surface properties of the biochar were characterized using pH and Fourier-transform infrared spectroscopy (FTIR) analysis. The results obtained demonstrate that all camphor-derived biochars were effective in H2S sorption. Certain threshold ranges ofthepyrolysis temperature and surfacepH were observed, which, when exceeded, have dramatic effects on the H2S adsorption capacity. The sorption capacity ranged from 1.2 mg/g to 121.4 mg/g. The biochar with 0.3 mm to 0.4 mm particle size possesses a maximum sorption capacity at 400 degrees C. The pH and FTIR analysis results showed that carboxylic and hydroxide radical groups were responsible for H2S sorption. These observations will be helpful in designing biochar as engineered sorbents for the removal of H2S. PMID:22916434

  9. 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. PMID:25656225

  10. 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

  11. Detection of hydrogen sulfide through photoluminescence quenching of penicillamine-copper nanocluster aggregates

    NASA Astrophysics Data System (ADS)

    Ma, Jia-Ying; Chen, Po-Cheng; Chang, Huan-Tsung

    2014-05-01

    We have developed a one-pot, inexpensive, simple and rapid method to synthesize photoluminescent copper nanocluster (Cu NC) aggregates from Cu2+ ions in 65% (v v-1) dimethylformamide aqueous solution containing penicillamine (PA) as a capping and reducing agent. As-prepared PA-Cu NC aggregates emit at 580 nm when excited at 326 nm, with a quantum yield of 2.0%. The photoluminescence of PA-Cu NC aggregates originate from ligand-to-metal charge transfer, which is supported by a long lifetime (126.5 ns) and a large Stokes shift (254 nm). As-prepared PA-Cu NC aggregates have different emission wavelengths with the same excitation wavelength in various organic-aqueous solutions. The PA-Cu NC aggregates are highly selective and sensitive to the detection of hydrogen sulfide (H2S), based on analyte-induced photoluminescence quenching through the formation of CuS nanoparticles. The probe allows the detection of H2S, with a linear range of 1-100 ?M and a limit of detection (signal-to-noise ratio = 3) of 500 nM. The practicality of this probe has been validated through the analysis of hot spring water samples.

  12. 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. PMID:25791320

  13. 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

  14. Removal of hydrogen sulfide at ambient conditions on cadmium/GO-based composite adsorbents.

    PubMed

    Florent, Marc; Wallace, Rajiv; Bandosz, Teresa J

    2015-06-15

    Cadmium-based materials with various hydroxide to carbonate ratios and their composites with graphite oxide were synthesized by a fast and simple precipitation procedure and then used as H2S adsorbents at ambient conditions in the dark or upon a visible light exposure. The structural properties and chemical features of the adsorbents were analyzed before and after hydrogen sulfide adsorption. The results showed that the high ratio of hydroxide to carbonate led to an improved H2S adsorption capacity. In moist conditions cadmium hydroxide was the best adsorbent. Moreover, it showed photoactive properties. While the incorporation of a graphene-based phase slightly decreased the extent of the improvement in the H2S adsorption capacity in moist conditions caused by photoactivity, its presence in the composites enhanced the performance in dry conditions. This was linked to photoactivity of CdS that can split H2S resulting in the formation of water in the system. The graphene-based phase enhanced the electron transfer and delayed the recombination of photoinduced charges. Carbonate-based materials showed a very good adsorption capacity in dark conditions in the presence of moisture. Upon the light exposure, CdS likely photocatalyzes the reduction of carbonate ions to formates/formaldehydes. Their deposition on the surface limits the number of sites available to H2S adsorption. PMID:25792480

  15. 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. PMID:23800663

  16. 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

  17. A breeding strategy to harness flavor diversity of Saccharomyces interspecific hybrids and minimize hydrogen sulfide production.

    PubMed

    Bizaj, Etjen; Cordente, Antonio G; Bellon, Jennifer R; Raspor, Peter; Curtin, Chris D; Pretorius, Isak S

    2012-06-01

    Industrial food-grade yeast strains are selected for traits that enhance their application in quality production processes. Wine yeasts are required to survive in the harsh environment of fermenting grape must, while at the same time contributing to wine quality by producing desirable aromas and flavors. For this reason, there are hundreds of wine yeasts available, exhibiting characteristics that make them suitable for different fermentation conditions and winemaking practices. As wine styles evolve and technical winemaking requirements change, however, it becomes necessary to improve existing strains. This becomes a laborious and costly process when the targets for improvement involve flavor compound production. Here, we demonstrate a new approach harnessing preexisting industrial yeast strains that carry desirable flavor phenotypes - low hydrogen sulfide (H(2) S) production and high ester production. A low-H(2) S Saccharomyces cerevisiae strain previously generated by chemical mutagenesis was hybridized independently with two ester-producing natural interspecies hybrids of S. cerevisiae and Saccharomyces kudriavzevii. Deficiencies in sporulation frequency and spore viability were overcome through use of complementary selectable traits, allowing successful isolation of several novel hybrids exhibiting both desired traits in a single round of selection. PMID:22385988

  18. The effects of acute hydrogen sulfide poisoning on cytochrome P450 isoforms activity in rats.

    PubMed

    Wang, Xianqin; Chen, Mengchun; Chen, Xinxin; Ma, Jianshe; Wen, Congcong; Pan, Jianchun; Hu, Lufeng; Lin, Guanyang

    2014-01-01

    Hydrogen sulfide (H2S) is the second leading cause of toxin related death (after carbon monoxide) in the workplace. H2S is absorbed by the upper respiratory tract mucosa, and it causes histotoxic hypoxemia and respiratory depression. Cocktail method was used to evaluate the influences of acute H2S poisoning on the activities of cytochrome P450 isoforms CYP2B6, CYP2D6, CYP3A4, CYP1A2, CYP2C19, and CYP2C9, which were reflected by the changes of pharmacokinetic parameters of six specific probe drugs, bupropion, metoprolol, midazolam, phenacetin, omeprazole, and tolbutamide, respectively. The experimental rats were randomly divided into two groups, control group and acute H2S poisoning group (inhaling 300?ppm for 2?h). The mixture of six probes was given to rats by oral administration and the blood samples were obtained at a series of time points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by LC-MS. The results for acute H2S poisoning and control groups were as follows: there was a statistically significant difference in the AUC and C max for bupropion, metoprolol, phenacetin, and tolbutamide, while there was no statistical pharmacokinetic difference for midazolam and omeprazole. Acute H2S poisoning could inhibit the activity of CYP2B6, CYP2D6, CYP1A2, and CYP2C9 in rats. PMID:24790991

  19. Hydrogen sulfide alleviates lead-induced photosynthetic and ultrastructural changes in oilseed rape.

    PubMed

    Ali, B; Song, W J; Hu, W Z; Luo, X N; Gill, R A; Wang, J; Zhou, W J

    2014-04-01

    The role of hydrogen sulfide (H2S) in alleviating lead (Pb) induced stress in oilseed rape (Brassica napus L.) was studied under laboratory conditions. Plants were grown hydroponically in greenhouse conditions under three levels (0, 100, and 400 µM) of Pb and three levels (0, 100 and 200 µM) of H2S donor, sodium hydrosulfide (NaHS). Application of H2S significantly improved the plant growth, root morphology, chlorophyll contents and photosynthetic activity in leaves of B. napus under Pb stress. Moreover, exogenously applied H2S significantly lowered the Pb concentration in shoots and roots of plants under Pb stress. The microscopic examination indicated that application of exogenous H2S enabled a clean mesophyll cell having a well developed chloroplast with thylakoid membranes and starch grains. A number of modifications could be observed in root tip cell i.e. mature mitochondria, long endoplasmic reticulum and golgibodies under combined application of H2S and Pb. On the basis of these findings, it can be concluded that application of exogenous H2S has a protective role on plant growth, net photosynthesis rate and ultrastructural changes in B. napus plants under high Pb exposures. PMID:24580818

  20. Hydrogen-sulfide-mediated vasodilatory effect of nucleoside 5'-monophosphorothioates in perivascular adipose tissue.

    PubMed

    Be?towski, Jerzy; Guranowski, Andrzej; Jamroz-Wi?niewska, Anna; Wolski, Andrzej; Ha?as, Krzysztof

    2015-07-01

    Hydrogen sulfide (H2S) is synthesized in perivascular adipose tissue (PVAT) and induces vasorelaxation. We examined whether the sulfur-containing AMP and GMP analogs AMPS and GMPS can serve as the H2S donors in PVAT. H2S production by isolated rat periaortic adipose tissue (PAT) was measured with a polarographic sensor. In addition, phenylephrine-induced contractility of aortic rings with (+) or without (-) PAT was examined. Isolated PAT produced H2S from AMPS or GMPS in the presence of the P2X7 receptor agonist BzATP. Phenylephrine-induced contractility of PAT(+) rings was lower than of PAT(-) rings. AMPS or GMPS had no effect on the contractility of PAT(-) rings, but used together with BzATP reduced the contractility of PAT(+) rings when endogenous H2S production was inhibited with propargylglycine. A high-fat diet reduced endogenous H2S production by PAT. Interestingly, AMPS and GMPS were converted to H2S by PAT of obese rats, and reduced contractility of PAT(+) aortic rings isolated from these animals even in the absence of BzATP. We conclude that (i) AMPS and GMPS can be hydrolyzed to H2S by PAT when P2X7 receptors are activated, (ii) a high-fat diet impairs endogenous H2S production by PAT, (iii) AMPS and GMPS restore the anticontractile effects of PAT in obese animals without P2X7 stimulation. PMID:26120822

  1. 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. PMID:26640616

  2. Highly sensitive hydrogen sulfide (H?S) 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 O? 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. PMID:24598078

  3. Role of the cystathionine ? lyase/hydrogen sulfide pathway in human melanoma progression.

    PubMed

    Panza, Elisabetta; De Cicco, Paola; Armogida, Chiara; Scognamiglio, Giosuč; Gigantino, Vincenzo; Botti, Gerardo; Germano, Domenico; Napolitano, Maria; Papapetropoulos, Andreas; Bucci, Mariarosaria; Cirino, Giuseppe; Ianaro, Angela

    2015-01-01

    In humans, two main metabolic enzymes synthesize hydrogen sulfide (H2 S): cystathionine ? lyase (CSE) and cystathionine ? synthase (CBS). A third enzyme, 3-mercaptopyruvate sulfurtransferase (3-MST), synthesizes H2 S in the presence of the substrate 3-mercaptopyruvate (3-MP). The immunohistochemistry analysis performed on human melanoma samples demonstrated that CSE expression was highest in primary tumors, decreased in the metastatic lesions and was almost silent in non-lymph node metastases. The primary role played by CSE was confirmed by the finding that the overexpression of CSE induced spontaneous apoptosis of human melanoma cells. The same effect was achieved using different H2 S donors, the most active of which was diallyl trisulfide (DATS). The main pro-apoptotic mechanisms involved were suppression of nuclear factor-?B activity and inhibition of AKT and extracellular signal-regulated kinase pathways. A proof of concept was obtained in vivo using a murine melanoma model. In fact, either l-cysteine, the CSE substrate, or DATS inhibited tumor growth in mice. In conclusion, we have determined that the l-cysteine/CSE/H2 S pathway is involved in melanoma progression. PMID:25205294

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

    PubMed

    Be?towski, 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. PMID:15280798

  5. Reaction of Hydrogen Sulfide with Disulfide and Sulfenic Acid to Form the Strongly Nucleophilic Persulfide.

    PubMed

    Cuevasanta, Ernesto; Lange, Mike; Bonanata, Jenner; Coitińo, E Laura; Ferrer-Sueta, Gerardo; Filipovic, Milos R; Alvarez, Beatriz

    2015-11-01

    Hydrogen sulfide (H2S) is increasingly recognized to modulate physiological processes in mammals through mechanisms that are currently under scrutiny. H2S is not able to react with reduced thiols (RSH). However, H2S, more precisely HS(-), is able to react with oxidized thiol derivatives. We performed a systematic study of the reactivity of HS(-) toward symmetric low molecular weight disulfides (RSSR) and mixed albumin (HSA) disulfides. Correlations with thiol acidity and computational modeling showed that the reaction occurs through a concerted mechanism. Comparison with analogous reactions of thiolates indicated that the intrinsic reactivity of HS(-) is 1 order of magnitude lower than that of thiolates. In addition, H2S is able to react with sulfenic acids (RSOH). The rate constant of the reaction of H2S with the sulfenic acid formed in HSA was determined. Both reactions of H2S with disulfides and sulfenic acids yield persulfides (RSSH), recently identified post-translational modifications. The formation of this derivative in HSA was determined, and the rate constants of its reactions with a reporter disulfide and with peroxynitrite revealed that persulfides are better nucleophiles than thiols, which is consistent with the ? effect. Experiments with cells in culture showed that treatment with hydrogen peroxide enhanced the formation of persulfides. Biological implications are discussed. Our results give light on the mechanisms of persulfide formation and provide quantitative evidence for the high nucleophilicity of these novel derivatives, setting the stage for understanding the contribution of the reactions of H2S with oxidized thiol derivatives to H2S effector processes. PMID:26269587

  6. Chemiluminescent detection of enzymatically produced hydrogen sulfide: substrate hydrogen bonding influences selectivity for H2S over biological thiols.

    PubMed

    Bailey, T Spencer; Pluth, Michael D

    2013-11-01

    Hydrogen sulfide (H2S) is now recognized as an important biological regulator and signaling agent that is active in many physiological processes and diseases. Understanding the important roles of this emerging signaling molecule has remained challenging, in part due to the limited methods available for detecting endogenous H2S. Here we report two reaction-based ChemiLuminescent Sulfide Sensors, CLSS-1 and CLSS-2, with strong luminescence responses toward H2S (128- and 48-fold, respectively) and H2S detection limits (0.7 ± 0.3, 4.6 ± 2.0 ?M, respectively) compatible with biological H2S levels. CLSS-2 is highly selective for H2S over other reactive sulfur, nitrogen, and oxygen species (RSONS) including GSH, Cys, Hcy, S2O3(2–), NO2(–), HNO, ONOO(–), and NO. Despite its similar chemical structure, CLSS-1 displays lower selectivity toward amino acid-derived thiols than CLSS-2. The origin of this differential selectivity was investigated using both computational DFT studies and NMR experiments. Our results suggest a model in which amino acid binding to the hydrazide moiety of the luminol-derived probes provides differential access to the reactive azide in CLSS-1 and CLSS-2, thus eroding the selectivity of CLSS-1 for H2S over Cys and GSH. On the basis of its high selectivity for H2S, we used CLSS-2 to detect enzymatically produced H2S from isolated cystathionine ?-lyase (CSE) enzymes (p < 0.001) and also from C6 cells expressing CSE (p < 0.001). CLSS-2 can readily differentiate between H2S production in active CSE and CSE inhibited with ?-cyanoalanine (BCA) in both isolated CSE enzymes (p < 0.005) and in C6 cells (p < 0.005). In addition to providing a highly sensitive and selective reaction-based tool for chemiluminescent H2S detection and quantification, the insights into substrate–probe interactions controlling the selectivity for H2S over biologically relevant thiols may guide the design of other selective H2S detection scaffolds. PMID:24093945

  7. Hydrogen sulfide as an endogenous regulator of vascular smooth muscle tone in trout.

    PubMed

    Dombkowski, Ryan A; Russell, Michael J; Olson, Kenneth R

    2004-04-01

    Hydrogen sulfide (H(2)S) is an endogenous vasodilator in mammals, but its presence and function in other vertebrates is unknown. We generated H(2)S from NaHS and examined the effects on isolated efferent branchial arteries from steelhead (stEBA) or rainbow (rtEBA) trout. H(2)S concentration was measured colorimetrically (CM) and with ion-selective electrodes (ISE) in rainbow trout plasma. NaHS produced a triphasic response consisting of a relaxation (phase 1), constriction (phase 2), and relaxation (phase 3) in both unstimulated vessels and in stEBA precontracted with carbachol (Carb). Phase 1 and phase 3 in stEBA were decreased and phase 2 increased in unstimulated vessels by K(+)(ATP) channel inhibition (glibenclamide), or a cocktail of inhibitors of cyclooxygenase, lipoxygenase, and cytochrome P-450 (indomethacin, esculetin, and clotrimazole). Inhibition of soluble guanylate cyclase with ODQ o NS-2028 inhibited phase 3 in stEBA, although NaHS decreased cGMP production by tEBA. stEBA phase 2 contractions were partially inhibited by the myosin light chain kinase inhibitor, ML-9, but unaffected by L-type calcium channel inhibition (methoxyverapamil), whereas contraction in tEBA was partially inhibited by nifedipine or removal of extracellular calcium. Phase 3 relaxations were more pronounced in stEBA precontracted with Carb and no epinephrine (NE) than those cont acted by KCl or K(2)SO(4). stEBA phase 2 and phase 3 responses were dose dependent (EC(50) = 1.1 +/- 1.2 x 10(-3) M and 6.7 +/- 0.9 x 10(-5) M, respectively; n = 7). NaHS was also vasoactive in steelhead bulbus arteriosus, celiac mesenteric arteries, and anterior cardinal veins. Rainbow trout plasma sulfide concentration was 4.0 +/- 0.3 x 10(-5) M, n = 4 (CM) and 3.8 +/- 0.4 x 10(-5) M, n = 9 (ISE); similar to phase 3 EC(50). Because NaHS has substantial vasoactive effects at physiological plasma concentrations, we propose that its soluble derivative, H(2)S, is a tonically active endogenous vasoregulator in trout. PMID:15003943

  8. ELECTROCHEMICAL DETERMINATION OF HYDROGEN SULFIDE AT CARBON NANOTUBE MODIFIED ELECTRODES. (R830900)

    EPA Science Inventory

    Carbon nanotube (CNT) modified glassy carbon electrodes exhibiting a strong and stable electrocatalytic response towards sulfide are described. A substantial (400 mV) decrease in the overvoltage of the sulfide oxidation reaction (compared to ordinary carbon electrodes) is...

  9. The reduction of selenium(IV) by hydrogen sulfide in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Pettine, Maurizio; Gennari, Francesca; Campanella, Luigi; Casentini, Barbara; Marani, Dario

    2012-04-01

    The rates for the reduction of Se(IV) by sulfides were measured in NaCl solutions as a function of pH (2-10), temperature (10-40 °C) and ionic strength (I = 0.01-1 M). The pseudo first-order rate constant (log k1) showed a complex dependence on pH with values decreasing from pH 2 to a minimum at pH 4.5, then increasing from pH 5.5 to a maximum near pH 8 and decreasing again at pH higher than 8. The values of the overall kinetic constant (k) calculated from the values of k1/[H2S]T can be determined from equations: logk=-0.15pH-1355.5/T+0.44I0.5+7.74 for the pH range 2-4.5 (? = ±0.16), logk=0.28pH-1090.9/T+0.60I0.5+4.68 for the pH range 5.5-7.6 (? = ±0.10) and logk=-0.50pH-1572.1/T+0.45I0.5+12.67 for the pH range 7.7-10 (? = ±0.05), from 10 to 40 °C and from 0.01 to 1 M ionic strength. The effect of pH and ionic strength on the reaction suggests that the reactions in natural waters are due to the following interactions: H2SeO3+H2S ? products HSeO3-+H2S ? products HSeO3-+HS ? products while under strong alkaline conditions (pH > 9) a fourth contribution by SeO32-+HS ? products is also possible. The overall rate expression over the entire pH range investigated can be determined from (H2A = H2SeO3; HA = HSeO3-; A = SeO32-) k=(kH2S-H2A[H]3+kH2S-HAKHA[H]2+kHS-HAKHAK1s[H]+kHS-AKHAKAK1s)/{([H]2+KHA[H]+KAKHA)([H]+K1s)} where kH2S-H2A=2409±566 M min, kH2S-HA=464±233 M min, kHS-HA = 4190 ± 573 M-1 min-1 and kHS-A = 650 ± 382 M-1 min-1 and KHA, KA and K1s are the dissociation constants of selenous acid and hydrogen sulfide. Kinetic runs in natural freshwater samples and natural seawater have confirmed results obtained in simple NaCl solutions suggesting that this reaction may play an important role under anoxic and hypoxic conditions. Sulfide concentrations under these conditions may range from micromolar to millimolar level and Se(IV) half times are in the order of a few hours to minutes, respectively.

  10. 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

  11. Monolayer-precision synthesis of molybdenum sulfide nanoparticles and their nanoscale size effects in the hydrogen evolution reaction.

    PubMed

    Seo, Bora; Jung, Gwan Yeong; Sa, Young Jin; Jeong, Hu Young; Cheon, Jae Yeong; Lee, Jeong Hyeon; Kim, Ho Young; Kim, Jin Chul; Shin, Hyeon Suk; Kwak, Sang Kyu; Joo, Sang Hoon

    2015-04-28

    Metal sulfide-based nanostructured materials have emerged as promising catalysts for hydrogen evolution reaction (HER), and significant progress has been achieved in enhancing their activity and durability for the HER. The understanding of nanoscale size-dependent catalytic activities can suggest critical information regarding catalytic reactivity, providing the scientific basis for the design of advanced catalysts. However, nanoscale size effects in metal sulfide-based HER catalysts have not yet been established fully, due to the synthetic difficulty in precisely size-controlled metal sulfide nanoparticles. Here we report the preparation of molybdenum sulfide (MoS2) nanoparticles with monolayer precision from one to four layers with the nearly constant basal plane size of 5 nm, and their size-dependent catalytic activity in the HER. Using density functional theory (DFT) calculations, we identified the most favorable single-, double-, and triple-layer MoS2 model structures for the HER, and calculated elementary step energetics of the HER over these three model structures. Combining HER activity measurements and the DFT calculation results, we establish that the turnover frequency of MoS2 nanoparticles in the HER increases in a quasi-linear manner with decreased layer numbers. Cobalt-promoted MoS2 nanoparticles also exhibited similar HER activity trend. We attribute the higher HER activity of smaller metal sulfide nanoparticles to the higher degree of oxidation, higher Mo-S coordination number, formation of the 1T phase, and lower activation energy required to overcome transition state. This insight into the nanoscale size-dependent HER activity trend will facilitate the design of advanced HER catalysts as well as other hydrotreating catalysts. PMID:25794552

  12. Production of hydrogen in non oxygen-evolving systems: co-produced hydrogen as a bonus in the photodegradation of organic pollutants and hydrogen sulfide

    SciTech Connect

    Sartoretti, C. Jorand; Ulmann, M.; Augustynski, J. ); Linkous, C.A. )

    2000-01-01

    This report was prepared as part of the documentation of Annex 10 (Photoproduction of Hydrogen) of the IEA Hydrogen Agreement. Subtask A of this Annex concerned photo-electrochemical hydrogen production, with an emphasis on direct water splitting. However, studies of non oxygen-evolving systems were also included in view of their interesting potential for combined hydrogen production and waste degradation. Annex 10 was operative from 1 March 1995 until 1 October 1998. One of the collaborative projects involved scientists from the Universities of Geneva and Bern, and the Federal Institute of Technology in Laussane, Switzerland. A device consisting of a photoelectrochemical cell (PEC) with a WO{sub 3} photoanode connected in series with a so-called Grazel cell (a dye sensitized liquid junction photovoltaic cell) was developed and studied in this project. Part of these studies concerned the combination of hydrogen production with degradation of organic pollutants, as described in Chapter 3 of this report. For completeness, a review of the state of the art of organic waste treatment is included in Chapter 2. Most of the work at the University of Geneva, under the supervision of Prof. J. Augustynski, was focused on the development and testing of efficient WO{sub 3} photoanodes for the photoelectrochemical degradation of organic waste solutions. Two types of WO{sub 3} anodes were developed: non transparent bulk photoanodes and non-particle-based transparent film photoanodes. Both types were tested for degradation and proved to be very efficient in dilute solutions. For instance, a solar-to-chemical energy conversion efficiency of 9% was obtained by operating the device in a 0.01M solution of methanol (as compared to about 4% obtained for direct water splitting with the same device). These organic compounds are oxidized to CO{sub 2} by the photocurrent produced by the photoanode. The advantages of this procedure over conventional electrolytic degradation are that much (an order of magnitude) less energy is required and that sunlight can be used directly. In the case of photoproduction of hydrogen, as compared to water splitting, feeding the anodic compartment of the PEC with an organic pollutant, instead of the usual supporting electrolyte, will bring about a substantial increase of the photocurrent at a given illumination. Thus, the replacement of the photo-oxidation of water by the photodegradation of organic waste will be accompanied by a gain in solar-to-chemical conversion efficiency and hence by a decrease in the cost of the photoproduced hydrogen. Taking into account the benefits and possible revenues obtainable by the waste degradation, this would seem to be a promising approach to the photoproduction of hydrogen. Hydrogen sulfide (H{sub 2}S) is another waste effluent requiring extensive treatment, especially in petroleum refineries. The so-called Claus process is normally used to convert the H{sub 2}S to elemental sulfur. A sulfur recovery process developed at the Florida Solar Energy Center is described briefly in Chapter 4 by Dr. C. Linkous as a typical example of the photoproduction of hydrogen in a non oxygen-evolving system. The encouraging results obtained in these investigations of photoelectrochemical hydrogen production combined with organic waste degradation, have prompted a decision to continue the work under the new IEA Hydrogen Agreement Annex 14, Photoelectrolytic Hydrogen Production.

  13. Olfactory neuron loss in adult male CD rats following subchronic inhalation exposure to hydrogen sulfide.

    PubMed

    Brenneman, K A; James, R A; Gross, E A; Dorman, D C

    2000-01-01

    Dysosmia and anosmia are reported to occur following human exposure to hydrogen sulfide (H2S) gas. The clinical association between H2S exposure and olfactory dysfunction in humans necessitates evaluation of the nasal cavity and olfactory system in experimental animals used to study H2S toxicity. The purpose of this study was to subchronically expose 10-week-old male CD rats to relatively low concentrations of H2S and to histologically evaluate the nasal cavity for exposure-related lesions. Rats (n = 12/group) were exposed via inhalation to 0, 10, 30, or 80 ppm H2S 6 h/d and 7 d/wk for 10 weeks. Following exposure to 30 and 80 ppm H2S, a significant increase in nasal lesions limited to the olfactory mucosa was observed. The lesions, which consisted of olfactory neuron loss and basal cell hyperplasia, were multifocal, bilaterally symmetrical, and had a characteristic rostrocaudal distribution pattern. Regions of the nasal cavity affected included the dorsal medial meatus and the dorsal and medial portions of the ethmoid recess. The no observed adverse effect level for olfactory lesions in this study was 10 ppm. For perspective, the American Conference of Governmental Industrial Hygienists threshold limit value (TLV) recommendation for H2S is currently 10 ppm (proposed revision: 5 ppm), so the concentrations employed in the present study were 3 and 8 times the TLV. These findings suggest that subchronic inhalation exposure to a relatively low level of H2S (30 ppm) can result in olfactory toxicity in rats. However, because of differences in the breathing style and nasal anatomy of rats and humans, additional research is required to determine the significance of these results for human health risk assessment. PMID:10805151

  14. Hydrogen Sulfide Is an Endogenous Regulator of Aging in Caenorhabditis elegans

    PubMed Central

    Qabazard, Bedoor; Li, Ling; Gruber, Jan; Peh, Meng Teng; Ng, Li Fang; Kumar, Srinivasan Dinesh; Rose, Peter; Tan, Choon-Hong; Dymock, Brian W.; Wei, Feng; Swain, Suresh C.; Halliwell, Barry

    2014-01-01

    Abstract Aims: To investigate the role of endogenous hydrogen sulfide (H2S) in the control of aging and healthspan of Caenorhabditis elegans. Results: We show that the model organism, C. elegans, synthesizes H2S. Three H2S-synthesizing enzymes are present in C. elegans, namely cystathionine ? lyase (CSE), cystathionine ? synthetase, and 3-mercaptopyruvate transferase (MPST or 3-MST). Genetic deficiency of mpst-1 (3-MST orthologue 1), but not cth-2 (CSE orthologue), reduced the lifespan of C. elegans. This effect was reversed by a pharmacological H2S donor (GYY4137). GYY4137 also reduced detrimental age-dependent changes in a range of physiological indices, including pharyngeal contraction and defecation. Treatment of C. elegans with GYY4137 increased the expression of several age-related, stress response, and antioxidant genes, whereas MitoSOX Red fluorescence, indicative of reactive oxygen species generation, was increased in mpst-1 knockouts and decreased by GYY4137 treatment. GYY4137 additionally increased the lifespan in short-lived mev-1 mutants with elevated oxidative stress and protected wild-type C. elegans against paraquat poisoning. The lifespan-prolonging and health-promoting effects of H2S in C. elegans are likely due to the antioxidant action of this highly cell-permeable gas. Innovation: The possibility that novel pharmacological agents based on the principle of H2S donation may be able to retard the onset of age-related disease by slowing the aging process warrants further study. Conclusion: Our results show that H2S is an endogenous regulator of oxidative damage, metabolism, and aging in C. elegans and provide new insight into the mechanisms, which control aging in this model organism. Antioxid. Redox Signal. 20, 2621–2630. PMID:24093496

  15. Hydrogen sulfide increases nitric oxide production and subsequent S-nitrosylation in endothelial cells.

    PubMed

    Chen, Ping-Ho; Fu, Yaw-Syan; Wang, Yun-Ming; Yang, Kun-Han; Wang, Danny Ling; Huang, Bin

    2014-01-01

    Hydrogen sulfide (H2S) and nitric oxide (NO), two endogenous gaseous molecules in endothelial cells, got increased attention with respect to their protective roles in the cardiovascular system. However, the details of the signaling pathways between H2S and NO in endothelia cells remain unclear. In this study, a treatment with NaHS profoundly increased the expression and the activity of endothelial nitric oxide synthase. Elevated gaseous NO levels were observed by a novel and specific fluorescent probe, 5-amino-2-(6-hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid methyl ester (FA-OMe), and quantified by flow cytometry. Further study indicated an increase of upstream regulator for eNOS activation, AMP-activated protein kinase (AMPK), and protein kinase B (Akt). By using a biotin switch, the level of NO-mediated protein S-nitrosylation was also enhanced. However, with the addition of the NO donor, NOC-18, the expressions of cystathionine-?-lyase, cystathionine-?-synthase, and 3-mercaptopyruvate sulfurtransferase were not changed. The level of H2S was also monitored by a new designed fluorescent probe, 4-nitro-7-thiocyanatobenz-2-oxa-1,3-diazole (NBD-SCN) with high specificity. Therefore, NO did not reciprocally increase the expression of H2S-generating enzymes and the H2S level. The present study provides an integrated insight of cellular responses to H2S and NO from protein expression to gaseous molecule generation, which indicates the upstream role of H2S in modulating NO production and protein S-nitrosylation. PMID:24971375

  16. Atorvastatin affects the tissue concentration of hydrogen sulfide in mouse kidneys and other organs.

    PubMed

    Wili?ski, Bogdan; Wili?ski, Jerzy; Somogyi, Eugeniusz; Piotrowska, Joanna; Góralska, Marta

    2011-01-01

    Hydrogen sulfide (H2S) is a crucial co-modulator of cardiovascular, nervous, digestive and excretory systems function. The pleiotropic action of atorvastatin exceeds simple 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibition and involves multiple biological mechanisms. This study assesses the influence of atorvastatin on the H2S tissue concentration in mouse brain, liver, heart and kidney. Twenty-four female CBA strain mice received an intraperitoneal injection. The mice were given one of the following solutions: 0.1 mg atorvastatin (5 mg/kg of body weight (b.w.)/day--group D1, n=8), 0.4 mg atorvastatin (20 mg/kg b.w./day--group D2, n=8) or a saline physiological control (0.2 ml--group C, n=8). A modified Siegel spectrophotometric method was used for the H2S tissue concentration measurements. There was a remarkable rise in the H2S concentration [?g/g] in the kidney (C: 5.26±0.09, D1: 5.77±0.11, p=0.0003; D2: 7.48±0.09, p<0.0001). There were also slight H2S tissue level changes in the brain (C: 1.61±0.01, D1: 1.75±0.03, p=0.0001; D2: 1.78±0.03, p<0.0001), the heart (C: 4.54±0.08, D1: 4.86±0.10, p=0.0027; D2: 4.56±0.07, p=0.6997) and the liver (C: 3.45±0.03, D1: 3.27±0.02, p=0.0001; D2: 3.31±0.02, p=0.0003). Our study supports the influence of atorvastatin on H2S tissue concentration in kidneys and other mouse organs. PMID:21441627

  17. Passive monitors to measure hydrogen sulfide near concentrated animal feeding operations.

    PubMed

    Pavilonis, Brian T; O'Shaughnessy, Patrick T; Altmaier, Ralph; Metwali, Nervana; Thorne, Peter S

    2013-06-01

    Hydrogen sulfide (H2S) is one of many airborne pollutants emitted by concentrated animal feeding operations (CAFOs). However, few studies have characterized ambient H2S levels near these facilities, largely due to the lack of low-cost, reliable, and easily transportable instrumentation available to researchers. We determined intermediate environmental H2S exposure near CAFOs using Radiello passive monitors. First, a laboratory study was performed to determine the accuracy of the device. Next, a total of eight passive H2S monitors were deployed bi-weekly in close proximity (<40 m) to a medium-sized swine confinement for seven months in order to determine the temporal and spatial variability of H2S. Finally, we measured H2S concentrations across two rural Iowa counties to characterize ambient exposure near thirteen CAFOs and two schools. The value of the temperature-adjusted H2S passive diffusion rate provided by the supplier was 29% larger than the 24 h rate determined experimentally. Concentrations of H2S measured near the medium-sized confinement were varied and ranged from 0.2 to 48.6 ppb depending on the sampling period and proximity to a lagoon on the property. Two-week concentrations near the schools were low (<1 ppb), while concentrations near the thirteen CAFOs ranged from 0.1 to 42.9 ppb. The passive monitors were effective in measuring H2S concentrations near a swine CAFO as long as they were exposed for a sufficient period of time (two weeks). Radiello passive monitors are a promising new device in measuring intermediate H2S exposure in rural populations. Measured values in excess of an Iowa state limit of 30 ppb (24 h average) suggest that enforcement actions are needed to mitigate H2S migration from swine CAFOs. PMID:23681048

  18. Proresolution effects of hydrogen sulfide during colitis are mediated through hypoxia-inducible factor-1?.

    PubMed

    Flannigan, Kyle L; Agbor, Terence A; Motta, Jean-Paul; Ferraz, José G P; Wang, Rui; Buret, Andre G; Wallace, John L

    2015-04-01

    During a course of colitis, production of the gaseous mediator hydrogen sulfide (H2S) is markedly up-regulated at sites of mucosal damage and contributes significantly to healing and resolution of inflammation. The signaling mechanisms through which H2S promotes resolution of colitis are unknown. We hypothesized that the beneficial effects of H2S in experimental colitis are mediated via stabilization of hypoxia-inducible factor (HIF)-1?. The hapten dinitrobenzene sulfonic acid was used to induce colitis in rats and mice. This resulted in an elevated expression of the H2S-producing enzyme, cystathionine ?-lyase (CSE), and HIF-1? at sites of mucosal ulceration, and the expression of these 2 enzymes followed a similar pattern throughout the course of colitis. This represented a functionally important relationship because the loss of CSE-derived H2S production led to decreased HIF-1? stabilization and exacerbation of colitis. Furthermore, application of an H2S-releasing molecule, diallyl disulfide (DADS), stabilized colonic HIF-1? expression, up-regulated hypoxia-responsive genes, and reduced the severity of disease during peak inflammation. Importantly, the ability of DADS to promote the resolution of colitis was abolished when coadministered with an inhibitor of HIF-1? in vivo (PX-478). DADS was also able to maintain HIF-1? expression at a later point in colitis, when HIF-1? levels would have normally returned to control levels, and to enhance resolution. Finally, we found that HIF-1? stabilization inhibited colonic H2S production and may represent a negative feedback mechanism to prevent prolonged HIF-1? stabilization. Our findings demonstrate an important link between H2S and HIF-1? in the resolution of inflammation and injury during colitis and provide mechanistic insights into the therapeutic value of H2S donors. PMID:25550470

  19. Regulation of mitochondrial bioenergetic function by hydrogen sulfide. Part II. Pathophysiological and therapeutic aspects

    PubMed Central

    Módis, Katalin; Bos, Eelke M; Calzia, Enrico; van Goor, Harry; Coletta, Ciro; Papapetropoulos, Andreas; Hellmich, Mark R; Radermacher, Peter; Bouillaud, Frédéric; Szabo, Csaba

    2014-01-01

    Emerging work demonstrates the dual regulation of mitochondrial function by hydrogen sulfide (H2S), 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 H2S on complex IV is enhanced, which may shift the balance of H2S from protective to deleterious. Several pathophysiological conditions are associated with an overproduction of H2S (e.g. sepsis), while in other disease states H2S levels and H2S 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 H2S-producing enzyme cystathionine ?-synthase (CBS), and utilize its product, H2S, 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 H2S-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. 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:23991749

  20. 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-?-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

  1. Selenium Inhibits Root Elongation by Repressing the Generation of Endogenous Hydrogen Sulfide in Brassica rapa

    PubMed Central

    Zheng, Mei-Yu; Xian, Ming; Qi, Zhong-Qiang; Li, You-Qin; Hu, Liang-Bin; Chen, Jian; Yang, Li-Fei

    2014-01-01

    Selenium (Se) has been becoming an emerging pollutant causing severe phytotoxicity, which the biochemical mechanism is rarely known. Although hydrogen sulfide (H2S) has been suggested as an important exogenous regulator modulating plant physiological adaptions in response to heavy metal stress, whether and how the endogenous H2S regulates Se-induce phytotoxicity remains unclear. In this work, a self-developed specific fluorescent probe (WSP-1) was applied to track endogenous H2S in situ in the roots of Brassica rapa under Se(IV) stress. Se(IV)-induced root growth stunt was closely correlated with the inhibition of endogenous H2S generation in root tips. Se(IV) stress dampened the expression of most LCD and DCD homologues in the roots of B. rapa. By using various specific fluorescent probes for bio-imaging root tips in situ, we found that the increase in endogenous H2S by the application of H2S donor NaHS could significantly alleviate Se(IV)-induced reactive oxygen species (ROS) over-accumulation, oxidative impairment, and cell death in root tips, which further resulted in the recovery of root growth under Se(IV) stress. However, dampening the endogenous H2S could block the alleviated effect of NaHS on Se(IV)-induced phytotoxicity. Finally, the increase in endogenous H2S resulted in the enhancement of glutathione (GSH) in Se(IV)-treated roots, which may share the similar molecular mechanism for the dominant role of H2S in removing ROS by activating GSH biosynthesis in mammals. Altogether, these data provide the first direct evidences confirming the pivotal role of endogenous H2S in modulating Se(IV)-induced phytotoxicity in roots. PMID:25333279

  2. Hydrogen sulfide reduces serum triglyceride by activating liver autophagy via the AMPK-mTOR pathway.

    PubMed

    Sun, Li; Zhang, Song; Yu, Chengyuan; Pan, Zhenwei; Liu, Yang; Zhao, Jing; Wang, Xiaoyu; Yun, Fengxiang; Zhao, Hongwei; Yan, Sen; Yuan, Yue; Wang, Dingyu; Ding, Xue; Liu, Guangzhong; Li, Wenpeng; Zhao, Xuezhu; Liu, Zhaorui; Li, Yue

    2015-12-01

    Autophagy plays an important role in liver triglyceride (TG) metabolism. Inhibition of autophagy could reduce the clearance of TG in the liver. Hydrogen sulfide (H2S) is a potent stimulator of autophagic flux. Recent studies showed H2S is protective against hypertriglyceridemia (HTG) and noalcoholic fatty liver disease (NAFLD), while the mechanism remains to be explored. Here, we tested the hypothesis that H2S reduces serum TG level and ameliorates NAFLD by stimulating liver autophagic flux by the AMPK-mTOR pathway. The level of serum H2S in patients with HTG was lower than that of control subjects. Sodium hydrosulfide (NaHS, H2S donor) markedly reduced serum TG levels of male C57BL/6 mice fed a high-fat diet (HFD), which was abolished by coadministration of chloroquine (CQ), an inhibitor of autophagic flux. In HFD mice, administration of NaSH increased the LC3BII-to-LC3BI ratio and decreased the p62 protein level. Meanwhile, NaSH increased the phosphorylation of AMPK and thus reduced the phosphorylation of mTOR in a Western blot study. In cultured LO2 cells, high-fat treatment reduced the ratio of LC3BII to LC3BI and the phosphorylation of AMPK, which were reversed by the coadministration of NaSH. Knockdown of AMPK by siRNA in LO2 cells blocked the autophagic enhancing effects of NaSH. The same qualitative effect was observed in AMPK?2(-/-) mice. These results for the first time demonstrated that H2S could reduce serum TG level and ameliorate NAFLD by activating liver autophagy via the AMPK-mTOR pathway. PMID:26442880

  3. A liquid crystal-based passive badge for personal monitoring of exposure to hydrogen sulfide.

    PubMed

    Robinson, Sheila E; Grinwald, Bart A; Bremer, Laura L; Kupcho, Kurt A; Acharya, Bharat R; Owens, Patrick D

    2014-01-01

    A new liquid crystal (LC)-based passive dosimeter badge for personal monitoring of exposure to hydrogen sulfide (H2S) gas is reported. When a thin film of LC supported on a surface functionalized with lead perchlorate Pb(ClO4)2 (the LC sensor) is exposed to H2S, the orientation of LC molecules in the film changes from perpendicular to parallel. This reorientation induces a change in the appearance of the LC film when viewed between crossed polarizers. A H2S dosimeter was fabricated by pairing a LC sensor with a glass substrate forming a headspace between the two surfaces, to control diffusion of H2S across the LC film. When the dosimeter is exposed to H2S, a bright front appears as a function of exposure time. An algorithm has been developed to correlate this response length and exposure dose. The dosimeters are functionally stable when subjected to extreme temperature and humidity fluctuations, and are immune to a number of potentially interfering chemicals, except mercaptans. These dosimeters detect H2S at 0.2 ppm TWA (8 hr) with ±20% overall accuracy. The dosimeters were used to monitor the personal exposure of personnel working in an oil refinery. The TWA concentrations measured by the LC-based dosimeters correlate strongly with the NIOSH 1063 method that uses a sorbent tube and a pump followed by laboratory analysis. Thus, the LC-based dosimeters can provide a sensitive tool for on-site assessment of personal exposure to H2S in different environments. PMID:24766440

  4. The immunomodulation of inducible hydrogen sulfide in Pacific oyster Crassostrea gigas.

    PubMed

    Sun, Zhibin; Wang, Lingling; Zhang, Tao; Zhou, Zhi; Jiang, Qiufen; Yi, Qilin; Yang, Chuanyan; Qiu, Limei; Song, Linsheng

    2014-10-01

    Hydrogen sulfide (H2S) is an important gasotransmitter, which plays indispensable roles in cardiovascular, nervous and immune systems of vertebrates. However, the information about the immunomodulation of H2S in invertebrates is still very limited. In the present study, the temporal expression profile of cystathionine ? lyase in oyster Crassostrea gigas (CgCSE) was investigated after the oysters were stimulated by lipopolysaccharide. The expression levels of CgCSE mRNA transcripts in hemocytes increased significantly at 12h (1.31-fold of the PBS group, P<0.05) after LPS stimulation. The immunomodulation of inducible H2S in oyster was examined by monitoring the alterations of both cellular and humoral immune parameters in response to the stimulations of LPS, LPS+Na2S and LPS+propargylglycine (PAG). The total hemocyte counts (THC) and hemolymph PO activity increased significantly after LPS stimulation, and the increase could be further enhanced by adding PAG, while inhibited by appending Na2S. The phagocytosis activity of hemocytes was also increased firstly after LPS treatment, and the increase was enhanced by adding Na2S but inhibited after appending PAG. The anti-bacterial activity in hemolymph increased at 3h post LPS treatment, and then decreased after adding PAG. The total SOD activity of hemolymph was also elevated at 6h post LPS treatment, and the elevated activity was depressed by adding Na2S. These results collectively indicated that H2S might play crucial roles in the immune response of oyster via modulating the turnover and phagocytosis of hemocytes, and regulating the anti-bacterial activity and proPO activation in the hemolymph. PMID:24699445

  5. Importance of hydrophilic pretreatment in the hydrothermal growth of amorphous molybdenum sulfide for hydrogen evolution catalysis.

    PubMed

    Bose, Ranjith; Balasingam, Suresh Kannan; Shin, Seokhee; Jin, Zhenyu; Kwon, Do Hyun; Jun, Yongseok; Min, Yo-Sep

    2015-05-12

    Amorphous molybdenum sulfide (MoSx) has been identified as an excellent catalyst for the hydrogen evolution reaction (HER). It is still a challenge to prepare amorphous MoSx as a more active and stable catalyst for the HER. Here the amorphous MoSx catalysts are prepared on carbon fiber paper (CFP) substrates at 200 °C by a simple hydrothermal method using molybdic acid and thioacetamide. Because the CFP is intrinsically hydrophobic due to its graphene-like carbon structure, two kinds of hydrophilic pretreatment methods [plasma pretreatment (PP) and electrochemical pretreatment (EP)] are investigated to convert the hydrophobic surface of the CFP to be hydrophilic prior to the hydrothermal growth of MoSx. In the HER catalysis, the MoSx catalysts grown on the pretreated CFPs reach a cathodic current density of 10 mA/cm(2) at a much lower overpotential of 231 mV on the MoSx/EP-CFP and 205 mV on the MoSx/PP-CFP, compared to a high overpotential of 290 mV on the MoSx of the nonpretreated CFP. Turnover frequency per site is also significantly improved when the MoSx are grown on the pretreated CFPs. However, the Tafel slopes of all amorphous MoSx catalysts are in the range of 46-50 mV/dec, suggesting the Volmer-Heyrovsky mechanism as a major pathway for the HER. In addition, regardless of the presence or absence of the pretreatment, the hydrothermally grown MoSx catalyst on CFP exhibits such excellent stability that the degradation of the cathodic current density is negligible after 1000 cycles in a stability test, possibly due to the relatively high growth temperature. PMID:25879493

  6. Hydrogen sulfide attenuates hypoxia-induced respiratory suppression in anesthetized adult rats.

    PubMed

    Li, Hui; Chen, Li; Hou, Xuefei; Zhou, Hua; Zheng, Yu

    2016-01-01

    Our previous study in vitro showed that hydrogen sulfide (H2S) could protect the medullary respiratory centers from injury induced by acute hypoxia in brainstem slices of neonatal rats. The present study was carried out to determine if H2S could exhibit similar protective effects in adult rats and to explore the underlying mechanisms of its protection. It was observed that hypoxia induced a diphasic respiratory response, an excitatory phase followed by an inhibitory one, as indicated by an increase followed by a decrease in frequency of rhythmic discharge of the diaphragm. Nissl staining revealed that some of the neurons in the medullary respiratory related nuclei were impaired in hypoxia rats. Hypoxia led to increases in the content of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as a decrease in the level of Bcl-2 mRNA of the medulla oblongata. Intracerebroventricular injection of 2.5mM NaHS (a donor of H2S) or L-cysteine (L-Cys, a substrate for H2S) could prevent inhibitory respiratory effect occurred in the rats with hypoxia. Exogenous application of NaHS and L-Cys could also reduce the content of MDA and the activities of SOD and GSH-Px, and increase the level of Bcl-2 mRNA expression of medulla oblongata caused by hypoxia. These results indicate that H2S could protect the medullary respiratory centers against injury induced by acute hypoxia in adult rats partly due to its anti-oxidant and anti-apoptotic effects. PMID:26365007

  7. Hydrogen sulfide alleviates cadmium-induced morpho-physiological and ultrastructural changes in Brassica napus.

    PubMed

    Ali, Basharat; Gill, Rafaqat A; Yang, Su; Gill, Muhammad B; Ali, Shafaqat; Rafiq, Muhammad T; Zhou, Weijun

    2014-12-01

    In the present study, role of hydrogen sulfide (H2S) in alleviating cadmium (Cd) induced stress in oilseed rape (Brassica napus L.) was studied under greenhouse conditions. Plants were grown hydroponically under three levels (0, 100, and 500µM) of Cd and three levels (0, 100 and 200µM) of H2S donor, sodium hydrosulfide (NaHS). Results showed that application of H2S significantly improved the plant growth, root morphology, chlorophyll contents, elements uptake and photosynthetic activity in B. napus plants under Cd stress. Moreover, addition of H2S reduced the Cd concentration in the leaves and roots of B. napus plants under Cd-toxicity. Exogenously applied H2S decreased the production of malondialdehyde and reactive oxygen species in the leaves and roots by improving the enzymatic antioxidant activities under Cd stress conditions. The microscopic examination indicated that application of exogenous H2S improved the cell structures and enabled a clean mesophyll cell having a well developed chloroplast with thylakoid membranes, and a number of mitochondria could be observed in the micrographs. A number of modifications could be found in root tip cell i.e. mature mitochondria, long endoplasmic reticulum and golgibodies under combined application of H2S and Cd. On the basis of these findings, it can be concluded that application of exogenous H2S has a protective role on plant growth, photosynthetic parameters, elements uptake, antioxidants enzyme activities and ultrastructural changes in B. napus under high Cd stress conditions. PMID:25255479

  8. Impaired hydrogen sulfide synthesis and IL-10 signaling underlie hyperhomocysteinemia-associated exacerbation of colitis.

    PubMed

    Flannigan, Kyle L; Agbor, Terence A; Blackler, Rory W; Kim, Janice J; Khan, Waliul I; Verdu, Elena F; Ferraz, Jose G P; Wallace, John L

    2014-09-16

    Vitamin B deficiencies, which can lead to hyperhomocysteinemia (Hhcy), are commonly reported in patients with inflammatory bowel disease (IBD) and may be a causative underlying factor. However, the mechanism for this effect is not known. Hydrogen sulfide (H2S) is a gaseous mediator that promotes tissue repair and resolution of inflammation. In experimental colitis, a marked increase in colonic H2S synthesis drives ulcer healing and resolution of inflammation. Because H2S synthesis is in part dependent upon enzymes that require vitamin B6 as a cofactor, we tested the hypothesis that Hhcy in rodent models would increase the susceptibility to colitis. In all three models tested, diet-induced Hhcy significantly exacerbated colitis. The usual elevation of colonic H2S synthesis after induction of colitis was absent in all three models of colitis. Administration of an H2S donor to Hhcy rats significantly decreased the severity of colitis. Compared with wild-type mice, interleukin (IL) 10-deficient mice on a normal diet had decreased levels of colonic H2S synthesis, a 40% increase in serum homocysteine, and a phenotype similar to wild-type mice with Hhcy. IL-10-deficient mice fed the vitamin B-deficient diet exhibited more severe colonic inflammation, but the normal elevation of colonic H2S synthesis was absent. Administration of IL-10 to the IL-10-deficient mice restored colonic H2S synthesis and significantly decreased serum homocysteine levels. These results suggest that the exacerbation of colitis in Hhcy is due in part to impaired colonic H2S synthesis. Moreover, IL-10 plays a novel role in promoting H2S production and homocysteine metabolism, which may have therapeutic value in conditions characterized by Hhcy. PMID:25187563

  9. Hydrogen sulfide in posthemorrhagic shock mesenteric lymph drainage alleviates kidney injury in rats

    PubMed Central

    Han, B.; Zhao, Z.G.; Zhang, L.M.; Li, S.G.; Niu, C.Y.

    2015-01-01

    Posthemorrhagic shock mesenteric lymph (PHSML) is a key factor in multiple organ injury following hemorrhagic shock. We investigated the role of hydrogen sulfide (H2S) in PHSML drainage in alleviating acute kidney injury (AKI) by administering D,L-propargylglycine (PPG) and sodium hydrosulfide hydrate (NaHS) to 12 specific pathogen-free male Wistar rats with PHSML drainage. A hemorrhagic shock model was established in 4 experimental groups: shock, shock+drainage, shock+drainage+PPG (45 mg/kg, 0.5 h prehemorrhage), and shock+drainage+NaHS (28 µmol/kg, 0.5 h prehemorrhage). Fluid resuscitation was performed after 1 h of hypotension, and PHMSL was drained in the last three groups for 3 h after resuscitation. Renal function and histomorphology were assessed along with levels of H2S, cystathionine-?-lyase (CSE), Toll-like receptor 4 (TLR4), interleukin (IL)-10, IL-12, and tumor necrosis factor (TNF)-? in renal tissue. Hemorrhagic shock induced AKI with increased urea and creatinine levels in plasma and higher H2S, CSE, TLR4, IL-10, IL-12, and TNF-? levels in renal tissue. PHSML drainage significantly reduced urea, creatinine, H2S, CSE, and TNF-? but not TLR4, IL-10, or IL-12. PPG decreased creatinine, H2S, IL-10, and TNF-? levels, but this effect was reversed by NaHS administration. In conclusion, PHSML drainage alleviated AKI following hemorrhagic shock by preventing increases in H2S and H2S-mediated inflammation. PMID:25945746

  10. Hydrogen sulfide endothelin-induced myocardial hypertrophy in rats and the mechanism involved.

    PubMed

    Yang, Fengyong; Liu, Zhen; Wang, Yajing; Li, Zhaoxin; Yu, Haichu; Wang, Qixin

    2014-12-01

    The aim of the study was to evaluate the clinical efficacy of hydrogen sulfide (H2S) treatment on the endothelin-induced cardiac hypertrophy. Sixty-four adult male rats, weighing from 180 to 200 g, were randomly divided into four groups: ten in normal group, ten in sham group, 44 in model group established by inducing the myocardial hypertrophy with endothelin. The myocardial hypertrophy model rats were randomly divided into two groups: 22 in the simple myocardial hypertrophy model group and 22 in the H2S treatment group. Rats in normal group were given 2 ml pure water by gavage per day, those in the sham group and simple cardiac hypertrophy model group were given 2 ml of saline by gavage per day, and rats in the pure cardiac hypertrophy with H2S treatment were given intraperitoneal injections of 2 ml NaHS saline per day for a period of 4 weeks. Left ventricular mass index, myocyte hypertrophy, volume fraction of myocardial interstitial collagen, myocardial hydroxyproline content and other indicators of cardiac hypertrophy were observed after 4 weeks. (1) There were significant differences on the ventricular mass between the treatment group and the cardiac hypertrophy group: The left ventricular mass decreased 21.4 % and the left ventricular mass index decreased 5.97 % (P < 0.05; (2) the smallest cardiomyocytes diameter and cardiomyocytes cross-sectional area decreased 12.5 and 10.8 %, respectively (P < 0.05) in the treatment group compared to the cardiac hypertrophy group; (3) the volume fraction of myocardial interstitial collagen and the myocardial hydroxyproline content decreased 22.3 and 31.3 % in treatment group compared with the cardiac hypertrophy group, respectively (P < 0.05). H2S had a good clinical efficacy in reducing left ventricular mass fraction and myocardial collagen levels, improving myocardial hypertrophy and decrease myocardial fibrosis. It is worthy for further clinical studies. PMID:24980860

  11. Relation between malodor, ambient hydrogen sulfide, and health in a community bordering a landfill

    PubMed Central

    Heaney, Christopher D.; Wing, Steve; Campbell, Robert L.; Caldwell, David; Hopkins, Barbara; Richardson, David; Yeatts, Karin

    2011-01-01

    Background Municipal solid waste landfills are sources of air pollution that may affect the health and quality of life of neighboring communities. Objectives To investigate health and quality of life concerns of neighbors related to landfill air pollution. Methods Landfill neighbors were enrolled and kept twice-daily diaries for 14 d about odor intensity, alteration of daily activities, mood states, and irritant and other physical symptoms between Jan–Nov, 2009. Concurrently, hydrogen sulfide (H2S) air measurements were recorded every 15-min. Relationships between H2S, odor, and health outcomes were evaluated using conditional fixed effects regression models. Results Twenty-three participants enrolled and completed 878 twice-daily diary entries. H2S measurements were recorded over a period of 80 d and 1-hr average H2S = 0.22 ppb (SD = 0.27; range: 0–2.30 ppb). Landfill odor increased 0.63 points (on 5-point Likert-type scale) for every 1 ppb increase in hourly average H2S when the wind was blowing from the landfill towards the community (95% confidence interval (CI): 0.29, 0.91). Odor was strongly associated with reports of alteration of daily activities (odds ratio (OR) = 9.0; 95% CI: 3.5, 23.5), negative mood states (OR = 5.2; 95% CI: 2.8, 9.6), mucosal irritation (OR = 3.7; 95% CI = 2.0, 7.1) and upper respiratory symptoms (OR = 3.9; 95% CI: 2.2, 7.0), but not positive mood states (OR = 0.6; 95% CI: 0.2, 1.5) and gastrointestinal (GI) symptoms (OR = 1.0; 95% CI: 0.4, 2.6). Conclusions Results suggest air pollutants from a regional landfill negatively impact the health and quality of life of neighbors. PMID:21679938

  12. Reactive Nitrogen Species and Hydrogen Sulfide as Regulators of Protein Tyrosine Phosphatase Activity

    PubMed Central

    2014-01-01

    Abstract Significance: Redox modifications of thiols serve as a molecular code enabling precise and complex regulation of protein tyrosine phosphatases (PTPs) and other proteins. Particular gasotransmitters and even the redox modifications themselves affect each other, of which a typical example is S-nitrosylation-mediated protection against the further oxidation of protein thiols. Recent Advances: For a long time, PTPs were considered constitutively active housekeeping enzymes. This view has changed substantially over the last two decades, and the PTP family is now recognized as a group of tightly and flexibly regulated fundamental enzymes. In addition to the conventional ways in which they are regulated, including noncovalent interactions, phosphorylation, and oxidation, the evidence that has accumulated during the past two decades suggests that many of these enzymes are also modulated by gasotransmitters, namely by nitric oxide (NO) and hydrogen sulfide (H2S). Critical Issues: The specificity and selectivity of the methods used to detect nitrosylation and sulfhydration remains to be corroborated, because several researchers raised the issue of false-positive results, particularly when using the most widespread biotin switch method. Further development of robust and straightforward proteomic methods is needed to further improve our knowledge of the full extent of the gasotransmitters-mediated changes in PTP activity, selectivity, and specificity. Further Directions: Results of the hitherto performed studies on gasotransmitter-mediated PTP signaling await translation into clinical medicine and pharmacotherapeutics. In addition to directly affecting the activity of particular PTPs, the use of reversible S-nitrosylation as a protective mechanism against oxidative stress should be of high interest. Antioxid. Redox Signal. 20, 2191–2209. PMID:24328688

  13. 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-?-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

  14. The Therapeutic Potential of Cystathionine ?-Synthetase/Hydrogen Sulfide Inhibition in Cancer

    PubMed Central

    Hellmich, Mark R.; Coletta, Ciro; Chao, Celia

    2015-01-01

    Abstract Significance: Cancer represents a major socioeconomic problem; there is a significant need for novel therapeutic approaches targeting tumor-specific pathways. Recent Advances: In colorectal and ovarian cancers, an increase in the intratumor production of hydrogen sulfide (H2S) from cystathionine ?-synthase (CBS) plays an important role in promoting the cellular bioenergetics, proliferation, and migration of cancer cells. It also stimulates peritumor angiogenesis inhibition or genetic silencing of CBS exerts antitumor effects both in vitro and in vivo, and potentiates the antitumor efficacy of anticancer therapeutics. Critical Issues: Recently published studies are reviewed, implicating CBS overexpression and H2S overproduction in tumor cells as a tumor-growth promoting “bioenergetic fuel” and “survival factor,” followed by an overview of the experimental evidence demonstrating the anticancer effect of CBS inhibition. Next, the current state of the art of pharmacological CBS inhibitors is reviewed, with special reference to the complex pharmacological actions of aminooxyacetic acid. Finally, new experimental evidence is presented to reconcile a controversy in the literature regarding the effects of H2S donor on cancer cell proliferation and survival. Future Directions: From a basic science standpoint, future directions in the field include the delineation of the molecular mechanism of CBS up-regulation of cancer cells and the delineation of the interactions of H2S with other intracellular pathways of cancer cell metabolism and proliferation. From the translational science standpoint, future directions include the translation of the recently emerging roles of H2S in cancer into human diagnostic and therapeutic approaches. Antioxid. Redox Signal. 22, 424–448. PMID:24730679

  15. Synopses of R and D in geothermal-geochemical engineering at the Lawrence Livermore National Laboratory 1976-1980

    SciTech Connect

    Harrar, J.E.

    1980-12-01

    Research is summarized on the following: geothermal field test apparatus; brine acidification as a means of scale control at the Salton Sea Geothermal Field; tests of seeding and other chemical methods for the control of scale at the Salton Sea Geothermal Field; tests of proprietary organic additives for the control of scale at the Salton Sea Geothermal Field; tests of generic organic compounds for control of scale at Salton Sea Geothermal Field; studies of the dissolution of geothermal scale; chemical measurement developments; chemical modeling of geothermal systems; processing of geothermal brine effluents for injection; hydrogen sulfide abatement using geothermal brine effluents; use of surface waters to supplement injection at the Salton Sea Geothermal Field; and measurement of injectability of geothermal brines. (MHR)

  16. Oxidative stress suppresses the cellular bioenergetic effect of the 3-mercaptopyruvate sulfurtransferase/hydrogen sulfide pathway

    SciTech Connect

    Módis, Katalin; Asimakopoulou, Antonia; Coletta, Ciro; Papapetropoulos, Andreas; Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Patras ; Szabo, Csaba

    2013-04-19

    Highlights: •Oxidative stress impairs 3-MST-derived H{sub 2}S production in isolated enzyme and in isolated mitochondria. •This impairs the stimulatory bioenergetic effects of H{sub 2}S in hepatocytes. •This has implications for the pathophysiology of diseases with oxidative stress. -- Abstract: Recent data show that lower concentrations of hydrogen sulfide (H{sub 2}S), as well as endogenous, intramitochondrial production of H{sub 2}S 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/H{sub 2}S pathway in vitro. Hydrogen peroxide (H{sub 2}O{sub 2}, 100–500 ?M) caused a concentration-dependent decrease in the activity of recombinant mouse 3-MST enzyme. In mitochondria isolated from murine hepatoma cells, H{sub 2}O{sub 2} (50–500 ?M) caused a concentration-dependent decrease in production of H{sub 2}S from 3-MP. In cultured murine hepatoma cells H{sub 2}O{sub 2}, (3–100 ?M), 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 H{sub 2}O{sub 2} (50 ?M). The current findings demonstrate that oxidative stress inhibits 3-MST activity and interferes with the positive bioenergetic role of the 3-MP/3-MST/H{sub 2}S 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.

  17. Feasibility of the hydrogen sulfide test for the assessment of drinking water quality in post-earthquake Haiti.

    PubMed

    Weppelmann, Thomas A; Alam, Meer T; Widmer, Jocelyn; Morrissey, David; Rashid, Mohammed H; De Rochars, Valery M Beau; Morris, J Glenn; Ali, Afsar; Johnson, Judith A

    2014-12-01

    In 2010, a magnitude 7.0 earthquake struck Haiti, severely damaging the drinking and wastewater infrastructure and leaving millions homeless. Compounding this problem, the introduction of Vibrio cholerae resulted in a massive cholera outbreak that infected over 700,000 people and threatened the safety of Haiti's drinking water. To mitigate this public health crisis, non-government organizations installed thousands of wells to provide communities with safe drinking water. However, despite increased access, Haiti currently lacks the monitoring capacity to assure the microbial safety of any of its water resources. For these reasons, this study was designed to assess the feasibility of using a simple, low-cost method to detect indicators of fecal contamination of drinking water that could be implemented at the community level. Water samples from 358 sources of drinking water in the Léogâne flood basin were screened with a commercially available hydrogen sulfide test and a standard membrane method for the enumeration of thermotolerant coliforms. When compared with the gold standard method, the hydrogen sulfide test had a sensitivity of 65 % and a specificity of 93 %. While the sensitivity of the assay increased at higher fecal coliform concentrations, it never exceeded 88 %, even with fecal coliform concentrations greater than 100 colony-forming units per 100 ml. While its simplicity makes the hydrogen sulfide test attractive for assessing water quality in low-resource settings, the low sensitivity raises concerns about its use as the sole indicator of the presence or absence of fecal coliforms in individual or community water sources. PMID:25182685

  18. Toxic hydrogen sulfide and dark caves: life-history adaptations in a livebearing fish (Poecilia mexicana, Poeciliidae).

    PubMed

    Riesch, Rüdiger; Plath, Martin; Schlupp, Ingo

    2010-05-01

    Life-history traits are very sensitive to extreme environmental conditions, because resources that need to be invested in somatic maintenance cannot be invested in reproduction. Here we examined female life-history traits in the Mexican livebearing fish Poecilia mexicana from a variety of benign surface habitats, a creek with naturally occurring toxic hydrogen sulfide (H2S), a sulfidic cave, and a non-sulfidic cave. Previous studies revealed pronounced genetic and morphological divergence over very small geographic scales in this system despite the absence of physical barriers, suggesting that local adaptation to different combinations of two selection factors, toxicity (H2S) and darkness, is accompanied by very low rates of gene flow. Hence, we investigated life-history divergence between these populations in response to the selective pressures of darkness and/or toxicity. Our main results show that toxicity and darkness both select for (or impose constraints on) the same female trait dynamics: reduced fecundity and increased offspring size. Since reduced fecundity in the sulfur cave population was previously shown to be heritable, we discuss how divergent life-history evolution may promote further ecological divergence: for example, reduced fecundity and increased offspring autonomy are clearly beneficial in extreme environments, but fish with these traits are outcompeted in benign habitats. PMID:20503881

  19. Hydrogen Sulfide Plays a Key Role in the Inhibitory Neurotransmission to the Pig Intravesical Ureter

    PubMed Central

    Fernandes, Vítor S.; Ribeiro, Ana S. F.; Martínez, Pilar; López-Oliva, María Elvira; Barahona, María Victoria; Orensanz, Luis M.; Martínez-Sáenz, Ana; Recio, Paz; Benedito, Sara; Bustamante, Salvador; García-Sacristán, Albino; Prieto, Dolores; Hernández, Medardo

    2014-01-01

    According to previous observations nitric oxide (NO), as well as an unknown nature mediator are involved in the inhibitory neurotransmission to the intravesical ureter. This study investigates the hydrogen sulfide (H2S) role in the neurogenic relaxation of the pig intravesical ureter. We have performed western blot and immunohistochemistry to study the expression of the H2S synthesis enzymes cystathionine ?-lyase (CSE) and cystathionine ?-synthase (CBS), measurement of enzymatic production of H2S and myographic studies for isometric force recording. Immunohistochemical assays showed a high CSE expression in the intravesical ureter muscular layer, as well as a strong CSE-immunoreactivity within nerve fibres distributed along smooth muscle bundles. CBS expression, however, was not consistently observed. On ureteral strips precontracted with thromboxane A2 analogue U46619, electrical field stimulation (EFS) and the H2S donor P-(4-methoxyphenyl)-P-4-morpholinylphosphinodithioic acid (GYY4137) evoked frequency- and concentration-dependent relaxations. CSE inhibition with DL-propargylglycine (PPG) reduced EFS-elicited responses and a combined blockade of both CSE and NO synthase (NOS) with, respectively, PPG and NG-nitro-L-arginine (L-NOARG), greatly reduced such relaxations. Endogenous H2S production rate was reduced by PPG, rescued by addition of GYY4137 and was not changed by L-NOARG. EFS and GYY4137 relaxations were also reduced by capsaicin-sensitive primary afferents (CSPA) desensitization with capsaicin and blockade of ATP-dependent K+ (KATP) channels, transient receptor potential A1 (TRPA1), transient receptor potential vanilloid 1 (TRPV1), vasoactive intestinal peptide/pituitary adenylyl cyclase-activating polypeptide (VIP/PACAP) and calcitonin gene-related peptide (CGRP) receptors with glibenclamide, HC030031, AMG9810, PACAP6–38 and CGRP8–37, respectively. These results suggest that H2S, synthesized by CSE, is involved in the inhibitory neurotransmission to the pig intravesical ureter, through an NO-independent pathway, producing smooth muscle relaxation via KATP channel activation. H2S also promotes the release of inhibitory neuropeptides, as PACAP 38 and/or CGRP from CSPA through TRPA1, TRPV1 and related ion channel activation. PMID:25415381

  20. Psoriasis is associated with low serum levels of hydrogen sulfide, a potential anti-inflammatory molecule.

    PubMed

    Alshorafa, Ammar K H; Guo, Qing; Zeng, Fanqin; Chen, Mingchun; Tan, Guozhen; Tang, Zengqi; Yin, Ruofei

    2012-01-01

    Psoriasis, characterized by circumscribed, red, thickened plaques with an overlying silver-white scale, is a common T-cell-mediated chronic inflammatory skin disease. Although hydrogen sulfide (H(2)S) has been shown to be a signaling molecule with both pro- or anti-inflammatory effects, its relationship with psoriasis has not been elucidated. In the present study, 15 patients with chronic progressive psoriasis and 15 healthy volunteers were investigated. Serum H(2)S levels in psoriasis patients were significantly lower than those of healthy controls (16.69 ± 5.47 ?M vs. 34.5 ± 6.39 ?M). In contrast, serum levels of tumor necrosis factor alpha (TNF-?), interleukin-6 (IL-6) and interleukin-8 (IL-8) were significantly higher in psoriasis patients than healthy controls (22.88 ± 6.24 pg/ml vs. 12.07 ± 3.68 pg/ml; 61.47 ± 8.21 pg/ml vs. 31.54 ± 13.73 pg/ml; and 39.43 ± 8.56 pg/ml vs. 20.55 ± 6.45 pg/ml, respectively). The serum H(2)S levels negatively correlated with clinical disease severity. Furthermore, treatment of HaCaT human keratinocytes with TNF-? increased the levels of nitric oxide (NO), IL-6 and IL-8 (32.21 ± 5.71 ?M vs. 3.22 ± 0.98 ?M; 203.96 ± 13.16 pg/ml vs. 13.57 ± 3.75 pg/ml; and 301.24 ± 30.17 pg/ml vs. 29.06 ± 10.91 pg/ml, respectively) in the culture media. Exogenous H(2)S inhibited the TNF-?-mediated upregulation of NO, IL-6 and IL-8 in a dose-dependent manner. In addition, H(2)S inhibited TNF-?-mediated activation of p38, extracellular-signal-regulated kinase and nuclear factor kappa B. In conclusion, H(2)S may play a protective role in the pathogenesis of psoriasis. H(2)S-releasing agents may be promising therapeutics for psoriasis. PMID:23132229

  1. Amperometric cell for subcutaneous detection of hydrogen sulfide in anesthetized experimental animals.

    PubMed

    Nagy, L; Filotás, D; Boros, M; Pozsgai, G; Pintér, E; Nagy, G

    2014-12-01

    Hydrogen sulfide (H2S) is a toxic gas. It has been recognized that H2S evolving in biochemical reactions in living organisms has an important role in different physiologic processes. Nowadays, H2S is known as an endogenous messenger molecule. Natural sulfurous spring water has been proved beneficial in the therapy of diseases of the skin and other organs (Boros et al 2013). In vivo real-time detection of local H2S concentration is an important but challenging task.We developed a two-electrode amperometric cell for selective subcutaneous detection of H2S in anesthetized mice. The cell is a small size implantable gas sensor containing a platinum disc anode and a silver cathode. The selectivity is provided by a membrane permeable only by gases. There is a buffered reversible electrochemical mediator solution in an oxidized form inside the cell. As gaseous H2S penetrates into the cell the mediator is reduced, and +0.4 V versus the reference is employed on the platinum working electrode. The reduced mediator is oxidized on the anode surface. The current provides an analytical signal representing the concentration of H2S.Appropriate shape, size and membrane material were selected, and optimal working parameters--such as mediator concentration, pH and cell voltage--were determined in vitro. The lower limit of detection in the stirred sample solution at pH = 5.5 was as small as 9.4 × 10(-7) M and a dynamic concentration range of 0-6 × 10(-4) M could be achieved.The detecting surfaces of the cell were covered with freshly dissected mouse skin to test dermal H2S permeability. In other experiments, the cell was implanted subcutaneously in an anesthetized mouse and the animal was submerged in a buffer solution containing different concentrations of H2S so that the skin surface over the sensor was covered by the solution. Measurements of subcutaneous H2S concentration were taken. The experiments clearly proved that H2S diffuses through the skin of the live mouse. PMID:25402396

  2. Hydrogen sulfide mediates the anti-survival effect of sulforaphane on human prostate cancer cells

    SciTech Connect

    Pei, Yanxi; College of Life Science, Shanxi University, Taiyuan ; Wu, Bo; Department of Pathophysiology, Harbin Medical University, Harbin ; Cao, Qiuhui; Wu, Lingyun; Department of Pharmacology, University of Saskatchewan, Saskatoon ; Yang, Guangdong

    2011-12-15

    Hydrogen sulfide (H{sub 2}S) is a novel gasotransmitter that regulates cell proliferation and other cellular functions. Sulforaphane (SFN) is a sulfur-containing compound that exhibits anticancer properties, and young sprouts of broccoli are particularly rich in SFN. There is consistent epidemiological evidence that the consumption of sulfur-containing vegetables, such as garlic and cruciferous vegetables, may help reduce the occurrence of prostate cancer. Here we found that a large amount of H{sub 2}S is released when SFN is added into cell culture medium or mixed with mouse liver homogenates, respectively. Both SFN and NaHS (a H{sub 2}S donor) decreased the viability of PC-3 cells (a human prostate cancer cell line) in a dose-dependent manner, and supplement of methemoglobin or oxidized glutathione (two H{sub 2}S scavengers) reversed SFN-reduced cell viability. We further found both cystathionine gamma-lyase (CSE) and cystathionine beta-synthase are expressed in PC-3 cells and mouse prostate tissues. H{sub 2}S production in prostate tissues from CSE knockout mice was only 20% of that from wild-type mice, suggesting CSE is a major H{sub 2}S-producing enzyme in prostate. CSE overexpression enhanced H{sub 2}S production and inhibited cell viability in PC-3 cells. In addition, both SFN and NaHS activated p38 mitogen-activated protein kinases (MAPK) and c-Jun N-terminal kinase (JNK). Pre-treatment of PC-3 cells with methemoglobin decreased SFN-stimulated MAPK activities. Suppression of both p38 MAPK and JNK reversed H{sub 2}S- or SFN-reduced viability of PC-3 cells. Our results demonstrated that H{sub 2}S mediates the inhibitory effect of SFN on the proliferation of PC-3 cells, which suggests that H{sub 2}S-releasing diet or drug might be beneficial in the treatment of prostate cancer. Highlights: Black-Right-Pointing-Pointer A large amount of H{sub 2}S is released from sulforaphane. Black-Right-Pointing-Pointer H{sub 2}S mediates the anti-survival effect of sulforaphane on human prostate cancer cells. Black-Right-Pointing-Pointer Cystathionine gamma-lyase is a major H{sub 2}S-producing enzyme in prostate tissues. Black-Right-Pointing-Pointer p38 MAPK and JNK contribute to H{sub 2}S and sulforaphane-reduced viability in prostate cancer cells.

  3. Mechanisms of hydrogen sulfide (H2S) action on synaptic transmission at the mouse neuromuscular junction.

    PubMed

    Gerasimova, E; Lebedeva, J; Yakovlev, A; Zefirov, A; Giniatullin, R; Sitdikova, G

    2015-09-10

    Hydrogen sulfide (H2S) is a widespread gasotransmitter also known as a powerful neuroprotective agent in the central nervous system. However, the action of H2S in peripheral synapses is much less studied. In the current project we studied the modulatory effects of the H2S donor sodium hydrosulfide (NaHS) on synaptic transmission in the mouse neuromuscular junction using microelectrode technique. Using focal recordings of presynaptic response and evoked transmitter release we have shown that NaHS (300 ?M) increased evoked end-plate currents (EPCs) without changes of presynaptic waveforms which indicated the absence of NaHS effects on sodium and potassium currents of motor nerve endings. Using intracellular recordings it was shown that NaHS increased the frequency of miniature end-plate potentials (MEPPs) without changing their amplitudes indicating a pure presynaptic effect. Furthermore, NaHS increased the amplitude of end-plate potentials (EPPs) without influencing the resting membrane potential of muscle fibers. L-cysteine, a substrate of H2S synthesis induced, similar to NaHS, an increase of EPC amplitudes whereas inhibitors of H2S synthesis (?-cyano-L-alanine and aminooxyacetic acid) had the opposite effect. Inhibition of adenylate cyclase using MDL 12,330A hydrochloride (MDL 12,330A) or elevation of cAMP level with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (pCPT-cAMP) completely prevented the facilitatory action of NaHS indicating involvement of the cAMP signaling cascade. The facilitatory effect of NaHS was significantly diminished when intracellular calcium (Ca(2+)) was buffered by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis acetoxymethyl ester (BAPTA-AM) and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid acetoxymethyl ester (EGTA-AM). Activation of ryanodine receptors by caffeine or ryanodine increased acetylcholine release and prevented further action of NaHS on transmitter release, likely due to an occlusion effect. Inhibition of ryanodine receptors by ryanodine or dantrolene also reduced the action of NaHS on EPC amplitudes. Our results indicate that in mammalian neuromuscular synapses endogenously produced H2S increases spontaneously and evoked quantal transmitter release from motor nerve endings without changing the response of nerve endings. The presynaptic effect of H2S appears mediated by intracellular Ca(2+) and cAMP signaling and involves presynaptic ryanodine receptors. PMID:26192092

  4. Hydrogen sulfide mediates the cardioprotective effects of gene therapy with PKG-I?.

    PubMed

    Das, Anindita; Samidurai, Arun; Hoke, Nicholas N; Kukreja, Rakesh C; Salloum, Fadi N

    2015-07-01

    Cyclic GMP-dependent protein kinase (PKG) is a serine-threonine kinase that mediates the cardioprotective effect of ischemic and pharmacologic preconditioning. Since hydrogen sulfide (H2S) has been implicated in mediating the cardioprotective effects of the cGMP modulators tadalafil and cinaciguat, we tested the hypothesis that myocardial gene therapy with PKG exerts cardioprotection against ischemia/reperfusion (I/R) injury through a mechanism involving H2S. Adult rat cardiomyocytes were infected with adenoviral vector encoding PKGI? or inactive mutant PKGI?K390A (K390A) for 24 h. Necrosis and apoptosis (n = 6/group) were determined after 90 min of simulated ischemia and 1 or 18 h of reoxygenation, respectively. To study the effect of PKGI? in vivo, mice received intramyocardial injections of adenoviral PKGI? or K390A. Four days later, the hearts were subjected to 30 min of ischemia followed by reperfusion for 24 h. The inhibitor of H2S-producing enzyme, cystathionine-?-lyase (CSE), dl-propargylglycine (PAG, 50 mg/kg, ip) was given 30 min before ischemia. PKGI? overexpression induced CSE expression, whereas cystathionine-?-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase expression was not changed. PKGI? overexpression increased H2S in the heart and cardiomyocytes in relation to control and PKGI?K390A. Moreover, PAG abolished protection with PKGI? in vitro by increasing necrosis (35.2 ± 1.7%, P < 0.05) and apoptosis (23.5 ± 1.8 %, P < 0.05) as compared to PKGI?-overexpressing cells (necrosis: 17.2 ± 0.9% and apoptosis: 13.2 ± 0.8%). In vivo, PKGI? overexpression reduced infarct size and preserved left ventricular fractional shortening as compared with K390A (P < 0.05) and PAG abolished the cardioprotective effect of PKGI?. The protective effect of myocardial gene therapy with PKGI? against I/R injury is mediated through a mechanism involving H2S signaling. PMID:26036467

  5. Hydrogen sulfide suicide: a new trend and threat to healthcare providers.

    PubMed

    Ruder, John B; Ward, Jeanette G; Taylor, Scott; Giles, Karon; Higgins, Thomas; Haan, James M

    2015-01-01

    First popularized in Japan, hydrogen sulfide (H2S) gas suicide is an underreported form of suicide with known risk for secondary disaster. Mortality rate commonly exceeds 90% because of the gas's lethal, noncontained nature. Instances in the United States are increasing, up from 2 cases in 2008 to 18 in 2010. Because H2S poisonings remain rare, there exists a lack of knowledge regarding the residual effects of gas venting after victim extrication. Identifying instances of the efficacious use of personal protection equipment (PPE) is critical in the effort to alleviate risks faced by hospital and rescue personnel. The current case demonstrates the effective use of PPEs after prolonged H2S exposure. In 2011, a 20-year-old man threatened suicide using H2S gas inside a vehicle on a remote rural highway. First responders identified a "rotten egg smell" and subsequently experienced low poisoning symptoms. After prolonged Hazmat-assisted extrication (4 hours) the patient was unconscious and experiencing seizures. He was decontaminated on-scene (20 minutes) and transported to the closest hospital (22 minutes). Ambulance personnel who wore PPE and used the ambulance's reverse ventilation system (RVS)reported no adverse effects. The patient was transferred to the authors' burn facility by helicopter (38 minutes). Life-flight personnel, who did not wear PPE (no ventilatory system available), complained of watery eyes, headache, and dizziness. Hospital personnel, who did not use PPE (or RVS), complained of watery eyes or headache. Exposed personnel demonstrated no deficits or residual effects. In spite of spontaneous movement, the patient began to seize and died. This case is unique given the multiple primary and secondary H2S gas exposures involved. Exposed personnel without RVS and not using PPE demonstrated moderate H2S symptoms. PPE (self-contained breathing apparatuses) and RVS were shown to be effective during an H2S emergency; however, there are currently limited data supporting their appropriate use. Until data demonstrating duration of H2S venting for small enclosed spaces are made available, PPEs should be required. PMID:25522151

  6. Effect of hydrogen sulfide on inflammatory cytokines in acute myocardial ischemia injury in rats

    PubMed Central

    LIU, FANG; LIU, GUANG-JIE; LIU, NA; ZHANG, GANG; ZHANG, JIAN-XIN; LI, LAN-FANG

    2015-01-01

    Hydrogen sulfide (H2S) is believed to be involved in numerous physiological and pathophysiological processes, and now it is recognized as the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide; however, the effects of H2S on inflammatory factors in acute myocardial ischemia injury in rats have not been clarified. In the present study, sodium hydrosulfide (NaHS) was used as the H2S donor. Thirty-six male Sprague Dawley rats were randomly divided into five groups: Sham, ischemia, ischemia + low-dose (0.78 mg/kg) NaHS, ischemia + medium-dose (1.56 mg/kg) NaHS, ischemia + high-dose (3.12 mg/kg) NaHS and ischemia + propargylglycine (PPG) (30 mg/kg). The rats in each group were sacrificed 6 h after the surgery for sample collection. Compared with the ischemia group, the cardiac damage in the rats in the ischemia + NaHS groups was significantly reduced, particularly in the high-dose group; in the ischemia + PPG group, the myocardial injury was aggravated compared with that in the ischemia group. Compared with the ischemia group, the levels of interleukin (IL)-1?, IL-6 and tumor necrosis factor-? (TNF-?) in the serum of rats in the ischemia + medium- and high-dose NaHS groups were significantly reduced, and the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA and nuclear factor ?-light-chain-enhancer of activated B cells (NF-?B) protein in the myocardial tissues of rats was significantly reduced. In the ischemia + PPG group, the TNF-?, IL-1? and IL-6 levels in the serum were significantly increased, the expression of ICAM-1 mRNA was increased, although without a significant difference, and the expression of NF-?B was increased. The findings of the present study provide novel evidence for the dual effects of H2S on acute myocardial ischemia injury via the modulation of inflammatory factors. PMID:25667680

  7. The continuous crystallization of sulfur formed by the liquid-phase reaction of hydrogen sulfide and sulfur dioxide

    SciTech Connect

    Stevens, C.A.; Lynn, S.

    1989-09-01

    The crystallization of elemental sulfur is a unit operation in a process being developed to remove hydrogen sulfide from industrial gas streams. The sulfur is formed by the irreversible, liquid-phase reaction of hydrogen sulfide (H{sub 2}S) and sulfur dioxide (SO{sub 2}). Low-temperature sulfur solubility data in triethylene glycol dimethyl ether (Triglyme) and diethylene glycol methyl ether (DGM) were collected. The effects of temperature and water concentration in the solvents on sulfur solubility were correlated. The thermal crystallization of sulfur from Triglyme was studied in a laboratory-scale experimental crystallizer. The dependence of crystal-size distribution on residence time, slurry density, impeller power input, and water concentration in the solvent was determined. A crystallization model, applicable to the experimental crystallizer, was derived from population balance theory and verified using the experimental data. The crystallization kinetics of the sulfur/Triglyme system were obtained from the crystallization model. The reactive crystallization of sulfur formed by the reaction between H{sub 2}S and SO{sub 2} was also studied. A reactor/crystallizer model was developed from the reaction kinetics and from the thermal crystallization kinetics. Reactive crystallization experiments verified the model. An industrial-sized reactor/crystallizer was designed from the model. 53 refs., 44 figs., 18 tabs.

  8. 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. PMID:22667349

  9. Thermally stable derivatives or propylenepolyamines as protective additives for lubricating oils used in compressors handling hydrogen sulfide-containing gas

    SciTech Connect

    Trofimov, V.A.; Panidi, I.S.; Spirkin, V.G.

    1995-09-01

    In the transmission of natural, associated, and petroleum gases containing hydrogen sulfide, carbon dioxide, water, and other corrosive impurities, problems are created by the saturation of the compressor lubricating oil with these impurities and failure of components of the lubricating and sealing system. Hydrogen sulfide is distinguished by the greatest affinity for oil and the highest corrosivity. Its solubility in oils may be as high as 10 g/liter under standard conditions. In the work reported here, we investigated the protective properties of salts and amides based on higher aliphatic, alkylaromatic, and unsaturated carboxylic acids with certain substituted propylenepolyamines. In synthesizing the additives, we used the following: a commercial C{sub 17} - C{sub 20} fraction of synthetic fatty acids (SFA): C{sub 25+} still bottoms; technical alkyl (C{sub 16} - C {sub 18}) salicylic acids; and oleic acid. From these materials, we obtained salts and amides of N,N-dimethylpropanediamine, N-benzylpropanediamine, N-cyanoethylpropanediamine, N,N,N`,N`-tetramethyldipropylenetriamine, and N,N-dimethyldipropylenetriamine.

  10. Catalytic performance and deactivation of precipitated iron catalyst for selective oxidation of hydrogen sulfide to elemental sulfur in the waste gas streams from coal gasification

    SciTech Connect

    Mashapa, T.N.; Rademan, J.D.; van Vuuren, M.J.J.

    2007-09-15

    The selective oxidation of hydrogen sulfide to elemental sulfur, using a commercial, precipitated silica promoted ferric oxide based catalyst, was investigated in laboratory and pilot-plant reactors. Low levels of hydrogen sulfide (1-3 vol%) can be readily removed, but a continuous slow decrease in catalyst activity was apparent. X-ray photoelectron spectroscopy showed that the loss of activity was due to the formation of ferrous sulfate, which is known to be less active than the ferric oxide. In addition, studies using a model feed showed that the propene and HCN impurities in the plant feed stocks also act as potent catalyst poisons.

  11. Biotreatment of refinery spent sulfidic caustics

    SciTech Connect

    Sublette, K.L.; Rajganesh, B.; Woolsey, M.; Plato, A.

    1995-12-31

    Caustics are used in petroleum refinering to remove hydrogen sulfide from various hydrocarbon streams. Spent sulfidic caustics from two Conoco refineries have been successfully biotreated on bench and pilot scale, resulting in neutralization and removal of active sulfides. Sulfides were completely oxidized to sulfate by Thiobacillus denitrificans. Microbial oxidation of sulfide produced acid, which at least partially neutralized the caustic.

  12. Effects of borax treatment on hydrogen sulfide emissions and sulfate reducing bacteria in stored swine manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Malodorous compounds and emissions produced from stored swine manure can pose both environmental and health issues. These nuisance odors largely result from compounds such as sulfides, volatile fatty acids, and phenols, which are produced as a result of anaerobic digestion of materials present in t...

  13. ARTICLE IN PRESS Modeling hydrogen sulfide emissions across the gas liquid interface

    E-print Network

    Aneja, Viney P.

    a Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA b 1911 Fountain Ridge Road, Chapel Hill, NC 27514, USA a r t i c l e i n f o Article history sulfide is produced as manure decomposes anaerobically, resulting from the mineralization of organic

  14. (Sulfide-oxide-silicate phase equilibria and associated fluid inclusion properties in the Salton Sea geothermal system, California)

    SciTech Connect

    McKibben, M.A.

    1988-06-01

    Our studies involved petrographic, fluid inclusion, geochemical and stable isotopic studies of drillcores and fluids from the Salton Sea geothermal system. Our initial studies revealed the presence of previously-unrecognized evaporitic anhydrite at depth throughout the geothermal system. The high salinity of the Salton Sea geothermal brines previously had been attributed to low-temperature dissolution of surficial evaporitic deposits by meteoric waters. Our microthermometric studies of halite--containing fluid inclusions in the meta-evaporites indicated that the high salinity of the geothermal brines is derived in part from the hydrothermal metamorphism of relatively deeply-buried salt and evaporites. In addition, our research concentrated on mineralized fractures in drillcores.

  15. [Exogenous hydrogen sulfide reduces vascular aging in D-galactose-induced subacute aging rats].

    PubMed

    Qiao, Wei-Li; Yang, Wen-Xue; Liu, Lei; Shi, Yue; Cui, Jie; Liu, Hong; Yan, Chang-Dong

    2014-06-25

    The present study was aimed to observe the protective effect of exogenous hydrogen sulfide (H?S) on vascular structural and functional changes of aorta in D-galactose-induced subacute aging rats. Adult male SD rats were randomly divided to five groups: the vehicle group, the D-galactose (D-gal) group, and the three NaHS groups treated with low (1 ?mol·kg?ą·d?ą), middle (10 ?mol·kg?ą·d?ą) or high (100 ?mol·kg?ą·d?ą) dose of NaHS respectively. The D-gal group rats were given subcutaneously injection of 125 mg/kg D-gal per day for eight weeks to induce subacute aging model. In the NaHS group, D-gal was administered as above but with NaHS intraperitoneally injected at a dosage of 1, 10, 100 ?mol·kg?ą·d?ą respectively. Equivalent volumes of saline were administered per day for eight weeks in vehicle group. Morphological changes of aorta were observed by HE and Masson staining. The level of H?S in serum, the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA), as well as anti-superoxide anions in vascular tissue were determined by spectrophotometry. Angiotensin II (AngII) levels in plasma were measured using competitive enzyme immunoassay. The expression of angiotensin II type 1 receptor (AT1R) in aorta was determined by Western blot. The results showed that the aging aortic morphologic changes in model rats were ameliorated in NaHS groups. Decreased vascular endothelial exfoliative cells and vascular smooth muscle cell (SMC) proliferation were shown in NaHS groups by HE staining. Masson staining analysis showed reduced relative contents of collagen fibers (P < 0.05) and SMC (P < 0.05) in NaHS groups. Compared to vehicle group, serum concentration of H?S in D-gal group was decreased, while it was increased in NaHS groups after treatment with NaHS (P < 0.05). In the D-gal group, the concentration of AngII in plasma was significantly increased compared with that in vehicle group, while it was decreased in NaHS groups (P < 0.05). Moreover, levels of vascular tissue anti-superoxide anion and the activity of SOD were obviously higher, MDA was significantly lower in all NaHS treated groups than those in the D-gal group respectively (P < 0.05). Western blot analysis showed that the expression of AT1R was increased in D-gal group compared with that in vehicle group, while it was decreased after treatment with NaHS compared with that in D-gal group (P < 0.05). These results suggest that exogenous H?S can ameliorate the age-related changes of aortic morphology, decrease the concentration of AngII in plasma, down-regulate the expression of AT1R in vascular tissue, and mitigate the level of oxidative stress. These changes delay the vascular aging in aging rats ultimately. PMID:24964843

  16. Corn or sorghum wet distiller's grains with solubles in combination with steam-flaked corn: In vitro fermentation and hydrogen sulfide production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of wet distiller's grains with solubles (WDG) on in vitro rate of gas production, in vitro dry matter disappearance (IVDMD), hydrogen sulfide (H2S) production, and volatile fatty acids (VFA) were evaluated. Five substrate treatments that were balanced for ether extract content were arran...

  17. Best Management Practices to Prevent and Control Hydrogen Sulfide and Reduced Sulfur Compound Emissions at Landfills That Dispose of Gypsum Drywall

    EPA Science Inventory

    Hydrogen sulfide (H2S) gas can be emitted from both construction and demolition (C&D) debris and municipal solid waste (MSW) landfills. H2S emissions may be problematic at a landfill as they can cause odor, impact surrounding communities, cause wear or dama...

  18. Combination of borax and quebracho condensed tannins treatment to reduce hydrogen sulfide, ammonia and greenhouse gas emissions from stored swine manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock producers are acutely aware for the need to reduce gaseous emissions from stored livestock waste and have been trying to identify new technologies to address the chronic problem. Besides the malodor issue, toxic gases emitted from stored livestock manure, especially hydrogen sulfide (H2S)...

  19. The removal of hydrogen sulfide from biogas in a microaerobic biotrickling filter using polypropylene carrier as packing material.

    PubMed

    Zhou, Qiying; Liang, Hong; Yang, Senlin; Jiang, Xia

    2015-04-01

    Biological removal of hydrogen sulfide in biogas is an increasingly adopted alternative to the conventional physicochemical processes, because of its economic and environmental benefits. In this study, a microaerobic biofiltration system packed with polypropylene carrier was used to investigate the removal of high concentrations of H2S contained in biogas from an anaerobic digester. The results show that H2S in biogas was removed completely under different inlet concentrations of H2S from 2065?±?234 to 7818?±?131 ppmv, and the elimination capacity of H2S in the filter achieved about 122 g H2S/m(3)/h. It was observed that the content of CH4 in biogas increased after the biogas biodesulfurization process, which was beneficial for the further utilization of biogas. The elemental sulfur and sulfate were the main sulfur species of H2S degradation, and elemental sulfur was dominant (about 80 %) under high inlet H2S concentration. The results of terminal restriction fragment length polymorphism (T-RFLP) and fluorescence in situ hybridization (FISH) show that the population of sulfide-oxidizing bacteria (SOB) species in the filter changed with different concentrations of H2S. The microaerobic biofiltration system allows the potential use of biogas and the recovery of elemental sulfur resource simultaneously. PMID:25701145

  20. Sulfur isotopic fractionation in vacuum UV photodissociation of hydrogen sulfide and its potential relevance to meteorite analysis

    PubMed Central

    Chakraborty, Subrata; Jackson, Teresa L.; Ahmed, Musahid; Thiemens, Mark H.

    2013-01-01

    Select meteoritic classes possess mass-independent sulfur isotopic compositions in sulfide and organic phases. Photochemistry in the solar nebula has been attributed as a source of these anomalies. Hydrogen sulfide (H2S) is the most abundant gas-phase species in the solar nebula, and hence, photodissociation of H2S by solar vacuum UV (VUV) photons (especially by Lyman-? radiation) is a relevant process. Because of experimental difficulties associated with accessing VUV radiation, there is a paucity of data and a lack of theoretical basis to test the hypothesis of a photochemical origin of mass-independent sulfur. Here, we present multiisotopic measurements of elemental sulfur produced during the VUV photolysis of H2S. Mass-independent sulfur isotopic compositions are observed. The observed isotopic fractionation patterns are wavelength-dependent. VUV photodissociation of H2S takes place through several predissociative channels, and the measured mass-independent fractionation is most likely a manifestation of these processes. Meteorite sulfur data are discussed in light of the present experiments, and suggestions are made to guide future experiments and models. PMID:23431159

  1. Sulfur isotopic fractionation in vacuum UV photodissociation of hydrogen sulfide and its potential relevance to meteorite analysis.

    PubMed

    Chakraborty, Subrata; Jackson, Teresa L; Ahmed, Musahid; Thiemens, Mark H

    2013-10-29

    Select meteoritic classes possess mass-independent sulfur isotopic compositions in sulfide and organic phases. Photochemistry in the solar nebula has been attributed as a source of these anomalies. Hydrogen sulfide (H2S) is the most abundant gas-phase species in the solar nebula, and hence, photodissociation of H2S by solar vacuum UV (VUV) photons (especially by Lyman-? radiation) is a relevant process. Because of experimental difficulties associated with accessing VUV radiation, there is a paucity of data and a lack of theoretical basis to test the hypothesis of a photochemical origin of mass-independent sulfur. Here, we present multiisotopic measurements of elemental sulfur produced during the VUV photolysis of H2S. Mass-independent sulfur isotopic compositions are observed. The observed isotopic fractionation patterns are wavelength-dependent. VUV photodissociation of H2S takes place through several predissociative channels, and the measured mass-independent fractionation is most likely a manifestation of these processes. Meteorite sulfur data are discussed in light of the present experiments, and suggestions are made to guide future experiments and models. PMID:23431159

  2. 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 ?-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

  3. Effects of ammonia and hydrogen sulfide on physical and biochemical properties of the claw horn of Holstein cows

    PubMed Central

    Higuchi, Hidetoshi; Kurumado, Hisatoshi; Mori, Maya; Degawa, Aiko; Fujisawa, Hideyo; Kuwano, Atsutoshi; Nagahata, Hajime

    2009-01-01

    The effects of ammonia and hydrogen sulfide on the physical and biochemical properties of the claw horn of Holstein cows were evaluated. Significant (P < 0.05, 0.01) decreases in hardness and elasticity were found in claw horns soaked in ammonia (NH3) and hydrogen sulfide (H2S) solutions compared with those that were soaked in water for 12, 24, and 48 h. Water absorption rate, as a indicator of permeability barrier function, increased significantly (P < 0.05) over time during the soaking period and was found to be dependent on the concentrations of NH3 and H2S in the solutions. The contents of ceramide, the main lipid component for the permeability barrier system of the stratum corneum, were significantly decreased in claw horns soaked in NH3 and H2S solutions compared with the values before soaking. Quantities of eluted protein released from claw horns treated with NH3 and H2S solutions were approximately 20 times and 30 to 40 times greater than those released from claw horns treated with water alone. Interestingly, the quantities of cytokeratin 10, the main cytoskeletal protein of the stratum corneum, eluted from claw horns treated with NH3 and H2S solutions were markedly greater than the quantity released from horns soaked in water. Our results suggest that abnormal changes in the physical property of claw horn caused by NH3 and H2S treatment are due to disruption of the biochemical property of the claw horn induced by these chemical agents derived from slurry. PMID:19337390

  4. After more than a century, iron sponge still soaks up hydrogen sulfide problems

    SciTech Connect

    Anerousis, J.P. )

    1994-09-01

    The oldest and simplest method for removing H[sub 2]S and other sulfur compounds, such as mercaptans, from gaseous streams is the iron sponge process. The basic technique consists of passing a sour gas stream (one containing H[sub 2]S or mercaptans, or both) across a bed of hydrated iron oxide. The chemical reaction produces iron sulfide and a small amount of by-product water. Although not a common practice, the spent material may be regenerated by exposing it to oxygen, which converts the mixed iron sulfides to their original iron oxide form. The iron sponge technique originated in Europe more than 100 years ago, and the earliest operators used a naturally occurring form of hydrated iron oxide known as bog iron or bog ore. As refinements were made in the process, it was found that more efficient sulfur removal could be attained by uniformly distributing the iron oxide hydrate across a substrate, and that active iron oxide could be prepared synthetically. Continual improvements in the synthetic iron sponge's composition focused on such issues as the crystalline forms of the hydrated iron oxide, size distribution of the active iron oxide particulates, overall chemical composition, size and nature of the typical wood substrate, moisture content, and degree of buffering. Modern iron sponge products are prepared with careful attention to each of these issues. The synthetic materials are characterized by high quality and uniform composition, and their overall characteristics optimize performance in typical gas-sweetening applications.

  5. Abiotic dehalogenation of 1,2-dichloroethane and 1,2-dibromoethane in aqueous solution containing hydrogen sulfide

    SciTech Connect

    Barbash, J.E.; Reinhard, M.

    1989-01-01

    The detection of significant levels of halogenated aliphatic contaminants in groundwater resources in the United States has spurred a considerable effort to understand the various mechanisms--both microbiological and abiotic--by which these compounds may be transformed. In aerobic environments, the abiotic reactions that predominate are elimination of hydrogen halide (dehydrohalogenation) and nucleophilic substitution by H{sub 2}O (hydrolysis). Little research has examined the rates and pathways of abiotic reactions that may be significant under hypoxic conditions. The dehalogenation of 1,2-dichloroethane (1,2-DCA) and 1,2-dibromoethane (EDB) in phosphate buffer was examined alone, and in phosphate buffer containing hydrogen sulfide. Kinetic runs were conducted at pH 7 over the temperature range from 25 to 87.5 C. Phosphate buffer catalyzed the hydrolysis of both 1,2-SCA and EDB. This catalysis was attributed to the buffer anion HPO4(2-). The rate laws for these transformations exhibit the following form: -d(RX)/dt=(K{sup 1}{sub H}) + K{sub HS{minus}}(HS{sup {minus}}) + K{sub HPO4(2-)}(HPO4(2-))(RX) where RX denotes either 1,2-DCA or EDB, and the rate constants correspond to the overall reactions.

  6. Effects of Hydrogen Sulfide on the Performance of a PEMFC R. Mohtadi,a,

    E-print Network

    Van Zee, John W.

    exchange membrane fuel cells PEMFCs consisting of Pt and Pt-Ru alloy electrodes is presented. Steady-state October 7, 2003. In a ``hydrogen challenged'' economy, the fuel for proton ex- change membrane fuel cells

  7. 40 CFR 721.10445 - 2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...New Uses for Specific Chemical Substances § 721...2-Propen-1-ol, reaction products with hydrogen...residues. (a) Chemical substance and significant...reporting. (1) The chemical substance identified as 2-propen-1-ol, reaction products with...

  8. 40 CFR 721.10445 - 2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...New Uses for Specific Chemical Substances § 721...2-Propen-1-ol, reaction products with hydrogen...residues. (a) Chemical substance and significant...reporting. (1) The chemical substance identified as 2-propen-1-ol, reaction products with...

  9. Inhibition of endogenous hydrogen sulfide synthesis by PAG protects against ethanol-induced gastric damage in the rat.

    PubMed

    Chávez-Pińa, Aracely Evangelina; Tapia-Alvarez, Gabriela Rubí; Navarrete, Andrés

    2010-03-25

    Hydrogen sulfide (H(2)S) is a gaseous mediator involved in a multitude of physiological functions; however the role of H(2)S in the gut is far from being understood completely. The aim of this study was to determine the effect of d-l-propargylglycine (PAG), an inhibitor of H(2)S synthesis, on ethanol-induced gastric injury in rat and to examine the role of l-cysteine, exogenous H(2)S, prostaglandins, non-protein sulphydryls groups, nitric oxide and K(ATP) channels in the gastroprotective effect of PAG. Administration of PAG (3.12 to 75mg/kg i.p.) or l-cysteine (0.3 to 300mg/kg, p.o.) exhibited a dose-dependent protective effect after intragastric administration of 1ml of ethanol to induce gastric injury. The gastroprotective effect of PAG (25mg/kg i.p.) was maintained after post-treatment with l-cysteine (10mg/kg p.o.), while NaHS (8.4mg/kg p.o.) inhibited this effect. The levels of gastric hydrogen sulfide were increased after ethanol-induced gastric damage and they were reverted by PAG while prostaglandin E(2) levels in gastric tissue were decreased by ethanol and PAG did not revert to this effect. Pretreatment with indomethacin (10mg/kg i.p.) and N-ethylmaleimide (NEM, 10mg/kg s.c.) resulted in a reversion of the gastroprotective effect of PAG while N(G)-nitro-l-arginine methyl ester (L-NAME, 70mg/kg s.c.), glibenclamide (1mg/kg i.p.) or diazoxide (3mg/kg i.p.) did not induce any changes. These results suggest that ethanol-induced gastric injury is related with an increment of endogenous H(2)S levels, and therefore a decrement of H(2)S levels by PAG is a benefit to protect gastric injury caused by ethanol. PMID:20035745

  10. Hydrogen sulfide and traffic-related air pollutants in association with increased mortality: a case-crossover study in Reykjavik, Iceland

    PubMed Central

    Finnbjornsdottir, Ragnhildur Gudrun; Elvarsson, Bjarki Thor; Gislason, Thorarinn; Rafnsson, Vilhjalmur

    2015-01-01

    Objectives To study the association between daily mortality and short-term increases in air pollutants, both traffic-related and the geothermal source-specific hydrogen sulfide (H2S). Design Population-based, time stratified case-crossover. A lag time to 4?days was considered. Seasonal, gender and age stratification were calculated. Also, the best-fit lag when introducing H2S >7?µg/m3 was selected by the Akaike Information Criterion (AIC). Setting The population of the greater Reykjavik area (n=181?558) during 2003–2009. Participants Cases were defined as individuals living in the Reykjavik capital area, 18?years or older (N=138?657), who died due to all natural causes (ICD-10 codes A00-R99) other than injury, poisoning and certain other consequences of external causes, or cardiovascular disease (ICD-10 codes I00-I99) during the study period. Main outcome measure Percentage increases in risk of death (IR%) following an interquartile range increase in pollutants. Results The total number of deaths due to all natural causes was 7679 and due to cardiovascular diseases was 3033. The interquartile range increased concentrations of H2S (2.6?µg/m3) were associated with daily all natural cause mortality in the Reykjavik capital area. The IR% was statistically significant during the summer season (lag 1: IR%=5.05, 95% CI 0.61 to 9.68; lag 2: IR%=5.09, 95% CI 0.44 to 9.97), among males (lag 0: IR%=2.26, 95% CI 0.23 to 4.44), and among the elderly (lag 0: IR%=1.94, 95% CI 0.12 to 1.04; lag 1: IR%=1.99, 95% CI 0.21 to 1.04), when adjusted for traffic-related pollutants and meteorological variables. The traffic-related pollutants were generally not associated with statistical significant IR%s. Conclusions The results suggest that ambient H2S air pollution may increase mortality in Reykjavik, Iceland. To the best of our knowledge, ambient H2S exposure has not previously been associated with increased mortality in population-based studies and therefore the results should be interpreted with caution. Further studies are warranted to confirm or refute whether H2S exposure induces premature deaths. PMID:25854971

  11. Highly selective and sensitive colorimetric probe for hydrogen sulfide by a copper (II) complex of azo-dye based on chemosensing ensemble approach

    NASA Astrophysics Data System (ADS)

    Zhang, Dengqing; Jin, Wusong

    2012-05-01

    A copper (II) complex of azo-dye (Cu-1) has been synthesized by the reaction of 1-(2-pyridylazo)-2-naphthol (1) with copper (II) chloride. The complex Cu-1 is able to selectively sense hydrogen sulfide over other anions followed by the release of compound 1 to give a remarkable change of UV-vis absorption at neutral pH in aqueous solution.

  12. Photogeneration of hydrogen from water by hybrid molybdenum sulfide clusters immobilized on titania.

    PubMed

    Recatalá, David; Llusar, Rosa; Gushchin, Artem L; Kozlova, Ekaterina A; Laricheva, Yuliya A; Abramov, Pavel A; Sokolov, Maxim N; Gómez, Roberto; Lana-Villarreal, Teresa

    2015-01-01

    Two new hybrid molybdenum(IV) Mo3 S7 cluster complexes derivatized with diimino ligands have been prepared by replacement of the two bromine atoms of [Mo3 S7 Br6 ](2-) by a substituted bipyridine ligand to afford heteroleptic molybdenum(IV) Mo3 S7 Br4 (diimino) complexes. Adsorption of the Mo3 S7 cores from sample solutions on TiO2 was only achieved from the diimino functionalized clusters. The adsorbed Mo3 S7 units were reduced on the TiO2 surface to generate an electrocatalyst that reduces the overpotential for the H2 evolution reaction by approximately 0.3?V (for 1?mA?cm(-2) ) with a turnover frequency as high as 1.4?s(-1) . The nature of the actual active molybdenum sulfide species has been investigated by X-ray photoelectron spectroscopy. In agreement with the electrochemical results, the modified TiO2 nanoparticles show a high photocatalytic activity for H2 production in the presence of Na2 S/Na2 SO3 as a sacrificial electron donor system. PMID:25359712

  13. Semi-Coke–Supported Mixed Metal Oxides for Hydrogen Sulfide Removal at High Temperatures

    PubMed Central

    Jie, Mi; Yongyan, Zhang; Yongsheng, Zhu; Ting, Guo; Huiling, Fan

    2012-01-01

    Abstract To improve the desulfurization efficiency of sorbents at low cost, modified semi-coke was used as the substrate for mixed metal oxides (ZFM; oxides of zinc [Zn], iron [Fe], and manganese [Mn]) in hot gas desulfurization. Performance of the prepared ZFM/modified semi-coke (MS) sorbents were evaluated in a fixed-bed reactor in the temperature range 400–550°C. Results showed that the molar ratio of Mn to Zn, effect of the substrate, the calcination temperature, and the sulfidation temperature influenced the performance of the sorbents. Optimum conditions for the preparation of the ZFM/MS sorbents were molar ratio of Mn(NO3)2·6H2O, Zn(NO3)2, and Fe(NO3)3, 0.6:1:2; mass ratio of ZFM0.6 to modified semi-coke support, 1:1; and calcination temperature, 600°C. The ZFM0.6/MS sorbent thus prepared exhibited the best sorption sulfur capacity of 27.46% at 450°C. PMID:22783061

  14. Hydrogen sulfide capture by limestone and dolomite at elevated pressure. 1: Sorbent performance

    SciTech Connect

    Yrjas, K.P.; Zevenhoven, C.A.P.; Hupa, M.M.

    1996-01-01

    Sulfur emission control in fossil fuel gasification plants implies the removal of H{sub 2}S from the product gas either inside the furnace or in the gas clean-up system. In a fluidized-bed gasifier, in-bed sulfur capture can be accomplished by adding a calcium-based sorbent such as limestone or dolomite to the bend and removing the sulfur from the system with the bottom ash in the form of CaS. This work describes the H{sub 2}S uptake by a set of physically and chemically different limestones and dolomites under pressurized conditions, typically for those in a pressurized fluidized-bed gasifier (2 MPa, 950 C). The tests were done with a pressurized thermobalance at two p{sub CO{sub 2}} levels. Thus, the sulfidation of both calcined and uncalcined sorbents could be analyzed. The effect of p{sub H{sub 2}S} was also investigated for uncalcined limestones and half-calcined dolomites. The results are presented as conversion of CaCO{sub 3} or CaO to CaS vs time plots. The results are also compared with the sulfur capture performance of the same sorbents under pressurized combustion conditions.

  15. Hydrogen sulfide capture by limestone and dolomite at elevated pressure. 2: Sorbent particle conversion modeling

    SciTech Connect

    Zevenhoven, C.A.P.; Yrjas, K.P.; Hupa, M.M.

    1996-03-01

    The physical structure of a limestone or dolomite to be used in in-bed sulfur capture in fluidized bed gasifiers has a great impact on the efficiency of sulfur capture and sorbent use. In this study an unreacted shrinking core model with variable effective diffusivity is applied to sulfidation test data from a pressurized thermogravimetric apparatus (P-TGA) for a set of physically and chemically different limestone and dolomite samples. The particle size was 250--300 {micro}m for all sorbents, which were characterized by chemical composition analysis, particle density measurement, mercury porosimetry, and BET internal surface measurement. Tests were done under typical conditions for a pressurized fluidized-bed gasifier, i.e., 20% CO{sub 2}, 950 C, 20 bar. At these conditions the limestone remains uncalcined, while the dolomite is half-calcined. Additional tests were done at low CO{sub 2} partial pressures, yielding calcined limestone and fully calcined dolomite. The generalized model allows for determination of values for the initial reaction rate and product layer diffusivity.

  16. Can microbially-generated hydrogen sulfide account for the rates of U(VI) reduction by a sulfate-reducing bacterium?

    SciTech Connect

    Boonchayaanant, Benjaporn; Gu, Baohua; Wang, Wei; Ortiz, Monica E; Criddle, Craig

    2010-01-01

    In situ remediation of uranium contaminated soil and groundwater is attractive because a diverse range of microbial and abiotic processes reduce soluble and mobile U(VI) to sparingly soluble and immobile U(IV). Often these processes are linked. Sulfate-reducing bacteria (SRB), for example, enzymatically reduce U(VI) to U(IV), but they also produce hydrogen sulfide that can itself reduce U(VI). This study evaluated the relative importance of these processes for Desulfovibrio aerotolerans, a SRB isolated from a U(VI)-contaminated site. For the conditions evaluated, the observed rate of SRB-mediated U(VI) reduction can be explained by the abiotic reaction of U(VI) with the microbially-generated H{sub 2}S. The presence of trace ferrous iron appeared to enhance the extent of hydrogen sulfide-mediated U(VI) reduction at 5 mM bicarbonate, but had no clear effect at 15 mM. During the hydrogen sulfide-mediated reduction of U(VI), a floc formed containing uranium and sulfur. U(VI) sequestered in the floc was not available for further reduction.

  17. Geothermal Gases--Community Experiences, Perceptions, and Exposures in Northern California.

    PubMed

    Chiu, Cindy H; Lozier, Matthew J; Bayleyegn, Tesfaye; Tait, Karen; Barreau, Tracy; Copan, Lori; Roisman, Rachel; Jackson, Rebecca; Smorodinsky, Svetlana; Kreutzer, Richard A; Yip, Fuyuen; Wolkin, Amy

    2015-12-01

    Lake County, California, is in a high geothermal-activity area. Over the past 30 years, the city of Clearlake has reported health effects and building evacuations related to geothermal venting. Previous investigations in Clearlake revealed hydrogen sulfide at levels known to cause health effects and methane at levels that can cause explosion risks. The authors conducted an investigation in multiple cities and towns in Lake County to understand better the risk of geothermal venting to the community. They conducted household surveys and outdoor air sampling of hydrogen sulfide and methane and found community members were aware of geothermal venting and some expressed concerns. The authors did not, however, find hydrogen sulfide above the California Environmental Protection Agency air quality standard of 30 parts per billion over one hour or methane above explosive thresholds. The authors recommend improving risk communication, continuing to monitor geothermal gas effects on the community, and using community reports and complaints to monitor and document geothermal venting incidents. PMID:26738314

  18. Production of Hydrogen by Superadiabatic Decomposition of Hydrogen Sulfide - Final Technical Report for the Period June 1, 1999 - September 30, 2000

    SciTech Connect

    Rachid B. Slimane; Francis S. Lau; Javad Abbasian

    2000-10-01

    The objective of this program is to develop an economical process for hydrogen production, with no additional carbon dioxide emission, through the thermal decomposition of hydrogen sulfide (H{sub 2}S) in H{sub 2}S-rich waste streams to high-purity hydrogen and elemental sulfur. The novel feature of the process being developed is the superadiabatic combustion (SAC) of part of the H{sub 2}S in the waste stream to provide the thermal energy required for the decomposition reaction such that no additional energy is required. The program is divided into two phases. In Phase 1, detailed thermochemical and kinetic modeling of the SAC reactor with H{sub 2}S-rich fuel gas and air/enriched air feeds is undertaken to evaluate the effects of operating conditions on exit gas products and conversion efficiency, and to identify key process parameters. Preliminary modeling results are used as a basis to conduct a thorough evaluation of SAC process design options, including reactor configuration, operating conditions, and productivity-product separation schemes, with respect to potential product yields, thermal efficiency, capital and operating costs, and reliability, ultimately leading to the preparation of a design package and cost estimate for a bench-scale reactor testing system to be assembled and tested in Phase 2 of the program. A detailed parametric testing plan was also developed for process design optimization and model verification in Phase 2. During Phase 2 of this program, IGT, UIC, and industry advisors UOP and BP Amoco will validate the SAC concept through construction of the bench-scale unit and parametric testing. The computer model developed in Phase 1 will be updated with the experimental data and used in future scale-up efforts. The process design will be refined and the cost estimate updated. Market survey and assessment will continue so that a commercial demonstration project can be identified.

  19. Modification of the EIC hydrogen sulfide abatement process to produce valuable by-products. Final report, May 4, 1981-May 4, 1982

    SciTech Connect

    Offenhartz, P. O'D.

    1982-06-01

    A program of analytical and experimental studies has been carried out to develop modifications of the CUPROSUL process for the desulfurization of geothermal steam. The objective of the program was to devise practical means to manipulate the chemistry of the process so that the consumption of raw materials could be controlled and a variety of valuable by-products could be produced. The process had been demonstrated, at one-tenth commercial scale, for steam of the Geysers' average composition in a configuration which resulted in essentially complete oxidation of sulfide to sulfate. The ability to control the extent of oxidation would increase process flexibility and extend its range of applicability to steams of widely varying composition. Preliminary market surveys of raw materials required for the process and by-products which could be produced indicated that controlling the oxidation of sulfides to produce elemental sulfur would probably be the preferred process option. Use of lime to treat sulfate-containing purge streams to produce by-product gypsum and ammonia for recycle or sale could also be justified for certain steam compositions. Recovery of ammonium sulfate alone from the purge stream would not normally be justified unless corecovery of other valuable by-products, such as boric acid, was possible at incremental cost. It was found that ferric sulfate was a highly effective, selective oxidant for the controlled oxidation of copper sulfide solids to produce elemental sulfur for sale and copper sulfate for recycle.

  20. Laminar shear flow increases hydrogen sulfide and activates a nitric oxide producing signaling cascade in endothelial cells.

    PubMed

    Huang, Bin; Chen, Chang-Ting; Chen, Chi-Shia; Wang, Yun-Ming; Hsieh, Hsyue-Jen; Wang, Danny Ling

    2015-09-01

    Laminar shear flow triggers a signaling cascade that maintains the integrity of endothelial cells (ECs). Hydrogen sulfide (H2S), a new gasotransmitter is regarded as an upstream regulator of nitric oxide (NO). Whether the H2S-generating enzymes are correlated to the enzymes involved in NO production under shear flow conditions remains unclear as yet. In the present study, the cultured ECs were subjected to a constant shear flow (12 dyn/cm(2)) in a parallel flow chamber system. We investigated the expression of three key enzymes for H2S biosynthesis, cystathionine-?-lyase (CSE), cystathionine-?-synthase (CBS), and 3-mercapto-sulfurtransferase (3-MST). Shear flow markedly increased the level of 3-MST. Shear flow enhanced the production of H2S was determined by NBD-SCN reagent that can bind to cysteine/homocystein. Exogenous treatment of NaHS that can release gaseous H2S, ECs showed an increase of phosphorylation in Akt(S473), ERK(T202/Y204) and eNOS(S1177). This indicated that H2S can trigger the NO-production signaling cascade. Silencing of CSE, CBS and 3-MST genes by siRNA separately attenuated the phosphorylation levels of Akt(S473) and eNOS(S1177) under shear flow conditions. The particular mode of shear flow increased H2S production. The interplay between H2S and NO-generating enzymes were discussed in the present study. PMID:26212441

  1. Hydrogen Sulfide Donor Protects Porcine Oocytes against Aging and Improves the Developmental Potential of Aged Porcine Oocytes

    PubMed Central

    Krejcova, Tereza; Smelcova, Miroslava; Petr, Jaroslav; Bodart, Jean-Francois; Sedmikova, Marketa; Nevoral, Jan; Dvorakova, Marketa; Vyskocilova, Alena; Weingartova, Ivona; Kucerova-Chrpova, Veronika; Chmelikova, Eva; Tumova, Lenka; Jilek, Frantisek

    2015-01-01

    Porcine oocytes that have matured in in vitro conditions undergo the process of aging during prolonged cultivation, which is manifested by spontaneous parthenogenetic activation, lysis or fragmentation of aged oocytes. This study focused on the role of hydrogen sulfide (H2S) in the process of porcine oocyte aging. H2S is a gaseous signaling molecule and is produced endogenously by the enzymes cystathionine-?-synthase (CBS), cystathionine-?-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST). We demonstrated that H2S-producing enzymes are active in porcine oocytes and that a statistically significant decline in endogenous H2S production occurs during the first day of aging. Inhibition of these enzymes accelerates signs of aging in oocytes and significantly increases the ratio of fragmented oocytes. The presence of exogenous H2S from a donor (Na2S.9H2O) significantly suppressed the manifestations of aging, reversed the effects of inhibitors and resulted in the complete suppression of oocyte fragmentation. Cultivation of aging oocytes in the presence of H2S donor positively affected their subsequent embryonic development following parthenogenetic activation. Although no unambiguous effects of exogenous H2S on MPF and MAPK activities were detected and the intracellular mechanism underlying H2S activity remains unclear, our study clearly demonstrates the role of H2S in the regulation of porcine oocyte aging. PMID:25615598

  2. Hydrogen sulfide preconditioning protects against myocardial ischemia/reperfusion injury in rats through inhibition of endo/sarcoplasmic reticulum stress

    PubMed Central

    Li, Changyong; Hu, Min; Wang, Yuan; Lu, Huan; Deng, Jing; Yan, Xiaohong

    2015-01-01

    Ischemia reperfusion (I/R) injury is a major cause of myocardial damage. Hydrogen sulfide (H2S), a gaseous signal molecule, has drawn considerable attention for its role in various pathophysiological processes. Multiple lines of evidence reveal the protective effects of H2S in various models of cardiac injury, however, the exact mechanism underlying this protective effect of H2S against myocardial I/R injury is not fully understood. The present study was designed to investigate whether H2S preconditioning attenuates myocardial I/R injury in rats and whether the observed protection is associated with reduced endo/sarcoplasmic reticulum (ER/SR) stress. We found that H2S preconditioning significantly reduced myocardial infarct size, preserved left ventricular function, and inhibited I/R-induced cardiomyocyte apoptosis in vivo. Furthermore, H2S preconditioning significantly attenuated I/R-induced ER/SR stress responses, including the increased expression of glucose-regulated protein 78, C/EBP homologous protein, and activate transcription factor in myocardium. Additionally, we demonstrate that H2S preconditioning attenuates ER/SR stress and inhibits cardiomyocyte apoptosis in an in vitro model of hypoxia/reoxygenation in rat H9c2 cardiac myocytes. In conclusion, these results suggest that H2S-attenuated ER/SR stress plays an important role in its protective effects against I/R-induced myocardial injury. PMID:26339339

  3. Hydrogen Sulfide Protects the Retina from Light-induced Degeneration by the Modulation of Ca2+ Influx*

    PubMed Central

    Mikami, Yoshinori; Shibuya, Norihiro; Kimura, Yuka; Nagahara, Noriyuki; Yamada, Masahiro; Kimura, Hideo

    2011-01-01

    Hydrogen sulfide (H2S) has recently been recognized as a signaling molecule as well as a cytoprotectant. Cystathionine ?-synthase (CBS) and cystathionine ?-lyase (CSE) are well-known as H2S-producing enzymes. We recently demonstrated that 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase (CAT) produces H2S in the brain and in vascular endothelium. However, the cellular distribution and regulation of these enzymes are not well understood. Here we show that 3MST and CAT are localized to retinal neurons and that the production of H2S is regulated by Ca2+; H2S, in turn, regulates Ca2+ influx into photoreceptor cells by activating vacuolar type H+-ATPase (V-ATPase). We also show that H2S protects retinal neurons from light-induced degeneration. The excessive levels of light exposure deteriorated photoreceptor cells and increased the number of TUNEL- and 8-hydroxy-2?-deoxyguanosine (8-OHdG)-positive cells. Degeneration was greatly suppressed in the retina of mice administered with NaHS, a donor of H2S. The present study provides a new insight into the regulation of H2S production and the modulation of the retinal transmission by H2S. It also shows a cytoprotective effect of H2S on retinal neurons and provides a basis for the therapeutic target for retinal degeneration. PMID:21937432

  4. In situ and wide range quantification of hydrogen sulfide in industrial gases by means of photoacoustic spectroscopy

    NASA Astrophysics Data System (ADS)

    Szabó, A.; Mohácsi, Á.; Gulyás, G.; Bozóki, Z.; Szabó, G.

    2013-06-01

    This paper describes a photoacoustic spectroscopy-based detector of hydrogen sulfide (H2S) in biogas, natural gas and oil process technology. The instrument is capable of measuring H2S concentrations over four orders of magnitude (from a few ppm level up to several per cent) in changing gas mixtures. Problems caused by harsh industrial circumstances, contamination and widely varying composition of gases can be overcome by optimizing wavelength modulation, resonance frequency tracking and an easy-to-use method enabling in situ monitoring calibration. A diode laser emitting around 1.57 µm served as the excitation source; at this wavelength spectral overlap between H2S and CO2 is substantial. Spectral interference was eliminated by optimizing the amplitude of wavelength modulation; furthermore, a simplified calibration method was implemented taking advantage of a nearby absorption line of CO2 providing fast and economical measurements. Frequency dependence of the photoacoustic signal was determined by two methods to ensure accuracy. For 10 s integration time and 6800 Hz modulation frequency, the minimum detectable concentration was 6 ppm (3?).

  5. Monte Carlo Simulations Probing the Adsorptive Separation of Hydrogen Sulfide/Methane Mixtures Using All-Silica Zeolites.

    PubMed

    Shah, Mansi S; Tsapatsis, Michael; Siepmann, J Ilja

    2015-11-10

    Selective removal of hydrogen sulfide (H2S) from sour natural gas mixtures is one of the key challenges facing the natural gas industry. Adsorption and pervaporation processes utilizing nanoporous materials, such as zeolites, can be alternatives to highly energy-intensive amine-based absorption processes. In this work, the adsorption behavior of binary mixtures containing H2S and methane (CH4) in seven different all-silica zeolite frameworks (CHA, DDR, FER, IFR, MFI, MOR, and MWW) is investigated using Gibbs ensemble Monte Carlo simulations at two temperatures (298 and 343 K) and pressures ranging from 1 to 50 bar. The simulations demonstrate high selectivities that, with the exception of MOR, increase with increasing H2S concentration due to favorable sorbate-sorbate interactions. The simulations indicate significant inaccuracies of predictions using unary adsorption data and ideal adsorbed solution theory. In addition, the adsorption of binary H2S/H2O mixtures in MFI is considered to probe whether the presence of H2S induces coadsorption and reduces the hydrophobic character of all-silica zeolites. The simulations show preferential adsorption of H2S from moist gases with a selectivity of about 18 over H2O. PMID:26473306

  6. Formaldehyde impairs learning and memory involving the disturbance of hydrogen sulfide generation in the hippocampus of rats.

    PubMed

    Tang, Xiao-Qing; Zhuang, Yuan-Yuan; Zhang, Ping; Fang, Heng-Rong; Zhou, Cheng-Fang; Gu, Hong-Feng; Zhang, Hui; Wang, Chun-Yan

    2013-01-01

    Formaldehyde (FA), a well-known indoor and outdoor pollutant, has been implicated as the responsible agent in the development of neurocognitive disorders. Hydrogen sulfide (H(2)S), the third gasotransimitter, is an endogenous neuromodulator, which facilitates the induction of hippocampal long-term potentiation, involving the functions of learning and memory. In the present study, we analyzed the effects of intracerebroventricular injection of FA on the formation of learning and memory and the generation of endogenous H(2)S in the hippocampus of rats. We found that the intracerebroventricular injection of FA in rats impairs the function of learning and memory in the Morris water maze and novel object recognition test and increases the formation of apoptosis and lipid peroxidation in the hippocampus. We also showed that FA exposure inhibits the expression of cystathionine ?-synthase, the major enzyme responsible for endogenous H(2)S generation in hippocampus and decreases the production of endogenous H(2)S in hippocampus in rats. These results suggested that FA-disturbed generation of endogenous H(2)S in hippocampus leads to the oxidative stress-mediated neuron damage, ultimately impairing the function of learning and memory. Our findings imply that the disturbance of endogenous H(2)S generation in hippocampus is a potential contributing mechanism underling FA-caused learning and memory impairment. PMID:23108488

  7. A Novel Mechanism of Formaldehyde Neurotoxicity: Inhibition of Hydrogen Sulfide Generation by Promoting Overproduction of Nitric Oxide

    PubMed Central

    Zhou, Cheng-Fang; Zhuang, Yuan-Yuan; Zhang, Ping; Gu, Hong-Feng; Hu, Bi

    2013-01-01

    Background Formaldehyde (FA) induces neurotoxicity by overproduction of intracellular reactive oxygen species (ROS). Increasing studies have shown that hydrogen sulfide (H2S), an endogenous gastransmitter, protects nerve cells against oxidative stress by its antioxidant effect. It has been shown that overproduction of nitric oxide (NO) inhibits the activity of cystathionine-beta-synthase (CBS), the predominant H2S-generating enzyme in the central nervous system. Objective We hypothesize that FA-caused neurotoxicity involves the deficiency of this endogenous protective antioxidant gas, which results from excessive generation of NO. The aim of this study is to evaluate whether FA disturbs H2S synthesis in PC12 cells, and whether this disturbance is associated with overproduction of NO. Principal Findings We showed that exposure of PC12 cells to FA causes reduction of viability, inhibition of CBS expression, decrease of endogenous H2S production, and NO production. CBS silencing deteriorates FA-induced decreases in endogenous H2S generation, neurotoxicity, and intracellular ROS accumulation in PC12 cells; while ADMA, a specific inhibitor of NOS significantly attenuates FA-induced decreases in endogenous H2S generation, neurotoxicity, and intracellular ROS accumulation in PC12 cells. Conclusion/Significance Our data indicate that FA induces neurotoxicity by inhibiting the generation of H2S through excess of NO and suggest that strategies to manipulate endogenous H2S could open a suitable novel therapeutic avenue for FA-induced neurotoxicity. PMID:23359814

  8. 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%. PMID:25763810

  9. Multichannel RRKM-TST and direct-dynamics CVT study of the reaction of hydrogen sulfide with ozone.

    PubMed

    Mousavipour, S Hosein; Mortazavi, Maryam; Hematti, Omid

    2013-08-01

    The kinetics of the reaction of ozone with hydrogen sulfide was studied theoretically. High-level ab initio calculations were carried out to build the potential energy surface. The mechanism of the title reaction was found to be much more complicated than what is reported in the literature to date. According to our results, six different chemically activated intermediates are involved along the proposed mechanism on its lowest singlet potential energy surface that play an important role in the kinetics of this system. Multichannel RRKM-TST and CVT calculations have been carried out to compute the temperature dependence of the individual rate constants for different channels and also the overall rate constant for the consumption of the reactants. The major products are sulfur dioxide and water at lower temperatures, in good agreement with experimental reports, while at higher temperatures, formation of the other products like O2, H2SO, and radicals like cis/trans-HOSO, SH, HO3, and OH also become important. PMID:23837601

  10. Hydrogen sulfide induces hyperpolarization and decreases the exocytosis of secretory granules of rat GH3 pituitary tumor cells.

    PubMed

    Mustafina, Alsu N; Yakovlev, Aleksey V; Gaifullina, Aisylu Sh; Weiger, Thomas M; Hermann, Anton; Sitdikova, Guzel F

    2015-10-01

    The aim of the present study was to evaluate the effects of hydrogen sulfide (H2S) on the membrane potential, action potential discharge and exocytosis of secretory granules in neurosecretory pituitary tumor cells (GH3). The H2S donor - sodium hydrosulfide (NaHS) induced membrane hyperpolarization, followed by truncation of spontaneous electrical activity and decrease of the membrane resistance. The NaHS effect was dose-dependent with an EC50 of 152 ?M (equals effective H2S of 16-19 ?M). NaHS effects were not altered after inhibition of maxi conductance calcium-activated potassium (BK) channels by tetraethylammonium or paxilline, but were significantly reduced after inhibition or activation of ATP-dependent potassium channels (KATP) by glibenclamide or by diazoxide, respectively. In whole-cell recordings NaHS increased the amplitude of KATP currents, induced by hyperpolarizing pulses and subsequent application of glibenclamide decreased currents to control levels. Using the fluorescent dye FM 1-43 exocytosis of secretory granules was analyzed in basal and stimulated conditions (high K(+) external solution). Prior application of NaHS decreased the fluorescence of the cell membrane in both conditions which links with activation of KATP currents (basal secretion) and activation of KATP currents and BK-currents (stimulated exocytosis). We suggest that H2S induces hyperpolarization of GH3 cells by activation of KATP channels which results in a truncation of spontaneous action potentials and a decrease of hormone release. PMID:26319431

  11. Hydrogen Sulfide Alleviates Cadmium-Induced Cell Death through Restraining ROS Accumulation in Roots of Brassica rapa L. ssp. pekinensis

    PubMed Central

    2015-01-01

    Hydrogen sulfide (H2S) is a cell signal molecule produced endogenously and involved in regulation of tolerance to biotic and abiotic stress in plants. In this work, we used molecular biology, physiology, and histochemical methods to investigate the effects of H2S on cadmium- (Cd-) induced cell death in Chinese cabbage roots. Cd stress stimulated a rapid increase of endogenous H2S in roots. Additionally, root length was closely related to the cell death rate. Pretreatment with sodium hydrosulfide (NaHS), a H2S donor, alleviated the growth inhibition caused by Cd in roots—this effect was more pronounced at 5??M NaHS. Cd-induced cell death in roots was significantly reduced by 5??M NaHS treatment. Under Cd stress, activities of the antioxidant enzymes were significantly enhanced in roots. NaHS + Cd treatment made their activities increase further compared with Cd exposure alone. Enhanced antioxidant enzyme activity led to a decline in reactive oxygen species accumulation and lipid peroxidation. In contrast, these effects were reversed by hydroxylamine, a H2S inhibitor. These results suggested that H2S alleviated the cell death caused by Cd via upregulation of antioxidant enzyme activities to remove excessive reactive oxygen species and reduce cell oxidative damage. PMID:26078819

  12. [THE ROLE OF HYDROGEN SULFIDE IN VOLUME-DEPENDENT MECHANISMS OF REGULATION OF VASCULAR SMOOTH MUSCLE CELLS CONTRACTILE ACTIVITY].

    PubMed

    Smagliy, L V; Gusakova, S V; Birulina, Yu G; Kovalev, I V; Orlov, S N

    2015-04-01

    The hydrogen sulfide (H2S) influence on the contractile activity of vascular smooth muscle cells (SMC) was studied on endothelium-denuded aortic ring segments of male Wistar rats with method of mechanography. Contractions of SMS were induced by incubation in high potassium solution as well as in hyper-, hypo- and isosmotic solutions. 5-100 LM of H2S donor--sodium hydrosulfide (NaHS) increased mechanical tension of SMC precontracted with high potassium solution that was abolished by bumetanide--the inhibitor of Na+, K+, 2Cl(-) -cotransporter (NKCC), but 100-1000 microM of NaHS relaxed SMS. NaHS (10 microM) increased the amplitude of hyper- and isosmotic contraction, but not of hyposmotic contraction. NaHS (ImM) decreased the amplitude of hyper-, iso-, and hyposmotic contractions. The direct measurements of NKCC activity with radionuclide method showed an increase in NKCC activity under the action of 5-100 microM of NaHS. These findings suggest that low concentrations of H2S participate in the NKCC activation. This mechanism underlines constrictive action of H2S on smooth muscle cells. PMID:26336742

  13. Hydrogen sulfide induces neuroprotection against experimental stroke in rats by down-regulation of AQP4 via activating PKC.

    PubMed

    Wei, Xia; Zhang, Bing; Cheng, Long; Chi, Meng; Deng, Lin; Pan, Hong; Yao, Xuan; Wang, Guonian

    2015-10-01

    Hydrogen sulfide (H2S) is now known as an important neuromodulator in the central nervous system. The aim of the current study was to investigate whether exogenous H2S gas can attenuate brain edema induced by experimental stroke and to clarify the potential mechanisms. Rats underwent 2-h middle cerebral artery occlusion (MCAO) and received 40 ppm or 80 ppm H2S inhalation for 3h at the beginning of reperfusion. The effects of H2S were investigated by evaluating neurological function, infarct size, brain edema volume, and aquaporin4 (AQP4) protein expression at 24h after reperfusion. Moreover, to explore the possible mechanisms for the neuroprotective effects of H2S, protein kinase C (PKC) activity was detected and a PKC inhibitor, Go6983, was used via intracerebral ventricular injection. Our results showed that 40 ppm or 80 ppm H2S inhalation significantly reduced neurological deficits, infarct size, and brain edema after MCAO. The expression of AQP4 in the peri-infarct area of brain was also inhibited after inhalation of H2S. PKC was activated by H2S treatment and the PKC inhibitor attenuated the neuroprotection of H2S with an increased AQP4 expression at the same time. In conclusion, H2S inhalation attenuates brain edema, reduces infarct volume, and improves neurologic function in a rat experimental stroke model. The therapeutic benefits of H2S inhalation are associated with down-regulation of AQP4 expression via activating PKC. PMID:26168888

  14. On-site measurements of hydrogen sulfide and sulfur dioxide emissions from tidal flat sediments of Ariake Sea, Japan

    NASA Astrophysics Data System (ADS)

    Abul Kalam Azad, Md.; Ohira, Shin-Ichi; Oda, Mitsutomo; Toda, Kei

    Emission variability of hydrogen sulfide and sulfur dioxide from tidal flat sediments to atmosphere in Ariake Sea, Japan was studied using a diffusion scrubber-based portable instrument. Ariake Sea is a typical closed sea consisting of a huge marsh area along the coast. Seasonal, spatial and diurnal variability in emission rates were examined. In addition, depth profiles of the gas emissions were examined with the profiles of anions, heavy metals, water and organic contents. Unexpectedly, SO 2 emission was much higher than H 2S in all measurements, while an opposite emission trend was observed in diurnal and spatial patterns of H 2S and SO 2 emissions. The mechanisms of these gas emissions are discussed. Total sulfur fluxes to the atmosphere as H 2S and SO 2 during the study averaged 7.1 ?g S m -2 h -1 for muddy sites and 28 ?g S m -2 h -1 for sandy sites. Sulfur fluxes from tidal flats were comparable to the artificial sulfur emission from the neighboring towns.

  15. Hydrogen Sulfide Alleviates Cadmium-Induced Cell Death through Restraining ROS Accumulation in Roots of Brassica rapa L. ssp. pekinensis.

    PubMed

    Zhang, Liping; Pei, Yanxi; Wang, Hongjiao; Jin, Zhuping; Liu, Zhiqiang; Qiao, Zengjie; Fang, Huihui; Zhang, Yanjie

    2015-01-01

    Hydrogen sulfide (H2S) is a cell signal molecule produced endogenously and involved in regulation of tolerance to biotic and abiotic stress in plants. In this work, we used molecular biology, physiology, and histochemical methods to investigate the effects of H2S on cadmium- (Cd-) induced cell death in Chinese cabbage roots. Cd stress stimulated a rapid increase of endogenous H2S in roots. Additionally, root length was closely related to the cell death rate. Pretreatment with sodium hydrosulfide (NaHS), a H2S donor, alleviated the growth inhibition caused by Cd in roots-this effect was more pronounced at 5??M NaHS. Cd-induced cell death in roots was significantly reduced by 5??M NaHS treatment. Under Cd stress, activities of the antioxidant enzymes were significantly enhanced in roots. NaHS + Cd treatment made their activities increase further compared with Cd exposure alone. Enhanced antioxidant enzyme activity led to a decline in reactive oxygen species accumulation and lipid peroxidation. In contrast, these effects were reversed by hydroxylamine, a H2S inhibitor. These results suggested that H2S alleviated the cell death caused by Cd via upregulation of antioxidant enzyme activities to remove excessive reactive oxygen species and reduce cell oxidative damage. PMID:26078819

  16. Impacts of a massive release of methane and hydrogen sulfide on oxygen and ozone during the late Permian mass extinction

    NASA Astrophysics Data System (ADS)

    Kaiho, Kunio; Koga, Seizi

    2013-08-01

    The largest mass extinction of animals and plants in both the ocean and on land occurred in the late Permian (252 Ma), largely coinciding with the largest flood basalt volcanism event in Siberia and an oceanic anoxic/euxinic event. We investigated the impacts of a massive release of methane (CH4) from the Siberian igneous province and the ocean and/or hydrogen sulfide (H2S) from the euxinic ocean on oxygen and ozone using photochemical model calculations. Our calculations indicated that an approximate of 14% decrease in atmospheric O2 levels would have occurred in the case of a large combined CH4 and H2S flux to the atmosphere, whereas an approximate of 8 to 10% decrease would have occurred from the CH4 flux and oxidation of all H2S in the ocean. The slight decrease in atmospheric O2 levels may have contributed to the extinction event. We demonstrate for the first time that a massive release of CH4 from the Siberian igneous province and a coincident massive release of CH4 and H2S did not cause ozone collapse. A collapse of stratospheric ozone leading to an increase in UV is not supported by the maximum model input levels for CH4 and H2S. These conclusions on O2 and O3 are correspondent to every H2S release percentages from the ocean to the atmosphere.

  17. Batch slurry photocatalytic reactors for the generation of hydrogen from sulfide and sulfite waste streams under solar irradiation

    SciTech Connect

    Priya, R.; Kanmani, S.

    2009-10-15

    In this study, two solar slurry photocatalytic reactors i.e., batch reactor (BR) and batch recycle reactor with continuous supply of inert gas (BRRwCG) were developed for comparing their performance. The performance of the photocatalytic reactors were evaluated based on the generation of hydrogen (H{sub 2}) from water containing sodium sulfide (Na{sub 2}S) and sodium sulfite (Na{sub 2}SO{sub 3}) ions. The photoreactor of capacity 300 mL was developed with UV-vis transparent walls. The catalytic powders ((CdS/ZnS)/Ag{sub 2}S + (RuO{sub 2}/TiO{sub 2})) were kept suspended by means of magnetic stirrer in the BR and gas bubbling and recycling of the suspension in the BRRwCG. The rate constant was found to be 120.86 (einstein{sup -1}) for the BRRwCG whereas, for the BR it was found to be only 10.92 (einstein{sup -1}). The higher rate constant was due to the fast desorption of products and suppression of e{sup -}/h{sup +} recombination. (author)

  18. Visualization of in Vivo Hydrogen Sulfide Production by a Bioluminescence Probe in Cancer Cells and Nude Mice.

    PubMed

    Tian, Xiaodong; Li, Zhiyan; Lau, Choiwan; Lu, Jianzhong

    2015-11-17

    Hydrogen sulfide (H2S) has emerged as an exciting endogenous gasotransmitter in addition to nitric oxide and carbon monoxide. However, its precise measurement in living cells and animals remains a challenge. In this study, a novel bioluminescence H2S probe was designed and synthesized by modifying the 6'-amino group of d-aminoluciferin into a 6'-azido group, which was highly selective against other reactive sulfur, nitrogen, and oxygen species. Our H2S probe azidoluciferin sensitively reacted with H2S to release d-aminoluciferin with a strong bioluminescence signal. On the basis of its high selectivity and sensitivity, the H2S probe was used to detect H2S production in live cancer cells and nude mice. The bioluminescence signal decreased in mice treated with propargylglycine, an inhibitor of H2S, suggesting that our H2S probe can detect endogenous H2S in real time, in vivo. Overall, the excellent sensing properties of the probe combined with its bioimaging capability make it a useful tool to study H2S biological roles. PMID:26482557

  19. 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

  20. Hydrogen sulfide modulates actin-dependent auxin transport via regulating ABPs results in changing of root development in Arabidopsis

    PubMed Central

    Jia, Honglei; Hu, Yanfeng; Fan, Tingting; Li, Jisheng

    2015-01-01

    Hydrogen sulfide (H2S) signaling has been considered a key regulator of plant developmental processes and defenses. In this study, we demonstrate that high levels of H2S inhibit auxin transport and lead to alterations in root system development. H2S inhibits auxin transport by altering the polar subcellular distribution of PIN proteins. The vesicle trafficking and distribution of the PIN proteins are an actin-dependent process. H2S changes the expression of several actin-binding proteins (ABPs) and decreases the occupancy percentage of F-actin bundles in the Arabidopsis roots. We observed the effects of H2S on F-actin in T-DNA insertion mutants of cpa, cpb and prf3, indicating that the effects of H2S on F-actin are partially removed in the mutant plants. Thus, these data imply that the ABPs act as downstream effectors of the H2S signal and thereby regulate the assembly and depolymerization of F-actin in root cells. Taken together, our data suggest that the existence of a tightly regulated intertwined signaling network between auxin, H2S and actin that controls root system development. In the proposed process, H2S plays an important role in modulating auxin transport by an actin-dependent method, which results in alterations in root development in Arabidopsis. PMID:25652660

  1. Hydrogen sulfide alleviates the aluminum-induced changes in Brassica napus as revealed by physiochemical and ultrastructural study of plant.

    PubMed

    Ali, Basharat; Qian, Ping; Sun, Rui; Farooq, Muhammad A; Gill, Rafaqat A; Wang, Jian; Azam, Muhammad; Zhou, Weijun

    2015-02-01

    In the present study, ameliorating role of hydrogen sulfide (H2S) in oilseed rape (Brassica napus L.) was studied with or without application of H2S donor sodium hydrosulfide (NaHS) (0.3 mM) in hydroponic conditions under three levels (0, 0.1 and 0.3 mM) of aluminum (Al). Results showed that addition of H2S significantly improved the plant growth, photosynthetic gas exchange, and nutrients concentration in the leaves and roots of B. napus plants under Al stress. Exogenously applied H2S significantly lowered the Al concentration in different plant parts, and reduced the production of malondialdehyde and reactive oxygen species by improving antioxidant enzyme activities in the leaves and roots under Al stress. Moreover, the present study indicated that exogenously applied H2S improved the cell structure and displayed clean mesophyll and root tip cells. The chloroplast with well-developed thylakoid membranes could be observed in the micrographs. Under the combined application of H2S and Al, a number of modifications could be observed in root tip cell, such as mitochondria, endoplasmic reticulum, and golgi bodies. Thus, it can be concluded that exogenous application of H2S under Al stress improved the plant growth, photosynthetic parameters, elements concentration, and biochemical and ultrastructural changes in leaves and roots of B. napus. PMID:25231737

  2. A Gas Chromatography-Mass Spectrometry Based Study on Urine Metabolomics in Rats Chronically Poisoned with Hydrogen Sulfide

    PubMed Central

    Deng, Mingjie; Zhang, Meiling; Sun, Fa; Ma, Jianshe; Hu, Lufeng; Yang, Xuezhi; Lin, Guanyang; Wang, Xianqin

    2015-01-01

    Gas chromatography-mass spectrometry (GS-MS) in combination with multivariate statistical analysis was applied to explore the metabolic variability in urine of chronically hydrogen sulfide- (H2S-) poisoned rats relative to control ones. The changes in endogenous metabolites were studied by partial least squares-discriminate analysis (PLS-DA) and independent-samples t-test. The metabolic patterns of H2S-poisoned group are separated from the control, suggesting that the metabolic profiles of H2S-poisoned rats were markedly different from the controls. Moreover, compared to the control group, the level of alanine, d-ribose, tetradecanoic acid, L-aspartic acid, pentanedioic acid, cholesterol, acetate, and oleic acid in rat urine of the poisoning group decreased, while the level of glycine, d-mannose, arabinofuranose, and propanoic acid increased. These metabolites are related to amino acid metabolism as well as energy and lipid metabolism in vivo. Studying metabolomics using GC-MS allows for a comprehensive overview of the metabolism of the living body. This technique can be employed to decipher the mechanism of chronic H2S poisoning, thus promoting the use of metabolomics in clinical toxicology. PMID:25954748

  3. Hydrogen sulfide restores a normal morphological phenotype in Werner syndrome fibroblasts, attenuates oxidative damage and modulates mTOR pathway.

    PubMed

    Talaei, F; van Praag, V M; Henning, R H

    2013-08-01

    Werner syndrome (WS) protein is involved in DNA repair and its truncation causes Werner syndrome, an autosomal recessive genetic disorder with a premature aging phenotype. WRN protein mutation is currently known as the primary cause of WS. In cultured WS fibroblasts, we found an increase in cytosolic aggregates and hypothesized that the phenotype is indirectly related to an excess activation of the mTOR (mammalian target of rapamycin) pathway, leading to the formation of protein aggregates in the cytosol with increasing levels of oxidative stress. As we found that the expression levels of the two main H2S producing enzymes, cystathionine ? synthase and cystathionine ? lyase, were lower in WS cells compared to normal, we investigated the effect of administration of H2S as NaHS (50?M). NaHS treatment blocked mTOR activity, abrogated protein aggregation and normalized the phenotype of WS cells. Similar results were obtained by treatment with the mTOR inhibitor rapamycin. This is the first report suggesting that hydrogen sulfide administered as NaHS restores proteostasis and cellular morphological phenotype of WS cells and hints to the importance of transsulfuration pathway in WS. PMID:23702336

  4. Kinetics of hydrolysis and oxidation of carbon disulfide by hydrogen peroxide in alkaline medium and application to carbonyl sulfide

    SciTech Connect

    Adewuyi, Y.G.; Carmichael, G.R.

    1987-02-01

    Kinetic studies of the oxidation of carbon disulfide by hydrogen peroxide in alkaline medium were made spectrophotometrically. The reaction of CS/sub 2/ with OH/sup -/ ion was found to be rate controlling and proceeded by the formation of a dithiocarbonate complex. The major reaction product was sulfate with sulfur occurring as colloidal suspensions only at pH values less than 8. The formation of sulfate increased exponentially with time and was also found to be dependent on the rate of hydrolysis of CS/sub 2/. In addition, the production of sulfate showed large induction periods, suggesting either a complex mechanism or formation by secondary reactions. The results obtained for carbon disulfide were extended to carbonyl sulfide (OCS) oxidation in alkaline solutions. The removal of OCS (acid gas) from mixtures of gases by alkaline liquid absorbents (e.g. NaOH) and oxidation of subsequent solutions to sulfate is an important industrial practice. 42 references, 14 figures, 2 tables.

  5. Hydrogen sulfide removal by Thiobacillus thioparus bacteria on seashell bed biofilters.

    PubMed

    Massoudinejad, M R; Manshouri, M; Khatibi, M; Adibzadeh, A; Amini, H

    2008-03-15

    The aim of this research is to achieve an efficient and cheap methods to remove H2S from the factories emissions. Four serial cylinders are designed, 40 cm in height and 15 cm in diameter each. They are filled with bivalve seashells with 63% porosity which contains Thiobacillus thioparus bacteria to the maximum height of 27.5 cm. By mixing phosphoric acid and sodium sulfide, H2S gas is released and its concentration is measured as mg m(-3) before injecting into the cylinders. A permanent measuring instrument is equipped to control the gas coming out of the cylinders. In order to prevent the outdoor environment from pollution, first the gas is sent through two activated carbon columns and then sent through a ferrous chloride scrubber. Finally it is burnt directly by flames. There were 550 sample readings in 15 weeks. The changes in the discharge of the air which carries the gas are considered between 1-12 L min(-1) and the concentration of the influent pollutant is considered between 1-140 mg m(-3). Also the humidity in the atmosphere is fixed between 77-93% and the optimum temperature required for growing of the microorganisms is retained between 20.5-30 degrees C. After feeding the system for three weeks the efficiency started to increase so that by the end of the final week of this research the efficiency reached to 90% with the discharge of 6 L min(-1) of the carrier gas. The results achieved from this research show that because of not using Filamentous bacteria, clogging did not occur in the biological system in biofilters. The amount of head loss in cylinder was only 2 mm water and during this research, head loss was the same due to unclogging of filter. On the other hand the traditional methods are expensive in terms of using chemicals, carbon recycling and using fuel and etc. Therefore researchers have started new studies in this field. The above mentioned method, according to high efficiency, inexpensiveness and easiness of control and maintenance is considered one of the best methods. PMID:18814657

  6. In situ optimization of pH for parts-per-billion electrochemical detection of dissolved hydrogen sulfide using boron doped diamond flow electrodes.

    PubMed

    Bitziou, Eleni; Joseph, Maxim B; Read, Tania L; Palmer, Nicola; Mollart, Tim; Newton, Mark E; Macpherson, Julie V

    2014-11-01

    A novel electrochemical approach to the direct detection of hydrogen sulfide (H2S), in aqueous solutions, covering a wide pH range (acid to alkali), is described. In brief, a dual band electrode device is employed, in a hydrodynamic flow cell, where the upstream electrode is used to controllably generate hydroxide ions (OH(-)), which flood the downstream detector electrode and provide the correct pH environment for complete conversion of H2S to the electrochemically detectable, sulfide (HS(-)) ion. All-diamond, coplanar conducting diamond band electrodes, insulated in diamond, were used due to their exceptional stability and robustness when applying extreme potentials, essential attributes for both local OH(-) generation via the reduction of water, and for in situ cleaning of the electrode, post oxidation of sulfide. Using a galvanostatic approach, it was demonstrated the pH locally could be modified by over five pH units, depending on the initial pH of the mobile phase and the applied current. Electrochemical detection limits of 13.6 ppb sulfide were achieved using flow injection amperometry. This approach which offers local control of the pH of the detector electrode in a solution, which is far from ideal for optimized detection of the analyte of interest, enhances the capabilities of online electrochemical detection systems. PMID:25263331

  7. Highly Efficient Photocatalytic Hydrogen Production of Flower-like Cadmium Sulfide Decorated by Histidine

    NASA Astrophysics Data System (ADS)

    Wang, Qizhao; Lian, Juhong; Li, Jiajia; Wang, Rongfang; Huang, Haohao; Su, Bitao; Lei, Ziqiang

    2015-09-01

    Morphology-controlled synthesis of CdS can significantly enhance the efficiency of its photocatalytic hydrogen production. In this study, a novel three-dimensional (3D) flower-like CdS is synthesized via a facile template-free hydrothermal process using Cd(NO3)2•4H2O and thiourea as precursors and L-Histidine as a chelating agent. The morphology, crystal phase, and photoelectrochemical performance of the flower-like CdS and pure CdS nanocrystals are carefully investigated via various characterizations. Superior photocatalytic activity relative to that of pure CdS is observed on the flower-like CdS photocatalyst under visible light irradiation, which is nearly 13 times of pure CdS. On the basis of the results from SEM studies and our analysis, a growth mechanism of flower-like CdS is proposed by capturing the shape evolution. The imidazole ring of L-Histidine captures the Cd ions from the solution, and prevents the growth of the CdS nanoparticles. Furthermore, the photocatalytic contrast experiments illustrate that the as-synthesized flower-like CdS with L-Histidine is more stable than CdS without L-Histidine in the hydrogen generation.

  8. Highly Efficient Photocatalytic Hydrogen Production of Flower-like Cadmium Sulfide Decorated by Histidine

    PubMed Central

    Wang, Qizhao; Lian, Juhong; Li, Jiajia; Wang, Rongfang; Huang, Haohao; Su, Bitao; Lei, Ziqiang

    2015-01-01

    Morphology-controlled synthesis of CdS can significantly enhance the efficiency of its photocatalytic hydrogen production. In this study, a novel three-dimensional (3D) flower-like CdS is synthesized via a facile template-free hydrothermal process using Cd(NO3)2•4H2O and thiourea as precursors and L-Histidine as a chelating agent. The morphology, crystal phase, and photoelectrochemical performance of the flower-like CdS and pure CdS nanocrystals are carefully investigated via various characterizations. Superior photocatalytic activity relative to that of pure CdS is observed on the flower-like CdS photocatalyst under visible light irradiation, which is nearly 13 times of pure CdS. On the basis of the results from SEM studies and our analysis, a growth mechanism of flower-like CdS is proposed by capturing the shape evolution. The imidazole ring of L-Histidine captures the Cd ions from the solution, and prevents the growth of the CdS nanoparticles. Furthermore, the photocatalytic contrast experiments illustrate that the as-synthesized flower-like CdS with L-Histidine is more stable than CdS without L-Histidine in the hydrogen generation. PMID:26337119

  9. Apparatus for use in sulfide chemiluminescence detection

    DOEpatents

    Spurlin, Stanford R. (Ames, IA); Yeung, Edward S. (Ames, IA)

    1987-01-01

    A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

  10. Apparatus for use in sulfide chemiluminescence detection

    DOEpatents

    Spurlin, S.R.; Yeung, E.S.

    1987-01-06

    A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

  11. Effect of hydrogen sulfide on chemical looping combustion of coal-derived synthesis gas over bentonite-supported metal-oxide oxygen carriers

    SciTech Connect

    Tian, H.J.; Simonyi, T.; Poston, J.; Siriwardane, R.

    2009-09-15

    The effect of hydrogen sulfide (H{sub 2}S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxides - such as iron oxide, nickel oxide, manganese oxide, and copper oxide - was investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H{sub 2}S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H{sub 2}S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H{sub 2}S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation decreased in the presence of H{sub 2}S for all four metal oxides.

  12. Effect of hydrogen sulfide on chemical looping of coal-derived synthesis gas over bentonite-supported metal---oxide oxygen carriers

    SciTech Connect

    Tian, H.; Simonyi, T.; Poston, J.; Siriwardane, R.

    2009-01-01

    The effect of hydrogen sulfide (H2S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxidesssuch as iron oxide, nickel oxide, manganese oxide, and copper oxideswas investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H2S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H2S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H2S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation decreased in the presence of H2S for all four metal oxides.

  13. Hydrogen sulfide modulates cadmium-induced physiological and biochemical responses to alleviate cadmium toxicity in rice

    PubMed Central

    Mostofa, Mohammad Golam; Rahman, Anisur; Ansary, Md. Mesbah Uddin; Watanabe, Ayaka; Fujita, Masayuki; Phan Tran, Lam-Son

    2015-01-01

    We investigated the physiological and biochemical mechanisms by which H2S mitigates the cadmium stress in rice. Results revealed that cadmium exposure resulted in growth inhibition and biomass reduction, which is correlated with the increased uptake of cadmium and depletion of the photosynthetic pigments, leaf water contents, essential minerals, water-soluble proteins, and enzymatic and non-enzymatic antioxidants. Excessive cadmium also potentiated its toxicity by inducing oxidative stress, as evidenced by increased levels of superoxide, hydrogen peroxide, methylglyoxal and malondialdehyde. However, elevating endogenous H2S level improved physiological and biochemical attributes, which was clearly observed in the growth and phenotypes of H2S-treated rice plants under cadmium stress. H2S reduced cadmium-induced oxidative stress, particularly by enhancing redox status and the activities of reactive oxygen species and methylglyoxal detoxifying enzymes. Notably, H2S maintained cadmium and mineral homeostases in roots and leaves of cadmium-stressed plants. By contrast, adding H2S-scavenger hypotaurine abolished the beneficial effect of H2S, further strengthening the clear role of H2S in alleviating cadmium toxicity in rice. Collectively, our findings provide an insight into H2S-induced protective mechanisms of rice exposed to cadmium stress, thus proposing H2S as a potential candidate for managing toxicity of cadmium, and perhaps other heavy metals, in rice and other crops. PMID:26361343

  14. Hydrogen sulfide modulates cadmium-induced physiological and biochemical responses to alleviate cadmium toxicity in rice.

    PubMed

    Mostofa, Mohammad Golam; Rahman, Anisur; Ansary, Md Mesbah Uddin; Watanabe, Ayaka; Fujita, Masayuki; Tran, Lam-Son Phan

    2015-01-01

    We investigated the physiological and biochemical mechanisms by which H2S mitigates the cadmium stress in rice. Results revealed that cadmium exposure resulted in growth inhibition and biomass reduction, which is correlated with the increased uptake of cadmium and depletion of the photosynthetic pigments, leaf water contents, essential minerals, water-soluble proteins, and enzymatic and non-enzymatic antioxidants. Excessive cadmium also potentiated its toxicity by inducing oxidative stress, as evidenced by increased levels of superoxide, hydrogen peroxide, methylglyoxal and malondialdehyde. However, elevating endogenous H2S level improved physiological and biochemical attributes, which was clearly observed in the growth and phenotypes of H2S-treated rice plants under cadmium stress. H2S reduced cadmium-induced oxidative stress, particularly by enhancing redox status and the activities of reactive oxygen species and methylglyoxal detoxifying enzymes. Notably, H2S maintained cadmium and mineral homeostases in roots and leaves of cadmium-stressed plants. By contrast, adding H2S-scavenger hypotaurine abolished the beneficial effect of H2S, further strengthening the clear role of H2S in alleviating cadmium toxicity in rice. Collectively, our findings provide an insight into H2S-induced protective mechanisms of rice exposed to cadmium stress, thus proposing H2S as a potential candidate for managing toxicity of cadmium, and perhaps other heavy metals, in rice and other crops. PMID:26361343

  15. Facile synthesis of titania nanowires via a hot filament method and conductometric measurement of their response to hydrogen sulfide gas.

    PubMed

    Munz, Martin; Langridge, Mark T; Devarepally, Kishore K; Cox, David C; Patel, Pravin; Martin, Nicholas A; Vargha, Gergely; Stolojan, Vlad; White, Sam; Curry, Richard J

    2013-02-01

    Titania nanostructures are of increasing interest for a variety of applications, including photovoltaics, water splitting, and chemical sensing. Because of the photocatalytical properties of TiO?, chemical processes that occur at its surface can be exploited for highly efficient nanodevices. A facile and fast synthesis route has been explored that is free of catalysts or templates. An environmental scanning electron microscopy (ESEM) system was employed to grow titania nanowires (NWs) in a water vapor atmosphere (?1 mbar) and to monitor the growth in situ. In addition, the growth process was also demonstrated using a simple vacuum chamber. In both processes, a titanium filament was heated via the Joule effect and NWs were found to grow on its surface, as a result of thermal oxidation processes. A variety of nanostructures were observed across the filament, with morphologies changing with the wire temperature from the center to the end points. The longest NWs were obtained for temperatures between ?730 °C and 810 °C. Typically, they have an approximate thickness of ?300 nm and lengths of up to a few micrometers. Cross sections prepared by focused-ion-beam milling revealed the presence of a porous layer beneath the NW clusters. This indicates that the growth of NWs is driven by oxidation-induced stresses in the subsurface region of the Ti filament and by enhanced diffusion along grain boundaries. To demonstrate the potential of titania NWs grown via the hot filament method, single NW devices were fabricated and used for conductometric sensing of hydrogen sulfide (H?S) gas. The NW electric resistance was found to decrease in the presence of H?S. Its variation can be explained in terms of the surface depletion model. PMID:23327919

  16. Involvement of Potassium Channels and Calcium-Independent Mechanisms in Hydrogen Sulfide-Induced Relaxation of Rat Mesenteric Small Arteries.

    PubMed

    Hedegaard, Elise R; Gouliaev, Anja; Winther, Anna K; Arcanjo, Daniel D R; Aalling, Mathilde; Renaltan, Nirthika S; Wood, Mark E; Whiteman, Matthew; Skovgaard, Nini; Simonsen, Ulf

    2016-01-01

    Endogenous hydrogen sulfide (H2S) is involved in the regulation of vascular tone. We hypothesized that the lowering of calcium and opening of potassium (K) channels as well as calcium-independent mechanisms are involved in H2S-induced relaxation in rat mesenteric small arteries. Amperometric recordings revealed that free [H2S] after addition to closed tubes of sodium hydrosulfide (NaHS), Na2S, and GYY4137 [P-(4-methoxyphenyl)-P-4-morpholinyl-phosphinodithioic acid] were, respectively, 14%, 17%, and 1% of added amount. The compounds caused equipotent relaxations in isometric myographs, but based on the measured free [H2S], GYY4137 caused more relaxation in relation to released free H2S than NaHS and Na2S in rat mesenteric small arteries. Simultaneous measurements of [H2S] and tension showed that 15 µM of free H2S caused 61% relaxation in superior mesenteric arteries. Simultaneous measurements of smooth muscle calcium and tension revealed that NaHS lowered calcium and caused relaxation of NE-contracted arteries, while high extracellular potassium reduced NaHS relaxation without corresponding calcium changes. In NE-contracted arteries, NaHS (1 mM) lowered the phosphorylation of myosin light chain, while phosphorylation of myosin phosphatase target subunit 1 remained unchanged. Protein kinase A and G, inhibitors of guanylate cyclase, failed to reduce NaHS relaxation, whereas blockers of voltage-gated KV7 channels inhibited NaHS relaxation, and blockers of mitochondrial complex I and III abolished NaHS relaxation. Our findings suggest that low micromolar concentrations of free H2S open K channels followed by lowering of smooth muscle calcium, and by another mechanism involving mitochondrial complex I and III leads to uncoupling of force, and hence vasodilation. PMID:26493746

  17. Hydrogen sulfide-induced itch requires activation of Cav3.2 T-type calcium channel in mice.

    PubMed

    Wang, Xue-Long; Tian, Bin; Huang, Ya; Peng, Xiao-Yan; Chen, Li-Hua; Li, Jun-Cheng; Liu, Tong

    2015-01-01

    The contributions of gasotransmitters to itch sensation are largely unknown. In this study, we aimed to investigate the roles of hydrogen sulfide (H2S), a ubiquitous gasotransmitter, in itch signaling. We found that intradermal injection of H2S donors NaHS or Na2S, but not GYY4137 (a slow-releasing H2S donor), dose-dependently induced scratching behavior in a ?-opioid receptor-dependent and histamine-independent manner in mice. Interestingly, NaHS induced itch via unique mechanisms that involved capsaicin-insensitive A-fibers, but not TRPV1-expressing C-fibers that are traditionally considered for mediating itch, revealed by depletion of TRPV1-expressing C-fibers by systemic resiniferatoxin treatment. Moreover, local application of capsaizapine (TRPV1 blocker) or HC-030031 (TRPA1 blocker) had no effects on NaHS-evoked scratching. Strikingly, pharmacological blockade and silencing of Cav3.2 T-type calcium channel by mibefradil, ascorbic acid, zinc chloride or Cav3.2 siRNA dramatically decreased NaHS-evoked scratching. NaHS induced robust alloknesis (touch-evoked itch), which was inhibited by T-type calcium channels blocker mibefradil. Compound 48/80-induced itch was enhanced by an endogenous precursor of H2S (L-cysteine) but attenuated by inhibitors of H2S-producing enzymes cystathionine ?-lyase and cystathionine ?-synthase. These results indicated that H2S, as a novel nonhistaminergic itch mediator, may activates Cav3.2 T-type calcium channel, probably located at A-fibers, to induce scratching and alloknesis in mice. PMID:26602811

  18. Monitoring of hydrogen sulfide via substrate-integrated hollow waveguide mid-infrared sensors in real-time.

    PubMed

    Petruci, Joăo Flávio da Silveira; Fortes, Paula Regina; Kokoric, Vjekoslav; Wilk, Andreas; Raimundo, Ivo Milton; Cardoso, Arnaldo Alves; Mizaikoff, Boris

    2014-01-01

    Hydrogen sulfide is a highly corrosive, harmful, and toxic gas produced under anaerobic conditions within industrial processes or in natural environments, and plays an important role in the sulfur cycle. According to the U.S. Occupational Safety and Health Administration (OSHA), the permissible exposure limit (during 8 hours) is 10 ppm. Concentrations of 20 ppm are the threshold for critical health issues. In workplace environments with human subjects frequently exposed to H2S, e.g., during petroleum extraction and refining, real-time monitoring of exposure levels is mandatory. Sensors based on electrochemical measurement principles, semiconducting metal-oxides, taking advantage of their optical properties, have been described for H2S monitoring. However, extended response times, limited selectivity, and bulkiness of the instrumentation are common disadvantages of the sensing techniques reported to date. Here, we describe for the first time usage of a new generation of compact gas cells, i.e., so-called substrate-integrated hollow waveguides (iHWGs), combined with a compact Fourier transform infrared (FTIR) spectrometer for advanced gas sensing of H2S. The principle of detection is based on the immediate UV-assisted conversion of the rather weak IR-absorber H2S into much more pronounced and distinctively responding SO2. A calibration was established in the range of 10-100 ppm with a limit of detection (LOD) at 3 ppm, which is suitable for occupational health monitoring purposes. The developed sensing scheme provides an analytical response time of less than 60 seconds. Considering the substantial potential for miniaturization using e.g., a dedicated quantum cascade laser (QCL) in lieu of the FTIR spectrometer, the developed sensing approach may be evolved into a hand-held instrument, which may be tailored to a variety of applications ranging from environmental monitoring to workplace safety surveillance, process analysis and clinical diagnostics, e.g., breath analysis. PMID:24256718

  19. Fluorescent probes for hydrogen sulfide (H2S) and sulfane sulfur and their applications to biological studies.

    PubMed

    Shimamoto, Kazuhito; Hanaoka, Kenjiro

    2015-04-30

    Hydrogen sulfide (H2S), a toxic gas with the smell of rotten eggs, plays key roles in many physiological processes, including relaxation of vascular smooth muscles, mediation of neurotransmission, inhibition of insulin signaling, and regulation of inflammation. The most commonly used methods or detecting H2S are the methylene blue method and the electrode method, but these methods require destructive sampling, e.g., homogenization of biological samples. On the other hand, the fluorescence detection method has been widely used in biological studies to study the physiological roles of H2S, because this technology provides real-time, easy-to-use, nondestructive detection in live cells or tissues. Many selective fluorescent probes for H2S have been reported. Sulfane sulfur compounds contain divalent sulfur atoms bonded to other sulfur atom(s), as in persulfides (R-S-SH) and polysulfides (R-S-Sn-S-R). They are currently attracting increasing interest because one of the mechanisms of activity regulation of proteins by H2S is sulfhydration of cysteine residues (RSH ? RSSH). Since H2S and sulfane sulfur are redox partners, they are very likely to coexist in biological systems, and from a reactivity point-of-view, sulfane sulfur seems likely to be much more effective than H2S in S-sulfhydration. Therefore, sulfane sulfur may be involved in mediating at least some of the biological activities of H2S. In this review, we summarize recent work on fluorescent probes selective for H2S and/or sulfane sulfur, and we briefly review their applications to biological studies. PMID:25461270

  20. Regulation of the Heme Oxygenase-1/carbon monoxide system by hydrogen sulfide in murine coxsackievirus B3-induced myocarditis.

    PubMed

    Zhang, S; Wu, T; Xia, T; Rong, X; Wu, T; Chu, M; Wu, R

    2015-01-01

    To explore the impact of hydrogen sulfide (H2S) on the heme oxygenase—1 (HO—1)/carbon monoxide (CO) system in coxsackie virus B3 (CVB3)—induced myocarditis. A total of 80 Balb/c mice were divided randomly into four groups designated N, C, P and S. Group N served as the negative control while groups C, P, and S were infected with CVB3 to induce myocarditis. Group P was additionally treated with DL—propargylglycine (PAG) to inhibit the generation of H2S while Group S was treated with NaHS, an H2S donor. Ten days after infection, heart sections were scored for histopathology. We also measured carboxyhemoglobin (COHb) levels in the blood and HO—1 expression by immunohistochemistry. 1. Each CVB3—infected group (C, P, and S) exhibited increased pathology, COHb levels, and HO—1 expression compared to uninfected controls. 2. Regarding histopathology, the score of group P was worse, while that of group S was better, than that of group C. 3. The P group COHb level was lower than group C, while the S group COHb level was higher than group C. 4. Positive HO—1 expression was seen in group C with reduced expression in group P and increased expression in group S. 5. A positive correlation was observed between the COHb concentration and HO—1expression; alternatively, a negative correlation was found between the histopathologic scores and both the concentration of COHb and the expression level of HO—1. Modulation of H2S can play a regulatory role in the pathogenesis of VMC by impacting the HO—1/CO pathway. PMID:26025406

  1. MPST but not CSE is the primary regulator of hydrogen sulfide production and function in the coronary artery.

    PubMed

    Kuo, Maggie M; Kim, Dae Hee; Jandu, Sandeep; Bergman, Yehudit; Tan, Siqi; Wang, Huilei; Pandey, Deepesh R; Abraham, Theodore P; Shoukas, Artin A; Berkowitz, Dan E; Santhanam, Lakshmi

    2016-01-01

    Hydrogen sulfide (H2S) has emerged as an important gasotransmitter in the vasculature. In this study, we tested the hypothesis that H2S contributes to coronary vasoregulation and evaluated the physiological relevance of two sources of H2S, namely, cystathionine-?-lyase (CSE) and 3-mercaptypyruvate sulfertransferase (MPST). MPST was detected in human coronary artery endothelial cells as well as rat and mouse coronary artery; CSE was not detected in the coronary vasculature. Rat coronary artery homogenates produced H2S through the MPST pathway but not the CSE pathway in vitro. In vivo coronary vasorelaxation response was similar in CSE knockout mice, wild-type mice (WT), and WT mice treated with the CSE inhibitor propargylglycine, suggesting that CSE-produced H2S does not have a significant role in coronary vasoregulation in vivo. Ex vivo, the MPST substrate 3-mercaptopyruvate (3-MP) and H2S donor sodium hydrosulfide (NaHS) elicited similar coronary vasoreactivity responses. Pyruvate did not have any effects on vasoreactivity. The vasoactive effect of H2S appeared to be nitric oxide (NO) dependent: H2S induced coronary vasoconstriction in the presence of NO and vasorelaxation in its absence. Maximal endothelial-dependent relaxation was intact after 3-MP and NaHS induced an increase in preconstriction tone, suggesting that endothelial NO synthase activity was not significantly inhibited. In vitro, H2S reacted with NO, which may, in part explain the vasoconstrictive effects of 3-MP and NaHS. Taken together, these data show that MPST rather than CSE generates H2S in coronary artery, mediating its effects through direct modulation of NO. This has important implications for H2S-based therapy in healthy and diseased coronary arteries. PMID:26519030

  2. A comparative evaluation of dried activated sludge and mixed dried activated sludge with rice husk silica to remove hydrogen sulfide

    PubMed Central

    2013-01-01

    The aim of this study was to investigate the effectiveness of dried activated sludge (DAS) and mixed dried activated sludge with rice husk silica (DAS & RHS) for removal of hydrogen sulfide (H2S). Two laboratory-scale filter columns (packed one litter) were operated. Both systems were operated under different conditions of two parameters, namely different inlet gas concentrations and different inlet flow rates. The DAS & RHS packed filter showed more than 99.96% removal efficiency (RE) with empty bed residence time (EBRT) of 45 to 90 s and 300 mg/L inlet concentration of H2S. However, the RE decreased to 96.87% with the EBRT of 30 s. In the same condition, the DAS packed filter showed 99.37% RE. Nonetheless, the RE was shown to have dropped to 82.09% with the EBRT of 30 s. The maximum elimination capacity (EC) was obtained in the DAS & RHS packed filter up to 52.32 g/m3h, with the RE of 96.87% and H2S mass loading rate of 54 g/m3h. The maximum EC in the DAS packed filter was obtained up to 44.33 g/m3h with the RE of 82.09% and the H2S mass loading rate of 54 g/m3h. After 53 days of operating time and 54 g/m3h of loading rates, the maximum pressure drop reached to 3.0 and 8.0 (mm H2O) for the DAS & RHS packed and DAS packed filters, respectively. Based on the findings of this study, the DAS & RHS could be considered as a more suitable packing material to remove H2S. PMID:23497048

  3. Hydrogen Sulfide Inhibits Formaldehyde-Induced Endoplasmic Reticulum Stress in PC12 Cells by Upregulation of SIRT-1

    PubMed Central

    Zhang, Ping; Chen, Li-Xun; Wang, Li; Xie, Ming; Wang, Chun-Yan; Tang, Xiao-Qing

    2014-01-01

    Background Formaldehyde (FA), a well-known environmental pollutant, has been classified as a neurotoxic molecule. Our recent data demonstrate that hydrogen sulfide (H2S), the third gaseous transmitter, has a protective effect on the neurotoxicity of FA. However, the exact mechanisms underlying this protection remain largely unknown. Endoplasmic reticulum (ER) stress has been implicated in the neurotoxicity of FA. Silent mating type information regulator 2 homolog 1 (SIRT-1), a histone deacetylases, has various biological activities, including the extension of lifespan, the modulation of ER stress, and the neuroprotective action. Objective We hypothesize that the protection of H2S against FA-induced neurotoxicity involves in inhibiting ER stress by upregulation of SIRT-1. The present study attempted to investigate the protective effect of H2S on FA-induced ER stress in PC12 cells and the contribution of SIRT-1 to the protection of H2S against FA-induced injuries, including ER stress, cytotoxicity and apoptosis. Principal Findings We found that exogenous application of sodium hydrosulfide (NaHS; an H2S donor) significantly attenuated FA-induced ER stress responses, including the upregulated levels of glucose-regulated protein 78, C/EBP homologous protein, and cleaved caspase-12 expression. We showed that NaHS upregulates the expression of SIRT-1 in PC12 cells. Moreover, the protective effects of H2S on FA-elicited ER stress, cytotoxicity and apoptosis were reversed by Sirtinol, a specific inhibitor of SIRT-1. Conclusion/Significance These data indicate that H2S exerts its protection against the neurotoxicity of FA through overcoming ER stress via upregulation of SIRT-1. Our findings provide novel insights into the protective mechanisms of H2S against FA-induced neurotoxicity. PMID:24587076

  4. Hydrogen sulfide delays nicotinamide-induced premature senescence via upregulation of SIRT1 in human umbilical vein endothelial cells.

    PubMed

    Zheng, Meihua; Qiao, Weili; Cui, Jie; Liu, Lei; Liu, Hong; Wang, Zhirong; Yan, Changdong

    2014-08-01

    The present study was designed to investigate the effect of hydrogen sulfide on cellular senescence of human umbilical vascular endothelial cells (HUVECs CC-2517) and its underlying mechanism. The premature senescence-like phenotype HUVECs (the fourth passage) was induced by treatment with nicotinamide (NAM, an inhibitor of SIRT1, 5 mmol/L, 12 h). Cells were cultured with sodium hydrosulfide (NaHS, 12.5, 25, 50 and 100 ?mol/L) for 48 h in premature senescence-like phenotype HUVECs. The fourth passage of HUVECs was considered as young group. Senescence-associated (SA)-?-galactosidase activities were detected to evaluate cell senescence, and the expression of SA heterochromatin foci (SAHF) was visualized by DAPI DNA staining. The mRNA and protein levels of SIRT1 were detected using RT-PCR and western blotting analysis, respectively. The results showed that ?-galactosidase positive cells and the formation of SAHF were markedly increased after treatment with NAM (5 mmol/L) for 12 h. We also found that NaHS (12.5 ?mol/L) had no effect on the percentage of SA ?-gal positive cells and the expression of SAHF, and the hallmarks decreased at the concentration of 25 and 50 ?mol/L, reaching the minimum at 50 ?mol/L, while the percentage of SA ?-gal positive cells and the expression of SAHF increased at the concentration of 100 ?mol/L. Furthermore, we found that both on protein and mRNA levels of SIRT1 in the Y+N+S50 group was significantly increased compared with that in Y+N group. In conclusion, NaHS delays senescence of HUVECs induced by NAM via upregulation of SIRT1 expression. PMID:24729176

  5. Effects of Hydrogen Sulfide on Modulation of Theta-Gamma Coupling in Hippocampus in Vascular Dementia Rats.

    PubMed

    Xu, Xiaxia; Liu, Chunhua; Li, Zhanyong; Zhang, Tao

    2015-11-01

    Our previous study showed that hydrogen sulfide (H2S) could alleviate the cognitive deficits in vascular dementia (VD) rats associated with the improvement of synaptic plasticity. Neural oscillations are reported to interact with each other through either identical-frequency or cross-frequency coupling. This study examined whether impaired neural couplings could be alleviated by H2S in the hippocampal CA3-CA1 of VD rats and explored its possible mechanism. A VD rat model was established by two-vessel occlusion. Sodium hydrosulfide (NaHS), a kind of H2S donor, was administered intraperitoneally (5.6 mg/kg/day) for 3 weeks. Local field potentials were simultaneously collected in the hippocampal CA3 and CA1. The effects of NaHS on the modulation of theta-gamma coupling were evaluated by using the measurements of both phase-phase coupling and phase-amplitude coupling, while several other approaches including behavior, electrophysiology, western blot, immunofluorescence staining were also employed. The results showed that NaHS significantly prevented spatial learning and memory impairments (p < 0.01). NaHS considerably alleviated the impairment of neural coupling in VD rats in an identical-frequency rhythm and between cross-frequency bands. Moreover, the expression of cystathionine-?-synthase (CBS) was markedly attenuated in VD rats. NaHS elevated the expression of CBS to maintain the intrinsic balance of H2S. Interestingly, it was observed that NaHS increased the protein expression of N-methyl-D-aspartic acid receptor 2A (NMDAR2A) in VD rats. In conclusion, the data suggest that NaHS played the neuroprotective role partly via modulating the expression of NMDAR2A in order to alleviate the impairments of neural couplings in VD rats. PMID:25773786

  6. Hydrogen sulfide protects against myocardial ischemia and reperfusion injury by activating AMP-activated protein kinase to restore autophagic flux.

    PubMed

    Xie, Hong; Xu, Qingrong; Jia, Jia; Ao, Guizhen; Sun, Ying; Hu, Lifang; Alkayed, Nabil J; Wang, Chen; Cheng, Jian

    2015-03-13

    How hydrogen sulfide (H2S) protects against myocardial ischemia-reperfusion (I/R) injury is poorly understood. By using a slow-releasing H2S donor, we investigated if H2S protected against myocardial I/R injury by activating AMPK and restoring I/R-impaired autophagic flux. Male rats received anterior descending coronary artery occlusion followed by reperfusion. The H2S donor ADT and/or the AMPK inhibitor, compound C (CC), were administered after occlusion. Infarction was analyzed histologically. AMPK activation was assessed in the ischemic heart by analyzing phosphorylation of AMPK and S6 ribosomal protein. Autophagy was assessed by analyzing the following markers: microtubule-associated protein 1 light chain 3 (LC3) I and II, lysosome associated membrane protein-2 (LAMP-2), P62 and beclin-1. We further investigated if blocking autophagic flux with chloroquine abolished ADT cardioprotection in vivo. Myocardial I/R reduced serum H2S levels, which was elevated by ADT. ADT enhanced AMPK activation and reduced infarction following I/R, and both effects were abolished by AMPK inhibition. Myocardial I/R induced autophagosome accumulation, as evidenced by the increased ratios of LC3-II/LC3-I, upregulation of beclin-1 and P62 and reduction in LAMP-2. ADT blunted these autophagic changes induced by I/R, indicating that ADT restored I/R-impaired autophagic flux. The AMPK inhibitor CC blocked ADT effects on restoring I/R-impaired autophagy flux. Moreover, chloroquine pretreatment abolished cardioprotection of ADT and increased autophagosome accumulation in the ADT-treated heart following I/R. In conclusion, AMPK activation and subsequent restoration of I/R-impaired autophagic flux are unrecognized mechanisms underlying cardioprotective effects conferred by H2S donors. PMID:25684185

  7. Hydrogen sulfide-induced itch requires activation of Cav3.2 T-type calcium channel in mice

    PubMed Central

    Wang, Xue-Long; Tian, Bin; Huang, Ya; Peng, Xiao-Yan; Chen, Li-Hua; Li, Jun-Cheng; Liu, Tong

    2015-01-01

    The contributions of gasotransmitters to itch sensation are largely unknown. In this study, we aimed to investigate the roles of hydrogen sulfide (H2S), a ubiquitous gasotransmitter, in itch signaling. We found that intradermal injection of H2S donors NaHS or Na2S, but not GYY4137 (a slow-releasing H2S donor), dose-dependently induced scratching behavior in a ?-opioid receptor-dependent and histamine-independent manner in mice. Interestingly, NaHS induced itch via unique mechanisms that involved capsaicin-insensitive A-fibers, but not TRPV1-expressing C-fibers that are traditionally considered for mediating itch, revealed by depletion of TRPV1-expressing C-fibers by systemic resiniferatoxin treatment. Moreover, local application of capsaizapine (TRPV1 blocker) or HC-030031 (TRPA1 blocker) had no effects on NaHS-evoked scratching. Strikingly, pharmacological blockade and silencing of Cav3.2 T-type calcium channel by mibefradil, ascorbic acid, zinc chloride or Cav3.2 siRNA dramatically decreased NaHS-evoked scratching. NaHS induced robust alloknesis (touch-evoked itch), which was inhibited by T-type calcium channels blocker mibefradil. Compound 48/80-induced itch was enhanced by an endogenous precursor of H2S (L-cysteine) but attenuated by inhibitors of H2S-producing enzymes cystathionine ?-lyase and cystathionine ?-synthase. These results indicated that H2S, as a novel nonhistaminergic itch mediator, may activates Cav3.2 T-type calcium channel, probably located at A-fibers, to induce scratching and alloknesis in mice. PMID:26602811

  8. Hydrogen sulfide enhances salt tolerance through nitric oxide-mediated maintenance of ion homeostasis in barley seedling roots

    PubMed Central

    Chen, Juan; Wang, Wen-Hua; Wu, Fei-Hua; He, En-Ming; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

    2015-01-01

    Hydrogen sulfide (H2S) and nitric oxide (NO) are emerging as messenger molecules involved in the modulation of plant physiological processes. Here, we investigated a signalling network involving H2S and NO in salt tolerance pathway of barley. NaHS, a donor of H2S, at a low concentration of either 50 or 100??M, had significant rescue effects on the 150?mM NaCl-induced inhibition of plant growth and modulated the K+/Na+ balance by decreasing the net K+ efflux and increasing the gene expression of an inward-rectifying potassium channel (HvAKT1) and a high-affinity K+ uptake system (HvHAK4). H2S and NO maintained the lower Na+ content in the cytoplast by increasing the amount of PM H+-ATPase, the transcriptional levels of PM H+-ATPase (HvHA1) and Na+/H+ antiporter (HvSOS1). H2S and NO modulated Na+ compartmentation into the vacuoles with up-regulation of the transcriptional levels of vacuolar Na+/H+ antiporter (HvVNHX2) and H+-ATPase subunit ? (HvVHA-?) and increased in the protein expression of vacuolar Na+/H+ antiporter (NHE1). H2S mimicked the effect of sodium nitroprusside (SNP) by increasing NO production, whereas the function was quenched with the addition of NO scavenger. These results indicated that H2S increased salt tolerance by maintaining ion homeostasis, which were mediated by the NO signal. PMID:26213372

  9. Industrial sources influence air concentrations of hydrogen sulfide and sulfur dioxide in rural areas of western Canada.

    PubMed

    Burstyn, Igor; Senthilselvan, Ambikaipakan; Kim, Hyang-Mi; Cherry, Nicola M; Pietroniro, Elise; Waldner, Cheryl

    2007-10-01

    A survey of monthly average concentrations of sulfur dioxide (SO2) and hydrogen sulfide (H2S) at rural locations in western Canada (provinces of Alberta, British Columbia, and Saskatchewan) was conducted in 2001-2002, as part of an epidemiological study of the effects of oil and gas industry emissions on the health of cattle. Repeated measurements were obtained at some months and locations. We aimed to develop statistical models of the effect of oil and gas infrastructure on air concentrations. The regulatory authorities supplied the information on location of the different oil and gas facilities during the study period and, for Alberta, provided data on H2S content of wells and flaring volumes. Linear mixed effects models were used to relate observed concentrations to proximity and type of oil and gas infrastructure. Low concentrations were recorded; the monthly geometric mean was 0.1-0.2 ppb for H2S, and 0.3-1.3 ppb for SO2. Substantial variability between repeated measurements was observed. The precision of the measurement method was 0.005 ppb for both contaminants. There were seasonal trends in the concentrations, but the spatial variability was greater. This was explained, in part, by proximity to oil/gas/bitumen wells and (for SO2) gas plants. Wells within 2 km of monitoring stations had the greatest impact on measured concentrations. For H2S, 8% of between-location variability was explained by proximity to industrial sources of emissions; for SO2 this proportion was 18%. In Alberta, proximity to sour gas wells and flares was associated with elevated H2S concentrations; however, the estimate of the effect of sour gas wells in the immediate vicinity of monitoring stations was unstable. Our study was unable to control for all possible sources of the contaminants. However, the results suggest that oil and gas extraction activities contribute to air pollution in rural areas of western Canada. PMID:17972769

  10. Antecedent hydrogen sulfide elicits an anti-inflammatory phenotype in postischemic murine small intestine: role of heme oxygenase-1

    PubMed Central

    Zuidema, Mozow Y.; Peyton, Kelly J.; Fay, William P.; Durante, William

    2011-01-01

    We recently demonstrated that preconditioning with an exogenous hydrogen sulfide donor (NaHS-PC) 24 h before ischemia and reperfusion (I/R) causes postcapillary venules to shift to an anti-inflammatory phenotype in C57BL/6J wild-type (WT) mice such that these vessels fail to support increases in postischemic leukocyte rolling (LR) and leukocyte adhesion (LA). The objective of the present study was to determine whether heme oxygenase-1 (HO-1) is a mediator of these anti-inflammatory effects noted during I/R in mice preconditioned with NaHS. Intravital fluorescence microscopy was used to visualize LR and LA in single postcapillary venules of the murine small intestine. I/R induced marked increases in LR and LA, effects that were prevented by NaHS-PC. Treatment with the HO inhibitor tin protoporphyrin IX, but not the inactive protoporphyrin CuPPIX, just before reperfusion prevented the anti-inflammatory effects of antecedent NaHS. The anti-inflammatory effects of NaHS-PC were mimicked by preconditioning with hemin, an agent that induces HO-1 expression. We then evaluated the effect of NaHS as a preconditioning stimulus in mice that were genetically deficient in HO-1 (HO-1?/? on an H129 background with appropriate WT strain controls). NaHS-PC was ineffective in HO-1?/? mice. Our work indicates that HO-1 serves as an effector of the anti-inflammatory effects of NaHS-PC during I/R 24 h later. PMID:21666111

  11. Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

    PubMed Central

    Sheng, Q. K.; Yang, Z. J.; Zhao, H. B.; Wang, X. L.; Guo, J. F.

    2015-01-01

    The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide (H2S), and 3-methylindole (skatole). Eighty swine (50.0±0.5 kg) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a 3×3 orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, H2S, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, H2S, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced H2S production (r = 0.9981). Fructan and Bs significantly interacted in H2S production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and H2S. PMID:26104530

  12. Estimation of hydrogen sulfide emission rates at several wastewater treatment plants through experimental concentration measurements and dispersion modeling.

    PubMed

    Llavador Colomer, Fernando; Espinós Morató, Héctor; Mantilla Iglesias, Enrique

    2012-07-01

    The management and operation of wastewater treatment plants (WWTP) usually involve the release into the atmosphere of malodorous substances with the potential to reduce the quality of life of people living nearby. In this type of facility, anaerobic degradation processes contribute to the generation of hydrogen sulfide (H2S), often at quite high concentrations; thus, the presence of this chemical compound in the atmosphere can be a good indicator of the occurrence and intensity of the olfactory impact in a specific area. The present paper describes the experimental and modelling work being carried out by CEAM-UMH in the surroundings of several wastewater treatment plants located in the Valencia Autonomous Community (Spain). This work has permitted the estimation of H2S emission rates at different WWTPs under different environmental and operating conditions. Our methodological approach for analyzing and describing the most relevant aspects of the olfactory impact consisted of several experimental campaigns involving intensive field measurements using passive samplers in the vicinity of several WWTPs, in combination with numerical simulation results from a diagnostic dispersion model. A meteorological tower at each WWTP provided the input values for the dispersion code, ensuring a good fit of the advective component and therefore more confidence in the modelled concentration field in response to environmental conditions. Then, comparisons between simulated and experimental H2S concentrations yielded estimates of the global emission rate for this substance at several WWTPs at different time periods. The results obtained show a certain degree of temporal and spatial (between-plant) variability (possibly due to both operational and environmental conditions). Nevertheless, and more importantly, the results show a high degree of uniformity in the estimates, which consistently stay within the same order of magnitude. PMID:22866577

  13. Protective effects of hydrogen sulfide inhalation on oxidative stress in rats with cotton smoke inhalation-induced lung injury

    PubMed Central

    HAN, ZHI-HAI; JIANG, YI; DUAN, YUN-YOU; WANG, XIAO-YANG; HUANG, YAN; FANG, TING-ZHENG

    2015-01-01

    The aim of the present study was to investigate the mechanism by which hydrogen sulfide (H2S) inhalation protects against oxidative stress in rats with cotton smoke inhalation-induced lung injury. A total of 24 male Sprague-Dawley rats were separated randomly into four groups, which included the control, H2S, smoke and smoke + H2S groups. A rat model of cotton smoke inhalation-induced lung injury was established following inhalation of 30% oxygen for 6 h. In addition, H2S (80 ppm) was inhaled by the rats in the H2S and smoke + H2S groups for 6 h following smoke or sham-smoke inhalation. Enzyme-linked immunosorbent assays were performed to measure various indices in the rat lung homogenate, while the levels of nuclear factor (NF)-?Bp65 in the lung tissue of the rats were determined and semiquantitatively analyzed using immunohistochemistry. In addition, quantitative fluorescence polymerase chain reaction was employed to detect the mRNA expression of inducible nitric oxide synthase (iNOS) in the rat lung tissue. The concentrations of malondialdehyde (MDA), nitric oxide (NO), inducible iNOS and NF-?Bp65, as well as the sum-integrated optical density of NF-?Bp65 and the relative mRNA expression of iNOS, in the rat lung tissue from the smoke + H2S group were significantly lower when compared with the smoke group. The concentrations of MDA, NO, iNOS and NF-?Bp65 in the H2S group were comparable to that of the control group. Therefore, inhalation of 80 ppm H2S may reduce iNOS mRNA transcription and the production of iNOS and NO in rats by inhibiting NF-?Bp65 activation, subsequently decreasing oxidative stress and cotton smoke inhalation-induced lung injury. PMID:26170929

  14. Hydrogen Sulfide Alleviates Myocardial Collagen Remodeling in Association with Inhibition of TGF-?/Smad Signaling Pathway in Spontaneously Hypertensive Rats

    PubMed Central

    Sun, Lili; Jin, Hongfang; Sun, Lujing; Chen, Siyao; Huang, Yaqian; Liu, Jia; Li, Zhenzhen; Zhao, Manman; Sun, Yan; Tang, Chaoshu; Zhao, Bin; Du, Junbao

    2014-01-01

    The study was designed to explore the role and possible mechanisms of hydrogen sulfide (H2S) in the regulation of myocardial collagen remodeling in spontaneously hypertensive rats (SHRs). We treated nine-week-old male SHRs and age- and sex-matched Wistar–Kyoto rats (WKYs) with NaHS (90 ?mol/kg?1·day?1) for 9 wks. At 18 wks, plasma H2S, tail arterial pressure, morphology of the heart, myocardial ultrastructure and collagen volume fraction (CVF), myocardial expressions of collagen I and III protein and procollagen I and III mRNA, transforming growth factor-?1 (TGF-?1), TGF-? type I receptor (T?R-I), type II receptor (T?R-II), p-Smad2 and 3, matrix metalloproteinase (MMP)-13 and tissue inhibitors of MMP (TIMP)-1 proteins were determined. TGF-?1-stimulated cultured cardiac fibroblasts (CFs) were used to further study the mechanisms. The results showed that compared with WKYs, SHRs showed a reduced plasma H2S, elevated tail artery pressure and increased myocardial collagen, TGF-?1, T?R-II, p-Smad2 and p-Smad3 expressions. However, NaHS markedly decreased tail artery pressure and inhibited myocardial collagen, TGF-?1, T?R-II, p-Smad2 and p-Smad3 protein expressions, but H2S had no effect on the expressions of MMP-13 and TIMP-1. Hydralazine reduced blood pressure but had no effect on myocardial collagen, MMP-13 and TIMP-1 expressions and TGF-?1/Smad signaling pathway. H2S prevented activation of the TGF-?1/Smad signaling pathway and abnormal collagen synthesis in CFs. In conclusion, the results suggested that H2S could prevent myocardial collagen remodeling in SHR. The mechanism might be associated with inhibition of collagen synthesis via TGF-?1/Smad signaling pathway. PMID:25222913

  15. Dysregulation of cystathionine ?-lyase (CSE)/hydrogen sulfide pathway contributes to ox-LDL-induced inflammation in macrophage.

    PubMed

    Wang, Xian-Hui; Wang, Fen; You, Shou-Jiang; Cao, Yong-Jun; Cao, Li-Dan; Han, Qiao; Liu, Chun-Feng; Hu, Li-Fang

    2013-11-01

    Hydrogen sulfide (H2S), mainly produced by cystathionine ?-lyase (CSE) in vascular system, emerges as a novel gasotransmitter exerting anti-inflammatory and anti-atherosclerotic effects. Alterations of CSE/H2S pathway may thus be involved in atherosclerosis pathogenesis. However, the underlying mechanisms are poorly understood. The present study showed that the levels of CSE mRNA and protein expression, as well as H2S production were decreased in ox-LDL-treated macrophage. CSE overexpression reduced the ox-LDL-stimulated tumor necrosis factor-? (TNF-?) generation in Raw264.7 and primary macrophage while CSE knockdown enhanced it. Exogenous supplementation of H2S with NaHS and Na2S also decreased the production of TNF-? and intercellular adhesion molecule-1 (ICAM-1) in ox-LDL-stimulated macrophage, and alleviated the adhesion of macrophage to endothelial monolayer. Cysteine, a CSE preferential substrate for H2S biosynthesis, produced similar effects on the pro-inflammatory cytokine generation, which were reversed by CSE inhibitors PAG and BCA, respectively. Moreover, NaHS and Na2S attenuated the phosphorylation and degradation of I?B? and p65 nuclear translocation, as well as JNK activation caused by ox-LDL. The JNK inhibitor suppressed the NF-?B transcription activity in ox-LDL-treated cells. Furthermore, inhibitors of NF-?B (PDTC), ERK (U0126 and PD98059) and JNK (SP600125) partially blocked the suppression by ox-LDL on the CSE mRNA levels. Taken together, the findings demonstrate that ox-LDL may down-regulate the CSE/H2S pathway, which plays an anti-inflammatory role in ox-LDL-stimulated macrophage by suppressing JNK/NF-?B signaling. The study reveals new therapeutic strategies for atherosclerosis, based on modulating CSE/H2S pathway. PMID:23872072

  16. Antecedent hydrogen sulfide elicits an anti-inflammatory phenotype in postischemic murine small intestine: role of BK channels

    PubMed Central

    Zuidema, Mozow Y.; Yang, Yan; Wang, Meifang; Kalogeris, Theodore; Liu, Yajun; Meininger, Cynthia J.; Hill, Michael A.; Davis, Michael J.

    2010-01-01

    The objectives of this study were to determine the role of calcium-activated, small (SK), intermediate (IK), and large (BK) conductance potassium channels in initiating the development of an anti-inflammatory phenotype elicited by preconditioning with an exogenous hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS). Intravital microscopy was used to visualize rolling and firmly adherent leukocytes in vessels of the small intestine of mice preconditioned with NaHS (in the absence and presence of SK, IK, and BK channel inhibitors, apamin, TRAM-34, and paxilline, respectively) or SK/IK (NS-309) or BK channel activators (NS-1619) 24 h before ischemia-reperfusion (I/R). I/R induced marked increases in leukocyte rolling and adhesion, effects that were largely abolished by preconditioning with NaHS, NS-309, or NS-1619. The postischemic anti-inflammatory effects of NaHS-induced preconditioning were mitigated by BKB channel inhibitor treatment coincident with NaHS, but not by apamin or TRAM-34, 24 h before I/R. Confocal imaging and immunohistochemistry were used to demonstrate the presence of BK? subunit staining in both endothelial and vascular smooth muscle cells of isolated, pressurized mesenteric venules. Using patch-clamp techniques, we found that BK channels in cultured endothelial cells were activated after exposure to NaHS. Bath application of the same concentration of NaHS used in preconditioning protocols led to a rapid increase in a whole cell K+ current; specifically, the component of K+ current blocked by the selective BK channel antagonist iberiotoxin. The activation of BK current by NaHS could also be demonstrated in single channel recording mode where it was independent of a change in intracellular Ca+ concentration. Our data are consistent with the concept that H2S induces the development of an anti-adhesive state in I/R in part mediated by a BK channel-dependent mechanism. PMID:20833953

  17. Tadalafil Integrates Nitric Oxide-Hydrogen Sulfide Signaling to Inhibit High Glucose-induced Matrix Protein Synthesis in Podocytes.

    PubMed

    Lee, Hak Joo; Feliers, Denis; Mariappan, Meenalakshmi M; Sataranatarajan, Kavithalakshmi; Choudhury, Goutam Ghosh; Gorin, Yves; Kasinath, Balakuntalam S

    2015-05-01

    Diabetes-induced kidney cell injury involves an increase in matrix protein expression that is only partly alleviated by current treatment, prompting a search for new modalities. We have previously shown that hydrogen sulfide (H2S) inhibits high glucose-induced protein synthesis in kidney podocytes. We tested whether tadalafil, a phosphodiesterase 5 inhibitor used to treat erectile dysfunction, ameliorates high glucose stimulation of matrix proteins by generating H2S in podocytes. Tadalafil abrogated high glucose stimulation of global protein synthesis and matrix protein laminin ?1. Tadalafil inhibited high glucose-induced activation of mechanistic target of rapamycin complex 1 and laminin ?1 accumulation in an AMP-activated protein kinase (AMPK)-dependent manner. Tadalafil increased AMPK phosphorylation by stimulating calcium-calmodulin kinase kinase ?. Tadalafil rapidly increased the expression and activity of the H2S-generating enzyme cystathionine ?-lyase (CSE) by promoting its translation. dl-Propargylglycine, a CSE inhibitor, and siRNA against CSE inhibited tadalafil-induced AMPK phosphorylation and abrogated the tadalafil effect on high glucose stimulation of laminin ?1. In tadalafil-treated podocytes, we examined the interaction between H2S and nitric oxide (NO). N(?)-Nitro-L-arginine methyl ester and 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one, inhibitors of NO synthase (NOS) and soluble guanylyl cyclase, respectively, abolished tadalafil induction of H2S and AMPK phosphorylation. Tadalafil rapidly augmented inducible NOS (iNOS) expression by increasing its mRNA, and siRNA for iNOS and 1400W, an iNOS blocker, inhibited tadalafil stimulation of CSE expression and AMPK phosphorylation. We conclude that tadalafil amelioration of high glucose stimulation of synthesis of proteins including matrix proteins in podocytes requires integration of the NO-H2S-AMPK axis leading to the inhibition of high glucose-induced mechanistic target of rapamycin complex 1 activity and mRNA translation. PMID:25752605

  18. NOSH-aspirin (NBS-1120), a dual nitric oxide and hydrogen sulfide-releasing hybrid, reduces inflammatory pain

    PubMed Central

    Fonseca, Miriam D; Cunha, Fernando Q; Kashfi, Khosrow; Cunha, Thiago M

    2015-01-01

    The development of nitric oxide (NO)- and hydrogen sulfide (H2S)-releasing nonsteroidal anti-inflammatory drugs (NSAIDs) has generated more potent anti-inflammatory drugs with increased safety profiles. A new hybrid molecule incorporating both NO and H2S donors into aspirin (NOSH-aspirin) was recently developed. In the present study, the antinociceptive activity of this novel molecule was compared with aspirin in different models of inflammatory pain. It was found that NOSH-aspirin inhibits acetic acid-induced writhing response and carrageenan (Cg)-induced inflammatory hyperalgesia in a dose-dependent (5–150 ?mol/kg, v.o.) manner, which was superior to the effect of the same doses of aspirin. NOSH-aspirin’s antinociceptive effect was also greater and longer compared to aspirin upon complete Freund’s adjuvant (CFA)-induced inflammatory hyperalgesia. Mechanistically, NOSH-aspirin, but not aspirin, was able to reduce the production/release of interleukin-1 beta (IL-1?) during Cg-induced paw inflammation. Furthermore, NOSH-aspirin, but not aspirin, reduced prostaglandin E2-induced hyperalgesia, which was prevented by treatment with a ATP-sensitive potassium channel (KATP) blocker (glibenclamide; glib.). Noteworthy, the antinociceptive effect of NOSH-aspirin was not associated with motor impairment. The present results indicate that NOSH-aspirin seems to present greater potency than aspirin to reduce inflammatory pain in several models. The enhanced effects of NOSH-aspirin seems to be due to its ability to reduce the production of pronociceptive cytokines such as IL-1 ? and directly block hyperalgesia caused by a directly acting hyperalgesic mediator in a mechanism dependent on modulation of KATP channels. In conclusion, we would like to suggest that NOSH-aspirin represents a prototype of a new class of analgesic drugs with more potent effects than the traditional NSAID, aspirin. PMID:26236481

  19. Hydrogen Sulfide Inhibits L-Type Calcium Currents Depending upon the Protein Sulfhydryl State in Rat Cardiomyocytes

    PubMed Central

    Tsai, Haojan; Tang, Chaoshu; Jin, Hongfang; Du, Junbao

    2012-01-01

    Hydrogen sulfide (H2S) is a novel gasotransmitter that inhibits L-type calcium currents (I Ca, L). However, the underlying molecular mechanisms are unclear. In particular, the targeting site in the L-type calcium channel where H2S functions remains unknown. The study was designed to investigate if the sulfhydryl group could be the possible targeting site in the L-type calcium channel in rat cardiomyocytes. Cardiac function was measured in isolated perfused rat hearts. The L-type calcium currents were recorded by using a whole cell voltage clamp technique on the isolated cardiomyocytes. The L-type calcium channel containing free sulfhydryl groups in H9C2 cells were measured by using Western blot. The results showed that sodium hydrosulfide (NaHS, an H2S donor) produced a negative inotropic effect on cardiac function, which could be partly inhibited by the oxidant sulfhydryl modifier diamide (DM). H2S donor inhibited the peak amplitude of I Ca, L in a concentration-dependent manner. However, dithiothreitol (DTT), a reducing sulfhydryl modifier markedly reversed the H2S donor-induced inhibition of I Ca, L in cardiomyocytes. In contrast, in the presence of DM, H2S donor could not alter cardiac function and L type calcium currents. After the isolated rat heart or the cardiomyocytes were treated with DTT, NaHS could markedly alter cardiac function and L-type calcium currents in cardiomyocytes. Furthermore, NaHS could decrease the functional free sulfhydryl group in the L-type Ca2+ channel, which could be reversed by thiol reductant, either DTT or reduced glutathione. Therefore, our results suggest that H2S might inhibit L-type calcium currents depending on the sulfhydryl group in rat cardiomyocytes. PMID:22590646

  20. Inhibition of hydrogen sulfide, methane, and total gas production and sulfate-reducing bacteria in in vitro swine manure by tannins, with focus on condensed quebracho tannins.

    PubMed

    Whitehead, Terence R; Spence, Cheryl; Cotta, Michael A

    2013-09-01

    Management practices from large-scale swine production facilities have resulted in the increased collection and storage of manure for off-season fertilization use. Odor and emissions produced during storage have increased the tension among rural neighbors and among urban and rural residents. Production of these compounds from stored manure is the result of microbial activity of the anaerobic bacteria populations during storage. In the current study, the inhibitory effects of condensed quebracho tannins on in vitro swine manure for reduction of microbial activity and reduced production of gaseous emissions, including the toxic odorant hydrogen sulfide produced by sulfate-reducing bacteria (SRB), was examined. Swine manure was collected from a local swine facility, diluted in anaerobic buffer, and mixed with 1 %?w/v fresh feces. This slurry was combined with quebracho tannins, and total gas and hydrogen sulfide production was monitored over time. Aliquots were removed periodically for isolation of DNA to measure the SRB populations using quantitative PCR. Addition of tannins reduced overall gas, hydrogen sulfide, and methane production by greater than 90 % after 7 days of treatment and continued to at least 28 days. SRB population was also significantly decreased by tannin addition. qRT-PCR of 16S rDNA bacteria genes showed that the total bacterial population was also decreased in these incubations. These results indicate that the tannins elicited a collective effect on the bacterial population and also suggest a reduction in the population of methanogenic microorganisms as demonstrated by reduced methane production in these experiments. Such a generalized effect could be extrapolated to a reduction in other odor-associated emissions during manure storage. PMID:23149758

  1. Assessment of geothermal development in the Imperial Valley of California. Volume 1. Environment, health, and socioeconomics

    SciTech Connect

    Layton, D.

    1980-07-01

    Utilization of the Imperial Valley's geothermal resources to support energy production could be hindered if environmental impacts prove to be unacceptable or if geothermal operations are incompatible with agriculture. To address these concerns, an integrated environmental and socioeconomic assessment of energy production in the valley was prepared. The most important impacts examined in the assessment involved air quality changes resulting from emissions of hydrogen sulfide, and increases in the salinity of the Salton Sea resulting from the use of agricultural waste waters for power plant cooling. The socioeconomics consequences of future geothermal development will generally be beneficial. (MHR)

  2. 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 of elevated methylglyoxal. Thus, ACS14 has the potential to be especially beneficial for diabetic patients pending further in vivo studies. PMID:24896242

  3. Hydrogen Sulfide Releasing Aspirin, ACS14, Attenuates High Glucose-Induced Increased Methylglyoxal and Oxidative Stress in Cultured Vascular Smooth Muscle Cells

    PubMed Central

    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 of elevated methylglyoxal. Thus, ACS14 has the potential to be especially beneficial for diabetic patients pending further in vivo studies. PMID:24896242

  4. Hydrogen sulfide-induced enhancement of gastric fundus smooth muscle tone is mediated by voltage-dependent potassium and calcium channels in mice

    PubMed Central

    Meng, Xiang-Min; Huang, Xu; Zhang, Chun-Mei; Liu, Dong-Hai; Lu, Hong-Li; Kim, Young-chul; Xu, Wen-Xie

    2015-01-01

    AIM: To investigate the effect of hydrogen sulfide (H2S) on smooth muscle motility in the gastric fundus. METHODS: The expression of cystathionine ?-synthase (CBS) and cystathionine ?-lyase (CSE) in cultured smooth muscle cells from the gastric fundus was examined by the immunocytochemistry technique. The tension of the gastric fundus smooth muscle was recorded by an isometric force transducer under the condition of isometric contraction with each end of the smooth muscle strip tied with a silk thread. Intracellular recording was used to identify whether hydrogen sulfide affects the resting membrane potential of the gastric fundus in vitro. Cells were freshly separated from the gastric fundus of mice using a variety of enzyme digestion methods and whole-cell patch-clamp technique was used to find the effects of hydrogen sulfide on voltage-dependent potassium channel and calcium channel. Calcium imaging with fura-3AM loading was used to investigate the mechanism by which hydrogen sulfide regulates gastric fundus motility in cultured smooth muscle cells. RESULTS: We found that both CBS and CSE were expressed in the cultured smooth muscle cells from the gastric fundus and that H2S increased the smooth muscle tension of the gastric fundus in mice at low concentrations. In addition, nicardipine and aminooxyacetic acid (AOAA), a CBS inhibitor, reduced the tension, whereas N?-nitro-L-arginine methyl ester, a nonspecific nitric oxide synthase, increased the tension. The AOAA-induced relaxation was significantly recovered by H2S, and the NaHS-induced increase in tonic contraction was blocked by 5 mmol/L 4-aminopyridine and 1 ?mol/L nicardipine. NaHS significantly depolarized the membrane potential and inhibited the voltage-dependent potassium currents. Moreover, NaHS increased L-type Ca2+ currents and caused an elevation in intracellular calcium ([Ca2+]i). CONCLUSION: These findings suggest that H2S may be an excitatory modulator in the gastric fundus in mice. The excitatory effect is mediated by voltage-dependent potassium and L-type calcium channels. PMID:25944997

  5. Ethanol and hydrogen production by two thermophilic, anaerobic bacteria isolated from Icelandic geothermal areas.

    PubMed

    Koskinen, Perttu E P; Beck, Steinar R; Orlygsson, Jóhann; Puhakka, Jaakko A

    2008-11-01

    Microbial fermentations are potential producers of sustainable energy carriers. In this study, ethanol and hydrogen production was studied by two thermophilic bacteria (strain AK15 and AK17) isolated from geothermal springs in Iceland. Strain AK15 was affiliated with Clostridium uzonii (98.8%), while AK17 was affiliated with Thermoanaerobacterium aciditolerans (99.2%) based on the 16S rRNA gene sequence analysis. Both strains fermented a wide variety of sugar residues typically found in lignocellulosic materials, and some polysaccharides. In the batch cultivations, strain AK17 produced ethanol from glucose and xylose fermentations of up to 1.6 mol-EtOH/mol-glucose (80% of the theoretical maximum) and 1.1 mol-EtOH/mol-xylose (66%), respectively. The hydrogen yields by AK17 were up to 1.2 mol-H2/ mol-glucose (30% of the theoretical maximum) and 1.0 mol-H2/mol-xylose (30%). The strain AK15 produced hydrogen as the main fermentation product from glucose (up to 1.9 mol-H2/mol-glucose [48%]) and xylose (1.1 mol-H2/mol-xylose [33%]). The strain AK17 tolerated exogenously added ethanol up to 4% (v/v). The ethanol and hydrogen production performance from glucose by a co-culture of the strains AK15 and AK17 was studied in a continuous-flow bioreactor at 60 degrees C. Stable and continuous ethanol and hydrogen co-production was achieved with ethanol yield of 1.35 mol-EtOH/mol-glucose, and with the hydrogen production rate of 6.1 mmol/h/L (H2 yield of 0.80 mol-H2/mol-glucose). PCR-DGGE analysis revealed that the AK17 became the dominant bacterium in the bioreactor. In conclusion, strain AK17 is a promising strain for the co-production of ethanol and hydrogen with a wide substrate utilization spectrum, relatively high ethanol tolerance, and ethanol yields among the highest reported for thermoanaerobes. PMID:18500766

  6. Hydrogen sulfide and nitric oxide metabolites in the blood of free-ranging brown bears and their potential roles in hibernation.

    PubMed

    Revsbech, Inge G; Shen, Xinggui; Chakravarti, Ritu; Jensen, Frank B; Thiel, Bonnie; Evans, Alina L; Kindberg, Jonas; Fröbert, Ole; Stuehr, Dennis J; Kevil, Christopher G; Fago, Angela

    2014-08-01

    During winter hibernation, brown bears (Ursus arctos) lie in dens for half a year without eating while their basal metabolism is largely suppressed. To understand the underlying mechanisms of metabolic depression in hibernation, we measured type and content of blood metabolites of two ubiquitous inhibitors of mitochondrial respiration, hydrogen sulfide (H2S) and nitric oxide (NO), in winter-hibernating and summer-active free-ranging Scandinavian brown bears. We found that levels of sulfide metabolites were overall similar in summer-active and hibernating bears but their composition in the plasma differed significantly, with a decrease in bound sulfane sulfur in hibernation. High levels of unbound free sulfide correlated with high levels of cysteine (Cys) and with low levels of bound sulfane sulfur, indicating that during hibernation H2S, in addition to being formed enzymatically from the substrate Cys, may also be regenerated from its oxidation products, including thiosulfate and polysulfides. In the absence of any dietary intake, this shift in the mode of H2S synthesis would help preserve free Cys for synthesis of glutathione (GSH), a major antioxidant found at high levels in the red blood cells of hibernating bears. In contrast, circulating nitrite and erythrocytic S-nitrosation of glyceraldehyde-3-phosphate dehydrogenase, taken as markers of NO metabolism, did not change appreciably. Our findings reveal that remodeling of H2S metabolism and enhanced intracellular GSH levels are hallmarks of the aerobic metabolic suppression of hibernating bears. PMID:24909614

  7. Hydrogen sulfide and nitric oxide are mutually dependent in the regulation of angiogenesis and endothelium-dependent vasorelaxation

    PubMed Central

    Coletta, Ciro; Papapetropoulos, Andreas; Erdelyi, Katalin; Olah, Gabor; Módis, Katalin; Panopoulos, Panagiotis; Asimakopoulou, Antonia; Gerö, Domokos; Sharina, Iraida; Martin, Emil; Szabo, Csaba

    2012-01-01

    Hydrogen sulfide (H2S) is a unique gasotransmitter, with regulatory roles in the cardiovascular, nervous, and immune systems. Some of the vascular actions of H2S (stimulation of angiogenesis, relaxation of vascular smooth muscle) resemble those of nitric oxide (NO). Although it was generally assumed that H2S and NO exert their effects via separate pathways, the results of the current study show that H2S and NO are mutually required to elicit angiogenesis and vasodilatation. Exposure of endothelial cells to H2S increases intracellular cyclic guanosine 5?-monophosphate (cGMP) in a NO-dependent manner, and activated protein kinase G (PKG) and its downstream effector, the vasodilator-stimulated phosphoprotein (VASP). Inhibition of endothelial isoform of NO synthase (eNOS) or PKG-I abolishes the H2S-stimulated angiogenic response, and attenuated H2S-stimulated vasorelaxation, demonstrating the requirement of NO in vascular H2S signaling. Conversely, silencing of the H2S-producing enzyme cystathionine-?-lyase abolishes NO-stimulated cGMP accumulation and angiogenesis and attenuates the acetylcholine-induced vasorelaxation, indicating a partial requirement of H2S in the vascular activity of NO. The actions of H2S and NO converge at cGMP; though H2S does not directly activate soluble guanylyl cyclase, it maintains a tonic inhibitory effect on PDE5, thereby delaying the degradation of cGMP. H2S also activates PI3K/Akt, and increases eNOS phosphorylation at its activating site S1177. The cooperative action of the two gasotransmitters on increasing and maintaining intracellular cGMP is essential for PKG activation and angiogenesis and vasorelaxation. H2S-induced wound healing and microvessel growth in matrigel plugs is suppressed by pharmacological inhibition or genetic ablation of eNOS. Thus, NO and H2S are mutually required for the physiological control of vascular function. PMID:22570497

  8. BDNF-TrkB pathway mediates neuroprotection of hydrogen sulfide against formaldehyde-induced toxicity to PC12 cells.

    PubMed

    Jiang, Jia-Mei; Zhou, Cheng-Fang; Gao, Sheng-Lan; Tian, Ying; Wang, Chun-Yan; Wang, Li; Gu, Hong-Feng; Tang, Xiao-Qing

    2015-01-01

    Formaldehyde (FA) is a common environmental contaminant that has toxic effects on the central nervous system (CNS). Our previous data demonstrated that hydrogen sulfide (H2S), the third endogenous gaseous mediator, has protective effects against FA-induced neurotoxicity. As is known to all, Brain-derived neurotropic factor (BDNF), a member of the neurotrophin gene family, mediates its neuroprotective properties via various intracellular signaling pathways triggered by activating the tyrosine kinase receptor B (TrkB). Intriguingly, our previous data have illustrated the upregulatory role of H2S on BDNF protein expression in the hippocampus of rats. Therefore, in this study, we hypothesized that H2S provides neuroprotection against FA toxicity by regulating BDNF-TrkB pathway. In the present study, we found that NaHS, a donor of H2S, upregulated the level of BDNF protein in PC12 cells, and significantly rescued FA-induced downregulation of BDNF levels. Furthermore, we found that pretreatment of PC12 cells with K252a, an inhibitor of the BDNF receptor TrkB, markedly reversed the inhibition of NaHS on FA-induced cytotoxicity and ablated the protective effects of NaHS on FA-induced oxidative stress, including the accumulation of intracellular reactive oxygen species (ROS), 4-hydroxy-2-trans-nonenal (4-HNE), and malondialdehyde (MDA). We also showed that K252a abolished the inhibition of NaHS on FA-induced apoptosis, as well as the activation of caspase-3 in PC12 cells. In addition, K252a reversed the protection of H2S against FA-induced downregulation of Bcl-2 protein expression and upregulation of Bax protein expression in PC12 cells. These data indicate that the BDNF-TrkB pathway mediates the neuroprotection of H2S against FA-induced cytotoxicity, oxidative stress and apoptosis in PC12 cells. These findings provide a novel mechanism underlying the protection of H2S against FA-induced neurotoxicity. PMID:25749582

  9. Emissions of ammonia, hydrogen sulfide, and odor before, during, and after slurry removal from a deep-pit swine finisher.

    PubMed

    Hoff, Steven J; Bundy, Dwaine S; Nelson, Minda A; Zelle, Brian C; Jacobson, Larry D; Heber, Albert J; Ni, Jinqin; Zhang, Yuanhui; Koziel, Jacek A; Beasley, David B

    2006-05-01

    It is a common practice in the midwestern United States to raise swine in buildings with under-floor slurry storage systems designed to store manure for up to one year. These so-called "deep-pit" systems are a concentrated source for the emissions of ammonia (NH3), hydrogen sulfide (H2S), and odors. As part of a larger six-state research effort (U.S. Department of Agriculture-Initiative for Future Agriculture and Food Systems Project, "Aerial Pollutant Emissions from Confined Animal Buildings"), realtime NH3 and H2S with incremental odor emission data were collected for two annual slurry removal events. For this study, two 1000-head deep-pit swine finishing facilities in central Iowa were monitored with one-year storage of slurry maintained in a 2.4 m-deep concrete pit (or holding tank) below the animal-occupied zone. Results show that the H2S emission, measured during four independent slurry removal events over two years, increased by an average of 61.9 times relative to the before-removal H2S emission levels. This increase persisted during the agitation process of the slurry that on average occurred over an 8-hr time period. At the conclusion of slurry agitation, the H2S emission decreased by an average of 10.4 times the before-removal emission level. NH3 emission during agitation increased by an average of 4.6 times the before-removal emission level and increased by an average of 1.5 times the before-removal emission level after slurry removal was completed. Odor emission increased by a factor of 3.4 times the before-removal odor emission level and decreased after the slurry-removal event by a factor of 5.6 times the before-removal emission level. The results indicate that maintaining an adequate barn ventilation rate regardless of animal comfort demand is essential to keeping gas levels inside the barn below hazardous levels. PMID:16739794

  10. Endogenous Prostaglandins and Afferent Sensory Nerves in Gastroprotective Effect of Hydrogen Sulfide against Stress-Induced Gastric Lesions

    PubMed Central

    Magierowski, Marcin; Jasnos, Katarzyna; Kwiecien, Slawomir; Drozdowicz, Danuta; Surmiak, Marcin; Strzalka, Malgorzata; Ptak-Belowska, Agata; Wallace, John L.; Brzozowski, Tomasz

    2015-01-01

    Hydrogen sulfide (H2S) plays an important role in human physiology, exerting vasodilatory, neuromodulatory and anti-inflammatory effects. H2S has been implicated in the mechanism of gastrointestinal integrity but whether this gaseous mediator can affect hemorrhagic lesions induced by stress has been little elucidated. We studied the effect of the H2S precursor L-cysteine, H2S-donor NaHS, the H2S synthesizing enzyme (CSE) activity inhibitor- D,L-propargylglycine (PAG) and the gastric H2S production by CSE/CBS/3-MST activity in water immersion and restraint stress (WRS) ulcerogenesis and the accompanying changes in gastric blood flow (GBF). The role of endogenous prostaglandins (PGs) and sensory afferent nerves releasing calcitonin gene-related peptide (CGRP) in the mechanism of gastroprotection induced by H2S was examined in capsaicin-denervated rats and those pretreated with capsazepine to inhibit activity of vanilloid receptors (VR-1). Rats were pretreated with vehicle, NaHS, the donor of H2S and or L-cysteine, the H2S precursor, with or without the concurrent treatment with 1) nonselective (indomethacin) and selective cyclooxygenase (COX)-1 (SC-560) or COX-2 (rofecoxib) inhibitors. The expression of mRNA and protein for COX-1 and COX-2 were analyzed in gastric mucosa pretreated with NaHS with or without PAG. Both NaHS and L-cysteine dose-dependently attenuated severity of WRS-induced gastric lesions and significantly increased GBF. These effects were significantly reduced by pretreatment with PAG and capsaicin denervation. NaHS increased gastric H2S production via CSE/CBS but not 3-MST activity. Inhibition of COX-1 and COX-2 activity significantly diminished NaHS- and L-cysteine-induced protection and hyperemia. NaHS increased expression of COX-1, COX-2 mRNAs and proteins and raised CGRP mRNA expression. These effects of NaHS on COX-1 and COX-2 protein contents were reversed by PAG and capsaicin denervation. We conclude that H2S exerts gastroprotection against WRS-induced gastric lesions by the mechanism involving enhancement in gastric microcirculation mediated by endogenous PGs, sensory afferent nerves releasing CGRP and the activation of VR-1 receptors. PMID:25774496

  11. BDNF-TrkB Pathway Mediates Neuroprotection of Hydrogen Sulfide against Formaldehyde-Induced Toxicity to PC12 Cells

    PubMed Central

    Gao, Sheng-Lan; Tian, Ying; Wang, Chun-Yan; Wang, Li; Gu, Hong-Feng; Tang, Xiao-Qing

    2015-01-01

    Formaldehyde (FA) is a common environmental contaminant that has toxic effects on the central nervous system (CNS). Our previous data demonstrated that hydrogen sulfide (H2S), the third endogenous gaseous mediator, has protective effects against FA-induced neurotoxicity. As is known to all, Brain-derived neurotropic factor (BDNF), a member of the neurotrophin gene family, mediates its neuroprotective properties via various intracellular signaling pathways triggered by activating the tyrosine kinase receptor B (TrkB). Intriguingly, our previous data have illustrated the upregulatory role of H2S on BDNF protein expression in the hippocampus of rats. Therefore, in this study, we hypothesized that H2S provides neuroprotection against FA toxicity by regulating BDNF-TrkB pathway. In the present study, we found that NaHS, a donor of H2S, upregulated the level of BDNF protein in PC12 cells, and significantly rescued FA-induced downregulation of BDNF levels. Furthermore, we found that pretreatment of PC12 cells with K252a, an inhibitor of the BDNF receptor TrkB, markedly reversed the inhibition of NaHS on FA-induced cytotoxicity and ablated the protective effects of NaHS on FA-induced oxidative stress, including the accumulation of intracellular reactive oxygen species (ROS), 4-hydroxy-2-trans-nonenal (4-HNE), and malondialdehyde (MDA). We also showed that K252a abolished the inhibition of NaHS on FA-induced apoptosis, as well as the activation of caspase-3 in PC12 cells. In addition, K252a reversed the protection of H2S against FA-induced downregulation of Bcl-2 protein expression and upregulation of Bax protein expression in PC12 cells. These data indicate that the BDNF-TrkB pathway mediates the neuroprotection of H2S against FA-induced cytotoxicity, oxidative stress and apoptosis in PC12 cells. These findings provide a novel mechanism underlying the protection of H2S against FA-induced neurotoxicity. PMID:25749582

  12. Endogenous prostaglandins and afferent sensory nerves in gastroprotective effect of hydrogen sulfide against stress-induced gastric lesions.

    PubMed

    Magierowski, Marcin; Jasnos, Katarzyna; Kwiecien, Slawomir; Drozdowicz, Danuta; Surmiak, Marcin; Strzalka, Malgorzata; Ptak-Belowska, Agata; Wallace, John L; Brzozowski, Tomasz

    2015-01-01

    Hydrogen sulfide (H2S) plays an important role in human physiology, exerting vasodilatory, neuromodulatory and anti-inflammatory effects. H2S has been implicated in the mechanism of gastrointestinal integrity but whether this gaseous mediator can affect hemorrhagic lesions induced by stress has been little elucidated. We studied the effect of the H2S precursor L-cysteine, H2S-donor NaHS, the H2S synthesizing enzyme (CSE) activity inhibitor- D,L-propargylglycine (PAG) and the gastric H2S production by CSE/CBS/3-MST activity in water immersion and restraint stress (WRS) ulcerogenesis and the accompanying changes in gastric blood flow (GBF). The role of endogenous prostaglandins (PGs) and sensory afferent nerves releasing calcitonin gene-related peptide (CGRP) in the mechanism of gastroprotection induced by H2S was examined in capsaicin-denervated rats and those pretreated with capsazepine to inhibit activity of vanilloid receptors (VR-1). Rats were pretreated with vehicle, NaHS, the donor of H2S and or L-cysteine, the H2S precursor, with or without the concurrent treatment with 1) nonselective (indomethacin) and selective cyclooxygenase (COX)-1 (SC-560) or COX-2 (rofecoxib) inhibitors. The expression of mRNA and protein for COX-1 and COX-2 were analyzed in gastric mucosa pretreated with NaHS with or without PAG. Both NaHS and L-cysteine dose-dependently attenuated severity of WRS-induced gastric lesions and significantly increased GBF. These effects were significantly reduced by pretreatment with PAG and capsaicin denervation. NaHS increased gastric H2S production via CSE/CBS but not 3-MST activity. Inhibition of COX-1 and COX-2 activity significantly diminished NaHS- and L-cysteine-induced protection and hyperemia. NaHS increased expression of COX-1, COX-2 mRNAs and proteins and raised CGRP mRNA expression. These effects of NaHS on COX-1 and COX-2 protein contents were reversed by PAG and capsaicin denervation. We conclude that H2S exerts gastroprotection against WRS-induced gastric lesions by the mechanism involving enhancement in gastric microcirculation mediated by endogenous PGs, sensory afferent nerves releasing CGRP and the activation of VR-1 receptors. PMID:25774496

  13. Selenium Sulfide

    MedlinePLUS

    Selenium sulfide, an anti-infective agent, relieves itching and flaking of the scalp and removes the dry, ... Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium ...

  14. Zinc sulfide liquefaction catalyst

    DOEpatents

    Garg, Diwakar (Macungie, PA)

    1984-01-01

    A process for the liquefaction of carbonaceous material, such as coal, is set forth wherein coal is liquefied in a catalytic solvent refining reaction wherein an activated zinc sulfide catalyst is utilized which is activated by hydrogenation in a coal derived process solvent in the absence of coal.

  15. The effects of crystallographic texture and hydrogen on sulfide stress corrosion cracking behavior of a steel using slow strain rate test method

    NASA Astrophysics Data System (ADS)

    Baik, Youl; Choi, Yong

    2014-12-01

    The effects of pre-charged hydrogen inside steel and the hydrogen ions on its surface on the sulfide stress corrosion cracking (SSCC) behavior was studied by slow strain rate tests. The specimen had an ASTM grain size number of about 11. Most of precipitates were 30-50 nm in size, and their distribution density was about 106 mm-2. The crystallographic texture consisted of major ?-fiber (<110>//RD) components with a maximum peak at {115}<110> relatively close to {001}<110>, and minor ?-fiber (<111>//ND) components with a peak slightly shifted from {111}<112> to {332}<113>. Hydrogen was pre-charged inside the steel by a high-temperature cathodic hydrogen charging (HTCHC) method. SSCC and corrosion tests were carried out in an electrolytic solution (NaCl: CH3COOH: H2O: FeCl2 = 50: 5: 944: 1, pH = 2.7). The corrosion potentials and the corrosion rates of the specimen without hydrogen charging for 24 hours were -490 mVSHE and 1.2 × 10-4 A cm-2, and those with charging were -520 mVSHE and 2.8 × 10-4 A cm-2, respectively. The corrosion resistance in the solution with 1000 ppm iron chloride added was decreased significantly, such that the corrosion potential and corrosion rate were -575 mVSHE and 3.5 × 10-4 A cm-2, respectively. Lower SSCC resistance of the pin-hole pre-notched specimen was observed at the open circuit potential than at the 100 mV cathodically polarized condition. Pre-charged hydrogen inside of the specimen had a greater influence on the SSCC behavior than hydrogen ions on the surface of the specimen during the slow strain rate test.

  16. 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.

  17. Diffuse helium and hydrogen degassing to reveal hidden geothermal resources in oceanic volcanic islands: The Canarian archipelago case study

    NASA Astrophysics Data System (ADS)

    Rodríguez, Fátima; Pérez, Nemesio M.; Padrón, Eleazar; Dionis, Samara; López, Gabriel; Melián, Gladys V.; Asensio-Ramos, María; Hernández, Pedro A.; Padilla, German; Barrancos, José; Marrero, Rayco; Hidalgo, Raúl

    2015-04-01

    During geothermal exploration, the geochemical methods are extensively used and play a major role in both exploration and exploitation phases. They are particularly useful to assess the subsurface temperatures in the reservoir, the origin of the fluid, and flow directions within the reservoir. The geochemical exploration is based on the assumption that fluids on the surface reflect physico-chemical and thermal conditions in the geothermal reservoir at depth. However, in many occasions there is not any evidence of endogenous fluids manifestations at surface, that traditionally evidence the presence of an active geothermal system. Discovery of new geothermal systems will therefore require exploration of areas where the resources are either hidden or lie at great depths. Geochemical methods for geothermal exploration at these areas must include soil gas surveys, based on the detection of anomalously high concentrations of some hydrothermal gases in the soil atmosphere, generally between 40 cm and 1 meter depth from the surface. Among soil gases, particularly interest has been addressed to non-reactive and/or highly mobile gases. They offer important advantages for the detection of vertical permeability structures, because their interaction with the surrounding rocks or fluids during the ascent toward the surface is minimum. This is the case of helium (He) and hydrogen (H2), that have unique characteristics as a geochemical tracer, owing to their chemical and physical characteristics. Enrichments of He and H2 observed in the soil atmosphere can be attributed almost exclusively to migration of deep-seated gas toward the surface. In this work we show the results of soil gas geochemistry studies, focused mainly in non-reactive and/or highly mobile gases as He and H2, in five minning grids at Tenerife and Gran Canaria, Canay Islands, Spain, during 2011-2014. The primary objective was to use different geochemical evidences of deep-seated gas emission to sort the possible geothermal potential in five minning grids, thus reducing the uncertainty inherent to the selection of the area with the highest success in the selection of future exploratory wells. By combining the overall information obtained by statistical-graphical analysis of the soil He and H2 data, visual inspection of their spatial distribution and analysis of some interesting chemical ratios, two of the five minning licenses, located at the southern and western parts of Tenerife Islands, seemed to show the highest geothermal potential of the five mining grids studied. These results will be useful for future implementation and development of geothermal energy in the Canaries, the only Spanish territory with potential high enthalpy geothermal resources.

  18. REMOVAL AND RECOVERY OF SULFIDE FROM TANNERY WASTEWATER

    EPA Science Inventory

    Recovery of sulfide from tannery waste was accomplished through acidification with sulfuric acid in a closed system and removing hydrogen sulfide formed by blowing with air. Sulfide was then absorbed in caustic solution to produce re-usable sodium sulfide/sulfhydrate liquor for t...

  19. Application of a long-lasting colloidal substrate with pH and hydrogen sulfide control capabilities to remediate TCE-contaminated groundwater.

    PubMed

    Sheu, Y T; Chen, S C; Chien, C C; Chen, C C; Kao, C M

    2015-03-01

    A long-lasting emulsified colloidal substrate (LECS) was developed for continuous carbon and nanoscale zero-valent iron (nZVI) release to remediate trichloroethylene (TCE)-contaminated groundwater under reductive dechlorinating conditions. The developed LECS contained nZVI, vegetable oil, surfactants (Simple Green™ and lecithin), molasses, lactate, and minerals. An emulsification study was performed to evaluate the globule droplet size and stability of LECS. The results show that a stable oil-in-water emulsion with uniformly small droplets (0.7 ?m) was produced, which could continuously release the primary substrates. The emulsified solution could serve as the dispensing agent, and nZVI particles (with diameter 100-200 nm) were distributed in the emulsion evenly without aggregation. Microcosm results showed that the LECS caused a rapid increase in the total organic carbon concentration (up to 488 mg/L), and reductive dechlorination of TCE was significantly enhanced. Up to 99% of TCE (with initial concentration of 7.4 mg/L) was removed after 130 days of operation. Acidification was prevented by the production of hydroxide ion by the oxidation of nZVI. The formation of iron sulfide reduced the odor from produced hydrogen sulfide. Microbial analyses reveal that dechlorinating bacteria existed in soils, which might contribute to TCE dechlorination. PMID:25463237

  20. Synthesis and anti-cancer potential of the positional isomers of NOSH-aspirin (NBS-1120) a dual nitric oxide and hydrogen sulfide releasing hybrid.

    PubMed

    Vannini, Federica; MacKessack-Leitch, Andrew C; Eschbach, Erin K; Chattopadhyay, Mitali; Kodela, Ravinder; Kashfi, Khosrow

    2015-10-15

    We recently reported the synthesis of NOSH-aspirin, a novel hybrid compound capable of releasing both nitric oxide (NO) and hydrogen sulfide (H2S). In NOSH-aspirin, the two moieties that release NO and H2S are covalently linked at the 1, 2 positions of acetyl salicylic acid, i.e., ortho-NOSH-aspirin. Here we report on the synthesis of meta- and para-NOSH-aspirins. We also made a head-to-head evaluation of the effects of these three positional isomers of NOSH-aspirin on colon cancer cell kinetics and induction of reactive oxygen species, which in recent years has emerged as a key event in causing cancer cell regression. Electron donating/withdrawing groups incorporated about the benzoate moiety significantly affected the potency of these compounds with respect to colon cancer cell growth inhibition. PMID:26323873

  1. Potential effects of hydrogen sulfide gas from geothermal energy conversion on two plant species native to northern New Mexico

    SciTech Connect

    Gonzales, G.J.

    1984-02-01

    Dry weight of topgrowth, water content of topgrowth, leaf nitrogen content, and leaf chlorophyll content were measured in well-watered, field-exposed little bluestem (Schizachyrium scoparium Nash.) and mountain brome (Bromus marginatus Nees.) plants fumigated with various mean levels of H/sub 2/S ranging from 0.05 to 3.58 ppM. The youngest fully expanded leaves were sampled for chlorophyll content after 60, 80, 100, and 140 and 60, 80, 120, and 140 h total of fumigation for little bluestem and mountain brome, respectively. All other responses were measured after 140 h total of fumigation. The plants received a 7-day fumigation-free period prior to the seventh week (140 h) of fumigations. Dry weight of little bluestem plants which received low concentrations of H/sub 2/S (0.11 ppM) increased by 94% of the control. Dry weight of little bluestem plants which received higher concentrations of H/sub 2/S (0.12 to 0.48 ppM) was reduced to the control level. At the highest H/sub 2/S concentration (2.39 ppM) dry weight of little bluestem was reduced by 44% of the control. Mountain brome was relatively unaffected at the different concentrations of H/sub 2/S until 3.58 ppM H/sub 2/S was received where dry weight was reduced by 37% of the control.

  2. Process for producing cadmium sulfide on a cadmium telluride surface

    DOEpatents

    Levi, Dean H. (Lakewood, CO); Nelson, Art J. (Longmont, CO); Ahrenkiel, Richard K. (Lakewood, CO)

    1996-01-01

    A process for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness.

  3. Hydrogen Sulfide Prolongs Postharvest Storage of Fresh-Cut Pears (Pyrus pyrifolia) by Alleviation of Oxidative Damage and Inhibition of Fungal Growth

    PubMed Central

    Gao, Shuai-Ping; Wu, Jun; Li, Yan-Hong; Zheng, Ji-Lian; Han, Yi; Liu, Yong-Sheng; Zhang, Hua

    2014-01-01

    Hydrogen sulfide (H2S) has proved to be a multifunctional signaling molecule in plants and animals. Here, we investigated the role of H2S in the decay of fresh-cut pears (Pyrus pyrifolia). H2S gas released by sodium hydrosulfide (NaHS) prolonged the shelf life of fresh-cut pear slices in a dose-dependent manner. Moreover, H2S maintained higher levels of reducing sugar and soluble protein in pear slices. H2S significantly reduced the accumulation of hydrogen peroxide (H2O2), superoxide radicals (•O2?) and malondialdehyde (MDA). Further investigation showed that H2S fumigation up-regulated the activities of antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT), and guaiacol peroxidase (POD), while it down-regulated those of lipoxygenase (LOX), phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO). Furthermore, H2S fumigation effectively inhibited the growth of two fungal pathogens of pear, Aspergillus niger and Penicillium expansum, suggesting that H2S can be developed as an effective fungicide for postharvest storage. The present study implies that H2S is involved in prolonging postharvest storage of pears by acting as an antioxidant and fungicide. PMID:24454881

  4. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    SciTech Connect

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  5. Hydrogen Sulfide Attenuates the Recruitment of CD11b+Gr-1+ Myeloid Cells and Regulates Bax/Bcl-2 Signaling in Myocardial Ischemia Injury

    PubMed Central

    Zhang, Youen; Li, Hua; Zhao, Gang; Sun, Aijun; Zong, Nobel C.; Li, Zhaofeng; Zhu, Hongming; Zou, Yunzeng; Yang, Xiangdong; Ge, Junbo

    2014-01-01

    Hydrogen sulfide, an endogenous signaling molecule, plays an important role in the physiology and pathophysiology of the cardiovascular system. Using a mouse model of myocardial infarction, we investigated the anti-inflammatory and anti-apoptotic effects of the H2S donor sodium hydrosulfide (NaHS). The results demonstrated that the administration of NaHS improved survival, preserved left ventricular function, limited infarct size, and improved H2S levels in cardiac tissue to attenuate the recruitment of CD11b+Gr-1+ myeloid cells and to regulate the Bax/Bcl-2 pathway. Furthermore, the cardioprotective effects of NaHS were enhanced by inhibiting the migration of CD11b+Gr-1+ myeloid cells from the spleen into the blood and by attenuating post-infarction inflammation. These observations suggest that the novel mechanism underlying the cardioprotective function of H2S is secondary to a combination of attenuation the recruitment of CD11b+Gr-1+ myeloid cells and regulation of the Bax/Bcl-2 apoptotic signaling. PMID:24758901

  6. Vasorelaxant Effect of a New Hydrogen Sulfide-Nitric Oxide Conjugated Donor in Isolated Rat Aortic Rings through cGMP Pathway.

    PubMed

    Wu, Dan; Hu, Qingxun; Ma, Fenfen; Zhu, Yi Zhun

    2016-01-01

    Endothelium-dependent vasorelaxant injury leads to a lot of cardiovascular diseases. Both hydrogen sulfide (H2S) and nitric oxide (NO) are gasotransmitters, which play a critical role in regulating vascular tone. However, the interaction between H2S and NO in vasorelaxation is still unclear. ZYZ-803 was a novel H2S and NO conjugated donor developed by H2S-releasing moiety (S-propyl-L-cysteine (SPRC)) and NO-releasing moiety (furoxan). ZYZ-803 could time- and dose-dependently relax the sustained contraction induced by PE in rat aortic rings, with potencies of 1.5- to 100-fold greater than that of furoxan and SPRC. Inhibition of the generations of H2S and NO with respective inhibitors abolished the vasorelaxant effect of ZYZ-803. ZYZ-803 increased cGMP level and the activity of vasodilator stimulated phosphoprotein (VASP) in aortic rings, and those effects could be suppressed by the inhibitory generation of H2S and NO. Both the inhibitor of protein kinase G (KT5823) and the inhibitor of KATP channel (glibenclamide) suppressed the vasorelaxant effect of ZYZ-803. Our results demonstrated that H2S and NO generation from ZYZ-803 cooperatively regulated vascular tone through cGMP pathway, which indicated that ZYZ-803 had therapeutic potential in cardiovascular diseases. PMID:26635911

  7. Kinetics of reduction of sulfur dioxide by hydrogen sulfide in the presence of sulfoxides, pyridine N-oxide, trioctylphosphine oxide and tributyl phosphate

    SciTech Connect

    Bikbaeva, G.G.; Baranovskaya, E.M.; Nikitin, Yu.E.

    1989-01-01

    The kinetic regularities were studied of the reduction of SO/sub 2/ by hydrogen sulfide in m-xylene containing 0.025 M of aliphatic sulfoxides, (C/sub 1/-C/sub 8/alkyl), diphenyl-, dibenzyl sulfoxides, tributyl phosphate (TBP), trioctylphosphine oxide (TOPO) at 25/degree/C, and 0.001-0.003 M pyridine N-oxide (PyO) at 21-60/degree/C. It was shown that the reaction proceeds with the participation of an SO/sub 2/ complex having the composition of R/sub n/XO...SO/sub 2/ (where X = S, P, N). The kinetic regularities for the reaction taking place in the presence of aromatic sulfoxides are explainable by the contribution to the reaction of intermediate SO/sub 2/ complexes. The equilibrium constants of the complexation of SO/sub 2/ with aliphatic sulfoxides, PyO, TOPO, and TBP and the rate constant of the limiting stage of the reaction were calculated.

  8. Application of ZnO single-crystal wire grown by the thermal evaporation method as a chemical gas sensor for hydrogen sulfide.

    PubMed

    Park, N K; Lee, S Y; Lee, T J

    2011-01-01

    A zinc oxide single-crystal wire was synthesized for application as a gas-sensing material for hydrogen sulfide, and its gas-sensing properties were investigated in this study. The gas sensor consisted of a ZnO thin film as the buffer layer and a ZnO single-crystal wire. The ZnO thin film was deposited over a patterning silicon substrate with a gold electrode by the CFR method. The ZnO single-crystal wire was synthesized over the ZnO thin film using zinc and activated carbon as the precursor for the thermal evaporation method at 800 degrees C. The electrical properties of the gas sensors that were prepared for the growth of ZnO single-crystal wire varied with the amount of zinc contained in the precursor. The charged current on the gas sensors increased with the increasing amount of zinc in the precursor. It was concluded that the charged current on the gas sensors was related to ZnO single-crystal wire growth on the silicon substrate area between the two electrodes. The charged current on the gas sensor was enhanced when the ZnO single-crystal wire was exposed to a H2S stream. The experimental results obtained in this study confirmed that a ZnO single-crystal wire can be used as a gas sensor for H2S. PMID:21446509

  9. Antidepressant-like and anxiolytic-like effects of hydrogen sulfide in streptozotocin-induced diabetic rats through inhibition of hippocampal oxidative stress.

    PubMed

    Tang, Zhuo-Jun; Zou, Wei; Yuan, Juan; Zhang, Ping; Tian, Ying; Xiao, Zhi-Fang; Li, Mang-Hong; Wei, Hai-Jun; Tang, Xiao-Qing

    2015-08-01

    Depression is highly prevalent in individuals with diabetes, and depressive symptoms are less responsive to current antidepressant therapies. Oxidative stress plays a major role both in the pathogenesis of diabetes and in major depression and anxiety disorders. Hydrogen sulfide (H2S), the third gaseous mediator, is a novel signaling molecule in the brain that has both antioxidative activity and antidepressant-like and anxiolytic-like effects. We hypothesized that H2S could produce antidepressant-like and anxiolytic-like effects in diabetic patients through its antioxidative effect. To test this hypothesis, we generated streptozotocin (STZ)-induced diabetic rats. We found that H2S alleviated depressive-like behaviors of STZ-induced diabetic rats in the forced swimming and tail suspension tests and reduced their anxiety-like behaviors in the elevated plus maze test. We also found that H2S significantly reduced levels of malondialdehyde and 4-hydroxynonenal and elevated levels of superoxide dismutase and reduced glutathione in the hippocampus of STZ-induced diabetic rats. The results provide evidence for antidepressant-like and anxiolytic-like effects of H2S in STZ-induced diabetic rats and suggest that the therapeutic effects may result from inhibition of hippocampal oxidative stress. These findings suggest that elevating H2S signaling is a potential target for treatment of depressive and anxiety disorders related to diabetes. PMID:25932716

  10. Emissions of ammonia, carbon dioxide, and hydrogen sulfide from swine wastewater during and after acidification treatment: effect of pH, mixing and aeration.

    PubMed

    Dai, X R; Blanes-Vidal, V

    2013-01-30

    This study aimed at evaluating the effect of swine slurry acidification and acidification-aeration treatments on ammonia (NH(3)), carbon dioxide (CO(2)) and hydrogen sulfide (H(2)S) emissions during slurry treatment and subsequent undisturbed storage. The study was conducted in an experimental setup consisting of nine dynamic flux chambers. Three pH levels (pH = 6.0, pH = 5.8 and pH = 5.5), combined with short-term aeration and venting (with an inert gas) treatments were studied. Acidification reduced average NH(3) emissions from swine slurry stored after acidification treatment compared to emissions during storage of non-acidified slurry. The reduction were 50%, 62% and 77% when pH was reduce to 6.0, 5.8 and 5.5, respectively. However, it had no significant effect on average CO(2) and H(2)S emissions during storage of slurry after acidification. Aeration of the slurry for 30 min had no effect on average NH(3), CO(2) and H(2)S emissions both during the process and from stored slurry after venting treatments. During aeration treatment, the NH(3), CO(2) and H(2)S release pattern observed was related to the liquid turbulence caused by the gas bubbles rather than to biological oxidation processes in this study. PMID:23246907

  11. Cadmium-Induced Hydrogen Sulfide Synthesis Is Involved in Cadmium Tolerance in Medicago sativa by Reestablishment of Reduced (Homo)glutathione and Reactive Oxygen Species Homeostases

    PubMed Central

    Cui, Weiti; Chen, Huiping; Zhu, Kaikai; Jin, Qijiang; Xie, Yanjie; Cui, Jin; Xia, Yan; Zhang, Jing; Shen, Wenbiao

    2014-01-01

    Until now, physiological mechanisms and downstream targets responsible for the cadmium (Cd) tolerance mediated by endogenous hydrogen sulfide (H2S) have been elusive. To address this gap, a combination of pharmacological, histochemical, biochemical and molecular approaches was applied. The perturbation of reduced (homo)glutathione homeostasis and increased H2S production as well as the activation of two H2S-synthetic enzymes activities, including L-cysteine desulfhydrase (LCD) and D-cysteine desulfhydrase (DCD), in alfalfa seedling roots were early responses to the exposure of Cd. The application of H2S donor sodium hydrosulfide (NaHS), not only mimicked intracellular H2S production triggered by Cd, but also alleviated Cd toxicity in a H2S-dependent fashion. By contrast, the inhibition of H2S production caused by the application of its synthetic inhibitor blocked NaHS-induced Cd tolerance, and destroyed reduced (homo)glutathione and reactive oxygen species (ROS) homeostases. Above mentioned inhibitory responses were further rescued by exogenously applied glutathione (GSH). Meanwhile, NaHS responses were sensitive to a (homo)glutathione synthetic inhibitor, but reversed by the cotreatment with GSH. The possible involvement of cyclic AMP (cAMP) signaling in NaHS responses was also suggested. In summary, LCD/DCD-mediated H2S might be an important signaling molecule in the enhancement of Cd toxicity in alfalfa seedlings mainly by governing reduced (homo)glutathione and ROS homeostases. PMID:25275379

  12. 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

  13. Hydrogen Sulfide Donor NaHS Reduces Organ Injury in a Rat Model of Pneumococcal Pneumosepsis, Associated with Improved Bio-Energetic Status

    PubMed Central

    Aslami, Hamid; Pulskens, Wilco P.; Kuipers, Maria T.; Bos, Aafkeline P.; van Kuilenburg, André B. P.; Wanders, Ronald J. A.; Roelofsen, Jeroen; Roelofs, Joris J. T. H.; Kerindongo, Raphaela P.; Beurskens, Charlotte J. P.; Schultz, Marcus J.; Kulik, Wim; Weber, Nina C.; Juffermans, Nicole P.

    2013-01-01

    Sepsis is characterized by a generalized inflammatory response and organ failure, associated with mitochondrial dysfunction. Hydrogen sulfide donor NaHS has anti-inflammatory properties, is able to reduce metabolism and can preserve mitochondrial morphology and function. Rats were challenged with live Streptococcus pneumonia or saline and infused with NaHS (36 µmol/kg/h) or vehicle. Lung and kidney injury markers were measured as well as mitochondrial function, viability and biogenesis. Infusion of NaHS reduced heart rate and body temperature, indicative of a hypo–metabolic state. NaHS infusion reduced sepsis–related lung and kidney injury, while host defense remained intact, as reflected by unchanged bacterial outgrowth. The reduction in organ injury was associated with a reversal of a fall in active oxidative phosphorylation with a concomitant decrease in ATP levels and ATP/ADP ratio. Preservation of mitochondrial respiration was associated with increased mitochondrial expression of ?–tubulin and protein kinase C–?, which acts as regulators of respiration. Mitochondrial damage was decreased by NaHS, as suggested by a reduction in mitochondrial DNA leakage in the lung. Also, NaHS treatment was associated with upregulation of peroxisome proliferator-activated receptor–? coactivator 1?, with a subsequent increase in transcription of mitochondrial respiratory subunits. These findings indicate that NaHS reduces organ injury in pneumosepsis, possibly via preservation of oxidative phosphorylation and thereby ATP synthesis as well as by promoting mitochondrial biogenesis. Further studies on the involvement of mitochondria in sepsis are required. PMID:23717435

  14. Sulfate and organic matter concentration in relation to hydrogen sulfide generation at inert solid waste landfill site - Limit value for gypsum.

    PubMed

    Asakura, Hiroshi

    2015-09-01

    In order to suggest a limit value for gypsum (CaSO4) for the suppression of hydrogen sulfide (H2S) generation at an inert solid waste landfill site, the relationship between raw material (SO4 and organic matter) for H2S generation and generated H2S concentration, and the balance of raw material (SO4) and product (H2S) considering generation and outflow were investigated. SO4 concentration should be less than approximately 100mg-SO4/L in order to suppress H2S generation to below 2000ppm. Total organic carbon (TOC) concentration should be less than approximately 200mg-C/L assuming a high SO4 concentration. The limit value for SO4 in the ground is 60mg-SO4/kg with 0.011wt% as gypsum dihydrate, i.e., approximately 1/10 of the limit value in inert waste as defined by the EU Council Decision (560mg-SO4/kg-waste). The limit value for SO4 in inert waste as defined by the EU Council Decision is high and TOC is strictly excluded. The cumulative amount of SO4 outflow through the liquid phase is much larger than that through the gas phase. SO4 concentration in pore water decreases with time, reaching half the initial concentration around day 100. SO4 reduction by rainfall can be expected in the long term. PMID:26123977

  15. Vasorelaxant Effect of a New Hydrogen Sulfide-Nitric Oxide Conjugated Donor in Isolated Rat Aortic Rings through cGMP Pathway

    PubMed Central

    Wu, Dan; Hu, Qingxun; Ma, Fenfen; Zhu, Yi Zhun

    2016-01-01

    Endothelium-dependent vasorelaxant injury leads to a lot of cardiovascular diseases. Both hydrogen sulfide (H2S) and nitric oxide (NO) are gasotransmitters, which play a critical role in regulating vascular tone. However, the interaction between H2S and NO in vasorelaxation is still unclear. ZYZ-803 was a novel H2S and NO conjugated donor developed by H2S-releasing moiety (S-propyl-L-cysteine (SPRC)) and NO-releasing moiety (furoxan). ZYZ-803 could time- and dose-dependently relax the sustained contraction induced by PE in rat aortic rings, with potencies of 1.5- to 100-fold greater than that of furoxan and SPRC. Inhibition of the generations of H2S and NO with respective inhibitors abolished the vasorelaxant effect of ZYZ-803. ZYZ-803 increased cGMP level and the activity of vasodilator stimulated phosphoprotein (VASP) in aortic rings, and those effects could be suppressed by the inhibitory generation of H2S and NO. Both the inhibitor of protein kinase G (KT5823) and the inhibitor of KATP channel (glibenclamide) suppressed the vasorelaxant effect of ZYZ-803. Our results demonstrated that H2S and NO generation from ZYZ-803 cooperatively regulated vascular tone through cGMP pathway, which indicated that ZYZ-803 had therapeutic potential in cardiovascular diseases. PMID:26635911

  16. Synergistic effect of antioxidant system and osmolyte in hydrogen sulfide and salicylic acid crosstalk-induced heat tolerance in maize (Zea mays L.) seedlings.

    PubMed

    Li, Zhong-Guang

    2015-09-01

    Salicylic acid (SA), is a plant hormone with multifunction that is involved in plant growth, development and the acquisition of stress tolerance. Hydrogen sulfide (H2S) is emerging similar functions, but crosstalk between SA and H2S in the acquisition of heat tolerance is not clear. Our recent study firstly reported that SA treatment enhanced the activity of L-cysteine desulfhydrase (L-DES), a key enzyme in H2S biosynthesis, followed by induced endogenous H2S accumulation, which in turn improved the heat tolerance of maize seedlings. (1) In addition, NaHS, a H2S donor, enhanced SA-induced heat tolerance, while its biosynthesis inhibitor DL-propargylglycine (PAG) and scavenger hydroxylamine (HT) weakened SA-induced heat tolerance. Also, NaHS had no significant effect on SA accumulation and its biosynthesis enzymes phenylalanine ammonia lyase (PAL) and benzoic-acid-2-hydroxylase (BA2H) activities, as well as significant difference was not observed in NaHS-induced heat tolerance of maize seedlings by SA biosynthesis inhibitors paclobutrazol (PAC) and 2-aminoindan-2-phosph- onic acid (AIP) treatment. (1) Further study displayed that SA induced osmolytes (proline, betaine and trehalose) accumulation and enhancement in activity of antioxidant system in maize seedlings. These results showed that antioxidant system and osmolyte play a synergistic role in SA and H2S crosstalk-induced heat tolerance of maize seedlings. PMID:26337076

  17. Alkali promoted molybdenum (IV) sulfide based catalysts, development and characterization for alcohol synthesis from carbon monoxide and hydrogen

    NASA Astrophysics Data System (ADS)

    Molina, Belinda Delilah

    For more than a century transition metal sulfides (TMS) have been the anchor of hydro-processing fuels and upgrading bitumen and coal in refineries worldwide. As oil supplies dwindle and environmental laws become more stringent, there is a greater need for cleaner alternative fuels and/or synthetic fuels. The depletion of oil reserves and a rapidly increasing energy demand worldwide, together with the interest to reduce dependence on foreign oil makes alcohol production for fuels and chemicals via the Fischer Tropsch synthesis (FTS) very attractive. The original Fischer-Tropsch (FT) reaction is the heart of all gas-to-liquid technologies; it creates higher alcohols and hydrocarbons from CO/H2 using a metal catalyst. This research focuses on the development of alkali promoted MoS2-based catalysts to investigate an optimal synthesis for their assistance in the production of long chain alcohols (via FTS) for their use as synthetic transportation liquid fuels. Properties of catalytic material are strongly affected by every step of the preparation together with the quality of the raw materials. The choice of a laboratory method for preparing a given catalyst depends on the physical and chemical characteristics desired in the final composition. Characterization methods of K0.3/Cs0.3-MoS2 and K0.3 /Cs0.3-Co0.5MoS2 catalysts have been carried out through Scanning Electron Microscopy (SEM), BET porosity and surface analysis, Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). Various characterization methods have been deployed to correlate FTS products versus crystal and morphological properties of these heterogeneous catalysts. A lab scale gas to liquid system has been developed to evaluate its efficiency in testing FT catalysts for their production of alcohols.

  18. Three Gaseous Neurotransmitters, Nitric oxide, Carbon Monoxide, and Hydrogen Sulfide, Are Involved in the Neurogenic Relaxation Responses of the Porcine Internal Anal Sphincter

    PubMed Central

    Folasire, Oladayo; Mills, Kylie A; Sellers, Donna J; Chess-Williams, Russ

    2016-01-01

    Background/Aims The internal anal sphincter (IAS) plays an important role in maintaining continence and a number of neurotransmitters are known to regulate IAS tone. The aim of this study was to determine the relative importance of the neurotransmitters involved in the relaxant and contractile responses of the porcine IAS. Methods Responses of isolated strips of IAS to electrical field stimulation (EFS) were obtained in the absence and presence of inhibitors of neurotransmitter systems. Results Contractile responses of the sphincter to EFS were unaffected by the muscarinic receptor antagonist, atropine (1 ?M), but were almost completely abolished by the adrenergic neuron blocker guanethidine (10 ?M). Contractile responses were also reduced (by 45% at 5 Hz, P < 0.01) following desensitisation of purinergic receptors with ?,?-methylene-ATP (10 ?M). In the presence of guanethidine, atropine, and ?,?-methylene-ATP, the remaining relaxatory responses to EFS were examined. These responses were not altered by the cyclooxygenase inhibitor, indomethacin (5 ?M), the vasoactive intestinal polypeptide receptor antagonist, [d-p-Cl-Phe6,Leu17]-vasoactive intestinal peptide (PheLeu-VIP; 100 nM), or the purinoceptor antagonists, 8-phenyltheophyline (P1 receptors) or suramin (P2 receptors). However, relaxation responses were reduced by N?-nitro-L-arginine (L-NNA; 100 ?M), an inhibitor of nitric oxide synthesis (40–50% reduction), zinc protoprophyrin IX (10 ?M), an inhibitor of carbon monoxide synthesis (20–40% reduction), and also propargylglycine (30 ?M) and aminooxyacetic acid (30 ?M), inhibitors of hydrogen sulphide synthesis (15–20% reduction). Conclusions Stimulation of IAS efferent nerves releases excitatory and inhibitory neurotransmitters: noradrenaline is the predominant contractile transmitter with a smaller component from ATP, whilst 3 gases mediate relaxation responses to EFS, with the combined contributions being nitric oxide > carbon monoxide > hydrogen sulfide. PMID:26486177

  19. Carbon dioxide and hydrogen sulfide degassing and cryptic thermal input to Brimstone Basin, Yellowstone National Park, Wyoming

    USGS Publications Warehouse

    Bergfeld, D.; Evans, William C.; Lowenstern, J. B.; Hurwitz, S.

    2012-01-01

    Brimstone Basin, a remote area of intense hydrothermal alteration a few km east of the Yellowstone Caldera, is rarely studied and has long been considered to be a cold remnant of an ancient hydrothermal system. A field campaign in 2008 confirmed that gas emissions from the few small vents were cold and that soil temperatures in the altered area were at background levels. Geochemical and isotopic evidence from gas samples (3He/4He ~ 3RA, ?13C-CO2 ~ ? 3‰) however, indicate continuing magmatic gas input to the system. Accumulation chamber measurements revealed a surprisingly large diffuse flux of CO2 (~ 277 t d-1) and H2S (0.6 t d-1). The flux of CO2 reduces the 18O content of the overlying cold groundwater and related stream waters relative to normal meteoric waters. Simple isotopic modeling reveals that the CO2 likely originates from geothermal water at a temperature of 93 ± 19 °C. These results and the presence of thermogenic hydrocarbons (C1:C2 ~ 100 and ?13C-CH4 = ? 46.4 to ? 42.8‰) in gases require some heat source at depth and refute the assumption that this is a “fossil” hydrothermal system.

  20. A Process Based Approach to Modeling Hydrogen Sulfide Emissions Across the Air-Surface Interface of Manure from Concentrated Animal Feeding Operations

    NASA Astrophysics Data System (ADS)

    Rumsey, I. C.; Aneja, V.

    2009-12-01

    Hydrogen sulfide (H2S) emissions from concentrated animal feeding operations (CAFOs) are an important concern due to their contribution to odor and their potential to form PMfine. CAFO manure surface emissions occur from barns floors, during waste storage and treatment, and following land application. There is a need for a process based model, which will provide a method for quantifying emissions in different production, management and environmental conditions. A process based air-surface interface mass transfer model with chemical reactions was developed based on theoretical principles and related published information on H2S emissions. Different approaches were used to calculate the three main components of the model: the dissociation constant, the Henry’s law constant, and the overall mass transport coefficient. The dissociation constant was calculated based on thermodynamic principles and was corrected for the ionic strength of the manure. Similarly, the Henry’s law constant was also calculated based on thermodynamic principles. The overall mass transfer coefficient was developed using a previously published air-surface interface mass transport model, which considered the most important properties affecting mass transport to be the diffusivity of H2S in air, the air viscosity, and the air density. These parameters were modeled using dimensional analysis, which identified the variables that needed to be measured to determine the relevant constant and exponents values. By using the previously published study’s model and their measured constant and exponent values, an appropriate overall mass transfer coefficient was developed. Sensitivity analysis of the process based air-surface interface mass transfer model showed predicted fluxes to be most dependent on manure sulfide concentration and manure pH, and to a smaller extent on wind speed and manure temperature. Model predicted fluxes were compared with measured H2S flux and meteorological and physiochemical measurements made from a swine waste anaerobic treatment lagoon using a dynamic flow-through chamber system. Measurements were conducted for all four seasonal periods. Model predicted fluxes were found to compare well to measured flux values. It is hypothesized that this model may be used to predict H2S emissions from a variety of manure surfaces, thus allowing a method for quantifying emissions in different production, management and environmental conditions.

  1. Selenium sulfide

    Integrated Risk Information System (IRIS)

    Selenium sulfide ; CASRN 7446 - 34 - 6 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

  2. Carbonyl sulfide

    Integrated Risk Information System (IRIS)

    Carbonyl sulfide ; CASRN 463 - 58 - 1 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

  3. Selective chemical dissolution of sulfides: An evaluation of six methods applicable to assaying sulfide-bound nickel

    USGS Publications Warehouse

    Klock, P.R.; Czamanske, G.K.; Foose, M.; Pesek, J.

    1986-01-01

    Six analytical techniques for the selective chemical dissolution of sulfides are compared with the purpose of defining the best method for accurately determining the concentration of sulfide-bound nickel. Synthesized sulfide phases of known elemental content, mixed with well-analyzed silicates, were used to determine the relative and absolute efficiency, based on Ni and Mg recovery, of the techniques. Tested leach-methods purported to dissolve sulfide from silicate phases include: brominated water, brominated water-carbon tetrachloride, nitric-hydrochloric acid, hydrogen peroxide-ammonium citrate, bromine-methanol and hydrogen peroxide-ascorbic acid. Only the hydrogen peroxide-ammonium citrate method did not prove adequate in dissolving the sulfide phases. The remaining five methods dissolved the sulfide phases, but the indicated amount of attack on the silicate portion ranged from 3% to 100%. The bromine-methanol method is recommended for assaying sulfide-Ni deposits when Ni is also present in silicate phases. ?? 1986.

  4. Chemistry, isotopic composition, and origin of a methane-hydrogen sulfide hydrate at the Cascadia subduction zone

    USGS Publications Warehouse

    Kastner, M.; Kvenvolden, K.A.; Lorenson, T.D.

    1998-01-01

    Although the presence of extensive gas hydrate on the Cascadia margin, offshore from the western U.S. and Canada, has been inferred from marine seismic records and pore water chemistry, solid gas hydrate has only been found at one location. At Ocean Drilling Program (ODP) Site 892, offshore from central Oregon, gas hydrate was recovered close to the sediment - water interface at 2-19 m below the seafloor, (mbsf) at 670 m water depth. The gas hydrate occurs as elongated platy crystals or crystal aggregates, mostly disseminated irregularly, with higher concentrations occurring in discrete zones, thin layers, and/or veinlets parallel or oblique to the bedding. A 2-to 3-cm thick massive gas hydrate layer, parallel to bedding, was recovered at ???17 mbsf. Gas from a sample of this layer was composed of both CH4 and H2S. This sample is the first mixed-gas hydrate of CH4-H2S documented in ODP; it also contains ethane and minor amounts of CO2. Measured temperature of the recovered core ranged from 2 to - 18??C and are 6 to 8 degrees lower than in-situ temperatures. These temperature anomalies were caused by the partial dissociation of the CH4-H2S hydrate during recovery without a pressure core sampler. During this dissociation, toxic levels of H2S (??34S, +27.4???) were released. The ??13C values of the CH4 in the gas hydrate, -64.5 to -67.5???(PDB), together with ??D values of - 197 to - 199???(SMOW) indicate a primarily microbial source for the CH4. The ??18O value of the hydrate H2O is +2.9???(SMOW), comparable with the experimental fractionation factor for sea-ice. The unusual composition (CH4-H2S) and depth distribution (2-19 mbsf) of this gas hydrate indicate mixing between a methane-rich fluid with a pore fluid enriched in sulfide; at this site the former is advecting along an inclined fault into the active sulfate reduction zone. The facts that the CH4-H2S hydrate is primarily confined to the present day active sulfate reduction zone (2-19 mbsf), and that from here down to the BSR depth (19-68 mbsf) the gas hydrate inferred to exist is a ???99% CH4 hydrate, suggest that the mixing of CH4 and H2S is a geologically young process. Because the existence of a mixed CH4-H2S hydrate is indicative of moderate to intense advection of a methane-rich fluid into a near surface active sulfate reduction zone, technically active (faulted) margins with organic-rich sediments and moderate to high sedimentation rates are the most likely regions of occurrence. The extension of such a mixed hydrate below the sulfate reduction zone should reflect the time-span of methane advection into the sulfate reduction zone. ?? 1998 Elsevier Science B.V. All rights reserved.

  5. MODIFICATION OF METHODS 9030 AND 9031 FOR THE ANALYSIS OF SULFIDE BY SPECIFIC ION ELECTRODE

    EPA Science Inventory

    Two OSW SW-846 methods (Method 9030 and 9031) used for the determination of sulfide have been modified to include the use of sulfide specific ion electrodes (SIE). urrently in both methods sulfide is converted to hydrogen sulfide and distilled into a scrubber solution for subsequ...

  6. Downhole geothermal well sensors comprising a hydrogen-resistant optical fiber

    DOEpatents

    Weiss, Jonathan D.

    2005-02-08

    A new class of optical fiber based thermal sensors has been invented. The new sensors comprise hydrogen-resistant optical fibers which are able to withstand a hot, hydrogen-containing environment as is often found in the downhole well environment.

  7. The Hydrogen Sulfide Donor NaHS Delays Programmed Cell Death in Barley Aleurone Layers by Acting as an Antioxidant

    PubMed Central

    Zhang, Ying-Xin; Hu, Kang-Di; Lv, Kai; Li, Yan-Hong; Hu, Lan-Ying; Zhang, Xi-Qi; Ruan, Long; Liu, Yong-Sheng; Zhang, Hua

    2015-01-01

    H2S is a signaling molecule in plants and animals. Here we investigated the effects of H2S on programmed cell death (PCD) in barley (Hordeum vulgare L.) aleurone layers. The H2S donor NaHS significantly delayed PCD in aleurone layers isolated from imbibed embryoless barley grain. NaHS at 0.25?mM effectively reduced the accumulation of superoxide anion (·O2?), hydrogen peroxide (H2O2), and malondialdehyde (MDA), promoted the activity of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and decreased those of lipoxygenase (LOX) in isolated aleurone layers. Quantitative-PCR showed that NaHS treatment of aleurone tissue led to enhanced transcript levels of the antioxidant genes HvSOD1, HvAPX, HvCAT1, and HvCAT2 and repressed transcript levels of HvLOX (lipoxygenase gene) and of two cysteine protease genes HvEPA and HvCP3-31. NaHS treatment in gibberellic acid- (GA-) treated aleurone layers also delayed the PCD process, reduced the content of ·O2?, and increased POD activity while decreasing LOX activity. Furthermore, ?-amylase secretion in barley aleurone layers was enhanced by NaHS treatment regardless of the presence or absence of GA. These data imply that H2S acted as an antioxidant in delaying PCD and enhances ?-amylase secretion regardless of the presence of GA in barley aleurone layers. PMID:26078814

  8. Olfactory mucosal necrosis in male CD rats following acute inhalation exposure to hydrogen sulfide: reversibility and the possible role of regional metabolism.

    PubMed

    Brenneman, Karrie A; Meleason, David F; Sar, Madhabananda; Marshall, Marianne W; James, R Arden; Gross, Elizabeth A; Martin, Joseph T; Dorman, David C

    2002-01-01

    Hydrogen sulfide (H2S) is a potent inhibitor of cytochrome oxidase (CO) and is associated with dysosmia and anosmia in humans and nasal lesions in exposed rodents. An improved understanding of the pathogenesis of these lesions is needed to determine their toxicological relevance. We exposed 10-week-old male CD rats to 0, 30, 80, 200, or 400 ppm H2S for 3 hours/day for 1 or 5 days consecutively. The nose was histologically examined 24 hours after H2S exposure, and lesion recovery was assessed at 2 and 6 weeks following the 5-day exposure. A single 3-hour exposure to > or = 80 ppm H2S resulted in regeneration of the respiratory mucosa and full thickness necrosis of the olfactory mucosa localized to the ventral and dorsal meatus, respectively. Repeated exposure to the same concentrations caused necrosis of the olfactory mucosa with early mucosal regeneration that extended from the dorsal medial meatus to the caudal regions of the ethmoid recess. Acute exposure to 400 ppm H2S induced severe mitochondrial swelling in sustentacular cells and olfactory neurons, which progressed to olfactory epithelial necrosis and sloughing. CO immunoreactive cells were more frequently observed in regions of the olfactory mucosa commonly affected by H2S than in regions that were not. These findings demonstrate that acute exposure to >80 ppm H2S resulted in reversible lesions in the respiratory and olfactory mucosae of the CD rat and that CO immunoreactivity may be a susceptibility factor for H2S-induced olfactory toxicity in the rat. PMID:11950163

  9. Cardioprotective effects and pharmacokinetic properties of a controlled release formulation of a novel hydrogen sulfide donor in rats with acute myocardial infarction

    PubMed Central

    Tran, Ba Hieu; Huang, Chengrong; Zhang, Qiuyan; Liu, Xu; Lin, Shizhou; Liu, Hongrui; Wang, Shujun; Zhu, Yi Zhun

    2015-01-01

    We previously reported that S-propargyl-cysteine (SPRC) exerts cardioprotective effects by elevating H2S levels via the CSE/H2S pathway. In the present study, we investigated the cardioprotective effects and pharmacokinetic properties of a controlled release formulation of SPRC (CR-SPRC) in an in vivo rat model of myocardial infarction (MI). Rats were randomly assigned to seven groups that were pre-treated with CR-SPRC daily for 7 days prior to ligation of the left anterior descending coronary artery to induce MI. Cardiac function and infarct size were determined after MI, and we examined the activity of antioxidant enzymes, expression of anti-inflammation proteins and hydrogen sulfide levels. Mixed-mode, reversed-phase and cation-exchange HPLC–MS/MS were used to compare the pharmacokinetic properties of CR-SPRC and SPRC. CR-SPRC significantly reduced infarct size and creatine kinase (CK) and lactate dehydrogenase (LDH) leakage and it preserved cardiac function during MI. CR-SPRC displayed antioxidant properties, preserving glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) levels whereas reducing malondialdehyde (MDA) levels. Moreover, CR-SPRC significantly reduced the protein levels of inflammatory biomarkers (phospho-NF-?B p65/NF-?B p65, TNF-?) and increased cystathionine-?-lyase (CSE) and I?-B? protein levels. CR-SPRC had better pharmacokinetic properties than SPRC, with a reduced concentration peak (Cmax), prolonged time to reach peak concentration (Tmax), prolonged mean residence time (MRTinf) and increased AUC0–t. CR-SPRC showed protective effects against MI via the CSE/H2S pathway and demonstrated better cardioprotective effects than SPRC by prolonging the release of endogenous H2S. PMID:26182378

  10. Effects of Tai Chi exercise on blood pressure and plasma levels of nitric oxide, carbon monoxide and hydrogen sulfide in real-world patients with essential hypertension.

    PubMed

    Pan, Xiaogui; Zhang, Yi; Tao, Sai

    2015-01-01

    Objective was to investigate the effects of Tai Chi exercise on nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) levels, and blood pressure (BP) in patients with essential hypertension (EH). EH patients were assigned to the Tai Chi exercise group (HTC, n?=?24), and hypertension group (HP, n?=?16) by patients' willingness. Healthy volunteers matched for age and gender were recruited as control (NP, n?=?16). HTC group performed Tai Chi (60?min/d, 6?d/week) for 12 weeks. Measurements (blood glucose, cholesterol, NO, CO, H2S and BP) were obtained at week 0, 6, and 12. SBP, MAP, and low-density lipoprotein cholesterol levels decreased, and high-density lipoprotein cholesterol levels increased by week 12 in the HTC group (all p?

  11. Effect of S-aspirin, a novel hydrogen-sulfide-releasing aspirin (ACS14), on atherosclerosis in apoE-deficient mice.

    PubMed

    Zhang, Huili; Guo, Changfa; Zhang, Alian; Fan, Yuqi; Gu, Ting; Wu, Duojiao; Sparatore, Anna; Wang, Changqian

    2012-12-15

    Hydrogen sulfide (H(2)S) is a novel gaseous mediator that plays important roles in atherosclerosis. The present study investigated the effect of a novel H(2)S-releasing aspirin, ACS14 (2-acetyloxybenzoic acid 4-(3-thioxo-3H-1,2-dithiol-5-yl)phenyl ester), on atherosclerotic plaques in fat-fed apoE(-/-) mice and the underlying mechanism with respect to CX3C chemokine receptor 1 (CX3CR1) in macrophages. Mouse macrophage cell line RAW264.7 or mouse peritoneal macrophages were preincubated with aspirin (50, 100 or 200?M), ACS14 (50, 100 or 200?M) or vehicle for 6h, and then stimulated with interferon (IFN)-? (500U/ml) or lipopolysaccharide (LPS; 10?g/ml) for 12h. ACS14, but not aspirin, dose-dependently inhibited IFN-? or LPS-induced CX3CR1 expression and CX3CR1-mediated chemotaxis in macrophages. The inhibitory effect of ACS14 on CX3CR1 expression was abolished by pretreatment with GW9662, a selective peroxisome proliferator-activated receptor (PPAR)-? antagonist, suggesting that suppression of macrophage CX3CR1 expression by ACS14 is PPAR-? dependent. Eight-week-old male apoE(-/-) mice received intraperitoneal ACS14 (15 or 30?mol/kg/day) or aspirin (15 or 30?mol/kg/day) 4 weeks after fat feeding. Twelve weeks after ACS14 or aspirin treatment, mice were sacrificed to evaluate the extent of atherosclerosis and CX3CR1 expression in brachiocephalic artery (BCA). We found that ACS14, but not aspirin, significantly downregulated CX3CR1 expression in atherosclerotic plaques. ACS14 considerably impeded the formation and development of atherosclerosis as compared to a molar equivalent dose of aspirin. These data indicate that ACS14 may prevent the progression of atherosclerosis by downregulating macrophage CX3CR1 expression via a PPAR-?-dependent mechanism. PMID:23085268

  12. Hydrogen sulfide-releasing NSAIDs inhibit the growth of human cancer cells: a general property and evidence of a tissue type-independent effect.

    PubMed

    Chattopadhyay, Mitali; Kodela, Ravinder; Nath, Niharika; Dastagirzada, Yosef M; Velázquez-Martínez, Carlos A; Boring, Daniel; Kashfi, Khosrow

    2012-03-15

    Hydrogen sulfide-releasing non-steroidal anti-inflammatory drugs (HS-NSAIDs) are an emerging novel class of compounds with significant anti-inflammatory properties. They consist of a traditional NSAID to which an H(2)S-releasing moiety is covalently attached. We examined the effects of four different HS-NSAIDs on the growth properties of eleven different human cancer cell lines of six different tissue origins. Human colon, breast, pancreatic, prostate, lung, and leukemia cancer cell lines were treated with HS-aspirin, -sulindac, -iburofen, -naproxen, and their traditional counterparts. HS-NSAIDs inhibited the growth of all cancer cell lines studied, with potencies of 28- to >3000-fold greater than that of their traditional counterparts. HS-aspirin (HS-ASA) was consistently the most potent. HS-NSAIDs inhibited cell proliferation, induced apoptosis, and caused G(0)/G(1) cell cycle block. Metabolism of HS-ASA by colon cells showed that the acetyl group of ASA was hydrolyzed rapidly, followed by hydrolysis of the ester bond linking the salicylate anion to the H(2)S releasing moiety, producing salicylic acid and ADT-OH from which H(2)S is released. In reconstitution studies, ASA and ADT-OH were individually less active than the intact HS-ASA towards cell growth inhibition. Additionally, the combination of these two components representing a fairly close approximation to the intact HS-ASA, was 95-fold less active than the intact HS-ASA for growth inhibition. Taken together, these results demonstrate that HS-NSAIDs have potential anti-growth activity against a wide variety of human cancer cells. PMID:22222427

  13. Hydrogen Sulfide Epigenetically Attenuates Homocysteine-Induced Mitochondrial Toxicity Mediated Through NMDA Receptor in Mouse Brain Endothelial (bEnd3) Cells.

    PubMed

    Kamat, Pradip K; Kalani, Anuradha; Tyagi, Suresh C; Tyagi, Neetu

    2015-02-01

    Previously we have shown that homocysteine (Hcy) caused oxidative stress and altered mitochondrial function. Hydrogen sulfide (H2S) has potent anti-inflammatory, anti-oxidative, and anti-apoptotic effects. Therefore, in the present study we examined whether H2S ameliorates Hcy-induced mitochondrial toxicity which led to endothelial dysfunction in part, by epigenetic alterations in mouse brain endothelial cells (bEnd3). The bEnd3 cells were exposed to 100??M Hcy treatment in the presence or absence of 30??M NaHS (donor of H2S) for 24?h. Hcy-activate NMDA receptor and induced mitochondrial toxicity by increased levels of Ca(2+), NADPH-oxidase-4 (NOX-4) expression, mitochondrial dehydrogenase activity and decreased the level of nitrate, superoxide dismutase (SOD-2) expression, mitochondria membrane potentials, ATP production. To confirm the role of epigenetic, 5'-azacitidine (an epigenetic modulator) treatment was given to the cells. Pretreatment with NaHS (30??M) attenuated the Hcy-induced increased expression of DNMT1, DNMT3a, Ca(2+), and decreased expression of DNMT3b in bEND3 cells. Furthermore, NaHS treatment also mitigated mitochondrial oxidative stress (NOX4, ROS, and NO) and restored ATP that indicates its protective effects against mitochondrial toxicity. Additional, NaHS significantly alleviated Hcy-induced LC3-I/II, CSE, Atg3/7, and low p62 expression which confirm its effect on mitophagy. Likewise, NaHS also restored level of eNOS, CD31, VE-cadherin and ET-1 and maintains endothelial function in Hcy treated cells. Molecular inhibition of NMDA receptor by using small interfering RNA showed protective effect whereas inhibition of H2S production by propargylglycine (PG) (inhibitor of enzyme CSE) showed mitotoxic effect. Taken together, results demonstrate that, administration of H2S protected the cells from HHcy-induced mitochondrial toxicity and endothelial dysfunction. PMID:25056869

  14. Replacement of hazardous chromium impregnating agent from silver/copper/chromium-impregnated active carbon using triethylenediamine to remove hydrogen sulfide, trichloromethane, ammonia, and sulfur dioxide.

    PubMed

    Wu, Li-Chun; Chung, Ying-Chien

    2009-03-01

    Activated carbon (AC) is widely used as an effective adsorbent in many applications, including industrial-scale air purification systems and air filter systems in gas masks. In general, ACs without chemical impregnation are good adsorbents of organic vapors but poor adsorbents of low-molecular-weight or polar gases such as chlorine, sulfur dioxide (SO2), formaldehyde, and ammonia (NH3). Impregnated ACs modified with metallic impregnating agents (ASC-carbons; e.g., copper, chromium, and silver) enhance the adsorbing properties of the ACs for simultaneously removing specific poisonous gases, but disposal of the chromium metal salt used to impregnate the ACs has the potential to result in situations that are toxic to both humans and the environment, thereby necessitating the search for replaceable organic impregnating agents that represent a much lower risk. The aim of this study was to assess the gas removal efficiency of an AC in which the organic impregnating agent triethylenediamine (TEDA) largely replaced the metallic impregnating agent chromium. We assessed batch and continuous adsorption capacities in situ for removing simulated hydrogen sulfide (H2S), trichloromethane (CHCl3), NH3, and SO2 gases. Brunauer-Emmet-Teller measurements and scanning electron microscopy analyses identified the removal mechanism by which TEDA-impregnated AS-carbon (dechromium ASC-carbon) adsorbs gases and determined the removal capacity for H2S, CHCl3, NH3, and SO2 to be 311, 258, 272, and 223 mg/g-C, respectively. These results demonstrate that TEDA-impregnated AS-carbon is significantly more efficient than ASC-carbon in adsorbing these four gases. Organic TEDA-impregnating agents have also been proven to be a reliable and environmental friendly agent and therefore a safe replacement of the hazardous chromium found in conventional ASC-carbon used in removing toxic gases from the airstream. PMID:19320264

  15. Hydrogen Sulfide Regulates Salt Tolerance in Rice by Maintaining Na+/K+ Balance, Mineral Homeostasis and Oxidative Metabolism Under Excessive Salt Stress

    PubMed Central

    Mostofa, Mohammad G.; Saegusa, Daisuke; Fujita, Masayuki; Tran, Lam-Son Phan

    2015-01-01

    Being a salt sensitive crop, rice growth and development are frequently affected by soil salinity. Hydrogen sulfide (H2S) has been recently explored as an important priming agent regulating diverse physiological processes of plant growth and development. Despite its enormous prospects in plant systems, the role of H2S in plant stress tolerance is still elusive. Here, a combined pharmacological, physiological and biochemical approach was executed aiming to examine the possible mechanism of H2S in enhancement of rice salt stress tolerance. We showed that pretreating rice plants with H2S donor sodium bisulfide (NaHS) clearly improved, but application of H2S scavenger hypotaurine with NaHS decreased growth and biomass-related parameters under salt stress. NaHS-pretreated salt-stressed plants exhibited increased chlorophyll, carotenoid and soluble protein contents, as well as suppressed accumulation of reactive oxygen species (ROS), contributing to oxidative damage protection. The protective mechanism of H2S against oxidative stress was correlated with the elevated levels of ascorbic acid, glutathione, redox states, and the enhanced activities of ROS- and methylglyoxal-detoxifying enzymes. Notably, the ability to decrease the uptake of Na+ and the Na+/K+ ratio, as well as to balance mineral contents indicated a role of H2S in ion homeostasis under salt stress. Altogether, our results highlight that modulation of the level of endogenous H2S genetically or exogenously could be employed to attain better growth and development of rice, and perhaps other crops, under salt stress. Furthermore, our study reveals the importance of the implication of gasotransmitters like H2S for the management of salt stress, thus assisting rice plants to adapt to adverse environmental changes.

  16. Target-induced nanocatalyst deactivation facilitated by core@shell nanostructures for signal-amplified headspace-colorimetric assay of dissolved hydrogen sulfide.

    PubMed

    Gao, Zhuangqiang; Tang, Dianyong; Tang, Dianping; Niessner, Reinhard; Knopp, Dietmar

    2015-10-01

    Colorimetric assay platforms for dissolved hydrogen sulfide (H2S) have been developed for more than 100 years, but most still suffer from relatively low sensitivity. One promising route out of this predicament relies on the design of efficient signal amplification methods. Herein, we rationally designed an unprecedented H2S-induced deactivation of (gold core)@(ultrathin platinum shell) nanocatalysts (Au@TPt-NCs) as a highly efficient signal amplification method for ultrasensitive headspace-colorimetric assay of dissolved H2S. Upon target introduction, Au@TPt-NCs were deactivated to different degrees dependent on H2S levels, and the degrees could be indicated by using a Au@TPt-NCs-triggered catalytic system as a signal amplifier, thus paving a way for H2S sensing. The combination of experimental studies and density functional theory (DFT) studies revealed that the Au@TPt-NCs with only 2-monolayer equivalents of Pt (?Pt = 2) were superior for H2S-induced nanocatalyst deactivation owing to their enhanced peroxidase-like catalytic activity and deactivation efficiency stemmed from the unique synergistic structural/electronic effects between Au nanocores and ultrathin Pt nanoshells. Importantly, our analytical results showed that the designed method was indeed highly sensitive for sensing H2S with a wide linear range of 10-100 nM, a slope of 0.013 in the regression equation, and a low detection limit of 7.5 nM. Also the selectivity, reproducibility, and precision were excellent. Furthermore, the method was validated for the analysis of H2S-spiked real samples, and the recovery in all cases was 91.6-106.7%. With the merits of high sensitivity and selectivity, simplification, low cost, and visual readout with the naked eye, the colorimetric method has the potential to be utilized as an effective detection kit for point-of-care testing. PMID:26327230

  17. Effects of conventional and hydrogen sulfide-releasing non-steroidal anti-inflammatory drugs in rats with stress-induced and epinephrine-induced gastric damage.

    PubMed

    Fomenko, Iryna; Sklyarov, Alexander; Bondarchuk, Tetyana; Biletska, Lilya; Panasyuk, Natalia; Wallace, John L

    2014-12-01

    Mechanisms of gastric defence under conditions of combined influence of acute stress and non-steroidal anti-inflammatory drugs (NSAIDs) are still poorly studied. The aim of this study was to explore the effects of different types of NSAIDs (naproxen, celecoxib and ATB-346) in producing experimental gastric lesions (induced by water-restraint stress (WRS) or by epinephrine (EPN) injection) and to determine the role of lipid peroxidation and the nitric oxide (NO) system in the pathogenesis of the damage. Male rats were used (eight per group) in this work. The NSAIDs were all administered at a dose 10?mg?kg(-1) 30?min prior to WRS or EPN injection. Administration of naproxen to the control rats caused development of gastric lesions, whereas administration of a hydrogen sulfide (H2S)-releasing NSAID (ATB-346) or a selective cyclooxygenase-2 inhibitor (celecoxib) did not cause gastric damage. In contrast, lipid peroxidation processes were enhanced in all groups as was the activity of NO synthase (NOS). Pretreatment with naproxen in the WRS model caused an increase in severity of damage and a decrease in NOS activity. ATB-346 displayed beneficial effects, manifested by a decrease in the area of gastric damage, but parameters of lipid peroxidation and the NOS system did not differ substantially from those in the group treated with naproxen. Administration of different NSAIDs under conditions of EPN-induced gastric damage resulted in the decrease in NOS activity and lipid peroxidation. None of the tested NSAIDs exacerbated EPN-induced gastric mucosal injury; indeed, they all reduced the extent of damage. PMID:25238023

  18. Evaluation of portable single-gas monitors for the detection of low levels of hydrogen sulfide and sulfur dioxide in petroleum industry environments.

    PubMed

    Hemingway, M A; Walsh, P T; Hardwick, K R; Wilcox, G

    2012-01-01

    Many portable single-gas monitors are used for the detection of low concentrations of hydrogen sulfide (H(2)S) and sulfur dioxide (SO(2)) in the workplace. With the recent lowering of the H(2)S and SO(2) ACGIH® threshold limit value (TLV®) the ability of these devices to selectively respond to these new lower levels is not well documented in petroleum industry environments, which often have potential interfering gases and vapors present as well as varying environmental conditions. Tests were carried out to measure the ability of various monitors with their respective sensors to correctly quantify and respond to H(2)S and SO(2) in a simulated petroleum industry environment. This included the identification of selected interference effects and estimation of the reliable lower limit of detection for real workplace environments. None of the H(2)S monitors responded at 0.1 times the new TLV (0.1 ppm), only some of them responded at the new TLV concentration (1 ppm), and all the monitors exposed to five times the new TLV (5 ppm) responded with reasonable accuracy. There was generally little effect of interferent gases and vapors on the H(2)S monitors. None of the SO(2) monitors responded at 0.1 and 1 times the new TLV (0.025 ppm and 0.25 ppm) concentrations, and all but one of them exposed to five times the new TLV (1.25 ppm) responded. There was much greater cross-sensitivity to interferents at the tested concentrations with the SO(2) monitors, which responded to six out of eight of the interferents tested. Results demonstrate that these monitors cannot reliably alarm and measure H(2)S or SO(2) concentrations at the new TLVs with an acceptable degree of accuracy. However, these monitors are designed to alarm as a safety device; these results do not change this important function. PMID:22500974

  19. Differential susceptibility to hydrogen sulfide-induced apoptosis between PHLDA1-overexpressing oral cancer cell lines and oral keratinocytes: role of PHLDA1 as an apoptosis suppressor.

    PubMed

    Murata, Takatoshi; Sato, Tsutomu; Kamoda, Takeshi; Moriyama, Hiromitsu; Kumazawa, Yasuo; Hanada, Nobuhiro

    2014-01-15

    Hydrogen sulfide (H2S) is a novel gasotransmitter that plays multiple biological roles in various body systems. In addition to its endogenous production, H2S is produced by bacteria colonizing digestive organs, including the oral cavity. H2S was previously shown to enhance pro-apoptotic effects in cancer cell lines, although the mechanisms involved remain unclear. To properly assess the anti-cancer effects of H2S, however, investigations of apoptotic effects in normal cells are also necessary. The aims of this study were (1) to compare the susceptibility to H2S-induced apoptosis between the oral cancer cell line Ca9-22 and oral keratinocytes that were derived from healthy gingiva, and (2) to identify candidate genes involved in the induction of apoptosis by H2S. The susceptibility to H2S-induced apoptosis in Ca9-22 cells was significantly higher than that in keratinocytes. H2S exposure in Ca9-22 cells, but not keratinocytes, enhanced the expression of pleckstrin homology-like domain, family A, member 1 (PHLDA1), which was identified through a differential display method. In addition, PHLDA1 expression increased during actinomycin D-induced apoptosis in Ca9-22 cells. Knockdown of PHLDA1 expression by small interfering RNA in Ca9-22 cells led to expression of active caspase 3, thus indicating apoptosis induction. The tongue cancer cell line SCC-25, which expresses PHLDA1 at a high level, showed similar effects. Our data indicate that H2S is an anti-cancer compound that may contribute to the low incidence of oral cancer. Furthermore, we demonstrated the role of PHLDA1 as an apoptosis suppressor. PMID:24270013

  20. Hydrogen Sulfide Levels and Nuclear Factor-Erythroid 2-Related Factor 2 (NRF2) Activity Are Attenuated in the Setting of Critical Limb Ischemia (CLI)

    PubMed Central

    Islam, Kazi N; Polhemus, David J; Donnarumma, Erminia; Brewster, Luke P; Lefer, David J

    2015-01-01

    Background Cystathionine ?-lyase, cystathionine ?-synthase, and 3-mercaptopyruvate sulfurtransferase are endogenous enzymatic sources of hydrogen sulfide (H2S). Functions of H2S are mediated by several targets including ion channels and signaling proteins. Nuclear factor-erythroid 2-related factor 2 is responsible for the expression of antioxidant response element–regulated genes and is known to be upregulated by H2S. We examined the levels of H2S, H2S-producing enzymes, and nuclear factor-erythroid 2-related factor 2 activation status in skeletal muscle obtained from critical limb ischemia (CLI) patients. Methods and Results Gastrocnemius tissues were attained postamputation from human CLI and healthy control patients. We found mRNA and protein levels of cystathionine ?-lyase, cystathionine ?-synthase, and 3-mercaptopyruvate sulfurtransferase were significantly decreased in skeletal muscle of CLI patients as compared to control. H2S and sulfane sulfur levels were significantly decreased in skeletal muscle of CLI patients. We also observed significant reductions in nuclear factor-erythroid 2-related factor 2 activation as well as antioxidant proteins, such as Cu, Zn-superoxide dismutase, catalase, and glutathione peroxidase in skeletal muscle of CLI patients. Biomarkers of oxidative stress, such as malondialdehyde and protein carbonyl formation, were significantly increased in skeletal muscle of CLI patients as compared to healthy controls. Conclusions The data demonstrate that H2S bioavailability and nuclear factor-erythroid 2-related factor 2 activation are both attenuated in CLI tissues concomitant with significantly increased oxidative stress. Reductions in the activity of H2S-producing enzymes may contribute to the pathogenesis of CLI. PMID:25977470