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1

Geothermal hydrogen sulfide removal  

SciTech Connect

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

Urban, P.

1981-04-01

2

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

SciTech Connect

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.

Not Available

1981-10-01

3

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

SciTech Connect

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.

Not Available

1980-04-01

4

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

SciTech Connect

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.

Sims, A.V.

1983-06-01

5

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

SciTech Connect

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

Sims, A.V.

1983-06-01

6

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

SciTech Connect

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.

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

1980-03-01

7

Impacts of meteorological factors on hydrogen sulfide concentration downwind of geothermal power plants  

NASA Astrophysics Data System (ADS)

Hydrogen sulfide (H2S) concentration in the city of Reykjavik, downwind of geothermal power plants has been studied with respect to meteorological factors as the odor and other effects are starting to become a nuisance. The main sources of H2S in Reykjavik City were the Nesjavellir and Hellisheidi Geothermal Power Plants, which are both less than 35 km east of the city. The H2S concentration in Reykjavik was correlated with the H2S emissions from the power plants but was also heavily influenced by weather conditions. The results showed that the H2S concentration at the Grensasvegur Measuring Station was elevated when the wind direction was from 54° to 125°, especially when the wind direction was stable for several hours. The H2S concentration in Reykjavik was highest when the wind speed in the city was between 1.5 and 4 m s-1, and decreased rapidly with higher wind speeds. H2S concentration showed correlation with the air temperature in the city below 3 °C and the concentration rose as the temperature decreased, and the air became more stable and was highest when there was a temperature inversion. The quantitative effects of precipitation on H2S concentration could not be determined in this study although the events with the highest H2S concentration occurred when there was no precipitation. The results showed that favorable conditions for high H2S events can be expected in Reykjavik 2-6 times per year and events with H2S concentration exceeding 50 ?g m-3 might be expected on average about 2 times per year. The results also indicate that events with high H2S concentration can be predicted by using a current weather forecast.

Olafsdottir, S.; Gardarsson, S. M.

2013-10-01

8

Natural near field sinks of hydrogen sulfide from two geothermal power plants in Iceland  

NASA Astrophysics Data System (ADS)

Hydrogen sulfide (H2S) emissions have been growing with the increasing utilization of geothermal resources. Atmospheric H2S concentration has been measured and studied but less is known about the natural sinks of the chemical. This study investigates the atmospheric depletion of H2S within a 35 km distance from two Icelandic power plants. The results showed that atmospheric oxidation by the OH radical was the largest sink in the area. The second largest sink was H2S uptake in surface water, in a neighboring lake, but it was, however, small compared to the reported difference of sulfur amount in the lake in- and outflow. Sulfur was found to accumulate in moss close to the power plants at a maximum rate of about 1500 mg S/kg moss per year and decreased exponentially from the source, being negligible at a distance of a few kilometers. Soil uptake was limited by diffusion of H2S into the porous media and was thus much smaller than the estimated soil uptake potential. Washout with precipitation was estimated to be the smallest sink due to the low H2S reactivity in the precipitation (pH = 5.6), compared to the surface water (pH ˜8). Depletion of H2S from the atmosphere in the study area was estimated to be about 1.2% of the 2012 power plants emissions of over 20,000 tons. Although the uncertainties in the depletion estimates were considerable, most of the H2S emitted from the power plants was strongly indicated to be transported out of the study area as H2S.

Olafsdottir, S.; Gardarsson, S. M.; Andradottir, H. O.

2014-10-01

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

CODE OF PRACTICE HYDROGEN SULFIDE  

E-print Network

Supervisors · Identify research projects and experiments that use hydrogen sulfide (H2S) or where H2S mayCODE OF PRACTICE HYDROGEN SULFIDE Rev January 2013 1 The following generic Code of Practice applies to all work areas within the University of Alberta that use hydrogen sulfide gas or where hydrogen

Machel, Hans

11

CODE OF PRACTICE HYDROGEN SULFIDE  

E-print Network

OF PRACTICE HYDROGEN SULFIDE 2 Responsibilities Supervisors Identify research projects and experimentsCODE OF PRACTICE HYDROGEN SULFIDE 1 The following generic Code of Practice applies to all work areas within the University of Alberta that use hydrogen sulfide gas. It outlines responsibilities, safe

Machel, Hans

12

30 CFR 250.808 - Hydrogen sulfide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 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...

2011-07-01

13

30 CFR 250.808 - Hydrogen sulfide.  

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

14

30 CFR 250.808 - Hydrogen sulfide.  

...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...

2014-07-01

15

30 CFR 250.808 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

16

30 CFR 250.808 - Hydrogen sulfide.  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

17

Hydrogen sulfide in signaling pathways.  

PubMed

For a long time hydrogen sulfide (H?S) was considered a toxic compound, but recently H?S (at low concentrations) has been found to play an important function in physiological processes. Hydrogen sulfide, like other well-known compounds - nitric oxide (NO) and carbon monoxide (CO) is a gaseous intracellular signal transducer. It regulates the cell cycle, apoptosis and the oxidative stress. Moreover, its functions include neuromodulation, regulation of cardiovascular system and inflammation. In this review, I focus on the metabolism of hydrogen sulfide (including enzymatic pathways of H?S synthesis from l- and d-cysteine) and its signaling pathways in the cardiovascular system and the nervous system. I also describe how hydrogen sulfide may be used as therapeutic agent, i.e. in the cardiovascular diseases. PMID:25444740

Olas, Beata

2015-01-15

18

Molecular Structure of Hydrogen Sulfide  

NSDL National Science Digital Library

Hydrogen Sulfide occurs naturally in crude petroleum, natural gas, volcanic gases, and hot springs. It can also result from bacterial breakdown of organic matter and it is responsible for the smell of rotten eggs. It is also produced by human and animal wastes. Although hydrogen sulfide is a toxic pollutant gas generally occurring in wastewater, it has been used to precipitate metals in wastewater treatment reactors. It has been proposed for stabilization of metals in soils and for formation of metal sulfide "quantum" particles for microelectronics applications.

2003-06-04

19

30 CFR 250.604 - Hydrogen sulfide.  

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

20

30 CFR 250.604 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

21

30 CFR 250.604 - Hydrogen sulfide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 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...

2011-07-01

22

30 CFR 250.604 - Hydrogen sulfide.  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

23

30 CFR 250.504 - Hydrogen sulfide.  

...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...

2014-07-01

24

30 CFR 250.504 - Hydrogen sulfide.  

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

25

30 CFR 250.504 - Hydrogen sulfide.  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

26

30 CFR 250.504 - Hydrogen sulfide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 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...

2011-07-01

27

30 CFR 250.504 - Hydrogen sulfide.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

28

30 CFR 250.604 - Hydrogen sulfide.  

...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...

2014-07-01

29

Endogenous production of hydrogen sulfide in mammals  

Microsoft Academic Search

Summary. Hydrogen sulfide is one of three gases involved in biological functions and synthesized in vivo. Like NO and CO, it seems to act as a neuromodulator: it modulates NMDA glutamate receptor function. CBS seems to be the only source of hydrogen sulfide in the brain, whereas the liver synthesizes hydrogen sulfide via cystathionase. In the heart, the third pathway

P. Kamoun

2004-01-01

30

Arsenic speciation in natural sulfidic geothermal waters  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

31

PRODUCTION OF HYDROGEN BY SUPERADIABATIC DECOMPOSITION OF HYDROGEN SULFIDE  

E-print Network

experimental investigations by GTI and UIC researchers on the generation of hydrogen-rich gases fromPRODUCTION OF HYDROGEN BY SUPERADIABATIC DECOMPOSITION OF HYDROGEN SULFIDE Rachid B. Slimane of hydrogen and elemental sulfur from hydrogen sulfide in H2S-containing waste gases. The key feature

32

Hydrogen recovery from hydrogen sulfide by oxidation and by decomposition  

SciTech Connect

Selective oxidation of hydrogen sulfide to hydrogen and sulfur oxides in a two-step process and the catalytic decomposition of hydrogen sulfide were studied for the recovery of hydrogen from hydrogen sulfide. Platinum, when adequately dispersed on a silica support, was found to be effective in reacting with hydrogen sulfide to produce hydrogen and platinum sulfide at 500 C. The platinum sulfide could then be treated with oxygen at 400 C to release sulfur oxides and regenerate the platinum. However, oxidation of sulfur dioxide to trioxide, retention of oxygen by platinum, and adsorption of hydrogen sulfide by the silica support also occurred, which resulted in a minor loss in hydrogen yield. In the decomposition of hydrogen sulfide, platinum sulfide was found to be catalytically active. The equilibrium hydrogen yields were measured experimentally over the range 350--650 C and compared with the values calculated on the basis of a model that included the S, allotropes, the H[sub 2]S[sub n] sulfanes, and HS. The values agreed well at low temperatures but deviated from each other up to 20% at high temperatures.

Yang, B.L.; Kung, H.H. (Northwestern Univ., Evanston, IL (United States). Ipatieff Lab. and Chemical Engineering Dept.)

1994-05-01

33

Hydrogen and sulfur recovery from hydrogen sulfide wastes  

DOEpatents

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.

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

1993-01-01

34

Hydrogen sulfide and translational medicine  

PubMed Central

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

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

2013-01-01

35

Hydrogen sulfide inhibits amyloid formation.  

PubMed

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

Rosario-Alomar, Manuel F; Quiñones-Ruiz, Tatiana; Kurouski, Dmitry; Sereda, Valentin; Ferreira, Eduardo B; Jesús-Kim, Lorraine De; Hernández-Rivera, Samuel; Zagorevski, Dmitri V; López-Garriga, Juan; Lednev, Igor K

2015-01-29

36

Handling hydrogen sulfide in drilling fluids  

SciTech Connect

This paper analyzes the effectiveness of several chemical scavengers for removing hydrogen sulfide from drilling fluids. This article begins by defining what constitutes a scavenger, followed by discussion of the types of reactions by which H{sub 2}S is removed and to which of these categories each scavenger belongs. The authors outline the two types of chemical processes by which sulfides are removed from the drilling fluid.

Singh, A.K.; Kohli, B.S. (Bombay Offshore Project, Oil and Natural Gas Commission, Bombay (IN)); Wendt, R.P. (Chemistry Dept., Loyala Univ., New Orleans, LA (US))

1989-12-01

37

Hydrogen sulfide to the rescue in obstructive kidney injury  

PubMed Central

Hydrogen sulfide is a gasotransmitter with far reaching effects on cell function. Studies show that depending on the context hydrogen sulfide can function as an ameliorative agent or as a mediator of kidney injury. PMID:24875544

Kasinath, Balakuntalam S.

2014-01-01

38

Cardioprotective effects of hydrogen sulfide  

PubMed Central

The gaseous mediator hydrogen sulfide (H2S) is synthesized mainly by cystathionine gamma-lyase in the heart and plays a role in the regulation of cardiovascular homeostasis. Here we first overview the state of the art in the literature on the cardioprotective effects of H2S in various models of cardiac injury. Subsequently, we present original data showing the beneficial effects of parenteral administration of a donor of H2S on myocardial and endothelial function during reperfusion in a canine experimental model of cardiopulmonary bypass. Overview of the literature demonstrates that various formulations of H2S exert cardioprotective effects in cultured cells, isolated hearts and various rodent and large animal models of regional or global myocardial ischemia and heart failure. In addition, the production of H2S plays a role in myocardial pre- and post-conditioning responses. The pathways implicated in the cardioprotective action of H2S are multiple and involve KATP channels, regulation of mitochondrial respiration, and regulation of cytoprotective genes such as Nrf-2. In the experimental part of the current article, we demonstrate the cardioprotective effects of H2S in a canine model of cardiopulmonary bypass surgery. Anesthetized dogs were subjected hypothermic cardiopulmonary bypass with 60 minutes of hypothermic cardiac arrest in the presence of either saline (control, n=8), or H2S infusion (1 mg/kg/h for 2 h). Left ventricular hemodynamic variables (via combined pressure-volume-conductance catheter) as well as coronary blood flow, endothelium-dependent vasodilatation to acetylcholine and endothelium-independent vasodilatation to sodium nitroprusside were measured at baseline and after 60 minutes of reperfusion. Ex vivo vascular function and high-energy phosphate contents were also measured. H2S led to a significantly better recovery of preload recruitable stroke work (p<0.05) after 60 minutes of reperfusion. Coronary blood flow was also significantly higher in the H2S group (p<0.05). While the vasodilatory response to sodium nitroprusside was similar in both groups, acetylcholine resulted in a significantly higher increase in coronary blood flow in the H2S-treated group (p<0.05) both in vivo and ex vivo. Furthermore, high-energy phosphate contents were better preserved in the H2S group. Additionally, the cytoprotective effects of H2S were confirmed also using in vitro cell culture experiments in H9c2 cardiac myocytes exposed to hypoxia and reoxygenation or to the cytotoxic oxidant hydrogen peroxide. Thus, therapeutic administration of H2S exerts cardioprotective effects in a variety of experimental models, including a significant improvement of the recovery of myocardial and endothelial function in a canine model of cardiopulmonary bypass with hypothermic cardiac arrest. PMID:21094267

Szabó, Gábor; Veres, Gábor; Radovits, Tamás; Ger?, Domokos; Modis, Katalin; Miesel-Gröschel, Christiane; Horkay, Ferenc; Karck, Matthias; Szabó, Csaba

2010-01-01

39

HYDROGEN SULFIDE -HIGH TEMPERATURE DRILLING CONTINGENCY PLAN  

E-print Network

HYDROGEN SULFIDE - HIGH TEMPERATURE DRILLING CONTINGENCY PLAN OCEAN DRILLING PROGRAM TEXAS A, Texas A&M University Research Park, 1000 Discovery Drive, College Station, Texas 77845-9547, as well of this publication may be obtained from the Director, Ocean Drilling Program, Texas A&M University Research Park

40

REVISED HYDROGEN SULFIDE DRILLING CONTINGENCY PLAN  

E-print Network

REVISED HYDROGEN SULFIDE DRILLING CONTINGENCY PLAN OCEAN DRILLING PROGRAM TEXAS A&M UNIVERSITY, Texas A&M University Research Park, 1000 Discovery Drive, College Station, Texas 77845-9547, as well of this publication may be obtained from the Director, Ocean Drilling Program, Texas A&M University Research Park

41

Mechanisms of hydrogen sulfide removal with steel making slag.  

PubMed

In the present study, we experimentally investigated the removal of hydrogen sulfide using steel-making slag (SMS) and clarified the mechanism of hydrogen sulfide removal with the SMS. The results proved that SMS is able to remove hydrogen sulfide dissolved in water, and the maximum removal amount of hydrogen sulfide per unit weight of the SMS for 8 days was estimated to be 37.5 mg S/g. The removal processes of hydrogen sulfide were not only adsorption onto the SMS, but oxidation and precipitation as sulfur. The chemical forms of sulfide adsorbed onto the SMS were estimated to be sulfur and manganese sulfide in the ratio of 81% and 19%, respectively. It is demonstrated here that the SMS is a promising material to remediate organically enriched coastal sediments in terms of removal of hydrogen sulfide. Furthermore, using SMS is expected to contribute to development of a recycling-oriented society. PMID:22894171

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

2012-09-18

42

Redetermination of piperidinium hydrogen sulfide structure  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

43

Geothermal energy use in hydrogen liquefaction  

Microsoft Academic Search

We propose the use of geothermal energy for hydrogen liquefaction, and investigate three possible cases for accomplishing such a task including (1) using geothermal output work as the input for a liquefaction cycle; (2) using geothermal heat in an absorption refrigeration process to precool the gas before the gas is liquefied in a liquefaction cycle; and (3) using part of

Mehmet Kanoglu; Ibrahim Dincer; Marc A. Rosen

2007-01-01

44

Production of Dissolved and Particulate Hydrogen Sulfide by Marine Phytoplankton  

NASA Astrophysics Data System (ADS)

Hydrogen sulfide is a reactive gas that in its dissolved form can be found as dissociated ions and meta-sulfide complexes, or in the particulate state as insoluble metal-sulfides. In oxygenated surface seawater the source of this hydrogen sulfide is the hydrolysis of dissolved carbonyl sulfide, but also emissions from marine phytoplankton. In this way, the phytoplankton production of hydrogen sulfide can affect the cycling of dissolved trace metals such as zinc, copper, and mercury. To examine phytoplankton production of hydrogen sulfide, four different phytoplankton species were grown in batch cultures and the concentrations of dissolved (<0.4 um) and particulate sulfide (>0.4 um) monitored over time. The chlorophyte Dunaliella produced the most hydrogen sulfide (diss>part), followed by the diatom Skeletonema (part>diss), the chryptophyte Rhodomonas (diss>part), and finally the prymnesiophyte E. huxleyi. (part>diss). Thus, all of the phytoplankton cultured emitted hydrogen sulfide, and the fact that particulate sulfide was present demonstrated that it reacts with metals to form insoluble metal sulfides, thus affecting metal cycling.

Grace, C.; Davis, J. A.; Cutter, G. A.

2002-12-01

45

Structure of 4-methylpyridinium Hydrogen Sulfide  

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

46

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

SciTech Connect

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.

Haimour, N.; Sandall, O.C.

1983-01-01

47

Selective Removal of Hydrogen Sulfide from Gases Containing Hydrogen Sulfide and Carbon Dioxide Using Diethanolamine  

Microsoft Academic Search

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

N. Haimour; O. C. Sandall

1983-01-01

48

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

...2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues. 721...2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues. (a...2-propen-1-ol, reaction products with hydrogen sulfide, distn. residues (PMN...

2014-07-01

49

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

Code of Federal Regulations, 2013 CFR

...2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues. 721...2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues. (a...2-propen-1-ol, reaction products with hydrogen sulfide, distn. residues (PMN...

2013-07-01

50

Hydrogen sulfide generation and detection system.  

PubMed

A test system has been devised for generation and measurement of hydrogen sulfide/air mixtures. Such a system has numerous applications, including toxicology studies, detector badge and tube evaluation, sorbent capacity measurements, and respirator cartridge or canister breakthrough testing. The system in this study utilizes an HNU photoionization analyzer for detection of H2S concentrations of 1.0 ppm to 26.0 ppm. Generation techniques for these low concentration levels, and also for much higher H2S concentrations, have been described. Special consideration has been given to H2S permeation of transfer tubing, and to the effects of water vapor interference upon the analyzer. PMID:6613852

Ackley, M W

1983-07-01

51

The mass budgets of carbonyl sulfide, dimethyl sulfide, carbon disulfide and hydrogen sulfide  

NASA Astrophysics Data System (ADS)

This study investigates the distribution and magnitudes of the global sources and sinks of carbonyl sulfide (OCS), hydrogen sulfide (H 2S), carbon disulfide (CS 2), and dimethyl sulfide (DMS). For OCS, H 2S and CS 2, balanced mass budgets are proposed. An inventory of sources has been assembled for dimethyl sulfide (DMS). For OCS, total global sources and sinks are estimated as 1.31±0.25 and 1.66±0.79 Tg a -1, respectively. Global sources and sinks of H 2S are estimated as 7.72±1.25 and 8.50±2.80 Tg a -1, respectively. Estimates of sources and sinks of CS 2 are 0.66±0.19 and 1.01±0.45 Tg a -1, respectively. For DMS only a sources estimate has been prepared, 24.45±5.30 Tg a -1. The budgets for OCS and DMS seem relatively secure, whilst those for H 2S and CS 2 contain much greater uncertainty. For DMS, more information on emissions from plants is required. For the other three species, data on soils and vegetation emissions are sparse, although the most urgent priorities might be to establish the role of freshwater wetlands and soils in non-tropical areas.

Watts, Simon F.

52

Amorphous molybdenum sulfides as hydrogen evolution catalysts.  

PubMed

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

Morales-Guio, Carlos G; Hu, Xile

2014-08-19

53

Preliminary air pollution survey of hydrogen sulfide: a literature review  

Microsoft Academic Search

This is a preliminary literature review representing present knowledge of hydrogen sulfide and its effects on humans, animals, plants and materials. Hydrogen sulfide is a colorless gas that has an obnoxious odor at low concentrations. The odor threshold is in the g\\/cu m range. In higher concentrations, the gas is toxic to humans and animals and corrosive to many metals.

Miner

1969-01-01

54

First Detection of Doubly Deuterated Hydrogen Sulfide  

NASA Astrophysics Data System (ADS)

This work was carried out using the Caltech Submillimeter Observatory and presents the observational study of HDS and D2S toward a sample of Class 0 sources and dense cores. We report the first detection of doubly deuterated hydrogen sulfide (D2S) in two dense cores and analyze the chemistry of these molecules, aiming to help understand the deuteration processes in the interstellar medium. The observed values of the D2S/HDS ratio and upper limits require an atomic D/H ratio in the accreting gas of 0.1-1. The study presented in this Letter supports the hypothesis that formaldehyde, methanol, and hydrogen sulfide are formed on the grain surfaces, during the cold prestellar core phase, where the CO-depleted gas has large atomic D/H ratios. The high values for the D/H ratios are consistent with the predictions of a recent gas-phase chemical model that includes H+3 and its deuterated isotopomers, H2D+, D2H+, and D+3 (Roberts, Herbst, & Millar). This research has been supported by NSF grant AST 99-80846 to the Caltech Submillimeter Observatory.

Vastel, C.; Phillips, T. G.; Ceccarelli, C.; Pearson, J.

2003-08-01

55

Oxidation of hydrogen sulfide by human liver mitochondria.  

PubMed

Hydrogen sulfide (H2S) is the third gasotransmitter discovered. Sulfide shares with the two others (NO and CO) the same inhibiting properties towards mitochondrial respiration. However, in contrast with NO or CO, sulfide at concentrations lower than the toxic (?M) level is an hydrogen donor and a substrate for mitochondrial respiration. This is due to the activity of a sulfide quinone reductase found in a large majority of mitochondria. An ongoing study of the metabolic state of liver in obese patients allowed us to evaluate the sulfide oxidation capacity with twelve preparations of human liver mitochondria. The results indicate relatively high rates of sulfide oxidation with a large variability between individuals. These observations made with isolated mitochondria appear in agreement with the main characteristics of sulfide oxidation as established before with the help of cellular models. PMID:24928562

Helmy, Nada; Prip-Buus, Carina; Vons, Corinne; Lenoir, Véronique; Abou-Hamdan, Abbas; Guedouari-Bounihi, Hala; Lombès, Anne; Bouillaud, Frédéric

2014-09-15

56

Hydrogen sulfide and polysulfides as biological mediators.  

PubMed

Hydrogen sulfide (H2S) is recognized as a biological mediator with various roles such as neuromodulation, regulation of the vascular tone, cytoprotection, anti-inflammation, oxygen sensing, angiogenesis, and generation of mitochondrial energy. It is produced by cystathionine ?-synthase (CBS), cystathionine ?-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST). The activity of CBS is enhanced by S-adenosyl methionine (SAM) and glutathionylation, while it is inhibited by nitric oxide (NO) and carbon monoxide (CO). The activity of CSE and cysteine aminotransferase (CAT), which produces the 3MST substrate 3-mercaptopyruvate (3MP), is regulated by Ca2+. H2S is oxidized to thiosulfate in mitochondria through the sequential action of sulfide quinone oxidoreductase (SQR), sulfur dioxygenase, and rhodanese. The rates of the production and clearance of H2S determine its cellular concentration. Polysulfides (H2Sn) have been found to occur in the brain and activate transient receptor potential ankyrin 1 (TRPA1) channels, facilitate the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus, and suppress the activity of phosphatase and tensin homolog (PTEN) by sulfurating (sulfhydrating) the target cysteine residues. A cross talk between H2S and NO also plays an important role in cardioprotection as well as regulation of the vascular tone. H2S, polysulfides, and their cross talk with NO may mediate various physiological and pathophysiological responses. PMID:25302704

Kimura, Hideo

2014-01-01

57

Hydrogen sulfide exposure in an adult male  

PubMed Central

Hydrogen sulfide (H2S) is responsible for many incidents of occupational toxic exposure, especially in the petroleum industry. The clinical effects of H2S depend on its concentration and the duration of exposure. H2S is immediately fatal when concentrations are over 500-1000 parts per million (ppm) but exposure to lower concentrations, such as 10-500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure. H2S may also affect multiple organs, causing temporary or permanent derangements in the nervous, cardiovascular, renal, hepatic, and hematological systems. We present a case of occupational exposure to H2S leading to multi-organ involvement, acute respiratory failure, organizing pneumonia, and shock resembling acute sepsis. The patient also developed mild obstructive and restrictive pulmonary disease and peripheral neuropathy. PMID:20103963

Doujaiji, Bassam; Al-Tawfiq, Jaffar A.

2010-01-01

58

Signaling of hydrogen sulfide and polysulfides.  

PubMed

It has been almost two decades since the first demonstration of hydrogen sulfide (H2S) as a physiological mediator of cognitive function and vascular tone. H2S is physiologically important because it protects various organs from ischemia-reperfusion injury besides regulating inflammation, oxygen sensing, cell growth, and senescence. The production, metabolism, and regulation of H2S have been studied extensively. H2S modulates target proteins through sulfhydration (or sulfuration) or by the reduction of cysteine disulfide bonds. A large number of novel H2S-donating compounds are being developed owing to the therapeutic potential of H2S. Recently, polysulfides, rather than H2S, have been identified as molecules that sulfhydrate (or sulfurate) their target proteins. Antioxid. Redox Signal. 22, 347-349. PMID:25178405

Kimura, Hideo

2015-02-10

59

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...

60

Hydrogen Production from Hydrogen Sulfide in IGCC Power Plants  

SciTech Connect

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

Elias Stefanakos; Burton Krakow; Jonathan Mbah

2007-07-31

61

Micro-aeration for hydrogen sulfide removal from biogas  

Microsoft Academic Search

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

Thanapong Duangmanee

2009-01-01

62

Removal of methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide from contaminated air by Thiobacillus thioparus TK-m.  

PubMed Central

Methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide were efficiently removed from contaminated air by Thiobacillus thioparus TK-m and oxidized to sulfate stoichiometrically. More than 99.99% of dimethyl sulfide was removed when the load was less than 4.0 g of dimethyl sulfide per g (dry cell weight) per day. PMID:2930168

Kanagawa, T; Mikami, E

1989-01-01

63

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

ERIC Educational Resources Information Center

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)

Sublette, Kerry L.

1989-01-01

64

Organization of the human mitochondrial hydrogen sulfide oxidation pathway.  

PubMed

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

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

2014-11-01

65

Hydrogen Sulfide and Ischemia - Reperfusion Injury  

PubMed Central

Gasotransmitters are lipid soluble, endogenously produced gaseous signaling molecules that freely permeate the plasma membrane of a cell to directly activate intracellular targets, thus alleviating the need for membrane-bound receptors. The gasotransmitter family consists of three members: nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S). H2S is the latest gasotransmitter to be identified and characterized and like the other members of the gasotransmitter family, H2S was historically considered to be a toxic gas and an environmental/occupational hazard. However with the discovery of its presence and enzymatic production in mammalian tissues, H2S has gained much attention as a physiological signaling molecule. Also, much like NO and CO, H2S’s role in ischemia/reperfusion (I/R) injury has recently begun to be elucidated. As such, modulation of endogenous H2S and administration of exogenous H2S has now been demonstrated to be cytoprotective in various organ systems through diverse signaling mechanisms. This review will provide a detailed description of the role H2S plays in different model systems of I/R injury and will also detail some of the mechanisms involved with its cytoprotection. PMID:20542117

Nicholson, Chad K.; Calvert, John W.

2010-01-01

66

{open_quotes}BIOX{close_quotes} hydrogen sulfide abatement process - application analysis  

SciTech Connect

A new hydrogen sulfide abatement process, known as {open_quotes}BIOX,{close_quotes} has been specifically developed for the geothermal industry. {open_quotes}BIOX{close_quotes} (biocide induced oxidation) successfully controls both primary and secondary emissions from cooling towers in pilot, demonstration, and commercial operations by air-wet oxidation. Independent laboratory tests recently controverted the efficacy of {open_quotes}BIOX{close_quotes} to catalytically oxidize sulfides to sulfate. Studies conducted in our laboratory with a simulated cooling tower indicate that the experimental conditions employed by Nardini, et al, are unrealistic for geothermal cooling towers. Furthermore, our investigations demonstrate that the {open_quotes}BIOX{close_quotes} process performs optimally at near neutral pH, a condition common to most geothermal cooling tower circulating water systems. A {open_quotes}BIOX{close_quotes} agent, trichloroisocyanuric acid (TCCA), proved to mitigate sulfide emissions much more efficiently than air, sodium hypochlorite or chlorine dioxide. {open_quotes}BIOX{close_quotes} is a proven, cost-effective H{sub 2}S abatement technology.

Gallup, D.L. [UNOCAL Corp., Santa Rosa, CA (United States)

1996-12-31

67

Sulfide scaling in low enthalpy geothermal environments; A survey  

Microsoft Academic Search

A review of the sulfide scaling phenomena in low-temperature environments is presented. While high-temperature fluids tend to deposit metal sulfides because of their high concentrations of dissolved metals and variations of temperature, pressure and fluid chemistry, low temperature media are characterized by very low metal content but much higher dissolved sulfide. In the case of the goethermal wells of the

A. Criaud; C. Fouillac

1989-01-01

68

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

PubMed

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

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

2014-09-15

69

Hydrogen Production from Water under Hydrothermal Conditions with Hydrogen Sulfide as a Reducer  

Microsoft Academic Search

The aim of this work is to investigate the hydrogen generation from hydrothermal water by using hydrogen sulfide as a reducer. The effects of reaction temperature, reaction time and the initial pH value of reaction solution on the production of hydrogen from hydrothermal water were investigated. The experimental results showed that hydrogen was produced from water when the reaction temperature

Cuixiang Ma; Fangming Jin; Peng Yan; Xu Zeng; Guangyi Zhang; Bing Wu

2009-01-01

70

Sulfide scaling in low enthalpy geothermal environments; A survey  

SciTech Connect

A review of the sulfide scaling phenomena in low-temperature environments is presented. While high-temperature fluids tend to deposit metal sulfides because of their high concentrations of dissolved metals and variations of temperature, pressure and fluid chemistry, low temperature media are characterized by very low metal content but much higher dissolved sulfide. In the case of the goethermal wells of the Paris Basin, detailed studies demonstrate that the relatively large concentrations of chloride and dissolved sulfide are responsible for corrosion and consequent formation of iron sulfide scale composed of mackinawite, pyrite and pyrrhotite. The effects of the exploitation schemes are far less important than the corrosion of the casings. The low-enthalpy fluids that do not originate from sedimentary aquifers (such as in Iceland and Bulgaria), have a limited corrosion potential, and the thin sulfide film that appears may prevent the progress of corrosion.

Criaud, A.; Fouillac, C. (Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France))

1989-01-01

71

Pulmonary excretion of hydrogen sulfide, methanethiol, dimethyl sulfide and dimethyl disulfide in mice.  

PubMed

Neither hydrogen sulfide nor any other volatile sulfur metabolites were found in the expired breath of mice given sodium sulfide intraperitoneally in doses up to the LD50. The detection system was sensitive to less than 0.1% of the sulfur in the given dose. The intraperitoneal administration of dimethyl disulfide resulted in its appearance in the expired breath of mice as well as much smaller amounts of both methanethiol and dimethyl sulfide. The intraperitoneal administration of methanethiol resulted in its pulmonary excretion as well as that of dimethyl sulfide. Administration of dimethyl sulfide led to its appearance alone in expired breath. Mice pretreated with ammonium acetate and then injected with dimethyl disulfide excreted the same three compounds via the lungs as above, but there were complex changes in the proportions and in the time sequence of their appearance. The absolute amounts of all three were increased, and the peak excretion for each was delayed. The amount excreted as dimethyl sulfide was particularly increased. PMID:755673

Susman, J L; Hornig, J F; Thomae, S C; Smith, R P

1978-01-01

72

Hydrogen evolution from water through metal sulfide reactions  

NASA Astrophysics Data System (ADS)

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

Saha, Arjun; Raghavachari, Krishnan

2013-11-01

73

Hydrogen evolution from water through metal sulfide reactions.  

PubMed

Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M2S(X)(-) (M = Mo and W, X = 4-6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo2S4(-) isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W2S4(-) and M2S5(-) isomers. In all the lowest energy H2 elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H2 elimination step involve a thiol (-SH) and a hydroxyl (-OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M2S4(-) and M2S5(-) clusters with water to liberate H2 are exothermic and involve modest free energy barriers. However, the reaction of water with M2S6(-) is highly endothermic with a considerable barrier due to saturation of the local bonding environment. PMID:24289348

Saha, Arjun; Raghavachari, Krishnan

2013-11-28

74

L-Cysteine, Hydrogen Sulfide, and Insulin Signaling in Diabetes  

E-print Network

L-Cysteine, Hydrogen Sulfide, and Insulin Signaling in Diabetes Prasenjit Manna LSU Health Sciences Center Diabetes has become an epidemic and remains a major public health issue worldwide. of L in diabetic animal studies. However, the molecular mechanism by which LC increases glucose utilization

Shyamasundar, R.K.

75

Health assessment document for hydrogen sulfide: review draft  

Microsoft Academic Search

Hydrogen sulfide is a highly toxic gas which is immediately lethal in concentrations greater than 2000 ppm. The toxic end-point is due to anoxia to brain and heart tissues which results from its interaction with the celluar enzyme cytochrome oxidase. Inhibition of the enzyme halts oxidative metabolism which is the primary energy source for cells. A second toxic end-point is

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

1986-01-01

76

Method for removing hydrogen sulfide from coke oven gas  

Microsoft Academic Search

An improved sulfur-ammonia process is disclosed for removing hydrogen sulfide from coke oven gases. In the improved process, a concentrator formerly used for standby operation is used at all normal times as an ammonia scrubber to improve the efficiency of gas separation during normal operation and is used as a concentrator for its intended standby functions during the alternative operations.

Ritter

1982-01-01

77

Diffusion of hydrogen sulfide (1); water (2); potassium chloride (3)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) hydrogen sulfide; (2) water; (3) potassium chloride

Winkelmann, J.

78

Diffusion of hydrogen sulfide (1); water (2); potassium iodide (3)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) hydrogen sulfide; (2) water; (3) potassium iodide

Winkelmann, J.

79

Evaluation of hydrogen sulfide concentrations in Norwegian reservoir fluids  

E-print Network

Knowledge of the hydrogen sulfide content in produced hics. petroleum fluids is important for planning of [HaS] control measures and for material selection. The Norwegian Continental Shelf is known for producing sweet crude oils, and [HaS] has...

Haland, Kjersti

1998-01-01

80

Synthesis of a photocontrollable hydrogen sulfide donor using ketoprofenate photocages.  

PubMed

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

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

2014-01-18

81

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...

82

Chromium(VI) Reduction by Hydrogen Sulfide in Aqueous  

E-print Network

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

Deng, Baolin

83

Kinetic study of hydrogen sulfide absorption in aqueous chlorine solution  

E-print Network

Kinetic study of hydrogen sulfide absorption in aqueous chlorine solution Jean-Baptiste VILMAINa. Chlorine is a top-grade oxidant, reacting with H2S with a fast kinetic rate and enhancing its mass transfer absorption of H2S in chlorine solution for acidic or circumneutral pH allowed to investigate the kinetics

Paris-Sud XI, Université de

84

Solubility and Permeation of Hydrogen Sulfide in Lipid Membranes  

PubMed Central

Hydrogen sulfide (H2S) is mainly known for its toxicity but has recently been shown to be produced endogenously in mammalian tissues and to be associated with physiological regulatory functions. To better understand the role of biomembranes in modulating its biological distribution and effects; we measured the partition coefficient of H2S in models of biological membranes. The partition coefficients were found to be 2.1±0.2, 1.9±0.5 and 2.0±0.6 in n-octanol, hexane and dilauroylphosphatidylcholine liposome membranes relative to water, respectively (25°C). This two-fold higher concentration of H2S in the membrane translates into a rapid membrane permeability, Pm?=?3 cm s?1. We used a mathematical model in three dimensions to gain insight into the diffusion of total sulfide in tissues. This model shows that the sphere of action of sulfide produced by a single cell expands to involve more than 200 neighboring cells, and that the resistance imposed by lipid membranes has a significant effect on the diffusional spread of sulfide at pH 7.4, increasing local concentrations. These results support the role of hydrogen sulfide as a paracrine signaling molecule and reveal advantageous pharmacokinetic properties for its therapeutic applications. PMID:22509322

Cuevasanta, Ernesto; Denicola, Ana; Alvarez, Beatriz; Möller, Matías N.

2012-01-01

85

Hydrogen and bioenergetics in the Yellowstone geothermal ecosystem  

PubMed Central

The geochemical energy budgets for high-temperature microbial ecosystems such as occur at Yellowstone National Park have been unclear. To address the relative contributions of different geochemistries to the energy demands of these ecosystems, we draw together three lines of inference. We studied the phylogenetic compositions of high-temperature (>70°C) communities in Yellowstone hot springs with distinct chemistries, conducted parallel chemical analyses, and carried out thermodynamic modeling. Results of extensive molecular analyses, taken with previous results, show that most microbial biomass in these systems, as reflected by rRNA gene abundance, is comprised of organisms of the kinds that derive energy for primary productivity from the oxidation of molecular hydrogen, H2. The apparent dominance by H2-metabolizing organisms indicates that H2 is the main source of energy for primary production in the Yellowstone high-temperature ecosystem. Hydrogen concentrations in the hot springs were measured and found to range up to >300 nM, consistent with this hypothesis. Thermodynamic modeling with environmental concentrations of potential energy sources also is consistent with the proposed microaerophilic, hydrogen-based energy economy for this geothermal ecosystem, even in the presence of high concentrations of sulfide. PMID:15671178

Spear, John R.; Walker, Jeffrey J.; McCollom, Thomas M.; Pace, Norman R.

2005-01-01

86

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

PubMed

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

Kashfi, Khosrow; Olson, Kenneth R

2013-03-01

87

A study of the reactions of arsinic and arsonic acids with hydrogen sulfide and hydrogen selenide  

E-print Network

another [I]. Arsemc trisulfide, As, S, an orange or yellow powder, is found in nature as the mineral orpiment. Arsenic trisulfide can be prepared by passing a stream of hydrogen sulfide through an acidic solution of arsenic trioxide. Arsenic disulfide... any effect on the course of the reaction, the carboxymethyl group was replaced with an a-carboxyethyl group. Following the reaction of this arsinic acid with hydrogen sulfide, pale yellow crystals were isolated which had a melting point of 139 ? 142...

Applegate, Cynthia Annette

1986-01-01

88

A FRET enzyme-based probe for monitoring hydrogen sulfide.  

PubMed

Fluorescently labeled cobalt peptide deformylase (Co-PDF) can be efficiently used as a fluorescence-resonance-energy-transfer-based sensing device for hydrogen sulfide (H(2)S). The proof of concept of our sensor system is substantiated by spectroscopic, structural, and theoretical results. Monohydrogen sulfide coordination to Co-PDF and Ni-PDF was verified by X-ray crystallography. Density functional theory calculations were performed to gain insight into the characteristics of the coordination adduct between H(2)S and the cobalt cofactor in Co-PDF. PMID:23072298

Strianese, Maria; Palm, Gottfried J; Milione, Stefano; Kühl, Olaf; Hinrichs, Winfried; Pellecchia, Claudio

2012-11-01

89

Hydrogen sulfide emission in sewer networks: a two-phase modeling approach to the sulfur cycle.  

PubMed

Wherever transport of anaerobic wastewater occurs, potential problems associated with hydrogen sulfide in relation to odor nuisance, health risk and corrosion exist. Improved understanding of prediction of hydrogen sulfide emission into the sewer atmosphere is needed for better evaluation of such problems in sewer networks. A two-phase model for emission of hydrogen sulfide along stretches of gravity sewers is presented to estimate the occurrence of both sulfide in the water phase and hydrogen sulfide in the sewer atmosphere. The model takes into account air-water mass transfer of hydrogen sulfide and interactions with other processes in the sulfur cycle. Various emission scenarios are simulated to illustrate the release characteristics of hydrogen sulfide. PMID:15484757

Yongsiri, C; Vollertsen, J; Hvitved-Jacobsen, T

2004-01-01

90

A fatality caused by accidental production of hydrogen sulfide.  

PubMed

A 55-year-old male Caucasian truck driver was dead at the scene after breathing hydrogen sulfide (H(2)S) produced by an accidental transfer of sodium hydrogen sulfide (NaHS) from a tanker truck to a tank containing 4% sulfuric acid (H(2)SO(4)) and iron(II) sulfate (FeSO(4)). Autopsy of the decedent's body revealed pulmonary edema and passive congestion in lungs, spleen, kidneys, and adrenal glands. Postmortem biological samples were analyzed for carbon monoxide, cyanide, ethanol, and drugs. Since a potential exposure to H(2)S was involved, blood was also analyzed for sulfide (S(2-)). The analysis entailed isolating S(2-) from blood as H(2)S using 0.5M H(3)PO(4), trapping the gas in 0.1M NaOH, and determining the electromotive force using a sulfide ion specific electrode. Acetaminophen at a concentration of 14.3 microg/ml was found in blood, and metoprolol was detected in the blood, liver, and kidney samples. The blood S(2-) level was determined to be 1.68 microg/ml. It is concluded that the cause of death was H(2)S poisoning associated with a hazardous material accident in an industrial situation. PMID:11728749

Chaturvedi, A K; Smith, D R; Canfield, D V

2001-12-01

91

Japanese experience of hydrogen sulfide: the suicide craze in 2008  

PubMed Central

Most of hydrogen sulfide poisoning has been reported as industrial accidents in Japan. However, since January 2008, a burgeoning of suicide attempts using homemade hydrogen sulfide gas has become evident. By April 2008, the fad escalated into a chain reaction nationwide. Mortality of the poisoning was very high. There were 220 cases of attempted gas suicides during the period of March 27 to June 15, killing 208. An introduction of new method of making the gas, transmitted through message boards on the internet, was blamed for this "outbreak". The new method entailed mixing bath additive and toilet detergent. The National Police Agency instructed internet providers to remove information that could be harmful. Of the victims of the fad in 2008, several cases were serious enough that family members were involved and died. Paramedics and caregivers were also injured secondarily by the gas. This fad has rapidly spread by internet communication, and can happen anywhere in the world. PMID:20920221

2010-01-01

92

Hydrogen sulfide removal from coal gas by zinc titanate sorbent  

Microsoft Academic Search

In this investigation mathematical modelling has been done for the reaction between solid spherical zinc titanate pellets and hydrogen sulfide, H2S at high temperatures (400–700°C). In this model, a second order equation which is obtained for the H2S concentration in the pellet is solved numerically using the ‘finite difference’ method. In this equation, the value of effective diffusivity of H2S

Sibel Ozdemir; Tevfik Bardakci

1999-01-01

93

Molecularly engineered quantum dots for visualization of hydrogen sulfide.  

PubMed

Among various fluorescence nanomaterials, the II-VI semiconductor nanocrystals (usually called quantum dots, QDs) should be very promising in sensing application because of their high quantum yields, capability for surface property manipulation, and unlimited possible chemical reactions. Herein, we present a fluorescence probe for hydrogen sulfide, which was prepared by first encapsulating inorganic cadmium telluride (CdTe) QDs in silica nanospheres, and subsequently engineering the silica surface with functional molecules azidocoumarin-4-acetic acid reactive to hydrogen sulfide. The nanohybrid probe exhibited two fluorescence bands centered at 452 and 657 nm, respectively. The red fluorescence at 657 nm of the nanohybrid probe is stable against H2S, while the blue fluorescence is specifically sensitive to H2S. The probe showed a distinct fluorescence color evolution from light magenta to blue upon exposure to different amounts of H2S, and a detection limit of 7.0 nM was estimated in aqueous solution. We further applied the nanohybrid probe for visual detection of gaseous H2S with a low concentration of 0.5 ppm using glass indicating spots sensors, suggesting its potential application for gaseous H2S sensing. Such an efficient on-site visual determination of gaseous hydrogen sulfide (H2S) is highly demanded in on-site environmental monitoring and protection. PMID:25615270

Yan, Yehan; Yu, Huan; Zhang, Yajiao; Zhang, Kui; Zhu, Houjuan; Yu, Tao; Jiang, Hui; Wang, Suhua

2015-02-18

94

Hydrogen and Sulfur Production from Hydrogen Sulfide Wastes  

E-print Network

sulfide is low enough for the plasma process to be economically competitive. In addition, the experiments show-that typical refinery acid-gas streams are compatible with the plasma process and that all by-products can be treated with existing technology....

Harkness, J.; Doctor, R. D.

95

Hydrogen evolution from water through metal sulfide reactions  

SciTech Connect

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.

Saha, Arjun; Raghavachari, Krishnan [Department of Chemistry, Indiana University, Bloomington, Indiana 47405 (United States)] [Department of Chemistry, Indiana University, Bloomington, Indiana 47405 (United States)

2013-11-28

96

The ground and excited states of hydrogen sulfide, methanethiol, and hydrogen selenide  

Microsoft Academic Search

Ab initio SCF and CI investigations of the ground and excited singlet electronic states of hydrogen sulfide 1, methanethiol 2, and hydrogen selenide 3 have been carried out. The moderately large atomic basis sets are augmented by bond functions for polarization and by sets of diffuse s and p functions to enable the description of the lower Rydberg excited states.

Arvi Rauk; Scott Collins

1984-01-01

97

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

PubMed

The use of drinking water treatment residuals (WTRs) to immobilize P in sediments is a novel approach for lake restoration. However, the lability of P in WTRs-amended sediments may vary with many factors, e.g., hydrogen sulfide content. Earlier works in our laboratory have demonstrated that WTRs are effective sorbents for hydrogen sulfide in water. Thus, we hypothesized that the lability of P in WTRs-amended sediments would not be increased by hydrogen sulfide. The results of this work suggested that this hypothesis was tenable. Compared to the raw sediments, the amended sediments had significantly lower P desorption potential in the presence of hydrogen sulfide at different times, pH and concentrations. Moreover, the amended sediments were also better able to adsorb hydrogen sulfide. In the amended sediments, the P, which was easily desorbed due to the effect of hydrogen sulfide, was transformed into the Fe/Al bound P. PMID:23453604

Wang, Changhui; Liu, Juanfeng; Pei, Yuansheng

2013-05-01

98

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

PubMed

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

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

2008-05-01

99

Combined adsorption and oxidation mechanisms of hydrogen sulfide on granulated coal ash.  

PubMed

Hydrogen sulfide is highly toxic to benthic organisms and may cause blue tide with depletion of dissolved oxygen in water column due to its oxidation. The purpose of this study is to reveal the combined adsorption and oxidation mechanisms of hydrogen sulfide on granulated coal ash that is a byproduct from coal electric power stations to apply the material as an adsorbent for hydrogen sulfide in natural fields. Sulfur species were identified in both liquid and solid phases to discuss removal mechanisms of the hydrogen sulfide with the granulated coal ash. Batch experiments revealed that hydrogen sulfide decreased significantly by addition of the granulated coal ash and simultaneously the sulfate ion concentration increased. X-ray absorption fine structure analyses showed hydrogen sulfide was adsorbed onto the granulated coal ash and successively oxidized by manganese oxide (III) contained in the material. The oxidation reaction of hydrogen sulfide was coupling with reduction of manganese oxide. On the other hand, iron containing in the granulated coal ash was not involved in hydrogen sulfide oxidation, because the major species of iron in the granulated coal ash was ferrous iron that is not easily reduced by hydrogen sulfide. PMID:22487226

Asaoka, Satoshi; Hayakawa, Shinjiro; Kim, Kyung-Hoi; Takeda, Kazuhiko; Katayama, Misaki; Yamamoto, Tamiji

2012-07-01

100

BOP shear rams for hydrogen sulfide service  

SciTech Connect

The shear rams in a blowout preventer (BOP) are critical components of the drilling system, which is expected to shear drillpipe and to seal the wellbore in all types of drilling fluids. The brittleness of high-strength tool steels when exposed to wellbore fluids containing H{sub 2}S has been recognized for many years by the drilling industry. The development in recent years of high-strength materials that are resistant to hydrogen embrittlement has made possible the manufacture of H{sub 2}S-resistant shear rams. This paper describes the fabrication of such shear rams. The cutting edge is made from a cobalt base (UNS R30035) and an iron-based superalloy (UNS S66286) joined by an electron-beam (EB) welding process. The discussion continues with the shearing tests of API 5A grades E, G, and S-135 drillpipe of two wall thicknesses with a 13 5/8-in. (346-mm), 10,000-psi (69-MPa) working-pressure (WP) ram BOP.

Canal, J.R. (Shaffer (US))

1989-12-01

101

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

Microsoft Academic Search

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.

Brandi Kiel Reese; Michael A. Anderson; Christopher Amrhein

2008-01-01

102

Thermodynamic assessment of geothermal energy use in hydrogen production  

Microsoft Academic Search

In this study, geothermal-based hydrogen production methods, and their technologies and application possibilities are discussed in detail. A high-temperature electrolysis (HTE) process coupled with and powered by a geothermal source is considered for a case study, and its thermodynamic analysis through energy and exergy is conducted for performance evaluation purposes. In this regard, overall energy and exergy efficiencies of the

M. Tolga Balta; Ibrahim Dincer; Arif Hepbasli

2009-01-01

103

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

Code of Federal Regulations, 2010 CFR

...measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60...PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF...Performance for Onshore Natural Gas Processing: SO2 Emissions...measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1...

2010-07-01

104

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

...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?...

2014-07-01

105

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

106

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

Code of Federal Regulations, 2012 CFR

...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?...

2012-07-01

107

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

Code of Federal Regulations, 2011 CFR

...Resources 2 2011-07-01 2011-07-01 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...

2011-07-01

108

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

Code of Federal Regulations, 2013 CFR

...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?...

2013-07-01

109

Dynamic viscosity estimation of hydrogen sulfide using a predictive scheme based on molecular dynamics.  

E-print Network

1 Dynamic viscosity estimation of hydrogen sulfide using a predictive scheme based on molecular on molecular dynamics results on Lennard-Jones spheres is proposed to model the viscosity of hydrogen sulfide is that the adjustment does not involve any viscosity data because only density values have been used in order

Boyer, Edmond

110

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...

111

Catalysts for the selective oxidation of hydrogen sulfide to sulfur  

DOEpatents

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.

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

2000-08-08

112

The electronic structure and catalytic properties of molybdenum sulfides in the coal hydrogenation process  

Microsoft Academic Search

Comparative analysis of the electronic structure of molybdenum sulfides and their catalytic activity in hydrogenation reactions\\u000a was performed from the results of Hartree-Fock ab initio quantum-chemical calculations using the STO 3-21G* and 6-311G basis\\u000a sets with geometry optimization. The model reactions of hydrogenation of aromatic and saturated hydrocarbons with hydrogen\\u000a and hydrogen sulfide were studied. It was shown that the

A. M. Gyul’maliev; M. A. Gyul’malieva; A. S. Maloletnev; M. Ya. Shpirt

2008-01-01

113

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

NASA Technical Reports Server (NTRS)

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.

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

114

Factors controlling the reactivity of hydrogen sulfide with hemeproteins†  

PubMed Central

Hemoglobin I (HbI) from the clam Lucina pectinata is an intriguing hemeprotein that binds and transports H2S to sulfide-oxidizing chemoautotrophic bacteria to maintain a symbiotic relationship and to protect the mollusk from H2S toxicity. Single point mutations at E7, B10 and E11 positions were introduced in the HbI heme pocket to define the reactivity of sulfide with hemeproteins. The functional and structural properties of mutant and wild type recombinant proteins were first evaluated using the well-known ferrous CO and O2 derivatives. The effects of these mutations on the ferric environment were then studied in the metaquo and hydrogen sulfide derivatives. The results obtained with the ferrous HbI mutants show that all the E7 substitutions and the PheB10Tyr mutation influence directly CO and O2 binding and stability while the B10 and E11 substitutions induce distal structural rearrangements that affect ligand entry and escape indirectly. For the metaquo-GlnE7His, PheB10Val, PheB10Leu and the E11 variants, two individual distal structures are suggested, one of which is associated with H-bonding interactions between the E7 residues and the bound water. Similar H-bonding interactions are invoked for these HbI-H2S mutant derivatives and the rHbI, altering in turn sulfide reactivity within these protein samples. This is evident in the resonance Raman spectra of these HbI-H2S complexes, which show reduction of heme iron as judged by the appearance of the ?4 oxidation state marker at 1356 cm?1, indicative of heme-FeII species. This reduction process depends strongly on distal mutations showing faster reduction for those HbI mutants exhibiting strongest H-bonding interactions. Overall, the results presented here show that: a. H2S association is regulated by steric constraints; b. H2S release is controlled by two competing reactions involving simple sulfide dissociation and heme reduction; c. at high H2S concentrations, reduction of the ferric center dominates; d. reduction of the heme is also enhanced in those HbI mutants having polar distal environments. PMID:19368335

Pietri, Ruth; Lewis, Ariel; León, Ruth G.; Casabona, Gullermina; Kiger, Laurent; Yeh, Syun-Ru; Fernandez-Alberti, Sebastian; Marden, Michael C.; Cadilla, Carmen L.; López-Garriga, Juan

2009-01-01

115

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

PubMed

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

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

2009-12-01

116

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

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

117

Biogeochemistry of dissolved hydrogen sulfide species and carbonyl sulfide in the western North Atlantic Ocean  

NASA Astrophysics Data System (ADS)

The biogeochemistry of total sulfide dissolved in the open ocean is a poorly understood component of the global sulfur cycle. Here, the cycling of total sulfide was examined in the western North Atlantic Ocean using specially developed sampling and analytical methods. Total sulfide (particulate + dissolved sulfide) concentrations ranged from <2-550 pmol/L; concentrations were highest in the mixed layer and decreased with depth. Significant levels (up to 19 pmol/L) of free sulfide (uncomplexed sulfide) were determined in the top 50 m of the water column. Sources of total sulfide were examined. In particular, the rate of carbonyl sulfide (OCS) hydrolysis was redetermined under oceanographic conditions, and the depth distribution of OCS was examined. The patterns of near-surface enrichment (up to 150 pmol/L) and depletion at depth observed in OCS depth profiles suggest in situ production of OCS. To quantify the sources and sinks of total sulfide in the mixed layer of the Sargasso Sea, a budget was constructed. The rate of total sulfide production was 5.5 pmol L -1 h -1 (OCS hydrolysis + atmospheric input), and total sulfide removal rate was 115 pmol L -1 h -1 (oxidation + particulate sinking). The significant difference between the known sources and sinks indicates that other processes are important for the cycling of sulfide. Similarities in the depth distribution of total sulfide and chlorophyll a, and results from recent laboratory experiments argue strongly in favor of biological involvement in the production of total sulfide in the open ocean.

Radford-Kn?ry, Joël; Cutter, Gregory A.

1994-12-01

118

Reactivity of hydrogen sulfide with peroxynitrite and other oxidants of biological interest.  

PubMed

Hydrogen sulfide (H(2)S) is an endogenously generated gas that can also be administered exogenously. It modulates physiological functions and has reported cytoprotective effects. To evaluate a possible antioxidant role, we investigated the reactivity of hydrogen sulfide with several one- and two-electron oxidants. The rate constant of the direct reaction with peroxynitrite was (4.8±1.4)×10(3)M(-1) s(-1) (pH 7.4, 37°C). At low hydrogen sulfide concentrations, oxidation by peroxynitrite led to oxygen consumption, consistent with a one-electron oxidation that initiated a radical chain reaction. Accordingly, pulse radiolysis studies indicated that hydrogen sulfide reacted with nitrogen dioxide at (3.0±0.3)×10(6)M(-1) s(-1) at pH 6 and (1.2±0.1)×10(7)M(-1) s(-1) at pH 7.5 (25°C). The reactions of hydrogen sulfide with hydrogen peroxide, hypochlorite, and taurine chloramine had rate constants of 0.73±0.03, (8±3)×10(7), and 303±27M(-1) s(-1), respectively (pH 7.4, 37°C). The reactivity of hydrogen sulfide was compared to that of low-molecular-weight thiols such as cysteine and glutathione. Considering the low tissue concentrations of endogenous hydrogen sulfide, direct reactions with oxidants probably cannot completely account for its protective effects. PMID:21034811

Carballal, Sebastián; Trujillo, Madia; Cuevasanta, Ernesto; Bartesaghi, Silvina; Möller, Matías N; Folkes, Lisa K; García-Bereguiaín, Miguel A; Gutiérrez-Merino, Carlos; Wardman, Peter; Denicola, Ana; Radi, Rafael; Alvarez, Beatriz

2011-01-01

119

Introducing the emission process of hydrogen sulfide to a sewer process model (WATS).  

PubMed

Emission of hydrogen sulfide in sewer networks results in odor, health and corrosion problems. These problems generally occur when wastewater is transported under anaerobic and turbulent conditions. Studies on integrated aerobic/anaerobic processes in sewers have led to a conceptual sewer process model, WATS (Wastewater Aerobic/anaerobic Transformations in Sewers). The WATS model accounts for the carbon cycle, reaeration and sulfide formation. However, to handle odor, health and corrosion problems more efficiently, other aspects of the sulfur cycle need to be included. Emphasis in this study is on an extension of the WATS model in terms of hydrogen sulfide emission. A fundamental concept of this extended model is related to emission of the molecular form of hydrogen sulfide and thereby to pH of wastewater. An engineering application of the extended WATS model includes different scenarios of sewer performance concerning hydrogen sulfide emission under dissolved oxygen-limited conditions. By applying the extended WATS model, users can more realistically cope with the fate of hydrogen sulfide. Consequently, when dealing with the sulfur cycle, users need no longer be restricted to the sulfide formation process but can also take transfer of hydrogen sulfide across the air-water interface into account. PMID:12666805

Yongsiri, C; Hvitved-Jacobsen, T; Vollertsen, J; Tanaka, N

2003-01-01

120

Reactivity of hydrogen sulfide with peroxynitrite and other oxidants of biological interest  

Microsoft Academic Search

Hydrogen sulfide (H2S) is an endogenously generated gas that can also be administered exogenously. It modulates physiological functions and has reported cytoprotective effects. To evaluate a possible antioxidant role, we investigated the reactivity of hydrogen sulfide with several one- and two-electron oxidants. The rate constant of the direct reaction with peroxynitrite was (4.8±1.4)×103M?1 s?1 (pH 7.4, 37°C). At low hydrogen

Sebastián Carballal; Madia Trujillo; Ernesto Cuevasanta; Silvina Bartesaghi; Matías N. Möller; Lisa K. Folkes; Miguel A. García-Bereguiaín; Carlos Gutiérrez-Merino; Peter Wardman; Ana Denicola; Rafael Radi; Beatriz Alvarez

2011-01-01

121

Lifelines Episode 10: Hydrogen Sulfide- What a Gas  

NSDL National Science Digital Library

This is a free audio podcast from the American Physiological Society. Discussion questions, related research, and other teaching resources are available by clicking "collections" tab in the left hand column. Segment 1: What a Gas. University of Alabama Â? Birmingham researchers Jeannette Doeller and David Kraus talk about the amazing properties of hydrogen sulfide gas. Although itÂ?s lethal in even minute quantities, our bodies produce it and use it to good effect. Episode 10 graphic courtesy of David Kraus. Begins at 1:15. Segment 2: Research Progress on Colon Cancer. John Carethers of the University of California San Diego explains his research findings on colon cancer and the role that the DNA mismatch repair system plays. Begins at 15:24.

APS Communications Office (American Physiological Society Communications Office)

2008-06-05

122

Fluorescent probes for hydrogen sulfide detection and bioimaging.  

PubMed

In comparison with other biological detection technologies, fluorescence bioimaging technology has become a powerful supporting tool for intracellular detection, and can provide attractive facilities for investigating physiological and pathological processes of interest with high spatial and temporal resolution, less invasiveness, and a rapid response. Due to the versatile roles of hydrogen sulfide (H2S) in cellular signal transduction and intracellular redox status regulation, fluorescent probes for the detection of this third signalling gasotransmitter have rapidly increased in number in recent years. These probes can offer powerful means to investigate the physiological actions of H2S in its native environments without disturbing its endogenous distribution. In this feature article, we address the synthesis and design strategies for the development of fluorescent probes for H2S based on the reaction type between H2S and the probes. Moreover, we also highlight fluorescent probes for other reactive sulfur species, such as sulfane sulfurs and SO2 derivatives. PMID:25029966

Yu, Fabiao; Han, Xiaoyue; Chen, Lingxin

2014-10-21

123

Hydrogen sulfide poisoning: review of 5 years' experience.  

PubMed

The workforce of Alberta, a province rich in fossil fuel, faces an increasing risk of exposure to hydrogen sulfide (H2S). Basic knowledge of the population exposed during the years 1969 to 1973 inclusive was accumulated to identify the immediate medical and management problems. Data were recorded from three sources of records: the Workers' Compensation Board of Alberta, the Alberta Hospital Services Commission and the provincial coroner's office. There were 221 cases of exposure to H2S. The overall mortality was 6%; 5% of victims were dead on arrival at hospital. Admission to hospital was required for 65% of the victims arriving at a hospital emergency room (78% of the 221). Acute problems were coma, dysequilibrium and respiratory insufficiency with pulmonary edema. Increased attention to cardiopulmonary resuscitation at the exposure site and during transportation to hospital is necessary to reduce the mortality from H2S exposure. No long-term adverse effects were apparent in the survivors. PMID:144553

Burnett, W W; King, E G; Grace, M; Hall, W F

1977-12-01

124

Endogenous hydrogen sulfide is involved in the pathogenesis of atherosclerosis  

SciTech Connect

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.

Qiao, Wang [Department of Pediatrics, Peking University First Hospital, Beijing 100034 (China)] [Department of Pediatrics, Peking University First Hospital, Beijing 100034 (China); Chaoshu, Tang [Department of Physiology and Pathophysiology, Health Sciences Center, Peking University, Beijing 100034 (China) [Department of Physiology and Pathophysiology, Health Sciences Center, Peking University, Beijing 100034 (China); Key Laboratory of Molecular Cardiovascular Medicine, Ministry of Education (China); Hongfang, Jin, E-mail: jinhongfang51@126.com [Department of Pediatrics, Peking University First Hospital, Beijing 100034 (China)] [Department of Pediatrics, Peking University First Hospital, Beijing 100034 (China); Junbao, Du, E-mail: junbaodu1@126.com [Department of Pediatrics, Peking University First Hospital, Beijing 100034 (China)] [Department of Pediatrics, Peking University First Hospital, Beijing 100034 (China)

2010-05-28

125

Protein-based nanobiosensor for direct detection of hydrogen sulfide  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

126

The metallization and superconductivity of dense hydrogen sulfide  

SciTech Connect

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.)

Li, Yinwei, E-mail: yinwei-li@jsnu.edu.cn; Hao, Jian; Li, Yanling [School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116 (China)] [School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116 (China); Liu, Hanyu [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatchewan S7N 5E2 (Canada)] [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatchewan S7N 5E2 (Canada); Ma, Yanming, E-mail: mym@jlu.edu.cn [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China)] [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China)

2014-05-07

127

Hydrogen sulfide (H 2S) in urban ambient air  

NASA Astrophysics Data System (ADS)

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.

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

128

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

DOEpatents

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.

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

2002-05-14

129

Nanoporous metal enhanced catalytic activities of amorphous molybdenum sulfide for high-efficiency hydrogen production.  

PubMed

We fabricated a robust electrocatalyst by chemically depositing an ultrathin layer of amorphous molybdenum sulfide on the internal surface of dealloyed nanoporous gold. The catalyst exhibits superior electrocatalysis toward hydrogen evolution reaction in both acidic and neutral media with 2-6 times improvement in catalytic activies compared to other molybdenum sulfide based materials. PMID:24554595

Ge, Xingbo; Chen, Luyang; Zhang, Ling; Wen, Yuren; Hirata, Akihiko; Chen, Mingwei

2014-05-21

130

Mechanism for the hydrogen sulfide-induced growth limitation in wetland macrophytes  

Microsoft Academic Search

Hydrogen sulfide, a phytotoxin that often accumulates in anoxic marine and freshwater marsh soils, suppressed the activity of alcohol dehydrogenase (ADH), the enzyme that catalyzes the terminal step in alcoholic fermentation, in the roots of two wetland macrophytes. This inhibition of root ADH activity with increasing sulfide concentration was associated with decreases in root total adenine nucleotide pool (ATP +

MARGUERITE S. KOCH; IRVING A. MENDELSSOHN; KAREN L. MCKEE

1990-01-01

131

No facilitator required for membrane transport of hydrogen sulfide  

PubMed Central

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

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

2009-01-01

132

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...

133

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

SciTech Connect

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

Houston, C.W.

1996-03-01

134

Development of a Biofilter with Tire-Derived Rubber Particle Media for Hydrogen Sulfide Odor Removal  

Microsoft Academic Search

The biofilter system containing tire-derived rubber particle (TDRP) filter media was utilized to treat the odorous gas contaminant,\\u000a hydrogen sulfide, in consideration of the economic advantage of reusing discarded tire materials and the high potential of\\u000a TDRP media for biofilm attachment. The pilot-scale system having 0.38 m3 of bed volume operated with synthetic hydrogen sulfide gas on continuous basis from a

Jaeyoung Park; Eric A. Evans; Timothy G. Ellis

2011-01-01

135

The Cardioprotective Actions of Hydrogen Sulfide in Acute Myocardial Infarction and Heart Failure  

PubMed Central

It has now become universally accepted that hydrogen sulfide (H2S), previously considered only as a lethal toxin, has robust cytoprotective actions in multiple organ systems. The diverse signaling profile of H2S impacts multiple pathways to exert cytoprotective actions in a number of pathological states. This paper will review the recently described cardioprotective actions of hydrogen sulfide in both myocardial ischemia/reperfusion injury and congestive heart failure. PMID:25045576

Polhemus, David J.; Calvert, John W.; Butler, Javed; Lefer, David J.

2014-01-01

136

Hydrogen sulfide as a potent cardiovascular protective agent.  

PubMed

Hydrogen sulfide (H2S) is a well-known toxic gas with the characteristic smell of rotten eggs. It is synthesized endogenously in mammals from the sulfur-containing amino acid l-cysteine by the action of several distinct enzymes: cystathionine-?-lyase (CSE), cystathionine-ß-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST) along with cysteine aminotransferase (CAT). In particular, CSE is considered to be the major H2S-producing enzyme in the cardiovascular system. As the third gasotransmitter next to nitric oxide (NO) and carbon monoxide (CO), H2S plays an important role in the regulation of vasodilation, angiogenesis, inflammation, oxidative stress and apoptosis. Growing evidence has demonstrated that this gas exerts a significant protective effect against the progression of cardiovascular diseases by a number of mechanisms such as vasorelaxation, inhibition of cardiovascular remodeling and resistance to form foam cells. The aim of this review is to provide an overview of the physiological functions of H2S and its protection against several major cardiovascular diseases, and to explore its potential health and therapeutic benefits. A better understanding will help develop novel H2S-based therapeutic interventions for these diseases. PMID:25058799

Yu, Xiao-Hua; Cui, Li-Bao; Wu, Kai; Zheng, Xi-Long; Cayabyab, Francisco S; Chen, Zhi-Wei; Tang, Chao-Ke

2014-11-01

137

Hydrogen sulfide anion regulates redox signaling via electrophile sulfhydration  

PubMed Central

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

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

138

Microbial Regulation of Host Hydrogen Sulfide Bioavailability and Metabolism  

PubMed Central

Hydrogen sulfide (H2S), generated through various endogenous enzymatic and non-enzymatic pathways, is emerging as a regulator of physiological and pathological events throughout the body. Bacteria in the gastrointestinal tract also produce significant amounts of H2S that regulates microflora growth and virulence responses. However, the impact of the microbiota on host global H2S bioavailability and metabolism remain unknown. To address this question, we examined H2S bioavailability in its various forms (free, acid labile or bound sulfane sulfur), cystathionine gamma lyase (CSE) activity and cysteine levels in tissues from germ free versus conventionally housed mice. Free H2S levels were significantly reduced in plasma and gastrointestinal tissues of germ free mice. Bound sulfane sulfur levels were decreased by 50–80% in germ free mouse plasma, adipose and lung tissues. Tissue CSE activity was significantly reduced in many organs from germ free mice, whereas tissue cysteine levels were significantly elevated compared to conventional mice. These data reveal that the microbiota profoundly regulates systemic bioavailability and metabolism of H2S. PMID:23466556

Shen, Xinggui; Carlström, Mattias; Borniquel, Sara; Jädert, Cecilia; Kevil, Christopher G; Lundberg, Jon

2014-01-01

139

Depolarizing actions of hydrogen sulfide on hypothalamic paraventricular nucleus neurons.  

PubMed

Hydrogen sulfide (H2S) is a novel neurotransmitter that has been shown to influence cardiovascular functions as well and corticotrophin hormone (CRH) secretion. Since the paraventricular nucleus of the hypothalamus (PVN) is a central relay center for autonomic and endocrine functions, we sought to investigate the effects of H2S on the neuronal population of the PVN. Whole cell current clamp recordings were acquired from the PVN neurons and sodium hydrosulfide hydrate (NaHS) was bath applied at various concentrations (0.1, 1, 10, and 50 mM). NaHS (1, 10, and 50 mM) elicited a concentration-response relationship from the majority of recorded neurons, with almost exclusively depolarizing effects following administration. Cells responded and recovered from NaHS administration quickly and the effects were repeatable. Input differences from baseline and during the NaHS-induced depolarization uncovered a biphasic response, implicating both a potassium and non-selective cation conductance. The results from the neuronal population of the PVN shed light on the possible physiological role that H2S has in autonomic and endocrine function. PMID:23691233

Khademullah, C Sahara; Ferguson, Alastair V

2013-01-01

140

Protective effect of hydrogen sulfide on pancreatic beta-cells.  

PubMed

Hydrogen sulfide (H2S) is recognized as a third gaseous signaling molecule behind nitric oxide (NO) and carbon monoxide (CO). In pancreatic beta-cells, H2S inhibits glucose-induced insulin release. There are multiple underlying mechanisms for this inhibitory process. Apart from these inhibitory effects, H2S also protects pancreatic islets from apoptotic cell death induced by high glucose. Moreover, expression of the H2S-producing enzyme, cystathionine ?-lyase (CSE), is induced by glucose stimulation. These observations suggest that H2S is produced in an inducible manner, as are the other two gaseous signaling molecules, NO and CO. We recently reported that a lack of CSE induces apoptotic beta-cell death and promotes the development of high-fat diet (HFD)-induced diabetes. These findings tempt us to suggest that H2S produced by CSE is part of a homeostatic mechanism used by pancreatic beta-cells to inhibit insulin release and reduce cellular stress evoked by glucose, possibly via the anti-oxidant properties of H2S. PMID:25461273

Okamoto, Mitsuhiro; Ishizaki, Toshimasa; Kimura, Toshihide

2014-11-13

141

Interactions between oxygen homeostasis, food availability, and hydrogen sulfide signaling  

PubMed Central

The ability to sense and respond to stressful conditions is essential to maintain organismal homeostasis. It has long been recognized that stress response factors that improve survival in changing conditions can also influence longevity. In this review, we discuss different strategies used by animals in response to decreased O2 (hypoxia) to maintain O2 homeostasis, and consider interactions between hypoxia responses, nutritional status, and H2S signaling. O2 is an essential environmental nutrient for almost all metazoans as it plays a fundamental role in development and cellular metabolism. However, the physiological response(s) to hypoxia depend greatly on the amount of O2 available. Animals must sense declining O2 availability to coordinate fundamental metabolic and signaling pathways. It is not surprising that factors involved in the response to hypoxia are also involved in responding to other key environmental signals, particularly food availability. Recent studies in mammals have also shown that the small gaseous signaling molecule hydrogen sulfide (H2S) protects against cellular damage and death in hypoxia. These results suggest that H2S signaling also integrates with hypoxia response(s). Many of the signaling pathways that mediate the effects of hypoxia, food deprivation, and H2S signaling have also been implicated in the control of lifespan. Understanding how these pathways are coordinated therefore has the potential to reveal new cellular and organismal homeostatic mechanisms that contribute to longevity assurance in animals. PMID:23233860

Iranon, Nicole N.; Miller, Dana L.

2012-01-01

142

Novel Insights Into Hydrogen Sulfide–Mediated Cytoprotection  

PubMed Central

Abstract Hydrogen sulfide (H2S) is a colorless, water soluble, flammable gas that has the characteristic smell of rotten eggs. Like other members of the gasotransmitter family (nitric oxide and carbon monoxide), H2S has traditionally been considered to be a highly toxic gas and environmental hazard. However, much like for nitric oxide and carbon monoxide, the initial negative perception of H2S has evolved with the discovery that H2S is produced enzymatically in mammals under normal conditions. As a result of this discovery, there has been a great deal of work to elucidate the physiological role of H2S. H2S is now recognized to be cytoprotective in various models of cellular injury. Specifically, it has been demonstrated that the acute administration of H2S, either prior to ischemia or at reperfusion, significantly ameliorates in vitro or in vivo myocardial and hepatic ischemia-reperfusion injury. These studies have also demonstrated a cardioprotective role for endogenous H2S. This review article summarizes the current body of evidence demonstrating the cytoprotective effects of H2S with an emphasis on the cardioprotective effects. This review also provides a detailed description of the current signaling mechanisms shown to be responsible for these cardioprotective actions. Antioxid. Redox Signal. 12, 1203–1217. PMID:19769484

Calvert, John W.; Coetzee, William A.

2010-01-01

143

Kinetics and mechanisms of hydrogen sulfide adsorption by biochars.  

PubMed

Three different biochars as cost-effective substitutes for activated carbon (AC) were tested for their hydrogen sulfide (H2S) adsorption ability. The biochars were produced from camphor (SC), bamboo (SB), and rice hull (SR) at 400°C by oxygen-limited pyrolysis. The surface area (SA), pH, and Fourier transform infrared spectras of the biochars and AC were compared. The maximum removal rates and the saturation constants were obtained using the Michaelis-Menten-type equation. The three biochars were found to be alkaline, and the SAs of the biochars were much smaller than that of the AC. The H2S breakthrough capacity was related to the local pH within the pore system of the biochar. The order observed in terms of both biochar and AC adsorption capacity was SR>SB>SC>AC. SR efficiently removed H2S within the inlet concentration range of 10-50 ?L/L. Biochars derived from agricultural/forestry wastes are a promising H2S adsorbent with distinctive properties. PMID:23455220

Shang, Guofeng; Shen, Guoqing; Liu, Liang; Chen, Qin; Xu, Zhiwei

2013-04-01

144

Hydrogen Sulfide Induced Disruption of Na+ Homeostasis in the Cortex  

PubMed Central

Maintenance of ionic balance is essential for neuronal functioning. Hydrogen sulfide (H2S), a known toxic environmental gaseous pollutant, has been recently recognized as a gasotransmitter involved in numerous biological processes and is believed to play an important role in the neural activities under both physiological and pathological conditions. However, it is unclear if it plays any role in maintenance of ionic homeostasis in the brain under physiological/pathophysiological conditions. Here, we report by directly measuring Na+ activity using Na+ selective electrodes in mouse cortical slices that H2S donor sodium hydrosulfide (NaHS) increased Na+ influx in a concentration-dependent manner. This effect could be partially blocked by either Na+ channel blocker or N-methyl-D-aspartate receptor (NMDAR) blocker alone or almost completely abolished by coapplication of both blockers but not by non-NMDAR blocker. These data suggest that increased H2S in pathophysiological conditions, e.g., hypoxia/ischemia, potentially causes a disruption of ionic homeostasis by massive Na+ influx through Na+ channels and NMDARs, thus injuring neural functions. Activation of delta-opioid receptors (DOR), which reduces Na+ currents/influx in normoxia, had no effect on H2S-induced Na+ influx, suggesting that H2S-induced disruption of Na+ homeostasis is resistant to DOR regulation and may play a major role in neuronal injury in pathophysiological conditions, e.g., hypoxia/ischemia. PMID:22474073

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

2012-01-01

145

New nitric oxide or hydrogen sulfide releasing aspirins.  

PubMed

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

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

2011-08-11

146

Endogenous hydrogen sulfide production is essential for dietary restriction benefits.  

PubMed

Dietary restriction (DR) without malnutrition encompasses numerous regimens with overlapping benefits including longevity and stress resistance, but unifying nutritional and molecular mechanisms remain elusive. In a mouse model of DR-mediated stress resistance, we found that sulfur amino acid (SAA) restriction increased expression of the transsulfuration pathway (TSP) enzyme cystathionine ?-lyase (CGL), resulting in increased hydrogen sulfide (H2S) production and protection from hepatic ischemia reperfusion injury. SAA supplementation, mTORC1 activation, or chemical/genetic CGL inhibition reduced H2S production and blocked DR-mediated stress resistance. In vitro, the mitochondrial protein SQR was required for H2S-mediated protection during nutrient/oxygen deprivation. Finally, TSP-dependent H2S production was observed in yeast, worm, fruit fly, and rodent models of DR-mediated longevity. Together, these data are consistent with evolutionary conservation of TSP-mediated H2S as a mediator of DR benefits with broad implications for clinical translation. PAPERFLICK: PMID:25542313

Hine, Christopher; Harputlugil, Eylul; Zhang, Yue; Ruckenstuhl, Christoph; Lee, Byung Cheon; Brace, Lear; Longchamp, Alban; Treviño-Villarreal, Jose H; Mejia, Pedro; Ozaki, C Keith; Wang, Rui; Gladyshev, Vadim N; Madeo, Frank; Mair, William B; Mitchell, James R

2015-01-15

147

Biofiltration of hydrogen sulfide by Sulfolobus metallicus at high temperatures.  

PubMed

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

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

2012-01-01

148

Early stages of sulfidation of iron and iron-chromium alloy in hydrogen sulfide  

SciTech Connect

Sulfidation of polycrystalline iron and an Fe-25 wt % Cr alloy at various partial pressures of H/sub 2/S in the temperature range of -170/sup 0/C to 500/sup 0/C was studied in situ in an ESCA spectrometer, and the sulfidized layers were investigated by depth profiling in an Auger spectrometer. The role of surface oxygen during sulfidation was investigated. The mode of sulfidation of sputter-clean iron was found to involve several stages: associative adsorption of H/sub 2/S at low temperatures, dissociative adsorption of H/sub 2/S at around ambient temperature, and the formation of first a sulfur-deficient iron sulfide and then stoichiometric FeS at slightly elevated temperatures as the H/sub 2/S pressure or the time of exposure was increased. Iron sulfides are more readily formed on the oxidized iron surface than on the sputter-clean surface. Chromia (Cr/sub 2/O/sub 3/) was found to be stable in an H/sub 2/S atmosphere at T less than or equal to 250/sup 0/C, but was converted to chromium sulfide at 300/sup 0/C. Chromium sulfide is more readily formed on the clean alloy surface than on the oxidized surface. During annealing in vacuum, there is surface chromium enrichment on the FeCr alloy, and this is enhanced in the presence of oxygen or sulfur on the surface. Sulfidation proceeds primarily by cation diffusion, and the growth of the sulfide layers was found to be more dependent on temperature than on time of exposure. Iron was found to be more mobile than chromium in the FeCr alloys.

Narayanacharyulu, P.B.V.

1982-07-01

149

Geothermal hydrogen sulfide and health in Rotorua, New Zealand  

SciTech Connect

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)

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

1984-02-15

150

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

E-print Network

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

Schlegel, H. Bernhard

151

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

NASA Astrophysics Data System (ADS)

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

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

2006-05-01

152

Targeting hydrogen sulfide as a promising therapeutic strategy for atherosclerosis.  

PubMed

Physiological concentrations of nitric oxide (NO) and carbon monoxide (CO) have multiple protective effects in the cardiovascular system. Recent studies have implicated hydrogen sulfide (H2S) as a new member of vasculoprotective gasotransmitter family, behaving similarly to NO and CO. H2S has been demonstrated to inhibit multiple key aspects of atherosclerosis, including atherogenic modification of LDL, monocytes adhesion to the endothelial cells, macrophage-derived foam cell formation and inflammation, smooth muscle cell proliferation, neointimal hyperplasia, vascular calcification, and thrombogenesis. H2S also decreases plasma homocysteine levels in experimental animal models. In the human body, H2S production is predominantly catalyzed by cystathionine-?-synthase (CBS) and cystathionine ?-lyase (CSE). CSE is the primary H2S-producing enzyme in the vasculature. Growing evidence suggests that atherosclerosis is associated with vascular CSE/H2S deficiency and that H2S supplementation by exogenous H2S donors (such as NaHS and GYY4137) attenuates, and H2S synthesis suppression by inhibitors (such as D, L-propargylglycine) aggravates the development of atherosclerotic plaques. However, it remains elusive whether CSE deficiency plays a causative role in atherosclerosis. A recent study (Circulation. 2013; 127: 2523-2534) demonstrates that decreased endogenous H2S production by CSE genetic deletion accelerates atherosclerosis in athero-prone ApoE-/- mice, pinpointing that endogenously produced H2S by CSE activation may be of benefit in the prevention and treatment of atherosclerosis. This study will facilitate the development of H2S-based pharmaceuticals with therapeutic applications in atherosclerosis-related cardiovascular diseases. PMID:24491853

Xu, Suowen; Liu, Zhiping; Liu, Peiqing

2014-03-15

153

Role of hydrogen sulfide in secondary neuronal injury.  

PubMed

In acute neuronal insult events, such as stroke, traumatic brain injury, and spinal cord injury, pathological processes of secondary neuronal injury play a key role in the severity of insult and clinical prognosis. Along with nitric oxide (NO) and carbon monoxide (CO), hydrogen sulfide (H2S) is regarded as the third gasotransmitter and endogenous neuromodulator and plays multiple roles in the central nervous system under physiological and pathological states, especially in secondary neuronal injury. The endogenous level of H2S in the brain is significantly higher than that in peripheral tissues, and is mainly formed by cystathionine ?-synthase (CBS) in astrocytes and released in response to neuronal excitation. The mechanism of secondary neuronal injury exacerbating the damage caused by the initial insult includes microcirculation failure, glutamate-mediated excitotoxicity, oxidative stress, inflammatory responses, neuronal apoptosis and calcium overload. H2S dilates cerebral vessels by activating smooth muscle cell plasma membrane ATP-sensitive K channels (KATP channels). This modification occurs on specific cysteine residues of the KATP channel proteins which are S-sulfhydrated. H2S counteracts glutamate-mediated excitotoxicity by inducing astrocytes to intake more glutamate from the extracellular space and thus increasing glutathione in neurons. In addition, H2S protects neurons from secondary neuronal injury by functioning as an anti-oxidant, anti-inflammatory and anti-apoptotic mediator. However, there are still some reports suggest that H2S elevates neuronal Ca(2+) concentration and may contribute to the formation of calcium overload in secondary neuronal injury. H2S also elicits calcium waves in primary cultures of astrocytes and may mediate signals between neurons and glia. Consequently, further exploration of the molecular mechanisms of H2S in secondary neuronal injury will provide important insights into its potential therapeutic uses for the treatment of acute neuronal insult events. PMID:24239876

Wang, Jun-Feng; Li, Yu; Song, Jin-Ning; Pang, Hong-Gang

2014-01-01

154

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

PubMed

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

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

2014-06-18

155

Hydrogen sulfide as a regulator of calcium channels.  

PubMed

An increasing body of evidence suggests the involvement of hydrogen sulfide (H(2)S) in different physiological and pathological processes. Similarly to the other gasotransmitters nitric oxide (NO) and carbon monoxide (CO), this bioactive compound is rapidly diffusible through the biological membranes and acts in a paracrine fashion. Despite the large amount of biological actions observed in vitro and in vivo upon stimulation with H(2)S donors, as well as by interfering with its synthesis, the molecular targets and mechanisms through which it exerts its intracellular effects are only partially known. A number of proteins are covalently modified by H(2)S through sulfhydration of specific cysteine residues. However, only in few cases their identity has been discovered and the functional role of this post-translational modification needs to be investigated in more detail. Great attention has been devoted to potassium channels, particularly K(ATP), as they are considered key mediators of H(2)S-induced effects, and their sulfhydration has been clearly demonstrated. Recently, different authors reported the ability of H(2)S to interfere with calcium homeostasis in neurons, cardiomyocytes and endothelial cells. Since calcium signaling is involved in all cell processes, these observations attracted increasing attention from basic biology and medicine. Although some effects of H(2)S on calcium signals can be ascribed to K(ATP) modulation, there is growing consensus about the existence of other targets for the gasotransmitter. Some of them are Ca(2+)-permeable channels. In this review we discuss the state of the art in this specific field, providing an updated report of H(2)S interaction with Ca(2+) channels and its functional outcomes. PMID:22840338

Munaron, Luca; Avanzato, Daniele; Moccia, Francesco; Mancardi, Daniele

2013-02-01

156

Biofiltration for control of carbon disulfide and hydrogen sulfide vapors  

SciTech Connect

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.

Fucich, W.J.; Yang, Y.; Togna, A.P. [Envirogen, Inc., Lawrenceville, NJ (United States); Alibeckoff, D. [Nylonge Corp., Elyria, OH (United States)

1997-12-31

157

Is Hydrogen Sulfide-Induced Suspended Animation General Anesthesia?  

PubMed Central

Hydrogen sulfide (H2S) depresses mitochondrial function and thereby metabolic rates in mice, purportedly resulting in a state of “suspended animation.” Volatile anesthetics also depress mitochondrial function, an effect that may contribute to their anesthetic properties. In this study, we ask whether H2S has general anesthetic properties, and by extension, whether mitochondrial effects underlie the state of anesthesia. We compared loss of righting reflex, electroencephalography, and electromyography in mice exposed to metabolically equipotent concentrations of halothane, isoflurane, sevoflurane, and H2S. We also studied combinations of H2S and anesthetics to assess additivity. Finally, the long-term effects of H2S were assessed by using the Morris water maze behavioral testing 2 to 3 weeks after exposures. Exposure to H2S decreases O2 consumption, CO2 production, and body temperature similarly to that of the general anesthetics, but fails to produce a loss of righting reflex or muscle atonia at metabolically equivalent concentrations. When combined, H2S antagonizes the metabolic effects of isoflurane, but potentiates the isoflurane-induced loss of righting reflex. We found no effect of prior H2S exposure on memory or learning. H2S (250 ppm), not itself lethal, produced delayed lethality when combined with subanesthetic concentrations of isoflurane. H2S cannot be considered a general anesthetic, despite similar metabolic suppression. Metabolic suppression, presumably via mitochondrial actions, is not sufficient to account for the hypnotic or immobilizing components of the anesthetic state. Combinations of H2S and isoflurane can be lethal, suggesting extreme care in the combination of these gases in clinical situations. PMID:22414854

Li, Rosie Q.; McKinstry, Andrew R.; Moore, Jason T.; Caltagarone, Breanna M.; Eckenhoff, Maryellen F.; Eckenhoff, Roderic G.

2012-01-01

158

Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide  

PubMed Central

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

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

2008-01-01

159

Role of hydrogen sulfide in skeletal muscle biology and metabolism.  

PubMed

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

Veeranki, Sudhakar; Tyagi, Suresh C

2014-11-25

160

Inhibitory action of hydrogen sulfide on muscarinic receptor-induced contraction of isolated porcine irides  

Microsoft Academic Search

We investigated the pharmacological actions of hydrogen sulfide (H2S) using sodium hydrosulfide (NaHS) and sodium sulfide (Na2S) as donors on isolated porcine irides in the presence of tone induced by muscarinic receptor stimulation. Furthermore, we also investigated the mechanism of action of H2S in this smooth muscle. Isolated porcine iris muscle strips were set up in organ baths and prepared

Emmanuel M. Monjok; Kaustubh H. Kulkarni; Ghislaine Kouamou; Marshalyn McKoy; Catherine A. Opere; Odelia N. Bongmba; Ya Fatou Njie; Sunny E. Ohia

2008-01-01

161

Methanol and hydrogen sulfide in comet P/Halley  

NASA Technical Reports Server (NTRS)

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%.

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

1994-01-01

162

Environmental exposure to hydrogen sulfide in central Slovakia (Ruzomberok area) in context of health risk assessment.  

PubMed

The activities of the kraft pulp-mill in Ruzomberok have great impact on ambient air quality in the town and the neighboring villages. The malodorous sulfur compounds adversely contribute to the overall emission profile. The reduced sulfur proportion forms the inorganic and organic compounds containing sulfur atoms in their lowest oxidation condition (S2-). The total sulfur proportion reduced includes hydrogen sulfide, mercaptans, dimethyl sulfide, dimethyl disulfide and other sulfur compounds. Hydrogen sulfide (H2S)--as mentioned above--is of prime importance. The kraft pulp-mill has measured of hydrogen sulfide contained in ambient air since 2002. The environmental samples were collected in 7 localities in all their selection based on the geographic, climatic and demographic factors. Four exposure localities in the Ruzomberok neighborhood, have been defined by the specified criteria. Exposure assessment was made for each exposure locality by determination of the average daily inhalation dose. The average concentration of H2S reached 5.8 microg x m(-3) in the most polluted locality (Cernová, 2003). To complete the health risk assessment, the standard risk characterization procedure was made by the Hazard Quotient (HQ) calculation for hydrogen sulfide exposure. The highest level of HQ, almost 7, was identified in the event of a worst case exposure scenario (using the 95% concentrations), as for exposure group C. Statistically significant decrease of reported H2S levels was noted during the entire measurement period (-0.25/year, p < 0.001). PMID:21361108

Drimal, Marek; Koppová, Kvetoslava; Klöslová, Zuzana; Fabiánová, Eleonóra

2010-12-01

163

On the adsorption/oxidation of hydrogen sulfide on activated carbons at ambient temperatures.  

PubMed

Activated carbons of various origins (bituminous coal, wood, coconut shells, and peat) were studied as adsorbents of hydrogen sulfide. Before the experiments the surface of the adsorbents was characterized by using the sorption of nitrogen, Boehm and potentiometric titrations, thermal analysis, and FTIR. The adsorbents were chosen to differ in their surface areas, pore volumes, and surface acidities. To broaden the spectrum of surface acidity, carbons were oxidized by using nitric acid and ammonium persulfate. After hydrogen sulfide adsorption the species present on the surface were analyzed using thermal analysis, ion chromatography, and elemental analysis. The H(2)S breakthrough capacity tests showed that the performances of different carbons differ significantly. For a good performance of carbons as hydrogen sulfide adsorbents a proper combination of surface chemistry of carbon and porosity is needed. It was demonstrated that a more acidic environment promotes the formation of sulfur oxides and sulfuric acid despite yielding small H(2)S removal capacities. On the other hand, a basic environment favors the formation of elemental sulfur (sulfur radicals) and yields high capacities. The presence of a sufficient amount of water preadsorbed on the carbon surface to facilitate dissociation also plays an important role in the process of H(2)S adsorption/oxidation. The results showed that there is a critical value in carbon surface acidity, which when exceeded results in a negligible hydrogen sulfide breakthrough capacity. This is consistent with the mechanism of H(2)S adsorption on unmodified carbons, where the rate-limiting step is the reaction of adsorbed hydrogen sulfide ion with dissociatively adsorbed oxygen. When the acidity is expressed as pH, its value should be higher than 5 to ensure the effective removal of hydrogen sulfide from the gas phase. Study of carbon regeneration using water washing and heat treatment showed that the adsorbents can be regenerated to about 40% of their initial capacity. PMID:16290378

Bandosz, Teresa J

2002-02-01

164

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

PubMed

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

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

2008-11-15

165

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

166

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

Code of Federal Regulations, 2011 CFR

...Resources 2 2011-07-01 2011-07-01 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...

2011-07-01

167

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

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

168

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

169

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

...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...

2014-07-01

170

Modeling hydrogen sulfide emissions across the gas–liquid interface of an anaerobic swine waste treatment storage system  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive “rotten egg” smell and is considered a toxic manure gas. In the southeastern United States, anaerobic waste treatment lagoons are widely used to store and treat hog excreta at commercial hog farms. Hydrogen sulfide is produced as manure decomposes anaerobically, resulting from the

Jessica Blunden; Viney P. Aneja; John H. Overton

2008-01-01

171

Associations of Ambient Hydrogen Sulfide Exposure with Self-Reported Asthma and Asthma Symptoms  

PubMed Central

Background Whether long-term, low-level hydrogen sulfide (H2S) gas is a cause of health effects, including asthma, is uncertain. Rotorua city, New Zealand, has the largest population exposed, from geothermal sources, to relatively high ambient levels of H2S. In a cross-sectional study, the authors investigated associations with asthma in this population. Methods A total of 1,637 adults, aged 18-65 years, were enrolled during 2008-2010. Residences and workplaces were geocoded. H2S exposures at homes and workplaces were estimated using city-wide networks of passive H2S samplers and kriging to create exposure surfaces. Exposure metrics were based on (1) time-weighted exposures at home and work; and (2) the maximum exposure (home or work). Exposure estimates were entered as quartiles into log-binomial regression models, with covariate data. Results Neither exposure metric showed evidence of increased asthma risk from H2S. However, some suggestion of exposure-related reduced risks for diagnosed asthma and asthma symptoms, particularly wheezing during the last 12 months, emerged. With the maximum exposure metric, the prevalence ratio for wheeze in the highest exposure quartile was 0.80 (0.65, 0.99) and, for current asthma treatment, 0.75 (0.52, 1.08). There was no evidence that this was caused by a “survivor effect”. Conclusions The study provided no evidence that asthma risk increases with H2S exposure. Suggestions of a reduced risk in the higher exposure areas are consistent with recent evidence that H2S has signaling functions in the body, including induction of smooth muscle relaxation and reduction of inflammation. Study limitations, including possible confounding, preclude definitive conclusions. PMID:23453847

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

2013-01-01

172

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

173

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...

174

Effect of sewer headspace air-flow on hydrogen sulfide removal by corroding concrete surfaces.  

PubMed

Hydrogen sulfide adsorption and oxidation by corroding concrete surfaces at different air-flows were quantified using a pilot-scale sewer reactor. The setup was installed in an underground sewer research station with direct access to wastewater. Hydrogen sulfide gas was injected into the headspace of the sewer reactor once per hour in peak concentrations of approximately 500 ppmv. The investigated range of sewer air-flows was representative for natural ventilated sewer systems, and covered both laminar and turbulent conditions. The experiments demonstrated a significant effect of sewer air-flow on the kinetics of hydrogen sulfide removal from the sewer headspace. From the lowest to the highest air-flow investigated, the rate of adsorption and oxidation increased more than threefold. At all air-flows, the reaction kinetics followed a simple n-th order rate equation with a reaction order of 0.8. The effect of air-flow on hydrogen sulfide adsorption and oxidation kinetics was quantified by a simple empirical equation. PMID:22755494

Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

2012-03-01

175

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

E-print Network

Giant Hydrogen Sulfide Plume in the Oxygen Minimum Zone off Peru Supports Chemolithoautotrophy , Julie LaRoche1,4 * 1 Research Division Marine Biogeochemistry, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, 2 Institute for General Microbiology, Christian-Albrechts- University, Kiel

Boyer, Edmond

176

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...

177

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...

178

Evolution of hydrogen sulfide in a fluidized bed coal gasification reactor  

Microsoft Academic Search

The rates of evolution of hydrogen sulfide have been measured for the steam\\/oxygen gasification of a devolatilized Western Kentucky bituminous coal, a New Mexico subbituminous coal, and a Texas lignite in a pilot-scale fluidized bed reactor, and a phenomenological model has been formulated to correlate the results. The model assumes instantaneous devolatilization and partial combustion of the coal followed by

Robert P. Ma; Richard M. Felder; James K. Ferrell

1989-01-01

179

Solubility of hydrogen sulfide in aqueous mixtures of monoethanolamine with N-methyldiethanolamine  

SciTech Connect

Alkanolamine aqueous solutions are frequently used for the removal of acidic gases, such as CO[sub 2] and H[sub 2]S, from gas streams in the natural gas and synthetic ammonia industries and petroleum chemical plants. The solubilities of hydrogen sulfide in aqueous mixtures of monoethanolamine (MEA) with N-methyl-diethanolamine (MDEA) have been measured at 40, 60, 80, and 100C and at partial pressures of hydrogen sulfide ranging from 1.0 to 450 kPa. The mixtures of alkanolamines studied are 4.95 kmol/m[sup 3] MEA, 3.97 kmol/m[sup 3] MEA + 0.51 kmol/m[sup 3] MDEA, 2.0 kmol/m[sup 3] MEA + 1.54 kmol/m[sup 3] MDEA, and 2.57 kmol/m[sup 3] MDEA aqueous solutions. The solubilities of hydrogen sulfide in aqueous alkanolamine solutions are reported as functions of the partial pressure of hydrogen sulfide at the temperatures of 40-100C.

Meng Hui Li; Keh Perng Shen (Chung Yuan Christian Univ., Chung Li (Taiwan, Province of China). Dept. of Chemical Engineering)

1993-01-01

180

Hydrogen sulfide protects astrocytes against H 2O 2-induced neural injury via enhancing glutamate uptake  

Microsoft Academic Search

Excess extracellular glutamate, the main excitatory neurotransmitter, may result in excitotoxicity and neural injury. The present study was designed to study the effect of hydrogen sulfide (H2S), a novel neuromodulator, on hydrogen peroxide (H2O2) -induced glutamate uptake impairment and cellular injuries in primary cultured rat cortical astrocytes. We found that NaHS (an H2S donor, 0.1-1000 ?M) reversed H2O2-induced cellular injury in

Ming Lu; Li-Fang Hu; Gang Hu; Jin-Song Bian

2008-01-01

181

Hydrogen sulfide oxidation and the arterial chemoreflex: effect of methemoglobin.  

PubMed

Endogenous H(2)S has been proposed to transduce the effects of hypoxia in the carotid bodies (CB). To test this hypothesis, we created a sink for endogenously produced H(2)S by inducing ?10% methemoglobinemia via the injection of 250 mg of sodium nitrite in spontaneously breathing anaesthetized sheep. Methemoglobinemia has been shown to catalyze the oxidation of large quantities of sulfide in the blood and tissues. We found that the presence of metHb completely abolished the ventilatory stimulation induced by 10 mg NaHS (i.v.), which in control conditions mimicked the effects of breathing 6-7 tidal volumes of nitrogen, confirming the dramatic increase in the oxidative power of the blood for sulfide. The ventilatory responses to hypoxia (10% O(2)), nitrogen and hyperoxia were in no way depressed by the metHb. Our results demonstrate that the ventilatory chemoreflex is not depressed in the presence of a high oxidative capacity for sulfide and challenge the view that H(2)S transduces the effects of hypoxia in the CB. PMID:21569867

Haouzi, Philippe; Bell, Harold; Philmon, Maeve

2011-08-15

182

Precipitation of heavy metals from coal ash leachate using biogenic hydrogen sulfide generated from FGD gypsum.  

PubMed

Investigations were undertaken to utilize flue gas desulfurization (FGD) gypsum for the treatment of leachate from the coal ash (CA) dump sites. Bench-scale investigations consisted of three main steps namely hydrogen sulfide (H(2)S) production by sulfate reducing bacteria (SRB) using sulfate from solubilized FGD gypsum as the electron acceptor, followed by leaching of heavy metals (HMs) from coal bottom ash (CBA) and subsequent precipitation of HMs using biologically produced sulfide. Leaching tests of CBA carried out at acidic pH revealed the existence of several HMs such as Cd, Cr, Hg, Pb, Mn, Cu, Ni and Zn. Molasses was used as the electron donor for the biological sulfate reduction (BSR) process which produced sulfide rich effluent with concentration up to 150 mg/L. Sulfide rich effluent from the sulfate reduction process was used to precipitate HMs as metal sulfides from CBA leachate. HM removal in the range from 40 to 100% was obtained through sulfide precipitation. PMID:23168629

Jayaranjan, Madawala Liyanage Duminda; Annachhatre, Ajit P

2013-01-01

183

A novel dinuclear ruthenium(II)-copper(II) complex-based luminescent probe for hydrogen sulfide.  

PubMed

A novel dinuclear ruthenium(II)-copper(II) complex, [Ru(bpy)2(phen-cyc)Cu](PF6)4 (bpy: 2,2'-bipyridine; cyc: 1,4,7,10-tetraazacyclododecane; phen: 1,10-phenanthroline), has been designed and synthesized by conjugating a ruthenium(II) complex with a cyclen-Cu(2+) complex. This has almost no luminescence due to the efficient quenching by Cu(2+) of the luminescence of the ruthenium(II) complex. In aqueous media, the reaction of [Ru(bpy)2(phen-cyc)Cu](PF6)4 with hydrogen sulfide results in the release of the Cu(2+) from the azamacrocyclic ring, accompanied by a ~130-fold increase in the luminescence intensity at 605 nm with a 159 nm Stokes shift. The dose-dependent luminescence enhancement shows a good linearity in a concentration range of 2.0 to 20 ?M, with a detection limit of 21.6 nM for hydrogen sulfide. In addition, the luminescence response of [Ru(bpy)2(phen-cyc)Cu](PF6)4 to hydrogen sulfide is very rapid and widely available in the pH range of 3.0-9.5. It also has excellent selectivity so it can distinguish hydrogen sulfide with no interference by other anions and amino acids. On the basis of these features, a rapid, highly selective and sensitive luminescence method for the detection of hydrogen sulfide under physiological conditions was established, using [Ru(bpy)2(phen-cyc)Cu](PF6)4 as a probe. PMID:25036000

Ye, Zhiqiang; An, Xin; Song, Bo; Zhang, Wenzhu; Dai, Zhichao; Yuan, Jingli

2014-09-14

184

Hemodynamic and metabolic effects of hydrogen sulfide during porcine ischemia/reperfusion injury.  

PubMed

In awake spontaneously breathing mice, inhaling gaseous hydrogen sulfide (H2S) produced a "suspended animation-like" metabolic status with hypothermia and reduced O2 demand, thus protecting from lethal hypoxia. Murine models may be questioned, however, because due to their large surface area/mass ratio, rodents can rapidly drop their core temperature. Therefore, we investigated whether intravenous H2S (Na2S, sodium sulfide) would induce a comparable metabolic response in anesthetized and mechanically ventilated pigs. Because H2S was reported to improve heart function after myocardial ischemia, we also investigated whether sulfide would influence the noradrenaline responsiveness during reperfusion after aortic occlusion. After 2 h of i.v. sulfide (0.2 mg.kg followed by 2 mg.kg.per h; n=8) or vehicle (n=8), animals underwent 30 minutes of aortic occlusion with nitroglycerine, esmolol, and adenosine-5'-triphosphate adjusted to maintain MAP at 80% to 120% of baseline. During reperfusion, noradrenaline was titrated to keep MAP greater than or equal to 80% of this level. Sulfide reduced heart rate and cardiac output without affecting stroke volume, markedly decreased the time and dose of noradrenaline required to maintain hemodynamic targets, and caused a drop in core temperature concomitant with lower O2 uptake and CO2 production. Although arterial PCO2 and acid-base status were comparable, arterial PO2 was lower in the sulfide group at the end of the experiment. Sulfide attenuated the reperfusion-related hyperlactatemia, although glycemia was higher at the end of the experiment. The parameters of inflammation and oxidative stress did not differ. Intravenous sulfide allowed reducing energy expenditure in an anesthetized large-animal model and improved the noradrenaline responsiveness during reperfusion after aortic occlusion. Investigations are warranted, hence, whether it may also protect other organs after I/R injury. PMID:18323742

Simon, Florian; Giudici, Riccardo; Duy, Cuong Nguyen; Schelzig, Hubert; Oter, Sükrü; Gröger, Michael; Wachter, Ulrich; Vogt, Josef; Speit, Günter; Szabó, Csaba; Radermacher, Peter; Calzia, Enrico

2008-10-01

185

Microbial community structure and sulfur biogeochemistry in mildly-acidic sulfidic geothermal springs in Yellowstone National Park.  

PubMed

Geothermal and hydrothermal waters often contain high concentrations of dissolved sulfide, which reacts with oxygen (abiotically or biotically) to yield elemental sulfur and other sulfur species that may support microbial metabolism. The primary goal of this study was to elucidate predominant biogeochemical processes important in sulfur biogeochemistry by identifying predominant sulfur species and describing microbial community structure within high-temperature, hypoxic, sulfur sediments ranging in pH from 4.2 to 6.1. Detailed analysis of aqueous species and solid phases present in hypoxic sulfur sediments revealed unique habitats containing high concentrations of dissolved sulfide, thiosulfate, and arsenite, as well as rhombohedral and spherical elemental sulfur and/or sulfide phases such as orpiment, stibnite, and pyrite, as well as alunite and quartz. Results from 16S rRNA gene sequencing show that these sediments are dominated by Crenarchaeota of the orders Desulfurococcales and Thermoproteales. Numerous cultivated representatives of these lineages, as well as the Thermoproteales strain (WP30) isolated in this study, require complex sources of carbon and respire elemental sulfur. We describe a new archaeal isolate (strain WP30) belonging to the order Thermoproteales (phylum Crenarchaeota, 98% identity to Pyrobaculum/Thermoproteus spp. 16S rRNA genes), which was obtained from sulfur sediments using in situ geochemical composition to design cultivation medium. This isolate produces sulfide during growth, which further promotes the formation of sulfide phases including orpiment, stibnite, or pyrite, depending on solution conditions. Geochemical, molecular, and physiological data were integrated to suggest primary factors controlling microbial community structure and function in high-temperature sulfur sediments. PMID:23231658

Macur, R E; Jay, Z J; Taylor, W P; Kozubal, M A; Kocar, B D; Inskeep, W P

2013-01-01

186

Carbon and hydrogen isotopic compositions of New Zealand geothermal gases  

NASA Astrophysics Data System (ADS)

Carbon and hydrogen isotopic compositions are reported for methane, hydrogen and carbon dioxide from four New Zealand geothermal areas: Ngawha, Wairakei, Broadlands and Tikitere. Carbon-13 contents are between -24.4 and -29.5%. (PDB) for methane, and between -3.2 and -9.1%. for carbon dioxide. Deuterium contents are between -142 and -197%. (SMOW) for methane and between -310 and -600%. for hydrogen. The different areas have different isotopic compositions with some general relationships to reservoir temperature. The isotopic exchange of hydrogen with water indicates acceptable reservoir temperatures of 180-260°C from most spring samples but often higher than measured temperatures in well samples. Indicated temperatures assuming 13C equilibria between CH 4 and CO 2 are 100-200°C higher than measured maxima. This difference may be due to partial isotopic equilibration or may reflect the origin of the methane. Present evidence cannot identify whether the methane is primordial, or from decomposing sediments or from reduction of magmatic CO 2. The isotopic equilibria between CH 4, CO 2, H 2 and H 2O are reviewed and a new semi-empirical temperature scale proposed for deuterium exchange between methane and water.

Lyon, G. L.; Hulston, J. R.

1984-06-01

187

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

PubMed

In December 2008, the U.S. Consumer Product Safety Commission (CPSC) began receiving reports about odors, corrosion, and health concerns related to drywall originating from China. In response, a detailed environmental health and engineering evaluation was conducted of 41 complaint and 10 non-complaint homes in the Southeast U.S. Each home investigation included characterization of: 1) drywall composition; 2) indoor and outdoor air quality; 3) temperature, moisture, and building ventilation; and 4) copper and silver corrosion rates. Complaint homes had significantly higher hydrogen sulfide concentrations (mean 0.82 vs. sulfide and silver sulfide corrosion compared to non-complaint homes (Cu(2)S: 476 vs. <32 Å/30 d, p<0.01; Ag(2)S: 1472 vs. 389 Å/30 d, p<0.01). The abundance of carbonate and strontium in drywall was also elevated in complaint homes, and appears to be useful objective marker of problematic drywall in homes that meet other screening criteria (e.g., constructed or renovated in 2006-2007, reports of malodor and accelerated corrosion). This research provides empirical evidence of the direct association between homes constructed with 'Chinese Drywall' in 2006-2007 and elevated corrosion rates and hydrogen sulfide concentrations in indoor air. PMID:22525559

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

2012-06-01

188

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

Code of Federal Regulations, 2011 CFR

...measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel Gas Engineering Practices, The Industrial Press, 93 Worth Street, New York, NY, 1966, First Edition, Second Printing, page 6/25...

2011-07-01

189

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

Code of Federal Regulations, 2013 CFR

...measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel Gas Engineering Practices, The Industrial Press, 93 Worth Street, New York, NY, 1966, First Edition, Second Printing, page 6/25...

2013-07-01

190

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

Code of Federal Regulations, 2012 CFR

...measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel Gas Engineering Practices, The Industrial Press, 93 Worth Street, New York, NY, 1966, First Edition, Second Printing, page 6/25...

2012-07-01

191

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

...measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel Gas Engineering Practices, The Industrial Press, 93 Worth Street, New York, NY, 1966, First Edition, Second Printing, page 6/25...

2014-07-01

192

Silver/Gold core-shell nanoprism-based plasmonic nanoprobes for highly sensitive and selective detection of hydrogen sulfide.  

PubMed

A simple and highly sensitive and selective hydrogen sulfide assay utilizing plasmonic nanoprobes is presented in this report. The assay employs the etching of silver in the Ag/Au core-shell nanoprisms, accompanied by surface plasmon resonance (SPR) signal depression and shift. Briefly, thin layers of gold are first coated onto silver nanoprisms. The thin gold layer not only guarantees the high stability of the plasmonic nanoprobes but also ensures the high selectivity toward hydrogen sulfide. Once hydrogen sulfide is introduced, the silver core is converted to Ag2 S mainly from its lateral walls. Moreover, the SPR peak is located in the NIR region that makes these plasmonic nanoprobes more appealing for the detection of hydrogen sulfide in real-world samples and in in vivo applications. PMID:25428438

Yang, Xinjian; Ren, Yuqian; Gao, Zhiqiang

2015-01-12

193

Occurrence of hydrogen sulfide in wine and in fermentation: influence of yeast strain and supplementation of yeast available nitrogen  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a powerful aroma compound largely produced by yeast during fermentation. Its occurrence in wines and other fermented\\u000a beverages has been associated with off-odors described as rotten egg and\\/or sewage. While the formation of hydrogen sulfide\\u000a (H2S) during fermentation has been extensively studied, it is the final H2S content of wine that is actually linked to potential

Maurizio Ugliano; Radka Kolouchova; Paul A. Henschke

2011-01-01

194

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

DOEpatents

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.

Siriwardane, Ranjani V. (Morgantown, WV)

1997-01-01

195

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

DOEpatents

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.

Siriwardane, R.V.

1999-02-02

196

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

DOEpatents

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.

Siriwardane, R.V.

1997-12-30

197

Durable regenerable sorbent pellets for removal of hydrogen sulfide coal gas  

DOEpatents

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.

Siriwardane, Ranjani V. (Morgantown, WV)

1999-01-01

198

Conditions Under Which Cracks Occur in Modified 13% Chromium Steel in Wet Hydrogen Sulfide Environments  

Microsoft Academic Search

Occurrence of cracks in an API 13% Cr steel, modified 13% Cr steel, and duplex stainless steel were compared in various wet, mild hydrogen sulfide (HâS) environments. The conditions under which cracks occurred in the modified 13% Cr steel in oil and gas production environments were made clear. No cracks occurred if pH > depassivation pH (pH{sub d}) and redox

T. Hara; H. Asahi

2000-01-01

199

The solubility of elemental sulfur in methane, carbon dioxide and hydrogen sulfide gas  

E-print Network

.80 251.40 313.50 818.30 4000 394.00 157.60 196.20 516.70 3000 119.00 84.40 101.80 254.00 2000 30.80 48.10 46.70 81.60 1000 9.20 26.10 30.00 40.20 50 PHYSICAL CONSTANTS OF HYDROGEN SULFIDE bCompressibility factors TABLE 2 100_______160______ 220...

Wieland, Denton R.

2013-10-04

200

Comparative study of using different materials as bacterial carriers to treat hydrogen sulfide  

Microsoft Academic Search

The use of support media for the immobilization of microorganisms is widely known to provide a surface for microbial growth\\u000a and protect the microorganisms from inhibitory compounds. In this study, molecular sieve, granular porous carbon, and ferric\\u000a oxide desulfurizer, immobilized with autotrophic bacteria capable of oxidizing ferrous iron to ferric iron, were developed\\u000a to treat hydrogen sulfide (H2S). Their corresponding

Zhiling Li; Tonghua Sun; Nanwen Zhu; Xinde Cao; Jinping Jia

2008-01-01

201

Laboratory Validation of a Passive Length-of-Stain Dosimeter for Hydrogen Sulfide  

Microsoft Academic Search

A direct reading, passive, length-of-stain, personal dosimeter has been developed for hydrogen sulfide (H2S). The dosimeter consists of a 5-mm ID, sealed glass tube about 130?mm long. Inside the sealed glass tube is a length of impregnated paper about 70?mm long. To use the dosimeter, one end of the tubing is broken off and the tube is inserted into a

ELMER S. McKEE; PAUL W. McCONNAUGHEY

1986-01-01

202

Computational prediction of hydrogen sulfide and methane separation at room temperature by anatase titanium dioxide  

NASA Astrophysics Data System (ADS)

Removal of hydrogen sulfide (H2S) is a key step for biogas purification. Herein, the adsorption of H2S and methane (CH4) on anatase titanium dioxide (TiO2) has been studied by first principle calculations. It is found that TiO2 offers excellent capacity for the H2S/CH4 separation. Using force-field molecular dynamics, this high separation capacity has been examined at room temperature.

Sun, Chenghua

2013-02-01

203

Operation optimization of Thiobacillus thioparus CH11 biofilter for hydrogen sulfide removal  

Microsoft Academic Search

Members of the autotrophic species, Thiobacillus thioparus CH11, were isolated from swine wastewater and immobilized with Ca-alginate to produce pellet packing materials for a novel biofilter system that controls hydrogen sulfide emission. The effect of operating parameters, including retention time, temperature, and inlet gas concentration, on the removal efficiency and capacity was evaluated. Criteria necessary for a scale-up design of

Ying-Chien Chung; Chihpin Huang; Ching-Ping Tseng

1996-01-01

204

Case report: Profound neurobehavioral deficits in an oil field worker overcome by hydrogen sulfide  

Microsoft Academic Search

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

KAYE H. KILBURN

1993-01-01

205

Evidence That Hydrogen Sulfide Exerts Antinociceptive Effects in the Gastrointestinal Tract by Activating KATP Channels  

Microsoft Academic Search

Hydrogen sulfide (H2S) functions as a neuromodulator, but whether it modulates visceral perception and pain is unknown. Cystathionine -synthase (CBS) and cystathionine--lyase (CSE) mediate enzymatic generation of H2S in mammalian cells. Here we have investigated the role of H2S in modulating nociception to colorectal distension, a model that mimics some features of the irritable bowel syndrome. Four graded (0.4-1.6 ml

Eleonora Distrutti; Luca Sediari; Andrea Mencarelli; Barbara Renga; Stefano Orlandi; Elisabetta Antonelli; Fiorenza Roviezzo; Antonio Morelli; Giuseppe Cirino; John L. Wallace; Stefano Fiorucci

2005-01-01

206

Inhibition of Hydrogen Sulfide Generation Contributes to Gastric Injury Caused by Anti-Inflammatory Nonsteroidal Drugs  

Microsoft Academic Search

Background & Aims: Hydrogen sulfide (H2S), an endog- enous gaseous mediator that causes vasodilation, is generated in mammalian tissues by cystathionine -synthase (CBS) and cystathionine--lyase (CSE). Here, we have investigated the role of H2S in a rodent model of nonsteroidal anti-inflammatory drug (NSAID) gastropathy. Methods: Rats were given acetyl salycilic acid (ASA) or an NSAID alone or in combination with

STEFANO FIORUCCI; ELISABETTA ANTONELLI; ELEONORA DISTRUTTI; GIOVANNI RIZZO; ANDREA MENCARELLI; STEFANO ORLANDI; RENATA ZANARDO; BARBARA RENGA; MOSES DI SANTE; ANTONIO MORELLI; GIUSEPPE CIRINO; JOHN L. WALLACE

2005-01-01

207

Bile-acid-activated farnesoid X receptor regulates hydrogen sulfide production and hepatic microcirculation  

Microsoft Academic Search

AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfide (H 2S) generation. METHODS: The regulation of CSE expression in response to FXR ligands was evaluated in HepG2 cells and in wild-type and FXR null mice treated with 6-ethyl chenodeoxycholic acid (6E-CDCA), a synthetic FXR ligand. The analysis demonstrated

Barbara Renga; Andrea Mencarelli; Marco Migliorati; Eleonora Distrutti; Stefano Fiorucci

2009-01-01

208

Toward a selective, sensitive, fast-responsive, and biocompatible two-photon probe for hydrogen sulfide in live cells.  

PubMed

Hydrogen sulfide has emerged as an exciting endogenous gasotransmitter in addition to nitric oxide and carbon dioxide. Noninvasive detection methods for hydrogen sulfide thus become indispensable tools for studying its diverse roles in biological systems. Accordingly, fluorescent probes for hydrogen sulfide have received great attention in recent years. A practically useful fluorescent probe for bioimaging of hydrogen sulfide should be selective, sensitive, fast-responsive, biocompatible, observable in the biological optical window, and capable of deep-tissue imaging. These sensing properties, however, are extremely difficult to achieve at the same time. Disclosed here is the two-photon fluorescent probe that meets all of these criteria. The probe belongs to a Michael acceptor system, which raised a serious selectivity issue over the competing biothiols such as cysteine and glutathione. We have addressed the selectivity issue by optimizing the electronic and steric interactions between biothiols and the probe, in addition to achieving very high sensitivity, fast-response, and biocompatibility. Also, the sensing mechanism suggested in the literature was revised. The probe thus enables us to image the endogenously produced hydrogen sulfide with negligible interference from other biothiols in live cells. The excellent sensing properties of the probe combined with its capability of bioimaging thus make it a practically useful tool for further studying biological roles of hydrogen sulfide. PMID:25495776

Singha, Subhankar; Kim, Dokyoung; Moon, Hyunsoo; Wang, Taejun; Kim, Ki Hean; Shin, Youn Ho; Jung, Junyang; Seo, Eunseok; Lee, Sang-Joon; Ahn, Kyo Han

2015-01-20

209

Biological hydrogen sulfide production in an ethanol-lactate fed fluidized-bed bioreactor.  

PubMed

Sulfate-reducing fluidized-bed bioreactor (FBR) fed with ethanol-lactate mixture was operated at 35 degrees C for 540 days to assess mine wastewater treatment, biological hydrogen sulfide production capacity and acetate oxidation kinetics. During the mine wastewater treatment period with synthetic wastewater, the sulfate reduction rate was 62 mmol SO(4)(2-)L(-1)d(-1) and Fe and Zn precipitation rates were 11 mmol Fe L(-1)d(-1) and 1 mmol Zn L(-1)d(-1). After this, the hydrogen sulfide production was optimized, resulting in sulfate reduction rate of 100 mmol SO(4)(2-)L(-1)d(-1) and H(2)S production rate of 73.2 mmol H(2)SL(-1)d(-1). The limiting step in the H(2)S production was the rate of acetate oxidation, being 50 mmol acetate L(-1)d(-1). Therefore, FBR batch assays were designed to determine the acetate oxidation kinetics, and following kinetic parameters were obtained: K(m) of 63 micromol L(-1) and V(max) of 0.76 micromol acetate g VSS(-1)min(-1). The present study demonstrates high-rate hydrogen sulfide production and high-rate mine wastewater treatment with ethanol and lactate fed fluidized-bed bioreactor. PMID:19716290

Nevatalo, Laura M; Mäkinen, Annukka E; Kaksonen, Anna H; Puhakka, Jaakko A

2010-01-01

210

Hazardous peak concentrations of hydrogen sulfide gas related to the sewage purification process.  

PubMed

The concentration of hydrogen sulfide in the atmosphere of a sewage purification plant in Norway was studied. Continuous measurements over several 3-week periods showed that the concentrations generally were lower than 2 ppm, but peak concentrations over 100 ppm were discovered. Rapid onset and decline characterized these peak concentrations, which occurred at regular intervals. Through evaluation of the time pattern of these peaks compared with plant operations, a specific process was identified as the likely causative factor of the spikes. Through simple remedial actions the hydrogen sulfide concentration associated with this activity was reduced from above 100 ppm to less than 2 ppm. Olfactory fatigue to hydrogen sulfide and strong offensive odors from other compounds in the sewage makes smell ineffective for signaling high concentrations. Peak concentrations may therefore pass unnoticed unless detected with continuous measuring equipment. The risk for exposure may be reduced by enclosing processes and through the use of spot extraction ventilation in areas with compacted anaerobic waste material. PMID:10772623

Søstrand, P; Tvedt, B; Eduard, W; Bye, E; Heldal, K

2000-01-01

211

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

PubMed

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

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

2005-10-01

212

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

PubMed

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

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

2013-06-01

213

Dechlorination of chloropicrin and 1,3-dichloropropene by hydrogen sulfide species: redox and nucleophilic substitution reactions.  

PubMed

The chlorinated fumigants chloropicrin (trichloronitromethane) and 1,3-dichloropropene (1,3-D) are extensively used in agricultural production for the control of soilborne pests. The reaction of these two fumigants with hydrogen sulfide species (H2S and HS-) was examined in well-defined anoxic aqueous solutions. Chloropicrin underwent an extremely rapid redox reaction in the hydrogen sulfide solution. Transformation products indicated reductive dechlorination of chloropicrin by hydrogen sulfide species to produce dichloro- and chloronitromethane. The transformation of chloropicrin in hydrogen sulfide solution significantly increased with increasing pH, indicating that H2S is less reactive toward chloropicrin than HS- is. For both 1,3-D isomers, kinetics and transformation products analysis revealed that the reaction between 1,3-D and hydrogen sulfide species is an S(N)2 nucleophilic substitution process, in which the chlorine at C3 of 1,3-D is substituted by the sulfur nucleophile to form corresponding mercaptans. The 50% disappearance time (DT50) of 1,3-D decreased with increasing hydrogen sulfide species concentration at a constant pH. Transformation of 1,3-D was more rapid at high pH, suggesting that the reactivity of hydrogen sulfide species in the experimental system stems primarily from HS-. Because of the relatively low smell threshold values and potential environmental persistence of organic sulfur products yielded by the reaction of 1,3-D and HS-, the effects of reduced sulfide species should be considered in the development of alternative fumigation practices, especially in the integrated application of sulfur-containing fertilizers. PMID:16536608

Zheng, Wei; Yates, Scott R; Papiernik, Sharon K; Guo, Mingxin; Gan, Jianying

2006-03-22

214

Hydrogen Sulfide Therapy Attenuates the Inflammatory Response in a Porcine Model of Myocardial Ischemia – Reperfusion Injury  

PubMed Central

Introduction Hydrogen sulfide (H2S) is produced endogenously in response to myocardial ischemia and thought to be cardioprotective. The mechanism underlying this protection has yet to be fully elucidated, but may be related sulfide’s ability to limit inflammation. This study investigates the cardioprotection provided by exogenous H2S, and its potential anti-inflammatory mechanism of action. Methods The mid-LAD coronary artery in 14 Yorkshire swine was acutely occluded for 60 minutes, followed by reperfusion for 120 minutes. Controls(7) received placebo, and treatment animals(7) received sulfide 10 minutes prior to and throughout reperfusion. Hemodynamic and functional measurements were obtained. Evans blue and TTC staining identified the area-at-risk and infarction. Coronary microvascular reactivity was assessed. Tissue was assayed for myeloperoxidase activity and pro-inflammatory cytokines. Results Pre-I/R hemodynamics were similar between groups, whereas post-I/R mean arterial pressure (mmHg) was reduced by 28.7±5.0 in controls vs. 6.7±6.2 in treatment animals (p=0.03). +LV dP/dt (mmHg/sec) was reduced by 1325±455 in controls vs. 416±207 in treatment animals (p=0.002). Segmental shortening in the area-at-risk was better in treatment animals. Infarct size (% of area-at-risk) in controls was 41.0±7.8% vs. 21.2±2.5% in the treated group (p=0.036). Tissue levels of IL-6, IL-8, and TNF? and MPO activity decreased in the treatment group. Treated animals demonstrated improved microvascular reactivity. Conclusions Therapeutic sulfide provides protection in response to I/R injury, improving myocardial function, reducing infarct size, and improving coronary microvascular reactivity, potentially through its anti-inflammatory properties. Exogenous sulfide may have therapeutic utility in clinical settings in which I/R injury is encountered. PMID:19660398

Sodha, Neel R.; Clements, Richard T.; Feng, Jun; Liu, Yuhong; Bianchi, Cesario; Horvath, Eszter M.; Szabo, Csaba; Stahl, Gregory L.; Sellke, Frank W.

2009-01-01

215

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

SciTech Connect

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

Micheal Roberts; Robert Zabransky; Shain Doong; Jerry Lin

2008-05-31

216

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

PubMed

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

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

2014-10-14

217

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

E-print Network

Generation of DNA-Damaging Reactive Oxygen Species via the Autoxidation of Hydrogen Sulfide under found that micromolar concentrations of H2S generated single-strand DNA cleavage. Mechanistic studies indicate that this process involved autoxidation of H2S to generate superoxide, hydrogen peroxide, and

Gates, Kent. S.

218

Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors  

DOEpatents

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.

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

2014-10-14

219

Long-term effects of hydrogen sulfide on Hexagenia limbata (ephemeroptera)  

Microsoft Academic Search

Nymphs of the mayfly Hexagenia limbata (Serville) were subjected to hydrogen sulfide in test chambers with a mud substrate into which they could burrow. Acute and chronic tests were in flow-through apparatus. At 17.8-18.3°C and Oâ of 4.5-6.6, 96-h LCââ was 0.165 mg\\/liter HâS and LCââ at 12 days was 0.060 mg\\/liter HâS. In chronic tests running 138 days with

D. M. Oseid; L. L. Jr. Smith

1975-01-01

220

Solubility of mixtures of hydrogen sulfide and carbon dioxide in aqueous N-methyldiethanolamine solutions  

SciTech Connect

Aqueous solutions of alkanolamines are commonly used to strip acid gases (H[sub 2]S and CO[sub 2]) from streams contaminated with these components. The two most widely used amines are monoethanolamine (MEA) and diethanolamine (DEA). The solubilities of mixtures of hydrogen sulfide and carbon dioxide in a 35 wt% (3.04 kmol/m[sup 3]) aqueous solution of N-methyldiethanolamine at 40 and 100C have been measured. Partial pressures of the acid gases ranged from 0.006 to 101 kPa at 40C and from 4 to 530 kPa at 100C.

Jou, Fang Yuan; Carroll, J.J.; Mather, A.E.; Otto, F.D. (Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical Engineering)

1993-01-01

221

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

NASA Astrophysics Data System (ADS)

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.

Kappes, Mariano Alberto

222

Molybdenum sulfide/N-doped CNT forest hybrid catalysts for high-performance hydrogen evolution reaction.  

PubMed

Cost effective hydrogen evolution reaction (HER) catalyst without using precious metallic elements is a crucial demand for environment-benign energy production. Molybdenum sulfide is one of the promising candidates for such purpose, particularly in acidic condition, but its catalytic performance is inherently limited by the sparse catalytic edge sites and poor electrical conductivity. We report synthesis and HER catalysis of hybrid catalysts composed of amorphous molybdenum sulfide (MoSx) layer directly bound at vertical N-doped carbon nanotube (NCNT) forest surface. Owing to the high wettability of N-doped graphitic surface and electrostatic attraction between thiomolybdate precursor anion and N-doped sites, ?2 nm scale thick amorphous MoSx layers are specifically deposited at NCNT surface under low-temperature wet chemical process. The synergistic effect from the dense catalytic sites at amorphous MoSx surface and fluent charge transport along NCNT forest attains the excellent HER catalysis with onset overpotential as low as ?75 mV and small potential of 110 mV for 10 mA/cm(2) current density, which is the highest HER activity of molybdenum sulfide-based catalyst ever reported thus far. PMID:24502837

Li, Dong Jun; Maiti, Uday Narayan; Lim, Joonwon; Choi, Dong Sung; Lee, Won Jun; Oh, Youngtak; Lee, Gil Yong; Kim, Sang Ouk

2014-03-12

223

An approach to global rovibrational analysis based on anharmonic ladder operators: Application to hydrogen selenide and hydrogen sulfide  

NASA Astrophysics Data System (ADS)

A formalism to model the ro-vibrational spectrum of triatomic asymmetric top molecules is presented. The quantum mechanical ro-vibrational kinetic and potential energy function is considered as a Taylor expansion in internal coordinates of Morse local oscillators. Thereafter, local Morse coordinates and momenta are expanded in terms of Morse Potential ladder operators. Only polyad-conserving terms are considered. Expansions of the kinetic and potential energies of the ro-vibrational Hamiltonian are considered up to sextic terms. The resulting Hamiltonian was diagonalized using a symmetry-adapted basis, generated by the eigenfunction method ( J.Q.Chen, Group Representation Theory for Physicists,World Scientific, 1989; R. Lemus, 2003 Mol.Phys., 101 2511-2528.). The model is applied to hydrogen sulfide (H_2S) and hydrogen selenide (H_2Se).

Perez-Bernal, F.; Carvajal, M.; Alvarez-Bajo, O.

2011-05-01

224

Effects of infusion of human methemoglobin solution following hydrogen sulfide poisoning.  

PubMed

Abstract Rationale. We have recently reported that infusion of a solution containing methemoglobin (MetHb) during exposure to hydrogen sulfide results in a rapid and large decrease in the concentration of the pool of soluble/diffusible H2S in the blood. However, since the pool of dissolved H2S disappears very quickly after H2S exposure, it is unclear if the ability of MetHb to "trap" sulfide in the blood has any clinical interest and relevance in the treatment of sulfide poisoning. Methods. In anesthetized rats, repetition of short bouts of high level of H2S infusions was applied to allow the rapid development of an oxygen deficit. A solution containing MetHb (600 mg/kg) or its vehicle was administered 1 min and a half after the end of H2S intoxication. Results. The injection of MetHb solution increased methemoglobinemia to about 6%, almost instantly, but was unable to affect the blood concentration of soluble H2S, which had already vanished at the time of infusion, or to increase combined H2S. In addition, H2S-induced O2 deficit and lactate production as well as the recovery of carotid blood flow and blood pressure were similar in treated and control animals. Conclusion. Our results do not support the view that administration of MetHb or drugs-induced methemoglobinemia during the recovery phase following severe H2S intoxication in sedated rats can restore cellular oxidative metabolism, as the pool of diffusible sulfide, accessible to MetHb, disappears rapidly from the blood after H2S exposure. PMID:25634666

Chenuel, B; Sonobe, T; Haouzi, P

2015-02-01

225

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

NASA Astrophysics Data System (ADS)

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.)

Blunden, Jessica

226

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

PubMed

Tungsten sulfides, including WS2 (crystalline) and WS3 (amorphous), were introduced to silicon nanowires, and both can promote the photoelectrochemical hydrogen production of silicon nanowires. In addition, more enhancement of energy conversion efficiency can be achieved by the loading of WS3, in comparison with loading of WS2. Polarization curves of WS3 and WS2 suggest that WS3 has higher catalytic activity in the hydrogen evolution reaction than WS2, affording higher energy conversion efficiency in silicon nanowires decorated with WS3. The higher electrocatalytic activity of WS3 correlates with the amorphous structure of WS3 and larger surface area of WS3, which result in more active sites in comparison with crystalline WS2. PMID:24905279

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

2014-07-01

227

Glutathione-garlic sulfur conjugates: slow hydrogen sulfide releasing agents for therapeutic applications.  

PubMed

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

Bhuiyan, Ashif Iqbal; Papajani, Vilma Toska; Paci, Maurizio; Melino, Sonia

2015-01-01

228

Hydrogen sulfide ameliorates lead-induced morphological, photosynthetic, oxidative damages and biochemical changes in cotton.  

PubMed

Poisonous lead (Pb), among heavy metals, is a potential pollutant that readily accumulates in soils and thus adversely affects physiological processes in plants. We have evaluated how exogenous H2S affects cotton plant physiological attributes and Pb uptake under Pb stress thereby understanding the role of H2S in physiological processes in plants. Two concentrations (0 and 200 ?M) of H2S donor sodium hydrosulfide (NaHS) were experimented on cotton plants under Pb stress (0, 50, and 100 ?M). Results have shown that Pb stress decreased plant growth, chlorophyll contents, SPAD value, photosynthesis, antioxidant activity. On the other hand, Pb stress increased the level of malondialdehyde (MDA), electrolyte leakage (EL), and production of H2O2 and uptake of Pb contents in all three parts of plant, viz. root, stem, and leaf. Application of H2S slightly increased plant growth, chlorophyll contents, SPAD value, photosynthesis, and antioxidant activity as compared to control. Hydrogen sulfide supply alleviated the toxic effects of lead on plant growth, chlorophyll contents, SPAD value, photosynthesis, and antioxidant activity in cotton plants. Hydrogen sulfide also reduced MDA, EL, and production of H2O2 and endogenous Pb levels in the three mentioned plant parts. On the basis of our results, we conclude that H2S has promotive effects which could improve plant survival under Pb stress. PMID:23852465

Bharwana, Saima Aslam; Ali, Shafaqat; Farooq, Muhammad Ahsan; Ali, Basharat; Iqbal, Naeem; Abbas, Farhat; Ahmad, Muhammad Sajid Aqeel

2014-01-01

229

Hydrogen sulfide ameliorates the kidney dysfunction and damage in cisplatin-induced nephrotoxicity in rat  

PubMed Central

Hydrogen Sulfide (H2S) prevents and treats a variety of disorders via its cytoprotective effects. However, the effects of H2S on rats with cisplatin (CP) nephrotoxicity are unclear. The aim was to study the effects of H2S on rats with CP nephrotoxicity. Thirty male Sprague-Dawley rats were divided into three groups: control group, nephrotoxic group received single dose of CP (6 mg kg-1) and nephrotoxic groups that received single dose 100 µmol kg-1 NaHS. On fifth day after injection, urine of each rat was collected over a 24-hr period. Animals were sacrificed 6 days after CP (or vehicle) treatment, and blood, urine, and kidneys were obtained, prepared for light microscopy evaluation, lipid peroxidation content and laboratory analysis. The results showed that plasma urea (226%), creatinine (271%), renal lipid peroxidation content (151%), Na and K fractional excretion, urine protein, volume and kidney weight in CP nephrotoxic rats were significantly higher and urine osmolarity and creatinine clearance lower than in controls. Increases of the proximal tubular cells apoptosis and mesangial matrix in CP nephrotoxicity group rats were observed. Hydrogen sulfide reversed the CP-induced changes in the experimental rats H2S prevented the progression of CP nephrotoxicity in rats possibly through its cytoprotective effects such as antioxidant properties.

Ahangarpour, Akram; Abdollahzade Fard, Amin; Gharibnaseri, Mohammad Kazem; Jalali, Taha; Rashidi, Iran

2014-01-01

230

Hydrogen sulfide removal from coal gas by the metal-ferrite sorbents made from the heavy metal wastewater sludge.  

PubMed

The metal-ferrite (chromium-ferrite and zinc-ferrite) sorbents made from the heavy metal wastewater sludge have been developed for the hydrogen sulfide removal from coal gas. The high temperature absorption of hydrogen sulfide from coal gas with the metal-ferrite sorbent in a fixed bed reactor was conducted in this study. The metal-ferrite powders were the products of the ferrite process for the heavy metal wastewater treatment. The porosity analysis results show that the number of micropores of the sorbents after sulfidation and regeneration process decreases and the average pore size increases due to the acute endothermic and exothermic reactions during the sulfidation-regeneration process. The FeS, ZnS, and MnS peaks are observed on the sulfided sorbents, and the chromium extraction of the CFR6 can fulfill the emission standard of Taiwan EPA. The suitable sulfidation temperature range for chromium-ferrite sorbent is at 500-600 degrees C. In addition, effects of various concentrations of H2 and CO were also conducted in the present work at different temperatures. By increasing the H2 concentration, the sulfur sorption capacity of the sorbent decreases and an adverse result is observed in the case of increasing CO concentration. This can be explained via water-shift reaction. PMID:18440697

Tseng, Ting Ke; Chang, Han Ching; Chu, Hsin; Chen, Hung Ta

2008-12-30

231

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

PubMed

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

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

2013-01-01

232

Hydrogen sulfide (H2S) and sour gas effects on the eye. A historical perspective.  

PubMed

The toxicology of hydrogen sulfide (H(2)S) and sour gas on the eye has a long history beginning at least with Ramazzini's observations [Ramazzini B. Diseases of Workers--De Morbis Artificum Diatriba--1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc.; 1964. 98-99 pp.]. In contrast, a recent review by Alberta Health and Wellness (AHW Report) concluded that there is little evidence of eye irritation following short-term exposures to H(2)S at concentrations up to 100ppm and that the H(2)S literature on the eye is a series of unsubstantiated claims reproduced in review articles dating back to the 1930s [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide: a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In this paper, we evaluated this claim through a historical review of the toxicology of the eye. Ramazzini noted the effects of sewer gas on the eye [Ramazzini B. Diseases of Workers--De Morbis Artificum Diatriba--1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc. 1964. 98-99 pp.]. Lehmann experimentally showed eye effects in men at 70-90ppm H(2)S and also in animals [Lehmann K. Experimentalle Studien uber den Einfluss technisch und hygienisch wichtiger Gase und Dampfe auf den Organismus. Arch Hyg 1892;14:135-189]. In 1923, Sayers, Mitchell and Yant reported eye effects in animals and men at 50ppm H(2)S. Barthelemy showed eye effects in animals and men at 20ppm H(2)S [Barthelemy HL. Ten years' experience with industrial hygiene in connection with the manufacture of viscose rayon. J Ind Hyg Toxicol 1939;21:141-51]. Masure experimentally showed that H(2)S is the causative agent of eye impacts in animals and men [Masure R. La Keratoconjunctivite des filatures de viscose; etude clinique and experiementale. Rev Belge Pathol 1950;20:297-341]. Michal upon microscopic examination of the rat's cornea, found nuclear pyknosis, edema and separation of cells in the eye following exposures for 3h at 36ppm H(2)S [Michal FV. Eye lesions caused by hydrogen sulfide. Cesk Ophthalmol 1950;6;5-8]. In 1975, in Alberta, irreversible eye damage and photophobia were experimentally produced in calves exposed to 20ppm H(2)S for 1week [Nordstrom GA. A study of calf response of ammonia and hydrogen sulfide gases. Thesis, University of Alberta, Department of Agricultural Engineering, Edmonton Alberta; 1975, 218 pp.]. Alberta Environmental Centre documented clinical irritation of the eye at 40ppm H(2)S in 6 hours in rats [Alberta Environmental Centre. Morphological observations in rats exposed for six hours to an atmosphere of 0, 56, or 420mg/m(3) hydrogen sulfide. AECV86-A1. Alberta Environmental Centre, Vegreville, Alberta; 1986b. 28 pp.]. In two sour gas blow-outs in Alberta, in the early 1980s, eye injury was documented in humans and animals at 0.5 ppm H(2)S. Community studies in the United States, Europe and New Zealand suggest that acute exposure to 25ppb H(2)S is the lowest concentration to irritate the eyes; with chronic exposure, serious eye effects are suggested. In contrast to the conclusion, all of the studies, except one, cited in the AHW Report indicate toxic effects on the eye below 100ppm H(2)S [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H(2)S): a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In addition, the AHW Report (2002) mis-presented two studies as 'clinical studies', claiming they reported no evidence of eye effects in humans from 2 and 30 ppm H(2)S for 30-40 minutes [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H(2)S): a technical review, Alberta Health and Wellness, October 2002, 81pp.]. PMID:16650463

Lambert, Timothy William; Goodwin, Verona Marie; Stefani, Dennis; Strosher, Lisa

2006-08-15

233

Geothermal  

NSDL National Science Digital Library

What part does geothermal energy play in satisfying energy demands? This informational piece, part of a series about the future of energy, introduces students to heat within the Earth as an energy source. Here students read about the uses, benefits, and limitations of geothermal energy. Articles and information on places around the world that use geothermal energy and geothermal use by schools in Iowa are available from a sidebar. A link to a map of geothermal hotspots around the world is provided, along with a link to an ABC News article about geothermal power.

Project, Iowa P.

2004-01-01

234

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 ...

235

Investigation of the active sites of rhodium sulfide for hydrogen evolution/oxidation using carbon monoxide as a probe.  

PubMed

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

Singh, Nirala; Upham, David C; Liu, Ru-Fen; Burk, Jonathan; Economou, Nick; Buratto, Steven; Metiu, Horia; McFarland, Eric W

2014-05-20

236

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

Microsoft Academic Search

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

Fernando Llavador Colomer; Héctor Espinós Morató; Enrique Mantilla Iglesias

2012-01-01

237

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

SciTech Connect

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)

Harrar, J.E. (comp.)

1980-12-01

238

Methane, carbon dioxide, and hydrogen sulfide production from the terminal methiol group of methionine by anaerobic lake sediments.  

PubMed

A significant portion of the sulfide in lake sediments may be derived from sulfur-containing amino acids. Methionine degradation in Lake Mendota (Wisconsin) sediments was studied with gas chromatographic and radiotracer techniques. Temperature optimum and inhibitor studies showed that this process was biological. Methane thiol and dimethyl sulfide were produced in sediments when 1-mumol/ml unlabeled methionine was added. When chloroform (an inhibitor of one-carbon metabolism) was added to the sediments, methane thiol, carbon disulfide, and n-propane thiol were produced, even when no methionine was added. When S-labeled methionine was added to the sediments in tracer quantities (1.75 nmol/ml), labeled hydrogen sulfide was produced, and a roughly equal amount of label was incorporated into insoluble material. Methane and carbon dioxide were produced from [methyl-C]methionine. Evidence is given favoring methane thiol as an intermediate in the formation of methane, carbon dioxide, and hydrogen sulfide from the terminal methiol group of methionine. Methionine may be an important source of sulfide in lake sediments. PMID:16345275

Zinder, S H; Brock, T D

1978-02-01

239

Methane, Carbon Dioxide, and Hydrogen Sulfide Production from the Terminal Methiol Group of Methionine by Anaerobic Lake Sediments  

PubMed Central

A significant portion of the sulfide in lake sediments may be derived from sulfur-containing amino acids. Methionine degradation in Lake Mendota (Wisconsin) sediments was studied with gas chromatographic and radiotracer techniques. Temperature optimum and inhibitor studies showed that this process was biological. Methane thiol and dimethyl sulfide were produced in sediments when 1-?mol/ml unlabeled methionine was added. When chloroform (an inhibitor of one-carbon metabolism) was added to the sediments, methane thiol, carbon disulfide, and n-propane thiol were produced, even when no methionine was added. When 35S-labeled methionine was added to the sediments in tracer quantities (1.75 nmol/ml), labeled hydrogen sulfide was produced, and a roughly equal amount of label was incorporated into insoluble material. Methane and carbon dioxide were produced from [methyl-14C]methionine. Evidence is given favoring methane thiol as an intermediate in the formation of methane, carbon dioxide, and hydrogen sulfide from the terminal methiol group of methionine. Methionine may be an important source of sulfide in lake sediments. PMID:16345275

Zinder, S. H.; Brock, T. D.

1978-01-01

240

A Hypothesis: Hydrogen Sulfide Might Be Neuroprotective against Subarachnoid Hemorrhage Induced Brain Injury  

PubMed Central

Gases such as nitric oxide (NO) and carbon monoxide (CO) play important roles both in normal physiology and in disease. Recent studies have shown that hydrogen sulfide (H2S) protects neurons against oxidative stress and ischemia-reperfusion injury and attenuates lipopolysaccharides (LPS) induced neuroinflammation in microglia, exhibiting anti-inflammatory and antiapoptotic activities. The gas H2S is emerging as a novel regulator of important physiologic functions such as arterial diameter, blood flow, and leukocyte adhesion. It has been known that multiple factors, including oxidative stress, free radicals, and neuronal nitric oxide synthesis as well as abnormal inflammatory responses, are involved in the mechanism underlying the brain injury after subarachnoid hemorrhage (SAH). Based on the multiple physiologic functions of H2S, we speculate that it might be a promising, effective, and specific therapy for brain injury after SAH. PMID:24707204

Yu, Yong-Peng; Chi, Xiang-Lin; Liu, Li-Jun

2014-01-01

241

Cobalt sulfide nanosheet/graphene/carbon nanotube nanocomposites as flexible electrodes for hydrogen evolution.  

PubMed

Flexible three-dimensional (3D) nanoarchitectures have received tremendous interest recently because of their potential applications in wearable electronics, roll-up displays, and other devices. The design and fabrication of a flexible and robust electrode based on cobalt sulfide/reduced graphene oxide/carbon nanotube (CoS2 /RGO-CNT) nanocomposites are reported. An efficient hydrothermal process combined with vacuum filtration was used to synthesize such composite architecture, which was then embedded in a porous CNT network. This conductive and robust film is evaluated as electrocatalyst for the hydrogen evolution reaction. The synergistic effect of CoS2 , graphene, and CNTs leads to unique CoS2 /RGO-CNT nanoarchitectures, the HER activity of which is among the highest for non-noble metal electrocatalysts, showing 10?mA?cm(-2) current density at about 142?mV overpotentials and a high electrochemical stability. PMID:25297454

Peng, Shengjie; Li, Linlin; Han, Xiaopeng; Sun, Wenping; Srinivasan, Madhavi; Mhaisalkar, Subodh G; Cheng, Fangyi; Yan, Qingyu; Chen, Jun; Ramakrishna, Seeram

2014-11-10

242

[Cyclosporin A-sensitive mitochondrial pore as a target of cardioprotective action of hydrogen sulfide donor].  

PubMed

In experiments on a model of ischemia-reperfusion in Langendorff isolated rat hearts and isolated mitochondria we studied the role of hydrogen sulfide donor - sodium hydrosulfide (NaHS, 7.4 mg/kg) in modulating the sensitivity ofmitochondrial permeability transition pore opening. It was shown that NaHS increased the reserves of rat myocardium and had cardioprotective effects from ischemia-reperfusion. In experiments on isolated mitochondria NaHS in concentrations of 10(-6), 10(-5) and 5 x 10(-5) mol/L inhibited Ca(2+)-induced swelling of mitochondria. Preincubation of isolated mitochondria with K+(ATphi)-channels inhibitor 5-hydroxydecanoate (10(-4) mol/L) reduced the protective effect of NaHS (10(-5) mol/L). Thus, we consider that NaHS protective effect from reperfusion disturbances of heart function was realized via inhibition of Ca(2+)-induced mitochondrial permeability transition pore opening. PMID:23650739

Shimanskaia, T V; Strutinskaia, N A; Vavilova, G L; Goshovskaia, Iu V; Semenikhina, E N; Sagach, V F

2013-02-01

243

Development of photo-controllable hydrogen sulfide donor applicable in live cells.  

PubMed

Hydrogen sulfide (H2S) has multiple physiological roles, for example, in vasodilation and inflammation. It is a highly reactive gas under ambient conditions, so controllable H2S donors are required for studying its biological functions. Here, we describe the design, synthesis and application of a H2S donor (SPD-2) that utilizes xanthone photochemistry to control H2S release. H2S generation from SPD-2 was completely dependent on UVA-irradiation (325-385nm), as confirmed by methylene blue assay and by the use of a H2S-selective fluorescent probe. SPD-2 was confirmed to provide controlled H2S delivery in live cells, and should be suitable for various biological applications. PMID:25499432

Fukushima, Naoki; Ieda, Naoya; Kawaguchi, Mitsuyasu; Sasakura, Kiyoshi; Nagano, Tetsuo; Hanaoka, Kenjiro; Miyata, Naoki; Nakagawa, Hidehiko

2015-01-15

244

Hydrogen sulfide-releasing aspirin inhibits the growth of leukemic Jurkat cells and modulates ?-catenin expression.  

PubMed

Hydrogen sulfide-releasing aspirin (HS-ASA) is a novel compound with potential against cancer. It inhibited the growth of Jurkat T-leukemia cells with an IC?? of 1.9 ± 0.2 ?M whereas that of ASA was >5000 ?M. It dose-dependently inhibited proliferation and induced apoptosis in these cells, causing a G?/G? cell cycle arrest. HS-ASA down-regulated ?-catenin protein levels and reduced mRNA and protein expression of ?-catenin/TCF downstream target genes cyclinD1 and c-myc. Aspirin up to 5 mM had no effect on ?-catenin expression. HS-ASA also increased caspase-3 protein levels and dose-dependently increased its activity. These effects were substantially blocked by z-VAD-fmk, a pan-caspase inhibitor. PMID:23896061

Chattopadhyay, Mitali; Nath, Niharika; Kodela, Ravinder; Sobocki, Tomasz; Metkar, Shalaka; Gan, Zong Yuan; Kashfi, Khosrow

2013-10-01

245

Increased growth and germination success in plants following hydrogen sulfide administration.  

PubMed

This study presents a novel way of enhancing plant growth through the use of a non-petroleum based product. We report here that exposing either roots or seeds of multicellular plants to extremely low concentrations of dissolved hydrogen sulfide at any stage of life causes statistically significant increases in biomass including higher fruit yield. Individual cells in treated plants were smaller (~13%) than those of controls. Germination success and seedling size increased in, bean, corn, wheat, and pea seeds while time to germination decreases. These findings indicated an important role of H2S as a signaling molecule that can increase the growth rate of all species yet tested. The increased crop yields reported here has the potential to effect the world's agricultural output. PMID:23614010

Dooley, Frederick D; Nair, Suven P; Ward, Peter D

2013-01-01

246

["Waste gas is not waste": advance in the research of hydrogen sulfide].  

PubMed

The discovery of endogenous gasotransmitters puts forwards a new concept, "waste gas is not waste". Hydrogen sulfide (H(2)S) is considered as a new member of gasotransmitter family, following nitric oxide (NO) and carbon monoxide (CO). Recently, the understanding of H(2)S biological effect and its mechanisms has been deepened, especially the pathophysiological significance of H(2)S in the various diseases such as cardiovascular diseases, neurological diseases, respiratory diseases, endocrine diseases, etc. This article reviews recent progress of basic, clinical and pharmacological researches related to endogenous H(2)S, including the regulatory effects of H(2)S on the cell proliferation, apoptosis, inflammation, angiogenesis and ion channels, the role of endogenous H(2)S pathway in the pathogenesis of various diseases, as well as the study of the H(2)S donor and H(2)S-related drugs. PMID:21170494

Jin, Hong-Fang; DU, Jun-Bao; Tang, Chao-Shu

2010-12-25

247

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

PubMed

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

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

2005-11-01

248

A highly responsive and selective fluorescent probe for imaging physiological hydrogen sulfide.  

PubMed

The discovery of hydrogen sulfide (H2S) as a novel gasotransmitter for cell signaling and other pathophysiological processes has spurred tremendous interest in developing analytical methods for its detection in biological systems. Herein, we report the development of a highly responsive and selective genetically encoded H2S probe, hsGFP, for the detection of H2S both in vitro and in living mammalian cells. hsGFP bestows a combination of favorable properties, including large fluorescence responses, high efficiency in folding and chromophore formation, and excellent sensitivity and selectivity toward H2S. As a genetically encoded probe, hsGFP can be readily and precisely localized to subcellular domains such as mitochondria, cell nuclei, and ion channels. hsGFP was further utilized to image H2S enzymatically produced from l-cysteine in human embryonic kidney (HEK) 293T cells. PMID:25141269

Chen, Zhi-jie; Ai, Hui-wang

2014-09-23

249

Increased Growth and Germination Success in Plants following Hydrogen Sulfide Administration  

PubMed Central

This study presents a novel way of enhancing plant growth through the use of a non-petroleum based product. We report here that exposing either roots or seeds of multicellular plants to extremely low concentrations of dissolved hydrogen sulfide at any stage of life causes statistically significant increases in biomass including higher fruit yield. Individual cells in treated plants were smaller (?13%) than those of controls. Germination success and seedling size increased in, bean, corn, wheat, and pea seeds while time to germination decreases. These findings indicated an important role of H2S as a signaling molecule that can increase the growth rate of all species yet tested. The increased crop yields reported here has the potential to effect the world's agricultural output. PMID:23614010

Dooley, Frederick D.; Nair, Suven P.; Ward, Peter D.

2013-01-01

250

Hydrogen sulfide causes vanilloid receptor 1-mediated neurogenic inflammation in the airways  

PubMed Central

Hydrogen sulfide (H2S) is described as a mediator of diverse biological effects, and is known to produce irritation and injury in the lung following inhalation. Recently, H2S has been found to cause contraction in the rat urinary bladder via a neurogenic mechanism. Here, we studied whether sodium hydrogen sulfide (NaHS), used as donor of H2S, produces responses mediated by sensory nerve activation in the guinea-pig airways. NaHS evoked an increase in neuropeptide release in the airways that was significantly attenuated by capsaicin desensitization and by the transient receptor potential vanilloid 1 (TRPV1) antagonist capsazepine. In addition, NaHS caused an atropine-resistant contraction of isolated airways, which was completely prevented by capsaicin desensitization. Furthermore, NaHS-induced contraction was reduced by TRPV1 antagonism (ruthenium red, capsazepine and SB366791), and was abolished by pretreatment with the combination of tachykinin NK1 (SR140333) and NK2 (SR48968) receptor antagonists. In anesthetized guinea-pigs, intratracheal instillation of NaHS increased the total lung resistance and airway plasma protein extravasation. These two effects were reduced by TRPV1 antagonism (capsazepine) and tachykinin receptors (SR140333 and SR48968) blockade. Our results provide the first pharmacological evidence that H2S provokes tachykinin-mediated neurogenic inflammatory responses in guinea-pig airways, and that this effect is mediated by stimulation of TRPV1 receptors on sensory nerves endings. This novel mechanism may contribute to the irritative action of H2S in the respiratory system. PMID:15937520

Trevisani, Marcello; Patacchini, Riccardo; Nicoletti, Paola; Gatti, Raffaele; Gazzieri, David; Lissi, Nicola; Zagli, Giovanni; Creminon, Christophe; Geppetti, Pierangelo; Harrison, Selena

2005-01-01

251

Design of a sorbent to enhance reactive adsorption of hydrogen sulfide.  

PubMed

A series of novel zinc oxide-silica composites with three-dimensionally ordered macropores (3DOM) structure were synthesized via colloidal crystal template method and used as sorbents for hydrogen sulfide (H2S) removal at room temperature for the first time. The performances of the prepared sorbents were evaluated by dynamic breakthrough testing. The materials were characterized before and after adsorption using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the composite with 3DOM structure exhibited remarkable desulfurization performance at room temperature and the enhancement of reactive adsorption of hydrogen sulfide was attributed to the unique structure features of 3DOM composites; high surface areas, nanocrystalline ZnO and the well-ordered interconnected macroporous with abundant mesopores. The introduction of silica could be conducive to support the 3DOM structure and the high dispersion of zinc oxide. Moisture in the H2S stream plays a crucial role in the removal process. The effects of Zn/Si ratio and the calcination temperature of 3DOM composites on H2S removal were studied. It demonstrated that the highest content of ZnO could reach up to 73 wt % and the optimum calcination temperature was 500 °C. The multiple adsorption/regeneration cycles showed that the 3DOM ZnO-SiO2 sorbent is stable and the sulfur capacity can still reach 67.4% of that of the fresh sorbent at the fifth cycle. These results indicate that 3DOM ZnO-SiO2 composites will be a promising sorbent for H2S removal at room temperature. PMID:25382853

Wang, Long-Jiang; Fan, Hui-Ling; Shangguan, Ju; Croiset, Eric; Chen, Zhongwei; Wang, Hui; Mi, Jie

2014-12-10

252

An investigation of the mechanisms of hydrogen sulfide-induced vasorelaxation in rat middle cerebral arteries.  

PubMed

Hydrogen sulfide (H(2)S) is an endogenous mediator with peripheral vasorelaxant effects; however, the mechanism of H(2)S-induced vasorelaxation in cerebral blood vessels has not been extensively studied. Vasorelaxation studies were performed on middle cerebral arteries from male Sprague Dawley rats using wire myography. Immunofluorescence staining was used to detect the presence of the H(2)S-producing enzyme cystathionine-?-lyase (CSE). CSE was present in the endothelium and smooth muscle of middle cerebral arteries. The CSE substrate, L-cysteine, induced vasorelaxation that was sensitive to the CSE inhibitor DL-propargylglycine. This relaxation was independent of endothelium, suggesting that H(2)S was produced in the vascular smooth muscle. The H(2)S donor, sodium hydrogen sulfide (NaHS; 0.1-3.0 mM) produced concentration-dependent relaxation, which was unaffected by endothelium removal. Nifedipine (3 ?M) significantly reduced the maximum relaxation elicited by NaHS. Inhibiting potassium (K(+)) conductance with 50 mM K(+) significantly attenuated NaHS-induced relaxation, however, selective blockers of ATP sensitive (K(ATP)), calcium sensitive (K(Ca)), voltage dependent (K(V)), or inward rectifier (K(ir)) channels alone or in combination did not affect the response to NaHS. 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS; 300 ?M) caused a significant rightward shift of the NaHS concentration-response curve, but this effect could not be explained by inhibition of Cl(-) channels or Cl(-)/HCO (3)(-) exchange, as selective blockade of these mechanisms had no effect. These findings suggest endogenous H(2)S can regulate cerebral vascular function. The H(2)S-mediated relaxation of middle cerebral arteries is DIDS sensitive and partly mediated by inhibition of L-type calcium channels, with an additional contribution by K channels but not K(ATP), K(Ca), K(V), or K(ir) subtypes. PMID:22801977

Streeter, E; Hart, J; Badoer, E

2012-10-01

253

Physical solubility of hydrogen sulfide and carbon dioxide in alkanolamine solutions  

SciTech Connect

The study was undertaken to develop a method that would make direct measurements of acid gases, hydrogen sulfide and carbon dioxide, physical solubilities in aqueous alkanolamine solutions possible. Hydrogen sulfide and carbon dioxide physical solubilities in 20, 35, and 50% by weight diethanolamine aqueous solutions were measured. The solubility measurements were made at acid gas partial pressure up to 1000 psia and temperatures of 80, 150, 240 F. The solubility of nitrous oxide in water and in protonated diethanolamine solution was also determined at 80 F. A method that allows for direct measurements of acid gases physical solubilities has been developed. The method eliminates amines reactivity with acid gases by protonating the amines prior to their contact with acid gases. CO{sub 2} physical solubility in aqueous DEA solutions occurs mainly in the water portion of the solution. Therefore, the physical solubility of CO{sub 2} in an aqueous amine solution must be corrected based on the fraction of water in the solution. However, H{sub 2}S physical solubility in aqueous DEA solutions is the same as H{sub 2}S solubility in water. At any acid gas partial pressure, the physical solubility of H{sub 2}S is higher than that of CO{sub 2} for the same solution concentration and for the same temperature. This is also true for their solubilities is pure water. The ratio of CO{sub 2} to H{sub 2}S physical solubility to N{sub 2}O solubility in aqueous DEA solutions is not the same as their ratio in pure water.

Abu-Arabi, M.K.

1988-01-01

254

Hydrogen sulfide is essential for Schwann cell responses to peripheral nerve injury.  

PubMed

Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from substances by three enzymes: cystathionine ?-synthase (CBS), cystathionine ?-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (MST). In human tissues, these enzymes are involved in tissue-specific biochemical pathways for H2 S production. For example, CBS and cysteine aminotransferase/MST are present in the brain, but CSE is not. Thus, we examined the expression of H2 S production-related enzymes in peripheral nerves. Here, we found that CSE and MST/cysteine aminotransferase, but not CBS, were present in normal peripheral nerves. In addition, injured sciatic nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration (WD); however, CSE was not up-regulated in peripheral axons. Using an ex vivo sciatic nerve explant culture, we found that the inhibition of H2 S production broadly prevented the process of nerve degeneration, including myelin fragmentation, axonal degradation, Schwann cell dedifferentiation, and Schwann cell proliferation in vitro and in vivo. Thus, these results indicate that H2 S signaling is essential for Schwann cell responses to peripheral nerve injury. Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from cystathionine ?-synthase (CBS), cystathionine ?-lyase (CSE), and 3-mercaptopyruvate sulfur transferase (MST). Here, we found that CSE and MST/CAT were present in normal peripheral nerves. Injured static nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration, but CSE was not up-regulated in peripheral axons. PMID:25123509

Park, Byung Sun; Kim, Hyun-Wook; Rhyu, Im Joo; Park, Chan; Yeo, Seung Geun; Huh, Youngbuhm; Jeong, Na Young; Jung, Junyang

2015-01-01

255

Hydrogen sulfide oxidation is coupled to oxidative phosphorylation in mitochondria of Solemya reidi  

SciTech Connect

Solemya reidi, a gutless clam found in sulfide-rich habitats, contains within its gills bacterial symbionts thought to oxidize sulfur compounds and provide a reduced carbon food source to the clam. However, the initial step or steps in sulfide oxidation occur in the animal tissue, and mitochondria isolated from both gill and symbiont-free foot tissue of the clam coupled the oxidation of sulfide to oxidative phosphorylation (adenosine triphosphate (ATP) synthesis). The ability of Solemya reidi to exploit directly the energy in sulfide for ATP synthesis is unprecedented, and suggests that sulfide-habitat animals that lack bacterial symbionts may also use sulfide as an inorganic energy source.

Powell, M.A.; Somero, G.N.

1986-08-01

256

Effective Hydrogen Generation from the Hydrogen Sulfide Solution by using Stratified Type Photocatalyst  

NASA Astrophysics Data System (ADS)

Stratified type photocatalyst with the extremely higher photocatalytic activities can be synthesized by using the chemical reaction between the Na2S solution and Cd(OH)2 precursors. This type of photocatalyst has the specific morphology which constructed by the nano-sized and capsule like formed structure, and the metal concentration was gradually changed in its wall. The "charge gradient" was formed at the metal sulfide and oxide/hydroxide junction in the wall, which favored for the separation of the photo excited electron-hole pair. Consequently, stratified type photocatalyst shows the high catalytic activity than the usual nano CdS particles. By the addition of sulfur compound into the bio reactor contained the sulfur reducing bacteria, the H2S gas concentration can increased to about 1000 times enlarge than the usual condition. Therefore, we can conclude that the enhancement of the H2S gas evolved from the bio reactor was successfully achievement, and we don't need to afraid the shortage risk of H2S supply. These H2S gas concentration can enlarged to 80% by using A type zeorite. Especially, Ca-A type zeorite is considered as the suitable material.

Takahashi, H.; Yokoyama, S.; Baba, Y.; Hayashi, T.; Tohji, K.

2008-02-01

257

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...

258

Density functional theory studies of the adsorption of hydrogen sulfide on aluminum doped silicane.  

PubMed

First principles total energy calculations have been performed to study the hydrogen sulfide (H2S) adsorption on silicane, an unusual one monolayer of Si(111) surface hydrogenated on both sides. The H2S adsorption may take place in dissociative or non-dissociative forms. Silicane has been considered as: (A) non-doped with a hydrogen vacancy, and doped in two main configurations; (B) with an aluminum replacing a hydrogen atom and (C-n; n?=?1, 2, 3) with an aluminum replacing a silicon atom at a lattice site. In addition, three supercells; 4x4, 3x3 and 2x2 have been explored for both non-doped and doped silicane. The non-dissociative adsorption takes place in geometries (A), (C-1), (C-2) and (C-3) while the dissociative in (B). Adsorption energies of the dissociative case are larger than those corresponding to the non-dissociated cases. In the dissociative adsorption, the molecule is fragmented in a HS structure and a H atom which are bonded to the aluminum to form a H-S-Al-H structure. The presence of the doping produces some electronic changes as the periodicity varies. Calculations of the total density of states (DOS) indicate that in most cases the energy gap decreases as the periodicity changes from 4x4 to 2x2. The features of the total DOS are explained in terms of the partial DOS. The reported charge density plots explain quite well the chemisorptions and physisorptions of the molecule on silicane in agreement with adsorption energies. PMID:23695768

Sánchez-Ochoa, Francisco; Guerrero-Sánchez, Jonathan; Canto, Gabriel I; Cocoletzi, Gregorio H; Takeuchi, Noboru

2013-08-01

259

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)

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.

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

260

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

USGS Publications Warehouse

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.

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

1987-01-01

261

Protein kinase G I? oxidation paradoxically underlies blood pressure lowering by the reductant hydrogen sulfide.  

PubMed

Dysregulated blood pressure control leading to hypertension is prevalent and is a risk factor for several common diseases. Fully understanding blood pressure regulation offers the possibility of developing rationale therapies to alleviate hypertension and associated disease risks. Although hydrogen sulfide (H2S) is a well-established endogenous vasodilator, the molecular basis of its blood-pressure lowering action is incompletely understood. H2S-dependent vasodilation and blood pressure lowering in vivo was mediated by it catalyzing formation of an activating interprotein disulfide within protein kinase G (PKG) I?. However, this oxidative activation of PKG I? is counterintuitive because H2S is a thiol-reducing molecule that breaks disulfides, and so it is not generally anticipated to induce their formation. This apparent paradox was explained by H2S in the presence of molecular oxygen or hydrogen peroxide rapidly converting to polysulfides, which have oxidant properties that in turn activate PKG by inducing the disulfide. These observations are relevant in vivo because transgenic knockin mice in which the cysteine 42 redox sensor within PKG has been systemically replaced with a redox-dead serine residue are resistant to H2S-induced blood pressure lowering. Thus, a primary mechanism by which the reductant molecule H2S lowers blood pressure is mediated somewhat paradoxically by the oxidative activation of PKG. PMID:25267801

Stubbert, Daniel; Prysyazhna, Oleksandra; Rudyk, Olena; Scotcher, Jenna; Burgoyne, Joseph R; Eaton, Philip

2014-12-01

262

Hydrogen sulfide prolongs postharvest shelf life of strawberry and plays an antioxidative role in fruits.  

PubMed

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

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

263

Bile-acid-activated farnesoid X receptor regulates hydrogen sulfide production and hepatic microcirculation  

PubMed Central

AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfide (H2S) generation. METHODS: The regulation of CSE expression in response to FXR ligands was evaluated in HepG2 cells and in wild-type and FXR null mice treated with 6-ethyl chenodeoxycholic acid (6E-CDCA), a synthetic FXR ligand. The analysis demonstrated an FXR responsive element in the 5’-flanking region of the human CSE gene. The function of this site was investigated by luciferase reporter assays, chromatin immunoprecipitation and electrophoretic mobility shift assays. Livers obtained from rats treated with carbon tetrachloride alone, or in combination with 6-ethyl chenodeoxycholic acid, were studied for hydrogen sulphide generation and portal pressure measurement. RESULTS: Liver expression of CSE is regulated by bile acids by means of an FXR-mediated mechanism. Western blotting, qualitative and quantitative polymerase chain reaction, as well as immunohistochemical analysis, showed that expression of CSE in HepG2 cells and in mice is induced by treatment with an FXR ligand. Administration of 6E-CDCA to carbon tetrachloride treated rats protected against the down-regulation of CSE expression, increased H2S generation, reduced portal pressure and attenuated the endothelial dysfunction of isolated and perfused cirrhotic rat livers. CONCLUSION: These results demonstrate that CSE is an FXR-regulated gene and provide a new molecular explanation for the pathophysiology of portal hypertension. PMID:19418582

Renga, Barbara; Mencarelli, Andrea; Migliorati, Marco; Distrutti, Eleonora; Fiorucci, Stefano

2009-01-01

264

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

PubMed

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

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

2014-08-01

265

Sulfide chemiluminescence detection  

DOEpatents

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.

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

1985-01-01

266

Sulfide chemiluminescence detection  

DOEpatents

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.

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

1985-11-26

267

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)

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.

Shyla, B.; Nagendrappa, G.

2012-10-01

268

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

SciTech Connect

Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash coat, and catalytic metals, to develop a regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor. The task of developing kinetic rate equations and modeling the direct oxidation process to assist in the design of large-scale plants will be abandoned since formulation of catalysts suitable for the removal of H{sub 2}S and COS is being in progress. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 46-570 seconds under reaction conditions to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases and evaluate their capabilities in reducing hydrogen sulfide and COS in coal gases. Simulated coal gas mixtures consist of 3,200-4,000-ppmv hydrogen sulfide, 1,600-20,000-ppmv sulfur dioxide, 18-27 v% hydrogen, 29-41 v% CO, 8-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of simulated coal gas mixtures to the reactor are 30 - 180 cm{sup 3}/min at 1 atm and 25 C (SCCM). The temperature of the reactor is controlled in an oven at 120-155 C. The pressure of the reactor is maintained at 40-210 psia. The molar ratio

K.C. Kwon

2009-09-30

269

Hydrogen sulfide increases excitability through suppression of sustained potassium channel currents of rat trigeminal ganglion neurons  

PubMed Central

Background Hydrogen sulfide (H2S), an endogenous gaseotransmitter/modulator, is becoming appreciated that it may be involved in a wide variety of processes including inflammation and nociception. However, the role and mechanism for H2S in nociceptive processing in trigeminal ganglion (TG) neuron remains unknown. The aim of this study is to investigate distribution of endogenous H2S synthesizing enzyme cystathionine-?-synthetase (CBS) expression and role of H2S on excitability and voltage-gated potassium channels of TG neurons. Methods Immunofluorescence studies were carried out to determine whether CBS was co-expressed in Kv1.1 or Kv1.4-positive TG neurons. Whole cell patch clamp recordings were employed on acutely isolated TG neurons from adult male Sprague Dawley rats (6–8?week old). von Frey filaments were used to examine the pain behavioral responses in rats following injection of sodium hydrosulfide. Results In rat TG, 77.3±6.6% neurons were immunoreactive for CBS, 85.1±3.8% for Kv1.1 and 97.8±1.1% for Kv1.4. Double staining showed that all CBS labeled cells were Kv1.1 and Kv1.4 positive, but only 92.2±6.1% of Kv1.1 and 78.2±9.9% of Kv1.4 positive cells contained CBS. Application of H2S donor NaHS (250??M) led to a significant depolarization of resting membrane potential recorded from TG neurons. NaHS application also resulted in a dramatic reduction in rheobase, hyperpolarization of action potential threshold, and a significant increase in the number of action potentials evoked at 2X and 3X rheobase stimulation. Under voltage-clamp conditions, TG neurons exhibited transient A-type (IA) and sustained outward rectifier K+ currents (IK). Application of NaHS did suppress IK density while did not change IA density of TG neurons (n=6). Furthermore, NaHS, a donor of hydrogen sulfide, produced a significant reduction in escape threshold in a dose dependent manner. Conclusion These data suggest that endogenous H2S generating enzyme CBS was co-localized well with Kv1.1 and Kv1.4 in TG neurons and that H2S produces the mechanic pain and increases neuronal excitability, which might be largely mediated by suppressing IK density, thus identifying for the first time a specific molecular mechanism underlying pain and sensitization in TG. PMID:23413915

2013-01-01

270

Phosphorylation of BK channels modulates the sensitivity to hydrogen sulfide (H2S)  

PubMed Central

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

Sitdikova, Guzel F.; Fuchs, Roman; Kainz, Verena; Weiger, Thomas M.; Hermann, Anton

2014-01-01

271

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)

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.

Rosales Lagarde, L.; Boston, P. J.; Campbell, A.

2013-12-01

272

The Possible Role of Hydrogen Sulfide as an Endogenous Smooth Muscle Relaxant in Synergy with Nitric Oxide  

Microsoft Academic Search

Hydrogen sulfide (H2S), which is well known as a toxic gas, is produced endogenously in mammalian tissues from L-cysteine mainly by two pyridoxal-5?-phosphate-dependent enzymes, cystathionine ?-synthetase and cystathionine ?-lyase. Recently, we showed that cystathionine ?-synthetase in the brain produces H2S, and that H2S facilitates the induction of hippocampal long-term potentiation by enhancing NMDA receptor activity. Here we show that mRNA

Rumiko Hosoki; Norio Matsuki; Hideo Kimura

1997-01-01

273

Chelating luminal zinc mimics hydrogen sulfide-evoked colonic pain in mice: possible involvement of T-type calcium channels  

Microsoft Academic Search

Luminal hydrogen sulfide (H2S) causes colonic pain and referred hyperalgesia in mice through activation of T-type Ca2+ channels. To test a hypothesis that H2S might chelate and remove endogenous Zn2+ that inhibits the Cav3.2 isoform of T-type Ca2+ channels, facilitating visceral nociception, we asked if intracolonic (i.col.) administration of Zn2+ chelators mimics H2S-induced visceral nociception. Visceral nociceptive behavior and referred

M. Matsunami; S. Kirishi; T. Okui; A. Kawabata

2011-01-01

274

Recovery of Gaseous Emission from Ground Level Area Sources of Ammonia and Hydrogen Sulfide Using Dynamic Isolation Flux Chambers  

Microsoft Academic Search

Controlled laboratory experiments were conducted to evaluate the recovery of ammonia (NH3) and hydrogen sulfide (H2S) emitted from ground level area sources (GLAS) using dynamic isolation flux chambers. H2S (80-4,000 ppb) and NH3 (5,000-40,000 ppb) were diffused through the flux chamber to simulate GLAS emissions while measuring the inlet and outlet flux chamber concentrations simultaneously. Results showed that the recovery

Sergio C. Capareda; Cale N. Boriack; Saqib Mukhtar; Atilla Mutlu; Bryan W. Shaw; Ronald E. Lacey; Calvin B. Parnell

2004-01-01

275

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

PubMed

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

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

1990-03-01

276

Bacteria-Derived Hydrogen Sulfide Promotes IL-8 Production from Epithelial Cells  

PubMed Central

Hydrogen sulfide (H2S), a volatile sulfur compound, is implicated as a cause of inflammation, especially when it is produced by bacteria colonizing gastrointestinal organs. However, it is unclear if H2S produced by periodontal pathogens affects the inflammatory responses mediated by oral/gingival epithelial cells. Therefore, the aims of this study were 1) to compare the in vitro production of H2S among 14 strains of oral bacteria and 2) to evaluate the effects of H2S on inflammatory response induced in host oral/gingival epithelial cells. P. gingivalis (Pg) produced the most H2S in culture, which, in turn, resulted in the promotion of proinflammatory cytokine IL-8 from both gingival and oral epithelial cells. The up-regulation of IL-8 expression was reproduced by the exogenously applied H2S. Furthermore, the mutant strains of Pg that do not produce major soluble virulent factors, i.e. gingipains, still showed the production of H2S, as well as the promotion of epithelial IL-8 production, which was abrogated by H2S scavenging reagents. These results demonstrated that Pg produces a concentration of H2S capable of up-regulating IL-8 expression induced in gingival and oral epithelial cells, revealing a possible mechanism that may promote the inflammation in periodontal disease. PMID:19932683

Chen, Weilin; Kajiya, Mikihito; Giro, Gabriela; Ouhara, Kazuhisa; Mackler, Harrison E.; Mawardi, Hani; Boisvert, Heike; Duncan, Margaret J.; Sato, Kimihiro; Kawai, Toshihisa

2010-01-01

277

Discrimination of the oral microbiota associated with high hydrogen sulfide and methyl mercaptan production  

PubMed Central

Both hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) are frequently detected in large amounts in malodorous mouth air. We investigated the bacterial composition of saliva of 30 subjects with severe oral malodor exhibiting extreme CH3SH/H2S ratios (high H2S but low CH3SH concentrations, n = 14; high CH3SH but low H2S concentrations, n = 16) and 13 subjects without malodor, using barcoded pyrosequencing analysis of the 16S rRNA gene. Phylogenetic community analysis with the UniFrac distance metric revealed a distinct bacterial community structure in each malodor group. The H2S group showed higher proportions of the genera Neisseria, Fusobacterium, Porphyromonas and SR1 than the other two groups, whereas the CH3SH group had higher proportions of the genera Prevotella, Veillonella, Atopobium, Megasphaera, and Selenomonas. Our results suggested that distinct bacterial populations in the oral microbiota are involved in production of high levels of H2S and CH3SH in the oral cavity. PMID:22355729

Takeshita, Toru; Suzuki, Nao; Nakano, Yoshio; Yasui, Masaki; Yoneda, Masahiro; Shimazaki, Yoshihiro; Hirofuji, Takao; Yamashita, Yoshihisa

2012-01-01

278

Hydrogen sulfide generation in simulated construction and demolition debris landfills: impact of waste composition.  

PubMed

Hydrogen sulfide (H2S) generation in construction and demolition (C&D) debris landfills has been associated with the biodegradation of gypsum drywall. Laboratory research was conducted to observe H2S generation when drywall was codisposed with different C&D debris constituents. Two experiments were conducted using simulated landfill columns. Experiment 1 consisted of various combinations of drywall, wood, and concrete to determine the impact of different waste constituents and combinations on H2S generation. Experiment 2 was designed to examine the effect of concrete on H2S generation and migration. The results indicate that decaying drywall, even alone, leached enough sulfate ions and organic matter for sulfate-reducing bacteria (SRB) to generate large H2S concentrations as high as 63,000 ppmv. The codisposed wastes show some effect on H2S generation. At the end of experiment 1, the wood/drywall and drywall alone columns possessed H2S concentrations > 40,000 ppmv. Conversely, H2S concentrations were < 1 ppmv in those columns containing concrete. Concrete plays a role in decreasing H2S by increasing pH out of the range for SRB growth and by reacting with H2S. This study also showed that wood lowered H2S concentrations initially by decreasing leachate pH values. Based on the results, two possible control mechanisms to mitigate H2S generation in C&D debris landfills are suggested. PMID:16933645

Yang, Kenton; Xu, Qiyong; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel; Booth, Matthew

2006-08-01

279

Inhibition of hydrogen sulfide generation from disposed gypsum drywall using chemical inhibitors.  

PubMed

Disposal of gypsum drywall in landfills has been demonstrated to elevate hydrogen sulfide (H(2)S) concentrations in landfill gas, a problem with respect to odor, worker safety, and deleterious effect on gas-to-energy systems. Since H(2)S production in landfills results from biological activity, the concept of inhibiting H(2)S production through the application of chemical agents to drywall during disposal was studied. Three possible inhibition agents - sodium molybdate (Na(2)MoO(4)), ferric chloride (FeCl(3)), and hydrated lime (Ca(OH)(2)) - were evaluated using flask and column experiments. All three agents inhibited H(2)S generation, with Na(2)MoO(4) reducing H(2)S generation by interrupting the biological sulfate reduction process and Ca(OH)(2) providing an unfavorable pH for biological growth. Although FeCl(3) was intended to provide an electron acceptor for a competing group of bacteria, the mechanism found responsible for inhibiting H(2)S production in the column experiment was a reduction in pH. Application of both Na(2)MoO(4) and FeCl(3) inhibited H(2)S generation over a long period (over 180 days), but the impact of Ca(OH)(2) decreased with time as the alkalinity it contributed was neutralized by the generated H(2)S. Practical application and potential environmental implications need additional exploration. PMID:21592650

Xu, Qiyong; Townsend, Timothy; Bitton, Gabriel

2011-07-15

280

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

PubMed

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

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

2015-01-01

281

High sensitivity near-infrared diode laser spectroscopy of hydrogen sulfide  

NASA Astrophysics Data System (ADS)

We have used high-sensitivity diode laser spectroscopy to measure the positions of some 130 rotation-vibration transitions in hydrogen sulfide (H2S). The absorption lines lie in the range 12,100-12,230 cm-1 (818-826 nm), corresponding to transitions from the ground vibrational state to upper levels with ?1, ?2, ?3=4,2,0; 3,2,1; 5,0,0; 4,0,1; 1,4,2; and 0,4,3. We believe that this is the first time these spectral features have been observed. Approximately 5 mW of light from a GaAlAs diode laser was frequency modulated at 1 GHz±10 MHz (two-tone FM) and double passed through a 2 m long cell containing approximately 100 Torr of H2S. The transmitted light was detected with a fast photodiode and the signal demodulated using heterodyne techniques. The frequencies of the spectral features were measured with an estimated uncertainty of 0.03 cm-1.

Tate, Duncan A.; Wang, Liang-Guo; Gallagher, Thomas F.

1993-10-01

282

Hydrogen sulfide cytoprotective signaling is endothelial nitric oxide synthase-nitric oxide dependent  

PubMed Central

Previous studies have demonstrated that hydrogen sulfide (H2S) protects against multiple cardiovascular disease states in a similar manner as nitric oxide (NO). H2S therapy also has been shown to augment NO bioavailability and signaling. The purpose of this study was to investigate the impact of H2S deficiency on endothelial NO synthase (eNOS) function, NO production, and ischemia/reperfusion (I/R) injury. We found that mice lacking the H2S-producing enzyme cystathionine ?-lyase (CSE) exhibit elevated oxidative stress, dysfunctional eNOS, diminished NO levels, and exacerbated myocardial and hepatic I/R injury. In CSE KO mice, acute H2S therapy restored eNOS function and NO bioavailability and attenuated I/R injury. In addition, we found that H2S therapy fails to protect against I/R in eNOS phosphomutant mice (S1179A). Our results suggest that H2S-mediated cytoprotective signaling in the setting of I/R injury is dependent in large part on eNOS activation and NO generation. PMID:24516168

King, Adrienne L.; Polhemus, David J.; Bhushan, Shashi; Otsuka, Hiroyuki; Kondo, Kazuhisa; Nicholson, Chad K.; Bradley, Jessica M.; Islam, Kazi N.; Calvert, John W.; Tao, Ya-Xiong; Dugas, Tammy R.; Kelley, Eric E.; Elrod, John W.; Huang, Paul L.; Wang, Rui; Lefer, David J.

2014-01-01

283

A Practical Look at the Chemistry and Biology of Hydrogen Sulfide  

PubMed Central

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

2012-01-01

284

Hydrogen sulfide, a potential novel drug, attenuates concanavalin A-induced hepatitis  

PubMed Central

Background Hydrogen sulfide (H2S) is known to exert anti-inflammatory properties. Apoptosis and autophagy play important roles in concanavalin A (Con A)-induced acute hepatitis. The purpose of this study was to explore both the effect and mechanism of H2S on Con A-induced acute hepatitis. Methods BALB/c mice were randomized into sham group, Con A-injection group, and 14 ?mol/kg of sodium hydrosulfide (NaHS, an H2S donor) pretreatment group. Results Aspartate aminotransferase, alanine aminotransferase, and pathological damage were significantly ameliorated by NaHS pretreatment. NaHS pretreatment significantly reduced the levels of interleukin-6 and tumor necrosis factor-? compared with those of the Con A group. The expression of Bcl-2, Bax, Beclin-1, and LC3-2, which play important roles in the apoptosis and autophagy pathways, were also clearly affected by NaHS. Furthermore, NaHS affected the p-mTOR and p-AKT. Conclusion H2S attenuates Con A-induced acute hepatitis by inhibiting apoptosis and autophagy, in part, through activation of the PtdIns3K-AKT1 signaling pathway. PMID:25246769

Cheng, Ping; Chen, Kan; Xia, Yujing; Dai, Weiqi; Wang, Fan; Shen, Miao; Wang, Chengfen; Yang, Jing; Zhu, Rong; Zhang, Huawei; Li, Jingjing; Zheng, Yuanyuan; Wang, Junshan; Zhang, Yan; Lu, Jie; Zhou, Yingqun; Guo, Chuanyong

2014-01-01

285

Hydrogen Sulfide Ameliorates Ischemia/Reperfusion-Induced Hepatitis by Inhibiting Apoptosis and Autophagy Pathways  

PubMed Central

Background. Hepatic ischemia/reperfusion (I/R) injury is an important clinical problem, and its consequences can seriously threaten human health. Apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. Hydrogen sulfide (H2S) is the third most common endogenously produced gaseous signaling molecule and is known to exert a protective effect against hepatic I/R injury. In this study, the purpose is to explore both the effect and mechanism of H2S on hepatic I/R injury. Methods. Balb/c mice were randomized into Sham, I/R, or two doses (14??mol/kg and 28??mol/kg) of sodium hydrosulfide (NaHS, an H2S donor) preconditioning groups. Results. NaHS significantly reduced the levels of TNF-? and IL-6 at 12?h and 24?h after injection compared with ischemia/reperfusion challenge alone. The expression of Bcl-2, Bax, Beclin-1, and LC3, which play important roles in the regulation of the apoptosis and autophagy pathways, was also clearly affected by NaHS. Furthermore, NaHS affected the p-JNK1, p-ERK1, and p-p38. Conclusion. Our results indicate that H2S attenuates hepatic I/R injury, at least in part, by regulating apoptosis through inhibiting JNK1 signaling. The autophagy agonist rapamycin potentiated this hepatoprotective effect by reversing the inhibition of autophagy by H2S. PMID:24966472

Cheng, Ping; Wang, Fan; Chen, Kan; Shen, Miao; Dai, Weiqi; Xu, Ling; Zhang, Yan; Wang, Chengfen; Li, Jingjing; Yang, Jing; Zhu, Rong; Zhang, Huawei; Zheng, Yuanyuan; Lu, Jie; Zhou, Yingqun; Guo, Chuanyong

2014-01-01

286

Role of hydrogen sulfide in the formalin-induced orofacial pain in rats.  

PubMed

Hydrogen sulfide (H2S) is a gasotransmitter synthesized in peripheral tissues by the enzyme cystathionine gamma-lyase (CSE). This gas has been documented to be involved in a wide variety of processes including inflammation and nociception. The aim of the present study was to investigate the role of the peripheral H2S pathway in nociceptive response to the orofacial formalin experimental model of pain. Orofacial pain was induced by subcutaneous injection of formalin (1.5%, 50 µl) into the upper lip of rats, and the time spent rubbing the face was measured at 3-min intervals for 45 min. Formalin induced a marked biphasic pain (first phase: 0-3 min; second phase: 15-33 min). Pretreatment with H2S donor (Na2S; 90 µmol/kg), CSE inhibitor (propargylglycine; 26.5 and 88.4 µmol/kg), or a preferential blocker of T-type Ca(2+) channels (mibefradil; 0.28 and 2.81 µmol/kg) attenuated the second phase of face rubbing when injected locally as well as systemically. Pretreatment with a selective blocker of K(+)ATP channels (glybenclamide; 2.81 µmol/kg) suppressed the Na2S-mediated attenuation of the formalin-induced pain second phase. Taken together these results suggest that endogenously produced H2S plays a pronociceptive role probably via T-type Ca(2+) channels, whereas exogenous H2S exerts antinociceptive effects mediated by K(+)ATP channels. PMID:24876060

Donatti, Alberto F; Araujo, Rebeca M; Soriano, Renato N; Azevedo, Leopoldo U; Leite-Panissi, Christie A; Branco, Luiz G S

2014-09-01

287

Actions of Hydrogen Sulfide on Sodium Transport Processes across Native Distal Lung Epithelia (Xenopus laevis)  

PubMed Central

Hydrogen sulfide (H2S) is well known as a highly toxic environmental chemical threat. Prolonged exposure to H2S can lead to the formation of pulmonary edema. However, the mechanisms of how H2S facilitates edema formation are poorly understood. Since edema formation can be enhanced by an impaired clearance of electrolytes and, consequently, fluid across the alveolar epithelium, it was questioned whether H2S may interfere with transepithelial electrolyte absorption. Electrolyte absorption was electrophysiologically measured across native distal lung preparations (Xenopus laevis) in Ussing chambers. The exposure of lung epithelia to H2S decreased net transepithelial electrolyte absorption. This was due to an impairment of amiloride-sensitive sodium transport. H2S inhibited the activity of the Na+/K+-ATPase as well as lidocaine-sensitive potassium channels located in the basolateral membrane of the epithelium. Inhibition of these transport molecules diminishes the electrochemical gradient which is necessary for transepithelial sodium absorption. Since sodium absorption osmotically facilitates alveolar fluid clearance, interference of H2S with the epithelial transport machinery provides a mechanism which enhances edema formation in H2S-exposed lungs. PMID:24960042

Erb, Alexandra; Althaus, Mike

2014-01-01

288

Genetic Targets of Hydrogen Sulfide in Ventilator-Induced Lung Injury – A Microarray Study  

PubMed Central

Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection. PMID:25025333

Spassov, Sashko; Pfeifer, Dietmar; Strosing, Karl; Ryter, Stefan; Hummel, Matthias; Faller, Simone; Hoetzel, Alexander

2014-01-01

289

Studies on the Changes in Lipid Peroxidation and Antioxidants in Fishes Exposed to Hydrogen Sulfide  

PubMed Central

In the present aquarium study, Oreochromis mossambicus Peters were exposed to two different concentrations of hydrogen sulfide (H2S) (4.9 and 6.6 mg/l), and the changes in lipid peroxidation (LP) products and antioxidants in test fishes were determined in time intervals of 12, 24, 48, 72, and 96 hours. The results showed that with respect to the H2S concentration and duration of exposure, alterations were observed in the concentration of LP products and antioxidants in the various organs of the test fishes. Malondialdehyde (MDA) content increased in the liver, gill, kidney, and brain on exposure to H2S up to 48 hours, and then the MDA content showed steady value up to 98 hours experimental period. Brain and kidney of fishes showed the maximum increase in concentration of reduced glutathione (GSH) on H2S treatment. The gradual decrease in concentration of GSH in the tissues of H2 S-exposed fishes after 48 to 96 hours compared with the control shows the loss of adaptive mechanisms and the oxidation of GSH to glutathione disulphide (GSSG). Slight increase in the activity of GSH-S-transferase and decrease in activity of GSH peroxidase demonstrated the incapability of the vital organs in neutralizing the peroxides generated in the oxidative stress condition. PMID:21170249

Sreejai, R.; Jaya, D. S.

2010-01-01

290

Actions of hydrogen sulfide on sodium transport processes across native distal lung epithelia (Xenopus laevis).  

PubMed

Hydrogen sulfide (H2S) is well known as a highly toxic environmental chemical threat. Prolonged exposure to H2S can lead to the formation of pulmonary edema. However, the mechanisms of how H2S facilitates edema formation are poorly understood. Since edema formation can be enhanced by an impaired clearance of electrolytes and, consequently, fluid across the alveolar epithelium, it was questioned whether H2S may interfere with transepithelial electrolyte absorption. Electrolyte absorption was electrophysiologically measured across native distal lung preparations (Xenopus laevis) in Ussing chambers. The exposure of lung epithelia to H2S decreased net transepithelial electrolyte absorption. This was due to an impairment of amiloride-sensitive sodium transport. H2S inhibited the activity of the Na+/K+-ATPase as well as lidocaine-sensitive potassium channels located in the basolateral membrane of the epithelium. Inhibition of these transport molecules diminishes the electrochemical gradient which is necessary for transepithelial sodium absorption. Since sodium absorption osmotically facilitates alveolar fluid clearance, interference of H2S with the epithelial transport machinery provides a mechanism which enhances edema formation in H2S-exposed lungs. PMID:24960042

Erb, Alexandra; Althaus, Mike

2014-01-01

291

An Antifungal Role of Hydrogen Sulfide on the Postharvest Pathogens Aspergillus niger and Penicillium italicum  

PubMed Central

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

Li, Yan-Hong; Hu, Liang-Bin; Yan, Hong; Liu, Yong-Sheng; Zhang, Hua

2014-01-01

292

Anti-Cancer Activity of New Designer Hydrogen Sulfide-Donating Hybrids  

PubMed Central

Abstract Significance: Hydrogen sulfide (H2S) is likely to join nitric oxide (NO) and carbon monoxide (CO) as the third gaseous transmitter, influencing an array of intracellular signaling cascades. Thus, H2S is implicated in numerous physiological processes and in the pathology of various diseases. Recent Advances: H2S-donating agents that liberate H2S slowly either alone or in combination with NO, the so-called NOSH compounds, are being synthesized, and these have been shown to have great potential against cancer. Critical Issues: An accurate determination of H2S levels is challenging. H2S and NO share many similar actions; do these similarities act to potentiate each other? Since many actions of H2S appear to be mediated through inhibition of inflammation and Nuclear factor kappa-light-chain-enhancer of activated B cells is a central player in this scenario, does S-nitrosylation of this transcription factor by NO affect its S-sulfhydration by H2S and vice versa? Future Directions: Deciphering the molecular targets of these novel hybrid agents and having genetically engineered animals should help us move toward targeted therapeutic applications. Human safety data with these new hybrids is essential. Antioxid. Redox Signal. 20, 831–846. PMID:23581880

2014-01-01

293

Hydrogen sulfide reduces regional myocardial ischemia injury through protection of mitochondrial function.  

PubMed

Hydrogen sulfide (H2S) is a signaling gasotransmitter, involved in various physiological and pathological processes. H2S-donating drugs have been tested to conjugate the beneficial effects of H2S with other pharmaceutical properties. It has been shown that the endogenous cystathionine-?-lyase (CSE)/H2S pathway participates in myocardial ischemia injury in isolated hearts in rats. The present study aimed to investigate the cytoprotective action of H2S against acute myocardial ischemia injury in rats. Isolated rat hearts were perfused and subjected to ischemic conditions for 4 h. The hearts were assigned to five groups: Sham, model, infarct plus low-dose (5 µmol/l) NaHS, infarct plus middle-dose (10 µmol/l) NaHS and infarct plus high-dose (20 µmol/l) NaHS. The administration of NaHS enhanced the activity of CSE, increased the content of H2S and reduced infarct volumes following myocardial ischemia injury. Furthermore, the administration of NaHS attenuated the injury to organelles (including the mitochondria, nucleus and myofilaments) by reducing lactate dehydrogenase activity, decreasing the level of mitochondrial malondialdehyde and increasing the activities of superoxide dismutase and glutathione peroxidase in the ischemic myocardial mitochondria. These protective effects of H2S against myocardial ischemia injury appeared to be mediated by its antioxidant activities and the preservation of mitochondrial function. PMID:25198340

Xie, Ying-Hua; Zhang, Nan; Li, Lan-Fang; Zhang, Qin-Zeng; Xie, Li-Jun; Jiang, Hong; Li, Li-Ping; Hao, Na; Zhang, Jian-Xin

2014-10-01

294

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

PubMed

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

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

2014-10-17

295

An iminocoumarin benzothiazole-based fluorescent probe for imaging hydrogen sulfide in living cells.  

PubMed

Hydrogen sulfide (H2S) has recently been identified as the third gaseous signaling molecule that is involved in regulating many important cellular processes. We report herein a novel fluorescent probe for detecting H2S based on iminocoumarin benzothiazole scaffold. The probe displayed high sensitivity and around 80-fold increment in fluorescence signal after reacting with H2S under physiological condition. The fluorescent intensity of the probe was linearly related to H2S concentration in the range of 0-100?M with a detection limit of 0.15?M (3?/slope). The probe also showed excellent selectivity towards H2S over other biologically relevant species, including ROS, RSS and RNS. Its selectivity for H2S is 32 folds higher than other reactive sulfur species. Furthermore, the probe has been applied for imaging H2S in living cells. Cell imaging experiments demonstrated that the probe is cell-permeable and can be used to monitor the alteration of H2S concentrations in living cells. We envisage that this probe can provide useful tools to further elucidate the biological roles of H2S. PMID:25640139

Zhang, Huatang; Xie, Yusheng; Wang, Ping; Chen, Ganchao; Liu, Ruochuan; Lam, Yun-Wah; Hu, Yi; Zhu, Qing; Sun, Hongyan

2015-04-01

296

Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis.  

PubMed

Hydrogen sulfide (H2 S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic plants with modulation expressions of two cysteine desulfhydrases and exogenous H2 S donor (sodium hydrosulfide, NaHS) and H2 S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2 S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H2 S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2 S level and decreased stress resistance. Moreover, H2 S up-regulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interestingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcriptionally regulated by H2 S, and was related with H2 S-induced antibacterial resistance. Moreover, H2 S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2 S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors. PMID:25329496

Shi, Haitao; Ye, Tiantian; Han, Ning; Bian, Hongwu; Liu, Xiaodong; Chan, Zhulong

2014-10-20

297

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

PubMed

Emerging work demonstrates the dual regulation of mitochondrial function by hydrogen sulfide (H2 S), including, at lower concentrations, a stimulatory effect as an electron donor, and, at higher concentrations, an inhibitory effect on cytochrome C oxidase. In the current article, we overview the pathophysiological and therapeutic aspects of these processes. During cellular hypoxia/acidosis, the inhibitory effect of H2 S on complex IV is enhanced, which may shift the balance of H2 S from protective to deleterious. Several pathophysiological conditions are associated with an overproduction of H2 S (e.g. sepsis), while in other disease states H2 S levels and H2 S bioavailability are reduced and its therapeutic replacement is warranted (e.g. diabetic vascular complications). Moreover, recent studies demonstrate that colorectal cancer cells up-regulate the H2 S-producing enzyme cystathionine ?-synthase (CBS), and utilize its product, H2 S, as a metabolic fuel and tumour-cell survival factor; pharmacological CBS inhibition or genetic CBS silencing suppresses cancer cell bioenergetics and suppresses cell proliferation and cell chemotaxis. In the last chapter of the current article, we overview the field of H2 S-induced therapeutic 'suspended animation', a concept in which a temporary pharmacological reduction in cell metabolism is achieved, producing a decreased oxygen demand for the experimental therapy of critical illness and/or organ transplantation. PMID:23991749

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

2014-04-01

298

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

299

Comparative proteomic analysis of differentially expressed proteins induced by hydrogen sulfide in Spinacia oleracea leaves.  

PubMed

Hydrogen sulfide (H2S), as a potential gaseous messenger molecule, has been suggested to play important roles in a wide range of physiological processes in plants. The aim of present study was to investigate which set of proteins is involved in H2S-regulated metabolism or signaling pathways. Spinacia oleracea seedlings were treated with 100 µM NaHS, a donor of H2S. Changes in protein expression profiles were analyzed by 2-D gel electrophoresis coupled with MALDI-TOF MS. Over 1000 protein spots were reproducibly resolved, of which the abundance of 92 spots was changed by at least 2-fold (sixty-five were up-regulated, whereas 27 were down-regulated). These proteins were functionally divided into 9 groups, including energy production and photosynthesis, cell rescue, development and cell defense, substance metabolism, protein synthesis and folding, cellular signal transduction. Further, we found that these proteins were mainly localized in cell wall, plasma membrane, chloroplast, mitochondria, nucleus, peroxisome and cytosol. Our results demonstrate that H2S is involved in various cellular and physiological activities and has a distinct influence on photosynthesis, cell defense and cellular signal transduction in S. oleracea leaves. These findings provide new insights into proteomic responses in plants under physiological levels of H2S. PMID:25181351

Chen, Juan; Liu, Ting-Wu; Hu, Wen-Jun; Simon, Martin; Wang, Wen-Hua; Chen, Juan; Liu, Xiang; Zheng, Hai-Lei

2014-01-01

300

Hydrogen sulfide in the pathogenesis of atherosclerosis and its therapeutic potential.  

PubMed

Hydrogen sulfide (H(2)S) was the third gaseous transmitter to be discovered, along with nitric oxide and carbon monoxide, and has been proposed to be involved in numerous physiological processes and pathology of various diseases. Hyperhomocysteinemia is an independent risk factor for cardiovascular disease, including atherosclerosis. Atherosclerosis is characterized by multiple key events including endothelial dysfunction, monocyte infiltration and their differentiation into macrophages, conversion of lesion-resident macrophages into foam cells, and smooth muscle cell proliferation. Increasing evidence has indicated that H(2)S plays a potentially significant role in all of these biological processes and that malfunction of H(2)S homeostasis may contribute to the pathogenesis of atherosclerosis. Experiments have demonstrated that H(2)S supplementation ameliorated many of these atherogenic processes and hence, such supplementation potentially may prove to be of therapeutic benefit in the prevention or treatment of atherosclerosis. H(2)S levels may be induced by the administration of H(2)S or H(2)S donors, or alternatively be reduced by the administration of specific cystathionine ?-synthase or cystathionine ?-lyase inhibitors. However, issues remain with the potential use of currently available H(2)S-modulating agents in a clinical setting. This review will provide a description of the current literature on the involvement of H(2)S in these key aspects of vascular biology that contribute to the development of atherosclerosis, as well as the therapeutic potential of currently available H(2)S-modulating agents. PMID:22115351

Lynn, Edward G; Austin, Richard C

2011-01-01

301

Hydrogen sulfide inhibits enzymatic browning of fresh-cut lotus root slices by regulating phenolic metabolism.  

PubMed

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?lL(-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

Sun, Ying; Zhang, Wei; Zeng, Tao; Nie, Qixing; Zhang, Fengying; Zhu, Liqin

2015-06-15

302

Inhibitory effect of hydrogen sulfide on ozone-induced airway inflammation, oxidative stress, and bronchial hyperresponsiveness.  

PubMed

Exposure to ozone has been associated with airway inflammation, oxidative stress, and bronchial hyperresponsiveness. The goal of this study was to examine whether these adverse effects of ozone could be prevented or reversed by hydrogen sulfide (H2S) as a reducing agent. The H2S donor sodium (NaHS) (2 mg/kg) or vehicle (PBS) was intraperitoneally injected into mice 1 hour before and after 3-hour ozone (2.5 ppm) or air exposure, and the mice were studied 24 hours later. Preventive and therapeutic treatment with NaHS reduced the ozone-induced increases in the total cells, including neutrophils and macrophages; this treatment also reduced levels of cytokines, including TNF-?, chemokine (C-X-C motif) ligand 1, IL-6, and IL-1? levels in bronchial alveolar lavage fluid; inhibited bronchial hyperresponsiveness; and attenuated ozone-induced increases in total malondialdehyde in bronchoalveolar lavage fluid and decreases in the ratio of reduced glutathione/oxidized glutathione in the lung. Ozone exposure led to decreases in the H2S production rate and in mRNA and protein levels of cystathionine-?-synthetase and cystathionine-?-lyase in the lung. These effects were prevented and reversed by NaHS treatment. Furthermore, NaHS prevented and reversed the phosphorylation of p38 mitogen-activated protein kinase and heat shock protein 27. H2S may have preventive and therapeutic value in the treatment of airway diseases that have an oxidative stress basis. PMID:25010831

Zhang, Pengyu; Li, Feng; Wiegman, Coen H; Zhang, Min; Hong, Yan; Gong, Jicheng; Chang, Yan; Zhang, Junfeng Jim; Adcock, Ian; Chung, Kian Fan; Zhou, Xin

2015-01-01

303

Cellular mechanism underlying hydrogen sulfide induced mouse tracheal smooth muscle relaxation: role of BKCa.  

PubMed

Recent studies have suggested that hydrogen sulfide (H2S), an important endogenous signaling gaseous molecule, participates in relaxation of smooth muscle. Nevertheless, the mechanism of this relaxation effect on respiratory system is still unclear. The present study aims to investigate the physiological function as well as cellular mechanism of H2S in tracheal smooth muscle. Application of the H2S donor, sodium hydrosulphide (NaHS) and the precursor of H2S, l-cysteine (l-Cys) induced mouse tracheal smooth muscle (TSM) relaxation in an epithelium-independent manner. The relaxation of TSM induced by NaHS was abrogated by iberiotoxin (IbTX), the large conductance calcium activated potassium channel (BKCa) blocker. In primary cultured mouse TSM cells, NaHS remarkably increased potassium outward currents in whole-cell patch clamp, hyperpolarized TSM cells and inhibited the calcium influx. All of these effects were significantly blocked by IbTX. Consistent with the results in vitro, administration of NaHS in vivo also reduced airway hyperresponsiveness in Ovalbumin (OVA)-challenged asthmatic mice. Our present study indicates that NaHS can induce mouse TSM relaxation by activating BKCa. These observations reveal the physiological function of H2S in airway, which provides a promising pharmacological target for the treatment of asthma and other respiratory diseases associated with over-contraction of TSM. PMID:25034810

Huang, Jiehong; Luo, Yu-li; Hao, Yuan; Zhang, Yi-lin; Chen, Peng-xiao; Xu, Jia-wen; Chen, Min-hui; Luo, Yong-feng; Zhong, Nan-Shan; Xu, Jun; Zhou, Wen-liang

2014-10-15

304

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

305

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

PubMed

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

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

2012-08-01

306

Emersion in the mangrove forest fish Rivulus marmoratus: A unique response to hydrogen sulfide  

SciTech Connect

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.

Abel, D.C.; Koenig, C.C.; Davis, W.P.

1987-01-01

307

Hydrogen Sulfide Detection Using a Gold Nanoparticle/Metalloprotein Based Probe  

NASA Astrophysics Data System (ADS)

We present a simple method for direct detection of hydrogen sulfide (H2S) in an aqueous solution. This method represents a novel biosensor based on metalloprotein cytochrome c (cyt c) with the localized surface plasmon resonance of gold nanoparticles (AuNPs). For this purpose, we develop a new approach based on attaching chemically-modified cyt c onto AuNPs. Here, by reacting H2S with protein heme center, its conformation changes in the locality of the heme moiety. The conformational changes occurring in the protein alter the spectral characteristics by changing the dielectric properties of AuNPs. The conformational changes of cyt c induced by the H2S interaction are characterized by the UV-visible absorption spectroscopy and the circular dichroism technique. The limit of the detection and sensitivity of the AuNPs/cyt c biosensor are evaluated by using UV-visible spectroscopy. According to the experiments, it is revealed that H2S can be detected at a concentration of 4.0 ?M (1.3 ppb) by the fabricated AuNPs/cyt c biosensor. In addition, the sensor retains activity and gives reproducible results after storage in 4°C for 60 d. This simple and cost-effective sensing platform provides a rapid and convenient detection for H2S at concentrations far below the hazardous limit.

Meisam, Omidi; Gh., Amoabediny; Yazdian, F.; Habibi-Rezaei, M.

2014-08-01

308

Measurements of atmospheric dimethylsulfide, hydrogen sulfide, and carbon disulfide during GTE/CITE 3  

NASA Technical Reports Server (NTRS)

Measurements of atmospheric dimethylsulfide (DMS), hydrogen sulfide (H2S), and carbon disulfide (CS2) were made over the North and South Atlantic Ocean as part of the Global Tropospheric Experiment/Chemical Instrumentation Test and Evaluation (GTE/CITE 3) project. DMS and CS2 samples were collected and analyzed using an automated gas chromatography/flame photometric detection system with a sampling frequency of 10 min. H2S samples were collected using silver nitrate impregnated filters and analyzed by fluorescence quenching. The DMS data from both hemispheres have a bimodal distribution. Over the North Atlantic this reflects the difference between marine and continental air masses. Over the South Atlantic it may reflect differences in the sea surface source of DMS, corresponding to different air mass source regions. The median boundary layer H2S and CS2 levels were significantly higher in the northern hemisphere than the southern hemisphere, reflecting the higher frequency of samples influenced by pollutant and/or coastal emissions. Composite vertical profiles of DMS and H2S are similar to each other, are consistent with a sea surface source. Vertical profiles of CS2 have maxima in the free troposphere, implicating a continental source. The low levels of H2S and CS2 found in the southern hemisphere constrain the role of these compounds in global budgets to significantly less than previously estimated.

Cooper, David J.; Saltzman, Eric S.

1993-01-01

309

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

PubMed

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

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

2014-01-01

310

Hydrogen sulfide interacts with calcium signaling to enhance the chromium tolerance in Setaria italica.  

PubMed

The oscillation of intracellular calcium (Ca(2+)) concentration is a primary event in numerous biological processes in plants, including stress response. Hydrogen sulfide (H2S), an emerging gasotransmitter, was found to have positive effects in plants responding to chromium (Cr(6+)) stress through interacting with Ca(2+) signaling. While Ca(2+) resemblances H2S in mediating biotic and abiotic stresses, crosstalk between the two pathways remains unclear. In this study, Ca(2+) signaling interacted with H2S to produce a complex physiological response, which enhanced the Cr(6+) tolerance in foxtail millet (Setaria italica). Results indicate that Cr(6+) stress activated endogenous H2S synthesis as well as Ca(2+) signaling. Moreover, toxic symptoms caused by Cr(6+) stress were strongly moderated by 50?M H2S and 20mM Ca(2+). Conversely, treatments with H2S synthesis inhibitor and Ca(2+) chelators prior to Cr(6+)-exposure aggravated these toxic symptoms. Interestingly, Ca(2+) upregulated expression of two important factors in metal metabolism, MT3A and PCS, which participated in the biosynthesis of heavy metal chelators, in a H2S-dependent manner to cope with Cr(6+) stress. These findings also suggest that the H2S dependent pathway is a component of the Ca(2+) activating antioxidant system and H2S partially contributes Ca(2+)-activating antioxidant system. PMID:25459298

Fang, Huihui; Jing, Tao; Liu, Zhiqiang; Zhang, Liping; Jin, Zhuping; Pei, Yanxi

2014-12-01

311

HIF-1 and SKN-1 Coordinate the Transcriptional Response to Hydrogen Sulfide in Caenorhabditis elegans  

PubMed Central

Hydrogen sulfide (H2S) has dramatic physiological effects on animals that are associated with improved survival. C. elegans grown in H2S are long-lived and thermotolerant. To identify mechanisms by which adaptation to H2S effects physiological functions, we have measured transcriptional responses to H2S exposure. Using microarray analysis we observe rapid changes in the abundance of specific mRNAs. The number and magnitude of transcriptional changes increased with the duration of H2S exposure. Functional annotation suggests that genes associated with protein homeostasis are upregulated upon prolonged exposure to H2S. Previous work has shown that the hypoxia-inducible transcription factor, HIF-1, is required for survival in H2S. In fact, we show that hif-1 is required for most, if not all, early transcriptional changes in H2S. Moreover, our data demonstrate that SKN-1, the C. elegans homologue of NRF2, also contributes to H2S-dependent changes in transcription. We show that these results are functionally important, as skn-1 is essential to survive exposure to H2S. Our results suggest a model in which HIF-1 and SKN-1 coordinate a broad transcriptional response to H2S that culminates in a global reorganization of protein homeostasis networks. PMID:21980473

Miller, Dana L.; Budde, Mark W.; Roth, Mark B.

2011-01-01

312

Bicarbonate-dependent effect of hydrogen sulfide on vascular contractility in rat aortic rings.  

PubMed

Hydrogen sulfide (H(2)S), an endogenous gaseous mediator, produces both vasorelaxation and vasoconstriction at different concentrations. We found in the present study that NaHS, an H(2)S donor, produced stronger vasorelaxant and weaker vasoconstrictive effects in HEPES solution compared with those achieved in Krebs solution. We further screened the buffer components and found that bicarbonate (HCO(3)(-)) was the ion to influence the effect of H(2)S. After examining the vasorelaxant effects of acetylcholine, a vasodilator by releasing nitric oxide, and isoprenaline, a ?-adrenoceptor agonist, in HEPES and Krebs buffers, we found the HCO(3)(-)-dependent effect was specific to H(2)S. Blockade of anion exchanger-2 activity with 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) or with HCO(3)(-)-free solution abolished the vasoconstrictive effect of NaHS. Moreover, NaHS decreased nitric oxide level in the rat aorta in HCO(3)(-)-containing buffer, but this effect was abolished by HCO(3)(-)-free buffer or DIDS. In summary, we found for the first time that H(2)S stimulates anion exchanger to transport extracellular HCO(3)(-) in exchange for intracellular superoxide anions, which may further inactivate nitric oxide and induces vasoconstriction. PMID:20660164

Liu, Yi-Hong; Bian, Jin-Song

2010-10-01

313

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

PubMed

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

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

2014-04-01

314

Manure ammonia and hydrogen sulfide emissions from a Western dairy storage basin.  

PubMed

The reporting of ammonia (NH) and hydrogen sulfide (HS) emissions from dairies to the federal government depends on the magnitude of the emissions. However, little is known about their daily NH and HS emissions and what influences those emissions. Emissions of NH and HS from two manure storage basins at a 4400-head western free-stall dairy were measured intermittently over 2 yr. Each basin went through stages of filling, drying, and then removal of the manure during the study period. Emissions were determined using backward Lagrangian Stochastic and vertical radial plume methods. Ammonia emissions ranged from 35 to 59 kg d in one basin and from 86 to 90 kg d in a second basin, corresponding to a range of 7 to 19 g d head. Basin NH emissions were highest during initial filling and when the manure was removed. Mean HS emissions ranged from 5 to 22 kg d (1.1-4.6 g d head). Basin HS emissions were highest when the basin was filling. Crusting of the basin surface reduced NH but not HS emissions. The cessation of basin filling reduced HS but not NH emissions. Air temperature and wind conditions were correlated with NH emissions. Barometric pressure decreases were correlated with episodic HS emissions. The variability in emissions with stage of manure handling and storage and meteorological conditions indicates that determining the maximum daily emissions and the annual emissions from such waste basins requires consideration of each stage in conjunction with the climatic conditions during the stage. PMID:25602327

Grant, Richard H; Boehm, Matthew T

2015-01-01

315

The role of the headspace in hydrogen sulfide removal during microaerobic digestion of sludge.  

PubMed

The role of the headspace (HS) in the microaerobic removal of hydrogen sulfide from biogas produced during sludge digestion was studied. Research was carried out in a pilot reactor with a total volume of 265 L, under mesophilic conditions. Biogas was successfully desulfurized (99%) by introducing pure oxygen (0.46 NL/L(fed)) into the recirculation stream when the HS volume was both 50.0 and 9.5 L. The removal efficacy dropped sharply to ?15% when the HS was reduced to 1.5 L. The system responded quickly to the operational changes imposed: micro-oxygenation stops and variations in supply, as well as HS volume reductions and increases. As the final result, the microaerobic process required a minimum surface into the gas space to occur, which along with the elemental sulfur deposition in this area indicated that the oxidation took place there. Additionally, the pattern of sulfur accumulation suggested that the removal occurred preferentially on certain materials, and pointed to a significant biological contribution. PMID:22949260

Ramos, I; Díaz, I; Fdz-Polanco, M

2012-01-01

316

The Effects of Acute Hydrogen Sulfide Poisoning on Cytochrome P450 Isoforms Activity in Rats  

PubMed Central

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 Cmax 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

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

2014-01-01

317

Hydrogen sulfide alleviates diabetic nephropathy in a streptozotocin-induced diabetic rat model.  

PubMed

Accumulating evidence has demonstrated that hydrogen sulfide (H2S) plays critical roles in the pathogenesis of chronic kidney diseases. This study was designed to investigate whether H2S has protective effects against diabetic nephropathy. Diabetic rats were induced by intraperitoneal injection of streptozotocin and administrated with H2S donor NaHS for 12 weeks. Rat glomerular mesangial cells were pretreated with NaHS or MAPK inhibitors (U0126, SP600125, and SB203580) prior to high glucose exposure, and cell proliferation was determined. Our findings suggest that H2S can improve renal function and attenuate glomerular basement membrane thickening, mesangial matrix deposition, and renal interstitial fibrosis in diabetic rats. H2S was found to reduce high glucose-induced oxidative stress by activating the Nrf2 antioxidant pathway and to exert anti-inflammatory effects by inhibiting NF-?B signaling. In addition, H2S reduced high glucose-induced mesangial cell proliferation by blockade of MAPK signaling pathways. Moreover, H2S was also found to inhibit the renin-angiotensin system in diabetic kidney. In conclusion, our study demonstrates that H2S alleviates the development of diabetic nephropathy by attenuating oxidative stress and inflammation, reducing mesangial cell proliferation, and inhibiting renin-angiotensin system activity. PMID:25164822

Zhou, Xiang; Feng, Yu; Zhan, Zhoubing; Chen, Jianchang

2014-10-17

318

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

SciTech Connect

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.

McKibben, M.A.

1988-06-01

319

Effects of hydrogen sulfide (H2S) on water intake and vasopressin and oxytocin secretion induced by fluid deprivation.  

PubMed

During dehydration, responses of endocrine and autonomic control systems are triggered by central and peripheral osmoreceptors and peripheral baroreceptors to stimulate thirst and sodium appetite. Specifically, it is already clear that endocrine system acts by secreting vasopressin (AVP), oxytocin (OT) and angiotensin II (ANG II), and that gaseous molecules, such as nitric oxide (NO) and carbon monoxide (CO), play an important role in modulating the neurohypophyseal secretion as well as ANG II production and thirst. More recently, another gas-hydrogen sulfide (H2S)-has been studied as a neuronal modulator, which is involved in hypothalamic control of blood pressure, heart frequency and temperature. In this study, we aimed to investigate whether H2S and its interaction with NO system could participate in the modulatory responses of thirst and hormonal secretion induced by fluid deprivation. For this purpose, Wistar male rats were deprived of water for 12 and 24h, and the activity of sulfide-generating enzymes was measured. Surprisingly, 24-h water deprivation increased the activity of sulfide-generating enzymes in the medial basal hypothalamus (MBH). Furthermore, the icv injection of sodium sulfide (Na2S, 260nmol), a H2S donor, reduced water intake, increased AVP, OT and CORT plasma concentrations and decreased MBH nitrate/nitrite (NOX) content of 24-h water-deprived animals compared to controls. We thus suggest that H2S system has an important role in the modulation of hormonal and behavioral responses induced by 24-h fluid deprivation. PMID:25436932

Coletti, R; Almeida-Pereira, G; Elias, L L K; Antunes-Rodrigues, J

2015-01-01

320

Inhibitory action of hydrogen sulfide on muscarinic receptor-induced contraction of isolated porcine irides.  

PubMed

We investigated the pharmacological actions of hydrogen sulfide (H(2)S) using sodium hydrosulfide (NaHS) and sodium sulfide (Na(2)S) as donors on isolated porcine irides in the presence of tone induced by muscarinic receptor stimulation. Furthermore, we also investigated the mechanism of action of H(2)S in this smooth muscle. Isolated porcine iris muscle strips were set up in organ baths and prepared for measurement of longitudinal isometric tension. The relaxant action of NaHS or Na(2)S on carbachol-induced tone was studied in the absence and presence of a K(+)-channel inhibitor and inhibitors/activators of enzymes of the biosynthetic pathways for H(2)S, prostanoid and nitric oxide production. In the concentration range, 10 nM to 100 microM, NaHS produced a concentration-dependent relaxation of carbachol-induced tone reaching a maximum of inhibition of 28% at 30 microM. The cyclooxygenase inhibitor, flurbiprofen (1 microM), enhanced relaxations induced by both NaHS and Na(2)S yielding IC(50) values of 7 microM and 70 microM, respectively. With exception of l-NAME (300 muM) inhibitors of cystathionine gamma-lyase, propargylglycine, (PAG) (1 mM) and beta-cyanoalanine, (BCA) (1 mM) and inhibitors of cystathionine beta-synthase, aminooxyacetic acid (AOA) (30 microM) and hydroxylamine (HOA) (30 microM) caused significant (P < 0.001) rightward shifts in the concentration-response curves to NaHS. An activator of cystathionine beta-synthase, SAM (100 microM), enhanced relaxations elicited by low concentrations of NaHS but attenuated responses caused by the higher concentrations of this H(2)S donor. The inhibitor of K(ATP) channel, glibenclamide (100 and 300 microM), blocked relaxations induced by NaHS. We conclude that the observed inhibitory action of NaHS and Na(2)S in isolated porcine irides is dependent on endogenous production of prostanoids and the biosynthesis of H(2)S by cystathionine gamma-lyase and cystathionine beta-synthase. Furthermore, relaxation induced by H(2)S is mediated, at least in part, by K(ATP) channels. Nitric oxide is not involved in the relaxation induced by this gas in the isolated porcine irides. PMID:18940190

Monjok, Emmanuel M; Kulkarni, Kaustubh H; Kouamou, Ghislaine; McKoy, Marshalyn; Opere, Catherine A; Bongmba, Odelia N; Njie, Ya Fatou; Ohia, Sunny E

2008-12-01

321

Hydrogen Sulfide Oxidation is Coupled to Oxidative Phosphorylation in Mitochondria of Solemya reidi  

Microsoft Academic Search

Solemya reidi, a gutless clam found in sulfide-rich habitats, contains within its gills bacterial symbionts thought to oxidize sulfur compounds and provide a reduced carbon food source to the clam. However, the initial step or steps in sulfide oxidation occur in the animal tissue, and mitochondria isolated from both gill and symbiont-free foot tissue of the clam coupled the oxidation

Mark A. Powell; George N. Somero

1986-01-01

322

Hydrogen sulfide oxidation is coupled to oxidative phosphorylation in mitochondria of Solemya reidi  

Microsoft Academic Search

Solemya reidi, a gutless clam found in sulfide-rich habitats, contains within its gills bacterial symbionts thought to oxidize sulfur compounds and provide a reduced carbon food source to the clam. However, the initial step or steps in sulfide oxidation occur in the animal tissue, and mitochondria isolated from both gill and symbiont-free foot tissue of the clam coupled the oxidation

M. A. Powell; G. N. Somero

1986-01-01

323

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

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.

Sartoretti, C. Jorand; Ulmann, M.; Augustynski, J. (Electrochemistry Laboratory, Department of Chemistry, University of Geneva (CH)); Linkous, C.A. (Florida Solar Energy Center, University of Central Florida (US))

2000-01-01

324

Hydrogen sulfide regulates ethylene-induced stomatal closure in Arabidopsis thaliana.  

PubMed

Hydrogen sulfide (H2 S) is a newly-discovered signaling molecule in plants and has caused increasing attention in recent years, but its function in stomatal movement is unclear. In plants, H2 S is synthesized via cysteine degradation catalyzed by D-/L-cysteine desulfhydrase (D-/L-CDes). AtD-/L-CDes::GUS transgenic Arabidopsis thaliana (L.) Heynh. plants were generated and used to investigate gene expression patterns, and results showed that AtD-/L-CDes can be expressed in guard cells. We also determined the subcellular localization of AtD-/L-CDes using transgenic plants of AtD-/L-CDes::GFP, and the results showed that AtD-CDes and AtL-CDes are located in the chloroplast and in the cytoplasm, respectively. The transcript levels of AtD-CDes and AtL-CDes were affected by the chemicals that cause stomatal closure. Among these factors, ACC, a precursor of ethylene, has the most significant effect, which indicates that the H2 S generated from D-/L-CDes may play an important role in ethylene-induced stomatal closure. Meanwhile, H2 S synthetic inhibitors significantly inhibited ethylene-induced stomatal closure in Arabidopsis. Ethylene treatment caused an increase of H2 S production and of AtD-/L-CDes activity in Arabidopsis leaves. AtD-/L-CDes over-expressing plants exhibited enhanced induction of stomatal closure compared to the wild-type after ethylene treatment; however, the effect was not observed in the Atd-cdes and Atl-cdes mutants. In conclusion, our results suggest that the D-/L-CDes-generated H2 S is involved in the regulation of ethylene-induced stomatal closure in Arabidopsis thaliana. PMID:23134300

Hou, Zhihui; Wang, Lanxiang; Liu, Jing; Hou, Lixia; Liu, Xin

2013-03-01

325

Treatment with hydrogen sulfide alleviates streptozotocin-induced diabetic retinopathy in rats  

PubMed Central

Background and Purpose Retinopathy, as a common complication of diabetes, is a leading cause of reduced visual acuity and acquired blindness in the adult population. The aim of present study was to investigate the therapeutic effect of hydrogen sulfide on streptozotocin (STZ)-induced diabetic retinopathy in rats. Experimental Approach Rats were injected with a single i.p. injection of STZ (60 mg·kg?1) to induce diabetic retinopathy. Two weeks later, the rats were treated with NaHS (i.p. injection of 0.1 mL·kg?1·d?1 of 0.28 mol·L?1 NaHS, a donor of H2S) for 14 weeks. Key Results Treatment with H2S had no significant effect on blood glucose in STZ-induced diabetic rats. Treatment with exogenous H2S enhanced H2S levels in both plasma and retinas of STZ-induced diabetic rats. Treatment with H2S in STZ-treated rats improved the retinal neuronal dysfunction marked by enhanced amplitudes of b-waves and oscillatory potentials and expression of synaptophysin and brain-derived neurotrophic factor, alleviated retinal vascular abnormalities marked by reduced retinal vascular permeability and acellular capillary formation, decreased vitreous VEGF content, down-regulated expressions of HIF-1? and VEGFR2, and enhanced occludin expression, and attenuated retinal thickening and suppressed expression of extracellular matrix molecules including laminin ?1 and collagen IV?3 expression in retinas of STZ-induced diabetic rats. Treatment with H2S in retinas of STZ-induced diabetic rats abated oxidative stress, alleviated mitochondrial dysfunction, suppressed NF-?B activation and attenuated inflammation. Conclusions and Implications Treatment with H2S alleviates STZ-induced diabetic retinopathy in rats possibly through abating oxidative stress and suppressing inflammation. PMID:23488985

Si, Yan-Fang; Wang, Jun; Guan, Juan; Zhou, Li; Sheng, Yu; Zhao, Juan

2013-01-01

326

Endogenous hydrogen sulfide in the rostral ventrolateral medulla/Bötzinger complex downregulates ventilatory responses to hypoxia.  

PubMed

Hydrogen sulfide (H2S) is now recognized as a new gaseous transmitter involved in several brain-mediated responses. The rostral ventrolateral medulla (RVLM)/Bötzinger complex is a region in the brainstem that is involved in cardiovascular and respiratory functions. Recently, it has been shown that exogenous H2S in the RVLM modulates autonomic function and thus blood pressure. In the present study, we investigated whether H2S, endogenously produced in the RVLM/Bötzinger complex, plays a role in the control of hypoxia-induced hyperventilation. Ventilation (VE) was measured before and after bilateral microinjection of Na2S (H2S donor, 0.04, 1 and 2 pmol/100 nl) or aminooxyacetate (AOA, 0.2, 1 and 2 pmol/100 nl, a cystathionine ?-synthase, CBS, inhibitor) into the RVLM/Bötzinger complex followed by a 60-min period of hypoxia (7% inspired O2) or normoxia exposure. Control rats received microinjection of vehicle. Microinjection of vehicle, AOA or Na2S did not change VE in normoxic conditions. Exposure to hypoxia evoked a typical increase in VE. Microinjection of Na2S (2 pmol) followed by hypoxia exposure attenuated the hyperventilation. Conversely, microinjection of AOA (2 pmol) into the RVLM/Bötzinger complex caused an increase in the hypoxia-induced hyperventilation. Thus, endogenous H2S in the RVLM/Bötzinger complex seems to play no role in the maintenance of basal pulmonary ventilation during normoxia whereas during hypoxia H2S has a downmodulatory function. Homogenates of RVLM/Bötzinger complex of animals previously exposed to hypoxia for 60 min exhibited a decreased rate of H2S production. Our data are consistent with the notion that the gaseous messenger H2S synthesis is downregulated in the RVLM/Bötzinger complex during hypoxia favoring hyperventilation. PMID:24953676

Donatti, Alberto F; Soriano, Renato N; Sabino, João P; Branco, Luiz G S

2014-08-15

327

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

PubMed

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

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

2014-10-01

328

Hydrogen sulfide is involved in dexamethasone-induced hypertension in rat.  

PubMed

Glucocorticoid (GC)-induced hypertension is a common clinical problem still poorly understood. The presence of GC receptor (GR) in vascular smooth muscle and endothelial cells suggests a direct role for GC in vasculature. In response to hemodynamic shear stress, endothelium tonically releases nitric oxide (NO), endothelial-derived hyperpolarizing factor (EDHF) and prostacyclin contributing to vascular homeostasis. Recently, hydrogen sulfide (H2S) has been proposed as a candidate for EDHF. H2S is endogenously mainly formed from L-cysteine by the action of cystathionine-?-synthase (CBS) and cystathionine-?-lyase (CSE). It plays many physiological roles and contributes to cardiovascular function. Here we have evaluated the role played by H2S in mesenteric arterial bed and in carotid artery harvested from rats treated with vehicle or dexamethasone (DEX; 1.5?mg/kg/day) for 8 days. During treatments systolic blood pressure was significantly increased in conscious rats. EDHF contribution was evaluated in ex-vivo by performing a concentration-response curve induced by acetylcholine (Ach) in presence of a combination of indomethacin and L-NG-Nitroarginine methyl ester in both vascular districts. EDHF-mediated relaxation was significantly reduced in DEX-treated group in both mesenteric bed and carotid artery. EDHF-mediated relaxation was abolished by pre-treatment with both apamin and charybdotoxin, inhibitors of small and big calcium-dependent potassium channels respectively, or with propargylglycine, inhibitor of CSE. Western blot analysis revealed a marked reduction in CBS and CSE expression as well as H2S production in homogenates of mesenteric arterial bed and carotid artery from DEX-treated rats. In parallel, H2S plasma levels were significantly reduced in DEX group compared with vehicle. In conclusion, an impairment in EDHF/H2S signaling occurs in earlier state of GC-induced hypertension in rats suggesting that counteracting this dysfunction may be beneficial to manage DEX-associated increase in blood pressure. PMID:25461303

d'Emmanuele di Villa Bianca, Roberta; Mitidieri, Emma; Donnarumma, Erminia; Tramontano, Teresa; Brancaleone, Vincenzo; Cirino, Giuseppe; Bucci, Mariarosaria; Sorrentino, Raffaella

2014-11-25

329

Pharmacological characterization of the vascular effects of aryl isothiocyanates: is hydrogen sulfide the real player?  

PubMed

Hydrogen sulfide (H?S) is an endogenous gasotransmitter, which mediates important physiological effects in the cardiovascular system. Accordingly, an impaired production of endogenous H?S contributes to the pathogenesis of important cardiovascular disorders, such as hypertension. Therefore, exogenous compounds, acting as H?S-releasing agents, are viewed as promising pharmacotherapeutic agents for cardiovascular diseases. Thus, this paper aimed at evaluating the H?S-releasing properties of some aryl isothiocyanate derivatives and their vascular effects. The release of H?S was determined by amperometry, spectrophotometry and gas/mass chromatography. Moreover, the vascular activity of selected isothiocyanates were tested in rat conductance (aorta) and coronary arteries. Since H?S has been recently reported to act as an activator of vascular Kv7 potassium channels, the possible membrane hyperpolarizing effects of isothiocyanates were tested on human vascular smooth muscle (VSM) cells by spectrofluorescent dyes. Among the tested compounds, phenyl isothiocyanate (PhNCS) and 4-carboxyphenyl isothiocyanate (PhNCS-COOH) exhibited slow-H?S-release, triggered by organic thiols such as L-cysteine. These compounds were endowed with vasorelaxing effects on conductance and coronary arteries. Moreover, these two isothiocyanates caused membrane hyperpolarization of VSM cells. The vascular effects of isothiocyanates were strongly abolished by the selective Kv7-blocker XE991. In conclusion, the isothiocyanate function can be viewed as a suitable slow H?S-releasing moiety, endowed with vasorelaxing and hypotensive effects, typical of this gasotransmitter. Thus, such a chemical moiety can be employed for the development of novel chemical tools for basic studies and promising cardiovascular drugs. PMID:24287004

Martelli, Alma; Testai, Lara; Citi, Valentina; Marino, Alice; Bellagambi, Francesca G; Ghimenti, Silvia; Breschi, Maria C; Calderone, Vincenzo

2014-01-01

330

Hydrogen sulfide as an allosteric modulator of ATP-sensitive potassium channels in colonic inflammation.  

PubMed

The ATP-sensitive potassium channel (K(ATP)) in mouse colonic smooth muscle cell is a complex containing a pore-forming subunit (Kir6.1) and a sulfonylurea receptor subunit (SUR2B). These channels contribute to the cellular excitability of smooth muscle cells and hence regulate the motility patterns in the colon. Whole-cell voltage-clamp techniques were used to study the alterations in K(ATP) channels in smooth muscle cells in experimental colitis. Colonic inflammation was induced in BALB/C mice after intracolonic administration of trinitrobenzene sulfonic acid. K(ATP) currents were measured at a holding potential of -60 mV in high K(+) external solution. The concentration response to levcromakalim (LEVC), a K(ATP) channel opener, was significantly shifted to the left in the inflamed smooth-muscle cells. Both the potency and maximal currents induced by LEVC were enhanced in inflammation. The EC(50) values in control were 6259 nM (n = 10) and 422 nM (n = 8) in inflamed colon, and the maximal currents were 9.9 ± 0.71 pA/pF (60 ?M) in control and 39.7 ± 8.8 pA/pF (3 ?M) after inflammation. As was seen with LEVC, the potency and efficacy of sodium hydrogen sulfide (NaHS) (10-1000 ?M) on K(ATP) currents were significantly greater in inflamed colon compared with controls. In control cells, pretreatment with 100 µM NaHS shifted the EC(50) for LEV-induced currents from 2838 (n = 6) to 154 (n = 8) nM. Sulfhydration of sulfonylurea receptor 2B (SUR2B) was induced by NaHS and colonic inflammation. These data suggest that sulfhydration of SUR2B induces allosteric modulation of K(ATP) currents in colonic inflammation. PMID:23115325

Gade, Aravind R; Kang, Minho; Akbarali, Hamid I

2013-01-01

331

Role of hydrogen sulfide, a gasotransmitter, in colonic pain and inflammation.  

PubMed

  Hydrogen sulfide (H2S), the third known gaseous transmitter following nitric oxide and carbon monoxide, is generated by multiple enzymes including cystathionine-?-lyase (CSE) in vivo. We previously demonstrated that H2S activates Cav3.2 T-type Ca(2+) channels expressed on sensory neurons, leading to hyperalgesia and facilitation of inflammation. Here, we describe the role of H2S in processing of colonic pain and inflammation. Intracolonic (i.col.) administration of NaHS, an H2S donor, to mice evoked colonic pain-like nociceptive behavior and referred hyperalgesia accompanied by phosphorylation of ERK in the superficial layers of spinal dorsal horn, a marker for excitation of nociceptive neurons. The pronociceptive effect of NaHS was abolished by inhibitors or knockdown of Cav3.2 and by an inhibitor of TRPA1, another target molecule of H2S. In rats with colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS), on the other hand, repeated i.col. administration of NaHS prevented colonic ulcer and inflammatory symptoms, which were inhibited by ablation of capsaicin-sensitive sensory neurons or T-type Ca(2+) channel inhibitor. NaHS, given i.col., caused phosphorylation of ERK in the spinal dorsal horn of rats with TNBS-induced colitis, but not of naïve rats. In TNBS-treated rats, Cav3.2 was upregulated in the dorsal root ganglia, while CSE was downregulated in the colon. Taken together, these findings suggest that inhibitors of the CSE/H2S/Cav3.2 or TRPA1 pathways might be useful for the treatment of colonic pain diseases such as irritable bowel syndrome, while H2S donors or Cav3.2 activators might be useful for the treatment of inflammatory bowel disease including Crohn's disease. PMID:25452234

Tsubota, Maho; Kawabata, Atsufumi

2014-01-01

332

Vascular complications of cystathionine ?-synthase deficiency: future directions for homocysteine-to-hydrogen sulfide research  

PubMed Central

Homocysteine (Hcy), a cardiovascular and neurovascular disease risk factor, is converted to hydrogen sulfide (H2S) through the transsulfuration pathway. H2S has attracted considerable attention in recent years for many positive effects on vascular health and homeostasis. Cystathionine ?-synthase (CBS) is the first, and rate-limiting, enzyme in the transsulfuration pathway. Mutations in the CBS gene decrease enzymatic activity, which increases the plasma Hcy concentration, a condition called hyperhomocysteinemia (HHcy). Animal models of CBS deficiency have provided invaluable insights into the pathological effects of transsulfuration impairment and of both mild and severe HHcy. However, studies have also highlighted the complexity of HHcy and the need to explore the specific details of Hcy metabolism in addition to Hcy levels per se. There has been a relative paucity of work addressing the dysfunctional H2S production in CBS deficiency that may contribute to, or even create, HHcy-associated pathologies. Experiments using CBS knockout mice, both homozygous (?/?) and heterozygous (+/?), have provided 15 years of new knowledge and are the focus of this review. These murine models present the opportunity to study a specific mechanism for HHcy that matches one of the etiologies in many human patients. Therefore, the goal of this review was to integrate and highlight the critical information gained thus far from models of CBS deficiency and draw attention to critical gaps in knowledge, with particular emphasis on the modulation of H2S metabolism. We include findings from human and animal studies to identify important opportunities for future investigation that should be aimed at generating new basic and clinical understanding of the role of CBS and transsulfuration in cardiovascular and neurovascular disease. PMID:20971760

Beard, Richard S.

2011-01-01

333

Metabolic and cardiac signaling effects of inhaled hydrogen sulfide and low oxygen in male rats  

PubMed Central

Low concentrations of inhaled hydrogen sulfide (H2S) induce hypometabolism in mice. Biological effects of H2S in in vitro systems are augmented by lowering O2 tension. Based on this, we hypothesized that reduced O2 tension would increase H2S-mediated hypometabolism in vivo. To test this, male Sprague-Dawley rats were exposed to 80 ppm H2S at 21% O2 or 10.5% O2 for 6 h followed by 1 h recovery at room air. Rats exposed to H2S in 10.5% O2 had significantly decreased body temperature and respiration compared with preexposure levels. Heart rate was decreased by H2S administered under both O2 levels and did not return to preexposure levels after 1 h recovery. Inhaled H2S caused epithelial exfoliation in the lungs and increased plasma creatine kinase-MB activity. The effect of inhaled H2S on prosurvival signaling was also measured in heart and liver. H2S in 21% O2 increased Akt-PSer473 and GSK-3?-PSer9 in the heart whereas phosphorylation was decreased by H2S in 10.5% O2, indicating O2 dependence in regulating cardiac signaling pathways. Inhaled H2S and low O2 had no effect on liver Akt. In summary, we found that lower O2 was needed for H2S-dependent hypometabolism in rats compared with previous findings in mice. This highlights the possibility of species differences in physiological responses to H2S. Inhaled H2S exposure also caused tissue injury to the lung and heart, which raises concerns about the therapeutic safety of inhaled H2S. In conclusion, these findings demonstrate the importance of O2 in influencing physiological and signaling effects of H2S in mammalian systems. PMID:22403348

Stein, Asaf; Mao, Zhengkuan; Morrison, Joanna P.; Fanucchi, Michelle V.; Postlethwait, Edward M.; Patel, Rakesh P.; Kraus, David W.; Doeller, Jeannette E.

2012-01-01

334

Hydrogen sulfide represses androgen receptor transactivation by targeting at the second zinc finger module.  

PubMed

Androgen receptor (AR) signaling is indispensable for the development of prostate cancer from the initial androgen-dependent state to a later aggressive androgen-resistant state. This study examined the role of hydrogen sulfide (H(2)S), a novel gasotransmitter, in the regulation of AR signaling as well as its mediation in androgen-independent cell growth in prostate cancer cells. Here we found that H(2)S inhibits cell proliferation of both androgen-dependent (LNCaP) and antiandrogen-resistant prostate cancer cells (LNCaP-B), with more significance on the latter, which was established by long term treatment of parental LNCaP cells with bicalutamide. The expression of cystathionine ?-lyase (CSE), a major H(2)S producing enzyme in prostate tissue, was reduced in both human prostate cancer tissues and LNCaP-B cells. LNCaP-B cells were resistant to bicalutamide-induced cell growth inhibition, and CSE overexpression could rebuild the sensitivity of LNCaP-B cells to bicalutamide. H(2)S significantly repressed the expression of prostate-specific antigen (PSA) and TMPRSS2, two AR-targeted genes. In addition, H(2)S inhibited AR binding with PSA promoter and androgen-responsive element (ARE) luciferase activity. We further found that AR is post-translationally modified by H(2)S through S-sulfhydration. Mutation of cysteine 611 and cysteine 614 in the second zinc finger module of AR-DNA binding domain diminished the effects of H(2)S on AR S-sulfhydration and AR dimerization. These data suggest that reduced CSE/H2S signaling contributes to antiandrogen-resistant status, and sufficient level of H(2)S is able to inhibit AR transactivation and treat castration-resistant prostate cancer. PMID:24942741

Zhao, Kexin; Li, Shuangshuang; Wu, Lingyun; Lai, Christopher; Yang, Guangdong

2014-07-25

335

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

PubMed

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

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

2013-06-01

336

Hydrogen sulfide regulates cardiovascular function by influencing the excitability of subfornical organ neurons.  

PubMed

Hydrogen sulfide (H2S), a gasotransmitter endogenously found in the central nervous system, has recently been suggested to act as a signalling molecule in the brain having beneficial effects on cardiovascular function. This study was thus undertaken to investigate the effect of NaHS (an H2S donor) in the subfornical organ (SFO), a central nervous system site important to blood pressure regulation. We used male Sprague-Dawley rats for both in vivo and in vitro experiments. We first used RT-PCR to confirm our previous microarray analyses showing that mRNAs for the enzymes required to produce H2S are expressed in the SFO. We then used microinjection techniques to investigate the physiological effects of NaHS in SFO, and found that NaHS microinjection (5 nmol) significantly increased blood pressure (mean AUC?=?853.5±105.7 mmHg*s, n?=?5). Further, we used patch-clamp electrophysiology and found that 97.8% (88 of 90) of neurons depolarized in response to NaHS. This response was found to be concentration dependent with an EC50 of 35.6 µM. Coupled with the depolarized membrane potential, we observed an overall increase in neuronal excitability using an analysis of rheobase and action potential firing patterns. This study has provided the first evidence of NaHS and thus H2S actions and their cellular correlates in SFO, implicating this brain area as a site where H2S may act to control blood pressure. PMID:25144759

Kuksis, Markus; Smith, Pauline M; Ferguson, Alastair V

2014-01-01

337

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

PubMed

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

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

2014-01-01

338

Vascular complications of cystathionine ?-synthase deficiency: future directions for homocysteine-to-hydrogen sulfide research.  

PubMed

Homocysteine (Hcy), a cardiovascular and neurovascular disease risk factor, is converted to hydrogen sulfide (H(2)S) through the transsulfuration pathway. H(2)S has attracted considerable attention in recent years for many positive effects on vascular health and homeostasis. Cystathionine ?-synthase (CBS) is the first, and rate-limiting, enzyme in the transsulfuration pathway. Mutations in the CBS gene decrease enzymatic activity, which increases the plasma Hcy concentration, a condition called hyperhomocysteinemia (HHcy). Animal models of CBS deficiency have provided invaluable insights into the pathological effects of transsulfuration impairment and of both mild and severe HHcy. However, studies have also highlighted the complexity of HHcy and the need to explore the specific details of Hcy metabolism in addition to Hcy levels per se. There has been a relative paucity of work addressing the dysfunctional H(2)S production in CBS deficiency that may contribute to, or even create, HHcy-associated pathologies. Experiments using CBS knockout mice, both homozygous (-/-) and heterozygous (+/-), have provided 15 years of new knowledge and are the focus of this review. These murine models present the opportunity to study a specific mechanism for HHcy that matches one of the etiologies in many human patients. Therefore, the goal of this review was to integrate and highlight the critical information gained thus far from models of CBS deficiency and draw attention to critical gaps in knowledge, with particular emphasis on the modulation of H(2)S metabolism. We include findings from human and animal studies to identify important opportunities for future investigation that should be aimed at generating new basic and clinical understanding of the role of CBS and transsulfuration in cardiovascular and neurovascular disease. PMID:20971760

Beard, Richard S; Bearden, Shawn E

2011-01-01

339

Predicted regional flux of hydrogen sulfide correlates with distribution of nasal olfactory lesions in rats.  

PubMed

Hydrogen sulfide (H(2)S) is a toxic gas that is released by both natural and industrial sources. H(2)S selectively targets the olfactory system in humans and rodents. The purpose of this study was to test the hypothesis that the distribution of H(2)S-induced nasal pathology is correlated with the location of high-flux areas within the upper respiratory tract. To investigate whether the location of the olfactory lesion is dependent on regional gas uptake patterns, a comparison was made between lesion locations and regions of high H(2)S flux predicted using a 3-dimensional, anatomically accurate computational fluid dynamics (CFD) model of rat nasal passages. Rats were exposed by inhalation to 0, 10, 30, or 80 ppm H(2)S for 6 h/day for 70 days. The regional incidence of olfactory lesions and predicted H(2)S flux were determined at the mid-dorsomedial meatus and the middle portion of the ethmoid recess, and their rank correlation was evaluated. At these 2 levels, regions lined by respiratory epithelium were predicted to exhibit the highest mass flux values; however, H(2)S exposure elicited little or no response in this tissue. In contrast, regions lined by olfactory epithelium showed a close correlation between H(2)S flux and lesion incidence (p < 0.005) for both the 30 and 80-ppm exposure groups. These results indicate that airflow-driven patterns of H(2)S uptake within the inherently sensitive olfactory epithelium play an important role in the distribution of H(2)S-induced lesions and should therefore be taken into consideration when extrapolating from nasal lesions in rats to estimates of risk to human health. PMID:11861968

Moulin, Frederic J-M; Brenneman, Karrie A; Kimbell, Julia S; Dorman, David C

2002-03-01

340

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

PubMed

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

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

2000-01-01

341

Passive monitors to measure hydrogen sulfide near concentrated animal feeding operations  

PubMed Central

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-hr 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-hr average) suggest that enforcement actions are needed to mitigate H2S migration from swine CAFOs. PMID:23681048

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

2014-01-01

342

Effects of Hydrogen Sulfide-releasing l-DOPA Derivatives on Glial Activation  

PubMed Central

The main lesion in Parkinson disease (PD) is loss of substantia nigra dopaminergic neurons. Levodopa (l-DOPA) is the most widely used therapy, but it does not arrest disease progression. Some possible contributing factors to the continuing neuronal loss are oxidative stress, including oxidation of l-DOPA, and neurotoxins generated by locally activated microglia and astrocytes. A possible method of reducing these factors is to produce l-DOPA hybrid compounds that have antioxidant and antiinflammatory properties. Here we demonstrate the properties of four such l-DOPA hybrids based on coupling l-DOPA to four different hydrogen sulfide-donating compounds. The donors themselves were shown to be capable of conversion by isolated mitochondria to H2S or equivalent SH? ions. This capability was confirmed by in vivo results, showing a large increase in intracerebral dopamine and glutathione after iv administration in rats. When human microglia, astrocytes, and SH-SY5Y neuroblastoma cells were treated with these donating agents, they all accumulated H2S intracellularly as did their derivatives coupled to l-DOPA. The donating agents and the l-DOPA hybrids reduced the release of tumor necrosis factor-?, interleukin-6, and nitric oxide from stimulated microglia, astrocytes as well as the THP-1 and U373 cell lines. They also demonstrated a neuroprotective effect by reducing the toxicity of supernatants from these stimulated cells to SH-SY5Y cells. l-DOPA itself was without effect in any of these assays. The H2S-releasing l-DOPA hybrid molecules also inhibited MAO B activity. They may be useful for the treatment of PD because of their significant antiinflammatory, antioxidant, and neuroprotective properties. PMID:20368333

Lee, Moonhee; Tazzari, Valerio; Giustarini, Daniela; Rossi, Ranieri; Sparatore, Anna; Del Soldato, Piero; McGeer, Edith; McGeer, Patrick L.

2010-01-01

343

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

PubMed Central

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

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

2015-01-01

344

Selective Catalytic Oxidation of Hydrogen Sulfide to Elemental Sulfur from Coal-Derived Fuel Gases  

SciTech Connect

The development of low cost, highly efficient, desulfurization technology with integrated sulfur recovery remains a principle barrier issue for Vision 21 integrated gasification combined cycle (IGCC) power generation plants. In this plan, the U. S. Department of Energy will construct ultra-clean, modular, co-production IGCC power plants each with chemical products tailored to meet the demands of specific regional markets. The catalysts employed in these co-production modules, for example water-gas-shift and Fischer-Tropsch catalysts, are readily poisoned by hydrogen sulfide (H{sub 2}S), a sulfur contaminant, present in the coal-derived fuel gases. To prevent poisoning of these catalysts, the removal of H{sub 2}S down to the parts-per-billion level is necessary. Historically, research into the purification of coal-derived fuel gases has focused on dry technologies that offer the prospect of higher combined cycle efficiencies as well as improved thermal integration with co-production modules. Primarily, these concepts rely on a highly selective process separation step to remove low concentrations of H{sub 2}S present in the fuel gases and produce a concentrated stream of sulfur bearing effluent. This effluent must then undergo further processing to be converted to its final form, usually elemental sulfur. Ultimately, desulfurization of coal-derived fuel gases may cost as much as 15% of the total fixed capital investment (Chen et al., 1992). It is, therefore, desirable to develop new technology that can accomplish H{sub 2}S separation and direct conversion to elemental sulfur more efficiently and with a lower initial fixed capital investment.

Gardner, Todd H.; Berry, David A.; Lyons, K. David; Beer, Stephen K.; Monahan, Michael J.

2001-11-06

345

Protective effect of hydrogen sulfide against cold restraint stress-induced gastric mucosal injury in rats.  

PubMed

Hydrogen sulfide (H2S) is an endogenous gaseous mediator plays a potential role in modulating gastric inflammatory responses. However, its putative protective role remains to be defined. The present study aimed to evaluate role of the exogenously released and endogenously synthesized H2S in cold restraint stress (CRS)-induced oxidative gastric damage in rats. Rats were restrained, and maintained at 4 °C for 3 h. The H2S donor, sodium hydrosulfide (NaHS) (60 ?mol/kg) was injected intraperitoneally (i.p.) before CRS. Our results revealed that NaHS pretreatment significantly attenuated ulcer index, free and total acid output, and pepsin activity in gastric juice along with decreased gastric mucosal carbonyl content and reactive oxygen species production. This was accompanied by increased gastric juice pH and mucin concentration in addition to restoring the deficits in the gastric reduced glutathione, catalase as well as superoxide dismutase enzyme activities. NaHS pretreatment markedly reduced the serum level of tumor necrosis factor (TNF-?) and myeloperoxidase activity compared to CRS-non-treated. Moreover, NaHS preadministration significantly abrogated the inflammatory and the deleterious responses of gastric mucosa in CRS. The protective effects of H2S were confirmed by gastric histopathological examination. However, pretreatment with the H2S-synthesizing enzyme, cystathionine-gamma-lyase inhibitor, beta-cyano-L-alanine (50 mg/kg, i.p.) reversed the gastroprotection afforded by the endogenous H2S. Collectively, our results suggest that H2S can protect rat gastric mucosa against CRS-induced gastric ulceration possibly through mechanisms that involve anti-oxidant and anti-inflammatory actions alongside enhancement of gastric mucosal barrier and reduction in acid secretory parameters. PMID:23812778

Aboubakr, Esam M; Taye, Ashraf; El-Moselhy, Mohamed A; Hassan, Magdy K

2013-12-01

346

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

PubMed

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

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

2014-12-01

347

Hydrogen Sulfide Increases Nitric Oxide Production and Subsequent S-Nitrosylation in Endothelial Cells  

PubMed Central

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

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

2014-01-01

348

Endogenous hydrogen sulfide mediates the cardioprotection induced by ischemic postconditioning in the early reperfusion phase  

PubMed Central

Hydrogen sulfide (H2S), produced by cystanthionine-?-lysase (CSE) in the cardiovascular system, has been suggested to be the third gasotransmitter in addition to nitric oxide (NO) and carbon monoxide (CO). The present study aimed to investigate the role of H2S in ischemic postconditioning (IPO) during the early period of reperfusion. IPO with 6 episodes of 10 sec reperfusion followed by 6 episodes of 10 sec ischemia (IPO 2’) was administered when reperfusion was initiated. Cardiodynamics and the concentration of H2S were measured at 1, 2, 3, 4, 5, 10, 20, 30, 60, 90 and 120 min of reperfusion. Lactate dehydrogenase (LDH) levels and infarct size were determined at the end of the reperfusion. The concentration of H2S was stable during the whole experiment in the control group, whereas it reached a peak at the first minute of reperfusion in the ischemia-reperfusion (IR) group. The concentration of H2S at the first minute of reperfusion in the IPO 2’ group was higher compared to that of the IR group, which correlated with cardioprotection including improved heart contractile function and reduced infarct size and LDH levels. However, the above effects of IPO 2’ were attenuated by pre-treatment with blockade of endogenous H2S production with DL-propargylglycine for 20 min prior to global ischemia. Furthermore, we found that other forms of IPO, IPO commencing at 1 min after reperfusion (delayed IPO) or lasting only for 1 min (IPO 1’), failed to increase the concentration of H2S and protect the myocardium. We conclude that the peak of endogenous H2S in the early reperfusion phase is the key to cardioprotection induced by IPO. PMID:23226785

HUANG, YI-E; TANG, ZHI-HAN; XIE, WEI; SHEN, XIN-TIAN; LIU, MI-HUA; PENG, XIANG-PING; ZHAO, ZHAN-ZHI; NIE, DE-BO; LIU, LU-SHAN; JIANG, ZHI-SHENG

2012-01-01

349

Cytoprotective Effects of Hydrogen Sulfide in Novel Rat Models of Non-Erosive Esophagitis  

PubMed Central

Non-erosive esophagitis is a chronic inflammatory condition of the esophagus and is a form of gastroesophageal reflux disease. There are limited treatment options for non-erosive esophagitis, and it often progresses to Barrett’s esophagus and esophageal carcinoma. Hydrogen sulfide has been demonstrated to be a critical mediator of gastric and intestinal mucosal protection and repair. However, roles for H2S in esophageal mucosal defence, inflammation and responses to injury have not been reported. We therefore examined the effects of endogenous and exogenous H2S in rat models of non-erosive esophagitis. Mild- and moderate-severity non-erosive esophagitis was induced in rats through supplementation of drinking water with fructose, plus or minus exposure to water-immersion stress. The effects of inhibitors of H2S synthesis or of an H2S donor on severity of esophagitis was then examined, along with changes in serum levels of a pro- and an anti-inflammatory cytokine (IL-17 and IL-10, respectively). Exposure to water-immersion stress after consumption of the fructose-supplemented water for 28 days resulted in submucosal esophageal edema and neutrophil infiltration and the development of lesions in the muscular lamina and basal cell hyperplasia. Inhibition of H2S synthesis resulted in significant exacerbation of inflammation and injury. Serum levels of IL-17 were significantly elevated, while serum IL-10 levels were reduced. Treatment with an H2S donor significantly reduced the severity of esophageal injury and inflammation and normalized the serum cytokine levels. The rat models used in this study provide novel tools for studying non-erosive esophagitis with a range of severity. H2S contributes significantly to mucosal defence in the esophagus, and H2S donors may have therapeutic value in treating esophageal inflammation and injury. PMID:25333941

Zayachkivska, Oksana; Havryluk, Olena; Hrycevych, Nazar; Bula, Nazar; Grushka, Oksana; Wallace, John L.

2014-01-01

350

Hydrogen sulfide impairs shear stress-induced vasodilation in mouse coronary arteries.  

PubMed

Hydrogen sulfide has emerged as an important endothelium-dependent vasodilator, but its role in shear stress-mediated dilation of coronary arteries is unclear. We examined the role of H2S on shear stress-mediated dilation of isolated mouse coronary arteries. In these vessels, Na2S produced concentration-dependent dilation, which was significantly inhibited by iberiotoxin and by 4-aminopyridine. In addition, BK and Kv currents in mouse coronary smooth muscle cells were directly activated by Na2S, suggesting that H2S produced vasodilation through BK and Kv channel activation. Using a pressure servo controller system, freshly isolated mouse coronary arteries were subjected to physiological levels of shear stress (1 to 25 dynes/cm(2)) and produced graded dilatory responses, but such effects were diminished in the presence of 100 ?M Na2S. Pre-incubation with the cystathionine ?-lyase inhibitor, D,L-propargylglycine (PPG), resulted in a paradoxical augmentation of shear stress-mediated vasodilation. However, in the presence of L-NAME or in coronary arteries from eNOS knockout mice, PPG inhibited shear stress-mediated vasodilation, suggesting an interaction between NO and H2S signaling. Na2S inhibited eNOS activity in cultured mouse aortic endothelial cells and reduced the level of phospho-eNOS(serine 1177). These results suggest that both NO and H2S are important shear stress-mediated vasodilators in mouse coronary arteries but there is a complex interaction between these two signaling pathways that results in paradoxical vasoconstrictive effects of H2S through inhibition of NO generation. PMID:24793048

Chai, Qiang; Lu, Tong; Wang, Xaio-Li; Lee, Hon-Chi

2015-02-01

351

Effects of pH and Lactate on Hydrogen Sulfide Production by Oral Veillonella spp.  

PubMed Central

Indigenous oral bacteria in the tongue coating such as Veillonella have been identified as the main producers of hydrogen sulfide (H2S), one of the major components of oral malodor. However, there is little information on the physiological properties of H2S production by oral Veillonella such as metabolic activity and oral environmental factors which may affect H2S production. Thus, in the present study, the H2S-producing activity of growing cells, resting cells, and cell extracts of oral Veillonella species and the effects of oral environmental factors, including pH and lactate, were investigated. Type strains of Veillonella atypica, Veillonella dispar, and Veillonella parvula were used. These Veillonella species produced H2S during growth in the presence of l-cysteine. Resting cells of these bacteria produced H2S from l-cysteine, and the cell extracts showed enzymatic activity to convert l-cysteine to H2S. H2S production by resting cells was higher at pH 6 to 7 and lower at pH 5. The presence of lactate markedly increased H2S production by resting cells (4.5- to 23.7-fold), while lactate had no effect on enzymatic activity in cell extracts. In addition to H2S, ammonia was produced in cell extracts of all the strains, indicating that H2S was produced by the catalysis of cystathionine ?-lyase (EC 4.4.1.1). Serine was also produced in cell extracts of V. atypica and V. parvula, suggesting the involvement of cystathionine ?-synthase lyase (EC 4.2.1.22) in these strains. This study indicates that Veillonella produce H2S from l-cysteine and that their H2S production can be regulated by oral environmental factors, namely, pH and lactate. PMID:24795374

Washio, Jumpei; Shimada, Yuko; Yamada, Masakazu; Sakamaki, Ryouichi

2014-01-01

352

Hydrogen sulfide upregulates heme oxygenase-1 expression in rats with volume overload-induced heart failure  

PubMed Central

The present study investigated the role of hydrogen sulfide (H2S), a novel gaseous transmitter, in chronic heart failure (CHF) induced by left-to-right shunt, leading to volume overload. Thirty male Sprague-Dawley rats were randomly divided into four groups: the shunt group, the sham group, the shunt + sodium hydrosulfide (NaHS) group and the sham + NaHS group. CHF was induced in the rats by abdominal aorta-inferior vena cava shunt operation. Rats in the shunt + NaHS and sham + NaHS groups were injected intraperitoneally with NaHS (H2S donor). Haemodynamic parameters were measured 8 weeks after surgery. In addition, left ventricular heme oxygenase (HO)-1 mRNA expression was measured by real-time PCR. Protein expression of HO-1 was evaluated by western blot analysis. Eight weeks after surgery, compared to the sham group, the left ventricular systolic pressure (LVSP) and left ventricular peak rate of contraction and relaxation (LV±dp/dtmax) were significantly reduced; the left ventricular end-diastolic pressure (LVEDP) was significantly increased in the shunt group (all P<0.05). However, NaHS increased LVSP and LV±dp/dtmax (all P<0.05) and decreased LVEDP (P<0.05). Protein expression of HO-1 was significantly decreased in the shunt group compared to that in the sham group (P<0.05). NaHS increased protein expression of HO-1 compared to that in the shunt group (P<0.05). HO-1 mRNA expression was significantly increased in the shunt + NaHS group compared to that in the shunt group (P<0.01). The present study demonstrated that H2S may play a protective role in volume overload-induced CHF by upregulating protein and mRNA expression of HO-1. PMID:24648967

ZHANG, CHAO-YING; LI, XIAO-HUI; ZHANG, TING; FU, JIN; CUI, XIAO-DAI

2013-01-01

353

Selenium inhibits root elongation by repressing the generation of endogenous hydrogen sulfide in Brassica rapa.  

PubMed

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

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

2014-01-01

354

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

PubMed

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

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

2014-12-01

355

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

NASA Astrophysics Data System (ADS)

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

Hubert, Casey R. J.

356

Quantitative evaluation of hydrogen sulfide at 0.3 M and 1.0 M-hydrogen-ion concentration  

E-print Network

insoluble in dilute acids are generally referred to as Group II cations and consist of antimony (III-V), arsenic (III-V), bismuth (III), cadmium (II), copper (II), lead (II), mercury (II), and tin (II-IV). Those forming hydroxides and sulfides soluble...* The copper (II) sulfide, precipitated from a dilute acid solution, was decomposed with nitric acid and sulfuric acid. Nitric acid was separated from the filtrate by evaporation, and the copper was electrodeposited from a dilute acid solution. The mixed...

Machel, Albert R.

1958-01-01

357

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

SciTech Connect

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.

Módis, Katalin [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)] [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States); Asimakopoulou, Antonia [Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Patras (Greece)] [Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Patras (Greece); Coletta, Ciro [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)] [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States); Papapetropoulos, Andreas [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States) [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States); Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Patras (Greece); Szabo, Csaba, E-mail: szabocsaba@aol.com [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)] [Department of Anesthesiology, University of Texas Medical Branch and Shriners Burns Hospital for Children, Galveston, TX (United States)

2013-04-19

358

Nile-red and Nile-blue-based near-infrared fluorescent probes for in-cellulo imaging of hydrogen sulfide.  

PubMed

Hydrogen sulfide has recently been identified as a biologically responsive species. The design and synthesis of fluorescence probes, which are constructed with Nile-red or Nile-blue fluorophores and a fluorescence-controllable dinitrophenyl group, for hydrogen sulfide are reported in this paper. The Nile-red-dinitrophenyl-ether-group-based probe (1a) is essentially non-fluorescent because of the inhibition of the photo-induced electron-transfer process; when the dinitrobenzene moiety is removed by nucleophilic substitution with the hydrosulfide anion, probe 1a is converted into hydroxy Nile red, eliciting a H2S-induced fluorescence turn-on signal. Furthermore, probe 1a has high selectivity and sensitivity for the hydrosulfide anion, and its potential for biological applications was confirmed by using it for real-time fluorescence imaging of hydrogen sulfide in live HeLa cells. The Nile-blue-dinitrobenzene-based probe (1b) has gradually diminishing brightness in the red-emission channel with increased hydrogen-sulfide concentration. Thus, this paper reports a comparative study of Nile-red and Nile-blue-based hydrogen-sulfide probes. PMID:25258280

Liu, Xiao-Dong; Fan, Chen; Sun, Ru; Xu, Yu-Jie; Ge, Jian-Feng

2014-11-01

359

Degradation of the pipe-steel structure upon long-term operation in contact with a hydrogen sulfide-containing medium  

Microsoft Academic Search

The phase composition and structure of defect portions of pipelines after long-term service in contact with a hydrogen sulfide-containing\\u000a medium have been investigated. From structural changes, the process of the initiation of cracks and fracture of a low-carbon\\u000a ferritic-pearlitic steel containing slag-induced laminations and precipitates of sulfides of the (Fe,Mn)S type has been reconstructed.\\u000a The conditions under which a block

V. M. Schastlivtsev; T. I. Tabatchnikova; N. A. Tereshchenko; I. L. Yakovleva

2011-01-01

360

Mechanism of action of hydrogen sulfide on cyclic AMP formation in rat retinal pigment epithelial cells.  

PubMed

Hydrogen sulfide (H(2)S), a colorless gas with the pungent odor of rotten eggs has been reported to produce pharmacological actions in ocular and non-ocular tissues. We have evidence that H(2)S, using sodium hydrosulfide (NaHS) and sodium sulfide (Na(2)S) as donors can increase cyclic AMP (cAMP) production in neural retina. In the present study, we investigated the mechanism of action of H(2)S on cyclic nucleotide production in rat retinal pigment epithelial cells (RPE-J). Cultured RPE-J cells were incubated for 30 min in culture medium containing the cyclic nucleotide phosphodiesterase (PDE) inhibitor, IBMX (2 mM). Cells were exposed to varying concentrations of NaHS, the H(2)S substrate (L-cysteine), cyclooxygenase (COX) inhibitors or the diterpene activator of adenylate cyclase, forskolin in the presence or absence of H(2)S biosynthetic enzymes or the ATP-sensitive potassium (K(ATP)) channel antagonist, glibenclamide. Following drug-treatment at different time intervals, cell homogenates were prepared for cAMP assay using a well established methodology. In RPE-J cells, NaHS (10 nM-1 ?M) produced a time-dependent increase in cAMP concentrations over basal levels which reached a maximum at 20 min. At this time point, both NaHS (1 nM-100 ?M) and L-cysteine (1 nM-10 ?M) produced a concentration-dependent significant (p<0.05) increase in cAMP concentrations over basal level. The effects of NaHS on cAMP levels in RPE-J cells was enhanced significantly (p<0.01) in the presence of the COX inhibitors, indomethacin and flurbiprofen. In RPE-J cells, the effects caused by forskolin (10 ?M) on cAMP production were potentiated by addition of low concentrations of NaHS. Both the inhibitor of cystathionine ?-synthase (CBS), aminooxyacetic acid (AOA, 1 mM) and the inhibitor of cystathionine ?-lyase (CSE), proparglyglycine (PAG, 1mM) significantly attenuated the increased effect of L-cysteine on cAMP production. The K(ATP) channel antagonist, glibenclamide (100 ?M) caused inhibition of NaHS induced-increase of cAMP formation in RPE-J cells. We conclude that, H(2)S (using H(2)S donor and substrate) can increase cAMP production in RPE-J cells, and removal of the apparent inhibitory effect of prostaglandins unmasks an excitatory activity of H(2)S on cAMP. Effects elicited by the H(2)S substrate on cAMP formation are dependent on biosynthesis of H(2)S catalyzed by the biosynthetic enzymes, CBS and CSE. In addition to the adenylyl cylcase pathway, K(ATP) channels are involved in mediating the observed effects of the H(2)S on cAMP production. PMID:22445555

Njie-Mbye, Ya Fatou; Kulkarni, Madhura; Opere, Catherine A; Ohia, Sunny E

2012-05-01

361

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

PubMed

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

Riesch, Rüdiger; Plath, Martin; Schlupp, Ingo

2010-05-01

362

[Hydrogen and oxygen isotopes of lake water and geothermal spring water in arid area of south Tibet].  

PubMed

The condition of water cycles in Tibet Plateau is a complex process, and the hydrogen and oxygen isotopes contain important information of this process. Based on the analysis of isotopic composition of freshwater lake, saltwater lake and geothermal water in the southern Tibetan Plateau, this study investigated water cycling, composition and variation of hydrogen and oxygen isotopes and the influencing factors in the study area. The study found that the mean values of delta18O and deltaD in Daggyaima lake water (-17.0 per thousand for delta18O and -138. 6 per thousand for deltaD), Langcuo lake water (-6.4 per thousand for delta18O and -87.4 per thousand for deltaD) and Dagejia geothermal water (-19.2 per thousand for delta18 and -158.2 per thousand for deltaD) all showed negative delta18O and deltaD values in Tibetan Plateau by the influence of altitude effects. Lake water and geothermal water were influenced by evaporation effects in inland arid area, and the slope of evaporation line was less than 8. Deuterium excess parameters of lake water and geothermal water were all negative. The temperature of geothermal reservoirs in Dagejia geothermal field was high,and oxygen shift existed in the relationship of hydrogen and oxygen isotopes. PMID:25338365

Xiao, Ke; Shen, Li-Cheng; Wang, Peng

2014-08-01

363

Annexin A1 Mediates Hydrogen Sulfide Properties in the Control of InflammationS  

PubMed Central

Hydrogen sulfide (H2S) is a gaseous mediator synthesized in mammalian tissues by three main enzymes—cystathionine-?-synthase (CBS), cystathionine-?-lyase (CSE), and 3-mercaptopyruvate-sulfurtransferase—and its levels increase under inflammatory conditions or sepsis. Since H2S and H2S-releasing molecules afford inhibitory properties in leukocyte trafficking, we tested whether endogenous annexin A1 (AnxA1), a glucocorticoid-regulated inhibitor of inflammation acting through formylated-peptide receptor 2 (ALX), could display intermediary functions in the anti-inflammatory profile of H2S. We first investigated whether endogenous AnxA1 could modulate H2S biosynthesis. To this end, a marked increase in CBS and/or CSE gene products was quantified by quantitative real-time polymerase chain reaction in aortas, kidneys, and spleens collected from AnxA1?/? mice, as compared with wild-type animals. When lipopolysaccharide-stimulated bone marrow-derived macrophages were studied, H2S-donor sodium hydrosulfide (NaHS) counteracted the increased expression of inducible nitric oxide synthase and cyclooxygenase 2 mRNA evoked by the endotoxin, yet it was inactive in macrophages harvested from AnxA1?/? mice. Next we studied the effect of in vivo administration of NaHS in a model of interleukin-1? (IL-1?)–induced mesenteric inflammation. AnxA1+/+ mice treated with NaHS (100 ?mol/kg) displayed inhibition of IL-1?-induced leukocyte adhesion/emigration in the inflamed microcirculation, not observed in AnxA1?/? animals. These results were translated by testing human neutrophils, where NaHS (10–100 ?M) prompted an intense mobilization (>50%) of AnxA1 from cytosol to cell surface, an event associated with inhibition of cell/endothelium interaction under flow. Taken together, these data strongly indicate the existence of a positive interlink between AnxA1 and H2S pathway, with nonredundant functions in the control of experimental inflammation. PMID:25077524

Brancaleone, Vincenzo; Mitidieri, Emma; Flower, Roderick J.; Cirino, Giuseppe; Perretti, Mauro

2014-01-01

364

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

SciTech Connect

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.

Pei, Yanxi [Department of Biology, Lakehead University, Thunder Bay (Canada) [Department of Biology, Lakehead University, Thunder Bay (Canada); College of Life Science, Shanxi University, Taiyuan (China); Wu, Bo [Department of Biology, Lakehead University, Thunder Bay (Canada) [Department of Biology, Lakehead University, Thunder Bay (Canada); Department of Pathophysiology, Harbin Medical University, Harbin (China); Cao, Qiuhui [Department of Biology, Lakehead University, Thunder Bay (Canada)] [Department of Biology, Lakehead University, Thunder Bay (Canada); Wu, Lingyun [Department of Pathophysiology, Harbin Medical University, Harbin (China) [Department of Pathophysiology, Harbin Medical University, Harbin (China); Department of Pharmacology, University of Saskatchewan, Saskatoon (Canada); Yang, Guangdong, E-mail: gyang@lakeheadu.ca [The School of Kinesiology, Lakehead University, Thunder Bay (Canada)] [The School of Kinesiology, Lakehead University, Thunder Bay (Canada)

2011-12-15

365

Hydrogen sulfide slows down progression of experimental Alzheimer's disease by targeting multiple pathophysiological mechanisms.  

PubMed

It has been previously reported that brain hydrogen sulfide (H2S) synthesis is severely decreased in Alzheimer's disease (AD) patients, and plasma H2S levels are negatively correlated with the severity of AD. Here we extensively investigated whether treatment with a H2S donor and spa-waters rich in H2S induces neuroprotection and slows down progression of AD. Studies with sodium hydrosulfide (a H2S donor) and Tabiano's spa-water were carried out in three experimental models of AD. Short-term and long-term treatments with sodium hydrosulfide and/or Tabiano's spa-water significantly protected against impairment in learning and memory in rat models of AD induced by brain injection of ?-amyloid1-40 (A?) or streptozotocin, and in an AD mouse model harboring human transgenes APPSwe, PS1M146V and tauP301L (3xTg-AD mice). The improvement in behavioral performance was associated with hippocampus was size of A? plaques and preservation of the morphological picture, as found in AD rats. Further, lowered concentration/phosphorylation levels of proteins thought to be the central events in AD pathophysiology, namely amyloid precursor protein, presenilin-1, A?1-42 and tau phosphorylated at Thr181, Ser396 and Ser202, were detected in 3xTg-AD mice treated with spa-water. The excitotoxicity-triggered oxidative and nitrosative stress was counteracted in 3xTg-AD mice, as indicated by the decreased levels of malondialdehyde and nitrites in the cerebral cortex. Hippocampus reduced activity of c-jun N-terminal kinases, extracellular signal-regulated kinases and p38, which have an established role not only in phosphorylation of tau protein but also in inflammation and apoptosis, was also found. Consistently, decrease in tumor necrosis factor-? level, up-regulation of Bcl-2, and down-regulation of BAX and the downstream executioner caspase-3, also occurred in the hippocampus of 3xTg-AD mice after treatment with Tabiano's spa-water, thus suggesting that it is also able to modulate inflammation and apoptosis. Our findings indicate that appropriate treatments with H2S donors and Tabiano's spa-waters, and may be other spa-waters rich in H2S content, might represent an innovative approach to slow down AD progression in humans by targeting multiple pathophysiological mechanisms. PMID:23726868

Giuliani, Daniela; Ottani, Alessandra; Zaffe, Davide; Galantucci, Maria; Strinati, Flavio; Lodi, Renzo; Guarini, Salvatore

2013-09-01

366

TRPA1 Has a Key Role in the Somatic Pro-Nociceptive Actions of Hydrogen Sulfide  

PubMed Central

Hydrogen sulfide (H2S), which is produced endogenously from L-cysteine, is an irritant with pro-nociceptive actions. We have used measurements of intracellular calcium concentration, electrophysiology and behavioral measurements to show that the somatic pronociceptive actions of H2S require TRPA1. A H2S donor, NaHS, activated TRPA1 expressed in CHO cells and stimulated DRG neurons isolated from Trpa1+/+ but not Trpa1?/? mice. TRPA1 activation by NaHS was pH dependent with increased activity at acidic pH. The midpoint of the relationship between NaHS EC50 values and external pH was pH 7.21, close to the expected dissociation constant for H2S (pKa 7.04). NaHS evoked single channel currents in inside-out and cell-attached membrane patches consistent with an intracellular site of action. In behavioral experiments, intraplantar administration of NaHS and L-cysteine evoked mechanical and cold hypersensitivities in Trpa1+/+ but not in Trpa1?/? mice. The sensitizing effects of L-cysteine in wild-type mice were inhibited by a cystathionine ?-synthase inhibitor, D,L-propargylglycine (PAG), which inhibits H2S formation. Mechanical hypersensitivity evoked by intraplantar injections of LPS was prevented by PAG and the TRPA1 antagonist AP-18 and was absent in Trpa1?/? mice, indicating that H2S mediated stimulation of TRPA1 is necessary for the local pronociceptive effects of LPS. The pro-nociceptive effects of intraplantar NaHS were retained in Trpv1?/? mice ruling out TRPV1 as a molecular target. In behavioral studies, NaHS mediated sensitization was also inhibited by a T-type calcium channel inhibitor, mibefradil. In contrast to the effects of NaHS on somatic sensitivity, intracolonic NaHS administration evoked similar nociceptive effects in Trpa1+/+ and Trpa1?/? mice, suggesting that the visceral pro-nociceptive effects of H2S are independent of TRPA1. In electrophysiological studies, the depolarizing actions of H2S on isolated DRG neurons were inhibited by AP-18, but not by mibefradil indicating that the primary excitatory effect of H2S on DRG neurons is TRPA1 mediated depolarization. PMID:23071662

Andersson, David A.; Gentry, Clive; Bevan, Stuart

2012-01-01

367

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

PubMed Central

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.

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

2015-01-01

368

Removing hydrogen sulfide from wastewater treatment facilities` air process streams with a biotrickling filter  

SciTech Connect

Control of hydrogen sulfide (H{sub 2}S) and odor emissions has been a major consideration for many wastewater treatment plants. Many different methods have been and are currently being used for H{sub 2}S and odor control. Most of the current methods involve absorption of H{sub 2}S and odors into a liquid solution or adsorption onto a solid matrix. These methods are either expensive or if not operated correctly can be inefficient. The Los Angeles County Sanitation Districts have developed a biological method to remove odors and H{sub 2}S from different off-gas streams at its main wastewater treatment plant, the Joint Water Pollution Control Plant (JWPCP). This treatment method, which is known as a biotrickling filter, uses a packed contactor device in which the air to be treated is blown through the packing. The H{sub 2}S and odor is removed by a scrubbing solution containing bacteria that is trickled down from the top of the contactor. Different types of column packing media were tested, with a rock-based media being the most effective. The rock media allowed the biotrickling filter to get over 98 percent removal of inlet H{sub 2}S, as long as H{sub 2}S loadings did not exceed 39 g-H{sub 2}S/m{sup 3}-hr (1.1 g-H{sub 2}S/ft{sup 3}-hr). Odor panel analyses indicated that inlet odors were reduced by 99 percent by the biotrickling filter. Due to the success of the research work, a full scale biotrickling filter is being put into operation at the JWPCP. The unit will replace existing caustic scrubbers and will be much less expensive to operate. Current costs to operate a caustic scrubber at the JWPCP is about $1,150 per million m{sup 3} ($33.00 per million ft3) of air treated. The biotrickling filter operational costs would be about one-fifth or $240 per million m{sup 3} ($7.00 per million ft{sup 3}) of air treated.

Morton, R.L.; Caballero, R.C. [County Sanitation Districts of Los Angeles County, Carson, CA (United States)

1997-12-31

369

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

PubMed Central

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

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

370

Annexin A1 mediates hydrogen sulfide properties in the control of inflammation.  

PubMed

Hydrogen sulfide (H2S) is a gaseous mediator synthesized in mammalian tissues by three main enzymes-cystathionine-?-synthase (CBS), cystathionine-?-lyase (CSE), and 3-mercaptopyruvate-sulfurtransferase-and its levels increase under inflammatory conditions or sepsis. Since H2S and H2S-releasing molecules afford inhibitory properties in leukocyte trafficking, we tested whether endogenous annexin A1 (AnxA1), a glucocorticoid-regulated inhibitor of inflammation acting through formylated-peptide receptor 2 (ALX), could display intermediary functions in the anti-inflammatory profile of H2S. We first investigated whether endogenous AnxA1 could modulate H2S biosynthesis. To this end, a marked increase in CBS and/or CSE gene products was quantified by quantitative real-time polymerase chain reaction in aortas, kidneys, and spleens collected from AnxA1(-/-) mice, as compared with wild-type animals. When lipopolysaccharide-stimulated bone marrow-derived macrophages were studied, H2S-donor sodium hydrosulfide (NaHS) counteracted the increased expression of inducible nitric oxide synthase and cyclooxygenase 2 mRNA evoked by the endotoxin, yet it was inactive in macrophages harvested from AnxA1(-/-) mice. Next we studied the effect of in vivo administration of NaHS in a model of interleukin-1? (IL-1?)-induced mesenteric inflammation. AnxA1(+/+) mice treated with NaHS (100 ?mol/kg) displayed inhibition of IL-1?-induced leukocyte adhesion/emigration in the inflamed microcirculation, not observed in AnxA1(-/-) animals. These results were translated by testing human neutrophils, where NaHS (10-100 ?M) prompted an intense mobilization (>50%) of AnxA1 from cytosol to cell surface, an event associated with inhibition of cell/endothelium interaction under flow. Taken together, these data strongly indicate the existence of a positive interlink between AnxA1 and H2S pathway, with nonredundant functions in the control of experimental inflammation. PMID:25077524

Brancaleone, Vincenzo; Mitidieri, Emma; Flower, Roderick J; Cirino, Giuseppe; Perretti, Mauro

2014-10-01

371

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

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.

Mashapa, T.N.; Rademan, J.D.; van Vuuren, M.J.J. [Sasol Technology Research & Development, Sasolburg (South Africa)

2007-09-15

372

Black carbon-mediated destruction of nitroglycerin and RDX by hydrogen sulfide.  

PubMed

The in situ remediation of sediments contaminated with explosives, including nitroglycerin and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), is desirable, particularly at bombing ranges where unexploded ordnance (UXO) renders excavation dangerous. Sulfides generated by biological sulfate reduction in sediments are potent nucleophiles and reductants that may contribute to the destruction of explosives. However, moderately hydrophobic explosives are likely to sorb to black carbons, which can constitute 10-30% of sediment organic carbon. In this study, we evaluated whether the black carbons accelerate these reactions or simply sequester explosives from aqueous phase reactions. Using environmentally-relevant sulfide and black carbon concentrations, our results indicated that black carbons accelerated the destruction of both compounds, yielding relatively harmless products on the time scale of hours. For both compounds, destruction increased with sulfide and graphite concentrations. Using sheet graphite as a model for graphene regions in black carbons, we evaluated whether graphene regions mediated the reduction of explosives by promoting electron transfer from sulfides. Our results demonstrated that the process was more complex. Using an electrochemical cell that enabled electron transfer from sulfides to explosives through graphite, but prevented nucleophilic substitution reactions, we found that nitroglycerin destruction, but not RDX destruction, could be explained by an electron transfer mechanism. Furthermore, surface area-normalized destruction rates for the same explosive varied for different black carbons. While black carbon-mediated destruction of explosives by sulfides is likely to be a significant contributor to their natural attenuation in sediments, a fundamental characterization of the reaction mechanisms is needed to better understand the process. PMID:20704242

Xu, Wenqing; Dana, Kathryn E; Mitch, William A

2010-08-15

373

Hydrogen sulfide mitigates hyperglycemic remodeling via liver kinase B1-adenosine monophosphate-activated protein kinase signaling.  

PubMed

Hyperglycemia (HG) reduces AMPK activation leading to impaired autophagy and matrix accumulation. Hydrogen sulfide (H2S) treatment improves HG-induced renovascular remodeling however, its mechanism remains unclear. Activation of LKB1 by the formation of heterotrimeric complex with STRAD and MO25 is known to activate AMPK. We hypothesized that in HG; H2S induces autophagy and modulates matrix synthesis through AMPK-dependent LKB1/STRAD/MO25 complex formation. To address this hypothesis, mouse glomerular endothelial cells were treated with normal and high glucose in the absence or presence of sodium hydrogen sulfide (NaHS), an H2S donor. HG decreased the expression of H2S regulating enzymes CBS and CSE, and autophagy markers Atg5, Atg7, Atg3 and LC3B/A ratio. HG increased galectin-3 and periostin, markers of matrix accumulation. Treatment with NaHS to HG cells increased LKB1/STRAD/MO25 formation and AMPK phosphorylation. Silencing the encoded genes confirmed complex formation under normoglycemia. H2S-mediated AMPK activation in HG was associated with upregulation of autophagy and diminished matrix accumulation. We conclude that H2S mitigates adverse remodeling in HG by induction of autophagy and regulation of matrix metabolism through LKB1/STRAD/MO25 dependent pathway. PMID:25127936

Kundu, Sourav; Pushpakumar, Sathnur; Khundmiri, Syed J; Sen, Utpal

2014-12-01

374

Biotreatment of refinery spent sulfidic caustics  

SciTech Connect

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.

Sublette, K.L.; Rajganesh, B.; Woolsey, M.; Plato, A. [Univ. of Tulsa, OK (United States)] [and others

1995-12-31

375

Hydrogen sulfide and radon in and over the western North Atlantic Ocean  

NASA Astrophysics Data System (ADS)

The first simultaneous measurements of H2S in air and seawater are presented and used to calculate the direction and magnitude of the air/sea flux for H2S. Measurements of atmospheric radon and carbonyl sulfide in the surface waters are used to examine the sources of H2S in the atmosphere and the surface ocean. A positive correlation between Rn-222 an atmospheric H2S was observed. Both Rn-222 and H2S were high in air masses traced back to North America. Measurements in seawater showed that uncomplexed sulfides are about 13 percent of total sulfide at 2 m depth. Atmospheric H2S and dissolved H2S in seawater were usually not far from saturation equilibrium. These results indicate that the ocean acted at some times as a source of atmospheric H2S but more frequently as a sink. Hydrolysis of COS and atmospheric deposition of H2S may both contribute to the budget of dissolved sulfide in seawater of the western North Atlantic Ocean.

Andreae, T. W.; Andreae, M. O.; Cutter, G. A.; Radford-Knoery, J.; Hussain, N.

1991-10-01

376

Dietary sulfur concentration affects rumen hydrogen sulfide concentrations in feedlot steers during transition and finishing.  

PubMed

Angus steers (n = 96; 321 ± 29 kg BW) were used to determine how previous exposure to increased dietary S would affect ruminal hydrogen sulfide concentrations ([H(2)S]) in the feedlot, to investigate the effects of dietary S on ruminal [H(2)S] during transition and finishing, and to determine if dietary S affects the glutathione status of finishing cattle. Steers were strip-grazed on smooth bromegrass (Bromus inermis L.) over a 35 d period and received a dry distillers grains plus solubles (DDGS) supplement at 1% of BW (DM basis) that contained either 0.50% S (LS; n = 4 plots) or the DDGS supplement with an additional 0.30% S from sodium sulfate (0.80% S in supplement; HS; n = 4 plots). On d 36 steers were moved from the pastures to feedlot pens with one-half of the steers on each treatment in the pasture period remaining on the same treatment during the feedlot period and half being switched to the other treatment (n = 6 pens). For the first 10 d in the feedlot, steers were fed hay ad libitum and 1% BW of the DDGS supplement representing their new treatment, followed by transition to finishing diets. Dietary S of transition and finishing diets were 0.2% to 0.3% S for LS and 0.5% to 0.6% S for HS. No interaction between pasture and feedlot treatment was observed (P ? 0.50), so data for the feedlot period were pooled by feedlot treatment (n = 12 pens). Rumen [H(2)S] were measured on d 35 of the pasture period and on d 46 while receiving ad libitum hay and supplement at 6 h after the feeding of the supplement and after 7 d on each of the 3 transition diets (d 53, 60, and 67) and on d 93, 126, and 155 of the study after receiving the finishing diet for 26, 59, and 88 d at 6 h after feeding. Ruminal [H(2)S] did not differ between treatment while steers were fed the supplement on forage-based diets. However, ruminal [H(2)S] of HS-fed steers was greater (P < 0.05) than LS-fed steers when transition diets and the finishing diets were fed. Relative to S intake, ruminal [H(2)S] increased disproportionally after 26 d on the finishing diet. This was followed by a decrease in [H(2)S] on d 59 of finishing, although S intake was increased (P < 0.05) compared with d 26 of finishing. It appears that factors other than S intake alone contribute to ruminal [H(2)S]. The amount of glutathione in the liver of steers did not differ (P = 0.47) because of dietary S, but the concentration of oxidized glutathione increased (P = 0.03) in HS-fed compared with LS-fed steers, suggesting that the potential for oxidative stress in cattle fed high-S diets may warrant further investigation. PMID:23255818

Drewnoski, M E; Richter, E L; Hansen, S L

2012-12-01

377

Enhanced hydrogen production from biomass via the sulfur redox cycle under hydrothermal conditions  

Microsoft Academic Search

A new method of hydrogen production from biomass via a sulfur redox cycle at moderate temperatures has been proposed. This method, which can utilize excess sulfur from hydrocarbon refining processes and waste or geothermal heat, consists of two half cycles: (1) hydrogen production from an aqueous alkaline solution at subcritical conditions of water, where sulfide, HS? and S2?, acts as

Putri Setiani; Javier Vilcáez; Noriaki Watanabe; Atsushi Kishita; Noriyoshi Tsuchiya

2011-01-01

378

The vitamin B12 analog cobinamide is an effective hydrogen sulfide antidote in a lethal rabbit model  

PubMed Central

Background and purpose Hydrogen sulfide (H2S) is a highly toxic gas for which no effective antidotes exist. It acts, at least in part, by binding to cytochrome c oxidase, causing cellular asphyxiation and anoxia. We investigated the effects of three different ligand forms of cobinamide, a vitamin B12 analog, to reverse sulfide (NaHS) toxicity. Methods New Zealand white rabbits received a continuous intravenous (IV) infusion of NaHS (3 mg/min) until expiration or a maximum 270 mg dose. Animals received six different treatments, administered at the time when they developed signs of severe toxicity: Group 1—saline (placebo group, N = 9); Group 2—IV hydroxocobalamin (N = 7); Group 3—IV aquohydroxocobinamide (N = 6); Group 4—IV sulfitocobinamide (N = 6); Group 5—intramuscular (IM) sulfitocobinamide (N = 6); and Group 6—IM dinitrocobinamide (N = 8). Blood was sampled intermittently, and systemic blood pressure and deoxygenated and oxygenated hemoglobin were measured continuously in peripheral muscle and over the brain region; the latter were measured by diffuse optical spectroscopy (DOS) and continuous wave near infrared spectroscopy (CWNIRS). Results Compared with the saline controls, all cobinamide derivatives significantly increased survival time and the amount of NaHS that was tolerated. Aquohydroxocobinamide was most effective (261.5 ± 2.4 mg NaHS tolerated vs. 93.8 ± 6.2 mg in controls, p < 0.0001). Dinitrocobinamide was more effective than sulfitocobinamide. Hydroxocobalamin was not significantly more effective than the saline control. Conclusions Cobinamide is an effective agent for inhibiting lethal sulfide exposure in this rabbit model. Further studies are needed to determine the optimal dose and form of cobinamide and route of administration. PMID:24716792

BRENNER, M.; BENAVIDES, S.; MAHON, S. B.; LEE, J.; YOON, D.; MUKAI, D.; VISEROI, M.; CHAN, A.; JIANG, J.; NARULA, N.; AZER, S. M.; ALEXANDER, C.; BOSS, G. R.

2014-01-01

379

Target-stimulated metallic HgS nanostructures on a DNA-based polyion complex membrane for highly efficient impedimetric detection of dissolved hydrogen sulfide.  

PubMed

Target-stimulated metallic HgS nanostructures formed on the DNA-based polyion complex (PIC) membrane were for the first time utilized as an efficient scheme for impedimetric detection of hydrogen sulfide (H2S) by coupling insoluble precipitation with sensitivity enhancement. PMID:24150530

Zhuang, Junyang; Fu, Libing; Lai, Wenqiang; Tang, Dianping; Chen, Guonan

2013-12-11

380

Endogenous hydrogen sulfide protects pancreatic beta-cells from a high-fat diet-induced glucotoxicity and prevents the development of type 2 diabetes.  

PubMed

Chronic exposure to high glucose induces the expression of cystathionine gamma-lyase (CSE), a hydrogen sulfide-producing enzyme, in pancreatic beta-cells, thereby suppressing apoptosis. The aim of this study was to examine the effects of hydrogen sulfide on the onset and development of type 2 diabetes. Middle-aged (6-month-old) wild-type (WT) and CSE knockout (CSE-KO) mice were fed a high-fat diet (HFD) for 8weeks. We determined the effects of CSE knockout on beta-cell function and mass in islets from these mice. We also analyzed changes in gene expression in the islets. After 8weeks of HFD, blood glucose levels were markedly increased in middle-aged CSE-KO mice, insulin responses were significantly reduced, and DNA fragmentation of the islet cells was increased. Moreover, expression of thioredoxin binding protein-2 (TBP-2, also known as Txnip) was increased. Administration of NaHS, a hydrogen sulfide donor, reduced TBP-2 gene levels in isolated islets from CSE-KO mice. Gene levels were elevated when islets were treated with the CSE inhibitor dl-propargylglycine (PPG). These results provide evidence that CSE-produced hydrogen sulfide protects beta-cells from glucotoxicity via regulation of TBP-2 expression levels and thus prevents the onset/development of type 2 diabetes. PMID:24246677

Okamoto, Mitsuhiro; Yamaoka, Mami; Takei, Masahiro; Ando, Tomomi; Taniguchi, Shigeki; Ishii, Isao; Tohya, Kazuo; Ishizaki, Toshimasa; Niki, Ichiro; Kimura, Toshihide

2013-12-13

381

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...

382

A Process Based Approach to Modeling Hydrogen Sulfide Emissions Across the Air-Surface Interface of Manure from Concentrated Animal Feeding Operations  

Microsoft Academic Search

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

I. C. Rumsey; V. Aneja

2009-01-01

383

A near-infrared reversible and ratiometric fluorescent probe based on Se-BODIPY for the redox cycle mediated by hypobromous acid and hydrogen sulfide in living cells.  

PubMed

We have developed a near-infrared (NIR) reversible and ratiometric fluorescence sensor based on Se-BODIPY for the redox cycle between hypobromous acid oxidative stress and hydrogen sulfide repair. Real-time imaging shows that the probe is able to monitor intracellular HBrO/H2S redox cycle replacement. PMID:23694993

Wang, Bingshuai; Li, Peng; Yu, Fabiao; Chen, Junsheng; Qu, Zongjin; Han, Keli

2013-06-28

384

Choice of ion-selective electrodes in potentiometric determination of mercaptans and hydrogen sulfide in condensates  

SciTech Connect

Ion-selective electrodes for the potentiometric analysis of sulfur content of high-sulfur gas condensates from fields in the Caspian lowlands and West Siberia were evaluated. The membrane electrodes are based on silver sulfide in combination with tungsten, copper, cadmium, lead, zirconium, and platinum. Tests were also conducted for titrants that form stable compounds with mercaptans as well as for solvents that would be compatible with the condensates and not stratify when the titrants were added. Anion-selective electrodes included iodine-selective, sulfide-selective, and thiocyanate-selective; cation-selective electrodes were cadmium-selective, copper-selective, and lead-selective. The preferred titrant was found to be either a solution of ammoniacal silver nitrate in isopropanol or a solution of silver nitrate in DMFA. Reduction and poisoning behavior along with service life and sensitivity were assessed. The electrodes were field tested and the procedure has been implemented at the Karachaganak field.

Kiyanskii, V.V.; Burakhta, V.A.

1988-05-01

385

Investigation of hydrogen sulfide stress corrosion cracking of PH 13-8 Mo stainless steel  

Microsoft Academic Search

Slow displacement rate tensile tests were carried out in a saturated H2S solution to investigate the effect of hydrogen embrittlement on notched tensile strength (NTS) and fracture characteristics of aged PH 13-8 Mo stainless steel. Hydrogen diffusivity, permeation flux and apparent hydrogen solubility were determined by an electrochemical permeation method, and correlated with the inherent microstructure of the specimens. All

L. W. Tsay; M. Y. Chi; H. R. Chen; C. Chen

2006-01-01

386

A study on the applicability of zinc acetate impregnated silica substrate in the collection of hydrogen sulfide by active sampling.  

PubMed

A novel substrate for the hydrogen sulfide determination in air was developed based on zinc acetate impregnated silica in glass tubes. Collected H2S is quantified by ion chromatography after sulfide oxidation to sulfate in an alkaline solution of H2O2. Laboratory tests were conducted in controlled atmosphere to evaluate uptake rate, linearity, sample stability, influence of relative humidity and interfering gases. A pilot study was also conducted in the field in order to assess the applicability of the substrate and to understand the effect that gases such NO2 and CH4 can have on the efficiency of collection of H2S. The new substrate has shown to have several advantages with respect to the charcoal substrate, that is the one of choice as reported by National Institute of Occupational Safety and Health (NIOSH) method. In particular it does not suffer from sulfur background and it is not influenced by interfering gases such as NO2 and CH4. PMID:25059159

Motta, Oriana; Cucciniello, Raffaele; Scicali, Claudio; Proto, Antonio

2014-10-01

387

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

PubMed

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

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

2013-10-29

388

Mercury methylation and hydrogen sulfide production among unexpected strains isolated from periphyton of two macrophytes of the Amazon.  

PubMed

The periphyton of macrophytes had previously been identified as important spots for mercury methylation in the Amazon basin, but the microorganisms that facilitate methylation in such compartment are still to be identified. Here, bacteria were isolated from periphyton associated with Eichhornia crassipes and Polygonum densiflorum in Widdel and Pfennig medium and tested for mercury methylation with a stable isotope tracer technique using (198)HgCl, hydrogen sulfide production and molybdate inhibition. Three Pleomorphomona spp., one unidentified Deltaproteobacteria, two Klebsiella spp., and one Tolumonas sp. were isolated. All except Tolumonas sp. were able to methylate mercury (up to 5% of the (198)HgCl added) and produce up to 4 mM of H(2)S, while the Deltaproteobacteria was also able to demethylate methylmercury. Although these bacteria may not be as strong mercury methylators as sulfate-reducing bacteria, they have the potential to contribute to methylmercury accumulation in the system. PMID:22329687

Achá, Dario; Pabón, Cecilia A; Hintelmann, Holger

2012-06-01

389

Passive colorimetric dosimeter tubes for ammonia, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen dioxide, and sulfur dioxide  

SciTech Connect

Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an 8-h period for several inorganic airborne contaminants in the range of their threshold limit values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NH/sub 3/), carbon monoxide (CO), carbon dioxide (CO/sub 2/), hydrogen sulfide (H/sub 2/S), nitrogen dioxide (NO/sub 2/), and sulfur dioxide (SO/sub 2/) in air. For each gas detection system, the sampler depends on the transfer of the gas by diffusion into a glass tube containing a colorimetric length of stain indicator. The stain length developed in a given period of time is compared to a calibration chart to determine, on the spot, the average gas concentration to which the dosimeter has been exposed. These dosimeters are known by the trade name Vapor Gard.

McKee, E.S.; Pritts, I.M.

1981-08-01

390

Passive colorimetric dosimeter tubes for ammonia, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen dioxide and sulfur dioxide  

SciTech Connect

Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an eight-hour period for several inorganic airborne contaminants in the range of their Threshold Limit Values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NH/sub 3/), carbon monoxide (CO), carbon dioxide (CO/sub 2/), hydrogen sulfide (H/sub 2/S), nitrogen dioxide (NO/sub 2/), and sulfur dioxide (SO/sub 2/) in air. For each gas detection system, the sampler depends on the transfer of the gas by diffusion into a glass tube containing a colorimetric length of stain indicator. The stain length developed in a given period of time is compared to a calibration chart to determine, on the spot, the average gas concentration to which the dosimeter has been exposed. These dosimeters are known by the trade name Vapor Gard.

McConnaughey, P.W.; McKee, E.S.; Pritts, I.M.

1985-07-01

391

A malonitrile-functionalized metal-organic framework for hydrogen sulfide detection and selective amino acid molecular recognition  

PubMed Central

A novel porous polymeric fluorescence probe, MN-ZIF-90, has been designed and synthesized for quantitative hydrogen sulfide (H2S) fluorescent detection and highly selective amino acid recognition. This distinct crystalline structure, derived from rational design and malonitrile functionalization, can trigger significant enhancement of its fluorescent intensity when exposed to H2S or cysteine molecules. Indeed this new metal-organic framework (MOF) structure shows high selectivity of biothiols over other amino acids and exhibits favorable stability. Moreover, in vitro viability assays on HeLa cells show low cytotoxicity of MN-ZIF-90 and its imaging contrast efficiency is further demonstrated by fluorescence microscopy studies. This facile yet powerful strategy also offers great potential of using open-framework materials (i.e. MOFs) as the novel platform for sensing and other biological applications. PMID:24621614

Li, Haiwei; Feng, Xiao; Guo, Yuexin; Chen, Didi; Li, Rui; Ren, Xiaoqian; Jiang, Xin; Dong, Yuping; Wang, Bo

2014-01-01

392

Final report on international key comparison APMP.QM-K41: 10 µmol/mol hydrogen sulfide in nitrogen  

NASA Astrophysics Data System (ADS)

This report presents the results of APMP.QM-K41, a key comparison. This comparison is designed to test the capabilities of the NMIs to measure and certify hydrogen sulfide at a nominal amount fraction of 10 µmol/mol in nitrogen. This comparison provides an opportunity to the NMIs in APMP to submit supporting evidence for CMC at the same level as CCQM-K41. The results from this comparison are linked with CCQM-K41. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Kim, Yong-Doo; Heo, Gwi-Suk; Lee, Sangil; Han, Qiao; Wu, Hai; Konopelko, Leonid A.; Kustikov, Yury A.; Malginov, Andrey V.; Gromova, Elena V.; Pankratov, Vladimir V.; Pavlov, Mikhai V.; Botha, Angelique

2014-01-01

393

A malonitrile-functionalized metal-organic framework for hydrogen sulfide detection and selective amino acid molecular recognition.  

PubMed

A novel porous polymeric fluorescence probe, MN-ZIF-90, has been designed and synthesized for quantitative hydrogen sulfide (H2S) fluorescent detection and highly selective amino acid recognition. This distinct crystalline structure, derived from rational design and malonitrile functionalization, can trigger significant enhancement of its fluorescent intensity when exposed to H2S or cysteine molecules. Indeed this new metal-organic framework (MOF) structure shows high selectivity of biothiols over other amino acids and exhibits favorable stability. Moreover, in vitro viability assays on HeLa cells show low cytotoxicity of MN-ZIF-90 and its imaging contrast efficiency is further demonstrated by fluorescence microscopy studies. This facile yet powerful strategy also offers great potential of using open-framework materials (i.e. MOFs) as the novel platform for sensing and other biological applications. PMID:24621614

Li, Haiwei; Feng, Xiao; Guo, Yuexin; Chen, Didi; Li, Rui; Ren, Xiaoqian; Jiang, Xin; Dong, Yuping; Wang, Bo

2014-01-01

394

2,6-dansyl azide as a fluorescent probe for hydrogen sulfide.  

PubMed

A second-generation sulfonyl azide-based fluorescent probe, 2,6-DNS-Az, has been developed for the quantitative detection of H2S in aqueous media such as phosphate buffer and bovine serum. Compare to the first-generation 1,5-DNS-Az probe, this probe shows both high sensitivity in phosphate buffer without the need for addition of surfactant and selectivity for sulfide over other anions and biomolecules, and thus can be used as a useful tool for detection of H2S in the biological system. PMID:24081526

Wang, Ke; Peng, Hanjing; Ni, Nanting; Dai, Chaofeng; Wang, Binghe

2014-01-01

395

The synergistic effect of hydrogen sulfide and nitrogen dioxide on the atmospheric corrosion of zinc  

SciTech Connect

A laboratory study of the effect of sub-ppm levels of H{sub 2}S and NO{sub 2} on the atmospheric corrosion of zinc in humid air is reported. Each sample was exposed individually to a synthetic atmosphere with careful control of pollutant concentrations, relative humidity, and flow conditions. Corrosion products were analyzed by grazing angle X-ray diffraction and X-ray photoelectron spectroscopy. Ion chromatography was employed to identify water soluble anions. The interaction of the pollutants with zinc metal was studied using trace gas analysis in real time. A strong H{sub 2}S/NO{sub 2} synergism was observed. The main solid product was zinc blende (ZnS), accompanied by small amounts of sulfate. The optically smooth zinc sulfide film was shown to grow by solid-state diffusion of ions, the rate controlling step being the deprotonation of H{sub 2}S adsorbed on the ZnS surface. NO{sub 2} acts as a cathodic depolarizer, forming HNO{sub 2}(g), resulting in a strongly increased rate of zinc sulfidation.

Svensson, J.E.; Johansson, L.G. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Inorganic Chemistry]|[Univ. of Goeteborg (Sweden)

1996-01-01

396

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

PubMed

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

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

2008-11-01

397

Silver sulfide nanoparticles sensitized titanium dioxide nanotube arrays synthesized by in situ sulfurization for photocatalytic hydrogen production.  

PubMed

Titanium dioxide (TiO2) nanotube arrays (TNAs) sensitized with silver sulfide (Ag2S) nanoparticles (NPs) were synthesized via facile in situ sulfurization. Metallic silver NPs were first loaded on TNAs through a simple electrodeposition process. The as-prepared Ag/TNAs composites were further treated with a solution of acetonitrile containing sulfur (S8) and dried in vacuum to obtain a new nanocomposite material comprising of TNAs sensitized with Ag2S NPs. In these composite nanostructures, ultrafine Ag2S NPs were well-dispersed and assembled on the exterior and interior walls of the TNAs. Owing to sensitizing with a narrow bandgap material like Ag2S and the homogeneous distribution of the Ag2S NP heterojunction structures over the surface of the TNAs, the synthesized nanocomposite samples exhibited remarkable capability to absorb visible light and showed a significant enhancement in the photocatalytic efficiency of hydrogen generation. Under visible light illumination (100mW/cm(2)), a maximum photoconversion efficiency of 1.21% and the highest hydrogen production rate of 1.13mL/cm(2)h were obtained from the TNA electrodes sensitized with Ag2S NPs. PMID:24183425

Liu, Xu; Liu, Zhongqing; Lu, Jinlin; Wu, Xuelian; Chu, Wei

2014-01-01

398

Hydrochemistry and hydrogen sulfide generating processes in the Malm aquifer, Bavarian Molasse Basin, Germany  

NASA Astrophysics Data System (ADS)

Knowledge about the hydrochemical conditions of deep groundwater is crucial for the design and operation of geothermal facilities. In this study, the hydrochemical heterogeneity of the groundwaters in the Malm aquifer, Germany, is assessed, and reasons for the extraordinarily high H2S concentrations in the central part of the Bavarian Molasse Basin are proposed. Samples were taken at 16 sites, for a total of 37 individual wells, to analyze cations, anions, gas loading and composition. The hydrochemical characteristics of the Malm groundwater in the center of the Molasse Basin are rather heterogeneous. Although the groundwater in the central basin is dominated by meteoric waters, there is a significant infiltration of saline water from higher strata. Care has to be taken in the interpretation of data from geothermal sites, as effects of chemical stimulation of the boreholes may not be fully removed before the final analyses. The distribution of H2S in the gas phase is correlated to the gas loading of the water which increases in the central basin. Temperatures, isotopic data and the sulfur mass balance indicate that H2S in the central basin is related to thermochemical sulfate reduction (south of Munich) and bacterial sulfate reduction (north of Munich).

Mayrhofer, Christina; Niessner, Reinhard; Baumann, Thomas

2013-12-01

399

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

Federal Register 2010, 2011, 2012, 2013

...in listing decisions under EPCRA...exposure factors when making determinations...in listing decisions under EPCRA...exposure factors when making determinations...EPA is not required to list hydrogen...exposure factors when making a...

2011-10-17

400

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

SciTech Connect

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)

Layton, D. (ed.)

1980-07-01

401

Hydrogen sulfide production by sulfate-reducing bacteria utilizing additives eluted from plastic resins.  

PubMed

In the present study it was demonstrated that organic additives eluted from plastic resins could be utilized as substrates by sulfate-reducing bacteria. Two laboratory-scale experiments, a microcosm experiment and a leaching experiment, were conducted using polyvinyl chloride (PVC) as a model plastic resin. In the former experiment, the conversion of sulfate to sulfide was evident in microcosms that received plasticized PVC as the sole carbon source, but not in those that received PVC homopolymer. Additionally, dissolved organic carbon accumulated only in microcosms that received plasticized PVC, indicating that the dissolved organic carbon originated from additives. In the leaching experiment, phenol and bisphenol A were found in the leached solutions. These results suggest that the disposal of waste plastics in inert waste landfills may result in the production of H(2)S. PMID:21135024

Tsuchida, Daisuke; Kajihara, Yusuke; Shimidzu, Nobuhiro; Hamamura, Kengo; Nagase, Makoto

2011-06-01

402

Cysteine dioxygenase and cysteine sulfinate decarboxylase genes of the deep-sea mussel Bathymodiolus septemdierum: possible involvement in hypotaurine synthesis and adaptation to hydrogen sulfide.  

PubMed

It has been suggested that invertebrates inhabiting deep-sea hydrothermal vent areas use the sulfinic acid hypotaurine, a precursor of taurine, to protect against the toxicity of hydrogen sulfide contained in the seawater from the vent. In this protective system, hypotaurine is accumulated in the gill, the primary site of sulfide exposure. However, the pathway for hypotaurine synthesis in mollusks has not been identified. In this study, we screened for the mRNAs of enzymes involved in hypotaurine synthesis in the deep-sea mussel Bathymodiolus septemdierum and cloned cDNAs encoding cysteine dioxygenase and cysteine sulfinate decarboxylase. As mRNAs encoding cysteamine dioxygenase and cysteine lyase were not detected, the cysteine sulfinate pathway is suggested to be the major pathway of hypotaurine and taurine synthesis. The two genes were found to be expressed in all the tissues examined, but the gill exhibited the highest expression. The mRNA level in the gill was not significantly changed by exposure to sulfides or thiosulfate. These results suggests that the gill of B. septemdierum maintains high levels of expression of the two genes regardless of ambient sulfide level and accumulates hypotaurine continuously to protect against sudden exposure to high level of sulfide. PMID:25501502

Nagasaki, Toshihiro; Hongo, Yuki; Koito, Tomoko; Nakamura-Kusakabe, Ikumi; Shimamura, Shigeru; Takaki, Yoshihiro; Yoshida, Takao; Maruyama, Tadashi; Inoue, Koji

2015-03-01

403

Hydrogen peroxide oxidation of mustard-model sulfides catalyzed by iron and manganese tetraarylporphyrines. Oxygen transfer to sulfides versus H(2)O(2) dismutation and catalyst breakdown.  

PubMed

Fe(III)- and Mn(III)-meso-tetraarylporphyrin catalysis of H(2)O(2) oxidation of dibenzyl and phenyl-2-chloroethyl sulfides, 1, is investigated in ethanol with the aim of designing catalytic systems for mustard decontamination. The sulfide conversion, the sulfoxide and sulfone yields, the oxygen transfer from H(2)O(2) to the sulfide, and the catalyst stability depend markedly on the metal, on the substituents of its ligand, and on the presence or the absence of a cocatalyst, imidazole or ammonium acetate. With Fe, sulfones, the only oxidation products, are readily obtained whatever the ligand (TPP, F(20)TPP, or TDCPP) and the cocatalyst; the oxygen transfer is fairly good, up to 95% when the catalyst concentration is small ([1]/[Cat] = 420); the catalyst breakdown is insignificant only in the absence of any cocatalyst. With Mn, the sulfide conversion is achieved completely when the ligand is TDCPP or TSO(3)PP, but not F(20)TPP or TPP; a mixture of sulfoxide, 2, and sulfone, 3, is always obtained with [2]/[3] = 3.5-0.85 depending on the ligand and the cocatalyst (electron withdrawing substituents favor 3 and NH(4)OAc, 2). The catalyst stability is very good, but the oxygen transfer is poor whatever the ligand and the cocatalyst. These results are discussed in terms of a scheme in which sulfide oxygenation, H(2)O(2) dismutation, and oxidative ligand breaking compete. It is shown that the efficiency of the oxygen transfer is related not only to the rate constant of the dismutation route but also to the concentration of the active metal-oxo intermediate, most likely a perferryl or permanganyl species, i.e., to the rate of its formation. PMID:11701009

Marques, A; Marin, M; Ruasse, M F

2001-11-16

404

Upregulation of Ca v3.2 T-type calcium channels targeted by endogenous hydrogen sulfide contributes to maintenance of neuropathic pain  

Microsoft Academic Search

Hydrogen sulfide (H2S) formed from l-cysteine by multiple enzymes including cystathionine-?-lyase (CSE) is now considered a gasotransmitter in the mammalian body. Our previous studies have shown that H2S activates\\/sensitizes Cav3.2 T-type Ca2+ channels, leading to facilitation of somatic and visceral nociception, and that CSE-derived endogenous H2S participates in inflammatory pain. Here, we show novel evidence for involvement of the endogenous

Tomoko Takahashi; Yuka Aoki; Kazumasa Okubo; Yumi Maeda; Fumiko Sekiguchi; Kenji Mitani; Hiroyuki Nishikawa; Atsufumi Kawabata

2010-01-01

405

Inhibition of T-type calcium channels and hydrogen sulfide-forming enzyme reverses paclitaxel-evoked neuropathic hyperalgesia in rats  

Microsoft Academic Search

Hydrogen sulfide (H2S), a gasotransmitter, facilitates pain sensation by targeting Cav3.2 T-type calcium channels. The H2S\\/Cav3.2 pathway appears to play a role in the maintenance of surgically evoked neuropathic pain. Given evidence that chemotherapy-induced neuropathic pain is blocked by ethosuximide, known to block T-type calcium channels, we examined if more selective T-type calcium channel blockers and also inhibitors of cystathionine-?–lyase

K. Okubo; T. Takahashi; F. Sekiguchi; D. Kanaoka; M. Matsunami; T. Ohkubo; J. Yamazaki; N. Fukushima; S. Yoshida; A. Kawabata

2011-01-01

406

Use of a Pharmacokinetic-Driven Computational Fluid Dynamics Model to Predict Nasal Extraction of Hydrogen Sulfide in Rats and Humans  

Microsoft Academic Search

Hydrogen sulfide (H2S) is a naturally occurring and industrially generated gas. Human exposure to H2S results in dose-related neurological, respiratory, and cardiovascular effects. Subchronic exposure of rats to 30 or 80 ppm H2S results in olfactory neuron loss and basal cell hyperplasia. Olfactory lesions commonly border main airflow streams in the rat, indicating an influence of airflow on H2S-induced lesion

Jeffry D. Schroeter; Julia S. Kimbell; Melvin E. Andersen; David C. Dorman

2006-01-01

407

Hydrogen Sulfide Inhibits High Glucose-induced Matrix Protein Synthesis by Activating AMP-activated Protein Kinase in Renal Epithelial Cells*?  

PubMed Central

Hydrogen sulfide, a signaling gas, affects several cell functions. We hypothesized that hydrogen sulfide modulates high glucose (30 mm) stimulation of matrix protein synthesis in glomerular epithelial cells. High glucose stimulation of global protein synthesis, cellular hypertrophy, and matrix laminin and type IV collagen content was inhibited by sodium hydrosulfide (NaHS), an H2S donor. High glucose activation of mammalian target of rapamycin (mTOR) complex 1 (mTORC1), shown by phosphorylation of p70S6 kinase and 4E-BP1, was inhibited by NaHS. High glucose stimulated mTORC1 to promote key events in the initiation and elongation phases of mRNA translation: binding of eIF4A to eIF4G, reduction in PDCD4 expression and inhibition of its binding to eIF4A, eEF2 kinase phosphorylation, and dephosphorylation of eEF2; these events were inhibited by NaHS. The role of AMP-activated protein kinase (AMPK), an inhibitor of protein synthesis, was examined. NaHS dose-dependently stimulated AMPK phosphorylation and restored AMPK phosphorylation reduced by high glucose. Compound C, an AMPK inhibitor, abolished NaHS modulation of high glucose effect on events in mRNA translation as well as global and matrix protein synthesis. NaHS induction of AMPK phosphorylation was inhibited by siRNA for calmodulin kinase kinase ?, but not LKB1, upstream kinases for AMPK; STO-609, a calmodulin kinase kinase ? inhibitor, had the same effect. Renal cortical content of cystathionine ?-synthase and cystathionine ?-lyase, hydrogen sulfide-generating enzymes, was significantly reduced in mice with type 1 diabetes or type 2 diabetes, coinciding with renal hypertrophy and matrix accumulation. Hydrogen sulfide is a newly identified modulator of protein synthesis in the kidney, and reduction in its generation may contribute to kidney injury in diabetes. PMID:22158625

Lee, Hak Joo; Mariappan, Meenalakshmi M.; Feliers, Denis; Cavaglieri, Rita C.; Sataranatarajan, Kavithalakshmi; Abboud, Hanna E.; Choudhury, Goutam Ghosh; Kasinath, Balakuntalam S.

2012-01-01

408

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

PubMed Central

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

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

2012-01-01

409

Degradation of hydrogen sulfide by Xanthomonas sp. strain DY44 isolated from peat.  

PubMed Central

Xanthomonas sp. strain DY44, capable of degrading H2S, was isolated from dimethyl disulfide-acclimated peat. This bacterium removed H2S either as a single gas or in the presence of the sulfur-containing compounds methanethiol, dimethyl sulfide, and dimethyl disulfide. The maximum specific H2S removal rate, obtained in the late stationary phase, was 3.92 mmol g of dry cells-1 h-1 (6.7 x 10(-16) mol cell-1 h-1) at pH 7 and 30 degrees C through a batch experiment in a basal mineral medium. Since Xanthomonas sp. strain DY44 exhibited no autotrophic growth with H2S, the H2S removal was judged not to be a consequence of chemolithotrophic activity. By using X-ray photoelectron spectroscopy, the metabolic product of H2S oxidation was determined to be polysulfide, which has properties very similar to those of elemental sulfur. Autoclaved cells (120 degrees C, 20 min) did not show H2S degradation, but cells killed by gamma-irradiation and cell extracts both oxidized H2S, suggesting the existence of a heat-labile intracellular enzymatic system for H2S oxidation. When Xanthomonas sp. strain DY44 was inoculated into fibrous peat, this strain degraded H2S without lag time, suggesting that it will be a good candidate for maintaining high H2S removability in the treatment of exhaust gases. PMID:1599238

Cho, K S; Hirai, M; Shoda, M

1992-01-01

410

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

PubMed

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

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

411

Degradation of hydrogen sulfide by Xanthomonas sp. strain DY44 isolated from peat.  

PubMed

Xanthomonas sp. strain DY44, capable of degrading H2S, was isolated from dimethyl disulfide-acclimated peat. This bacterium removed H2S either as a single gas or in the presence of the sulfur-containing compounds methanethiol, dimethyl sulfide, and dimethyl disulfide. The maximum specific H2S removal rate, obtained in the late stationary phase, was 3.92 mmol g of dry cells-1 h-1 (6.7 x 10(-16) mol cell-1 h-1) at pH 7 and 30 degrees C through a batch experiment in a basal mineral medium. Since Xanthomonas sp. strain DY44 exhibited no autotrophic growth with H2S, the H2S removal was judged not to be a consequence of chemolithotrophic activity. By using X-ray photoelectron spectroscopy, the metabolic product of H2S oxidation was determined to be polysulfide, which has properties very similar to those of elemental sulfur. Autoclaved cells (120 degrees C, 20 min) did not show H2S degradation, but cells killed by gamma-irradiation and cell extracts both oxidized H2S, suggesting the existence of a heat-labile intracellular enzymatic system for H2S oxidation. When Xanthomonas sp. strain DY44 was inoculated into fibrous peat, this strain degraded H2S without lag time, suggesting that it will be a good candidate for maintaining high H2S removability in the treatment of exhaust gases. PMID:1599238

Cho, K S; Hirai, M; Shoda, M

1992-04-01

412

Enhanced adsorption of hydrogen sulfide on mixed zinc/cobalt hydroxides: effect of morphology and an increased number of surface hydroxyl groups.  

PubMed

Mixed zinc and cobalt hydroxides were synthesized using a precipitation method and tested as adsorbents of hydrogen sulfide from either dry or moist air. The adsorption capacity increased with an increase in the content of cobalt in the structure of mixed hydroxides. The synergistic effect was demonstrated by a fourfold increase in the amount of hydrogen sulfide adsorbed on the surface of the best performing mixed hydroxide in comparison with the hypothetical mixture of the two hydroxides. The initial and exhausted materials were characterized by FTIR, thermal analysis, potentiometric titration, X-ray diffraction, SEM/EDX, and adsorption of nitrogen. The results obtained suggest that an increase in the content of cobalt results in an increase in amorphicity level and in an increase in the number of hydroxyl groups. These groups, besides providing higher basicity thereby increasing the extent of H2S dissociation in the presence of water, are the main active centers reacting with hydrogen sulfide. Defects in the structure and oxygen vacancies result in the oxidation of some H2S to sulfites and sulfates. PMID:23755994

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

2013-09-01

413

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

PubMed

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(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. PMID:19597947

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

2010-02-01

414

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

SciTech Connect

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.

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

2000-10-01

415

Paracetamol (acetaminophen) decreases hydrogen sulfide tissue concentration in brain but increases it in the heart, liver and kidney in mice.  

PubMed

The biological action ofN-acetyl-p-aminophenol - paracetamol (acetaminophen) has been demonstrated to involve different mechanisms and is still not clear. Hydrogen sulfide (H2S) has been shown to play an important role in many physiological and pathological processes including nociception. The interaction between acetaminophen and endogenous H2S is unknown. Twenty four female CBA strain mice were administered intraperitoneal injections of N-acetyl-p-aminophenol solution: paracetemol in doses of 30 mg/kg b.w. per day (group D1, n = 8) or 100 mg/kg b.w. per day (group D2, n = 8).. The control group (n = 8) received physiologica