Hydrogen sulfide reduces oxidative stress in Huntington's disease via Nrf2

The pathophysiology of Huntington's disease involves high levels of the neurotoxin quinolinic acid. Quinolinic acid accumulation results in oxidative stress, which leads to neurotoxicity. However, the molecular and cellular mechanisms by which quinolinic acid contributes to Huntington's disease pathology remain unknown. In this study, we established in vitro and in vivo models of Huntington's disease by administering quinolinic acid to the PC12 neuronal cell line and the striatum of mice, respectively. We observed a decrease in the levels of hydrogen sulfide in both PC12 cells and mouse serum, which was accompanied by down-regulation of cystathionine β-synthase, an enzyme responsible for hydrogen sulfide production. However, treatment with NaHS(a hydrogen sulfide donor) increased hydrogen sulfide levels in the neurons and in mouse serum, as well as cystathionine β-synthase expression in the neurons and the mouse striatum, while also improving oxidative imbalance and mitochondrial dysfunction in PC12 cells and the mouse striatum. These beneficial effects correlated with upregulation of nuclear factor erythroid 2-related factor 2 expression. Finally, treatment with the nuclear factor erythroid 2-related factor 2inhibitor ML385 reversed the beneficial impact of exogenous hydrogen sulfide on quinolinic acid-induced oxidative stress. Taken together, our findings show that hydrogen sulfide reduces oxidative stress in Huntington's disease by activating nuclear factor erythroid 2-related factor 2,suggesting that hydrogen sulfide is a novel neuroprotective drug candidate for treating patients with Huntington's disease.

Hydrogen sulfide responsive nanoplatforms: Novel gas responsive drug delivery carriers for biomedical applications

Hydrogen sulfide(H_(2)S)is a toxic,essential gas used in various biological and physical processes and has been the subject of many targeted studies on its role as a new gas transmitter.These studies have mainly focused on the production and pharmacological side effects caused by H_(2)S.Therefore,effective strategies to remove H_(2)S has become a key research topic.Furthermore,the development of novel nanoplatforms has provided new tools for the targeted removal of H_(2)S.This paper was performed to review the association between H_(2)S anddisease,relatedH_(2)S inhibitory drugs,aswell as H_(2)S responsive nanoplatforms(HRNs).This review first analyzed the role of H_(2)S in multiple tissues and conditions.Second,common drugs used to eliminate H_(2)S,as well as their potential for combination with anticancer agents,were summarized.Not only the existing studies on HRNs,but also the inhibition H_(2)S combined with different therapeutic methods were both sorted out in this review.Furthermore,this review provided in-depth analysis of the potential of HRNs about treatment or detection in detail.Finally,potential challenges of HRNs were proposed.This study demonstrates the excellent potential of HRNs for biomedical applications.

Absorption characteristics,model,and molecular mechanism of hydrogen sulfide in morpholine acetate aqueous solution

The solubility of H_(2)S was measured in solutions of N-butyl-N-methylmorpholine acetate([Bmmorp][Ac])containing 20%-40%(mass)water at experimental temperatures ranged from 298.15 to 328.15 K and pressures up to 320 k Pa.The total solubility of H_(2)S increased with higher temperatures,lower pressures,and reduced water content.The reaction equilibrium thermodynamic model was used to correlate the solubility data.The results indicate that the chemical reaction equilibrium constant decrease with increasing water content and temperature,whereas Henry constant increase with increasing water content and temperature.Compared with other ionic liquids,H_(2)S exhibits a higher physical absorption enthalpy and a lower chemical absorption enthalpy in[Bmmorp][Ac]aqueous solution.This suggests that[Bmmorp][Ac]has a strong physical affinity for H_(2)S and low energy requirement for desorption.Quantum chemical methods were used to investigate the molecular mechanism of H_(2)S absorption in ionic liquids.The interaction energy analysis revealed that the binding of H_(2)S with the ionic liquid in a1:2 ratio is more stable.Detailed analyses by the methods of the interaction region indicator and the atoms in molecules were conducted to the interactions between H_(2)S and the ionic liquid.

Synthesis of High Purity Lithium Sulfide for Sulfide Solid Electrolyte Applications through Hydrogen Reduction of Lithium Sulfate

This paper is aimed to present a clean,inexpensive and sustainable method to synthesize high purity lithium sulfide(Li_(2)S)powder through hydrogen reduction of lithium sulfate(Li_(2)SO_(4)).A three-step reduction process has been successfully developed to synthesize well-crystallized and single-phase Li_(2)S powder by investigating the melting,sintering and reduction behavior of the mixtures of Li_(2)SO_(4)-Li_(2)S.High purity alumina was found to be the most suitable crucible material for producing high purity Li_(2)S,because it was not attacked by the Li_(2)SO_(4)-Li_(2)S melt during heating,as compared with other materials,such as carbon,mullite,quartz,boron nitride and stainless steel.The use of synthesized LizS resulted in higher purity and substantially higher room temperature ionic conductivity(2.77 mS·cm^(-1))for the argyrodite sulfide electrolyte Li_(6)PS_(5)Cl than commercial Li_(2)S(1.12 mS·cm^(-1)).This novel method offers a great opportunity to produce battery grade Li_(2)S for sulfide solid electrolyte applications.

Comparative study on the hydrogen storage performance of as-milled MgRENi rapid quenched alloy catalyzed by metal sulfides

The composites of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)as-quenched alloy and 3 wt.%M(M=CoS,CoS_(2),MoS_(2))catalyst were prepared by high-speed vibration ball mill.The effects of metal sulfides on the hydrogenation and dehydrogenation dynamics of alloys were compared.The results show that the as-milled composites contain a large number of amorphous embedded by a small amount of nanocrystals,and there are many point defects.After ball milling,the crystal grain size in the composites containing CoS is relatively larger,followed by CoS_(2)and MoS_(2)again.After hydrogenation,the amorphous phase is crystallized to form Mg_(2)NiH_(4),YH_(3),Pr_(8)H_(18.96),Sm_(3)H_7,Mg,Co or Mo phases,however,Mg_(2)Ni,YH_(2),PrH_(2)and Ni_(3)Y phases appeared after dehydrogenation.The maximum hydrogenation capacity of the composites containing CoS,CoS_(2)and MoS_(2)are 3.939,4.265 and 4.507 wt.%,respectively.The hydrogenation saturation ratio of composite containing MoS_(2)is higher than that of the composites containing CoS and CoS_(2).The dehydrogenation activation energy of the composites containing CoS,CoS_(2)and MoS_(2)is 107.76,68.43 and 63.28 kJ.mol^(-1).H_(2).On the improvement of hydrogen storage performance of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)alloy,the catalytic effect of MoS_(2)sulfide is better than that of CoS_(2)sulfide,and which is better than CoS sulfide.

Kinetics of hydrogen sulfide decomposition in a DBD plasma reactor operated at high temperature

The present study investigates the kinetics of hydrogen sulfide （H2S） decomposition into hydrogen and sulfur carded out in a nonthermal plasma dielectric barrier discharge （NTP-DBD） reactor operated at ,-430 K for in situ removal of sulfur condensed inside the reactor walls. The dissociation of H2S was primarily initiated by the excitation of carder gas （At） through electron collisions which appeared to be the rate determining step. The experiments were carded out with initial concentration of H2S varied between 5 and 25 vol% at 150 mL/min （at standard temperature and pressure） flow rate in the input power range of 0.5 to 2 W. The reaction rate model based on continuous stirred tank reactor （CSTR） model failed to explain the global kinetics of H2S decomposition, probably due to the multiple complex reactions involved in H2S decomposition, whereas Michaelis-Menten model was satisfactory. Typical results indicated that the reaction order approached zero with increasing inlet concentration.

Hydrogen sulfide protects against amyloid beta-peptide induced neuronal injury via attenuating inflammatory responses in a rat model

Neuroinflammation has been recognized to play a critical role in the pathogenesis of Alzheimer＇s disease （AD）, which is pathologically characterized by the accumulation of senile plaques containing activated microglia and amyloid β-peptides （Aβ）. In the present study, we examined the neuroprotective effects of hydrogen sulfide （H2S） on neuroinflammation in rats with Aβ1-40 hippocampal injection. We found that Aβ-induced rats exhibited a disorder of pyramidal cell layer arrangement, and a decrease of mean pyramidal cell number in the CA1 hippocampal region compared with those in sham operated rats. NaHS （a donor of H2S, 5.6 mg/kg/d, i.p.） treatment for 3 weeks rescued neuronal cell death significantly. Moreover, we found that H2S dramatically suppressed the release of TNF-α, IL-1β and IL-6 in the hippocampus. Consistently, both immunohistochemistry and Western blotting assays showed that H2S inhibited the upregulation of COX-2 and the activation of NF-κB in the hippocampus. In conclusion, our data indicate that H2S suppresses neuroinflammation via inhibition of the NF-κB activation pathway in the Aβ-induced rat model and has potential value for AD therapy.

Exogenous Hydrogen Sulfide Enhanced Antioxidant Capacity, Amylase Activities and Salt Tolerance of Cucumber Hypocotyls and Radicles

In the present experiment, effects of sodium hydrosulfide （NariS）, a H2S donor, on the oxidative damage, antioxidant capacity and the growth of cucumber hypocotyls and radicles were studied under 100 mmol L^-1 NaCl stress. NaCl treatment significantly induced accumulation of H2O2 and thiobarbituric acid-reactive substances （TBARS） in cucumber hypocotyls and radicles, and application of NariS dramatically reduced the accumulation of H/O2 and lipid peroxidation. However, the alleviating effects greatly depended on the concentrations of NariS, and 400 ~tmol L-1 NariS treatment showed the most significant effects. Corresponding to the change of lipid peroxidation, higher activities of antioxidant enzymes as well as the antioxidant capacity indicated as DPPH scavenging ac＇tivity, chelating activity of ferrous ions and hydroxyl radical （.OH） scavenging activity were induced by Naris treatment under NaCI stress, especially by 400 Ixmol L-I Naris treatment. With the alleviating lipid peroxidation, the amylase activities in cotyledons were increased, and the length of cucumber hypocotyls and radicles were significantly promoted by NariS treatment under NaCI stress. Unlike the effects of NariS, pretreatment with other sodium salts including Na2S, NazSO4, NaHSO4, Na2SO3, NaHSO3 and NaAc did not show significant effects on the growth of cucumber hypocotyls and radicles. These salts do not release H2S. Based on above results, it can be concluded that the effects of NariS in the experiment depended on the H2S rather than other compounds derived from NariS, and the alleviating effects might related with its function in modulating antioxidant capacity and amylase activities.

Therapeutic importance of hydrogen sulfide in age-associated neurodegenerative diseases

Hydrogen sulfide(H2S)is a gasotransmitter that acts as an antioxidant and exhibits a wide variety of cytoprotective and physiological functions in age-associated diseases.One of the major causes of age-related diseases is oxidative stress.In recent years,the importance of H2S has become clear,although its antioxidant function has not yet been fully explored.The enzymes cystathionineβ-synthase,cystathionineγ-lya-se,and 3-mercaptopyruvate sulfurtransferase are involved in the enzymatic production of H2S.Previously,H2S was considered a neuromodulator,given its role in long-term hippocampal potentiation,but it is now also recognized as an antioxidant in age-related neurodegeneration.Due to aerobic metabolism,the central nervous system is vulnerable to oxidative stress in brain aging,resulting in age-associated degenerative diseases.H2S exerts its antioxidant effect by limiting free radical reactions through the activation of antioxidant enzymes,including superoxide dismutase,catalase,and glutathione peroxidase,which protect against the effects of aging by regulating apoptosis-related genes,including p53,Bax,and Bcl-2.This review explores the implications and mechanisms of H2S as an antioxidant in age-associated neurodegenerative diseases,including Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,and Down syndrome.

A hypothesis for treating inflammation and oxidative stress with hydrogen sulfide during age-related macular degeneration

Age-related macular degeneration（AMD） is a leading cause of blindness and is becoming a global crisis since affected people will increase to 288 million by 2040.Genetics,age,diabetes,gender,obesity,hypertension,race,hyperopia,iris-color,smoking,sun-light and pyroptosis have varying roles in AMD,but oxidative stress-induced inflammation remains a significant driver of pathobiology.Eye is a unique organ as it contains a remarkable oxygengradient that generates reactive oxygen species（ROS） which upregulates inflammatory pathways.ROS becomes a source of functional and morphological impairments in retinal pigment epithelium（RPE）,endothelial cells and retinal ganglion cells.Reports demonstrated that hydrogen sulfide（H2S） acts as a signaling molecule and that it may treat ailments.Therefore,we propose a novel hypothesis that H2S may restore homeostasis in the eyes thereby reducing damage caused by oxidative injury and inflammation.Since H_2S has been shown to be a powerful antioxidant because of its free-radicals＇ inhibition properties in addition to its beneficial effects in age-relatedconditions,therefore,patients may benefit from H2S salubrious effects not only by minimizing their oxidant and inflammatory injuries to retina but also by lowering retinal glutamate excitotoxicity.

Protective Effects of Hydrogen Sulfide on Portal Hypertensive Vasculopathy in Rabbits by Activating AKT-NF-κB Pathway

The role of hydrogen sulfide（H;S） in portal hypertension（PH）-induced esophagus-gastric junction vascular lesions in rabbits was observed. The rabbit PH models were established. The animals were randomly divided into the following groups: normal, PH, PH+sodium hydrosulfide（PH+S）, PH+propargylglycine（PH+PPG）. The plasma H;S levels, apoptosis of esophageal-gastric junction vascular smooth muscle cells, and the expression of nuclear transcription factor-κB（NF-κB）, p-AKT, IκBa and Bcl-2 were detected. The cystathionine γ lyase（cystathionine-gamma-splitting enzyme, CSE） in the junction vascular tissue was measured. The results showed that the plasma H;S levels and the CSE expression levels had statistically significant difference among different groups（P<0.05）. As compared with PH group, plasma H;S levels were declined obviously（11.9±4.2 vs. 20.6±4.5, P<0.05）, and CSE expression levels in the junction vascular tissue were notably reduced（1.7±0.6 vs. 2.8±0.8, P<0.05）, apoptosis rate of vascular smooth muscle cells per unit area was significantly decreased（0.10±0.15 vs. 0.24±0.07, P<0.05）, and the expression levels of p-AKT and NF-κB were significantly decreased（2.31±0.33 vs. 3.04±0.38, P<0.05; 0.33±0.17 vs. 0.51±0.23, P<0.05）, however, IκBa and Bcl-2 expression increased obviously（5.57±0.17 vs. 3.67±0.13, P<0.05; 0.79±0.29 vs. 0.44±0.36, P<0.05） in PH+PPG group. As compared with PH group, H;S levels were notably increased（32.7±7.3 vs. 20.6±4.5, P<0.05）, the CSE levels in the junction vascular tissue were significantly increased（6.3±0.7 vs. 2.8±0.8, P<0.05）, apoptosis rate of vascular smooth muscle cells per unit area was significantly increased（0.35±0.14 vs. 0.24±0.07, P<0.05）, and the expression levels of p-AKT and NF-κB were significantly increased（4.29±0.49 vs. 3.04±0.38, P<0.05; 0.77±0.27 vs. 0.51±0.23, P<0.05）, yet IκBa and Bcl-2 expression decreased significantly（3.23±0.24 vs. 3.67±0.13, P<0.05; 0.31±0.23 vs. 0.48±0.34, P<0.05） in PH+S group. It is concluded that esophagus-gastric junction vascular lesions happen under PH, and apoptosis of smooth muscle cells is declined. H;S can activate NF-κB by the p-AKT pathway, leading to the down-regulation of Bcl-2, eventually stimulating apoptosis of vascular smooth muscle cells, easing PH. H;S/CSE system may play an important role in remission of PH via the AKT-NF-κB pathway.

Hydrogen sulfide inhibits beta-amyloid peptide-induced apoptosis in PC12 cells and the underlying mechanisms

BACKGROUND：Studies have demonstrated that hydrogen sulfide（H2S） levels are 55% lower in brains of Alzheimer＇s disease（AD） patients than in age-matched normal individuals,which suggests that H2S might be involved in some aspects of AD pathogenesis.OBJECTIVE：To observe the protective mechanisms of varied concentrations of H2S against β-amyloid-peptide（Aβ） induced apoptosis in pheochromoytoma（PC12） cells,and to analyze the pathway of action.DESIGN,TIME AND SETTING：A controlled,observational,in vitro experiment was performed at Neurophysiology Laboratory in Zhongshan Medical School,Sun Yat-sen University between July 2006 and May 2007.MATERIALS：PC12 cells were provided by the Animal Experimental Center of Medical School of Sun Yat-sen University.Glybenclamide,rhodamine123,and dihydrorhodamine123 were purchased from Sigma（USA）.METHODS：PC12 cells were incubated at 37 ℃ in a 5% CO2-enriched incubator with RPMI-1640 medium,supplemented with 5% horse-serum and 10% fetal bovine serum.Cells in logarithmic growth curves received different treatment：The PC12 cells were maintains at 37 ℃ with the original medium,then incubated in Aβ25-35,sodium hydrosulfide（NaHS）,glybenclamide,NaHS＋ Aβ25-35,or pretreated with glybenclamide 30 minutes prior to administration of and Aβ25-35,respectively.MAIN OUTCOME MEASURES：（1） The survival rate of PC12 cells was detected by MTT assay and Hoechst staining.（2） The apoptosis rate of PC12 cells was detected utilizing flow cytometry with propidium iodide staining,and morphological changes of apoptotic cells were observed.（3） The mitochondrial membrane potential was detected by Rhodamine123-combined flow cytometry.（4） The intracellular reactive oxygen species content was detected by dihydrorhodamine123-combined flow cytometry.RESULTS：Aβ25-35 induced significantly decreased viability and increased percentage of apoptosis in PC12 cells,as well as dissipated mitochondrial membrane potential expression and an overproduction of reactive oxygen species.When PC12 cells were co-treated with NaHS and Aβ25-35,the decreased cell viability induced by 20 μmol/L Aβ25-35 was concentration-dependently blocked by NaHS（50,100,and 200 μmol/L）.NaHS（100 μmol/L） obviously reduced the percentage of apoptotic PC12 cells induced by 20 μmol/L Aβ25-35.In addition,100 μmol/L NaHS inhibited mitochondrial membrane potential dissipation and reactive oxygen species overproduction.When the ATP-sensitive K channel（KATP） inhibitor,glybenclamide,was administered 30 minutes prior to NaHS and Aβ25-35 treatment,the NaHS-dependent cellular protection was partly blocked.This resulted in reduced PC12 cell viability and increased the percentage of apoptosis,as well as significantly blocked mitochondrial membrane potential preservation and inhibited reactive oxygen species overproduction due to NaHS treatment.CONCLUSION：NaHS protected PC12 cells against Aβ25-35-induced damage.NaHS-dependent cellular protection was associated with mitochondrial membrane potential preservation and inhibition of reactive oxygen species overproduction.The KATP channel inhibitor,glybenclamide,significantly blocked the cellular protective effects of NaHS,indicating that KATP channel activation plays an important role in NaHS-induced protection of PC12 cells to Aβ25-35-induced damage.

Role of hydrogen sulfide in portal hypertension and esophagogastric junction vascular disease

AIM: To investigate the association between endogenous hydrogen sulfide (H2S) and portal hypertension as well as its effect on vascular smooth muscle cells.

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

AIM:To investigate the effect of hydrogen sulfide(H2S)on smooth muscle motility in the gastric fundus.METHODS:The expression of cystathionineβ-synthase(CBS)and cystathionineγ-lyase(CSE)in cultured smooth muscle cells from the gastric fundus was examined by the immunocytochemistry technique.The tension of the gastric fundus smooth muscle was recorded by an isometric force transducer under the condition of isometric contraction with each end of the smooth muscle strip tied with a silk thread.Intracellular recording was used to identify whether hydrogen sulfide affects the resting membrane potential of the gastric fundus in vitro.Cells were freshly separated from the gastric fundus of mice using a variety of enzyme digestion methods and whole-cell patch-clamp technique was used to find the effects of hydrogen sulfide on voltage-dependent potassium channel and calcium channel.Calcium imaging with fura-3AM loading was used to investigate the mechanism by which hydrogen sulfide regulates gastric fundus motility in cultured smooth muscle cells.RESULTS:We found that both CBS and CSE were expressed in the cul tured smooth muscle cel ls from the gastric fundus and that H2S increased the smooth muscle tension of the gastric fundus in mice at low concentrations.In addition,nicardipine and aminooxyacetic acid(AOAA),a CBS inhibitor,reduced the tension,whereas Nω-nitro-L-arginine methyl ester,a nonspecific nitric oxide synthase,increased the tension.The AOAA-induced relaxation was significantly recovered by H2S,and the Na HS-induced increase in tonic contraction was blocked by 5 mmol/L4-aminopyridine and 1μmol/L nicardipine.Na HS significantly depolarized the membrane potential and inhibited the voltage-dependent potassium currents.Moreover,Na HS increased L-type Ca2+currents and caused an elevation in intracellular calcium([Ca2+]i).CONCLUSION:These findings suggest that H2S may be an excitatory modulator in the gastric fundus in mice.The excitatory effect is mediated by voltagedependent potassium and L-type calcium channels.

Transfer and Reactivity of Hydrogen Sulfide with Immobilized Hemeproteins in Polymeric Matrix

Hydrogen sulfide (H2S) has been related to be toxic and to have a role in human physiological functions. Therefore, there is a necessity to comprehend ways to scavenger hydrogen sulfide from different media. Here, we used recombinant metaquo-Hemoglobin I (metHbI) from Lucina pectinata and metaquo-myoglobin (metMb) encapsulated in the tetramethyl orthosilicate gel (TMOS), to facilitate the understanding of H2S transfer toward these metaquo-hemeproteins. In this sol-gel environment, metHbI binds and releases H2S with rate constants of 0.0597 M-1·s-1 and 6.67 × 10-5 s-1, respectively. The process generates an H2S affinity constant (kon/koff) of 8.9 × 102 M-1, which is 107 lowers than the analogous constant in solution (6.3 × 109 M-1). Although the H2S koff for the rHbI-H2S complex is almost similar with both sol-gel and solution. To further understand how the H2S koff from rHbI-H2S in solution (5 μM) is influenced by the protein concentration gradient, metHbI and metMb (25 μM) encapsulated in TMOS sol-gel. Under these circumstances, the H2S transfer from a solution of the rHbI-H2S complex to encapsulated hemeprotein resulted in koff values of 1.90 × 10-4 s-1, and 2.09 × 10-4 s-1 leading to the formation of rHbI-H2S and Mb-H2S species, respectively. The results suggest that the: 1) extreme ionic TMOS construct limits the H2S pathways to reach the hemeprotein active center, 2) possible interaction with metHbI hydrophilic forces increases the hydrogen bonding networking and decreases the H2S association constant, 3) hemeproteins concentration gradients between solution and sol-gels also influence its hydrogen sulfide transfer. In the presence of oxygen or hydrogen peroxide metMb generated a mixture of Mb-H2S and sulfmyoglobin derivative, while encapsulated metHbI reaction did not produce the sulfheme species. Consequently, the results show that metHbI encapsulated in TMOS is an excellent trap for H2S from solution or gas media.

Evaluation of the effect of hydrogen sulfide postconditioning by p-v loop against myocardial i/r injury in rats

Objectives To evaluate the effect of hydrogen sulfide(H2S) postconditioning on myocardial ischemia-reperfusion (I/R) by pressure-volume loop(P-V loop). Methods The I/R model of rat in vivo was established by ligating the left anterior descending coronary artery for 30min and reperfusing for 120 min.Wistar rats(n=32) were ran- domly divided into 4 groups;Sham operation,ischemia-reperfusion (I/R),Ischemic postconditioning(IPO) and H2S postconditioning.In sham operation,there was no ligation.In IPO,at the start of reperfusion,three cycles of 30s reperfusion and 30s LAD reocclusion preceded the 3h of reperfusion. In H2S postconditioning,NaHS(15μmol/kg,Sodium hydrosulfide)was administrated before coronary artery reperfusion. The heart rate(HR),I/R arrhythmia,the left ventricular end-systolic pressure(LVESP),left ventricular enddiastolic pressure(LVEDP),the slope of the end- systolic P-V relation(ESPVR) and the slope of the end-diastolic P-V relation(EDPVR) were detected.Infarct size was determined by scanning the images of the rat heart ventricular sections stained with Evans blue and TTC.Results Compared with I/R group,the I/R arrhythmia and the infarct size were decreased significantly(PPP2S postconditioning group.Conclusions Myocardial I/R injury was decreased by H2S post-conditioning, and it was sensitive and accurate to evaluate the heart function by P-V loop.

Effect of Exogenous Hydrogen Sulfide(H_2S) on the Electrocardiogram(ECG) of Rats Generally Anaesthetized by Zoletil

Hydrogen sulfide （H2S） is the third gaseous signaling molecule discovered in recent years, and plays an important physiological role in the cardivascular system. To explore the effects of different doses of exogenous H2S on the electrocardiogram （ECG） of rats generally anesthetized by zoletil, different doses of NariS solution were used for the intervention of intraperitoneal injection 20 rain before the zoletil anesthesia. The ECGs of rats from each treatment group during the time range of 10^th-50^th min were determined under general anesthesia, and then were compared with those from the control group. The results showed that exogenous H2S could significantly reduce the Q-T interval time limit, thus played a role in slowing tachycardia or arrhythmia and other anomalies, thereby protecting the heart. S-T segment and T segment evaluation values were significantly reduced, which might be associated with bradycardia.

Research Development of Control Technology of Hydrogen Sulfide in Biogas Slurry

In order to provide help for the accurate application of biogas slurry in the field, the application of biogas slurry and control technology of hydrogen sulfide in biogas slurry were reviewed. Results of recent researches suggested that source control and end-treatment were the two measures to remove hydrogen sulfide in biogas slurry, including physical method, chemical method and biological method. Some conventional deodorizing methods were introduced and compared.

Hydrogen Sulfide May Function Downstream of Nitric Oxide in Ethylene-Induced Stomatal Closure in Vicia faba L.

Pharmacological, laser scanning confocal microscopic （LSCM）, and spectrophotographic approaches were used to study the roles of hydrogen sulfide （H2S） and nitric oxide （NO） in signaling transduction of stomatal movement in response to ethylene in Viciafaba L. Ethylene treatment resulted in the dose-dependent stomatal closure under light, and this effect was blocked by the inhibitors of H2S biosynthesis in V. faba L. Additionally, ethylene induces H2S generation and increases L-/D-cysteine desulfhydrase （pyridoxalphosphate-dependent enzyme） activity in leaves of V. faba L. Inhibitors of H2S biosynthesis have no effect on the ethylene-induced stomatal closure, NO accumulation, and nitrate reductase （NR） activity in guard cells or leaves of II. faba L. Moreover, the ethylene-induced increase of H2S levels and L-/D- cysteine desulfhydrase activity declined when NO generation was inhibited. Therefore, we conclude that H2S and NO probably are involved in the signal transduction pathway of ethylene-induced stomatal closure. H2S may represent a novel component downstream of NO in the ethylene-induced stomatal movement in V. faba L.

The Modification of Diphenyl Sulfide to Pd/C Catalyst and Its Application in Selective Hydrogenation of p-Chloronitrobenzene

In this study, diphenyl sulfide(Ph2S) was employed to prepare a series of Ph2S-modified Pd/C catalysts(Pd–Ph2S/C). Catalyst characterization carried out by Brunner–Emmet–Teller(BET), energy dispersive spectrometer(EDS), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and CO chemisorption uptake measurements suggested a chemical interaction between Ph2 S and Pd. The ligand was preferably absorbed on the active site of Pd metal but after increasing the amount of Ph2 S, the adsorption of Ph2 S on Pd metal tended to be saturated and the excess of Ph2 S partially adsorbed on the activated carbon. A part of Pd atoms without adsorbing any Ph2 S still existed, even for the saturated Pd–Ph2S/C catalyst. The Pd–Ph2S/C catalysts exhibited a good selectivity of p-chloroaniline(p-CAN) in the hydrogenation of p-chloronitrobenzene(p-CNB). However,the chemisorption between Ph2 S and Pd was not so strong that part of Ph2 S was leached from Pd–Ph2S/C catalyst during the hydrogenation, which caused the decline of the selectivity of p-CAN over the used Pd–Ph2S/C catalyst.Resulfidation of the used Pd–Ph2S/C catalyst was effective to resume its stability, and the regenerated Pd–Ph2S/C catalyst could be reused for at least ten runs with a stable catalytic performance.