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BACKGROUND RESULTS CONCLUSION A colorimetric method for the quantification of hydrogen sulfide (H₂S) produced in microbial fermentations was developed using lead gelled alginate microparticles packed in glass columns. The formation of a lead sulfide complex, between H₂S and lead ion (Pb2+) immobilized on the microparticles, allowed simple and accurate quantification by colorimetry.The microparticle‐loaded columns were calibrated and showed significant analytical sensitivity. The calibration curve of the system showed a correlation coefficient (r2) of 0.995 and a detection limit of 1.29 ± 0.02 μg L−1. The application of the columns in laboratory wine fermentations was able to detect variations in H2S production from 10.6 to 23.5 μg L−1 by increasing the sugar content in the medium, and from 10.6 to 3.2 μg L−1 with decreasing nitrogen content in the medium.Validation of the proposed method was carried out by determining H₂S in a vinic fermentation model, the results of which were compared with those obtained using a reference chemical method. The data obtained showed no statistically significant differences between the two methods, confirming the reliability and accuracy of the developed system. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The Martinique island, located in the Caribbean Sea, is subject to the stranding of Sargassum algae, which decompose and release toxic gases, such as hydrogen sulfide or ammonia. This study aims to investigate the atmospheric corrosion of zinc in these conditions. For this purpose, three sites in Martinique more or less impacted by Sargassum algae stranding were selected. Mass loss results after 1‐year exposure range from 1.9 µm for the site least impacted to 45.3 µm for the site most affected by Sargassum algae. This high value proves that the presence of Sargassum algae caused significant zinc degradation. The morphological structures and properties of the corrosion products obtained at the impacted and non‐impacted sites differ significantly. In the absence of Sargassum algae, "classical" corrosion products based on hydrozincite, simonkoleite, gordaite, and zinc hydroxylsulfate are observed. In the area close to the Sargassum seaweed stranding, the presence of elemental sulfur products, zinc hydroxylsulfate, and sphalerite is reported. [ABSTRACT FROM AUTHOR]

The discovery of new classes of regulatory molecules in human and animal metabolism always leads to a large-scale study of their properties in the context of biochemistry, physiology, and pharmacology. About 20 years ago, hydrogen sulfide (H2S) and its derivatives called reactive sulfur species (RSS), such as persulfides, polysulfides, nitrosothiols, sulfenic acids, and others became one of such classes of molecules. The participation of RSS in a variety of physiological and pathological processes, including the regulation of vascular tone, inflammation, long-term potentiation in the central nervous system, etc., has been shown. Changes in RSS levels or patterns of modification of their targets are associated with a wide range of cardiovascular, oncological, neurodegenerative, and other pathologies. For a part of these processes, mechanisms have been studied that involve direct modification of regulatory (NF-κB, Keap1) or effector (GAFD, eNOS, TRPA1) proteins through reactions of cysteine residues and metal-containing centers with APS. The presence of different regulated enzymatic systems producing RSS and numerous molecular targets allows us to consider H2S and its derivatives as an important class of small regulatory molecules. H2S is belongs to the class of so-called "gasotransmitters," along with nitric oxide (II) and carbon monoxide. Over the last 20 years, a vast amount of data on the biochemistry of these compounds and approaches to their study has been accumulated. [ABSTRACT FROM AUTHOR]

The bare SnS 2 usually exhibits many undesirable gas-sensing performances such as low selectivity, slow response/recovery, and poor stability in the application field of gas sensors. Heterojunction and morphology engineering are crucial for achieving high-performance SnS 2 -based gas sensors. Here, we firstly fabricated SnS 2 nanoflowers, and subsequently on the SnS 2 nanoflowers' microstructure in-situ constructed Se/SnO 2 /SnS 2 /SnSe 2 /SnSe nanocomposites by two-step solvothermal methods. In contrast to the pure SnS 2 and SnSe 2 samples, the Se/SnSe 2 /SnS 2 -based composites display a remarkable improvement in the H 2 S sensing properties. The phase composition, microstructure, and gas-sensing properties of the composites are well modulated by varying the S/Se ratio. The test results reveal that the S/Se-0.2 (SnS 2 /SnSe 2 ratio = 1:5) sensor exhibits a high gas response of Ra/Rg = 11.07 and a fast response and recovery of 6 s/148 s toward 200 ppm H 2 S at 200 °C. More importantly, the S/Se-0.2 sensor shows remarkable selectivity, good reproducibility, and excellent long-term stability to H 2 S with a low detection limit of 250 ppb. The sensing mechanism is also investigated based on XRD, XPS, and SEM analysis. The strengthened gas sensitivity for the S/Se-0.2 sensor is the synergistic effects of the microstructure, defects, and multiple heterojunctions. Our work paves a new road for the design and optimization of SnS 2 -based gas sensors. [ABSTRACT FROM AUTHOR]

Metal-halide perovskite (MHP) nanocrystals (NCs) have unique advantages in the gas sensing field, but the poor stability restricts their widespread applications. In this work, the CsPbBr 3 @Fe 2 O 3 heterojunction NCs were synthesized successfully by simple solution process and subsequent surface modification strategy for constructing a gas sensor. The Fe 2 O 3 shell layer was obtained through thermal decomposition of acetylacetone iron (AAI) at 400 °C. The resulting CsPbBr 3 @Fe 2 O 3 heterostructured NCs exhibit a higher gas-sensing performance to H 2 S than pure CsPbBr 3 and Fe 2 O 3 , respectively. Upon exposure to 10 ppm H 2 S, the response value of 4.12 was obtained at a moderate working temperature of 350 °C, while the response was fast both in terms of response time and recovery time, i.e. , 1.84 s and 24.20 s, respectively. This might be the best performance for MHP sensors, to the best of our knowledge. The excellent gas-sensitive response might be attributed to the formation of a heterojunction which promotes the electron migration from CsPbBr 3 to Fe 2 O 3. [ABSTRACT FROM AUTHOR]

In this study, we have examined the air quality within a revitalized, post-industrial urban area in Łódź, Poland. The use of Dron technology with mobile measurement equipment allowed for accurate assessment of air quality (particulate matter and gaseous pollutants) and factors influencing air quality (wind speed and direction) on a local scale in an area of 0.18 km2 and altitudes from 2 to 50 m. The results show that the revitalization carried out in the Lodz special economic zone area contributed to eliminate internal air pollution emitters through the use of ecological and effective heat sources. The exceedances permissible concentration values were local, and concerned mainly the higher measurement zones of the troposphere (more than 30 m above ground level). In the case of gaseous pollutants, higher wind speeds were associated with a decrease in the concentration of SO2 and an increase in H2S concentration. In both cases, the wind contributed to the occurrence of local areas of accumulation of these gaseous pollutants in the spaces between buildings or wooded areas. [ABSTRACT FROM AUTHOR]

Both melatonin and hydrogen sulfide (H2S) mitigate chromium (Cr) toxicity in plants, but the specific interaction between melatonin and H2S in Cr detoxification remains unclear. In this study, the interaction between melatonin and H2S in Cr detoxification was elucidated by measuring cell wall polysaccharide metabolism and antioxidant enzyme activity in maize. The findings revealed that exposure to Cr stress (100 μM K2Cr2O7) resulted in the upregulation of L-/D-cysteine desulfhydrase (LCD/DCD) gene expression, leading to a 77.8% and 27.3% increase in endogenous H2S levels in maize leaves and roots, respectively. Similarly, the endogenous melatonin system is activated in response to Cr stress. We found that melatonin had a significant impact on the relative expression of LCD/DCD, leading to a 103.3% and 116.7% increase in endogenous H2S levels in maize leaves and roots, respectively. In contrast, NaHS had minimal effects on the relative mRNA expression of serotonin-Nacetyltransferase (SNAT) and endogenous melatonin levels. The production of H2S induced by melatonin is accompanied by an increase in Cr tolerance, as evidenced by elevated gene expression, elevated cell wall polysaccharide content, increased pectin methylesterase activity, and improved antioxidant enzyme activity. The scavenging of H2S decreases the melatonin-induced Cr tolerance, while the inhibitor of melatonin synthesis, p-chlorophenylalanine (p-CPA), has minimal impact on H2S-induced Cr tolerance. In conclusion, our findings suggest that H2S serves as a downstream signaling molecule involved in melatonin-induced Cr tolerance in maize. [ABSTRACT FROM AUTHOR]

Vitamin D receptors are expressed in many organs and tissues, which suggests that vitamin D (VD) affects physiological functions beyond its role in maintaining bone health. Deficiency or inadequacy of 25(OH)VD is widespread globally. Population studies demonstrate that a positive association exists between a high incidence of VD deficiency and a high incidence of chronic diseases, including dementia, diabetes, and heart disease. However, many subjects have difficulty achieving the required circulating levels of 25(OH)VD even after high-dose VD supplementation, and randomized controlled clinical trials have reported limited therapeutic success post-VD supplementation. Thus, there is a discordance between the benefits of VD supplementation and the prevention of chronic diseases in those with VD deficiency. Why this dissociation exists is currently under debate and is of significant public interest. This review discusses the downregulation of VD-metabolizing genes needed to convert consumed VD into 25(OH)VD to enable its metabolic action exhibited by subjects with metabolic syndrome, obesity, and other chronic diseases. Research findings indicate a positive correlation between the levels of 25(OH)VD and glutathione (GSH) in both healthy and diabetic individuals. Cell culture and animal experiments reveal a novel mechanism through which the status of GSH can positively impact the expression of VD metabolism genes. This review highlights that for better success, VD deficiency needs to be corrected at multiple levels: (i) VD supplements and/or VD-rich foods need to be consumed to provide adequate VD, and (ii) the body needs to be able to upregulate VD-metabolizing genes to convert VD into 25(OH)VD and then to 1,25(OH)2VD to enhance its metabolic action. This review outlines the association between 25(OH)VD deficiency/inadequacy and decreased GSH levels, highlighting the positive impact of combined VD+LC supplementation on upregulating GSH, VD-metabolizing genes, and VDR. These effects have the potential to enhance 25(OH)VD levels and its therapeutic efficacy. [ABSTRACT FROM AUTHOR]

Abstract In this study, we have examined the air quality within a revitalized, post-industrial urban area in Łódź, Poland. The use of Dron technology with mobile measurement equipment allowed for accurate assessment of air quality (particulate matter and gaseous pollutants) and factors influencing air quality (wind speed and direction) on a local scale in an area of 0.18 km2 and altitudes from 2 to 50 m. The results show that the revitalization carried out in the Lodz special economic zone area contributed to eliminate internal air pollution emitters through the use of ecological and effective heat sources. The exceedances permissible concentration values were local, and concerned mainly the higher measurement zones of the troposphere (more than 30 m above ground level). In the case of gaseous pollutants, higher wind speeds were associated with a decrease in the concentration of SO2 and an increase in H2S concentration. In both cases, the wind contributed to the occurrence of local areas of accumulation of these gaseous pollutants in the spaces between buildings or wooded areas.

Cystathionine gamma-lyase (CSE) is a key enzyme in reverse transsulfuration pathway and contributes to the majority of H 2 S generation in liver tissues via cysteine metabolism. Dysfunction of the CSE/H 2 S system is linked to both chronic and acute liver damage. This study investigated the regulatory role of CSE deficiency on diethylnitrosamine (DEN)-induced liver damage in mice. A single injection of DEN was administered into 4-week-old male CSE knockout (CSE-KO) mice and wild-type (WT) littermates, and the mice were sacrificed at 28 weeks of age. Compared to age-matched WT mice, CSE-KO mice spontaneously developed steatosis with increased oxidative stress and higher expressions of inflammation and fibrosis-related genes at 28-weeks of age. Following DEN injection, CSE-KO mice experienced more severe liver damage in comparison with the WT group as reflected by elevated levels of lipid accumulation, increased activities of alanine aminotransferase and aspartate aminotransferase, higher oxidative stress and fibrosis development, and increased expressions of inflammation and fibrosis-related genes. No visible tumors were observed in both types of mice with DEN treatment. In addition, the expression levels of the three H 2 S-generating proteins (CSE, cystathionine beta-synthase, and 3-mercaptopyruvate sulfurtransferase) and the H 2 S production rate in liver tissues were unaffected by DEN. Taken together, our study demonstrates that CSE provides a significant hepatoprotective effect and deficiency of CSE exaggerates DEN-induced liver damage in mice. Based on these findings, it can be suggested that targeting the CSE/H 2 S signaling pathway could be a potential therapeutic target for the treatment of liver diseases. • Older CSE-KO mice spontaneously developed steatosis with increased oxidative stress. • CSE deficiency exaggerates diethylnitrosamine-induced liver damage in mice. • Diethylnitrosamine does not affect H 2 S signals in mouse liver. • CSE/H 2 S system would be a target for treating liver diseases. [ABSTRACT FROM AUTHOR]

This research aims to investigate and quantify potential damage resulting from induced superficial defects on the surface of wires use on tensile armor of flexible pipes. Different values of kt factors and H2S concentration in aggressive gas mixtures with CO2, were analysed to determine the operational conditions that do not result in rupture of the tensile reinforcement during service, under the conditions studied. The tests were based on NACE TM0316 standard, using a 4-point bend test. Two superficial notches were created, which generated known stress concentration factor Kt values of 1.5 and 2.0, and three gaseous concentrations (220, 700, and 1100 ppm of H2S in CO2) were used. After bending tests, the samples were evaluated by metallographic and fractographic analysis, weight loss and liquid penetrant inspection. The results were then analysed using analysis of variance (ANOVA). Only the samples exposed to 220 ppm of H2S in CO2 did not rupture at both Kt values. However, for the Kt value of 2.0, cracks were observed in the longitudinal direction of the wires, originating from the machined notch. Additionally, the samples exposed to 700 ppm and 1100 ppm of H2S had a significantly higher damage score (approximately 15x) than the samples exposed to 220 ppm, regardless of the Kt value.

Abstract Over the recent years, ever-increasing population growth and higher wastewater production has been a challenge for decentralized wastewater treatment plants (WWTPs). In addition, sludge treatment due to high cost for equipment and place make authorities to find a sustainable approach in both of economical and technical perspectives. One of the proposed solutions is transferring the sludge produced from decentralized WWTP to centralized WWTP. However, the appropriate proportional ratio of raw sludge to raw sewage is a challenge, otherwise, it make anaerobic conditions and sewage rotting along the sewer network based on permissible limit of dihydrogen sulfide (H2S) gas (5 ppm). In the present study, seven reactors with different ratios of sludge to raw sewage (0, 15, 20, 25, 50, 75, 100) were used to stimulate the feasibility of transferring Shahrake Gharb WWTP sludge along the wastewater transfer pipe to the centralized sewage treatment south Tehran WWTP plant in Tehran, Iran. The septic situation and H2S emission of different reactors within 7 h (Time to reach the compound in the south treatment plant) was analyzed by gas meter. The results indicated that the optimum ratio of sludge to raw sewage was 15% without H2S production during 7 h. In addition, due to the high volume of sludge produced by the Shahrake Gharb WWTP, the optimal ratio of lime to total solids (TS) in sludge (gr/gr) (0.6) increased the sludge loading rate from 15 to 30% without any H2S emission during the stimulation study period. Therefore, the lime stabilization and transfer of sludge from a decentralized WWTP to a centralized WWTP is a feasible way to manage the sludge and enhance the treatment capacity in local WWTP.

Increasing concern over the safety of consumable products, particularly aquatic products, due to freshness issues, has become a pressing issue. Therefore, ensuring the quality and safety of aquatic products is paramount. To address this, a dual-mode colorimetric–fluorescence sensor utilizing Ce-MOF as a mimic peroxidase to detect H2S was developed. Ce-MOF was prepared by a conventional solvothermal synthesis method. Ce-MOF catalyzed the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide (H2O2) to produce blue oxidized TMB (oxTMB). When dissolved, hydrogen sulfide (H2S) was present in the solution, and it inhibited the catalytic effect of Ce-MOF and caused the color of the solution to fade from blue to colorless. This change provided an intuitive indication for the detection of H2S. Through steady-state dynamic analysis, the working mechanism of this sensor was elucidated. The sensor exhibited pronounced color changes from blue to colorless, accompanied by a shift in fluorescence from none to light blue. Additionally, UV–vis absorption demonstrated a linear correlation with the H2S concentration, ranging from 200 to 2300 µM, with high sensitivity (limit of detection, LOD = 0.262 μM). Fluorescence intensity also showed a linear correlation, ranging from 16 to 320 µM, with high selectivity and sensitivity (LOD = 0.156 μM). These results underscore the sensor's effectiveness in detecting H2S. Furthermore, the sensor enhanced the accuracy of H2S detection and fulfilled the requirements for assessing food freshness and safety. [ABSTRACT FROM AUTHOR]

To help meet emission standards, hydrogen sulfide (H2S) from geothermal production may be injected back into the subsurface, where basalt offers, in theory, the capacity to mineralize H2S into pyrite. Ensuring the viability of this pollution mitigation technology requires information on how much H2S is mineralized, at what rate and where. To date, monitoring efforts of field‐scale H2S reinjection have mostly occurred via mass balance calculations, typically capturing less than 5% of the injected fluid. While these studies, along with laboratory experiments and geochemical models, conclude effective H2S mineralization, their extrapolation to quantify mineralization and its persistence over time leads to considerable uncertainty. Here, a geophysical methodology, using time‐domain induced polarization (TDIP) logging in two of the injection wells (NN3 and NN4), is developed as a complementary tool to follow the fate of H2S re‐injected at Nesjavellir geothermal site (Iceland). Results show a strong chargeability increase at +40 days, interpreted as precipitation of up to 2 vol.% based on laboratory relationships. A uniform increase is observed along NN4, whereas it is localized below 450 m in NN3. Changes are more pronounced with larger electrode spacing, indicating that pyrite precipitation takes place away from the wells. Furthermore, a chargeability decrease is observed at later monitoring rounds in both wells, suggesting that pyrite is either passivated or re‐dissolved after precipitating. These results highlight that a sequence of overlapping reactive processes (pyrite precipitation, passivation, pore clogging and possibly pyrite re‐dissolution) results from H2S injection and that TDIP monitoring is sensitive to this sequence. Plain Language Summary: High‐temperature geothermal production is responsible for air pollution due to hydrogen sulfide (H2S) present in the magmatic fluid. To help meet emission standards, H2S may be injected back into the subsurface, where basalt offers the capacity to transform H2S into pyrite. Transformation into an immobile mineral prevents further transport into the atmosphere, sea, surface streams, or lakes. However, ensuring the viability of this pollution mitigation technology requires information such as how much H2S is mineralized, at what rate and where, which are highly uncertain due to the heterogeneity and inaccessibility of subsurface processes. Here, a geophysical monitoring methodology is developed and tested during the re‐injection of H2S at Nesjavellir geothermal site in south‐west Iceland. According to laboratory studies, pyrite precipitation is expected to increase the electrical capacitance, "chargeability," of the subsurface. Using the so‐called time‐domain induced‐polarization (TDIP) method embedded in a wireline logging tool, the chargeability of a 2 m‐wide cylinder around the injection wells is measured with high spatial‐resolution before and during H2S injection. A strong chargeability increase at +40 days indicates that up to 2% pyrite is formed. A subsequent decrease at later rounds raises questions on whether pyrite is re‐dissolved or passivated by other secondary minerals. Key Points: H2S reinjection in basalt and mineralization into pyrite was monitored using TDIP logging in two of the injection wellsChargeability increases observed at +40 days (first monitoring round) correspond to 1%–2% pyrite precipitation with great spatial variabilitySubsequent monitoring rounds show a decrease in chargeability, suggesting that pyrite is either passivated or re‐dissolved [ABSTRACT FROM AUTHOR]

In this work, CdS thin films were prepared on glass substrates using the chemical bath deposition method. The samples were used as a gas sensor for NO2 in the range of 5–50 ppm and H2S in the range of 10–50 ppm. The sensor was operated at room temperature and activated by UV LED illumination of 395 nm. The morphology, optical, and electrical properties of this nanostructure were examined using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, spectroscopic ellipsometry, UV–Vis spectroscopy and 3D optical profilometry. The films are highly sensitive to NO2 and H2S with a response of 75 and 52% at 50 ppm respectively. Furthermore, they showed good long duration stability and short response/recovery times. The sensor response to NO2 gas increases linearly with increasing gas concentration, while for H2S gas the rate of increase of the sensor response becomes greater from 20 ppm. The results obtained suggest that the developed sensor may have great application potential to detect toxic gases such as H2S and NO2 at room temperature. [ABSTRACT FROM AUTHOR]

Context: Hydrogen sulfide gas poses significant risks to both human health and the environment, with the potential to induce respiratory and neurological effects, and a heightened fatality risk at elevated concentrations. This article investigates the catalytic decomposition of H2S on a Sc-Ti3C2O2 single-atom catalyst(SAC) using the density functional theory-based first-principles calculation approach. Initially, the adsorption behavior of H2S on Ti3C2O2-MXene was examined, revealing weak physical adsorption between them. Subsequently, the transition metal atom Sc was introduced to the Ti3C2O2 surface, and its stability was studied, demonstrating high stability. Further exploration of H2S adsorption on Sc-Ti3C2O2 revealed direct dissociation of H2S gas molecules into HS* and H*, with HS* binding to Sc and H* binding to O on the Ti3C2O2 surface, resulting in OH groups. Using the transition state search method, the dissociation of H2S molecules on the SAC's surface was investigated, revealing a potential barrier of 2.45 eV for HS* dissociation. This indicates that the H2S molecule can be dissociated into H2 and S with the action of the Sc-Ti3C2O2 SAC. Moreover, the S atom left on the catalyst surface can aggregate to produce elemental S8, desorbing on the catalyst surface, completing the catalytic cycle. Consequently, the Sc-Ti3C2O2 SAC is poised to be an efficient catalyst for the catalytic decomposition of H2S. Methods: The Dmol3 module in Materials Studio software based on density functional theory is used in this study. The generalized gradient approximation method GGA-PBE is used for the exchange–correlation function. The complete LST/QST and the NEB methods in the Dmol3 module were used to study the minimum energy path of the dissociation of hydrogen sulfide molecules on the catalyst surface. [ABSTRACT FROM AUTHOR]

Aquaporins are intrinsic membrane proteins with the capacity to mediate the transport of uncharged molecules such as H 2 O, H 2 O 2 , NO, or CO 2. H 2 O 2 , NO, and H 2 S engage in crosstalk under plant oxidative stress. Aquaporin activity could be regulated by thiol-based oxidative post-translational modifications, that is, S -nitrosation, S -sulfenylation, or persulfidation. Land plants have evolved with a complex mechanism of water uptake facilitated by the activity of aquaporins under normal and challenging environments. However, we lack a clear understanding of its interactions with reactive oxygen species, particularly hydrogen peroxide (H 2 O 2) and the gasotransmitters nitric oxide (NO) and hydrogen sulfide (H 2 S), under oxidative stress. Here, we assess the crosstalk of aquaporin function, H 2 O 2 homeostasis, and NO-H 2 S signaling in plants and provide a computational prediction of cysteine-based oxidative post-translational modifications (oxiPTMs) in plant aquaporins. We propose that aquaporin activity could be regulated by three major oxiPTMs, S -nitrosation, S -sulfenylation, and persulfidation, mediated by NO, H 2 O 2 , and H 2 S, respectively. Therefore, aquaporins might be key players in the gasotransmitter-mediated long-distance oxidative stress signals in plant cells. [ABSTRACT FROM AUTHOR]

This article aims to investigate the atmospheric corrosion of carbon steel in a marine environment abundant in hydrogen sulfide (H2S) resulting from the decomposition of Sargassum seaweed. To accomplish this, four sites with varying degrees of impact were chosen along the coast of Martinique. The corrosion rates of steel were evaluated through mass loss measurements. After one year of exposure, the corrosion rates were notably high, particularly in atmospheres rich in Cl− ions and H2S, ranging from 107 µm to 983 µm. Complementing these findings, surface and product morphologies were characterized using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). These analyses revealed a significant degradation of the corrosion surface in the most affected atmospheres compared to those unaffected by Sargassum seaweed strandings. Lepidocrocite (γFeOOH) was identified as the predominant product regardless of the exposure atmosphere. However, goethite (αFeOOH) was found to be present in atmospheres most impacted by H2S. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of biochar structure on hydrogen sulfide (H2S) emissions during sludge aerobic composting, corncob biochar, beech biochar, and rice husk biochar were used as exogenous additives, which have different microscopic characteristics. The results showed that biochar reduced H2S emissions mainly by the indirect effect of the pile. Specifically, the cumulative emission of H2S in the corncob biochar group, beech biochar group, and rice husk biochar group decreased by 12.91%, 50.47%, and 36.21% compared with the control group without biochar addition, respectively. Then, it was observed by X-ray diffraction that sulfur and sulfate were formed on corncob biochar and rice husk biochar as well as sulfur was formed on beech biochar. Besides, according to microbial community analysis, the addition of beech biochar reduced the abundance of Hydrogenispora in mature stages and inhibited sulfur-related respiration compared with the other groups. In addition, the redundancy analysis showed that main factors that affected H2S emissions during aerobic composting were pile temperature and pH, followed by organic matter. What' more, the influence of biochar structure on H2S emissions depended on the total pore volume, followed by the specific surface area and the average pore diameter. This study provided evidence for biochar structure and microbial mechanism to affect H2S emissions from the sludge aerobic composting pile. [ABSTRACT FROM AUTHOR]

The role of hydrogen sulfide (H2S) on the phenotypic change of astrocytes following cerebral ischemia/reperfusion (I/R) in mice was investigated in present study. We tested the expression of glial fibrillary acidic protein (GFAP), A2 phenotype marker S100a10, and A1 phenotype marker C3 protein and assessed the change of BrdU/GFAP-positive cells, GFAP/C3-positive cells, and GFAP/S100a10-positive cells in mice hippocampal tissues to evaluate the change of astrocyte phenotypes following cerebral I/R. The role of H2S on the phenotypic change of astrocytes following cerebral I/R in mice was investigated by using H2S synthase cystathionine-γ-lyase (CSE) knockout mice (KO). The results revealed that cerebral I/R injury promoted the astrocytes proliferation of both A1 and A2 phenotypes, which were more significant in mice of H2S synthase CSE KO than in mice of wild type (WT). Interestingly, supplement with H2S could inhibit the A1 phenotype proliferation but promote the proliferation of A2 phenotype, suggesting that H2S could regulate the transformation of astrocytes to A2 phenotype following cerebral I/R, which is beneficial for neuronal recovery. Besides, we found that H2S-mediated change of astrocyte phenotype is related to inhibiting the RhoA/ROCK pathway. Furthermore, both H2S and ROCK inhibitor could ameliorate the brain injury of mice at 9 days after cerebral I/R. In conclusion, H2S regulates the phenotypic transformation of astrocytes to A2 phenotype following the cerebral I/R via inhibiting RhoA/ROCK pathway and then exerts the neuroprotective effect against the subacute brain injury. [ABSTRACT FROM AUTHOR]

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Microwave thermal therapy (MWTT) is a novel clinical treatment of tumors via inducing thermal effect and anti‐tumor immune response, exhibiting advantages of deep penetration, minimal invasion, and high heat conversion efficiency. However, effective ablation is difficult to cover the entire tumor area, and heat‐shock protein 90 (HSP90) is often upregulated after ablation to generate heat tolerance of sublethal tumors and weaken the induced antitumor immune effect, resulting in a high rate of tumor recurrence and metastasis. Herein, a multifunctional nanoregulator of metal phenolic network‐coated ZnS (ZnS@Ga‐tannic acid, ZGT) is proposed to release H2S for synergically enhancing MWTT. Under the costimulation of MW radiation and acidic tumor microenvironment, ZGT can improve the MW thermal effects of tumors to promote thermal damage and release H2S to induce tumor apoptosis. The released H2S can also inhibit the production of ATP and then downregulate the expression of HSP90, strengthening the activated systemic antitumor immune response after ablation. This nanoregulator provides a new way for achieving compensation effect for MWTT. The strategy of H2S gas to downregulate HSP90 and positively regulate antitumor immune response introduces a novel direction for reducing the risk of tumor recurrence and metastasis after thermal therapy. [ABSTRACT FROM AUTHOR]

Direct decomposition of H 2 S not only generates H 2 but also reduces sulfur (S) emission. Proper catalysts and/or reactant materials are needed to catalyze its dissociation and accommodate the decomposed S in an economical way. Here, by using the density functional theory (DFT) based calculations, we show that Aluminum (Al) can facilitate the dehydrogenation of H 2 S and the formation of H 2. The remaining S adatoms continue to accumulate on Al surface to reach high S coverage (>0.6 monolayer, ML). Then, S atoms react with surface Al atoms to afford a layer of amorphous Al 2 S 3 (a cathode material for Al–S battery) at relatively low temperature (e.g. 773 K), which will transform into crystal phase at higher temperature (e.g. 1073 K). Our research presents a new way to produce H 2 and Al 2 S 3 from H 2 S and Al. [Display omitted] • H 2 S molecules can decompose on all three low-index Al surfaces via two dehydrogenation steps. For the first step, the rank of the energy barriers is Al(110) < Al(111) < Al(100), while for the second step, it changes to Al(100) < Al(111) < Al(110). • As The H 2 S coverage increases, the first H 2 S dehydrogenation barrier becomes slightly higher. • On the S-covered Al(111), the H 2 S dehydrogenation barrier increase with the increasing S coverage. • At high S coverage (5/8 ML), S adatoms react with the surface Al atoms to form Al 2 S 3. A layer of amorphous Al 2 S 3 will be formed at 773 K and will transform into the crystal phase at higher temperature (1073 K). [ABSTRACT FROM AUTHOR]

Oxidative stress induced by excess reactive oxygen species (ROS) is a primary pathogenic cause of acute kidney injury (AKI). Development of an effective antioxidation system to mitigate oxidative stress for alleviating AKI remains to be investigated. This study presents the synthesis of an ultra‐small Platinum (Pt) sulfur cluster (Pt5.65S), which functions as a pH‐activatable prefabricated nanozyme (pre‐nanozyme). This pre‐nanozyme releases hydrogen sulfide (H2S) and transforms into a nanozyme (Ptzyme) that mimics various antioxidant enzymes, including superoxide dismutase and catalase, within the inflammatory microenvironment. Notably, the Pt5.65S pre‐nanozyme exhibits an endo‐exogenous synergy‐enhanced antioxidant therapeutic mechanism. The Ptzyme reduces oxidative damage and inflammation, while the released H2S gas promotes proneurogenesis by activating Nrf2 and upregulating the expression of antioxidant molecules and enzymes. Consequently, the Pt5.65S pre‐nanozyme shows cytoprotective effects against ROS/reactive nitrogen species (RNS)‐mediated damage at remarkably low doses, significantly improving treatment efficacy in mouse models of kidney ischemia‐reperfusion injury and cisplatin‐induced AKI. Based on these findings, the H2S‐generating pre‐nanozyme may represent a promising therapeutic strategy for mitigating inflammatory diseases such as AKI and others. [ABSTRACT FROM AUTHOR]

Objective: To investigate the correlation between serum irisin (Irisin), sclerostin (SOST), hydrogen sulfide (H2S ) and bone density and bone metabolism markers in patients with knee osteoarthritis (KOA) combined with osteoporosis (OP), and to analyze the predictive value of Irisin, SOST, and H2S for KOA complicated with OP. Methods: 179 KOA patients who were admitted to our hospital from April 2020 to April 2023 were selected, and patients were divided into OP group (68 cases) and non-OP group (111 cases) according to whether they were combine with OP. The levels of serum Irisin, SOST, H2S and bone metabolism markers osteocalcin (OC), bone alkaline phosphatase (BALP), type I procollagen N-terminal propeptide (PINP), tartrate-resistant acid phosphatase allogenic (TRACP5b), bone density of femoral neck and lumbar spine L1~4 were detected. The correlation between serum Irisin, SOST, H2S and bone density of femoral neck and lumbar spine L1~4 and serum bone metabolic markers were analyzed by Pearson, the predictive value of serum Irisin, SOST and H2S for KOA combine with OP were analyzed by receiver operating characteristic (ROC) curve. Results: The levels of serum Irisin, H2S, OC, BALP and PINP, bone density of femoral neck and lumbar spine L1~4 in OP group were lower than those in non-OP group (P<0.05), while the levels of TRACP and SOST were higher than those in non-OP group (P<0.05). Serum Irisin and H2S levels in OP group were positively correlated with bone density of femoral neck and lumbar spine L1~4, serum OC, BALP and PINP levels (P<0.05), and negatively correlated with serum TRACP level (P<0.05). SOST level was negatively correlated with bone density of femoral neck and lumbar spine L1~4, serum OC, BALP and PINP levels (P<0.05), and positively correlated with serum TRACP level (P<0.05). The area under the curve of Irisin, SOST and H2S in predicting KOA combined with OP was 0.784, 0.773 and 0.755 respectively, the area under the curve of combined prediction of KOA combine with OP was 0.908, which was higher than that of single prediction. Conclusion: Serum Irisin and H2S levels decreased and SOST levels increased in patients with KOA combined with OP. Low levels of Irisin, H2S and high levels of SOST are associated with decreased bone mineral density and abnormal bone metabolism, which can be used to predict abnormal bone metabolism and risk of bone loss in patients with KOA combine with OP. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H 2 S) gas is a dual menace since it is not only hazardous to human health and the environment, but it is also flammable. Given these crucial considerations, the need for competent gas sensors for H 2 S detection becomes apparent. In this endeavor, an investigation of the gas-sensing prowess inherent in sensors made from assembled nanosheets of ZnO–NiO arranged into intricate flower-like structures. The sensing materials were prepared using a straightforward solvothermal process. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to thoroughly examine the sensor's chemical properties and structural composition. The gas-sensing abilities of the sensing materials were rigorously assessed, which included a close examination of their electrical response to varied concentrations of H 2 S. The efficacy of the sensors may be due to the synergistic interactions between their distinct flower-like design, endowing them with an expansive surface area for optimum gas adsorption, and the significant catalytic impact supplied by the composition of ZnO–NiO. The results show that the ZnO–NiO flower-like sensors have high sensitivity, selectivity, and stability to H 2 S gas. Within the studied range, the response and recovery times were 51.43 s and 38.11 s respectively at 250 °C in 100 ppm H 2 S. This amalgamation of attributes manifests as an enhancement in the sensors' gas-sensing capabilities, highlighting their suitability for such an application. This research complements the explanation offered by first-principles calculations based on Density Functional Theory (DFT) to dive into the fundamentals of this gas-sensing mechanism. [ABSTRACT FROM AUTHOR]

The bimetallic metal–organic frameworks (MOFs), Cu/Co-MOF, was synthesized through a solvothermal method and calcined to obtain CuO/Co3O4 composites. By adjusting the molar ratio between Cu and Co ions, a composite material of CuO/Co3O4 (Cu:Co = 1:1) was developed and showed excellent sensing capabilities, and the response reached as high as 196.3 for 10 ppm H2S detection. Furthermore, the optimal operating temperature as low as 40 °C was found. In comparison with the sensors prepared by pristine CuO and pristine Co3O4, the sensor based on CuO/Co3O4 composite exhibited a significant response. Additionally, the sensor can detect H2S gas down to 300 ppb. The gas sensing mechanism is discussed in depth from the perspective of p–p heterojunction formation between the p-type CuO and p-type Co3O4. The as-prepared CuO/Co3O4 composite-based sensor is expected to find practical application in the low-power monitoring of H2S. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S), previously regarded as a toxic exhaust and atmospheric pollutant, has emerged as the third gaseous signaling molecule following nitric oxide (NO) and carbon monoxide (CO). Recent research has revealed significant biological effects of H2S in a variety of systems, such as the nervous, cardiovascular, and digestive systems. Additionally, H2S has been found to impact reproductive system function and may have therapeutic implications for reproductive disorders. This paper explores the relationship between H2S and male reproductive disorders, specifically erectile dysfunction, prostate cancer, male infertility, and testicular damage. Additionally, it examines the impact of H2S regulation on the pathophysiology of the female reproductive system, including improvements in preterm birth, endometriosis, pre-eclampsia, fetal growth restriction, unexplained recurrent spontaneous abortion, placental oxidative damage, embryo implantation, recovery of myometrium post-delivery, and ovulation. The study delves into the regulatory functions of H2S within the reproductive systems of both genders, including its impact on the NO/cGMP pathway, the activation of K+ channels, and the relaxation mechanism of the spongy smooth muscle through the ROCK pathway, aiming to broaden the scope of potential therapeutic strategies for treating reproductive system disorders in clinical settings. [ABSTRACT FROM AUTHOR]

In developing the highly acidic oil and gas resources which are abundant in China, the set cement in the wellbore will long endure the erosion of the acid media such as H2S, and the this seriously threatens the safe operation and production of the oil and gas wells. To deal with this problem, a ZnFe-LDHs type corrosion inhibitor against the corrosion by the H2S is developed through hydrothermal coprecipitation method. Set cement samples containing the selected ZnFe-LDHs are soaked in 5% Na2S solution at room temperature and 60 č for 1 d, 3 d, 7 d, 14 d and 28 d, respectively. The ability of ZnFe-LDHs to resist H2S corrosion and the mechanisms of this resistance are then studied through compressive strength measurement, XRD and SEM. The study shows that the ZnFe-LDHs made at crystallization of 90 č and Zn/Fe molar ratio of (1 –4):1 has satisfactory corrosion control performance; it increases the compressive strength of the set cement and the compressive strength of the set cement increases with increase in the molar ratio of Zn/Fe, that is, the ZnFe-LDHs with Zn/Fe molar ratio of 4:1 has the best effect on the compressive strength of the set cement; the compressive strength of the set cement is increased by 10.11%. When the set cement sample are soaked in Na2S solution, the early strength of the set cement decreases. After soaking for 7 d, the compressive strength of the set cement soaked at room temperature and at 60 č is increased by 8.73% and 4.96%, respectively. When the soaking time is longer than 7 d, the compressive strength of the set cement becomes stable, the reason for this is that ZnFe-LDHs is able to promote hydration reaction, and in the later stage of the soaking, ZnFe-LDHs react with Na2S to produce ZnS, thereby increasing the density of the set cement and preventing the corrosion of H2S to the set cement. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF) materials with various shapes and sizes are recognized as outstanding templates for preparing porous metal oxides used as gas-sensitive materials. Here, a facile synthetic strategy is developed to assemble ZIF-67 and ZIF-8 into Co3O4/ZnO hollow porous nanofibers with an MOF-on-MOF heterojunction for gas-sensing applications. The fabricated sensor using this innovative MOF-on-MOF nanomaterial demonstrates high gas sensor response, low limit of detection, remarkable selectivity, and excellent stability to H2S gas. Notably, the Co3O4/ZnO nanofibers show a maximum response of 50 and 1080 at 200 ppb and 5 ppm of H2S under optimal conditions, respectively. Furthermore, the gas-sensing mechanism is proposed in detail, and theoretical calculations based on first-principles further reveal the performance of Co3O4/ZnO nanofibers in enhancing the sensing of H2S. This study offers an approach for fabricating dual MOF-based nanostructures with abundant pores and high surface area for high-performance gas-sensing applications. [ABSTRACT FROM AUTHOR]

Over the recent years, ever-increasing population growth and higher wastewater production has been a challenge for decentralized wastewater treatment plants (WWTPs). In addition, sludge treatment due to high cost for equipment and place make authorities to find a sustainable approach in both of economical and technical perspectives. One of the proposed solutions is transferring the sludge produced from decentralized WWTP to centralized WWTP. However, the appropriate proportional ratio of raw sludge to raw sewage is a challenge, otherwise, it make anaerobic conditions and sewage rotting along the sewer network based on permissible limit of dihydrogen sulfide (H2S) gas (5 ppm). In the present study, seven reactors with different ratios of sludge to raw sewage (0, 15, 20, 25, 50, 75, 100) were used to stimulate the feasibility of transferring Shahrake Gharb WWTP sludge along the wastewater transfer pipe to the centralized sewage treatment south Tehran WWTP plant in Tehran, Iran. The septic situation and H2S emission of different reactors within 7 h (Time to reach the compound in the south treatment plant) was analyzed by gas meter. The results indicated that the optimum ratio of sludge to raw sewage was 15% without H2S production during 7 h. In addition, due to the high volume of sludge produced by the Shahrake Gharb WWTP, the optimal ratio of lime to total solids (TS) in sludge (gr/gr) (0.6) increased the sludge loading rate from 15 to 30% without any H2S emission during the stimulation study period. Therefore, the lime stabilization and transfer of sludge from a decentralized WWTP to a centralized WWTP is a feasible way to manage the sludge and enhance the treatment capacity in local WWTP. [ABSTRACT FROM AUTHOR]

Cysteine and its derivatives, including H2S, can influence bacterial virulence and sensitivity to antibiotics. In minimal sulfate media, H2S is generated under stress to prevent excess cysteine and, together with incorporation into glutathione and export into the medium, is a mechanism of cysteine homeostasis. Here, we studied the features of cysteine homeostasis in LB medium, where the main source of sulfur is cystine, whose import can create excess cysteine inside cells. We used mutants in the mechanisms of cysteine homeostasis and a set of microbiological and biochemical methods, including the real-time monitoring of sulfide and oxygen, the determination of cysteine and glutathione (GSH), and the expression of the Fur, OxyR, and SOS regulons genes. During normal growth, the parental strain generated H2S when switching respiration to another substrate. The mutations affected the onset time, the intensity and duration of H2S production, cysteine and glutathione levels, bacterial growth and respiration rates, and the induction of defense systems. Exposure to chloramphenicol and high doses of ciprofloxacin increased cysteine content and GSH synthesis. A high inverse relationship between log CFU/mL and bacterial growth rate before ciprofloxacin addition was revealed. The study points to the important role of maintaining cysteine homeostasis during normal growth and antibiotic exposure in LB medium. [ABSTRACT FROM AUTHOR]

Background: Our previous research shows that Curcumin (CUR) attenuates myocardial ischemia-reperfusion injury (MIRI) by reducing intracellular total RNA m6A levels. However, the mechanism remains unknown. Methods: For ischemia-reperfusion (IR), H9c2 cells were cultured for 6 h in serum-free low-glycemic (1 g/L) medium and a gas environment without oxygen, and then cultured for 6 h in high-glycemic (4.5 g/L) medium supplemented with 10% FBS and a 21% oxygen environment. The effects of different concentrations of CUR (5, 10, and 20 µM) treatments on signaling molecules in conventionally cultured and IR-treated H9c2 cells were examined. Results: CUR treatment significantly up-regulated the H2S levels, and the mRNA and protein expression of cystathionine γ-lyase (CSE), and down-regulated the mRNAs and proteins levels of thiosulfate sulfurtransferase (TST) and ethylmalonic encephalopathy 1 (ETHE1) in H9c2 cells conventionally cultured and subjected to IR. Exogenous H2S supply (NaHS and GYY4137) significantly reduced intracellular total RNA m6A levels, and the expression of RNA m6A "writers" METTL3 and METTL14, and increased the expression of RNA m6A "eraser" FTO in H9c2 cells conventionally cultured and subjected to IR. CSE knockdown counteracted the inhibitory effect of CUR treatment on ROS production, promotion on cell viability, and inhibition on apoptosis of H9c2 cells subjected to IR. Conclusion: CUR attenuates MIRI by regulating the expression of H2S level-regulating enzymes and increasing the endogenous H2S levels. Increased H2S levels could regulate the m6A-related proteins expression and intracellular total RNA m6A levels. [ABSTRACT FROM AUTHOR]

Composite membranes were prepared from lignin alkali (LA), polyvinyl alcohol (PVA), and cellulose nanofibrils (CNF) using a simple, low-cost, and environmentally friendly method. The deodorization performances and structures of these membranes were also characterized. The sample referred to as L3C3P5 prepared with a solution containing 35.7 wt% LA, 53.6 wt% PVA, and 10.7 wt% CNF showed the best deodorization properties, and the H2S adsorption time reached 36 min. The adsorption performance was further improved by adding nano-CuO to the membrane, and the H2S adsorption time of the doped membrane L3C3P5C4 reached 60 min. While the H2S adsorption performance improved, structural analysis revealed that the addition of nano-CuO reduced the crystallinity in the membrane, caused the membrane to crack, and led to a decrease in the mechanical properties. The surface oxygens in the L3C3P5C4 membrane were primarily C–O bonds and lattice oxygens in CuO. After the H2S adsorption reaction, the lattice oxygen disappeared, and CuS products appeared. [ABSTRACT FROM AUTHOR]

Leaf senescence is the terminal stage of leaf development, and its initiation and progression are closely controlled by the integration of a myriad of endogenous signals and environmental stimuli. It has been documented that WRKY transcription factors (TFs) play essential roles in regulating leaf senescence, yet the molecular mechanism of WRKY-mediated leaf senescence still lacks detailed elucidation in crop plants. In this study, we cloned and identified a tobacco WRKY TF gene, designated NtWRKY70b, acting as a positive regulator of natural leaf senescence. The expression profile analysis showed that NtWRKY70b transcript levels were induced by aging and hydrogen peroxide (H2O2) and downregulated upon hydrogen sulfide (H2S) treatment. The physiological and biochemical assays revealed that overexpression of NtWRKY70b (OE) clearly promoted leaf senescence, triggering increased levels of reactive oxygen species (ROS) and decreased H2S content, while disruption of NtWRKY70b by chimeric repressor silencing technology (SRDX) significantly delayed the onset of leaf senescence, leading to a decreased accumulation of ROS and elevated concentration of H2S. The quantitative real-time PCR analysis showed that the expression levels of various senescence-associated genes and ROS biosynthesis-related genes (NtRbohD and NtRbohE) were upregulated in OE lines, while the expression of H2S biosynthesis-related genes (NtDCD and NtCYSC1) were inhibited in OE lines. Furthermore, the Yeast one-hybrid analysis (Y1H) and dual luciferase assays showed that NtWRKY70b could directly upregulate the expression of an ROS biosynthesis-related gene (NtRbohD) and a chlorophyll degradation-related gene (NtPPH) by binding to their promoter sequences. Accordingly, these results indicated that NtWYKY70b directly activated the transcript levels of NtRbohD and NtPPH and repressed the expression of NtDCD and NtCYCS1, thereby promoting ROS accumulation and impairing the endogenous H2S production, and subsequently accelerating leaf aging. These observations improve our knowledge of the regulatory mechanisms of WRKY TFs controlling leaf senescence and provide a novel method for ensuring high agricultural crop productivity via genetic manipulation of leaf senescence in crops. [ABSTRACT FROM AUTHOR]

First principles were used to study the adsorptive dissociation process of H2S on the Cr(111) plane, and adsorptions of H2S molecules and their dissociated products on the Cr(111) plane were studied using adsorption energy, adsorption configuration, and Partial density of states (PDOS) plots, all of which are biased to- ward inclined adsorption on the Cr(111) plane. At the same time, the co-adsorption of HS/H and S/H was studied, and it was found that the co-adsorbed species had obvious interactions on the Cr(111) surface. Finally, the transition state of the dissociation reaction was determined using linear synchronization and quadratic synchronization transformation methods. It is known that the activation energies of the first and second steps dissociation are 1.65 eV and 0. 82 eV respectively, and the dissociation process of H2S molecule on the Cr(111) surface is an exothermic reaction, and the reaction energy is -2.90 eV. [ABSTRACT FROM AUTHOR]

The residential area in the main urban area of Chongqing was selected for field investigation. The sewage quality, flow rate, H2S and other indicators of the inlet and outlet of the septic tank in the residential area were measured, and the impact of the abolition of the septic tank on the drainage system and the surrounding environment was analyzed. The result showed that（1） from the flow point of view, according to the results of the community flow, there was little difference in the flow before and after the septic tank on weekdays or weekends, and the cancellation of the septic tank had little effect on the total amount of sewage entering the municipal pipe network;（2） from the water quality, the septic tank had a higher reduction rate for COD, BOD5 and SS. The average decline rate of COD/TN was 43%. The average decline rate of COD/TP was 38%;（3） according to the measured results of H2S in the community, the average concentration of H2S in the septic tank was 8. 20 mg/m³, and the average concentration of H2S in the sewage pipeline was 2. 70 mg/m³. Canceling the septic tank could effectively reduce the risk of odor emission that could be obviously perceived by human senses, and had a positive effect on improving the air quality of the community. [ABSTRACT FROM AUTHOR]

The trend of research using mixed metal oxide as a selective adsorbent for H2S gas is increasing. Inline with that, this paper evaluated the performance of Zn-Fe/Al2O3 adsorbent in adsorbing H2S as one of the steps in biogas purification process. The Zn-Fe/Al2O3 was successfully synthesized by microwave-assisted wet impregnation technique. The results showed that some operation parameters such as biogas space velocity, H2S inlet concentration, and biogas humidity had obvious influence on the performance of the gas adsorber. At low gas hourly space velocity (GHSV) of 1750 h−1, low H2S inlet concentrations (100 ppm), and no moisture in biogas, the highest breakthrough capacity was achieved with 3.23 mg H2S per gram adsorbent. Fresh and spent adsorbents were characterized by SEM–EDX to investigate the impact of H2S adsorption on the physical properties of the adsorbent. According to the good performance in removing H2S under ambient conditions, the Zn-Fe/Al2O3 is expected to be a promising adsorbent for H2S adsorption in biogas purification process. [ABSTRACT FROM AUTHOR]

BACKGROUND: To our best knowledge, no experimental study has previously investigated the simultaneous effects of adding Fe powder for the decrease of hydrogen sulfide (H2S) in biogas and the removal of phosphate (PO4‐P) in continuous anaerobic digestion (AD). This study investigated the effects of iron (Fe) powder (5 g L−1) in AD to remove H2S and PO4‐P. A comparative experiment was conducted using two semi‐continuous‐flow anaerobic digesters treating primary sludge at decreasing hydraulic retention times (HRTs) of 20 to 10 days. RESULTS: The addition of Fe powder to AD removed > 98% of H2S at all HRTs, and removed 64–72% of PO4‐P, with the highest removal efficiency at HRT = 10 d. The addition of Fe powder to AD had no noticeable effect on biogas production or pH, but it increased the CH4 content (62.7–66.0% in Fe‐treated vs 58.2–60.4% in the Control) partly due to the greater presence of Methanoregulaceae. The relative abundance of the microbial groups was more affected by HRT than by the addition of Fe powder. The presence of Fe powder notably increased the abundance of Spirochaetaceae and Syntrophaceae. CONCLUSION: As shown, the addition of Fe powder can improve the management of both H2S in the biogas and PO4‐P in the digested sludge in the AD system. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

ABSTRACT: A large amount of hydrogen sulfide (H2S) is produced in the process of chicken breeding, which can cause serious inflammation and oxidative damage to the respiratory system of chickens. Tea tree oil (TTO) has antioxidant and anti-inflammatory properties. No studies have been reported on the use of TTO in H2S-induced lung injury in chickens. Therefore, in this study, 240 one-day-old Roman pink laying hens were randomly and equally divided into 3 groups: control group (CON), H2S exposure group (AVG, containing H2S), and TTO treatment group (TTG, containing H2S and 0.02 mL/L TTO) to establish an experimental model of TTO treatment with H2S exposure for a period of 42 d. Hematoxylin and eosin (H&E) staining was used to detect lung histopathology. Gene expression profiles were analyzed using transcriptomics. The underlying mechanism of the amelioration of lung injury by TTO was further revealed by antioxidant enzyme assays and qRT-PCR. The results showed that H2S exposure induced significant gene expression of CYP450s (CYP1B1 and CYP1C1) (P < 0.05), and caused intense oxidative stress, apoptosis and inflammation compared with CON. TTO could reduce ROS production and enhance antioxidant capacity (SOD, CAT, T-AOC, and GSH-PX) by regulating the CYP450s/ROS pathway (P < 0.05). Compared with the control group, the treatment group showed significantly decreased expression of apoptotic (Caspase-8, Caspase-3, Bid and Fas) (P < 0.05) and inflammatory (IL-4, IL-16, NF-κB, TNF-α and IFN-γ) (P < 0.05) factors in the lung. This study revealed that TTO regulated CYP450s/ROS pathway to alleviate H2S-induced lung injury in chickens. These results enrich the theory of the action mechanism of TTO on H2S-exposed chicken lungs and are of great value for the treatment of H2S-exposed animals.

Objective This study aimed to investigate the regulatory effects of exogenous hydrogen sulfide (H2S) on seed germination, seedling growth, and reactive oxygen species (ROS) homeostasis in alfalfa under chromium (Cr) ion (III) stress. Methods The effects of 0–4 mM Cr(III) on the germination and seedling growth of alfalfa were first assessed. Subsequently, following seed NaHS immersion, the influence of H2S on alfalfa seed germination and seedling growth under 2 mM Cr(III) stress was investigated, and the substance contents and enzyme activities associated with ROS metabolism were quantified. Results Compared to the control group, alfalfa plant germination was delayed under 2 mM Cr(III) stress for up to 48 h (p

As an important endogenous gasotransmitter, hydrogen sulfide (H2S) plays a critical role in various physiological functions and has been regarded as a biomarker of cancer due to its overexpression in cancer cells. In addition, the early stages of cancer are often accompanied by abnormalities in the intracellular microenvironments, and distinguishing between cancer cell/tissues and normal cell/tissues is of great significance to the accuracy of cancer diagnosis. However, deep insights into the simultaneous detection of H2S and viscosity/polarity variations in cancer cells/tissues are rarely reported. In this work, we designed and synthesized a mitochondria-targeting fluorescent probe PDQHS, which exhibits high selectivity for H2S with an emission peak around 632 nm and excellent response (17-fold) to viscosity/polarity beyond 706 nm. Meanwhile, PDQHS shows good biocompatibility and can specifically accumulate into mitochondria. Using PDQHS, the visual distinguishing of cancer cells from normal cells was achieved via dual-channel detection of H2S and viscosity/polarity. More importantly, PDQHS has been successfully applied to visualize endogenous and exogenous H2S in living cells and tumor tissue. Obviously, compared to the detection of a single biomarker, monitoring multiple biomarkers simultaneously through dual-channel response is conducive to amplifying the detection signal, providing a more sensitive and reliable imaging tool in the tumor region, which is beneficial for cancer prediction. [ABSTRACT FROM AUTHOR]

Rapid growth in the annual production of organic solid waste has become a huge challenge worldwide. Aerobic composting technology is one of the mainstream technologies based on utilizing organic solid waste resources. However, during the composting process, microorganisms are highly active, constantly decomposing organic matter and often produce large amounts of foul-smelling gases that are released in atmosphere, especially ammonia (NH3) and hydrogen sulfide (H2S) ; these gases have serious impacts on human and animal health as well as environmental quality. The present study focuses on summarizing the generation mechanism and transformation pathway of NH3 and H2S during the aerobic composting process of organic solid waste. Concerning the aspects of controlling endogenous parameters (C / N ratio, aeration rate, initial moisture content, and initial pH) and exogenous material addition (chemical, physical, and biological additives), this study introduces the synergistic emission reduction technologies of NH3 and H2S. Furthermore, this study proposes prospects for future research directions based on the research status quo in this field. A review of existing research has shown that various composting parameters interact with each other and must be considered and optimized together. The effect of regulating the endogenous parameters within the compost pile is limited. However, further optimization of the endogenous parameters and coupling of exogenous material addition can improve the emission reduction efficiency of NH3 and H2S during composting; this will help in promoting the green and efficient development of aerobic composting technology. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) has been recently recognized as an important gasotransmitter with cardioprotections, and iron is vital for various cellular activities. This study explored the regulatory role of H2S on iron metabolism and mitochondrial functions in cultured rat cardiac cells. Rotenone, a mitochondrial complex I inhibitor, was used for establishing an in vitro model of ischemic cell damage. It was first found that rotenone induced oxidative stress and lipid peroxidation and decreased mitochondrial membrane potential and ATP generation, eventually causing cell death. The supplement of H2S at a physiologically relevant concentration protected from rotenone-induced ferroptotic cell death by reducing oxidative stress and mitochondrial damage, maintaining GPx4 expression and intracellular iron level. Deferiprone, an iron chelator, would also protect from rotenone-induced ferroptosis. Further studies demonstrated that H2S inhibited ABCB8-mediated iron efflux from mitochondria to cytosol and promoted NFS1-mediated Fe-S cluster biogenesis. It is also found that rotenone stimulated iron-dependent H2S generation. These results indicate that H2S would protect cardiac cells from ischemic damage through preserving mitochondrial functions and intracellular Fe-S cluster homeostasis. [ABSTRACT FROM AUTHOR]

The accurate and effective identification of hydrogen sulfide holds great significance for environmental monitoring. Azide-binding fluorescent probes are powerful tools for hydrogen sulfide detection. We combined the 2'-Hydroxychalcone scaffold with azide moiety to construct probe Chal-N3, the electron-withdrawing azide moiety was utilized to block the ESIPT process of 2'-Hydroxychalcone and quenches the fluorescence. The fluorescent probe was triggered with the addition of hydrogen sulfide, accompanied by great fluorescence intensity enhancement with a large Stokes shift. With excellent fluorescence properties including high sensitivity, specificity selectivity, and wider pH range tolerance, the probe was successfully applied to natural water samples. [ABSTRACT FROM AUTHOR]

Context: MOFs are promising candidates for the capture of H2S and CO2 from raw biogas. The presence of H2S residues in natural gas pipelines can cause corrosive damage and reduce energy efficiency. H2S capture from biogas presents several challenges due to its high toxicity and its corrosiveness. Microporous MOFs incorporating Lewis basic sites have demonstrated efficient capture of small and polar gas molecules such as CO2 and H2S from gas binary mixtures. In the quest to design and investigate functional materials to support the energy transition, specifically for the purification of RNG gas, we theoretically investigated the potential of s-heptazine-based IRH-1 for H2S capture from CH4 mixtures. IRH-1 exhibited significantly higher adsorption capacities for H2S (2.60 mmol/g) and CO2 (2.68 mmol/g) compared to CH4 (0.98 mmol/g) at 100 kPa and 298 K simulated by GCMC. All computed average energies for H2S were below 20 kJ/mol, indicating an exothermic physisorption behavior within the pores of IRH-1. IAST revealed remarkable H2S selectivity of IRH-1 for CH4/H2S binary mixtures at 5%, 10%, 15%, and 20% of H2S at 100 kPa. Methods: GCMC simulations were performed with the BIOVIA Materials Studio 5.0 package using LJ potentials and UFF parameters to investigate the adsorption of pure H2S gas in the IRH-1 material. The IAST method was used to predict the adsorption behavior of H2S in different H2S/CH4 gas mixtures. The IAST calculations were performed using the Python package pyIAST, which allows the prediction of adsorption isotherms for mixed gases based on the adsorption isotherms for pure gases by numerical integration of the Gibbs adsorption approach. [ABSTRACT FROM AUTHOR]

A nitrogen-doped carbon microsphere sorbent with a hierarchical porous structure was synthesized via aggregation-hydrothermal carbonization. The Hg0 adsorption performance of the nitrogen-doped carbon microsphere sorbent was tested and compared with that of the coconut shell activated carbon prepared in the laboratory. The effect of H2S on Hg0 adsorption was also investigated. The nitrogen-doped carbon microsphere sorbent exhibited superior mercury removal performance compared with that of coconut shell activated carbon. In the absence of H2S at a low temperature (⩽ 100 °C), the Hg0 removal efficiency of the nitrogen-doped carbon microsphere sorbent exceeded 90%. This value is significantly higher than that of coconut shell activated carbon, which is approximately 45%. H2S significantly enhanced the Hg0 removal performance of the nitrogen-doped carbon microsphere sorbent at higher temperatures (100–180 °C). The hierarchical porous structure facilitated the diffusion and adsorption of H2S and Hg0, while the nitrogen-containing active sites significantly improved the adsorption and dissociation capabilities of H2S, contributing to the generation of more active sulfur species on the surface of the nitrogen-doped carbon microsphere sorbent. The formation of active sulfur species and HgS on the sorbent surface was further confirmed using X-ray photoelectron spectroscopy and Hg0 temperature-programmed desorption tests. Density functional theory was employed to elucidate the adsorption and transformation of Hg0 on the sorbent surface. H2S adsorbed and dissociated on the sorbent surface, generating active sulfur species that reacted with gaseous Hg0 to form HgS. [ABSTRACT FROM AUTHOR]

The pathological mechanisms and treatments of osteoarthritis (OA) are critical topics in medical research. This paper reviews the regulatory mechanisms of hydrogen sulfide (H2S) in OA and the therapeutic potential of H2S donors. The review highlights the importance of changes in the endogenous H2S pathway in OA development and systematically elaborates on the role of H2S as a third gaseous transmitter that regulates inflammation, oxidative stress, and pain associated with OA. It also explains how H2S can lessen bone and joint inflammation by inhibiting leukocyte adhesion and migration, reducing pro-inflammatory mediators, and impeding the activation of key inflammatory pathways such as nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK). Additionally, H2S is shown to mitigate mitochondrial dysfunction and endoplasmic reticulum stress, and to modulate Nrf2, NF-κB, PI3K/Akt, and MAPK pathways, thereby decreasing oxidative stress-induced chondrocyte apoptosis. Moreover, H2S alleviates bone and joint pain through the activation of Kv7, K-ATP, and Nrf2/HO-1-NQO1 pathways. Recent developments have produced a variety of H2S donors, including sustainedrelease H2S donors, natural H2S donors, and synthetic H2S donors. Understanding the role of H2S in OA can lead to the discovery of new therapeutic targets, while innovative H2S donors offer promising new treatments for patients with OA. [ABSTRACT FROM AUTHOR]