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The gasotransmitters nitric oxide (NO) and hydrogen sulfide (H 2 S) play important roles not only in maintaining physiological functions, but also in pathological conditions and events. Importantly, these molecules show a complex interplay in cancer biology, demonstrating both tumor-promoting and anti-tumor activities depending on their concentration, flux, and the environmental redox state. Additionally, various cell types respond differently to NO and H 2 S. These gasotransmitters can be synergistically combined with traditional anticancer treatments such as radiotherapy, immunotherapy, chemotherapy, and phototherapy. Notably, NO, and more recently H 2 S, have been shown to reverse multidrug resistance. Nanomaterials to deliver NO donors and, to a lesser extent, H 2 S donors, have emerged as a promising approach for targeted delivery of these gasotransmitters. Nanotechnology has advanced the delivery of anticancer drugs, enhancing efficiency and reducing side effects on non-cancerous cells. This review highlights recent progress in the design of NO and H 2 S-releasing nanomaterials for anticancer effects. It also explores the interactions between NO and H 2 S, which are crucial for developing combined therapies and nanomedicines with minimal side effects. • This review integrates recent nitric oxide (NO) and hydrogen sulfide (H 2 S) releasing nanomaterials in cancer treatment. • Research gaps are identified where further contributions can enhance understanding of the physiological roles of NO and H 2 S. • Gaps are explored throughout, highlighting potential avenues for exploration in cancer treatment using NO and H 2 S. [ABSTRACT FROM AUTHOR]

Classical homocystinuria is a rare disease caused by mutations in cystathionine β-synthase (CBS) gene (OMIM 613381). CBS catalyzes the first step of the transsulfuration pathway that converts homocysteine (Hcy) into cystathionine (Cysta) via a number of co-substrates and mechanisms. Formation of Cysta by condensation of Hcy and cysteine (Cys) produces a molar equivalent of hydrogen sulfide (H 2 S). H 2 S plays important roles in cognitive and vascular functions. Clinically, patients with CBS deficiency present with vascular, ocular, neurological and skeletal impairments. Biochemically, CBS deficiency manifests with elevated Hcy and reduced concentration of Cysta in plasma and urine. A number of pathogenic variants of human CBS have been characterized by their residual enzymatic activity, but very few studies have examined H 2 S production by pathogenic CBS variants, possibly due to technical hurdles in H 2 S detection and quantification. We describe a method for the real-time, continuous quantification of H 2 S formed by wild-type and pathogenic variants of human recombinant CBS, as well as by fibroblast extracts from healthy controls and patients diagnosed with CBS deficiency. The method takes advantage of the specificity and high affinity of hemoglobin I of the clam Lucina pectinata toward H 2 S and is based on UV–visible spectrophotometry. Comparison with the gold-standard, end-point H 2 S quantification method employing monobromobimane, as well as correlations with CBS enzymatic activity determined by LC-MS/MS showed agreement and correlation, and permitted the direct, time-resolved determination of H 2 S production rates by purified human recombinant CBS and by CBS present in fibroblast extracts. Rates of H 2 S production were highest for wild-type CBS, and lower for pathogenic variants. This method enables the examination of structural determinants of CBS that are important for H 2 S production and its possible relevance to the clinical outcome of patients. [Display omitted] • Hydrogen sulfide (H 2 S) is produced by transsulfuration enzymes and the microbiome. • Cystathionine beta-synthase (CBS) is the major intracellular source of H 2 S. • The chemical properties of H 2 S challenge its quantitation in biological specimens. • Hemoglobin I of Lucina pectinata serves as a specific biosensor to detect H 2 S. • H 2 S formed by purified CBS and in human fibroblasts are quantifiable in real time. [ABSTRACT FROM AUTHOR]

• Inoculation increase the temperature, reduce the pH value and improve the GI. • Inoculants reduce the release of NH 3 and H 2 S. • Inoculants reduces the content of nitrogen compounds and increases the content of sulfur compounds. • There is correlation between physicochemical indexes and nitrogen and sulfur compounds in SS. In this study, high temperature thermotolerant nitrifying bacteria (TNB) and high temperature thermotolerant sulfide oxidizing bacteria (TSOB) were obtained from compost samples and inoculated into sewage sludge (SS) compost. The effects of inoculation on physical and chemical parameters, ammonia and hydrogen sulfide release, nitrogen form and sulfur compound content change and physical-chemical properties during nitrogen and sulfur conversion were studied. The results showed that inoculation of TNB and TSOB increased the temperature, pH, OM degradation, C/N ratio and germination index (GI) of compost. Compared with the control treatment (CK), the addition of inoculants reduced the release of NH 3 and H 2 S, and transformed them into nitrogen and sulfur compounds, the hydrolysis of polymeric ferrous sulfate was promoted, resulting in relatively high content of sulfite and sulfate. At the same time, the physical and chemical properties of SS have a strong correlation with nitrogen and sulfur compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

This study evaluated the effectiveness of using iron (Fe) powder and ferrous chloride (FeCl2) to decrease hydrogen sulfide (H2S) concentration ([ H2S ]) from biogas production by anaerobic digestion (AD) of primary sludge, and to decrease phosphate (PO4-P) concentration ([ PO4-P ]) in the sludge. [ H2S ] and [ PO4-P ] removal increased as doses of Fe powder and FeCl2 increased to a certain point. Optimal supplementation was 5 g/L for Fe powder (H2S reduction=98% , PO4-P removal=95%) and 0.5 g/L for FeCl2 (H2S reduction=98% , PO4-P removal=97%). Appropriate dosage of Fe powder or FeCl2 can control [ H2S ] in biogas and decrease [ PO4-P ] in AD effluent, but excessive dosage can inhibit the digestion. The biogas production and methane content were higher with Fe powder compared with FeCl2 , but neither treatment had a significant effect on methane yield. The measured biogas production was accurately captured by the first-order kinetic model, as evidenced by a strong fit with high R2 values (0.957–0.980), and the deviations between the measured and predicted biogas production using the first-order kinetic model were <10%. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide is produced through industrial sources such as textiles, oil and gas refineries, and paper. Exposure to high concentrations of hydrogen sulfide has caused death in industrial environments. Various methods, including adsorption, have been considered a suitable approach due to low energy consumption, lower costs, and high efficiency. In this research, the synthesis and optimization of MIPs@H2S-specific nanoadsorbent of hydrogen sulfide gas were done using the response surface method. Initially, the synthesis of MIPs\NIPs@H2S nanoadsorbent was done by the SIP method and four variables, including dose, temperature, concentration, and flow, which were decided upon utilizing RSM with central compound design. Thirty experiments were also designed to optimize the variables affecting the adsorption capacity. Besides, physical characteristics were determined by FTIR, XRD, FE-SEM, BET, and total pore volume and nitrogen adsorption. The analysis of variance indicated a linear model, while the adsorbent dosage and temperature are the most important process variables to calculate the optimal operating conditions of the process affecting the H2S adsorption capacity. The projected results of the linear correlation demonstrated excellent concurrence with the experimental observations. The optimal process variables obtained from numerical optimization were equal to the adsorbent dose of 1.32 gr, concentration of 752.2 PPM, flow of 85 ml/min, and temperature being equal to 42.5 °C. Based on the optimal conditions, the highest adsorption capacity of MIPs@H2S (61.28 mg/g = 94.7%) and NIPs@H2S (6.14 mg/g = 9.14%) was obtained. The C.C.D. method is suitable for the optimization of hydrogen sulfide adsorption experiments and improved nanoadsorbents. The contours showed that increasing the dose, concentration, and flow along with decreasing the temperature increases the adsorption capacity and efficiency. [ABSTRACT FROM AUTHOR]

The changes and transformation laws of intermediate liquid-phase products during the anaerobic degradation of lignite by sulfate-reducing bacteria in the formation of hydrogen sulfide play an important role in supplementing and improving the existing theories on the genesis of hydrogen sulfide gas in coal mines. In this paper, H2S gas and key intermediate liquid-phase products produced during the anaerobic degradation of lignite by sulfate-reducing bacteria were detected and analyzed by gas chromatography and gas chromatography-mass spectrometry. The results showed that the process of hydrogen sulfide production from lignite degradation by sulfate-reducing bacteria can be roughly divided into four stages: slow production phase, rapid growth phase, steady production phase, and slight decline phase. In this reaction system, the SO42− concentration showed a decreasing trend, the pH value showed an increasing trend, and the ORP value decreased and then slightly increased with time. Ten volatile component types were detected during the experiment: straight-chain alkanes, branched-chain alkanes, alcohols, aldehydes, ketones, olefins, amines, lipids, acids and phenols. The key components in the intermediate liquid phase products were straight chain alkanes, straight chain alkanes, acids, alcohols, phenols and amines. PAHs, alkanes, and phenols are closely related to H2S production, while amides stimulate nitrogen production. The process is divided into three stages: hydrolysis stage, H2S gas production stage, and decay stage. Liquid-phase intermediates play an important role in the formation process of coal mine BSR hydrogen sulfide and the mechanism of coal mine H2S genesis. [ABSTRACT FROM AUTHOR]

Background: Hydrogen sulfide (H2 S) is the third most crucial gas that is produced inside the body, and at physiological levels, it increases a wide range of health properties, such as anti-inflammatory antioxidant effects. Objectives: This study aimed at evaluating the impact of H2 S administration on oxidative stress (OS) in the heart and liver tissues of diabetic rats. Methods: Twenty-eight Wistar rats were randomly divided into 4 groups, namely, the healthy control group, the diabetic group, and diabetic groups treated with 50 µM/kg and 100 µM/kg of H2 S. After 60 days of treatment, the animals were sacrificed, and biochemical and OS markers were determined using colorimeter methods. In addition, the liver tissue underwent histological assessment. Results: The findings revealed that H2 S controlled the weight of rats and significantly decreased fasting blood sugar (FBS) in the treatment group with a dose of 50 µM/kg and 100 µM/kg (P

Abstract Background Se (selenium) pollution is an emerging environmental concern. Excessive Se induces phytotoxicity. The endogenous H2S (hydrogen sulfide) was involved in plant adaptation to Se stress, but the signaling player of H2S remains unclear. Methods The study was conducted in a hydroponic system with different chemicals added to the treatment solution. Fluorescent tracking was performed to detect endogenous signaling molecules in plant tissues. Physiological changes were determined based on pharmaceutics and histochemical experiments. Gene expression was analyzed using qRT-PCR. The data were summarized using hierarchical cluster and Pearson correlation analysis. Results Se stress inhibited B. rapa growth (e.g. root elongation, shoot height, and seedling fresh weight and dry weight) in both dose- and time-dependent manners, with approximately 50% of root growth inhibition occurred at 20 µM Se. Se stress induced ROS (reactive oxygen species) accumulation and oxidative injury in B. rapa. Se exposure resulted in the upregulation of LCDs (L-cysteine desulfhydrase) and DCDs (D-cysteine desulfhydrase) encoding enzymes for H2S production in B. rapa at early stage of Se exposure, followed by downregulation of these genes at late stage. This was consistent with the change of endogenous H2S in B. rapa. Enhancing endogenous H2S level with NaHS (H2S donor) stimulates endogenous Ca2+ in B. rapa upon Se exposure, accompanied the attenuation of growth inhibition, ROS accumulation, oxidative injury, and cell death. The beneficial effects of H2S on detoxifying Se were blocked by decreasing endogenous Ca2+ level with Ca2+ channel blocker or Ca2+ chelator. Finally, hierarchical cluster combined with correlation analysis revealed that Ca2+ might acted as downstream of H2S to confer Se tolerance in B. rapa. Conclusion Ca2+ was an important player of H2S in the regulation of plant physiological response upon Se stress. Such findings extend our knowledge of the mechanism for Se-induced phytotoxicity. Graphical Abstract

The rheumatoid arthritis (RA) microenvironment is often followed by a vicious circle of high inflammation, endogenous gas levels imbalance, and poor treatment. To break the circle, we develop a dual-gas-mediated injectable hydrogel for modulating the immune microenvironment of RA and simultaneously releasing therapeutic drugs. The hydrogel (DNRS gel) could be broken down on-demand by consuming excessive nitric oxide (NO) and releasing therapeutic hydrogen sulfide (H2S), resulting in endogenous gas restoration, inflammation alleviation, and macrophage polarization to M2 type. Additionally, the hydrogel could suppress osteoclastogenesis and enhance osteogenesis. Furthermore, the intra-articularly injected hydrogel with methotrexate (MTX/DNRS gel) significantly alleviated inflammation and clinical symptoms and promoted the repair of bone erosion in the collagen-induced arthritis rat model. As a result, in vivo results demonstrated that MTX/DNRS gel restored the microenvironment and improved the therapeutic effect of MTX. This study provides a novel understanding of developing versatile smart delivery platforms for RA treatment.

Objective: Urinary bladder dysfunction, that is one of the most common diabetic complications, is associated with bladder overactivity, increased bladder capacity and also impaired bladder smooth muscle contractions. The involvement of hydrogen sulfide (H2S) in pathological disorders such as diabetes mellitus has been suggested. NaHS-treatment can distinctly reduce high glucose-induce cytotoxicity and oxidative stress. Reactive oxygen species are produced in increased concentrations in diabetes and may cause tissue damage, thus impaired smooth muscle function. The aim of the study was to investigate the role of H2S and reactive oxygen scavenger (ROS) on carbachol-induced detrusor smooth muscle contractions under high glucose conditions. Materials and Methods: Cumulative (10 nM-30 µM) carbachol contraction responses were obtained in bladder detrusor smooth muscle strips isolated from male New Zealand albino rabbits bladder in control group and in high glucose conditions (30 min incubation in Krebs’ Henseleit solution with high glucose). Responses were repeated in the presence of sodium hydrosulfide (NaHS), catalase, superoxide dismutase (SOD) and their combinations. Contractions were expressed as a percentage of 80 mM K+ response and p

Abstract This study aimed to investigate the operation of three parallel biotrickling filters (BTFs) in removing H2S at different pH conditions (haloalkaliphilic, neutrophilic, and acidophilic) and their associated microbial population in the biodesulfurization process. BTF columns were inoculated with enriched inoculum and experiments were performed by gradually reducing Empty Bed Retention Time (EBRT) and increasing inlet concentration in which the maximum removal efficiency and maximum elimination capacity in EBRT 60 s reached their maximum level in haloalkaline condition (91% and 179.5 g S-H2S m−3 h−1). For visualizing the attached microbial biofilms on pall rings, Scanning Electron Microscopy (SEM) was used and microbial community structure analysis by NGS showed that the most abundant phyla in haBTF, nBTF, and aBTF belong to Gammaproteobacteria, Betaproteobacteria, and Acidithiobacillia, respectively. Shannon and Simpson indexes evaluation showed a lower diversity of bacteria in the aBTF reactor than that of nBTF and haBTF and beta analysis indicated a different composition of bacteria in haBTF compared to the other two filters. These results indicated that the proper performance of BTF under haloalkaliphilic conditions is the most effective way for H2S removal from air pollutants of different industries. Graphical Abstract

Abstract Background Salinity is one major abiotic stress affecting photosynthesis, plant growth, and development, resulting in low-input crops. Although photosynthesis underlies the substantial productivity and biomass storage of crop yield, the response of the sunflower photosynthetic machinery to salinity imposition and how H2S mitigates the salinity-induced photosynthetic injury remains largely unclear. Seed priming with 0.5 mM NaHS, as a donor of H2S, was adopted to analyze this issue under NaCl stress. Primed and nonprime seeds were established in nonsaline soil irrigated with tape water for 14 d, and then the seedlings were exposed to 150 mM NaCl for 7 d under controlled growth conditions. Results Salinity stress significantly harmed plant growth, photosynthetic parameters, the structural integrity of chloroplasts, and mesophyll cells. H2S priming improved the growth parameters, relative water content, stomatal density and aperture, photosynthetic pigments, photochemical efficiency of PSII, photosynthetic performance, soluble sugar as well as soluble protein contents while reducing proline and ABA under salinity. H2S also boosted the transcriptional level of ribulose 1,5-bisphosphate carboxylase small subunit gene (HaRBCS). Further, the transmission electron microscope showed that under H2S priming and salinity stress, mesophyll cells maintained their cell membrane integrity and integrated chloroplasts with well-developed thylakoid membranes. Conclusion The results underscore the importance of H2S priming in maintaining photochemical efficiency, Rubisco activity, and preserving the chloroplast structure which participates in salinity stress adaptation, and possibly sunflower productivity under salinity imposition. This underpins retaining and minimizing the injury to the photosynthetic machinery to be a crucial trait in response of sunflower to salinity stress.

Abstract Removing sour gas from any suitable gas sweetening technology in a cost-effective and environmentally responsible manner is a major challenge. This paper discusses how to safely and economically dispose of small amounts of acid gases resulting from the amine sweetening process. A two-stage Claus desulfurization unit was studied and simulated to treat acid gases resulting from natural gas sweetening operations in Ras Gharib oil fields (Egypt). These acid gases are used as feedstock for the proposed plant to produce a valuable product, such as elemental sulfur, which is used as a raw material in many industries. Although many sulfur recovery techniques are available for various conditions and applications, the Claus process is a critical and widely used method for recovering elemental sulfur from gaseous hydrogen sulfide. This work represents the potential benefits of treating acid gases with high hydrogen sulfide content. In addition, operational variables that could affect sulfur production and sulfur recovery efficiency of the studied Claus unit were studied and optimized. Aspen HYSYS simulation software (version 9) was used to evaluate the economic aspects and optimize the operational parameters of the unit for producing sulfur from acid background gases. The results showed that the maximum sulfur production was achieved at a catalytic converter reactor temperature of 270 °C and 210 °C for the first and second catalytic reactor, respectively, with an air flow rate of 933.3 kg mol/h. The economic study of the proposed desulfurization unit showed that the Claus unit would be economically acceptable with an expected return on investment of approximately 10% and an average payback period of 10 years. Moreover, the introduced plant has a positive impact on the environment by reducing the concentration of hydrogen sulfide in the gas from 69.58 to 0.16%.

Abstract The escalating drug resistance among microorganisms underscores the urgent need for innovative therapeutic strategies and a comprehensive understanding of bacteria's defense mechanisms against oxidative stress and antibiotics. Among the recently discovered barriers, the endogenous production of hydrogen sulfide (H2S) via the reverse transsulfuration pathway, emerges as a noteworthy factor. In this study, we have explored the catalytic capabilities and crystal structure of cystathionine γ-lyase from Pseudomonas aeruginosa (PaCGL), a multidrug-opportunistic pathogen chiefly responsible for nosocomial infections. In addition to a canonical l-cystathionine hydrolysis, PaCGL efficiently catalyzes the production of H2S using l-cysteine and/or l-homocysteine as alternative substrates. Comparative analysis with the human enzyme and counterparts from other pathogens revealed distinct structural features within the primary enzyme cavities. Specifically, a distinctly folded entrance loop could potentially modulate the access of substrates and/or inhibitors to the catalytic site. Our findings offer significant insights into the structural evolution of CGL enzymes across different pathogens and provide novel opportunities for developing specific inhibitors targeting PaCGL.

Abstract A static batch arrangement composed of anti-leak vials coupled to gas chromatography is proposed as a complementary system for performance assessment of biogas desulfurization by adsorption. For testing, a modified commercial activated carbon produced by controlled thermal treatment in the presence of iron(III) species improved biogas desulfurization. The adsorbents showed a superior hydrogen sulfide removal compared to ordinary one. Pseudo-first-order, pseudo-second-order, and Bangham’s kinetic models were used to fit experimental data. All studied samples followed pseudo-first-order model, indicating the predominance of physisorption, and Bangham’s model, confirming that the micropores structure played an important role for gases diffusion and adsorbent capacity. Additionally, the materials were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, scanning electron microscopy and energy-dispersive spectroscopy. The thermal treatment associated with iron impregnation caused significant modifications in the surface of the materials, and the iron species showed two main benefits: an expressive increase in the specific area and the formation of specific adsorption sites for hydrogen sulfide removal. The results reinforce the advantages of iron-modified adsorbents in relation to their non-modified counterparts. The analytical methodology based on the confinement of multiple gases contributes to improving the understanding of the hydrogen sulfide adsorption process using pressure swing adsorption technology. Graphical Abstract

Background: Diabetes mellitus (DM) is a long-term metabolic disease accompanied by difficulties in wound healing placing a severe financial and physical burden on patients. As one of the important signal transduction molecules, both endogenous and exogenous hydrogen sulfide (H2S) was found to promote diabetic wound healing in recent studies. H2S at physiological concentrations can not only promote cell migration and adhesion functions, but also resist inflammation, oxidative stress and inappropriate remodeling of the extracellular matrix. Aim of Review: The purpose of this review is to summarize current research on the function of H2S in diabetic wound healing at all stages, and propose future directions. Key Scientific Concepts of Review: In this review, first, the various factors affecting wound healing under diabetic pathological conditions and the in vivo H2S generation pathway are briefly introduced. Second, how H2S may improve diabetic wound healing is categorized and described. Finally, we discuss the relevant H2S donors and new dosage forms, analyze and reveal the characteristics of many typical H2S donors, which may provide new ideas for the development of H2S-released agents to improve diabetic wound healing.

The imidazolium-based supported ionic liquids (IL) in activated carbon (AC) is an exciting strategy for developing new adsorbents for H2S removal from biogas. In this work, the influence of IL on AC was discovered by examining the effect of ultrasonic stirring as an impregnation method, AC particle size and IL anion type. AC300μm-[Bmim]Cl-U5 demonstrated the highest H2S adsorption capacity of 8.25±0.38 mg H2S/g and was obtained through [Bmim]Cl impregnated on 300 μm AC size through the ultrasonic stirring for five minutes at room temperature. Adsorption/desorption study confirmed the regeneration ability of AC300μm-[Bmim]Cl-U5 up to three cycles with a maximum adsorption capacity of 14.24±0.43 mg H2S/g. The SEM images confirmed the presence of IL on the AC surface and were further explained through BET analysis. TGA measurement indicated the thermal stability of pristine IL, the fresh and exhausted adsorbent. Therefore, this study proves the potential of ultrasonic-assisted supported IL as a promising adsorbent for H2S removal from biogas that exhibit excellent properties in high adsorption capacity and thermal stability.

Transition metal chalcogenides have been identified as low-cost and efficient electrocatalysts to promote the hydrogen evolution reaction in alkaline media. However, the identification of active sites and the underlying catalytic mechanism remain elusive. In this work, we employ operando X-ray absorption spectroscopy and near-ambient pressure X-ray photoelectron spectroscopy to elucidate that NiS undergoes an in-situ phase transition to an intimately mixed phase of Ni3S2 and NiO, generating highly active synergistic dual sites at the Ni3S2/NiO interface. The interfacial Ni is the active site for water dissociation and OH* adsorption while the interfacial S acts as the active site for H* adsorption and H2 evolution. Accordingly, the in-situ formation of Ni3S2/NiO interfaces enables NiS electrocatalysts to achieve an overpotential of only 95 ± 8 mV at a current density of 10 mA cm−2. Our work highlighted that the chemistry of transition metal chalcogenides is highly dynamic, and a careful control of the working conditions may lead to the in-situ formation of catalytic species that boost their catalytic performance. Transition metal chalcogenides are effective and economical electrocatalysts for the hydrogen evolution reaction in alkaline media, yet active sites and catalytic mechanisms remain unclear. Here the authors use operando spectroscopy to study the in-situ conversion of NiS to highly active Ni3S2/NiO dual-site catalysts for the alkaline hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) is a gaseous signaling molecule produced in the body by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST). H2S is crucial in various physiological processes associated with female mammalian reproduction. These include estrus cycle, oocyte maturation, oocyte aging, ovulation, embryo transport and early embryo development, the development of the placenta and fetal membranes, pregnancy, and the initiation of labor. Despite the confirmed presence of H2S-producing enzymes in all female reproductive tissues, as described in this review, the exact mechanisms of H2S action in these tissues remain in most cases unclear. Therefore, this review aims to summarize the knowledge about the presence and effects of H2S in these tissues and outline possible signaling pathways that mediate these effects. Understanding these pathways may lead to the development of new therapeutic strategies in the field of women’s health and perinatal medicine. [ABSTRACT FROM AUTHOR]

Small molecule donors (SMDs) play subtle roles in the signaling mechanism and disease treatments. While many excellent SMDs have been developed, dosage control, targeted delivery, spatiotemporal feedback, as well as the efficiency evaluation of small molecules are still key challenges. Accordingly, fluorescent small molecule donors (FSMDs) have emerged to meet these challenges. FSMDs enable controllable release and non-invasive real-time monitoring, providing significant advantages for drug development and clinical diagnosis. Integration of FSMDs with chemotherapeutic, photodynamic or photothermal properties can take full advantage of each mode to enhance therapeutic efficacy. Given the remarkable properties and the thriving development of FSMDs, we believe a review is needed to summarize the design, triggering strategies and tracking mechanisms of FSMDs. With this review, we compiled FSMDs for most small molecules (nitric oxide, carbon monoxide, hydrogen sulfide, sulfur dioxide, reactive oxygen species and formaldehyde), and discuss recent progress concerning their molecular design, structural classification, mechanisms of generation, triggered release, structure–activity relationships, and the fluorescence response mechanism. Firstly, from the large number of fluorescent small molecular donors available, we have organized the common structures for producing different types of small molecules, providing a general strategy for the development of FSMDs. Secondly, we have classified FSMDs in terms of the respective donor types and fluorophore structures. Thirdly, we discuss the mechanisms and factors associated with the controlled release of small molecules and the regulation of the fluorescence responses, from which universal guidelines for optical properties and structure rearrangement were established, mainly involving light-controlled, enzyme-activated, reactive oxygen species-triggered, biothiol-triggered, single-electron reduction, click chemistry, and other triggering mechanisms. Fourthly, representative applications of FSMDs for trackable release, and evaluation monitoring, as well as for visible in vivo treatment are outlined, to illustrate the potential of FSMDs in drug screening and precision medicine. Finally, we discuss the opportunities and remaining challenges for the development of FSMDs for practical and clinical applications, which we anticipate will stimulate the attention of researchers in the diverse fields of chemistry, pharmacology, chemical biology and clinical chemistry. With this review, we hope to impart new understanding thereby enabling the rapid development of the next generation of FSMDs. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) causes irreversible cell loss and neurological dysfunctions. Presently, there is no an effective clinical treatment for SCI. It can be the only intervention measure by relieving the symptoms of patients such as pain and fever. Free radical-induced damage is one of the validated mechanisms in the complex secondary injury following primary SCI. Hydrogen sulfide (H2S) as an antioxidant can effectively scavenge free radicals, protect neurons, and improve SCI by inhibiting the p38MAPK/mTOR/NF-κB signaling pathway. In this report, we analyze the pathological mechanism of SCI, the role of free radical-mediated the p38MAPK/mTOR/NF-κB signaling pathway in SCI, and the role of H2S in scavenging free radicals and improving SCI. [ABSTRACT FROM AUTHOR]

To monitor the biological function of H2S in real time, this investigation demonstrated the design and synthesis of a novel fluorescent probe integrated with cyanine and 2,4-dinitrophenol for the qualitative and quantitative detection of H2S. An NIR sensitive sensor (FS-HS-1) was provided with a straightforward process. Spectroscopy experiments elucidated that FS-HS-1 could selectively detect H2S in a PBS solution (containing 40% acetonitrile) with a 111-fold fluorescence enhancement at 715 nm (ex. 605 nm). The response towards NaHS occurred in less than 2 min, and the detection limit was confirmed to be as low as 4.47 ± 0.11 nmol/L. Furthermore, the probe is capable of monitoring changes in exogenous H2S concentrations within living cells with confocal and 2P imaging. [ABSTRACT FROM AUTHOR]

Despite hydrogen sulphide (H2S) has been predicted to be the major reservoir of S-bearing species on the icy mantles of interstellar grains, no solid H2S has been detected so far. A crucial parameter that governs whether or not a species remains frozen on to the grain mantles is its binding energy (BE). We present a new computational study of the H2S BE on a large amorphous water ice surface, constituted by 200 water molecules. The resulting H2S BE distribution ranges from 57 K (0.5 kJ mol−1) to 2406 K (20.0 kJ mol−1), with the average μ = 984 K (8.2 kJ mol−1). We discuss the reasons why the low bound of the newly computed BE distribution, which testifies to the very weak interaction of H2S with the ice surface, has never been found by previous theoretical or experimental works before. In addition, the low H2S BEs may also explain why frozen H2S is not detected in interstellar ices. Following previous molecular dynamics studies that show that the energy of reactions occurring on ice surfaces is quickly absorbed by the water molecules of the ice and conservatively assuming that 10 per cent of the HS + H → H2S formation energy (−369.5 kJ mol−1) is left to the newly formed H2S, its energy is more than twice the largest BE and five times the average BE and, hence, H2S will most likely leave the water surface. [ABSTRACT FROM AUTHOR]

Simple Summary: Dairy farming is a significant source of pollutant gas emissions, contributing to climate change and air quality degradation. Understanding these emissions in milk production promotes productive efficiency and sustainable resource use. The aim of this paper is to provide a comprehensive analysis of ammonia and greenhouse gas emissions in dairy farming, utilizing bibliometric analysis methods. Articles featuring experimental data collection were selected, exclusively in English. The databases considered were Scopus and Web of Science. The analyses were conducted using Bibliometrix version 4.0.0 and VOSviewer version 1.6.20 tools to create knowledge maps visualizing information on research countries, institutions, author collaborations, and keyword networks. The search yielded 187 articles related to major pollutant gases such as methane, ammonia, carbon dioxide, nitrous oxide, and hydrogen sulfide. This study provided valuable insights into gas emission sources, air quality, environmental sustainability, and animal welfare, as well as identifying gaps and critical points in research on the topic. Ammonia and greenhouse gas emissions in dairy farming are crucial for climate change mitigation and sustainable agriculture. This research can contribute to academic interests while enhancing agricultural practices and informing environmental policies. The relevance of this research will persist with the growing demand for sustainable practices, as more researchers and organizations recognize the importance of gas emissions and mitigation research. A deeper understanding of gas emissions in milk production is crucial for promoting productive efficiency, sustainable resource use, and animal welfare. This paper aims to analyze ammonia and greenhouse gas emissions in dairy farming using bibliometric methods. A total of 187 English-language articles with experimental data from the Scopus and Web of Science databases (January 1987 to April 2024) were reviewed. Publications notably increased from 1997, with the highest number of papers published in 2022. Research mainly focuses on ammonia and methane emissions, including quantification, volatilization, and mitigation strategies. Other gases like carbon dioxide, nitrous oxide, and hydrogen sulfide were also studied. Key institutions include the University of California–Davis and Aarhus University. Bibliometric analysis revealed research evolution, identifying trends, gaps, and future research opportunities. This bibliometric analysis offers insights into emissions, air quality, sustainability, and animal welfare in dairy farming, highlighting areas for innovative mitigation strategies to enhance production sustainability. This research contributes to academia, enhancing agricultural practices, and informing environmental policies. It is possible to conclude that this research is a valuable tool for understanding the evolution of research on gas emissions in dairy cattle facilities, providing guidance for future studies and interventions to promote more sustainable production. [ABSTRACT FROM AUTHOR]

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]

Hydrogen sulfide (H2S) is a novel gasotransmitter. Sucrose (SUC) is a source of cellular energy and a signaling molecule. Maize is the third most common food crop worldwide. However, the interaction of H2S and SUC in maize thermotolerance is not widely known. In this study, using maize seedlings as materials, the metabolic and functional interactions of H2S and SUC in maize thermotolerance were investigated. The data show that under heat stress, the survival rate and tissue viability were increased by exogenous SUC, while the malondialdehyde content and electrolyte leakage were reduced by SUC, indicating SUC could increase maize thermotolerance. Also, SUC-promoted thermotolerance was enhanced by H2S, while separately weakened by an inhibitor (propargylglycine) and a scavenger (hypotaurine) of H2S and a SUC-transport inhibitor (N-ethylmaleimide), suggesting the interaction of H2S and SUC in the development of maize thermotolerance. To establish the underlying mechanism of H2S–SUC interaction-promoted thermotolerance, redox parameters in mesocotyls of maize seedlings were measured before and after heat stress. The data indicate that the activity and gene expression of H2S-metabolizing enzymes were up-regulated by SUC, whereas H2S had no significant effect on the activity and gene expression of SUC-metabolizing enzymes. In addition, the activity and gene expression of catalase, glutathione reductase, ascorbate peroxidase, peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, and superoxide dismutase were reinforced by H2S, SUC, and their combination under non-heat and heat conditions to varying degrees. Similarly, the content of ascorbic acid, flavone, carotenoid, and polyphenol was increased by H2S, SUC, and their combination, whereas the production of superoxide radicals and the hydrogen peroxide level were impaired by these treatments to different extents. These results imply that the metabolic and functional interactions of H2S and sucrose signaling exist in the formation of maize thermotolerance through redox homeodynamics. This finding lays the theoretical basis for developing climate-resistant maize crops and improving food security. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the long-term effect of oral administration of Caesalpinia coriaria Jacq (Cascalote) wild fruit extract to lambs on ruminal methane, carbon monoxide, and hydrogen sulfide production and in vitro fermentation profile. Rumen liquor (RL) was collected from lambs administered with 0- (RL0), 30- (RL30), and 60- (RL60) mL of aqueous extract of the C. coriaria fruit for 60 days per lamb, as well as during incubation, 0-, 0.6-, 1.2-, and 1.8- mL of C. coriaria fruit extract was added to each RL type. There was a dose-dependent increase in gas production with increasing levels of C. coriaria extract. The RL30 lambs had the lowest (P = 0.013) methane output (g CH4/kg DM) at 24 h, and RL30 with 1.8 mL/g DM had the lowest (P = 0.031) CH4 (g CH4/kg DM) at 48 h. Furthermore, diets fermented with RL0 produced the highest (P = 0.001) short-chain fatty acid (SCFA, mmol/g DM) and metabolizable energy (ME, MJ/kg DM 24 h), while diets incubated with RL30 produced the lowest. Without plant extract addition, 30 mL oral supplementation of C. coriaria fruit extract/day/lamb was optimal for digestion, ME, and SCFA. Therefore, 60 mL/d/lamb containing 1.2–1.8 mL fruit extract/g DM seemed to be a feasible means of decreasing emissions of gas production, ME, SCFA, CO, H2S, and CH4. [ABSTRACT FROM AUTHOR]

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Hydrogen sulfide (H2S) is an important reactive sulfur species that is involved in many biological functions, and H2S imbalances have been indicated as a potential biomarker for various diseases. Different H2S donors have been developed to deliver H2S directly to biological systems, but few reports include donors with optical responses that allow for tracking of H2S release. Moreover, donor systems that use the same chemistry to deliver H2S across a palette of fluorescent responses remain lacking. Here we report five thiol‐activated fluorescence turn‐on COS/H2S donors that utilize blue, yellow, orange, red, and near infrared‐emitting dyes functionalized with an H2S‐releasing sulfenyl thiocarbonate scaffold. Upon treatment with thiols, each donor provides a fluorescence turn‐on response (3–310‐fold) and high H2S release efficiencies (>60 %). Using combined electrode and fluorescence experiments, we directly correlate the measured H2S release with the fluorescence response. All donors are biocompatible and release H2S in live cell environments. In addition, we demonstrate that the NIR donor allows for imaging H2S release in live rats via subcutaneous injection of the donor loaded into an alginate gel, which to the best of our knowledge is the first in vivo tracking of H2S release from a fluorogenic donor in non‐transparent organisms. [ABSTRACT FROM AUTHOR]

As an important gas signaling molecule, hydrogen sulfide (H2S) affects multiple organ systems, including the nervous, cardiovascular, digestive, and genitourinary, reproductive systems. In particular, H2S not only regulates female reproductive function but also holds great promise in the treatment of male reproductive diseases and disorders, such as erectile dysfunction, prostate cancer, varicocele, and infertility. In this review, we summarize the relationship between H2S and male reproductive organs, including the penis, testis, prostate, vas deferens, and epididymis. As lower urinary tract symptoms have a significant impact on penile erection disorders, we also address the potential ameliorative effects of H2S in erectile dysfunction resulting from bladder disease. Additionally, we discuss the regulatory role of H2S in cavernous smooth muscle relaxation, which involves the NO/cGMP pathway, the RhoA/Rho-kinase pathway, and K+ channel activation. Recently, various compounds that can alleviate erectile dysfunction have been reported to be at least partly dependent on H2S. Therefore, understanding the role of H2S in the male reproductive system may help develop novel strategies for the clinical treatment of male reproductive system diseases. [ABSTRACT FROM AUTHOR]

In this research, zinc sulfide (ZnS) nanostructure powder was successfully synthesized via two-stage annealing (Ar + H 2 S). The annealing under argon medium was responsible for eliminating impurities such as SO 4 , SO 3 and SO 2. The annealing under hydrogen sulfide (H 2 S) medium also led to compensation of sulfur and establishment of Zn to S stoichiometric ratio following sintering. Investigation of different flow rates of H 2 S gas indicated that 30 mL/min would contribute to optimal Zn to S stoichiometric ratio. The Zn to S stoichiometric ratio before sintering under H 2 S medium was 1.28, which increased to 1.55 after annealing under H 2 S medium. The ceramic obtained from ZnS powder annealed under H 2 S medium at 30 mL/min had density of 99.98% and IR transmission of 62% within 8–12 μm range (wavenumbers of 1250–850 cm−1). [ABSTRACT FROM AUTHOR]

Because preparation circumstances are limited, the relationship between spherical porous zinc sulfide (ZnS) and cells is rarely investigated. Thus, using the hydrothermal approach, four different types of ZnS spheres with consistent size, high dispersion, and stability were created in this research by varying the temperature, duration, solvent ratio, and pH level of the hydrothermal process. Three structures are present in the generated particle spheres: solid, hollow, and mesoporous structures. In addition to causing a significant variation in the particle spheres' specific surface area, porosity, and surface roughness, the distinct architectures also have an impact on ZnS particle spheres' capacity to produce hydrogen sulfide (H 2 S) gas in an acidic environment. Experiments on hemolysis and cytotoxicity demonstrated that ZnS particle spheres with varying concentrations and shapes exhibited no cytotoxicity and good biocompatibility. According to cellular uptake trials, ZnS particle spheres with a rougher surface structure and a bigger specific surface area are more likely to be absorbed by macrophages and release more H 2 S gas. This activity of releasing H 2 S gas by H+ action and MA phagocytosis by employing ZnS as a donor lays the groundwork for later particles to load medicines and carry out biological functions. [ABSTRACT FROM AUTHOR]

Simple Summary: Mitochondria could respond adaptively to mild stress, a process known as mitohormesis. This review introduces the various factors that can induce mitohormesis, including hydrogen sulfide (H2S), physical stimulation, exercise, reactive oxygen species (ROS), calcium, unfolded mitochondrial proteins (UPRmt), and integrated stress response (ISR). These factors regulate mitochondrial hormetic stimulation through mechanisms such as mitochondrial quality control (MQC) and mitophagy, which are essential for maintaining mitochondrial homeostasis. The modulation of mitochondrial stress through mitohormesis holds great promise for improving human health and treating a range of diseases. The review emphasizes the need for further exploration of the underlying mechanisms and the development of targeted therapeutic strategies that harness the power of mitochondria to promote longevity and combat age-related diseases. Mitochondria, essential organelles orchestrating cellular metabolism, have emerged as central players in various disease pathologies. Recent research has shed light on mitohormesis, a concept proposing an adaptive response of mitochondria to minor disturbances in homeostasis, offering novel therapeutic avenues for mitochondria-related diseases. This comprehensive review explores the concept of mitohormesis, elucidating its induction mechanisms and occurrence. Intracellular molecules like reactive oxygen species (ROS), calcium, mitochondrial unfolded proteins (UPRmt), and integrated stress response (ISR), along with external factors such as hydrogen sulfide (H2S), physical stimuli, and exercise, play pivotal roles in regulating mitohormesis. Based on the available evidence, we elucidate how mitohormesis maintains mitochondrial homeostasis through mechanisms like mitochondrial quality control and mitophagy. Furthermore, the regulatory role of mitohormesis in mitochondria-related diseases is discussed. By envisioning future applications, this review underscores the significance of mitohormesis as a potential therapeutic target, paving the way for innovative interventions in disease management. [ABSTRACT FROM AUTHOR]

The formation of hydrogen sulfide (H2S) in petroleum reservoirs by anaerobic microbial activity (through sulfate-reducing microorganisms, SRMs) is called biogenic souring of reservoirs and poses a risk in the petroleum industry as the compound is extremely toxic, flammable, and corrosive, causing devastating damage to reservoirs and associated surface facilities. In this paper, we present a workflow and the tools to assess biogenic souring from a pragmatic engineering perspective. The retention of H2S in the reservoir due to the reactions with iron-bearing rock minerals (e.g., siderite) is shown in a theoretical approach here and supported with literature data. Cases are provided for two fields under secondary (waterflooding) and tertiary flooding with microbial enhanced oil recovery (MEOR). The use of the Monte Carlo method as a numerical modeling tool to incorporate uncertainties in the measured physical/chemical/biochemical data is demonstrated as well. A list of studies conducted with different chemicals alone or in combination with various biocides to mitigate biogenic souring provides an overview of potential inhibitors as well as possible applications. Furthermore, the results of static and dynamic inhibition tests using molybdate are presented in more detail due to its promising mitigation ability. Finally, a three-step workflow for the risk assessment of biogenic souring and its possible mitigation is presented and discussed. [ABSTRACT FROM AUTHOR]

Desulfurization is a necessary process to reduce the corrosiveness of natural gas. In this regard, H2S adsorption on porous materials has gained attention in the development of new eco-friendly technologies. Although there are many experimental and theoretical studies about gas adsorption on MOFs, so far, there has been no theoretical work about desulfurization of natural gas or biogas through H2S adsorption on MOF BTC. Therefore, the objective of this study was to preselect by ab initio calculations which metal center M2+, such as Co2+, Ni2+, Cu2+, or Zn2+, has the highest potential for selective desulfurization of natural gas. DFT calculations were performed at B3LYP-D3/6-311++G(2d,p)+LanL2DZ level for H2O, H2S, COS, CO2, and CH4 adsorption on M-BTC MOF clusters in order to obtain adsorption complex equilibrium geometries, adsorption energies and thermodynamic properties. It was found that Zn-BTC MOF cluster has the highest potential for selective H2S removal from dry natural gas streams, since its adsorption energy is −79.4 kJ mol−1, which is 2.4 times higher than CH4. Furthermore, H2S adsorption on Zn-BTC MOF is an exothermic process and thermodynamically favorable. Through NBO and EDA analyses, it was found that d electrons transfer from adsorbate to metal center unoccupied orbitals contributes mainly to a possible H2S chemisorption on Zn-BTC and Co-BTC, while for CO2 and CH4 adsorption, non-bonded interactions predominate. Most of the gases coordinate to coordinatively unsaturated site of BTC MOF cluster at axial position, indicating a stronger interaction with metal center compared to linkers. [ABSTRACT FROM AUTHOR]

In urban drainage systems, falling sewage in drop structures expedites the mass transfer of hydrogen sulfide (H2S) and oxygen (O2). This process is important for sewer odor and corrosion control; however, direct experiments and relevant knowledge are limited. This study conducted laboratory experiments using two typical forms of falling sewage: free-falling jet and attached-falling jet. The results show that mass transfer coefficient KL and concentration deficit ratio r (the ratio of upstream-to-downstream gas concentration deficiency) increase with an increase of sewage drop height (0.2–1.4 m) and with a decrease of flow rate (0.9–2.0 L/min). Nonlinear correlations between r and the hydraulic parameters were proposed. The free-falling jet contributed about 40% more mass transfer than the attached-falling jet. The mass transfer rate in free-falling drop structures of this study was 3–13 times that in gravity sewers without drop structures. In addition, O2 is an appropriate surrogate gas for studying H2S mass transfer. Finally, the mass transfer of O2 in a prototype drop structure was estimated: if the drop height is <3 m , the jet may not break up, the mass transfer at the jet surface can be neglected, and almost all the mass transfer happens at the bottom pool of the drop structure; however, if the drop height is >6 m , falling droplets are the main (>80%) contributor. This study provides a tool for estimating the mass transfer in drop structures, which can optimize the design of drop structures to control sewer odor and pipe corrosion. [ABSTRACT FROM AUTHOR]

• The growth and development of plants are significantly affected by abiotic stress, ultimately influencing their quality and yield. Further, the effects of global warming and alterations in rainfall patterns are leading to substantial losses in crop productivity. • The stressors disrupt cellular redox homeostasis, leading to the generation of reactive oxygen species (ROS) and oxidative stress in plants. • Gasotransmitters, such as carbon monoxide, nitric oxide, and hydrogen sulfide, emerge as crucial signaling molecules in response to abiotic stress. • These gasotransmitters play a key role in modulating cellular activities, interacting with signal transduction components, boosting antioxidant enzyme activity, and enhancing plant tolerance to diverse stress conditions. • The article aims to familiarize readers with the production and interaction of gasotransmitters in plants under abiotic stress, emphasizing their potential in developing climate-smart cultivars for improved agriculture production in the face of changing climate scenarios. The growth and development of plants are significantly affected by abiotic stress, ultimately influencing their quality and yield. Further, the effects of global warming and alterations in rainfall patterns are leading to substantial losses in crop productivity. The detrimental effects of such stress include the disruption of cellular redox homeostasis, the generation of reactive oxygen species (ROS), and oxidative stress in different cellular compartments, leading to their accumulation in various regions of the plant. This accumulation ultimately causes deleterious effects on proteins, lipids, carbohydrates, and DNA, which can result in membrane impairment and cell death. To counter these stressors and maintain essential balance, plants employ various mechanisms. Notably, the study of gasotransmitters in plants has garnered substantial attention, particularly in the context of abiotic stress. Gasotransmitters, a class of signaling molecules, play a crucial role in the functioning of plants under stress conditions. Examples of gasotransmitters include carbon monoxide, nitric oxide, and hydrogen sulfide. Furthermore, when plants experience combined stress, these gasotransmitters modulate cellular activities by interacting with other components of signal transduction. These gasotransmitters, in turn, boost the activity of several antioxidant enzymes, mitigate ROS harm, and enhance plant tolerance to diverse stress conditions. Therefore, the primary goal of this article is to familiarize readers with the production of gasotransmitters in plants, triggered by abiotic stress. Additionally, the interaction of gasotransmitters in plants under abiotic stress is discussed. Hence, understanding the specific and multifactorial stress conditions in which gasotransmitters are produced and exploring the crosstalk between various gasotransmitters can help elucidate how plants withstand multiple abiotic stresses effectively. Thus, due to their promising potential in agriculture, gasotransmitters are expected to find widespread adoption in the near future to enhance agriculture production through developing climate-smart cultivars, especially in the context of changing climate scenarios. [ABSTRACT FROM AUTHOR]

To investigate the effect of hydrogen sulfide (H2S) on ferroptosis and functional impairment induced by oxidized high-density lipoprotein (ox-HDL) in human umbilical vein endothelial cells (HUVECs), and to explore its mechanisms. METHODS: The HUVECs were cultured in vitro and exposed to 200 mg/L ox-HDL, ferroptosis inhibitor ferrostatin-1 (Fer-1), protein kinase B (PKB/Akt) inhibitor MK-2206 2HCl (MK), Akt agonist SC79, and/or H2S for 24 h. Western blot was used to identify the relevant proteins. Intracellular levels of reactive oxygen species (ROS) were analyzed by flow cytometry and immunofluorescence staining. Intracellular iron was measured using an iron detectionkit. The number of monocytes adhering to endothelial cells was counted using the monocyte adhesion assay. RESULTS: Compared with control group, acyl-CoA synthetase long-chain family member 4 (ACSL4) protein expression in ox-HDL group was elevated by 1.45-fold (P<0. 01), glutathione peroxidase 4 (GPX4) protein expression was decreased by 29. 79% (P<0. 05), and ROS levels and iron ion content were elevated by 4. 81-fold and 1. 40-fold, respectively (P< 0.01). The ratios of p-PI3K/PI3K and p-Akt/Akt were decreased by 45. 65% and 41. 68%, respectively (P<0. 01), endothelial cell function-related protein IL-6, ICAM-1 and TNF-a expression was elevated 1. 18-fold, 1. 24-fold and 1. 41-fold (P<0. 05), respectively, eNOS protein expression was decreased by 35. 24% (P<0. 01), and monocyte adhesion was elevated 3. 43-fold (P<0. 01). Compared with ox-HDL group, the endothelial cell iron death-related protein ACSL4 was decreased by 22. 32% (P<0. 05), GPX4 was increased by 1. 27-fold (P<0. 01), and the p-Akt/Akt ratio was increased by 1.52-fold (P<0. 01) in ox-HDL+H2S group. The fluorescence microscopy results showed that the ROS was decreased by 50. 35% (P<0. 01). The IL-6, ICAM-1 and TNF-a protein expression was decreased by 13. 34%, 9. 83% and 13. 46% (P<0. 05), respectively, eNOS was elevated by 1. 22-fold (P<0. 01), and the number of monocyte adhesion was decreased by 59. 05% (P<0. 01). Compared with ox-HDL group, GPX4 protein expression in ox-HDL+SC79 group was elevated by 1. 49-fold (P<0. 01), ACSL4 expression was decreased by 20. 72% (P<0. 05), and ROS and iron ions were decreased by 59. 31% and 23. 85% (P<0. 05), respectively. Compared with ox-HDL+H2S group, GPX4 protein expression was decreased by 21.28%, and ACSL4 protein expression was increased by 1. 16-fold in ox-HDL+H2S+MK group (P< 0. 05). CONCLUSION: H,S activates Akt to inhibit ox-HDL-induced ferroptosis in HUVECs and alleviate their functional damage. [ABSTRACT FROM AUTHOR]

Objective: Urinary bladder dysfunction, that is one of the most common diabetic complications, is associated with bladder overactivity, increased bladder capacity and also impaired bladder smooth muscle contractions. The involvement of hydrogen sulfide (H2S) in pathological disorders such as diabetes mellitus has been suggested. NaHS-treatment can distinctly reduce high glucose-induce cytotoxicity and oxidative stress. Reactive oxygen species are produced in increased concentrations in diabetes and may cause tissue damage, thus impaired smooth muscle function. The aim of the study was to investigate the role of H2S and reactive oxygen scavenger (ROS) on carbachol-induced detrusor smooth muscle contractions under high glucose conditions. Materials and Methods: Cumulative (10 nM-30 µM) carbachol contraction responses were obtained in bladder detrusor smooth muscle strips isolated from male New Zealand albino rabbits bladder in control group and in high glucose conditions (30 min incubation in Krebs' Henseleit solution with high glucose). Responses were repeated in the presence of sodium hydrosulfide (NaHS), catalase, superoxide dismutase (SOD) and their combinations. Contractions were expressed as a percentage of 80 mM K+ response and p<0.05 was accepted as statistically significant. Results: Cumulative contractile responses were elicited with carbachol in control group and these responses were significantly increased in the presence of high glucose. Increased carbachol contractile responses in high glucose were significantly reduced in the presence of catalase, SOD and NaHS. Conclusion: Depending on these results we may propose that H2S donors and ROS scavengers have probable benefits in treating diabetic complications such as urinary bladder dysfunction. [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]

The article presents the results of hydrochemical studies of waterbodies with varying degrees of development of anaerobic conditions (up to the appearance of meromixia with sulfide anoxia) in the Porya Guba Bay (Kandalaksha Bay, White Sea, Kandalaksha State Nature Reserve). It is shown that these waterbodies, which are at different stages of isolation from the sea, have a unique hydrological and hydrochemical structure, formed at a certain stage of their evolution. The vertical stratification of water, with the development of all phenomena accompanying stagnation, is more pronounced in the most distant parts of their water area from the sea, where elevated contents of hydrogen sulfide (up to 16.5 mg/L), phosphates, silicon, nitrite, and ammonium nitrogen are noted in bottom anaerobic water. However, the concentrations of all major ions are comparable to those in seawater and hardly chance at all vertically. Analysis of the distribution of the hydrochemical parameters of the distant reaches of Ozerki Lagoon made it possible to conclude that, due to changes that have occurred with this waterbody over the past 90 years, it can now most likely be classified as meromictic. [ABSTRACT FROM AUTHOR]

Many living beings use exogenous and/or endogenous gases to attain evolutionary benefits. We make a comprehensive assessment of one of the major gaseous reservoirs in the human body, i.e., the bowel, providing extensive data that may serve as reference for future studies. We assess the intestinal gases in healthy humans, including their volume, composition, source and local distribution in proximal as well as distal gut. We analyse each one of the most abundant intestinal gases including nitrogen, oxygen, nitric oxide, carbon dioxide, methane, hydrogen, hydrogen sulfide, sulfur dioxide and cyanide. For every gas, we describe diffusive patterns, active trans -barrier transport dynamics, chemical properties, intra-/extra-intestinal metabolic effects mediated by intracellular, extracellular, paracrine and distant actions. Further, we highlight the local and systemic roles of gasotransmitters, i.e., signalling gaseous molecules that can freely diffuse through the intestinal cellular membranes. Yet, we provide testable hypotheses concerning the still unknown effects of some intestinal gases on the myenteric and submucosal neurons. • Many living beings make use the mechanical and/or chemical properties of gases. • We focus on an eminent gaseous reservoir in the human body, i.e., the healthy intestine. • We analyse volume, composition, local distribution and source of each intestinal gas. • We describe the intra-/extra-intestinal physiological roles of intestinal exogenous and endogenous gases. • We highlight the local and systemic roles of gasotransmitters. [ABSTRACT FROM AUTHOR]

Recent technological advances in microcontroller systems enable novel biogas monitoring capabilities. This study investigates microcontroller-based quantification of methane and hydrogen sulfide concentrations in biogas derived from anaerobic digestion. Anaerobic digesters were fed either 100% cow dung substrates or a 50:50 mixture of cow dung with municipal solid waste (MSW). Methane levels were monitored using an MQ-4 sensor, hydrogen sulfide via an MQ-136 sensor, and temperature with a K-type thermocouple, all integrated with an ATmega 2560 microcontroller system. The 100% cow dung digester produced biogas with maximum methane concentrations of 3488 ppm at 21 days, indicating improved methane production compared to the 50:50 mixture of cow dung with MSW. Hydrogen sulfide reached 195 ppm and 192 ppm for the 100% cow dung and mixed digesters. Mesophilic temperature conditions were maintained throughout the digestion process. Real-time quantification of biogas composition demonstrates the capabilities of microcontroller-based anaerobic digester monitoring to provide precise methane and hydrogen sulfide measurements. [ABSTRACT FROM AUTHOR]