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This review examines the central role of hydrogen, particularly green hydrogen from renewable sources, in the global search for energy solutions that are sustainable and safe by design. Using the hydrogen square, safety measures across the hydrogen value chain—production, storage, transport, and utilisation—are discussed, thereby highlighting the need for a balanced approach to ensure a sustainable and efficient hydrogen economy. The review also underlines the challenges in safety assessments, points to past incidents, and argues for a comprehensive risk assessment that uses empirical modelling, simulation-based computational fluid dynamics (CFDs) for hydrogen dispersion, and quantitative risk assessments. It also highlights the activities carried out by our research group SaRAH (Safety, Risk Analysis, and Hydrogen) relative to a more rigorous risk assessment of hydrogen-related systems through the use of a combined approach of CFD simulations and the appropriate risk assessment tools. Our research activities are currently focused on underground hydrogen storage and hydrogen transport as hythane.

The interest in hybrid polymer electrolyte membrane fuel cells (PEMFC) fuelled by hydrogen in shipping has seen an unprecedented growth in the last years, as it could allow zero-emission navigation. However, technical, safety, and regulatory barriers in PEMFC ship design and operation are hampering the use of such systems on a large scale. While several studies analyse these aspects, a comprehensive and up-to-date overview on hydrogen PEMFCs for shipping is missing. Starting from the survey of past/ongoing projects on FCs in shipping, this paper presents an extensive review on maritime hydrogen PEMFCs, outlining the state of the art and future trends for hydrogen storage and bunkering, powertrain, and regulations. In addition to the need for a clear regulatory framework, future studies should investigate the development of an efficient fuel supply chain and bunkering facilities ashore. As for the onboard power system, health-conscious energy management, low-temperature heat recovery, and advancements in fuel processing have emerged as hot research topics.

Background Prokaryotes have relatively small genomes, densely-packed with protein-encoding sequences. RNA sequencing has, however, revealed surprisingly complex transcriptomes and here we report the transcripts present in the model hyperthermophilic Archaeon , Thermococcus kodakarensis , under different physiological conditions. Results Sequencing cDNA libraries, generated from RNA isolated from cells under different growth and metabolic conditions has identified >2,700 sites of transcription initiation, established a genome-wide map of transcripts , and consensus sequences for transcription initiation and post-transcription regulatory elements. The primary transcription start sites (TSS) upstream of 1,254 annotated genes, plus 644 primary TSS and their promoters within genes, are identified. Most mRNAs have a 5'-untranslated region (5'-UTR) 10 to 50 nt long (median = 16 nt), but ~20% have 5'-UTRs from 50 to 300 nt long and ~14% are leaderless. Approximately 50% of mRNAs contain a consensus ribosome binding sequence. The results identify TSS for 1,018 antisense transcripts, most with sequences complementary to either the 5'- or 3'-region of a sense mRNA, and confirm the presence of transcripts from all three CRISPR loci, the RNase P and 7S RNAs, all tRNAs and rRNAs and 69 predicted snoRNAs. Two putative riboswitch RNAs were present in growing but not in stationary phase cells. The procedure used is designed to identify TSS but, assuming that the number of cDNA reads correlates with transcript abundance, the results also provide a semi-quantitative documentation of the differences in T. kodakarensis genome expression under different growth conditions and confirm previous observations of substrate-dependent specific gene expression. Many previously unanticipated small RNAs have been identified, some with relative low GC contents (≤50%) and sequences that do not fold readily into base-paired secondary structures, contrary to the classical expectations for non-coding RNAs in a hyperthermophile. Conclusion The results identify >2,700 TSS, including almost all of the primary sites of transcription initiation upstream of annotated genes, plus many secondary sites, sites within genes and sites resulting in antisense transcripts. The T. kodakarensis genome is small (~2.1 Mbp) and tightly packed with protein-encoding genes, but the transcriptomes established also contain many non-coding RNAs and predict extensive RNA-based regulation in this model Archaeon .

Herbivorous marsupials such as kangaroos and wallabies have been reported to produce significantly lower methane emissions than ruminant livestock despite eating a similar diet, yet the microbial mechanisms underlying this difference remain poorly understood. Here, we conduct a comparative study of fecal microbiomes of 14 marsupial species to provide the first investigation of hydrogen-cycling genetic capacity across these animals. Through comparative analysis with fecal microbiomes of high- and low-methane-producing animals, we identify enrichment of bacterial genes for alternative hydrogen uptake and disposal pathways in some marsupials, supporting competition for hydrogen playing a role in the level of methane production. These data also indicate variation in hydrogen management between marsupials, including within species, suggesting methane emission capacity may vary at the level of the individual.

Soil microorganisms collectively consume 70 million tonnes of atmospheric hydrogen (H 2 ) a year, regulating atmospheric composition and climate change. In turn, consuming this dependable trace gas enables these microorganisms to survive even when their preferred organic energy sources are exhausted. Despite the importance of H 2 consumption for soil biodiversity and atmospheric regulation, the signals and sensors that regulate this process remain to be understood. Here, we demonstrate that a model soil bacterium turns on the machinery required for atmospheric H 2 consumption in direct response to being limited by organic carbon availability, through the process of catabolite repression. Specifically, in the absence of a sensor of the organic carbon source glycerol, a H 2 -consuming hydrogenase is highly expressed and active. These findings suggest that organic carbon levels have a major role in regulating trace gas oxidation, with implications for predicting how trace gas consumption and soil biodiversity respond to environmental change.

Although solar‐driven interfacial evaporation offers a sustainable pathway for desalination and wastewater remediation, its practical implementation remains limited by both the high vaporization enthalpy and rigid hydrogen‐bond network of water and performance degradation in complex water matrices. This study introduces a dual‐regulation strategy that integrates internal structural optimization with external‐field physical modulation. In particular, an Fe‐catalyzed pyrrole polymerization process yields a carbon‐based aerogel (CPP) with integrated ferromagnetism and enriched pyrrolic nitrogen sites. This synergy increases the intermediate‐water fraction, reduces vaporization enthalpy, and accelerates phase‐transition kinetics. Under one‐sun illumination (1 kW m −2 ), the CPP evaporator achieves an evaporation rate and efficiency of 2.78 kg m −2 h −1 and 84.0%, respectively, without magnetic assistance. After applying a 10 mT magnetic field, these values increase to 3.30 kg m −2 h −1 and 99.7%, respectively. Moreover, the system demonstrates stable salt self‐cleaning in seawater, resilience in organic wastewater, and multifunctionality in pollutant removal, achieving a tetracycline degradation rate of 89% when coupled with a solar‐driven advanced oxidation process. This study offers a generalizable framework that couples structural design with external‐field modulation for next‐generation solar evaporation systems.

The transition from diesel to zero-emission heavy-duty vehicles (HDV) is a critical decision for industry stakeholders, shaped by uncertainty, technological competition, and irreversible investments. This research examines how fleet operators navigate the choice between fuel cell hydrogen (FCH) and battery electric (BE) HDV, considering market dynamics, policy incentives, and infrastructure development. Using a real options framework, we capture the value of waiting for new information before committing to decarbonization, while integrating innovation diffusion models to account for adoption patterns. We determine when a fleet should switch to FCH HDV and how many vehicles to adopt at the trigger. Our approach provides insights into optimal investment timing, policy effectiveness, and the factors driving the large-scale deployment of clean HDV. JEL Classification: Q42, Alternative Energy Sources; Q48, Energy: Government Policy; R40, Transportation Economics: General; C15, Statistical Simulation Methods: General; D81, Criteria for Decision-Making under Risk and Uncertainty

Hydrogen plays a central role in regulating the anaerobic biodegradation of organic materials to carbon dioxide and methane. At an intermediate stage, alcohols and fatty acids are fermented to acetate, CO2 and H2. Methanogens consume this H2, gaining energy by reducing CO2 and the CH3-moieties of methanol, methylamines and acetate to CH4, and growing by assimilating these same substrates into biomass. There are seven biochemical steps in the H2-dependent pathway of CO2 reduction to CH4 in Methanobacterium thermoautotrophicum, a very common inhabitant of anaerobic digestors, several of which can be catalyzed by more than one enzyme. The choice of which enzyme is synthesized and therefore used in methanogenesis is determined by the availability of H2. With high H2 availability, M. thermoautotrophicum cells grow rapidly but their overall growth yield (YCH4; biomass synthesized per mole of CH4 synthesized) is lower than for cells growing more slowly under H2-limited conditions. Experiments are reported that document the relationships between H2 availability, alternative methane gene expression and growth yield, and that demonstrate H2-dependent reversible switching between rapid, relatively inefficient growth and slower more efficient growth. This switch is controlled by the mixing rate of the impeller in fed-batch fermentors sparged with CO2 and H2.

Similar to other types of cancer, acidification of tumor microenvironment is an important feature of osteosarcoma, and a major source of cellular stress that triggers cancer aggressiveness, drug resistance, and progression. Among the different effects of low extracellular pH on tumor cells, we have recently found that short-term exposure to acidosis strongly affects gene expression. This alteration might also occur for the most commonly used housekeeping genes (HKG), thereby causing erroneous interpretation of RT-qPCR data. On this basis, by using osteosarcoma cells cultured at different pH values, we aimed to identify the ideal HKG to be considered in studies on tumor-associated acidosis. We verified the stability of 15 commonly used HKG through five algorithms (NormFinder, geNorm, BestKeeper, ΔCT, coefficient of variation) and found that no universal HKG is suitable, since at least four HKG are necessary for proper normalization. Furthermore, according to the acceptable range of values, YWHAZ, GAPDH, GUSB, and 18S rRNA were the most stable reference genes at different pH. Our results will be helpful for future investigations focusing on the effect of altered microenvironment on cancer behavior, particularly on the effectiveness of anticancer therapies in acid conditions.

The evidence for the beneficial effects of drinking hydrogen-water (HW) is rare. We aimed to investigate the effects of HW consumption on oxidative stress and immune functions in healthy adults using systemic approaches of biochemical, cellular, and molecular nutrition. In a randomized, double-blind, placebo-controlled study, healthy adults (20–59 y) consumed either 1.5 L/d of HW ( n  = 20) or plain water (PW, n  = 18) for 4 weeks. The changes from baseline to the 4th week in serum biological antioxidant potential (BAP), derivatives of reactive oxygen, and 8-Oxo-2′-deoxyguanosine did not differ between groups; however, in those aged ≥ 30 y, BAP increased greater in the HW group than the PW group. Apoptosis of peripheral blood mononuclear cells (PBMCs) was significantly less in the HW group. Flow cytometry analysis of CD4 + , CD8 + , CD20 + , CD14 + and CD11b + cells showed that the frequency of CD14 + cells decreased in the HW group. RNA-sequencing analysis of PBMCs demonstrated that the transcriptomes of the HW group were clearly distinguished from those of the PW group. Most notably, transcriptional networks of inflammatory responses and NF-κB signaling were significantly down-regulated in the HW group. These finding suggest HW increases antioxidant capacity thereby reducing inflammatory responses in healthy adults.