npj Microgravity

Spaceflight imposes unique physiological stresses on mammals, including microgravity and cosmic radiation, which drive complex molecular adaptations. However, the systemic and temporal dynamics of space-induced epigenetic regulation remain poorly understood. We constructed a comprehensive DNA methylome BodyMap across 12 organs or tissues from mice exposed to long-duration spaceflight across three time points using Reduced Representation Bisulfite Sequencing (RRBS). We also performed RNA-seq for five organs and integrated with DNA methylome. We mapped the methylome and transcriptome landscapes and found that spaceflight induces limited but highly tissue-specific differentially methylated CpGs (DMCs). Most spaceflight-induced methylation changes were reverted toward baseline within one to six months of post-flight. Functional enrichment analysis of DMCs highlighted metabolic and mitochondrial dysregulation commonly across organs, while developmental responses in immune, reproductive, and structural tissues were tissue-specific. Transcriptome data revealed that spaceflight suppressed immune and increased inflammatory responses at the multi-organ level, triggering a phenomenon resembling aging. Our study provides a comprehensive DNA methylome BodyMap across 12 organs/tissues in spaceflight mice, elucidating the tissue specificity of epigenetic changes. These insights are essential for developing biomarkers and countermeasures to safeguard astronaut health during extended missions.

Space biology literature is growing exponentially. Existing infrastructure has not kept pace with organizing, synthesizing, and disseminating this knowledge. We present SpaceBio SpaceBio Knowledge Hub (www.spacebio.space), an integrated digital ecosystem that combines artificial intelligence, real-time data integration, and open-access infrastructure to advance research, education, and collaboration in microgravity, space biology and space exploration. The platform applies AI-driven approaches including natural language processing, machine learning, and automated content generation to construct a semantic atlas of the field. The atlas reveals the hierarchical thematic organization underlying microgravity-induced biological responses, space mission infrastructure, planetary science, and astrobiology. As part of this effort, SpaceBio is moving toward the construction of a LiteratOmics framework for microgravity, and space biology a systematic, AI-enabled approach to mining, integrating, and structuring the primary literature generated by omics-driven spaceflight research, treating the scientific literature itself as a navigable data layer alongside genomic, transcriptomic, and proteomic datasets. Built on a scalable, cloud-based architecture with a user-centered interface, SpaceBio supports literature exploration, data integration, and knowledge discovery for researchers, educators, students, industry partners, and citizen scientists. The platform also functions as a community-building ecosystem. It integrates hands-on research initiatives, AI-generated educational content, pilot data science projects, and social responsibility programs that broaden participation without compromising scientific rigor. AI-enabled digital environments can transform fragmented literature into a navigable knowledge landscape. SpaceBio accelerates research productivity, strengthens STEM education, and supports the global space life sciences community as human space exploration enters in the most ambitious era.

Despite extensive research on vestibular function in microgravity, particularly during orbital and parabolic flight exposure, several gaps remain regarding the spontaneous behavior of vestibular organs under non-terrestrial gravitoinertial conditions. In particular, semicircular canal function, typically assessed through vestibulo-ocular reflex (VOR) recordings, has yielded inconsistent findings, with reports describing either no effect or reduced performance in microgravity. Moreover, many of these studies are limited by methodological constraints that reduce the interpretability of their conclusions. To clarify these discrepancies, we evaluated horizontal and vertical VOR responses during parabolic flights to assess semicircular canal function under transient weightlessness. Participants were passively rotated at a constant frequency and amplitude during normogravity and microgravity phases, centered along the head vertical or inter-aural axis. Eye movements were recorded binocularly using infrared eye-tracking in darkness to eliminate visual influences, while participants were tightly restrained to minimize proprioceptive variability. Results show a reduction in VOR gain during microgravity in both axes, despite consistent rotational stimulation across gravity conditions. In addition, VOR gain remained reduced after parabolas in the horizontal plane, whereas vertical VOR performance was preserved. These are the first results to demonstrate an immediate alteration of semicircular canal function in weightlessness. Possible sources of the reduction in VOR performance in 0g are discussed. We also propose that the observed post-flight effects reflect a down-weighting of semicircular canal inputs during multisensory integration.

The present-day martian surface is generally considered inhospitable to life because of low atmospheric pressure, intense surface radiation, global desiccation, and oxidizing chemistry which has been increasing since the late Noachian. However, shallow martian subsurface regions where mineralogy has shown groundwater movement may include localized hypersaline environments capable of retaining liquid water and supporting microbial metabolism. Haloferax volcanii, a model halophilic archaeon, has previously been shown to survive under low-pressure martian conditions (24 mbar) and to grow anaerobically supported by the Mars-relevant oxyanions nitrate and perchlorate under high-salinity conditions. Here, we investigated whether H. volcanii could actively grow under a combination of environmental and chemical conditions relevant to potentially habitable shallow subsurface martian lacustrine settings. Cultures were incubated for 160 days under anoxic, CO2-enriched, low-pressure conditions (24 mbar) in hypersaline liquid media supplemented with nitrate or perchlorate. Growth was observed in all low-pressure treatments and was confirmed by increases in optical density and biological reduction of nitrate and perchlorate. Scanning electron microscopy revealed extensive biofilm formation in low-pressure cultures, and Raman spectroscopy demonstrated the persistence of carotenoid biosignatures after prolonged incubation under martian conditions. Water loss remained below 4% across all treatments, indicating long-term stability of hypersaline brines throughout the experiment. These results demonstrate for the first time that a halophilic archaeon is capable of active growth and metabolism under a Mars-relevant combination of low pressure, high salinity, anoxia, and oxidizing chemistry, providing experimental support for the potential habitability of localized shallow subsurface martian environments. ImportanceThe search for cellular life is a major objective of future Mars exploration. While many studies have examined whether microorganisms can survive under martian conditions, far fewer have demonstrated active growth and metabolism. Here, we document Haloferax volcanii as the first halophilic archaeon capable of active growth under a defined combination of Mars-relevant low atmospheric pressure, high salinity, anoxia, and oxidizing chemical conditions. These findings expand the current understanding of the environmental limits of microbial growth and provide experimental evidence that localized brine environments in the shallow martian subsurface could support active microbial metabolism, if suitable organics and liquid water are present. In addition, this study establishes a practical framework for cultivating halophilic microorganisms under low-pressure martian conditions and may help guide future efforts to detect, cultivate, and characterize potential extant life on Mars.

Micro and nano plastics (MNPs) have become ubiquitous contaminants in the environment with their occurrence being detected in air, water and food. They can cross biological barriers and slowly build up in different organs, including the placenta, raising concerns about possible impacts on maternal and fetal health. Placenta, a highly metabolically active organ composed primarily of trophoblast cells, requires substantial energy for proper development and function. However, the effects of MNPs exposure on trophoblast biology and mitochondrial health remain poorly understood. This study investigated the in vivo systemic accumulation of MNP in different organs of pregnant mice and their localization within various organelles in vitro. These effects influenced trophoblast energy metabolism and led to reduced migration. Mice received fluorescent polystyrene MNPs via their drinking water. Biodistribution was evaluated in vivo using IVIS whole-body imaging, while ex vivo fluorescence imaging confirmed accumulation of these particles in multiple organs and cells. In parallel, human HTR-8/SVneo trophoblast cells were exposed to MNPs, demonstrating rapid cellular uptake and mitochondrial and nuclear localization via fluorescence microscopy. TEM analysis uncovered mitochondrial structural alterations and the localization of MNPs. Seahorse analysis revealed impaired mitochondrial respiration and oxygen consumption rates, indicating compromised cellular bioenergetics in MNPs-treated cells, which led to inflammation, altered mtDNA copy number, and impaired trophoblast migration. Overall, these findings indicate that pregnant mice exposed to MNPs undergo systemic transfer, with trophoblast uptake marked by mitochondrial dysfunction, inflammation, and reduced migration. Our study identifies mitochondrial dysfunction as a central mechanism underlying MNP-mediated placental toxicity and underscores the potential role of environmental microplastic exposure in adverse pregnancy outcomes.

Older adults sustain disproportionately severe injuries from trip-induced falls during obstacle crossing. Such falls depend partly on forward momentum when the foot crosses the obstacle. MOSAP, an index of passive dynamic gait stability, reflects this momentum. We quantified MOSAP and a synergy index from uncontrolled manifold analysis of step length and extrapolated center of mass in 25 young (21.6 {+/-} 3.5 yr) and 23 older adults (68 {+/-} 4.3 yr) during unobstructed and obstructed walking, to test whether MOSAP increases during obstacle crossing and whether it is actively stabilized at each step. Both groups increased MOSAP progressively over two approach steps by reducing forward momentum and shifting the center of mass posteriorly. Older adults showed greater increases at the crossing steps. The synergy index was positive for all steps, showing that deviations in step length and extrapolated center of mass covaried to stabilize MOSAP at step-specific values. The synergy index was not influenced by age. We conclude that adults actively recruit passive body mechanics while approaching and crossing obstacles to reduce the risk of a trip becoming a fall. Older adults amplify this strategy to compensate for diminished neuromuscular corrective capabilities.

Wood is commonly used in the building sector, emitting volatile organic compounds (VOCs) contributing to indoor air quality. These VOC profiles can have a pleasant smell and positive effects e.g., induce relaxation. Contrarily, VOCs can have adverse health effects in higher concentrations. Therefore, some VOCs are regulated by guide values (GV). Potentially positive and negative effects of pinewood emissions, ranging from 0.2 mg/m3 (German GV I for bicyclic terpenes) to 2.0 mg/m3 (GV II) were investigated in an experimental 2 h exposure study using a within-subject design. Thirty-two healthy participants rated the perception, pleasantness, symptoms of irritation, and indicators of well-being. During a demanding working memory task (n-back) and a resting period, heart rate (HR) and HR variability (HRV) changes were measured. Before and after each session physiological markers of sensory irritation were assessed. Ratings indicated that the exposure to GV I and GV II were not perceived as more intense or pleasant. Mostly concentration-independent effects were revealed, indicating that inter-individual factors influenced the ratings rather than the VOCs. The pinewood odors during the n-back task did not cause distraction nor did it facilitate performance as previously suggested. HR/V changes indicated that pinewood odors during and after the n-back tasks did not induce relaxation. Only symptoms of nasal irritation showed some weak concentration-dependency, not supported by physiological markers or comparable ratings of sensory irritation. In conclusion, the fact that no distinct odor is detected suggests that interfering factors potentially prevent the regulation of odors at relevant indoor air concentrations.

Advanced footwear technology (AFT) has transformed competitive running, yet individual and sex-specific responses to different AFT models remain unclear, particularly near race pace. This study examined running economy (RE) and gait biomechanics in response to three top-tier AFT models (Shoe A: adidas Pro Evo 2; Shoe B: Nike Alphafly 3; Shoe C: On CloudBoom Strike 2) in 14 male and 12 female well-trained runners at sex-specific submaximal speeds (16 and 14 km{middle dot}h-{superscript 1}). RE, spatiotemporal, and joint kinematic/kinetic data were collected via indirect calorimetry, accelerometry, and three-dimensional motion capture with force platforms. RE was significantly lower in Shoe C than Shoe A (males: 2.1%; females: 1.4%) and Shoe B (males: 1.9%; females: 0.9%), with 73% of runners responding favourably to Shoe C, a more consistent response than previously reported. Despite being lightest, Shoe A produced the poorest RE, challenging conventional mass-economy assumptions. Biomechanically, Shoe C elicited greater impact magnitude, lower ankle quasi-stiffness, and greater ankle angular velocity during early stance. Female runners showed smaller RE improvements, potentially related to lower running velocity and body mass limiting midsole engagement. The most efficient AFT enabled these well-trained runners to be more spring-like through tolerating higher forces and faster angular velocities without greater demand on metabolic cost.

Climate-driven warming is challenging the physiological limits of aquatic ectotherms, with cardiac performance emerging as one of the key determinants of thermal tolerance. Cardiac function relies on mitochondrial ATP production, and mitochondrial dysfunction has been linked to cardiac failure at critical temperatures. However, mitochondria are plastic and may represent a target for interventions aimed at improving thermal tolerance in fish. Exercise training improves whole-animal performance in fish, including cardiac thermal performance, and improves mitochondrial function in other taxa. However, its effects on the thermal sensitivity of cardiac mitochondria remain unknown. This study investigated whether exercise-training alters cardiac mitochondrial performance at optimal and critical temperatures in rainbow trout Oncorhynchus mykiss. Farmed rainbow trout were subjected to a four-week exercise training regime, while control fish remained under standard rearing conditions. Cardiac mitochondrial respiration was assessed in permeabilised heart fibres at 16{degrees}C (optimal growth temperature) and 26{degrees}C (temperature associated with cardiac arrhythmia) and several biochemical and nuclear indicators were measured. No significant differences were detected between treatments for any measured variable. However, trained fish generally exhibited higher maximal respiratory capacities and respiratory control ratios, particularly at the elevated temperature, suggesting subtle improvements in mitochondrial function despite considerable inter-individual variation. Temperature influenced mitochondrial performance, increasing proton leak and reducing coupling efficiency. These findings demonstrate that cardiac mitochondrial function is thermally sensitive and represents a potential targeted for improving thermal resilience in aquaculture species.

Survival analysis is a workhorse assay in Drosophila research to evaluate somatic fitness. It is indispensable in the study of ageing and insightful in immunity, metabolism, radiobiology, toxicology, ecology, and others. While conceptually simple, lifespan measurement is labour-intensive because it requires the continuous manual maintenance of large experimental cohorts. Here, we describe Drosben, an approach that combines a 3D-printed device to transfer flies from several vials simultaneously, a paper system for quick data recording and accompanying software that automatically digitalises life tables for analysis. We show that using Drosben reduces the time investment to perform lifespan assays by ~85%, with improved speed regardless of experience handling Drosophila vials. Using Drosben, we address the effects on longevity of chronic feeding of indole-acetic acid (IAA), naphthalene-acetic acid (NAA) and trimethoprim (TMP) -- compounds used to control heterologous targeted protein degradation systems. We find that IAA and NAA have noticeable deleterious effects while TMP has a small protective effect specifically in females. We further show that strong static magnetic fields do not affect Drosophila lifespan. Our work suggests that Drosben can cheaply accelerate research where lifespan is used as a life history trait.

The suspension culture of pluripotent stem (PS) cells in stirred bioreactors poses a delicate balance between maintaining homogeneous cell dispersion and avoiding excessive shear stress that can compromise cell viability and pluripotency. In this study, we used computational fluid dynamics (CFD) coupled with a discrete particle method (DPM) to simulate iPS cell behavior in a 5 mL delta-impeller stirred tank. Our analysis revealed that upward flow at the tank bottom and downward flow at the top are critical for maintaining a stable suspension. To optimize the stirring protocol, we applied Bayesian optimization to identify a time-dependent stirring schedule that begins with a high-speed phase for resuspension, followed by a low-speed phase for sustained suspension with minimal hydrodynamic stress. The optimized schedule demonstrated improved suspension ratio and reduced slip velocity, indicating lower mechanical stress on cells. These findings provide engineering insights into scalable bioreactor operation, contributing to the design of robust iPS cell manufacturing systems.

Evidence from the Cassini mission confirmed that Saturn's moon Enceladus hosts a subsurface alkaline ocean where rock-water reactions may generate redox disequilibria capable of supporting microbial metabolisms. To investigate potential microbial survival under simulated Enceladus ocean conditions, we used thermodynamic modeling to develop a salt formulation consistent with one possible Enceladus ocean composition and supplemented it with putative microbial energy sources to create a growth medium. The medium was inoculated with samples from diverse ocean world analog environments on Earth to determine which microorganisms could persist under Enceladus-like conditions. The microorganisms persisting in this geochemically bounded medium were heterotrophic, metabolically versatile bacteria with low carbon requirements. Genomic and physiological analyses further showed the presence of multiple stress-response pathways, sodium- based bioenergetic systems, osmoregulation strategies, and other adaptations consistent with survival in alkaline, low-nutrient settings. These results suggest that some stress-tolerant heterotrophic bacteria may serve as useful model organisms for life in Enceladus' subsurface ocean. These findings demonstrate the value of geochemically modeled media as a framework for constraining habitability, identifying relevant biosignatures, and probing potential microbial survival strategies beyond Earth.

Manual intervention for concrete repair and replacement comes at high environmental and economic costs. Bioconcrete, which can be formed by bacteria via microbially-induced carbonate precipitation (MICP), is a sustainable method for concrete repair. Bioconcrete-forming bacteria can be incorporated into the concrete at mixing and then heal cracks where and when they occur. Bioconcrete is not intentionally made by bacteria; rather, it is a byproduct of alterations to the local environment that occur during their normal metabolic activities. Bacteria thus make bioconcrete by different metabolic mechanisms, and the environment plays a substantial role in the yield and physical properties of the bioconcrete produced by a given bacterium. The ureolytic bacterium Sporosarcina pasteurii is the most commonly used model organism for MICP, but it requires urea supplementation, which is not feasible for all applications because of nitrogenous waste. In particular, the marine environment is understudied for bioconcrete applications, yet there is a need for self-healing structures in this environment, wherein urea and nitrogenous waste would be detrimental to native biota. Here, we assessed the ability of S. pasteurii to form bioconcrete under marine-like media conditions with urea and calcium supplementation. We found that S. pasteurii generated higher bioconcrete yields in these media conditions compared to standard growth media. We then designed an enrichment protocol to isolate and characterize non-urea-requiring bioconcrete-forming bacteria from Atlantic seawater. We identified three isolates, from the Sulflitobacter, Marinobacter, and Bacillus genera, two of which yielded higher bioconcrete yields in seawater-mimicking media compared to non-ureolytic bacteria utilized in prior literature. Moreover, scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy revealed distinct chemical and structural features of the bioconcrete produced by bacteria in seawater-mimicking medium and between ureolytic and non-ureolytic cultures. Overall, our work establishes a pipeline for the isolation and characterization of novel bioconcrete-forming bacteria from marine samples, with potential for application to marine self-healing materials.

Moderate hypoxia is increasingly recognized as a physiological driver of neuroprotection and neuroregeneration. In this first randomised, double-blind, controlled, four-arm trial, we demonstrate the cognitive and neuroplastic effects of cognitive training under moderate inspiratory hypoxia in humans. Healthy volunteers underwent three weeks of either cognitive or sham training under normobaric hypoxia (12% O2) or normoxia (20% O2) for 3.5 hours daily, six days per week. Participants were assessed at baseline, treatment completion, and one-month follow-up. The primary outcome was change in a broad cognitive composite score. Additional cognitive, blood-based, and neuroimaging outcomes were assessed, including measurement of the presynaptic protein SV2A with [11C]UCB-J positron emission tomography (PET) and neural activity through functional magnetic resonance imaging (fMRI). In total, 126 participants were randomised to hypoxia-cognitive training (H-CT: n=36), hypoxia-sham training (H-ST: n=30), normoxia- cognitive training (N-CT: n=30), or normoxia-sham training (N-ST: n=30). Intention-to-treat analyses showed no effect of H-CT relative to N-ST in the primary outcome at treatment completion (primary endpoint; treatment effect=0.11, 95% CI=[-0.06;0.28], p=0.19), but improvements emerged at follow-up (treatment effect=0.17, 95% CI=[0.01;0.34], p=0.04). N-CT induced transient improvement in the primary outcome at treatment completion (treatment effect=0.20, 95% CI=[0.02;0.38], p=0.03), which rendered non-significant at follow-up. Finally, H-ST showed no significant cognitive change relative to N-ST. Moderate hypoxia was safe and well-tolerated. Cognitive benefits were accompanied by decreased hippocampal presynaptic density measured with [11C]UCB-J PET. In conclusion, three weeks of H-CT can enhance cognition with associated effects on neuroplasticity, although with a delayed onset of effects on cognition.

Traumatic brain injury (TBI) is a characteristic feature of neurodegenerative diseases such as Alzheimers disease and chronic traumatic encephalopathy. Small animal models have been used to establish clinically relevant biomarkers of neuropathology, however, they show significant anatomical differences from humans and are affected by artificial experimental manipulations, making them often unsuitable for longitudinal study of repetitive mild TBI. Building on a previous study of neuropathology in headbutting bovids in the wild, this pilot study investigated whether freely headbutting domestic goats, which naturally engage in low-intensity, high-frequency head impacts, accumulate measurable biomarkers of neurodegeneration in cerebrospinal fluid (CSF) and brain tissue. Over a six-month period, three male goats (Capra hircus) were allowed to freely headbutt under continuous video surveillance. Monthly CSF samples were collected, and concentrations of key neurodegeneration biomarkers were measured via multiplex immunoassays, including amyloid {beta} ; peptides (A {beta} 40, A {beta} 42), total and phosphorylated tau (tTau and pTau), glial fibrillary acidic protein (GFAP), S100 calcium-binding protein B (S100B), and neurofilament M (NF-M). Postmortem immunohistochemistry was conducted on prefrontal cortical tissues using antibodies targeting pTau, GFAP, and S100B. Head impact kinematics were quantified using horn-mounted accelerometer and inclinometer sensors that recorded linear acceleration, rotational velocity, and head orientation during naturally occurring headbutting events. Several notable trends were observed. Phosphorylated tau as well as reactive astrocytes were detected in the brain tissue, mirrored by elevated GFAP detected in the CSF. PET TSPO was unsuccessful, however, FDG PET revealed frontal-dominant activity in all goats, and one with asymmetrical activation. Overall, the goats sustained 5,000-7,000 head impacts each over six months, with forces up to 388 N and peak acceleration up to 16.5 g. This multi-modal observational study is the first to characterize neurodegeneration biomarkers and kinematics in headbutting goats. Even at one year old, the combination of pTau and gliosis in both the brain tissue and CSF indicates that the goat s repetitive head impacts begin to show neurodegenerative consequences early in life. Likely, the severity of these consequences increases with headbutts and age, eventually resulting in chronic neurodegeneration. This system shows promise as a large-animal model for the longitudinal study of the onset and progression of neurodegenerative disease.

Biocontainment systems designed to attenuate the spread of mobile DNA are challenging to evaluate within microbiomes of engineered environments. To better understand how toxin-based biocontainment systems affect horizontal gene transfer (HGT) in a microbiome, we evaluated the host range of pairs of plasmids using orthogonal catalytic RNA (cat-RNA) that amend distinct barcodes to 16S rRNA following HGT. We show that mobilizable (5 kb) and self-mobilizable (60 kb) plasmids, which use the same RP4 transfer machinery but different origins of replication, overlap in their host range when conjugated in parallel into a wastewater community, with 127 of the 143 amplicon sequence variants (ASVs) presenting barcoding signals from both plasmids (89%). We also find that mobilizable plasmids with or without the Escherichia coli CcdB toxin overlap in host range in a wastewater community. Among the two most abundant orders, CcdB attenuated the barcoding signal in Aeromonadales more consistently than Enterobacteriales, which have F plasmids containing the CcdB-CcdA toxin-antitoxin system used for biocontainment. Also, CcdB decreased the abundance of the mobilizable plasmid by >100-fold and yielded mutations in 85% of the reads. Together, these findings reveal how pairs of plasmids expressing orthogonal cat-RNA can be used to monitor the effects of plasmid-encoded traits on mobile DNA persistence following HGT. They also highlight challenges when using biocontainment systems containing genes related to those found in the microbiomes targeted for engineering.

Advanced footwear technology (AFT) improves running economy and is widely credited with recent performance improvements in road running, with observational analyses consistently demonstrating that women have improved more than men. In contrast, laboratory studies generally report similar running economy responses to AFT in both sexes, leaving the observational-experimental divergence unresolved. A fundamental limitation of observational work is the absence of a control condition, making it impossible to separate AFT-related gains from concurrent performance trends. We addressed this by comparing performances between pre-AFT (2009-2015) and AFT (2017-2024) eras across road-running events (10km, half marathon, marathon) and throwing events (shot put, discus, javelin, hammer), the latter serving as an active control condition subject to the same broad athletic trends but unaffected by footwear technology. The top 50 performances per event, era, and sex were converted to World Athletics points and analysed using linear mixed-effects models. Performances improved significantly between eras ({beta} = 0.294, p < .001), with gains substantially larger in road running than in throwing ({beta} = 0.731, p < .001). The sex-specific pattern of improvement also differed between event categories (era x event type x sex interaction, {beta} = 0.786, p < .001): road-running improvements were greater in women than men (4.51% vs 2.62%), whereas throwing improvements did not differ by sex (0.93% vs 1.14%). These findings suggest that AFT benefits women more than men in competition, whether through a greater physiological response or more effective translation of economy gains to race performance, and suggest current laboratory protocols may be insufficiently sensitive to detect potential sex-specific effects.

Rare earth elements (REEs) are critical components of green technologies, but current mining and purification methods remain environmentally unsustainable due to their high energy consumption and intensive chemical requirements. Bio-hydrometallurgical processes have the potential to concentrate and recover REEs at a circumneutral pH. Work presented here uses bacteria at neutral pH to concentrate REEs from solution and subsequently recover those REEs using sodium citrate. Shewanella oneidensis MR-1 was incubated anaerobically in a culture media solution spiked with 14 REEs and yttrium for one to six days. REE concentrations remaining in solution were then compared to REE concentrations on cell pellets. For these same timepoints, the loosely bound extracellular polymeric substance (LB-EPS) was removed from cells prior to quantifying REEs on pellets to narrow down the location of REE binding. Moreover, cell pellets collected after 5 days in REE spiked solution were subjected to a time series desorption assay using sodium citrate. Shewanella oneidensis at a starting OD600 of 0.6 adsorbed 1.18mg/g of REE after 3 days. 80% of these REEs were located in the LB-EPS. In 10 minutes, 0.5 M sodium citrate desorbed about 75% of REEs from cells and over 95% after 24 hours. This method was also applied to Alaskan coal and showed that 68-86% of REEs were desorbed form S. oneidensis. This study elucidates the REE binding location and capacity of S. oneidensi, REE removal efficiency of sodium citrate overtime, and the application of this sustainable biotechnology for REE recovery at a circumneutral pH from Alaskan coal.

Although microplastics and nanoplastics (MP/NP) are pervasive environmental contaminants, our understanding of cellular toxicity remains incomplete, as adverse effects are often attributed to long-term intracellular accumulation, while the spatiotemporal onset of cellular damage remains poorly defined. Here, we employ chemical-bond-selective stimulated Raman scattering (SRS) microscopy and cell models that decouple continuous exposure from intracellular retention to directly visualize clinically derived MP/NP-cell interactions. Cellular stress occurs primarily during MP/NP exposure, accompanied by alterations in lipid droplet (LD) composition. In contrast, following extracellular removal, intracellularly retained MP/NP become largely inert, with recovery of lipid metabolism and cellular functions. Lipidomics identifies arachidonic acid (AA) as a key dysregulated metabolite, and SRS imaging further reveals transient, spatially confined AA enrichment in MP/NP-proximal LDs during uptake. Importantly, phospholipid coating of MP/NP attenuates LD alterations and cytotoxicity while preserving particle internalization, establishing uptake-driven metabolic stress, rather than long-term intracellular retention, as primary source of MP/NP-induced damage.

Accurate measurement of cellular oxygen levels is essential for understanding the balance between oxygen demand and supply in tissues. However, conventional methods only yield compromised results. We harnessed the oxygen dependence of bioluminescence to develop OxyBLI--a noninvasive optical method that directly monitors oxygen levels in specific cell populations of intact experimental animals. We characterized OxyBLI signals across various critical situations associated with common interventions. Hypoxic breathing and subsequent systemic tissue hypoxia caused blood to be redistributed in a way that prioritized brain oxygenation. In contrast, hyperoxic breathing sharply increased tissue oxygenation, which promptly returned to the target level owing to a vasoconstrictor response. These findings are expected to help resolve the long-standing clinical issue regarding the risks and benefits of administering supplemental oxygen to acutely ill patients. Our multifaceted approach, which presents multiple challenges to individual animals over time, will advance our understanding of the delicate interaction between hypoxia and hyperoxia.