Search Results (8)

This paper presents a theoretical engineering feasibility analysis of the RK-X photocatalytic process for In Situ Resource Utilisation (ISRU) on Mars. Experimental validation under simulated Martian conditions is the essential next step before any mission deployment claim can be made. The RK-X process converts the two most abundant Martian resources, atmospheric carbon dioxide (CO₂) and subsurface water ice (H₂O), into formic acid (HCOOH) and oxygen (O₂) through a fulvic acid-based photocatalytic cycle validated at the industrial scale in Hungary. A reference module processing 10 tonnes of CO₂ per Earth year yields 10.459 tonnes of formic acid and 3.636 tonnes of oxygen, sufficient to sustain a six-person crew for approximately two Earth years with a 198% safety margin over nominal respiratory demand. The economic analysis indicates that importing equivalent oxygen from Earth costs $1.82–$3.64 million per year; equivalent energy storage (Li-ion) costs $30.5–$61 million for one-time use. Formic acid stores 15.25 MWh of energy in ambient-stable liquid form at a round-trip efficiency of 68.64% without cryogenic infrastructure. A photovoltaic array of 55.37 m² provides the primary energy source; a kilowatt-class nuclear fission reactor constitutes the strategic opportunity for continuous, dust-storm-immune operation with free thermal co-generation. Three critical research gaps have been identified requiring laboratory validation before Mars deployment: (i) catalyst performance at the Martian CO₂ partial pressure (p(CO₂) < 10 mbar, T = 15 °C); (ii) water ice and dry ice extraction at an operational scale; and (iii) integrated closed-loop system demonstration. Built on Earth-proven chemistry with identified, addressable development pathways, the RK-X process theoretically resolves the problems of oxygen supply, seasonal energy storage, water management, and cryogenic infrastructure within a single closed-loop chemical cycle. Full article

Heart failure with preserved ejection fraction (HFpEF) represents a growing clinical challenge, accounting for more than half of all cases of heart failure, for which there are currently no effective treatments. Emerging evidence identifies mitochondrial dysfunction as a central mechanism linking metabolic comorbidities, systemic inflammation, and energy failure in HFpEF. This review provides a comprehensive overview of the metabolic–mitochondrial mechanisms underlying the pathophysiology of HFpEF. Loss of metabolic flexibility, characterized by reduced fatty acid and glucose oxidation, leads to energy inefficiency, lipid accumulation, and oxidative stress. Structural and functional mitochondrial abnormalities, including damaged cristae, altered fission-fusion dynamics, and impaired oxidative phosphorylation, contribute to diastolic dysfunction and ventricular remodeling. In parallel, chronic inflammation and redox imbalance amplify mitochondrial damage through cytokine- and ROS-mediated pathways, creating a cycle of bioenergetic failure. From a therapeutic perspective, strategies aimed at restoring mitochondrial homeostasis, such as physical training, metabolic modulation, SGLT2 inhibition, ketone supplementation, and mitochondria-targeted antioxidants, show promising preclinical results. However, clinical translation remains limited. Deepening the understanding of mitochondrial metabolism could enable the development of personalized treatments capable of improving outcomes for HFpEF patients. Full article

Nucleoside analogues are used as drugs and as labels in laboratory-based research. However, the effect of different nucleoside analogue mechanism(s) on cell sensitivity or mutagenesis is unclear. This is particularly important in cancer treatments where checkpoint proteins and DNA damage factors are often mutated. We tested six nucleoside analogues in fission yeast, Schizosaccharomyces pombe. We found that the mutations in the DNA replication checkpoint cause unique sensitivity profiles towards chemotherapeutic nucleoside analogues (gemcitabine, 5-fluorouracil, cytarabine) and the non-clinical analogue bromodeoxyuridine. Antiretroviral compounds, zidovudine and lamivudine, did not alter cell growth. We compared half-maximal inhibitory concentration (IC50) doses between checkpoint deficient yeast strains, examining culture growth and DNA mis-segregation. Intriguingly, gemcitabine and bromodeoxyuridine doses above the IC50 promoted better growth. Above each compound’s IC50 dose we saw that cells were insensitive to nucleoside analogue re-exposure, particularly in DNA replication checkpoint mutants (cds1∆, rad3∆). Thus, pairing nucleoside analogue use with personal genomics may inform drug choice, dose, and schedule. Finally, these data indicate that resistance may be predictable, informing clinical strategy. Full article

Mitochondrial integrity is indispensable for pulmonary cellular homeostasis, with its dysfunction increasingly being implicated as a central mechanism in the etiology of respiratory disorders. We present a comprehensive overview of the integral role played by mitochondrial dynamics, such as fusion, fission, mitophagy, intracellular trafficking, and biogenesis, in maintaining pulmonary homeostasis. This study further explores how perturbations in these processes contribute to the pathogenesis of diverse lung disorders, including chronic obstructive pulmonary disease (COPD), bronchopulmonary dysplasia (BPD), pulmonary arterial hypertension (PAH), idiopathic pulmonary fibrosis (IPF), and drug-induced lung disease. It further explores how perturbations in these processes contribute to the pathogenesis of diverse lung disorders—for example, chronic obstructive pulmonary disease (COPD; responsible for roughly 55% of chronic respiratory disease cases), bronchopulmonary dysplasia (BPD; affecting up to 45% of infants born before 29 weeks of gestation), pulmonary arterial hypertension (PAH; a rare condition causing about 22,000 deaths worldwide in 2021), idiopathic pulmonary fibrosis (IPF; 0.33–4.51 cases per 10,000 persons), and drug-induced lung disease. Evidence demonstrates that mitochondria-triggered apoptosis, metabolic shifts, and subsequent inflammatory signaling act together to drive airway tissue remodeling and fibrotic progression across these lung diseases. Furthermore, this review evaluates the therapeutic potential of mitochondrial-targeted drugs, such as MitoQ and SS31, and metformin, which have shown promise in basic and preclinical studies. Preclinical and early clinical evaluations include an ongoing trial of the mitochondrial-targeted antioxidant MitoQ (NCT02966665, phase 1) in COPD, a 4-month open-label DCA study in PAH patients, and studies determining the preclinical efficacy of SS-31 and metformin in IPF models. Ultimately, integrating mitochondrial biomarkers into clinical practice holds the potential not only to facilitate early disease detection but also to enable the development of precision therapies, thereby offering renewed hope for patients afflicted with chronic lung diseases. Full article

Alzheimer’s disease (AD) is a progressive and incurable neurodegenerative disorder that primarily affects persons aged 65 years and above. It causes dementia with memory loss and deterioration in thinking and language skills. AD is characterized by specific pathology resulting from the accumulation in the brain of extracellular plaques of amyloid-β and intracellular tangles of phosphorylated tau. The importance of mitochondrial dysfunction in AD pathogenesis, while previously underrecognized, is now more and more appreciated. Mitochondria are an essential organelle involved in cellular bioenergetics and signaling pathways. Mitochondrial processes crucial for synaptic activity such as mitophagy, mitochondrial trafficking, mitochondrial fission, and mitochondrial fusion are dysregulated in the AD brain. Excess fission and fragmentation yield mitochondria with low energy production. Reduced glucose metabolism is also observed in the AD brain with a hypometabolic state, particularly in the temporo-parietal brain regions. This review addresses the multiple ways in which abnormal mitochondrial structure and function contribute to AD. Disruption of the electron transport chain and ATP production are particularly neurotoxic because brain cells have disproportionately high energy demands. In addition, oxidative stress, which is extremely damaging to nerve cells, rises dramatically with mitochondrial dyshomeostasis. Restoring mitochondrial health may be a viable approach to AD treatment. Full article

Amyotrophic lateral sclerosis (ALS) is a fatal multisystem disease characterized by progressive death of motor neurons, loss of muscle mass, and impaired energy metabolism. More than 40 genes are now known to be associated with ALS, which together account for the majority of familial forms of ALS and only 10% of sporadic ALS cases. To date, there is no consensus on the pathogenesis of ALS, which makes it difficult to develop effective therapy. Accumulating evidence indicates that mitochondria, which play an important role in cellular homeostasis, are the earliest targets in ALS, and abnormalities in their structure and functions contribute to the development of bioenergetic stress and disease progression. Mitochondria are known to be highly dynamic organelles, and their stability is maintained through a number of key regulatory pathways. Mitochondrial homeostasis is dynamically regulated via mitochondrial biogenesis, clearance, fission/fusion, and trafficking; however, the processes providing “quality control” and distribution of the organelles are prone to dysregulation in ALS. Here, we systematically summarized changes in mitochondrial turnover, dynamics, calcium homeostasis, and alterations in mitochondrial transport and functions to provide in-depth insights into disease progression pathways, which may have a significant impact on current symptomatic therapies and personalized treatment programs for patients with ALS. Full article

David Lewis’s attempt to defuse grandfather paradoxes consistently without special restrictions on the ability of time travelers to act in the past is controversial. Kadri Vihvelin uses the case of possible autoinfanticide—killing one’s infant self—to argue on Lewisian grounds that Lewis is wrong, since all counterfactual attempts at autoinfanticide would fail. I present a new defense of Lewis against Vihvelin premised on the possibility of personal reinstatement, where a person who dies prematurely is replicated from information collected from a previous live scan. I argue on Lewisian grounds that in a Vihvelin case where Suzy does not attempt to kill Baby Suzy, Vihvelin has not shown that Suzy would have failed had she tried to kill Baby Suzy. For, Baby Suzy might have been reinstated. Hence, even granting Vihvelin’s own assumptions, a Lewisian can assert that Suzy can kill Baby Suzy. Reinstatement does not require a “big” miracle; so autoinfanticide is no biggie. Full article

Unlike bolus insulin secretion mechanisms, basal insulin secretion is poorly understood. It is essential to elucidate these mechanisms in non-hyperinsulinaemia healthy persons. This establishes a baseline for investigation into pathologies where these processes are dysregulated, such as in type 2 diabetes (T2DM), cardiovascular disease (CVD), certain cancers and dementias. Chronic hyperinsulinaemia enforces glucose fueling, depleting the NAD+ dependent antioxidant activity that increases mitochondrial reactive oxygen species (mtROS). Consequently, beta-cell mitochondria increase uncoupling protein expression, which decreases the mitochondrial ATP surge generation capacity, impairing bolus mediated insulin exocytosis. Excessive ROS increases the Drp1:Mfn2 ratio, increasing mitochondrial fission, which increases mtROS; endoplasmic reticulum-stress and impaired calcium homeostasis ensues. Healthy individuals in habitual ketosis have significantly lower glucagon and insulin levels than T2DM individuals. As beta-hydroxybutyrate rises, hepatic gluconeogenesis and glycogenolysis supply extra-hepatic glucose needs, and osteocalcin synthesis/release increases. We propose insulin’s primary role is regulating beta-hydroxybutyrate synthesis, while the role of bone regulates glucose uptake sensitivity via osteocalcin. Osteocalcin regulates the alpha-cell glucagon secretory profile via glucagon-like peptide-1 and serotonin, and beta-hydroxybutyrate synthesis via regulating basal insulin levels. Establishing metabolic phenotypes aids in resolving basal insulin secretion regulation, enabling elucidation of the pathological changes that occur and progress into chronic diseases associated with ageing. Full article