Before giant manta rays (Mobula birostris) can grow to up to 30 feet long and 4,409 pounds, they must start small like most living things. Giant manta ray babies (called pups) in Central America don’t have their size to protect them from orca whales (Orcinus orca) and the numerous sharks in the open ocean. Their solution—sticking to the coast, where there is plenty of food to help them grow and defend themselves. A new study published today in the journal Frontiers in Fish Science details the baby rays’ behavior.
“We show that manta rays’ lifestyle isn’t a one-size-fits-all behavior. Giant manta rays in Central America undergo a dramatic shift in space use as they mature,” Jeffry Madrigal-Mesén, a study co-author and project leader of Mantas Costa Rica, said in a statement. “Juveniles remained strictly within shallow nearshore waters that serve as coastal refuges, but most of the tracked adults executed long-distance transboundary migrations along the continental shelf break into Central America.”
In the study, the team used multiple methods to track and identify mantas at five locations between 2018 and 2025. Acoustic telemetry uses underwater sound pulses to monitor fish movements and allowed the team to track 59 individual rays. With satellite telemetry, transmitters track movement and behavior from a distance and helped the team track large-scale movements of 12 individuals. Lastly, photo identification helped to identify individual manta rays.
“If we hadn’t used all three technologies together, we simply wouldn’t have been able to piece this puzzle together,” explained Madrigal-Mesén. “Combining these tools turned fragmented data into a unified, undeniable story.”
The team ended up with a dataset of over 12,000 detections. The data showed that young mantas (those with a body about 10 feet or less) stick to shallow coastal refuges. In these more shallow spots, the pups have a safe place that doesn’t overlap with their predators’ hunting grounds. They have plenty of food and places to hide, and even get essential services like cleaning from reefs.
“Mature adults can rely on their massive body size and their ability to dive deep to evade threats. But juveniles don’t have that luxury,” said Madrigal-Mesén. “What is truly amazing is seeing how strictly young manta rays stick to coastal waters as long-term refuges. We see the same individuals more often than once a year. In fact, just recently, they were sighted again at the exact same tagging location. It is always a joy to see them again—they have truly become a part of the family.”
By comparison, nine mature mantas in the study went on expansive migrations along the continental shelf break. One manta ray nicknamed Mickey Mouse because of a spot pattern on his belly had movements that suggest the fish also continue to display loyalty to a particular site once they grow up. Unusually approachable for a manta, Mickey Mouse allowed the team tag him multiple times over several years, which provided a continuous dataset. In 2020, he logged 462 acoustic detections at a coastal hub called El Secreto. He returned to the same shelf in 2023, and stayed there for 38 days.
“Nearshore cleaning stations transcend basic hygienic function; they act as primary social hubs where courtship and reproductive interactions take place,” said Madrigal-Mesén. “Returning to a predictable coastal depot allows mature rays to prioritize social and cleaning needs before undertaking large-scale regional migrations.”
Once they leave coastal regions, adult manta rays face different dangers. Coastal areas are often legally protected marine reserves, but the open ocean is another story. They no longer have legal protection and are exposed to dangers from industrial fisheries and vessel strikes.
According to the team, this shows that marine protected areas alone are not enough to protect this highly mobile species as it swims across Central America. They say that multi-national “conservation swimways” that link the domestic juvenile coastal refuges with adult migratory corridors could help keep the endangered rays safe.
“This study opens a new chapter for manta ray research in Central America,” Madrigal-Mesén concluded. “We hope it sparks fresh enthusiasm and encourages future collaborators to join us in executing the new ideas and research projects we have planned for the conservation of this species.”
The post Baby manta rays stick to the shallows to avoid sharks and orca appeared first on Popular Science.
A plant-derived compound called ailanthone reduced HSV-1 replication in several cell models and eased corneal disease in a mouse model of herpes simplex keratitis, according to the study. The researchers found that ailanthone acted mainly after the virus entered cells and linked much of this effect to reduced expression of integrin beta 2, or ITGB2, a host protein that supports viral replication. The results identify ailanthone as a potential drug candidate, but the experiments do not establish that it is safe or effective in people.
The team began by screening natural compounds and testing ailanthone in African green monkey kidney Vero cells infected with HSV-1. Concentrations of 100 to 3,000 nanomolar reduced transcription of the viral immediate-early genes ICP0 and ICP4 and the late gene gD in a dose-dependent manner. The compound also reduced plaque formation and the concentration of progeny virus released into culture. Ailanthone had a half-maximal cytotoxic concentration above 10,000 nanomolar in these cells, while its half-maximal effective concentration against viral replication was 197.4 nanomolar, giving a selectivity index greater than 50. It also suppressed HSV-1-induced increases in the inflammatory cytokine genes IL-1B and TNF-α.
Antiviral activity was subsequently observed in human corneal epithelial cells, a model more directly relevant to the tissue affected by keratitis. Ailanthone concentrations of 100 to 500 nanomolar markedly reduced the cytopathic effects of HSV-1F, lowered expression of ICP0, ICP4 and gD, and reduced the viral induction of IL-1B and TNF-α. Its effective concentration in these cells was 50.16 nanomolar, with a cytotoxicity concentration above 10,000 nanomolar and a selectivity index greater than 100. The researchers also tested the compound in human retinal pigment epithelial ARPE-19 cells, where it reduced viral gene expression, plaque formation and progeny-virus titers while showing low cytotoxicity.
Activity was not restricted to the laboratory HSV-1F strain. In ARPE-19 cells, ailanthone concentration-dependently inhibited the late gD gene in the clinical acyclovir-resistant strain HSV-1/153, whereas 1,000 nanomolar acyclovir had little effect. The compound’s effective concentration was 35.05 nanomolar against HSV-1F and 227.4 nanomolar against HSV-1/153, with selectivity indices above 100 for both strains. A time-of-addition experiment indicated that ailanthone did not prevent attachment of HSV-1 to cells. It reduced entry under one experimental schedule and had its strongest effect on post-entry replication, where it lowered gD expression.
To investigate how the compound might work, the researchers combined computational target prediction with protein-interaction network analysis. They identified 36 targets shared by ailanthone and herpes simplex keratitis, then selected ITGB2 as a highly connected hub in the resulting network and as a top candidate in molecular docking. The predicted docking score for ailanthone and ITGB2 was −8.6 kcal per mole. Computational predictions alone cannot establish direct binding, so the team also performed a drug affinity responsive target stability assay in THP-1 cell lysates. Ailanthone protected ITGB2 from digestion by the protease pronase E in a dose-dependent manner, while acyclovir did not, providing biochemical evidence consistent with a direct interaction.
Functional experiments then tested whether ITGB2 was necessary for the antiviral effect. Three independent small interfering RNAs reduced ITGB2 messenger RNA and protein in THP-1 cells. Following HSV-1 infection, this knockdown lowered gD messenger RNA and protein and reduced the number of plaques produced when culture supernatants were transferred to fresh Vero cells. The converse pattern appeared when ITGB2 was overexpressed: elevated ITGB2 increased gD expression in infected cells, and it partially counteracted the reduction in gD protein caused by ailanthone in 293T and ARPE-19 cells. Together, these loss- and gain-of-function results support the conclusion that ailanthone’s antiviral activity is mediated at least partly by lowering ITGB2.
The researchers next tested ailanthone in an acute mouse model of HSV-1 keratitis. Six-week-old male BALB/c mice received a corneal scratch followed by application of HSV-1F, then received intraperitoneal ailanthone at 1 or 5 milligrams per kilogram or acyclovir at 5 milligrams per kilogram on days 1, 3 and 5 after infection. The methods section states that six animals were assigned to each group, although the discussion says five mice per group were used in the animal experiment. The 5-milligram-per-kilogram ailanthone treatment significantly reduced clinical disease scores, improved the appearance of the cornea under normal and cobalt-blue illumination, and lowered fluorescein staining scores on days 3 and 5. Hematoxylin and eosin staining at day 6 also indicated reduced corneal inflammation, and viral titers in ocular swabs were significantly lower than in infected mice given vehicle.
Analysis of mouse corneal tissue was consistent with the proposed mechanism. ITGB2 was upregulated in the corneas of infected animals, and ailanthone reduced its fluorescence intensity in a dose-dependent manner. Acyclovir did not significantly alter corneal ITGB2 levels. The investigators interpreted this as evidence that ailanthone differs from a direct viral DNA-replication inhibitor: the data are consistent with modulation of a host dependency factor rather than action solely through a viral enzyme. However, the study did not determine precisely how binding to ITGB2 leads to lower protein abundance. The authors note that transcriptional regulation, changes in messenger-RNA stability, or enhanced protein degradation could all be involved, and dedicated experiments would be required to distinguish among them.
Several limitations constrain how far the findings can be generalized. The cell experiments used established lines, including corneal epithelial and retinal pigment epithelial cells, rather than primary human corneal cells or an intact human immune system. The animal experiment examined acute primary infection in young male mice, whereas recurrent reactivation and the inflammation associated with repeated episodes are important features of human herpes simplex keratitis. Ailanthone was administered by intraperitoneal injection, but no topical ophthalmic formulation, corneal penetration, intraocular distribution, or optimized dosing regimen was evaluated. Long-term ocular toxicity and safety under repeated exposure also remain unknown. The natural compound may additionally affect multiple targets, and compensation among integrins could limit or alter its effects. The evidence therefore supports further preclinical investigation of ailanthone and ITGB2 as a host-directed antiviral strategy, not a clinical recommendation or a claim of human therapeutic benefit.
Subject of Research: Preclinical evaluation of ailanthone as a host-directed inhibitor of HSV-1 replication and herpes simplex keratitis.
Article Title: Natural compound ailanthone alleviates herpes simplex keratitis in mice by inhibiting HSV-1 replication
Article References: Chen, L., Yang, E., Zhang, X., Zhang, L., Wu, L., Chen, S., Jin, W., Qin, Q., Chen, R., Wu, J., & Chen, D. (2026). Natural compound ailanthone alleviates herpes simplex keratitis in mice by inhibiting HSV-1 replication. Frontiers in Pharmacology, 17, Article 1937590. https://doi.org/10.3389/fphar.2026.1937590
Image Credits: AI Generated
DOI: 10.3389/fphar.2026.1937590
Keywords: HSV-1, herpes simplex keratitis, ailanthone, ITGB2, host-directed antivirals, viral replication, corneal infection, mouse model, integrin beta 2, drug resistance, Natural, compound
Researchers at ETH Zurich and the Paul Scherrer Institute in Villigen, Switzerland, have produced a high-intensity beam of muonium atoms in a cold state, an experimental advance that could enable a direct test of whether gravity acts differently on second-generation matter. The peer-reviewed study in Nature Physics describes a new method for generating muonium in superfluid helium. The resulting atoms travel at similar speeds and almost parallel to one another, properties required for a future interferometer that would measure the tiny influence of gravity on muonium.
The study did not conduct that gravitational measurement or find evidence that gravity departs from its expected behavior for ordinary matter; it instead developed the beam source needed for the proposed test. The experiment is designed to examine the universality of free fall and the equivalence of gravitational and inertial mass, a cornerstone of Albert Einstein’s theory of gravitation. In ordinary matter, bodies fall at the same rate at a given point within a gravitational field, while the equivalence principle links gravitational mass with inertial mass.
According to the research team, this principle has so far been demonstrated only with ordinary matter or first-generation antimatter. Muonium is a neutral atom formed from a positively charged antimuon and a negatively charged electron, making it a second-generation probe. A gravity experiment with this exotic atom would test whether the equivalence continues to hold for particles outside the first generation.
Muonium has two characteristics that make it useful for this test: it is neutral, and it belongs to a heavier and less familiar generation of particles. A neutral object allows gravitational behavior to be studied without the weak gravitational signal being masked by stray electromagnetic fields, which can dominate the behavior of charged particles. At the same time, muonium is exceptionally difficult to produce and control.
Its constituent muon decays after only about 2.2 microseconds. Earlier sources generated muonium atoms that flew off in many directions at different speeds and were therefore unsuitable for the precision required in a gravity experiment. The researchers addressed this problem by creating a cold, intense and well-directed beam.
The antimuons were directed into a thin layer of superfluid helium that had been cooled close to absolute zero, at minus 273 degrees Celsius. Superfluid helium is a quantum fluid in which individual helium atoms lose their identity and in which impurities are not tolerated. Lead author Jesse Zhang said the researchers used the superfluid as an “atomic cannon,” exploiting the conversion of chemical potential into kinetic energy to propel the newly formed muonium atoms out of the liquid.
When an antimuon encounters a free electron in the superfluid helium, it forms a neutral muonium atom with positive chemical potential. The atom is forced out of the liquid, and as it reaches the surface, that chemical potential is converted into kinetic energy. The resulting boost sends the muonium vertically out of the helium.
Importantly, the atoms must move through the quantum liquid at a suitable speed without collisions, because excessive scattering would prevent them from reaching the surface within their very short lifetime. The high-intensity antimuon beam from PSI allows many muonium atoms to be generated for the planned experiments. Anna Soter, a professor of physics at ETH Zurich and member of the research team, said the cold state is what makes the proposed gravity experiment possible.
In this context, “cold” does not mean that the atoms are motionless; it means that they propagate at similar speeds and nearly parallel to one another. This improved control over direction and velocity is important because the planned instrument will use the wave properties of the atoms to create an interference pattern. A very small shift in that pattern caused by Earth’s gravitational pull would provide a measure of gravity’s effect on muonium.
The study establishes the upstream beam capability rather than reporting the result of that comparison. The next stage of the program is the development of a muonium interferometer. According to the researchers, they hoped to test the method for the first time with the atomic beam in the year of the announcement and, if that worked as expected, to carry out the actual gravity experiment two or three years later.
Those are planned milestones rather than completed measurements. If the interference pattern of muonium shifts differently from the pattern expected for ordinary matter, Soter said the result would be surprising and could, among other theoretical possibilities, point toward the existence of a fifth force. No fifth force has been proven, and the present work provides no evidence for one.
The team’s primary aim is to measure whether the equivalence between gravitational and inertial mass applies to a second-generation particle. Physics recognizes four fundamental interactions: gravity, electromagnetism, the strong interaction and the weak interaction. A fifth force has been proposed repeatedly, but it has never been established.
Soter emphasized that the researchers are open-minded about what the measurement may show while keeping the immediate objective focused on the first such test. The new beam is therefore an enabling experimental result, not a demonstration that Einstein’s theory has been challenged or overturned. Beyond the planned gravity measurement, the high-intensity muonium beam is expected to enable more precise laser-spectroscopy experiments.
These could allow muonium to be measured more accurately than in previous work and provide information about the muon’s mass and fundamental physical constants, which are stated goals of the research group. The same experimental source can thus serve two purposes: supplying a cold, directed beam for a gravitational comparison and providing a larger, better-controlled population of muonium for detailed spectroscopic study. The reported advance addresses a major technical obstacle while leaving the central scientific question unresolved.
A successful gravitational test will still require an interferometer capable of resolving a minuscule shift in an interference pattern while dealing with muonium’s short lifetime, beam quality and other sources of uncertainty. The study’s demonstrated result is the generation of a high-intensity, superthermal muonium beam in superfluid helium, with atoms emerging in the cold state needed for future work. Whether muonium falls exactly as expected for ordinary matter remains to be measured.
The beam nevertheless supplies the experimental foundation for testing gravitational universality in a second-generation particle, a comparison that had not previously been carried out with muonium.
Subject of Research: A cold muonium beam developed for future tests of gravitational universality and laser spectroscopy
Article Title: Novel particle beam could challenge Einstein’s Theory of Gravity
Article References: Novel particle beam could challenge Einstein’s Theory of Gravity. Original publication (Bibliographic details unavailable.)
Image Credits: AI Generated
DOI: Not provided
Keywords: muonium, muon beam, gravity, gravitational universality, equivalence principle, interferometry, superfluid helium, laser spectroscopy, ETH Zurich, Paul Scherrer Institute, Novel, particle
The PLOS One editors have issued an expression of concern for a 2024 case study concerning the digital economy, innovation factor allocation and industrial structure transformation in China’s Yangtze River Delta city cluster. The notice, published on October 21, 2026, states that the article was identified as one of a series of submissions for which the journal has concerns about the integrity or reliability of the peer-review process. Readers are advised to interpret the original study with this issue in mind.
The notice does not report a new scientific finding, identify an error in the paper or evaluate the study’s scientific validity. According to the editors, PLOS did not assess the article’s integrity or scientific validity when following up on the matter. The expression of concern therefore records a concern about the circumstances surrounding peer review rather than announcing that the study’s data, methods or conclusions have been disproved. The editors also state that they have no concerns regarding the authors’ conduct during the peer-review process.
The affected article was published in PLOS One in 2024 under the title “Digital economy, innovation factor allocation and industrial structure transformation—A case study of the Yangtze River Delta city cluster in China.” The supplied notice does not provide the study’s findings, population details, analytical methods, model estimates, uncertainty measures or specific mechanisms linking the subjects named in the title. As a result, the notice does not support conclusions about the relationship between digital-economy development, innovation factors and industrial structure in the region, nor does it establish whether any reported association or causal effect is reliable.
For the wider research record, the immediate effect is that the 2024 article is accompanied by an editorial notice questioning the integrity or reliability of its peer-review process. The notice does not provide details about the submissions or explain the specific basis for the journal’s concerns. It also does not announce a correction, replacement analysis or revised conclusion. The central status of the paper’s scientific validity remains unevaluated in the supplied material, while the issue is sufficiently significant for PLOS One to advise readers to consider it when interpreting the study.
Subject of Research: A PLOS One expression of concern concerning peer-review reliability in a Yangtze River Delta regional-economy case study.
Article Title: Expression of Concern: Digital economy, innovation factor allocation and industrial structure transformation—A case study of the Yangtze River Delta city cluster in China
Article References: The PLOS One Editors (2026). Expression of Concern: Digital economy, innovation factor allocation and industrial structure transformation—A case study of the Yangtze River Delta city cluster in China. PLOS One, 21(10), e0360867. https://doi.org/10.1371/journal.pone.0360867
Image Credits: AI Generated
DOI: 10.1371/journal.pone.0360867
Keywords: PLOS One, expression of concern, peer review, research integrity, digital economy, innovation factors, industrial structure, Yangtze River Delta, China, Expression, Concern, Digital
A nurse-led chronic disease management clinic in the urology department of a tertiary hospital recorded 14,013 outpatient registrations between July 2024 and September 2026, according to a single-center retrospective descriptive study using routinely collected service records. The clinic primarily supported long-term management of patients with prostate and bladder cancer while also providing specialty nursing services for other urological conditions. Its follow-up system marked 3,547 of 3,553 assigned tasks as successful, a task-level success rate of 99.83%. These figures describe service activity and record completion; the study did not measure whether the clinic improved clinical outcomes or economic performance.
The clinic was established in July 2024 within the hospital’s existing specialty nursing outpatient service framework. Its operating model included staffing and qualification requirements, professional training, clearly defined nursing responsibilities, physician–nurse collaboration, standardized procedures, information-system support and quality management. Nurses worked within their authorized scope of practice, while urologists participated in medical assessment and treatment decisions when required. The service had four reported components: patient assessment and follow-up planning; treatment follow-up and adverse-event monitoring; rehabilitation guidance and health promotion; and assistance with healthcare policies and basic nursing care.
Monthly registrations increased from 147 in July 2024 to a peak of 710 in August 2026, with fluctuations during the reporting period. Total registration fees were CNY 152,758. The clinic delivered 14,246 prostate cancer-related injections, 3,523 urinary catheterizations, 2,777 intravesical instillation procedures and 2,142 urinary catheter removals. It also assisted patients with prostate or bladder cancer in applying for outpatient chronic and special disease insurance benefits. The study reports these counts as routine service activities, but it did not compare the procedures with those delivered elsewhere or evaluate their individual clinical effects.
Follow-up management was integrated into the clinic’s information system, which contained records for 1,111 patients. Of these, 953 patients had been followed up and 951 had successful follow-up records. Nurses also executed 3,553 follow-up tasks, of which 3,547 were successful, corresponding to the reported 99.83% task-level rate. The descriptive data do not specify the duration or effectiveness of patient follow-up, assess whether missed contacts influenced treatment adherence or health outcomes, or establish how the results would compare with another care model.
Because the research covered one tertiary hospital and relied on routinely collected records, it cannot establish how the clinic would operate in smaller facilities, under different staffing arrangements or in other health systems. The findings offer a documented example of a nurse-led outpatient service with defined responsibilities, standardized workflows, follow-up documentation and collaboration with urologists. The authors stated that further research is needed to evaluate the model’s clinical outcomes and economic implications. Accordingly, the registration growth, procedural workload and high proportion of completed follow-up tasks should be interpreted as descriptions of implementation and recorded service delivery, not as evidence of improved survival, fewer complications, lower costs or other patient benefits.
Subject of Research: Operation and service activity of a nurse-led chronic disease management clinic in hospital urology
Article Title: Development and implementation of a nurse-led chronic disease management clinic in the urology department of a tertiary hospital: a descriptive study
Article References: Liu, C., Xia, Y., Jia, X., Wang, R., Li, T., Ma, Y., & Long, H. (2026). Development and implementation of a nurse-led chronic disease management clinic in the urology department of a tertiary hospital: a descriptive study. BMC Nursing. https://doi.org/10.1186/s12912-026-05566-z
Image Credits: AI Generated
DOI: 10.1186/s12912-026-05566-z
Keywords: nurse-led care, urology, outpatient nursing, chronic disease management, prostate cancer, bladder cancer, patient follow-up, service implementation, descriptive study, Development, implementation, nurse-led
Longitudinal airflow can sharply suppress the drifting and ablation of the electrical arc formed between a train’s pantograph and overhead contact wire, according to a modeling and experimental study of pantograph–catenary systems under low-pressure conditions. The researchers built a magnetohydrodynamic model that coupled electric, magnetic, thermal, fluid and arc-motion dynamics, then tested the method in a vacuum chamber with copper and carbon electrodes. In experiments conducted at atmospheric pressure, increasing the airflow to 45 metres per second reduced the measured arc drift height from 27.6 millimetres to zero and shortened the arc-root distance from 51.3 to 3.9 millimetres. The same airflow setting also produced progressively less carbon-electrode damage, supporting the proposal as a possible current-collection control method for railways operating at high altitude.
The need for such control arises because the pantograph–catenary system carries the electrical energy used by electric trains, while the stability of its contact strongly affects operating safety and efficiency. Lower atmospheric pressure presents a particularly difficult environment. The study notes that reduced air density and breakdown-field strength can lower the ignition threshold for pantograph–catenary arcs, increase their frequency and duration, and enlarge the region affected by arcing. Repeated arcing can cause irreversible high-temperature ablation and electrical wear on contact wires and pantograph strips. It can also generate broad-band electromagnetic interference that may affect onboard signalling and traction-control systems, with potential consequences including insulator flashover and disruption of the traction network. These background risks motivate efforts to understand and restrain the spatial movement of arcs in plateau environments.
Existing arc models include the Cassie and Mayr black-box approaches, which support analysis of interactions between arcs and traction-network circuits but do not represent an arc’s changing spatial shape. Magnetohydrodynamic models offer a more physical alternative by coupling electromagnetic, flow and thermal fields. Previous work represented crosswind effects on pantograph–catenary arcs and examined how decreasing pressure affects arc-root jumping, in which the root forms at a new location after the elongated column reaches a critical length. Other studies have shown that magnetic fields can stabilize welding and switching arcs. Airflow regulation, however, has been investigated more extensively in welding than in pantograph–catenary systems, whose dissimilar electrodes, high operating speed, open environment, changing electrode gap and constrained vehicle installation space make their arc dynamics more complicated.
The new model represents an arc initially 6 millimetres long and 2 millimetres in diameter between a copper anode and a carbon cathode. It includes the surrounding air, both electrodes and a central longitudinal-airflow channel beneath the copper electrode, including a 1.5-millimetre control-airflow inlet. A separate inlet represents train-induced airflow and was set to 40 metres per second. Calculations covered pressures of 101, 80 and 60 kilopascals, longitudinal airflow from zero to 80 metres per second and a total simulation time of 25 milliseconds. Air properties were adjusted with pressure, while the electrodes were assigned distinct densities, resistivities, thermal conductivities and heat capacities. The governing equations represented electrical potential and current, magnetic-vector potential, mass and momentum conservation, energy conservation, viscous dissipation, Joule heating and net volumetric radiation.
The calculations use several explicit simplifications. Arc ignition is omitted, and the plasma is treated as being in local thermodynamic equilibrium. Flow in the air and arc domains is assumed laminar and incompressible, while metal vapour generated by electrode evaporation and phase change is excluded. These assumptions make it possible to examine large-scale arc motion and temperature distribution but prevent the simulation from directly calculating electrode mass loss, crack width or crater area. Copper was assigned the anode and carbon the cathode; a Gaussian distribution represented current entering through the copper electrode, and the bottom of the carbon electrode was grounded. The air boundary was treated as magnetically insulated, and the initial temperatures were set to 300 kelvin for the air and electrodes and 5,000 kelvin for the arc domain. The experimental apparatus was separate from the numerical model and provided direct physical measurements of damage.
Without longitudinal airflow, the simulated arc passed through two stages. During the first 10 milliseconds, its column elongated continuously, bent under airflow influence, and developed greater drift height and arc-root distance. From 10 to 25 milliseconds, the column and root distance fluctuated through repeated shortening and elongation. The authors associate this behaviour with the electrical and mechanical limits of the arc: once a column reaches a critical length, the voltage and energy available between the electrodes may no longer sustain continuous burning, and a shorter path of lower resistance may form on the electrode surface. The resulting root “jump” shortened the column before airflow stretched it again. Arc development became faster and both drift height and root distance increased as pressure fell. Temperature briefly exceeded 10,000 kelvin and reached a maximum within roughly two to three milliseconds before fluctuating, while arc voltage rose as the column lengthened and resistance increased.
Longitudinal airflow changed these trajectories in the simulations. As speed increased, drift height, root distance and temperature all declined, with the greatest reductions occurring at lower airflow speeds before the curves began to level off. At 101 kilopascals, the calculated drift height fell from 37.5 millimetres without control airflow to zero at 45 metres per second, while root distance decreased from 57.3 to 3.7 millimetres and temperature dropped from 12,900 to 8,650 kelvin. The airflow needed to eliminate drift was 45, 40 and 35 metres per second at pressures of 101, 80 and 60 kilopascals, respectively; speeds required to bring root distance below 5 millimetres were 45, 40 and 30 metres per second. The authors attribute the stronger response at lower pressure to reduced plasma density, which weakens the arc’s inherent rigidity, Lorentz force and thermal buoyancy, allowing airflow load to become a more dominant influence on its motion.
The temperature response also revealed a practical plateau. The researchers defined the optimal airflow speed as the point after which increasing speed by 5 metres per second changes arc temperature by less than 3 per cent. At atmospheric pressure this occurred at 40 metres per second, compared with 30 metres per second at 60 kilopascals. The reported temperature reduction was 33.8 per cent at 101 kilopascals and 38.1 per cent at 60 kilopascals. Airflow strengthened convective heat removal, which lowered plasma temperature and, in turn, increased deionization and reduced Joule heating. Once thermal exchange approached saturation and the minimum temperature required for self-sustaining arc combustion was approached, further increases in speed produced little additional cooling. The model therefore indicates that the airflow speeds required for control decline as ambient pressure falls.
Laboratory testing used a vacuum chamber capable of controlling pressure with an accuracy of plus or minus 100 pascals, a constant-current supply rated from zero to 150 amperes, an arc igniter, a fan with continuously adjustable airflow from zero to 60 metres per second, a high-speed camera and an oscilloscope. Airflow at the electrode outlet was measured with an anemometer accurate to plus or minus 0.5 metres per second. The camera operated at 6,400 frames per second with an exposure of five microseconds, while each two-second arc test was repeated five times and the mean was reported. Tests at 101 kilopascals used airflow speeds of zero, 20, 30 and 45 metres per second. Without control airflow, high-speed images showed increasing arc drift. At 45 metres per second, drift was virtually absent during the final development phase and root distance was substantially shortened, with observed morphologies broadly consistent with the numerical results.
The experiments also found reductions in carbon-electrode ablation that increased with airflow speed. Microscopy showed shorter ablation areas, smaller craters and narrower crack propagation as the controlled airflow rose. The maximum crack width was 66.7 micrometres without airflow and decreased at higher speeds, while analytical weighing showed progressively less mass loss from the carbon electrode. The proposed mechanism is that stronger airflow promotes arc-root slippage, shortening the time the root remains at one point, while convective cooling lowers temperature and local energy density. These are experimental observations rather than direct outputs of the simulation: because the model omits electrode evaporation and metal-vapour transport, it cannot quantitatively predict ablation rates or near-electrode energy balances. The study therefore demonstrates reduced damage under its controlled laboratory conditions, not a complete first-principles calculation of all processes responsible for electrode wear or a proven field performance level in operating plateau railways.
Subject of Research: Experimental and numerical evaluation of airflow control of pantograph–catenary arcs at low pressure.
Article Title: Research on regulation method for suppression of pantograph-catenary arc by airflow in low-pressure environment
Article References: Xu, Z., Wang, S., Dong, K., & Gao, G. (2026). Research on regulation method for suppression of pantograph-catenary arc by airflow in low-pressure environment. iScience, 29(11), Article 117951. https://doi.org/10.1016/j.isci.2026.117951
Image Credits: AI Generated
DOI: 10.1016/j.isci.2026.117951
Keywords: pantograph–catenary systems, railway electrification, electric arcs, low-pressure environments, longitudinal airflow, magnetohydrodynamic modelling, electrode ablation, high-speed rail, plateau railways, arc suppression, Research, regulation
A retrospective study of 1,307 patients undergoing elective percutaneous vertebroplasty for osteoporotic vertebral compression fractures found that 136, or 10.4%, had a puncture-site wound event within two weeks of surgery. The composite outcome included erythema or swelling, bleeding or exudate, subcutaneous hematoma, and infection. After adjustment for patient and procedural factors, suture closure was associated with more than twice the risk of the composite outcome, while diabetes, mildly elevated international normalized ratio, and multilevel treatment were also associated with higher risk.
The findings come from consecutive patients treated at Ningde Municipal Hospital in China between January 2022 and June 2026. Patients were excluded if they underwent surgery for a new fracture, had uncontrolled coagulation disorders, received concomitant open spinal surgery, required an intraoperative incision at the puncture site, had malignant tumors or abnormal immune status, or lacked key clinical or follow-up information. The analysis therefore describes elective vertebroplasty performed within one hospital system, rather than all fracture patients or all puncture wounds treated after other forms of spine surgery.
Researchers extracted information from electronic medical records, operative and anesthesia records, laboratory reports, dressing-change notes, wound-clinic assessments, and documented telephone follow-up. All puncture sites were covered with waterproof dressings and assessed within two weeks through inpatient observation, clinical review, or telephone follow-up. A wound event was counted only when explicitly documented in the records. Erythema, swelling, bleeding, exudate, hematoma, and infection were combined into one patient-level outcome, counted once even if a patient experienced several types of event, while individual components were also summarized separately.
Closure was not assigned through a randomized comparison. The operating physician selected nonsuture or suture closure according to intraoperative bleeding, exudation, skin condition, wound tension, and routine practice. Sutured wounds were typically closed with one 3-0 Vicryl Rapide stitch. Among the 1,307 patients, 774 received nonsuture closure and 533 received sutures. An early event was recorded in 53 nonsuture cases, or 6.8%, and in 83 sutured cases, or 15.6%. The crude risk ratio for any event was 2.27, with a 95% confidence interval of 1.64 to 3.15 and a P value below 0.001.
After the researchers adjusted for closure method, diabetes, INR above 1.2, age, sex, body mass index, and multilevel treatment, the association with suturing remained. The adjusted risk ratio was 2.24, with a 95% confidence interval of 1.59 to 3.16 and P below 0.001. Diabetes was associated with an adjusted risk ratio of 1.57, with a 95% confidence interval of 1.11 to 2.21 and P equal to 0.010. An INR above 1.2, defined using the hospital laboratory’s upper reference limit, was associated with an adjusted risk ratio of 1.66, with a 95% confidence interval of 1.08 to 2.57 and P equal to 0.022. Multilevel treatment had an adjusted risk ratio of 1.73, with a 95% confidence interval of 1.03 to 2.89 and P equal to 0.038.
The component findings were concentrated in relatively common superficial manifestations rather than infection. Erythema or swelling occurred in 4.1% of patients with nonsuture closure and 10.9% of those with sutures, producing a crude risk ratio of 2.63, with a 95% confidence interval of 1.73 to 3.99. Bleeding or exudate occurred in 2.7% and 5.8% of the respective groups, with a crude risk ratio of 2.14 and a 95% confidence interval of 1.25 to 3.69. Subcutaneous hematoma was uncommon, affecting two nonsuture cases and three sutured cases, and its wide confidence interval included no difference. Infection was documented in one nonsuture case and no sutured cases, too few events to model infection separately.
Age, sex, and body mass index were not independently associated with the composite outcome in the primary adjusted model. Each additional decade of age had an adjusted risk ratio of 1.15, with a 95% confidence interval of 0.94 to 1.41 and P equal to 0.186. Female sex had an adjusted risk ratio of 0.96, with a 95% confidence interval of 0.66 to 1.39 and P equal to 0.829, while each 1 kg/m² increase in body mass index had an adjusted risk ratio of 1.07, with a 95% confidence interval of 0.99 to 1.17 and P equal to 0.091. These estimates mean that the study did not find clear independent associations for those demographic and anthropometric measures, not that they have no relationship to wound events in every clinical setting.
The suture result is particularly notable because the design cannot establish that suturing caused the additional events. The authors excluded several conditions that could make closure decisions unusual, including uncontrolled coagulation disorders, concomitant open surgery, and wounds requiring an intraoperative incision. Even so, surgeons may have selected sutures for locally difficult wounds, bleeding, exudation, poor skin condition, or excessive tension. Those unrecorded features could confound the comparison, while the fact that sutured patients may have had more wound checks or suture-removal visits could also increase the likelihood that mild redness or exudate was noticed and recorded. The finding should therefore be interpreted as an adjusted observational association rather than proof that sutures themselves produce wound inflammation or other complications.
Several other constraints limit what the study can establish. Follow-up was retrospective and varied among inpatient observation, wound-clinic examination, and telephone reporting, so assessment intensity and recording thresholds were not standardized. Very mild redness or transient bleeding may have been missed, and the records did not consistently capture event duration, patient discomfort, additional care, revisits, or hospitalization. The composite endpoint improved capture of local findings but combined conditions with different causes and severities. Only one infection occurred within two weeks, preventing meaningful analysis of surgical-site infection or later infections. The single-center design and the selected elective population also limit generalizability to open spine surgery, malignant disease, immunosuppression, or puncture sites requiring remedial closure.
Overall, the study identifies four factors associated with the short-term local wound status after elective vertebroplasty: suture closure, diabetes, elevated INR, and multilevel treatment. Its practical signal is that early observation may be especially relevant for patients with these characteristics, although the findings do not establish a clinical rule or a preferred closure technique. Because closure was clinician-selected, follow-up was not standardized, and the endpoint combined mild events with rare infection, the results point to priorities for further prospective research rather than definitive guidance. Within those limits, the observed 15.6% event rate after suturing compared with 6.8% after nonsuture closure provides the clearest signal in the cohort, while the observational design makes the mechanism unresolved.
Subject of Research: Factors associated with early puncture-site wound events after percutaneous vertebroplasty for osteoporotic vertebral compression fractures
Article Title: Factors associated with early puncture-site wound events after percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a retrospective cohort study
Article References: He, X., Huang, C., Zheng, B., Wu, X., Huang, C., Lu, S., Huang, Y., Chen, J., Huang, J., & Li, B. (2026). Factors associated with early puncture-site wound events after percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a retrospective cohort study. Frontiers in Medicine, 13, Article 1988843. https://doi.org/10.3389/fmed.2026.1988843
Image Credits: AI Generated
DOI: 10.3389/fmed.2026.1988843
Keywords: Percutaneous vertebroplasty, Osteoporotic fractures, Puncture-site wounds, Suture closure, Diabetes, Coagulation, Multilevel treatment, Retrospective cohort, Postoperative care, Factors, associated, early
A survey-based study of 246 village-level social welfare data operators found that business architecture, cross-organizational collaboration and technological readiness were positively and statistically significantly associated with perceived e-government integration impact in two Indonesian regencies. The research, focused on Gunung Kidul and Bangkalan, examined organizational, institutional, relational and technological capabilities associated with social welfare data integration. Governance and leadership and information policy did not show statistically significant direct relationships with perceived integration impact in the pooled sample.
The authors analyzed the survey with partial least squares structural equation modeling. In their framework, e-government integration impact, or EGII, represents perceived improvements in information, system and service quality, responsiveness and public trust. E-government integration scope, or EGIS, describes the breadth of integration across data, applications, electronic communication and knowledge-sharing processes.
EGII was strongly associated with EGIS, meaning that operators reporting more favorable perceived integration outcomes also tended to report broader integration. Because this was an observational analysis of survey responses, the results establish statistical relationships rather than causal effects. The findings identify three capabilities with significant direct relationships to EGII in the pooled model: business architecture, cross-organizational collaboration and technological readiness.
The evidence does not provide operational definitions for these constructs, but the results show that their measured levels were associated with respondents’ assessments of e-government integration outcomes. By contrast, governance and leadership and information policy had no statistically significant direct relationships with EGII in that analysis. This absence of a detected direct relationship does not establish that the two factors are unimportant or that they operate only through indirect pathways, because the supplied findings do not report such indirect effects.
A regency-based robustness analysis found that some relationships were sensitive to local implementation conditions. Significant differences between Gunung Kidul and Bangkan were reported for the technological-readiness-to-EGII relationship and the EGII-to-EGIS relationship. The geographic comparison therefore cautions against assuming that the same capability relationships apply uniformly across the two regencies, although it does not identify the specific local practices responsible for those differences.
Its direct contribution is to show which measured interoperability capabilities were associated with perceived integration impact in the surveyed population, alongside evidence that some relationships varied between the two regencies.
Subject of Research: Survey-based analysis of interoperability capabilities for social welfare data integration in two Indonesian regencies
Article Title: Determinants of E-government interoperability capabilities for social welfare data integration in Gunung Kidul and Bangkalan Regencies, Indonesia
Article References: Fikri, R., Purnomo, E. P., Pribadi, U., Mohamed, A. M., & Mohammad, N. B. (2026). Determinants of E-government interoperability capabilities for social welfare data integration in Gunung Kidul and Bangkalan Regencies, Indonesia. Discover Sustainability. https://doi.org/10.1007/s43621-026-04608-5
Image Credits: AI Generated
DOI: 10.1007/s43621-026-04608-5
Keywords: social welfare data, e-government, interoperability, Indonesia, PLS-SEM, technological readiness, cross-organizational collaboration, business architecture, digital governance, public services, Determinants, capabilities
The Federal Aviation Administration (FAA) has granted US aerospace and defense company BETA Technologies a first-of-its-kind authorization to conduct flights with prospective customers aboard its electric vertical takeoff and landing (VTOL) aircraft, marking a significant step toward commercial operations.
The approval, granted under a Special Airworthiness Certificate for market surveys, allows the aerospace and defence company to demonstrate its ALIA A250 aircraft to prospective operators and other participants. It also expands the geographic scope of the company’s flight operations.
The authorization comes after a safety review by FAA experts and represents a step toward commercial deployment, although the aircraft has not yet received full type certification for routine commercial service.
BETA completed its first flight under the new authorization on October 20, traveling 34 nautical miles (39 miles) in 20 minutes.
The ALIA A250 departed Plattsburgh International Airport in New York, taking off vertically before transitioning to conventional wing-borne flight. It then landed vertically at Patrick Leahy Burlington International Airport in Vermont.
Designed to operate with or without runway access, the aircraft can potentially support passenger transportation, cargo delivery, medical services and defense operations. It features dual pilot controls and is designed to carry up to five passengers or more than 1,200 pounds of cargo.
According to BETA, the A250 shares several major systems with its conventional takeoff and landing (CTOL) aircraft, including electric propulsion, flight control computers, batteries and charging infrastructure.
The common architecture allows the company to apply operational experience and technical improvements across both aircraft.
BETA said its CTOL and VTOL aircraft have accumulated more than 250,000 nautical miles of combined flight experience.
The company previously received FAA market-survey authorization for its CTOL aircraft and completed its first crewed electric VTOL transition flight in 2024.
“This authorization brings vertical flight closer to the people and places that will put it to work, building on BETA’s track record of industry firsts,” said Kyle Clark, BETA’s founder and CEO.
The latest certificate permits market-survey flights rather than unrestricted commercial passenger services. BETA must still complete the FAA’s full certification process before beginning routine commercial operations.
The US government is working to accelerate the testing and integration of advanced air mobility aircraft into national airspace.
In March, Transportation Secretary Sean Duffy announced the eVTOL Integration Pilot Program (eIPP), which supports testing of next-generation aircraft in real-world operating environments.
The program includes eight selected projects spanning 28 states, involving aircraft manufacturers, operators and government partners.
The projects cover urban air taxis, regional passenger transportation, cargo networks, emergency medical response, autonomous flight and offshore transportation.
The FAA said BETA’s authorization would allow the company to demonstrate its aircraft across a broader range of operating conditions, subject to applicable restrictions.
“The FAA is committed to working with American innovators to safely integrate these new aircraft into our national airspace, while maintaining the rigorous safety standards that have made the United States a global leader in aviation,” said FAA Administrator Bryan Bedford.
BETA is continuing flight testing and working toward full type certification as it prepares its electric aircraft for potential commercial applications.
Sediments from a small mountain lake in Bosnia and Herzegovina preserve an approximately 16,000-year record of summer temperature change in the Western Balkans, revealing abrupt climatic shifts whose effects varied across Europe. Researchers at Eötvös Loránd University reconstructed past mean July temperatures from chironomid remains and other lake-sediment indicators, then used pollen, sediment particles, organic matter and geochemical elements to track associated changes in vegetation, erosion and lake conditions. Two peer-reviewed studies published in 2026 examine different periods in the same sequence, together covering the Late Glacial, the Holocene and more recent centuries.
The reconstructed record shows that a large cooling event associated with the Younger Dryas lowered estimated mean July temperatures at Lake Prokoško by approximately 2.3°C, a change intermediate between estimates from Alpine lakes and those farther east. The lake, which covers 4.8 hectares at an elevation of 1,670 metres in the Vranica Mountains of the Dinaric Alps, also records a later Middle Holocene interval in which estimated summer temperatures may have exceeded present-day levels. These findings emerge from a paleoclimate reconstruction based on biological, chemical and physical evidence preserved in lake sediments, rather than from direct instrumental measurements.
Lake Prokoško occupies a climatically significant position between Western, Central and Eastern Europe. Over thousands of years, remains from the surrounding landscape and the lake’s own ecosystem accumulated in bottom sediments, providing material for reconstructing regional environmental and climatic history. One study, published in Palaeogeography, Palaeoclimatology, Palaeoecology, focused on rapid changes between approximately 16,000 and 10,000 years ago during the Late Glacial and beginning of the Holocene. A separate study in Quaternary Science Reviews traced conditions through the Holocene to the present, extending the interpretation of the sediment sequence across the full period represented by the two investigations.
Chironomids, a group of aquatic insects also known as non-biting midges, supplied the principal temperature indicator. Their larvae occupy lake sediments and differ in their preferences for water temperature, oxygen levels and nutrient conditions. After moulting, larvae leave chitinous head capsules that sink to the lake bed, where they can be preserved for tens of thousands of years. The researchers identified the species represented in different sediment layers and compared the fossil assemblages with faunal and climate data from hundreds of modern European lakes. This comparison supported estimates of mean July temperature, while the accompanying pollen, sediment, organic-matter and chemical records provided evidence about forests, soil erosion, lake productivity and other environmental changes.
The oldest layers examined reflect cold conditions near the end of the last glacial period. At around 14,600 years ago, reconstructed mean July temperatures around Lake Prokoško were below 8°C. They subsequently rose by approximately 2.6°C within a comparatively short interval, reaching around 10.2°C. The reconstruction associates this warming with increased biological activity in the lake, spreading vegetation and more stable conditions in the catchment. The youngest sediments in the study cover the most recent millennium, where the chironomid community reflected not only temperature changes but also centuries of alpine grazing, greater nutrient input and the later expansion of nutrient-rich conditions.
The early warming ended abruptly when the Younger Dryas began around 12,900 years ago, the last major cooling episode at the close of the last glacial period. Estimated mean July temperatures at Lake Prokoško fell by approximately 2.3°C to about 7.9°C. Cold-water chironomid species became more abundant, while increased erosion transported more clastic material into the lake. Comparisons with reconstructions elsewhere in Europe revealed a marked spatial contrast: summer cooling of 3–4°C has been reconstructed at many Alpine lakes, whereas decreases in the Eastern and Southern Carpathians were generally less than 1°C. The Lake Prokoško estimate falls between those geographic extremes.
The researchers connect this west-to-east gradient, which becomes weaker toward the east, to oceanic and atmospheric changes in the North Atlantic region. For the Carpathian Basin, the contrast illustrates that the same large-scale climatic event can produce different responses in Western, Central and Eastern Europe. Lake Prokoško consequently provides a regional reference point for examining how the magnitude of a shared climate signal varied geographically. The researchers also emphasize that alpine lakes respond sensitively to relatively small temperature changes: variations in ice-cover duration, water stratification, oxygen content and biological activity can accompany those changes, making small mountain lakes useful environmental archives.
Warming resumed at the end of the Younger Dryas. Between approximately 11,800 and 11,400 years ago, reconstructed mean July temperatures increased by around 2.9°C. By about 10,500 years ago, they may have reached approximately 12.6°C. The lake became more productive, its ice-free season lengthened, and closed-canopy forests developed in the catchment, reducing erosion. Temperatures did not remain constant throughout the Holocene. Around 6,800 years ago, reconstructed mean July temperatures may have reached approximately 14°C, meaning that some summers around Lake Prokoško were warmer than those experienced today. The researchers distinguish this Middle Holocene warmth from present-day warming: the earlier conditions were mainly seasonal and driven by gradual changes in Earth’s orbital parameters that increased Northern Hemisphere summer insolation, whereas current warming is global, year-round, more rapid and primarily associated with human-caused greenhouse gas emissions.
A cooling trend began around 6,000 to 5,500 years ago during the Neoglacial transition toward a cooler Late Holocene. Reconstructed mean July temperatures fell from approximately 14°C to around 12.8°C, then to 11.8°C by about 5,670 years ago. Pollen evidence indicates that people were altering the landscape around the lake by the end of the Neolithic, approximately 6,000 years ago. Plants associated with grazing and open habitats became more common, followed later by more intensive forest use and the expansion of open areas. The same sediment archive therefore records both reconstructed climatic variability and the growing influence of human land use, although it does not by itself establish that human activity caused the temperature changes documented in the sequence.
Later Holocene temperatures continued to vary. Around 3,000 years ago, another significant cooling began, with mean summer temperatures falling from approximately 14.7°C to 12°C. Around 2,000 years ago, reconstructed temperatures rose during the Roman Warm Period, reaching approximately 13.3°C. Over the past millennium, centuries of alpine grazing opened the surrounding landscape and increased the nutrient load entering Lake Prokoško. The chironomid community changed significantly around 700 years ago, and species preferring more nutrient-rich waters became increasingly common over the following 500 years. Together, the two studies show that the lake’s fossil and sediment record captures environmental responses shaped by both regional climate change and local human transformation, while also demonstrating that estimates for individual periods remain reconstructions derived from sediment proxies and modern comparative data.
Subject of Research: Paleoclimate reconstruction of summer temperature variability in the Western Balkans
Article Title: Where three climate zones meet
Article References: Where three climate zones meet. Original publication (Bibliographic details unavailable.)
Image Credits: AI Generated
DOI: Not provided
Keywords: Lake Prokoško, Western Balkans, summer temperatures, paleoclimate, chironomid fossils, Younger Dryas, Holocene, climate reconstruction, land use, alpine lake, three, climate
Cardiovascular magnetic resonance measurements identified a hemodynamic pattern associated with death or heart-transplant referral or listing in people with Fontan circulation, according to a retrospective study of 182 patients followed at a moderate-altitude center. Patients who later experienced the composite outcome had a lower superior vena cava flow index than those who did not. In time-to-event analysis, each 0.1-liter-per-minute-per-square-meter increase in the indexed flow was associated with a 30% lower hazard of the outcome.
The association remained in an exploratory model that also included ventricular ejection fraction, but the researchers said the estimate requires prospective, multicenter validation before clinical application. The cohort comprised people who had undergone Fontan palliation between 1999 and 2021 at a tertiary institution approximately 5,118 feet above sea level. Fontan circulation passively directs systemic venous blood into the pulmonary arteries without the support of a sub-pulmonary ventricle.
Eligible participants had a clinically indicated CMR examination at least five years after Fontan completion, a threshold selected to match the center’s routine surveillance practice. For patients with multiple examinations, investigators used the last CMR obtained before an outcome or censoring. Most participants, 173 of 182, or 95%, had an extracardiac conduit Fontan circulation, and 76, or 42%, underwent a Damus–Kaye–Stansel anastomosis.
At CMR, the median body surface area was 1.43 square meters, with an interquartile range of 1.16 to 1.69 square meters. The median age at Fontan completion was 3.2 years, and the median interval between surgery and imaging was 10.9 years. Median follow-up after CMR was 4.7 years, while participants’ median home elevation was 5,221 feet above sea level.
Hypoplastic left heart syndrome was the most common underlying diagnosis, accounting for 35% of the cohort, followed by tricuspid atresia at 30%. The systemic ventricle was left-dominant in 53% and right-dominant in 47%. Magnetic resonance examinations were performed on 1.5- or 3.0-tesla scanners, with cine imaging used to assess ventricular function and phase-contrast sequences used to measure blood flow.
The primary endpoint combined death with referral or listing for heart transplantation. Fourteen patients, or 7.7% of the cohort, met that endpoint during follow-up: two died and 12 were referred or listed for transplantation. Among patients who experienced the outcome, the median time from CMR to the first qualifying event was 1.2 years, with an interquartile range of 0.5 to 2.5 years.
The median superior vena cava flow index was 0.54 liters per minute per square meter among patients with the primary outcome, compared with 0.82 liters per minute per square meter among those without it; the difference was statistically significant, with a p-value of 0.011. The superior vena cava-to-ascending-aorta flow ratio was also lower in the event group, with medians of 0.22 and 0.30, respectively. Several other CMR flow measures did not differ significantly between patients with and without the primary outcome.
These included flow indices in the ascending aorta, right pulmonary artery, left pulmonary artery and inferior vena cava, as well as calculated systemic-to-pulmonary collateral flow. Receiver operating characteristic analysis indicated that superior vena cava flow index discriminated between patients who met the endpoint and those who did not with an area under the curve of 0.74 and a 95% confidence interval of 0.56 to 0.92. A data-derived threshold of 0.66 liters per minute per square meter, selected using the Youden index, yielded 70% sensitivity and 75% specificity.
Kaplan–Meier curves showed significantly poorer event-free survival among patients below that threshold. Because the threshold and discrimination measures came from the same cohort, they are exploratory rather than externally validated clinical cutoffs. Univariable Cox proportional hazards regression found a hazard ratio of 0.70 for each 0.1-liter-per-minute-per-square-meter increase in superior vena cava flow index, with a 95% confidence interval of 0.50 to 0.92 and a p-value of 0.008.
Right-dominant ventricular morphology was also associated with a higher hazard than left-ventricular dominance, with a hazard ratio of 3.21, a 95% confidence interval of 1.00 to 10.29 and a p-value of 0.049. The investigators constructed a two-variable Cox model containing superior vena cava flow index and ejection fraction. Each one-percentage-point increase in ejection fraction was associated with an adjusted hazard ratio of 0.92, with a 95% confidence interval of 0.86 to 0.97.
Because only 14 primary events occurred, the multivariable analysis was deliberately restricted and was intended to test whether the flow association persisted beyond ventricular function rather than develop a full prediction model. Internal bootstrap analysis using 2,500 resamples produced a median hazard ratio of 0.71 for superior vena cava flow index and 0.92 for ejection fraction, close to the original adjusted estimates. Collinearity between the two variables was negligible, with a Spearman absolute correlation below 0.1, an R-squared value of 0.008 and a variance inflation factor of 1.01.
Tests did not indicate violation of the proportional-hazards assumption. Ventricular measures also differed according to morphology: in the right-dominant subgroup, patients with events had larger indexed ventricular volumes and lower ejection fraction than those without events, whereas comparable differences were not statistically significant in the smaller left-dominant event subgroup. The study does not establish why lower superior vena cava flow was associated with poorer outcomes.
One proposed explanation is that chronic hypobaric exposure at moderate altitude promotes pulmonary vasoconstriction and raises pulmonary vascular resistance, potentially restricting passive flow through the Fontan pathway. However, pulmonary vascular resistance was not directly measured, and the cohort included no sea-level comparator, so the study cannot determine whether altitude caused the observed hemodynamic pattern. Other possible contributors include anatomical differences in the superior vena cava, systemic venovenous collateral vessels that divert blood around the pulmonary vascular bed, and differences in preload or single-ventricle filling.
The findings therefore associate reduced indexed flow with an unfavorable hemodynamic state rather than demonstrate a specific underlying mechanism. Important limitations constrain the results. The retrospective, single-center design creates the possibility of selection bias, and clinically performed CMR examinations were not acquired at standardized surveillance intervals.
Selecting the last scan before an outcome or censoring may introduce reverse-causation bias because patients approaching clinical deterioration could have been imaged nearer the event. Clinically relevant potential confounders—including functional class, cardiopulmonary exercise capacity, resting oxygen saturation, natriuretic peptide levels, catheterization-derived Fontan pressure and pulmonary vascular resistance, pulmonary vasodilator therapy, arrhythmia burden and the severity of liver disease—were unavailable or not incorporated. The small number of events also leaves the multivariable estimates vulnerable to overfitting despite the deliberately parsimonious model and bootstrap resampling.
Furthermore, the predominance of fenestrated extracardiac conduit Fontan circulation limits generalizability to other surgical configurations. The results position superior vena cava flow index as a candidate prognostic marker that may complement ventricular size and ejection fraction in longitudinal assessment of Fontan circulation, but they do not establish a clinical measurement rule or treatment strategy. Prospective, multicenter studies comparing cohorts across elevations would be needed to test the temporal relationship, determine whether altitude modifies the association, and establish external validity.
The authors also identified four-dimensional flow CMR as a possible tool for characterizing three-dimensional flow patterns and energy loss within the Fontan pathway. Further work could compare imaging signatures with exercise physiology, biomarkers of end-organ dysfunction and pulmonary vascular imaging. Until those studies are completed, the association between reduced superior vena cava flow and adverse outcomes should be regarded as an exploratory finding that requires independent validation.
Subject of Research: Association between CMR-derived blood flow and adverse outcomes in people with Fontan circulation
Article Title: Cardiovascular magnetic resonance–derived hemodynamics predict adverse outcomes after Fontan palliation
Article References: Platnick, C., Frank, B., Romanowicz, J., Gonzalez De Alba, C., Chase, M., Umer, A., Chaudhuri, N. R., Awori, J., Chauhan, D., Mascio, C. E., Udassi, J. P., & Hedjazi Moghari, M. (2026). Cardiovascular magnetic resonance–derived hemodynamics predict adverse outcomes after Fontan palliation. Frontiers in Cardiovascular Medicine, 13, Article 1937933. https://doi.org/10.3389/fcvm.2026.1937933
Image Credits: AI Generated
DOI: 10.3389/fcvm.2026.1937933
Keywords: Fontan circulation, cardiovascular magnetic resonance, superior vena cava flow, heart transplantation, congenital heart disease, risk stratification, ventricular function, moderate altitude, flow quantification, retrospective cohort, Cardiovascular, magnetic
On Oct. 21, 2008, the Indian Space Research Organization launched its first mission to the moon. The mission was named Chandrayaan-1, and it consisted of both an orbiter and an impactor.
Chandrayaan-1 launched from the Satish Dhawan Space Center on an Indian rocket called the Polar Satellite Launch Vehicle, or PSLV-XL. (Launch occurred at 8:52 p.m. EDT, though it was about 6:22 a.m. local time at the launch site on Oct. 22.)
It arrived in lunar orbit about three weeks later and dropped off the Moon Impact Probe, which crashed into the moon on Nov. 14. The rest of the Chandrayaan-1 spacecraft stayed in orbit, where it collected and transmitted data from the moon to Earth for about a year. The mission ended abruptly 14 months ahead of its planned end date when scientists lost contact with the probe.
The Indian Space Research Organisation, or ISRO, had a lot riding on the success of Chandrayaan-1 moon mission, which marked the first-ever deep space mission by the Indian space agency. It was also the first mission to the moon for India, a country that hopes to launch its own crewed spacecraft and build a space station.
Chandrayaan-1 did more than just demonstrate that India's space program was capable of launching missions to the moon; it also returned some amazing science results, like evidence of water ice on the moon.
"In September 2009, scientists published results of data collected by the American M3 instrument which had detected absorption features on the polar regions of the surface of the Moon usually linked to hydroxyl- and/ or water-bearing molecules," NASA said in a mission overview.
The spacecraft carried 11 instruments to study the moon, five of them built by ISRO. The rest were experiments for the European Space Agnecy and NASA.
"In addition to the five Indian instruments, the spacecraft carried scientific equipment from the United States, the United Kingdom, Germany, Sweden, and Bulgaria," NASA said.
It took until Nov. 8, 2008 for Chandrayaan-1 to enter lunar orbit, where it stayed until contact was lost in August 2009, most likely due to a power supply failure caused by overheating.
"This was short of the spacecraft’s planned two-year lifetime, although ISRO noted that at least 95% of its mission objectives had been accomplished by then," NASA wrote.
India did not stop at the moon with Chandrayaan-1. In 2019, the country launched the Chandrayaan-2 orbiter, which carried the Vikram lander and Pragyan rover. Chandrayaan-2 reached lunar orbit successfully, but the Vikram landing failed.
The Chandrayaan-3 misson followed in 2023, which successfully landed a new Vikram lander and Pragyan rover near the moon's south pole. India plans to launch the Chandryaan-4 mission to return moon samples to Earth in 2028.
Want more space history? Check out our full On This Day In Space Story archive and watch our On This Day In Space videos on YouTube.
As the smoke clears from its outrageous Roadster demo, Tesla reported Q3 earnings on Wednesday - and the cold reality is that revenue has flatlined.
Tesla said it earned $1.7 billion in net income on $28.0 billion in revenue in the quarter that ended in September 2026. Revenues were flat, while profits dropped 4 percent compared to the third quarter of 2025, when the company earned $1.4 billion in net income on $28.1 billion in revenue. Tesla's revenue came in above Wall Street expectations of $27.9 billion, according to data compiled by LSEG. Tesla's own company-compiled expectations predicted Q3 revenues of $28.3 billion.
The earnings …
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