Thursday, May 28, 2026

Clearing the expressway for bubble blockages to achieve high-efficiency green hydrogen production

The Korea Advanced Institute of Science and Technology (KAIST)

As the global transition toward carbon neutrality accelerates, "water electrolysis"—a technology that splits water electrically to produce clean hydrogen—is drawing significant attention. However, a major limitation has been the decline in efficiency caused by bubbles formed during the electrolysis process that block the pathways. A domestic research team has resolved this challenge by developing an innovative technology that rapidly discharges bubbles and boosts hydrogen production efficiency, much like clearing an expressway through a heavily congested road.

KAIST announced on May 28th that a research team led by Professor Jinwoo Lee from the Department of Chemical and Biomolecular Engineering, in collaboration with a research team led by Dr. Sungjun Kim from KRICT (President Suk-min Shin) and a research team led by Professor Jang Yong Lee from Konkuk University (President Jong-phil Won), has departed from the conventional method of simply increasing catalytic activity itself. Instead, they have successfully secured both water electrolysis performance and stability simultaneously by newly designing a "pathway" inside the catalyst layer through which water and gas pass.

Using paper-thin 2D mesoporous carbon (a thin carbon structure with numerous nanoscale pores) nanosheets, the research team created a low-tortuosity structure where materials can move without obstruction. Simply put, they implemented a "highway-like pathway" inside the catalyst layer through which water and gas can pass rapidly, instead of a narrow and complex alleyway.

Furthermore, ruthenium (Ru) nanoclusters (ultrafine metal particles several nanometers in size) were stably anchored onto the defect-introduced carbon surface to accelerate the hydrogen evolution reaction rate. Simultaneously, the interface structure was controlled to prevent catalyst degradation even during long-term operation.

Through this technology, it was confirmed that bubbles generated during the water electrolysis process were rapidly discharged without accumulating inside the catalyst layer, and a stable reaction was maintained even under extreme environments with high current density.

As a result, the technology recorded a world-class performance of 17.1 A cm⁻² at 80°C, vastly exceeding the 2026 target set by the U.S. Department of Energy (DOE). This figure represents the amount of current flowing per unit area; a higher value signifies that more hydrogen can be produced faster.

In addition, it demonstrated practical industrial applicability by operating stably for over 1,000 hours even under a low noble metal loading condition (0.09 mgRu cm⁻²). This means that the amount of ruthenium, a precious metal used in the catalyst, has been significantly reduced, which can also enhance the economic viability of water electrolysis systems.

The core of this research lies not simply in making a "good catalyst," but in newly designing the pathway itself through which hydrogen is formed. In conventional water electrolysis devices, bubbles generated during the reaction process accumulate inside, blocking the flow of water and electricity, which leads to a degradation in performance. The research team solved this problem by changing the structure of the catalyst layer so that bubbles can exit rapidly.

This technology holds great significance as it opens the way to produce eco-friendly hydrogen more affordably and efficiently in the future. Hydrogen is currently attracting attention as a core clean energy source for the carbon-neutral era, but it has faced limitations due to high production costs and low system efficiency. In particular, conventional high-performance water electrolysis devices required large amounts of expensive noble metals, making large-scale commercialization difficult.

The research team explained that this technology demonstrates the potential to achieve high performance and stability with only a small amount of noble metals. It is expected to expand into various fields in the future, including large-scale green hydrogen production, eco-friendly power generation systems, hydrogen vehicles/eco-friendly mobility, and carbon-neutral industrial processes.

Professor Jinwoo Lee stated, "This research is a technology that improves water electrolysis efficiency by designing not only the catalyst itself but also the path through which energy flows. Since high-efficiency green hydrogen production is possible with only a small amount of noble metals, we expect to accelerate the commercialization of eco-friendly hydrogen production in the future."

In this study, PhD students Jaeho Byeon and Minkyeong Ban from the KAIST Department of Chemical and Biomolecular Engineering participated as co-first authors. The research findings were published online on May 22, 2026, in Joule, the world's leading academic journal in the energy field, and will be featured in the formal issue of Joule on September 16.

※ Paper Title: Outperforming water electrolysis through catalyst layer structuring with defective 2D mesoporous carbon, DOI: 10.1016/j.joule.2026.102478

※ Author Information: A total of 18 authors including Jaeho Byeon (KAIST, co-first author), Minkyeong Ban (KAIST, co-first author), Liangliang Xu (co-first author), Seunggeon Lee, Seongbeen Kim, Seonggyu Lee, Seongmin Shin, Donghyeok Son, Wonchul Park, Jinkyu Park, Hoyoung Kim, Dongyoon Woo, Seongseop Kim, Dong Young Chung, Jaewook Nam, Jang Yong Lee (Konkuk University, corresponding author), Sungjun Kim (KRICT, corresponding author), and Jinwoo Lee (KAIST, corresponding author).

This research was conducted with support from the National Research Foundation of Korea’s "AEM Water Electrolysis Technology Development" (RS-2024-00467234), the "Nano-Future Materials Source Technology Development" (RS-2023-00235596), the Ministry of Education’s "Ph.D. Student Research Support Project" (RS-2025-25424765), the Korea Research Institute of Chemical Technology (KS2522-10), and the Lotte Chemical Carbon Neutral Center.

< Development of World-Class Anion Exchange Membrane Water Electrolysis via Carbon-Induced Ru-C Bonds and Catalyst Layer Structural Design >

< 2D Mesoporous Catalyst Layer-Based Green Hydrogen Production Technology (AI-Generated Image) >

Credit

KAIST

Journal

Joule

DOI

10.1016/j.joule.2026.102478

Method of Research

Meta-analysis

Subject of Research

Not applicable

Article Title

Outperforming water electrolysis through catalyst layer structuring with defective 2D mesoporous carbon,

Article Publication Date

22-May-2026

Cannabis use does not lower testosterone

A UNIGE study shows that young men who use cannabis tend to have higher levels of male sex hormones, with no clear impact on fertility.

Université de Genève

The effects of cannabis on the hormonal system and male fertility remain controversial within the scientific community. A study conducted by the University of Geneva (UNIGE), in collaboration with the Swiss Center for Applied Human Toxicology (SCAHT), provides a new answer by showing that cannabis use does not reduce testosterone levels in young men and may even increase its testicular synthesis. However, this increase in hormone levels cannot be directly linked to fertility. These conclusions are based on a detailed analysis of plasma samples from 94 Swiss conscripts. In addition, the researchers identified two new hormonal biomarkers that may help detect regular cannabis use. The findings have been published in Communications Medicine.

Some studies suggest that cannabis may reduce sperm count, concentration, and motility. These effects are believed to be linked to the endocannabinoid system—a network of chemical messengers and receptors in the brain and reproductive organs that interacts with sex hormones. However, the findings of studies conducted so far — particularly regarding the impact of cannabis use on testosterone — have often been contradictory.

To investigate further, a team from the Section of Pharmaceutical Sciences at the UNIGE Faculty of Science, led by Professor Serge Rudaz and in collaboration with SCAHT, conducted an in-depth analysis of steroid hormones — including sex hormones such as androgens, progestogens, and estrogens — in blood plasma samples from Swiss conscripts aged 18 to 23. The cohort included 47 confirmed cannabis users and 47 non-users. The major innovation of this study lies in extending the analysis to hundreds of hormones, whereas previous research focused solely on testosterone.

Increase in Testosterone

“Our results show that cannabis use would lead to an increase of about 23% in testosterone in young men,’’ explains Serge Rudaz. ‘‘But by taking a closer look at all male sex hormones — the androgens — we were able to locate the source of this increase specifically in the testes. Androgens produced by the adrenal glands were not affected by this increase.’’ Cannabis therefore appears to have a direct effect on the testes, and more specifically on Leydig cells, which produce testosterone.

Thanks to this broader analysis, the team was also able to identify two potential new biomarkers of cannabis use: hydroxyprogesterone (11B-OHP4) and dihydroprogesterone (5B-DHP4). “These are two metabolites derived from progesterone, another important sex hormone. The increase in their concentration among users is so high that they could be used to monitor endocrine disruptions linked to regular cannabis exposure. Above all, this discovery should encourage the scientific community to expand studies to new hormones that have so far been overlooked, and which may also play a role in the male reproductive system,” explains Mathieu Galmiche, a former postdoctoral researcher in the UNIGE Section of Pharmaceutical Sciences, now at the Karolinska Institutet in Stockholm and the study’s first author.

No Link to Sperm Quality

However, this increase in hormone levels among cannabis users should not be interpreted as an indicator of sperm quality. The link between testosterone and fertility remains very complex to decipher. Furthermore, the observed increase could represent a compensatory response by the body to reduced sensitivity of certain androgen receptors in the presence of cannabis. It is also possible that men with naturally higher testosterone levels are more prone to risk-taking behavior and, consequently, more likely to use cannabis.

While cannabis appears to affect certain biological mechanisms related to reproduction, the exact clinical implications for the fertility of young men remain unclear. Further research is needed to determine whether a toxicity threshold exists and to assess potential long-term effects.

Journal

Communications Medicine

DOI

10.1038/s43856-026-01469-x

Method of Research

News article

Subject of Research

Not applicable

Article Title

Cannabis consumption is associated with altered steroid metabolism in young men

Soil vapor transport improves soil moisture simulations in drylands

Institute of Atmospheric Physics, Chinese Academy of Sciences

image:
Half-hourly observed (Obs) and simulated (Sim-vapor) soil moisture at two depths and latent heat flux at site US-SRM in 2007 by CLM5 with the soil vapor transport scheme
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Credit: Lv Bingrong and Zhang Xia

Soil moisture is a key variable in the Earth system, influencing evapotranspiration, surface energy exchange, vegetation activity, and climate feedbacks. Yet in arid and semi-arid regions, land-surface models often struggle to realistically represent soil drying. A common issue is that shallow soils are simulated as wetter than observed, which can affect the representation of drought and land–atmosphere interactions.

To address this problem, researchers from the Institute of Atmospheric Physics, Chinese Academy of Sciences, introduced a simplified soil vapor transport scheme into the Community Land Model version 5 (CLM5). The study was recently published in Atmospheric and Oceanic Science Letters.

The research targets a long-recognized limitation in conventional land-surface models. Under extremely dry surface conditions, upward liquid water movement becomes very weak or nearly ceases. As a result, near-surface soil layers may dry too slowly in models, leading to unrealistic wet biases.

The revised model incorporates an additional pathway: the movement of water vapor through soil pores. Even when liquid transport is strongly suppressed, moisture can still move upward in vapor form. By representing this process, the model produces more realistic drying in near-surface soil layers.

“When the surface soil becomes very dry, liquid water pathways can nearly shut down, but moisture does not stop moving altogether. Water vapor can still move through soil pores, and this often overlooked process has important effects on dryland soil moisture simulations,” says Dr. Xia Zhang, corresponding author of the study.

The improvement extends beyond soil moisture. Simulations with the revised model show better performance in latent heat flux, including stronger daytime evapotranspiration during dry periods and reduced excessive nighttime condensation compared with the original model. These results suggest that representing soil vapor transport can improve simulations of land–atmosphere exchange under water-limited conditions.

The study demonstrates that soil vapor transport is not a negligible process in dry environments, but a key physical mechanism influencing the development of drought conditions in model simulations. Incorporating this pathway may therefore help alleviate persistent wet biases in arid and semi-arid regions.

These findings point to a practical pathway for improving drought representation and land–atmosphere coupling in next-generation land-surface and Earth system models. As dryland processes become increasingly important for understanding climate variability and change, a more realistic representation of soil moisture transport may contribute to more reliable simulations of both regional hydrology and climate.

Journal

Atmospheric and Oceanic Science Letters

DOI

10.1016/j.aosl.2026.100822

Plants select growth strategies by spying on their neighbors’ scents

Society for Experimental Biology

image:
Illustration demonstrating plant-to-plant communication.
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Credit: Velemir Ninkovic

New research reveals that plants have the ability to detect their neighbours' growth rates through aromatic cues called volatile organic compounds (VOCs) and subsequently adjust how much energy they invest into their own growth or defence strategies through responsive gene expression.

VOCs are carbon-based chemicals that evaporate easily into the air and are commonly produced by plants to communicate with herbivores, pollinators and even other plants. They are also responsible for the wide variety of fragrances that plants generate, and are often used in the manufacturing of perfumes, cosmetics, food and cleaning products.

Up until now, most of the research on plant-produced VOCs has focused on damaged plants releasing alarm-like chemical signals that warn neighbors to activate their anti-herbivore defenses. This new study published in the Journal of Experimental Botany describes a previously unrecognised role for healthy plant VOCs in competitive growing environments.

“Healthy non-damaged plants are constantly releasing their own chemical ‘fingerprint’ into the air, and their neighbors actively read these signals to adjust not only their defenses, but their entire growth strategy,” says author Dr Velemir Ninkovic from the Swedish University of Agricultural Sciences. “This is like a continuous conversation between neighbors, and the finding that these background VOCs can reshape growth and gene activity opens up a new dimension in how we understand plant communication.”

To better understand the role of these VOCs from healthy plants, Dr Ninkovic and his team conducted two laboratory experiments using three distinct cultivars of barley (Hordeum vulgare) that grow at different rates (slow “Fairytale”, intermediate “Luhkas” and fast “Salome”) and express different VOC profiles. Barley is one of the world's most important cereal crops, so insights into how it grows, defends itself, and interacts with neighboring plants have direct practical relevance for agriculture.

The slow-growing Fairytale cultivar and fast-growing Salome cultivar were exposed to VOCs from all three cultivars, and the effects on their growth and defence strategies were measured by analysing the physical properties of the plants and changes in gene expression after 25 days.

The researchers found that exposure to different VOC profiles triggered shifts in total plant biomass, whereas VOCs from plants with similar growth rates had negligible effects.

“VOC receiver plants adjusted their growth to match the competitive pressure signaled by their neighbor's scent: they grew more when exposed to a fast-growing neighbor and less when exposed to a slow-growing one,” says Dr Ninkovic. “This effect was seen consistently across all parts of the plant leaves, stems, and roots rather than the plant simply reshuffling resources between its parts.”

Genetic analysis revealed that these shifts in biomass were linked to changes in growth and defence related pathways. Shifts towards the slow-growing Fairytale VOC profile were associated with an up-regulation in stress-response genes that help to protect against herbivores and a down-regulation in cellular transport and DNA replication genes, whereas the opposite pattern was true for shifts towards the fast-growing Salome VOC profile.

This study found that the VOCs most strongly associated with these growth signals include benzyl nitrile, linalool and octanal, which are responsible for a wide variety of iconic floral fragrances such as lavender and citrus, as well as more metallic, and earthy scents.

“Plants release a rich blend of volatile compounds as a normal part of their biology, and it would make evolutionary sense for neighbors to have developed the ability to pick up on each other's chemical signals over millions of years of co-existence,” says Dr Ninkovic. “We believe this type of constitutive VOC interaction may likely be widespread across the plant kingdom, though the specific compounds involved and the strength of the response will probably vary greatly between species.”

------

Additional authors: André Åbonde, Merlin Rensing, Jannicke Gallinger, Vasti Thamara Juárez-González, Iris Dahlin, Dimitrije Markovic and German Martinez

The Journal of Experimental Botany is a partially open access journal published on behalf of the Society for Experimental Biology by Oxford University Press. The aim of the Journal of Experimental Botany is to publish papers that advance our understanding of plant biology.

Journal

Journal of Experimental Botany

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Volatiles released by undamaged plants mediate the adaptive growth strategies in neighbors

Article Publication Date

28-May-2026

A new approach to urban planning with less car traffic and lower carbon emissions

Potsdam Institute for Climate Impact Research (PIK)

Urban planning needs to tackle greenhouse gas emissions – and an important way to achieve this is by reducing the number and length of car commutes. This can be achieved primarily by ensuring that homes are located close to city centres and workplaces, so well-targeted building densification becomes a critical lever. City-wide population density and transport links are of secondary importance. These are the findings of a new study in Environmental Research Letters, led by the Potsdam Institute for Climate Impact Research (PIK) in collaboration with the University of California, Berkeley, the University of Sussex and other partners.

Using ten million mobility data points from Berlin, Boston, Los Angeles, the San Francisco Bay Area, Rio de Janeiro and Bogotá, the research team was able to reveal direct links between urban structure and car commuting with unprecedented detail, beyond mere correlations. The newly developed approach shows how planners can use GPS data, travel patterns and artificial intelligence to determine where in a metropolitan region a particular measure will have the greatest impact.

“Our model reveals the actual interdependencies between various urban factors even before we determine their specific effects,” explains Felix Wagner, who completed his PhD at PIK in 2025 and led the study as part of his doctoral research. “This fundamentally changes the recommendations that can be responsibly given to planners. Distances to city centres and working places are key. And urban densification cannot be viewed in isolation: one must understand how urban density relates to secondary factors such as connectivity, accessibility and the choice of residential location.”

A ring-shaped corridor around the city centre

One of the study’s key findings is that, in more monocentric metropolitan regions such as Berlin and Boston, the most valuable sites for infill development are neighbourhoods arranged in a ring around the centre. The area here is less densely built-up, yet the city centre remains easily accessible. In Boston, densification would ideally extend between 10 and 21 kilometres from the city centre; in Rio de Janeiro, the respective ring-shaped corridor would stretch up to 40 kilometres outwards from the centre. In polycentric cities such as Los Angeles and the San Francisco Bay Area, emissions could be reduced by further densification of areas with a high concentration of job opportunities.

The study also challenges the common practice in urban research of treating urban structural variables as independent of one another: using a causal analysis, the research team demonstrates that they are, in some cases, closely interlinked. For instance, population density and road connectivity are strongly coupled. In contrast, income only has an indirect influence on driving behaviour, mainly through the choice of residential location. This research builds on a study from 2023 published in Nature Communications, which highlights the significance of the built environment for carbon emissions: an aspect that has so far been missing from many economic studies on this topic.

Look at local conditions

“Urban planning experts often discuss densification as a one-size-fits-all policy that is either implemented or not,” says PIK researcher Felix Creutzig, a co-author of the study. “However, our data show that a single measure can significantly shorten commuting distances in one neighbourhood, yet have little effect two kilometres away. This spatial specificity has been missing until now.” In Berlin, for example, emissions per journey vary between minus 0.8 and plus 2.9 kilograms of CO₂ relative to the city average, depending on the neighbourhood – an indication of the potential for targeted climate policy measures tailored to local conditions.

For neighbourhoods further away from employment centres, the study finds that urban planning measures alone are not sufficient. Supplementary strategies such as transit-oriented urban development, restrictions on new developments in greenfield areas, carpooling and home-working arrangements could be helpful here.

The study was produced as part of the CircEUlar project, funded by the European Union’s Horizon Europe programme. The source code, which enables other researchers to build on the methodology, is available at https://github.com/wagnerfe/xml4uf.

Journal

Environmental Research Letters

DOI

10.1088/1748-9326/ae6881

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Refining urban typologies: Causal insights into urban form, car commuting, and related CO₂ emissions

Article Publication Date

28-May-2026

A “Balrog” in the Tunnels: Scientists discover a new cave cricket species on the tiny island of Kastellorizo, Greece

Pensoft Publishers

Newly discovered Dolichopoda balrogi sp. nov. in the artificial tunnel of Kastellorizo — image:
Newly discovered *Dolichopoda* *balrogi* sp. nov. in the artificial tunnel of Kastellorizo on 17 October 2025 - Female individual.
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Credit: Konstantinos Kalaentzis

Despite the intensity of modern exploration, the eastern Mediterranean continues to yield unexpected discoveries. On the small Greek island of Kastellorizo, researchers have documented a previously unknown cave cricket thriving within a network of man-made tunnels.

The species, named Dolichopoda balrogi, was described by researchers from Greece and published in the open-access Journal of Orthoptera Research. This discovery highlights how even small and seemingly ordinary habitats can shelter unique and previously unknown life.

A mysterious cricket in underground tunnels

The new species belongs to the genus Dolichopoda, a group of cave crickets that inhabit dark, humid environments such as caves, crevices, and underground spaces across southern Europe and the eastern Mediterranean. These insects are well known to evolutionary biologists because their isolated populations often evolve into distinct species on islands or in separate cave systems.

On the easternmost Greek island of Kastellorizo, researchers surveyed an artificial tunnel that serves as the island's sole accessible land cave. To their surprise, they encountered a population of cave crickets bearing characteristics of the cave-dwelling genus Dolichopoda. Detailed morphological and molecular study confirmed that the specimens represented a species new to science.

Why “balrogi”?

The species name balrogi was inspired by the Balrog, a legendary fire-demon from J.R.R. Tolkien’s The Lord of the Rings. In Tolkien’s story, the Balrog is an ancient creature hidden deep beneath the mountains, emerging from darkness. Its discovery is a fitting parallel; the cricket's preference for deep, dark tunnel systems kept it outside the known record for decades.

The name also alludes to the circumstances of discovery of the species, which was found exclusively in a man-made tunnel. In Tolkien’s narrative, the Balrog is revealed only after the Dwarves “delved too deep”; similarly, Dolichopoda balrogi was discovered on Kastellorizo due to anthropogenic excavation on Mount Vigla, as the island lacks accessible caves. The epithet thus symbolically links deep excavation with the revelation of hidden subterranean fauna.

Fortunately, unlike Tolkien’s fearsome creature, Dolichopoda balrogi is harmless - although equally well adapted to life in darkness.

Hidden biodiversity in unexpected places

Kastellorizo is a very small island, covering only about 9 square kilometers. Yet its position in the eastern Mediterranean between Asia and Europe makes it an important biogeographic hotspot.

The discovery of D. balrogi demonstrates that even small islands can host unique endemic species. It also suggests that artificial underground environments, such as tunnels and abandoned infrastructure, can function as refuges for specialised cave-dwelling organisms.

“These findings remind us that biodiversity discoveries are not limited to remote tropical forests or deep oceans. Even familiar landscapes and human-made structures can harbour species that have remained unnoticed.”
- Konstantinos Kalaentzis (lead researcher)

Protecting small and fragile ecosystems

Cave-adapted organisms like Dolichopoda crickets often have very restricted distributions, sometimes occurring in only a single cave or underground system. Because of this, they can be particularly vulnerable to habitat disturbance. The authors suggest that documenting and understanding these hidden species is an important first step toward their conservation.

As research continues across the Mediterranean, the researchers note that the countless Greek islands - many still poorly explored biologically - are likely to hold many more hidden biodiversity treasures awaiting discovery.

Journal

Journal of Orthoptera Research

DOI

10.3897/jor.35.187943

Subject of Research

Animals

Article Title

Delving too deep: Morphological and molecular description of the cave-dwelling Dolichopoda balrogi sp. nov. (Orthoptera, Rhaphidophoridae) from Kastellorizo Island, Greece

Article Publication Date

27-May-2026

Artificial tunnel of Kastellorizo.

Bayesian inference phylogenetic tree based on mitochondrial COI sequences of Dolichopoda species.

Credit

Konstantinos Kalaentzis