Electrochemical production of fuels from solar energy, commonly referred to as solar-fuel production, is a key technology for converting abundant yet intermittent solar energy into a stable energy source. Typically, this process employs an electrolyzer coupled with photovoltaic (PV) cells through an electronic maximum power point tracking (MPPT) system. Here, we propose a chemical MPPT system, integrated directly into the electrolyzer, to enable stand-alone and unmanned liquid solar-fuel production with stabilized concentration changes from sunrise to sunset. The working principle of the MPPT system is derived from the impedance and heat-transfer properties of the electrolyzer, which incorporates a solid-state electrolyte exhibiting ionic resistivity with a negative temperature coefficient. Application of the mathematical model to a real electrolyzer energized by a commercially-available monocrystalline-Si PV panel for producing pure aqueous formic-acid solution demonstrated a high utilization factor (85%) of PV energy and a 2% external solar-to-formic-acid (eSTF) energy efficiency for 0.1 kg of formic acid from pure water and carbon dioxide (CO2) during daytime operation, all without the use of a conventional electronic MPPT system.
The origin of life (OoL) is a fundamental and long-standing scientific question. Although a variety of plausible hypotheses had been put forward, how life began on the prebiotic Earth from a pile of prehistoric inert chemicals (gases) is still a puzzle to us. Here, to unify the existing hypotheses to cover the entire scenarios, the author proposed the “nanozymes hypothesis” of the OoL on Earth, in which natural mineral nanozymes (MN-zymes) and their later upgraded organic/inorganic hybridized nanozymes played multiple key roles in the initial emergence of life molecules, especially in the manner of “inorganic photosynthesis” under primitive Earth conditions. Under the hypothesis framework, proteins, DNA, and RNA might emerged near-simultaneously, as a result of the diversity of nanozymes and catalyses, and multiple physical and chemical key roles of the MN-zymes. Besides nanozyme aspects, several fundamental and key issues on the topic are briefly discussed and several essential elements and conditions for the natural selection and survival of life molecules are proposed.
This community will be removed from the instance in the near future because it is unmoderated, does not align with the instance's focus, and frequently introduces political content into the local feed, which is contrary to the instance's goal of minimizing political content.
Alternative versions of aboringdystopia are available on other instances:
I would prefer locking the community to avoid losing visibility of the posts, but unfortunately locking a community is not an available feature.
EDIT: As Trying2KnowMyself pointed out below, it is possible to restrict the community to moderator posts. So, I have done that instead to preserve older content.
Scientists in South Korea have discovered that a probiotic bacterium found in kimchi may help the body flush out tiny plastic particles before they can build up in organs. In lab tests, the kimchi-derived microbe clung tightly to nanoplastics even under conditions designed to mimic the human intestine, where other bacteria quickly lost their grip.
Photochemical upconversion has several potential applications in optoelectronics. However, there is yet to be demonstrated a rational approach to high efficiencies in nanoscale solid-state devices. Here we demonstrate that the liquid triplet fusion medium, 9,10-bis(n-octyl-diisopropylsilylethynyl)anthracene (NODIPS-An), which behaves as a solid on excitonic timescales, can achieve high-efficiency upconversion on the nanoscale. Owing to its amorphous structure, there are highly-coupled sites that trap upconverted states and prevent the back transfer that plagues nanoscale upconversion systems. With NODIPS-An filling the pores of a sensitized alumina nano-scaffold, we achieve an absolute photon upconversion efficiency of 8.2(4)%. The majority of efficiency losses are attributed to fluorescence and triplet energy transfer yields, and thus the self-trapping of excitons within the triplet fusion medium is demonstrated to effectively prevent the back transfer of excitons to the sensitizer. Strategies are proposed to improve the fluorescence yield and triplet energy transfer to pursue higher efficiencies in nanoscale solid-state photochemical upconversion devices.
Coumarin-based derivatives are recognized as tunable photonic building blocks due to their strong light–matter interaction and relevance for both linear and nonlinear optical applications. This work presents an investigation of the linear optical properties and multiphoton excitation response of four derivatives coupled with benzothiazole and benzimidazole moieties. The compounds 7-diethylamino-coumarin-benzothiazole, 6-bromo-coumarin-benzothiazole, and 7-diethylamino-coumarin-benzimidazole exhibit nearly identical absorption maxima (∼423–428 nm) and emission peaks (∼485 nm), while displaying pronounced differences in molar absorptivity and ground to first excited-state transition dipole moment (μ01). The 7-diethylamino-substituted derivatives show enhanced molar absorptivity (∼5.3 × 104 L mol–1 cm–1) and larger transition dipole moment (μ01 ∼ 8.1 D) compared to the bromo-substituted (μ01 ∼ 5.5 D). In contrast, 7-hydroxyl-coumarin-methyl-benzimidazole exhibits a distinct spectral signature characterized by a larger Stokes shift and lower molar absorptivity, with an intermediate μ01 ∼ 7.0 D reflecting a different electronic balance within the conjugated framework. Multiphoton excitation experiments using femtosecond laser pulses demonstrate efficient two-photon (800 nm) and three-photon (1200 nm) excited fluorescence for all derivatives. Remarkably, the hydroxylated derivative combines an exceptionally high fluorescence quantum yield (∼48%) with a measurable excited-state lifetime (∼3 ns), identifying it as the most promising candidate for bright photoluminescent probing under one-, two-, and three-photon excitation.
To achieve precise printing using high-viscosity paste on insulating substrates, we propose a mechanical pulling force and alternating current comodulation electrohydrodynamic (MAC-EHD) printing method. The technique effectively refines the liquid bridges of high-viscosity paste during deposition by leveraging the synergistic effect of mechanical pulling force and electric field force, thereby improving printing resolution. In addition, it achieves in situ neutralization of charge through an alternating electric field, enhancing the stability of the printing process. To address the challenge of controlling process parameters in MAC-EHD printing, we develop a high-precision prediction model for the MAC-EHD printing mode. This model determines the range of process parameters required for well MAC-EHD printing mode. Experimental results demonstrate that the flexible transparent conductive panels fabricated using this technology exhibit superior performance. These findings validate the advantages of MAC-EHD printing in terms of high resolution and high molding accuracy for high-viscosity paste deposition.
Banner image:Poison dart frog of the species Ranitomeya aetherea, described from the Juruá River Basin, western Amazon, in 2023. Image courtesy of Alexander Mônico.
Scientists race to study the Amazon’s frogs before they disappear
The Amazon is home to the world’s greatest amphibian diversity, with an estimated 1,525 species, of which only 810 have been formally described by science.
This megadiversity is under pressure from climate change and human activity, threatening the risk of species going extinct before scientists even get a chance to describe them.
Recent research indicates that the combination of increased temperature and exposure to pesticides can alter tadpoles’ growth and development in the Amazon.
Amphibians play a central role in controlling insects, including disease-transmitting mosquitoes, while also contributing to natural control of agricultural pests — a service valued in Brazil at more than a billion dollars annually.
MANAUS, Brazil — Crouched over the leaf litter, where dry leaves accumulate on the forest floor, a researcher tries to capture a distinct croak using a directional microphone. Identifying the sound of a small frog is often one of the conclusive proofs that a new species has been found. It’s nighttime. He wears long clothing as protection against mosquitoes and ants, and boots to keep his feet dry. Finding amphibians in the Amazon doesn’t require high-tech equipment; it actually dates back to explorations by early-20th-century naturalists.
That’s how biologist Igor Kaefer, a professor at the Federal University of Amazonas in Brazil, describes a typical day of fieldwork in search of amphibians in the Amazon. Kaefer was part of a group responsible for describing Amazophrynella bilinguis in 2019. The very description of the little toad gives an idea of how difficult it is to find: females measure about 2 centimeters (less than an inch), and their brown head and back make them “disappear” among the leaves and branches.
Home to an estimated 1,525 species of amphibians, the Amazon Basin is the most diverse ecosystem in the world when it comes to frogs, an order that includes toads and tree frogs. However, occurrence records have been confirmed for only about 810 of those. So going into the field and finding a new-to-science species is not unlikely.
“In almost every inventory conducted in a remote area, you come back with more than one new species for synthesis,” Kaefer says.
But finding a species in the field, analyzing it, and publishing the description takes “at least five,” he adds.
This constant stream of new-to-science discoveries masks another fact: from 2001 to 2010, only 12% of studies on Brazilian amphibians focused on Amazonian species, compared to 60% in the Atlantic Forest. This shows that studies are concentrated in Brazil’s southeast and points out some of the difficulties of conducting research in the world’s largest tropical rainforest, such as limited infrastructure, hard-to-reach areas, and lack of personnel.
“Biologists who know about amphibians are the real threatened species in the Amazon,” Kaefer says.
More than 2,000 amphibian species are threatened worldwide, making them the most vulnerable group of vertebrates on the planet. Of this total, 48% are directly threatened by habitat loss. This adds another layer of complexity to the knowledge gap regarding Amazonian amphibians: we may be losing entire populations before we even know they exist.
Biologist Guilherme Azambuja searches for tadpoles in a puddle in the Amazon. Image courtesy of Guilherme Azambuja.
Why are there so many species of amphibians in the Amazon?
Viewed from above, the Amazon Rainforest looks like a seamless green block, but it’s composed of a mosaic of distinct habitats: dry land, floodplains, streams, and seasonally flooded areas. This heterogeneity is even more pronounced when it comes to amphibians that are just a few centimeters long. Even in a stretch of forest that seems homogeneous to the human eye, some variations regarding moisture, forest height, soil type, and water type are decisive for amphibians.
“Over millions of years, species have diversified and specialized in these many habitats and in different environmental conditions,” Kaefer says. “This means that they have adapted in very distinct ways to different places. Even within a large group of amphibians, we find species with differences that are very subtle but enough for us to recognize a new one.”
The most significant example of these subtle differences is found in species from the genus Synapturanus, called disc frogs because of their round, flat profiles. These species live underground and have short reproductive periods, which makes them difficult to observe. Lineages that used to be seen as a single species are now only distinguished by approaches that combine genetic examination, vocalization monitoring and bone analysis based on 3D models.
Neblinaphryne imeri, a species described only in 2024, from Pico da Neblina. Image courtesy of Taran Grant.
It was precisely this diversity that attracted Kaefer to the Amazon. Originally from the southern state of Rio Grande do Sul, he arrived in Manaus, the capital of Amazonas state, in 2008 to pursue his doctoral studies, accompanied by his friend, Daiani Kochhann, now a professor at the State University of Vale do Acaraú, in Ceará state. While Kochhann’s career was focused on the study of Amazonian fish, she was convinced by her colleague to invest in the little frogs as well — a field where scientists still have much to discover.
Kochhann says Amazonian diversity isn’t defined only by the sheer number of species, but also includes the richness of reproductive behaviors. She cites the case of frogs, which most schoolchildren are taught go through two life stages, first as tadpoles, before metamorphosing into adults.
“In the Amazon, however, some species face very complex variations regarding this pattern, such as parental care, or tadpoles that hatch from the egg and live freely right away,” Kochhann says. “Some lay eggs in water; others in damp soil. And there are species that we only know in their adult phase, whose tadpoles we have never seen.”
These differences also pose a challenge for Kochhann’s research area of physiology: scientists need to know these organisms’ functions and processes, from cells to tissues and organs. Above all, they need to understand how they function in the face of increasing environmental strain, including climate change impacts.
“When we talk about climate change and amphibians, the big questions are which species will survive, which will not, and how this process will occur,” Kochhann says. “In the case of amphibians, the urgency is greater because they have characteristics that make them especially vulnerable to rising temperatures and drier climates, such as cutaneous respiration, which depends on skin moisture. Having little data on the Amazon means not understanding enough about these processes and risks.”
Data from Brazil’s National Council for Scientific and Technological Development (CNPq) indicate that only five groups in the country’s Northern region, which includes much of the Brazilian Amazon, formally study amphibians in their research; three of them are systematically focused on amphibian ecology and physiology.
A search by Mongabay found 9,062 scientific articles on Amazonian amphibians published in the last 10 years, only 3% of which explicitly describe new species. Climate, on the other hand, has been a central topic in the scientific literature: the keyword comes up in 3,411 of the papers, even though a data gap persists regarding amphibians’ tolerance to higher temperatures and their adaptive capacities.
Adult female of the species Ranitomeya aetherea, described from the Juruá River Basin, western Amazon, in 2023. Image courtesy of Alexander Mônico.
Climate change and pesticides: Emerging extinction risks
In addition to this risk, climate change interacts with other factors that also affect amphibians, such as water contamination by pesticides and heavy metals. Biologist Guilherme Azambuja investigates precisely these interactions, which are still little explored in the literature on the Amazon.
“One of the biggest challenges I faced was the lack of studies in this field for tropical environments such as the Amazon,” he says. “We end up resorting to results obtained in Europe or North America, which compromises comparisons with our reality.”
The darker colors show the areas of the planet with higher projected risks for frog species due to increased aridity. Image courtesy of Wu et al., 2024.
In a paper published in February this year, Azambuja tested the isolated effects of warming and exposure to the insecticide methomyl — an extremely toxic substance used in crops, with high water solubility — on tadpoles from two species, Osteocephalus taurinus and Scinax ruber. In a second phase, exposure to methomyl was tested at two temperatures: 26.5° and 30° Celsius (79.7° and 86° Fahrenheit).
In both species, the higher temperatures reduced the animals’ final mass. “When the temperature increases, their metabolism accelerates, hindering mass gain,” Azambuja says.
With higher temperatures and faster metabolism, tadpole respiration also increases, which may explain their greater susceptibility to absorbing substances present in water in warmer scenarios. In the case of O. taurinus, the link was clear: heat doubled methomyl’s lethal toxicity.
But the results also showed there are no absolutes in nature, with species responding differently to multiple stress factors. In terms of lethality, the tree frog S. ruber proved to be sensitive to methomyl regardless of temperature.
For Azambuja, this variation between species is the central point. It is precisely because species diversity is so high that responses to the same conditions also vary. Therefore, the lack of knowledge about these animals and their lifestyles means we can’t fully understand the impacts of these challenges or which species may be at greater risk.
In any case, Azambuja says, adaptation to temperature or substances takes a toll on amphibians, even the most resistant ones. “Body size decreases, resulting in thinner and smaller animals. While they are resistant, they may have lower sexual fitness and face reproductive challenges. Sometimes an animal tolerates warmer environments but remains at a level of stress that may not be sustainable in the long run, leading to organism collapse,” he says.
Harlequin toads of the species Atelopus spumarius, endemic to the Amazon. Image courtesy of Jaime Culebras/ASI.
What are we about to lose?
Making the case for amphibian conservation can be difficult: considered “disgusting” by society, these little frogs face invisible threats, and their contribution to ecosystems is rarely appreciated. At the Federal University of Ceará, Karoline Ceron is trying to change this reality with a powerful argument: money.
“By proposing research to assign economic value to amphibians in Brazil, we want to work alongside those who influence decision-making in the country, considering agribusiness’s major role in policymaking,” she says. “We want to establish a dialogue between two worlds: that of conservation and that of production.”
Still in progress, her research estimates that amphibians help prevent $1.18 billion in agricultural losses in Brazil, simply by consuming insects that attack crops. In soy plantations in the Cerrado biome, for example, amphibians likely save around half a million dollars a year in pesticides, by eating approximately 300 million invertebrates in those areas.
They also play a role in public health, especially in the tropics. With amphibians’ decline, part of the natural control of disease vectors like mosquitoes, which can transmit malaria and dengue fever, becomes lost. Research conducted across Central America found an increase in malaria cases related to the loss of amphibian populations.
“There is a synergistic risk, therefore,” Ceron says. “Loss of amphibian populations can lead to increased use of pesticides and insecticides in both rural and urban areas, which in turn would create new contamination and environmental poisoning.”
This story was first published here in Portuguese on April 13, 2026.
Mammalian eyes are exposed to visible light but cannot perform photosynthesis. Here, we show that introducing a nanoscale, structurally and functionally preserved thylakoid system, LEAF (light-reaction enriched thylakoid NADPH-foundry), into corneal cells enables light-driven bona fide photosynthetic production of NADPH and ATP, similar to plant leaves, which alleviates oxidative stress and inflammation. LEAF acts in two domains. Intracellularly, it integrates with host cells to supply NADPH and ATP via intact photosynthetic electron transport, restoring redox balance. Extracellularly, photosynthesized NADPH enhances endogeneous antioxidant enzyme activity and reduces reactive oxygen species in the local environment. These results establish a strategy for using light as an energy input in mammalian metabolic systems and suggest a possible cross-kingdom, endosymbiosis-like interaction in which animal cells derive functional benefits from plant-derived photosynthetic neo-organelles.
Mammalian eyes are exposed to visible light but cannot perform photosynthesis. Here, we show that introducing a nanoscale, structurally and functionally preserved thylakoid system, LEAF (light-reaction enriched
thylakoid NADPH-foundry), into corneal cells enables light-driven bona fide photosynthetic production of NADPH and ATP, similar to plant leaves, which alleviates oxidative stress and inflammation. LEAF acts in two domains. Intracellularly, it integrates with host cells to supply NADPH and ATP via intact photosynthetic electron transport, restoring redox balance. Extracellularly, photosynthesized NADPH enhances endogeneous antioxidant enzyme activity and reduces reactive oxygen species in the local environment. These results establish a strategy for using light as an energy input in mammalian metabolic systems and suggest a possible cross-kingdom, endosymbiosis-like interaction in which animal cells derive functional benefits from plant-derived photosynthetic neo-organelles.
Electrical signalling across distinct populations of brain cells underpins cognitive and emotional function. However, approaches that selectively regulate electrical signalling between two cellular components of a mammalian neural circuit remain sparse. Here we engineered an electrical synapse composed of two connexin proteins found in Morone americana (white perch fish)—connexin 34.7 and connexin 35—to accomplish mammalian circuit modulation. By exploiting protein mutagenesis, devising a new in vitro system for assaying connexin hemichannel docking, and performing computational modelling of hemichannel interactions, we uncovered a structural motif that contributes to electrical synapse formation. Targeting this motif, we designed connexin 34.7 and connexin 35 hemichannels that dock with each other to form an electrical synapse but not with other major connexins expressed in the mammalian central nervous system. We validated this electrical synapse in vivo using worms (Caenorhabditis elegans) and mice (Mus musculus). We demonstrate that it can strengthen communication across neural circuits composed of pairs of distinct cell types and modify behaviour accordingly. Thus, we establish ‘long-term integration of circuits using connexins’ (LinCx) for precision circuit editing in mammals.
Electrical signalling across distinct populations of brain cells underpins cognitive and emotional function. However, approaches that selectively regulate electrical signalling between two cellular components of a mammalian neural circuit remain sparse. Here we engineered an electrical synapse composed of two connexin proteins found in Morone americana (white perch fish)—connexin 34.7 and connexin 35—to accomplish mammalian circuit modulation. By exploiting protein mutagenesis, devising a new in vitro system for assaying connexin hemichannel docking, and performing computational modelling of hemichannel interactions, we uncovered a structural motif that contributes to electrical synapse formation. Targeting this motif, we designed connexin 34.7 and connexin 35 hemichannels that dock with each other to form an electrical synapse but not with other major connexins expressed in the mammalian central nervous system. We validated this electrical synapse in vivo using worms (Caenorhabditis elegans) and mice (Mus musculus). We demonstrate that it can strengthen communication across neural circuits composed of pairs of distinct cell types and modify behaviour accordingly. Thus, we establish ‘long-term integration of circuits using connexins’ (LinCx) for precision circuit editing in mammals.
Optimal sleep has a vital role in promoting healthy ageing and enhancing longevity. Here we propose Sleep Chart to assess the relationship between self-reported sleep duration and 23 biological ageing clocks derived from in vivo imaging, plasma proteomics and metabolomics. First, a systemic, U-shaped pattern emerges between sleep duration and biological age gaps across nine brain and body systems and three omics technologies. The sample-specific lowest biological age gaps are achieved between 6.4 and 7.8 h of sleep duration, varying by organ and sex in the UK Biobank (aged 37–84 years). Furthermore, short (<6 h) and long (>8 h) sleep duration, compared with a normal sleep duration (6–8 h), are associated with increased risk of systemic diseases beyond the brain and all-cause mortality, with evidence from genetic correlations and time-to-incident survival predictions, such as depression and diabetes. Finally, the pathways by which long and short sleep duration are associated with late-life depression differ: ageing clocks may partially mediate the pathway for long sleep duration, while short sleep duration shows a more direct link. Although Mendelian randomization does not provide strong evidence that disease causally affects sleep, it cannot completely exclude such reverse causality. Our findings suggest a cross-organ, multi-omics U-shaped relationship between sleep duration and biological ageing clocks, highlighting the potential of sleep optimization to promote healthy ageing, lower disease risk and extend longevity.
Optimal sleep has a vital role in promoting healthy ageing and enhancing longevity. Here we propose Sleep Chart to assess the relationship between self-reported sleep duration and 23 biological ageing clocks derived from in vivo imaging, plasma proteomics and metabolomics. First, a systemic, U-shaped pattern emerges between sleep duration and biological age gaps across nine brain and body systems and three omics technologies. The sample-specific lowest biological age gaps are achieved between 6.4 and 7.8 h of sleep duration, varying by organ and sex in the UK Biobank (aged 37–84 years). Furthermore, short (<6 h) and long (>8 h) sleep duration, compared with a normal sleep duration (6–8 h), are associated with increased risk of systemic diseases beyond the brain and all-cause mortality, with evidence from genetic correlations and time-to-incident survival predictions, such as depression and diabetes. Finally, the pathways by which long and short sleep duration are associated with late-life depression differ: ageing clocks may partially mediate the pathway for long sleep duration, while short sleep duration shows a more direct link. Although Mendelian randomization does not provide strong evidence that disease causally affects sleep, it cannot completely exclude such reverse causality. Our findings suggest a cross-organ, multi-omics U-shaped relationship between sleep duration and biological ageing clocks, highlighting the potential of sleep optimization to promote healthy ageing, lower disease risk and extend longevity.
https://pubs.rsc.org/en/content/articlelanding/2026/el/d5el00177cOpen linkView original on mander.xyz
