How an Odd Property of Acid Created Self-Healing Iron? (Chemistry)

An odd quirk of iron led, eventually, to the first self-healing materials. An iron bar, dipped in strong acid, was just fine. Dipped in weak acid, it was eaten away to nothing. Here’s why a diluted acid will succeed when a strong acid fails.

The Industrious Michael Faraday

Michael Faraday spent the first half of the 19th century doing, roughly, everything. The amount of things, in science, that are named “Faraday,” is frankly obscene and something should be done about it. What with the Faraday cage and the Faraday constant and the Faraday effect, few people know of the relatively minor phenomenon known as the Faraday paradox of electrochemistry, also called the Faraday paradox of passivation. The “electrochemistry,” and “passivation,” differentiate it from the more well-known Faraday Paradox which is named for Faraday, and illustrates Faraday’s Law of Electromagnetic Induction – because apparently Faraday did not go on even one single vacation during his lifetime.

This particular Faraday phenomenon was noted by Michael Faraday when he dipped an iron bar in very concentrated nitric acid. He had also dipped iron in weakened nitric acid, and the acid ate away at the metal quickly, so he must have expected a huge reaction. He was disappointed. After a little bubbling, the iron bar sat there, at rest in concentrated acid. Faraday guessed that some reaction with the strong acid had caused the outer surface of the iron to form a film that protected the rest of the bar. Being Michael Faraday he was right. What he didn’t realize, that he had taken the first step towards the creation of the first kind of self-healing materials.

The Process of Passivation

When he was conducting his experiment, Faraday had luck on his side. Most of the time this particular process takes a bit more rigging than lowering a metal into acid, but Faraday had stumbled on two materials that managed to go through passivation at room temperature. Passivation is the creation of a coating over a metal surface that renders it unresponsive, or passive, in the face of elements that would otherwise corrode it.

Concentrated nitric acid has an interesting property. It promotes oxidization. In biology, oxidization happens when materials combine with oxygen – in other words, when they burn. Chemistry has a slightly different definition for the same word. A material is oxidized when it gives up an electron. The more electrons it gives up, the more it is oxidized. Concentrated nitric acid is an oxidizing agent, an rips electrons off materials dipped in it. Iron is particularly susceptible to nitric acid’s effects. After its electrons are ripped away, the biological sense of oxidization takes over, and oxygen does combine with the iron on the surface to create an iron oxide layer. The layer is impervious to the acid, and the interior iron is protected until the oxide layer is scraped off. Dilute nitric acid can’t get the same oxidization reaction going, and so it will continue to eat away at the iron until the iron is dissolved.

Electrochemistry and Self-Healing Materials

Over time people other than Michael Faraday saw fit to involve themselves in science. They began looking at the results that Faraday had achieved with iron and acid – and electrochemistry was born. Iron, when treated only with strong nitric acid, was not particularly useful. The slightest scratch and the patina was scraped away. There was also the unfortunate fact that acid didn’t work on just any metal.

What worked on lots of other metals was electricity. Nothing rips electrons away like a process designed to rip electrons away. Dipping metals in solution and applying a voltage that “pumps” electrons away oxidizes the outer layers of a metal quickly. Meanwhile, metals that receive electrons are “reduced.” Oxidation and reduction are often enough to put a coating on a metal, but chemists took it one step further. They started adding chemicals to the solutions that would combine with the metals while they were in their reduced, or oxidized, state, and plate the surface. This can be done for decoration, as in “gold-plating,” but there are more useful applications. This is what lead to the original self-healing materials.

As low-tech as it is, one of the most common self-healing materials was invented back in 1913, when someone figured out that adding a little chrome to iron made it less likely to get stained and corroded. Iron alone stains, and then pits, and then is eaten away. Not so when chrome is added. The iron and chrome grab oxygen atoms and form an oxide that coats and protects the surface. Scratch the surface, and the iron and chrome beneath grab on to oxygen, re-forming the protective layer. Because of Faraday’s experiment in the 19th century, people at the beginning of the 20th century understood the principles of how to make a self-healing material.

In a nod to Faraday’s original experiment, often the process of making or repairing stainless steel involves his original experiment. Immersing the whole thing in strong nitric acid oxidizes any free iron on the surface of the steel, allowing it to be removed, so the self-healing steel can be repaired and shine.

This article is republished here from Gizmodo under common creative licenses

Non-hereditary Mutation Acts as Natural Gene Therapy in Patient with Rare Disease (Biology)

Scientists at a research center supported by FAPESP identified a non-inherited mutation in blood cells from a patient with GATA2 deficiency that may have prevented bone marrow failure and other clinical manifestations.

Researchers affiliated with the Center for Cell-Based Therapy (CTC ( in Ribeirão Preto, Brazil, have identified for the first time a non-hereditary mutation in blood cells from a patient with GATA2 deficiency, a rare autosomal disease caused by inherited mutations in the gene that encodes GATA-binding protein 2 (GATA2). GATA2 regulates the expression of many genes that play a key role in developmental processes and cell renewal.

Lung tissue from patient with GATA2 deficiency, displaying pulmonary alveolar proteinosis and inflammatory lymphoplasmacytic infiltrate. ©CTC

The researchers believe the non-hereditary (somatic) mutation may have acted as a kind of natural gene therapy, preventing the disease from damaging the process of blood cell renewal (hematopoiesis), so that the patient did not develop such typical clinical manifestations as bone marrow failure, hearing loss and lymphedema (blockage of the lymphatic system).

An article on the study is published ( in the journal Blood, featuring on the cover and with an editorial commentary (

The findings pave the way for the use of gene therapy and changes in genetic counseling for families with the hereditary disorder. “When a germline [inherited] mutation in GATA2 is detected, the patient’s family has to be investigated because there may be silent cases,” Luiz Fernando Bazzo Catto, first author of the article, told.

CTC is a Research, Innovation and Dissemination Center (RIDC ( funded by São Paulo Research Foundation – FAPESP and hosted by the University of São Paulo’s Ribeirão Preto Medical School (FMRP-USP), where Catto is a PhD candidate. His thesis advisor is Professor Rodrigo Calado (, corresponding author of the article and a member of CTC.

The patient was identified when his two sons were undergoing medical treatment at the blood center of the hospital run by FMRP-USP. One of the siblings was diagnosed with moderate aplastic anemia (a bone marrow disorder in which the body stops producing enough new blood cells) and psoriatic arthritis. His low red blood cell count and immune cell deficiency worsened over the following five years and he died aged 27 from a lung infection. Post-mortem DNA sequencing confirmed his germline mutation and GATA2 deficiency diagnosis.

His brother began treatment at the hospital aged 25, with a history of recurrent lung infections, hypothyroidism, deep-vein thrombosis and deafness. Sequencing of his leukocytes and skin fibroblasts also confirmed an identical germline mutation.

To find out from which parent the brothers inherited the mutation, the researchers sequenced the mother’s and father’s DNA. The mother did not have the mutation. The 61-year-old father had exactly the same mutation as his sons in sperm and skin fibroblasts. He was asymptomatic, and his blood count and lymphocytes were within the normal range.

“This discovery raised the question whether the father transmitted the mutation or acquired it but didn’t pass it on to his sons,” Catto said.

In search of an answer, the researchers used next-generation sequencing to estimate the proportion of normal blood cells in the father’s bone marrow, preventing clinical manifestations of GATA2 deficiency, and of cells similar to his children’s.

The results showed that 93% of his leukocytes had the somatic mutation that confers protection from the clinical manifestations of GATA2 deficiency. The remaining 7% carried the mutation associated with the disorder. “This 7% were a remnant of the original clone,” Catto said.

Treatment prospect

The researchers also sequenced the father’s T-lymphocytes, which are long-lived, to find out whether his somatic mutation could induce normal cell production for a long time. The analysis showed that the somatic mutation occurred early in their lives and in the development of hematopoietic stem cells, which have the potential to form blood. “It’s very likely that the father had acquired the somatic mutation in his blood a long time ago,” Catto said.

To see if the father’s blood cells could maintain the activity for a long time, they measured the telomeres of his peripheral blood leukocytes. Telomeres are repetitive sequences of non-coding DNA at the tip of chromosomes that protect them from damage. Each time cells divide, their telomeres become shorter. They eventually become so short that division is no longer possible, and the cells die or become senescent.

The telomeres analyzed by the researchers were long. “This indicates that these blood cells can remain active for a long time,” Catto said.

A hypothesis formulated in the article is that the existence of the somatic mutation in the father’s blood cells, and its restoration of the blood cell renewal process, may have contributed to the non-manifestation of extra-hematological symptoms of GATA2 deficiency such as deafness, lymphedema, and thrombosis. Early hematopoietic recovery in patients with the disease, via a bone marrow transplant or in future via gene therapy, could be beneficial and avoid other clinical complications, the authors suggest in the article on the study.

“A sort of natural gene therapy occurred in this patient,” Calado said. “It’s as if he embodied an experiment and a medium-term prospect of analogous gene therapy treatment in patients with GATA2 deficiency.”

Besides contributing to an advance in treatment of the disease and genetic counseling, the study also provides new knowledge about the biology of hematopoietic stem cells. “The findings help us understand better how stem cells can recover by repairing an initial genetic defect,” Calado said.

References: Luiz Fernando B. Catto, Gustavo Borges, André L. Pinto, Diego V. Clé, Fernando Chahud, Barbara A. Santana, Flavia S. Donaires, Rodrigo T. Calado; Somatic genetic rescue in hematopoietic cells in GATA2 deficiency. Blood 2020; 136 (8): 1002–1005. doi:

Provided by FAPESP

NIST Sensor Experts Invent Supercool Mini Thermometer (Engineering)

Researchers at the National Institute of Standards and Technology (NIST) have invented a miniature thermometer with big potential applications such as monitoring the temperature of processor chips in superconductor-based quantum computers, which must stay cold to work properly.

Two of NIST’s superconducting thermometers for measuring cryogenic temperatures are glued to the lower left and upper right of this amplifier. The miniature thermometers, made of niobium on a layer of silicon dioxide, measure the temperature of the amplifier or other device based on a frequency signal. ©Wheeler/NIST.

NIST’s superconducting thermometer measures temperatures below 1 Kelvin (minus 272.15 ?C or minus 457.87 ?F), down to 50 milliKelvin (mK) and potentially 5 mK. It is smaller, faster and more convenient than conventional cryogenic thermometers for chip-scale devices and could be mass produced. NIST researchers describe the design and operation in a new journal paper [].

Just 2.5 by 1.15 millimeters in size, the new thermometer can be embedded in or stuck to another cryogenic microwave device to measure its temperature when mounted on a chip. The researchers used the thermometer to demonstrate fast, accurate measurements of the heating of a superconducting microwave amplifier.

The technology is a spinoff of NIST’s custom superconducting sensors for telescope cameras, specifically microwave detectors delivered for the BLAST balloon [] and [].

“This was a fun idea that quickly grew into something very helpful,” group leader Joel Ullom said. “The thermometer allows researchers to measure the temperature of a wide range of components in their test packages at very little cost and without introducing a large number of additional electrical connections. This has the potential to benefit researchers working in quantum computing or using low-temperature sensors in a wide range of fields.”

The thermometer consists of a superconducting niobium resonator coated with silicon dioxide. The coating interacts with the resonator to shift the frequency at which it naturally vibrates. Scientists suspect this is due to atoms “tunneling” between two sites, a quantum-mechanical effect.

The NIST thermometer is based on a new application of the principle that the natural frequency of the resonator depends on the temperature. The thermometer maps changes in frequency, as measured by electronics, to a temperature. By contrast, conventional thermometers for sub-Kelvin temperatures are based on electrical resistance. They require wiring routed to room-temperature electronics, adding complexity and potentially causing heating and interference.

The NIST thermometer measures temperature in about 5 milliseconds (thousandths of a second), much faster than most conventional resistive thermometers at about one-tenth of a second. The NIST thermometers are also easy to fabricate in only a single process step. They can be mass produced, with more than 1,200 fitting on a 3-inch (approximately 75-millimeter) silicon wafer.

References: J. Wheeler, M.R. Vissers, M. Malnou, J. Hubmayr, J.N. Ullom, and J. Gao. Sub-Kelvin Thermometer for On-Chip Measurements of Microwave Devices Utilizing Two-Level Systems in Superconducting Microresonators. Applied Physics Letters 117, 192601 (2020). DOI: 10.1063/5.0029351 []

Provided by NIST

The Long Road to Dementia (Neuroscience)

The chain reaction which leads to toxic protein deposits in Alzheimer’s disease starts even earlier than assumed. Researchers from Tübingen, Germany show how this process could be stopped early on.

Artistic visualization of protein deposits in the vicinity of nerve cells, as they occur in Alzheimer’s disease. Symbolic image – not for editorial use. Source: nobeastsofierce –

Alzheimer’s disease develops over decades. It begins with a fatal chain reaction in which masses of misfolded beta-amyloid proteins are produced that in the end literally flood the brain. Researchers including Mathias Jucker from the Hertie Institute for Clinical Brain Research (HIH) in Tübingen and the German Center for Neurodegenerative Diseases (DZNE) show in the journal Nature Neuroscience that this chain reaction starts much earlier in mice than commonly assumed. This means that in addition to the well-known early phase of the disease with protein deposits but without symptoms of dementia, there is an even earlier phase in which the chain reaction is triggered by invisible tiny seeds of aggregation. If this is confirmed to occur also in humans, a treatment addressing the causes of disease would have to prevent this process. The scientists have already identified an antibody that might accomplish this.

To this end, they searched among the already known antibodies directed against misfolded beta-amyloid proteins for antibodies that can recognize and possibly also eliminate these early seeds of aggregation that currently escape biochemical detection. Of the six antibodies investigated, only aducanumab had an effect: Transgenic mice that were treated for only 5 days before the first protein deposits manifested, later on in life showed only half of the usual amount of deposits in their brains. “This acute antibody treatment obviously removes seeds of aggregation, and the generation of new seeds takes quite some time, so that much less deposits are formed in the weeks and months after the treatment.” Mathias Jucker commented on the findings. “Indeed, the mice had only half the brain damage six months after this acute treatment.”

Although research on Alzheimer’s has been dealing with seeds of aggregation for quite some time, nobody really knows what they look like. They are currently only defined by their role as triggers for this fatal chain reaction. In this respect, they are similar to so-called prions that cause BSE in cattle, scrapie in sheep and Creutzfeldt-Jakob disease in humans. Pathogenic prions force their correctly folded peers into their abnormal shape. Jucker and coworkers therefore used the antibody aducanumab to learn more about the structure of the seeds of aggregation. They were able to show that aducanumab recognizes protein aggregates, but not individual beta-amyloid chains. The scientists now hope to use the antibody as a fishhook to isolate and better describe these seeds of aggregation.

“Our results suggest that we need to focus more on this very early phase of Alzheimer’s and look for biomarkers for it. We also need more antibodies that recognize different types of the seeds of aggregation and help us to understand how they trigger the chain reaction and how they can be used for therapy,” Jucker said.

There is currently consensus that treatment of Alzheimer’s disease must begin earlier, not when memory decline has already begun. However, the results of the Tübingen scientists are now redefining the term “earliness” in mice. Until now, the phase with protein deposits but without symptoms of dementia has been considered to be “early”. The new studies suggest that a treatment of Alzheimer’s that addresses the causes should start much earlier.

References: Uhlmann, R.E., Rother, C., Rasmussen, J. et al. Acute targeting of pre-amyloid seeds in transgenic mice reduces Alzheimer-like pathology later in life. Nat Neurosci (2020).

Provided by German Center for Neurodegenerative Diseases (DZNE)

Environmental Scientists New Ozonation Method Treats Water From Antibiotic Residues (Chemistry)

Clean drinking water is considered to be one of the earth’s most precious and threatened resources. Recent studies show that increasing concentrations of pharmaceuticals can be found in surface waters, which can end up in drinking water. TalTech environmental scientists are looking for ways to treat drinking water from hazardous pharmaceutical residues.

Researchers at TalTech Laboratory of Environmental Technology ©TalTech

TalTech research group of the Laboratory of Environmental Technology led by Senior Researcher Niina Dulova published an article in the journal Environmental Research titled “Individual and simultaneous degradation of sulfamethoxazole and trimethoprim by ozone, ozone/hydrogen peroxide and ozone/persulfate processes: A comparative study”.

Niina Dulova says, “Removal of hazardous micropollutants of different origins from water is still one of the unresolved problems in today’s environmental technology. Our study investigated application of new efficient water treatment methods for elimination of two micropollutants: sulfamethoxazole and trimethoprim. These antibiotics are widely used to treat lung and kidney diseases both in veterinary and human medicine.”

The application of advanced oxidation processes that take advantage of the high oxidizing capacity of radicals is considered to be the most effective tool for removal of micropollutants from water. These technologies are applied to remove poorly biodegradable substances from water almost completely through mineralization. Advanced oxidation processes can be classified in different ways, but they are mostly divided into categories according to the source of free radicals. Conventionally the oxidants used to form free radicals include hydrogen peroxide (H2O2) and ozone (O3), but in recent years other alternative oxidants, such as persulfate (PS), have been used increasingly.

“In our study we focused on the O3, combined O3/H2O2 and O3/PS processes. The latter, O3/PS technology, is an evolving promising solution in the field of radical-based oxidation processes. The efficiency of the O3/PS process in the decomposition of antibiotic residues (sulfamethoxazole, trimethoprim and a combination of sulfamethoxazole and trimethoprim) in water has not been studied previously and our findings are promising,” Niina Dulova says.

The current EU Water Framework Directive does not address the issues of these antibiotic residues in water. Therefore, our wastewater treatment plants do not consider it necessary to tackle the problem. However, the situation will change over the next five years as the European Union is on the way towards establishing stricter water framework directives. This would also change the requirements for our water treatment plants. The best solution in this case would be the introduction of a new water treatment technology, i.e. a free radical based process,” Dulova says.

Currently ozone is mainly used in water treatment plants for water disinfection, which, however, is not sufficient to remove hazardous pharmaceutical residues. Only using ozone also for oxidation would remove antibiotic residues from water.

Niina Dulova says, “If you ask why water containing antibiotic residues is hazardous to people, the answer is be very concrete: when exposed to water contaminated with such antibiotic residues, bacteria develop resistance to these antibiotics. This, in turn, makes it increasingly difficult to treat people exposed to these bacteria with antibiotics in the future.”

References: Sawaira Adil, Bareera Maryam, Eun-Ju Kim, Niina Dulova,
Individual and simultaneous degradation of sulfamethoxazole and trimethoprim by ozone, ozone/hydrogen peroxide and ozone/persulfate processes: A comparative study, Environmental Research, Volume 189, 2020, 109889, ISSN 0013-9351,

Provided by Estonian Research Council

Killing Cancer Naturally: New Process To Produce Compounds With Anti-cancer Properties (Oncology / Medicine)

Scientists have uncovered a method of combining natural organic compounds which can create anticancer drugs with minimal side effects.

In the past decades, cancer has surpassed many other diseases to become the current second leading cause of death globally, with one in six people dying from it. This concerning position has given it a unique and ubiquitous position in global culture, so much so that finding a cure for cancer is considered one of the most noble things any person can do. Sadly, humanity hasn’t arrived at this cure yet; tons of research is being conducted to explore every angle of cancer, trying to find a weakness.

Only time will truly tell if this is the new door opening to the elusive cure for cancer, but this is a sure and definite step in the right direction. ©Tokyo University of Science

A group of scientists from the Tokyo University of Science, led by Prof Kouji Kuramochi, has also been dedicated to this mission. In their search for a weapon against cancer, they turned to a specific set of organic compounds called “phenazines.” Phenazines are a large group of nitrogen-containing “heterocycles” (or compounds with a ring structure composed of at least two different elements). More than a hundred phenazine compounds are found naturally, and over 6000 can be “synthesized.” Of these, N-alkylphenazin-1-ones (phenazinones) are a minor group of phenazines that are known to have antibacterial, antifungal, and cytotoxic activities. Cytotoxicity is an exciting property in cancer research, because, if we can “direct” cytotoxic compounds to work against cancer cells, we can eliminate the cancer.

“Pyocyanin, lavanducyanin, lavanducyanin-derived WS-9659 A, WS-9659 B, and marinocyanins A and B, all different types of phenazines, show cytotoxic activities, against cancer cells. However, these compounds are difficult to derive from their natural sources such as bacteria,” reports Prof Kuramochi.

Determined to shed more light on them and harness their properties for good, the scientists experimented with synthesizing these compounds through several methods. They performed “halogenation” (the process of adding halogens like chlorine and bromine) and “oxidative condensation” (or addition of an oxidant and a water molecule) on various compounds.

Their strategy succeeded in the highly efficient and selective synthesis of N-alkyl-2-halophenazin-1-ones. Of all the synthesized compounds, they found that 2-chloropyocyanin exhibited high cytotoxicity toward the lung cancer cells. Their findings published in American Chemical Society Omega, explain the logistics of their study in full technical detail.

Prof Kuramochi believes that their discovery also has a beneficial effect on the living world. “We have established a highly versatile synthetic method that is simple and can be applied to the synthesis of many natural products,” he says. Since the oxidative coupling reaction proceeds only with oxygen, it is an environmentally friendly synthetic method.”

What’s more, this novel technique overcomes one of the main drawbacks of the existing techniques. The traditional chlorination of N-alkylphenazin-1-ones with selectively occurs at the 4-position, meaning that the compounds that form out of that reaction are the undesired N-alkyl-4-chlorophenazin-1-ones. This novel synthesis technique overcomes this issue, and allows, for the first time, the synthetic production of WS-9659 B!

Prof Kuramochi and his team look forward to verifying the effects of phenazinones in animal studies and clinical trials. In the development of anticancer drugs, drugs that have little effect on normal cells and act selectively on cancer cells are ideal drug candidates with few side effects.

These new compounds are more than four times more selectively toxic to cancer cells than normal cells. Only time will truly tell if this is the new door opening to the elusive cure for cancer, but this is a sure and definite step in the right direction.

References: Haruki Kohatsu, Shogo Kamo, Masateru Furuta, Shusuke Tomoshige, and Kouji Kuramochi, “Synthesis and Cytotoxic Evaluation of N-alkyl-2-halophenazin-1-ones”, ACS Omega 2020, 5, 42, 27667–27674.

Provided by Tokyo University of Science

An Acebuchin-oil-enriched Diet Helps To Reduce Hypertension (Neuroscience)

An acebuchin-oil-enriched diet reduces oxidative stress at the retinal level, produced by hypertension, to a greater degree than extra virgin olive oil.

An acebuchin-oil-enriched diet helps to reduce arterial blood pressure, as shown by a study carried out by the Cardiovascular Physiopathology research group at the Physiology Department of the University of Seville. Furthermore, their work shows that acebuche oil has a greater impact in reducing hypertension than extra virgin olive oil.

©Santana Garrido et al.

This research group from the US Faculty of Pharmacy, led by Professor Carmen María Vázquez Cueto together with Professor Alfonso Mate Barrero, has been investigating the physiopathological mechanisms involved in the development of arterial hypertension (AHT) for over 20 years, with special interest in finding natural products that help to alleviate the organ damage caused by this disorder. The acebuche, also know as the wild olive tree, is a variety of tree widely found throughout Spain and covering almost nine million hectares in Andalusia. However, little data is available on the composition and therapeutic potential of acebuchin oil. The studies mainly focus on the composition and pharmacological effects of olive tree leaves and extra virgin olive oil.

Following their research, in which they gave mice a diet enriched with acebuchin oil or extra virgin olive oil, the researchers detected that the acebuchin-oil-enriched diet significantly reduced blood pressure in hypertensive animals. However, a lesser antihypertensive effect was found in animals fed a diet enriched with extra virgin olive oil.

At the same time, the study showed that the diet enriched in acebuchin oil reduces ocular oxidative stress produced by AHT to a greater degree than the diet enriched in extra virgin olive oil. Furthermore, the former also has a greater impact in regulating the systems related with this oxidative stress.

In particular, the researchers studied variations in the morphology of the hypertensive retina, which are prevented by the acebuched-oil-enriched diet. AHT causes a change in the retina’s morphology (showing “thinned” layers in the retina). This outcome can be counteracted with an acebuchin-oil-enriched diet, obtaining better results than with a diet enriched in extra virgin olive oil.

AHT is a high-prevalence disease on a global scale (30-45% of the general population) where systolic blood pressure values rise above 139 mmHg and/or diastolic blood pressure is above 89 mmHg. AHT damage manifests itself in different organs and is a major risk factor in cardiovascular, kidney, brain and eye diseases. In particular, AHT constitutes an important risk factor for the development of retinal vascular diseases, such as hypertensive retinopathy and retinal arterial and venous obstructions, which are associated with high-prevalence ocular pathologies such as cataracts, glaucoma, age-related macular degeneration and choroidopathies.

The Cardiovascular Physiopathology research group has applied to the Spanish Patent and Trademark Office (OEPM), through the University of Seville, for a patent on the “Use of acebuchin oil in retinal damage associated with arterial hypertension and associated retinal pathologies”.

References: Santana-Garrido, Á.; Reyes-Goya, C.; Pérez-Camino, M.C.; André, H.; Mate, A.; Vázquez, C.M. Retinoprotective Effect of Wild Olive (Acebuche) Oil-Enriched Diet against Ocular Oxidative Stress Induced by Arterial Hypertension. Antioxidants 2020, 9, 885.

Provided by University of Seville

Ancient Zircon Minerals From Mars Reveal The Elusive Internal Structure of The Red Planet (Planetary Science)

The uranium-bearing mineral zircon is an abundant constituent of Earth’s continental crust, providing information about the age and origin of the continents and large geological features such as mountain chains and giant volcanoes. But unlike Earth, Mars’s crust is not evolved and is compositionally similar to the crust found under the Earth’s oceans, where zircon is rare. Therefore, zircon is not expected to be a common mineral on Mars.

Figure 1: The NWA 7533 zircon-rich meteorite containing fragments of the ancient crust of Mars. Credit: University of Copenhagen

“We were quite surprised and excited when we found so many zircons in this martian meteorite. Zircon are incredible durable crystals that can be dated and preserve information that tell us about their origins. Having access to so many zircons is like opening a time window into the geologic history of planet,” describes Professor Martin Bizzarro from the GLOBE Institute, who led the study.

The team investigated the ancient Martian meteorite NWA 7533 (Figure 1), dubbed “Black Beauty”, which was discovered in the desert of Morocco in 2011. After crushing 15 grams of this rock, they extracted about 60 zircons. By age-dating the zircons, they found that the majority of crystals date back to about 4.5 billion years ago, namely the very beginning of the planet’s life. But they also made an unexpected discovery: some of the zircons defined much younger ages, ranging from about 1500 million years down to 300 million years.

“These young ages were a great surprise”, says Bizzarro. “The Black Beauty meteorite is believed to come from the southern hemisphere of Mars, which does not have any young volcanic terrains. The only possible source for these young zircons is the Tharsis volcanic province located in the northern hemisphere of the planet, which contains large volcanoes that were recently active,” Martin Bizzarro adds.

The Tharsis bulge on Mars is an enormous volcanic province that hosts the largest volcanoes in the Solar System, which are up to 21 km high. Scientists believe that this volcanic province is the expression of very deep magmatism that erupts on the planets surface. The analogy on Earth is the Hawaiian volcanic chain of islands, which is also believed to reflect deep-seated volcanic activity. But because of plate tectonics, the Pacific Plate is constantly moving such that, instead of accumulating at one single location, a chain of progressively younger volcanic islands has formed. Since Mars does not have plate tectonics, the volcanoes pile up at one single location and as a result grow to gigantic sizes.

If Bizzarro’s team is correct, it means that the young zircons may contain information about the deep, inaccessible interior of Mars. This is the first time that scientists have direct access to the deep interior of the red planet via these samples, which may allow them to uncover the internal structure and composition of Mars.

“Having samples of the deep interior of Mars is key. This means that we can now use these zircons to probe the origin of the volatile elements on Mars, including its water, and see how it compares with Earth and other planets in the Solar System,” explains Mafalda Costa, first other of the new study.

But to understand the nature of the deep martian interior, the researchers turned to the analysis of the isotopic composition of the element hafnium in the same zircons.

“Because hafnium is a major elemental constituent of zircon, it retains a memory of where the zircon formed,” says Martin Bizzarro. “We found that the hafnium isotope composition of the young zircons is unlike any of the known Martian meteorites, which indicates that the young zircons come from a primitive reservoir that we did not know existed in the interior of Mars,” he adds.

Figure 2: Unravelling the internal structure of Mars. An upwelling plume of primitive material rises from the deep mantle, feeding a volcanoes at the planet’s surface. Credit: University of Copenhagen

The hafnium isotope composition of the young zircons is similar to the most primitive objects in the Solar System, that is, chondrite meteorites. These chondrite meteorites are samples of asteroids that have never been modified since their formation. This implies that the deep interior of Mars has essentially not been modified since the formation of the planet (Figure 2). The existence of such a primitive reservoir is expected for a planet lacking plate tectonics. In contrast to Earth, where material formed at surface is continuously recycled into the interior by plate tectonics, the deep interior of Mars has remained unchanged since the birth of the planet and, as such, preservers its initial composition.

Finally, the discovery that zircon may be abundant on the Martian surface may guide the future robotic exploration of the planet, especially in the framework of returning samples to Earth.

“Our study makes clear that a return mission targeted at acquiring zircon-bearing samples will be of high scientific value towards understanding the geologic history of Mars,” concludes Martin Bizzarro.

“The internal structure and geodynamics of Mars inferred from a 4.2 Gyr zircon record” published in the Proceedings of the National Academy of Sciences.

References: Maria M. Costa et al. The internal structure and geodynamics of Mars inferred from a 4.2-Gyr zircon record, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2016326117

Provided by University of Copenhagen

Extremely Rare Parasitic Crustacean Discovered in Museum Shark Collection (Paleontology)

Scientists have discovered an extremely rare species of cymothoid from the mouth of a museum specimen of a deep-sea shark caught from the East China Sea, suggesting its wide distribution around the globe.

The Elthusa splendida specimen described in the paper (Photo: Shinpei Ohashi). ©Shinpei Ohashi

Cymothoids are a family of isopods (a type of crustacean) that are ectoparasites of fish. Some species in this family are also known as tongue-biter or tongue-eating louse (e.g., Cymothoa exigua).

Assistant Professor Ryota Kawanishi and Dr. Shinpei Ohashi from Hokkaido University have reported the discovery of an extremely rare species of cymothoid, Elthusa splendida, from the East China Sea. Their paper, published in the journal Species Diversity, expands the range of this species to almost the opposite sides of the Earth.

Cymothoids are a diverse family of more than 300 species of parasites, and parasitize a wide variety of fish, from freshwater to the deep sea. A recent study into the genetics of the family has shown that it is highly likely that they evolved in the deep sea and diversified. A number of deep sea cymothoids, however, are poorly studied, primarily due to the difficulty of deep sea sampling.

The locations where the hosts of the original specimen of Elthusa splendida (T) and the specimen in this study (P) were collected (Ryota Kawanishi & Shinpei Ohashi, Species Diversity, © 2020 The Japanese Society of Systematic Zoology). ©Ryota Kawanishi & Shinpei Ohashi, Species Diversity, © 2020 The Japanese Society of Systematic Zoology

Elthusa splendida is the least studied of all deep sea cymothoids. Only five specimens have ever been cataloged and described, in 1981. Those specimens were recovered from a Cuban dogfish, a deep-sea shark, which was captured off southern Brazil in the western South Atlantic. No additional specimens have been reported since then.

In the current study, the scientists discovered the specimen of Elthusa splendida while processing fish specimens at the Fisheries Science Center, Hokkaido University Museum (HUMZ), Hakodate. The specimen was found in a Japanese spurdog, also a deep-sea shark, that had been collected from the East China Sea in June 2003 and preserved in formalin. The scientists confirmed the identification of the specimen by comparing the morphological features of the specimen with the original description of the species. The unique feature that defines Elthusa splendida is the presence of four pits on the first pereonite (first segment behind the head); this feature was examined using a computerized 3D measurement system. DNA sequencing was not used for identification as the sequence of the original specimen is unknown.

A scientific line diagram of Elthusa splendida, illustrating the physical characteristics of the specimen (Ryota Kawanishi & Shinpei Ohashi, Species Diversity, © 2020 The Japanese Society of Systematic Zoology). ©Ryota Kawanishi & Shinpei Ohashi, Species Diversity, © 2020 The Japanese Society of Systematic Zoology

This discovery is important as it shows the distribution of Elthusa splendida extends from two locations that are almost antipodal to each other — almost as far as it is physically possible to be on the planet. The scientists suggest that other species of deep sea cartilaginous fish in the genus Squalus (to which both the Cuban dogfish and the Japanese spurdog belong) can potentially serve as hosts for this parasite. They have also confirmed that Elthusa splendida is rare among other Elthusa species in parasitizing the mouth of the host, rather than the gills; furthermore, even among those cymothoids that parasitize the mouth, Elthusa splendida is one of the rare species that attach to the palate.

This study indicates that there is much that remains to be investigated when it comes to deep sea cymothoids. The scientists also propose using existing specimens of fish in museums across the world to reveal the distribution of cymothoids; from a broader perspective, this work suggests the hidden value of museum natural history collections in studying parasites.

References: Ryota Kawanishi, Shinpei Ohashi. First Record of the Rare Parasitic Isopod Elthusa splendida (Cymothoidae) from the Pacific Ocean, Based on a Specimen Found in a Museum Shark Collection. Species Diversity. November 16, 2020.
DOI: 10.12782/specdiv.25.343

Provided by Hokkaido University