Nanoscale 'tattoos' for individual cells could provide early warnings for health problems

Engineers have developed nanoscale tattoos dots and wires that adhere to live cells in a breakthrough that puts researchers one step closer to tracking the health of individual cells. The new technology allows for the first time the placement of optical elements or electronics on live cells with tattoo-like arrays that stick on cells while flexing and conforming to the cells' wet and fluid outer structure. 

They 're talking about putting something like an electronic tattoo on a living object tens of times smaller than the head of a pin. It's the first step towards attaching sensors and electronics on live cells. The structures were able to stick to soft cells for 16 hours even as the cells moved.

The researchers built the tattoos in the form of arrays with gold, a material known for its ability to prevent signal loss or distortion in electronic wiring. They attached the arrays to cells that make and sustain tissue in the human body, called fibroblasts. The arrays were then treated with molecular glues and transferred onto the cells using an alginate hydrogel film, a gel-like laminate that can be dissolved after the gold adheres to the cell. The molecular glue on the array bonds to a film secreted by the cells called the extracellular matrix.

This work has shown we can attach complex nanopatterns to living cells, while ensuring that the cell doesn't die. It's a very important result that the cells can live and move with the tattoos because there's often a significant incompatibility between living cells and the methods engineers use to fabricate electronics.

The researcher's ability to attach the dots and wires in an array form is also crucial. To use this technology to track bioinformation, researchers must be able to arrange sensors and wiring into specific patterns not unlike how they are arranged in electronic chips.

This is an array with specific spacing, not a haphazard bunch of dots. 

Kam Sang Kwok et al, Toward Single Cell Tattoos: Biotransfer Printing of Lithographic Gold Nanopatterns on Live Cells, Nano Letters (2023). DOI: 10.1021/acs.nanolett.3c01960

Cancers Protect Themselves Against Their Own Mutations

Tumors overexpress certain genes to survive a growing pile of harmful mutations, a trait that scientists could exploit to target with drugs.

Most cancerous tumors accumulate thousands of potentially protein-damaging mutations over time, yet they mysteriously continue to thrive. Now, a new computational study helps explain how that is possible: Tumors with a large number of mutations upregulate genes that minimize misfolded proteins to protect them from their own mutations.

To reveal that coping mechanism, researchers explored the gene expression of nearly 10,300 human tumors across 33 cancer types catalogued in the Cancer Genome Atlas database.3 They found consistent upregulation of chaperone proteins and the proteasome, which respectively prevent and degrade misfolded proteins. Next, the researchers validated their findings using cell line data from the Cancer Cell Line Encyclopedia. The cell lines showed similar expression patterns, and when the scientists calculated the effect of knocking down the upregulated genes, higher mutational loads correlated with reduced cell viability. These results suggest that the gene upregulation protects tumors.

This discovery signals a general vulnerability in many tumors that could be exploited, for example by using chaperone and proteasome inhibitors. Scientists developed such drugs decades ago, but this new information might help target them to the tumors that will be most vulnerable.

https://elifesciences.org/reviewed-preprints/87301

A Realistic Way to Make Space Habitats From Asteroids

We can build space habitats from asteroids by spinning them fast enough. That's what Professor Adam Frank suggests in a recent paper he co-wrote. In this interview, we discussed the idea, how realistic it is and what technology will be needed to achieve it, what applications it can have and when we can expect something like that.

A Drug For Regrowing Teeth Could Be Available Within The Next Decade

Teeth don't grow back once we become adults: any wear and tear is permanent – as those of us with fillings will know – which is why it's important to keep them as clean and healthy as we can. However, this is something scientists are now looking to change. It's been announced that clinical trials for a potential tooth regrowth treatment are set to begin in July 2024, building on decades of research in the field. If those trials are successful, therapeutic drugs could be available by 2030. A team from the Medical Research Institute at Kitano Hospital in Japan is in charge of the trial, which is targeting people with anodontia, a rare genetic condition that prevents baby teeth and adult teeth from growing in the normal way. The treatment would initially target young children with the condition, but further down the line, the researchers think it could also be used more broadly – with people who have more common dental problems, such as gum disease, for example. Here's how it works: having found a link between a specific gene called USAG-1 and limits on tooth growth in mice, the researchers then moved on to tests that tried to block the expression of USAG-1.An antibody was discovered that could safely block some of the activity of USAG-1 in mice and ferrets without leading to any serious side effects, leading to induced tooth growth. The next step is to see if the same chemical reactions can be controlled in humans. We're talking about potential rather than reality at the moment, but it might be possible to use the new drug to prompt the growth of a third generation of teeth in the mouth, after baby teeth and full-sized adult teeth. As the researchers point out in a recent scientific review, the benefit of the approach is that teeth growth is being triggered in a natural way, through a process known as bone morphogenetic protein (BMP) signaling. Our bodies are naturally doing the work, without any complicated engineering of stem cells required. The team also suggests that advancements in scanning technology (such as mass spectrometry, for example) will make it easier to spot biomarkers indicating the people who will benefit most from the treatment. Anti-USAG-1 antibody treatment in mice is effective for tooth regeneration and can be a breakthrough in treating tooth anomalies in humans," write the researchers.

https://www.nature.com/articles/s41598-021-93256-y

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Videos of snakes eating themselves

Changing flies into degradable plastics?

Imagine using insects as a source of chemicals to make plastics that can biodegrade later—with the help of that very same type of bug. That concept is closer to reality than you might expect. Researchers describe their progress to date, including isolation and purification of insect-derived chemicals and their conversion into functional bioplastics, at the fall meeting of the American Chemical Society (ACS).

Researchers have been developing methods for several years to transform natural products—such as glucose obtained from  sugar cane or trees—into degradable, digestible polymers that don't persist in the environment. But those natural products are harvested from resources that are also used for food, fuel, construction and transportation.

So some researchers began searching for alternative sources that wouldn't have these competing applications.

And they thought of using waste products left over from farming black soldier flies. The larvae of these flies contain many proteins and other nutritious compounds, so the immature insects are increasingly being raised for animal feed and to consume wastes. However, the adults have a short life span after their breeding days are over and are then discarded. How about using them instead of useless plastics?

When  researchers examined the dead flies, they determined that chitin is a major component. This nontoxic, biodegradable, sugar-based polymer strengthens the shell, or exoskeleton, of insects and crustaceans. Manufacturers already extract chitin from shrimp and crab shells for various applications, and researchers now  have been applying similar techniques using ethanol rinses, acidic demineralization, basic deproteinization and bleach decolorization to extract and purify it from the insect carcasses.

Fly-sourced chitin powder is probably purer, since it lacks the yellowish colour and clumpy texture of the traditional product. Researchers also note that obtaining chitin from flies could avoid possible concerns over some seafood allergies. Some other researchers isolate chitin or proteins from fly larvae, but this is the first time the use chitin from discarded adult flies, which—unlike the larvae—aren't used for feed.

Harvesting of building blocks from insect feedstocks for transformation into carbohydrate-derived superabsorbent hydrogels, ACS Fall 2023. www.acs.org/meetings/acs-meetings/fall-2023.html

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Scientists theorize a hidden phase transition between liquid and a solid

Anything made out of plastic or glass is known as an amorphous material. Unlike many materials that freeze into crystalline solids, the atoms and molecules in amorphous materials never stack together to form crystals when cooled. In fact, although we commonly think of plastic and glass as "solids," they instead remain in a state that is more accurately described as a supercooled liquid that flows extremely slowly.

And although these "glassy dynamic" materials are ubiquitous in our daily lives, how they become rigid at the microscopic scale has long eluded scientists.

Now, researchers  have discovered molecular behavior in supercooled liquids that represents a hidden phase transition between a liquid and a solid.

Their improved understanding applies to ordinary materials like plastics and glass, and could help scientists develop new amorphous materials for use in medical devices, drug delivery, and additive manufacturing.

Specifically, using theory, computer simulations,  and previous experiments, the scientists explained why the molecules in these materials, when cooled, remain disordered like a liquid until taking a sharp turn toward a solid-like state at a certain temperature called the onset temperature—effectively becoming so viscous that they barely move. This onset of rigidity—a previously unknown phase transition—is what separates supercooled from normal liquids.

Any supercooled liquid continuously jumps between multiple configurations of molecules, resulting in localized particle movements known as excitations. In their proposed theory, the researchers treated the excitations in a 2D supercooled liquid as though they were defects in a crystalline solid.

As the supercooled liquid's temperature increased to the onset temperature, they propose that every instance of a bound pair of defects broke apart into an unbounded pair. At precisely this temperature, the unbinding of defects is what made the system lose its rigidity and begin to behave like a normal liquid. "The onset temperature for glassy dynamics is like a melting temperature that 'melts' a supercooled liquid into a liquid. This should be relevant for all supercooled liquids or glassy systems.

The theory and simulations captured other key properties of glassy dynamics, including the observation that, over short periods of time, a few particles moved while the rest of the liquid remained frozen.

Dimitrios Fraggedakis et al, Inherent-state melting and the onset of glassy dynamics in two-dimensional supercooled liquids, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2209144120

Source of hidden consciousness in 'comatose' brain injury patients found

 Researchers have identified brain injuries that may underlie hidden consciousness, a puzzling phenomenon in which brain-injured patients are unable to respond to simple commands, making them appear unconscious despite having some level of awareness.

This study suggests that patients with hidden consciousness can hear and comprehend verbal commands, but they cannot carry out those commands because of injuries in brain circuits that relay instructions from the brain to the muscles.

The findings could help physicians more quickly identify brain-injured patients who might have hidden consciousness and better predict which patients are likely to recover with rehabilitation.

Hidden consciousness, also known as cognitive motor dissociation (CMD), occurs in about 15% to 25% of patients with brain injuries stemming from head trauma, brain hemorrhage, or cardiac arrest.

In previous research, researchers found that subtle brainwaves detectable with EEG are the strongest predictor of hidden consciousness and eventual recovery for unresponsive brain-injured patients. But the precise pathways in the brain that become disrupted in this condition were unknown.

Part 1

In the new study, the researchers used EEG to examine 107 brain injury patients. The technique can determine when patients are trying, though unable, to respond to a command such as "keep opening and closing your right hand."

The analysis detected CMD in 21 of the patients. 
The researchers then analyzed structural MRI scans from all of the patients.

Using a technique they developed called bi-clustering analysis, they were able to identify patterns of brain injury that are shared among patients with CMD and contrast to those without CMD.

The researchers found that all of the CMD patients had intact brain structures related to arousal and command comprehension, supporting the notion that these patients were hearing and understanding the commands but were unable to carry them out.  They saw that all of the CMD patients had deficits in brain regions responsible for integrating comprehended motor commands with motor output, preventing CMD patients from acting on verbal commands.

The findings may allow researchers to better understand which brain injury patients have CMD, which will be useful for clinical trials that support recovery of consciousness.

Eva Franzova, Qi Shen, Kevin Doyle, Justine M Chen, Jennifer Egbebike, Athina Vrosgou, Jerina C Carmona, Lauren Grobois, Gregory A Heinonen, Angela Velazquez, Ian Jerome Gonzales, Satoshi Egawa, Sachin Agarwal, David Roh, Soojin Park, E Sander Connolly, Jan Claassen. Injury patterns associated with cognitive motor dissociation. Brain, 2023; DOI: 10.1093/brain/awad197

Part 2

Annular Eclipse

Mysterious Form of Vision Loss May Brew Inside The Gut!

In some glaucoma patients, vision loss mysteriously progresses despite treatment, and new research from China points to immune cells that migrate from the digestive tract to the eyes. These "gut-retina axis" cells bind a specific protein and gain access to the eye's light-sensitive tissue, where they damage retinal ganglion cells (RGCs). Glaucoma, classified as a group of neurodegenerative diseases, is an umbrella term for eye diseases caused by loss of RGCs, whose axons form the optic nerve which transmits visual information to the brain. Your optic nerve is sending this to your brain's visual cortex to process right now, if you're reading with your eyes. A leading cause of blindness, glaucoma is currently incurable; treatment aims to halt disease progression. These new findings emphasize the importance of the gut-retina axis in glaucoma pathogenesis and for the development of therapeutic strategies. Pressure inside the eyeball, called elevated intraocular pressure (EIOP), is the main risk factor for glaucoma. Lowering EIOP is a primary goal of treatment, but it isn't always successful in stopping progression of the disease.

Previous studies hinted that immune system T cells may play a role in glaucoma damage, but the underlying mechanism has been unclear. T cells and other circulating immune cells are normally denied permission to enter the retina.

These very scientists were part of a 2021 study that found a subset of CD4+ T cells express a gut-homing receptor, integrin β7, which somehow gained entry to the retina with a little help from a protein called mucosal addressin cell adhesion molecule 1 (MAdCAM-1). 

In their new study, tehy confirmed a link between CD4+ T cells that express integrin β7, MAdCAM-1, and glaucoma disease severity in patients.

Part 1

The first step was to test blood samples from 519 glaucoma patients and 189 healthy controls. A significantly higher percentage of β7-expressing CD4+ T cells was found in glaucoma patients compared to healthy controls, and glaucoma patients with more of these cells in their blood had more severe eye damage.

Using an EIOP-induced mouse model of glaucoma, researchers next showed that to gain access to the retina, β7+ CD4+ T cells in these early stage glaucoma mice must make a detour through the gut.

The team found the β7+ CD4+ T cells of EIOP-induced mice were reprogrammed in the gut, so they could use integrin β7 as a kind of license, returning to the blood circulation functionally equipped to travel to the retina.

While normal T cells are unable to bind to MAdCAM-1 in the retina, the gut-licensed cells were able to do so, allowing them access to the eye tissue, which "eventually led to neuroinflammation".

The ability to induce MAdCAM-1 expression on retinal [vessels] might be one of the mechanisms whereby gut-licensed β7+ CD4+ T cells cross the blood-retina barrier and invade the retina, To investigate the link between these suspect cells and proteins and glaucoma damage, the team administered antibodies to mice that blocked the β7+ CD4+ T cells' interaction with MAdCAM-1. Inhibiting the communication with MAdCAM-1 significantly reduced the damage caused by glaucoma.

https://www.science.org/doi/10.1126/scitranslmed.adg1656

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Part 2

Blood factor can turn back time in the aging brain

Platelets are behind the cognitive benefits of young blood, exercise and the longevity hormone klotho. In a remarkable convergence, scientists have discovered that the same blood factor is responsible for the cognitive enhancement that results from young blood transfusion, the longevity hormone klotho, and exercise.

In a trio of papers appearing in Nature, Nature Aging and Nature Communications, three research teams identify platelet factor 4 (PF4) as a common messenger of each of these interventions.

As its name suggests, PF4 is made by platelets, a type of blood cell that alerts the immune system when there is a wound and helps to form clots. It turns out that PF4 is also a cognitive enhancer. Under its influence, old mice recover the sharpness of middle age and young mice get smarter.

Young blood, klotho, and exercise can somehow tell your brain, 'Hey, improve your function'. With PF4, we're starting to understand the vocabulary behind this rejuvenation.

Part 1

Parabiosis: an experiment in which two animals are linked together by their blood circulation. When a young, sprightly animal is connected to an aging animal, the aging animal becomes more youthful–its muscles more resilient, its brain more capable of learning.

In 2014, researchers found that plasma, consisting of blood minus red blood cells, mimicked parabiosis: young blood plasma, injected into old animals, was restorative. When they compared young plasma to old plasma, they found it contained much more PF4. Just injecting PF4 into old animals was about as restorative as young plasma. It calmed down the aged immune system in the body and the brain. Old animals treated with PF4 performed better on a variety of memory and learning tasks.

PF4 actually causes the immune system to look younger, it's decreasing all of these active pro-aging immune factors, leading to a brain with less inflammation, more plasticity and eventually more cognition.

A decade ago, other researchers showed that klotho enhances cognition in young and old animals and also makes the brain more resistant to age-related degeneration. 

But the researchers knew its effects had to be indirect because klotho molecules, injected into the body, never reached the brain. They found that one connection was PF4, released by platelets after an injection of klotho. PF4 had a dramatic effect on the hippocampus, the brain region responsible for making memories, where it enhanced the formation of new neural connections at the molecular level.

Exercise can keep the mind sharp for decades. Researchers also found that platelets released PF4 into the bloodstream following exercise. So exercise  also improved cognition in old animals. 

But for a lot of people with health conditions, mobility issues or of advanced age, exercise isn't possible, so pharmacological intervention is an important area of research. We can now target platelets to promote neurogenesis, enhance cognition and counteract age-related cognitive decline.

Adam B. Schroer et al, Platelet factors attenuate inflammation and rescue cognition in ageing, Nature (2023). DOI: 10.1038/s41586-023-06436-3. www.nature.com/articles/s41586-023-06436-3

Park, C. et al. Platelet factors are induced by longevity factor klotho and enhance cognition in young and aging mice, Nature Aging (2023). DOI: 10.1038/s43587-023-00468-0. www.nature.com/articles/s43587-023-00468-0

Odette Leiter et al, Platelet-derived exerkine CXCL4/platelet factor 4 rejuvenates hippocampal neurogenesis and restores cognitive function in aged mice, Nature Communications (2023). DOI: 10.1038/s41467-023-39873-9

Part 2

Sugars affect brain 'plasticity,' helping with learning, memory, recovery

Can you recognize someone you haven't seen in years, but forget what you had for breakfast yesterday? Our brains constantly rearrange their circuitry to remember familiar faces or learn new skills, but the molecular basis of this process isn't well understood. Recently scientists reported that sulfate groups on complex sugar molecules called glycosaminoglycans (GAGs) affect "plasticity" in the brains of mice. Determining how GAGs function could help us understand how memory and learning work in humans, and provide ways to repair neural connectivity after injuries.

The researchers will present their results today at the fall meeting of the American Chemical Society (ACS).

The sugars that sweeten fruits, candies or cakes are actually just a few simple varieties of the many types of sugars that exist. When strung together, they can make a wide array of complex sugars. GAGs are formed by then attaching other chemical structures, including sulfate groups.

If we study the chemistry of GAGs in the brain, we can learn about brain plasticity and hopefully, in the future, use this information to restore or enhance neural connections involved in memory. These sugars regulate numerous proteins, and their structures change during development and with disease.

In the brain, the most common GAG form is chondroitin sulfate, which is found throughout the extra cellular matrix surrounding the brain's many cells. Chondroitin sulfate can also form structures known as "perineuronal nets," which wrap around individual neurons and stabilize the synaptic connections between them.

One way a GAG's function can be changed is through sulfation motifs, or patterns of sulfate groups tacked onto the sugar chains.

Source: Harnessing chemistry to understand the roles of glycans in neuroplasticity, ACS Fall 2023.

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Cleaning water with 'smart rust' and magnets
Pouring flecks of rust into water usually makes it dirtier. But researchers have developed special iron oxide nanoparticles they call "smart rust" that actually makes it cleaner. Smart rust can attract many substances, including oil, nano- and microplastics, as well as the herbicide glyphosate, depending on the particles' coating. And because the nanoparticles are magnetic, they can easily be removed from water with a magnet along with the pollutants. Now, the team is reporting that they've tweaked the particles to trap estrogen hormones that are potentially harmful to aquatic life.
Using magnetic rust nanoparticles to clean water

These ‘living’ rocks can give birth to baby stones

The staggering science behind trovants, the rocks that can grow, move – and reproduce.

Trovants are bulbous, otherworldly stones that grow over time, thus appearing to be alive. Parent rocks can even push out baby trovants, which then grow independently.

The sandstone structures are found mainly in Romania, with the most famous cluster in and around a village named Costeşti. There, a Trovants Museum Natural Reserve celebrates and protects them.

The stones’ smooth curves give the appearance of modern, man-made sculptures. They feature heavily in local folklore, with people at one time believing them to be giant dinosaur eggs, plant fossils or alien creations. The word trovant was coined by a naturalist and means cemented sand.

Worms Frozen for 46,000 Years are the Oldest Known Living Animals

Nematodes buried in Siberian permafrost may be able to stay in a state of suspended animation indefinitely, according to recent findings.

Microscopic worms unearthed from Siberian permafrost might belong to a species that went extinct elsewhere on Earth long ago. Researchers said that the tiny, 46,000-year-old nematodes use genes similar to those of their modern-day relatives to enter a state of hibernation where the worms can live indefinitely across tens of thousands of years. The findings were recently published in PLOS Genetics

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Microplastics are adsorbing zinc oxide from sunscreens and microbea...

A new study by a research team from Diamond Light Source looks at how microplastics wastes may interact with zinc oxide (ZnO) nanomaterials in freshwater and seawater scenarios. It also evaluated, a ZnO-based sunscreen and an exfoliating cleanser with microbeads in its composition under the same conditions.

Study discovers pairing of electrons in artificial atoms, a quantum state predicted more than 50 years ago

Researchers observed a quantum state that was theoretically predicted more than 50 years ago by Japanese theoreticians but so far eluded detection. By tailoring an artificial atom on the surface of a superconductor, the researchers succeeded in pairing the electrons of the so-called quantum dot, thereby inducing the smallest possible version of a superconductor. The work appears in the journal Nature.

Usually, electrons repel each other due to their negative charge. This phenomenon has a huge impact on many materials properties such as the electrical resistance. The situation changes drastically if the electrons are "glued" together to pairs thereby becoming bosons. Bosonic pairs do not avoid each other like single electrons, but many of them can reside at the very same location or do the very same motion.

One of the most intriguing properties of a material with such electron pairs is superconductivity, the possibility to let an electrical current flow through the material without any electrical resistance. For many years, superconductivity has found many important technological applications, including magnetic resonance imaging or highly sensitive detectors for magnetic fields.

Today, the continuous downscaling of electronic devices heavily guides investigations on how superconductivity can be induced into much smaller structures at the nanoscale.

Researchers have now realized the pairing of electrons in an artificial atom called quantum dot, which is the smallest building block for nanostructured electronic devices. They locked the electrons into tiny cages that they built from silver, atom-by-atom. By coupling the locked electrons to an elemental superconductor, the electrons inherited the tendency towards pairing from the superconductor.

the researchers related the experimental signature, a spectroscopic peak at very low energy, to the quantum state predicted in the early 1970s by Kazushige Machida and Fumiaki Shibata.

While the state has so far eluded  direct detection by experimental methods, recent work by researchers from the Netherlands and Denmark show it is beneficial for suppressing unwanted noise in transmon qubits, an essential building block of modern quantum computers.

 Lucas Schneider et al, Proximity superconductivity in atom-by-atom crafted quantum dots, Nature (2023). DOI: 10.1038/s41586-023-06312-0

Climatic changes put the brakes on spider's 'gift-giving'

Being wary of gifts from males of the species takes on a new meaning among a South American spider species known to woo females with silk-wrapped food parcels.

Scientists in South America and Australia have discovered that environmental stresses, such as large variations in rainfall and floods in the rivers, tend to change the mating rituals of these semi-aquatic Neotropical spiders which live in riparian habitats in Uruguay and Brazil.

They found that during moderate to harsh lean times, gift-giving spider Paratrechalea ornata males often offer females a deceptive or worthless gift, rather than a food gift.

This study found this behavior probably corresponds with periods of time when food is more difficult to find so some males might 'cheat' by offering fake gifts.

While males of some spider populations offer prey to females as a way to convince them to mate, there might be less bountiful periods when males are more deceptive with their 'nuptial' gifts.

When local environmental conditions are harsh, these fake parcels become more common rather than the exception and both males and females become smaller and need less food, researchers say, warning of the long-term affects of climate change on spider, insect and other organisms' survival.

In times of plenty, females will usually reject males if they offer fake gifts but they may eventually have to accept the gifts with no food inside when most males are forced to cheat.

Maria J. Albo et al, Stressful environments favor deceptive alternative mating tactics to become dominant, BMC Biology (2023). DOI: 10.1186/s12915-023-01664-5

Sniffing nanoparticles loaded with mRNA could lead to advanced lung therapeutics

Researchers  have optimized a polymer-based mRNA vehicle for targeted lung delivery and demonstrated the potential of the platform for mucosal vaccination against respiratory pathogens.

In a paper, "Polymer nanoparticles deliver mRNA to the lung for mucosal vaccination," published in Science Translational Medicine, the team introduces their creation of inhalable messenger RNA (mRNA) for therapeutic use.

Clinical research has been searching for an efficient and targeted way to deliver mRNA to the lungs for various therapeutic applications, including protein replacement therapies, gene editing and vaccination. The main challenges have been maintaining mRNA stability and avoiding immune interference.

Researchers now  created PACE (Polymerized Albumin Conjugates for mRNA Encapsulation) polymer formulations to deliver local mRNA to the lungs. The researchers optimized PACE polyplexes to enhance mRNA protection, transfection efficiency, and antigen presentation for effective lung-specific therapeutic and vaccination strategies.

To stabilize PACE, an optimized ratio of polyethylene glycol (PEG) molecules were integrated into the polymer structure during the enzymatic copolymerization process, which stabilized the polyplexes and modified key characteristics. PEG was able to affect the size, surface charge, and other properties of the polyplexes, making them more suitable for loading and effective at mRNA delivery to lung cells.

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The researchers encapsulated mRNA encoding the spike protein from SARS-CoV-2 into PACE and inoculated mice susceptible to SARS-CoV-2 infection. Mice received a 10-μg dose of PACE-mRNA delivered intranasally on days 0 and 28. The development of adaptive immunity in the mediastinal lymph nodes was tested and confirmed 14 days after the boost.

Part 1

After assessing the local immune response, the researchers examined lung tissues, blood serum, and bronchoalveolar lavage fluid for local and systemic antigen-specific T-cell and antibody responses. Transfection occurred primarily in lung epithelial cells and antigen-presenting cells, two cell types that are relevant targets for pulmonary diseases

The vaccination successfully increased spike protein-specific CD8⁺ T cells in the lung tissue and circulating CD8⁺ T cells in the bloodstream. CD8⁺ T cells expressed markers indicative of tissue-resident memory. Both circulating and mucosal IgG antibodies were found at significantly higher concentrations in vaccinated mice.

Mice were then introduced to a lethal dose of SARS-CoV-2. PACE-mRNA vaccination significantly reduced the viral burden in the lungs and improved the weight and survival of the vaccinated mice. This protection was attributed to the spike protein-specific immune response induced by the vaccination. The control group showed no evidence of a spike protein-specific immune response and did not exhibit reduced viral load or improved survival after the viral challenge. The study presents PACE-mRNA polyplexes as a promising method for efficient and targeted mRNA delivery to the lungs with potential benefits for both therapeutic protein expression and mucosal vaccination against respiratory pathogens.

The study also illustrates the importance of animal models as opposed to cell culture alone in determining real-world effects. The positive results indicate that more research is warranted, with further testing planned on larger animal models.

Alexandra Suberi et al, Polymer nanoparticles deliver mRNA to the lung for mucosal vaccination, Science Translational Medicine (2023). DOI: 10.1126/scitranslmed.abq0603

Part 2

Oil eating microbes reshape droplets to optimize biodegradation

 Scientists have found that one kind of oil-eating microbe reshapes droplets to optimize biodegradation. In their study, reported in the journal Science, the group isolated Alcanivorax borkumensis bacteria specimens in a lab setting, fed them crude oil, and then watched how they worked together to eat the oil as quickly and efficiently as possible. 

Prior research has shown that there are many microbes living in the ocean that feed on oil, eventually cleaning away oil not cleaned up by human efforts. Prior research has also shown that such microbes are not able to consume crude oil until it disperses into droplets, which can take a long time. In this new effort, the researchers sought to learn more about the process of crude oil consumption by sea microbes. To that end, they collected A. borkumensis specimens and tested them in their lab.

Under a microscope, the research team observed that A. borkumensis formed biofilms around oil droplets—but they did so in two major ways. In one experiment, A. borkumensis samples that had not been exposed to crude oil before were introduced to simple crude oil droplets. Groups of the bacteria converged on a droplet, forming a sphere. The sphere shape persisted until the entire oil droplet had been consumed.

But when the team exposed samples with experience consuming crude oil, their behavior was much more advanced. Initially, upon converging on a droplet, a sphere formed—but then finger-like protrusions formed, radiating out from the sphere, each completely covered with bacteria. The result was much faster, more efficient consumption of the droplet.

The researchers suggest that the formation of the protrusions results in more oil surface area exposure, allowing more of the bacteria to consume the oil droplet at the same time, compared to the simple sphere, resulting in faster consumption.

M. Prasad et al, Alcanivorax borkumensis biofilms enhance oil degradation by interfacial tubulation, Science (2023). DOI: 10.1126/science.adf3345. www.science.org/doi/10.1126/science.adf3345

Terry J. McGenity et al, Bacteria stretch and bend oil to feed their appetite, Science (2023). DOI: 10.1126/science.adj4430

Researchers discover how stem cells choose their identity

Researchers discovered that stem cells first specialize into a functional cell and then move to their proper location—rather than the other way around. They revealed a new model to show how stem cells specialize into functional cells. They found that their position in the organ is not as important as current models claim. Rather, stem cells choose their identity first and only then move to their appropriate position.

These discoveries were made using intestinal organoids and the new TypeTracker technique, which can now be used to understand other organs at the cellular level and the effects of mutations and medications.

Our intestines contain different types of cells, each of which has a specific task. Just like in many other places in our body, the cells in the intestines are constantly renewed: stem cells develop into specialized cells that perform a function, for example, to secrete substances that protect the intestine or to absorb nutrients from food.

From previous research we know that stem cells reside in the valleys of the intestinal wall (the 'crypts'), while most specialized and functional cells are located at the top of the mountains (the 'villi').

The cells in the intestinal wall are renewed about every week, using the stem cells in the crypts that grow, divide and migrate to the villi. We used to think that by moving upwards to the villus, the stem cells are instructed to become a functional cell. This has been a very appealing model, as it naturally explains how these functional cells are positioned at the right location. However, our data shows a different picture.

This data was obtained using organoids: mini-organs that mimic the original organ so realistically that scientists can use them to unravel its functioning or to test medicines.

The identity of the cells is determined by certain proteins. Stem cells adopted their functional identity much earlier than previously thought. They did so when still deep inside the crypt, before migrating towards the villus region that was thought to provide the trigger to start the specialization process.

Xuan Zheng et al, Organoid cell fate dynamics in space and time, Science Advances (2023). DOI: 10.1126/sciadv.add6480. www.science.org/doi/10.1126/sciadv.add6480

Why killer bacteria affect some people more severely

Why are certain people more severely affected than others by invasive streptococcal infections? According to a new study the answer lies in our genome. Carriers of a certain variant of the STING gene are at greater risk, particularly if they encounter the bacterial strains that have increased in the western world since the 1980s. The findings, published in Nature Communications, could pave the way for better treatments in cases where disease development is often rapid and fatal.

Group A streptococci are fairly common bacteria that can cause, among other things, strep throat or impetigo. However, if the bacteria become invasive, the situation can become very dangerous. In this case, the name sometimes changes to murder bacteria or flesh-eating bacteria and can give rise to life-threatening conditions such as blood poisoning and septic shock, or soft tissue infections that may make an amputation necessary.

Invasive streptococcal infections have increased in recent decades. The reason for this is not fully understood.

The outcome of infections can vary considerably, and it is still unknown why certain infected individuals develop life-threatening conditions while others don’t.

It depends on an interplay between the genes in people and bacteria.

The researchers’ hypothesis proved to be correct – the genes are different and that affects the risk of developing serious conditions.

The results, published in Nature Communications, provide a molecular explanation of how group A streptococci give rise to tissue-degrading and life-threatening inflammation.

The study also shows how the severity of an infection depends on the interplay between one gene – STING – in our immune system and a bacterial enzyme found in the bacteria that have become more prevalent in the western world since the 1980s. This explains why some people are more severely affected than others.

A person with the ”bad” gene variant of STING has a 20 per cent risk of having a limb amputated in the event of an invasive infection by the worst bacteria. For people with the ”good” gene variant, the risk is only three per cent. The percentage of patients suffering from septic shock also differs depending on the interplay between our STING variants and the bacteria’s enzyme activity.

“The difference is due to a unique combination of genetic material from the host and pathogen. This is partly due to that fact that the immune system of people with a certain variant of the STING gene triggers a misguided and dangerous inflammatory response. The other factor is that the outcome also depends on whether we are infected by the bacteria that are more aggressive because they have a very active variant of the NADase enzyme. Conversely, normal activation of the immune system due to another STING variant and lower bacterial enzyme activity is associated with protection.

The researchers also studied the evolution of the different STING variants in humans. The results show that the risk variant of STING appeared in humans around 35,000 years ago and that it spread to varying degrees around the world in connection with the first agricultural revolution 10,000 years ago. The consequence today is that the risk variant of STING is more common in some parts of the world than others.

https://www.nature.com/articles/s41467-023-39771-0

Major 'Population Correction' Coming For Humanity, Scientist thinks

A little over two centuries ago, in the year 1800, roughly a billion people called Earth home.

Just a century later, it had grown by another 600 million.

Today, there are around 8 billion people on the planet.

That sort of growth is unsustainable for our ecosphere, risking a 'population correction' that according to a new study could occur before the century is out. The prediction is the work of population ecologist William Rees from the University of British Columbia in Canada. He argues that we're using up Earth's resources at an unsustainable rate, and that our natural tendencies as humans make it difficult for us to correct this "advanced ecological overshoot".

The result could be some kind of civilizational collapse that 'corrects' the world's population, Rees says – one that could happen before the end of the century in a worst case scenario. Only the richest and most resilient societies would be left.

"Homo sapiens has evolved to reproduce exponentially, expand geographically, and consume all available resources," Rees writes in his published paper.
For most of humanity's evolutionary history, such expansionist tendencies have been countered by negative feedback. However, the scientific revolution and the use of fossil fuels reduced many forms of negative feedback, enabling us to realize our full potential for exponential growth."

Rees points out our dominance over the planet has made us forget that we are still governed by natural selection. What's more, our natural inclination towards short-term thinking, which served us exceedingly well in our evolutionary past, continues to compel us to take as much as we can possibly get when it's available.
Part 1

This has fueled the excessive consumption and pollution that a portion of the current world population is now responsible for, which is set to increase as financial security and population sizes increase, Rees argues. A changing climate is evidence of the strain the planet is already under but it's only a tiny fraction of the overall problem of overshoot, Rees argues. As Rees points out, as we continue to use an abundance of fossil fuels we're simultaneously ignoring the other symptoms of overshoot too. From our consumption of biomass to the disruption of planetary nutrient cycles, these interlinked problems are all propelling Earth's sixth mass extinction and risking a chaotic break-down of our planet's essential life-support systems.

What's more, our proposed solutions, such as switching to renewables don't actually address the problem of exponential population growth and in fact further contribute to the excess consumption that goes along with it. The question is whether improvements in technology – in everything from combating climate change to increasing food production – are capable of keeping pace with the growing demands our consumption places on the planet. If innovation can't provide solutions, food shortages, habitat instability, war, and disease may well start to make an impact in population numbers, this study predicts. "While no major symptom of overshoot can be adequately addressed in isolation from the others, addressing overshoot directly would reduce all important symptoms simultaneously," Rees explains. Another point that Rees makes – and he's not the first to do so – is that we need to be much more aware of the peril that we're in, and should be working out ways to get a better balance between our give-and-take relationship with the planet. "In the best of all possible worlds, the whole transition might actually be managed in ways that prevent unnecessary suffering of millions (billions?) of people, but this is not happening – and cannot happen – in a world blind to its own predicament," writes Rees.

https://www.mdpi.com/2673-4060/4/3/32

Part 2

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WHO’s first traditional-medicine summit
Yesterday kicked off the first-ever World Health Organization (WHO) summit dedicated to traditional medicine, including disciplines as wide-ranging as Ayurveda, yoga, homeopathy and complementary therapies. Billions of people use traditional healing systems, so some researchers have called for more rigorous science, such as randomized control trials or systematic reviews, to understand these practices and to ensure the safety of products such as herbal medicines. But some scientists worry that the summit will be insufficiently critical, resulting in “the often-before voiced platitudes and wishful thinking”, according to complementary-medicine researcher Edzard Ernst.

https://www.nature.com/articles/d41586-023-02636-z?utm_source=Natur...

Using magnetic rust nanoparticles to clean water

Scientists find way to wipe a cell's memory to better reprogram it as a stem cell

In a study published in Nature,  scientists have resolved a long-standing problem in regenerative medicine. They developed a new method to reprogram human cells to better mimic embryonic stem cells, with significant implications for biomedical and therapeutic uses.

In a revolutionary advance in the mid-2000s, it was discovered that the non-reproductive adult cells of the body, called somatic cells, could be artificially reprogrammed into a state that resembles embryonic stem (ES) cells which have the capacity to then generate any cell of the body.

The ability to artificially reprogram human somatic cells, such as skin cells, into these so-called induced pluripotent stem (iPS) cells provided a way to make an essentially unlimited supply of ES-like cells, with widespread applications in disease modeling, drug screening and cell-based therapies.

However, a persistent problem with the conventional reprograming process is that iPS cells can retain an epigenetic memory of their original somatic state, as well as other epigenetic abnormalities. This can create functional differences between the iPS cells and the ES cells they're supposed to imitate, and specialized cells subsequently derived from them, which limits their use.

Researchers have now developed a new method, called transient-naïve-treatment (TNT) reprogramming, that mimics the reset of a cell's epigenome that happens in very early embryonic development. This significantly reduces the differences between iPS cells and ES cells and maximizes the effectiveness of how human iPS cells can be applied. 

By studying how the somatic cell epigenome changed throughout the reprogramming process, they pinpointed when epigenetic aberrations emerged, and introduced a new epigenome reset step to avoid them and erase the memory.

TNT reprogramming will establish a new benchmark for cell therapies and biomedical research, and substantially advance their progress.

https://www.nature.com/articles/s41586-023-06424-7?utm_medium=affil...

Why Does It Take a While For a Tan to Show Up? Scientists Have Finally Worked It Out

Your skin's response to Sun exposure may seem delayed, but there's a good reason for it, scientists have found.

Through experiments on both human and mouse skin, researchers  have discovered that the development of a tan only occurs after the skin has taken care of emergency DNA repair.

We have two mechanisms designed to protect the skin from exposure to dangerous UV radiation. 

The first mechanism repairs the DNA in the skin cells damaged by the radiation, while the second mechanism involves increased production of melanin, which darkens the skin in order to protect it from future exposure to radiation.

The delay in tanning is a result of resource prioritization. Basically, all of the cell's resources mobilize to repair radiation damage as quickly as possible. It's only once that task is complete that the cell can allocate resources to the production of melanin.

To test this hypothesis, the researchers first exposed human skin, obtained from consenting surgery patients and cultured in petri dishes, to UVB radiation. This was so that they could study the activity in the cell in response to radiation damage. They confirmed that a protein kinase called ATM, activated by DNA damage and critical to cell repair, springs into action shortly after exposure to UVB radiation. That's interesting, but the team needed more information. So, the follow-up step was to trigger the activation of ATM in the absence of UVB exposure and observe the results. This phase of the experiment was conducted on mouse models, and more human skin samples in petri dishes. In both mouse and human skin, a tan developed after an interval, even in the absence of harmful radiation. A close inspection of the cellular processes involved showed that the activation of ATM blocks the activation of the MITF protein responsible for increasing melanin production, so that DNA repair can take precedence.

The genetic information must be protected from mutations, so this repair mechanism takes precedence inside the cell during exposure to ultraviolet radiation from the sun.

The team suspects that DNA repair may even harness some of the components of the pigmentation mechanism in order to maximize the chances of cell survival, and minimize the chances of mutation. The discovery, the team says, could be used to help study, understand, prevent, and treat the effects of skin radiation damage.

https://www.sciencedirect.com/science/article/abs/pii/S0022202X2302...

Parasites Are Actually Vital For Some Species' Survival, Study Shows

Parasites are understandably unpopular. Some cause horrible illnesses in their hosts, and even the less dangerous ones are often creepy or gross.

While they can be monsters, parasites aren't all bad. Many organisms benefit from species that survive by sucking the very life from others. Even their hosts might get a kickback or two.
Now a new study suggests some species can only survive in certain habitats if parasites are there, too.

Parasites come in many shapes and sizes, from viruses and amoebae to plants like mistletoe and animals like nematodes or mosquitoes. They all use a host for resources, which they typically harm but don't kill. As the late entomologist E.O. Wilson put it, parasites are "predators that eat prey in units of less than one."

Similar to the way predators can help regulate their overall ecosystem, parasites often provide overlooked ecological services that are only obvious in their absence.
the horrors of individual parasitic infections belie the surprising value these creatures offer for their broader community.

"Parasites and pathogens are an integral part of any ecosystem. Despite their bad reputation, parasites play a key role in shaping population dynamics, community structure, and biodiversity, thanks to their influence on the balance between the species in that ecosystem
Part 1

In a new study, researchers focused on how parasites influence populations of tiny crustaceans commonly called "water fleas," from the genus Daphnia.
Daphnia grow up to 5 millimeters long, inhabiting various freshwater habitats where they feed on single-celled algae, bacteria, and protists. In turn, they serve as a food source for other larger aquatic species, like fish, tadpoles, and insects.

Using two Daphnia species with differing levels of parasite resistance, the researchers tested how the presence of parasites affected an ecological phenomenon known as the competitive exclusion principle, or Gause's law, among the water fleas.

Biodiversity is a key feature of healthy ecosystems, Orlansky and Ben-Ami note, and related species can share space if their relationships with predators and natural resources are different enough.

According to Gause's law, however, two species with identical niches in the same habitat can't coexist indefinitely at constant levels. If they're too similar, even a small advantage can help one species dominate, leaving others to eventually die out or seek a different niche.
The Daphnia species in this study are adapted to small rock pools – relatively enclosed habitats where many aquatic lifeforms can't migrate or come and go on their own.
Part 2

This tightens competition among the creatures living there, the researchers explain, making rivalry a big factor in determining the pools' biodiversity. With so few other niches to fall back on, any species that can't compete will struggle to survive.

Most animals serve as hosts or carriers for parasites of some kind, and water fleas are no exception. It's rare to find a species with nearly total parasite resistance, yet the study did include one Daphnia species with an almost supernatural ability to withstand parasites.

"In the population of water fleas in Israel, we found one species called Daphnia similis, whose nickname in the laboratory is 'Super Daphnia' due to its almost complete resistance to parasites.
Nevertheless, this 'Super Daphnia' does not become the dominant Daphnia species in ponds.
The most common species is actually Daphnia magna, which is highly vulnerable to a wide variety of parasites."

To figure out why, the researchers simulated an ecosystem in the lab, placing the two Daphnia species together in habitats either with or without parasites.

In a habitat free of parasites, not only did the parasite-sensitive D. magna outcompete its parasite-resistant relative, the study found, but it was the only Daphnia left standing.
Things played out differently in habitats with parasites, however, where D. magna proved less dominant and Super Daphnia managed to establish a population and coexist with D. magna – thanks to a little help from parasites.

"The results of these experiments emphasize the important role of parasites in shaping biodiversity, as the parasites can mediate competition between Daphnia species.
Although Super Daphnia excels at resisting parasites, its overall competitive ability still doesn't match that of D. magna and without parasites it "would probably become extinct when it shares the same habitat."
This work shows that coexistence of these two Daphnia species is only possible through the mediation of a parasite..
By learning details like this about the ecological sway of parasites, the researchers say, we may gain new insights to help us fend off invasive species or better protect endangered wildlife.

https://www.frontiersin.org/articles/10.3389/fmicb.2023.1135252/full

Part 3

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India Is About to Attempt Its First Ever Moon Landing Can anybody else ever feel the same way Neil Armstrong felt when he first stepped on the moon? Or how Watson, Rosalind Franklin and Crick felt when they first discovered the double helix of DNA? Their experiences are mind blowing and no amount of money can buy you that thrill. Can anybody feel the same way scientists feel when they discover/invent something for the first time and report it to the world? NO. Nothing in this world compares to it. Experience at least some of it when the Indian Space Research Organisation (ISRO) mission Chandrayaan-3 will deploy its lander and rover to the surface of the Moon on 23rd Aug. Chandrayaan-3, is all set to make a soft and successful landing on the south polar region of the Moon around 6.04pm today, August 23. In case of 'unfavourable conditions' the landing may be postponed to August 27. But that is not on the cards right now. Viewers can watch the live landing on the ISRO website, its YouTube channel, Facebook, and public broadcaster DD National TV starting at 5:27 PM (IST) on August 23 (today). Every success by a space agency means more free-to-use data for both the scientific community and the public. Come join us on this epic journey.

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Gravitational Waves: Ripples In Space-Time

 Quantum entanglement of photons captured in real-time

Researchers  recently demonstrated a novel technique that allows the visualization of the wave function of two entangled photons, the elementary particles that constitute light, in real-time.

Using the analogy of a pair of shoes, the concept of entanglement can be likened to selecting a shoe at random. The moment you identify one shoe, the nature of the other (whether it is the left or right shoe) is instantly discerned, regardless of its location in the universe. However, the intriguing factor is the inherent uncertainty associated with the identification process until the exact moment of observation.

The wave function, a central tenet in quantum mechanics, provides a comprehensive understanding of a particle's quantum state.  For instance, in the shoe example, the "wave function" of the shoe could carry information such as left or right, the size, the color, and so on.

More precisely, the wave function enables quantum scientists to predict the probable outcomes of various measurements on a quantum entity, e.g. position, velocity, etc.

This predictive capability is invaluable, especially in the rapidly progressing field of quantum technology, where knowing a quantum state which is generated or input in a quantum computer will allow to test the computer itself. Moreover, quantum states used in quantum computing are extremely complex, involving many entities that may exhibit strong non-local correlations (entanglement).

Knowing the wave function of such a quantum system is a challenging task—this is also known as quantum state tomography or quantum tomography in short. With the standard approaches (based on the so-called projective operations), a full tomography requires large number of measurements that rapidly increases with the system's complexity (dimensionality).

Previous experiments conducted with this approach by the research group showed that characterizing or measuring the high-dimensional quantum state of two entangled photons can take hours or even days. Moreover, the result's quality is highly sensitive to noise and depends on the complexity of the experimental setup.

Part 1

The projective measurement approach to quantum tomography can be thought of as looking at the shadows of a high-dimensional object projected on different walls from independent directions. All a researcher can see is the shadows, and from them, they can infer the shape (state) of the full object. For instance, in CT scan (computed tomography scan), the information of a 3D object can thus be reconstructed from a set of 2D images.

In classical optics, however, there is another way to reconstruct a 3D object. This is called digital holography, and is based on recording a single image, called interferogram, obtained by interfering the light scattered by the object with a reference light.

Researchers now  extended this concept to the case of two photons.

Reconstructing a biphoton state requires superimposing it with a presumably well-known quantum state, and then analyzing the spatial distribution of the positions where two photons arrive simultaneously. Imaging the simultaneous arrival of two photons is known as a coincidence image. These photons may come from the reference source or the unknown source. Quantum mechanics states that the source of the photons cannot be identified. This results in an interference pattern that can be used to reconstruct the unknown wave function. This experiment was made possible by an advanced camera that records events with nanosecond resolution on each pixel.

This method is exponentially faster than previous techniques, requiring only minutes or seconds instead of days. Importantly, the detection time is not influenced by the system's complexity—a solution to the long-standing scalability challenge in projective tomography.

The impact of this research goes beyond just the academic community. It has the potential to accelerate quantum technology advancements, such as improving quantum state characterization, quantum communication, and developing new quantum imaging techniques.

Danilo Zia et al, Interferometric imaging of amplitude and phase of spatial biphoton states, Nature Photonics (2023). DOI: 10.1038/s41566-023-01272-3

Part 2

Bilinguals may have a memory advantage

In any communication, we generate myriad predictions regarding what we are about to hear. To begin with—when we only have one or two letters to go on—the pool of potential candidate words is massive. The more letters we guess correctly, the more the pool of candidate words narrows down, until our brain clicks and we find the right word.

In natural communication, we rarely wait to hear the entire word before we begin to plan what to say back. As soon as we hear the first sounds of a word, our brain uses this information, and together with other clues—such as frequency, context and experience—fills in the blanks, cutting down from a vast list of potential candidate words to predict the target word. But what if you are a bilingual with languages that have similar sounding words? Well, then, the list of candidate words is much larger. This may sound negative—making it more difficult to predict words. But a new study, published in Science Advances, has revealed that this may actually give bilinguals an advantage when it comes to memory.

The languages of a bilingual are interconnected. The same neural apparatus that processes our first language also processes our second language. So it is easy to see why, upon hearing the first sounds of a word, potential candidate words are activated, not only from one language, but from the other one as well.

For instance, upon hearing the sounds "k" and "l", a Spanish-English bilingual will automatically activate both the words "clock" and "clavo" (nail in Spanish). This means the bilingual has a tougher cutting down job to do in order to settle on the correct word, simply because there is more to cut down to get to the target. It is not surprising then that bilinguals usually take more time to retrieve or recognize words in psychological and linguistic experiments.

The findings showed that recognition memory for objects with many competitors (such as beaker, beetle, speaker) was enhanced relative to items with low competitors (such as carriage) in both monolinguals and bilinguals. In addition, bilinguals showed the effect for cross-language competitors as well (for example clock, clavo)—giving an overall memory advantage.

Interestingly, second language proficiency played a crucial role. The memory advantage was most profound in bilinguals with high second language proficiency than in bilinguals with low second language proficiency and monolinguals. Clearly, to play bilingual hangman efficiently, you need to develop high proficiency in the second language, so that its words become competitors alongside those of the first language.

Part 1

The eye tracking data confirmed that items with more competitors were looked at the longest, which led to the memory advantage for those items later on. These findings show that the bilingual cognitive system is highly interactive and can impact other cognitive components such as recognition memory.

Other studies also show enhanced memory processing in bilinguals relative to monolinguals in categorization tasks that require suppressing distracting information. This could certainly indicate that bilinguals are more efficient at multi-tasking and more able to focus on the task at hand, especially when the task requires ignoring irrelevant information (think trying to work in a noisy café).

The picture that emerges is one where bilingualism is a cognitive tool that enhances basic cognitive functions, such as memory and categorization. Bilingual hangman is a tougher game, but one that, ultimately, pays off.

Now  what about multilinguals like me?

Matias Fernandez-Duque et al, Speakers of different languages remember visual scenes differently, Science Advances (2023). DOI: 10.1126/sciadv.adh0064

Part 2

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Silica particles found in food and makeup could be chemically reactive, study finds

New research has revealed that the mineral silica, a common food additive and popular cosmetics ingredient, is not a chemically inert substance, as has long been supposed.

As described in a new study, researchers placed commercially available silica particles in a water solution with biomolecules containing compounds called thiols. These thiol-containing biomolecules are widespread in nature and in the human body, for instance, in the form of glutathione, a key antioxidant found in most cells. When exposed to silica, the thiol biomolecules underwent redox chemical reactions. These reactions, in which electrons are lost, could degrade or alter the molecules' function, potentially posing health risks. For instance, low levels of glutathione can lead to increased oxidative stress in the body that can damage all manner of cellular components, from membranes to DNA.

The findings highlight the need for further research into the reactivity of silica, especially given its extensive usage in everyday products.

Silica—another name for compounds of silicon and oxygen—is a colorless, odorless, tasteless material. While silica occurs naturally in foods including leafy greens, manufacturers often add tiny, sand-like particles of silica as an anticaking agent to soups and coffee creamers, for instance. 

For cosmetics, including skin care products, silica serves as a bulking or absorbing agent, or as an abrasive in scrubs. In health care, silica particles have also found significant use in the delivery of drugs and for medical imaging purposes. For those applications, silica particles are manufactured to have tiny holes, or pores, into which pharmaceuticals and other substances can be slotted.

For the study, the  researchers purchased commercially available, pure silica particles, sold as a dry powder.

Yangjie Li et al, Silica particles convert thiol-containing molecules to disulfides, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2304735120

Teens Who Smoke Show Reduced Brain Matter, Scientists Discover

Neurological imaging reveals people more inclined to begin smoking as teenagers tend to have reduced gray matter in two important brain regions, indicating they may play a significant role in inhibition and addiction.

An international team of researchers compared MRI brain scans from over 800 people, collected from the UK, Germany, France and Ireland across different time points. These volunteers also answered questionnaires on personality traits. The researchers then compared those who began smoking by age 14 with non-smokers and repeated this again with the same patients at ages 19 and 23. The images revealed those who took up smoking from the age of 14 had comparitively less gray matter in the left ventromedial prefrontal cortex; a part of the brain involved in emotional regulation, decision-making, and self-control. Scans taken five years later revealed the opposite part of this same brain region (on the right) was also reduced in the smoker group compared to non-smokers. This side of the ventromedial prefrontal cortex has also been linked to pleasure. The ventromedial prefrontal cortex is a key region for dopamine, the brain's pleasure chemical. As well as a role in rewarding experiences, dopamine has long been believed to affect self-control.

https://www.nature.com/articles/s41467-023-40079-2

Caffeine in Your Blood May Affect Body Fat And Diabetes Risk, Study Finds

The levels of caffeine in your blood could affect the amount of body fat you carry, a factor that in turn could determine your risk of developing type 2 diabetes and cardiovascular diseases. Those are the findings of a recent study that used genetic markers to establish a more definitive link between caffeine levels, BMI, and type 2 diabetes risk. The researchers suggest that calorie-free caffeinated drinks could be explored as a potential means of helping reduce body fat levels. Genetically predicted higher plasma caffeine concentrations were associated with lower BMI and whole body fat mass. Furthermore, genetically predicted higher plasma caffeine concentrations were associated with a lower risk of type 2 diabetes. Approximately half of the effect of caffeine on type 2 diabetes liability was estimated to be mediated through BMI reduction. In general, those with variations affecting the genes – namely CYP1A2 and a gene that regulates it, called AHR – tend to break caffeine down more slowly, allowing it to remain in the blood longer. Yet they also tend to drink less caffeine in general.

https://bmjmedicine.bmj.com/content/2/1/e000335

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First complete sequence of a human Y chromosome

For decades, the Y chromosome—one of the two human sex chromosomes—has been notoriously challenging for the genomics community to sequence due to the complexity of its structure.

Now, this elusive area of the genome has been fully sequenced, a feat that finally completes the set of end-to-end human chromosomes and adds 30 million new bases to the human genome reference, mostly from challenging-to-sequence satellite DNA. These bases reveal 41 additional protein-coding genes, and provide crucial insight for those studying important questions related to reproduction, evolution, and population change.

The complete, annotated Y chromosome reference is available for use on the UCSC Genome Browser and can be accessed via Github.

When scientists and clinicians study an individual's genome, they compare the individuals' DNA to that of a standard reference to determine where there is variation. Until now, the Y chromosome portion of the human genome has contained large gaps which made it difficult to understand variation and associated disease.

The structure of the Y chromosome has been challenging to decode because some of the DNA is organized in palindromes—long sequences that are the same forward and backward—spanning up to more than a million base pairs. Moreover, a very large part of the Y chromosome that was missing from the previous version of the Y reference is satellite DNA—large, highly repetitive regions of non-protein-coding DNA. On the Y chromosome, two satellites are interlinked with each other, further complicating the sequencing process.

The researchers were able to achieve a gapless read of the Y chromosome due to advances in long-read sequencing technology and new, innovative computational assembly methods that could deal with the repetitive sequences and transform the raw data from sequencing into a usable resource.

These new method assemblies allowed the team to tackle some of the particularly challenging aspects of the Y chromosome, such as pinpointing precisely where an inversion occurs in a palindromic sequence—a technique that can be used to find other inversions. The methods established in the paper will allow scientists to complete more end-to-end reads of human Y chromosomes to get a better understanding of how this genetic material affects the diverse human population.

The complete Y chromosome reference will allow scientists to better study a myriad of features about this part of the human genome in a way that has never before been possible.

The complete sequence of a human Y chromosome, Nature (2023). DOI: 10.1038/s41586-023-06457-y. www.nature.com/articles/s41586-023-06425-6. On bioRxiv: DOI: 10.1101/2022.12.01.518724

How a cup of water can unlock the secrets of our universe

Researchers have made a discovery that could change our understanding of the universe. In their study published in Science Advances, they reveal, for the first time, that there is a range in which fundamental constants can vary, allowing for the viscosity needed for life processes to occur within and between living cells. This is an important piece of the puzzle in determining where these constants come from and how they impact life as we know it.

In 2020, the same scientists found that the viscosity  of liquids is determined by fundamental physical constants, setting a limit on how runny a liquid can be. Now this result is taken into the realm of life sciences.

Fundamental physical constants shape the fabric of the universe we live in. Physical constants are quantities with a value that is generally believed to be both universal in nature and to remain unchanged over time—for example the mass of the electron. They govern nuclear reactions and can lead to the formation of molecular structures essential to life, but their origin is unknown. This research might bring scientists one step closer to determining where these constants come from.

Understanding how water flows in a cup turns out to be closely related to the grand challenge to figure out fundamental constants. Life processes in and between living cells require motion and it is viscosity that sets the properties of this motion. If fundamental constants change, viscosity would change too impacting life as we know it. For example, if water was as viscous as tar life would not exist in its current form or not exist at all. This applies beyond water, so all life forms using the liquid state to function would be affected.

Any change in fundamental constants including an increase or decrease would be equally bad news for flow and for liquid-based life. We expect the window to be quite narrow: for example, viscosity of our blood would become too thick or too thin for body functioning with only a few percent change of some fundamental constants such as the Planck constant or electron charge.

Surprisingly, the fundamental constants were thought to be tuned billions of years ago to produce heavy nuclei in stars and back then life as we know it today didn't exist. There was no need for these constants to be fine-tuned at that point to also enable cellular life billions of years later, and yet these constants turn out to be bio-friendly to flow in and between living cells. An accompanying conjecture is that multiple tunings may have been involved and this then suggests a similarity to biological evolution where traits were acquired independently. Through evolutionary mechanisms, fundamental constants may be the result of nature arriving at sustainable physical structures. It remains to be seen how the principles of evolution can be helpful to understand the origin of fundamental constants.

Kostya Trachenko, Constraints on fundamental physical constants from bio-friendly viscosity and diffusion, Science Advances (2023). DOI: 10.1126/sciadv.adh9024. www.science.org/doi/10.1126/sciadv.adh9024

Evidence of carbonic acid found in interstellar space for the first time

An international team of astrophysicists, astronomers and chemists has found evidence of carbonic acid (HOCOOH) in interstellar space, marking the first time it has been detected in such a setting. In their paper published in The Astrophysical Journal, the group describes their discovery, where it was found, and what it might mean for research into the origins of life.

Prior research has led to the discovery of acetic and formic acid in interstellar space; both are carboxylic acids, as is carbonic acid. All three are believed to be building blocks of life. Finding them in such distant places gives credence to theories that suggest that they were delivered to Earth via comets or meteorites. In this new effort, the researchers were studying the molecular cloud G+0.693-0.027 near the center of the Milky Way when they found evidence of HOCOOH.

Carboxylic acids have a carbon atom and are doubly bonded to an oxygen atom. They are also singly bonded to a hydroxyl group. Carbonic acid is formed here on Earth when CO2 mixes and dissolves in water. It produces the acidic effect in soft drinks. It is also responsible for the increasing acidity of the oceans due to increased amounts of atmospheric CO2. The research team notes that carbonic acid has been observed on several of Jupiter's moons, on comets and on Mercury and Mars—but this is the first time it has been detected in interstellar space. They also note that the presence of carbonic acid in an interstellar molecular cloud suggests a high degree of complexity in the interstellar medium, which means it may also harbor amino-acid-related compounds.

They also found an upper limit to the abundance of HOCOOH with respect to diatomic hydrogen in the molecular cloud, which they suggest hints at the possibility that carbonic acid may be abundant in interstellar space. They note that one of the reasons carbonic acid has not been spotted in interstellar space until now, despite its apparent abundance, is that it is undetectable by radio astronomical observations.

 Miguel Sanz-Novo et al, Discovery of the Elusive Carbonic Acid (HOCOOH) in Space, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/ace523

Spectroscopy, Explained

Scientists discover a previously unknown way cells break down proteins

Short-lived proteins control gene expression in cells to carry out a number of vital tasks, from helping the brain form connections to helping the body mount an immune defense. These proteins are made in the nucleus and are quickly destroyed once they've done their job.

Despite their importance, the process by which these proteins get broken down and removed from cells once they are no longer needed has eluded scientists for decades—until now.

It is well established that cells can break down proteins by tagging them with a small molecule called ubiquitin. The tag tells the proteasome that the proteins are no longer needed, and it destroys them. 

However, sometimes the proteasome breaks down proteins without the help of ubiquitin tags, leading researchers to suspect that there was another, ubiquitin-independent mechanism of protein degradation.

Researchers now  identified a protein called midnolin that plays a key role in degrading many short-lived nuclear proteins. The study shows that midnolin does so by directly grabbing the proteins and pulling them into the cellular waste-disposal system, called the proteasome, where they are destroyed.

Because the proteins broken down by this process modulate genes with important functions related to the brain, the immune system, and development, scientists may eventually be able to target the process as a way of controlling protein levels to alter these functions and correct any dysfunction.

Xin Gu et al, The midnolin-proteasome pathway catches proteins for ubiquitination-independent degradation, Science (2023). DOI: 10.1126/science.adh5021.

Study shows that astrocytes in the cortex modulate the dominant behavior of male mice

The social behavior of animals has been the key focus of extensive neuroscience and biomedical studies, as it is often aligned with behaviors observed in humans. Better understanding these behaviors and the neural processes underpinning them could ultimately also have implications for the treatment of different psychiatric disorders that affect how humans socialize with others.

Researchers recently conducted a study specifically exploring male dominance behavior among male mice. These behaviours naturally lead to the formation of social hierarchies among groups of mice, with some males accessing more food and water than others. 

A recent paper, published in Nature Neuroscience, highlights the role of astrocytes in the outer layer of the brain (i.e., the cortex), in modulating the dominance behavior of male mice. In addition, it sheds some light on the specific neural processes through which astrocytes modulate these behaviours.

The results gathered by the researchers hint at the involvement of communication between dmPFC astrocytes and neurons in the dominant behaviour of male mice. 

This work implies that astrocytes also play critical role in computing and processing high-order brain functions. It also suggests that such intercellular interplay may decipher the etiology of many psychiatric disorders.

 Kyungchul Noh et al, Cortical astrocytes modulate dominance behavior in male mice by regulating synaptic excitatory and inhibitory balance, Nature Neuroscience (2023). DOI: 10.1038/s41593-023-01406-4

Nguyen T. Phi et al, Control of social hierarchy beyond neurons, Nature Neuroscience (2023). DOI: 10.1038/s41593-023-01392-7

 Unlocking the secrets to brain diseases: When proteins get stuck at the solid phase

Many diseases affecting the brain and nervous system are linked to the formation of protein aggregates, or solid condensates, in cells from their liquid form condensate, but little is known about this process.

This liquid-to-solid transition can trigger the formation of what are called amyloid fibrils. These can further form plaques in neurons causing neurodegenerative diseases such as Alzheimer's.

Biomedical Engineers have now developed sophisticated optical techniques to monitor at close range the process by which these protein aggregates form.

By testing a protein associated with amyotrophic lateral sclerosis—ALS disease, which affected astrophysicist Professor Stephen Hawking—the Sydney engineers closely monitored the transition of this protein from its liquid to solid phase.

Proteins regularly form condensates during liquid-to-liquid phase separation in a wide range of critical and healthy biological functions, such as the formation of human embryos. This process assists biochemical reactions where protein concentrations are critical and also promotes healthy protein–protein interactions. However, this process also increases the risk of dysfunctional aggregation, where unhealthy aggregates of solid proteins form in human cells.

This can lead to aberrant structures associated with neurodegenerative diseases because the proteins no longer exhibit rapid reversibility back to liquid form.  It is therefore crucial to monitor condensate dynamics, as they directly affect pathological states.

The world-first nanoscale optical observation of this process has allowed the team to determine that the transition from liquid to solid protein starts at the interface of the protein condensates. This window onto the phase transition also revealed that the internal structures of these protein agglomerates are heterogenous, where previously they were thought to be homogeneous.

Yi Shen et al, The liquid-to-solid transition of FUS is promoted by the condensate surface, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2301366120