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Precision tumor imaging with a fluorescence probe and engineered enzymes

Successful cancer surgery depends on a surgeon’s ability to remove tumors, while minimizing harm to healthy tissues. Surgeons currently use glowing dyes which mark cancer cells to help differentiate from healthy cells, but these dyes aren’t perfect and will light up some healthy tissues too. For the first time, researchers including those from the University of Tokyo developed what they call a bioorthogonal fluorescence probe and a matching reporter enzyme that can activate the probe selectively at targeted tumor sites. This enables high-contrast tumor visualization with very low background. This study was performed in mice.

Cancer is a universal issue which affects uncountably many people around the world. Many will turn to surgery in the hope a surgeon will be able to completely remove a tumor leaving healthy tissues unaffected. Various tools and techniques have been developed over the years to improve the way these surgeries are performed, and visual imaging methods such as glowing dyes have proven to be very useful. But one drawback is that some probes can also be activated in healthy tissues by endogenous enzymes, creating background fluorescence and making it harder to judge what should be removed. The opposite is also possible, where cancer cells are left unmarked and are missed during surgery, increasing the chance of recurrence.

“Our group acknowledged this current shortcoming and improved upon this way to make cancer cells light up inside the body. In tests on mice, we delivered a special enzyme to tumors and used a fluorescence probe that only turns on when that enzyme is present,” said Associate Professor Ryosuke Kojima from the Laboratory of Chemical Biology and Molecular Imaging at the University of Tokyo. “Older probes often light up healthy tissue by mistake, creating background noise, but our highly selective, or bioorthogonal, dye probe is designed to stay completely off unless it meets its matching engineered enzyme. We essentially trained the enzyme through repeated mutation and selection, a form of directed evolution, so it could activate the probe strongly enough to work inside living animals.”

Microbes harvest metals from meteorites aboard space station

If humankind is to explore deep space, one small passenger should not be left behind: microbes. In fact, it would be impossible to leave them behind, since they live on and in our bodies, surfaces and food. Learning how they react to space conditions is critical, but they could also be invaluable fellows in our endeavor to explore space.

Microorganisms such as bacteria and fungi can harvest crucial minerals from rocks and could provide a sustainable alternative to transporting much-needed resources from Earth.

Researchers from Cornell and the University of Edinburgh collaborated to study how those microbes extract platinum group elements from a meteorite in microgravity, with an experiment conducted aboard the International Space Station. They found that “biomining” fungi are particularly adept at extracting the valuable metal palladium, while removing the fungus resulted in a negative effect on nonbiological leaching in microgravity.

Pearls & Oy-sters: Reversible Leukoencephalopathy and Parkinsonism Due to CNS Involvement in Cryoglobulinemia

What is metabolic dysfunction–associated steatotic liver disease?

Metabolic dysfunction–associated steatotic liver disease (MASLD) involves accumulation of fat in the liver and may progress to liver inflammation and scarring.

The main risk factors for MASLD are obesity and type 2 diabetes.

Usually people with MASLD show no symptoms but some may feel tired or have pain or discomfort in the upper right side of their abdomen.

Eating a low-carbohydrate, low-fat, and low-calorie diet; avoiding alcohol; and exercise are the first-line of treatment for MASLD. sciencenewshighlights ScienceMission https://sciencemission.com/What-Is–MASLD

This JAMA Patient Page describes metabolic dysfunction–associated steatotic liver disease (MASLD) and its risk factors, symptoms and complications, diagnosis, and treatment.

Continue reading “Pearls & Oy-sters: Reversible Leukoencephalopathy and Parkinsonism Due to CNS Involvement in Cryoglobulinemia” | >

How an overlooked electrostatic force could drive the motor of the future

When we hear about moving objects with electricity, most of us imagine a “pulling force.” Positive and negative charges attract each other, drawing objects together. It is natural to think that this attractive force—known as electrostatic force—is what makes things move.

However, this force is not very strong, and it has not been suitable for driving large machines in our daily lives. For that reason, most practical motors rely on a different mechanism. For example, the motors in electric fans and electric vehicles do not use electricity directly to create motion. Instead, they use electricity to generate a magnetic field, and then use that magnetic force to rotate.

Neutrons Illuminate the Magnetic Dance of Chiral Phonons

Neutron scattering has provided a new and broader view of the twirling collective atomic vibrations in a magnetic crystal.

Phonons—quantized conveyors of sound and heat in solids—are usually visualized as collective vibrations in which atoms simply bounce back and forth, almost as if they were weights on springs. However, atoms can sometimes form “chiral phonons” that twirl and swivel clockwise or counterclockwise, in a way that resembles a coordinated dance [1]. When these circular, chiral motions entrain ionic charge, they generate a magnetic moment, which suggests that there might be a way to control sound and heat using magnetic fields. Until recently, this magnetic dance was primarily observed using optical techniques, granting access to only one corner of the “stage”—the point in the phonon’s momentum space where the momentum is nearly zero. Song Bao of Nanjing University in China and his collaborators have now broadened the view of momentum space by using inelastic neutron spectroscopy.

NASA’s MAVEN detects first evidence of lightning-like activity on Mars

While sifting through the extensive data collected by NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft over the last decade, scientists discovered a familiar type of electromagnetic signal commonly caused by lightning. This rare find represents the first direct indication of lightning activity on Mars. The team recently published their findings in Science Advances, where they describe the event and why it’s so difficult to detect lightning-like activity on Mars.

Whistler waves are low-frequency radio wave signals generated by lightning, which create an impulse that propagates through a planet’s magnetosphere, following along the magnetic field lines. The whistler waves disperse due to the slower velocity of the lower frequencies through the plasma of the ionosphere and magnetosphere. These waves are typical on Earth, but have also been observed on Jupiter, Saturn and Neptune. All of these planets all possess strong magnetic fields and corresponding magnetospheres, facilitating the movement of whistler waves.

Mars, on the other hand, does not have a global, Earth-like magnetic field. This is because the internal activity that causes these magnetic fields ceased on Mars billions of years ago. This may contribute to the fact that lightning-like discharges in the Martian atmosphere have not yet been observed. But lightning-like activity on Mars is not impossible.

Superfluids emerge in 2D moiré crystal formed from time, study predicts

Conventional crystals are materials in which atoms arrange themselves in repeating spatial patterns. Time crystals, on the other hand, are phases of matter characterized by repeating motions over time without constantly heating up, breaking a physical rule known as time-translation symmetry.

Researchers at East China Normal University and Shanghai Jiao Tong University recently predicted the formation of a new type of time crystal, dubbed a two-dimensional (2D) moiré time crystal. This crystal was theorized to emerge when periodic perturbations (i.e., regular, repeated disturbances) are applied to ultracold atoms held in a smooth, continuous trap, as opposed to an optical lattice trap. The paper is published in the journal Physical Review Letters.

“We were inspired by two exciting concepts in physics,” Keye Zhang, professor at East China Normal University and co-senior author of the paper, told Phys.org. “The first is the concept of ‘twistronics,’ where twisting atom-thin layers creates moiré patterns with exotic material properties. While the second is that of ‘time crystals’ (a new phase of matter with persistent rhythmic motion). We wondered: could we combine these ideas by treating time itself as a dimension that can be ‘twisted’?”

Physicists discover long-predicted ‘clock magnetism’ in an atomically thin crystal

Strange things happen to materials when you peel them down, layer by layer, from thick chunks all the way to sheets just an atom thick. Reporting in the journal Nature Materials, a team led by physicists at The University of Texas at Austin has experimentally demonstrated a sequence of exotic magnetic phases in an ultrathin material that fully realizes, for the first time, a theoretical model of two-dimensional magnetism first proposed in the 1970s. The researchers say the advance might inspire new ultracompact technologies.

The sequence of exotic magnetic phases involves two key transitions that occur as certain materials cool down towards absolute zero. Both transitions have been observed experimentally on their own before, but never together in a complete sequence.

When the researchers cooled an atomically thin sheet of nickel phosphorus trisulfide (NiPS3) to temperatures between −150 and −130° C, the material entered the first special magnetic phase, called a Berezinskii–Kosterlitz–Thouless (BKT) phase. In this regime, the magnetic orientations associated with individual atoms in the material—known as magnetic moments—form swirling patterns called vortices. Pairs of these vortices wind in opposite directions, one clockwise and the other counterclockwise, and remain tightly bound together.

3D-printed ‘plug’ links fiber optics to photonic chips with low loss

Physicists and chemists at Heidelberg University have realized a photonic microchip that is driven by light just as easily as electronic components via a “plug.” Their development could serve as the basis for fast and cost-effective production of photonic integrated systems that are of great importance for implementing innovative computing and communications systems.

Prof. Dr. Wolfram Pernice of the Kirchhoff Institute for Physics headed up the research on this novel coupling concept for light-controlled chips. The results appear in the journal Science Advances.

Smart fluorescent molecules provide cheaper path to sharper microscopy images

Multiphoton microscopy is used in biomedical research to study cells and tissues. Today, so-called two-photon microscopy is used to study processes within cells, but the technique has limitations in terms of image resolution. Four-photon microscopy provides images with higher resolution. However, such instruments are very expensive and, when studying biological material, the powerful laser light required can damage samples.

“In this project, we have developed molecules to visualize molecular-level details and monitor processes using the more common two-photon microscopy technique. These molecules have the capacity to achieve higher resolution than with four-photon microscopy, although two-photon microscopy is used,” says the project coordinator Joakim Andréasson, Professor at the Department of Chemistry and Chemical Engineering at Chalmers University of Technology.

“In the long term, results from studies of this kind may provide new insights into diseases, pharmaceuticals and the very smallest building blocks of life.”

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