. Scientific Frontline

Thursday, September 28, 2023

Purdue researchers develop a new type of intelligent architected materials for industry applications

Products made with intelligent architected materials developed at Purdue University have the ability to change from one stable configuration to another stable configuration and back again. The technology is being tested in new aircraft runway mats, nonpneumatic tires and other applications.
Image Credit: Provided by the researchers. Courtesy of Purdue University

Purdue University civil engineering researchers have developed patent-pending intelligent architected materials that can dissipate energy caused by bending, compression, torque and tensile stresses, avoiding permanent plastic deformation or damage, and may also exhibit shape memory properties that allow them to have actuation capacity.

Avoiding damage makes the material reusable and improves human safety and structure durability in products across several industrial sectors.

Pablo Zavattieri, the Jerry M. and Lynda T. Engelhardt Professor in Civil Engineering, leads the research team that has developed this new class of intelligent architected materials.

“These materials are designed for fully recoverable, energy-dissipating structures, akin to what is referred to as architected shape memory materials, or phase transforming cellular materials, known as PXCM,” Zavattieri said. “They can also exhibit intelligent responses to external forces, changes in temperature and other external stimuli.”

Intelligent architected materials such as these have a wide range of potential applications due to their unique properties.

Hunting anything that flies

Pillar from Göbekli Tepe depicting a vulture with its wings spread. 
Photo Credit: © Nadja Pöllath / SNSB-SPM

Birds were an important source of food for hunter-gatherer communities in Upper Mesopotamia at the beginning of the Neolithic period. Besides mammals, ranging from aurochs to hares, or fish, foragers also pursued an impressively large spectrum of bird species in Southeast Anatolia 11,000 years ago. They were hunted mainly, but not exclusively, in autumn and winter – at the time of year, when many bird species form larger flocks and migratory birds cross the area. The species lists are therefore very extensive: At the famous Early Neolithic settlement and the world's oldest temple complex of Göbekli Tepe, for example, c. 18 km northeast of present-day Şanlıurfa (SE Anatolia, Turkey), the researchers identified the remains of at least 84 bird species. Dr. Nadja Pöllath, curator at the Bavarian State Collection for Palaeoanatomy (Staatssammlung für Paläoanatomie München SNSB-SPM) and Prof. Joris Peters, chair of the Institute for Palaeoanatomy, Domestication Research and History of Veterinary Medicine at LMU München and director of the state collection, identified the Neolithic bird bones with the aid of the reference skeletons of the state collection.

The researchers were surprised by the large number of small passerine birds identified at Göbekli Tepe, comprising mainly starlings and buntings. In principle, the Early Neolithic inhabitants of Göbekli Tepe hunted birds in all habitats – mainly in the open grassland and wooded steppe in their direct surroundings, but also in the wetlands and gallery forest somewhat further away.

Listening to atoms moving at the nanoscale

Professor Jan Seidel and his research lab have been using specialised techniques to listen to atoms moving.
Photo Credit: UNSW FLEET Centre.

Understanding how the phenomenon of ‘crackling noise’ occurs at the microscopic scale could have implications for new research in materials science and medicine.

Scientists from UNSW Sydney and the University of Cambridge have used novel methods to listen to the sounds of atoms moving under pressure – a phenomenon known as ‘crackling noise’.

These atomic movements occur in avalanches – they are similar to snow avalanches, but made of atoms – and follow very well-defined statistical rules.

Crackling noise can be observed every day, from crumpling paper and candy wrapping, to the crackling of your cereal, as well as in natural occurrences, such as earthquakes.

In a study recently published in Nature Communications, Professor Jan Seidel and his lab, from the School of Material Science and Engineering, were able to record the crackling noise of just a few hundred atoms, in experiments that lasted over eight hours.

Parkinson’s: are our neurons more vulnerable at night?

More dopaminergic neurons in the adult Drosophila brain survive in control flies (left) than in flies mutant for the circadian cycle (right).
Image Credit: © Lou Duret

Disturbances in sleep patterns and the internal biological clock are frequently associated with Parkinson’s disease. However, the link between biological rhythm and neuronal degeneration remains unclear. A team from the University of Geneva (UNIGE) investigated the destruction of neurons at different times of the day, using the fruit fly as a study model. The scientists discovered that the type of cellular stress involved in Parkinson’s disease was more deleterious to neurons when it occurred at night. This work can be read in the journal Nature Communications.

Parkinson’s disease is a progressive neurodegenerative disorder characterized by the destruction of certain neurons in the brain: dopamine neurons. The main symptoms of this disease are tremors, slowness of movement and muscular stiffness. Epidemiological studies show that other disorders may be associated, such as disturbances of sleep and of the circadian cycle.

This cycle, defined by the alternate periods of wakefulness and sleep, lasts around 24 hours and constitutes the human body’s internal clock that regulates almost all its biological functions. In particular, the circadian clock controls the secretion of the ‘‘sleep hormone’’(melatonin) at the end of the day, variations in body temperature (lower in the early morning and higher during the day), and metabolism in periods of fasting (during sleep) or energy intake (during daytime meals).

Topological Insulator Catalysts for High-Yield Room-Temperature Synthesis of Organoureas


The unique quantum properties of bismuth selenide make it a promising catalyst for the synthesis of organic ureas, as demonstrated by scientists at Tokyo Tech. Thanks to its topological surface states, the proposed catalyst exhibits remarkably high catalytic activity and durability when used for the synthesis of various urea derivatives, which are widely utilized as nitrogen fertilizers.

Synthetic fertilizers, one the most important developments in modern agriculture, have enabled many countries to secure a stable food supply. Among them, organic ureas (or organoureas) have become prominent sources of nitrogen for crops. Since these compounds do not dissolve immediately in water, but instead are slowly decomposed by soil microorganisms, they provide a stable and controlled supply of nitrogen, which is crucial for plant growth and function.

However, traditional methods to synthesize organoureas are environmentally harmful due to their use of toxic substances, such as phosgene. Although alternative synthesis strategies have been demonstrated, these either rely on expensive and scarce noble metals or employ catalysts that cannot be reused easily.

Low-grade intestinal inflammation a long time after radiotherapy

Photo Credit: Jo McNamara

Patients who have undergone pelvic radiotherapy may live with low-grade chronic inflammation of the lower intestine 20 years after the treatment. This has been shown in a study by researchers at the University of Gothenburg.

Radiotherapy is often necessary to cure or slow down cancer. Even though today’s radiotherapies feature a high level of precision, healthy tissue in and around the radiation field is still affected. This study highlights a previously unknown side effect of radiotherapy to the lower abdomen.

The mucous membrane of the large intestine is normally protected against contact with bacteria in feces by a thin barrier of mucus. In the current study, researchers at the University of Gothenburg have shown that radiotherapy to the pelvic area affects this thin layer of mucus, allowing bacteria to come into contact with cells on the surface of the intestine. This could be a reason for the low-grade inflammation that the researchers also found in intestines that had been exposed to radiotherapy several years previously.  

“Anti-tangle” molecule could aid search for new dementia treatments, say scientists

Scientists at Bath have found a way of blocking the protein tangles that are associated with dementia diseases
Photo Credit: NCI

Scientists have identified a molecule that can prevent tangling of a brain protein that is linked to diseases such as Parkinson’s. The findings may provide insights into new ways of treating or diagnosing the early stages of dementia.

Alpha-synuclein, a protein found in brain cells, is commonly associated with neurodegenerative diseases such as Parkinson's, a debilitating neurological disorder affecting millions worldwide.

Like all proteins, it is made up of a long strand of molecules called amino acids. When it’s made, this strand folds in on itself to form a complex but precise 3D shape, made up of sub-structures and loops.

In healthy individuals, alpha-synuclein interacts with cell membranes where it plays a role in how brain cells (neurons) communicate with each other, but as a person ages, the 3D shape of the protein can malformed, or “misfolded”, causing it to start sticking together to form toxic clumps in the brain.

Over time these clumps continue to stack, forming fibers that can interfere with the protein’s normal role, eventually killing brain cells, contributing to the development of Parkinson's and related dementia diseases.

Plants on Ash Dumps Experience Nutrient Deficiency

Scientists studied two ash dumps in the Middle Urals.
Photo Credit: From the personal archive of Anna Betekhtina

Many nutrients, especially nitrogen, are not available to plants on ash dumps, biologists from the Ural Federal University and the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences (IPAE UB RAS) have found out. Despite the fact that nitrogen accumulates in the soil of ash dumps as a result of overgrowth, its availability to plants is very low. This situation is unique, because usually the nitrogen content in the soil is directly related to nitrogen content in plants. The description of chemical analysis of plants and soils of ash dumps scientists published in the journal "Ecology". 

"Nitrogen is one of the most important elements of plant nutrition, and its availability determines the productivity of plant communities. At various natural sites, a single pattern has been shown: when the nitrogen content in the soil increases, its amount in plants also increases. Such dynamics is described in many works of Russian and foreign scientists. However, our results turned out to be quite different. The results obtained on other natural objects cannot be transferred to technogenic landscapes, such as ash dumps", explains Anna Betekhtina, senior researcher of the Laboratory of Restorative Ecology at UrFU.

Two-decade monitoring of M87 unveils a precessing jet connecting to a spinning black hole

Schematic representation of the tilted accretion disk model. The black hole spin axis is assumed to align vertically. The jet direction stands almost perpendicular to the disk plane. The misalignment between the black hole spin axis and disk rotation axis triggers the precession of disk and jet.
Illustration Credit: Yuzhu Cui et al. (2023), Intouchable Lab@Openverse and Zhejiang Lab.

In a tale of cosmic patience spanning more than two decades, it has been discovered that the nearby radio galaxy M87, located 55 million light-years from the Earth and harboring a black hole 6.5 billion times more massive than the Sun, exhibits an oscillating jet. This investigation found the jet swinging up and down with an amplitude of about 10 degrees.

The international collaboration team consisting of researchers from 45 institutions around the world, including Dr. Satoko Sawada-Satoh of Osaka Metropolitan University’s Graduate School of Science, analyzed data observed from 2000 to 2022. They unveiled a recurring 11-year cycle in the precessing motion of the jet base, as predicted by Einstein’s general relativity. This work successfully linked the dynamics of the jet with the central supermassive black hole, offering evidence for the existence of M87’s black hole spin.

Wednesday, September 27, 2023

Noninvasive, ultrasound-based brain biopsy is feasible

Graduate student Lu Xu wears a device designed by engineers, at Washington University in St. Louis, that targets ultrasound waves to precise spots in the brain. Such targeting is the first step in a sonobiopsy, a noninvasive technique invented by Washington University researchers that uses ultrasound and microbubbles to release biomolecules from brain tumors. The biomolecules then can be collected via a blood draw, analyzed and used to inform treatment decisions. Xu is part of a research team that demonstrated that sonobiopsy is safe and feasible for use in people.
Photo Credit: Courtesy of Hong Chen

The blood-brain barrier, the body’s way of shielding sensitive brain tissue from viruses, toxins and other harmful substances in the blood, can pose a problem for physicians caring for patients with suspected brain diseases such as cancer. Molecular and genetic information would be invaluable for confirming a diagnosis and guiding treatment decisions, but such molecules are normally confined to the brain by the barrier. Neurosurgeons routinely perform surgical brain biopsies to obtain this data on brain tumors, but such procedures carry risks and are not feasible for all tumors or for many other kinds of brain diseases.

Researchers at Washington University in St. Louis have developed an anatomically precise technique called sonobiopsy that uses ultrasound and microbubbles to disrupt the barrier temporarily and allow RNA, DNA and proteins from the brain to spill out into the blood, where they can be detected and analyzed. The researchers developed and previously tested the technique in animals. In a new study, available online in the journal NPJ Precision Oncology, they showed that the technique is feasible and safe for use in people, and could open the door to noninvasive biopsies for suspected brain tumors and other brain diseases.

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