Researchers uncover critical clues about the origin of heart arrhythmias

Immunofluorescent staining demonstrating fibroblasts expressing the Channelrhodopsin protein in heart scar tissue. The ChR2-expressing fibroblast (green, arrow) is in close proximity to cardiomyocytes (red) within scar.
Image Credit: Courtesy of UCLA Health

In a research article published today in the journal Science, UCLA researchers have found that fibroblasts – scar-forming cells that reside in the scar tissue of an injured heart -- directly play a role in promoting a disturbance of the heart rhythm, otherwise known as an arrhythmia. This finding holds promise for novel approaches to life threatening rhythm problems of the heart. 

Every year in the U.S., sudden cardiac death kills upwards of 350,000 people who have had no previous symptoms of heart disease, and in the majority of cases, the underlying cause is an arrhythmia. While there is a strong association between the amount of scar tissue in the heart and the likelihood of an arrhythmia to occur, whether fibroblasts in scar tissue directly communicated with cardiac muscle cells to promote arrhythmias was not known.

In cardiac scar tissue, cardiac muscle cells are surrounded by cardiac fibroblasts and often come in close contact with cardiac fibroblasts. "For decades, scientists have wondered whether the cardiac fibroblasts are electrically passive and just form scar tissue or whether by coming in close contact with myocytes, they directly increased the excitability of cardiac muscle cells and promoted life threatening arrhythmias in vivo," said Dr. Arjun Deb, senior author, professor of medicine and director of the UCLA Cardiovascular Theme, at the David Geffen School of Medicine. 

Ultrasound may rid groundwater of toxic ‘forever chemicals’

PFAS is notoriously difficult to clean from the environment, but ultrasound may offer a more effective solution compared to past efforts.
Photo Credit: Edward Jenner

New research suggests that ultrasound may have potential in treating a group of harmful chemicals known as PFAS to eliminate them from contaminated groundwater.

Invented nearly a century ago, per- and poly-fluoroalkyl substances, also known as “forever chemicals,” were once widely used to create products such as cookware, waterproof clothing and personal care items. Today, scientists understand that exposure to PFAS can cause a number of human health issues such as birth defects and cancer. But because the bonds inside these chemicals don’t break down easily, they’re notoriously difficult to remove from the environment.

Such difficulties have led researchers at The Ohio State University to study how ultrasonic degradation, a process that uses sound to degrade substances by cleaving apart the molecules that make them up, might work against different types and concentrations of these chemicals.

By conducting experiments on lab-made mixtures containing three differently sized compounds of fluorotelomer sulfonates – PFAS compounds typically found in firefighting foams – their results showed that over a period of three hours, the smaller compounds degraded much faster than the larger ones. This is in contrast to many other PFAS treatment methods in which smaller PFAS are actually more challenging to treat.

Revolutionary X-ray microscope unveils sound waves deep within crystals

Scientists developed a groundbreaking technology that allows them to see sound waves and microscopic defects inside crystals, promising insights that connect ultrafast atomic motion to large-scale macroscopic behaviors.
Photo Credit: Olivier Bonin/SLAC National Accelerator Laboratory

Scientists developed a groundbreaking technology that allows them to see sound waves and microscopic defects inside crystals, promising insights that connect ultrafast atomic motion to large-scale macroscopic behaviors.

Researchers at the Department of Energy’s SLAC National Accelerator Laboratory. Stanford University, and Denmark Technical University have designed a cutting-edge X-ray microscope capable of directly observing sound waves at the tiniest of scales – the lattice level within a crystal. These findings, published last week in Proceedings of the National Academy of Sciences, could change the way scientists study ultrafast changes in materials and the resulting properties.

“The atomic structure of crystalline materials gives rise to their properties and associated ‘use-case’ for an application,” said one of the researchers, Leora Dresselhaus-Marais, an assistant professor at Stanford and SLAC. “The crystalline defects and atomic scale displacements describe why some materials strengthen while others shatter in response to the same force. Blacksmiths and semiconductor manufacturing have perfected our ability to control some types of defects, however, few techniques today can image these dynamics in real-time at the appropriate scales to resolve how those the distortions connect to the bulk properties.”

Solar cell material can assist self-driving cars in the dark

Rui Zhang, postdoc fellow at IFM is one of the principle authors to the article published in Nature Photonics.
Photo Credit: Olov Planthaber

Material used in organic solar cells can also be used as light sensors in electronics. This is shown by researchers at Linköping University who have developed a type of sensor able to detect circularly polarized red light. Their study, published in Nature Photonics, paves the way for more reliable self-driving vehicles and other uses where night vision is important.

Some beetles with shiny wings, firefly larvae and colorful mantis shrimps reflect a particular kind of light known as circularly polarized light. This is due to microscopic structures in their shell that reflect the electromagnetic light waves in a particular way.

Circularly polarized light also has many technical uses, such as satellite communication, bioimaging and other sensing technologies. This is because circularly polarizing light carries a vast amount of information, due to the fact that the electromagnetic field around the light beam spirals either to the right or to the left.

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.