. Scientific Frontline

Monday, March 11, 2024

Reconfigurable electronics: More functionality on less chip area

Lukas Wind, Masiar Sistani und Walter Weber (left to right)
Photo Credit: Courtesy of Technische Universität Wien

Even the most complicated data processing on a computer can be broken down into small, simple logical steps: You can add individual bits together, you can reverse logical states, you can use combinations such as "AND" or "OR". Such operations are realized on the computer by very specific sets of transistors. These sets then form larger circuit blocks that carry out more complex data manipulations.

In the future, however, the design of electronic circuits could look completely different: For years, people have been thinking about the possibilities offered by electronic circuits that do not perform a physically fixed task, but can be switched flexibly depending on the task at hand – a new kind of reprogramming that does not take place at the software level, but at the fundamental hardware level: directly on the transistors, the nanoscale building blocks of electronic circuits.

This is exactly what a research team at TU Wien has now achieved: they have developed intelligent, controllable transistors and combined them into circuits that can be reliably and quickly switched back and forth between different tasks. This means that the same functionality as before can be accommodated on less chip space. This does not only save manufacturing costs, but also energy, and it enables higher computing speeds.

Saturday, March 9, 2024

Shape-shifting ultrasound stickers detect post-surgical complications

Three variations of the soft, flexible ultrasound sticker device displayed on a finger.
Photo Credit: Jiaqi Liu / Northwestern University

Researchers led by Northwestern University and Washington University School of Medicine in St. Louis have developed a new, first-of-its-kind sticker that enables clinicians to monitor the health of patients’ organs and deep tissues with a simple ultrasound device.

When attached to an organ, the soft, tiny sticker changes in shape in response to the body’s changing pH levels, which can serve as an early warning sign for post-surgery complications such as anastomotic leaks. Clinicians then can view these shape changes in real time through ultrasound imaging.

Currently, no existing methods can reliably and non-invasively detect anastomotic leaks — a life-threatening condition that occurs when gastrointestinal fluids escape the digestive system. By revealing the leakage of these fluids with high sensitivity and high specificity, the non-invasive sticker can enable earlier interventions than previously possible. Then, when the patient has fully recovered, the biocompatible, bioresorbable sticker simply dissolves away — bypassing the need for surgical extraction.

The study is published in the journal Science. The paper outlines evaluations across small and large animal models to validate three different types of stickers made of hydrogel materials tailored for the ability to detect anastomotic leaks from the stomach, the small intestine and the pancreas.

Lung cancer cells protected from cigarette smoke damage, researchers find

New research shows how lung cancer cells can survive better and exhibit less cell damage when exposed to cigarette smoke in cell culture experiments compared to non-cancerous lung cells. Image shows non-cancerous lung cells (left) and lung cancer cells (right), subjected to the same concentration of cigarette smoke condensate. Non-cancerous cells have more pronounced protein aggregation granules (shown with an arrow), stained by Proteostat, a type of cell damage that can eventually lead to cell death.
Image Credit: Krasilnikova Lab / Penn State
(CC BY-NC-ND 4.0 DEED)

Lung cancer cells survive better and exhibit less cell damage when exposed to cigarette smoke in cell culture experiments compared to non-cancerous lung cells. New research by a team of undergraduate students led by a Penn State molecular biologist may have revealed how lung cancer cells can persist in smoke. The mechanism could be related to how cancer cells develop resistance to pharmaceutical treatments as well.

The team found that a protein, which is expressed at high levels in some lung cancer cells and acts as a pump to transport molecules across the cell membrane, could potentially be clearing the damaging molecules coming from cigarette smoke. These molecules, if left uncleared inside the cells, can lead to protein aggregation that can damage and eventually kill lung cells.

“Cigarette smoke contains carcinogenic compounds, such as hydrocarbons and reactive oxygen and nitrogen species, that can damage cells in various ways,” said Maria Krasilnikova, associate research professor of biochemistry and molecular biology in the Eberly College of Science at Penn State and the lead author of the paper. “One way these compounds can damage cells is by causing proteins to misfold, which can lead to the formation of protein aggregates.”

Loss of nature costs more than previously estimated

Photo Credit: Christian Heitz

Researchers propose that governments apply a new method for calculating the benefits that arise from conserving biodiversity and nature for future generations.

The method can be used by governments in cost-benefit analyses for public infrastructure projects, in which the loss of animal and plant species and ‘ecosystem services’ – such as filtering air or water, pollinating crops or the recreational value of a space – are converted into a current monetary value.

This process is designed to make biodiversity loss and the benefits of nature conservation more visible in political decision-making.

However, the international research team says current methods for calculating the values of ecosystem services “fall short” and have devised a new approach, which they believe could easily be deployed in Treasury analysis underpinning future Budget statements.

Their approach, published in the journal Science, takes into consideration the increase in monetary value of nature over time as human income increases, as well as the likely deterioration in biodiversity, making it more of a scarce resource.

When Plants Flower: Scientists ID Genes, Mechanism in Sorghum

Brookhaven Lab biologist Meng Xie and postdoctoral fellow Dimiru Tadesse with sorghum plants like those used in this study. Note that these plants are flowering, unlike those the scientists engineered to delay flowering indefinitely to maximize their accumulation of biomass.
Photo Credit: Kevin Coughlin/Brookhaven National Laboratory

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Oklahoma State University have identified key genes and the mechanism by which they control flowering in sorghum, an important bioenergy crop. The findings, just published in the journal New Phytologist, suggest strategies to delay sorghum flowering to maximize plant growth and the amount of biomass available for generating biofuels and bioproducts.

“Our studies elucidate the gene regulatory network controlling sorghum flowering and provide new insights into how these genes could be leveraged to improve sorghum for achieving bioenergy goals,” said Brookhaven Lab biologist Meng Xie, one of the leaders of the research.

Sorghum is particularly well suited for sustainable agriculture because it can grow on marginal lands in semiarid regions and can tolerate relatively high temperatures. Like many plants, its growth and flowering (reproductive) cycles are regulated by the duration of daily sunlight. And once plants start to flower, they stop growing, which has important implications for the accumulation of biomass.

For example, one natural sorghum variety can reach nearly 20 feet in height, only transitioning to the reproductive flowering phase near the end of the summer growing season when the duration of daylight diminishes. Other “day-neutral” lines flower earlier, after reaching about three feet in height, producing less vegetation but more grain.

What Makes Birds So Smart?

The avian brain is smaller than that of many mammals, but just as capable.
Photo Credit: Kevin Mueller

Researchers at Ruhr University Bochum explain how it is possible for the small brains of pigeons, parrots and corvids to perform equally well as those of mammals, despite their significant differences.

Since the late 19th century, it has been a common belief among researchers that high intelligence requires the high computing capacity of large brains. They also discovered that the cerebral cortex as typical of mammals, is necessary to analyze and link information in great detail. Avian brains, by contrast, are very small and lack any structure resembling a cortex. Nevertheless, scientists showed that parrots and corvids are capable of planning for the future, forging social strategies, recognizing themselves in the mirror and building tools. These and similar aptitudes put them on a par with chimpanzees. Even less gifted birds, such as pigeons, learn orthographic rules that enable them to recognize typos in short words or classify pictures according to categories such as “impressionism”, “water” or “man-made”. How do they do it with such small brains and without a cortex? With their article in Trends in Cognitive Science, Professor Onur Güntürkün, Dr. Roland Pusch and Professor Jonas Rose from Ruhr University Bochum come closer to solving this more than one hundred-year-old puzzle.

Researchers develop artificial building blocks of life

Structural comparison of DNA and the artificial TNA, a Xeno nucleic acid with the natural base pairs AT and GC and an additional base pair (XY).
Image Credit: Courtesy of University of Cologne

For the first time, scientists from the University of Cologne (UoC) have developed artificial nucleotides, the building blocks of DNA, with several additional properties in the laboratory. They could be used as artificial nucleic acids for therapeutic applications.

DNA carries the genetic information of all living organisms and consists of only four different building blocks, the nucleotides. Nucleotides are composed of three distinctive parts: a sugar molecule, a phosphate group and one of the four nucleobases adenine, thymine, guanine and cytosine. The nucleotides are lined up millions of times and form the DNA double helix, similar to a spiral staircase. Scientists from the UoC’s Department of Chemistry have now shown that the structure of nucleotides can be modified to a great extent in the laboratory. The researchers developed so-called threofuranosyl nucleic acid (TNA) with a new, additional base pair. These are the first steps on the way to fully artificial nucleic acids with enhanced chemical functionalities. The study ‘Expanding the Horizon of the Xeno Nucleic Acid Space: Threose Nucleic Acids with Increased Information Storage’ was published in the Journal of the American Chemical Society.

How the Body Copes With Airway Closure

Image Credit: Scientific Frontline stock image

There is perhaps no bodily function more essential for humans and other mammals than breathing. With each breath, we suffuse our bodies with oxygen-rich air that keeps our organs and tissues healthy and working properly — and without oxygen, we can survive mere minutes.

But sometimes, our breathing becomes restricted, whether due to infection, allergies, exercise, or some other cause, forcing us to take deep, gasping breaths to quickly draw in more air.

Now, researchers at Harvard Medical School have identified a previously unknown way in which the body counteracts restricted breathing — a new reflex of the vagus nerve that initiates deep breathing. Their work is published in Nature.

The research, conducted in mice, reveals a rare and mysterious cell type in the lungs that detects airway closure and relays the signal to the vagus nerve — the information highway that connects the brain to almost every major organ. After the signal reaches the brain, a gasping reflex is initiated that helps the animal compensate for the lack of air.

Reptile roadkill reveals new threat to endangered lizard species

The western spiny-tailed skink.
Photo Credit: Dr. Holly Bradley

The chance sighting of a dead snake beside a sandy track in remote Western Australia, and the investigation of its stomach contents, has led Curtin University researchers to record the first known instance of a spotted mulga snake consuming a pygmy spiny-tailed skink, raising concerns for a similar-looking, endangered lizard species.

Lead researcher Dr Holly Bradley from Curtin’s School of Molecular and Life Sciences said the discovery of the partially digested pygmy spiny-tailed skink within the snake had implications for the vulnerable western spiny-tailed skink species.

“Found about 300km east of Geraldton and likely killed by a vehicle, the snake’s consumption of the pygmy spiny-tailed skink raises concerns about the susceptibility of similar-sized juvenile western spiny-tailed skinks, which also inhabit the Mid-West region and are classified as endangered,” Dr Bradley said.

“Pygmy spiny-tailed skinks look and act a lot like babies of the endangered western spiny-tailed skink, which live in the same area, so if these snakes are preying on one of them, they are likely also preying on the other.

Exploring the Surface Properties of NiO with Low-Energy Electron Diffraction


Antiferromagnetic (AF) crystals like NiO are experiencing a renaissance as promising materials for ultrafast spintronics. To re-establish old experimental results of surface property investigations and present new theoretical analysis, researchers from Sophia University carried out low-energy electron diffraction (LEED) analysis of AF crystal NiO. They reported an I-V spectra of ‘half-order beam’ and observed a surface wave resonance effect, providing useful insights into energy-temperature dependence of LEED and coherent spin exchange scattering in NiO.

Spintronics is a field that deals with electronics that exploit the intrinsic spin of electrons and their associated magnetic moment for applications such as quantum computing and memory storage devices. Owing to its spin and magnetism exhibited in its insulator-metal phase transition, the strongly correlated electron systems of nickel oxide (NiO) have been thoroughly explored for over eight decades. Interest in its unique antiferromagnetic (AF) and spin properties has seen a revival lately, since NiO is a potential material for ultrafast spintronics devices.

Despite this rise in popularity, exploration of its surface magnetic properties using low-energy electron diffraction (LEED) technique has not received much attention since the 1970s. To review the understanding of the surface properties, Professor Masamitsu Hoshino and Emeritus Professor Hiroshi Tanaka, both from the Department of Materials and Life Sciences at Sophia University, Japan, revisited the surface LEED crystallography of NiO. The results of their quantitative experimental study investigating the coherent exchange scattering in Ni2+ ions in AF single crystal NiO were reported in The European Physical Journal D.

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