. Scientific Frontline

Wednesday, December 20, 2023

Moderate low-carbohydrate diet is beneficial for adults with type 1 diabetes

Sofia Sterner Isaksson and Marcus Lind, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg.
Photo Credit: Malin Arnesson, Johan Wingborg

A moderate low-carbohydrate diet for adults with type 1 diabetes has advantages over traditional diet. The average blood sugar level is reduced and the time with good values during a 24-hour period is increased, without any negative health impact. This has been shown in a study carried out at the University of Gothenburg.

The study published in The Lancet Regional Health - Europe is the largest of its kind to date. Participants were for different periods randomly assigned in a crossover manner to eat a traditional diet with 50% of the energy from carbohydrates, or a moderate low-carbohydrate diet with 30% of the energy from carbohydrates.

This is a moderate reduction in carbohydrates, with 24-hour monitoring of all participants via continuous glucose monitoring (CGM). Blood glucose levels were recorded at least every 15 minutes during the 16 weeks of the study, and were followed up by a dietitian and diabetes nurse.

The researchers emphasize that for safety reasons, major changes in carbohydrate intake in type 1 diabetes should always be made in consultation with the healthcare provider. Individuals should not make these dietary changes on their own, especially not for children with type 1 diabetes. The current study concerns only adults.

Inhaled statins show promise as effective asthma treatment

This diagram shows how the inhaled medication pitavastatin may play a beneficial role in reducing obstructive airway diseases such as asthma.
Illustration Credit: Courtesy of University of California at Davis

Statins are a class of drugs commonly used to lower bad cholesterol, but can they also treat obstructive airway diseases, such as asthma?

UC Davis Health pulmonologists taking part in an NIH-funded study are exploring an innovative approach to determine whether statins may help treat obstructive airway diseases by delivering the medication via inhalation.

“Delivering statins by inhalation is a creative way to deploy a drug that has potent biological effects in pre-clinical cell-based and animal model studies,” said Amir A. Zeki, the principal investigator of the study and professor of internal medicine who specializes in pulmonary, critical care and sleep medicine. “Because oral statins do not penetrate the airway compartment at high enough levels to be effective, delivering statins directly to the lung via inhalation might achieve better local tissue drug levels, and therefore, better clinical results. This allows the use of lower drug doses to achieve efficacy while also minimizing systemic side effects.”

Scientists uncover link between the ocean’s weather and global climate

Oceanic weather systems (mesoscale eddies) from data overlaid with atmospherically driven climate-scale currents (black lines), which can be extracted with a coarse graining technique developed in the lab of Hussein Aluie. The image reveals how these ocean weather systems are energized (red) or weakened (blue) when interacting with climate-scales, which follows a pattern mirroring the global atmospheric circulation.
Illustration Credit: Benjamin Storer

Using mechanical rather than statistical analysis, the team offers a new framework for understanding the climate system.

An international team of scientists has found the first direct evidence linking seemingly random weather systems in the ocean with climate on a global scale. Led by Hussein Aluie, an associate professor in the University of Rochester’s Department of Mechanical Engineering and staff scientist at the University’s Laboratory for Laser Energetics, the team reported their findings in Science Advances.

The ocean has weather patterns like what we experience on land, but on different time and length scales, says lead author Benjamin Storer, a research associate in Aluie’s Turbulence and Complex Flow Group. A weather pattern on land might last a few days and be about 500 kilometers wide, while oceanic weather patterns such as swirling eddies last three to four weeks but are about one-fifth the size.

Cosmic lights in the forest

TACC’s Frontera, the fastest academic supercomputer in the US, is a strategic national capability computing system funded by the National Science Foundation.
Photo Credit: TACC.

Like a celestial beacon, distant quasars make the brightest light in the universe. They emit more light than our entire Milky Way galaxy. The light comes from matter ripped apart as it is swallowed by a supermassive black hole. Quasar light reveals clues about the large-scale structure of the universe as it shines through enormous clouds of neutral hydrogen gas formed shortly after the Big Bang on the scale of 20 million light years across or more. 

Using quasar light data, the National Science Foundation (NSF)-funded Frontera supercomputer at the Texas Advanced Computing Center (TACC) helped astronomers develop PRIYA, the largest suite of hydrodynamic simulations yet made for simulating large-scale structure in the universe.

“We’ve created a new simulation model to compare data that exists at the real universe,” said Simeon Bird, an assistant professor in astronomy at the University of California, Riverside. 

Bird and colleagues developed PRIYA, which takes optical light data from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey (SDSS). He and colleagues published their work announcing PRIYA in the Journal of Cosmology and Astroparticle Physics (JCAP). 

Research offers a reason why diversity in plant species causes higher farming yield, solving 'a bit of a mystery'

Co-author Peggy Schultz collects data on plots with undergraduate workers.
Photo Credit: KU Marketing

A study appearing in Nature Communications based on field and greenhouse experiments at the University of Kansas shows how a boost in agricultural yield comes from planting diverse crops rather than just one plant species: Soil pathogens harmful to plants have a harder time thriving.

“It’s commonly observed that diverse plant communities can be more productive and stable over time,” said corresponding author James Bever, senior scientist with the Kansas Biological Survey & Center for Ecological Research and Foundation Distinguished Professor of Ecology & Evolutionary Biology at KU. “Range lands with numerous species can show increased productivity. But the reason for this has been a bit of a mystery.”

While crop rotation and other farming and gardening practices long have reflected benefits of a mix of plants, the new research puts hard data to one important mechanism underpinning the observation: the numbers of microorganisms in the soil that eat plants.

“Diverse agricultural communities have the potential to keep pathogens at bay, resulting in greater yields,” Bever said. “What we show is that a major driver is the specialization of pathogens, particularly those specific to different plant species. These pathogens suppress yields in low-diversity communities. A significant advantage of rangeland diversity is that less biomass is consumed by pathogens, allowing more biomass for other uses, such as cattle. The same process is crucial for agricultural production.”

Aerogel can become the key to future terahertz technologies

Aerogel can obtain high hydrophobicity by simple chemical modifications.
Photo Credit: Thor Balkhed

High-frequency terahertz waves have great potential for a number of applications including next-generation medical imaging and communication. Researchers at Linköping University, Sweden, have shown, in a study published in the journal Advanced Science, that the transmission of terahertz light through an aerogel made of cellulose and a conducting polymer can be tuned. This is an important step to unlock more applications for terahertz waves.

The terahertz range covers wavelengths that lie between microwaves and infrared light on the electromagnetic spectrum. It has a very high frequency. Thanks to this, many researchers believe that the terahertz range has great potential for use in space exploration, security technology and communication systems, among other things. In medical imaging, it can also be an interesting substitute for X-ray examinations as the waves can pass through most non-conductive materials without damaging any tissue.

However, there are several technological barriers to overcome before terahertz signals can be widely used. For example, it is difficult to create terahertz radiation in an efficient way and materials that can receive and adjust the transmission of terahertz waves are needed.

Uncovering the role of beta diversity in ecosystems

Karen Castillioni observes beta diversity in a prairie habitat.
Photo Credit: College of Biological Sciences

As climate change progresses, scientists want to better understand how species interact across habitats to preserve diversity. Key to these efforts is the concept of beta diversity, which explores species that thrive exclusively in specific habitats. The University of Minnesota's Cedar Creek Ecosystem Science Reserve in East Bethel is an ideal place to study beta diversity because it gives researchers access to many distinct habitats in one place. 

Karen Castillioni, a postdoctoral research associate in the College of Biological Sciences, along with Associate Professor Forest Isbell, wanted to know how beta diversity affects plant biomass, the total mass of living plants in a given area. Plant biomass is crucial for various ecological and environmental functions, including carbon sequestration and supporting food webs.

During the first phase of an experiment at Cedar Creek called BetaDIV, the researchers looked at five habitats: oak savanna, where bur oak tree dominates; coniferous forest, where white pine dominates; deciduous forest, where red maple dominates; bog, where tamarack dominates; and an old grassland where big bluestem dominates.

An Electrifying Improvement in Copper Conductivity

Xiao Li, a materials scientist, holds samples of highly conductive metal wires created on the patented Shear Assisted Processing and Extrusion platform. 
Photo Credit: Andrea Starr | Pacific Northwest National Laboratory

A common carbon compound enables remarkable performance enhancements when mixed in just the right proportion with copper to make electrical wires. It’s a phenomenon that defies conventional wisdom about how metals conduct electricity. The findings, reported December 2023 in the journal Materials & Design, could lead to more efficient electricity distribution to homes and businesses, as well as more efficient motors to power electric vehicles and industrial equipment. The team has applied for a patent for the work, which was supported by the Department of Energy (DOE) Advanced Materials and Manufacturing Technologies Office.

Materials scientist Keerti Kappagantula and her colleagues at DOE’s Pacific Northwest National Laboratory discovered that graphene, single layers of the same graphite found in pencils, can enhance an important property of metals called the temperature coefficient of resistance. This property explains why metal wires get hot when electric current runs through them. Researchers want to reduce this resistance while enhancing a metal’s ability to conduct electricity. For several years they have been asking whether metal conductivity be increased, especially at high temperatures, by adding other materials to it. And if yes, can these composites be viable on a commercial scale?

Now, they’ve demonstrated they can do just that, using a PNNL-patented advanced manufacturing platform called ShAPE™. When the research team added 18 parts per million of graphene to electrical-grade copper, the temperature coefficient of resistance decreased by 11 percent without decreasing electrical conductivity at room temperature. This is relevant for the manufacturing of electric vehicle motors, where an 11 percent increase in electrical conductivity of copper wire winding translates into a 1 percent gain in motor efficiency.

Natto Consumption Suppresses Arteriosclerosis

Photo Credit: Seiya Maeda

Natto is widely recognized for inhibiting arteriosclerosis, yet its underlying mechanism remains elusive. Researchers led by the University of Tsukuba studied the effects of natto on arteriosclerosis in mice. The findings showed that consuming natto induced changes in the intestinal microflora, suppressing inflammation and preventing arteriosclerosis.

Atherosclerosis, a chronic condition characterized by the accumulation of lipid and inflammatory cells within the blood vessel walls, causes cardiovascular diseases, such as heart disease and stroke. Natto, a food rich in vitamin K2, has shown promise in mitigating cardiovascular diseases by enhancing arterial flexibility and modulating inflammatory responses. However, the reason why natto suppresses arteriosclerosis remains elusive.

Insects already had a variety of defense strategies in the Cretaceous

Larva of a wedge-shaped beetle in amber, which could have lived inside other insects like its modern counterparts. 
Image Credit: © Carolin Haug

Analyses of amber show that insect larvae were already using a wide variety of tactics to protect themselves from predators 100 million years ago.

Early life stages of insects fulfill important functions in our ecosystems. They decompose dead bodies and wood, forming soil and returning various elements into material cycles. Not least, they are a major food source for many larger animals such as birds and mammals. This has led to many insect larvae developing structures and strategies for reducing the danger of being eaten. These include features like spines and hairs, but also camouflage and concealment. Over millions of years, a wide variety of such adaptation strategies have developed.

Researchers at LMU and the universities of Greifswald and Rostock have studied particularly well-preserved fossils from Burmese amber and have been able to demonstrate that such anti-predator mechanisms had already evolved very diverse forms in insect larvae during the Cretaceous period 100 million years ago. This includes well-known strategies such as that employed by lacewing larvae, which carry various plant and animal materials on their back to give them camouflage, or the ploy of mimicking the appearance of certain plant parts.

Discovery: plants use “trojan horse” to fight mold invasions

Photo Credit: Gábor Adonyi

UC Riverside scientists have discovered a stealth molecular weapon that plants use to attack the cells of invading gray mold. 

If you’ve ever seen a fuzzy piece of fruit in your fridge, you’ve seen gray mold. It is an aggressive fungus that infects more than 1,400 different plant species: almost all fruits, vegetables, and many flowers. It is the second most damaging fungus for food crops in the world, causing billions in annual crop losses.

A new paper in the journal Cell Host & Microbe describes how plants send tiny, innocuous-seeming lipid “bubbles” filled with RNA across enemy lines, into the cells of the aggressive mold. Once inside, different types of RNA come out to suppress the infectious cells that sucked them in.

“Plants are not just sitting there doing nothing. They are trying to protect themselves from the mold, and now we have a better idea how they’re doing that,” said Hailing Jin, Microbiology & Plant Pathology Department professor at UCR and lead author of the new paper.

Previously, Jin’s team discovered that plants are using the bubbles, technically called extracellular vesicles, to send small RNA molecules able to silence genes that make the mold virulent. Now, the team has learned these bubbles can also contain messenger RNA, or mRNA, molecules that attack important cellular processes, including the functions of organelles in mold cells. 

Toxic chemicals found in oil spills and wildfire smoke detected in killer whales

Orcas (killer whales)
Photo Credit: Bart van Meele

Toxic chemicals produced from oil emissions and wildfire smoke have been found in muscle and liver samples from Southern Resident killer whales and Bigg’s killer whales.

A study published in Scientific Reports is the first to find polycyclic aromatic hydrocarbons (PAHs) in orcas off the coast of B.C., as well as in utero transfer of the chemicals from mother to fetus.

“Killer whales are iconic in the Pacific Northwest—important culturally, economically, ecologically and more. Because they are able to metabolically process PAHs, these are most likely recent exposures. Orcas are our canary in the coal mine for oceans, telling us how healthy our waters are,” said senior author Dr. Juan José Alava, principal investigator of the UBC Ocean Pollution Research Unit and adjunct professor at Simon Fraser University.

PAHs are a type of chemical found in coal, oil and gasoline which research suggests are carcinogenic, mutagenic, and have toxic effects on mammals. Their presence in the ocean comes from several sources, including oil spills, burning coal and forest fire smoke particles.

Researchers analyzed muscle and liver samples from six Bigg’s, or transient, killer whales and six Southern Resident killer whales (SRKWs) stranded in the northeastern Pacific Ocean between 2006 and 2018. They tested for 76 PAHs and found some in all samples, with half the PAHs appearing in at least 50 per cent of the samples. One compound, a PAH derivative called C3-phenanthrenes/anthracenes, accounted for 33 per cent of total contamination across all samples. These forms of PAHs, known as alkylated PAHs, are known to be more persistent, toxic, and to accumulate more in the bodies of organisms or animals than parental PAHs.

Tuesday, December 19, 2023

Enlarged Spaces in Infant Brains Linked to Higher Risk of Autism, Sleep Problems

Dea Garic, PhD, and Mark Shen, PhD, both in the UNC School of Medicine’s Department of Psychiatry, have found that enlarged perivascular spaces in the brains of babies, caused by an accumulation of excess cerebrospinal fluid, have a 2.2 times greater chance of developing autism later in life.
Photo Credit: Courtesy of University of North Carolina at Chapel Hill

Throughout the day and night, cerebrospinal fluid (CSF) pulses through small fluid-filled channels surrounding blood vessels in the brain, called perivascular spaces, to flush out neuroinflammation and other neurological waste. A disruption to this vital process can lead to neurological dysfunction, cognitive decline, or developmental delays.

For the first time, researchers Dea Garic, PhD, and Mark Shen, PhD, both at the UNC School of Medicine’s Department of Psychiatry, discovered that infants with abnormally enlarged perivascular spaces have a 2.2 times greater chance of developing autism compared to infants with the same genetic risk. Their research also indicated that enlarged perivascular spaces in infancy are associated with sleep problems seven to 10 years after diagnosis.

“These results suggest that perivascular spaces could serve as an early marker for autism,” said Garic, assistant professor of psychiatry and a member of the Carolina Institute for Developmental Disabilities (CIDD).

The researchers studied infants at increased likelihood for developing autism, because they had an older sibling with autism. They followed these infants from 6-24 months of age, before the age of autism diagnosis. Their study, published in JAMA Network Open, found that thirty percent of infants who later developed autism had enlarged perivascular spaces by 12 months. By 24 months of age, nearly half of the infants diagnosed with autism had enlarged perivascular spaces.

Molecular jackhammers’ ‘good vibrations’ eradicate cancer cells

Ciceron Ayala-Orozco is a research scientist in the Tour lab at Rice University, and lead author on the study.
Photo Credit: Jeff Fitlow/Rice University

The Beach Boys’ iconic hit single “Good Vibrations” takes on a whole new layer of meaning thanks to a recent discovery by Rice University scientists and collaborators, who have uncovered a way to destroy cancer cells by using the ability of some molecules to vibrate strongly when stimulated by light.

The researchers found that the atoms of a small dye molecule used for medical imaging can vibrate in unison ⎯ forming what is known as a plasmon ⎯ when stimulated by near-infrared light, causing the cell membrane of cancerous cells to rupture. According to the study published in Nature Chemistry, the method had a 99 percent efficiency against lab cultures of human melanoma cells, and half of the mice with melanoma tumors became cancer-free after treatment.

“It is a whole new generation of molecular machines that we call molecular jackhammers,” said Rice chemist James Tour, whose lab has previously used nanoscale compounds endowed with a light-activated paddlelike chain of atoms that spins continually in the same direction to drill through the outer membrane of infectious bacteria, cancer cells and treatment-resistant fungi.

Researchers Find They Can Stop Degradation of Promising Solar Cell Materials

An illustration of metal halide perovskites. They are a promising material for turning light into energy because they are highly efficient, but they also are unstable. Georgia Tech engineers showed in a new study that both water and oxygen are required for perovskites to degrade. The team stopped the transformation with a thin layer of another molecule that repelled water.
Image Credit: Courtesy of Juan-Pablo Correa-Baena

Georgia Tech materials engineers have unraveled the mechanism that causes degradation of a promising new material for solar cells — and they’ve been able to stop it using a thin layer of molecules that repels water.

Their findings are the first step in solving one of the key limitations of metal halide perovskites, which are already as efficient as the best silicon-based solar cells at capturing light and converting it into electricity. They reported their work in the Journal of the American Chemical Society.

“Perovskites have the potential of not only transforming how we produce solar energy, but also how we make semiconductors for other types of applications like LEDs or phototransistors. We can think about them for applications in quantum information technology, such as light emission for quantum communication,” said Juan-Pablo Correa-Baena, assistant professor in the School of Materials Science and Engineering and the study’s senior author. “These materials have impressive properties that are very promising.”

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