Scientists finally solve a 100-year-old mystery in the air we breathe

 Researchers at the University of Warwick have developed a new method that makes it possible to predict how irregularly shaped nanoparticles move through the air. These particles are a major category of air pollution and have long been difficult to model accurately. The new approach is the first that is both simple and predictive, allowing scientists to calculate particle motion without relying on overly complex assumptions.

Each day, people inhale millions of microscopic particles, including soot, dust, pollen, microplastics, viruses, and engineered nanoparticles. Some of these particles are so small that they can penetrate deep into the lungs and even enter the bloodstream. Exposure has been linked to serious health problems, including heart disease, stroke, and cancer.Most airborne particles do not have smooth or symmetrical shapes. However, traditional mathematical models usually assume these particles are perfect spheres because spherical shapes make equations easier to solve. This simplification limits scientists' ability to accurately track how real-world particles behave, especially those with irregular shapes that may pose greater health risks.

Reviving a Century-Old Equation for Modern Science

A researcher at the University of Warwick has now introduced the first straightforward method that can predict how particles of virtually any shape move through air. The study, published in Journal of Fluid Mechanics Rapids, updates a formula that is more than 100 years old and addresses a major gap in aerosol science.

The paper's author, Professor Duncan Lockerby, School of Engineering, University of Warwick said: "The motivation was simple: if we can accurately predict how particles of any shape move, we can significantly improve models for air pollution, disease transmission, and even atmospheric chemistry. This new approach builds on a very old model -- one that is simple but powerful -- making it applicable to complex and irregular-shaped particles."

Correcting a Key Oversight in Aerosol Physics

The breakthrough came from taking a fresh look at one of the foundational tools in aerosol science, known as the Cunningham correction factor. First introduced in 1910, the correction factor was designed to explain how drag forces on tiny particles differ from classical fluid behavior.

In the 1920s, Nobel Prize winner Robert Millikan refined the formula. During that process, a simpler and more general correction was overlooked. Because of this, later versions of the equation remained restricted to particles that were perfectly spherical, limiting their usefulness for real-world conditions.

Professor Lockerby's work restructures Cunningham's original idea into a broader and more flexible form. From this revised framework, he introduces a "correction tensor" -- a mathematical tool that accounts for drag and resistance acting on particles of any shape, including spheres and thin discs. Importantly, the method does not rely on empirical fitting parameters.

Source: ScienceDaily

Scientists turn sunflower oil waste into a powerful bread upgrade

 As interest grows in healthier alternatives to traditional wheat-based foods, scientists are exploring new ingredients that can improve nutrition without sacrificing practicality. One promising option is partially defatted sunflower seed flour (SF), a material left behind after sunflower oil is produced. This underused by-product has shown strong potential for enriching bread with protein, fiber, and antioxidant compounds.

"Our aim was to optimize the reuse of sunflower seed flour considering its high protein and chlorogenic acid content," says biologist Leonardo Mendes de Souza Mesquita, who is currently based at the Institute of Biosciences of the University of São Paulo (IB-USP) in Brazil. He is the lead author of a study published in ACS Food Science & TechnologyTesting Sunflower Flour in Bread Recipes

To evaluate how sunflower seed flour performs in baking, the research team prepared bread recipes that replaced wheat flour (WF) with sunflower seed flour (SF) at levels ranging from 10% to 60%. Each version was carefully analyzed for its chemical makeup, dough behavior, and the physical characteristics of the finished bread.

"Sunflower seed flour has been shown to contain a very high percentage of protein, from 40% to 66%, as well as dietary fiber, iron, calcium, and high levels of chlorogenic acid, a phenolic compound associated with antioxidant, anti-inflammatory, and hypoglycemic effects," Mesquita explains. He adds that using this by-product increases the nutritional value of bread while lowering the environmental footprint of sunflower oil production. Because it is sold cheaply to avoid disposal, sunflower seed flour is also a low-cost ingredient.

Major Gains in Protein and Antioxidants

The results showed clear nutritional improvements. Breads made with sunflower seed flour contained significantly more protein and fiber than standard wheat bread. At the highest substitution level, the bread reached 27.16% protein, compared with 8.27% in conventional bread. Antioxidant levels rose alongside protein content.

Antioxidant activity was measured using Trolox, a water-soluble analog of vitamin E that serves as a reference standard. The values recorded in sunflower flour breads were much higher than those seen in bread made entirely from wheat flour.

"The result reinforces the potential of sunflower seed flour to promote health benefits associated with reducing oxidative stress," says Mesquita. He also notes strong inhibition of digestive enzymes, including α-amylase (92.81%) and pancreatic lipase (25.6%), suggesting that bread containing SF or SFE may help slow the digestion of starches and fats.

Clean Processing and Food Safety

Another key finding involves how sunflower oil is produced. According to the researchers, industrial extraction relies on mechanical pressing rather than chemical solvents. As a result, the leftover flour is free from processing contaminants, aside from residues already present from agricultural sunflower cultivation.

Source: ScienceDaily

Gut bacteria can sense their environment and it’s key to your health

 

The gut microbiome, also called the gut flora, plays a vital role in human health. This enormous and constantly changing community of microorganisms is shaped by countless chemical exchanges, both among the microbes themselves and between microbes and the human body. For these interactions to work, gut bacteria must be able to detect nutrients and chemical signals around them. Despite their importance, scientists still know relatively little about the full range of signals that bacterial receptors can recognize.

A key question remains. Which chemical signals matter most to beneficial gut bacteria?

Moving Beyond Pathogens in Microbiology Research

Until now, much of what scientists understand about bacterial sensing has come from studying model organisms, especially disease-causing bacteria. Far less attention has been given to commensals, the non-pathogenic or beneficial microbes that naturally live in the human body. This gap has left researchers wondering what kinds of chemical information these helpful bacteria are actually detecting in their environment.An international research team led by Victor Sourjik set out to address that question. The group included scientists from the Max Planck Institute for Terrestrial Microbiology, the University of Ohio and the Philipps-University Marburg. Their work focused on Clostridia, a group of motile bacteria found in large numbers in the human gut that are known to support gut health.

Gut Bacteria Detect a Wide Range of Nutrients

The researchers found that receptors from the human gut microbiome can recognize a surprisingly broad array of metabolic compounds. These substances include breakdown products from carbohydrates, fats, proteins, DNA, and amines. Through systematic screening, the team also identified clear patterns. Different types of bacterial sensors showed distinct preferences for certain classes of chemicals.

This finding revealed that gut bacteria are not responding randomly to their environment but are selectively tuned to specific metabolic signals.

Lactate and Formate Stand Out as Key Signals

By combining laboratory experiments with bioinformatic analysis, the researchers identified multiple chemical ligands that bind to sensory receptors controlling bacterial movement. These receptors help motile bacteria detect nutrients that are especially valuable for growth. The results suggest that movement in these bacteria is primarily driven by the search for food.

Among all the chemicals tested, lactic acid (lactate) and formic acid (formate) appeared most frequently as stimuli. This suggests that these compounds may serve as especially important nutrient sources for gut bacteria.

Cross-Feeding Supports a Healthy Microbiome

Some gut bacteria can produce lactate and formate themselves, highlighting the importance of 'cross-feeding'. In this process, one bacterial species releases metabolites that other species use as food. This kind of cooperation helps stabilize the gut ecosystem.

Source: ScienceDaily