Plucking key evidence from air

PhD candidate Emily Bibbo and Dr Mariya Goray at the DNA forensics research room at Flinders University.
Photo Credit: Courtesy of Flinders University

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Human DNA can be successfully recovered from air-conditioning units and airborne particles, enabling the identification of individuals in a room even after surfaces have been wiped clean of fingerprints or touch DNA.
• Methodology: Researchers conducted a pilot study sampling air-conditioning units in four offices and four homes, while also testing portable air collection devices with various filters to measure DNA collection efficacy across different timeframes and occupancy levels.
• Key Data: While 62% of forensic casework in 2020 involved trace evidence with often poor success rates, this study confirmed that air-conditioning units retain DNA from previous users, whereas active air sampling effectively captures DNA from recent occupants.
• Significance: This technique offers a critical forensic breakthrough by allowing investigators to detect the presence of offenders who use countermeasures, such as wearing gloves or cleaning surfaces, by targeting aerosolized skin cells and saliva.
• Future Application: Law enforcement agencies may incorporate air sampling devices or HVAC swabbing into crime scene processing protocols to establish a suspect's presence when traditional physical evidence is absent or destroyed.
• Branch of Science: Forensic Science
• Additional Detail: The study suggests that while air samples represent a snapshot of recent activity, the components of air-conditioning units act as a historical archive, preserving the genetic profiles of past room users.

Discovery of how limiting damage from an asthma attack could stop disease

Scientists at King’s have discovered a new cause for asthma that sparks hope for treatment that could prevent the life-threatening disease.
Image Credit: Copilot DALL-E 3 AI Generated

Most current asthma treatments stem from the idea that it is an inflammatory disease. Yet, the life-threatening feature of asthma is the attack or the constriction of airways, making breathing difficult. A new study, published in the journal Science, shows for the first time that many features of an asthma attack—inflammation, mucus secretion, and damage to the airway barrier that prevents infections - result from this mechanical constriction in a mouse model.

The findings suggest that blocking a process that normally causes epithelial cell death could prevent the damage, inflammation, and mucus that result from an asthma attack.

Professor Jody Rosenblatt from the School of Basic & Medical Biosciences said: “Our discovery is the culmination of more than ten years of work. As cell biologists who watch processes, we could see that the physical constriction of an asthma attack causes widespread destruction of the airway barrier. Without this barrier, asthma sufferers are far more likely to get long-term inflammation, wound healing, and infections that cause more attacks. By understanding this fundamental mechanism, we are now in a better position to prevent all these events.”

Rapid, simultaneous detection of multiple bacteria achieved with handheld sensor

Marking bacteria electrochemically for rapid detection   
From left: Image of bacteria labeled with electrochemical markers, an electrochemical instrument to measure the data, and an image of the data displayed on a smartphone.     
Image Credit: Hiroshi Shiigi, Osaka Metropolitan University

Hearing the words E. coli or salmonella and food poisoning comes to mind. Rapid detection of such bacteria is crucial in preventing outbreaks of foodborne illness. While the usual practice is to take food samples to a laboratory to see the type and quantity of bacteria that forms in a petri dish over a span of days, an Osaka Metropolitan University research team has created a handheld device for quick on-site detection.

Led by Professor Hiroshi Shiigi of the Graduate School of Engineering, the team experimented with a biosensor that can simultaneously detect multiple disease-causing bacterial species within an hour.

“The palm-sized device for detection can be linked to a smartphone app to easily check bacterial contamination levels,” Professor Shiigi explained.

His team synthesized organic metallic nanohybrids of gold and copper that do not interfere with each other, so that electrochemical signals can be distinguished on the same screen-printed electrode chip of the biosensor. These organic−inorganic hybrids are made up of conductive polymers and metal nanoparticles. The antibody for the specific target bacteria was then introduced into these nanohybrids to serve as electrochemical labels.

Prehistoric henge reveals centuries-old sacred site in Lincolnshire

An aerial view of the excavation site at Crowland.
Photo Credit: The Anchor Church Field Project

Archaeologists from Newcastle University have unearthed evidence for an evolving sacred landscape spanning centuries in Crowland, Lincolnshire.

Crowland today is dominated by the ruins of its medieval abbey. However, local tradition holds that the area was the site of an Anglo-Saxon hermitage belonging to Saint Guthlac, who died in the year 714 and was famed for his life of solitude, having given up a life of riches as the son of a nobleman.

When his uncorrupted body was discovered 12 months after his death, Guthlac was venerated by a small monastic community dedicated to his memory. Guthlac’s popularity while he was alive, and the success of this cult and the pilgrimage it inspired, were key factors in the establishment of Crowland Abbey in the 10th century to honor the saint.

Early historical sources for Guthlac’s life exist, mainly through the Vita Sancti Guthlaci (Life of Saint Guthlac) written shortly after his death by a monk called Felix. Although there is little other evidence about his life, it was believed that Guthlac created his hermitage from a previously plundered barrow, or burial mound. For years, archaeologists have tried to find its location, and while Anchor Church Field was widely held to be the most likely site, the lack of excavation and the increasing impact of agricultural activity in the area have prevented a comprehensive understanding of the area.   

The team, which also included experts from the University of Sheffield, excavated Anchor Church Field and, to their surprise, found a much more complex and older history than they expected.

The first discovery they made was a previously unknown Late Neolithic or early Bronze Age henge, a type of circular earthwork and one of the largest ever discovered in eastern England.

Airy cellulose from a 3D printer

Complexity and lightness: Empa researchers have developed a 3D printing process for biodegradable cellulose aerogel.
Photo Credit: Empa

Ultra-light, thermally insulating and biodegradable: Cellulose-based aerogels are versatile. Empa researchers have succeeded in 3D printing the natural material into complex shapes that could one day serve as precision insulation in microelectronics or as personalized medical implants.

At first glance, biodegradable materials, inks for 3D printing and aerogels don't seem to have much in common. All three have great potential for the future, however: "green" materials do not pollute the environment, 3D printing can produce complex structures without waste, and ultra-light aerogels are excellent heat insulators. Empa researchers have now succeeded in combining all these advantages in a single material. And their cellulose-based, 3D-printable aerogel can do even more.

The miracle material was created under the leadership of Deeptanshu Sivaraman, Wim Malfait and Shanyu Zhao from Empa's Building Energy Materials and Components laboratory, in collaboration with the Cellulose & Wood Materials and Advanced Analytical Technologies laboratories as well as the Center for X-ray Analytics. Together with other researchers, Zhao and Malfait had already developed a process for printing silica aerogels in 2020. No trivial task: Silica aerogels are foam-like materials, highly open porous and brittle. Before the Empa development, shaping them into complex forms had been pretty much impossible. "It was the logical next step to apply our printing technology to mechanically more robust bio-based aerogels," says Zhao.

The researchers chose the most common biopolymer on Earth as their starting material: cellulose. Various nanoparticles can be obtained from this plant-based material using simple processing steps. Doctoral student Deeptanshu Sivaraman used two types of such nanoparticles – cellulose nanocrystals and cellulose nanofibers – to produce the "ink" for printing the bio-aerogel.

Cystic fibrosis: why infections persist despite therapy

The anchor points present on the surface of the airways in cystic fibrosis (left image, in red) decrease when the balance between the two cell signaling pathways is restored (right image).
Image Credit: Marc Chanson et al, 2024

Cystic fibrosis is a genetic disease that causes serious and sometimes fatal respiratory and digestive disorders. A new treatment, available since 2020, improves lung function and quality of life. However, it does not always eradicate the bacteria responsible for respiratory infections. By studying 3D models of human lung cells, scientists at the University of Geneva (UNIGE) discovered that this drug does not prevent the development on the surface of the respiratory tract of ''docking stations'' to which bacteria attach themselves to infect the body. These docking stations result from a disruption in the signals involved in cell development in the respiratory system. By combining the current treatment with other molecules, it may be possible to restore cell balance and thus better prevent bacterial infections. These results are published in the American Journal of Respiratory Cell and Molecular Biology.

Cystic fibrosis is the most common genetic disease. Each year, it affects one in every 3,300 newborns in Switzerland. Mutations in the gene responsible for the CFTR protein cause the secretion of excessively thick mucus, which obstructs the airways. Although a triple therapy, available in Switzerland since 2020, has improved the quality of life of people with cystic fibrosis, it is not suitable for all those affected and does not always prove effective.

New sunflower family tree reveals multiple origins of flower symmetry

A new sunflower family tree reveals that flower symmetry evolved multiple times independently. Chrysanthemum lavandulifolium, on the upper left, and Artemisia annua, upper right, are closely related species from the same tribe; the former has bilaterally symmetric flowers — the rays — and the latter does not. Rudbeckia hirta, lower left, from the sunflower tribe has bilaterally symmetric flowers, and Eupatorium chinense, lower right, from the Eupatorieae tribe does not; these two tribes are closely related groups. A sunflower, center, shows flowers with bilateral symmetry — the large petal-like flowers in the outer row — and without bilateral symmetry — the small flowers in the inner rows.
Photo Credits: Guojin Zhang, Ma laboratory / Pennsylvania State University
(CC BY-NC-ND 4.0 DEED)

The sunflower family tree revealed that flower symmetry evolved multiple times independently, a process called convergent evolution, among the members of this large plant family, according to a new analysis. The research team, led by a Penn State biologist, resolved more of the finer branches of the family tree, providing insight into how the sunflower family — which includes asters, daisies and food crops like lettuce and artichoke — evolved.

A paper describing the analysis and findings, which researchers said may help identify useful traits to selectively breed plants with more desirable characteristics is available online and will be published in an upcoming print edition of the journal Plant Communications.

“Convergent evolution describes the independent evolution of what appears to be the same trait in different species, like wings in birds and bats,” said Hong Ma, Huck Chair in Plant Reproductive Development and Evolution, professor of biology in the Eberly College of Science at Penn State and the leader of the research team. “This can make it difficult to determine how closely related two species are by comparing their traits, so having a detailed family tree based on DNA sequence is crucial to understanding how and when these traits evolved.”

Scientists discover potential treatment approaches for polycystic kidney disease

cientists would like to know how cysts form in polycystic kidney disease (PKD). Here, they compared two 3-D mini-kidney models. On the left, a model shows a mini kidney with a gene mutation that causes cysts to form. On the right, researchers used gene editing to correct a gene mutation, preventing the development of cysts.
Image Credit: Vishy, et al., Cell Stem Cell 2024

Researchers have shown that dangerous cysts, which form over time in polycystic kidney disease (PKD), can be prevented by a single normal copy of a defective gene. This means the potential exists that scientists could one day tailor a gene therapy to treat the disease. They also discovered that a type of drug, known as a glycoside, can sidestep the effects of the defective gene in PKD. The discoveries could set the stage for new therapeutic approaches to treating PKD, which affects millions worldwide. The study, partially funded by the National Institutes of Health (NIH), is published in Cell Stem Cell.

Scientists used gene editing and 3-D human cell models known as organoids to study the genetics of PKD, which is a life-threatening, inherited kidney disorder in which a gene defect causes microscopic tubes in the kidneys to expand like water balloons, forming cysts over decades. The cysts can crowd out healthy tissue, leading to kidney function problems and kidney failure. Most people with PKD are born with one healthy gene copy and one defective gene copy in their cells.

“Human PKD has been so difficult to study because cysts take years and decades to form,” said senior study author Benjamin Freedman, Ph.D., at the University of Washington, Seattle. “This new platform finally gives us a model to study the genetics of the disease and hopefully start to provide answers to the millions affected by this disease.”

The Rotisserie-Inspired Device That Could Revolutionize Cancer Surgery

The Zavaleta Lab’S Raman Rotisserie Device Creates a Map of the Surface of a Resected Tumor to Aid Surgeons in the Operating Room.
Photo Credit: Alex Czaja

Like many Texans, Cristina Zavaleta grew up enjoying the culinary delights of the state’s famous smokehouse BBQs. She couldn’t have imagined that those humble rotisseries of her childhood would one day inspire a game-changing device for the operating room that could help surgeons prevent tumor recurrence.

On a team excursion to Disneyland, the WiSE Gabilan Assistant Professor of Biomedical Engineering and her students were reminded of rotisseries when they encountered a food vendor at the Star Wars-themed land, Galaxy’s Edge. It was a lightbulb moment. The rotisserie configuration was a perfect way of intricately scanning excised tumors, with the help of the Zaveleta Lab’s unique nanoparticles, to light up where the cancerous tissue may not have been entirely removed from the patient. Surgeons could then be guided to precisely remove the remaining tumor, all while the patient is still under anesthesia. The result would reduce the need for traumatic repeat surgeries and potential cancer recurrence and metastasis.

Zavaleta and her team built the device, which they dubbed the Raman Rotisserie. It physically rotates a tumor specimen and works in conjunction with an imaging technique known as Raman spectroscopy, which scans the surface of the excised tumor. Their research, which aims to improve the success rate of breast cancer lumpectomies, has now been published in NPJ Imaging.

Feeding the lonely brain

Study finds that lonely women experienced increased activation in regions of the brain associated with food cravings
Photo Credit: Ryanwar Hanif

A new UCLA Health study has found that women who perceive themselves to be lonely exhibited activity in regions of the brain associated with cravings and motivation towards eating especially when shown pictures of high calorie foods such as sugary foods. The same group of women also had unhealthy eating behaviors and poor mental health.

Arpana Gupta, Ph.D., a researcher and co-director of the UCLA Goodman-Luskin Microbiome Center, wanted to research the negative impacts of loneliness, especially as people continue to be working remotely after the COVID-19 pandemic, and how the brain interplays with social isolation, eating habits, and mental health. While it is established that obesity is linked to depression and anxiety, and that binge eating is understood to be a coping mechanism against loneliness, Gupta wanted to observe the brain pathways associated with these feelings and behaviors.

“Researching how the brain processes loneliness and how this is related to obesity and health outcomes hasn't been done,” said Gupta, senior author of the paper, which is published in JAMA Network Open. 

The researchers surveyed 93 women about their support system and their feelings of loneliness and isolation, then separated them into two groups: those who scored high on the perceived social isolation scale, and those who scored low. The researchers found that women who had higher levels of social isolation tended to have higher fat mass, lower diet quality, greater cravings, reward-based eating, and uncontrolled eating, and increased levels of anxiety and depression.