“We saw that transgender men treated with testosterone increased their muscle volume by an average of 21 percent over six years, but also that the amount of abdominal fat increased by 70 percent,” says Tommy Lundberg, docent at the Department of Laboratory Medicine, Karolinska Institutet. “In addition, they had more liver fat and higher levels of ‘bad’ LDL cholesterol, which may increase the risk of cardiovascular disease.”

The researchers followed 17 adult transgender men and 16 transgender women who were prescribed treatment with testosterone and oestrogen, respectively. They used magnetic resonance imaging (MRI) to map body composition and measured metabolic risk factors via blood tests, blood pressure and vascular stiffness. The scans were conducted before the start of hormone therapy, after one year and after five to six years.

The results show that long-term hormone therapy leads to several major changes in both body composition and metabolic risk factors, particularly in transgender men. The changes in fat volumes continued over time, while the greatest changes in muscle mass and strength occurred after just one year of treatment.

“Previous studies in this area have been relatively short-term, up to two years,” explains Tommy Lundberg. “Our results show that it is important to continue monitoring the long-term health effects of hormone therapy in transgender individuals to prevent cardiovascular disease and other health issues.”

In transgender women receiving oestrogen treatment, the changes were not as pronounced. Their muscle volume decreased by an average of seven percent after five years of treatment, whereas muscle strength remained unchanged. The transgender women increased their total fat volume but gained less abdominal fat.

Tissue samples from muscle, fat and skin were also taken as part of the study. The next step is to analyse these tissue samples to understand the interaction between genetic sex and sex hormones. The researchers are investigating, among other things, how hormone treatment affects skeletal muscle gene expression and the mechanisms behind changes in adipose tissue.

“In addition to the health aspects, our research contributes to increased knowledge about reasonable expectations of the masculinising and feminising effects of sex hormone treatment,” says Tommy Lundberg. “However, some of the changes were relatively modest and should raise caution regarding expectations of long-term and large changes in this patient group.”

The research was funded by Region Stockholm, the Thuring Foundation, the 1.6 Million Club, the Centre for Innovative Medicine at Karolinska Institutet, the Swedish Research Council, the Swedish Medical Association, the Novo Nordisk Foundation and the European Foundation for Studies of Diabetes.

Two of the co-authors are employed by AMRA Medical AB. Tommy Lundberg has been compensated for expert opinions on aspects related to skeletal muscle changes in transgender individuals and reimbursed for travelling to give lectures on the same topic.

In recent years, TNT has started to be replaced with DNAN, but until now very little was known about how this substance impacts the environment and how long it can remain in the soil.

Researchers at the University of York have been studying the environmental impact of the explosive, TNT, for more than a decade. They have shown that the chemical compound, which is used by the military around the world, remains in the roots of plants where it inhibits growth and development.

Now a new study, led by Professor Neil Bruce at the University of York’s Department of Biology and Director of the Centre for Novel Agricultural Products (CNAP), however, has shown that DNAN has similar effects to TNT, but accumulates throughout the plant and lingers for longer.

Professor Neil Bruce said: “Similarly to TNT, DNAN reacts with a key plant enzyme, generating reactive superoxide, which is highly damaging to cells. Over the course of our research we have genetically engineered plants to successfully detoxify land contaminated with munitions.

“Unfortunately DNAN is a very different story to TNT, as it accumulates in the above ground parts of the plant. While plants can use natural processes to reduce the toxicity of TNT, our studies found that plants appear to have no natural way of fighting off the toxic effects of DNAN, meaning that it persists in the plant and is toxic at much lower concentrations.”

Researchers warn that as DNAN is present throughout the plant and not just the root system, as is the case with TNT, there is a greater risk of animals eating the infected plant, introducing the toxin into the food chain.

In previous studies by the York team, genetically modified grass was grown on land contaminated with military explosives, which successfully degraded contaminants to non-detectable levels in their plant tissues, but as yet there is currently no such method to remove or reduce DNAN.

The US is estimated to have over 10 million hectares of military land contaminated with constituents of explosives and the US government estimates that remediation of unexploded ordinances on US military training ranges alone will cost $16-165 billion.

Dr Liz Rylott, co-author of the study from the University of York’s Department of Biology, said: “Recent years have seen an escalation in military explosives due to global conflicts, and so we are potentially looking at vast scales of pollution, which means there is an urgent need, and interest in, developing sustainable plant-based remediation strategies.

“We also don’t know what the limits of DNAN toxicity are in humans, so our hope is that our latest research will highlight that more work is urgently needed to understand its effects.”

This research, published in the journal Nature Plants, was funded by the Strategic Environmental Research and Development Program (SERDP) of the U.S. Department of Defense and was in collaboration with researchers at the U.S. Army Engineer Research and Development Center (ERDC), U.S. Army Corps of Engineers.

Existing research shows that natural sounds, like birdsong, can lower blood pressure, heart, and respiratory rates, as well as self-reported stress and anxiety. Conversely, anthropogenic soundscapes, like traffic or aircraft noise, are hypothesized to have negative effects on human health and wellbeing in a variety of ways.

In the new study, 68 student volunteers listened to three 3-minute soundscapes: a nature soundscape recorded at sunrise in West Sussex, U.K., the same soundscape combined with 20 mile per hour road traffic sounds, and the same soundscape with 40 mile per hour traffic sounds. General mood and anxiety were assessed before and after the soundscapes using self-reported scales.

The study found that listening to a natural soundscape reduced self-reported stress and anxiety levels, and also enhanced mood recovery after a stressor. However, the benefits of improved mood associated with the natural soundscape was limited when traffic sounds were included. The natural soundscape alone was associated with the lowest levels of stress and anxiety, with the highest levels reported after the soundscape that included 40 mile per hour traffic.

The authors conclude that reducing traffic speed in urban areas might influence human health and wellbeing not only through its safety impacts, but also through its effect on natural soundscapes.

The authors add: “Our study shows that listening to natural soundscapes can reduce stress and anxiety, and that anthropogenic sounds such as traffic noise can mask potential positive impacts. Reducing traffic speeds in cities is therefore an important step towards more people experiencing the positive effects of nature on their health and wellbeing.”

Almost 10 billion people are expected to inhabit Earth by 2050, so agricultural production will become increasingly critical to feeding the growing population. Over the past six decades, much of the growth in food production has stemmed from technological advances, including the widespread development and use of better crop varieties. But some studies have suggested that the growth in production has leveled off, raising concerns about future food availability, especially in the low- and middle-income countries with the highest population growth.

In the new study, the researchers developed standardized measures for production and yield for 144 crops, covering 98 percent of global agricultural land. These measures allow scientists and policymakers to compare agricultural productivity across different countries and regions. The researchers found that there has been no discernable slowdown in the global growth of crop yields during the last six decades — any observed slowdown in specific crops, regions or countries has been offset by gains in others. Their findings show that yields grew annually at a rate equivalent to about 33 kg of wheat per hectare.

While the study’s findings are reassuring from a global food supply perspective, the researchers caution that sustainable food production and the affordability of food will continue to be challenges to global food security. They emphasize that these concerns are particularly relevant in the face of intensifying climate change and increased demand for food due to population and income growth.

The authors add: “Utilizing a comprehensive caloric-based index of production and yield for 144 crops, covering 98% of global agricultural land and food output, this paper reveals that, on an aggregate level, global yield growth — a vital indicator of agricultural productivity — has not slowed over the past six decades. This steady growth equates to an annual increase of approximately 33 kilograms of wheat per hectare, highlighting continued productivity gains worldwide.”

The study, published in the journal Science Advances, shows that the oceans not only capture and redistribute the sun’s heat, but produce gases that make particles with immediate climatic effects, for example through the brightening of clouds that reflect this heat.

It broadens the climatic impact of marine sulfur because it adds a new compound, methanethiol, that had previously gone unnoticed. Researchers only detected the gas recently, because it used to be notoriously hard to measure and earlier work focussed on warmer oceans, whereas the polar oceans are the emission hotspots.

The research was led by a team of scientists from the Institute of Marine Sciences (ICM-CSIC) and the Blas Cabrera Institute of Physical Chemistry (IQF-CSIC) in Spain. They included Dr Charel Wohl, previously at ICM-CSIC and now at the University of East Anglia (UEA) in the UK.

Their findings represent a major advance on one of the most groundbreaking theories proposed 40 years ago about the role of the ocean in regulating the Earth’s climate.

This suggested that microscopic plankton living on the surface of the seas produce sulfur in the form of a gas, dimethyl sulphide, that once in the atmosphere, oxidizes and forms small particles called aerosols.

Aerosols reflect part of the solar radiation back into space and therefore reduce the heat retained by the Earth. Their cooling effect is magnified when they become involved in making clouds, with an effect opposite to, but of the same magnitude as, that of the well-known warming greenhouse gases, such as carbon dioxide or methane.

The researchers argue that this new work improves our understanding of how the climate of the planet is regulated by adding a previously overlooked component and illustrates the crucial importance of sulfur aerosols. They also highlight the magnitude of the impact of human activity on the climate and that the planet will continue to warm if no action is taken.

Dr Wohl, of UEA’s Centre for Ocean and Atmospheric Sciences and one of the lead authors, said: “This is the climatic element with the greatest cooling capacity, but also the least understood. We knew methanethiol was coming out of the ocean, but we had no idea about how much and where. We also did not know it had such an impact on climate.

“Climate models have greatly overestimated the solar radiation actually reaching the Southern Ocean, largely because they are not capable of correctly simulating clouds. The work done here partially closes the longstanding knowledge gap between models and observations.”

With this discovery, scientists can now represent the climate more accurately in models that are used to make predictions of +1.5 ºC or +2 ºC warming, a huge contribution to policy making.

“Until now we thought that the oceans emitted sulfur into the atmosphere only in the form of dimethyl sulphide, a residue of plankton that is mainly responsible for the evocative smell of shellfish,” said Dr Martí Galí, a researcher at the ICM-CSIC and another of the main study authors.

Dr Wohl added: “Today, thanks to the evolution of measurement techniques, we know that plankton also emit methanethiol, and we have found a way to quantify, on a global scale, where, when and in what quantity this emission occurs.

“Knowing the emissions of this compound will help us to more accurately represent clouds over the Southern Ocean and calculate more realistically their cooling effect.”

The researchers gathered all the available measurements of methanethiol in seawater, added those they had made in the Southern Ocean and the Mediterranean coast, and statistically related them to seawater temperature, obtained from satellites.

This allowed them to conclude that, annually and on a global average, methanethiol increases known marine sulfur emissions by 25%.

“It may not seem like much, but methanethiol is more efficient at oxidising and forming aerosols than dimethyl sulfide and, therefore, its climate impact is magnified,” said co-lead Dr Julián Villamayor, a researcher at IQF-CSIC.

The team also incorporated the marine emissions of methanethiol into a state-of-the-art climate model to assess their effects on the planet’s radiation balance.

It showed the impacts are much more visible in the Southern Hemisphere, where there is more ocean and less human activity, and therefore the presence of sulfur from the burning of fossil fuels is lower.

The work was supported by funding from organisations including the European Research Council and Spanish Ministry of Science and Innovation.

Led by Xing Wang, a professor of bioengineering and of chemistry at the U. of I., the researchers describe their advance in the journal Science Robotics.

Inspired by the gripping power of the human hand and bird claws, the researchers designed the NanoGripper with four bendable fingers and a palm, all in one nanostructure folded from a single piece of DNA. Each finger has three joints, like a human finger, and the angle and degree of bending are determined by the design on the DNA scaffold.

“We wanted to make a soft material, nanoscale robot with grabbing functions that never have been seen before, to interact with cells, viruses and other molecules for biomedical applications,” Wang said. “We are using DNA for its structural properties. It is strong, flexible and programmable. Yet even in the DNA origami field, this is novel in terms of the design principle. We fold one long strand of DNA back and forth to make all of the elements, both the static and moving pieces, in one step.”

The fingers contain regions called DNA aptamers that are specially programmed to bind to molecular targets — the spike protein of the virus that causes COVID-19, for this first application — and trigger the fingers to bend to wrap around the target. On the opposite side, where the wrist would be, the NanoGripper can attach to a surface or other larger complex for biomedical applications such as sensing or drug delivery.

To create a sensor to detect the COVID-19 virus, Wang’s team partnered with a group led by Illinois electrical and computer engineering professor Brian Cunningham, who specializes in biosensing. They coupled the NanoGripper with a photonic crystal sensor platform to create a rapid, 30-minute COVID-19 test matching the sensitivity of the gold-standard qPCR molecular tests used by hospitals, which are more accurate than at-home tests but take much longer.

“Our test is very fast and simple since we detect the intact virus directly,” Cunningham said. “When the virus is held in the NanoGripper’s hand, a fluorescent molecule is triggered to release light when illuminated by an LED or laser. When a large number of fluorescent molecules are concentrated upon a single virus, it becomes bright enough in our detection system to count each virus individually.”

In addition to diagnostics, the NanoGripper could have applications in preventive medicine by blocking viruses from entering and infecting cells, Wang said. The researchers found that when NanoGrippers were added to cell cultures that were then exposed to COVID-19, multiple grippers would wrap around the outside of the viruses. This blocked the viral spike proteins from interacting with receptors on the cells’ surface, preventing infection.

“It would be very difficult to apply it after a person is infected, but there’s a way we could use it as a preventive therapeutic,” Wang said. “We could make an anti-viral nasal spray compound. The nose is the hot spot for respiratory viruses, like COVID or influenza. A nasal spray with the NanoGripper could prevent inhaled viruses from interacting with the cells in the nose.”

The NanoGripper could easily be engineered to target other viruses, such as influenza, HIV or hepatitis B, Wang said. In addition, Wang envisions using the NaoGripper for targeted drug delivery. For example, the fingers could be programmed to identify specific cancer markers, and grippers could carry cancer-fighting treatments directly to the target cells.

“This approach has bigger potential than the few examples we demonstrated in this work,” Wang said. “There are some adjustments we would have to make with the 3D structure, the stability and the targeting aptamers or nanobodies, but we’ve developed several techniques to do this in the lab. Of course it would require a lot of testing, but the potential applications for cancer treatment and the sensitivity achieved for diagnostic applications showcase the power of soft nanorobotics.”

The National Institutes of Health and the National Science Foundation supported this work. Wang and Cunningham are affiliated with the Carl R. Woese Institute for Genomic Biology and the Holonyak Micro and Nanotechnology Lab at the U. of I.

Editor’s note: To reach Xing Wang, email @illinois.edu” title=”mailto:xingw@illinois.edu”>xingw@illinois.edu.

The paper “Bioinspired designer DNA NanoGripper for virus sensing and potential inhibition” is available from @aaas.org” title=”mailto:robopak@aaas.org”>robopak@aaas.org. DOI: 10.1126/scirobotic

This work was supported in part by NIH grants R21EB031310, R44DE030852 and R21AI166898.