“The massive use of antibiotics and antimicrobials in people and animals has led to these substances appearing in unexpected environmental samples,” said Irantzu Vergara, researcher in the UPV/EHU’s IBeA group. Drugs that do not end up fully metabolised in the body reach the environment through various routes (such as manure, sewage sludge used as fertilisers, etc.), are leached into the soil and may end up transferring to crops or earthworms, which are at the base of the food chain. “Although no short-term toxicity has been demonstrated in humans, the unintended consumption of antibiotics in the diet can cause problems for allergic individuals; and the effects of long-term exposure remain unknown. However, the biggest problem associated with this contamination is the spread of multi-resistant bacteria; it is difficult to find an effective treatment in the event of infection, which is responsible for 33,000 deaths per year across Europe,” explained Vergara.

To address this problem, the IBeA research group has developed two analytical methods enabling very low concentrations of antimicrobials in vegetables and earthworms to be detected: “Although high drug concentrations can be expected in manure, much lower concentrations are expected after these substances have transferred to plants or earthworms, so sensitive methods are needed to detect them,” said Vergara.

The methods developed by Vergara in the UPV/EHU labs enable a wide range of antimicrobial drugs to be simultaneously determined, as well as various products deriving from their transformation. As the researcher explained, “the drugs can be excreted in their original form or transformed after being metabolised (after undergoing certain changes in the body). What is more, these are very sensitive compounds which, under conditions of temperature, humidity, light, etc., can be very easily degraded and transformed in the environment.”

The methods constitute a significant breakthrough, as “until now there have been no analytical methods to simultaneously study a wide range of antimicrobials in plants and earthworms, and they did not focus on the analysis of transformation products, either. Each family of antibiotics has different physicochemical properties, and it is very important that the same analytical method can be used to analyse all of them. We have also achieved pretty low detection limits, which allow us to detect very low concentrations of these substances in the environment.”

Samples of vegetables taken in different locations across the Basque Autonomous Community

In the case of vegetables, the research group took samples from different locations of the Basque Country, from both organic and non-organic agriculture. “We set out to measure the scale of the antibiotics problem in the Basque Autonomous Community. The analytical studies conducted revealed data on the existence of antimicrobial drugs and their derivatives in vegetables: we found that there is a transfer of both antimicrobials and degradation products between soil and vegetables. In other words, there is a problem of antimicrobial contamination in the Basque Country,” she added.

In the case of earthworms, however, they conducted an experiment under controlled conditions of exposure, in other words “this is a study designed and conducted in the laboratory using earthworms. We wanted to check whether, in the case of contaminated soil, the earthworms that feed on this soil are able to accumulate antimicrobials in their bodies. The study did in fact reveal an accumulation of these antimicrobials in the body, which generate a large variety of previously unreported transformation products.”

Vergara stressed the need to “continue multidisciplinary research along these lines, as this is a problem that is going to affect everyone over the coming decades.” Water treatment plants currently do not have fully effective treatments to remove residual drugs, and this water is often used for irrigation. “As there is such a large, constant input of antimicrobials into the environment, the bacteria are getting used to coexisting with them and generating resistance,” she explained. The researcher warned that “in fact, there are already cases in which there are no effective treatments for people who become infected with multi-resistant bacteria. It is important to drive forward research in order to minimise the problem or to start to look for solutions in the short to medium term.”

Known as piezoelectricity, the ability to trade between mechanical stress and electric charge can be harnessed widely in capacitors, actuators, transducers and sensors like accelerometers and gyroscopes for next-generation electronics. However, integrating these materials into miniaturized systems has been difficult due to the tendency of electromechanically active materials to — at the submicrometer scale, when the thickness is just a few millionths of an inch — get “clamped” down by the material they are attached to, which significantly dials down their performance.

Rice University researchers and collaborators at the University of California, Berkeley have found that a class of electromechanically active materials called antiferroelectrics may hold the key to overcoming performance limitations due to clamping in miniaturized electromechanical systems. A new study published in Nature Materials reports that a model antiferroelectric system, lead zirconate (PbZrO₃), produces an electromechanical response that can be up to five times greater than that of conventional piezoelectric materials even in films that are only 100 nanometers (or 4 millionths of an inch) thick.

“We’ve been using piezoelectric materials for decades,” said Rice materials scientist Lane Martin, who is the corresponding author on the study. “Recently there has been a strong motivation to further integrate these materials into new types of devices that are very small — as you would want to do for, say, a microchip that goes inside your phone or computer. The problem is that these materials are typically just less usable at these small scales.”

According to current industry standards, a material is considered to have very good electromechanical performance if it can undergo a 1% change in shape — or strain — in response to an electric field. For an object that measures 100 inches in length, for instance, getting 1 inch longer or shorter represents 1% strain.

“From a materials science perspective, this is a significant response, since most hard materials can only change by a fraction of a percent,” said Martin, the Robert A. Welch Professor, professor of materials science and nanoengineering and director of the Rice Advanced Materials Institute.

When conventional piezoelectric materials are scaled down to systems less than a micrometer (1,000 nanometers) in size, their performance generally deteriorates significantly due to the interference of the substrate, which dampens their ability to change shape in response to electric field or, conversely, to generate voltage in response to a change in shape.

According to Martin, if electromechanical performance were rated on a scale of 1-10 — where 1 is lowest performance and 10 is the industry standard of 1% strain — then clamping is typically expected to bring conventional piezoelectrics’ electromechanical response down from a 10 to the 1-4 range.

“To understand how clamping impacts motion, first picture being in a middle seat on an airplane with no one on either side of you — you’d be free to adjust your position if you get uncomfortable, overheated, etc.,” Martin said. “Now picture the same scenario, except now you’re seated between two huge offensive linemen from Rice’s football team. You’d be ‘clamped’ between them such that you really couldn’t meaningfully adjust your position in response to a stimulus.”

The researchers wanted to understand how very thin films of antiferroelectrics — a class of materials that remained understudied until recently due to a lack of access to “model” versions of the materials and to their complex structure and properties — changed their shape in response to voltage and whether they were likewise susceptible to clamping.

First, they grew thin films of the model antiferroelectric material PbZrO ₃ with very careful control of the material thickness, quality and orientation. Next, they performed an array of electrical and electromechanical measurements to quantify the responses of the thin films to applied electric voltage.

“We found the response was considerably larger in the thin films of antiferroelectric material than what is achieved in similar geometries of traditional materials,” said Hao Pan, a postdoctoral researcher in Martin’s research group and lead author on the study.

Measuring shape change at such small scales was not an easy feat. In fact, optimizing the measurement setup required so much labor the researchers documented the process in a separate publication.

“With the perfected measurement setup, we can get a resolution of two picometers — that’s about a thousandth of a nanometer,” Pan said. “But just showing that a shape change happened doesn’t mean we understand what’s going on, so we had to explain it. This was one of the first studies to reveal the mechanisms behind this high performance.”

With support from their collaborators at the Massachusetts Institute of Technology, the researchers used a state-of-the-art transmission electron microscope to observe the nanoscale material shapeshift with atomic resolution in real time.

“In other words, we watched the electromechanical actuation as it was happening, so we could see the mechanism for the large shape changes,” Martin said. “What we found was that there is an electric voltage-induced change in the crystal structure of the material, which is like the fundamental building unit or single type of Lego block from which the material is built. In this case, that Lego block gets reversibly stretched with applied electric voltage, giving us a big electromechanical response.”

Surprisingly, the researchers found that not only does clamping not interfere with material performance, but it in fact enhances it. Together with collaborators at Lawrence Berkeley National Laboratory and Dartmouth College, they recreated the material computationally in order to get another view of how the clamping affects the actuation under applied electric voltage.

“Our results are the culmination of years of work on related materials, including the development of new techniques to probe them,” Martin said. “By figuring out how to make these thin materials work better, we’re hoping to enable the development of smaller and more powerful electromechanical devices or microelectromechanical systems (MEMS) — and even nanoelectromechanical systems (NEMS) — that use less energy and can do things we never thought possible before.”

For the first time in the history of astronomy, researchers at the Niels Bohr Institute have witnessed the birth of three of the universe’s absolute earliest galaxies, somewhere between 13.3 and 13.4 billion years ago.

The discovery was made using the James Webb Space Telescope, which brought these first ‘live observations’ of formative galaxies down to us here on Earth.

Through the telescope, researchers were able to see signals from large amounts of gas that accumulate and accrete onto a mini-galaxy in the process of being built. While this is how galaxies are formed according to theories and computer simulations, it had never actually been witnessed.

“You could say that these are the first ‘direct’ images of galaxy formation that we’ve ever seen. Whereas the James Webb has previously shown us early galaxies at later stages of evolution, here we witness their very birth, and thus, the construction of the first star systems in the universe,” says Assistant Professor Kasper Elm Heintz from the Niels Bohr Institute, who led the new study.

Galaxies born shortly after the Big Bang

The researchers estimate the birth of the three galaxies to have occurred roughly 400-600 million years after the Big Bang, the explosion that began it all. While that sounds like a long time, it corresponds to galaxies forming during the first three to four percent of the universe’s 13.8-billion-year overall lifetime.

Shortly after the Big Bang, the universe was an enormous opaque gas of hydrogen atoms — unlike today, where the night sky is speckled with a blanket of well-defined stars.

“During the few hundred million years after the Big Bang, the first stars formed, before stars and gas began to coalesce into galaxies. This is the process that we see the beginning of in our observations,” explains Associate Professor Darach Watson.

The birth of galaxies took place at a time in the history of the universe known as the Epoch of Reionization, when the energy and light of some of the first galaxies broke through the mists of hydrogen gas.

It is precisely these large amounts of hydrogen gas that the researchers captured using the James Webb Space Telescope’s infrared vision. This is the most distant measurement of the cold, neutral hydrogen gas, which is the building block of the stars and galaxies, discovered by scientific researchers to date.

Adds to the understanding of our origins

The study was conducted by Kasper Elm Heintz, in close collaboration with, among others, research colleagues Darach Watson, Gabriel Brammer and PhD student Simone Vejlgaard from the Cosmic Dawn Center at the University of Copenhagen’s Niels Bohr Institute — a center whose stated goal is to investigate and understand the dawn of the universe. This latest result brings them much closer to doing just that.

The research team has already applied for more observation time with the James Webb Space Telescope, with hopes of expanding upon their new result and learning more about the earliest epoch in the formation of galaxies.

“For now, this is about mapping our new observations of galaxies being formed in even greater detail than before. At the same time, we are constantly trying to push the limit of how far out into the universe we can see. So, perhaps we’ll reach even further,” says Simone Vejlgaard.

According to the researcher, the new knowledge contributes to answering one of humanity’s most basic questions.

“One of the most fundamental questions that we humans have always asked is: ‘Where do we come from?’. Here, we piece together a bit more of the answer by shedding light on the moment that some of the universe’s first structures were created. It is a process that we’ll investigate further, until hopefully, we are able to fit even more pieces of the puzzle together,” concludes Associate Professor Gabriel Brammer.

The study was conducted by researchers Kasper E. Heintz, Darach Watson, Gabriel Brammer, Simone Vejlgaard, Anne Hutter, Victoria B. Strait, Jorryt Matthee, Pascal A. Oesch, Pall Jakobsson, Nial R. Tanvir, Peter Laursen, Rohan P. Naidu, Charlotte A. Mason, Meghana Killi, Intae Jung, Tiger Yu-Yang Hsiao, Abdurro’uf, Dan Coe, Pablo Arrabal Haro, Steven L. Finkelstein, & Sune Toft.

The Danish portion of the research is funded by the Danish National Research Foundation and the Carlsberg Foundation.

HOW THEY DID IT

Researchers were able to measure the formation of the universe’s first galaxies by using sophisticated models of how light from these galaxies was absorbed by the neutral gas located in and around them. This transition is known as the Lyman-alpha transition.

By measuring the light, the researchers were able to distinguish gas from the newly formed galaxies from other gas. These measurements were only possible thanks to the James Webb Space Telescope’s incredibly sensitive infrared spectrograph capabilities.

ABOUT THE EARLY UNIVERSE

The universe began its “life” about 13.8 billion years ago in an enormous explosion — the Big Bang. The event gave rise to an abundance of subatomic particles such as quarks and electrons. These particles aggregated to form protons and neutrons, which later coalesced into atomic nuclei. Roughly 380,000 years after the Big Bang, electrons began to orbit atomic nuclei, and the simplest atoms of the universe gradually formed.

The first stars were formed after a few hundred million years. And within the hearts of these stars, the larger and more complex atoms that we have around us were formed.

Later, stars coalesced into galaxies. The oldest galaxies known to us were formed about 3-400 million years after the Big Bang. Our own solar system came into being about 4.6 billion years ago — more than 9 billion years after the Big Bang.