Incontinence could point to future disability

More frequent incontinence linked to higher chance of bigger health issues

Peer-Reviewed Publication

RUSH UNIVERSITY MEDICAL CENTER

If you are one of the 30% to 50% of women experiencing urinary incontinence, new research suggests that it could turn into a bigger health issue.

Having more frequent urinary incontinence and leakage amounts is associated with higher odds of disability, according to RUSH researchers in a study published in the January issue of Menopause.

“Often symptoms from urinary incontinence are ignored until they become bothersome or limit physical or social activities,” said Sheila Dugan, MD, chair of the Department of Physical Medicine and Rehabilitation at RUSH. “Because this study suggests that urinary incontinence is associated with disability, exploring treatment options in the early stages may help decrease this outcome in midlife women.”

Urinary incontinence affects many women at some point during their lifetime, she said. Some women will leak urine when they sneeze or cough, which is called stress incontinence.

“When you sneeze or cough, there is a mechanical pressure from your belly that overwhelms the sphincter and you leak,” she said.

Others suffer from urge incontinence, which is an overwhelming urge to urinate, such as when they get close to a restroom. Women who experience both have what’s called mixed urinary incontinence, Dugan said.

Researchers considered the amount and frequency of the incontinence and whether the study participant had stress incontinence, urge incontinence, or both.

Researchers then measured disability by the World Health Organization disability assessment scale as the outcome of interest.

“We found that mixed incontinence was the most highly correlated with disability, along with daily incontinence and larger amounts of incontinence,” Dugan said.

Dugan helped create the Program for Abdominal and Pelvic Health at RUSH, which treats several types of conditions, including urinary incontinence. Each patient is examined to determine the causes and treatment options. For example, muscles are evaluated to uncover whether tight bands in the muscles are causing incontinence or whether weak muscles are to blame.

“In a case of tight muscles, a woman may try to tighten the muscles further with more exercise, not knowing that it may make the incontinence worse,” Dugan said. “Pelvic floor muscles support pelvic organs and organ problems can lead to muscle problems or vice versa. One patient may have incontinence due to hip arthritis, another from a difficult delivery, or it can be caused by cancer treatment, for example, radiation in the pelvic area.”

There are a number of potential causes, or even a combination of causes, of incontinence. The data used was from a larger clinical trial called SWAN (the Study of Women Across the Nation) that included more than 1,800 participants. SWAN was initiated in 1994 with seven sites across the U.S. to identify changes that occur during the menopause transition in midlife women and their effects on subsequent health and risk for age-related diseases.

“More studies are needed to show what causes this association, with a focus on prevention,” Dugan said.

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JOURNAL

Menopause

 

Healthcare ethics? Think like an engineer

Innovation in healthcare and biomedicine is in decline, with few tools to assist researchers and entrepreneurs to generate innovative solutions to their problems.

Peer-Reviewed Publication

NATIONAL UNIVERSITY OF SINGAPORE, YONG LOO LIN SCHOOL OF MEDICINE

 

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AN EXAMPLE OF BRAINSWARMING: BRAINSWARMING GRAPHS WERE DESIGNED AS A MEANS OF VISUALISING PROBLEM SOLVING AND FACILITATING SIMULTANEOUS IDEA GENERATION IN A PROBLEM-SOLVING. A SHORT DESCRIPTION OF THE PROBLEM TO BE SOLVED, IN THE CASE STUDY, THE GOAL IS PLACED AT THE TOP OF A TWO-DIMENSIONAL GRAPH ON ANY MEDIUM THAT ALLOWS ADAPTATION AND VISUALISATION, WITH THE AVAILABLE RESOURCES AT THE BOTTOM OF THE GRAPH. THE GOAL IS ITERATIVELY REFINED DOWNWARDS BY PLACING MORE DETAILED EXPRESSIONS OF THE SAME GOAL UNDERNEATH IT. FINALLY, A LINK IS THEN CREATED WHEN THE REFINED GOAL AND AVAILABLE RESOURCES ARE ABLE TO FORM A SOLUTION.

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CREDIT: YONG LOO LIN SCHOOL OF MEDICINE, NATIONAL UNIVERSITY OF SINGAPORE (NUS MEDICINE)

Researchers from the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine) and the University of Oxford have successfully demonstrated how problem-solving techniques used in engineering, known as Innovation Enhancing Techniques, can be adapted and used to improve creativity in problem-solving when it comes to abstract problems faced in healthcare and biomedicine.

Traditional ‘brainstorming’ suffers from inherent biases, such as those relating to group dynamics. To tackle this, Dr Tony McCaffrey, an AI researcher and cognitive psychologist, developed a suite of Innovation Enhancing Techniques (IETs) based on his Obscure Features Hypothesis.

This new cognitive theory of innovation posits that innovative solutions typically emerge from two key steps: first, identifying a rarely or never-before noticed (obscure) feature of a problem's elements, and second, constructing a solution based on this obscure feature. These IETs are crafted to enhance creative problem-solving by helping individuals overcome psychological barriers such as functional fixedness, the tendency to view objects solely in their conventional roles, thereby enabling the generation of innovative ideas.

These techniques were devised for engineering and design problems, which involve solving practical goals, such as building a bridge, using physical materials, such as bricks and cement. However, healthcare and science problems often involve solving abstract goals that may not be easily measurable -- such as improving patients’ health -- using intangible resources – such as software and data. This work is the first to successfully apply these methods to problems in the realm of healthcare and science.

Enhancing creativity and idea generation in biomedicine not only fosters novel approaches to healthcare challenges but also streamlines the research and development process. This can lead to more rapid discovery and implementation of cost-effective healthcare solutions, reducing overall healthcare expenditures. Additionally, creative problem-solving can uncover more efficient uses of existing resources and technologies, potentially lowering the barriers to accessing advanced medical treatments. When directly applied to bioethical goals such as justice and fairness, as in this study, IETs can also be used to further other ethical priorities, including enhanced respect for individuals’ control over their own lives as well as greater fairness in health-related aspects of life.

Hence, to equip researchers, practitioners, and entrepreneurs from diverse fields with innovative tools, a team led by Professor Julian Savulescu from the Centre for Biomedical Ethics at NUS Medicine, alongside Dr. Sebastian Porsdam Mann and Anuraag Vazirani from the University of Oxford, showcased the adaptability of these techniques in generating solutions for problems with abstract goals using intangible resources. Their study, published in Scientific Reports, illustrates this through a case study involving blockchain technology to achieve ethical goals in biomedicine, identifying 100 potential solutions using two IETS --BrainSwarming and the Generic Parts Technique.

BrainSwarming begins with placing the primary objective – in this study, advancing ethical goals in biomedicine - at the top of a two-dimensional graph. This visual representation can be created on digital platforms, whiteboards, or paper. Blockchain technology, the key resource in this study, is placed at the bottom of the graph. The main goal is then broken down into more specific sub-goals.

Next, in order to refine their resources beyond the principle components of Blockchain, the team applied the Generic Parts Technique (GPT), to each artefact. This technique is used to supply new information or to help re-interpret existing information about the resources involved in a problem-solving effort by systematically breaking down the resource into its components.

The teams were subsequently able to identify 100 possible solutions, via links between the refined goals and available resources, that were created and visualised -- representing the potential uses of blockchain technologies to further ethical objectives in clinical and research contexts.

The researchers point out that their success in using these techniques demonstrates their wide applicability across fields and problem types.

“The successful application of these techniques has vast potential to enable individuals to generate innovative ideas across disciplines. These techniques can act as force multipliers for the creative efforts of researchers, entrepreneurs, and other innovators, with significant downstream benefits for individuals and society,” said Prof Savulescu, a senior author of the study.

JOURNAL

Scientific Reports

DOI

10.1038/s41598-023-50232-y 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

BrainSwarming, blockchain, and bioethics: applying Innovation Enhancing Techniques to healthcare and research

ARTICLE PUBLICATION DATE

10-Jan-2024

 

Aging mouse sperm affects MicroRNA, increasing the risk of neurodevelopmental disorders

Peer-Reviewed Publication

TOHOKU UNIVERSITY

 

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RESEARCHERS HAVE DISCOVERED THAT THE THE AGE OF THE MICE IMPACTS MICRORNAS.

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CREDIT: TOHOKU UNIVERSITY

A recent study has reported that changes in mice sperm microRNAs brought about by aging may affect the growth and development of offspring. The finding adds to the growing literature on the effects of paternal aging on offspring.

Details of the study were published in the journal Scientific Reports on December 7, 2023.

Marriages and childbearing later in life are increasingly becoming the norm. Whilst the impacts of maternal age on offspring, such as a higher risk of miscarriage and Down syndrome, are widely understood, the impacts from the paternal side are less so.

Yet this is changing. Recent epidemiological studies have demonstrated that paternal aging exerts a more substantial influence on the heightened risk of neurodevelopmental disorders such as autism spectrum disorder.

A research team led by Professor Noriko Osumi from the Department of Developmental Neuroscience at the Tohoku University Graduate School of Medicine has previously revealed that epigenetic factors, including histone modifications in spermatogenesis and DNA methylation in mice sperm, undergo changes with age. These alterations might lead to transgenerational effects.

However, the impact of paternal aging on microRNAs (miRNAs), small, non-coding RNA molecules that play a crucial role in regulating gene expression, remains under explored.

To rectify this, the same research team has conducted a comprehensive analysis of age-related variations in microRNAs in mice sperm. They compared microRNAs in sperm from mice aged 3, 12, and 20 months and identified the microRNAs that had changed in quantity.

The researchers discovered significant age-associated differences in the microRNAs. Some changes were in microRNAs responsible for regulating the nervous system and genes related to autism spectrum disorder, and these altered microRNAs included those transferred to fertilized eggs.

"Our study reveals the potential association between alteration in sperm microRNAs caused by paternal aging, underscoring the significance of investigating the impact of sperm microRNAs on offspring, an aspect that has been relatively overlooked in previous research," states Osumi.

The anticipation is that further exploration of epigenetic factors, specifically microRNAs, will not only contribute to unraveling the pathogenic mechanisms underlying neurodevelopmental disorders but will also offer insights into promoting the health and disease prevention of successive generations.

Osumi points out that their study widens the net when it comes to exploring the link between paternal age and potential health complications in children. "While the age-related changes in oocytes are well-documented, the focus has predominantly centered on the fertility of sperm. Recognizing the myriad epigenetic transformations associated with sperm aging, as exemplified by the microRNAs examined in this study, becomes imperative."

The findings also gain relevance in the context of Japan's rapidly declining birthrate, which necessitates incorporating the perspective on sperm-related factors in advancing reproductive medicine.

Venn diagram showing the number of miRNAs expressed in sperm samples from mice aged 3 M, 12 M and 20 M. A total of 447 miRNAs were expressed, and about half of them are common. 

The expression levels of miR-10a-5p (left) and miR-146a-5p (right), microRNAs reported to be transferred to the fertilized egg, changes with age. 

CREDIT

Kazusa Miyahara et al.

JOURNAL

Scientific Reports

DOI

10.1038/s41598-023-47878-z 

ARTICLE TITLE

Investigating the impact of paternal aging on murine sperm miRNA profiles and their potential link to autism spectrum disorder

Singapore study reveals impact of early life adversity on a child’s brain development

Peer-Reviewed Publication

AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH (A*STAR), SINGAPORE

Leveraging neuroimaging data from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort, researchers from A*STAR’s Singapore Institute for Clinical Sciences (SICS) identified an association between early life adversity and the pace of brain development in childhood.

SINGAPORE – A study led by researchers from A*STAR's Singapore Institute for Clinical Sciences (SICS) has found evidence suggesting that children exposed to elevatec levels of early life adversity (ELA) exhibit an accelerated pattern of brain development during the preschool years. When exposed to ELA, such as a mother's mental and physical health challenges during pregnancy, the child’s brain undergoes accelerated development in order to adapt to the adverse circumstances. This hastened pace of brain development could lead to a higher risk of adverse cognitive and mental health outcomes. The paper, “The influence of early-life adversity on the coupling of structural and functional brain connectivity across childhood” was published in Nature Mental Health on 4 January 2024.

Exposure to ELA is a recognised risk factor for poor health outcomes throughout life. This includes an increased risk of cognitive impairment as well as the development of mental health disorders such as major depressive disorders. Exposure to ELA in the prenatal period triggers changes in the pace of brain development across childhood, most prominent during the preschool period – a crucial time window whereby experience-dependent learning and adaptation set the stage for future brain function. Previous studies suggest that ‘accelerated brain development’ is an adaptive mechanism to early life challenges and may mediate the association between ELA and poor mental health and cognitive outcomes.

To effectively quantify the impact of ELA, the research team adopted a scoring framework created by Professor Patricia Silveira at McGill University, to produce a composite score of ELA which considered factors that extend across a population. These factors focused on exposures experienced before birth, encompassing the mother's mental and physical health during pregnancy as well as the family’s structure and financial circumstances. When we add up or combine different risk factors, it gives us a better prediction of child’s outcome. Using this composite score, the study team stratified the GUSTO cohort into different levels of cumulative ELA exposure. The pace of brain development was then examined across children exposed to different levels of ELA.

To model the pace of brain development across childhood, the study team utilised multi-modal MRI scans from the GUSTO birth cohort. These MRI brain scans were acquired from 549 children at three time-points, ages 4.5, 6.0 and 7.5 years, allowing the study team to examine the link between ELA and brain development in a longitudinal manner. As most mental health disorders have roots in childhood, the study of developmental trajectories in a longitudinal manner is strongly relevant. In this study, a measure which combines structural connectivity and functional connectivity of the brain was used to provide insights into the association between brain structure and function. This measure, known as structure-function coupling (SC-FC), reflects a child’s potential for neuroplasticity, the brain's ability to adapt and reorganise itself to learn, recover from injury, and adjust to new experiences. In early childhood, the brain is expected to be less specialised and more adaptable, matching a decreasing trajectory of SC-FC over childhood.

Led by Dr Tan Ai Peng, Principal Investigator with A*STAR’s SICS and clinician with National University Hospital, along with Dr Chan Shi Yu, a researcher at A*STAR’s SICS, the study found that exposure to high levels of ELA is linked to a faster decline in SC-FC between ages 4.5 and 6, indicating accelerated brain development. This accelerated pattern of brain development is likely an adaptive mechanism when exposed to environmental cues that requires ‘maturity’. Although this is meant to be a ‘protective mechanism’ against adversity, it does have negative implications in the long term as it results in a shorter window of neuroplasticity and adaptive-learning. Notably, results from this study pinpoint the period between ages 4.5 and 6 years as a potential window for early intervention to improve outcomes for children who were exposed to ELA.

“Our study provided evidence that exposure to early-life challenges affects the pace of brain development across childhood. This, in turn, has significant effects on future cognitive and mental health outcomes. If we can develop screening tools to detect accelerated brain development, we will be able to implement interventions earlier, and prevent cascading consequences of accelerated brain development for mental health.” said, Dr Tan Ai Peng

Already looking forward, the researchers have identified important areas for future investigation – determining whether ELA’s effects on accelerated brain development across childhood set the stage for premature brain ageing in later stages of life, and the effectiveness of intervention strategies that could mitigate the effects of ELA exposure such as the promotion of psychological resilience through cognitive behavioural therapy.

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JOURNAL

Nature Mental Health

DOI

10.1038/s44220-023-00162-5 

ARTICLE TITLE

The influence of early-life adversity on the coupling of structural and functional brain connectivity across childhood

ARTICLE PUBLICATION DATE

4-Jan-2024

 

Smallpox vaccine efficiently induces immunity against monkeypox virus infection in people living with HIV

An observational study conducted by researchers at Pompeu Fabra University and Hospital del Mar determine that intradermal administration of the JYNNEOS vaccine against smallpox induces an efficient immune response that should protect people living with HIV

Peer-Reviewed Publication

UNIVERSITAT POMPEU FABRA - BARCELONA

 

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FROM LEFT TO RIGHT: ITZIAR ARRIETA, MARINA DE FILIPPI, DIANA WORTMANN, ANDREAS MEYERHANS, MARTA SISTERÉ-ORÓ, ROBERT GÜERRI-FERNÁNDEZ, NATALIA GARCÍA-GIRALT, JUAN DU. 

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CREDIT: HOSPITAL DE LA MAR.

Researchers from the Infection Biology Lab at the Department of Medicine and Life Sciences (MELIS) at Pompeu Fabra University and the HIV Unit at Hospital del Mar Research Institute have shown that intradermal vaccination with the JYNNEOS vaccine against smallpox is the best option to protect people living with HIV from contracting the monkeypox virus. This route of vaccine administration requires less material to inject each patient, extending the available vaccine doses by a factor of five. The results of this observational study also indicate that individuals with a low level of CD4 T cells, a type of white blood cell essential to properly fight new infections, need a booster dose 28 days after the first dose to compensate for their immunosuppressed status.

Monkeypox (mpox) is a zoonotic virus of the variola virus family that causes smallpox. Mpox causes an infectious disease that can spread autochthonously between humans through direct contact and respiratory routes. The most common symptoms of monkeypox infection are fever, headache, muscle pain, swollen lymph nodes, rash, respiratory and rectal symptoms, and exhaustion. Its severity depends on age and the response of the immune system to resist pathogens and parasites.

Prior to the spring of 2022, monkeypox used to appear in the form of single outbreaks in endemic areas of Central and West Africa, but at this time a global outbreak occurred that facilitated human-to-human transmission. Transmission was mainly between men who had sex with men, a population group with many HIV-infected individuals, who are particularly susceptible to monkeypox virus infection and pathogenicity.

Although there is no specific vaccine against monkeypox, the smallpox vaccine protects eight out of ten people from monkeypox infection due to the antigenic relatedness between the two viruses.

 

Fighting monkeypox while living with HIV

Results of the study published today in Journal of Medical Virology indicate that the activity of T cells, responsible for the response against pathogens, homeostasis and the system's memory, in HIV-1-infected individuals, whose viral load was controlled by antiretroviral therapy, was enhanced after vaccination with the JYNNEOS smallpox vaccine. T cell responses were equivalent to those of healthy control individuals.

Among individuals living with HIV infection, there is an at-risk group that deserves special attention. It comprises so-called immunological non-responders (INR), individuals who control their viral loads after antiretroviral therapy but only partially recover their CD4 T-lymphocyte count.

“Our study shows that these INRs may need a booster dose 28 days after the first vaccination to generate an efficient T cell response and thus be protected against monkeypox”, explains Robert Güerri, the Hospital del Mar clinician who coordinated the vaccination study and is also an associate professor at UPF. Together, the new findings underscore the importance of specific studies on the immune response among people with HIV, especially those with lower CD4 white blood cells.  

 

Vaccine administration routes modulate the immune response

Before the monkeypox outbreak in the spring of 2022, the JYNNEOS vaccine was administered subcutaneously to protect the population. But due to the increased vaccine demands, in August 2022, American and European health authorities proposed the intradermal administration route of the JYNNEOS vaccine. Via this route, the vaccine is released into the upper layer of the skin where many immune cells are located. But most importantly, this procedure extends the available vaccine doses by a factor of five, increasing vaccine availability without compromising its efficacy.

In contrast to the T-cell response of HIV-1-infected individuals who received the JYNNEOS vaccine subcutaneously, all individuals who received the vaccine intradermally generated a significant T-cell response. Therefore, intradermal vaccination was more effective in activating specific antiviral immunity.

“Our results clearly support the proposed dose-sparing vaccination route also for the protection of immunocompromised individuals who need the vaccine the most”, adds Andreas Meyerhans, an ICREA researcher and UPF full professor, who coordinated the experimental part of the study.

This study provides an early indication of how best to proceed with preventive vaccination against monkeypox in a group of individuals at high risk of infection. However, further studies should confirm and expand on the observations derived from a small number of vaccinated individuals.

 

Reference article

Sisteré-Oró et al., Pan-pox-specific T cell responses in HIV-1-infected individuals after JYNNEOS vaccination. J Med Virol. 2023 Dec. DOI: doi:10.1002/jmv.29317

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JOURNAL

Journal of Medical Virology

DOI

10.1002/jmv.29317 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Pan-pox-specific T cell responses in HIV-1-infected individuals after JYNNEOS vaccination

 

Psychotherapy effective in treating post-traumatic stress disorder following multiple traumatic events

International meta-study: Team led by researchers from the University of Münster reports encouraging results for patients and therapists

Peer-Reviewed Publication

UNIVERSITY OF MÜNSTER

 

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PROF NEXHMEDIN MORINA (LEFT) AND DR THOLE HOPPEN

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CREDIT: THOLE HOPPEN

Psychotherapy is an effective treatment for adults with post-traumatic stress disorder (PTSD) following exposure to multiple traumatic events. This is the conclusion arrived at by an international team of researchers led by psychologists Dr Thole Hoppen and Prof Nexhmedin Morina from the Department for Clinical Psychology and Psychotherapy at the University of Münster (Germany). The efficacy of psychotherapeutic interventions for treating PTSD in adults has been well-documented in various studies. However, until now, it had not been established whether the efficacy of psychotherapeutic interventions varies depending on whether the disorder is caused by one single event – for example, a traffic accident – or by multiple traumatic events such as during warfare or repeated incidents of sexual or physical violence. The meta-analysis, carried out based on data from around 10,600 patients, has now been published in the journal Lancet Psychiatry.

In this study, the team of researchers – which also included Prof Richard Meiser-Stedman from the University of East Anglia (UK), Dr Ahlke Kip from the University of Münster, and Prof Marianne Skogbrott Birkeland from the Research Centre for Violence and Traumatic Stress Studies in Norway – evaluated 137 empirical articles published over the past four decades on the treatment of PTSD in adults. Nexhmedin Morina concludes: “The data show that several psychological interventions are highly effective in treating PTSD following multiple traumatic events – in fact, they are about as effective as when the PTSD follows a single trauma.” These results had, to date, only been reported for the treatment of children and adolescents with PTSD. Now, this study confirms that it also applies in the treatment of PTSD in adults. This is “very encouraging news” for both patients and therapists.

Around four per cent of the global population suffers from PTSD as a result of traumatic events. The characteristic symptoms of PTSD include distressing intrusive traumatic memories, avoidance behaviour and difficulty with emotional regulation. The new findings have implications for the clinical practice and training of psychotherapists and mental health professionals more generally. “Our data helps remove treatment barriers for patients with a history of multiple traumatic events,” says Thole Hoppen. “In addition to patients’ fear of talking about their traumatic experiences, some psychotherapists hesitate to directly address traumatic experiences during treatment,” he adds. “However, trauma-focused cognitive behavioural therapy – a form of psychotherapy which helps process the traumatic memories – is not only very effective according to the accumulated data but more effective than non-trauma-focused interventions.” As a result, trauma-focused cognitive behavioural therapy is the first line of treatment recommended in national and international treatment guidelines. However, adds Hoppen, future research requires longer-term data to enable a more solid estimation of the long-term efficacy of the treatment.

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JOURNAL

The Lancet Psychiatry

DOI

10.1016/S2215-0366(23)00373-5 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The efficacy of psychological interventions for adult post-traumatic stress disorder following exposure to single versus multiple traumatic events: a meta-analysis of randomised controlled trials

ARTICLE PUBLICATION DATE

11-Jan-2024

FIAT LUX

Capturing greenhouse gases with the help of light

Peer-Reviewed Publication

ETH ZURICH

 

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IN THE NEW PROCESS, AIR IS CHANNELLED THROUGH A LIQUID TO CAPTURE CO2. IF THE LIQUID IS IRRADIATED WITH LIGHT, THE GREENHOUSE GAS IS RELEASED AGAIN AND CAN BE COLLECTED (AI-​GENERATED SYMBOL IMAGE).

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CREDIT: ETH ZURICH

If we want to slow down global warming, we need to drastically reduce greenhouse gas emissions. Among other things, we need to do without fossil fuels and use more energy-​​efficient technologies. However, reducing emissions alone won’t do enough to meet the climate targets. We must also capture large quantities of the greenhouse gas CO2 from the atmosphere and either store it permanently underground or use it as a carbon-​​neutral feed material in industry. Unfortunately, the carbon capture technologies available today require a lot of energy and are correspondingly expensive.

That’s why researchers at ETH Zurich are developing a new method that uses light. With this process, in the future, the energy required for carbon capture will come from the sun.

Light-​controlled acid switch

Led by Maria Lukatskaya, Professor of Electrochemical Energy Systems, the scientists are exploiting the fact that in acidic aqueous liquids, CO2 is present as CO2, but in alkaline aqueous liquids, it reacts to form salts of carbonic acid, known as carbonates. This chemical reaction is reversible. A liquid’s acidity determines whether it contains CO2 or a carbonate.

To influence the acidity of their liquid, the researchers added molecules, called photoacids, to it that react to light. If such liquid is then irradiated with light, the molecules make it acidic. In the dark, they return to the original state that makes the liquid more alkaline.

This is how the ETH researchers’ method works in detail: The researchers separate CO2 from the air by passing the air through a liquid containing photoacids in the dark. Since this liquid is alkaline, the CO2 reacts and forms carbonates. As soon as the salts in the liquid have accumulated to a significant degree, the researchers irradiate the liquid with light. This makes it acidic, and the carbonates transform to CO2. The CO2 bubbles out of the liquid, just as it does in a bottle of cola, and can be collected in gas tanks. When there is hardly any CO2 left in the liquid, the researchers switch off the light and the cycle starts all over again, with the liquid ready to capture CO2.

It all depends on the mixture

In practice, however, there was a problem: the photoacids used are unstable in water. “In the course of our earliest experiments, we realised that the molecules would decompose after one day,” says Anna de Vries, a doctoral student in Lukatskaya’s group and lead author of the study.

So Lukatskaya, de Vries and their colleagues analysed the decay of the molecule. They solved the problem by running their reaction not in water but in a mixture of water and an organic solvent. The scientists were able to determine the optimum ratio of the two liquids by laboratory experiments and were able to explain their findings thanks to model calculations carried out by researchers from the Sorbonne University in Paris.

For one thing, this mixture enabled them to keep the photoacid molecules stable in the solution for nearly a month. For another, it ensured that light could be used to switch the solution back and forth as required between being acidic and being alkaline. If the researchers were to use the organic solvent without water, the reaction would be irreversible.

Doing without heating

Other carbon capture processes are cyclical as well. One established method works with filters that collect the CO2 molecules at ambient temperature. To subsequently remove the CO2 from the filters, these have to be heated to around 100 degrees Celsius. However, heating and cooling are energy-​intensive: they account for the major share of the energy required by the filter method. “In contrast, our process doesn’t need any heating or cooling, so it requires much less energy,” Lukatskaya says. More than that, the ETH researchers’ new method potentially works with sunlight alone.

“Another interesting aspect of our system is that we can go from alkaline to acidic within seconds and back to alkaline within minutes. That lets us switch between carbon capture and release much more quickly than in a temperature-​driven system,” de Vries explains.

With this study, the researchers have shown that photoacids can be used in the laboratory to capture CO2. Their next step on the way to market maturity will be to further increase the stability of the photoacid molecules. They also need to investigate the parameters of the entire process to optimise it further.

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JOURNAL

Chemistry of Materials

DOI

10.1021/acs.chemmater.3c02435 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Solvation-​Tuned Photoacid as a Stable Light-​Driven pH Switch for CO2 Capture and Release