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A net zero emissions plan for the UK

In its new report, the government’s advisory Committee on Climate Change (CCC) says we should aim to reduce greenhouse gas emissions to net zero by 2050. It wants a legislated UK target for a 100% reduction in greenhouse gases from 1990 levels, which should cover all sectors of the economy, including international aviation and shipping, and be in the place this year. It should be met via UK effort, without relying on internationally traded carbon credits. With its higher emissions from agriculture, Wales should set a target for a 95% cut in emissions by 2050. Better-placed Scotland should aim for net-zero emissions by 2045, and in the interim 70% by 2030 and 90% by 2040; the Scottish government has now agreed to that.

UK Committee on Climate Change recommends net zero emissions by 2050

However, the CCC says all this will need new policies: “current policy is insufficient for even the existing targets”. Its proposals certainly are quite ambitious. For example, the CCC looks to extensive electrification, particularly of transport. By 2035 at the latest, “all new cars and vans should be electric (or use a low-carbon alternative such as hydrogen)”. Electrification of heating is also backed strongly, with both these policies aided by a major expansion of renewable and other low-carbon power generation, including possibly some nuclear. Their scenarios have around a doubling of electricity demand, with all power produced from zero/low-carbon sources, compared to 50% today. The CCC says that could, for example, “require 75 GW of offshore wind in 2050, compared to 8 GW today and 30 GW targeted by the Government’s sector deal by 2030. 75 GW of offshore wind would require up to 7500 turbines and could fit within 1–2% of the UK seabed, comparable to the area of sites already leased for wind projects by the Crown Estate”.

The CCC also wants to see the development of a hydrogen economy to service demands for some industrial processes, for energy-dense applications in long-distance heavy goods vehicles (HGVs) and ships, and for electricity supply and heating in peak periods, topping up the heat provided mainly by electric heat pumps. By 2050 “a new low-carbon industry is needed with UK hydrogen production capacity of comparable size to the UK’s current fleet of gas-fired power stations”. In addition, the CCC sees carbon capture and storage (CCS) expanding in industry especially, and thinks direct air capture may be viable, but it also calls for vast expansion of tree planting and carbon sequestration via revised farming practices, as well as a shift to less meat-eating, to further cut emissions.

Costs not prohibitive

Crucially the CCC says that, despite its ambitious technology programme, the “overall costs are manageable” although they “must be fairly distributed”. There have been rapid cost reductions from mass deployment for key technologies, e.g. the committee says, offshore wind and batteries for electric vehicles (EVs), so “we now expect that a net-zero GHG [greenhouse gas] target can be met at an annual resource cost of up to 1–2% of GDP to 2050, the same cost as the previous expectation for an 80% reduction from 1990”. However, “the transition, including for workers and energy bill payers, must be fair, and perceived to be fair. Government should develop the necessary frameworks to ensure this. An early priority must be to review the plan for funding and the distribution of costs for businesses, households and the Exchequer.”

the CCC adopts a belt and braces approach
Dave Elliott

“Electricity bill payers (households and businesses) currently pay around £7bn a year towards the roll-out of low-carbon power,” the CCC says. “This is expected to rise to around £12bn by 2030 then fall to 2050 as contracts for existing renewable generators come to an end and they are replaced by newer cheaper generation (e.g. our scenarios involve an annual resource cost of around £4bn in 2050). For households, the average costs so far, of £105 per household per year in 2016, have been more than outweighed by savings from improved energy efficiency: energy bills fell £115 in real terms from 2008 to 2016. That balance will continue to 2030 (i.e. overall bills need not rise as a result of climate policy).” And, generally, while the programme would need increased investment, that would be offset by reduced fuel costs: “For example, wind and solar farms are costly to build, but avoid the need to pay for gas and coal; energy efficiency involves an upfront cost followed by reduced energy use.” And by 2050, the CCC says, EV/electrification should “cut the annual costs of UK transport by around £5bn”.

Power-to-gas marginal

A key message underlying this optimism is that most of the technologies will be cheaper and offer cost-saving routes forward, although “CCS and hydrogen are important exceptions requiring both increased upfront spend and higher fuel costs”. Interestingly, in this context, the technical annex downplays the hydrogen “power-to-gas” (P2G) electrolysis route: “The cost of electricity would have to be less than £10/MWh for electrolysis to be the same cost as we expect for gas reforming with CCS in the UK, or energy consumption from electrolysis would have to reduce significantly. While there is some opportunity to utilize some ‘surplus’ electricity (e.g. from renewables generating at times of low demand) for hydrogen production, our modelling shows that the quantity is likely to be small in comparison to the potential scale of hydrogen demand. Producing hydrogen in bulk from electrolysis would be much more expensive and would entail extremely challenging build rates for zero-carbon electricity generation capacity.”

Hydrogen: the word from the UK’s Committee on Climate Change

Illustration of globe covered in wind turbines and solar panels

In its net-zero 2050 scenario CCC has a vast 270 TWh of hydrogen production, compared to around 300 TWh of electricity generation currently. Most (225 TWh) of this 270 W is produced from 29 GW of Steam Methane Reformation (SMR) plants using fossil gas, coupled with CCS to make it lower carbon. And only 2 TWh gets used for power-grid balancing. By contrast, there’s only 6–17 GW of renewable-powered electrolyser capacity at max (indeed just 2–7 GW is cited later on), depending on load factors, which the CCC says could range from 30–90%, with 74% efficiency. Running 90% of the time makes better use of the electrolyser, thus reducing costs. But that implies going beyond just using occasional renewable output surpluses (available maybe 30% of the time), so more renewable capacity would be needed, adding to the cost. “Our scenarios assume that hydrogen production at scale is done via gas-reforming with CCS rather than electrolysis,” the CCC says. “If all hydrogen in our scenarios were produced via electrolysis this would increase electricity generation by over 305 TWh.”

On the fossil-gas SMR side, the CCC assumes methane reformation is 80% efficient and that CCS can capture 95% of process carbon dioxide. But it says these estimates “should be considered upper bounds”. They do seem very high. The likely net carbon saving for the proposed Leeds H21 SMR/CCS project has been put at 59% compared to normal gas heating. So P2G still looks worth backing, not least as it avoids curtailment, with some claiming that it will be competitive by 2035.

Renewables to the fore

Although the CCC is cautious on bioenergy, with its estimates of global bioenergy supply potential being “notably lower than assumed in many of the scenarios assessed by the IPCC”, renewables are otherwise pushed hard but, the committee claims, not unrealistically: “Our scenarios are based on existing technologies and make conservative assumptions around their development and take-up of low-carbon behaviours. If mass roll-out of currently niche technologies leads to rapid cost reductions (e.g. as witnessed globally for batteries and solar panels and in Europe for offshore wind), the scenarios will be significantly easier to deliver.”

Overall, the CCC says “while the policy challenge in delivering these scenarios is undeniable, there is good reason to believe that the range of options could be wider and/or cheaper than we have assumed”. For example, it sees nuclear costs falling by 28% by 2050 and it also seems to see nuclear possibly playing a role in grid-balancing. Presumably the CCC is thinking of future small modular reactors, some of which are claimed will be more flexible than the existing, or planned, large plants. That seems some way off.

However, on this and some of the other technology options, the CCC adopts a belt and braces approach: “if the speculative options to reduce UK emissions do not develop sufficiently, or if there is a shortfall in delivery of the other elements of the scenarios, then international carbon units (i.e. credits or offsets) could provide contingency”. For example, it suggests that the UK “could support a net-zero target for aviation, requiring that all emissions are offset by removals”, assuming, presumably, they can’t be cut significantly in other ways, technically or by reducing demand. The latter option, and the prospect that flying will cost more, may be one of the less popular aspects of the plan. However, the CCC analysis also provides ammunition for those who argue that there will be no need for, or indeed room for, nuclear in this future system.

Job-exposure matrix sheds light on plutonium workers’ radiation exposure

Researchers in the UK have developed a new method for evaluating plutonium workers’ historical internal radiation exposure. They focused their study on workers employed at the start of plutonium operations at the Sellafield (formerly Windscale) nuclear reprocessing facility (J. Radiol. Prot. 10.1088/1361-6498/ab1168).

Internal exposure to plutonium, which decays via alpha particle emission, is a recognised health hazard. But with little specific information available, potential risks from plutonium exposure have largely been assessed through knowledge of radiation exposure risks in general, much of which comes from external exposure to photon radiation such as gamma and X-rays. However, due to its high linear energy transfer rate, alpha particle radiation exhibits significantly enhanced biological effects at the cellular level, creating a specific need to investigate the associated exposure risks.

“To obtain more direct estimates of potential internal exposure risks, epidemiological studies of plutonium workers need to be conducted,” explains lead author Tony Riddell, from Public Health England’s Centre for Radiation, Chemical and Environmental Hazards. “These studies require individual plutonium exposure estimates that are as accurate and unbiased as possible.”

The Sellafield workforce includes one of the world’s largest cohorts of plutonium workers. Through the support of the workforce, this group has been comprehensively monitored for internal exposure to plutonium, primarily through inhalation.

However, for 630 workers employed there at the start of plutonium operations, from 1952 to 1963, the historical urinalysis results available do not provide sufficiently accurate and unbiased exposure assessments. These results were based on a threshold level of urinary plutonium excretion, which was suitable for operational protection purposes at the time, but tended to overestimate exposure, leading to underestimation of any risks if used in epidemiological analyses.

“This means these early workers are excluded from epidemiological studies of exposure risks, which significantly reduces the power of these studies,” says Riddell. “Early workers are important for assessing potential exposure risks because they usually received some of the highest plutonium exposures and, due to the passage of time, health outcomes for these workers will now be largely known.”

To solve this problem, Riddell and colleagues employed an approach called a job-exposure matrix (JEM). The JEM approach uses exposure data from other sources to estimate the average exposure that a typical worker (in the same work group) would have received in a given period. Substituting the missing data with these JEM estimates allowed the researchers to build a more reliable picture of the early workers’ radiation exposure.

“To overcome the problem of missing or deficient exposure data, we used more reliable data from other relevant workers (‘exposure analogues’) along with statistical, mathematical and empirical analyses to estimate the average exposures for a typical worker at Windscale/Sellafield for all combinations of specific occupation and year required to build the JEM,” explains principal investigator Frank De Vocht from the University of Bristol.

The authors note that the exposure analogues approach developed in this study provides a generic methodological advance that is potentially transferable to other internally exposed workers, and which may permit other epidemiological cohorts to include significant groups of workers who otherwise might have been excluded due to the lack of reliable exposure information.

“It’s likely that replacing the missing or unreliable exposure data with JEM-derived values in future epidemiological studies could have considerable impact on the risk estimates which can be produced,” adds De Vocht.

The MR-linac: initial clinical experience

The Elekta Unity is the first high-field MR-guided radiotherapy system. The device integrates a diagnostic quality 1.5 T MR scanner with a state-of-the-art linear accelerator, and in the second half of last year received both the European CE mark and FDA 510(k) clearance.

The Royal Marsden and the Institute of Cancer Research (ICR) was among the first sites to acquire an Elekta Unity. And last September, it announced the first patient treatment in the UK using an MR-linac. Tami Freeman spoke to Uwe Oelfke, head of the joint department of physics at The Royal Marsden and the ICR, to find out more about the hospital’s initial clinical experience of MR-guided radiotherapy.

TF: Why did The Royal Marsden/ICR decided to install an Elekta Unity MR-linac?

UO: It can provide us with the opportunity to see what we want to treat, and with exceptional soft-tissue contrast. With MRI, we can now see the complete relevant anatomy prior to and during treatment, and that provides a tremendous advantage.

How did the initial set-up and implementation go?

The commissioning process was very straightforward; it took some time but we had extremely good support from Elekta. We had to train physicists and radiographers to work in the environment of a magnetic field, but we started these efforts way before our first treatment. We also hired some new staff and now have two radiographers and a physicist assigned to the operation of this machine.

Your first treatments were on patients with prostate cancer, why was this particular cancer type chosen?

One reason for choosing the prostate was that Alison Tree [consultant clinical oncologist at The Royal Marsden] is the lead of the prostate tumour site group in Elekta’s MR-linac consortium. She wrote the protocol that is used for all prostate treatments in the consortium.

For us, it was also the easiest site to adopt. On a purely practical level, there’s no large organ motion expected and there are many patients available. These prostate treatments are part of the PRISM clinical trial, which states that we should include 30 patients. We have finished treatments on 11 patients now.

Are you working closely with the other sites in the MR-linac consortium?

Yes, for the founding members of the consortium there is a common data sharing protocol called the MOMENTUM framework. All seven international centres have signed up to this and we are sharing the data, which are stored in a central database at UMC in Utrecht.

The aim is that all MR-linac treatments will be part of trials. But — with the exception of UMC Utrecht, which has two MR-linacs — each institution only has one. In order to get sufficient patient numbers for the clinical studies we have to use the same protocols, share the study data and analyse all the data together. That’s the spirit of this consortium.

How has having MR guidance impacted the treatments?

Even for a case like the prostate, we have observed anatomical changes that we have never seen before — simply because we couldn’t. For instance, the placement of the bowel with respect to the prostate target completely varied daily for some patients; this was a big surprise to us. We can also see, for example, the bladder filling in detail over the time of treatment. It is very nice to have the ability to see what is really happening in the patient.

MR images of the patient are recorded prior to every fraction, do you use these for treatment replanning?

Every day, with no exceptions. For each fraction delivered on our linac, we adapt the whole treatment plan to the new anatomy. Our philosophy is that if we have this adaptation workflow integrated, and we can do it quickly, then we don’t have to deal with decisions to adapt or not to adapt. It’s much easier to have one strategy and do the optimum that you can for each patient.

Does plan adaptation add much time to the treatment?

When we started the whole procedure, one patient took on the order of 45 minutes, while a normal treatment takes around 15 to 20 minutes. Now we are achieving, depending a little on how difficult the case is, time slots of about 35 minutes. But there’s still quite a bit of room for improvement, with improved software components for instance.

The Royal Marsden/ICR recently begun treating rectal cancer with the Unity, will any other indications be treated too?

We have now treated two rectal cancer patients. The next site will definitely be the bladder, the patient is already selected. Then head-and-neck and breast cancer are the next indications. Everything is going very well, the machine has basically no downtime, so it’s our task to ramp up the patient numbers. At the moment we treat around four to five patients per day, but I think along the road between 10 and 15 should be possible.

What else is planned for the future?

More patients, more indications, and there are also some technical aspects where we are working with Elekta on improving the performance of the machine, for instance in motion management and tumour tracking. We are also developing a way to perform functional MRI on this machine — it’s a great platform for applied research.

How would functional MR be employed?

For prostate cancer, for instance, we could use it to identify the dominant inter-prostate lesion, using diffusion weighted imaging. But it also gives us ample opportunity to run functional imaging while we are treating the patient. Then we can analyse these data for differential changes and see whether we can see early indications of treatment response.

We estimate that in one year we could perform up to 500 functional MRI prostate scans, in only one centre. Then if other centres join us, we could maybe record 2000 scans in a year — how else could you collect this amount of data? The patients are in place and while we are optimizing the new plan, we can do functional imaging. It’s something we call “biomarker discovery for free”.

Once a physicist: David Roberts

What sparked your initial interest in physics?

I never thought I’d become a physicist, but a seed was planted when I happened to pick up Stephen Hawking’s A Brief History of Time to kill time on my long drive to college. During that maiden 17-hour ride from my home in Alabama to university in New York, I don’t think I really understood anything of Hawking’s book, but the weirdness of time slowing down, and the black-hole paradoxes stuck with me. Then, soon after I arrived on campus, an older grad student turned me onto the Feynman Lectures. Because of Richard Feynman, I suddenly cared how electrons worked, and even more, how maths could explain it. Looking back, though, a more mundane impulse that led me towards a physics degree was the challenge of pursuing, from what I understood, the most difficult degree on campus. I wanted to see if I could hack it.

What did your physics degrees and following research focus on?

My physics background includes BS and MEng degrees from Cornell University, US, and a DPhil from the University of Oxford, UK, as a Marshall Scholar. My DPhil was focused on the theoretical aspects of quantum fluids. My academic career continued at the École normale supérieure in France, Princeton University, US, and Los Alamos National Laboratory, before I joined the US State Department. I continued working on quantum fluids after my degree, but was also fortunate to work with some smart folks on various interesting topics including genetics, geophysics and astrophysics. All of it was theoretical work with almost no immediate practical applications. I realize now how lucky I was to actually get paid to work on these cool puzzles.

Did you ever consider a permanent academic career, and how did your interest in politics and policy emerge?

I quickly fell for physics research as an undergraduate and fully expected to continue with research as a permanent academic career. As a physicist, I lived and worked in various countries from the UK and France to South Africa and Chile, and I had collaborators from all around the world. As I discovered new places, I became more interested in how the world worked in geopolitical terms rather than at the atomic level.

What was it like working as the US ambassador’s science adviser in Tokyo after the Fukushima crisis, and how did you get this role?

In 2010–2011 I was at the US State Department working on the contentious transboundary water issues in the Nile basin, with the idea that I would return to research in a year. Then the nuclear disaster happened at Fukushima, and I was asked on short notice to go to Tokyo to be the ambassador’s science adviser for a year, to assist the embassy with the recovery. I realized that that would probably be the end of my academic career, but I couldn’t pass up the opportunity. It was a steep learning curve as I knew little about nuclear reactors and even less about risk communication, all the while operating in an alien culture. My physics background proved valuable not only for technical aspects of the job but also in establishing relationships with my Japanese counterparts.

You’re now the co-founder of 110th Street Films. How did that come about and what does the company do?

During my time as a diplomat, I began writing articles in the New York Times, Wall Street Journal, Atlantic, etc and one of my articles sparked interest in a documentary adaptation. Although it did not pan out, I began to shift my focus from writing and international relations to my first love – film. After a few years filled with some twists and turns, I co-founded the production company 110th Street Films, with Billy Shebar – someone who actually knows how to make great films – and we are working on various film projects with some of my heroes. How did I go from thinking about Bose–Einstein condensates to creating satirical Trump animations? I really don’t have a clue.

How has your physics background been helpful in your work, if at all?

Whenever I worry that I don’t know what I am doing, I say to myself “How hard can this be? It’s not quantum field theory.” Actually, the human element of diplomacy and making a film is probably just as complex as the trickiest physics problems, but my physics background has given me confidence in approaching new problems, and that has been one the biggest assets in my career.

Any advice for today’s students?

Take some risks and don’t be afraid of getting off the path.

You can follow David Roberts on Twitter at @DRobertsNYC; 110thstreet.com

Vibrations guide tiny glass beads through an underwater maze

The behaviour of some particles on the vibrating surfaces of Chladni plates is reversed underwater, a new study reveals. The discovery was made by Kourosh Latifi, Harri Wijaya, and Quan Zhou at Aalto University in Finland. They observed that glass beads on a submerged vibrating plate move towards antinodes, where the plate’s amplitude of vibration is highest. The underwater effect could be useful in a variety of medical and biological applications, including the manipulation of living cells.

In 1787 the German physicist Ernst Chladni put sand on a vibrating plate and observed that the grains settle on the nodal lines where the plate’s amplitude of vibration is zero. In contrast, he observed that finer particles move towards the plate’s antinodes where the amplitude is a local maximum.

A century later, Michael Faraday explained both behaviours. He concluded that the vibrations cause the larger grains to move laterally across the plate until they reach a node – where they no longer get lateral kicks and therefore remain in place. As for why the smaller particles did the opposite, Faraday argued that air currents just above the plates tend to push the lighter particles towards the antinodes – an effect known as acoustic streaming.

Drag effect

In their new study, Zhou’s team observed that relatively large (750 µm-diameter) glass beads migrate to antinodes when the plate is submerged in water. This occurs, they argue, because the fluid drag experienced by the beads makes it more difficult for them to jump up from the plate’s surface. At the same time, they are forced to move laterally by both travelling waves on the plate’s surface and gravity (the latter is a result of the plate being bent up and down). Over one complete cycle of oscillation, they showed, the net horizontal force is always directed towards the plate’s antinodes. They also found that the beads can move in circles when the plate is vibrated at non-resonant frequencies.

Using their observations, Zhou and colleagues created a statistical model to predict the locations of the glass beads across a wide spectrum of vibration frequencies. Then they used their model to create complex combinations of both resonant and non-resonant frequencies that achieved the dynamic control of the motions of both individual and groups of particles. This allowed them to direct a single bead through a maze; to simultaneously move two beads along both L- and C-shaped paths; and to split a large cluster of beads in half.

The technique is relatively simple because it uses just one vibrational source to produce complex particle motions. If scaled-down to work on microscopic objects such as living cells and other tiny objects, it could be extremely useful for biological and medical applications. According to the team, possible applications include biotechnologies and tissue engineering, pharmaceutical research and microsystem assembly.

The study is described in Physical Review Letters.

Battle of the elements: helium’s crucial role in physics

Helium is colourless, odourless, non-toxic and inert. At first glance it might sound like a rather dull element. Yet helium is anything but — it is quite simply the life-blood of physics.

Helium is created in large quantities in stars through the fusion of hydrogen. On Earth it is the product of radioactive decay from uranium and thorium isotopes in the Earth’s crust and can be found trapped underground in natural gas reservoirs. Helium is non-renewable — once released from the ground as a mixture with natural gas, it escapes into the atmosphere. Shortages of helium, therefore, have become regular occurrences in recent years after uses of the gas have expanded meaning it remains an expensive and precious commodity.

Despite this, helium is still an essential component of many physics experiments. Its cooling properties are used to chill materials to near absolute zero allowing their fascinating properties to be studied. Helium is also used to cool superconducting magnets that are used in many big-science facilities, especially high-energy physics. For example, CERN’s Large Hadron Collider required 130 tonnes of the stuff to chill the 27 km-circumference accelerator to 1.9 K. Away from basic science, helium also plays a critical role in healthcare by cooling the magnets in magnetic resonance imaging machines and is used in the manufacture of microchips and optical fibres.

My first encounter with helium — besides the odd birthday-party balloon — was during my PhD. Each week I went to the on-site liquefier to collect a 100-litre dewar of liquid helium and pushed it back to my lab where it was used to cool a cryostat to measure the heat capacity of different materials. It was during this time when I became aware of its fascinating low-temperature properties.

The most common isotope of helium is helium-4, which consists of two neutrons and two protons. Helium has only one other naturally-occurring isotope — helium-3 (containing two protons and one neutron). In the Earth’s atmosphere there is one helium-3 atom for around every million helium-4 atoms.

Both isotopes of helium share one bizarre property: superfluidity. Below 4.2 K, helium-4 becomes a liquid but then at 2.17 K it is a superfluid, allowing it to flow without losing kinetic energy. This allows it to literally climb up walls. The unusual physics of helium has led to many Nobel prizes in physics, highlighting its importance to the field.

Lev Landau shared the 1962 Nobel Prize for Physics for developing the theoretical framework of superfluidity while Pyotr Kapitsa shared the 1978 Nobel prize for his experimental work on the superfluidity of helium-4, which he carried out in the late 1930s. The discovery of superfluidity in helium-3 at 2.49 mK in the early 1970s led to the 1996 Nobel Prize for Physics being awarded to David Lee, Douglas Osheroff and Robert Richardson while in 2003 Anthony Leggett shared that year’s prize for his theoretical work on helium-3.

Helium not only has fascinating properties and is crucial when it comes to great discoveries in physics, but it is also the stuff of stars and helps saves lives too.

What’s your favourite element? Contact us at pwld@ioppublishing.org with your pick – and the reason why – or via Twitter using the hashtag #battleofelements.

The art of continuous transformation

Back when the 18-year-old Susanne Klein was considering her subject options for university, friends and family assumed that it was a straightforward pick between a degree in law (her father was a barrister) or German literature (her strongest subject at school). It turns out they were half-right. Klein did indeed face a binary choice – just not the one that everyone had anticipated. “When I went to register at university, I wasn’t sure whether to opt for German literature or physics,” she explains. “I flipped a coin, that’s literally how I decided, and once it landed for physics I figured why not – this will be much more of a challenge. I’ve never looked back.”

Since then, it’s fair to say that Klein has made a point of defying convention. In her student days, she admits to being driven to succeed, at least in part, by the somewhat unenlightened guidance of one physics professor. “He actually said to me ‘physics is not for girls, you are on the wrong course’,” she explains. “I thought to myself: ‘you old bastard – I’ll show you’!”

Spurred on, Klein has taken the path less travelled as a professional physicist, pushing and crossing boundaries between industry and academia, theoretical and experimental research, as well as her homeland in Germany and adopted home in the UK – long before Brexit was even a word. In her latest incarnation, Klein finds herself at another interface – this time between art and science – as an Engineering and Physical Sciences Research Council (EPSRC) manufacturing fellow in the Centre for Fine Print Research at the University of the West of England (UWE) in Bristol.

Art for art’s sake

Based in the UWE arts faculty, the fellowship sees Klein heading up a five-year project (2018–2023), funded to the tune of £1.2 million, with the goal of reimagining two 19th-century printing processes – Woodburytype and Lippmann photography. These historic technologies have been largely forgotten as they were not commercially competitive, despite the fact that they produce prints far superior to anything available today. “My task is to find out how they did it and then give these processes a 21st-century makeover so that they are cheaper, faster and more accessible,” Klein explains.

That makeover seeks to exploit Klein’s diverse research experience – spanning colloidal chemistry, optics and 3D printing – as well as an extensive network of industry and academic contacts developed over two decades working as a senior scientist at Hewlett-Packard (HP). If she and her team are successful, the resulting high-quality, continuous-tone printing processes will likely find a range of high-end commercial applications: from original works of art and designer fashion to the packaging of luxury goods and unhackable anticounterfeiting for pharmaceuticals and credit cards.

So what’s life like working as a scientist surrounded by artists? Klein sees a lot of hands-on knowledge, craftsmanship and deep understanding among her UWE colleagues, adding that “people are very generous with that knowledge”. However, boundaries remain between the two cultures. “Science is almost forgotten in art,” she says. “There is a real block, in the sense that a lot of people who study art hated science in school.”

For Klein, though, this feels like an opportunity. By helping arts students and researchers to understand the science better, she reasons, it should be possible for them to deliver better outcomes in their art. “If you know how to make your inks and how colour is generated, for example, you don’t need to experiment so much – there is less trial and error.”

Industry insights

Klein’s current research post at UWE is no outlier. Throughout her career, she has sought new research directions on a regular basis. A PhD in theoretical physics – which focused on analytical methods for treatment planning in radiation therapy – was followed by a stint at Deutsche Telekom, Germany’s biggest telecommunications company, where she worked on next-generation optical switching technologies for fibre-optic networks. Then came the move to the UK – permanent as it turns out – as a Royal Society research associate, working on theoretical and experimental aspects of classical optics in Michael Berry’s group at the University of Bristol.

For the most part, though, Klein’s “scientific DNA” has been shaped by the time she spent as an industrial R&D scientist at HP Labs in Bristol. Her unwillingness to be typecast was evident – in fact encouraged – at HP, where her research programme spanned from liquid crystals and advanced display materials, through 3D printing technologies to optical cryptography.

That adaptability and openness to new research pathways holds a lesson for early-career scientists, says Klein. “Physics can come across as a dull, secret society – an unattractive choice for free spirits who want to be creative. I try to show young people that physics is something exciting, collaborative, an adventure. You just have to dare.”

I try to show young people that physics is something exciting, collaborative, an adventure

Having crossed from academia to industry and back again on several occasions, Klein is well placed to advise on what it takes to prosper on both sides of the fence. Money, of course, is right up there. “At HP, as long as you sold your project to the company you were never short of money for your R&D,” Klein explains. “And I was a good seller of the science, both within HP as well as to the customers.”

Put another way, successful science is not just about the results, it’s the story you tell about those results – and telling that story with passion, energy and enthusiasm. “You have to be a good entertainer and be remembered as a person who is really connected with the science,” Klein adds. “If you just show your results, the audience will fall asleep and you will be forgotten.”

For Klein, that passion for science (and art) remains as strong as ever – perhaps not surprising given that the EPSRC fellowship is very much her dream job. “The environment at UWE suits my personality and approach. I can spread my wings,” she concludes. “You can apply your ideas directly and quickly here. I also get to be more eccentric and no-one notices.”

Susanne Klein in brief

Things she does when not doing science: taekwondo (Klein is a black belt, 3rd dan) and mountain biking (she ran all-female group in Gloucestershire for several years, exasperated by the macho male mountain-biking culture)

Three “must-haves” for a desert island: book – The Long Ships: a Saga of the Viking Age by Frans Bengtsson; music – Seasick Steve; possession – Swiss army knife

On women in physics: “I don’t want to tell young women it’s easy. When you go into physics there’s no red carpet – you have to fight for it. If you know that, and you’re ready for it, then it’s no problem.”

On optimism: “When I was young, I thought we’d have a world revolution, and everyone would be equal by the time I was grown up. Well I’m still waiting!”

Human immunity is perhaps a touchy-feely process

Spreading T-cells — The researchers used reflection interference microscopy, amongst other techniques, to study the complex interplay between the area of spreading T-cells and substrate stiffness. (Courtesy: PNAS)

T lymphocytes, or T cells, are an essential subset of white blood cells that play an important role in human immunity. At a very elementary level, one can think of T-cells as the immune system’s infantry: they actively seek out and identify disease and mount more and more effective defence against subsequent attacks.

T-cells begin life in the thymus, hence the “T”, where they are trained for their job. The T-cell identifies friend or foe by looking for specific molecules, called antigens, found at the surface of offending cells. T-cells then trigger the entire immune machinery to counter the disease and, fascinatingly, to keep a memory of the attack — a feature that is exploited for vaccination.

To do its job of identification, a T-cell needs to make intimate contact with its target, the cell presenting the antigen, by spreading on it. For a long time, the propensity for any cell to spread has been known to depend not just on the chemistry of the antigens at the cell surface, but also on the tactile forces that the interacting cells exert on their environment.

Sensitivity to mechanical cues has been demonstrated for a large number of cell types and this so-called mechanosensitivity has been linked to the T-cell’s ability to identify disease. But the jury is still out as to whether or not the extent of T-cell spreading increases or decreases with the stiffness of the surface over which they spread.

A new spread of experiments

Researchers from the Centre Interdisciplinaire de Nanoscience de Marseille have reported the most comprehensive set of experiments yet demonstrating the importance of substrate stiffness in cell spreading (PNAS 10.1073/pnas.1811516116).

The researchers first prepared substrates from polydimethlysiloxane (PDMS) substrates, a biologically inert material that can easily be made with a dynamic range of Young’s moduli. They created substrates with an unprecedented range of stiffness: 0.5–7000 kPa.

Next, the team functionalized the PDMS surfaces with specific proteins to form a reconstruction of the antigen-resenting cell surface. Importantly, they functionalized the PDMS with chemistry specific to T-cells, not the generic mechanism of cell spreading, known as integrin mediated adhesion, that’s found in all cells.

T-cells seeded on such surfaces exhibited a bi-phasic response to substrate stiffness. The researchers found that the maximum spread area of the cells increased with substrate stiffness up to 5 kPa, and then decreased for further increases in stiffness.

In the next set of experiments, the researchers reintroduced the integrin-mediated adhesion molecules to the PDMS surface and found that the biphasic response of the T-cells to substrate stiffness was lost. Instead, cell spreading was seen to increase monotonically with substrate stiffness, thus restoring the classical, integrin-mediated, cell-spreading behaviour.

Getting the spread on the data

To explain this curious behaviour, the team developed a physical model to describe the competition between the adhesion bonds at the cell substrate interface and the substrate elasticity.

They found that to generate the biphasic behaviour demonstrated by T-cells, the bond adhesion needed to be stiff and highly sensitive to force. Interestingly, the authors suggest that such mechanosensitivity could arise from the link between the binding sites of the adhesion molecules and the cell’s cytoskeleton, rather than the bond between receptors and their counterparts alone.

This result places new importance on the tactile interactions between cells and the surfaces (or pathogens) that they spread on.

“The importance of these results comes from the fact that the diverse response of T cells to the mechanics of their environment is not due to the cell type but to the mechanics of the adhesion molecules,” says second author Celine Dinet. “And even though the classical behaviour is not so clear, it is related to the type of adhesion molecules used.” The new knowledge gained “should inform future studies on T cell mechanoresponse,” she adds.

T cells team — Celine Dinet (front left) and the “T cells on smart substrates” team. (Courtesy: Celine Dinet)

Europe puts organic chemicals on groundwater watch list

A method for identifying potential groundwater contaminants has been described by a pan-European collaboration of public bodies and industry. The group tested its new framework with pilot studies of pharmaceutical products and per- and polyfluoroalkyl substances (PFASs), which are commonly used in textile stain guards, greaseproof papers, fluoropolymer manufacture, coatings, and aqueous film-forming foams.

“Monitoring is costly and given the vast array of different compounds that may potentially contaminate groundwater, a prioritization of which compounds to collect new monitoring data for is a pragmatic way forward,” says Dan Lapworth of the British Geological Survey.

Groundwater quality in the European Union is monitored by law but the list of contaminants that fall within the scope of the legislation is far from exhaustive. Typically, substances that are newly developed, or that have only recently been detected in the environment, are not included.

For many such potential contaminants, regulatory bodies lack the monitoring data that would demonstrate a hazard. But as agencies are not required to test for uncontrolled substances, these data are not formally sought.

To tackle this dilemma, researchers and regulators from multiple European countries established a voluntary framework for populating and maintaining a groundwater watch list of emerging organic contaminants (EOCs).

“Although there are other emerging substances, such as nanomaterials, microplastics, and biological contaminants, EOCs probably represent the largest and most diverse group of emerging contaminants,” says Lapworth. “Other groups such as nanomaterials have already had a lot of attention and are starting to be addressed within the relevant EU regulation.”

The aim is for participating countries across Europe to produce a dynamic list of potential pollutants so that they can either be included within existing regulations or classified as not currently of concern.

As emerging organic contaminants have, by definition, not been adequately studied, the group formulated a selection method to populate the groundwater watch list that acknowledges a lack of environmental information. The first step is to catalogue substances already detected in groundwater, i.e. with proven contamination potential, or chemicals with properties that make leaching and transport to groundwater likely. This second, theoretical measure accounts for new chemicals that have not yet had time to reach the subsurface environment.

The next stage ranks candidate substances according to their toxicity and bioaccumulation potential. Any EOC that scores highly at both stages can be put on the watch list, although the study authors suggest limiting the list to the 30 substances of most concern.

By constantly reassessing monitoring data, regulators can set new legal quality standards for a given substance as soon as environmental evidence makes it appropriate. In this case the contaminant would move off the groundwater watch list to be replaced by a new EOC.

To demonstrate the approach, the collaboration undertook two pilot studies targeting pharmaceutical products and PFASs. The studies showed that voluntary data from participating countries are enough to inform decisions about whether EOCs should be monitored within the framework of the groundwater watch list, but that results should be provided in a strictly defined form to maintain consistency between sources.

The team hopes that the first groundwater watch list, which will be refined after its implementation this year, will let regulators make the most of scarce resources by focusing attention on the most hazardous and widespread groundwater pollutants.

The collaboration reported its findings in Environmental Research Letters (ERL).

Magnetic beads help treat preeclampsia

Roughly one in 20 women develops preeclampsia during pregnancy, a high blood pressure condition that can be life-threatening to both mother and baby. The disease is characterized by a massive increase in sFlt-1 (the soluble form of the vascular endothelial growth factor 1), which is released by the placenta into the maternal bloodstream. It is this growth factor that causes blood vessel wall dysfunction by binding two important angiogenic molecules that are responsible for maintaining healthy blood vessel walls. These molecules are endogenous PIGF (placental growth factor) and VEGF (vascular endothelial growth factor). A new proof-of-concept study has now shown that magnetic beads functionalized with VEGF as a “competitive” ligand can selectively capture sFlt-1 and reduce its level in blood by 40%, thus freeing up endogenous PIGF and VEGF so they can do their job.

Preeclampsia leads to high blood pressure and kidney disfunction and the condition affects an estimated 6-8% of pregnant women in the US. It can cause severe complications for the mother (such as seizures, stroke, renal failure and liver problems) and the baby (low birth weight, preterm delivery and even stillbirth). There is currently no cure for the disease.

One way to reduce the concentration of sFlt-1 in the bloodstream is to capture it in a technique called extracorporeal apheresis. Indeed, researchers have recently shown that columns made of materials like dextran sulphate can reduce sFlt-1 concentrations by 18% in blood samples of women with preterm preeclampsia. This strategy is nonspecific, however, and may have its own potential adverse effects because it not only binds sFlt-1 but many other molecules too.

Competitive biomimetic approach

Researchers in France have now developed a specific apheresis approach to restore a healthy physiological angiogenic balance.

In their experiments, they grafted magnetic beads with ligands of SFlt-1, which competes with PIGF in blood. To increase the capture of sFlt-1 over PIGF, they chose to use VEGF as a competitive ligand that has a ten times greater affinity for sFlt-1 than does PIGF. This competitive biomimetic approach thus captures circulating sFlt-1 while releasing endogenous PIGF, thereby increasing the amount of bioavailable PIGF, they say.

The team proved that its technique worked by integrating it into a microfluidic device that mimics real apheresis. It found that the magnetic beads decreased sFlt-1 by 40% and freed up two times more PIGF, reducing the sFlt-1/PIGF ratio by 63% in the blood plasma of preeclamptic patients.

Towards in vivo animal tests

“This was a proof-of-concept study and our approach aims to restore physiological levels of angiogenic factors,” says study lead author Vassilis Tsatsaris, who is a professor of obstetrics and gynaecology at Cochin Hospital in Paris. “The reduction of sFlt-1 and the release of angiogenic factors is very significant and promising.”

The researchers, reporting their work in Hypertension, say that they would now like to optimize the grafting process and develop apheresis columns based on their technique. They would then like to test out the technique in animals in vivo.

Hypertension is published by the American Heart Association and this research was funded by the French National Agency for Research.