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CityU physics: east meets west on a growth trajectory

City University of Hong Kong’s Department of Physics may be a relative newcomer, but faculty and students are taking advantage of its location – Hong Kong has long billed itself as “Asia’s world city” – and their own global connections to build a regional powerhouse for research and education.

“This is still a new department and we’re undergoing major expansion,” explains Xun-Li Wang, head of department and chair professor of physics at CityU. “Incoming faculty have a pivotal role to play in shaping the future of the physics programme. Generous funding – at national, university and department level – enables staff to quickly establish new research groups and to prioritize international collaborations.”

New is the key word here. The CityU Department of Physics was only formed in 2017, after the university chose to create distinct disciplinary specialisms from the former combined physics and materials science programme. For Wang, the opportunity is compelling: “We aim to create one of the leading centres of excellence for physics in the Asia-Pacific region – and in double-quick time.”

Xun-Li Wang, CityU Hong Kong — Xun-Li Wang: “This is still a new department and we’re undergoing major expansion.” (Courtesy: CityU Hong Kong)

With this in mind, and perhaps even more so given the current political unrest in the Territory, a proactive and global recruitment strategy is hard-wired into the physics department’s DNA. In terms of department size, Wang expects to have around 30 faculty members on board by 2027 (versus an initial staff cohort of 12 when the department launched).

Postgraduate numbers, currently at 63, will also scale rapidly over the same timeframe to around 150 PhD students, while the number of postdoctoral researchers and research assistants (currently 30) is forecast to triple by 2027. In addition, the department has just launched a taught Masters degree programme, with an expected intake of 40 students.

It’s all about connection

Among the recent arrivals at CityU is Wei Bao, who joined last year as chair professor of physics specializing in experimental studies of quantum magnetism and unconventional superconductivity using elastic and inelastic neutron scattering. He is currently recruiting for PhD students and postdocs as he builds a new research team to investigate a range of correlated electronic phenomena in condensed matter, often under extreme conditions (low temperature, high pressure or high magnetic field).

Wei-Bao, CityU Hong Kong — Wei Bao: “If you look at our collective resumé, it’s clear that we are recruiting high-calibre staff with a real depth of experience.” (Courtesy: CityU Hong Kong)

Prior to CityU, Bao spent the previous decade working at Renmin University in Beijing, where he built up an extensive network of friends and collaborators. “Relocating to CityU allows me to maintain strong connections with my colleagues in mainland China,” he explains, “though I also have plenty of established collaborations with scientists at other Hong Kong universities. Equally important to me is that I feel a lot more connected here to my international colleagues.”

Bao’s international connections have their origins in the US, where he spent the formative years of his research career. After a stint as a visiting student at AT&T Bell Laboratories, Bao completed his PhD at the Johns Hopkins University in Baltimore, followed by postdoctoral work at Brookhaven National Laboratory and a technical staff position at Los Alamos National Laboratory.

Subsequently, that international mindset has underpinned much of Bao’s research, which relies on access to leading-edge neutron facilities – for example, the Spallation Neutron Source (at Oak Ridge National Laboratory in the US), the Institut Laue Langevin (Grenoble, France) and J-PARC (Tokai, Japan), among others. “One of the first things I say to early-career scientists is: ‘Join me and see the world!’”, he explains.

Closer to home, Bao sees significant opportunities taking shape around the China Spallation Neutron Source (CSNS), a big-science facility that’s under development in Dongguan City, just across the border from Hong Kong in mainland China. The Joint Laboratory on Neutron Scattering (Joint Lab), a collaboration between CityU and the Institute of High Energy Physics of the Chinese Academy of Sciences, aims to take advantage of CityU’s proximity to strengthen cooperation with CSNS scientists and engineers on specialist training, research and equipment R&D.

“We have a mechanism through the Joint Lab to closely engage with the planning and exploitation of the CSNS,” explains Bao. “Our vision is to become the Hong Kong champion for neutron scattering and an international gateway into this state-of-the-art facility and others like it in mainland China.”

Beyond his own research interests, Bao reckons the quality of CityU’s physics faculty (currently 20 permanent staff) is one of the department’s biggest selling points to early-career researchers. “This is a new department, but if you look at our collective resumé it’s clear that we are recruiting high-calibre staff with a real depth of experience.”

Four of those faculty, for example, are Fellows of the American Physical Society. There’s also top-down encouragement for younger faculty to pursue curiosity-driven research. “We want our physicists to fully embrace the intellectual freedom of Hong Kong and scout for possibility wherever their line of enquiry takes them,” Bao explains.

He continues: “All of our faculty at CityU are well connected internationally. That’s a big plus for PhD students seeking attractive postdoc positions and ultimately intending to pursue a long-term career in academic research.”

Location, location, location

CityU’s role as a regional hub for globally minded physicists is a recurring theme in conversations with the university’s senior physicists. Take Condon Lau, an assistant professor at CityU who specializes in fundamental biophysical and biochemical studies using techniques such as laser spectroscopy and magnetic resonance imaging.

Condon Lau, CityU Hong Kong — Condon Lau: “I have a lot of international collaborators as a direct result of CityU’s exchange activity. There’s a ‘trickle-up’ effect for sure.” (Courtesy: CityU Hong Kong)

“I joined CityU five years ago because of its aggressive plans for expansion,” he explains. “There are openings in lots of different research areas, which makes it an attractive destination for developing your career.”

Lau himself is a study in the globe-trotting research scientist. Before joining CityU, he spent several years as a postdoctoral fellow at the University of Hong Kong, the Territory’s oldest academic institution. That followed an extended early-career spell in the US and an undergraduate degree at Princeton and PhD at MIT.

He now heads up his own 10-strong research team, including five PhD students for whom he is primary supervisor and another three that he co-supervises. For Lau, the big selling point of CityU is Hong Kong itself. “The Territory is a multicultural and multinational melting pot,” he explains. “The whole economic model here is based on an outward-facing mindset to engage with mainland China and the rest of the world.”

That macro, state-level approach is replicated at undergraduate and postgraduate level with the help of generous travel bursaries that enable students to attend overseas conferences and secure research internships at leading international institutions.

It’s a win-win, says Lau. “It’s good for the students in terms of their domain knowledge, breadth of experience and contacts. It’s good for the research groups here at CityU as well. I have a lot of international collaborators as a direct result of this exchange activity and co-author papers with groups in Mexico, China and the US. There’s a ‘trickle-up’ effect for sure.”

Funding is also geared towards attracting the best overseas talent to Hong Kong. The Hong Kong PhD Fellowship Scheme, for example, is a selective programme (there are around 250 recipients each year) that provides postgraduates with an annual salary of around US$40,000. That salary is topped up with US$1700 a year for work-related travel, with supplements from CityU. A similar programme is now also in place to attract postdoctoral scientists to Hong Kong.

One other big draw, especially for entrepreneurially inclined physicists, is the Greater Bay Area initiative. This ambitious regional investment programme aims to transform the Pearl River Delta (encompassing Hong Kong, Macau, Shenzhen and nearby cities in Guangdong) into a technology and innovation powerhouse that, its backers hope, will ultimately rival Silicon Valley in California.

“There’s a lot of tech investment and a real start-up culture in this part of the world,” says Lau. “That culture extends to CityU, where the university is very supportive of students and faculty seeking to patent and commercialize their breakthroughs.”

Call for applications

CityU Department of Physics is currently seeking applications from outstanding scholars for several open faculty positions. Core areas of interest include (but are not limited to): theoretical and computational physics; spectroscopy and imaging; low-dimensional systems and quantum materials; soft matter and biophysics; and atomic, molecular and optical physics.

The department also invites applications and expressions of interest for its PhD programme. Candidates able to demonstrate outstanding performance versus research capability, communication and interpersonal skills, and leadership potential are encouraged to apply through the Hong Kong PhD Fellowship Scheme.

End of the scientific paper, BBQ lighter bodged into biology apparatus, why spaghetti curls when cooked

After more than 350 years of expanding human knowledge, has the scientific paper passed its sell-by-date? The answer is yes, according to James Somers in his article “The scientific paper is obsolete”, which appears in The Atlantic.

Somers points out that the format of a paper – text and equations illustrated with figures – has not really changed at all since the first journals appeared in 1665. But thanks to computers, science has changed and today concepts and results are much more dynamic and therefore difficult to represent on static pages – even if those pages are presented online.

A particular problem, according to Somers, is a lack of interactivity with readers. This makes sense to me because I find the best way to understand a difficult concept is to “play” with it – looking at it from different perspectives and scenarios. This can be difficult to do from a static description.

While scientific papers could benefit from a technology boost, sometimes low-tech solutions are the best. Georgia Tech’s Gaurav Byagathvalli and Saad Bhamla (pictured above) have come up with a way of converting a BBQ lighter into an electroporator – which applies a jolt of electricity to temporarily open the walls of living cells. The technique is used by biologists to introduce substances such as chemicals, drugs, or DNA into the cells.

While electroporators are readily available, they tend to be beyond the budgets of high schools and other educational institutes. Byagathvalli and Bhamla hope that their ElectroPen devices will allow electroporation to be taught to students around the globe.

Dried spaghetti has long perplexed physicists because of its tendency to break into three pieces when bent, rather than two pieces. Now, Nathaniel Goldberg and Oliver O’Reilly of the University of California, Berkeley have tackled another puzzle related to the stringy pasta.

When dried spaghetti softens while being cooked in boiling water, it tends to curl into a U-shape. To try to understand why, Goldberg and O’Reilly have proposed a “minimal model for the cooking-induced deformation of spaghetti and related food products”.

Multi-modal nanoprobes reveal hidden magnetism

A “multi-messenger” approach that was first employed to study astrophysical phenomena such as black hole mergers can also bring insights to the ultra-small realm of quantum physics. So say researchers at Columbia University in the US, who have investigated the electrical, magnetic and optical properties of a strained metal oxide thin film at the nanoscale using a combination of several imaging and measurement techniques. The strategy, which has already unearthed an unexpected magnetic phase in the film, represents a new way to explore these quantum materials and could make it easier to design new ones with tailor-made properties.

The multi-messenger approach in astronomy involves combining simultaneous measurements from different instruments, including infrared, optical, X-ray and gravitational-wave telescopes. In the past few years, researchers have begun using this strategy to build up a much more detailed picture of intergalactic phenomena than would be possible with individual techniques alone.

A team led by Dmitri Basov has now extended this revolutionary approach to the nanoscale. In their work, Basov and colleagues studied La_2/3Ca_1/3MnO₃ (LCMO), which belongs to a family of colossal magnetoresistive manganites (AE_1−xRE_xMnO₃, where AE is alkali earth and RE, rare earth) that contain two distinct and competing phases: insulator and metal. This property makes it a promising material for making phase-programmable memories for next-generation computing applications.

A combination of measurement techniques

In a previous work, Basov and colleagues found that a magnetic metallic phase can be unexpectedly switched on in LCMO by simultaneously applying mechanical strain and laser light pulses. In their latest experiments, the researchers placed a thin film of LCMO (grown on a NdGaO₃ substrate) under the tip of super-resolution scanning near-field optical microscope. They then applied strain in one direction to the material while also exciting it with 130-femtosecond-long light pulses from a 1.5 eV (visible light) laser.

By using a combination of measurement techniques – atomic force microscopy, scanning near-field optical microscopy, magnetic force microscopy and ultrafast laser excitation, all at low temperatures – the researchers were able to measure the photo-induced phase transition as the antiferromagnetic insulator material became a conducting ferromagnetic metal containing nanometre-scale domains. This unexpected switch is completely reversible, and could make for the basis of a phase-programmable memory, the researchers say.

“The process is non-thermal, meaning that there is a large energy barrier between the two phases,” team member Jingdi Zhang tells Physics World. “Thermal fluctuations therefore do not destroy the stability of the ferromagnetic phase. The phase change is also ultra-fast.”

Team member Alex McLeod adds that while it is relatively common to study these materials with scanning probes, this is the first time that optical nano-imaging has been combined with magnetic nano-imaging, and all at the very low temperatures where quantum materials show their merits. Investigating quantum materials with multi-messenger nano-probes could accelerate worldwide efforts to engineer these materials with new properties, he says.

Physics in the 2020s: what will happen over the decade ahead

“Technological leap”

The researchers say that they would like to better understand the dynamics of the phase transition they observed. To that end, they are performing ultrafast X-ray scattering measurements (in conjunction with super-resolution near-field microscopy) that can probe lattice, charge, and magnetic degrees of freedom at the nanoscale, hoping to unravel the mechanism behind this ultra-stable and all-optical phase change.

The scientists, who report their work in Nature Materials, say they are also looking for “sibling” material systems to LCMO that undergo phase changes upon ultrafast optical excitation. The multimodal nanoscience approach to studying quantum physics phenomena is, they say, a “technological leap for how scientists can explore quantum materials to unearth new phenomena and guide future functional engineering of these materials for real-world applications.”

Cryogenics for Quantum Applications

We still don’t understand physics

Buddha — Cosmic questions: Anthony Aguirre’s new book borrows the concept of koans from Zen Buddhism: stories or riddles used during meditation to reach insight. (Courtesy: iStock/tarchutchai)

Physicists often begin as wide-eyed students who are thrilled by the idea of studying the universe’s deepest and most fundamental mysteries. This grand vision is encouraged by a popular-science landscape that repeatedly produces media about the mysteries of cosmology, particle physics and quantum mechanics. Ultimately, many are disappointed. The first physics course that students take at university is focused on boxes sliding on incline planes, and cars driving on circular roads. Few students, and virtually none who aren’t high grade earners in their early classes, will get the opportunity to try their hand at research in what is known as “fundamental physics”. In some sense, Anthony Aguirre’s Cosmological Koans: a Journey to the Heart of Physics (or, for readers in the US and Canada, “A journey to the heart of physical reality”) may become part of the problem here. But it is also a reminder of what physics never has been and maybe should be professionally.

I approached Aguirre’s text expecting to find a unique approach to well-worn territory, popular science for non-scientists. The book adapts the idea of a Zen koan – a story (sometimes in the form of a riddle or poem) meant to provoke a Zen Buddhist practitioner’s intellect. As Aguirre explains in the introduction, he has no intention of conflating East Asian religious and cultural precepts with ideas in physics, but rather wants to use a practice similar to that of Zen Buddhism to provoke his reader into thought. Thus, we find 360 pages, organized into 51 koans, each of which provides insight into some aspect of fundamental physics, while also highlighting questions that are left unanswered, because they remain beyond our current understanding.

I was somewhat sceptical of the decision to centre the koans on a journey through Asia, since Aguirre is neither Asian nor Asian American. But eventually I found myself pleased with the choice, which both seemed like a nod of respect to the koan’s originating homelands, but also a conscientious move away from the frankly boring and repetitive centring of Europe in nearly every popular book about physics. In fact, Aguirre for the most part leaves the history of physics out of it entirely. The koans are of his own imagination, so they don’t function as a nonsensical alternative history of physics.

For all of our elaborate computational and experimental abilities, we don’t understand basic things like why time works the way it does

As a professional physicist, I was initially unsure of what the book had to offer me, but this is where Cosmological Koans truly excelled. Rarely do I read a book that reminds me of why physics was exciting to me in the first place, yet Aguirre has written a text that will not only be exciting for enthusiastic and attentive high-school students, but will also be refreshing for the professional physicist. Aguirre reminds us that for all of our elaborate computational and experimental abilities – from being able to take data that images the universe at about 380,000 years old to formulating intricate models of how dark matter behaves – we still don’t understand basic things like why time works the way it does.

In a world where science is generally expected to serve capitalist or state interests, there isn’t a lot of room for questions that touch on philosophy. Histories of physics repeatedly teach us that even my research area of particle cosmology has received sustained governmental support in the US because historically it grew out of the Manhattan Project. Even within this esoteric realm, there are limits. Spending years thinking primarily about the fundamental nature of time is not something a physicist can do for a living wage. The popular-science media complex that gives young people this impression is completely misleading. The questions that are most exciting to the general public simply don’t have the right kind of economic value in a capitalist system.

Aguirre himself has played an active role in challenging this status quo. In addition to his work as a cosmologist, he has spent a significant fraction of his time over the last 15 years trying to create opportunities for scientists to ask these basic questions through his leadership of the Foundational Questions Institute, better known as FQXi. It is from FQXi, for example, that I was able to get funding to study how race and gender shape social definitions of “the observer” and ultimately research outcomes in science. FQXi is also one of the major sources of funding for research in fundamental quantum mechanics.

Cosmological Koans, then, reads as a natural extension of this work. It’s possible that physicists are a more natural audience for the text than the general public, since it can get a bit heady mathematically. I might not give a copy to my mother, who will readily confess that she is overwhelmed by arithmetic. But I would strongly recommend it to students and professional scientists alike who want to stay grounded in what the big open questions in physics are. I also think the science fan who is willing to put a little work into the reading process will find this text to be enormously intellectually nourishing. For my part, I plan to keep my copy in my office, in case I ever forget why I do what I do or how mysterious the universe continues to be.

2019 Allen Lane 400pp £20hb

Alpha DaRT treatment proves a success in first-in-human trial

Diffusing alpha-emitters radiation therapy (DaRT) uses interstitial radioactive seeds that continually release short-lived alpha-emitting atoms to treat cancer. Researchers in Israel have now published the positive results of a first-in-human clinical study evaluating the feasibility, safety and efficacy of this novel radiotherapy technique (Int. J. Radiat. Oncol. Biol. Phys. 10.1016/j.ijrobp.2019.10.048).

The clinical trial examined Alpha DaRT treatment, developed by Alpha Tau Medical. The therapy uses seeds (10 mm long and 0.7 mm diameter) impregnated with ²²⁴Ra atoms, which are implanted percutaneously into a solid tumour. As the ²²⁴Ra decays, short-lived daughter atoms (²²⁰Rn, ²¹⁶Po, ²¹²Bi, ²¹²Po and²⁰⁸PB), which are mainly alpha emitters, are continually released into the tumour.

Alpha radiation has a high relative biological effectiveness, enabling the use of a lower radiation dose to induce damage. The diffusing emitters create a cluster of high-energy alpha particles that destroy tumour tissue over a radius of 3 mm and do not affect healthy surrounding tissue.

First-in-human trial

The study, led by principal investigator Aron Popovtzer, of Rabin Medical Center and Tel Aviv University, included 22 patients at Rabin Medical Center in Israel and six patients at the Instituto Scientifico Romagnolo per Lo Studio e la Cura dei Tumori in Italy. All patients had biopsy-proven squamous cell carcinoma (SCC) of the skin and head-and-neck, with 39% having primary and 61% recurrent tumours that were no larger than 5 cm.

The researchers note that the patient cohort was elderly (a median age of 81) and represented a highly unfavourable prognostic risk group. Many were not candidates for surgery due to increased risk of morbidity. Three patients were treated twice for two separate tumours. All patients with recurrent disease had either received radiotherapy, surgical excision or both, with 13 of the 31 lesions previously treated using external-beam radiation therapy.

Before the procedure, which was performed in an outpatient setting under local anaesthesia, patients had a CT scan to determine the pre-treatment tumour volume and plan the number of Alpha DaRT seeds required. Alpha DaRT seed strands were placed at 5-mm intervals, extending 5 mm beyond the tumour edge to achieve adequate dosimetric coverage, and at a distance of at least 10 mm from major blood vessels. The team also performed a post-procedure CT to confirm that seed positions conformed to the treatment plan.

Between three and 169 seeds were inserted into each tumour, with an average of 28 seeds. Treatment lasted 16 days on average. Patients attended multiple follow-up visits within 45 days, for tests including radioactivity measurements at the tumour site, at different body sites, and in blood and urine samples. The authors point out that that radiation levels to the lungs, kidneys and bone marrow were well within the maximum tolerated doses, and that no measurable radioactivity was detected in blood and urine samples 30 days after treatment.

Complete response — Scalp SCC showed complete response at day 30. (Courtesy: *Int. J. Radiat. Oncol. Biol. Phys.* 10.1016/j.ijrobp.2019.10.048)

Out of 28 evaluable lesions, 78.6% had a tumour reduction of 100% and 21.4% had reductions between 30% and 100%, many within 14 days following treatment completion. Fifteen of 16 patients who did not receive prior radiotherapy had a complete response, and seven of 12 patients who had prior radiotherapy also had a complete response. Five lesions that showed complete response developed a local relapse at the site of DaRT implantation within a median of five months.

The participants sustained only mild-to-moderate toxicities from the Alpha DaRT treatment. Nearly half of the patients experienced an acute toxicity of Grade 2; no patients had Grade 3 or higher toxicities, and all cases resolved within 30 days. In eight patients where seeds were inserted adjacent (less than 5 mm) to bone and teeth, none developed osteoradionecrosis.

“The initial local response, with 60% manifesting complete resolution of disease, seems superior compared to outcomes previously reported using standard re-irradiation,” the authors stated. “Favourable response achieved with Alpha DaRT therapy had similar effectiveness in recurrent as in primary treatment tumours. These findings may in part be attributed to the enhanced radiobiologic attributes associated with alpha particle therapy, which could potentially overcome radioresistant clones.”

Alpha Tau Medical is currently conducting and initiating clinical trials in Canada, France, Israel, Japan and Russia, for breast, head-and-neck and skin cancer, with interim results expected to become available in 2020. A clinical trial for use of Alpha DaRT on pancreatic cancer will also commence this year.

“Collaborations with numerous cancer centres around the world have been initiated for the investigation of Alpha DaRT for the treatment of additional indications,” Alpha Tau Medical’s clinical research manager Na’ama Barel told Physics World. “Protocols in process include those for indications such as vulvar cancer in the UK, skin cancer in Thailand and prostate cancer at multiple locations.”

Nutrient flow in the brain is controlled by blood-vessel dilation, reveals network model

A new model based on the blood-vessel network in a rat brain shows that the vessel position within its circulatory network does not influence the blood flow nor how nutrients are transported. Instead, transport is controlled mostly by the dilation of vessels. As well as providing new insights into the circulatory system, the model could lead to better artificial tissues and brain-scanning techniques – and might even improve the performance of solar panels.

The human circulatory system is a complex network of interconnected blood vessels – arteries, veins and capillaries – that transports oxygen, hormones, nutrients, and waste throughout the body.

In the brain, if a certain neuron needs more nutrients, it will release signalling molecules that will cause the tiny muscles around a nearby blood vessel to relax. This widens (dilates) the vessel, increasing the blood flow and local nutrient availability. Blood flow fluctuations are therefore a sign of an increased brain activity and can be used for scanning brain tissues – using functional magnetic resonance imaging (fMRI).

Important questions

Increasing the blood flow to certain brain regions is complicated from the perspective of flow dynamics and researchers are keen to understand how transport networks adapt to their changing environment. Questions include how exactly does dilation bring more blood to a certain region in the brain? Does the position of the capillary within the entire vessel network influence the blood flow, or is the nutrient transport efficiency only related to the vessel dilation?

To answer these questions, physicists at the Max Planck Institute for Dynamics and Self-Organization in Germany led by Karen Alim created a theoretical model of blood flows in a previously reconstructed brain-vessel network.

Building upon an advanced dataset of the full microvasculature of a rat obtained by two-photon microscopy at David Kleinfeld’s lab at the University of California San Diego, Alim’s team had access to both the dynamic and static properties of the vessel network brain comprising over 20,000 individual vessels. The dataset also included information on the blood flow in these vessels. Using this information, they analysed the nutrient supply dynamics under different scenarios.

The power of dilation

Alim and colleagues found that controlling the nutrient and metabolite supply by vessel dilation is not influenced by the vessel network architecture, nor the position of the respective vessel within the architecture. Since the flow is coupled in these systems, the key role is played by vessel dilation, especially if nutrient and particle transport by advection (fluid motion) is considered.

Alim says that their “findings were quite surprising. The global coupling, so the exact network position of a single vessel that is dilating, does not matter when it comes to nutrient supply.”

“The situation becomes more complicated when it comes to the transport of resources in the flow stream, which is a non-linear problem,” she adds. If a single vessel dilates, it brings more nutrient to its close surrounding, thus depriving the remaining blood of nutrients. This means that downstream of this particular vessel, spatial correlations need to be considered, to accommodate the competition for nutrients between nearby vessels.

Better solar panels

Alim’s results show how all of the events shaping the structure of a network, like in this case a tiny region in a rat brain, can self-organize to produce a high level of control necessary to keep neurons alive and functioning. Her model could provide tools to better understand the design of a functional artificial tissues, or to improve the fMRI process to detect local increase in brain activity.

Working with theoretical models has a large advantage of having the possibility to adapt the framework for other applications. The team is also studying an inverse problem of using blood flow to transport heat. Their model organisms are snakes; by looking at the 3D vasculature of a heat-detecting organ, the team aims at understanding the dynamics of these flows and using them in bionic direction to improve the design of solar panels.

Marcus Roper of the University of California Los Angesles UCLA told Physics World that he has seen the “specific data set that Dr. Alim’s group analyzed. Personally, it feels overwhelming, for the number of vessels that it contains. I am amazed that they were able to tease out such a clean and compelling explanation.”

He speculated whether the pathological blood vessel networks created by tumors or the disrupted networks that are re-established in the brain following traumatic brain injury could also possess the self-organization properties reported by Alim’s team. “Obviously, we are a long way from the rubber meeting the road in terms of clinical applications, but I think that understanding physical principles for how the network functions is necessary if we are to use these new data streams to their fullest potential,” he adds.

The research is described in Physical Review Letters.

Brookhaven chosen to host major US nuclear physics facility

The US Department of Energy (DOE) has chosen Brookhaven National Laboratory in Long Island, New York, as the site of a next-generation Electron-Ion Collider (EIC), beating off competition from the Thomas Jefferson National Accelerator Laboratory in Newport News, Virginia. The facility, costing between $1.6bn and $2.6bn, will aim to study the structure of protons and neutrons in unprecedented detail. It will be designed and built over the coming decade with the first experiments starting in 2029 or 2030.

The EIC will smash together electrons and protons to probe the strong nuclear force and the role of gluons in nucleons and nuclei. Such an accelerator was rated as one of the top priorities for nuclear physics by a 15-strong National Academies of Sciences, Engineering, and Medicine panel in 2018. In its report, it highlighted several scientific goals for the facility including how nucleons’ properties emerge from interactions among quarks and gluons; how quark-gluon interactions create nuclear binding; and how a dense nuclear environment affects quarks and gluons, their correlations, and their interactions.

[The Electron-Ion Collider is] not only a success for Brookhaven, but for the world
Doon Gibbs

“This facility will deepen our understanding of nature and is expected to be the source of insights ultimately leading to new technology and innovation,” says US energy secretary Dan Brouillette.

Building the EIC at Brookhaven will involve the lab revamping its existing Relativistic Heavy Ion Collider (RHIC) accelerator complex, which currently collides heavy nuclei such as gold and copper to produce a quark-gluon plasma – a state of matter though to have been present in the very early universe. The 3.8 km-long RHIC is now expected to shut down in 2024 to make way for the EIC, which will involve adding an electron ring and other components to the existing set-up. The EIC will then consist of two intersecting accelerators — one producing an intense beam of electrons and the other a high-energy beam of protons or heavier atomic nuclei. Each high-luminosity beam will be steered into head-on collisions with the particles produced providing clues to the internal nature of protons and their components.

World-class research

Brookhaven director Doon Gibbs told Physics World that the decision for the lab to host the EIC represents “not only a success for Brookhaven, but for the world”. China is the only other country with plans for a similar EIC facility, but its machine would involve significantly lower energy and intensity than the planned Brookhaven facility. Gibbs notes that the cost range will be refined as the design develops in next couple of years, and that funds for the facility are subject to yearly appropriations from the US Congress.

The DOE emphasizes that the project will involve several partners both in the US and abroad. Indeed, the Jefferson Lab is expected to contribute to the construction of the new EIC and the research that it will pursue. According to Robert Tribble, Brookhaven’s deputy director for science and technology, negotiations will soon take place with the Jefferson Laboratory over details of the partnership. Other DOE laboratories will also contribute to the construction of the facility and the research it will carry out.

Collaboration receives $1.25m to accelerate development of effective topical drugs

A research consortium from Bath University, the UK’s National Physical Laboratory (NPL) and Colorado School of Mines has been awarded $1.25 million funding from the US Food and Drug Administration to develop improved techniques to assess the performance of topically applied drug products.

Skin disorders such as eczema, acne and psoriasis are common, long-term conditions that often require frequent application of creams and lotions. And with skin diseases accounting for a third of all childhood disease, there’s an ongoing need for more effective topical drugs.

To develop such drugs requires accurate, reproducible and non-invasive methods for analysing topical drug delivery. Existing approaches, such as skin penetration tests, microdialysis and tape-stripping, can be time-consuming, expensive and technically challenging. Instead, the new project will employ state-of-the art imaging techniques to analyse how drugs interact with the skin in real time.

The five-year project brings together NPL’s specialists in advanced Raman spectroscopy and mass spectrometry imaging with leading experts in topical drug delivery and formulation, dermal pharmacokinetic modelling and skin bioavailability at Bath University and Colorado School of Mines.

“The project aims to develop and validate a novel and non-invasive application of Raman and mass spectroscopic techniques to evaluate the bioavailability of a topically applied drug in the skin,” explains Bath University’s Richard Guy. “The successful attainment of this objective will advance regulatory science and accelerate the route-to-market of new drug products.”

NPL will provide expertise in stimulated Raman spectroscopy – a non-invasive, accurate and sensitive tool used to determine the rate and extent at which a topically administered drug becomes available at its site of action within the skin. The method enables analysis of the drug and quantification of its transport across the skin in real time. One key challenge that the team aim to overcome is distinguishing the signal from the drug in the skin from background signals originating from the skin itself. Alongside, mass spectrometry imaging enables rigorous calibration and validation of the Raman results.

“Coherent Raman-based optical imaging methods enable non-invasive, real-time chemical measurements,” says Natalie Belsey, senior research scientist at NPL. “The mass spectrometry imaging capability at NPL brings major benefits of sensitivity and chemical specificity. In combination, these complementary spectroscopic imaging methods offer a powerful technology tool kit with which to asses and enhance the performance of formulated drug products.”

Looking forward to a new decade of physics, listening to graphene-based headphones

The 2020s could be the decade in which we get the first evidence of life on another planet. Closer to home, physicists will hopefully be making important contributions to the development of low-carbon energy systems – and reducing the amount of energy used in their labs.

In this first podcast of the decade we discuss what new and wonderful things physics could bring us over the next ten years.

We also give our impressions of headphones that have speaker components made of graphene. So tune-in to find out if Physics World editors are tipping graphene as an audio technology of the future.

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CityU physics: east meets west on a growth trajectory

It’s all about connection

Location, location, location

Call for applications

End of the scientific paper, BBQ lighter bodged into biology apparatus, why spaghetti curls when cooked