All posts by jonathan

Getting crystallography to regional Australia, a SCANZ initiative

Helen Maynard-Casely (helenmc@ansto.gov.au)

The Society of Crystallography for Australia and New Zealand (or SCANZ) have a great history of holding our national meetings in rural (regional) locations.  Known as the CRYSTALS meetings, past conferences have criss-crossed though the Australian continent as well as making a couple of trans-Tasman trips to New Zealand http://scanz.iucr.org/events.

It has been realised that having our meetings in regional locations gives SCANZ a fantastic opportunity to hold outreach events promoting crystallography to audiences who get little in the way of public science events.  Australia and New Zealand have highly urbanised populations (75 % of Australians and 85 % of New Zealanders live in cities) and are treated to a large range of science events.  However, those that live in regional areas don’t have such ready access to such events and are often a ‘missed out’ audience.  With SCANZ’s history (we started out as ‘Bush Crystallographers’) and the fact that we bring some great international and domestic invited speakers to our meetings, through schemes like the 1987 lecture fund, there is great opportunity to hold public science events in the regional locations of our national conference visits.

With that in mind, and that our CRYSTALS 31 https://crystal31.com/ meeting was being held in the wonderful Margaret River area, we organised our first public outreach event in conjunction with the conference.   ‘Science at the Caves’, was a mini-science festival held at Ngilgi Caves https://www.margaretriver.com/members/ngilgi-cave/ just before the conference kicked off on the 3rd December.

With the aim to explore the connections between crystals and caves, we had talks from invited speaker Ulrike Troitzsch (Australian National University) on her coral research (the starting story for calcium carbonate) as well as Andre Courtis a local cave guide. As well as hands-on activities demonstrating crystallography to everyone.

Supported by the conference chair and SCANZ executive, the hope is now for each future CRYSTALS meeting to have a public outreach event and to build up sci-comm expertise in the crystallography community.

 

The IUCr Associates Programme

The IUCr Associates Programme, which launched this year at the IUCr Congress in Hyderabad, underpins many of the Union’s outreach and education initiatives. Some of these activities include its bursary scheme which supports students to attend international meetings, a Visiting Professor scheme and building crystallography capacity in Africa and other parts of the world.

One winner of a student bursary is Feng-Ren Fan, a PhD student at Fudan University, China. Feng-Ran had this to stay about his experience of attending the Shanghai International Crystallographic School, “The course helped develop my understanding of group theory and crystallography, and the application of both theories. Another important area I learnt about was the Bilbao Crystallographic Server, this is a very powerful tool for people working in the physical sciences”. Feng-Ran went on to say, “I definitely learnt a lot and enjoyed the school very much. Thank you for a nice experience!”

Scientists joining the Associates Programme are offered a series of benefits and tools to help them network, share ideas and discover more about crystallography. For example, the benefits include:

  • Discounts on the open-access fee for publishing an article in an IUCr journal
  • A number of free article downloads from IUCr journals
  • Discounts on books from other publishers such as Wiley and Oxford University Press
  • Professional networking opportunities, such as access to the IUCr LinkedIn discussion group and job listings
  • Resources to help in your professional development

To learn more about the Associates Programme please follow this link.

A 20% discount is currently available on the three-year joining fee of USD 200 (USD 160 with the discount). A reduced rate of USD 60 (USD 48 with the discount) is available for students, retired scientists and those from developing countries.

Take advantage of this limited-time discount by joining now.

If you have any questions about the Associates Programme please get in touch by emailing us at associates@iucr.org or by submitting your query via this web form.

 

LAAMP at the World Science Forum

Dr Michele Zema, IUCr and Dr Jean-Paul Ngome-Abiaga, UNESCO

Synchrotron light sources are comparable to super microscopes that probe the inner structure of matter. They produce very intense pulses of light (from infrared radiation to X-rays), with wavelengths and intensities that allow detailed studies of objects ranging in size from human cells to viruses and proteins, down to atoms, with a precision that is not possible by other means. They allow researchers to investigate the structure and properties of a wide range of materials, from proteins to provide information for designing new and better drugs, probing novel materials for biotechnology, analyzing soils for green agriculture, to engineering applications, and the examination of archeological artifacts.

Because of their high costs and multidisciplinary use, large-scale synchrotron light sources facilities provide strong opportunities for integration through networking and cost-sharing, and promote multi-disciplinary collaboration with the wider global community, while promoting science diplomacy and peace at large.

Thus, light sources have become prime enablers of scientific and technological progress and innovation, conducive to sustainable development in line with the United Nations 2030 Agenda.

Through a project entitled Utilisation of light source and crystallographic sciences to facilitate the enhancement of knowledge and improve the economic and social conditions in targeted regions of the world, the International Council for Science (ICSU) is partnering with the International Union of Pure and Applied Physics (IUPAP) and the International Union of Crystallography (IUCr) to enhance Advanced Light Sources (AdLS) and crystallographic sciences in Africa, Mexico and Caribbean and Middle East (LAAMP).

You can read more about the LAAMP project here and its kick-off meeting at IUCr2017 here.

A thematic session by LAAMP entitled “Light sources and crystallographic sciences for sustainable development” has been approved to be part of the programme of the next World Science Forum which will be held at the King Hussein Bin Talal Convention Centre, Dead Sea, Jordan, November 7-11, 2017.

The session will showcase how light sources have revolutionized research in many science and technology disciplines, and has successfully contributed to the socio-economic development of countries and regions by:

  • Creating international scientific communities
  • Improving education and creating new job opportunities
  • Discussing next steps following the establishment of light sources in the South (mainly Africa and Latin America) while learning from the experience of SESAME
  • Increasing awareness for decision-makers of the major advances light sources can bring to regions and the identification of the best locations for the sustainable development of such infrastructure
  • Advocating, through global initiatives such as the International Year of Crystallography and the International Year of Light
  • Developing a critical mass of highly qualified human capital (including the African science diaspora) needed to reach the Sustainable Development Goals (SDGs) and regional framework agreements like the African Union Agenda 2063

The overall objective of the session is to portray a scalable model for light sources initiatives in the developing regions. The outcome is designed to empower and inspire researchers, scientists, engineers, technologists and policy makers to take proactive roles in their countries and regions to drive towards a densified science cooperation to improve international relations between countries and to develop the human capacity that enables researchers in the Global South to get the most from light sources, and to be meaningful contributors to the 2030 Agenda for sustainable development.

 

 

IUCr 2017 Hyderabad:Blog Day 8, Monday 28 August:Closing with culture

Dr Clare Sansom, Department of Biological Sciences,  Birkbeck College, London, UK

It is an appalling cliché, but of course a true one, to say that all good things must come to an end. And this, of course, includes IUCr conferences. After an intense programme of first-class science lasting a bit over a week, the 24th International Union of Crystallography congress ended on August 28 with the third plenary lecture. The topic for this final plenary, by Giacomo Chiari from the Getty Conservation Institute, Los Angeles, USA, illustrated the breadth as well as the depth of our subject: his title was ‘Crystallography in Art and Cultural Heritage’.

Chiari began an engaging lecture by describing his feeling when he received the invitation to be one of the plenary speakers as “like you might feel when your data start proving your hypothesis”. He dedicated the talk to fellow Italian crystallographer Davide Viterbo, an emeritus professor at Universitá del Piemonte Orientale, Alessandria, Italy and a past president of the Italian Crystallographic Association, who died last May. He then explained that crystallography and heritage overlap in two ways – in the depiction of crystals in artworks and in the use of crystallographic techniques to understand and preserve them – and that his lecture would be principally concerned with the second.

But what is ‘cultural heritage’, anyway? One useful concise definition is “every material testament regarding [man] and [his] cultures”. The key word here is ‘material’; thus, Shakespeare’s plays themselves are not part of cultural heritage, although a First Folio – or any other physical copy – will be. And although it is not restricted to ‘high’ culture, objects must have significance. It is difficult to argue a case for preserving an ‘ordinary’ shopping-list, unless (for example) it is a list of pigments that Michelangelo gave to his servant. People who study contemporary culture frequently encounter the problem that some artefacts of genuine interest, such as film sets, were not designed to be preserved.

For most of the rest of his lecture, Chiari gave examples of how crystallographic techniques are used to study artefacts and the technology that had been used to make them. Some of the earliest of these were the polished ‘green stone’ axes that were developed in the Neolithic period and that were the first tools that were strong enough to cut down trees. Neutron diffraction has been used to analyse the surface textures of these axes and thence to try to deduce the technologies used to make them.

Coming much closer to the present day, the first commercially successful photographs were images exposed onto light-sensitive silver plates, known as daguerreotypes.  These were produced during the mid-19th century, with the oldest being the most valuable. In about 1860 the deposition process changed from cladding to electroplating; the latter process creates a micro-crystalline image with a preferred orientation, and this can be detected – and the daguerreotype dated to after 1860 – using a diffractometer. A similar process can be used to detect whether gilded medieval paintings were ‘touched up’ centuries later.

Lapis lazuli is a deep blue metamorphic rock that was prized throughout antiquity for its colour. It was one of the most expensive of the pigments available to medieval artists and for some centuries later. X-ray diffraction can be used to identify subtle differences between batches of this and other early pigments, to detect layers of painting-over and sometimes even to distinguish between artists by the exact hues they used.

In thanking Chiari for his fascinating lecture, conference chair Gautam Desiraju reflected on the interdisciplinary nature of the congress, with a programme designed to cross the ‘divide’ between structural chemists and structural biologists. This plenary, however, which had been organised by the relatively new IUCr Commission on Art and Cultural Heritage, had taken interdisciplinarity to a new level. He hoped that it had opened delegates’ eyes to a new aspect of their subject.

Desiraju then led into the conference’s closing ceremony. He thanked all participants on behalf of the local organising committee for contributing to the meeting’s success, stressing, again, the number and diversity of delegates and presenters. The IUCr is flourishing and taking on new projects. There will now be a W.H. and W.L. Bragg Prize – awarded to crystallographers relatively early in their careers – to complement the Ewald Prize, and funds will be available for supporting crystallography and crystallographers in Africa, South-East Asia and Latin America. The newly-established Associates’ Programme now allows individuals to contribute directly to the Union and to have a real stake in its success. These initiatives will be overseen by a new executive committee with Sven Lidin becoming the new President and Marvin Hackert stepping aside – but not down – into the role of immediate Past President. And there is a significant change in the Union’s office in Chester, UK: the Hyderabad meeting marked the retirement of its inexhaustible Executive Secretary, Mike Dacombe.

Lidin, Hackert and other members of the Executive Committee, joined Desiraju on the stage for one last, and very pleasant, duty: the award of no fewer than 26 poster prizes, far too many to be listed here. The judges must have had a very hard job to pick those winners from a field of about 700 largely excellent posters. The very end of the closing ceremony saw the handover of the baton to the next host city, Prague. The 25th IUCr Congress and General Assembly will be held there from August 22-30, 2020 and this blogger is greatly looking forward to being there.

 

Addendum: Dragons’ Den Session 2 Winners

The Dragons’ Den competition for young crystallographers’ research ideas took place over two sessions, with two prizes awarded at the end of each one. The first session was reported on in depth on Day 4 of this blog. In the spirit of fairness, I now name the equally deserved winners of the second heat, held on Saturday 26th, here. They were both postdocs: the prize sponsored by Springer Nature went to G. Subramanian and the one donated by the meeting’s local organising committee to S. G. Ramesh.

 

IUCr 2017 Hyderabad:Blog Day 8, Monday 28 August: Crystallography in Space

Day 8, Monday 28 August: Crystallography in Space

Dr Clare Sansom, Department of Biological Sciences,  Birkbeck College, London, UK

In general terms, crystallography can be thought of as a science of the very small, and space science as a science of the very large. For most crystallographers, therefore, it might take a bit of imagination to link the two. But crystallography does have a role in space science, and this was explored in a popular and thought-provoking special session in Hyderabad.  This came about as a result of a collaboration between IUCr and the Committee on Space Research (COSPAR) that was set up during the International Year of Crystallography; COSPAR and IUCr organised a capacity-building workshop on crystallography in space research in Puebla, Mexico in April 2016, and the IUCr session was organised as a follow-up to that. Its chair, Hanna Dabkowska (Vice President, IUCr 2017-2020) from McMaster University in Canada, had been one of the lecturers in Puebla.

The first talk, by NASA’s Dave Blake, had one of the most immediately engaging titles of any conference presentation: ‘Mineralogical Results from the Mars Science Laboratory Rover Curiosity’. The results he presented came from the first in situ analysis of minerals on the surface of Mars. The rover vehicle Curiosity is the largest exploration vehicle to have yet been landed on the surface of the ‘red planet’. It collects small specimens of rock and dust from the Martian surface to analyse using its 10 complex instruments; the initial aim of all these experiments was to answer the question ‘has it ever been possible for Mars to support life?’ As the Martian environment bears some similarities to those that probably existed on Earth when life first emerged there 3.7 billion years ago, a positive answer to this question would have important implications for theories of the origin of life. It landed in a crater named Gale in August 2012 and will remain on Mars for about two more years.

Blake explained that the ‘Swiss army knife’ of experiments carried by Curiosity includes a diffractometer about the size of a large briefcase. This instrument, which has been named CheMin, is being used to analyse bedrock from Gale and materials taken from the sides of Mount Sharp, a 3-mile high mountain (more accurately, mound of rubble) in the centre of the crater. Briefly, X-ray diffraction patterns from these minerals were consistent with the theory that the rover had landed at the end of an ancient river system and that the environment had gradually dried out and oxidised over geological time. If this is correct, Curiosity’s mission has already succeeded: Gale Crater is ‘an environment that could once have supported some form of life’. If you like, you can explore the data for yourself; it is all free to download.

The next two speakers, Tomoki Nakamura from Tohoku University, Japan and Helen Maynard-Casely from the Australian synchroton site, ANSTO, took crystallography even further afield by presenting, respectively, studies of minerals from small asteroids and from Saturn’s moon Titan. The small asteroids were the first planet-like bodies to be formed in the Solar System; Nakamura uses both X-ray crystallography and basic mineralogy to analyse samples of dust and debris that have been returned to Earth from one of these, the oddly shaped near-Earth asteroid Itokawa, by the Hayabusa spacecraft. His group has been able to piece together a ‘life history’ for this asteroid from the point when it was formed over 4 billion years ago. This involves intense internal heating and cooling followed by an impact with another space body that shattered it into many fragments; many of these fragments then re-accreted to form the smaller, peanut-shaped object we see today. This project is part of the Japanese-led ISAS Small Body Exploration Strategy to analyse the structures of small asteroids and meteorites, which is expected to last well into the 2020s.

Maynard-Casely began her engaging talk by reminding us of Blake’s comment that CheMin, on the Curiosity Rover, was the only diffractometer located outside the Solar System and of Nakamura’s comments about the complexity of returning samples to Earth from Itokawa, which is far closer to Earth than Saturn. Studying the materials on Titan’s freezing surface, where the temperature is always close to 90K, is therefore very difficult. This surface consists of ‘lakes and seas’ and areas that are covered by crystalline residues analogous to those seen on dried-up lake beds. But the environment is far too cold for water: remote analysis of samples obtained by a small ‘lander’ jettisoned from the Cassini space probe identified high concentrations of benzene and ethane, and a benzene crystal form with a shorter bond length than normal benzene crystals.  Maynard-Casely mixed the two compounds in her lab in conditions that mimic those on Titan, and formed a novel material: a co-crystal with ethane molecules inhabiting the channels between the benzene rings. She is beginning to produce a ‘mineralogy’ of organic materials thought to exist on icy moons like Titan.

The formal session ended with presentations by Yuki Kimura from Hokkaido University, Sapporo, Japan, on the formation of dust particles under micro-gravity and by Giuditta Perversi, a Ph.D. student at Edinburgh University, Scotland, on the low-temperature properties of magnetite. They were followed by a lively discussion; it is clear that the collaboration between COSPAR and IUCr has many years to run.

 

IUCr 2017 Hyderabad:Blog Day 7, Sunday 27 August: Building BRICS to collaboration in crystallography

Day 7, Sunday 27 August: Building BRICS to collaboration in crystallography

Dr Clare Sansom, Department of Biological Sciences,  Birkbeck College, London, UK

One of the most interesting series of sessions at IUCr has taken the overall theme of ‘crystallography in emerging nations’. Out of these, the one held on Saturday afternoon – ‘the role for development in the BRICS countries’ – will be of most interest to crystallographers in the host nation, India. The acronym BRICS stands for five large middle income countries: Brazil, Russia, India, China and South Africa. These disparate countries nevertheless share some important characteristics. They are economically important with large populations (India and China are the two most populous countries on earth) and on average fast-growing economies. Together, they account for about 40% of the world’s population. All have established communities of scientists working in many disciplines, including crystallography; this short session explored how they could work together more.

The session began with a short introduction by two South Africans, Jean-Paul Ngome Abiaga, who is now based in France working in UNESCO’s Capacity Building in Science and Engineering section, and Andreas Roodt from the University of the Free State. They described current initiatives for promoting cooperation between the five countries, including the BRICS Scientific, Technological and Innovation Framework Programme for funding multinational research and innovation projects. Modelled on the European Union’s Framework programmes if on a much smaller scale, this supports projects in 10 thematic areas; the two that are of most interest to crystallographers are ‘materials science, including nanotechnology’ and ‘biotechnology and medicine’. Applications should include partners from at least three BRICS countries. This is a promising scheme, but one with undoubted bureaucratic ‘teething problems’: its first call for proposals closed in August 2016, but the first grants are only now being awarded.

One senior scientist from each country then took to the floor to present some aspect crystallography there. The Russian representative (a late replacement for Mikhail Kovalchuk) described her country’s long history in the subject, which goes back to Evgraf Fedorov’s derivation of the 230 space groups in 1891. Distinguished crystallographers of the Soviet era include Alexey Shubnikov, who was one of the founders of the IUCr. Since the 1990s, Russian science, like much of Russian society, has turned west towards Europe and Russia is a key participant in (for example) the European XFEL project. Separately, Alexander Blagov from the Russian Academy of Science in Moscow described research at one of Russia’s own ‘mega-facilities’, the Kurchatov Synchrotron Radiation Source.

Marcia Fantini from the University of Sao Paolo in Brazil focused on opportunities for crystallographers in her country today. The only synchrotron light source in Latin America is based there, a second is under construction and there are 17 research groups in the country with crystallography as their principal focus. The Chinese perspective was presented by Xiao-Dong Su from Peking University, Beijing, who remembered hosting the then frail, 83-year-old Dorothy Hodgkin among many hundreds of delegates at the 16th IUCr congress there in 1993.  Chinese crystallography has developed rapidly since then, following the rapid growth of the Chinese economy, and many structural scientists are returning from positions in the US, Europe and Japan. There are plans to update at least one of the three Chinese synchrotrons, and to build a free electron laser facility. South Africa is the only BRICS country not to have its own synchrotron, and, indeed, there are none in Africa. However, as Susan Bourne of the University of Cape Town said, its crystallography community is ‘small but very active’. And it, too, has a long history, going back to Reginald James, a professor at the same institution who had studied under W.L. Bragg in Manchester, UK. His students in South Africa included Aaron Klug, who was to win the 1982 Nobel prize for chemistry for structures of protein-nucleic acid complexes. It must be admitted that James is best known internationally as a member of Ernest Shackleton’s ill-fated expedition to the South Pole.

The Indian slot, taken by A. Nangla from CSIR in Pune, took a rather different form. Rather than presenting crystallography in India, he described a problem that he thought scientific collaboration between BRICS countries might contribute to solving: the often-quoted gap between basic research and application in the ‘real world’. This gap is bridged faster when there is a recognised need for the technology (‘market pull’ rather than ‘technology push’). He suggested that it might be particularly useful for BRICS crystallographers to collaborate in some specific areas with known applications and where they have established research strength, and cited MOFs as an example. These have many current and potential applications, including gas storage, photocatalysis and drug delivery.

These talks were followed by two shorter ones by younger scientists from India and Russia, describing research in crystal growth and hydrogen bonding respectively, and a ‘perspective on the BRICS initiative’ presented by three South African PhD students. The meeting ended with a round table discussion with a panel that included John Helliwell from the University of Manchester, UK, as well as the speakers. Almost all contributions were very positive about the potential for collaboration between the countries although there was some disagreement about the form that any grant programme should take, and there was much support for delegates from other African countries where crystallography is less advanced. If the BRICS initiative is handled well, there are clearly many opportunities for it to support crystallography and other structural sciences throughout the developing world.

 

IUCr 2017 Hyderabad:Blog Day 6, Saturday 26 August: Imaging Protein Dynamics

Day 6, Saturday 26 August:Imaging Protein Dynamics

Dr Clare Sansom, Department of Biological Sciences,  Birkbeck College, London, UK

One of the most exciting developments in macromolecular crystallography in the last decade – and one that is already proving game-changing for the discipline – is the use of exceptionally fast and intense pulses of X-rays generated by free-electron lasers to image proteins in motion. Free-electron laser facilities are more complex and expensive to build even than synchrotrons, and only a handful have come on line so far. John Spence of the Physics department at Arizona State University, who gave the second plenary lecture at IUCr 2017, is the director of one of these: the NSF-funded BioXFEL, which is physically located in Buffalo, New York.

Spence studied for his Ph.D. in Melbourne, Australia and spent a few years as a postdoc in the University of Oxford, UK before moving to Arizona in 1976. During over four decades there he has accumulated honours, including foreign membership of the Australian Academy of Science and the UK’s Royal Society.  He spent many productive years working in protein electron microscopy before switching, fairly late in his career, to the emerging field of free electron laser crystallography.

He began his talk by quoting the great US physicist, Richard Feynman, as saying that “every living thing can be understood by the wiggling and jiggling of atoms”. He remembered having been told as a student in the early 1970s that it would never be possible to visualise atoms in motion; now, thanks to free-electron lasers (which were invented in 1971, but not used in crystallography for over thirty years) this has become a cornerstone of his research. He paid a generous tribute to Henry Chapman, who leads the free electron laser facility at DESY in Hamburg, Germany, whose “drive, ambition and deep understanding of diffraction physics” have played an important part in establishing the technique in structural biology.

Free-electron lasers work by wiggling fast-moving electrons sideways as they pass through a magnetic field. This generates tiny pulses of X-ray photons that last no more than a few femtoseconds (1fs = 10-15s) and that can be used instead of lower-intensity X-ray beams in protein crystallography. This offers numerous advantages: the pulses are so fast that they cause little damage to protein crystals, despite their intensity; they can take consecutive ‘snapshots’ of proteins moving at room temperature in near real time; and they can generate structures successfully from crystals that are too small for conventional X-ray crystallography.

Spence spent much of the rest of his talk describing examples of protein structures that have been studied using this approach and where new insights have been generated. It is now possible to take ‘snapshots’ of proteins in motion only about 150 fs apart, which is fast enough to resolve the process of photon absorption by retinal bound to rhodopsin in the human eye.  It is therefore possible to observe the stages in the cis-trans isomerisation from 11-cis-retinal to the all-trans isomer, which leads to a conformational change in rhodopsin that activates its bound G-protein.

Light sensitive reactions are some of the easiest to observe using this technique, but only a small fraction of proteins are in fact light sensitive. Spence described how it can also be used to look at reactions that are triggered by mixing, such as enzyme catalysis. Here the components to be mixed are placed in capillary tubes one inside each other; the protein is micro-crystalline and the reaction is triggered once the components are combined and the ligand has diffused into the micro-crystals. He explained how his group produces prototypes of the nanoscale components necessary for this technology using a 3D printer before describing two examples – visualisations of the mechanisms of gene expression regulation with riboswitches, and beta-lactamase binding to penicillin antibiotics – in some detail. The beta-lactamase example is particularly important because this enzyme is one of the commonest causes of antimicrobial resistance.

In the final part of his talk, Spence discussed some recent developments and other novel ideas that are still on the drawing board. It is now possible to study the structures of membrane proteins with laser-generated X-ray beams by delivering nanocrystals of the proteins using a tube of viscous material, memorably described as both a ‘grease gun’ and a ‘toothpaste jet’.  This – and the visualisation of intact virus particles – is still tricky and time-consuming; in contrast, nanocrystals of soluble proteins are becoming tractable enough that it is possible to ‘shoot first, ask questions afterwards’. The minimum X-ray pulse size is becoming even shorter, with a few machines generating pulses only a few tens of attoseconds (1as = 10-18s) long. He described briefly some of the experiments that will become possible once this type of laser is in routine use for crystallography. And, having started with a quote from Feynmann, he ended with one from a scientist who flourished some 150 years earlier. As Sir Humphrey Davy, the inventor of electrochemistry, wrote in 1806 (in paraphrase): “Nothing promotes the advancement of science so much as a new instrument”.


IUCr 2017 Hyderabad:Blog Day 5, Friday 25 August: Metal-Organic Frameworks as Porous Dynamic Structures

Day 5, Friday 25 August: Metal-Organic Frameworks as Porous Dynamic Structures

Dr Clare Sansom, Department of Biological Sciences,  Birkbeck College, London, UK


Every IUCr congress includes three plenary lectures by distinguished scientists from different areas of crystallography. The first plenary of the 2017 meeting was given by Professor Susumu Kitagawa, the director of the Institute for Integral Cell-Material Sciences (iCeMS) in Kyoto, Japan. He was introduced by the current IUCr President, Professor Marvin Hackert of the University of Texas at Austin, Texas, USA.

Hackert began with a potted history of Kitagawa’s research career, which started in the 1970s with a PhD in hydrocarbon chemistry at the University of Tokyo. Apart from a year at Texas A & M University he has spent his entire career in Japan, moving first to the private Kindai University in Osaka and then Tokyo Metropolitan University. He was appointed as a professor in the chemistry department of Kyoto University in 1998 and has remained there ever since. His time in Kyoto, in particular, has been marked by a succession of prestigious awards including, earlier this year, the 58th Fujihara Award. This yearly award is given by the Fujihara Foundation of Science to “researchers who have made significant contributions to scientific and technological advancement”.

Kitagawa began by dedicating his lecture to a great French materials scientist, Gérard Férey, who had made significant contributions to the crystal chemistry of porous solids and had sadly died a few days before the start of the meeting at the age of 76. He introduced the main part of the lecture by referring to the pressing need for novel materials in order to maintain the world’s rapidly growing population while remaining within ecological limits. Gases have an important role to play here, as energy sources and in manufacturing, but they also have disadvantages: they are very difficult to control and particularly to store. Porous materials can hold and store gases, and transport; Kitagawa has spent much of his career studying novel materials known generally as porous coordination polymers (PCPs) and a sub-class of these, metal-organic frameworks or MOFs.

In very general terms, these materials can be thought of as regular building frameworks on the nanoscale, with tiny, regularly-spaced ‘holes’ that can hold gas molecules. They typically form crystalline particles with each ‘side’ about 1mm in length with the repeat unit – the ‘block’ from which the particle is built up – about 1nm3. Strictly speaking a porous coordination polymer is defined as a compound with repeats that extend in one, two or most often three dimensions, and MOFs are PCPs with metals incorporated into the framework.

Since the first MOFs were synthesised, three ‘generations’ of these materials have been defined. The structures of first-generation MOFs were very fragile and they could collapse after the gas they were holding was removed. Second- and third-generation MOFs retain their structure when gas is removed and are said to have permanent porosity. Their ‘very special’ properties combine some that are typical organic solids (like softness) with others that are more typical of metals (like crystallinity).

These soft porous compounds have many uses, including the storage and transport of dangerous gases. Kitagawa illustrated this point with a photo of an object that ‘[had been] a van’ that was transporting acetylene (C2H2) when the gas exploded; this could have been avoided if the acetylene had been stored in the pores of a MOF. Chemical separation processes such as distillation use an extraordinarily high proportion of the world’s energy resources, and these versatile compounds offer opportunities to make several of these more energy-efficient and thus ‘change the world’ .

Kitagawa ended his lecture with a rather complex exploration of some properties that can be altered by changing the nature of the metal and organic parts of a MOF. The novel ‘fourth-generation’ MOFs that are currently being designed have even more complex and varied properties that are affected by, for example, the material’s anisotropy, the number and nature of any defects and the pore size. And although they are generally crystalline solids at room temperature, they change phase to form liquids or glasses when temperature and pressure are raised; these, too, have interesting properties, and some powdery crystals re-form as spherulites when melted and then cooled. There are bound to be MOFs yet to be discovered that will have even more unusual and useful properties. In thanking Kitagawa for an excellent lecture that had held the attention of the large audience throughout, Hackert pointed out that there is still much to discover in this exciting field for today’s young scientists.

 

IUCr2017 Hyderabad: Blog Day 4, Thursday 24 August: Dragons’ Den

Day 4, Thursday 24 August: Dragons’ Den

Dr Clare Sansom, Department of Biological Sciences,  Birkbeck College, London, UK

The TV show Dragons’ Den was invented in Japan but has become a worldwide brand. For anyone who has managed to avoid it so far – any residents of Mars, for example – it involves entrepreneurs pitching their business ideas to an audience of investors, or ‘dragons’, who quiz them in depth before deciding whether and how much to invest in the embryo businesses. Many variants of the Den have been spawned: the last to date, but by no means the least, in crystallography.

Regular #IUCr2017 delegates who are under the age of 35 and have no permanent academic position were encouraged to submit a proposal for research funding before the date of the congress, and the best of these have been chosen for presentation to a panel of senior scientists or ‘dragons’. The dragons’ task is then to choose the best ideas to receive INR 1,50,000 in grant funding. The idea proved very popular with younger delegates, and a large number of good proposals were received. No fewer than 43 were chosen to pitch their ideas in two sessions, 22 this afternoon (Thursday 24th) and the remaining 23 on Saturday morning.

The rules of the game were simple. Each finalist had two minutes to present his or her idea, interrupted by a large placard after 90 seconds and a final bell after which the presentation had to stop. The dragons – Ashwini Nangia, Massimo Nespolo, Amit Sharma, Christian Lehmann and Keith Moffatt – then had four minutes to grill the candidate.

Twenty-one candidates entered the Den on Thursday, as one was unable to attend at the last minute. The slick, fast-moving format and the eclectic nature of the students’ interesting ideas ensured that the session held the audience’s attention throughout. One or more presenters cited almost every technique that main meeting covers, except for exceptionally expensive ones: not surprisingly, neither high resolution electron microscopy nor free electron laser spectroscopy got a mention.

There were far too many presentations to describe here. Those that caught this blogger’s attention included a proposal to kick-start protein crystallography in Tunisia through collaborating with ESRF in Grenoble; a study of the mechanism of aldose-aldose oxidoreductases; and an exploration of the idea that a few bacterial species can incorporate arsenic into their DNA backbones in place of phosphorus.

The audience had not been told anything of what the dragons might have been looking for, but the questions that cropped up again and again gave some of it away. Many were quizzed about the references in their proposals; they had clearly been asked to cite at least two relevant research papers and to avoid self-citation. Many were asked exactly what they would spend the award money on if they won, which showed up ideas that were too ambitious or too vague. Some projects, however, fit the sum offered just right; the audience clearly warmed to Atahar Parveen, a postdoc in Hyderabad, who wanted to buy a computer so she could run simulations from home and spend more time with her young daughters. A few competitors were also caught out by being asked scientific questions linked to their proposals that they had not quite been expecting.

After the last candidate had made his pitch, the dragons retreated into another room to deliberate. This did not take long, and representatives of the event sponsors, STOE and Elsevier, then announced the two worthy winners. STOE, based in Darmstadt, Germany, has been manufacturing equipment for the ‘non-destructive’ analysis of crystals and powders since before X-rays were discovered, and now makes diffractometers; the global publishing giant Elsevier needs no introduction. Today, STOE’s prize was awarded to Nami Matsubura, a PhD student working in France, and the Elsevier prize to Joanna Wojnarska from Krakow, Poland. Both winners spoke well, clearly understood the science behind their ideas and described feasible projects. Matsubura’s project will be an extension of her PhD work, involving the synthesis and analysis of novel tellurates that might be used as components of electronic devices; she intends to use her prize for travel to a lab in Belgium. Wojnarska’s mainly computer-based project involves engineering novel non-centrosymmetric materials from highly symmetrical ‘building blocks’. Only the most promising molecules will be synthesised and crystallised.

The Dragons’ Den will be back on Saturday when the second set of candidates jostle to interest the dragons in their ideas. If you are reading this at the conference before then, that session is greatly recommended.

IUCr2017 Hyderabad: Blog Day 3, Wednesday 23 August: Collaborative Drug Development in India

Day 3, Wednesday 23 August: Collaborative Drug Development in India

Dr Clare Sansom, Department of Biological Sciences,  Birkbeck College, London, UK

For many decades, India has been well-known worldwide for producing cheap, generic versions of essential medicines, in a valuable role that led it to be termed ‘the world’s pharmacy’. The Indian drug discovery industry is much newer, dating only from the 1980s, and if you see success only in terms of drugs registered by the FDA it has had very little. No novel compound discovered in India during the last thirty years has yet reached the market. The challenges currently faced by the Indian pharmaceutical industry, however, are mirrored worldwide and, as in many other countries, increasing collaboration between the various sectors of drug research – academia, government and industry – is seen as key to increasing productivity. This was the theme of an interesting and very well attended session in the IUCr parallel programme. The session focused on an area of research that is equally applicable in innovative drug research and generic drug development, that is a key strength of Indian science, and that has a strong association with crystallography: solid state forms in drug formulations.

With the designated session chair, G. Sahni from CSIR in New Delhi, absent ill, the session was chaired by Gautam Desiraju (IIS, Bangalore). His first task was to introduce himself as the first speaker, and he began by re-stating some of the problems with the Indian pharmaceutical industry in an era in which increased investment is leading to disappointingly few novel drugs on the market. In this context, research into novel drug formulations is a cheaper alternative that plays to India’s strengths in solid state and crystal chemistry. Drug compounds can exist in a variety of forms including salts, co-crystals, solvates and amorphous forms, and each of these can be polymorphic. There are many ways to alter the physical properties of a drug compound; the aim of drug developers is to move their most promising molecules into the so-called ‘golden region’ with high aqueous solubility but high membrane permeability. He ended his talk with an example; the antibacterials norfloxacin and sulfathiazole can be delivered as a mixture, but co-crystallisation will improve the permeability of the mixture without changing the efficacy of either compound.

Regulatory agencies have been involved in solid-state chemistry since the effects of crystal form on drug stability were first noticed in the 1960s. Steve Byrn, who has worked in industry and regulatory affairs and is now at Purdue University in Indiana, USA, explained how regulators approach these issues. He cited the example of the HIV protease inhibitor ritonavir, which was known for a time as the ‘magic Johnson drug’ for the dramatic improvements it offered to patients with AIDS. However, it formed insoluble spherulites in the soft gel capsules in which it was dissolved, reducing its bioavailability and thus its effectiveness. For a while, it was only available in a liquid form that tasted so bad that some patients quipped that they would rather die from AIDS. Some 80% of drugs currently under development have potential problems with solubility. Byrn described the concept of ‘equivalence’ that the FDA uses to determine whether forms of a product will behave in the same way. For two formulations to be equivalent they must have the same microstructure; a new drug polymorphism is not a generic but a novel entity.

With Dr Sahni absent, Professor A. Nangia, the director of the National Chemical Laboratory at Pune, India, gave an unscripted, largely autobiographical talk. He has worked in drug discovery in government and academia and as an entrepreneur, and he described the changes that he has seen in the research funding landscape in India throughout his 30-year career. Before the millennium, funding was low but safe; since then there have been ups and downs but on average there have been more funds available, and students recently graduating from his lab have gained experience with state-of-the-art equipment. Funding is also available for research-based startup companies, but there have been few genuine successes so far. A lively discussion focused on possible reasons for this, with the academic bias of the peer review process and the need for market ‘pull’ as well as technology ‘push’ emerging as likely reasons.

Dr A. Venkateswarlu from Dr Reddy’s Institute of Life Sciences (DRILS) in Hyderabad looked at the role of co-crystals in drug development from a manager’s perspective, starting by stressing the difference between drug substance (the active compound) and drug product (the finished tablet or capsule, in which that compound has been combined with other ingredients). Any molecule that alters the drug’s activity when combined with a drug substance – as co-crystal components may – is also considered a drug substance. He applied the well-established SWOT model (strengths, weaknesses, opportunities and threats) to pharmaceutical co-crystals. A different co-crystal form will sometimes offer a solution to problematic pharmacokinetics and can also add to intellectual property, although not to the same extent as a completely novel compound would. The final talk was entertaining, eclectic and entirely unscripted; the speaker, India Glycols’ R.K. Khandal, abandoned his slides saying that the material he had prepared had all been covered. A.V. Rama Rao, owner of contract research company Avra Laboratories in Hyderabad, summed up the session, stressing again the rewards and challenges of working in industry.