Many of us have contemplated buying a reconditioned phone. It might be that bit older but it has a new screen and works as well as those in the shop-front. I’m not sure, however, that any of us have thought of investing in a reconditioned liver – but it could be coming to a body near you.
Researchers based in São Paulo’s Institute of Biosciences have been developing a technique to create and repair transplantable livers. The proof-of-concept study published in Materials Science and Engineering by the Human Genome and Stem Cell Research Centre (HUG-CELL) is based on tissue bioengineering techniques known as decellularisation and recellularisation.
The organs of some donors are sometimes damaged in traffic accidents, but these may soon be transplantable if the HUG-CELL team realises its goal.
The decellularisation and recellularisation approach involves taking an organ from a deceased donor and treating it with detergents and enzymes to remove all the cells from the tissue. What remains is the organ’s extracellular matrix, containing its original structure and shape.
This extracellular matrix is then seeded with cells from the transplant patient. The theoretical advantage of this method is that the body’s immune system won’t rile against the new organ as it already contains cells from the patient’s own body, thereby boosting the chance of long-term acceptance.
However, the problem with the decellularisation process is that it removes the very molecules that tell cells to form new blood vessels. This weakens cell adhesion to the extracellular matrix. To get around this, the researchers have introduced a stage between decellularisation and recellularisation. After decellularising rat livers, the scientists injected a solution that was rich in the proteins produced by lab-grown liver cells back into the extracellular matrix. These proteins then told the liver cells to multiply and form blood vessels.
These cells then grew for five weeks in an incubator that mimicked the conditions inside the human body. According to the researchers, the results showed significantly improved recellularisation.
“It’s comparable to transplanting a ‘reconditioned’ liver, said Mayana Zatz, HUG-CELL’s principal investigator and co-author of the article. “It won't be rejected because it uses the patient’s own cells, and there’s no need to administer immunosuppressants.”
Extracellular matrix of a decellularised liver | Image Credit: HUG-CELL/USP
Obviously, there is a yawning gap between proof of concept and the operating theatre, but the goal is to scale up the process to create human-sized livers, lungs, hearts, and skin for transplant patients.
“The plan is to produce human livers in the laboratory to scale,” said lead author Luiz Carlos de Caires-Júnior to Agência FAPESP. “This will avoid having to wait a long time for a compatible donor and reduce the risk of rejection of the transplanted organ."
This technique could also be used to repair livers given by organ donors that are considered borderline or non-transplantable. “Many organs available for transplantation can’t actually be used because the donor has died in a traffic accident,” Caires-Júnior added. “The technique can be used to repair them, depending on their status.”
Even if we are at the early stages of this approach, it bodes well for future research. And for those on the organ transplant list, a reconditioned liver would be as good as a new one – complete with their very own factory settings.
Read the paper here: https://www.sciencedirect.com/science/article/abs/pii/S0928493120337814
In this new series, members of the SCI Mid-Career group offer advice on career management and how to overcome career challenges.
In our latest interview, we hear from David Freeman, Research & Technology Director for Croda’s Energy Technologies business.
Please tell us about yourself and your career journey.
After a PhD in organic chemistry, I started my career with ICI Paints in Slough in 1998, working in a product development role. Within a couple of years, I moved to another ICI business, Uniqema, and had various technical roles around the chemical synthesis or process development of new materials.
These early roles – and the people I worked with during this time – had a big impact on me in terms of ways of working and how to deal with people. I subsequently joined Croda in 2006 and have since had further technical roles – initially around the technical management of Synthesis programmes in Croda, then technical management of Applications programmes, and finally on to my current role of R&T Director for Croda’s Energy Technologies business.
This last transition was probably the most interesting and challenging as it forced me to think much more strategically about the “what” rather than the “how” and what leadership versus management was all about. I see this area as being hugely important to the Mid-Career group.
What are your keys to managing your career at this stage?
Development remains really important to me from a personal perspective. I have always driven my own development, but been well supported by the organisations I’ve worked for: both by technical management teams and HR teams. At the mid-careers stage, there are lots of important things to think about but I consider the following to be key:
What challenges are there around mid-career support?
I feel very fortunate to have worked for organisations where development is extremely important – support is always on hand when I need it. The key challenge is a personal one and it’s about making enough time to focus on the right development areas. We are all busy but if we want to develop ourselves enough, then we will find that time!
When you live in a cold country, you think of hot days as a blessing. Air conditioning units are for those in far-away places – humid countries where the baked earth smell rises to meet you when you step off the plane.
But cooling comes at a cost. According to the UN Environment Programme, it accounts for 7% of global greenhouse gas emissions. Some of us are visual learners; so, the sheer cost of cooling really hit me when I stared up at an apartment building in Hong Kong with hundreds of air conditioning units perched above the windows like birds.
And it isn’t just the Hong Kongers feeling the heat. The cooling industry as a whole is under pressure to cut its greenhouse gas emissions. The International Energy Agency expects emissions from cooling to double by 2030 due to heat waves, population growth, urbanisation, and the growing middle class. By 2050, it forecasts that space cooling will consume as much electricity as China and India do today.
Air conditioning units cling to a building
All of this was captured by the Cooling Suppliers: Who's Winning the Race to Net Zero report released by the Race to Zero campaign, the Kigali Cooling Efficiency Program (K-CEP), Carbon Trust and other partners in the UN Environment Programme-hosted Cool Coalition.
This report's authors found that only five of the 54 cooling companies they assessed have committed to net-zero targets. The document outlines three areas that must be addressed on the Cooling Climate Pathway: super-efficient appliances, ultra-low global warming refrigerants, and the widespread adoption of passive cooling measures such as clever home design and urban planning.
So, while builders adjust window sizes, introduce trees for shading, and choose materials (such as terracotta cooling systems) thoughtfully to temper the sun’s gaze, others are availing of different methods.
For example, the COP26 (the 2021 UN Climate Change Conference) Champions Team has just released its Net Zero Cooling Action Plan that includes a Cool Calculator tool to help companies and governments run simple calculations to see where they could decarbonise their cooling systems. Similarly, the UK's Environmental Investigation Agency (EIA) has launched a net-zero cooling product guide that showcases energy-efficient products run on natural refrigerants.
Green walls are one of many passive cooling approaches used to reduce our reliance on mechanical systems.
However, it’s clear that the softly-softly approach won’t suffice. The EIA has called on governments to do more to encourage organisations to adopt sustainable cooling, to make concrete policy commitments, and speed-up the phase-out of climate-warming refrigerants such as hydrofluorocarbons.
“The development and expansion of net-zero cooling is a critical part of our Race to Zero emissions,” said Nigel Topping, UK High Level Champion for COP26. “In addition to technological breakthroughs and ambitious legislation, we also need sustainable consumer purchasing to help deliver wholesale systems change.”
We all love the technological panacea – innovations that will cure all the climate ills we have inflicted on the world. But the solution will also involve stodgy government regulations and changing consumer habits, and a reliance on the continued fall in renewable power generation.
For those in traditionally cooler climes, it’s no longer someone else’s problem. It was a balmy 22°C in London this week and we’re not even in April yet. So, it’s certainly time to turn up the heat on the cooling industry.
Variously known as zucchini, courgette, baby marrows and summer squash, this frost tender crop is a valuable addition for gardens and allotments. Originating in warm temperate America, the true zucchini was developed by Milanese gardeners in the 19th century and popularised in the UK by travellers in Italy. It quickly matures in 45 to 50 days from planting out in open ground by early May in the south and a couple of weeks later farther north.
Alternatively, use cloches as frost protection for early crops. Earliness is also achieved by sowing seed in pots of openly draining compost by mid-April in a greenhouse or cold frame. Courgettes have large, energy-filled seeds. Consequently, germination and subsequent growth are rapid.
Sow seed singly in 10cm diameter pots and plant out when the first 2-3 leaves are expanding (illustration number 1). Alternatively, garden centres supply transplants. These should be inspected carefully, avoiding those with yellowing leaves or wilting foliage. Each plant should have white healthy-looking roots without browning.
Illustration 1: Courgette seedlings germinated in a greenhouse.
Courgettes grow vigorously and each plant should be allocated at least 1 metre spacing within and between rows. They require copious watering and feeding with a balanced fertiliser containing equal quantities of nitrogen, phosphorus and potassium.
Botanically, they are dioecious plants, having separate male and female flowers, (illustration number 2). They are beloved by bees, hence supporting biodiversity in the garden. Slugs are their main pest, causing browsing wounds on courgette fruits; mature late-season foliage is usually infected by powdery mildew fungi that cause little harm.
Illustration 2: Bee-friendly (and tasty) courgette flower.
Quick maturing succulent courgettes are hybrid cultivars, producing harvestable 15-25 cm long fruit (berries) before the seeds begin forming (illustration number 3). Harvest regularly at weekly intervals before the skins (epicarps) begin strengthening and toughening. Skin colour varies with different cultivars from deep green to golden yellow. The choice rests on gardeners’ preferences.
Courgettes are classed and cooked as vegetables and their dietary value is retained by steaming thinly sliced fruits. Courgettes are a low-energy food but contain useful amounts of folate, potassium and vitamin A (retinol). The latter boosts immune systems, helping defend against illness and infection and increasing respiratory efficiency. Eyesight is also protected by increasing vision in low light.
Illustration 3: Courgette fruit ready for the table.
Courgettes are, therefore, valuable dietary additions year-round. Courgette flowers are bonuses, used as garnishes or dipped in batter as fritters or tempura. Overall, the courgette is a most useful plant that provides successional cropping using ground vacated by over-wintered vegetables such as cabbage, Brussels sprouts or leeks.
Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.
Every day, there are subtle signs that machine learning is making our lives easier. It could be as simple as a Netflix series recommendation or your phone camera automatically adjusting to the light – or it could be something even more profound. In the case of two recent machine-learning developments, these advances could make a tangible difference to both microscopy, cancer treatment, and our health.
The first is an artificial intelligence (AI) tool that improves the information gleaned from microscopic images. Researchers at the University of Gothenburg have used this deep machine learning to enhance the accuracy and speed of analysis.
The tool uses deep learning to extract as much information as possible from data-packed images. The neural networks retrieve exactly what a scientist wants by looking through a huge trove of images (known as training data). These networks can process tens of thousands of images an hour whereas some manual methods deliver about a hundred a month.
Machine learning can be used to follow infections in a cell.
In practice, this algorithm makes it easier for researchers to count and classify cells and focus on specific material characteristics. For example, it can be used by companies to reduce emissions by showing workers in real time whether unwanted particles have been filtered out.
“This makes it possible to quickly extract more details from microscope images without needing to create a complicated analysis with traditional methods,” says Benjamin Midtvedt, a doctoral student in physics and the main author of the study. “In addition, the results are reproducible, and customised. Specific information can be retrieved for a specific purpose."
The University of Gothenburg tool could also be used in health care applications. The researchers believe it could be used to follow infections in a cell and map cellular defense mechanisms to aid the development of new medicines and treatments.
Machine learning by colour
On a similar thread, machine learning has been used to detect cancer by researchers from the National University of Singapore. The researchers have used a special dye to colour cells by pH and a machine learning algorithm to detect the changes in colour caused by cancer.
The researchers explain in their APL Bioengineering study that the pH (acidity level) of a cancerous cell is not the same as that of a healthy cell. So, you can tell if a cell is cancerous if you know its pH.
With this in mind, the researchers have treated cells with a pH-sensitive dye called bromothymol blue that changes colour depending on how acidic the solution is. Once dyed, each cell exudes its unique red, green, and blue fingerprint.
By isolating a cell’s pH, researchers can detect the presence of cancer.
The authors have also trained a machine learning algorithm to map combinations of colours to assess the state of cells and detect any worrying shifts. Once a sample of the cells is taken, medical professionals can use this non-invasive method to get a clearer picture of what is going on inside the body. And all they need to do all of this is an inverted microscope and a colour camera.
“Our method allowed us to classify single cells of various human tissues, both normal and cancerous, by focusing solely on the inherent acidity levels that each cell type tends to exhibit, and using simple and inexpensive equipment,” said Chwee Teck Lim, one of the study’s authors.
“One potential application of this technique would be in liquid biopsy, where tumour cells that escaped from the primary tumour can be isolated in a minimally invasive fashion from bodily fluids.”
The encouraging sign for all of us is that these two technologies are but two dots on a broad canvas, and machine learning will enhance analysis. There are certainly troubling elements to machine learning but anything that helps hinder disease is to be welcomed.
Machine Learning-Based Approach to pH Imaging and Classification of Single Cancer Cells:
Quantitative Digital Microscopy with Deep Learning:
What do grape stalks, pineapple leaves, corn cobs, rice husks, sheep’s wool, and straw have in common? Apart from being natural materials, they have all been used to insulate homes. Increasingly, people are turning towards natural, sustainable materials as climate change and waste have become bigger problems.
Existing building insulation materials such as synthetic rock wool are excellent at keeping our homes warm in winter, but the conversation has moved beyond thermal performance. Energy use, re-usability, toxicity, and material disposal are all live considerations now, especially with regulations and emissions targets tightening. So, rock wool might perform better than straw bale insulation but straw is biodegradable, reusable, easy to disassemble, and doesn’t require large amounts of energy to process.
Sheep’s wool and hemp insulation have also become attractive to homeowners and housebuilders alike, but an even more encouraging prospect is the use of waste materials to create next generation insulation. In this spirit, researchers at Flinders University in Adelaide, Australia, have taken waste cooking oil, wool offcuts, and sulphur to process a novel housing insulation material.
Recycled paper is one of many waste materials that has found its way into domestic insulation.
To make this composite, they followed several stages. In the first stage of the synthesis, the researchers used inverse vulcanisation to create a polysulphide polymer from canola oil triglyceride and sulphur. They then mixed this powdered polymer with wool and coated the fibres through electrostatic attraction. This mixture was compressed through mild heating to provoke S−S metathesis in the polymer and bind the wool. The wool bolsters the tensile strength of the material, makes it less flammable, and provides excellent insulation. The result is a sustainable building material that fulfils its function without damaging the environment.
For Associate Professor Justin Chalker, the lead author of this study, this work provides an ideal jumping-off point. “The promising mechanical and insulation properties of this composite bodes well for further exploration in energy saving insulation in our built environment,” he said.
It is clear that ventures like the one in Adelaide will continue to sprout all over the world. After all, necessity dictates that we change the way we build our homes and treat materials.
A recent report from Emergen Research predicts that the global insulation materials market will be worth US $82.96 billion (£59.78 billion) by 2027. The same report was also at pains to mention that the increasing demand for reduced energy consumption in buildings will be a significant factor in influencing industry growth.
“Market revenue growth is high and expected to incline rapidly going ahead due to rising demand for insulation materials... to reduce energy consumption in buildings,” it said. One of the main reasons given for this increased green building demand was stricter environmental regulations.
And Emergen isn’t the only organisation feeling the ground moving. Online roofing merchant Roofing Megastore, which sells more than 30,000 roofing materials, has detected a shift towards environmentally friendly materials, with many homeowners sourcing these products themselves.
Rock wool insulation panels have come under greater scrutiny in recent times.
Having analysed two years of Google search data on sustainable building materials, the company found that synthetic roof tiles are generating the most interest from the public. Like the Flinders insulation, these roof tiles make use of waste materials, in this case recycled limestone and plastic. And you don’t need to look far down the list to find sustainable insulation materials, with sheep’s wool insulation in 9th place, wood fibre insulation in 10th, and hemp insulation in 12th.
Over time, the logic of the progression towards natural, less energy-intensive building materials will become harder to ignore. “Traditional materials such as synthetic glass mineral wool offer high levels of performance but require large amounts of energy to produce and must be handled with care while wearing PPE,” the company noted. “Natural materials such as hemp or sheep’s wool, however, require very little energy to create and can be installed easily without equipment.”
So, the next time you look down at your nutshells, spent cooking oil, or tattered woollen sweater, think of their potential. In a few years, these materials could be sandwiched between your walls, keeping you warm all winter.
Insulating composites made from sulphur, canola oil, and wool (2021): https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cssc.202100187?af=R
Rising anxiety about air pollution, physical, and mental health, exacerbated by Covid-19 and concerns about public transport, has seen an increase in the popularity of cycling around Europe, leading many cities to transform their infrastructure correspondingly.
These days, Amsterdam is synonymous with cycling culture. Images of thousands of bikes piled up in tailor-made parking facilities continue to amaze and it is routinely held up as an example of greener, cleaner, healthier cities. Because The Netherlands is so flat, people often believe it has always been this way. But, in the 1970s, Amsterdam was a gridlocked city dominated by cars. The shift to cycling primacy took work and great public pressure.
For some cities, however, the pandemic has provided an unexpected opportunity on the roads. Milan's Deputy Mayor for Urban Planning, Green Areas and Agriculture, Pierfrancesco Maran, has explained that, "We tried to build bike lanes before, but car drivers protested". Now, however, numbers have increased from 1,000 to 7,000 on the main shopping street. "Most people who are cycling used public transport before”, he said. “But now they need an alternative”.
Creating joined up cycling networks is a major challenge for urban planners.
In Paris, the Deputy Mayor David Belliard does not seem concerned that the city’s investment since the start of the pandemic will go to waste. “It's like a revolution," he said. “Some sections of this road are now completely car-free. The more you give space for bicycles, the more they will use it.” They are committed to creating a cycle culture, providing free cycling lessons and subsidising the cost of bike repairs. The city intends to create more than 650km of cycle lanes in the near future.
The success in these two cities has been supported by local government but it has also been fuelled by an understandable (and encouraged) avoidance of public transport and fewer cars on the road generally. Going forward, however, it seems likely that those last two factors won’t be present. So how do you create a cycling culture in your city in the long run?
The answer is both simple and difficult: cyclists (and pedestrians) need to have priority over cars. In Brussels, where 40km of cycle track have been put down in the last year, specific zones have been implemented where this is the case, and speed limits have been reintroduced across the city.
In Copenhagen, in the late 1970s, the Danish Cyclists’ Federation arranged demonstrations demanding more cycle tracks and a return to the first half of the century, when cyclists had dominated the roads. Eventually, public pressure paid off — although there is still high demand for more cycle lanes. A range of measures, including changes made to intersections, make cyclists feel safer and local studies show that, as cyclist numbers increase, safety also increases. In many parts of the city, it is noticeable how little of the wide roads are actually available to cars: bikes, joggers, and pedestrians are all accommodated.
Segregated cycleways, like this one in Cascais, Portugal, make people more likely to cycle.
But, if you were starting from scratch, you might not simply add cycle lanes to existing roads and encourage behavioural changes on the road. Segregated, protected bike lanes like those introduced in Paris are the next level up and the results suggest they work — separated from the roads, more people are inclined to try cycling.
Dutch experts suggest, where possible, going even further. Frans Jan van Rossem, a civil servant specialising in cycling policy in Utrecht, believes the best option is to create solitary paths, separated from the road by grass, trees, or elevated concrete. Consistency is also important. Cities need networks of cycle tracks, not just a few highways. Again, prioritising cyclists is key to the Dutch approach. Many cities have roads where cars are treated as guests, restricted by a speed limit of 30km/hour and not permitted to pass. Signage is also key.
In London, Mayor Sadiq Khan’s target is for 80% of journeys to be made by walking, cycling, and/or public transport by 2041. Since 2018, the city has been using artificial intelligence to better understand road use in the city and plan new cycle routes in the capital. However, the experience of other European capitals suggests that, "if you build it, they will come" might be a better approach than working off current usage.
A completely clean, renewable energy system that can be produced locally and that can easily power heat, energy storage and transportation, and travel — that's the future that promoters of a hydrogen economy envisage.
If it sounds a bit like rocket science, that's because it is. Hydrogen is what's used to fuel rockets — that’s how powerful it is. In fact, it’s three times more powerful as a fuel than gas or other fossil-based sources. And, after use, it’s frequently converted to drinking water for astronauts.
US President Joe Biden has highlighted the potential of hydrogen in his ambitious plans for economic and climate recovery and a number of recent reports have been encouraging about hydrogen’s breakthrough moment, including McKinsey and Company (Road Map to a US Hydrogen Economy, 2020) and the International Energy Agency.
Hydrogen fuel cells provide a tantalising glimpse into our low-carbon future
The McKinsey report claims that, by 2030, the hydrogen sector could generate 700,000 jobs and $140bn in revenue, growing to 3.4 million jobs and $750bn by 2050. It also believes it could account for a 16% reduction in CO2 emissions, a 36% reduction in NOx emissions, and supply 14% of US energy demand.
So how does it work?
Simply put, hydrogen fuel cells combine hydrogen and oxygen atoms to produce electricity. The hydrogen reacts with oxygen across an electrochemical cell and produces electricity, water, and heat.
This is what gets supporters so excited. In theory, hydrogen is a limitless, incredibly powerful fuel source with no direct emissions of pollutants or greenhouse gases.
So what's the problem?
Right now, there are actually a few problems. The process relies on electrolysis and steam reforming, which are extremely expensive. The IEA estimates that to produce all of today’s dedicated hydrogen output from electricity would require 3,600TWh, more than the total annual electricity generation of the European Union.
Moreover, almost 95% of hydrogen currently is produced using fossil fuels such as methane, natural gas, or coal (this is called "grey hydrogen"). Its production is responsible for annual CO2 emissions equivalent to those of Indonesia and the United Kingdom combined. In addition, its low density makes it difficult to store and transport — it must be under high pressure at all times. It’s also well-known for being highly flammable — its use as a fuel has come a long way since the Hindenburg Disaster but the association still makes many people nervous.
A Hydrogen refuelling station Hafencity in Hamburg, Germany. Infrastructure issues must be addressed if we are to see more hydrogen-fuelled vehicles on our roads. | Image credit: fritschk / Shutterstock.com
So there are quite a few problems. What’s the good news?
In the last few years, we've seen how rapidly investment, innovation, and infrastructure policy can completely transform individual renewable energy industries. For example, the IEA analysis believes the declining costs of renewables and the scaling up of hydrogen production could reduce the cost of producing hydrogen from renewable electricity 30% by 2030.
Some of the issues around expense could be resolved by mass manufacture of fuel cells, refuelling equipment, and electrolysers (which produce hydrogen from electricity and water), made more likely by the increased interest and urgency. Those same driving forces could improve infrastructural issues such as refuelling stations for private and commercial vehicles, although this is likely to require coordination between various stakeholders, including national and local governments, industry, and investors.
The significant gains in renewable energy mean that “green” hydrogen, where renewable electricity powers the electrolysis process, is within sight.
The IEA report makes clear that international co-operation is “vital” to progress quickly and successfully with hydrogen energy. R&D requires support, as do first movers in mitigating risks. Standards need to be harmonised, good practice shared, and existing international infrastructure built on (especially existing gas infrastructure).
If hydrogen can be as efficient and powerful a contributor to a green global energy mix as its proponents believe, then it's better to invest sooner rather than later. If that investment can help power a post-Covid economic recovery, even better.