Primitive meteorites preserve information about the conditions at the birth of the Sun and planets. The meteorite components show an inhomogeneous concentration of a radioactive isotope of aluminum. This variation suggests that an additional amount of the radioactive aluminum was introduced shortly after the Solar System started forming. A nearby supernova explosion is the best candidate for this injection of new radioactive isotopes. But a supernova that was close enough to deliver the amount of isotopes seen in meteorites would have also created a blast wave strong enough to rip the nascent Solar System apart.

A team led by Doris Arzoumanian at the National Astronomical Observatory of Japan proposed a new explanation of how the Solar System acquired the amount of isotopes measured in meteorites while surviving the supernova shock. Stars form in large groups called clusters inside giant clouds of molecular gas. These molecular clouds are filamentary. Small stars like the Sun usually form along the filaments and large stars, which will explode in a supernova, usually form at the hubs where multiple filaments cross.

Assuming that the Sun formed along a dense molecular gas filament, and a supernova exploded at a nearby filament hub, the team’s calculation showed that it would take at least 300,000 years for the blast wave to break up the dense filament around the forming Solar System. The components of meteorites enriched in radioactive isotopes formed in approximately the first 100,000 years of Solar System formation inside the dense filament. The parent filament may have acted as a buffer to protect the young Sun and helped catch the radioactive isotopes from the supernova blast wave and channel them into the still forming Solar System.

In the digestive system, there’s a delicate balance of bacterial populations. When this balance is disrupted, bad bacteria can take over the colon, causing it to swell, resulting in colitis. Certain diseases, including inflammatory bowel disease and Crohn’s disease, involve chronic colitis and currently require immunosuppressants to treat them. These drugs are expensive and non-specific, sometimes giving rise to antibiotic-resistant bacteria.

An alternative strategy is to deliver beneficial bacteria, or probiotics, to help restore balance. But to reach the colon, a treatment must first pass through stomach acid, withstand being cleared out by the intestine, then fight for space alongside the numerous invading bacteria. Pairing probiotics with a drug delivery system could make this strategy feasible, though most current approaches simply protect the probiotics from digestion without affecting the microbes responsible for the condition. So, Zhenzhong Zhang, Junjie Liu, Jinjin Shi and colleagues wanted to combine probiotics with specialized microgel spheres that could not only protect the good bacteria, but also actively help clear out the bad.

To create their system, the researchers combined sodium alginate, tungsten and calcium-containing nanoparticles into small, spherical microgels, then coated them with beneficial, probiotic bacteria. The gels protected the bacteria as they made their way through the stomach and increased their retention time in the colon. Once there, calprotectin proteins — highly expressed during colitis — bound to the calcium and disassembled the gels, allowing the tungsten to escape. By displacing molybdenum in a key enzyme substrate of the bad bacterium Enterobacteriaceae, tungsten inhibited the microbe’s growth while leaving the probiotics unaffected. In experiments using a colitis mouse model, the system allowed probiotics to proliferate in the intestine without any side effects. Additionally, mice with the microgel spheres did not exhibit many of the hallmarks of colitis, such as shortened colons or damaged intestinal barriers, showing that the delivery system could be a viable treatment strategy. Though the researchers also want to prove its utility in more advanced preclinical models, they say that this work provides a new perspective into treatments using colonizing probiotics.

The authors acknowledge funding from the National Natural Science Foundation of China, the Outstanding Youth Foundation of Henan Province and the China Postdoctoral Science Foundation.

Research by Lancaster University’s School of Engineering and the UK Centre for Ecology and Hydrology combined a tidal range power generation model with its cost model to demonstrate the viability of tidal power.

Professor George Aggidis, Head of Energy Engineering at Lancaster University, said: “The obvious question for the UK, with one of the best tidal resources globally, is why haven’t we already got a tidal barrage scheme?”

The research published in Energy demonstrates the benefits of tidal energy, which does not suffer from unpredictable intermittency as power is generated both day and night.

The creation of a tidal barrage could operate for 120 years or more to meet future demand and storage problems.

Professor Aggidis said: “There is an urgent need to kick-start the selection and development of schemes around Britain. Tidal range generation is predictable renewable energy driven by the gravitational pull of the moon and sun. The environmental and economic benefits are huge as barrages can protect coastal areas from flooding and sea level rise. With two-way generation and pumping, the full range of existing tides can be maintained within impoundments to protect and support low-lying intertidal areas such as saltmarshes and mudflats.

Our studies show that with modern technology and operating procedures, estuarine barrages are the only practical way to protect these vital habitats. Coastal lagoons have also been proposed for several locations around Britain’s coast. Schemes will provide jobs in construction and manufacturing for generations to come as well as opportunities for transport, communication, conservation, and recreation. In the long-term they will provide reliable power with reduced costs.”

The UK has the second highest tidal range in the world and offers the UK a level of independence from global prices and in the long-term cheap clean power.

Currently the Tidal Range projects under commercial consideration offer an achievable 10 GW installed capacity, delivering over 20TWh/y, about 5% of UK energy use. Based on the UK relevant resource availability there is the potential to further increase this installed capacity over 4 to 5 times with other tidal range project sites around the UK.

Such developments are essential to assist the UK to reduce its carbon emissions by replacing fossil fuel power stations. The current UK total generating capacity is around 42.8 GW that includes fossil fuels (19.2GW 44.9%), renewables (16.5GW, 38.5%), and low carbon (7.1GW — 16.6%). The La Rance Tidal Range plant in France today generates the cheapest electricity in the EDF fleet — cheaper than nuclear.