Pre-term infants appear to mature better if they are shielded from most wavelengths of visible light, from violet to orange. But it has been a challenge to develop a controllable light filter for pre-term incubators that can switch between blocking out all light–for sleeping–and all but red light to allows medical staff and parents to check up on the kids when they’re awake. Now researchers describe a proof-of-concept mirror that switches between reflective and red-transparent states when a small voltage is applied.
The research team had previously identified a magnesium-iridium reflective thin film that transforms into a red-transparent state when it incorporates protons. Providing those protons in a way that is practical for pre-term incubators, however, was the challenge. The typical method–using dilute hydrogen gas–is unacceptable in a hospital setting. So the team created a stack of thin films that includes both an ion storage layer and the magnesium-iridium layer: a voltage drives protons from the ion storage layer to the magnesium-iridium layer, transforming it into its red-transparent state. Reversing the voltage transforms it back into a reflective mirror.
The researchers report that the device still allows some undesirable light wavelengths through, but a force of just 5 V changes the device’s state in as little as 10 seconds. The researchers are now looking at other materials to improve colour filtering and switching speed. EurekAlert

The introduction of CT pulmonary angiography has been associated with an 80% rise in the detection of pulmonary emboli in the US, but with little change in death rates.
Professor Renda Soylemez Wiener and colleagues argue this is evidence of over-diagnosis. They say some patients are helped, but many are harmed by the adverse effects of unnecessary treatment.
This article is the first of a series looking at the risks and harms of over-diagnosis in a range of common conditions. The series, together with the Preventing Overdiagnosis conference in September, are part of the BMJ’s Too Much Medicine campaign to help tackle the threat to health and the waste of money caused by unnecessary care.
Pulmonary embolism has been described as one of the most commonly missed deadly diagnoses. Until recently, ventilation-perfusion (VQ) scanning was the first line test, but a new technology introduced in 1998

Nurses have been warned about wearing nail extensions and using nail polish after a poll suggested infection control was being put at risk by fashion-conscious NHS staff.
Guidance states that fingernails should be short and free of varnish. But an online poll of nearly 500 student nurses found lapses were commonplace with 60% reporting nail extensions and polish being used.
The Royal College of Nursing said the findings were ‘worrying’.
The survey was carried out by Cardiff University and London’s City University. Overall each of the 488 students who took part reported seeing at least one breach in infection control rules by health staff once other problems, such as a failure to wash hands as well as breaches of nail care were taken into account.
The researchers said the survey showed lapses were widespread.
Tom Sandford, of the RCN, added: ‘Fingernails should be short and free of nail varnish. False nails should not be worn. Nail varnish and extensions harbour bacteria and prevent good hand hygiene. Health organisations should uphold clear local policies on uniforms and work-wear and their implications for infection control and health and safety.’ BBC

For patients with advanced gastric cancer, treatment with chemotherapy after surgery can reduce the risk of cancer related death by 34% over five years compared to surgery alone.
Prof Sung Hoon Noh, a gastric surgeon from Yonsei University College of Medicine, Korea, presented 5-year follow-up from the phase III CLASSIC trial, which added combination chemotherapy to a standard surgical procedure called D2 gastrectomy. The chemotherapy regimen studied in the trial is called XELOX, which is a combination of the drugs capecitabine and oxaliplatin.
CLASSIC was a multinational open-label randomised phase III trial performed in South Korea, China and Taiwan. Patients with stage II

Tiny silicon crystals caused no health problems in monkeys three months after large doses were injected, marking a step forward in the quest to bring such materials into clinics as biomedical imaging agents, according to a new study.
The findings suggest that the silicon nanocrystals, known as quantum dots, may be a safe tool for diagnostic imaging in humans. The nanocrystals absorb and emit light in the near-infrared part of the spectrum, a quality that makes them ideal for seeing deeper into tissue than traditional fluorescence-based techniques.
‘Quantum dots, or nanocrystals, are very, very promising for biomedical imaging applications, but everyone