Cadmium zinc telluride (CZT), a hard-to-manufacture semiconductor produced by only a handful of companies, is enabling a quiet revolution in medical imaging, science, and security by delivering faster scans, lower radiation doses, and far more precise X-ray and gamma-ray detection. "You get beautiful pictures from this scanner," says Dr Kshama Wechalekar, head of nuclear medicine and PET. "It's an amazing feat of engineering and physics." The BBC reports: Kromek is one of just a few firms in the world that can make CZT. You may never have heard of the stuff but, in Dr Wechalekar's words, it is enabling a "revolution" in medical imaging. This wonder material has many other uses, such as in X-ray telescopes, radiation detectors and airport security scanners. And it is increasingly sought-after. Investigations of patients' lungs performed by Dr Wechalekar and her colleagues involve looking for the presence of many tiny blood clots in people with long Covid, or a larger clot known as a pulmonary embolism, for example. The 1-million-pound scanner works by detecting gamma rays emitted by a radioactive substance that is injected into patients' bodies. But the scanner's sensitivity means less of this substance is needed than before: "We can reduce doses about 30%," says Dr Wechalekar. While CZT-based scanners are not new in general, large, whole-body scanners such as this one are a relatively recent innovation. CZT itself has been around for decades but it is notoriously difficult to manufacture. "It has taken a long time for it to develop into an industrial-scale production process," says Arnab Basu, founding chief executive of Kromek. [...] The newly formed CZT, a semiconductor, can detect tiny photon particles in X-rays and gamma rays with incredible precision -- like a highly specialized version of the light-sensing, silicon-based image sensor in your smartphone camera. Whenever a high energy photon strikes the CZT, it mobilizes an electron and this electrical signal can be used to make an image. Earlier scanner technology used a two-step process, which was not as precise. "It's digital," says Dr Basu. "It's a single conversion step. It retains all the important information such as timing, the energy of the X-ray that is hitting the CZT detector -- you can create color, or spectroscopic images."

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alternative_right shares a report from ScienceAlert: Engineers at Cornell University have created the blackest fabric on record, finding it absorbs 99.87 percent of all light that dares to illuminate its surface. [...] In this case, the Cornell researchers dyed a white merino wool knit fabric with a synthetic melanin polymer called polydopamine. Then, they placed the material in a plasma chamber, and etched structures called nanofibrils -- essentially, tiny fibers that trap light. "The light basically bounces back and forth between the fibrils, instead of reflecting back out -- that's what creates the ultrablack effect," says Hansadi Jayamaha, fiber scientist and designer at Cornell. The structure was inspired by the magnificent riflebird (Ptiloris magnificus). Hailing from New Guinea and northern Australia, male riflebirds are known for their iridescent blue-green chests contrasted with ultrablack feathers elsewhere on their bodies. The Cornell material actually outperforms the bird's natural ultrablackness in some ways. The bird is blackest when viewed straight on, but becomes reflective from an angle. The material, on the other hand, retains its light absorption powers when viewed from up to 60 degrees either side. The findings have been published in the journal Nature Communications.

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Psychology Today reports: In a study conducted in Milan, Italy, and published in November 2025, the sight of a person dressed as Batman led to a nearly doubled rate of people giving up their seat to a pregnant woman. Over the course of 138 subway rides, researchers found that people who saw "Batman" standing near the pregnant woman were far more altruistic than those who did not. Researchers are calling this the "Batman effect," suggesting a form of "involuntary" mindfulness may be at play. Noticing these subtle social cues appears to shift people's typical, automatic reactions. Most interestingly, 44 percent of the people questioned reported they did not even consciously register Batman's presence... The superhero costume serves as a visual nudge, pulling us out of our default, self-focused mode and into a more generous, attentive state. More from Futurism: Batman showing up is just one — albeit striking — way of promoting what's called "prosocial behavior," or the act of helping others around you, via introducing an unexpected event, the researchers write. "Our findings are similar to those of previous research linking present-moment awareness (mindfulness) to greater prosociality," said study lead author Francesco Pagnini, a professor of clinical psychology at the Università Cattolica in Milan, in a statement about the work. "This may create a context in which individuals become more attuned to social cues." Thanks to Black Parrot (Slashdot reader #19,622) for sharing the article.

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Twenty years after surgeons in France performed the world's first face transplant, the experimental field that procedure launched is now confronting a troubling record of patient deaths, buried negative data and a healthcare system that leaves recipients financially devastated and medically vulnerable. About 50 face transplants have been performed globally since Isabelle Dinoire received her partial face graft at University Hospital CHU Amiens-Picardie in November 2005. A 2024 JAMA Surgery study reported five-year graft survival of 85% and 10-year survival of 74%, concluding that the procedure is "an effective reconstructive option for patients with severe facial defects." The study did not track psychological wellbeing, financial outcomes, employment status or quality of life. Roughly 20% of face transplant patients have died from rejection, kidney failure, or heart failure. The anti-rejection medications that keep transplanted faces alive can destroy kidneys and weaken immune systems to the point where routine infections become life-threatening. In the United States, the Department of Defense has funded most operations, treating them as a frontier for wounded veterans, because private insurers refuse to cover the costs. Patients who survive the surgery often find themselves unable to afford medications, transportation to follow-up appointments or basic caregiving. The field's long-term grants cover surgical innovation but not the lifelong needs of the people who receive these transplants.

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Je connaissais déjà l'aérogel de silice (on trouve plein de vidéos sur internet), mais c'est un matériaux fragile et friable.
L'aérogel de graphène semble beaucoup plus solide.
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