Natural blood clots, which include platelets (light blue clumps) and red blood cells in a fibrin mesh, can take minutes to form.Credit: Anne Weston, EM STP, The Francis Crick Institute/Science Photo Library Red blood cells modified with Nobel-prizewinning chemistry can snap together to form clots that staunch bleeding in seconds. That's according to a study, published on 29 April in Nature1, that tested the technology in rats. The method, called click clotting, produces clots that are stronger than either natural clots or a commercial product used to stop bleeding. If shown to be safe and effective in people, the approach could provide a rapid way to induce haemostatis, the body's natural process for controlling bleeding, and to stem potentially deadly blood loss during surgery or after injuries. 'It's really cool,' says Ashley Brown, a biomedical engineer jointly at the University of North Carolina in Chapel Hill and North Carolina State University in Raleigh, who was not involved in the study. 'Particularly in emergency medicine, there's a large need for materials that can be easily transported and rapidly induce haemostasis.'...

Under a microscope, a bouquet of lollipop-like structures, each smaller than a grain of sand, waves gently in a petri dish of liquid. Suddenly, they snap together, like the jaws of a Venus flytrap, as a scientist waves a small magnet over the dish. What was previously an assemblage of tiny passive structures has transformed instantly into an active robotic gripper. The lollipop gripper is one demonstration of a new type of soft magnetic hydrogel developed by engineers at MIT and their collaborators at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland and the University of Cincinnati. In a study appearing today in the journal Matter, the MIT team reports on a new method to print and fabricate the gel, which can be made into complex, magnetically activated three-dimensional structures. The new gel could be the basis for soft, microscopic, magnetically responsive robots and materials. Such magno-bots could be used in medicine, for instance to release drugs or grab biopsies when directed by an external magnet....

The book traces the course of the movement in various disciplines, such as the rise of evidence-based medicine in the 90s, looking at the rebels who led the charge, the barriers they faced, and why the use of evidence is crucial at a time when misinformation is rife....

Scientists have discovered that the unsung brain cells called astrocytes form extensive networks in the mouse brain1 ' networks similar in some respects to the brain circuits formed by the more celebrated brain cells called neurons. The researchers compiled a whole-brain, 3D map of astrocyte networks, which the authors say is the first of its kind. It , shows that webs of the cells connect far-flung regions of the brain, allowing the cells to exchange molecules with each other over long distances. 'It's a secret subway system we didn't know was there,' says Shane Liddelow, a neuroscientist at NYU Grossman School of Medicine in New York City and a co-author of a paper published today in Nature describing the work. 'This opens up a whole new avenue of investigation.' The work is 'a fundamentally important advance in our understanding of nervous system structure', says David Lyons, a neurobiologist at the University of Edinburgh, UK, who was not involved with the research. He adds that so far, this new evidence of complex astrocyte networks raises more questions than it answers. 'Clearly we are some way from understanding what the functional relevance and role of such [networks] is, but there are a myriad of possibilities.'...