Researchers have uncovered a hidden side of material formation by tracking what happens as specially designed molecules are heated.
Category: materials
A Solid-State Pathway to Neutrino Mass
New density-functional-theory calculations describe the radioactive decay of tritium bound to graphene, offering a way to model experiments that could open cleaner windows onto neutrino mass.
The discovery that neutrinos oscillate—shifting among three “flavors” (electron, muon, and tau) as they propagate—showed that these elusive particles must have mass. Yet their absolute mass scale and the mass ordering (whether the lightest neutrino state is predominantly electron-, muon-, or tau-like) remain unknown. Determining these properties is a central goal of modern particle physics. A promising approach involves measuring the energy spectrum of electrons emitted in nuclear 
decay, particularly from tritium: Because the neutrino carries away part of the decay energy, a nonzero neutrino mass slightly modifies the spectrum of emitted electrons. Precision experiments such as KATRIN have pushed this method to its limit, setting an upper bound of about 0.45 eV on the neutrino mass [1]. While KATRIN uses molecular tritium gas, new strategies aim to go further by embedding tritium in engineered materials.
Tiny forces, big effects: How particle interactions control the flow of soft materials
Sitting in a restaurant, you reach for the ketchup bottle, eyeing the basket of fries in front of you. You give the bottle a shake, then a tap. For a moment, nothing happens—the ketchup clings stubbornly to the glass. Then, all at once, it lets go and rushes out, sometimes in a steady stream, sometimes in a messy surge that threatens to flood the basket.
That awkward moment when ketchup stops behaving like a solid and suddenly starts flowing like a liquid is called “yielding.” Scientists see the same kind of behavior in many everyday and advanced materials, from toothpaste, paints and concrete to 3D-printing inks and electrodes used in next-generation batteries. Yet, what actually causes a material to hold its shape one moment and suddenly let go the next has been surprisingly hard to pin down, especially deep inside dense, opaque fluids where particle motion is difficult to see.
A new approach to cancer vaccination yields more powerful T cells
MIT engineers have developed a new way to amplify the T-cell response to mRNA vaccines—an advance that could lead to much more powerful cancer vaccines and stronger protection against infectious diseases.
Most vaccines generate both antibodies and T cells that can target the vaccine antigen by activating antigen-presenting cells, such as dendritic cells. In this study, the researchers boosted the T-cell response with a new type of vaccine adjuvant (a material that can help stimulate the immune system). The new adjuvant consists of mRNA molecules encoding genes that turn on immune signaling pathways and promote a supercharged T-cell response.
In studies in mice, this mRNA-encoded adjuvant enabled the immune system to completely eradicate most tumors, either on its own or delivered along with a tumor antigen. The adjuvant also boosted the T-cell response to vaccines against influenza and COVID-19.
80 years after the Trinity nuclear test, scientists identify new molecule-trapping crystal formed in the blast
Matter behaves strangely under extreme conditions, and often, remnants of these behaviors are left behind even when conditions return to normal. The Trinity nuclear test in 1945 left behind such remnants, and now, 80 years after the explosion, researchers have identified another unique example of what happens when various materials are heated to temperatures exceeding 1,500 °C (2,730 °F) and put under pressures tens of thousands of times atmospheric pressure.
The team describes a clathrate compound never before found among nuclear-explosion products in their new study, published in the Proceedings of the National Academy of Sciences.
Lab-grown diamond device could change how radiation doses are measured
A team led by researchers from Tokyo Metropolitan University, in collaboration with Tohoku University and Orbray Co., Ltd., using heteroepitaxial diamond materials developed by Orbray, have shown that lab-grown diamonds might realize a radiation dosimeter compatible with both medical diagnosis and radiation therapy.
The work is published in the journal Medical Physics.
They demonstrated that a diamond-based dosimeter could accurately measure doses in the same energy range as diagnostic X-rays, with far better sensitivity per volume than conventional detectors. Using the same device for dosimetry during both diagnosis and therapies could enable improved consistency.
