Soft matter, hard rules: Emulsions follow the laws of granular suspension rheology.

August 25, 2026| Source: Proceedings of the National Academy of Sciences of the United States of America

The flow of dense emulsions underlies applications from food and pharmaceutical processing to bioengineering, yet their rheology remains difficult to interpret under conventional volume-imposed conditions. Here, we change the control variable to osmotic-pressure using a recently developed instrument-the Capillarytron. This approach reveals a unified rheological structure where the osmotic pressure [Formula: see text], by controlling droplet deformation, sets a pressure-dependent jamming volume fraction. When expressed in terms of the distance to this jamming point, all rheological data-spanning both [Formula: see text]- and [Formula: see text]-imposed measurements-collapse onto a single power-law divergence, akin to granular suspensions. The resulting constitutive relations provide a predictive, parameter-free description of emulsion rheology across Newtonian, yielding, and shear-thinning regimes. Together with recent results on soft spheres, our findings point to a unifying paradigm: Soft amorphous materials-from soft spheres to emulsions and likely foams-obey the same hard rules as granular suspensions, with softness entering through a pressure-dependent jamming point. This framework rationalizes Herschel-Bulkley rheology, assigns its parameters microscopic meaning, and opens perspectives on rigidity transitions in soft, deformable systems, including biological tissues.

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Extensive glacier loss in the coterminous United States.

Glaciers populate the mountain ranges of the western conterminous United States and despite their importance to alpine hydrology, their area and volume change have never been comprehensively evaluated. Our study shows that since the mid-twentieth century about one-quarter of the glaciers have disappeared and the overall area and volume are reduced by one-third. The pattern of glacier shrinkage suggests most glaciers in the conterminous United States are largely maintained by local topographic in

Physical/TechOctober 20, 2026

Reaction-based cryo-EM resolves the continuous conformational spectrum of CTP synthase catalysis.

Capturing enzymes under native turnover conditions remains a grand challenge in structural biology. Here, we develop a reaction-based cryo-electron microscopy (cryo-EM) strategy that directly samples Drosophila melanogaster cytidine triphosphate synthase (CTPS) from actively catalyzing mixtures containing only natural substrates and allosteric effectors. By integrating reaction-based sampling with three-dimensional variability analysis, we resolve a continuous conformational spectrum of CTPS dur

Physical/TechOctober 20, 2026

GTP orchestrates CTP synthase via an allosteric effector-cycling mechanism.

Cytidine triphosphate (CTP), a fundamental building block of RNA, plays vital roles in diverse biological processes. CTP synthase (CTPS) is the only known enzyme for de novo synthesis of CTP. Efficient CTPS catalysis requires guanosine triphosphate (GTP) in a dose-dependent, nonconsumptive manner; however, the precise mechanism by which GTP drives CTP formation remains unclear. Here, we integrate a series of cryo-EM structures of Drosophila melanogaster CTPS captured from actively catalyzing sam

Physical/TechOctober 20, 2026

Antiferromagnetism and tightly bound Cooper pairs induced by kinetic frustration.

Antiferromagnetism and superconductivity are often viewed as competing orders in correlated electron systems. Here, we demonstrate that kinetic frustration in hole motion facilitates their coexistence within the square-lattice repulsive Hubbard model. Combining exact analytical solutions on tailored geometries with large-scale numerical simulations, we reveal a robust pairing mechanism: Holes on opposite sublattices behave as if they carry opposite effective charges due to spin singlet formation

Physical/TechOctober 20, 2026

Coordinated transformations of the labyrinth and occiput during the dinosaur-bird transition.

Evolutionary shape changes of the vertebrate semicircular canals (SCCs) are often ascribed to evolutionary transitions in locomotion, including the origin of flight during the dinosaur-bird transition. However, the potential for transformations of braincase architecture to influence SCC shape independent of sensory-functional adaptation has generally been overlooked. We evaluate the influence of both factors using a large dataset of 146 living and recently extinct crown birds, including taxa rep