Analysis: Science & Technology — 24 October 2026
Cryo-EM captures Plasmodium’s moving junction as it invades red blood cells
Chi-Min Ho’s lab at Columbia University has imaged Plasmodium’s moving junction at the instant it enters a red blood cell. Using cryo-electron microscopy, the team resolved a ring of protein anchors that briefly open a portal, then vanish as the membrane reseals. Four proteins in each anchor generate electrostatic forces that crowd lipids, reverse membrane curvature, and let the merozoite slip through. Independent parasitologist Jake Baum described the work as biophysics, not conventional molecular biology.
Plasmodium still kills about 600,000 people a year. Invasion was filmed in the 1970s, but the portal is too small and too fast for earlier methods. Scientists already knew the parasite inserts anchors, locks on with surface proteins, and pushes through in under a minute. Ho’s group found three proteins form a dense wedge under the membrane; a fourth tethers the invader. Some lipids slough off and reassemble as a coat around the parasite.
The structure is a plausible drug target because blocking invasion would halt the blood-stage cycle. The team used a protein-design platform to make an inhibitor that stopped entry in test tubes; it has not been tested in animals. Related apicomplexans such as Toxoplasma appear to use similar machinery. Whether the same remodeling holds in living hosts, and how fast resistance would arise, remain open.
Sources: Quanta Magazine; Cell (doi: 10.1016/j.cell.2026.06.012).
Silicon carbide spin defects lose more energy through internal conversion than expected
University of Chicago researchers led by Giulia Galli report a first-principles method that models the full optical cycle of spin defects, including internal conversion—energy dumped into lattice vibrations rather than photons or spin flips. Published in Physical Review Letters, the framework uses many-body wavefunctions and runs in the GPU-optimized WEST code. For a nitrogen-vacancy center in diamond, the calculations matched spectroscopy: internal conversion dominates singlet decay but is minor for triplets.
Spin defects in diamond and silicon carbide are candidate qubits because their states can be initialized and read with light. Internal conversion has been hard to compute in solids with hundreds of atoms. The group validated the method on diamond NV centers, then applied it to a divacancy in silicon carbide.
In SiC, internal conversion shortens the excited triplet lifetime far more than earlier models allowed, resolving a long-standing mismatch with experiment. Galli said the magnitude exceeded expectations. Whether the effect generalizes to silicon defects is untested. The simulations remain computationally heavy.
Sources: ScienceDaily; Physical Review Letters (doi: 10.1103/y6z6-h16k); University of Chicago.
Plain silicon grating extracts chiral Smith-Purcell light from electron beams
Wu Lin and Dong Zhaogang at the Singapore University of Technology and Design report that Smith-Purcell radiation—light emitted when electrons skim a periodic surface—is inherently chiral. In Nature Communications they used a plain silicon grating and two symmetry-breaking geometries to make that chirality measurable. Shrinking the grating pitch from 120 to 100 nanometers raised the circular-polarization degree to 0.87, more than double the previous Smith-Purcell record; simulations reach 0.98. Reversing the geometric twist flipped the handedness.
Free-electron sources can in principle span infrared to X-rays by changing grating period or beam energy. Earlier chiral schemes relied on complex nanostructures. The SUTD work shows a simple grating plus beam offset or pitch reduction is enough.
Some materials fluoresce under electron bombardment and swamp the signal. Reaching X-ray wavelengths would require still smaller features or higher electron energies, where quantum effects may appear. The result is a laboratory demonstration of polarization control, not yet a compact source.
Sources: Phys.org; Nature Communications.