Browse Articles

Angstrom-fluidic chemical synapses for accurate cancer diagnosis

Push until it breaks: engineering is stronger when we know its limits

A functional atlas of transposon-encoded products and their integration into host networks

Tuning electron back-donation to switch reaction pathway in CO2 hydrogenation

Glycosylation orchestrates megakaryocytic fate of hematopoietic stem cells via Wnt-MUC13 signaling

Asymmetric fluorinated sulfonamide electrolyte solvent for high-voltage and wide-temperature Li-metal batteries

Spatiotemporally coupled sulfur chemistry for stable silicon-90+ anodes

Bulk delivery of a preassembled apical surface initiates epithelial lumen formation

Abstract During de novo lumenogenesis, epithelial cells establish luminal identity by directing apical cargo to an apical membrane initiation site (AMIS). Although this process has been widely studied, the mechanisms governing AMIS formation and its progression into a luminal precursor remain poorly understood. Here we combine quantitative light and electron microscopy with proximity proteomics to demonstrate that apical cargo is delivered to the AMIS in large apical precursor organelles, termed vacuolar apical compartments (VACs). VACs possess a microvilli-rich cortex and undergo exocytic fusion at the AMIS to generate a nascent lumen. Lumen initiation is tightly coordinated with the assembly and rearrangement of apical cell junctions and requires the Crumbs complex protein PatJ. Together, our results show that PatJ is a key structural determinant of the apical-lateral interface and indicate that VACs act as specialized transport organelles that deliver a preassembled apical surface to the AMIS, enabling rapid and efficient lumen initiation.

Deterministic wet etching of aspheric fiber microlenses with tunable conic geometry for tailored optical functionality

Abstract Efficient coupling between guided optical fiber modes and radiated fields in the surrounding medium remains a fundamental limitation across photonics, sensing, and biophotonics. Micro-lensed fibers offer a promising solution, yet scalable fabrication with predictable geometry and deterministic optical performance has remained elusive. Here, we introduce laser-controlled wet-chemical etching (LCWCE), a single-parameter strategy that directly sculpts micro-lenses, from hyperbolic to parabolic and prolate elliptical profiles, on standard optical fibers. Local laser illumination establishes an axially confined etching-rate gradient, enabling sub-micrometer control of curvature and working distance independent of fiber type or internal structure. A physics-separated multiphysics framework combining wave optics, heat-transfer, and temperature-dependent etching kinetics captures the observed geometry evolution and validates the underlying mechanism. LCWCE enables milliwatt-scale, minimal-power fiber-based optical trapping, as well as minimally invasive in vivo dendritic detection and single-cell neural interrogation beyond 1.5 mm depth in live brains, transforming ubiquitous optical fibers into scalable, high-performance photonic probes.

CAFs shape the immunosuppressive microenvironment of pancreatic cancer through the Lin28b-STING Axis

Evaluating technology upgrades as a complement to traditional bill assistance programs

Molecular-level insight into water adsorption and projected atmospheric water harvesting performance in a hydrolytically stable MOF

Lying mirror using structured surfaces

Abstract We introduce an all-optical system, termed the “lying mirror”, to hide input information by transforming it into misleading, ordinary-looking patterns that effectively camouflage the underlying image data and deceive the observers. This misleading transformation is achieved through passive light-matter interactions of the incident light with an optimized structured diffractive surface, enabling the optical concealment of any form of secret input data without any digital computing. These lying mirror designs were shown to camouflage different types of input image data, exhibiting robustness against a range of adversarial manipulations, including random image noise as well as unknown, random rotations, shifts, and scaling of the object features. The feasibility of the lying mirror concept was also validated experimentally using a structured micro-mirror array along with multi-wavelength illumination at 480, 550 and 600 $${nm}$$ n m , covering the blue, green and red image channels. Furthermore, we created a broadband lying mirror that operates across a continuous spectral range, enhancing its adaptability under diverse illumination conditions. This framework showcases the power of structured diffractive surfaces for visual information processing and might find various applications in defense, security and entertainment.

Atomic-scale engineering of Pt shells on chiral Au nanoparticles for enhanced oxygen reduction

An exact approach for describing adsorption and catalysis of interacting species in lattice models

Lattice models provide a useful framework for studying the adsorption and catalysis of interacting species. For such systems, the mean-field and quasi-chemical approximations are widely used. At equilibrium, full enumeration of the grand-canonical partition function would allow for an exact solution to these problems. However, the combinatorial complexity confines this approach to small systems. In this work, we consider how large a lattice needs to be for full enumeration to yield a feasible solution for equilibrium systems. As representative applications, we consider adsorption isotherms and the rate of a catalytic bimolecular reaction for the case that the surface reaction is the rate-limiting step. In these applications, we show that full enumeration on appropriately chosen small lattices accurately reproduces the converged results of Monte Carlo simulations on much larger lattices. We find that the commonly employed mean-field approximation can be off by up to five orders of magnitude and the quasi-chemical approximation is also inaccurate, while results from full enumeration are exact and converged. Our results are promising for studies aiming to quantify surface phenomena from first principles. Moreover, the full enumeration approach can be extended to kinetics, making this approach feasible for both equilibrium and kinetic studies of surface phenomena.

Atomistic determination of bending rigidity in the HPV-16 capsid

The assembly of viral capsids emerges from local interactions between protein building blocks that collectively generate highly ordered shells with defined geometry and robust mechanical properties. However, a quantitative link between atomistic interactions and the macroscopic elastic parameters that determine capsid shape and rigidity has remained elusive. Here, we present an atomistic framework that bridges molecular interactions and continuum-scale mechanics in human papillomavirus type 16 (HPV-16). Using all-atom molecular dynamics simulations with umbrella sampling, we evaluate the potential of mean force governing angular deviations between neighboring L1 pentamers and extract both the preferred interaction angle and the associated bending modulus. We find a clear decoupling between spontaneous curvature of the capsid and bending rigidity. While the optimal interaction angle remains almost invariant across changes in pH and ionic strength, the bending modulus, which is an order of magnitude larger than any previous estimates, is strongly modulated by the electrostatic environment: protonation enhances angular stiffness at low ionic strength, whereas electrostatic screening suppresses this effect at higher salt concentrations. Our results identify inter-capsomer rigidity as a key determinant of capsid size and shape and provide a quantitative framework for linking specific protein–protein interactions to the emergent mechanical properties of self-assembled viral capsids.

60th birthday Carlos Vega Festschrift: Reality, dream or simulation?

Intrinsic structure and interfacial tension of the HDL/LDL water interface

The coexistence line between the high-density liquid (HDL) and the low-density liquid (LDL) phases of water lies in the supercooled, high pressure region of the phase diagram where water is metastable with respect to ice, relaxation is slow, and the low free-energy cost of forming interfaces between the HDL and LDL phases can lead to soft, fluctuating, and morphologically complex domains. These conditions make both the structure and the thermodynamics of the interface difficult to access not only experimentally but also in computer simulations. Here, we study explicit HDL-rich/LDL-rich coexistence in long simulations at constant temperature, volume, and number of water molecules in elongated cells that promote interface stability. Using a high 1:1:8 aspect ratio proved key to obtaining two stable planar interfaces that persist for the full simulation time of about 1.35 μs. These interfaces bound an HDL-rich slab containing transient LDL-rich droplets, while the surrounding LDL-rich phase contains a fluctuating population of ice-like crystallites. This complex morphology makes the pressure anisotropy inadequate for measuring the interfacial tension of the HDL/LDL boundary. An analysis based on capillary wave theory, including the intrinsic interfacial broadening, reveals instead a very soft boundary, with γ = 4.25 ± 0.25 mN/m. These results point to an HDL/LDL interface that is weak, structured, and easily distorted by the competing liquid and crystalline fluctuations present in this region of the phase diagram.

Förster resonance energy transfer, including transient coherent effects

We formulate the weak intramolecular coupling Förster resonance energy transfer theory in a form suitable for calculating the ultrafast non-linear response of molecular systems. This is done through a formally exact factorization of the time-dependent molecular statistical operator into the system and bath components. Combining this factorization with unperturbed environment evolution, we generalize the traditional Förster master equation for the state population probabilities into a complete master equation for the system’s reduced statistical operator. The traditional Förster theory applies in the limit where the intermolecular coupling is weak and the system–bath coupling is strong. Our derivation explicitly yields a time-nonlocal Förster-type master equation that remains valid even in the limit of vanishing system–bath coupling. The theory predicts a rapid initial coherent evolution of populations arising from a transient initial coherence-dependent term, which induces a “slippage” of the initial condition that persists during subsequent rate-controlled transfer. Comparison with exact numerical results confirms the clear improvement of the present generalization over earlier formulations of the Förster theory and delineates its range of validity.

Role of electron correlation on the adenine dimer interaction for non-equilibrium geometries: A benchmark quantum Monte Carlo study

The accurate description of non-covalent interactions is critical for understanding the structure, dynamics, and eventual function of biomolecules. The adenine dimer serves as a benchmark system for computational methods due to its role in nucleic acid structures and its rich conformational landscape. In this study, we employ benchmark diffusion quantum Monte Carlo (DMC) methods to investigate the relative energies and role of electron correlation on a set of adenine dimer conformations generated via a search of the potential energy landscape using the global optimizer algorithm. Relative DMC energies are compared against a wide range of density functional theory (DFT) approximation results. We find that although most of the DFT functionals perform well for low-energy structures, their accuracy varies significantly for higher-energy conformations, including stacked and T-shaped structures. A large fraction of the variation is due to the treatment of the van der Waals interaction. BLYP, B3LYP, and PBE0 significantly improve with added D4 dispersion, while the recent r2SCAN-D4 and ωB97M-V functionals show the least scatter and closest agreement with the DMC. These findings highlight the delicate nature of these interactions in biomolecular systems and provide guidance for simulations of their structure and dynamics and for the development of machine learned interatomic potentials.