Finite element-based nonlinear dynamic optimization of nanomechanical resonators.

Nonlinear dynamic simulations of mechanical resonators have been facilitated by the advent of computational techniques that generate nonlinear reduced order models (ROMs) using the finite element (FE) method. However, designing devices with specific nonlinear characteristics remains inefficient since it requires manual adjustment of the design parameters and can result in suboptimal designs. Here, we integrate an FE-based nonlinear ROM technique with a derivative-free optimization algorithm to enable the design of nonlinear mechanical resonators.

SMC motor proteins extrude DNA asymmetrically and can switch directions.

Structural maintenance of chromosomes (SMC) complexes organize the genome via DNA loop extrusion. Although some SMCs were reported to do so symmetrically, reeling DNA from both sides into the extruded DNA loop simultaneously, others perform loop extrusion asymmetrically toward one direction only. The mechanism underlying this variability remains unclear.

Global regulators enable bacterial adaptation to a phenotypic trade-off.

Cellular fitness depends on multiple phenotypes that must be balanced during evolutionary adaptation. For instance, coordinating growth and motility is critical for microbial colonization and cancer invasiveness. In bacteria, these phenotypes are controlled by local regulators that target single operons, as well as by global regulators that impact hundreds of genes.

Programmable Magnetic Hysteresis in Orthogonally-Twisted 2D CrSBr Magnets via Stacking Engineering.

Twisting 2D van der Waals magnets allows the formation and control of different spin-textures, as skyrmions or magnetic domains. Beyond the rotation angle, different spin reversal processes can be engineered by increasing the number of magnetic layers forming the twisted van der Waals heterostructure. Here, pristine monolayers and bilayers of the A-type antiferromagnet CrSBr are considered as building blocks.

Passive and active suppression of transduced noise in silicon spin qubits.

Addressing and mitigating decoherence sources plays an essential role in the development of a scalable quantum computing system, which requires low gate errors to be consistently maintained throughout the circuit execution. While nuclear spin-free materials, such as isotopically purified silicon, exhibit intrinsically promising coherence properties for electron spin qubits, the omnipresent charge noise, when converted to magnetic noise under a strong magnetic field gradient, often hinders stable qubit operation within a time frame comparable to the data acquisition time. Here, we demonstrate both open- and closed-loop suppression techniques for the transduced noise in silicon spin qubits, resulting in a more than two-fold (ten-fold) improvement of the inhomogeneous coherence time (Rabi oscillation quality) that leads to a single-qubit gate fidelity of over 99.

Exogenous fatty acids inhibit fatty acid synthesis by competing with endogenously generated substrates for phospholipid synthesis in Escherichia coli.

Exogenous fatty acids are directly incorporated into bacterial membranes, heavily influencing cell envelope properties, antibiotic susceptibility, and bacterial ecology. Here, we quantify fatty acid biosynthesis metabolites and enzymes of the fatty acid synthesis pathway to determine how exogenous fatty acids inhibit fatty acid synthesis in Escherichia coli. We find that acyl-CoA synthesized from exogenous fatty acids rapidly increases concentrations of long-chain acyl-acyl carrier protein (acyl-ACP), which inhibits fatty acid synthesis initiation.

EMT-related cell-matrix interactions are linked to states of cell unjamming in cancer spheroid invasion.

Epithelial-to-mesenchymal transitions (EMT) and unjamming transitions provide two distinct pathways for cancer cells to become invasive, but it is still unclear to what extent these pathways are connected. Here, we addressed this question by performing 3D spheroid invasion assays on epithelial-like (A549) and mesenchymal-like (MV3) cancer cell lines in collagen-based hydrogels, where we varied both the invasive character of the cells and matrix porosity. We found that the onset time of invasion was correlated with the matrix porosity and vimentin levels, while the spheroid expansion rate correlated with MMP1 levels.

autoMEA: machine learning-based burst detection for multi-electrode array datasets.

Neuronal activity in the highly organized networks of the central nervous system is the vital basis for various functional processes, such as perception, motor control, and cognition. Understanding interneuronal connectivity and how activity is regulated in the neuronal circuits is crucial for interpreting how the brain works. Multi-electrode arrays (MEAs) are particularly useful for studying the dynamics of neuronal network activity and their development as they allow for real-time, high-throughput measurements of neural activity.

Order-Disorder Balance in Silk-Elastin-like Polypeptides Determines Their Self-Assembly into Hydrogel Networks.

The biofabrication of recombinant structural proteins with a range of mechanical or structural features usually relies on the generation of protein libraries displaying variations in terms of amino acid composition, block structure, molecular weight, or physical/chemical cross-linking sites. This approach, while highly successful in generating a wealth of knowledge regarding the links between design features and material properties, has some inherent limitations related to its low throughput. This slows down the pace of the development of recombinant structural proteins.

All eukaryotic SMC proteins induce a twist of -0.6 at each DNA loop extrusion step.

Eukaryotes carry three types of structural maintenance of chromosome (SMC) protein complexes, condensin, cohesin, and SMC5/6, which are ATP-dependent motor proteins that remodel the genome via DNA loop extrusion (LE). SMCs modulate DNA supercoiling but remains incompletely understood how this is achieved. Using a single-molecule magnetic tweezers assay that directly measures how much twist is induced by individual SMCs in each LE step, we demonstrate that all three SMC complexes induce the same large negative twist (i.

Air-stable, aluminium oxide encapsulated graphene phototransistors.

Graphene has garnered significant interest in optoelectronics due to its unique properties, including broad wavelength absorption and high mobility. However, its weak stability in ambient conditions requires encapsulation for practical applications. In this study, we investigate graphene CVD-grown field-effect transistors fabricated on Si/SiOwafers, encapsulated with aluminum oxide (AlO) of different thicknesses.

Quadrupolar Resonance Spectroscopy of Individual Nuclei Using a Room-Temperature Quantum Sensor.

Nuclear quadrupolar resonance (NQR) spectroscopy reveals chemical bonding patterns in materials and molecules through the unique coupling between nuclear spins and local fields. However, traditional NQR techniques require macroscopic ensembles of nuclei to yield a detectable signal, which obscures molecule-to-molecule variations. Solid-state spin qubits, such as the nitrogen-vacancy (NV) center in diamond, facilitate the detection and control of individual nuclei through their local magnetic couplings.

A major step forward toward high-resolution nanopore sequencing of full-length proteins.

In a recent publication in Nature, Motone et al. report the development of a protein sequencing method using nanopores that enables the reading of long protein strands. This method allows for multi-pass re-reading and can detect single amino acid substitutions as well as post-translational modifications (PTMs).

Mechanoelectric sensitivity reveals destructive quantum interference in single-molecule junctions.

Quantum interference plays an important role in charge transport through single-molecule junctions, even at room temperature. Of special interest is the measurement of the destructive quantum interference dip itself. Such measurements are especially demanding when performed in a continuous mode of operation.

Temperature-Dependent Characterization of Long-Range Conduction in Conductive Protein Fibers of Cable Bacteria.

Multicellular cable bacteria display an exceptional form of biological conduction, channeling electric currents across centimeter distances through a regular network of protein fibers embedded in the cell envelope. The fiber conductivity is among the highest recorded for biomaterials, but the underlying mechanism of electron transport remains elusive. Here, we performed detailed characterization of the conductance from room temperature down to liquid helium temperature to attain insight into the mechanism of long-range conduction.

Electron-Beam Writing of Atomic-Scale Reconstructions at Oxide Interfaces.

The epitaxial growth of complex oxides enables the production of high-quality films, yet substrate choice is restricted to certain symmetry and lattice parameters, thereby limiting the technological applications of epitaxial oxides. In comparison, the development of free-standing oxide membranes gives opportunities to create novel heterostructures by nonepitaxial stacking of membranes, opening new possibilities for materials design. Here, we introduce a method for writing, with atomic precision, ionically bonded crystalline materials across the gap between an oxide membrane and a carrier substrate.

Long-Lived Magnetization in an Atomic Spin Chain Tuned to a Diabolic Point.

Scaling magnets down to where quantum size effects become prominent triggers quantum tunneling of magnetization (QTM), profoundly influencing magnetization dynamics. Measuring magnetization switching in an Fe atomic chain under a carefully tuned transverse magnetic field, we observe a nonmonotonic variation of magnetization lifetimes around a level crossing, known as the diabolic point (DP). Near DPs, local environment effects causing QTM are efficiently suppressed, enhancing lifetimes by three orders of magnitude.

Universal control of four singlet-triplet qubits.

The coherent control of interacting spins in semiconductor quantum dots is of strong interest for quantum information processing and for studying quantum magnetism from the bottom up. Here we present a 2 × 4 germanium quantum dot array with full and controllable interactions between nearest-neighbour spins. As a demonstration of the level of control, we define four singlet-triplet qubits in this system and show two-axis single-qubit control of each qubit and SWAP-style two-qubit gates between all neighbouring qubit pairs, yielding average single-qubit gate fidelities of 99.

A temperature-sensitive metabolic valve and a transcriptional feedback loop drive rapid homeoviscous adaptation in Escherichia coli.

All free-living microorganisms homeostatically maintain the fluidity of their membranes by adapting lipid composition to environmental temperatures. Here, we quantify enzymes and metabolic intermediates of the Escherichia coli fatty acid and phospholipid synthesis pathways, to describe how this organism measures temperature and restores optimal membrane fluidity within a single generation after a temperature shock. A first element of this regulatory system is a temperature-sensitive metabolic valve that allocates flux between the saturated and unsaturated fatty acid synthesis pathways via the branchpoint enzymes FabI and FabB.

Metropolitan-scale heralded entanglement of solid-state qubits.

A key challenge toward future quantum internet technology is connecting quantum processors at metropolitan scale. Here, we report on heralded entanglement between two independently operated quantum network nodes separated by 10 kilometers. The two nodes hosting diamond spin qubits are linked with a midpoint station via 25 kilometers of deployed optical fiber.

PlsX and PlsY: Additional roles beyond glycerophospholipid synthesis in Gram-negative bacteria.

The unique asymmetry of the Gram-negative outer membrane, with glycerophospholipids (GPLs) in the inner leaflet and lipopolysaccharide (LPS) in the outer leaflet, works to resist external stressors and prevent the entry of toxic compounds. Thus, GPL and LPS synthesis must be tightly controlled to maintain the integrity of this essential structure. We sought to decipher why organisms like possess two redundant pathways-PlsB and PlsX/Y-for synthesis of the GPL precursor lysophosphatidic acid (LPA).

Leveraging the versatile properties of bacterial spores in materials.

Inspired by biological functions of living systems, researchers have engineered cells as independent functional materials or integrated them within a natural or synthetic matrix to create engineered living materials (ELMs). However, the 'livingness' of cells in such materials poses serious drawbacks, such as a short lifespan and the need for cold-chain logistics. Bacterial spores have emerged as a game changer to bypass these shortcomings as a result of their intrinsic dormancy and resistance against harsh conditions.

Proximity-Induced Exchange Interaction and Prolonged Valley Lifetime in MoSe/CrSBr Van-Der-Waals Heterostructure with Orthogonal Spin Textures.

Heterostructures, composed of semiconducting transition-metal dichalcogenides (TMDC) and magnetic van-der-Waals materials, offer exciting prospects for the manipulation of the TMDC valley properties via proximity interaction with the magnetic material. We show that the atomic proximity of monolayer MoSe and the antiferromagnetic van-der-Waals crystal CrSBr leads to an unexpected breaking of time-reversal symmetry, with originally perpendicular spin directions in both materials. The observed effect can be traced back to a proximity-induced exchange interaction via first-principles calculations.