Browse Articles
Discover research articles across all indexed journals
Frontline acalabrutinib, lenalidomide and rituximab for advanced stage follicular lymphoma with high tumor burden: phase II trial
Length scales in electrolytes
The elusive presence of an anomalously increasing screening length at high ionic concentrations hampers a complete image of interactions in electrolytes. Theories that extend the diluted Debye–Hückel framework to higher concentrations predict, in addition to the expected decreasing Debye length, an increasing significant scale of the order of at most a few ionic diameters. More recent surface force balance experiments with different materials succeeded in measuring increasing length scales that, however, turned out to extend over tenths or even hundreds of ionic diameters. While simulation work has managed to characterize the former, the latter still avoids detection, generating doubts about its true origin. Here, we provide a step forward in the clarification of such a conundrum. We have studied by extensive molecular dynamics simulation the properties of a generic model of electrolyte, lithium tetrafluoroborate dissolved in ethylene-carbonate, in a vast range of salt concentrations continuously joining the Debye non-interacting limit to the opposite overcharged solvent-in-salt states. On one side, we have accurately determined the macroscopic concentration-induced structural, dielectric, and transport modifications; on the other, we have quantified the resulting nanoscale ion organization. Based only on the simulation data, without resorting to any uncontrolled hypotheses or phenomenological parameters, we identify a convincing candidate for the measured anomalously increasing length, whose origin has possibly been misinterpreted.
Compact eye camera with two-third wavelength phase-delay metalens
Förster resonance energy transfer in inhomogeneous and absorptive environment
We present an analytical model for Förster resonance energy transfer (FRET) between a donor and an acceptor placed in an inhomogeneous and absorptive environment characterized by a complex dielectric function, e.g., near a metal–dielectric structure. By extending the standard approach to FRET to include energy transfer (ET) channel to the environment, we show that, in the absence of plasmonic enhancement effects, the Förster radius, which defines the characteristic distance for efficient FRET, is reduced due to a competing ET process. We demonstrate that the reduction in the Förster radius can dramatically affect fluorescence from large ensemble of molecules whose emission kinetics is dominated by FRET-induced concentration quenching. In particular, we perform numerical calculations for dye-doped polymer films deposited on top of a metallic substrate to find that, at high dye concentrations, the emission kinetics slows down considerably as compared to the same films on a glass substrate, in sharp contrast to acceleration of single-molecule fluorescence near the metal. Furthermore, the effective fluorescence decay rate exhibits a non-monotonic behavior with varying film thickness, consistent with the experiment, indicating a non-trivial interplay between the metal quenching and concentration quenching mechanisms.
Lithium intercalated FeSe as a high-temperature superconducting ferromagnet
Abstract Merging superconductivity and ferromagnetism in a single material may promise unparalleled quantum properties for next-generation devices. Here, we bring together the two antagonistic phenomena at a record-high temperature via electric-field controlled lithiation of FeSe. The in-situ gating allows us to switch the simple compound of FeSe between a nonmagnetic superconductor and a superconducting ferromagnet. In the latter state, itinerant ferromagnetism persists from above 200 K to a temperature well below the superconducting transition temperature (45 K), as demonstrated not only by magneto-transport but also via scanning superconducting quantum interference device (sSQUID) microscopy. Interestingly, applying certain in-plane magnetic fields enhances superconductivity, reflecting the intimate interplay between high-temperature superconductivity and ferromagnetism. Density-functional theory calculations further reveal the instability of FeSe toward ferromagnetism at a moderate lithium concentration. These findings open up fresh opportunities in iron-based superconductors that interface dissipationless electronics and spintronics.
Modeling CO2 adsorption in flexible MOFs with open metal sites via fragment-based neural network potentials
Metal–organic frameworks (MOFs) with open metal sites (OMS) are among the most promising porous materials for gas adsorption and separation, owing to their strong and selective interactions with guest molecules. However, simulating adsorption in such systems with high accuracy and efficiency remains a key challenge due to the need to model complex guest–MOF interactions and framework flexibility. Classical force fields often lack the precision to capture these effects, while ab initio methods are computationally prohibitive for large-scale, long-timescale simulations. In this work, we developed a neural network potential (NNP) trained on highly accurate density functional theory (PBE-D4/def2-TZVP) level data derived from a single representative fragment of the Mg-MOF-74 framework, a prototypical OMS-containing MOF, with CO2 molecules. Despite the limited training domain, the NNP accurately captured both intra- and inter-molecular interactions in the CO2–Mg-MOF-74 system, including those involving the open metal sites. We integrated this NNP into a hybrid molecular dynamic and grand canonical Monte Carlo simulation workflow, enabling accurate modeling of CO2 adsorption in flexible MOFs. This approach allows accounting for both framework dynamics and complex host–guest interactions with chemical accuracy and computational efficiency. Our results highlight the crucial role of framework flexibility in adsorption behavior and demonstrate that fragment-based NNP, when combined with advanced simulation techniques, offer a powerful and efficient approach for realistically modeling adsorption processes in MOFs with open metal sites.
Unprecedented large-scale aquifer recovery through human intervention
Taming the virtual space for incremental full configuration interaction
Incremental full configuration interaction (iFCI) closely approximates the FCI limit with polynomial cost through a many-body expansion of the correlation energy, providing highly accurate total energies within a given basis set. To extend iFCI beyond previous basis set limitations, this work introduces a novel natural orbital (NO) screening approach, incremental NO full configuration interaction (iNO-FCI). By consideration of the importance of virtual orbital selection in the convergence of iFCI, iNO-FCI maximizes the consistency between orbitals selected for each correlated body. iNO-FCI employs a principle of cancellation of errors and ensures that the same set of virtual NOs is used for interdependent terms. This strategy significantly reduces computational cost without compromising precision. Computational savings of up to 95% are demonstrated, allowing access to larger basis sets that were previously computationally prohibitive. iNO-FCI is herein introduced and benchmarked for several difficult test cases involving double-bond dissociation, biradical systems, conjugated π systems, and the spin gap of a Cu-based transition metal complex.
Light-driven modulation of proximity-enhanced functionalities in hybrid nano-scale systems
Abstract Advancing quantum information and communication technology requires smaller and faster components with actively controllable functionalities. This work presents an all-optical strategy for dynamically modulating magnetic properties via proximity effects controlled by light. We demonstrate this concept using hybrid nanoscale systems composed of C₆₀ molecules proximitized to a cobalt metallic ferromagnetic surface, where proximity interactions are particularly strong. Our findings show that by inducing excitons in the C60 molecules with resonant ultrashort light pulses, we can significantly modify the interaction at the Cobalt/C60 interface, leading to a remarkable 60% transient shift in the frequency of the Co dipolar ferromagnetic resonance mode. This effect, detected via a specifically designed time-resolved Magneto-Optical Kerr Effect (tr-MOKE) experiment, persists on a timescale of hundreds of picoseconds. Since this frequency shift directly correlates with a transient change in the anisotropy field—an essential parameter for technological applications—our findings establish a new material platform for ultrafast optical control of magnetism at the nanoscale.
Functional amyloid proteins confer defence against predatory bacteria
Inverted perovskite solar cells via multifunctional potassium sorbate to etch PEDOT:PSS and modify the PEDOT:PSS/perovskite interface
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been widely used as a hole transport layer in inverted perovskite solar cells (PSCs). However, the PSS chains on the surface of PEDOT:PSS can absorb water molecules in humid environments, which accelerates the degradation of the perovskite at the PEDOT:PSS/perovskite interface (hereafter referred to as the PP interface). In addition, the mismatched valence band levels between PEDOT:PSS and perovskite result in a high defect density at the PP interface, leading to significant open-circuit voltage loss. To address these issues, inspired by semiconductor etching processes, we employed an ethanol solution of potassium sorbate to etch the surface of PEDOT:PSS. After etching with ethanol, the sorbate anion and potassium ions from potassium sorbate fill the positions left by the etched PEDOT and PSS chains, forming new electrostatic interactions. This not only improves the conductivity of PEDOT:PSS but also improves the energy level matching between PEDOT:PSS and perovskite, facilitating hole transport at the PP interface. As a result, the open-circuit voltage of the device increased from 1.085 to 1.144 V, and the power conversion efficiency improved from 17.54% to 21.10%. The –C=O group of potassium sorbate also acts as a Lewis base, forming a Lewis adduct with the uncoordinated Pb2+ ions at the PP interface, significantly reducing the defect density and enhancing the stability of the PSCs. This approach provides new insights and methods for improving both the efficiency and stability of inverted PSCs.
One-hour extraction-free loop-mediated isothermal amplification HPV DNA assay for point-of-care testing in Maputo, Mozambique
Abstract Human papillomavirus (HPV) is responsible for nearly all cases of cervical cancer. Affordable point-of-care DNA testing is needed for cervical cancer screening in low- and middle-income countries, where most cervical cancer cases occur. HPV DNA testing typically requires complex lab infrastructure and trained personnel. In this work, we develop a loop-mediated isothermal amplification (LAMP)-based HPV DNA test, which targets three of the most oncogenic HPV types (HPV16, HPV18, HPV45) and a cellular control and achieves analytical sensitivity comparable to gold standard methods. Our extraction-free sample preparation strategy permits adding sample lysate directly to the LAMP reaction. We utilize a low-cost benchtop heater/fluorimeter, delivering results in less than one hour. We analytically evaluate our assay with clinical samples in Houston, Texas ( n = 38) and Maputo, Mozambique ( n = 191). Results show 100% and 93% concordance, respectively, with a reference test widely used in low-resource settings. This sensitive and specific four-step assay can potentially expand cervical cancer screening in resource-limited settings.
The COVID-19 pandemic transformed this scientist into a research-integrity sleuth
High-pressure-induced phase transition in 2-amino-6-nitrobenzothiazole
In situ high-pressure synchrotron angular dispersive x-ray diffraction (ADXRD) experiments reveal a pressure-induced structural phase transition in the molecular crystal of 2-amino-6-nitrobenzothiazole (C7H5N3O2S, 2A6NBT) at ∼2.0 GPa. Furthermore, in situ high-pressure Fourier transform-infrared absorption and Raman spectroscopy experiments confirm the occurrence of this phase transition and clarify the structural evolution. The N–H⋯N and C–H⋯O hydrogen bonds (along the c-axis direction), as well as the N–H⋯O hydrogen bonds (along the b-axis direction) and van der Waals force, are enhanced due to interlayer compression. When the pressure reaches about 2.0 GPa, the collapse of the molecular layer space and the distortion of the N–H⋯N hydrogen bond make the hydrogen-bonding network rearrange, leading to the phase transition. Finally, the evolution of molecular stacking is further illustrated by first principles calculations. This study provides important insights for the development of new supramolecular polymorphism containing various types of hydrogen-bonded interactions.
Artificial transneurons emulate neuronal activity in different areas of brain cortex
Abstract Rapid development of memristive elements emulating biological neurons creates new opportunities for brain-like computation at low energy consumption. A first step toward mimicking complex neural computations is the analysis of single neurons and their characteristics. Here we measure and model spiking activity in artificial neurons built using diffusive memristors. We compare activity of these artificial neurons with the spiking activity of biological neurons measured in sensory, pre-motor, and motor cortical areas of the monkey (male) brain. We find that artificial neurons can operate in diverse self-sustained and noise-induced spiking regimes that correspond to the activity of different types of cortical neurons with distinct functions. We demonstrate that artificial neurons can function as trans-functional devices (transneurons) that reconfigure their behaviour to attain instantaneous computational needs, each capable of emulating several biological neurons.
Author Correction: Stress dynamically modulates neuronal autophagy to gate depression onset
Iron speciation and coordination in lithium borate glasses
This study explores the impact of Li2O content and Fe2O3 addition on the physical, optical, and structural properties of lithium borate glasses. Optical absorption spectra and XANES pre-edge features confirm the absence of significant Fe2+, indicating that iron is predominantly present as Fe3+. The optical absorption spectra exhibit characteristic features of Fe3+ ions, including a blue shift of the absorption edge as Li2O content increases, which is attributed to the conversion of BO3 to BO4 units. X-ray absorption spectroscopy reveals that Fe3+ ions are present in tetrahedral coordination, with the coordination number increasing at low Li2O concentrations. Raman spectroscopy further confirms that iron alters the connectivity of the borate network by disrupting superstructural borate units and forming links with boron atoms, particularly when Fe3+ occupies tetrahedral sites.
Seedless: on-the-fly pulse calculation for NMR experiments
Abstract NMR experiments require sequences of radio frequency (RF) pulses to manipulate nuclear spins. Signal is lost due to non-uniform excitation of nuclear spins resonating at different energies (chemical shifts) and inhomogeneity in the RF unavoidably generated by hardware over the sample volume. To overcome this, we present Seedless, a tool to calculate NMR pulses that compensate for these effects to enhance control of magnetisation and boost signal. As calculations take only a few seconds using an optimised GRadient Ascent Pulse Engineering (GRAPE) implementation, this now allows pulses to be generated in a few seconds, allowing them to be optimised for individual samples and spectrometers (“on-the-fly”). Each calculated pulse requires bands of chemical shift to be identified, over which one of 4 transforms will be performed, selected from a set that covers all commonly used applications. Using imaging experiments, we demonstrate our pulses effectively both increase the size of the coil volume and signal-to-noise in all experiments. We illustrate the approach by showing sensitivity gains in 1, 2 and 3D applications suitable for chemical and biological NMR. Seedless provides a means to enhance sensitivity in all pulse sequences in a manner that can be tailored to different samples and hardware being used.
Polaritronics: Energy and electron transport through polaritonic states
Polaritronics is a new branch of research that involves the study of polaritonic states and their applications in optoelectronic devices. Polaritonic states are distinguished by the inheritance of light and matter properties together. The cavity quantum electrodynamics picture of a two-level system interacting with a photon can define these states. Here, polaritonic devices perform classical operations through the collective interactions of an Avogadro number of molecules. By doing so, the newly formed states inherit a low effective mass and, therefore, behave similar to lightweight carriers of charge. At the same time, it possesses a collective coherence length as large as the mode volume of the cavity. This allows us to engineer hybrid devices that are specific in functions with quantization in both energy and momentum. This perspective gives glimpses of our views on polaritronics and its applications in quantum sensing and communication. We also pitch into understanding the limitations of such techniques along with the future outlook to obtain outperforming devices for real-world applications.