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A high-valence bismuth(V) nanoplatform triggers cancer cell death and anti-tumor immune responses with exogenous excitation-free endogenous H2O2- and O2-independent ROS generation

Single-pixel microscopic imaging through complex scattering media

Microscopic imaging through complex scattering media is recognized to be challenging. Here, we report high-resolution single-pixel microscopic imaging through complex scattering media. This is developed via an integration of temporal corrections with single-pixel microscopic imaging to enhance the quality of the reconstructed object images and achieve high resolution in complex scattering environments. By adopting a fixed pattern as a temporal carrier, the effect of dynamic scaling factors induced by complex scattering media, which disturb the recorded light intensities, is removed. Artificial targets and biological specimens are tested in optical experiments, and feasibility of the proposed approach is validated to show that the developed single-pixel microscopic imaging system exhibits high robustness against complex scattering. This work offers a promising solution for high-resolution microscopic imaging through thick, dynamic, and complex scattering media.

Fast 3D printing of fine, continuous, and soft fibers via embedded solvent exchange

Phase-gradient force-based optical array sorter

Microparticle sorting is crucial for applications in biomedicine, environmental monitoring, and biochip technology. However, traditional optical sorting methods often rely on external equipment, such as microfluidic devices. In this Letter, we proposed a phase-gradient force-based optical array sorting (POAS) scheme, which achieves the accurate transporting and sorting of the particles by regulating the phase-gradient force based on the physical characteristics of the particles. The method combines the function of particle transporting and sorting, eliminating the need for external auxiliary equipment. Based on the POAS scheme, we used the complex amplitude beam shaping algorithms to design a 1 × 2 array sorting beam with the controllable phase-gradient forces. The array sorting beam was used to experimentally sort two kinds of particles with different sizes, and the particles are first transported and then precisely sorted at the designated sorting nodes. All the parameters of the sorting beam were adjustable, which greatly enhances the flexibility and scalability of the optical sorting technology. This study provides an alternative scheme for the high-throughput particle sorting, which can be easily integrated into the optical sorting chips for applications in medical detection and drug delivery.

Centromere positioning orchestrates telomere bouquet formation and the initiation of meiotic differentiation

Surface phonons in the 1/f noise of Bi2Se3

Temperature dependence of the 1/f noise intensity in Bi2Se3 features a weak structure of unknown origin. Comparing the noise structure with the Raman spectrum of Bi2Se3, we found that it is the image of the surface phonon spectrum of this topological insulator. It also revealed that the low intensity of both noise bands composing the structure in the topological regime is due to the weak interaction of the Dirac electrons with the surface phonons of Bi2Se3. One of these noise bands has been found to correspond to the boson peak of the amorphous Se surface atoms, while the other one is well fitted by the Eliashberg function of amorphous Bi. It indicates that the interaction of the Dirac electrons with the thermal motion of the Se and Bi atoms, in the first and second atomic layers of the first quintuple Se–Bi–Se–Bi–Se surface cell, respectively, is the microscopic source of the surface 1/f noise in this quantum material. A step-like noise increase observed at a surface-bulk transition in a Bi2Se3 film is assigned to a Fano resonance. This proves that the electron–phonon coupling is involved in the microscopic mechanism of 1/f noise in solids.

Positively charged specificity site in cyclin B1 is essential for mitotic fidelity

Abstract Phosphorylation of substrates by cyclin-dependent kinases (CDKs) is the driving force of cell cycle progression. Several CDK-activating cyclins are involved, yet how they contribute to substrate specificity is still poorly understood. Here, we discover that a positively charged pocket in cyclin B1, which is exclusively conserved within B-type cyclins and binds phosphorylated serine- or threonine-residues, is essential for correct execution of mitosis. HeLa cells expressing pocket mutant cyclin B1 are strongly delayed in anaphase onset due to multiple defects in mitotic spindle function and timely activation of the E3 ligase APC/C. Pocket integrity is essential for APC/C phosphorylation particularly at non-consensus CDK1 sites and full in vitro ubiquitylation activity. Our results support a model in which cyclin B1’s pocket facilitates sequential substrate phosphorylations involving initial priming events that assist subsequent pocket-dependent phosphorylations even at non-consensus CDK1 motifs.

Erratum: “Oxygen diffusion coefficients in ferroelectric hafnium zirconium oxide thin films” [Appl. Phys. Lett. <b>124</b>, 252905 (2024)]

A dendritic hexamer acceptor enables 19.4% efficiency with exceptional stability in organic solar cells

Abstract To achieve the commercialization of organic solar cells (OSCs), it is crucial not only to enhance power conversion efficiency (PCE) but also to improve device stability through rational molecular design. Recently emerging giant molecular acceptor (GMA) materials offer various advantages, such as precise chemical structure, high molecular weight (beneficial to film stability under several external stress), and impressive device efficiency, making them a promising candidate. Here, we report a dendritic hexamer acceptor developed through a branch-connecting strategy, which overcomes the molecular weight bottleneck of GMAs and achieves a high production yield over 58%. The dendritic acceptor Six-IC exhibits modulated crystallinity and miscibility with the donor, thus better morphology performance compared to its monomer, DTC8. Its charge transport ability is further enhanced by additional channels between the armed units. Consequently, the binary OSCs based on D18:Six-IC achieves a cutting-edge efficiency of 19.4% for high-molecular weight acceptor based systems, as well as decent device stability and film ductility. This work reports high-performance OSCs based on dendritic molecule acceptor with a molecular weight exceeding 10000 g/mol and shares the understanding for designing comprehensively high-performing acceptor materials.

GaN-based shallow-trench vertical Hall devices

In this Letter, a GaN-based vertical Hall device is designed and experimentally fabricated, offering an effective solution for in-plane magnetic field detection. By introducing a shallow trench structure between the excitation and sensing electrodes, the short-circuit current flowing into sensing contacts in GaN-based vertical Hall devices was strongly suppressed. Through TCAD simulation analysis, the optimal range of the shallow trench depth was determined, which was then confirmed by the experimental data. From the experimental results, the sensitivity was found to be improved by 4674.7%, from 3.8 to 177.6 mV/AT, while nonlinearity was reduced by 95.5%, from 19.17% to 0.87%. The effects of device width and sensing electrode length on the device performance were also investigated in detail. Finally, this work experimentally validated the device's angle detection capability, indicating that the GaN-based vertical Hall sensor could be combined with the currently well-established horizontal Hall sensors to create high-performance monolithic integrated three-dimensional Hall sensors.

A data-consistent model of the last glaciation in the Alps achieved with physics-driven AI

Abstract 25 thousand years ago, the European Alps were covered by the kilometre-thick Alpine Ice Field. Numerical modelling of this glaciation has been challenged by model-data disagreements, including overestimations of ice thickness. We tackle this issue by applying the Instructed Glacier Model, a three-dimensional model enhanced with physics-informed machine learning. This approach allows us to produce 100 Alps-wide and 17 thousand-year-long simulations at 300 m resolution. Previously unfeasible due to computational costs, our experiment both increases model-data agreement in ice extent and reduces the offset in ice thickness by between 200% and 450% relative to previous studies. Our results have implications for better estimating former ice velocities, ice temperature, basal conditions, erosion processes, and paleoclimate in the Alps. This study demonstrates that physics-informed machine learning can help overcome the bottleneck of high-resolution glacier modelling and better test parameterisations, both of which are required to accurately describe complex topographies and ice dynamics.

Hanle spin precession induced inverted magnetoresistance in chiral/semiconductor systems

In the past decade, chiral materials have drawn significant attention because it is widely claimed that they can act as spin injectors/detectors due to the chirality-induced spin selectivity effect. Nevertheless, the microscopic origin of this effect is not understood, which generates the need for transport experiments that confirm the spin-dependent transport in chiral materials. Hanle spin precession measurements can unambiguously prove the injection and detection of a spin accumulation in a non-magnetic material, as was shown with traditional ferromagnetic injectors/detectors. Here, we model and analyze in detail the Hanle spin precession-induced magnetoresistance for chiral/semiconductor systems and find that the signal is inverted as compared to the ferromagnetic case. We explicitly model the spin injection and detection by both a chiral system and a ferromagnetic system, as well as the spin transport in a semiconductor, for a general set of (spin) transport parameters that cover the relevant experimental regime. For all sets of parameters, we find that the Hanle signals for a chiral system and ferromagnet are each other's opposites. We also discuss the implications for four terminal nonlocal spin transport experiments with separate chiral spin injector and detectors.

Fluorescein-based SynNotch adaptors for regulating gene expression responses to diverse extracellular and matrix-based cues

Te nanomesh-monolayer WSe2 vertical van der Waals heterostructure for high-performance photodetector

Recently, two-dimensional tungsten diselenide (WSe2) has attracted extensive attention due to their unique properties, exhibiting excellent properties in electronics, optoelectronics, and valleytronics. However, the limited light absorption efficiency of monolayer WSe2 severely hinders its practical applications. To address this challenge, vertical Te-WSe2 heterojunctions consisting of Te nanomesh and monolayer WSe2 nanofilm have been prepared using the two-step vapor deposition method, which significantly enhances the optoelectronic performance. Te-WSe2 heterojunction photodetector exhibits a high responsivity of 1.3 A/W and a specific detectivity of 1 × 1010 Jones under the irradiation of 460 nm light source. This study demonstrates the controllable fabrication of large-scale of Te-WSe2 vertical heterojunctions. The underlying mechanism for the performance enhancement of Te-WSe2 heterojunction photodetector was elucidated based on the Ohm-like type-I band-aligned structure. The research can be further extended to other Te-based mixed-dimensional heterojunctions, providing valuable theoretical and experimental support for the application of next-generation integrated optoelectronic devices.

Camel milk is a neglected source of brucellosis among rural Arab communities

Abstract The World Health Organization describes brucellosis as one of the world’s leading zoonotic diseases, with the Middle East a global hotspot. Brucella melitensis is endemic among livestock populations in the region, with zoonotic transmission occurring via consumption of raw milk, amongst other routes. Control is largely via vaccination of small ruminant and cattle populations. Due to sociocultural and religious influences camel milk (camelus dromedarius) is widely consumed raw, while milk from other livestock species is largely boiled. To investigate the potential public health impact of Brucella in camels we conduct a cross-sectional study in southern Jordan including 227 herds and 202 livestock-owning households. Here we show daily consumption of raw camel milk is associated with Brucella seropositive status among the study population, ORadj 2.19 (95%CI 1.23–3.94) on multivariable analysis, highlighting the need for socioculturally appropriate control measures; targeted interventions among the camel reservoir being crucial for effective control.

Fabrication and characterization of heteroepitaxial Zn2GeO4 films on sapphire via radio frequency magnetron sputtering

In this study, we explored the fabrication, structural characteristics, and optical properties of Zn2GeO4 thin films grown on c-cut Al2O3 substrates via radio frequency magnetron sputtering. The crystalline quality, surface morphology, and optical characteristics were comprehensively evaluated at various annealing temperatures, and the 700 °C-annealed film presented the best crystallization quality. XRD and TEM results revealed the microstructure of Zn2GeO4 film and confirmed that the epitaxial relationship is Zn2GeO4 (0006)//Al2O3 (0006) with Zn2GeO4 [11¯00]//Al2O3 [11¯00]. O 1s spectrum indicated the bandgap of the 700 °C-annealed film is 4.98 eV. UV-Vis-Near Infrared spectroscopy showed that the average transmittance reached approximately 85% in the visible region, and the optical bandgap of Zn2GeO4 film annealed at 700 °C was about 5.02 eV.

Non-linear enhancement of ultrafast X-ray diffraction through transient resonances

Abstract Diffraction-before-destruction imaging with ultrashort X-ray pulses can visualize non-equilibrium processes, such as chemical reactions, with sub-femtosecond precision in the native environment. Here, a nanospecimen diffracts a single X-ray flash before it disintegrates. The sample structure can be reconstructed from the coherent diffraction image (CDI). State-of-the-art X-ray snapshots lack high spatial resolution because of weak diffraction signal. Bleaching effects from photo-ionization significantly restrain image brightness scaling. We find that non-linear transient ion resonances can overcome this barrier if X-ray laser pulses are shorter than in most experiments. We compared snapshots from individual  ≈ 100 nm Xe nanoparticles as a function of pulse duration and incoming X-ray fluence. Our experimental results and Monte Carlo simulations suggest that transient resonances can increase ionic scattering cross sections significantly beyond literature values. This provides a novel avenue towards substantial improvement of the spatial resolution in CDI in combination with sub-femtosecond temporal precision at the nanoscale.

Physics-informed genetic algorithms (PIGAs) facilitating LIBS spectral normalization with shockwave characteristics

Inspired by physics-informed neural networks (PINNs) inheriting both the interpretability of physical laws and the efficient integration capability of machine learning, we propose a framework based on stoichiometric ablation for LIBS spectral normalization, encoding physical constraints between LIBS intensities and shockwave characteristics (temperature Tshock and pressure P) into optimization algorithms with multiple independent objectives, named physics-informed genetic algorithms (PIGAs). It is characterized by its applicability to the wider laser energy range, covering laser-induced breakdown to significant plasma shielding and spectral lines undergoing self-absorption, outperforming the widely used physical linear or multivariate data-driven normalization methods. The home-made end-to-end LAP-RTE codes serve as the benchmark to validate the physical reciprocal-logarithmic transformation and its extensibility to self-absorption spectral lines for PIGAs. Next, experimental spectral lines are statistically used to validate PIGAs' correction effects; the median RSDs of spectral intensities can be effectively reduced by 85% (corrected by P) and 88% (corrected by Tshock) for 108 Fe I lines, while for 33 Fe II lines, reduced by 77% (corrected by P) and 86% (corrected by Tshock). Seventeen self-absorption lines are also corrected effectively, with RSDs being reduced by 78% (corrected by P) and 89% (corrected by Tshock). Our proposed idea of combining optimization methods to quantify unknown parameters in normalization strategies can also be extended to excavate the correlation between parameters for other low-temperature plasma fields with similar processes.

Spatiotemporal transcriptome and metabolome landscapes of cotton fiber during initiation and early development

High-throughput screening and research of nitrogen reduction on 2D metal–organic framework: First-principles study

Developing efficient nitrogen reduction reaction (NRR) catalysts remains challenging. Two-dimensional metal–organic frameworks (MOFs) stand out because of their large holes and high metal utilization. Based on first-principles high-throughput calculations, we studied the catalytic capacity of MOF catalyst TM3 (HITP)2 for NRR. Our calculated results indicate that among 29 catalytic structures, Mo3(HITP)2 and Os3(HITP)2 exhibit excellent activity for NRR, with the overpotential being 0.39 and 0.43 V, respectively. The unoccupied 4d orbitals of Mo are especially closer to the antibonding N-2p orbitals, leading to better nitrogen activation and lower overpotential. In addition, a descriptor related to charge variation and the electronegativity of metals and coordinating atoms is established, which has a good volcano plot relationship with the limiting potential of NRR and can provide ideas for catalyst screening. This research contributes valuable insights for the screening of NRR catalysts based on MOF.