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Investigation of the 4<i>f</i>146<i>s</i>2 1<i>S</i>0−4<i>f</i>135<i>d</i>6<i>s</i>2 (<i>J</i> <b>=</b> 2) clock transition at 431 nm of 171Yb atoms trapped in an optical lattice

With the aid of an optical frequency divider based on an optical frequency comb, the frequency of a laser at 431 nm is divided from a cavity-stabilized laser at 578 nm. Using the frequency-stabilized 431 nm laser, we observe a 2.5 kHz linewidth 4f146s2 1S0−4f135d6s2 (J = 2) transition of 171Yb atoms trapped in an optical lattice. By measuring the lattice-induced frequency shift, we determine the magic wavelength of the optical lattice for the 431 nm transition to be 797.97(20) nm. The frequency of the 431 nm transition is measured to be 695 171 054 856.9(1.1) kHz by referencing to the 1S0−3P0 transition at 578 nm of Yb atoms.

Allylic C–H oxygenation of unactivated internal olefins by the Cu/azodiformate catalyst system

Abstract Allylic ethers and alcohols are essential structural motifs commonly present in natural products and pharmaceuticals. Direct allylic C–H oxygenation of internal alkenes is one of the most direct methods, bypassing the necessity for an allylic leaving group that is needed in the traditional Tsuji–Trost reaction. Herein, we develop an efficient and practical method for synthesizing (E)-allyl ethers from readily available internal alkenes and alcohols or phenols via selective allylic C–H oxidation. Key advances include the use of a Cu/Azodiformate catalyst system to facilitate remote allylic C–H activation and the achievement of excellent chemoselectivity through a dynamic ligand exchange strategy using a bis(sulfonamide) ligand. This method features a broad substrate scope and functional group tolerance, successfully applied to the synthesis of various challenging medium-sized cyclic ethers (7-10 members) and large-ring lactones (14-20 members), with high regioselectivity and stereoselectivity.

Voronoi diagrams metallic mesh for transparent EMI shielding

Recently, the transparent electromagnetic interference (EMI) shielding film, which is optical transparent, conductive, and EMI shielding, is widely employed in fields of display, solar cell, EMI shielding, and so on. Here, we utilized Voronoi diagram randomized metallic mesh and 3D printing technology to achieve transparent EMI shielding on curved surface. For the metal grid based on Voronoi diagram, one can realize highly homogeneous light transmission, with that optical performance is superior to that of regular and random quadrilateral mesh. The designed Voronoi diagram meshes were fabricated using aerosol jet (AJ) technology, which needs no mask and can achieve patterns on curved surfaces. The Voronoi metal meshes were fabricated on a 40 × 40 mm2 planar and a plano–convex lens with a diameter of 10 mm and a crown height of 3.7 mm. We investigated the optical transmittance of the Voronoi metal mesh grid and also the imaging performance of plano–convex lens with mesh grid. Furthermore, we analyzed the EMI shielding characteristics of the fabricated Voronoi mesh grids in the Ku-band (12–18 GHz) by using a vector network analyzer, which is higher than 23 dB. Therefore, the proposed Voronoi diagram and AJ technology can provide good diffraction uniformity and an effective method to fabricate the metal mesh grids on conformal surfaces.

Higher magnesium depletion score increases the risk of all‑cause and cardiovascular mortality in US adults with diabetes

Background Both dietary magnesium and serum magnesium are associated with the prognosis of diabetic patients. However, the impact of the magnesium depletion score (MDS), which assesses systemic magnesium deficiency, on the prognosis of diabetic patients remains unclear. This cohort study aims to explore the potential association between the MDS and all-cause and cardiovascular mortality in diabetic patients. Methods In this study, we analyzed data from 5,219 diabetic individuals from National Health and Nutrition Examination Survey (NHANES) 2003–2018. Participant mortality information was sourced from the National Death Index records. MDS was divided into lower MDS (0–1 points), middle MDS (2 points), and higher MDS (3–5 points) groups. Weighted multivariable Cox regression was utilized to explore the potential association between MDS and mortality in diabetic patients. Stratified analyses and sensitivity analyses were employed to validate the robustness of our findings. Results Among the 5,219 participants included in this study, 1,212 experienced all-cause mortality, and 348 experienced cardiovascular mortality. Weighted multivariable Cox regression indicated that higher MDS was strongly linked to a heightened risk of mortality in all models, including the fully adjusted model (all-cause mortality: HR = 1.58, 95% CI: 1.20–2.08; cardiovascular mortality: HR = 1.92, 95% CI: 1.28–2.88). In the stratified analysis, we found that the association between MDS and all-cause mortality was stronger among individuals aged &lt;60 years. No significant differences were found in the relationship between MDS and mortality within other subgroups. In the sensitivity analyses, our results remained robust. Conclusions An increase in MDS is significantly correlated with a higher risk of all-cause and cardiovascular mortality in diabetic patients. The risk of all-cause mortality was higher in diabetic patients aged &lt;60. Early monitoring and management of MDS, as well as optimizing magnesium nutritional status, may benefit diabetic patients.

Increasing certainty in projected local extreme precipitation change

Sub-cycle nanotip field emission of electrons driven by air plasma generated THz pulses

Terahertz pulses generated by two-color laser plasmas have reported peak field strengths exceeding MV/cm, and when illuminating metal nanotips, the near-field enhancement at the tip apex should result in extremely high bunch charges and electron energies via sub-cycle cold-field emission. Here, electron emission from tungsten nanotips driven by THz pulses generated by a long filament air-plasma is reported. Electron energies up to 1.1 keV and bunch charges up to 2×105 electrons per pulse were detected, well below values expected for peak field calculated via the time-averaged Poynting vector. Investigations revealed a failure in the use of the time-averaged Poynting vector when applied to long filament THz pulses, due to spatiotemporal restructuring of the THz pulse in the focus. Accounting for this restructuring significantly reduces the field strength to approximately 160 kV/cm, consistent with the observed electron bunch charges, peak energies, and their dependence on the tip position in the THz focus. Despite these findings, our results surpass previous THz plasma-driven electron generation by an order of magnitude in both electron energy and bunch charge, and a path to increasing these by an additional order of magnitude by modification of the THz optics is proposed.

Motivation, barriers and preferences of lifestyle changes among older adults with frailty and mild cognitive impairments: A scoping review of qualitative analysis

Lifestyle intervention has proven effective in managing older adults’ frailty and mild cognitive impairment issues. What remains unclear is how best to encourage lifestyle changes among older adults with frailty and Mild Cognitive Impairment (MCI). We conducted searches in electronic literature searches such as PubMed, Scopus, Cochrane Reviews, ProQuest, and grey resources to find articles published in English between January 2010 and October 2023. This review focused on research using a qualitative study design. We extracted data on publication year, location, the aim of the study, study population, involved intervention, barriers, motivations, and preferences reported in the articles. Out of 5226 retrieved, 253 articles were selected after the deletion of duplicates, title, abstract screening, and. We included fourteen articles for final analysis at the end of the review process. The two main themes generated from this review are intrinsic and extrinsic factors in motivations and barriers to lifestyle changes. The most reported motivators were the perceived benefits of lifestyle intervention and self-efficacy. Among the obstacles participants face are perceived adverse effects of intervention, lack of knowledge, existing impairment (physical or mental), and social support. Lifestyle change motivations and barriers among older adults mainly were intrinsic factors such as the perceived benefit of the intervention, self-efficacy, knowledge, familial commitment, and existing impairments. There is a need to empower older adults to overcome the barriers with support from healthcare professionals, the community, and the family.

Dynamic allostery in the peptide/MHC complex enables TCR neoantigen selectivity

Abstract The inherent antigen cross-reactivity of the T cell receptor (TCR) is balanced by high specificity. Surprisingly, TCR specificity often manifests in ways not easily interpreted from static structures. Here we show that TCR discrimination between an HLA-A*03:01 (HLA-A3)-restricted public neoantigen and its wild-type (WT) counterpart emerges from distinct motions within the HLA-A3 peptide binding groove that vary with the identity of the peptide’s first primary anchor. These motions create a dynamic gate that, in the presence of the WT peptide, impedes a large conformational change required for TCR binding. The neoantigen is insusceptible to this limiting dynamic, and, with the gate open, upon TCR binding the central tryptophan can transit underneath the peptide backbone to the opposing side of the HLA-A3 peptide binding groove. Our findings thus reveal a novel mechanism driving TCR specificity for a cancer neoantigen that is rooted in the dynamic and allosteric nature of peptide/MHC-I binding grooves, with implications for resolving long-standing and often confounding questions about T cell specificity.

Junction-based deep mesa termination for multi-kilovolt vertical <b> <i>β</i> </b>-Ga2O3 power devices

Deep mesa is an effective edge termination widely deployed in high-voltage power devices. However, its effectiveness requires the minimal distance between mesa and electrode edge and is susceptible to charges in the dielectric passivation, posing challenges in practical implementation. Here, we propose a deep mesa termination encapsulated by p-type materials, which functions as a reduced-surface-field (RESURF) structure and enables a wide design and process window. We demonstrate the RESURF-mesa design in vertical Ga3O3 diodes. In this design, a 5 μm deep mesa, which is intentionally not aligned with the anode edge, is encapsulated by p-type nickel oxide (NiO). This termination has been applied to devices on three Ga2O3 wafers with epitaxial doping concentrations ranging from 1.2 × 1016 to 5 × 1016 cm−3, enabling an average one-dimensional junction field of 4.2–4.4 MV/cm in all wafers. Additionally, the diode with 1.2 × 1016 cm−3 doping achieves a specific on-resistance (RON,sp) of 4.05 mΩ·cm2 and a breakdown voltage of 3214 V, resulting in a power figure of merit of 2.55 GW/cm2, which is among the highest in multi-kilovolt β-Ga2O3 diodes. The above results demonstrate the RESURF-mesa termination as a versatile and effective solution for wide bandgap and ultra-wide bandgap power devices.

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.