Operando-reconstructed polyatomic ion layers boost the activity and stability of industrial current-density water splitting.

Metal-organic frameworks have garnered attention as highly efficient pre-electrocatalysts for the oxygen evolution reaction (OER). Current structure-activity relationships primarily rely on the assumption that the complete dissolution of organic ligands occurs during electrocatalysis. Herein, modeling based on NiFe Prussian blue analogs (NiFe-PBAs) show that cyanide ligands leach from the matrix and subsequently oxidize to corresponding inorganic ions (ammonium and carbonate) that re-adsorb onto the surface of NiFe OOH during the OER process. Interestingly, the surface-adsorbed inorganic ions induce the OER reaction of NiFe OOH to switch from the adsorbate evolution to the lattice-oxygen-mediated mechanism, thus contributing to the high activity. In addition, this reconstructed inorganic ion layer acting as a versatile protective layer can prevent the dissolution of metal sites to maintain contact between catalytic sites and reactive ions, thus breaking the activity-stability trade-off. Consequently, our constructed NiFe-PBAs exhibit excellent durability for 1250 h with an ultralow overpotential of 253 mV at 100 mA cm-2. The scale-up NiFe-PBAs operated with a low energy consumption of ∼4.18 kWh m-3 H2 in industrial water electrolysis equipment. The economic analysis of the entire life cycle demonstrates that this green hydrogen production is priced at US$2.59/ [Formula: see text] , meeting global targets (

Altered gut microbe metabolites in patients with alcohol­induced osteonecrosis of the femoral head: An integrated omics analysis.

Excessive alcohol consumption is considered to be a major risk factor of alcohol-induced osteonecrosis of the femoral head (AONFH). The gut microbiota (GM) has been reported to aid in the regulation of human physiology and its composition can be altered by alcohol consumption. The aim of the present study was to improve the understanding of the GM and its metabolites in patients with AONFH. Metabolomic sequencing and 16S rDNA analysis of fecal samples were performed using liquid chromatography-mass spectrometry to characterize the GM of patients with AONFH and healthy normal controls (NCs). Metagenomic sequencing of fecal samples was performed to identify whether GM changes on the species level were associated with the expression of gut bacteria genes or their associated functions in patients with AONFH. The abundance of 58 genera was found to differ between the NC group and the AONFH group. Specifically, Klebsiella, Holdemanella, Citrobacter and Lentilactobacillus were significantly more abundant in the AONFH group compared with those in the NC group. Metagenomic sequencing demonstrated that the majority of the bacterial species that exhibited significantly different abundance in patients with AONFH belonged to the genus Pseudomonas. Fecal metabolomic analysis demonstrated that several metabolites were present at significantly different concentrations in the AONFH group compared with those in the NC group. These metabolites were products of vitamin B6 metabolism, retinol metabolism, pentose and glucuronate interconversions and glycerophospholipid metabolism. In addition, these changes in metabolite levels were observed to be associated with the altered abundance of specific bacterial species, such as Basidiobolus, Mortierella, Phanerochaete and Ceratobasidium. According to the results of the present study, a comprehensive landscape of the GM and metabolites in patients with AONFH was revealed, suggesting the existence of interplay between the gut microbiome and metabolome in AONFH pathogenesis.

Imaging through thick scattering media based on envelope-informed learning with a simulated training dataset.

Computational imaging faces significant challenges in dealing with multiple scattering through thick complex media. While deep learning has addressed some ill-posed problems in scattering imaging, its practical application is limited by the acquisition of the training dataset. In this study, the Gaussian-distributed envelope of the speckle image is employed to simulate the point spread function (PSF), and the training dataset is obtained by the convolution of the handwritten digits with the PSF. This approach reduces the requirement of time and conditions for constructing the training dataset and enables a neural network trained on this dataset to reconstruct objects obscured by an unknown scattering medium in real experiments. The quality of reconstructed objects is negatively correlated with the thickness of the scattering medium. Our proposed method provides a new way, to the best of our knowledge, to apply deep learning in scattering imaging by reducing the time needed for constructing the training dataset.

Association between history of cannabis use and outcomes after total hip or knee arthroplasty: a systematic review and meta-analysis.

Background: Cannabis use may be increasing as countries legalize it and it becomes socially acceptable. A history of cannabis use may increase risk of complications after various kinds of surgery and compromise functional recovery. Here we systematically reviewed and meta-analyzed available evidence on how history of cannabis use affects recovery after hip or knee arthroplasty (THA/TKA). Methods: The PubMed, EMBASE, and Web of Science databases were comprehensively searched and studies were selected and analyzed in accordance with the PRISMA guidelines. The methodological quality of included studies was assessed based on the Newcastle-Ottawa Scale, while quality of evidence was evaluated according to the "Grading of recommendations assessment, development, and evaluation" system. Data on various outcomes were pooled when appropriate and meta-analyzed. Results: The systematic review included 16 cohort studies involving 5.91 million patients. Meta-analysis linked history of cannabis use to higher risk of the following outcomes: revision (RR 1.68, 95% CI 1.31-2.16), mechanical loosening (RR 1.77, 95% CI 1.52-2.07), periprosthetic fracture (RR 1.85, 95% CI 1.38-2.48), dislocation (RR 2.10, 95% CI 1.18-3.73), cardiovascular events (RR 2.49, 95% CI 1.22-5.08), cerebrovascular events (RR 3.15, 95% CI 2.54-3.91), pneumonia (RR 3.97, 95% CI 3.49-4.51), respiratory failure (RR 4.10, 95% CI 3.38-4.97), urinary tract infection (RR 2.46, 95% CI 1.84-3.28), acute kidney injury (RR 3.25, 95% CI 2.94-3.60), venous thromboembolism (RR 1.48, 95% CI 1.34-1.63), and deep vein thrombosis (RR 1.42, 95% CI 1.19-1.70). In addition, cannabis use was associated with significantly greater risk of postoperative transfusion (RR 2.23, 95% CI 1.83-2.71) as well as higher hospitalization costs. Conclusion: History of cannabis use significantly increases the risk of numerous complications and transfusion after THA or TKA, leading to greater healthcare costs. Clinicians should consider these factors when treating cannabis users, and pre-surgical protocols should give special consideration to patients with history of cannbis use.

Interlayer Delocalized Electrons Activate Basal Plane for Ultrahigh-Current-Density Hydrogen Evolution.

The basal plane of transition metal dichalcogenides (TMDCs) is inert for the hydrogen evolution reaction (HER) due to its low-efficiency charge transfer kinetics. We propose a strategy of filling the van der Waals (vdW) layer with delocalized electrons to enable vertical penetration of electrons from the collector to the adsorption intermediate vertically. Guided by density functional theory, we achieve this concept by incorporating Cu atoms into the interlayers of tantalum disulfide (TaS2). The delocalized electrons of d-orbitals of the interlayered Cu can constitute the charge transfer pathways in the vertical direction, thus overcoming the hopping migration through vdW gaps. The vertical conductivity of TaS2 increased by 2 orders of magnitude. The TaS2 basal plane HER activity was extracted with an on-chip microcell. Modified by the delocalized electrons, the current density increased by 20 times, reaching an ultrahigh value of 800 mA cm-2 at -0.4 V without iR compensation.

Full-range depth-encoded swept source polarization sensitive optical coherence tomography.

To realize the high sensitivity polarization sensitive optical coherence tomography (PS-OCT) imaging, a fiber-based full-range depth-encoded swept source PS-OCT (SS-PS-OCT) method is proposed. The two OCT images corresponding to the orthogonal polarized input light are located on the high sensitivity imaging region of the opposite sides relative to the zero optical path difference position. The full-range OCT images can be obtained by implementing the spatial phase modulation in the reference arm. The detection sensitivity of the system was measured experimentally to be 67 dB when the imaging depth approaching to 2 mm. The imaging of the biological tissue verifies that the proposed full-range depth-encoded SS-PS-OCT system has the higher detection sensitivity compared with the conventional depth encoded SS-PS-OCT system. Finally, we demonstrated the full-range high sensitivity phase retardation image of the bovine tendon and skin of human fingertip. The fiber-based full-range depth-encoded SS-PS-OCT method can realize the high sensitivity birefringence imaging in the medical diagnosis scenes with the requirements for long imaging range and high detection sensitivity.

General phase-difference imaging of incoherent digital holography.

The hologram formed by incoherent holography based on self-interference should preserve the phase difference information of the object, such as the phase difference between the mutually orthogonal polarizations of anisotropic object. How to decode this phase difference from this incoherent hologram, i.e., phase-difference imaging, is of great significance for studying the properties of the measured object. However, there is no general phase-difference imaging theory due to both diverse incoherent holography systems and the complicated reconstruction process from holograms based on the diffraction theory. To realize phase-difference image in incoherent holography, the relationship between the phase difference of the object and the image reconstructed by holograms is derived using a general physical model of incoherent holographic systems, and then the additional phase that will distort this relationship in actual holographic systems is analyzed and eliminated. Finally, the phase-difference imaging that is suitable for the most incoherent holographic systems is realized and the general theory is experimentally verified. This technology can be applied to phase-difference imaging of anisotropic objects, and has potential applications in materials science, biomedicine, polarized optics and other fields.

Functionalized chitosan hydrogel promotes osseointegration at the interface of3D printed titanium alloy scaffolds.

Autogenous bone transplantation is a prevalent clinical method for addressing bone defects. However, the limited availability of donor bone and the morbidity associated with bone harvesting have propelled the search for suitable bone substitutes. Bio-inspired scaffolds, particularly those fabricated using electron beam melting (EBM) deposition technology, have emerged as a significant advancement in this field. These 3D-printed titanium alloy scaffolds are celebrated for their outstanding biocompatibility and favorable elastic modulus. Thermosensitive chitosan hydrogel, which transitions from liquid to solid at body temperature, serves as a popular carrier in bone tissue engineering. Icariin (ICA), known for its efficacy in promoting osteoblast differentiation from bone marrow mesenchymal stem cells (BMSCs), plays a crucial role in this context. We developed a system combining a 3D-printed titanium alloy with a thermosensitive chitosan hydrogel, capable of local bone regeneration and integration through ICA delivery. Our in vitro findings reveal that this system can gradually release ICA, demonstrating excellent biocompatibility while fostering BMSC proliferation and osteogenic differentiation. Immunohistochemistry and Micro-CT analyses further confirm the effectiveness of the system in accelerating in vivo bone regeneration and enhancing osseointegration. This composite system lays a significant theoretical foundation for advancing local bone regeneration and integration.

Frequency selection rule for the HDHF Lissajous scanning imaging with a low-voltage one axis actuated PZT scanner based on an asymmetric fiber cantilever.

Lissajous micro scanners are very attractive in compact laser scanning applications for biomedical endoscopic imaging, such as confocal microscopy, endomicroscopy or optical coherence tomography. The scanning frequencies have a very important effect on the quality of the resulting Lissajous scanning imaging. In this paper, we propose a frequency selection rule for high definition and high frame-rate (HDHF) Lissajous scanning imaging, by deriving the relationship among the scanning field of view (FOV), actuation frequencies and pixel size based on the characteristics of the scanning trajectory. The minimum sampling rate based on the proposed frequency selection rule is further discussed. We report a lead zirconate titanate piezoelectric ceramic (PZT) based Lissajous fiber scanner to achieve HDHF Lissajous scanning imaging. Based on the frequency selection rule, different frequency combinations are calculated, under which the Lissajous fiber scanner can work at the frame rate (FR) of 10 Hz, 20 Hz, 40 Hz and 52 Hz. The trajectory evolution of the Lissajous scanning at the frame rate of 10 Hz has been obtained to verify the applicability of the proposed rule. The measured resolution of the scanner is 50.8 lp/mm at the unit optical magnification, and the measured FOV at the FR of 10 Hz and 40 Hz are 1.620 mm ×1.095 mm and 0.405 mm ×0.27 mm, respectively. HDHF Lissajous scanning images of the customized spatial varying binary pattern are obtained and reconstructed at the FR of 10 Hz and 40 Hz, demonstrating the practicability of the frequency selection rule.

Durable CO2 conversion in the proton-exchange membrane system.

Electrolysis that reduces carbon dioxide (CO2) to useful chemicals can, in principle, contribute to a more sustainable and carbon-neutral future1-6. However, it remains challenging to develop this into a robust process because efficient conversion typically requires alkaline conditions in which CO2 precipitates as carbonate, and this limits carbon utilization and the stability of the system7-12. Strategies such as physical washing, pulsed operation and the use of dipolar membranes can partially alleviate these problems but do not fully resolve them11,13-15. CO2 electrolysis in acid electrolyte, where carbonate does not form, has therefore been explored as an ultimately more workable solution16-18. Herein we develop a proton-exchange membrane system that reduces CO2 to formic acid at a catalyst that is derived from waste lead-acid batteries and in which a lattice carbon activation mechanism contributes. When coupling CO2 reduction with hydrogen oxidation, formic acid is produced with over 93% Faradaic efficiency. The system is compatible with start-up/shut-down processes, achieves nearly 91% single-pass conversion efficiency for CO2 at a current density of 600 mA cm-2 and cell voltage of 2.2 V and is shown to operate continuously for more than 5,200 h. We expect that this exceptional performance, enabled by the use of a robust and efficient catalyst, stable three-phase interface and durable membrane, will help advance the development of carbon-neutral technologies.

Reconstructing Hydrogen-Bond Network for Efficient Acidic Oxygen Evolution.

Developing highly active oxygen evolution reaction (OER) catalysts in acidic conditions is a pressing demand for proton-exchange membrane water electrolysis. Manipulating proton character at the electrified interface, as the crux of all proton-coupled electrochemical reactions, is highly desirable but elusive. Herein we present a promising protocol, which reconstructs a connected hydrogen-bond network between the catalyst-electrolyte interface by coupling hydrophilic units to boost acidic OER activity. Modelling on N-doped-carbon-layer clothed Mn-doped-Co3O4 (Mn-Co3O4@CN), we unravel that the hydrogen-bond interaction between CN units and H2O molecule not only drags the free water to enrich the surface of Mn-Co3O4 but also serves as a channel to promote the dehydrogenation process. Meanwhile, the modulated local charge of the Co sites from CN units/Mn dopant lowers the OER barrier. Therefore, Mn-Co3O4@CN surpasses RuO2 at high current density (100 mA cm-2 @ ~538 mV).

Imaging objects hidden inside the strongly scattering media based on bidirectional ghost imaging.

We demonstrate a novel, to the best of our knowledge, method for imaging objects hidden inside the strongly scattering media based on bidirectional ghost imaging (GI). In this method, GI is performed separately on both sides of the object, resulting in two GI results. Through an autocorrelation operation to the two GI results, the convolution between the autocorrelation of the object and the point spread function (PSF) of the strongly scattering media can be recovered. Therefore, the object can be recovered by obtaining the PSF of the strongly scattering media through noninvasive measurement or numerical calculation. Simulation and experimental results show that bidirectional ghost imaging (BGI) can reconstruct high-quality images, particularly when the thickness of the strongly scattering media greatly exceeds the scattering mean free path.

Overlapping speckle correlation algorithm for high-resolution imaging and tracking of objects in unknown scattering media.

Optical imaging in scattering media is important to many fields but remains challenging. Recent methods have focused on imaging through thin scattering layers or thicker scattering media with prior knowledge of the sample, but this still limits practical applications. Here, we report an imaging method named 'speckle kinetography' that enables high-resolution imaging in unknown scattering media with thicknesses up to about 6 transport mean free paths. Speckle kinetography non-invasively records a series of incoherent speckle images accompanied by object motion and the inherently retained object information is extracted through an overlapping speckle correlation algorithm to construct the object's autocorrelation for imaging. Under single-colour light-emitting diode, white light, and fluorescence illumination, we experimentally demonstrate 1 µm resolution imaging and tracking of objects moving in scattering samples, while reducing the requirements for prior knowledge. We anticipate this method will enable imaging in currently inaccessible scenarios.

Maximum helical dichroism enabled by an exceptional point in non-Hermitian gradient metasurfaces.

Helical dichroism (HD) utilizing unbounded orbital angular momentum degree of freedom, has provided an important means of exploring chiral effects in diverse wave systems, surpassing the two-state constraint in circular dichroism that relies on intrinsic spin. However, the naturally feeble chiral signals that arise during wave-matter interactions pose significant challenges to the effective enlargement of HD. Here, we introduce a new paradigm for realizing maximum HD through non-Hermitian gradient metasurfaces by engineering a chiral exceptional point (EP) in intrinsic topological charge. The non-Hermitian gradient metasurfaces are empowered by the asymmetric coupling feature at the EP, enabling flexible construction to realize versatile chirality control in extreme circumstances where one chiral vortex is totally reflected and the opposite counterpart is completely absorbed or transmitted into the customized vortex modes. As the manifestation of the maximum HD, we present the first experimental demonstration of perfect chirality-selected vortex transmission in acoustics. Our findings open new venues to achieve maximum chirality and explore chiral physics of wave-matter interactions, which can boost many vortical applications in asymmetric chirality manipulation, one-way propagation, and information multiplexing.

Geometric Phase in Twisted Topological Complementary Pair.

Geometric phase enabled by spin-orbit coupling has attracted enormous interest in optics over the past few decades. However, it is only applicable to circularly-polarized light and encounters substantial challenges when applied to wave fields lacking the intrinsic spin degree of freedom. Here, a new paradigm is presented for achieving geometric phase by elucidating the concept of topological complementary pair (TCP), which arises from the combination of two compact phase elements possessing opposite intrinsic topological charge. Twisting the TCP leads to the generation of a linearly-varying geometric phase of arbitrary order, which is quantified by the intrinsic topological charge. Notably distinct from the conventional spin-orbit coupling-based theories, the proposed geometric phase is the direct result of the cyclic evolution of orbital-angular-momentum transformation in mode space, thereby exhibiting universality across classical wave systems. As a proof of concept, the existence of this geometric phase is experimentally demonstrated using scalar acoustic waves, showcasing the remarkable ability in the precise manipulation of acoustic waves at subwavelength scales. These findings engender a fresh understanding of wave-matter interaction in compact structures and establish a promising platform for exploring geometric phase, offering significant opportunities for diverse applications in wave systems.

Sequential *CO management via controlling in situ reconstruction for efficient industrial-current-density CO2-to-C2+ electroreduction.

Sequentially managing the coverage and dimerization of *CO on the Cu catalysts is desirable for industrial-current-density CO2 reduction (CO2R) to C2+, which required the multiscale design of the surface atom/architecture. However, the oriented design is colossally difficult and even no longer valid due to unpredictable reconstruction. Here, we leverage the synchronous leaching of ligand molecules to manipulate the seeding-growth process during CO2R reconstruction and construct Cu arrays with favorable (100) facets. The gradient diffusion in the reconstructed array guarantees a higher *CO coverage, which can continuously supply the reactant to match its high-rate consumption for high partial current density for C2+. Sequentially, the lower energy barriers of *CO dimerization on the (100) facets contribute to the high selectivity of C2+. Profiting from this sequential *CO management, the reconstructed Cu array delivers an industrial-relevant FEC2+ of 86.1% and an FEC2H4 of 60.8% at 700 mA cm-2. Profoundly, the atomic-molecular scale delineation for the evolution of catalysts and reaction intermediates during CO2R can undoubtedly facilitate various electrocatalytic reactions.

Controlling the directional excitation of surface plasmon polaritons using tunable non-Hermitian metasurfaces.

In this work, we propose an efficient approach to controlling the directional excitation of surface plasmon polaritons (SPPs) by dynamically modulating the real-part perturbation in a passive parity-time symmetric metasurface. This non-Hermitian system can experience two exceptional points that can induce two unidirectional excitation states of SPPs along opposite directions. Empowered by its superior modulation depth, the energy ratio and energy intensities of two excited SPP states can be effectively manipulated by this non-Hermitian metasurface. To demonstrate these findings, we design and numerically verify non-Hermitian metasurfaces integrated with an Sb2Se3 phase-change material. Our work provides a promising platform for the controllable engineering of SPP excitations, holding significant potential for the development of new plasmonic devices, including on-chip SPP sources, routers and sorters, and integrated optical circuits.

Switchable supermode emission in a doubly-coupled-ring system for multifunctional integrated photonic devices.

Effective integration of optical modes within chip-scale devices is critical to realize functional light emission, as it offers abundant physics and a versatile ability to control the mode evolution. Here, we present an efficient approach to achieve switchable emission by flexibly controlling supermode states in a doubly-coupled-ring system with four guided modes. The lasing conditions, which rely on the system's Hamiltonian, are revealed to yield multiple supermode states, including an exceptional-point state, a (quasi-)dark state, and a bright state. By freely engineering the coupling rate via phase-change material, the proposed system allows the generation of any desired states, enabling switchable and multifunctional emissions in fixed on-chip structures. Beyond the manipulation of various supermode emission states, our work presents a promising path toward the development of multifunctional integrated photonic devices, which may have applications in light storage, optical isolation, sensing, and so on.

O-POSSUM and P-POSSUM as predictors of morbidity and mortality in older patients after hip fracture surgery: a meta-analysis.

BACKGROUND: The POSSUM model has been widely used to predict morbidity and mortality after general surgery. Modified versions known as O-POSSUM and P-POSSUM have been used extensively in orthopedic surgery, but their accuracy is unclear. This systematic review evaluated the predictive value of these models in older patients with hip fractures. METHODS: This study was performed and reported based on the "Preferred reporting items for systematic reviews and meta-analyses" guidelines. PubMed, Cochrane, EMBASE, and Web of Science were comprehensively searched for relevant studies, whose methodological quality was evaluated according to the "Methodological index for non-randomized studies" scale. Revman 5 was used to calculate weighted ratios of observed to expected morbidity or mortality. RESULTS: The meta-analysis included 10 studies, of which nine (2549 patients) assessed the ability of O-POSSUM to predict postoperative morbidity, nine (3649 patients) assessed the ability of O-POSSUM to predict postoperative mortality, and four (1794 patients) assessed the ability of P-POSSUM to predict postoperative mortality. The corresponding weighted ratios of observed to expected morbidity or mortality were 0.84 (95% CI 0.70-1.00), 0.68 (95% CI 0.49-0.95), and 0.61 (95% CI 0.16-2.38). CONCLUSIONS: While O-POSSUM shows reasonable accuracy in predicting postoperative morbidity in older patients with hip fractures, both P-POSSUM and O-POSSUM substantially overestimate postoperative mortality. The POSSUM model should be optimized further for this patient population.