Self-Healing Liquid Metal Magnetic Hydrogels for Smart Feedback Sensors and High-Performance Electromagnetic Shielding

Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocompatibility,custom shape,and self-healing.Herein,a conductive,stretchable,adaptable,self-healing,and biocompatible liquid metal GaInSn/Ni-based composite hydrogel is developed by incorporating a magnetic liquid metal into the hydrogel framework through crosslinking polyvinyl alcohol(PVA)with sodium tetraborate.The excellent stretchability and fast self-healing capability of the PVA/liquid metal hydrogel are derived from its abundant hydrogen binding sites and liquid metal fusion.Significantly,owing to the magnetic constituent,the PVA/liquid metal hydrogel can be guided remotely using an external magnetic field to a specific position to repair the broken wires with no need for manual operation.The composite hydrogel also exhibits sensitive deformation responses and can be used as a strain sensor to monitor various body motions.Additionally,the multifunctional hydrogel displays absorption-dominated electromagnetic interference(EMI)shielding properties.The total shielding performance of the composite hydrogel increases to~62.5 dB from~31.8 dB of the pure PVA hydrogel at the thickness of 3.0 mm.The proposed bioinspired multifunctional magnetic hydrogel demonstrates substantial application potential in the field of intelligent wearable devices.

Self-Modifying Nanointerface Driving Ultrahigh Bidirectional Thermal Conductivity Boron Nitride-Based Composite Flexible Films

While boron nitride(BN) is widely recognized as the most promising thermally conductive filler for rapidly developing high-power electronic devices due to its excellent thermal conductivity and dielectric properties,a great challenge is the poor vertical thermal conductivity when embedded in composites owing to the poor interracial interaction causing severe phonon scattering.Here,we report a novel surface modification strategy called the "self-modified nanointerface" using BN nanocrystals(BNNCs) to efficiently link the interface between BN and the polymer matrix.Combining with ice-press assembly method,an only 25 wt% BNembedded composite film can not only possess an in-plane thermal conductivity of 20.3 W m-1K-1but also,more importantly,achieve a through-plane thermal conductivity as high as 21.3 W m-1K-1,which is more than twice the reported maximum due to the ideal phonon spectrum matching between BNNCs and BN fillers,the strong interaction between the self-modified fillers and polymer matrix,as well as ladder-structured BN skeleton.The excellent thermal conductivity has been verified by theoretical calculations and the heat dissipation of a CPU.This study provides an innovative design principle to tailor composite interfaces and opens up a new path to develop high-performance composites.

Active straining engineering on self-assembled stacked Ni-based hybrid electrode for ultra-low overpotential

Generating sufficient strains on metal surfaces are highly challenging owing to that most metals can deform plastically to relax the strains on the surfaces.In this work,we developed a facile but highly efficient stacked deposition strategy to in situ activation and reconstruction of NiO/NiOOH on Ni matrix,following with the migration of Fe ions to NiOOH.The Fe sites on the Ni/NiO/NiOOH facilitate the formation of the stable*OH oxygenated intermediates,and the Ni matrix in the catalyst provides the catalyst excellent stability.The oxygen evolution reaction(OER)performance of the stacked NiFe-5 with compressive strain displays the strengthened binding to oxygenated intermediates and superior OER activity,the ultralow overpotentials of 162 versus reversible hydrogen electrode at 10 mA cm^(-2).On the other hand,the Ni-5 without the incorporation of Fe has shown an outstanding hydrogen evolution reaction(HER)activity,affording an overpotential of 47 mV at 10 mA cm^(-2).The NiFe-5‖Ni-5 enables the overall water splitting at a voltage of 1.508 V to achieve 20 mA cm^(-2) with remarkable durability.The stacked deposition strategy improves binding strength of Ni-based catalysts to oxygenated intermediates via generating compressive strain,causing high catalytic activities on OER and HER.

Critical illness polyneuropathy and myopathy:a systematic review

Critical illness polyneuropathy and critical illness myopathy are frequent complications of severe illness that involve sensorimotor axons and skeletal muscles, respectively. Clinically, they manifest as limb and respiratory muscle weakness. Critical illness polyneuropathy/myopathy in isolation or combination increases intensive care unit morbidity via the inability or difficulty in weaning these patients off mechanical ventilation. Many patients continue to suffer from decreased exercise capacity and compromised quality of life for months to years after the acute event. Substantial progress has been made lately in the understanding of the pathophysiology of critical illness polyneuropathy and myopathy. Clinical and ancillary test results should be carefully interpreted to differentiate critical illness polyneuropathy/myopathy from similar weaknesses in this patient population. The present review is aimed at providing the latest knowledge concerning the pathophysiology of critical illness polyneuropathy/myopathy along with relevant clinical, diagnostic, differentiating, and treatment information for this debilitat- ing neurological disease.

Review:Fabrication and Application of Zwitterion-based Functional Coatings

Zwitterion-based materials by virtue of their special physical and chemical characteristics have attracted researchers to utilize them for fabricating functional coatings. The simultaneous presence of positive and negative charges renders the zwitterion-based materials with electrostatically induced hydration properties, which enables a high resistance towards oily pollutants, nonspecific protein adsorption, bacterial adhesion and biofilm formation. This review starts from the working mechanism of zwitterions and covers the fabrication strategies of zwitterion-based functional coatings, namely the zwitterion-bearing binder route, the zwitterion-bearing additive route and the post-generation of coatings containing zwitterionic precursors. The applications of zwitterion-based functional coatings are discussed, including medical implants, marine antifouling and oil-resistant coatings, with focus on the relevant mechanisms of the zwitterion-containing coatings for a specific performance. Finally, some comments and perspectives on the current situation and future development of zwitterion-based functional coatings are given.

Evaluation of a <i>Brassica napus</i>Auxin-Repressed Gene Induced by Flea Beetle Damage and <i>Sclerotinia sclerotiorum</i>Infection

Biotic stresses negatively affect canola growth and production. Flea beetle damage and Sclerotinia sclerotiorum (S. sclerotiorum) infection are two of the worst biotic stresses for canola. Auxin Repressed Proteins (ARPs) responsive to several abiotic stresses have been reported. However, information about ARPs induced by Flea beetle damage and S. sclerotiorum infection, their roles in biotic stress tolerance are still lacking in canola. ESTs for an Auxin Repressed Protein 1 (BnARP1) were highly represented (expressed) in a Brassica napus subtractive library developed after leaf damage by the crucifer flea beetle (Phyllotreta cruciferae). Expression of this gene was under different developmental control in B. napus, and it was co-induced in B. napus by flea beetle feeding, S. sclerotiorum infection, drought and cold. A total of 25 BnARP genes were represented in different B. napus stress and development EST libraries and indicated larger, diversified families than known earlier. Dwarf phenotypes, primary root growth inhibition, lateral root enhancement, reduced sensitivity to 2, 4-D, and reduced PIN1 and LOX expression in transgenic Arabidopsis expression lines suggest that BnARP1 is an auxin repressor that prevents auxin transport and supports an interaction between the auxin and jasmonate signalling pathways. And the increased survival after S. sclerotiorum infection in transgenic over-expression Arabidopsis suggests that BnARP1 could play a role in S. sclerotiorum tolerance through connecting auxin and jasmonate signalling pathways.

Realizing optimized interfacial polarization and impedance matching with CNT-confined Co nanoparticles in hollow carbon microspheres for enhanced microwave absorption

The hollow porous structure with exceptional interfacial effect and customizable internal environment shows significant potential for application as electromagnetic shielding and absorption materials.However,designing hollow porous electromagnetic absorbers with both desirable impedance matching and high loss capability remains a challenge.Herein,3D hollow porous electromagnetic microspheres were constructed by assembling 0D Co magnetic nanoparticles,1D carbon nanotubes,and 2D carbon nanosheets.Due to the sufficient sites for Co^(2+)riveting,the high loading of magnetic carbon nanotubes(CoNC)and porous carbon spheres formed high-density interfaces,enhancing the interfacial polarization.Furthermore,high-density CoNC were grown in situ on the hollow porous carbon(HPC)microsphere,forming a highly dispersed 3D magnetic network that inhibited the aggregation of magnetic nanoparticles and enhanced magnetic coupling.Therefore,the asprepared CoNC/HPC microspheres exhibited excellent microwave absorption(MA)performance,with a minimum reflection loss of-33.2 dB and an effective bandwidth of 5.5 GHz at a thickness of only 1.8 mm.The interfacial polarization mechanism for enhanced MA performance was demonstrated by electron holography and density functional theory calculations.Magnetic holography and micromagnetic simulations also revealed magnetic confinement and coupling mechanism.This work provides a new approach for designing electromagnetic absorbers with optimized impedance matching and loss capability.

Asymmetric Cu Sites for Enhanced CO_(2)Electroreduction to C_(2+)Products

Cu-based electrocatalysts can have excellent activity for the generation of C_(2+)products from a CO_(2)reduction reaction(CO_(2)RR).Cuδ+species is crucial in tuning the performance of the catalysts.Herein,we discovered that Si-doped Cu catalysts had excellent performance for electrochemical CO_(2)to C_(2+)products.A high Faradaic efficiency(FE)of 84.7%was achieved with a current density of 289mA cm^(−2)in the flow-cell system.In situ experimental results showed that the significant reconstruction occurred during the electrolysis,resulting in the formation of the asymmetric Cu sites(Cu^(0)-Cu^(+)).The ratio of Cu^(0)and Cu^(+)could be tuned by changing Si content.Controlled experiments and theoretical calculations demonstrated that the asymmetric Cu sites caused by the appropriate Si doping promoted CO_(2)activation and strengthened the adsorption of^(*)CO intermediate.This was beneficial to the subsequent^(*)CO–^(*)CO dimerization step,and thus,accounted for the enhancement of C_(2+)selectivity.

Efficient nitrate electroreduction over Mn-doped Cu catalyst via regulating N-containing intermediates adsorption configuration

The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to its sluggish kinetics,multiple intermediates,and various reaction pathways.In this study,Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO_(3)^(-)-to-NH_(3)conversion.The doping of Mn into Cu resulted in exceptional performance,achieving a FE of 95.8%and an NH_(3)yield rate of 0.91 mol g^(-1)h^(-1)at-0.6 V in a neutral electrolyte at low NO_(3)^(-)concentration.Detailed experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO_(2)~--to-NH_(3)and induced a distinct configuration of*NO.This alteration decreased the energy barrier of*NO-to-*NOH,consequently promoting the conversion of NO_(3)^(-)-to-NH_(3).

Two-dimensional perovskite Pb_(2)Nb_(3)O_(10) photodetectors

For the first time,we report high-performance two-dimensional(2D)perovskite Pb_(2)Nb_(3)O_(10) photodetectors(PNO PDs).The few-layer PNO nanosheets are obtained successfully through a simple calcination and liquid exfoliation method.The individual PNO nanosheet devices with various structures(Au-PNO-Au,Au-PNO-Ti,Ti-PNO-Ti)are fabricated and investigated.The Au-PNO-Ti device exhibits a high rectification factor(∼102)owing to a large Schottky barrier difference between the PNO nanosheet and two asymmetric electrodes.Notably,the Au-PNO-Ti device shows excellent self-powered performance,including high responsivity(2.8 A/W),high detectivity(1.1×10^(12) Jones),and fast speed(0.2/1.2 ms)at 350 nm light illumination.This work not only suggests the performance of the PNO nanosheet PDs but also sheds light on the development of high-stability and high-performance devices based on 2D perovskite niobate in the future.

Hierarchical polypyrrole@cobalt sulfide-based flexible on-chip microsupercapacitors with ultrahigh energy density for selfcharging system

Herein,we prepare the unique hierarchical polypyrrole@cobalt sulfide(PPy-hs@CoS)hollow sphere-based nanofilms as interdigitated electrodes for flexible on-chip micro-supercapacitors(MSC).Benefiting from the excellent flexibility and high electrical conductivity of PPy-hs combined with the great electrochemical activity of CoS,such PPy-hs@CoS composite material can not only inhibit the volume expansion of PPy but also promote the diffusion of the electrolyte ions.The PPy-hs@CoS filmbased electrode delivers a greatly improved specific capacitance and small resistance.Density functional theory calculations infer that OH−prefers to bind to PPy on CoS@PPy and confirms the synergistic effect of each component for enhanced reaction kinetics.A quasi-solid-state on-chip flexible asymmetric MSC based on PPy-hs@CoS and activated carbon(AC)microelectrodes exhibits large areal-specific capacitance(131.9 mF/cm2 at 0.3 mA/cm2),ultrahigh energy density(0.041 mWh/cm2@0.224 mW/cm2 and 25.6 mWh/cm3@140.6 mW/cm3),and long cycle lifespan.We demonstrate the possibility to scale up the PPy-hs@CoS nanofilm microelectrode by arranging two of our asymmetric MSC in series and parallel connections,which respectively increase the output voltage and current.A self-charging system by connecting our asymmetric MSCs with a piece of commercial solar cells is developed as a potential possible mode for future highly durable and high-voltage integrated electronics.

Scalable and flexible porous hybrid film as a thermal insulating subambient radiative cooler for energy-saving buildings

Passive daytime radiative cooling(PDRC)is one of the promising alternatives to electrical cooling and has a significant impact on worldwide energy consumption and carbon neutrality.Toward real-world applications,however,the parasitic heat input and heat leakage pose crucial challenges to commercial and residential buildings cooling.The integrating of radiative cooling and thermal insulation properties represents an attractive direction in renewable energy-efficient building envelope materials.Herein,we present a hierarchically porous hybrid film as a scalable and flexible thermal insulating subambient radiative cooler via a simple and inexpensive inverse high internal phase emulsion strategy.The as-prepared porous hybrid film exhibits an intrinsic combination of high solar reflectance(0.95),strong longwave infrared thermal emittance(0.97),and low thermal conductivity(31 mW/(m K)),yielding a subambient cooling temperature of~8.4℃ during the night and~6.5℃ during the hot midday with an average cooling power of~94 W/m^(2) under a solar intensity of~900 W/m^(2).Promisingly,combining the superhydrophobicity,durability,superelasticity,robust mechanical strength,and industrial applicability,the film is favorable for large-scale,sustainable and energy-saving applications in a wide variety of climates and complicated surfaces,enabling a substantial reduction of energy costs,greenhouse gas emission and associated ozone-depleting from traditional cooling systems.

Influence of patellofemoral joint degeneration on clinical outcomes after medial unicompartmental knee arthroplasty

Background:Patellofemoral joint(PFJ)degeneration has traditionally been regarded as a contraindication to unicompartmental knee arthroplasty(UKA).More recently,some researchers have proposed that PFJ degeneration can be ignored in medial UKA,and others have proposed that this change should be reviewed in PFJ degenerative facets and severity.This study aimed to systematically evaluate the effect of PFJ degeneration on patient-reported outcome measures(PROMs)and revision rates after medial UKA.Methods:Electronic databases(PubMed,Embase,Web of Science,etc.)were searched for studies assessing the influence of PFJ degeneration on medial UKA.A random-effects meta-analysis was conducted for the Oxford knee score(OKS),Knee society score(KSS),and revision rates and stratified by PFJ degenerative facets(medial/lateral/trochlear/unspecified),severe PFJ degeneration(bone exposed),and bearing type(mobile/fixed).Heterogeneity was assessed by the Cochran Q test statistic and chi-squared tests with the I-squared statistic.Results:A total of 34 articles with 7007 knees(2267 with PFJ degeneration)were included(5762 mobile-bearing and 1145 fixed-bearing and 100 unspecified).Slight to moderate degenerative changes in the medial and trochlear facets did not decrease the OKS and KSS,and only lateral facets significantly decreased the OKS(mean difference[MD]=-2.18,P<0.01)and KSS(MD=-2.61,P<0.01).The severity degree of PFJ degeneration had no additional adverse effect on the OKS,KSS,or revision rates.For mobile-bearing UKA,only lateral PFJ degeneration significantly decreased the OKS(MD=-2.21,P<0.01)and KSS(MD=-2.44,P<0.01).For fixed-bearing UKA,no correlation was found between PROMs/revision rates and PFJ degeneration.Conclusion:For medial mobile-bearing UKA,slight to moderate degenerative changes in the PFJ,except lateral facet,did not compromise PROMs or revision rates.For medial fixed-bearing UKA,although it might not be conclusive enough,PROMs or revision rates were not adversely affected by PFJ degeneration(regardless of the facet).

Determining the contribution of Mo single atoms components in MoO_(2)nanocatalyst in transfer hydrogenation

Nanocatalysts are likely to contain undetected single-atom components,which may have been ignored but have significant effect in catalytic reactions.Herein,we report a catalyst composed of Mo single atoms(SAs)and MoO_(2)nanoparticles(NPs)(MoSAs-MoO_(2)@NC),which is an exact model to understand how the SAs contribute to the nanocatalyst.Both experimental results and the density functional theory calculations reveal that Mo SAs on nitrogen-doped carbon provides the reaction zone for nitro reduction,while MoO_(2)is the active site for decomposing hydrazine hydrate to produce H*.Thanks to the synergy between Mo SAs and MoO_(2)NPs,this catalyst exhibits noble metal-like catalytic activity(100%conversion at 4 min)for the dechlorination-proof transfer hydrogenation.Additionally,the hydrogen migration on the catalyst is verified by the electrochemical tests in the absence of a hydrogen source.This work provides a model for further study on the coexistence of single atoms in nanoparticle catalysts.

Comparison of clinical outcomes among total knee arthroplasties using posterior-stabilized,cruciate-retaining,bi-cruciate substituting,bi-cruciate retaining designs:a systematic review and network meta-analysis

Background:Despite the advent of innovative knee prosthesis design,a consistent first-option knee implant design in total knee arthroplasty(TKA)remained unsettled.This study aimed to compare the clinical effects among posterior-stabilized(PS),cruciate-retaining(CR),bi-cruciate substituting(BCS),and bi-cruciate retaining designs for primary TKA.Methods:Electronic databases were systematically searched to identify eligible randomized controlled trials(RCTs)and cohort studies from inception up to July 30,2021.The primary outcomes were the range of knee motion(ROM),and the secondary outcomes were the patient-reported outcome measures(PROMs)and complication and revision rates.Confidence in evidence was assessed using Confidence in Network Meta-Analysis.The Bayesian network meta-analysis was performed for synthesis.Results:A total of 15 RCTs and 18 cohort studies involving 3520 knees were included.The heterogeneity and inconsistency were acceptable.There was a significant difference in ROM at the early follow-up when PS was compared with CR(mean difference[MD]=3.17,95%confidence interval[CI]0.07,7.18)and BCS was compared with CR(MD=9.69,95%CI 2.18,17.51).But at the long-term follow-up,there was no significant difference in ROM in any one knee implant compared with the others.No significant increase was found in the PROMs and complication and revision rates at the final follow-up time.Conclusions:At early follow-up after TKA,PS and BCS knee implants significantly outperform the CR knee implant in ROM.But in the long run,the available evidence suggests different knee prostheses could make no difference in clinical outcomes after TKA with extended follow-up.

“Zero‑Strain” NiNb_(2)O_(6) Fibers for All‑Climate Lithium Storage

Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term cyclability.Here,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical properties.During Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O movement.Such superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.

Trithorax Group Proteins Act Together with a Polycomb Group Protein to Maintain Chromatin Integrity for Epigenetic Silencing during Seed Germination in Arabidopsis

Polycomb group （PcG） and trithorax group （trxG） proteins have been shown to act antagonistically to epigenetically regulate gene expression in eukaryotes. The trxG proteins counteract PcG-mediated floral repression in Arabidopsis, but their roles in other developmental processes are poorly understood. We investigated the interactions between the trxG genes, ARABIDOPSIS HOMOLOG OF TRITHORAX1 （ATX1） and ULTRAPETALA1 （ULT1）, and the PcG gene EMBRYONIC FLOWER 1 （EMF1） during early development. Unexpectedly, we found that mutations in the trxG genes failed to rescue the early-flowering phenotype of emfl mutants. Instead, emfl atxl ultl seedlings showed a novel swollen root phenotype and massive deregulation of gene expression. Greater ectopic expression of seed master regulatory genes in emfl atxl ultl triple than in emfl single mutants indicates that PcG and trxG factors together repress seed gene expression after germination. Furthermore, we found that the widespread gene derepression is asso- ciated with reduced levels of H3K27me3, an epigenetic repressive mark of gene expression, and with globally altered chromatin organization. EMF1, ATXl, and ULT1 are able to bind the chromatin of seed genes and ULT1 can physically interact with ATX1 and EMF1, suggesting that the trxG and EMF1 proteins directly associate at target gene loci for EMFl-mediated gene silencing. Thus, while ATXl, ULT1, and EMF1 interact antagonistically to regulate flowering, they work together to maintain chromatin integrity and prevent precocious seed gene expression after germination.

Molecular regulation of sucrose catabolism and sugar transport for development~ defence and phloem function

Sucrose （Suc） is the major end product of photosynthesis in mesophyll cells of most vascular plants. It is loaded into phloem of mature leaves for long-distance translocation to non-photosynthetic organs where it is unloaded for diverse uses. Clearly, Suc transport and metabolism is central to plant growth and development and the functionality of the entire vascular system. Despite vast information in the literature about the physiological roles of individual sugar metabolic enzymes and transporters, there is a lack of systematic evaluation about their molecular regulation from transcriptional to post-translational levels. Knowledge on this topic is essential for understanding and improving plant development, optimizing resource distri- bution and increasing crop productivity. We therefore focused our analyses on molecular control of key players in Suc metabolism and transport, including： （i） the identifica- tion of promoter elements responsive to sugars and hormones or targeted by transcription factors and micro- RNAs degrading transcripts of target genes; and （ii） modulation of enzyme and transporter activities through protein-protein interactions and other post-translational modifications. We have highlighted major remaining questions and discussed opportunities to exploit current understanding to gain new insights into molecular control of carbon partitioning for improving plant performance.

Integration of filter membrane and Ca_(2)Nb_(3)O_(10) nanosheets for high performance flexible UV photodetectors

We report that the integration of filter membrane and Ca_(2)Nb_(3)O_(10)nanosheets(FM@CNO) UV photodetector(UV PD) shows high performance and excellent flexibility. The Ca_(2)Nb_(3)O_(10)nanosheets were prepared by a facile solid-state reaction and liquid exfoliation process. The Ca_(2)Nb_(3)O_(10)nanosheets can be integrated into the pores of a filter membrane via a simple vacuum filtration method. The FM@CNO UV PD shows high performance under 300 nm light illumination at 5 V bias, including high responsivity(0.08 AW^(-1)), high detectivity(1.1 × 10^(12)Jones), high UV/visible rejection ratio(3.86 × 10^(3)) and fast speed(0.12/1.24 ms). Furthermore, the FM@CNO device exhibits excellent flexibility after many bending cycles.In addition, the FM@CNO array device was used as a pixel array detector for UV imaging. This work provides a novel approach to achieve high performance flexible PDs based on filter membrane and two dimensional materials.

Analysis of uterine CD49a^(+) NK cell subsets in menstrual blood reflects endometrial status and association with recurrent spontaneous abortion

Maternal uterine immune cells,especially natural killer(NK)cells,are important for successful pregnancy,and an abnormal number or function of uterine NK cells is closely correlated with an impaired endometrial environment and miscarriage.However,there are currently no noninvasive testing methods using reliable indicators that accurately predict uterine changes leading to miscarriage.Here,we confirmed that before implantation,menstrual blood(MB)from healthy donors had 70%CD49a^(+)tissue-resident NK(trNK)cells,the majority of which were CD49a^(+)Eomes+NK cells.Importantly,MB from patients with recurrent spontaneous abortion(RSA)had many fewer CD49a^(+)trNK cells than MB from controls.Analysis of uNK cell populations in MB may better predict an abnormal endometrial environment associated with miscarriage than peripheral blood(PB)analysis.Therefore,we suggest using MB-and CD49a-related markers as a promising noninvasive way to evaluate endometrial status.