With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Ni...With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Nickel-based catalysts are renowned for their outstanding activity and selectivity in this process.The impact of metal-support interaction(MSI),on Ni-based catalyst performance has been extensively researched and debated recently.This paper reviews the recent research progress of MSI on Ni-based catalysts and their characterization and modulation strategies in catalytic reactions.From the perspective of MSI,the effects of different carriers(metal oxides,carbon materials and molecular sieves,etc.)are introduced on the dispersion and surface structure of Ni active metal particles,and the effect of MSI on the activity and stability of DRM reactions on Ni-based catalysts is discussed in detail.Future research should focus on better understanding and controlling MSI to improve the performance and durability of nickel-based catalysts in CH_(4)-CO_(2)reforming,advancing cleaner energy technologies.展开更多
By simplifying catalyst-product separation and reducing phosphorus waste,heterogeneous hydroformylation offers a more sustainable alternative to homogeneous processes.However,heterogeneous hydroformylation catalysts d...By simplifying catalyst-product separation and reducing phosphorus waste,heterogeneous hydroformylation offers a more sustainable alternative to homogeneous processes.However,heterogeneous hydroformylation catalysts developed thus far still suffer from the issues of much lower activity and metal leaching,which severely hinder their practical application.Here,we demonstrate that incorporating phosphorus(P)atoms into graphitic carbon nitride(PCN)supports facilitates charge transfer from Rh to the PCN support,thus largely enhancing electronic metal-support interactions(EMSIs).In the styrene hydroformylation reaction,the activity of Rh_(1)/PCN single-atom catalysts(SACs)with varying P contents exhibited a volcano-shaped relationship with P doping,where the Rh_(1)/PCN SAC with optimal P doping showed exceptional activity,approximately 5.8-and 3.3-fold greater than that of the Rh_(1)/g-C_(3)N_(4)SAC without P doping and the industrial homogeneous catalyst HRh(CO)(PPh_(3))_(3),respectively.In addition,the optimal Rh_(1)/PCN SAC catalyst also demonstrated largely enhanced multicycle stability without any visible metal aggregation owing to the increased EMSIs,which sharply differed from the severe metal aggregation of large nanoparticles on the Rh_(1)/g-C_(3)N_(4)SAC.Mechan-istic studies revealed that the enhanced catalytic performance could be attributed to electron-deficient Rh species,which reduced CO adsorption while simultaneously promoting alkene adsorption through increased EMSIs.These findings suggest that tuning EMSIs is an effective way to achieve SACs with high activity and durability.展开更多
Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,medi...Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,mediated by suitable optical media.There are many emerging photonic applications of spin-orbit interactions(SOI)of light,such as control of the optical wave propagation via the spin,enhanced optical manipulation,and generation of structured optical fields.Unfortunately,current applications are based on symmetric SOI,that is,the behaviours of polarized photons with two opposite spins are opposite,leading to the limit of spin-based multiplexers.The symmetry of SOI can be broken in our proposed metasurfaces,consisting of spatially varying birefringence,which can arbitrarily and independently build SOI for two opposite spins without reduction of optical energy usage.We obtain three kinds of dual-functional metasurfaces at visible and infrared wavelengths with high efficiency.Our concept of generation of asymmetric SOI for two spins,using anisotropic metasurfaces,will open new degrees of freedoms for building new types of spin-controlled multifunctional shared-aperture devices for the generation of complex structured optical fields.展开更多
Human-object interaction(HOIs)detection is a new branch of visual relationship detection,which plays an important role in the field of image understanding.Because of the complexity and diversity of image content,the d...Human-object interaction(HOIs)detection is a new branch of visual relationship detection,which plays an important role in the field of image understanding.Because of the complexity and diversity of image content,the detection of HOIs is still an onerous challenge.Unlike most of the current works for HOIs detection which only rely on the pairwise information of a human and an object,we propose a graph-based HOIs detection method that models context and global structure information.Firstly,to better utilize the relations between humans and objects,the detected humans and objects are regarded as nodes to construct a fully connected undirected graph,and the graph is pruned to obtain an HOI graph that only preserving the edges connecting human and object nodes.Then,in order to obtain more robust features of human and object nodes,two different attention-based feature extraction networks are proposed,which model global and local contexts respectively.Finally,the graph attention network is introduced to pass messages between different nodes in the HOI graph iteratively,and detect the potential HOIs.Experiments on V-COCO and HICO-DET datasets verify the effectiveness of the proposed method,and show that it is superior to many existing methods.展开更多
Mineral–microbe interactions indirectly affect the geochemical fluxes and biogeochemical cycling of a large number of elements. Among them are toxic heavy metals (e.g. chromium), radionuclides (uranium and technetium...Mineral–microbe interactions indirectly affect the geochemical fluxes and biogeochemical cycling of a large number of elements. Among them are toxic heavy metals (e.g. chromium), radionuclides (uranium and technetium), and nitrogen. Heavy metals and radionuclides enter the environment from various sources such as mining activity, nuclear weapons production, metallurgical and chemical industries. Other metals, such as lead, arsenic, antimony, and cadmium, are enriched in certain environments by either natural or anthropogenic processes. Because many of these metals and radionuclides are carcinogens, their release into the environment and their fate cause intense scientific and public concern and are the subject of substantial research. Nitrate enters the environment largely through agricultural activity. Human health risks from nitrate uptake from drinking water supplies run the gamut from increased cancer risk to birth defects.展开更多
The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of inter...The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of interest for improving crop management and developing new strategies for plant diseases control. The aim of this work is to investigate the components involved in this interaction and, for this purpose, a proteomic approach was used. 2-D maps of the protein extracts from the single components in various interactions between plants (potato, bean, tobacco or tomato), pathogens (Botrytis cinerea, Rhizoctonia solani or Pythium ultimum) and biocontrol fungi (Trichoderma atroviride strain P1 or Trichoderma harzianum strain T22) were obtained. The proteome of each partner was collected separately and extracted by acetone precipitation in presence of trichloroacetic acid and a reducing agent (DTT). The extracted proteins were separated by isoelectrofocusing (IEF), using IPG (Immobilized pH gradient) strips, followed by SDS-PAGE. In order to improve resolution the separations were performed both on wide than narrow pH range and on different gel lengths. Differential spots were noted in the proteome of the three-way interaction when compared to each single component. These were further characterized by mass spectrometry and in silico analysis with the aim of identifying and cloning the relative genes. During the in vitro interaction of T. harzianum strain T22 with tomato and the culture filtrate or cell walls of pathogens, the spot number was higher than in the presence of pathogen biomass. In terms of Trichoderma differential proteins displayed on 2D gels, the most important changes were obtained in the presence of P. ultimum . During the in vivo interaction with tomato, the antagonist proteome changed much more in presence of soilborne fungi R. solani and P. ultimum than with the foliar fungus B. cinerea, both in terms of total and increased or novel spots. In silico analysis of some of those spots revealed homology with intracellular enzymes (GTPases, hydrolases) and with stress-related proteins (heat shock proteins HSP70, bacteriocin cloacin). Specific proteins in the plant proteome, i.e. pathogenesis-related proteins, have been identified during the in vivo interaction of bean with R. solani and T. atroviride strain P1. This is in agreement with the demonstrated ability of these beneficial fungi to induce plant systemic disease resistance by activating expression of defence-related genes. Proteins extracted from T. atrovride strain P1 which were analysed by mass spectrometry, revealed some interesting homologies with a fungal hydrophobin of Pleurotus ostreatus and an ABC transporter of Ralstonia metallidurans. These could represent molecular factors involved in the antagonistic mechanisms of Trichoderma and play a role in the three-way interaction with the plant and other microbes.展开更多
Studying the microstructure and intermolecular interactions of ionic liquid(IL)systems is of great importance.In this work,molecular dynamics(MD)simulations were performed on 1-butyl-3-methylimidazolium hexafluorophos...Studying the microstructure and intermolecular interactions of ionic liquid(IL)systems is of great importance.In this work,molecular dynamics(MD)simulations were performed on 1-butyl-3-methylimidazolium hexafluorophosphate([Bmim][PF6])+water+ethanol and[Bmim][PF6]+water+isopropanol ternary systems.Radial distribution functions were calculated,and the interaction energies between ion pairs and mixed solvents of different compositions were decomposed into Coulombic interaction energies and Lennard-Jones(LJ)potentials.The microstructure and intermolecular interactions of the ternary systems were studied based on the results,and the phase behaviors of the systems were discussed.The results show that water tends to interact with the anion and polar part of the cation,while alcohols prefer to interact with the anion and nonpolar part of the cation.The Coulombic interaction dominates over the anion-solvent interaction,while the LJ interaction dominates over the cation-solvent interaction.The association state of the ion pair has a smal effect on the LJ interaction,but a significant effect on the Coulombic interaction.展开更多
The hydration film on particle surface plays an important role in bubble-particle adhesion in mineral flotation process. The thicknesses of the hydration films on natural hydrophobic coal and hydrophilic mica surfaces...The hydration film on particle surface plays an important role in bubble-particle adhesion in mineral flotation process. The thicknesses of the hydration films on natural hydrophobic coal and hydrophilic mica surfaces were measured directly by atomic force microscopy (AFM) based on the bending mode of the nominal constant compliance regime in AFM force curve in the present study. Surface and solid-liquid interfacial energies were calculated to explain the forming mechanism of the hydration film and atomic force microscopy data. The results show that there are significant differences in the structure and thickness of hydration films on coal and mica surfaces. Hydration film formed on mica surface with the thickness of 22.5 nm. In contrast, the bend was not detected in the nominal constant compliance regime. The van der Waals and polar interactions between both mica and coal and water molecules are characterized by an attractive effect, while the polar attractive free energy between water and mica (-87.36 mN/m) is significantly larger than that between water and coal (-32.89 mN/m), which leads to a thicker and firmer hydration layer on the mica surface. The interfacial interaction free energy of the coal/water/bubble is greater than that of mica. The polar attractive force is large enough to overcome the repulsive van der Waals force and the low energy barrier of film rupture, achieving coal particle bubble adhesion with a total interfacial free energy of-56.30 mN/m.展开更多
Taking into consideration the gas compressibility and chemical reaction reversibility, a model was developed to study the interactions between gas flow and chemical reaction in porous media and resolved by the finite ...Taking into consideration the gas compressibility and chemical reaction reversibility, a model was developed to study the interactions between gas flow and chemical reaction in porous media and resolved by the finite volume method on the basis of the gas-solid reaction aA(g)+bB(s)cC(g)+dD(s).The numerical analysis shows that the equilibrium constant is an important factor influencing the process of gas-solid reaction. The stoichiometric coefficients, molar masses of reactant gas, product gas and inert gas are the main factors influencing the density of gas mixture. The equilibrium constant influences the gas flow in porous media obviously when the stoichiometric coefficients satisfy a/c≠1.展开更多
Two copper(Ⅰ)coordination polymers,{[Cu_(2)(4-bpo)_(2)(CH_(3)CN)_(2)(PPh_(3))_(2)](BF_(4))_(2)}_(n)(1),{[Cu(4-bpo)(CH3CN)(dppe)_(0.5)]BF_(4)}_(n)(2)(PPh_(3)=triphenylphosphine,dppe=1,2-bis(diphenyl phosphino)ethane,4...Two copper(Ⅰ)coordination polymers,{[Cu_(2)(4-bpo)_(2)(CH_(3)CN)_(2)(PPh_(3))_(2)](BF_(4))_(2)}_(n)(1),{[Cu(4-bpo)(CH3CN)(dppe)_(0.5)]BF_(4)}_(n)(2)(PPh_(3)=triphenylphosphine,dppe=1,2-bis(diphenyl phosphino)ethane,4-bpo=2,5-bis(4-pyridyl)-1,3,4-oxadiazole),have been synthesized and characterized by IR,^(1)H NMR,^(19)F NMR,^(11)B NMR,elemental analysis and X-ray crystal structure analysis.The structural analysis shows that complexes 1 and 2 consist of diverse and interesting 2D supramolecular structures formed by inter-chain interactions.For 1,π-stacking interactions result in the construction of 1D bilayer chain and 2D supramolecular network.Compound 2 exhibits a 1D ladder-like chain and a 1D+1D→2D/3D supramolecular structure formed byπ-stacking interactions.Solid-state emission spectra of complexes 1 and 2 have been studied,displaying the existence of ILCT/MLCT excited states.展开更多
In order to implement cost-effective machining of gr anite materials with diamond impregnated tools, we should realize low tool w ear, low energy consumption, and high cutting efficiency, while the accuracy of the wor...In order to implement cost-effective machining of gr anite materials with diamond impregnated tools, we should realize low tool w ear, low energy consumption, and high cutting efficiency, while the accuracy of the workpiece surfaces are maintained to be satisfactory. It is understood that the main factors affecting the tool wear, the energy, and the efficiency during the machining process are related to the tribological interactions that occur at the interface between the diamond tool surface and the workpiece. Based on this consideration, we propose a new machining method to machine granite materia ls to achieve improved cost effectiveness. In the proposed method, the tribologi cal interactions are maintained to a minimum. Based on the analyses of the experimental results, the following conclusions can be drawn: The wear performance is greatly dependent on the machining parameters and their combination. Therefore, optimum machining parameters must be set up at first in order to optimize the tribological characteristics of segments and thereby sawbl ade performance. These may be realized by balancing the energy expended by frict ion and the mechanical load on diamond crystal. The geometry and structure of diamond segments are another important criterion f or the diamond saw blade. Using a seven-layer structure for multi-blades sawin g and applying segments with side slots for trimming application had greatly red uced the frictions in the sawing processes. The wetting and bonding between diamonds and matrix alloys have been considered as the prerequisite for high wear performance of the segments. Diamonds coated w ith Ti-Cr alloy by a unique technique can effectively improve its wetting c apability and provide more storage space for debris, thereby reducing friction i nteractions.展开更多
An in-depth analysis on the cooperativity of intermolecular interactions including hydrogen bonding andπ-π stacking in 1,3,5-triamino-2,4,6-trinitrobenzene(TATB) crystal was studied. Two quantities, cooperativity ra...An in-depth analysis on the cooperativity of intermolecular interactions including hydrogen bonding andπ-π stacking in 1,3,5-triamino-2,4,6-trinitrobenzene(TATB) crystal was studied. Two quantities, cooperativity rate and energy, were defined to evaluate the nature and strength of cooperativity in a series of clusters diverging from 1D to 3D prototypes. The origin and mechanism of the cooperative effect were settled to demonstrate that the nature of cooperativity is determined by whether the non-covalent interactions compete or promote with each other, which is manifested by the changing trend of electron transfer. There exists obvious cooperative effect in intra-layer and inter-layer structures as they own the equivalent non-covalent interactions, while anti-cooperative effect is also observed if two interactions correlate with each other. On the whole, in the process of crystal formation, the apparent cooperativity is the check and balance of the two effects, which is capable to support a global interaction among all of molecules and contribute to the stabilization of system. Based on the results, one may get a new insight to understand the relationship between non-covalent interactions and low impact sensitivity.展开更多
The finite element method was used to solve fluid dynamic interaction problems between the crust and mantle of the Earth. To consider different mechanical behaviours, the lithosphere consisting of the crust and upper ...The finite element method was used to solve fluid dynamic interaction problems between the crust and mantle of the Earth. To consider different mechanical behaviours, the lithosphere consisting of the crust and upper mantle was simulated as fluid-saturated porous rocks, while the upper aesthenospheric part of the mantle was simulated as viscous fluids. Since the whole lithosphere was computationally simulated, the dynamic interaction between the crust and the upper mantle was appropriately considered. In particular, the mixing of mantle fluids and crustal fluids was simulated in the corresponding computational model. The related computational simulation results from an example problem demonstrate that the mantle fluids can flow into the crust and mix with the crustal fluids due to the resulting convective flows in the crust-mantle system. Likewise, the crustal fluids can also flow into the upper mantle and mix with the mantle fluids. This kind of fluids mixing and exchange is very important to the better understanding of the governing processes that control the ore body formation and mineralization in the upper crust of the Earth.展开更多
Nonlinear interactions between the quasi 5-day wave and tides based on meteor radar observation in the Mesosphere and Lower Thermosphere(MLT) at Maui are studied in this paper.Strong sum interaction between quasi 5-da...Nonlinear interactions between the quasi 5-day wave and tides based on meteor radar observation in the Mesosphere and Lower Thermosphere(MLT) at Maui are studied in this paper.Strong sum interaction between quasi 5-day wave and diurnal tide,and evident difference interaction between quasi 5-day wave and semidiurnal tide are observed during the time of attention.However,their difference and sum counterparts are clearly weaker.The secondary waves generated from those interactions beat with the tide and show intense modulation at the period of 5 days which confirms the existence of their interactions.Additionally,correlation coefficients among these waves are calculated to further explore their interactions and find that they can persist for several days although they are highly intermittent.The energy exchange among these waves can be reversible during the observational time.The periods when the significant difference interaction between the quasi 5-day wave and semidiurnal tide occur are much shorter than those when the significant sum interaction between the quasi 5-day wave and diurnal tide occur.Moreover,these two strong interactions can take place simultaneously.In generally,this study provides the proof of nonlinear interactions between quasi 5-day wave and tides which were seldom reported before.展开更多
Taking stearic acid as the raw material,N-(2-(dimethylamino)ethyl)stearamide(C18N2N)was synthesized.A new surfactant was prepared by mixing C18N2N and cinnamic acid(TA)with fixed ratio.This surfactant was formed by no...Taking stearic acid as the raw material,N-(2-(dimethylamino)ethyl)stearamide(C18N2N)was synthesized.A new surfactant was prepared by mixing C18N2N and cinnamic acid(TA)with fixed ratio.This surfactant was formed by noncovalent electrostatic interactions,which avoided complicated synthetic procedures.The surface activity and rheological properties of the surfactant were investigated with a surface tensiometer and a rheometer.The critical micelle concentration(cmc)and the surface tension at cmc(γ_(cmc))of the surfactant were 0.11 mmol/L and 32.4 mN/m,indicative of strong aggregation and adsorption ability.The maximum amount adsorbed(Γ_(max))and the minimum molecular area occupied(A_(min))were 2.77μmol/m^(2)and 0.6 nm^(2).Wormlike micelles were formed at the concentration of 25 mmol/L.When the concentration was over 100 mmol/L,the zero-shear viscosity(η_(0))abruptly increased and then reached the maximum value for the surfactant of C18N2N/TA containing 150 mmol/L TA.The solution viscosity was as high as 1761.38 Pa·s.The effects of temperature on the rheological behavior were also considered.With the increase of temperature,the viscosity gradually increased.And when the temperature reached 40℃,η_(0)of the solution with the concentration of 100 mmol/L achieved the maximum value of 1370.386 Pa·s.When the temperature continued to rise,η_(0)began to decrease with further increasing temperature.A remarkable viscosity of 305.55 Pa·s was still remained at 50℃.The viscoelastic solutions showed good temperature resistance and shear resistance.The surfactant solutions applied as the fracturing fluid were also investigated.This surfactant also showed excellent sand-carrying performance,and the settling rate of the sand was merely 0.26 cm/min.This surfactant could be simply prepared and showed excellent performance,which expanded the preparation and application field of novel surfactants.展开更多
The seminal report ofα-diimine palladium and nickel catalysts in 1995 represented a major breakthrough in the preparation of functionalized polyolefin materials.Owing to the high abundance and low cost of nickel,nick...The seminal report ofα-diimine palladium and nickel catalysts in 1995 represented a major breakthrough in the preparation of functionalized polyolefin materials.Owing to the high abundance and low cost of nickel,nickel-based catalysts have great application prospects in the industrialization process of olefin coordination polymerization.In this work,various N-aryl substituents with different electronic effects were synthesized and introduced intoα-diimine ligands.The aspreparedα-diimine nickel catalysts showed high polymerization activity(0.9×10^(7)–3.0×10^(7)g·mol^(−1)·h^(−1))in ethylene polymerization,generating polyethylene products with adjustable molecular weights(Mn values:7.4×10^(4)–146.9×10^(4)g·mol^(−1))and branching densities(31/1000 C–68/1000 C).The resulting polyethylene products showed excellent mechanical properties,with high tensile strength(up to 25.0 MPa)and high strain at break values(up to 3890%).The copolymerization of ethylene and polar monomers can also be achieved by these nicekel complexes,ultimately preparing functionalized polyolefins.展开更多
This article reviews the roles of host-microbe interactions in intestinal disorders and tumors from the perspective of host cell-microbial cell crosstalk.As a crucial environmental factor in the gut,gut microbiota sig...This article reviews the roles of host-microbe interactions in intestinal disorders and tumors from the perspective of host cell-microbial cell crosstalk.As a crucial environmental factor in the gut,gut microbiota significantly influences host intestinal pathologies and tumors,and this interaction is bidirectional.Gut microbes can directly adhere to and contact epithelial cells,activating intracellular signaling pathways and affecting the development of inflammation and cancer.Simultaneously,gut microbes can produce various proteins,secondary metabolites or exosomes;these bacterial-derived products can regulate intestinal epithelial cells,immune,and neuronal cells in a contact-independent manner,thereby influencing disease progression.Recent research has increasingly focused on the regulatory factors shaping the gut microbiota.Notably,the host has been identified as a key factor influencing gut microbiota.For instance,specific adhesion proteins on the surface of host intestinal cells,intestinal immunity,and even the host’s blood type can impact the composition and function of the gut microbiota.These altered microbial communities can,in turn,further affect the host’s intestine,influencing the progression of intestinal diseases and tumors.Therefore,elucidating the bidirectional interplay between the host and microbiota is essential for a deeper understanding of disease pathogenesis and will provide a theoretical foundation and guidance for the precise modulation of gut microbiota in the future.展开更多
Energetic materials face critical challenges in balancing energy density and safety,driving the development of low-sensitivity high-energy materials.Though vital for modern defense and civilian applications,low-sensit...Energetic materials face critical challenges in balancing energy density and safety,driving the development of low-sensitivity high-energy materials.Though vital for modern defense and civilian applications,low-sensitivity high-energy materials remain scarce,with 1,3,5-trinitro-2,4,6-triaminobenzene as the only deployed example.Planar lamellar energetic crystals,which utilize weak interlamellarπ-πstacking for mechanical energy dissipation,have shown significant promise.However,their rational design is constrained by insufficient understanding of intermolecular interaction synergy.This review synthesizes the structural features of planar lamellar energetic crystals,emphasizing three core elements:the single-atomic-thickness planar stacking architecture,the"strong intralamellar and weak interlamellar interaction"paradigm(key to balancing energy density and safety for low-sensitivity high-energy materials,LSHEMs),and the role of molecular planarity in reducing shear slip barriers.It categorizes design strategies into two frameworks:H–bonding dominated(single-component:cross-shaped assembly,strong H–bonding in high symmetric molecules;multi-component methods:tenon-and-mortise,acceptor-donor separation)and other intermolecular interactions(e.g.,π-πstacking-drivenπ-π2max model,π-hole recognition).Case studies in single/multi-component crystals confirm that these strategies tune interaction synergy to achieve target packing motifs.The review highlights that interaction engineering is pivotal for PLEC design,offering a targeted theoretical framework for rational development of LSHEMs(to address the scarcity of practical LSHEMs)and guiding future crystal engineering for energy-safety balanced systems.展开更多
Objective:Severe diastasis recti abdominis(DRA)in the postpartum period may lead to long‑term functional impairment in women.However,the independent effects and interactions of perinatal risk factors during the early ...Objective:Severe diastasis recti abdominis(DRA)in the postpartum period may lead to long‑term functional impairment in women.However,the independent effects and interactions of perinatal risk factors during the early postpartum recovery window have not been fully elucidated.This study aims to analyze the risk factors and interaction effects associated with severe postpartum DRA and to identify characteristics of high‑risk populations.Methods:This retrospective cohort study included postpartum women who underwent postpartum rehabilitation treatment at Hengyang Maternal and Child Health Hospital between January 2019 and August 2022,with a postpartum interval of 42 to 180 d.The inter-rectus distance was measured using palpation combined with caliper assessment.According to the inter-rectus distance,participants were divided into 4 groups:A severe DRA group(separation distance≥4 cm),a moderate DRA group(3.0 to 3.9 cm),a mild DRA group(2.0 to 2.9 cm),and a normal group(<2 cm).The moderate DRA,mild DRA,and normal groups were combined as the control group.Receiver operating characteristic(ROC)curve analysis was used to evaluate continuous variables and determine optimal cutoff values for stratification.The chi-square test was used to compare differences in influencing factors between the severe DRA group and the control group.Binary Logistic regression analysis was further performed to investigate the effects of various factors on severe DRA,and interaction analysis within the binary Logistic regression model was used to identify high-risk populations.Results:A total of 525 postpartum women were ultimately included,including 112 in the severe DRA group,257 in the moderate DRA group,98 in the mild DRA group,and 58 in the normal group.The overall incidence of DRA was 89.0%,while the incidence of severe DRA was 21.3%.The diagnostic cutoff values for body mass index(BMI),neonatal birth weight,and gestational weight gain were 22.55 kg/m^(2),3350 g,and 12.25 kg,respectively.Participants with BMI≥22.55 kg/m^(2),neonatal birth weight≥3350 g,gestational weight gain≥12.25 kg,multiparity,cesarean delivery,or number of fetuses≥2 had significantly higher incidences of severe DRA(all P<0.05).Binary Logistic regression analysis showed that neonatal birth weight≥3350 g,gestational weight gain≥12.25 kg,cesarean delivery,and multiparity were independent risk factors for severe DRA(all P<0.05).The interaction among neonatal birth weight≥3350 g,multiparity,and cesarean delivery showed the strongest association with severe DRA(OR=7.10,95%CI 3.43 to 14.71).When all 3 risk factors were present simultaneously,the incidence of severe DRA reached 61.76%.Conclusion:Neonatal birth weight≥3350 g,gestational weight gain≥12.25 kg,cesarean delivery,and multiparity are important independent risk factors for severe postpartum DRA,and significant synergistic amplification effects exist among these factors.This study clarified the characteristics of high-risk populations and may provide a basis for targeted early screening and intervention.展开更多
基金supported by the Natural Science Foundation of Shanxi Province(202203021221155)the Foundation of National Key Laboratory of High Efficiency and Low Carbon Utilization of Coal(J23-24-902)。
文摘With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Nickel-based catalysts are renowned for their outstanding activity and selectivity in this process.The impact of metal-support interaction(MSI),on Ni-based catalyst performance has been extensively researched and debated recently.This paper reviews the recent research progress of MSI on Ni-based catalysts and their characterization and modulation strategies in catalytic reactions.From the perspective of MSI,the effects of different carriers(metal oxides,carbon materials and molecular sieves,etc.)are introduced on the dispersion and surface structure of Ni active metal particles,and the effect of MSI on the activity and stability of DRM reactions on Ni-based catalysts is discussed in detail.Future research should focus on better understanding and controlling MSI to improve the performance and durability of nickel-based catalysts in CH_(4)-CO_(2)reforming,advancing cleaner energy technologies.
基金supported by the Petrochemical Research Institute Foundation(21-CB-09-01)the National Natural Science Foundation of China(22302186,22025205)+1 种基金the China Postdoctoral Science Foundation(2022M713030,2023T160618)the Fundamental Research Funds for the Central Universities(WK2060000058,WK2060000038).
文摘By simplifying catalyst-product separation and reducing phosphorus waste,heterogeneous hydroformylation offers a more sustainable alternative to homogeneous processes.However,heterogeneous hydroformylation catalysts developed thus far still suffer from the issues of much lower activity and metal leaching,which severely hinder their practical application.Here,we demonstrate that incorporating phosphorus(P)atoms into graphitic carbon nitride(PCN)supports facilitates charge transfer from Rh to the PCN support,thus largely enhancing electronic metal-support interactions(EMSIs).In the styrene hydroformylation reaction,the activity of Rh_(1)/PCN single-atom catalysts(SACs)with varying P contents exhibited a volcano-shaped relationship with P doping,where the Rh_(1)/PCN SAC with optimal P doping showed exceptional activity,approximately 5.8-and 3.3-fold greater than that of the Rh_(1)/g-C_(3)N_(4)SAC without P doping and the industrial homogeneous catalyst HRh(CO)(PPh_(3))_(3),respectively.In addition,the optimal Rh_(1)/PCN SAC catalyst also demonstrated largely enhanced multicycle stability without any visible metal aggregation owing to the increased EMSIs,which sharply differed from the severe metal aggregation of large nanoparticles on the Rh_(1)/g-C_(3)N_(4)SAC.Mechan-istic studies revealed that the enhanced catalytic performance could be attributed to electron-deficient Rh species,which reduced CO adsorption while simultaneously promoting alkene adsorption through increased EMSIs.These findings suggest that tuning EMSIs is an effective way to achieve SACs with high activity and durability.
基金supported by 973 Program of China (2013CBA01700)National Natural Science Funds (61622508, 61575032)
文摘Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,mediated by suitable optical media.There are many emerging photonic applications of spin-orbit interactions(SOI)of light,such as control of the optical wave propagation via the spin,enhanced optical manipulation,and generation of structured optical fields.Unfortunately,current applications are based on symmetric SOI,that is,the behaviours of polarized photons with two opposite spins are opposite,leading to the limit of spin-based multiplexers.The symmetry of SOI can be broken in our proposed metasurfaces,consisting of spatially varying birefringence,which can arbitrarily and independently build SOI for two opposite spins without reduction of optical energy usage.We obtain three kinds of dual-functional metasurfaces at visible and infrared wavelengths with high efficiency.Our concept of generation of asymmetric SOI for two spins,using anisotropic metasurfaces,will open new degrees of freedoms for building new types of spin-controlled multifunctional shared-aperture devices for the generation of complex structured optical fields.
基金Project(51678075)supported by the National Natural Science Foundation of ChinaProject(2017GK2271)supported by the Hunan Provincial Science and Technology Department,China。
文摘Human-object interaction(HOIs)detection is a new branch of visual relationship detection,which plays an important role in the field of image understanding.Because of the complexity and diversity of image content,the detection of HOIs is still an onerous challenge.Unlike most of the current works for HOIs detection which only rely on the pairwise information of a human and an object,we propose a graph-based HOIs detection method that models context and global structure information.Firstly,to better utilize the relations between humans and objects,the detected humans and objects are regarded as nodes to construct a fully connected undirected graph,and the graph is pruned to obtain an HOI graph that only preserving the edges connecting human and object nodes.Then,in order to obtain more robust features of human and object nodes,two different attention-based feature extraction networks are proposed,which model global and local contexts respectively.Finally,the graph attention network is introduced to pass messages between different nodes in the HOI graph iteratively,and detect the potential HOIs.Experiments on V-COCO and HICO-DET datasets verify the effectiveness of the proposed method,and show that it is superior to many existing methods.
文摘Mineral–microbe interactions indirectly affect the geochemical fluxes and biogeochemical cycling of a large number of elements. Among them are toxic heavy metals (e.g. chromium), radionuclides (uranium and technetium), and nitrogen. Heavy metals and radionuclides enter the environment from various sources such as mining activity, nuclear weapons production, metallurgical and chemical industries. Other metals, such as lead, arsenic, antimony, and cadmium, are enriched in certain environments by either natural or anthropogenic processes. Because many of these metals and radionuclides are carcinogens, their release into the environment and their fate cause intense scientific and public concern and are the subject of substantial research. Nitrate enters the environment largely through agricultural activity. Human health risks from nitrate uptake from drinking water supplies run the gamut from increased cancer risk to birth defects.
文摘The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of interest for improving crop management and developing new strategies for plant diseases control. The aim of this work is to investigate the components involved in this interaction and, for this purpose, a proteomic approach was used. 2-D maps of the protein extracts from the single components in various interactions between plants (potato, bean, tobacco or tomato), pathogens (Botrytis cinerea, Rhizoctonia solani or Pythium ultimum) and biocontrol fungi (Trichoderma atroviride strain P1 or Trichoderma harzianum strain T22) were obtained. The proteome of each partner was collected separately and extracted by acetone precipitation in presence of trichloroacetic acid and a reducing agent (DTT). The extracted proteins were separated by isoelectrofocusing (IEF), using IPG (Immobilized pH gradient) strips, followed by SDS-PAGE. In order to improve resolution the separations were performed both on wide than narrow pH range and on different gel lengths. Differential spots were noted in the proteome of the three-way interaction when compared to each single component. These were further characterized by mass spectrometry and in silico analysis with the aim of identifying and cloning the relative genes. During the in vitro interaction of T. harzianum strain T22 with tomato and the culture filtrate or cell walls of pathogens, the spot number was higher than in the presence of pathogen biomass. In terms of Trichoderma differential proteins displayed on 2D gels, the most important changes were obtained in the presence of P. ultimum . During the in vivo interaction with tomato, the antagonist proteome changed much more in presence of soilborne fungi R. solani and P. ultimum than with the foliar fungus B. cinerea, both in terms of total and increased or novel spots. In silico analysis of some of those spots revealed homology with intracellular enzymes (GTPases, hydrolases) and with stress-related proteins (heat shock proteins HSP70, bacteriocin cloacin). Specific proteins in the plant proteome, i.e. pathogenesis-related proteins, have been identified during the in vivo interaction of bean with R. solani and T. atroviride strain P1. This is in agreement with the demonstrated ability of these beneficial fungi to induce plant systemic disease resistance by activating expression of defence-related genes. Proteins extracted from T. atrovride strain P1 which were analysed by mass spectrometry, revealed some interesting homologies with a fungal hydrophobin of Pleurotus ostreatus and an ABC transporter of Ralstonia metallidurans. These could represent molecular factors involved in the antagonistic mechanisms of Trichoderma and play a role in the three-way interaction with the plant and other microbes.
文摘Studying the microstructure and intermolecular interactions of ionic liquid(IL)systems is of great importance.In this work,molecular dynamics(MD)simulations were performed on 1-butyl-3-methylimidazolium hexafluorophosphate([Bmim][PF6])+water+ethanol and[Bmim][PF6]+water+isopropanol ternary systems.Radial distribution functions were calculated,and the interaction energies between ion pairs and mixed solvents of different compositions were decomposed into Coulombic interaction energies and Lennard-Jones(LJ)potentials.The microstructure and intermolecular interactions of the ternary systems were studied based on the results,and the phase behaviors of the systems were discussed.The results show that water tends to interact with the anion and polar part of the cation,while alcohols prefer to interact with the anion and nonpolar part of the cation.The Coulombic interaction dominates over the anion-solvent interaction,while the LJ interaction dominates over the cation-solvent interaction.The association state of the ion pair has a smal effect on the LJ interaction,but a significant effect on the Coulombic interaction.
基金Project(2014BAB01B03)supported by the National Key Technology R&D Program During the 12th Five-Yean Plan of ChinaProject(51774286)supported by the National Natural Science Foundation of ChinaProject(BK20150192)supported by the Natural Science Foundation of Jiaaagsu Province,China
文摘The hydration film on particle surface plays an important role in bubble-particle adhesion in mineral flotation process. The thicknesses of the hydration films on natural hydrophobic coal and hydrophilic mica surfaces were measured directly by atomic force microscopy (AFM) based on the bending mode of the nominal constant compliance regime in AFM force curve in the present study. Surface and solid-liquid interfacial energies were calculated to explain the forming mechanism of the hydration film and atomic force microscopy data. The results show that there are significant differences in the structure and thickness of hydration films on coal and mica surfaces. Hydration film formed on mica surface with the thickness of 22.5 nm. In contrast, the bend was not detected in the nominal constant compliance regime. The van der Waals and polar interactions between both mica and coal and water molecules are characterized by an attractive effect, while the polar attractive free energy between water and mica (-87.36 mN/m) is significantly larger than that between water and coal (-32.89 mN/m), which leads to a thicker and firmer hydration layer on the mica surface. The interfacial interaction free energy of the coal/water/bubble is greater than that of mica. The polar attractive force is large enough to overcome the repulsive van der Waals force and the low energy barrier of film rupture, achieving coal particle bubble adhesion with a total interfacial free energy of-56.30 mN/m.
基金Projects(51304035,50974030)supported by the National Natural Science Foundation of ChinaProject(20110491512)supported by the Postdoctoral Science Foundation of China+2 种基金Project(20130042120034)supported by the Specialized Research Fund for the Doctoral Program of Higher Education(New Teachers),ChinaProject(120401008)supported by the Fundamental Research Funds for Central Universities,ChinaProject(L20150173)supported by the Scientific Research Fund of Liaoning Provincial Education Department,China
文摘Taking into consideration the gas compressibility and chemical reaction reversibility, a model was developed to study the interactions between gas flow and chemical reaction in porous media and resolved by the finite volume method on the basis of the gas-solid reaction aA(g)+bB(s)cC(g)+dD(s).The numerical analysis shows that the equilibrium constant is an important factor influencing the process of gas-solid reaction. The stoichiometric coefficients, molar masses of reactant gas, product gas and inert gas are the main factors influencing the density of gas mixture. The equilibrium constant influences the gas flow in porous media obviously when the stoichiometric coefficients satisfy a/c≠1.
文摘Two copper(Ⅰ)coordination polymers,{[Cu_(2)(4-bpo)_(2)(CH_(3)CN)_(2)(PPh_(3))_(2)](BF_(4))_(2)}_(n)(1),{[Cu(4-bpo)(CH3CN)(dppe)_(0.5)]BF_(4)}_(n)(2)(PPh_(3)=triphenylphosphine,dppe=1,2-bis(diphenyl phosphino)ethane,4-bpo=2,5-bis(4-pyridyl)-1,3,4-oxadiazole),have been synthesized and characterized by IR,^(1)H NMR,^(19)F NMR,^(11)B NMR,elemental analysis and X-ray crystal structure analysis.The structural analysis shows that complexes 1 and 2 consist of diverse and interesting 2D supramolecular structures formed by inter-chain interactions.For 1,π-stacking interactions result in the construction of 1D bilayer chain and 2D supramolecular network.Compound 2 exhibits a 1D ladder-like chain and a 1D+1D→2D/3D supramolecular structure formed byπ-stacking interactions.Solid-state emission spectra of complexes 1 and 2 have been studied,displaying the existence of ILCT/MLCT excited states.
文摘In order to implement cost-effective machining of gr anite materials with diamond impregnated tools, we should realize low tool w ear, low energy consumption, and high cutting efficiency, while the accuracy of the workpiece surfaces are maintained to be satisfactory. It is understood that the main factors affecting the tool wear, the energy, and the efficiency during the machining process are related to the tribological interactions that occur at the interface between the diamond tool surface and the workpiece. Based on this consideration, we propose a new machining method to machine granite materia ls to achieve improved cost effectiveness. In the proposed method, the tribologi cal interactions are maintained to a minimum. Based on the analyses of the experimental results, the following conclusions can be drawn: The wear performance is greatly dependent on the machining parameters and their combination. Therefore, optimum machining parameters must be set up at first in order to optimize the tribological characteristics of segments and thereby sawbl ade performance. These may be realized by balancing the energy expended by frict ion and the mechanical load on diamond crystal. The geometry and structure of diamond segments are another important criterion f or the diamond saw blade. Using a seven-layer structure for multi-blades sawin g and applying segments with side slots for trimming application had greatly red uced the frictions in the sawing processes. The wetting and bonding between diamonds and matrix alloys have been considered as the prerequisite for high wear performance of the segments. Diamonds coated w ith Ti-Cr alloy by a unique technique can effectively improve its wetting c apability and provide more storage space for debris, thereby reducing friction i nteractions.
基金the support from the National Natural Science Foundation of China (No. 21875184)the Natural Science Foundation of Shaanxi Province (No. 2022JC-10)Youth Talent of Shaanxi “TeZhi” Program。
文摘An in-depth analysis on the cooperativity of intermolecular interactions including hydrogen bonding andπ-π stacking in 1,3,5-triamino-2,4,6-trinitrobenzene(TATB) crystal was studied. Two quantities, cooperativity rate and energy, were defined to evaluate the nature and strength of cooperativity in a series of clusters diverging from 1D to 3D prototypes. The origin and mechanism of the cooperative effect were settled to demonstrate that the nature of cooperativity is determined by whether the non-covalent interactions compete or promote with each other, which is manifested by the changing trend of electron transfer. There exists obvious cooperative effect in intra-layer and inter-layer structures as they own the equivalent non-covalent interactions, while anti-cooperative effect is also observed if two interactions correlate with each other. On the whole, in the process of crystal formation, the apparent cooperativity is the check and balance of the two effects, which is capable to support a global interaction among all of molecules and contribute to the stabilization of system. Based on the results, one may get a new insight to understand the relationship between non-covalent interactions and low impact sensitivity.
基金Project(10872219) supported by the National Natural Science Foundation of China
文摘The finite element method was used to solve fluid dynamic interaction problems between the crust and mantle of the Earth. To consider different mechanical behaviours, the lithosphere consisting of the crust and upper mantle was simulated as fluid-saturated porous rocks, while the upper aesthenospheric part of the mantle was simulated as viscous fluids. Since the whole lithosphere was computationally simulated, the dynamic interaction between the crust and the upper mantle was appropriately considered. In particular, the mixing of mantle fluids and crustal fluids was simulated in the corresponding computational model. The related computational simulation results from an example problem demonstrate that the mantle fluids can flow into the crust and mix with the crustal fluids due to the resulting convective flows in the crust-mantle system. Likewise, the crustal fluids can also flow into the upper mantle and mix with the mantle fluids. This kind of fluids mixing and exchange is very important to the better understanding of the governing processes that control the ore body formation and mineralization in the upper crust of the Earth.
基金Supported by the National Natural Science Foundation of China(41174126)the Specialized Fund for Comprehensive Study and Evaluation of the Polar Environment(CHINARE2014-02-03)
文摘Nonlinear interactions between the quasi 5-day wave and tides based on meteor radar observation in the Mesosphere and Lower Thermosphere(MLT) at Maui are studied in this paper.Strong sum interaction between quasi 5-day wave and diurnal tide,and evident difference interaction between quasi 5-day wave and semidiurnal tide are observed during the time of attention.However,their difference and sum counterparts are clearly weaker.The secondary waves generated from those interactions beat with the tide and show intense modulation at the period of 5 days which confirms the existence of their interactions.Additionally,correlation coefficients among these waves are calculated to further explore their interactions and find that they can persist for several days although they are highly intermittent.The energy exchange among these waves can be reversible during the observational time.The periods when the significant difference interaction between the quasi 5-day wave and semidiurnal tide occur are much shorter than those when the significant sum interaction between the quasi 5-day wave and diurnal tide occur.Moreover,these two strong interactions can take place simultaneously.In generally,this study provides the proof of nonlinear interactions between quasi 5-day wave and tides which were seldom reported before.
文摘Taking stearic acid as the raw material,N-(2-(dimethylamino)ethyl)stearamide(C18N2N)was synthesized.A new surfactant was prepared by mixing C18N2N and cinnamic acid(TA)with fixed ratio.This surfactant was formed by noncovalent electrostatic interactions,which avoided complicated synthetic procedures.The surface activity and rheological properties of the surfactant were investigated with a surface tensiometer and a rheometer.The critical micelle concentration(cmc)and the surface tension at cmc(γ_(cmc))of the surfactant were 0.11 mmol/L and 32.4 mN/m,indicative of strong aggregation and adsorption ability.The maximum amount adsorbed(Γ_(max))and the minimum molecular area occupied(A_(min))were 2.77μmol/m^(2)and 0.6 nm^(2).Wormlike micelles were formed at the concentration of 25 mmol/L.When the concentration was over 100 mmol/L,the zero-shear viscosity(η_(0))abruptly increased and then reached the maximum value for the surfactant of C18N2N/TA containing 150 mmol/L TA.The solution viscosity was as high as 1761.38 Pa·s.The effects of temperature on the rheological behavior were also considered.With the increase of temperature,the viscosity gradually increased.And when the temperature reached 40℃,η_(0)of the solution with the concentration of 100 mmol/L achieved the maximum value of 1370.386 Pa·s.When the temperature continued to rise,η_(0)began to decrease with further increasing temperature.A remarkable viscosity of 305.55 Pa·s was still remained at 50℃.The viscoelastic solutions showed good temperature resistance and shear resistance.The surfactant solutions applied as the fracturing fluid were also investigated.This surfactant also showed excellent sand-carrying performance,and the settling rate of the sand was merely 0.26 cm/min.This surfactant could be simply prepared and showed excellent performance,which expanded the preparation and application field of novel surfactants.
基金supported by the National Key R&D Program of China(2021YFA1501700)Fundamental Research Funds for the Central Universities(WK9990000142).
文摘The seminal report ofα-diimine palladium and nickel catalysts in 1995 represented a major breakthrough in the preparation of functionalized polyolefin materials.Owing to the high abundance and low cost of nickel,nickel-based catalysts have great application prospects in the industrialization process of olefin coordination polymerization.In this work,various N-aryl substituents with different electronic effects were synthesized and introduced intoα-diimine ligands.The aspreparedα-diimine nickel catalysts showed high polymerization activity(0.9×10^(7)–3.0×10^(7)g·mol^(−1)·h^(−1))in ethylene polymerization,generating polyethylene products with adjustable molecular weights(Mn values:7.4×10^(4)–146.9×10^(4)g·mol^(−1))and branching densities(31/1000 C–68/1000 C).The resulting polyethylene products showed excellent mechanical properties,with high tensile strength(up to 25.0 MPa)and high strain at break values(up to 3890%).The copolymerization of ethylene and polar monomers can also be achieved by these nicekel complexes,ultimately preparing functionalized polyolefins.
文摘This article reviews the roles of host-microbe interactions in intestinal disorders and tumors from the perspective of host cell-microbial cell crosstalk.As a crucial environmental factor in the gut,gut microbiota significantly influences host intestinal pathologies and tumors,and this interaction is bidirectional.Gut microbes can directly adhere to and contact epithelial cells,activating intracellular signaling pathways and affecting the development of inflammation and cancer.Simultaneously,gut microbes can produce various proteins,secondary metabolites or exosomes;these bacterial-derived products can regulate intestinal epithelial cells,immune,and neuronal cells in a contact-independent manner,thereby influencing disease progression.Recent research has increasingly focused on the regulatory factors shaping the gut microbiota.Notably,the host has been identified as a key factor influencing gut microbiota.For instance,specific adhesion proteins on the surface of host intestinal cells,intestinal immunity,and even the host’s blood type can impact the composition and function of the gut microbiota.These altered microbial communities can,in turn,further affect the host’s intestine,influencing the progression of intestinal diseases and tumors.Therefore,elucidating the bidirectional interplay between the host and microbiota is essential for a deeper understanding of disease pathogenesis and will provide a theoretical foundation and guidance for the precise modulation of gut microbiota in the future.
基金supported by the National Natural Science Foundation of China under Grant No.22505100.
文摘Energetic materials face critical challenges in balancing energy density and safety,driving the development of low-sensitivity high-energy materials.Though vital for modern defense and civilian applications,low-sensitivity high-energy materials remain scarce,with 1,3,5-trinitro-2,4,6-triaminobenzene as the only deployed example.Planar lamellar energetic crystals,which utilize weak interlamellarπ-πstacking for mechanical energy dissipation,have shown significant promise.However,their rational design is constrained by insufficient understanding of intermolecular interaction synergy.This review synthesizes the structural features of planar lamellar energetic crystals,emphasizing three core elements:the single-atomic-thickness planar stacking architecture,the"strong intralamellar and weak interlamellar interaction"paradigm(key to balancing energy density and safety for low-sensitivity high-energy materials,LSHEMs),and the role of molecular planarity in reducing shear slip barriers.It categorizes design strategies into two frameworks:H–bonding dominated(single-component:cross-shaped assembly,strong H–bonding in high symmetric molecules;multi-component methods:tenon-and-mortise,acceptor-donor separation)and other intermolecular interactions(e.g.,π-πstacking-drivenπ-π2max model,π-hole recognition).Case studies in single/multi-component crystals confirm that these strategies tune interaction synergy to achieve target packing motifs.The review highlights that interaction engineering is pivotal for PLEC design,offering a targeted theoretical framework for rational development of LSHEMs(to address the scarcity of practical LSHEMs)and guiding future crystal engineering for energy-safety balanced systems.
基金supported by the Natural Science Foundation of Hunan Province,China(2024JJ7069)。
文摘Objective:Severe diastasis recti abdominis(DRA)in the postpartum period may lead to long‑term functional impairment in women.However,the independent effects and interactions of perinatal risk factors during the early postpartum recovery window have not been fully elucidated.This study aims to analyze the risk factors and interaction effects associated with severe postpartum DRA and to identify characteristics of high‑risk populations.Methods:This retrospective cohort study included postpartum women who underwent postpartum rehabilitation treatment at Hengyang Maternal and Child Health Hospital between January 2019 and August 2022,with a postpartum interval of 42 to 180 d.The inter-rectus distance was measured using palpation combined with caliper assessment.According to the inter-rectus distance,participants were divided into 4 groups:A severe DRA group(separation distance≥4 cm),a moderate DRA group(3.0 to 3.9 cm),a mild DRA group(2.0 to 2.9 cm),and a normal group(<2 cm).The moderate DRA,mild DRA,and normal groups were combined as the control group.Receiver operating characteristic(ROC)curve analysis was used to evaluate continuous variables and determine optimal cutoff values for stratification.The chi-square test was used to compare differences in influencing factors between the severe DRA group and the control group.Binary Logistic regression analysis was further performed to investigate the effects of various factors on severe DRA,and interaction analysis within the binary Logistic regression model was used to identify high-risk populations.Results:A total of 525 postpartum women were ultimately included,including 112 in the severe DRA group,257 in the moderate DRA group,98 in the mild DRA group,and 58 in the normal group.The overall incidence of DRA was 89.0%,while the incidence of severe DRA was 21.3%.The diagnostic cutoff values for body mass index(BMI),neonatal birth weight,and gestational weight gain were 22.55 kg/m^(2),3350 g,and 12.25 kg,respectively.Participants with BMI≥22.55 kg/m^(2),neonatal birth weight≥3350 g,gestational weight gain≥12.25 kg,multiparity,cesarean delivery,or number of fetuses≥2 had significantly higher incidences of severe DRA(all P<0.05).Binary Logistic regression analysis showed that neonatal birth weight≥3350 g,gestational weight gain≥12.25 kg,cesarean delivery,and multiparity were independent risk factors for severe DRA(all P<0.05).The interaction among neonatal birth weight≥3350 g,multiparity,and cesarean delivery showed the strongest association with severe DRA(OR=7.10,95%CI 3.43 to 14.71).When all 3 risk factors were present simultaneously,the incidence of severe DRA reached 61.76%.Conclusion:Neonatal birth weight≥3350 g,gestational weight gain≥12.25 kg,cesarean delivery,and multiparity are important independent risk factors for severe postpartum DRA,and significant synergistic amplification effects exist among these factors.This study clarified the characteristics of high-risk populations and may provide a basis for targeted early screening and intervention.
