Search

The entanglement of multiple spatially separated remote quantum nodes is the foundation for constructing quantum information networks. Moreover, the entanglement between multiple quantum nodes can also be applied to distributed quantum computing and quantum precision measurement. It is imperative to achieve higher entanglement between multiple quantum nodes. In this paper, a scheme is proposed to achieve entanglement of three distant atomic ensembles through cavity enhancement via interference and real-time feedforward. In this scheme, only three sets of cavity enhanced atomic systems are required. The optical resonant cavity enhances the interaction between light and atoms, improving the efficiency of the Stokes and anti Stokes light fields generated through stimulated Raman scattering, and achieving high entanglement between light and atoms. Under this premise, the entanglement between three remote quantum nodes can be achieved through interference and real-time feedforward. This method can be extended to larger and even more complex quantum information networks, thus having potential applications in quantum information science. [ABSTRACT FROM AUTHOR]

The formation of carbides in steel is determined by the type and quantity of alloying elements. Carbides will affect the microstructure and mechanical properties of steel materials. The magnetic field is an important factor affecting the precipitation of carbides. In this paper, the common precipitated phase M6C (M=Fe,Mo) carbides are selected as the research object. The magnetic moments of η-Fe2C,Fe3C,Fe2Mo4C，Fe3Mo3C-I，Fe3Mo3C-II and Fe4Mo2C are calculated by first-principles. The magnetic moment of Fe4Mo2C is the largest with the value of 7.04μB. The magnetic moment is not only related to the number of Fe atoms in carbides, but also closely related to the crystallographic occupation of Fe atoms. By simulating the magnetic heat capacity, magnetic entropy, magnetic enthalpy and magnetic free energy of carbides, the carbides were analyzed from the thermodynamic point of view. The results show that the magnetic field will increase the magnetic heat capacity and magnetic entropy of carbides. The strong magnetic field will increase the magnetic free energy of M6C and improve its stability. This work provides a theoretical basis and technical reference for studying the magnetic properties of nuclear fusion materials. [ABSTRACT FROM AUTHOR]

Fatigue failure is one of the important failure forms of mechanical components. In this paper, the fatigue mechanical properties and microstructure evolution of high entropy alloy FeCrNiCoCu alloy were investigated by molecular dynamics simulation under the stress variable ε=0.08. It was found that the FeCrNiCoCu model exhibited obvious cyclic softening and cyclic hardening during cyclic loading, and cyclic softening and cyclic hardening occurred alternately. Through the analysis of the model structure, it is found that there are residual dislocations and layer dislocations at the end of each cycle, and these defects directly affect the fatigue stress of the next cycle. The statistical analysis of the total energy and the percentage of disordered atoms in the model shows that the total energy of the model tends to increase. The percentage of disordered atoms in the model gradually increases and finally stabilizes at about 0.09. Disordered atoms have a direct impact on the generation and annihilation of dislocations, and then on cyclic hardening and cyclic softening. [ABSTRACT FROM AUTHOR]

The development of information communication and military electronics technology puts forward higher and higher requirements on the high-temperature magnetism of magnetic materials, and it is of great significance to study the magnetic materials that work efficiently and stably in high-temperature environments. In this paper, the effects of Fe, Co ratio and rare earth elements (Gd, Tb, Dy) doping on FeCo crystal structure, magnetic exchange constant and high-temperature magnetism are investigated by combining the first nature principle and Monte Carlo method. The results show that the crystal structure of the alloy transforms from body-centered cubic to simple and face-centered cubic with the increase of Co content, and the Fe-Co bond length is the shortest and the nearest-neighbor magnetic exchange constant increases from 18.05 meV to 30.03 meV when the Co content is 50%, which raises the Curie temperature of FeCo to 1580 K, which is an increase of 60% in Curie temperature compared with that of Fe. After doping rare earth elements into the FeCo system, it is found that the doping of 3.125% content of Er, Dy, and Tb increases the Curie temperature of FeCo by 60 K, 45 K, and 20 K, respectively, and the electronic configuration reconstruction leads to the strong exchange interaction between rare earth elements and Fe and Co is the main reason for the Curie temperature increase. [ABSTRACT FROM AUTHOR]

The calculation of charge transition energy level(CTL) and defect formation energy are of significant importance for exploring potential n-type or p-type doping in materials. Based on the first-principles method, combined with the theory of two-dimensional charged defect correction method, as well as effectively convert the semi-local functional results of CTL to hybrid functional accuracy, this paper systematically studied 12 kinds of n-type and p-type substitute dopants in the two-dimensional hexagonal gallium nitride(h-GaN) system. Among which n-type doping includes CGa, SiGa, GeGa, ON, SN,SeN and p-type doping includes BeGa, MgGa, CaGa, CN, SiN,GeN. The results show that the most stable charge states for n-type system are 0 and 1+, and the donor ionization energy is distributed in the energy range of ～0.4 to ～0.6 eV lower than the conduction band minimum(CBM), characterized as deep donor energy level, which will capture the holes in p-type h-GaN and affect the hole conductivity. The most stable charge state of the p-type system is 1-, 0(except for GeN), and 1+, and the accetpor ionization energy is distributed in the energy range higher than the valence band maximum(VBM) ～1.25 to 2.85 eV, characterized as deep acceptor energy level, which will capture electrons(holes) in n(p) h-GaN and affect the conductivity of n(p) carriers. In Conclusion, it is difficult for two-dimensional h-GaN system to achieve n or p-type doping through single defect, and it is necessary to consider the complex defects to achieve bipolar doping experimentally. [ABSTRACT FROM AUTHOR]

The study of the behavior of the metal microdroplet impacting on a solid surface is of great significance for predicting the morphology of the microdroplet and realizing high-precision print manufacturing. However, due to the difficulty of performing experiments on metal microdroplets impacting at the micro/nanoscale, the morphology change and thermo-capillary effect mechanism involving metal microdroplets impacting on rough surfaces are still unclear. In this paper, molecular dynamics simulations are used to study the dynamic behavior of the gallium-indium microdroplet impacts on rough surfaces, and quantitatively analyze the effects of the impact velocity, the rough structure, and the different temperatures on the impact behavior of the microdroplet. The results show that with the increase of the impact velocity, the microdroplet shows three modes of deposition, bouncing and splashing, and the maximum spreading factor of the microdroplet shows a power function relationship with the Weber number. In addition, by modifying the rough structure of the substrate, it is found that changes in the spacing or height of the structure have different influences on the bouncing behavior of the microdroplet, which could effectively promote or inhibit the bouncing behavior. Finally, it is analyzed that the spreading diameter of the microdroplet becomes larger with the increase of temperature, and the viscous dissipation generated also increases. The results provide a theoretical basis for the effective pre-diction of the impact behavior of metal microdroplets. [ABSTRACT FROM AUTHOR]

In this paper, the molecular dynamics(MD) method and modified Dreiding-TKX-50 force field were used to calculate the interaction energies between the important crystal surface layer of TKX-50 and the solvent layer. The crystal morphologies of TKX-50 in different solvents were predicted by the modified attachment energy model and compared with experimental results. The results showed that the main crystal faces in the vacuum morphology of TKX-50 crystal are(0 2 0),(0 1 1),(1 1-1) and(1 0 0). The predicted crystal morphology of TKX-50 after the interaction of water(H2O) and N, N-dimethylformamide(DMF) solvent is approximately shuttle shaped, with aspect ratios of 1.857 and 2.073. The predicted crystal morphology of TKX-50 after the action of ethylene glycol(EG) solvent is bulk and the aspect ratio is 2.320. [ABSTRACT FROM AUTHOR]

With the large-scale use of lead-based ceramics, causing serious environmental and health problems, in order to be able to find alternative materials for lead-based ceramics, people have begun to explore lead-free ceramic materials. (K0.5Na0.5)NbO3 materials have become representative of lead-free ceramic materials due to their excellent ferroelectric properties, but the temperature sensitivity of KNN ceramics makes its application range extremely limited. Based on this consideration, based on the first principles method of density functional theory, this paper explores the ferroelectric properties of nine systems (K0.5Na0.5)Nb1-xTaxO3 (x=0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1) nine systems. The results show that with the increase of Ta concentration, the lattice constant changes, so it is speculated that the orthogonal-monoclinic phase transition of KNN material occurs with the increase of Ta concentration; the incorporation of Ta can reduce the sintering difficulty of KNN material, and with the increase of Ta concentration, the formation difficulty gradually decreases; in the doping system, the Ta-4f orbital and Na-3p, K-4p and O-2s orbital electrons are hybridized, so that the state density peak of the conduction band bottom Nb-4d and Na-3p electrons moves towards the high-energy region. The gap width shows an increasing trend; When analyzing the ferroelectric mechanism of KNN material, it was found that the iron polarization type of KNN is ion displacement polarization, and does not have polarization ability in the [001] direction. Analysis of the polarization intensity of each system after doping, it is found that with the increase of Ta concentration, the polarization intensity gradually decreases, but the polarization has an upward trend when doping at low concentration, which may be caused by the presence of orthogonal and monoclinic MPBs in low concentration, from which it can be judged that low concentration doping is conducive to improving the ferroelectric properties of KNN materials. [ABSTRACT FROM AUTHOR]

Elements of the group IV, carbon, silicon, germanium, tin and lead, have similar valence electron configurations, but with different superconductivity. Tin and lead can achieve superconductivity under normal pressure, silicon and germanium require high pressure to become superconducting, while the superconductivity of the conventional crystal structure of carbon has not been found at both normal pressure and high pressures. Pressure affects superconductivity in large part by changing the crystal structure and the positions of atoms. In this paper, the first-principles calculations based on the density functional theory (DFT) is used to explore the favorable conditions for inducing superconductivity by comparing and analyzing the crystal structures, electronic structures, phonon properties and superconducting properties of five group IV elements (C, Si, Ge, Sn, Pb) systematically. These results indicate that the higher the number of electron states near the Fermi level, the lower the pressure required for the metallic system to achieve superconductivity. Besides, in a metallic system, the existence of a band gap near the Fermi level will make it easier for the electrons to be localized near the Fermi level, thus increasing the number of electron states near the Fermi level and improving the superconductivity. This work provides ideas for revealing the superconducting mechanism and improving the superconductivity of materials. [ABSTRACT FROM AUTHOR]

Chemi-resistance sensors play an important role in air quality, food detection and human respiration detection. The gas-sensing mechanism analysis of the adsorption between the modifier, thiol, on the sensor and the volatile organic compounds (VOCs) to be detected is an important means to select the thiol and predict the adsorption capacity and specificity. In this paper, two common thiols, 11-mercapto-1-undecyl alcohol (MUD) and 4-methoxybenzyl mercaptan (MTT), and six typical VOCs (ethanol ETN, isopropanol IPA, acetone ACN, n-hexane HXN, toluene TLN, benzaldehyde BND) were selected, based on density functional theory (DFT), the surface electrostatic potential (ESP) was calculated and the gas adsorption model was established. The adsorption energy was calculated in the gas adsorption model, and the weak interaction was analyzed to explain the mechanism of gas adsorption from a microscopic point of view. The experimental results show that MUD molecules with hydroxyl groups can adsorb gases with hydroxyl groups (such as ETN, IPA) in the form of hydrogen bonds, and have a strong selective effect; MTT molecules with benzene rings and gas molecules with benzene ring structure (such as TLN, BND) will form π-π stacking between benzene rings during adsorption, and the adsorption is based on dispersion interaction, which indicating that MTT molecules have a strong adsorption effect on gases with benzene ring structure. The study found that the strength of its dispersion interaction adsorption is related to the absolute value of the surface ESP of the molecule. In this paper, the gas-sensing mechanism of gas adsorption by sensor surface modifiers is explored, and theoretical guidance is provided for the selection of surface modifiers and the prediction of experimental results. [ABSTRACT FROM AUTHOR]

In order to obtain a highly sensitive biosensor, in this paper, a non pass metal insulator metal (MIM) wave guide sensor that can excite quadruple Fano resonance is designed. The top and bottom symmetric structure is adopted, and a vertical rectangular cavity and two horizontal rectangular cavities interact with the bus wave guide to obtain the quadruple Fano resonance. The finite difference time domain (FDTD) method is used to calculate the transmission characteristics of the structure and the normalized magnetic field in the Z direction, and the mechanism of its Fano resonance is analyzed in detail. By calculating the transmission spectrum adjusted by the structural geometric parameters, it is obtained that the transmission and resonance position of the four Fano resonance peaks can be independently adjusted by changing the structural geometric parameters. In addition, it was found that adding different concentrations of glucose solutions to the structure can achieve high refractive index sensing sensitivity (S), the highest sensitivity can reach 2736.98nm/RIU, indicating that this structure has high sensitivity to changes in refractive index, This provides a new approach for designing and optimizing nanometre scale refractive index sensors, which can be applied for performance testing before circuit construction. [ABSTRACT FROM AUTHOR]

Production of hydrogen from photocatalytic water splitting provides a feasible strategy to solve the energy crisis and environmental pollution problems. In this paper, it is proposed that monolayer Janus Ga2SSe is an efficient photocatalyst for water splitting by first principles calculation. The structural stability analysis shows that monolayer Janus Ga2SSe has energetic and dynamic stability. The electronic properties show that the monolayer Janus Ga2SSe is an indirect band gap semiconductor, which is conducive to reducing the recombination probability of carriers. The analysis of photocatalytic performance shows that the band edge position of monolayer Janus Ga2SSe is suitable for photocatalytic water splitting with the range of PH=0-14. In addition, the monolayer Janus Ga2SSe has high UV and visible light absorption, large internal electric field, and small carrier effective mass, which ensures the effective separation and rapid migration of photogenerated carriers to the reactive site to participate in the redox reaction of water. The results provide valuable theoretical guidance for the synthesis of monolayer Janus Ga2SSe and its potential application as a photocatalyst for water splitting. [ABSTRACT FROM AUTHOR]

In a double Λ-type four-wave mixing system, the influence of probe field intensity on Autler-Townes (AT) splitting is investigated. As the weak-probe intensity increases, the distance of AT splitting generated from dressed-states resonance remains unchanged, but gradually the line-widths increase and the heights decrease until the doublet disappears. While the strong coupling field is detuned, the AT doublet which is asymmetrically located on both sides of the single-photon resonance peak gradually tends to be showed symmetrically. In this paper, we discuss the probe field effects in detail by using the dressed-state model. It is proposed that the effective Raman coherence between atomic ground-states can be controlled by the probe intensity, thereby affecting the characteristics of AT splitting. [ABSTRACT FROM AUTHOR]

The type and position of substituents will affect the molecular structure and chemical bond strength of energetic materials, and thus affect their impact sensitivity. In this paper, the influence of amino group and methyl group on impact sensitivity of trinitrobenzene energetic materials is analyzed based on first principles. According to the calculated elastic constants, the volume modulus (B), shear modulus (G), Young's modulus (E) and Poisson's ratio (v) are obtained by Voigt-Reuss-Hill averaging method. Subsequently, the effects of the type and quantity of amino and methyl substituents on mechanical parameters, band structures, and density of states are analyzed. To a certain extent, the number of amino groups is negatively correlated with the impact sensitivity, but positively correlated with the band gap width, and the impact sensitivity of a group of amino polynitroaromatic materials can be judged by comparing the band gap values. In comparison to amino groups, the number of methyl groups displays a stronger correlation with mechanical properties and exerts a more significant influence on the total density of states. Although no direct correlation is observed between the number of methyl groups and the material's impact sensitivity, it does exhibit a negative correlation with the band gap width. Therefore, the impact sensitivity of a group of nitroaromatic energetic materials containing methyl substituents cannot be solely determined based on the magnitude of the band gap value. [ABSTRACT FROM AUTHOR]

In this paper, the electronic structure and optical properties of vacancy defect wurtzite BN are studied based on the first principle calculation. Hence we spoke on the calculated energy band structure and density of states, it turns out that the impurity level appears near the Fermi level due to the lack of B and N in the defect system. Compared with the intrinsic system, with the increase of vacancy concentration, the impurity energy levels become more and the transition energy decreases. The density of states of wurtzite BN with N vacancy defect generally moves to the low energy region, and the energy level is significantly higher than that of wurtzite BN with B vacancy defect. From the analysis of complex dielectric function and optical absorption spectrum, it is found that the absorption of wurtzite BN in the visible region gradually increases with the increase of vacancy concentration. In particular, B22N24 has better absorption effect in the visible region. [ABSTRACT FROM AUTHOR]

Helium exists widely in the implosion process of nuclear fusion and cosmic stars in the warm dense state. Its thermodynamic properties and radiative transport parameters play an important role in the design of fusion experiments and the study of star structure evolution. In this paper, the quantum Langevin molecular dynamics method, which fully considers the physical effects of electron and ion collisions in warm dense matter, is used to simulate the response characteristics of helium ions and electrons in a wide ρ-T region. The state of equation database and electronic thermal conductivity database of warm dense helium in the temperature range of 10-60 kK and density range of 1-24 g/cm³ are constructed, and the radiative opacity of warm and dense helium at this temperature density is calculated. The results of this paper can provide necessary input parameters for fusion physics research and modeling of many basic astrophysical problems. [ABSTRACT FROM AUTHOR]

In this paper, the complexation characteristics of CdTe QDs using butyrylcholine and thiocholine as capping agents were studied with density functional theory (DFT). The stable complexation configurations were first optimized, based on which the relevant adsorption energies, charge densities, UV-Vis absorption spectra and frontier molecular orbital were calculated. It is found that the adsorption energy of butyrylcholine on CdTe QDs is very small, and the electron interaction between butyrylcholine and CdTe QDs is quite weak, which therefore can be attributed to physical adsorption. In the meantime, the absorption intensity of ultraviolet and visible light is weak as well. In contrast, the electron interaction between thiocholine and CdTe QDs is strong, which is chemical adsorption, and the absorption intensity of ultraviolet and visible light is strong. The research results provide theoretical support for the detection of butyrylcholinesterase using CdTe QDs in the experiment. [ABSTRACT FROM AUTHOR]

In this paper, the electronicstructures and magnetic properties of SnO2 doped with non-metallic elements (N) and transition metal elements (Mo, Ru, Rh, Pd) are calculated and analyzed based on the first principles approach. The results show that: the formation energy is closely related to the transition metal atomic radius, with the increase of the transition metal atomic radius, the formation energy is decreasing, where the N-Mo doping system has the lowest formation energy, so the system is the easiest to doping formation. Energy band structure analysis shows that due to the number and distribution of spin up/spin down impurity energy levels of the doping system are asymmetric, the doping systems are magnetic generation. Further exploration of the density of states shows that the magnetic properties of the doped system are due to the p-d orbital hybridisation between the transition metal atoms and the N atoms, the vacancies in the outermost electron orbitals and the single electron coupling. The results show that the SnO2 system is magnetic due to the introduction of doping atoms, and the doped system exhibits subferromagnetic properties, with the best magnetic moment of 1.88 μB for the N-Rh doped system, which is expected to be a good dilute magnetic semiconductor material. [ABSTRACT FROM AUTHOR]

g3 (green gas for gird) environmental protection gas (C4F7N/CO2 mixture), as the most potential new environmentally friendly insulating substitute gas for SF6, has received extensive attention in recent years. Defects such as partial discharge and overheating are detected by analyzing the decomposed components in the g3 gas-insulated combined switchgear, which plays an important role in the evaluation and diagnosis of the operation status of power equipment. In this paper, the modification of Si atoms is proposed to improve the gas sensing and adsorption properties of MoS2. Based on the calculation method of density functional theory (DFT), the intrinsic properties of MoS2 are explored through parameters such as adsorption energy, charge transfer, density of states and local density of states. The adsorption gas-sensing mechanisms of MoS2 and Si-MoS2 to the typical decomposition components of g3 gas—COF2, CF4, CF3CN. The analysis shows that Si atoms have a stable doping structure on the surface of MoS2. Compared with the intrinsic MoS2, the conductivity of MoS2 modified by Si atoms has been effectively enhanced; Si-MoS2 exhibits strong chemical adsorption to COF2 and CF4 gases, it is weak physical adsorption to CF3CN, the adsorption strength is CF4＞COF2＞CF3CN, and in the adsorption process Si-MoS2 always acts as an electron donor, transferring electrons to gas molecules; Si-modified MoS2 has selective adsorption to g3 gas decomposition components. It provides a theoretical basis for the development of MoS2 high-performance gas sensors for detecting CF4 and COF2 gases. The research results are also of great significance in reducing greenhouse gas emissions and improving the operational stability of GIS (Gas Insulated Switchgear). [ABSTRACT FROM AUTHOR]

Based on the fact that block copolymers can self-assemble to form many ordered structures under soft confinement conditions, they are widely used in catalysis, electronic devices, optical sensing and other fields. At present, only the self-assembly morphology of linear triblock copolymers under soft confinement has been analyzed. There is no unified conclusion on the self-assembly behavior of copolymers under soft confinement. Based on this background, this paper focuses on studying the morphology of triblock copolymer particles under soft confinement. A phase diagram is constructed by tuning the volume fractions of the three blocks (fA, fB, and fC). Our simulations predicted various unique self-assembled nanostructures, including lamella + sphere, cylinder, perforated layer, lamella + cylinder, core-shell patch. By changing the selectivity between the block and the solvent, the morphology transition of the copolymer with the chain length ratio of 1:x:1 was predicted. The morphology transition mechanism was verified by calculating the ratio of ＜DEE²＞ to the average length (L), the average bond length of B block chains, and their contact number. [ABSTRACT FROM AUTHOR]

In this paper, we have investigated the controlling of the dipole-dipole (D-D) interaction and detuning amount on the quantum memory assisted (QMA) entropy uncertainty of the two-atom system in Markovian and non-Markovian processes. It is found that the memory effect of the reservoir environment causes the dynamical behaviour of the QMA entropy uncertainty of the two-atom system to show a phenomenon of oscillation, the rising trend of the QMA entropy uncertainty is slowed down, and it can suppress the decoherence effect of the system caused by quantum noise in the non-Markovian process. In addition, the D-D interaction has significant control ability to reduce the QMA entropy uncertainty and it has stronger control ability than the detuning amount. [ABSTRACT FROM AUTHOR]

This paper is based on the X-ray photoelectron spectroscopy (XPS and X-ray absorption spectroscopy (XAS with the synchrotron radiation technology. It aims to test the electronic structures of dilute magnetic semiconductor GaMnN films with different Mn doping concentrations prepared by metal organic chemical vapor deposition technology (MOCVD, to explore the influences of Mn doping concentration on the local environment and electronic states of the magnetic atom Mn, and hence to expose the mechanism for the change of material ferromagnetism. The XPS and XAS data analysis show that Mn2+ and Mn3+ coexist in the film samples, the proportion of Mn2+ in sample D is as high as 70%-80%; the N vacancy increases with the increase of Mn doping concentration and it can reduce the hole concentration, as a result, the exchange interaction between Mn 3d and N 2p orbitals is reduced, which weakens the ferromagnetism of the system. In addition, Mn doping concentration also affects the strength of the p-d coupling hybridization ability of GaMnN films. When the Mn doping concentration is 0.018, the system has a strong p-d coupling hybridization ability. [ABSTRACT FROM AUTHOR]

In this paper, V-shaped and W-shaped hole blocking layer (HBL) structures are designed to re- duce the hole leakage into the n-type region of AlGaN -based deep ultraviolet laser diodes (DUV - LDs). DUV - LDs with reference rectangular, V-shaped and W-shaped hole - blocking layer structures are simulated by Crosslight software. Numerical research on the energy band, n-region hole concentration, radiative recombination rate, electro-optical conversion efficiency, output power, carrier concentration in the active region and other characteristics of the three different structures, are conducted respectively. The results show that DUV - LD with a W-shaped hole blocking layer has higher hole effective barrier height, higher radiative recombination rate, lower hole leakage and better slope efficiency, which can effectively reduce the hole leakage in the n-type region of the deep ultraviolet laser diode, and improve its optical and electrical performance. [ABSTRACT FROM AUTHOR]

In this paper, based on Hill kinetics and Michaelis-Menten equation, we built a theoretical model to study the kinetics of H2 AT120 protein phosphorylation promoting the oncogenic transformation. We found that in H2 AubK119-H2 AT120 D-H2 AT120 P signaling pathway, the vaccinia-related kinase 1(VRK1) regulates the kinetic behavior of H2 AT120 protein phosphorylation. Overexpression or underexpression of VRK will cause abnormalities in the phosphorylation process of H2 AT120, which leads to improper gene expression and oncogenic transformation. By investigating the dynamic stability of the H2 AubK119-H2 AT120 D-H2 AT120 P signaling pathway system, we found that the H2 AubK119, H2 AT120 D, and H2 AT120 P present Hopf bifurcation. It confirms the transition characteristics of the system’s evolutionary dynamics over time. This shows that the phosphorylation of H2 AT120 protein promotes the complexity of cancer occurrence and development. Based on the model in this article, we explained the carcinogenic regulation characteristics of VRK, H2 AT12 ubiquitination and [H2 AT120 D] mutation. The results can be used to further understand the carcinogenic mechanism induced by the H2 AubK119-H2 AT120 D-H2 AT120 P signaling circuit. The theoretical results are consistent with the experiment, revealing a carcinogenic mechanism of epigenetic changes caused by phosphorylation of H2 AT120 protein, which can provide a theoretical basis for the design to prevent cancers induced by histone mutations. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) seriously endanger the ecological environment and human health, so it is of great significance to detect VOCs gases with typical functional groups. In this paper, the sensing properties of VOCs gas C2H2, C2H4, HCOOH, CH3OH, HCHO and CH3COCH3 molecules with typical functional groups on the surface of anatase TiO2(101) were investigated. The results show that when the surface with oxygen vacancy defects adsorbs polar molecules, the larger the dipole moment is, the more stable the adsorption system is; when the surface with oxygen vacancy defects is adsorbed on non-polar molecules, the lower the saturation degree of C atom bonding, the more stable the adsorption system. The analysis shows that the differential charge density and charge layout reflect the influence of the size of the dipole moment and the degree of C atom bond saturation on the ability of gas molecules to gain or lose electrons. For polar molecules, the ability of the O atom in the functional group of the gas molecule to gain electrons is OCH3COCH3＞OHCHO＞OCH3OH＞OHCOOH. For non-polar molecules, the ability of the C atom in the functional group to gain electrons is CC2H2＞CC2H4.The analysis of the density of states diagram reveals that the peak position and size of the adsorption system at the Fermi energy level are also influenced by the dipole moment and the saturation of C atoms, which is essentially due to the different redox ability of different functional groups with the material surface. Therefore, the degree of adsorption stability on the surface of the material is closely related to the dipole moment of polar molecules or the degree of bond saturation of C atoms of non-polar molecules. It is of great significance to explore the adsorption gas sensing of organic gases by studying the dipole moment of the gas and the degree of C bond saturation. [ABSTRACT FROM AUTHOR]

Iridium acetylacetonate is a transition metal organic complex composed of transition metal Ir and acetylcaetonato. It is also an important green phosphorescent material and a component of many iridium luminescent materials. In this paper, firstly, the structures of the Ir(acac)3 and [Ir(acac)3]2 were fully optimized at density function theory (DFT), the Infrared and Raman spectra were discussed. Secondly, excited states property is studied by CIS. The results of calculate shows that the electronic absorption spectrum of Ir(acac)3 and [Ir(acac)3]2 are in UV spectral region, absorption peaks of Ir(acac)3 are 260nm,350nm,414nm, absorption peaks of [Ir(acac)3]2 are 299nm,353nm and 401nm . Compared with their gas condition, the absorption in the CH3CN is blue- shifted. The results show that the spectrum by Kunkely and Arnd Vogler include the complex of characteristic absorption spectrum of Ir(acac)3 and [Ir(acac)3]2 . It proves that Ir(acac)3 is exist at higher concentration. Finally, the proportion of monomeric Ir(acac)3 and oligomers [Ir(acac)3]2 could calculated, discusses the forming reason of oligomers [Ir(acac)3]2 . [ABSTRACT FROM AUTHOR]

In this paper, the molecular geometry of dihydromyricetin was optimized based on density flooding theory (DFT)using B3LYP flooding combined with 6-31G group, based on which the active sites of dihydromyricetin molecules were calculated using water as solvent and the infrared spectra was analyzed. The electrostatic potential results showed that the nucleophilic active site of dihydromyricetin is located near the phenolic hydroxyl atom (H23) ; while the electrophilic active site is located in and near the oxygen atom (O32) . The results of frontline molecular orbital studies indicate that the highest occupied orbitals (HOMO) of dihydromyricetin molecules are located near ketone oxygen (O32)and hydroxyl oxygen (O20), indicating that these sites are susceptible to reaction with electrophilic reagents. And the lowest occupied orbitals (LUMO) are located in the carbon atom (C12, C13, C14) region, indicating that these regions can react with nucleophilic reagents. The results of the simplified Fukui function (f) confirm that the electrophilic activity of the f-value of the oxygen atom reagents. The results of the simplified Fukui function (f) confirm that the electrophilic activity of the f-value of the oxygen atom located in the C-O-C bond is larger than those of the oxygen atom in other sites; while the f+ value of the carbon atom located in C8 is larger, so the nucleophilic activity is stronger in this site. The infrared spectral data of dihydromyricetin obtained by theoretical calculations do not differ much from those obtained experimentally, which indicates that the theoretical calculations may be reliable. Thus, it provides some theoretical reference for the experimental and theoretical studies of the relationship between the structure and properties of dihydromyricetin. [ABSTRACT FROM AUTHOR]

CO, SO2, H2S are typical toxic gases gushing out of coal and surrounding rock or produced during production in mines. In the paper, first principles and density functional theory were used to study the adsorption characteristics of rare earth element Sc-doped ZnO on single gas molecules (CO, SO2, H2S). Through the analysis of the Mulliken, band structure, DOS and DCD of each system, the results show that: Sc-ZnO(001)-Zn position doping system has the best stability, the adsorption energy of Sc-ZnO on individual CO, SO2 and H2S molecules was -0.140 eV, -1.885 eV and -0.093 eV, respectively, of which the adsorption of SO2molecules was chemical adsorption and the rest was physical adsorption. The feasibility of Sc-ZnO as a semiconductor gas sensor to detect three toxic gases was determined, especially for SO2 gas, which provided theoretical guidance for Sc-ZnO as a gas sensing material to detect toxic gas in mines. [ABSTRACT FROM AUTHOR]

Nickel – based superalloy, its high-temperature mechanical properties are directly related to the operational safety and service life of the engine, is one of the key materials for manufacturing advanced acroengine hot – section components. In the paper, the influence of ruthenium (Ru) cluster on the deformation mechanism of Ni/Ni, Al nanowire was studied by using the modified analytical embedded atomic model(MAEAM) and mo- lecular dynamics (MD). The obtained results showed that the clastic modulus and yield strength of alloy nanowires decreased with increasing temperature as the uniaxial tensile strain was used. The deformation of nanowires at the lower temperature was caused by the generation and emission of dislocations, leading to lattice slippage. As the anharmonic effect of lattice thermal vibration was unobvious, the significant blocking effect of Ru cluster on the crystalline glide resulted in a slippage area, the distribution of which was only between the cluster and the Ni/Ni, Al phase interface and was asymmetric. At the higher temperature, the deformation of nanowire resulted from the lattice slippage attributing to dislocation emission. Due to the remarkable anharmonic effect of vibration, Ru cluster could ineffectively impede lattice glide and the slip region was asymmetrically distributed with respect to Ru cluster in the Ni3 Al phase. Finally, the influence of Ru clusters on the deformation of nanowire was further analysed from the perspective of its microstructure and stability. [ABSTRACT FROM AUTHOR]

The regulation of PT symmetry in the PT (Parity-Time) symmetric optical waveguide system is mainly realized by the periodic change of complex refractive index materials. In this paper, we give a configuration of manipulating the PT symmetry for the neutral waveguide with additional periodic modulation in the coupled dual-channel waveguide system. After the system is converted into an equivalent unmodulated system with renormalization parameters by high-frequency approximation, it is found that the PT symmetry of the system can be regulated by introducing an additional single-frequency periodic modulation optical waveguide, and the energy spectrum characteristics of the system with periodic modulation of non-Hermitian three-channel waveguide are discussed, Finally, the dynamic evolution of light in non-Hermitian three-channel optical waveguide is given by analytical and numerical methods. [ABSTRACT FROM AUTHOR]

Co, Ni and As doped pyrite crystals have different physical properties that affect their gold-bearing properties and oxidation behavior. In this paper, CASTEP software based on density functional theory was used to investigate the electronic structures of Co, Ni and As doped gold-bearing pyrites and to analyze their stabilities accordingly. Combining the semiconductor type and energy analysis, the order of stability of gold-bearing pyrites with different crystal defects is Fe32S63AsAu< Fe32S64Au< Fe31S64CoAu< Fe31S64NiAu, i.e. As-substituted gold-bearing pyrite is more susceptible to oxidation during oxidation pretreatment. This study can further explain the oxidation pretreatment pattern of gold-bearing pyrites with crystal defects in micro-dipping gold ores. [ABSTRACT FROM AUTHOR]

In recent years, rare-earth(RE) borate materials have attracted much attention because of their rich structures and excellent optical properties. In this paper, we use a first-principles high-throughput screening tool to obtain five high-performing short-wavelength rare-earth boronate materials and further investigate their electronic structures and optical properties. The results show that the UV cut-off edges and birefringences of these materials are 210 nm, 0.0934@1064 nm (LaB3O6), 246 nm, 0.0880@1064 nm (LaBO3), 347 nm, 0.0815@1064 nm (LuBO3), 272 nm, 0.0914@1064 nm ( ScBO3), 279 nm, 0.0920@1064 nm (Sc3B5O12). In this paper, we analyzed the mechanism of the influence of each atomic and ionic group on the birefringence using the projected density of states, real space atomic real cuts, and Born effective charge, and the results showed that RE-O groups and B-O polyhedra make the main contributions in determining the optical properties. [ABSTRACT FROM AUTHOR]

BACKGROUND: Percutaneous vertebroplasty is the most widely used method for the treatment of osteoporotic vertebral compression fractures, and most studies have concluded that percutaneous vertebroplasty increases the probability of adjacent vertebral secondary compression fractures in patients with osteoporotic vertebral compression fractures. However, controversy remains regarding the risk factors associated with adjacent vertebral re-fracture caused after percutaneous vertebroplasty. OBJECTIVE: To summarize the influencing factors of adjacent vertebral compression fractures after percutaneous vertebroplasty in patients with osteoporotic vertebral compression fractures, in order to provide a certain reference for reducing the risk of its occurrence as well as formulating the corresponding treatment plan. METHODS: Using “osteoporosis, fracture, percutaneous vertebroplasty, adjacent vertebral compression fractures, risk factors” as the Chinese search terms, “osteoporosis, osteoporotic vertebral compression fractures, percutaneous vertebroplasty, adjacent vertebral compression fractures, risk factors” as English search terms, computerized searches were conducted on CNKI, Wanfang Medical Network, VIP, PubMed, Springer, ScienceDirect, and Elsevier databases. The search timeframe focuses on January 2018 through September 2023, with the inclusion of a few classic forward literature. The literature was screened by reading the titles and abstracts, and 83 papers were finally included in the review. RESULTS AND CONCLUSION: (1) Osteoporotic vertebral compression fractures are one of the most common complications of osteoporosis, placing elderly patients at a significant risk of disability and death. Percutaneous vertebroplasty is a practical and effective treatment for osteoporotic vertebral compression fractures. (2) With the popularity of percutaneous vertebroplasty, its secondary vertebral compression fractures have gradually increased, with adjacent vertebral compression fractures being the most common. (3) Previous studies have only discussed the effects of factors such as bone mineral density, multiple vertebral fractures, body mass index, age, sex, amount of bone cement, cement leakage, and anti-osteoporosis treatment on secondary compression fractures of adjacent vertebrae after percutaneous vertebroplasty, and summarized the number of vertebral fractures, timing of the operation, surgical approach, cement material, diffuse distribution of bone cement, recovery height of the injured vertebrae, and wearing of a support after surgery, which is not yet comprehensive. The analysis of the specific mechanisms of risk factor-induced adjacent vertebral fractures is relatively rare. (4) The results of the article showed that low bone mineral density, advanced age, perimenopausal women, multiple vertebral fractures, excessive recovery of the height of the injured vertebrae, cement leakage, comorbid underlying diseases, and poor lifestyle habits were the risk factors for secondary adjacent vertebral compression fractures after percutaneous vertebroplasty, and that maintaining a normal body mass index, early surgery, bilateral percutaneous vertebroplasty, use of a new type of cement material, an appropriate volume of bone cement injection and uniform cement dispersion, regular anti-osteoporosis treatment, and postoperative brace wearing are protective factors for secondary adjacent vertebral compression fractures after percutaneous vertebroplasty. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bibliometrics and visual analyses based on thematic literature are particularly important for understanding the foundation and frontiers of postmenopausal osteoporosis research. OBJECTIVE: To perform bibliometric, citation, and visualization analyses of highly cited SCI papers in postmenopausal osteoporosis research over the last 20 years. METHODS: The top 100 highly cited papers on postmenopausal osteoporosis published between 2003 and 2022 included in SCI-EXPANDED catalog of the Web of Science database were obtained for bibliometric measure and visual analysis using CiteSpace software. RESULTS AND CONCLUSION: The top 100 highly cited papers have a total of 67 377 citations in the Web of Science Core Collection, with an annual average of 49.17 citations per paper. Postmenopausal osteoporosis research primarily involves medical, engineering, biological, and multidisciplinary fields. The subcategories are dominated by endocrinology and metabolism, and medicine: internal medicine. Stable and close cooperative network relationships have been formed globally. United States, University of California System, Cummings, and Steven R are the country, research institution, and author, respectively, with the most highly-cited publications. The frontiers of postmenopausal osteoporosis research mainly include calcium and vitamin D supplementation and fracture risk, clinical studies of bisphosphonates in the treatment of postmenopausal osteoporosis, atypical femur fracture, clinical studies of new drugs and sequential treatment of postmenopausal osteoporosis, predictors of fracture risk, mid- and long-term follow-up of osteoporotic vertebral compression fractures, genetic polymorphisms and hereditary factors, formulation and updating of clinical practice guidelines for postmenopausal osteoporosis. Large cohort studies, high-quality randomized controlled trials, systematic reviews, meta-analyses, and clinical practice guidelines are the great engines that drive the development of clinical research in postmenopausal osteoporosis. We should make efforts in the above areas to improve China’s international influence in the field of osteoporosis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Currently, there is no drug that can completely cure osteoarthritis and its pathogenesis is still unclear. Circular RNAs (circRNAs) are differentially expressed in patients with osteoarthritis and are closely associated with various pathological processes in osteoarthritis. circRNAs play an important role in various physiological and pathological processes, such as chondrocyte homeostasis, extracellular matrix formation, and inflammatory response. OBJECTIVE: To mainly review the effects of circRNAs on pathological factors related to osteoarthritis, as well as the types and expression levels of circRNAs in osteoarthritis. METHODS: Related articles published from 1976 to August 2023 were retrieved from CNKI, WanFang, VIP, PubMed, Medline, Web of Science and Elsevier databases. The keywords were “osteoarthritis, circular RNA, non-coding RNA, synovial tissue, chondrocytes” in Chinese and English, respectively. All the relevant articles were screened, summarized, analyzed, and finally 69 papers were included in the review. RESULTS AND CONCLUSION: circRNAs are non-coding RNAs widely found in eukaryotic cells, with covalently closed continuous loop structure, but with no 5′ hat structure and 3′poly A tail, which are involved in multi-gene and multi-target regulatory networks and cannot be degraded by nucleic acid exonucleases (RNase R). circRNAs have a high abundance, high conservativeness and stability, and cell and tissue specificity. circRNAs have biological functions such as acting as molecular sponges for miRNAs, regulating linear RNA transcription and RNA shearing, interacting with RNA-bound proteins, and translating proteins. circRNAs regulate chondrocyte apoptosis and proliferation, degradation of cartilage extracellular matrix, and inflammation and other physiopathologic processes. circRNAs are expected to become biomarkers and potential therapeutic targets for clinical diagnosis and prognosis of osteoarthritis, and may become a new strategy for clinical treatment of osteoarthritis in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Excessive accumulation of uric acid in the body can lead to diseases such as hyperuricemia and gout, which is a risk factor for cardiovascular and renal dysfunction. Many sports medicine organizations at home and abroad advocate the formulation of exercise prescription to prevent and treat chronic diseases, but this method has not been effectively carried out in the prevention and treatment of hyperuricemia. OBJECTIVE: Based on an overview of the formation of hyperuricemia and the regulation of uric acid by exercise and its related mechanisms, to condense a program suitable for popular exercise to prevent and assist in the treatment of hyperuricemia, and to propose precautions to be taken when exercising for patients with different stages of hyperuricemia. METHODS: PubMed and CNKI were searched for relevant literature published before October 2023 using the keywords of “uric acid, gout, aerobic exercise, strength training, high-intensity interval training, obesity” in English and Chinese, respectively. Initial screening was done by reading the titles and abstracts to exclude repetitive studies and literature with irrelevant content, and finally 64 papers were included for review. RESULTS AND CONCLUSION: The formation of hyperuricemia is caused by excessive synthesis of uric acid by the liver, insufficient excretion by the kidneys, or both. Exercise can improve the uric acid level in the body by regulating the activity of antioxidant enzymes, the expression of uric acid excretion protein and lipid metabolism. Aerobic exercise, strength training, high-intensity intermittent exercise can effectively regulate uric acid levels, reduce inflammation, promote the expression of uric acid excretion protein and lipid metabolism, and achieve good results in the prevention and treatment of hyperuricemia. Currently, there is a lack of research on the mechanisms underlying direct regulation of uric acid levels by exercise, and future studies need to explore in greater depth the possible mechanisms of regulation of uric acid levels by exercise and refine the effects of different exercise modalities on patients with different characteristics of hyperuricemia. [ABSTRACT FROM AUTHOR]

BACKGROUND: The application of orthodontic force triggers autophagy in the periodontal tissue via diverse signaling pathways, augmenting or attenuating the activity of relevant cell types such as periodontal ligament cells, osteocytes, osteoclasts, and osteoblasts, thus facilitating the process of periodontal remodeling. OBJECTIVE: To review the research progress in orthodontic force mediated autophagy in periodontal tissue and its impact on orthodontic tooth movement. METHODS: The PubMed, Web of Science, China Biology Medicine disc and CNKI were searched for literature published from 2010 to 2023 to summarize the progress in orthodontics-related autophagy. And 76 papers were finally included in the analysis and discussion. RESULTS AND CONCLUSION: Orthodontic force can trigger a series of biochemical signal changes through periodontal mechanical receptors and aseptic inflammation they cause, leading to autophagy in periodontal tissue. Subsequently, autophagy generates corresponding feedback through cascaded amplified signaling pathways such as Phosphoinositide 3-kinase/protein kinase B, Hippo, and mitogen-activated protein kinase pathways, promoting periodontal tissue remodeling and ultimately achieving tooth movement and stability. Orthodontic force-induced autophagy can differentially regulate bone resorption on the tooth pressure side and bone formation on the tension side. Related targets have good prospects in the clinical application of orthodontic treatment. Orthodontics and autophagy have complex mechanisms. However, existing research has only focused on exploring the role of autophagy in orthodontic tooth movement. Further exploration is needed to investigate the mutual regulatory effects between autophagy and orthodontic tooth movement, as well as the interactions between upstream mechanical receptors and signaling pathways involved in related pathways. [ABSTRACT FROM AUTHOR]

BACKGROUND: Gait is one of the optimal indicators of functional status in older adults. Gait parameters are associated with adverse health outcomes in older adults. OBJECTIVE: To summarize and compare the practical value of gait parameters, and to review the progress of research on spatio-temporal parameters and the risk of adverse health outcomes in older adults. METHODS: PubMed, Web of Science, and CNKI were searched for relevant literature published from January 2010 to June 2023 using the search terms of “gait speed, walking speed, step length, cadence, step frequency, step time, walking base, aged and elderly” in English and Chinese, respectively. A total of 52 papers were finally included for the systematic review. RESULTS AND CONCLUSION: Currently, researchers have focused on three basic temporal-spatial parameters, namely, step speed, step length and step frequency, to explore their association with adverse health outcomes in older adults. Reduced gait speed in older adults may increase the risk of falls, all-cause mortality, and may be an independent predictor of all-cause mortality. Older adults with slow gait speed are at higher risk of cognitive decline, and may be the preferred gait parameter in assessing cognitive impairment in older adults. Older adults with slow gait speed are more likely to have debilitating or common chronic illnesses, and are at higher risk of hospitalization and public care. Step length is positively correlated with individual height and lower limb length, but age-induced shortening of step length is not related to height or lower limb length, and shortening of step length reflects reduced physical function in older adults, and shortening of step length is a risk factor for falls and cognitive decline in older adults. Stride frequency is often used as a measure of exercise intensity, and a stride frequency of ≥ 100 steps/minute is predictive of all-cause mortality, and slowing of step frequency may lead to a higher risk of falls, hospitalization and all-cause mortality in older adults. Changes in gait parameters are closely related to the level of physical fitness in older adults, and there may be a bidirectional relationship between the two. The results of the study will provide a theoretical basis for further improving risk screening in clinical populations, refining health risk assessment in the elderly, improving health protection and promoting active health in the elderly. [ABSTRACT FROM AUTHOR]

The physical and chemical adsorptions of hydrogen are the basic forms for hydrogen storage, and the dissociation energy barrier of H2molecules is an important factor determining the kinetic performance of reversible hydrogen storage. Nanoclusters are important scale for studying the hydrogen-storage properties of materials. Studying interaction properties between hydrogen and Na-Al clusters can understand the hydrogen-storage properties of Na-Al hydrides at nano scale. In this paper,the adsorption and dissociation properties of H2molecules on the small alloy cluster Na2Al6are studied by density functional theory. The results show that the physical adsorption of H2molecule on Na2Al6cluster is very weak,but it can be dissociated easily. The dissociation energy barrier of hydrogen molecule is very low,and the dissociation can occur at moderate temperature. The nanostructured Na2Al6clusters have good chemical hydrogen-storage properties. [ABSTRACT FROM AUTHOR]

Void is a common defect in the preparation of FeCrNiCoCu high - entropy alloy. Thus, this paper employs molecular dynamic simulation to build FeCrNiCoCu models with void for uniaxial tension simulation, and explores the effect of the voids location, void radius and deformation temperature on the mechanical properties. It is found that the void in the crystal with the Z -axis orientation of [111] and at the grain-boundary(GB) will seriously reduce the yield strain and yield stress, but have little effect on the Young's modulus of the model. With the increase of the void radius at the grain boundary, in the elastic stage, the increase of the void radius increases the area of stress concentration, which is conducive to dislocation nucleation, and the mechanical proper- ties of the model decrease accordingly. In the plastic deformation stage, with the increase of the void radius, the initial dislocations tend to expand to the crystal with the Z axis orientation of [001]. The model maintains good mechanical properties at medium and low temperatures; at high temperature, the mechanical properties decrease significantly. In the high temperature plastic deformation stage, the total length of dislocation in the model is low, and the average flow stress is also low. [ABSTRACT FROM AUTHOR]

Two-dimensional Ag2S is a semiconductor material with an indirect wide band gap.It has received extensive attention due to its unique mechanical properties in and out of plane.In this paper,the electronic and optical properties of two-dimensional Ag2S are studied by first-principles calculations based on density functional theory.The two-dimensional Ag2S has strong directional anisotropy.By replacing S with O at different concentrations,it is found that the band gap value increases first and then decreases with the increase of O concentration.Due to the introduction of O element,the symmetry of the two-dimensional Ag2S structure is reduced,which causes the distribution discretization of energy band,light absorption and light reflection.The light absorption and light reflection peaks at 4.56～5.36 eV in the y direction gradually decrease with the increase of doping concentration,and there is an obvious blue shift. [ABSTRACT FROM AUTHOR]

In hydrogen liquefaction process,precooling cycle is an important link,among which the unit energy consumption of MR is relatively low,so it is particularly important to optimize the performance of MR.In this paper,the experimental system of VLE was built by the method of single-phase liquid phase cycle,and the properties of VLE in the ternary system R290+R600a+N2were studied.The temperature range of 273.15 K～323.15 K was used to study the ternary mixing medium R290+R600a+N2,and 18 groups of experimental data were obtained.At the same time,Peng-Pobinson-Stryjek-Vera （PRSV） equation of state combined with van der Waals（vdW） mixing rule was used to calculate the VLE properties of the ternary system.By comparing the experimental data with the calculated results,the average absolute relative deviation AARDp of the system pressure is 0.85%,and the average absolute deviation AADy1,AADy2and AADy3of the system components R290,R600a and N2are 0.0064,0.0027 and 0.0063,respectively. [ABSTRACT FROM AUTHOR]

BACKGROUND: Scoliosis mainly refers to sequence abnormalities in the coronal, sagittal, and axial positions of the spine, with a Cobb angle of ≥ 10°. The patients may experience symptoms such as unequal shoulder height and back asymmetry. Severe cases may affect the patient’s cardiopulmonary function, thereby affecting their daily life. Conservative treatment can control the progression of scoliosis and avoid later surgery. Scoliosis orthosis is currently a commonly used and effective treatment measure in conservative treatment. OBJECTIVE: To summarize and analyze the current research status, hotspots, and trends of scoliosis orthoses both domestically and internationally, providing reference for related research. METHODS: Using bibliometrics and visual analysis as tools, and using a comparison between China and foreign countries as a method, this paper analyzes the literature on scoliosis orthosis journals in the past decade. Based on bibliometrics, the current status of research on scoliosis orthoses is determined. Citespace software is used to analyze key words and identify the current hotspots and future trends in scoliosis orthosis research. RESULTS AND CONCLUSION: (1) At present, the number of literature on scoliosis orthoses is still on a fluctuating upward trend. China and the United States are the main countries for research, with a literature share of over 40%. However, the average citation rate of foreign language literature by Chinese scholars is relatively low. (2) The basic fields of domestic research are mainly surgery and pediatrics, while orthotics and clinical neurology are mainly studied abroad. Among them, there is also a certain number of documents in domestic Chinese medicine, indicating that China is also engaged in the combination of Chinese and Western treatment of scoliosis. The National Natural Science Foundation of China has the highest proportion in the aspect of Chinese and foreign literature, reflecting the importance of the fund attaches to the research of scoliosis orthosis. (3) The authors with the highest number of publications are Qiu Yong and Negrini Stefano, and the most published institutions are the Spinal Surgery Department of Gulou Hospital affiliated to Nanjing University Medical College and UDICE-French Research University. Domestic and foreign authors and institutions have certain communications about this, but not closely, which requires relevant institutions and scholars to further explore and study. (4) From the research hotspots and future trends, the main treatment type is adolescent idiopathic scoliosis, while the production method of the short-column side bending orthosis is three-dimensinoal printing, and the main treatment index is convex progression. The ultimate purpose of treatment is to improve the quality of life of the patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, as the popularity of long-distance fitness running continues to rise, more research progress has been made on related scientific issues. Among them, the landing pattern of long-distance running is an important biomechanical research hotspot at the level of running technique. OBJECTIVE: Using CiteSpace to visualize and analyze the relevant literature, the article sorts through the last decade’s literature on the subject to identify the current state, hot spots, and trends in the footprint as well as to further discuss the main research hotspots of the foot strike pattern from a biomechanical perspective. METHODS: “Foot strike pattern,” “Rearfoot strike,” “non-Rearfoot strike,” “Forefoot strike” and “Midfoot strike” were used as keywords to search the Web of Science Core Collection database. RESULTS AND CONCLUSION: A total of 896 relevant papers were finally included. The number of articles published in a year showed an overall upward trend. The top three countries in terms of the number of publications were the United States, China and the United Kingdom; the top three institutions were Harvard University, Shanghai University of Sports and the University of Massachusetts; and the top three authors were Davis Irene S, Hamill Joseph and Fu Weijie. The keywords “barefoot running, runner, injury, footing pattern, kinesiology” appear more frequently, and the keyword clusters include “energy cost, loading rate, footing pattern, risk factors, gait analysis”, and the relevant research still continues to be hot to this day. After analyzing the above data in detail, we found that the overall research intensity of foot strike pattern has remained stable in recent years, and the hotspot mainly focuses on the biomechanical research of foot strike pattern; the trend of this kind of research focuses on the influence and adaptability of different strike patterns (forefoot strike and rearfoot strike) on long-distance runners (barefoot, shoes, distance, speed, injury risk, running economy and energy consumption, etc.). Therefore, there is no “standardized optimal landing,” but there may be “individualized optimal landings.” It is suggested that researchers should select the optimal landing pattern and running technique strategy according to their own habitual way, movement pattern characteristics, exercise level and task attributes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Stem cell therapy has become an emerging method of treating pathological scars. miRNAs are involved in scarring mechanisms, and the targeted action of some stem cell sources of miRNA is mediated by exosomes. OBJECTIVE: To review the biological properties of miRNA derived from mesenchymal stem cells and its derivatives, the mechanism of treatment of scarring through anti-inflammation, suppression of excessive tissue reconstruction and antioxidation. METHODS: The first author used a computer in September 2023 to retrieve the relevant literature published from January 2000 to September 2023, searching for “stem cell, exosome, miRNA, keloid” in English, and “stem cells, exosome, keloid” in Chinese, eventually incorporating 74 papers for analysis. RESULTS AND CONCLUSION: (1) miRNAs with high expression of exosomes derived from mesenchymal stem cells increase the proportion of M2-type macrophages by promoting the polarization of macrophages, target the regulation of transforming growth factor β, transforming growth factor β receptors or related signaling pathways, inhibit the expression of pro-inflammatory factors, promote the expression of anti-inflammatory factors and other mechanisms to inhibit inflammation and thus suppress scar lesions. (2) miRNAs with high expression of exosomes derived from mesenchymal stem cells can reduce the secretion of matrix metalloproteinases, regulate the balance between matrix metalloproteinase inhibitors and matrix metalloproteinases, inhibit the proliferation and migration of fibroblasts and myofibroblasts, directly reduce the production of collagen and other mechanisms, and ultimately lead to the normal degradation of extracellular matrix, thereby inhibiting excessive tissue remodeling and cicatricial lesions. (3) miRNAs with high expression of exosomes from mesenchymal stem cells can improve the resistance of scar fibroblasts to oxidative stress by regulating reactive oxygen species and hypoxia-inducing factors, and then regulate the proliferation and apoptosis of scar fibroblasts to inhibit scar lesions. (4) Exosomes derived from mesenchymal stem cells have good prospects for scar treatment. Studies on this aspect can find mirnas that regulate inflammatory cells, inflammatory factors, signaling pathways, matrix metalloproteinases, fibroblasts, reactive oxygen species, hypoxia-inducing factors and other key factors from the three aspects of inflammation, tissue remodeling and oxidative stress. Then, by inducing mesenchymal stem cells with high expression of the above miRNA, exosomes were extracted, and finally verified and clinical trials were carried out. [ABSTRACT FROM AUTHOR]

BACKGROUND: Osteoarthritis is a common chronic inflammation of joints caused by degenerative changes of articular cartilage. More and more studies have shown that mechanical stress is closely related to the development of osteoarthritis. The Hippo pathway is not only involved in the development of tissue cells, but also an effecting factor of mechanical stress, which is involved in the regulation of bone metabolism and cartilage metabolism. OBJECTIVE: Regulation of the Hippo pathway may become one of the new targets for intervention in osteoarthritis. Therefore, this paper reviewed the research on the effect of mechanical stress regulation of the Hippo pathway on osteoarthritis to provide ideas for the pathogenesis of osteoarthritis and provide a new theoretical basis for the treatment of osteoarthritis. METHODS: PubMed, Web of Science, Embase, CNKI, VIP, and WanFang databases were used for a literature search for articles published from inception to 2023 concerning the influence of mechanical stress on osteoarthritis and mechanical stress, Hippo pathway, and osteoarthritis. A total of 75 articles were finally reviewed. RESULTS AND CONCLUSION: (1) Different mechanical stresses may play different roles in cell proliferation, apoptosis and differentiation, osteoarthritis inflammation, and vascular homeostasis in osteoarthritis. (2) Hard extracellular matrix, low cell density, medium shear force, medium tensile force, and compression force can achieve cell proliferation, osteogenic differentiation, and vascular homeostasis, and inhibit inflammatory response by activating YAP/TAZ. (3) Soft extracellular matrix, high cell density, excessive shear force, excessive tensile force, and compressive force inhibit cell proliferation, enhance cartilage differentiation, disrupt vascular homeostasis, and promote inflammation through inactivation of YAP/TAZ, thus promoting the process of osteoarthritis. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the continuous improvement and progress of artificial intelligence technology in the treatment of spinal deformity, a large number of studies have been invested in this field, but the main research status, hot spots and development trends are still unclear. OBJECTIVE: To visually analyze the literature related to artificial intelligence in the field of spinal deformities by using bibliometrics, identify the research hotspots and shortcomings in this field, and provide references for future research. METHODS: The core database of Web of Science was used to search the articles related to artificial intelligence in the field of spinal deformities published from inception to 2023. The data were visually analyzed by Citespace 5.6.R5 and VOSviewer 1.6.19. RESULTS AND CONCLUSION: (1) A total of 165 papers were included, and the number of papers published in this field showed a fluctuating upward trend. The author with the largest number of articles is Lafage V, and the country with the largest number of articles is China. (2) Keyword analysis results show that adolescent scoliosis, deep learning, classification, precision and robot are the main keywords. (3) The in-depth analysis results of co-cited and highly cited articles show that artificial intelligence has three hotspots in the field of spinal deformities, including the use of U-shaped architecture (a mature mode of deep learning convolutional neural networks) to automatically measure imaging parameters (Cobb angle and accurate segmentation of paraspinal muscles), multiview correlation network architecture (i.e., spine curvature assessment framework), and robot-guided spinal surgery. (4) In the field of artificial intelligence treatment of spinal malformations, the mechanism research such as genomics is very weak. In the future, unsupervised hierarchical clustering and other machine learning techniques can be used to study the basic mechanism of susceptibility genes in the field of spinal deformities by genome-wide association analysis and other genomics research methods. [ABSTRACT FROM AUTHOR]

BACKGROUND: The pathogenesis of osteoporosis is complex, and its essence is the weakening of bone formation and the enhancement of bone absorption caused by various reasons, resulting in the imbalance of bone metabolism. In recent years, N6-methyladenosine has been found (N6-methyladenosine, m6A) methylation can prevent and treat osteoporosis by regulating bone metabolism. OBJECTIVE: Taking the regulation of bone metabolism by m6A methylation as an entry point, to systematically sort out and summarize the research progress of m6A methylation in osteoporosis, so as to provide certain theoretical reference bases for the search of new therapeutic targets for osteoporosis. METHODS: CNKI, WanFang, VIP, PubMed, MEDLINE, Nature, and Cochrane databases were retrieved for relevant literature published from database inception to 2023. The keywords were “osteoporosis, m6A methylation, bone metabolism, bone marrow mesenchymal stem cells, osteoblasts, osteoclasts” in Chinese and English. Duplicates and obsolete non-referenced documents were excluded, and a total of 73 standard papers were included for further review. RESULTS AND CONCLUSION: m6A methylation can affect the activity and differentiation of bone marrow mesenchymal stem cells, osteoblasts, and osteoclasts through various pathways to regulate bone metabolism and prevent osteoporosis. The regulatory process of m6A methylation is extremely complex, and its related proteins play different roles in different cells. Even in the same kind of cells, the same type of proteins may have radically different roles, regulating different physiological and pathological processes. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The effect of post-activation potentiation on sports performance is characterized by increased muscle mobility and increased rate of muscle force generation. In this paper, Meta-analysis is used to quantitatively evaluate the effects of post-activation potentiation on sprint speed, jumping performance, and kinetic parameters (peak impulse, peak power, maximum ground reaction force, rate of force generation, etc.) after activation of relative strength levels in the lower limbs. METHODS: Electronic databases such as CNKI, WanFang, Web of Science, PubMed, and Medline were retrieved for randomized control, random crossover, or clear grouping according to the relative strength levels of the lower limbs (non-randomized controls) on the post-activation potentiation effect after activation induced by the relative strength level of the lower limbs. Free weight equipment and rapid telescopic compound exercises were used as main intervention methods in each group. The publication time of the literature was from the inception of each database until August 5, 2023. Endnote software was used to manage the literature. Literature quality assessment was conducted using the PEDro scale for randomized controlled trials and ROBINS-I 2.0 standards for nonrandomized controlled trials. Revman5.4 and Stata15.0 software were used to conduct publication bias evaluation, subgroup analysis and sensitivity analysis of the extracted data, and forest plots were produced for Meta-analysis. RESULTS: Eleven documents (seven randomized controlled trials and four non-randomized controlled trials) were finally included, including 216 subjects. Overall, the methodological quality of the literature was high. According to the grouping standard of 1-repetition maximum/body mass > 2 for the strong group and 1-repetition maximum/body mass ≤ 2 for the normal group, there were 99 subjects in the strong group and 117 subjects in the normal group, all of whom were male. The positive effect of post-activation potentiation on sprint performance in the strong group was significantly higher than that in the normal group [standardized mean difference (SMD)=-1.34, 95% confidence interval (CI): -1.74 to -0.93, P < 0.000 01]; the positive effect of post-activation potentiation on vertical jump height showed no significant difference between the strong and normal group (SMD=0.30, 95% CI: -0.07 to 0.66, P=0.11); the positive effect of post-activation potentiation showed no significant difference between the strong and normal groups in terms of peak impulse (SMD=-0.07, 95% CI:-0.62 to 0.47, P=0.61], peak power (SMD=0.21, 95% CI:-0.29 to 0.72, P=0.12), maximum ground reaction force (SMD=0.31, 95% CI: -0.20 to 0.81, P=0.16) and force generation rate (SMD=0.36, 95% CI: -0.11 to 0.82, P=0.39). CONCLUSION: The post-activation potentiation effect in the strong group can significantly increase the short-distance sprint speed. The potentiation effect after activation of the relative strength level of the lower limbs has similar effects on the kinematic and kinetic parameters, including explosive vertical jump height, peak impulse, peak power, maximum ground reaction force and force generation rate. [ABSTRACT FROM AUTHOR]

Graphene films,as a two-dimensional material,are excellent lubricants for improving the tribomechanical properties of micro/nano electro-mechanical systems ( MEMS/NEMS) . In order to investigate the influence of substrate material and graphene layer number on its friction reduction performance,this paper investigates the influence of graphene layer number on the friction reduction effect by preparing graphene coatings with different layer numbers on different substrates and using a combination of atomic force microscopy ( AFM) experiments and molecular dynamics ( MD) simulations. And by establishing the analytical model of the friction performance of graphene coatings with different layer numbers,it was investigated that the interlayer slip of graphene is the main factor to produce the wear reduction. The results show that the graphene coating has excellent wear reduction effect on both silicon substrate and copper substrate under different loads,and the friction decreases gradually with the increase of the number of graphene layers,and reaches the optimal 99. 3% wear reduction effect when the number of graphene layers is more than 10. The simulation analysis reveals that as the number of layers increases,the dry friction between graphene and substrate transforms into interlayer friction of graphene and generates interlayer shear slip,and the interlayer slip of graphene is the main factor leading to the excellent wear reduction performance of multilayer graphene. [ABSTRACT FROM AUTHOR]