Search

Abstract Background Triangular fibrocartilage complex (TFCC) injuries, especially Palmer type IB, pose surgical management challenges due to associated distal radial ulnar joint (DRUJ) instability. Traditional surgeries entail risks of complications. Arthroscopic repair presents advantages but lacks consensus on optimal techniques. To evaluate arthroscopic dual-bone tunnel repair in patients with Palmer type IB TFCC injuries of the wrist. Methods In this retrospective case series, grip strength ratio, joint range of motion, pain visual analogue scale (VAS), modified Mayo wrist score, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were assessed before and 12 months after surgery. Results The cohort consisted of 45 patients. At 12 months, the grip strength ratio improved from 0.71 ± 0.08 to 0.93 ± 0.05 (P

ObjectivesThe inter-ship structure between double-layer shells is an important bridge for the transmission of acoustic vibration from pressure shell to light shell. To reduce the impact on the acoustic vibration radiation level of ships, a double-layer acoustic bridge inter-ship structure is proposed and its acoustic vibration transmission characteristics studied.MethodsThe finite element method is used to establish a finite-length double-layer cylindrical shell acoustic vibration radiation model of an inter-board double-layer acoustic bridge. The differences between the sound and vibration transmission of the double-layer acoustic bridge and those of a traditional single-layer acoustic bridge structure are compared and analyzed. Finally, the influence of the double-layer acoustic bridge's structure, structural parameters and axial distribution spacing on its acoustic radiation and vibration transmission characteristics is revealed.ResultsThe results show that the double-layer acoustic bridge connection structure between double cylindrical shells has a better noise reduction effect than the traditional single-layer acoustic bridge structure. The effect of the "2-1" double-layer acoustic bridge structure model on reducing vibration transmission between double cylindrical shells is better than that of "1-2" and "2-2" double-layer acoustic bridge structures. Three different "1-1" double-layer acoustic bridge connection structures show similar vibration transmission reduction effects. The spacing of the bottom acoustic bridge ribs and the width of the transverse plate have a great influence on the vibration transmission reduction effect of the double-layer shell structure, while the height of the acoustic bridge has little effect. The closer the axial distribution of double-layer acoustic bridges between double cylindrical shells, the worse the vibration transmission reduction effect.ConclusionsThe results of this study can provide references for the shock absorption and noise reduction design of the inter-board structures of ships.

ObjectiveIn order to further improve the speed and accuracy of calculating the acoustic scattering fields of underwater concave targets, the acoustic scattering characteristics of underwater corner reflector complexes are studied. MethodBy applying the Kirchhoff approximation and ray tracing methods, and considering the multiple effects of scattering and occlusion by corner reflectors, a simplified acoustic scattering prediction model of an underwater corner reflector complex is established and a rapid prediction method （i.e. modified planar element method, PEM）of acoustic scattering fields is proposed. The acoustic scattering field of a corner reflector complex is calculated by this method and verified via finite element simulation; on this basis, an analysis is made of the characteristics of octahedral corner reflectors, combined polyhedral corner reflectors and cluster-based and space-based strong scattering targets. ResultsThe results show that the modified PEM allows the rapid and accurate calculation of the acoustic fields scattered by diagonal reflectors. The acoustic scattering fields of octahedral corner reflectors and combined polyhedral corner reflectors varies with the incident wave frequency, angle and reflector complex distance. ConclusionThe results of this study can provide important technical support for the design of underwater passive interferer models.

Abstract Background Polyunsaturated fatty acids (PUFAs) have demonstrated significant therapeutic potential across a wide range of disease. The aim of this study was to investigate the potential impact of PUFA intake on the prevalence of erectile dysfunction (ED). Methods The study included a total of 3730 participants from the National Health and Nutrition Examination Survey (NHANES) 2001–2004. Univariate analysis, multivariate regression analysis, subgroup analysis and machine learning were utilized to explore the relationship of variables to ED. Dose response curves were constructed to observe the linear or nonlinear relationship between PUFA intake and the prevalence of ED. Propensity score matching (PSM) was used for sensitivity analysis. Finally, the potential mechanistic link between PUFA intake and ED was explored. Results Through univariate and multivariate regression analysis results before and after PSM and XGBoost algorithm model results, arachidonic acid (AA) was chosen as the main research object. The consumption of AA was found to be associated with a decreased prevalence of ED under the fully adjusted model [OR = 0.33 (0.20, 0.56), P

ObjectivesIn order to further improve the accuracy of torpedoes in the acoustic homing identification of complex surface targets, a simulation study on the acoustic scattering characteristics of surface ship motion attitudes in random waves is carried out. MethodsTo effectively solve this problem based on Kirchhoff approximation theorem and six-degrees-of-freedom (DOFs) motion decomposition and synthesis method, a simplified prediction model for the multi-path acoustic scattering of surface targets is established. In this model, the effects of sea waves on the amplitude and period of a ship's six-DOFs motion are described by empirical statistics, and the rotation matrix and translation matrix are used to realize the coordinate transformation of each vertex of the surface target in a continuous motion state. On this basis, the model is used to analyze the contribution and influence of six-DOFs motion attitudes on the acoustic scattering characteristics of a surface ship from different horizontal detection angles.ResultsThe results show that the rolling and yawing motions have a great influence on the acoustic scattering of the target in the abeam detection, while the pitching motion has a great effect on the acoustic scattering in the bow and stern directions. Thus, the relationship between the surface ship's motion attitudes and acoustic scattering echoes is grasped.ConclusionsThis study can provide technical support for sonar equipment in the location and identification of surface targets.

Deregulation of cell cycles can result in a variety of cancers, including breast cancer (BC). In fact, abnormal regulation of cell cycle pathways is often observed in breast cancer, leading to malignant cell proliferation. CDK4/6 inhibitors (CDK4/6i) can block the G1 cell cycle through the cyclin D-cyclin dependent kinase 4/6-inhibitor of CDK4-retinoblastoma (cyclinD-CDK4/6-INK4-RB) pathway, thus blocking the proliferation of invasive cells, showing great therapeutic potential to inhibit the spread of BC. So far, three FDA-approved drugs have been shown to be effective in the management of advanced hormone receptor positive (HR+) BC: palbociclib, abemaciclib, and ribociclib. The combination strategy of CDK4/6i and endocrine therapy (ET) has become the standard therapeutic regimen and is increasingly applied to advanced BC patients. The present study aims to clarify whether CDK4/6i can also achieve a certain therapeutic effect on Human epidermal growth factor receptor 2 positive (HER2+) BC. Studies of CDK4/6i are not limited to patients with estrogen receptor positive/human epidermal growth factor receptor 2 negative (ER+/HER2-) advanced BC, but have also expanded to other types of BC. Several pre-clinical and clinical trials have demonstrated the potential of CDK4/6i in treating HER2+ BC. Therefore, this review summarizes the current knowledge and recent findings on the use of CDK4/6i in this type of BC, and provides ideas for the discovery of new treatment modalities.

Abstract The characteristics of traction network (TN) of the three‐phase 3‐kV traction power supply system (TPSS) are: three‐phase conductors are flat layout (layout‐1, layout‐2); the material and cross‐section of conductors are ferromagnetic and irregular, respectively. So the phase impedance matrix (PIM) is unbalanced and the closed‐form formula for conductor impedance is hard to get. To address these issues, firstly, the PIM is derived, and the cause of unbalance is revealed. From the perspective of structure optimization, a new flat layout (layout‐3) and an equilateral triangle layout (layout‐4) is proposed. Then, to calculate the wideband frequency self‐ and mutual impedances of the special phase conductors, a frequency‐ and current‐dependent closed‐form formula based on 4‐parameters equivalent tubular conductor (ETC) model is proposed. Furthermore, an equivalent TN circuit model at 50 Hz is established to calculate the receiving‐end voltage and its negative sequence voltage unbalance factor (NSVUF). Finally, using these two indexes, the performances of the layout‐1 to 4 are evaluated and compared. The results show that the conductor spacing and power supply frequency affect the two indexes much while the dimension of the power supply rail (PSR) not; layout‐4 can completely balance the receiving‐end voltage and improve its magnitude which can enhance the power supply capability.

Target strength (TS) and circular synthetic aperture sonar (CSAS) images provide essential information for active acoustic detection and recognition of non-cooperative unmanned undersea vehicles (UUVs), which pose a significant threat to underwater preset facilities. To access them, we propose an iterative physical acoustics (IPA)-based method to simulate the multiple acoustic scattered fields on rigid surfaces in high-frequency cases. It uses the Helmholtz integral equation with an appropriate Green's function in terms of the Neumann series, and then incorporates the ideas of triangulation and iteration into a numerical implementation. Then two approximate analytic formulae with precise physical meanings are derived to predict the TS and CSAS images of concave targets, respectively. There are no restrictions on the surface's curvature and the order of multiple scattering. The method is validated against the finite element method (FEM) for acoustic scattering from a sphere segment and against an experiment involving an X-rudder UUV's stern. On this basis, we simulate and analyze the TS and CSAS images of an X-rudder UUV. In addition, the influence of the angle of adjacent rudders on the multiple scattering characteristics is discussed. Results show that this method can potentially predict accurate UUV features, especially the multiple scattered features.

PurposeIt is currently controversial whether smoke exposure is associated with the risk of kidney stones. Herein, publicly available databases were combined to explore relationships with the risk of nephrolithiasis in terms of smoking status and serum cotinine concentrations.Materials and methodsFirst, we conducted an observational study using data from 2007 to 2018, based on the National Health and Nutrition Examination Survey (NHANES) database. Univariate analysis, multivariate logistic regression, trend testing, restricted cubic spline (RCS), and multiple imputation (MI) were the main analytical methods of our study. Then, A Mendelian randomization (MR) analysis was performed to explore the causal relationship between serum cotinine and nephrolithiasis. Genetic instruments for serum cotinine and pooled data for kidney stones were derived from publicly available large-scale genome-wide association studies (GWAS). Inverse-variance weighting (IVW) was the primary method for our MR analysis.ResultsA total of 34,657 and 31,352 participants were included in the observational study based on smoking status and serum cotinine concentrations, respectively. Under full adjustment of covariates, current smokers had an increased risk of kidney stones compared to non-smokers [OR = 1.17 (1.04–1.31), P = 0.009, P for trend = 0.010]. Compared with serum cotinine of

Metasurfaces open up unprecedented potential for applications in acoustic deflection. Achieving adaptive control of a scattered sound field (SSF) using a flexible metasurface structure is of great scientific interest. However, as the conventional finite element method (FEM) is limited by computational efficiency, it is necessary to develop a fast and accurate method to predict the SSF. In this work, we design a chessboard device with an array of square grooves for the modulation of SSF and develop a fast calculation method for 3D SSF using a Kirchhoff approximation phase correction. Several SSF spatial modulations obtained using the chessboard model are computed with a fast algorithm. In addition, an experimental test-case in a semi-anechoic chamber, contrasted and analyzed scattered acoustic pressure using FEM, is designed to regulate the SSF performance of the chessboard device. Field measurements obtained show that the spatial directivity of chessboard device can be modified by artificially programming the phase or depth distribution of the groove array. The chessboard device and associated fast calculation method lend themselves to applications in the acoustic stealth of targets in air or water.

Disulfide bonds are dynamic covalent bonds, which are easy to cleave and reform upon chemical stimulus. Various methods including the oxidative coupling of thiols and polymerization of disulfide-containing monomers have been developed for the synthesis of poly(disulfide)s. However, installing small amounts of disulfide units in the main chain of polyolefins has received much less attention. Herein, we report a novel strategy for incorporating cleavable disulfide units into the backbone of polyolefins using commercially available diallyl disulfide (DADS) as a comonomer via metathesis copolymerization. The copolymerization of diallyl disulfide with cyclooctene occurred using the second-generation Grubbs catalyst under mild conditions, allowing for the synthesis of copolymers with adjustable disulfide content ranging from 0.7 to 8.5 mol%, and the molecular weight of the obtained copolymers ranged from 5.8 kg·mol−1 to 42.8 kg·mol−1. The resulting polyolefins with disulfide insertion retained excellent thermal processability and exhibited degradability. Treatment of the copolymer (8.5 mol% disulfide content) with tri-n-butylphosphine resulted in a significant reduction in molecular weight from 5.8 kg·mol−1 to 1.6 kg·mol−1. Successful copolymerization with diallyl disulfide provides a convenient and effective method for obtaining degradable polyolefins.

Abstract Cascaded H‐bridge inverter (CHBI) is widely used in the industry application for its outstanding features. However, CHBI needs a large number of isolated DC sources. If some of the DC sources are out of work, the DC voltage cannot maintain the desired value and even decreases to zero, thus degrading the quality of the output voltage of the CHBI. Thus, a soft‐switching modulation strategy based on the carrier phase shift SPWM is proposed in this paper to cope with the DC source failure. The strategy is proposed to achieve two goals: 1) one is to adjust the DC voltage of faulty cells back to the normal; 2) the other one is to make the pulse width modulation (PWM) pulses of each cell change without cell voltage level‐skip. The correction and efficiency are verified by a prototype of three‐cell CHBI built in the laboratory.

The sharing economy has greatly promoted the rapid development and application of spatial crowdsourcing. Although privacy-preserving spatial task matching as an indispensable part has been extensively explored, existing schemes cannot be deployed into the practical environment due to drawbacks in the one-side location protection, the matching efficiency, and the dynamic updates. In this study, we propose a novel Secure and Efficient Spatial Task Matching framework (SESTM) with utilizing multi-user searchable encryption and secure index technique, which enables to preserve the location privacy of requesters and workers while achieving efficient task allocation and good user scalability. Specifically, requesters firstly transform and encrypt their task locations before being outsourced, and we secondly design a secure and dynamic tree-based index SD-Tree for SC-server to merge these uploaded encrypted data without knowing their underlying content. Finally, SESTM provides efficient task matching services for multiple workers based on encrypted queries. Furthermore, SD-Tree also provides fast delete and insert operations under logarithmic time to reduce the dynamic update overhead for real SC services. Extensive theoretical analysis and performance evaluation demonstrate the practicality of our method.

In this paper, a new precast self-centering rocking shear wall system (PSCRSW) mainly composed of precast reinforced concrete (RC) wall, V-shaped steel brace and pre-pressed disc spring friction damper (PDSFD) are proposed to enhance the seismic resilience of steel moment resisting frame (SMRF). The mechanical behavior of PDSFD was investigated and simulated. The skeleton model of PSCRSW was theoretically derived and numerically validated, and the hysteretic performance under different design parameters was discussed and compared with that of the conventional RC shear wall. Based on the analyses, design principles and suggestions for PSCRSW were given. Then, an efficient seismic resilient design method for enhancement of SMRF was proposed, which considers performance objectives of multiple seismic hazard levels and has less design iteration. A typical SMRF was adopted as the prototype to be enhanced by the presented PSCRSW and design method. Reliable numerical models for the prototype and the enhanced SMRF were established, and nonlinear dynamic analyses were performed to assess the effectiveness of enhancing strategy. The results show that PSCRSW can realize approximate yielding behavior, displacement capacity and lateral strength to the conventional shear wall and can significantly lower the residual drift and wall damage. During the design, the ratio of preload to friction force for PSCRSW was suggested to be 1.5~2.0, and the bearing capacity for the wall was suggested to be amplified 1.2 times. Thereby, desirable bearing and self-centering performances can be guaranteed. The presented design method is capable of achieving the inter-story drift ratio targets and the expected roof drift ratios simultaneously, and the seismic resilience of the chosen SMRF was significantly improved by a large margin of reduction in residual inter-story drift and frame member damages.

The denoising and detection of transient disturbances are two important subjects for power quality monitoring and analysis. To effectively denoise and detect transient disturbances under noisy conditions, an improved iterative adaptive kernel regression method is proposed in this paper. The proposed method has advantages in that it does not need to estimate the noise variance or a filter threshold, and has both denoising and detection capabilities for transient disturbances. Simulation results demonstrate that the proposed method provides excellent denoising effects, which can not only suppress noise effectively but also preserve disturbance features of sudden change points well. Additionally, it provides good detection and location performance for single and combined transient disturbances, even under strong noise conditions. Finally, the effectiveness of the proposed method is further verified by using real disturbance data.

In this study, in a novel buckling-restrained steel plate shear wall (BRSPSW) with out-of-plane deformation spaces, angle steel stiffeners have been installed so as to create gaps between the steel plate and the covering concrete slabs. A finite element model has been developed to analyse the effect of the gap. According to the finite element results, seismic performance of this novel BRSPSW has been tested under cyclic loading at the scale ratio of 1/3. The failure pattern, hysteretic characteristics, skeleton curve, equivalent stiffness, ductility, and energy dissipation have all been systematically analysed. A stiffened steel plate shear wall (SPSW) has also been tested in order to determine the differences between these two steel shear walls in load-carrying capability and the function and significance of the gap. The test results show that the novel BRSPSW does not only significantly enhance the ultimate bearing capacity, stiffness, ductility, and accumulated energy dissipation of the SPSW but also keep the steel plate basically intact at the end of the test. This can be attributed to the existence of the gaps between the infilled steel plate and the covering concrete slabs. The hysteretic characteristics and the strength and deformation characteristics of this novel BRSPSW have been simulated by using the finite element model, and the test results are in good agreement with the finite element results. Hence, the BRSPSW is an excellent steel plate shear wall to be used in high rise structure to resist horizontal loadings.

A novel cost-effective isolator reinforced by engineering plastics has been designed and manufactured for seismic protection for low-rise buildings in less developed areas. The reinforcement is flexible in tension, which is similar to fiber-reinforced isolators. However, available solutions for fiber-reinforced isolators are not applicable, because the Poisson effect of engineering plastics cannot be neglected, which is done for fiber reinforcement. In this paper, analytical solutions for compression and bending stiffness for rectangular isolators reinforced by engineering plastics are proposed, with both the Poisson effect of the reinforcement and the effect of rubber compressibility taken into consideration. Then, the simplified solutions are also derived, which can greatly improve calculation efficiency. To validate the solutions, finite element analysis is conducted on a set of isolators with different reinforcement stiffnesses. The results show the superiority of the proposed solutions to the previous solutions for fiber-reinforced isolators. A series of experimental tests of the isolators are also carried out to verify the solutions. Both the analytical and the simplified solutions match well with the experimental results.

In railway electrification systems, the harmonic impedance of the traction network is of great value for avoiding harmonic resonance and electrical matching of impedance parameters between trains and traction networks. Therefore, harmonic impedance identification is beneficial to suppress harmonics and improve the power quality of the traction network. As a result of the coupling characteristics of the traction power supply system, the identification results of harmonic impedance may be inaccurate and controversial. In this context, an identification method based on a data evolution mechanism is proposed. At first, a harmonic impedance model is established and the equivalent circuit of the traction network is established. According to the harmonic impedance model, the proposed method eliminates the outliers of the measured data from trains by the Grubbs criterion and calculates the harmonic impedance by partial least squares regression. Then, the data evolution mechanism based on the sample coefficient of determination is introduced to estimate the reliability of the identification results and to divide results into several reliability levels. Furthermore, in the data evolution mechanism through adding new harmonic data, the low-reliability results can be replaced by the new results with high reliability and, finally, the high-reliability results can cover all frequencies. Moreover, the identification results based on the simulation data show the higher reliability results are more accurate than the lower reliability results. The measured data verify that the the data evolution mechanism can improve accuracy and reliability, and their results prove the feasibility and validation of the proposed method.

The excessive use of power electronics makes power quality problems in power grids increasingly prominent. The estimation of the harmonic parameters of harmonic sources in the power grid and the division of harmonic responsibilities are of great significance for the evaluation of power quality. At present, methods for estimating harmonic parameters and harmonic responsibilities need to provide the amplitude and phase information of the current and voltage of the point of common coupling (PCC). However, in practical engineering applications, the general power quality monitor only provides the amplitude information of the voltage and current of the measured point and the phase difference information between them. Missing phase information invalidates existing methods. Based on the partial least squares regression method, the present work proposes a method for estimating harmonic parameters in the case of monitoring data without phase. This method only needs to measure the amplitude information of the harmonic voltage and current of the PCC and the phase difference between them, then use the measurable data to estimate the harmonic parameters and the harmonic responsibility of each harmonic source. It provides a new way to effectively solve the problem that the measured data of the project has no phase information. The feasibility and effectiveness of the proposed method are proved by simulation data and measured engineering data.

Deregulation of cell cycles can result in a variety of cancers, including breast cancer (BC). In fact, abnormal regulation of cell cycle pathways is often observed in breast cancer, leading to malignant cell proliferation. CDK4/6 inhibitors (CDK4/6i) can block the G1 cell cycle through the cyclin D-cyclin dependent kinase 4/6-inhibitor of CDK4-retinoblastoma (cyclinD-CDK4/6- INK4-RB) pathway, thus blocking the proliferation of invasive cells, showing great therapeutic potential to inhibit the spread of BC. So far, three FDAapproved drugs have been shown to be effective in the management of advanced hormone receptor positive (HR+) BC: palbociclib, abemaciclib, and ribociclib. The combination strategy of CDK4/6i and endocrine therapy (ET) has become the standard therapeutic regimen and is increasingly applied to advanced BC patients. The present study aims to clarify whether CDK4/6i can also achieve a certain therapeutic effect on Human epidermal growth factor receptor 2 positive (HER2+) BC. Studies of CDK4/6i are not limited to patients with estrogen receptor positive/human epidermal growth factor receptor 2 negative (ER+/HER2-) advanced BC, but have also expanded to other types of BC. Several pre-clinical and clinical trials have demonstrated the potential of CDK4/6i in treating HER2+ BC. Therefore, this review summarizes the current knowledge and recent findings on the use of CDK4/6i in this type of BC, and provides ideas for the discovery of new treatment modalities. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the efficacy of combined Vitamin D and zoledronic acid injection therapy in the treatment of osteoporosis. The control group received zoledronic acid injections through intravenous infusion. In contrast, the observation group was administered vitamin D drops in addition to the standard treatment. Comparative analysis revealed that the observation group demonstrated a significantly higher total effective rate than the control group. Post-treatment assessments indicated that levels of N-terminal propeptide of type I collagen and β-isomerized C-terminal telopeptide were substantially lower in the observation group as compared to the control group. The 25-hydroxyvitamin D levels in the observation group were notably higher. Post-treatment evaluations showed that the observation group had significantly higher bone mineral density in the femoral neck, hip joint, and L1–4 segments. The Oswestry Disability Index score was also found to be lower in the observation group post-treatment, indicating a reduction in disability. The incidence of adverse reactions was significantly lower in the observation group compared to the control group. In conclusion, the combination of Vitamin D and zoledronic acid injection demonstrates substantial effectiveness in treating osteoporosis by improving bone metabolic indices and bone mineral density while also enhancing the safety profile of the drug. [ABSTRACT FROM AUTHOR]

Target strength (TS) and circular synthetic aperture sonar (CSAS) images provide essential information for active acoustic detection and recognition of non-cooperative unmanned undersea vehicles (UUVs), which pose a significant threat to underwater preset facilities. To access them, we propose an iterative physical acoustics (IPA)-based method to simulate the multiple acoustic scattered fields on rigid surfaces in high-frequency cases. It uses the Helmholtz integral equation with an appropriate Green's function in terms of the Neumann series, and then incorporates the ideas of triangulation and iteration into a numerical implementation. Then two approximate analytic formulae with precise physical meanings are derived to predict the TS and CSAS images of concave targets, respectively. There are no restrictions on the surface's curvature and the order of multiple scattering. The method is validated against the finite element method (FEM) for acoustic scattering from a sphere segment and against an experiment involving an X-rudder UUV's stern. On this basis, we simulate and analyze the TS and CSAS images of an X-rudder UUV. In addition, the influence of the angle of adjacent rudders on the multiple scattering characteristics is discussed. Results show that this method can potentially predict accurate UUV features, especially the multiple scattered features. [ABSTRACT FROM AUTHOR]