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Abstract Objective Clinically, it has been found that patients undergoing knee replacement have a high incidence of concomitant hallux valgus. In this study, we analyzed whether patients with osteoarthritis who underwent surgery and those patient who did not have surgery had an increased risk of hallux valgus by Mendelian randomization and performed reverse causal analysis. Design Genomewide association study (GWAS) data for osteoarthritis, categorized by knee arthritis with joint replacement, knee arthritis without joint replacement, hip arthritis with joint replacement, and hip arthritis without joint replacement.And acquired hallux valgus were downloaded for Mendelian randomized studies. MR analysis was performed using inverse variance-weighted (IVW), weighted median, and MR-Egger methods. MR-egger regression, MR pleiotropic residuals and outliers (MR-presso), and Cochran's Q statistical methods were used to evaluate heterogeneity and pleiotropy. Results The IVW results indicate that, compared to healthy individuals, patients who meet the criteria for knee osteoarthritis joint replacement surgery have a significantly higher risk of acquired hallux valgus. There were no significant causal relationships found for the remaining results. No significant heterogeneity or multiplicity was observed in all the Mr analyses. Conclusion Our study supports the increased risk of acquired hallux valgus in patients eligible for knee replacement. There is necessary for clinicians to be concerned about the hallux valgus status of patients undergoing knee arthroplasty.

Objective Glucocorticoid (GC) overuse is strongly associated with steroid‐induced osteonecrosis of the femoral head (SINFH). However, the underlying mechanism of SINFH remains unclear. This study aims to investigate the effect of dexamethasone (Dex)‐induced oxidative stress on osteocyte apoptosis and the underlying mechanisms. Methods Ten patients with SINFH and 10 patients with developmental dysplasia of the hips (DDH) were enrolled in our study. Sixty rats were randomly assigned to the Control, Dex, Dex + N‐Acetyl‐L‐cysteine (NAC), Dex + Dibenziodolium chloride (DPI), NAC, and DPI groups. Magnetic resonance imaging (MRI) was used to examine edema in the femoral head of rats. Histopathological staining was performed to assess osteonecrosis. Immunofluorescence staining with TUNEL and 8‐OHdG was conducted to evaluate osteocyte apoptosis and oxidative damage. Immunohistochemical staining was carried out to detect the expression of NOX1, NOX2, and NOX4. Viability and apoptosis of MLO‐Y4 cells were measured using the CCK‐8 assay and TUNEL staining. 8‐OHdG staining was conducted to detect oxidative stress. 2′,7′‐Dichlorodihydrofluorescein diacetate (DCFH‐DA) staining was performed to measure reactive oxygen species (ROS). The expression of NOX1, NOX2, and NOX4 in MLO‐Y4 cells was analyzed by Western blotting. Multiple comparisons were performed using one‐way analysis of variance (ANOVA). Results In patients and the rat model, hematoxylin–eosin (HE) staining revealed a significantly higher rate of empty lacunae in the SINFH group than in the DDH group. Immunofluorescence staining indicated a significant increase in TUNEL‐positive cells and 8‐OHdG‐positive cells in the SINFH group compared to the DDH group. Immunohistochemical staining demonstrated a significant increase in the expression of NOX1, NOX2, and NOX4 proteins in SINFH patients compared to DDH patients. Moreover, immunohistochemical staining showed a significant increase in the proportion of NOX2‐positive cells compared to the Control group in the femoral head of rats. In vitro, Dex significantly inhibited the viability of osteocyte cells and induced apoptosis. After Dex treatment, the intracellular ROS level increased. However, Dex treatment did not alter the expression of NOX proteins in vitro. Additionally, NAC and DPI inhibited the generation of intracellular ROS and partially alleviated osteocyte apoptosis in vivo and in vitro. Conclusion This study demonstrates that GC promotes apoptosis of osteocyte cells through ROS‐induced oxidative stress. Furthermore, we found that the increased expression of NOXs induced by GC serves as an important source of ROS generation.

Abstract Background The relationship between aging and osteoporosis is well established. However, the relationship between the body's physiological age, i.e. epigenetic age, and osteoporosis is not known. Our goal is to analyze the bidirectional causal relationship between epigenetic clocks and osteoporosis using a bidirectional Mendelian randomization study. Methods We used SNPs closely associated with GrimAge, Hannum, PhenoAge, and HorvathAge in epigenetic age and SNPs closely associated with femoral neck bone mineral density, lumbar spine bone mineral density, and forearm bone mineral density as instrumental variables, respectively, using the inverse variance weighting method and several other MR methods to assess the bidirectional causal relationship between epigenetic age and osteoporosis. Result There was no evidence of a clear causal relationship of epigenetic age (GrimAge, Hannum, PhenoAge, and HorvathAge) on femoral neck bone mineral density, lumbar spine bone mineral density, and forearm bone mineral density. In reverse Mendelian randomization analysis showed a significant causal effect of lumbar spine bone mineral density on GrimAge: odds ratio (OR) = 0.692, 95% confidence interval (CI) = (0.538–0.890), p = 0.004. The results suggest that a decrease in lumbar spine bone mineral density promotes an acceleration of GrimAge. Conclusion There was no significant bidirectional causal relationship between epigenetic age and osteoporosis A decrease in lumbar spine bone density may lead to an acceleration of the epigenetic clock "GrimAge". Our study provides partial evidence for a bidirectional causal effect between epigenetic age and Osteoporosis.

Abstract Few‐shot action recognition aims to learn a classification model with good generalisation ability when trained with only a few labelled videos. However, it is difficult to learn discriminative feature representations for videos in such a setting. The Elastic Temporal Alignment (ETA) for few‐shot action recognition is proposed. First, a convolutional neural network is employed to extract feature representations of video frames sparsely sampled from videos. In order to obtain the similarity of two videos, a temporal alignment estimation function is utilised to estimate the matching score between each pair of frames from the two videos through an elastic alignment mechanism. The analysis shows that when we judge whether two frames from respective videos are matched, multiple adjacent frames in the videos should be considered, so as to embody the temporal information. Thus, before feeding per‐frame feature vectors of videos into the temporal alignment estimation function, a temporal message passing function is leveraged to propagate the information of per‐frame features in the temporal domain. The method has been evaluated on four action recognition datasets, including Kinetics, Something‐Something V2, HMDB51, and UCF101. The experimental results verify the effectiveness of ETA and show its superiority over state‐of‐the‐art methods.

The purpose of this meta‐analysis was to identify if patient‐specific instrumentation (PSI) could increase the accuracy of the correction in high tibial osteotomy (HTO) and to explore the assessment indices and the necessity of using a PSI in HTO. A systematic search was carried out using online databases. A total of 466 patients were included in 11 papers that matched the inclusion criteria. To evaluate the accuracy of PSI‐assisted HTO, the weight bearing line ratio (WBL%), hip‐knee‐ankle angle (HKA), mechanical medial proximal tibial angle (mMPTA), and posterior tibial slope angle (PTSA) were measured preoperatively and postoperatively and compared to the designed target values. Statistical analysis was performed after strict data extraction with Review Manager (version 5.4). Significant differences were detected in WBL% (MD = −36.41; 95% CI: −42.30 to −30.53; p

IntroductionThe causal relationship between Coronavirus disease 2019 (COVID-19) and osteoporosis (OP) remains uncertain. We aimed to assess the effect of COVID-19 severity (severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, COVID-19 hospitalization, and severe COVID-19) on OP by a two-sample Mendelian randomization (MR) study.MethodsWe conducted a two-sample MR analysis using publicly available genome-wide association study (GWAS) data. Inverse variance weighting (IVW) was used as the main analysis method. Four complementary methods were used for our MR analysis, which included the MR–Egger regression method, the weighted median method, the simple mode method, and the weighted mode method. We utilized the MR-Egger intercept test and MR pleiotropy residual sum and outlier (MR-PRESSO) global test to identify the presence of horizontal pleiotropy. Cochran’s Q statistics were employed to assess the existence of instrument heterogeneity. We conducted a sensitivity analysis using the leave-one-out method.ResultsThe primary results of IVW showed that COVID-19 severity was not statistically related to OP (SARS-CoV-2 infection: OR (95% CI) = 0.998 (0.995 ~ 1.001), p = 0.201403; COVID-19 hospitalization: OR (95% CI) =1.001 (0.999 ~ 1.003), p = 0.504735; severe COVID-19: OR (95% CI) = 1.000 (0.998 ~ 1.001), p = 0.965383). In addition, the MR-Egger regression, weighted median, simple mode and weighted mode methods showed consistent results. The results were robust under all sensitivity analyses.ConclusionThe results of the MR analysis provide preliminary evidence that a genetic causal link between the severity of COVID-19 and OP may be absent.

To improve the economic benefits of engineered cementitious composites and control the repair cycle, repair materials were designed, with the key components of the mixture being low-cost polypropylene (PP) fibers and fast-setting sulfoaluminate cement. The effects of water/binder ratio, fiber content, and aggregate particle size on the flowability, mechanical properties, and toughness of the polypropylene fiber-reinforced sulfoaluminate cementitious composite (PP-SACC) were explored. Based on experimentally measured axial tensile stress–strain curves, a constitutive model of PP-SACC was derived in terms of fiber content and water/binder ratio. Additionally, the correlation coefficients representing the relationships of the mixture indices with the tensile properties were explored based on revised gray relational analysis. Test results indicated that fiber content and water/binder ratio were the most important factors affecting the mechanical properties, toughness, and fluidity of the material; in contrast, the influence of aggregate size was slight. The PP-SACC mixture with an aggregate size of 75 µm, a water/binder ratio of 0.30, and a fiber content of 3.0% demonstrated an excellent degree of toughness and exhibited a flexural hardening phenomenon under bending load.

The procoagulant effect of microparticles (MPs) contributes to hypercoagulability-induced thrombosis. We provide preliminary findings of the MPs-Activated Clotting Time (MPs-ACT) assay to determine the procoagulant activity of MPs. MPs-rich plasma was obtained and recalcified. Changes in plasma viscoelasticity were evaluated and the time to the peak viscoelastic changes was defined as the MPs-ACT. MPs concentration was measured by flow cytometry. Coagulation products produced during plasma clotting were identified by fibrin and fibrinopeptide A. MPs were prepared in vitro and added to standard plasma to simulate pathological samples. In addition, reproducibility and sensitivity were evaluated. We confirmed the linear relationship between MPs-ACT and MP concentrations. Dynamic changes in fibrin production were depicted. We simulated the correlation between MPs-ACT and standard plasma containing MPs prepared in vitro. The reproducibility of high-value and low-value samples was 6.0% and 10.8%, respectively. MPs-ACT sensitively detected hypercoagulable samples from patients with pre-eclampsia, hip fractures, and lung tumors. MPs-ACT largely reflects the procoagulant effect of MPs. MPs-ACT sensitively and rapidly detects hypercoagulability with MPs-rich plasma. It may be promising for the diagnosis of hypercoagulable states induced by MPs.

BackgroundOsteoarthritis has the characteristics of degenerative changes in articular cartilage and secondary osteoporosis, and it is a common chronic irreversible joint disease. In addition to affecting articular cartilage, subchondral bone, joint capsule and synovial membrane also undergo pathological changes during the development of the disease. Multiple studies have revealed that patients with osteoarthritis were found to have a significantly increased risk of osteoporosis, which also contributes to the progression of osteoarthritis. However, in the current existing studies, we found that no scholars have used bibliometric analysis in the study of the relationship between osteoarthritis and osteoporosis. From the perspective of bibliometrics, this study summarizes in detail the degree of cooperation between countries, research institutions, authors, and related journals in the field of osteoarthritis and osteoporosis research and their respective influence. In this way, the evolution of knowledge structure, the change of research focus and the hot topics with research potential in the future can be further visualized and analyzed.MethodsSearch the Web of Science core collection in Science Citation Index Expanded for articles and reviews of research on osteoarthritis and osteoporosis from 1998 to 2021. Bibliometric tools such as VOSviewer, CiteSpace, were be frequently used in our study. They are mainly used to analyze collaborations between countries, research institutions, and publication authors. Meantime, co-citation analysis of journals, co-occurrence analysis of keywords and subject categories will also be reflected in the study.ResultsAccording to the search strategy, 1,078 publications were included during the period 1998–2021. And the number of annual publications on the relationship between osteoarthritis and osteoporosis is on the rise. The United States has achieved the most and contributed the most in this field and the Boston University was the most prolific institution. For the statistical analysis of published publications, Reginster JY had the highest number of publications, while Felson DT had the highest co-citation frequency. Respectively, Osteoarthritis And Cartilage was the most productive journal in this area of research. The keywords “inflammation,” “expression,” and “mesenchymal stem cells” may also be the development trend and research hotspot of the future research direction in this field.ConclusionsIn our study, the relationship between osteoarthritis and osteoporosis was analyzed by using literature measurement. These analysis results can lead researchers to learn more directly about the trend in this area and provide guidance for determining popular research directions.

In contrast to most existing works on robust unit commitment (UC), this study proposes a novel big-M-based mixed-integer linear programming (MILP) method to solve security-constrained UC problems considering the allowable wind power output interval and its adjustable conservativeness. The wind power accommodation capability is usually limited by spinning reserve requirements and transmission line capacity in power systems with large-scale wind power integration. Therefore, by employing the big-M method and adding auxiliary 0-1 binary variables to describe the allowable wind power output interval, a bilinear programming problem meeting the security constraints of system operation is presented. Furthermore, an adjustable confidence level was introduced into the proposed robust optimization model to decrease the level of conservatism of the robust solutions. This can establish a trade-off between economy and security. To develop an MILP problem that can be solved by commercial solvers such as CPLEX, the big-M method is utilized again to represent the bilinear formulation as a series of linear inequality constraints and approximately address the nonlinear formulation caused by the adjustable conservativeness. Simulation studies on a modified IEEE 26-generator reliability test system connected to wind farms were performed to confirm the effectiveness and advantages of the proposed method.

With the increasing penetration of renewable energy, power grid operators are observing both fast and large fluctuations in power and voltage profiles on a daily basis. Fast and accurate control actions derived in real time are vital to ensure system security and economics. To this end, solving alternating current (AC) optimal power flow (OPF) with operational constraints remains an important yet challenging optimization problem for secure and economic operation of the power grid. This paper adopts a novel method to derive fast OPF solutions using state-of-the-art deep reinforcement learning (DRL) algorithm, which can greatly assist power grid operators in making rapid and effective decisions. The presented method adopts imitation learning to generate initial weights for the neural network (NN), and a proximal policy optimization algorithm to train and test stable and robust artificial intelligence (AI) agents. Training and testing procedures are conducted on the IEEE 14-bus and the Illinois 200-bus systems. The results show the effectiveness of the method with significant potential for assisting power grid operators in real-time operations.

The Variable Series Reactors (VSRs) can efficiently control the power flow through the adjustment of the line reactance. When they are appropriately allocated in the power network, the transmission congestion and generation cost can be reduced. This paper proposes a planning model to optimally allocate VSRs considering AC constraints and multi-scenarios including base case and contingencies. The planning model is originally a non-convex large scale mixed integer nonlinear program (MINLP), which is generally intractable. The proposed Benders approach decomposes the MINLP model into a mixed integer linear program (MILP) master problem and a number of nonlinear subproblems. Numerical case studies based on IEEE 118-bus demonstrate the high performance of the proposed approach.

The emergence of the direct current point of common coupling (DC-PCC) brings about new difficulties to the simulation and analysis of voltage sourced converter-based multi-terminal direct current (VSC-MTDC) system. To solve this problem, this paper proposes a unified model to calculate DC-PCC voltages and DC line currents by means of quasi-admittance matrixes. The model consists of differential equations of DC-PCC injection currents and line currents and quasi-admittance matrixes are established to update the MTDC system. Thus the simulations and eigen-analysis of VSC-MTDC can be carried out by using the proposed model. On this basis, a simulation methodology of AC/DC hybrid system containing DC-PCCs is derived. Finally, the proposed method is verified in a 3-terminal 1-PCC system and a 4-terminal 2-PCC system. The simulations are consistent with the eigen-analysis results, which demonstrate the correctness and feasibility of the methodology. The analysis indicates that oscillations after faults in different systems have different dynamic performances while different DC topologies and DC-PCC numbers have little influence on system small-signal dynamics.

Abstract Controlled islanding is considered to be the last countermeasure to prevent a system-wide blackout in case of cascading failures. It splits the system into self-sustained islands to maintain transient stability at the expense of possible loss of load. Generator coherence identification is critical to controlled islanding scheme as it helps identify the optimal cut-set to maintain the transient stability of the post-islanding systems. This paper presents a novel approach for online generator coherency identification using phasor measurement unit (PMU) data and dynamic time warping (DTW). Results from the coherence identification are used to further cluster non-generator buses using spectral clustering with the objective of minimizing power flow disruptions. The proposed approach is validated and compared to existing methods on the IEEE 39-bus system and WECC 179-bus system, through which its advantages are demonstrated.

Abstract Background To investigate the association between the coaptation height of mitral valve and mitral regurgitation after mitral valve repair. Methods From Sep 2014 to Jun 2015, 20 patients underwent mitral valve valvuloplasty for mitral regurgitation were included. Ring annuloplasty was performed in all cases. Mitral valve short-axis dimension (MVd), coaptation height (CH), Left ventricular ejection fraction (LVEF) were measured by the transesophageal echocardiography before the operation in operation room and 3 months and 12 months after the operation by the transthoracic echocardiography. A degree from 0 to 4 was used to measure the degree of mitral regurgitation. Results There were 14 patients with 0, 3 patients with 1, 3 patients with 2 of mitral regurgitation 12 months after the operation. CH (3.53 ± 1.91 mm) increased significantly at 3 months (5.05 ± 1.09 mm) and 12 months after operation (5.22 ± 1.15 mm) (p

A connected graph G is said to be a cactus if any two cycles have at most one vertex in common. The multiplicative sum Zagreb index of a graph G is the product of the sum of the degrees of adjacent vertices in G. In this paper, we introduce several graph transformations that are useful tools for the study of the extremal properties of the multiplicative sum Zagreb index. Using these transformations and symmetric structural representations of some cactus graphs, we determine the graphs having maximal multiplicative sum Zagreb index for cactus graphs with the prescribed number of pendant vertices (cut edges). Furthermore, the graphs with maximal multiplicative sum Zagreb index are characterized among all cactus graphs of the given order.

A prefabricated pumping station is a new type of pumping station that plays an important role in the construction of sponge cities in developing countries. It solves the problem of urban water-logging and makes great contributions to the sustainable development of water resources. In order to research the influence of different installation positions of pumps on the internal hydraulic performance of a prefabricated pumping station, based on ANSYS software, the computational fluid dynamics (CFD) numerical simulation method was used to analyze the internal flow state of the prefabricated pump station. In this research, the optimal geometric parameters of pump installation in a prefabricated pumping station are given. The results show that when the distance between the connecting line of two pumps and the center of the sump is L = 0.2 R, the distance between the two pumps is S = 0.6 R, and the suspension height of the two pumps is H = 0.6 D, the internal flow pattern of the prefabricated pump station is better. (R is the cross-sectional radius of the sump and D is the diameter of the nozzle of the pump horn.) These research results have certain guiding significance for improvement of the hydraulic performance and operation efficiency of prefabricated pump stations. They also provide a theoretical basis for parameter selection for prefabricated pumping stations.

BackgroundThis study assessed the role of surgical ablation for atrial fibrillation (AF) in decreasing tricuspid regurgitation (TR) and right‐sided heart remodeling in patients after mitral valve procedure. Methods and ResultsBetween 1994 and 2014, 1568 consecutive patients with AF undergoing mitral valve procedure were identified. In 26.0% (n=408), surgical ablation of AF was used. Propensity‐score matching (PSM) was performed on the basis of 41 known perioperative risk variables. Survival, reoperation, stroke, and moderate‐to‐severe TR, as well as echocardiography indices in long‐term follow‐up, were compared in 406 matched patient pairs (ablated and nonablated groups). The nonablated group showed significantly higher risks of death (hazard ratio [HR], 1.644; 95% CI, 1.081–2.501; P=0.020), reoperation (HR, 2.644; 95% CI, 1.299–5.466; P=0.008), and moderate‐to‐severe TR (HR, 1.436; 95% CI, 1.059–1.948; P=0.020), associated with a significantly deteriorated cardiac function, progression of TR, and right‐sided heart remodeling after 5‐year follow‐up. In a subgroup comparison of ablated patients with sinus rhythm versus AF recurrence, a PSM analysis was performed at the 5‐year follow‐up. The recurrent group showed significantly higher risks of moderate‐to‐severe TR (HR, 2.427; 95% CI, 1.261–4.671; P=0.008). AF recurrence was associated with progressive TR and significant deterioration in right‐sided heart remodeling. ConclusionsIn a retrospective PSM analysis, mitral valve disease with AF was associated with TR progression as well as right‐sided heart remodeling, which are alleviated by surgical ablation.

BACKGROUND: Ganglionated plexi (GP) ablation has been become an adjunct to pulmonary vein isolation (PVI). This study describes the long-term results of minimally invasive surgical PVI, ablation of GPs, and exclusion of the left atrial appendage for atrial fibrillation (AF). METHODS: Long-term follow-up of 55 months was performed in 139 consecutive patients (age 58.3±20.8 years) with symptomatic, drug-refractory lone AF who underwent minimally invasive surgical PVI, GPs ablation, and exclusion of the left atrial appendage. Success was defined as freedom from AF, atrial flutter, or atrial tachycardia off antiarrhythmic drugs. RESULTS: AF was paroxysmal in 77.7%, persistent in 12.2% and long-standing persistent in 10.1%. Single-procedure success rate was 71.7%, 59.4% and 46.6% at 12, 24 and 60 months respectively. Single-procedure success rate was 72.9%, 62.6% and 51.8% for paroxysmal AF, 64.7%, 35.3%, and 28.2% for persistent AF, 71.4%, 64.3% and 28.6% for long-standing persistent AF at 12, 24 and 60 months respectively. Duration of AF>24 months (hazard ratio [HR]: 3.09, 95% confidence interval [CI]: 1.51 to 6.32; p = 0.002), left atrial diameter≥40 mm (HR: 4.03, 95% CI: 1.88 to 8.65; p

OBJECTIVE: To assess the efficacy of video-assisted minimally invasive surgical vs. catheter ablation for the long-standing persistent AF. METHODS: We performed a retrospective comparative analysis in a series of 166 long-standing persistent AF patients treated between 2006 and 2009 with either video-assisted minimally invasive ablation (83 patients), or catheter ablations (83 patients). The catheter group was screened using a 'pair-matched case-control' methodology in order to select appropriate statistical comparison candidates out of 169 long-standing persistent AF patients which were potentially suitable for surgery, but have been treated with catheter approaches in order to balance major prognostic factors between the two groups. Follow-up for all patients ranged from 1 to 3.6 years. RESULTS: No patient died postoperatively. One patient suffered from stroke in the surgical group but recovered before discharge. Freedom from AF was obtained in 59.0% and 74.7% during follow-up in the catheter group and the surgical group respectively (P = 0.047). Patients in the catheter group had a significantly higher rate of recurrent arrhythmia (P = 0.011, hazard ratio: 0.555, 95% CI: 0.354 to 0.872) compared with the surgically treated group. The freedom from antiarrhythmic drugs was 44.6% in the catheter group and 61.4% in the surgical group (P = 0.043). CONCLUSIONS: The video-assisted minimally invasive ablation was safe and effective, and had an optimistic success rate for patients with long-standing persistent AF in our retrospective comparative study. Thus, further randomized studies addressing this issue seem to be justified.

Our previous studies have shown that early exercise intervention after stroke increases neural activity and synaptic plasticity and promotes the recovery of nerve fiber bundle integrity in the brain. However, the effect of exercise on the repair of myelin in the brain and the related mechanism are still unclear. In this study, we randomly divided the rats into three groups. Before and after 28 days of intervention, body weight, nerve function, the infarct size, white matter fiber bundle integrity, and nerve myelin structure and function were observed by measuring body weight, analysis of modified neurological severity score, CatWalk gait analysis, MRI, luxol fast blue staining, immunofluorescence, and transmission electron microscopy. Changes in the expression of proteins in the MEK/ERK pathway were assessed. The results showed that early exercise intervention resulted in neurological recovery, decreased the infarct volume and increased nerve fiber integrity, the myelin coverage area, myelin basic protein (MBP) fluorescence intensity expression, and myelin thickness. Furthermore, the expression level of MBP was significantly increased after early exercise intervention, while the expression levels of p-MEK1/2 and pERK1/2 were significantly reduced. In the cell study, MBP expression levels were significantly higher in the oxygen and glucose deprivation and administration group.In summary, early exercise intervention after stroke can promote myelin repair by inhibiting the MEK/ERK signaling pathway. [ABSTRACT FROM AUTHOR]