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We conducted this study to evaluate the effect of rTMS combined with rPMS on stroke patients with arm paralysis after CSCNTS.A case-series of four stroke patients with arm paralysis, ages ranging from 39 to 51 years, that underwent CSCNTS was conducted. Patients were treated with 10 HZ rTMS on the contralesional primary motor cortex combined with 20 HZ rPMS on groups of elbow and wrist muscles for 15 days.The muscle tone of elbow flexor muscle (EFM), elbow extensor muscle (EEM), wrist flexor muscle (WFM) and flexor digitorum (FD) reduced immediately after operation followed by increasing gradually. After rehabilitation, the muscle tone of EEM and EFM reduced by 14% and 11%, respectively. There was a 13% and 45% change ratio in WFM and FD. The numeric rating scale (mean = 5.75 ± 1.71) was significantly lower (mean = 3.25 ± 1.90,The rehabilitation of stroke patients with arm paralysis after CSCNTS is a long, complicated process which includes great change of neuropathic pain, muscle tone, and muscle strength. In order to enhance the neural connection between the contralesional hemisphere and the hemiplegic limb, alleviate postoperative complications, as well as accelerate the rehabilitation process, we can consider to use rTMS combined with rPMS.

This paper is concerned with the problem of developing more efficient stabilization conditions for discrete-time Takagi-Sugeno fuzzy systems, i.e., not only reducing the conservatism but also (at the same time) alleviating the complexity of fuzzy control synthesis. Firstly, under the framework of traditional fuzzy stabilization, the recent multiple-sums-based method reported in the literature is improved by removing all the redundant variables, and thus the same feasible stabilization range can be obtained at the cost of more economical computational burden. Secondly, in order to further enhance the control efficiency, a dynamic trade-off between conservatism and complexity is established by proposing a new online evaluator of the updated system variation information across two adjacent sampling instants, and thus the so-called resilient stabilization is developed for reducing the conservatism without increasing or even alleviating the complexity. Moreover, all the determined matrices at the farthest sampling instant can be entirely removed without introducing any conservatism due to the proposed substitution technique. Finally, the superiority and effectiveness of our proposed methods are illustrated by a set of simulation comparisons with relevant research results reported in recent literature.

Chronic inflammation and oxidative stress are major triggers of the imbalance between protein synthesis and degradation during the pathogenesis of immobilization-induced muscle atrophy. This study aimed to elucidate the effects of hydrogen sulfide (H

Background Kinesio Taping (KT) is proved useful to many musculoskeletal disorders. But the mechanism remains unclear. The kinesio tape works by sticking to the skin surface. So exploring the interaction between the tape and the skin and analyzing its biomechanical influence may be an effective way to explore the mechanism of the tape. Objectives This study aimed to investigate the effect of Kinesio taping and taping methods on skin deformation during knee joint flexion and extension motion and further explore its possible functional mechanisms. Methods Ten healthy and pain-free subjects (4 males, 6 females) were recruited in this study. The skin observation area on the anterior side of the right thigh of the subjects was divided into 11 segments by 12 reflective marker points for distance measurement, from the distal knee to the proximal knee, the length of the interval was L1 to L11, and the total length was L0. Subjects were treated with no KT (NT), resting positive taping (RPT), resting negative taping (RNT), stretching positive taping (SPT), and stretching negative taping (SNT). A Qualisys infrared high-speed three-dimensional spatial coordinate capture system was used to observe changes in the length of the observed skin surface on the right anterior thigh during right knee flexion and extension in the sitting position. Results During right knee flexion and extension in the seated position in 10 subjects, all skin segment deformations produced significant differences between intervention groups (P P = 0.07). During right knee flexion and extension, total length, L0, and spacing lengths, L1, L6, and L11, were longer in the NT group than in all other groups. L0 and L1 were both longer in the stretched position than in the rest position; L11 also showed this trend. Conclusions The usage of the KT had an effect on the biomechanical changes of the skin, resulting in changes in skin deformation. I-tape, natural tension taping can shorten the skin distance between the two ends of the tape. Limb position during taping may influence the KT’s effects. However, the change in taping direction showed no significant effects on skin deformation during exercise. KT may apply a pre-stress in the biomechanics of the skin.

The problem of enhancing the robust performance of nonlinear fault estimation (FE) is addressed by proposing a novel real-time gain-scheduling mechanism for discrete-time Takagi-Sugeno fuzzy systems. The real-time status of the operating point for the considered nonlinear plant is characterized by using these available normalized fuzzy weighting functions at both the current and the past instants of time. To achieve this, the developed fuzzy real-time gain-scheduling mechanism produces different switching modes by introducing key tunable parameters. Thus, a pair of exclusive FE gain matrices is designed for each switching mode on the strength of time-varying balanced matrices developed in this study, respectively. Since the implementation of more FE gain matrices can be scheduled according to the real-time status of the operating point at each sampling instant, the robust performance of nonlinear FE will be enhanced over the previous methods to a great extent. Finally, considerable numerical comparisons are implemented in order to illustrate that the proposed method is much superior to those existing ones reported in the literature.

BackgroundPrenatal synthetic glucocorticoid (sGC) exposure increases the susceptibility to cognitive and affective disorders in postnatal life. We previously demonstrated that prenatal sGC exposure results in an increase in corticotropin-releasing hormone (CRH) receptor type 1 (CRHR1) expression in the hippocampus of rats, and CRHR1 is involved in synapse formation via regulation of C-X-C chemokine ligand 5 (CXCL5) in hippocampus. We sought to investigate that the roles of CRHR1 and CXCL5 in learning and memory impairment caused by prenatal sGC exposure.MethodsPregnant rats were administered with saline or dexamethasone (DEX) from gestational day (GD) 14 to GD21. DEX offspring at 2-day old were treated with saline and CRHR1 antagonists (antalarmin and CP154526) for 7 days. Some DEX offspring received intra-hippocampal injection of AAV9 carrying CXCL5 gene. Spatial learning and memory was assessed by Morris water maze test. Immunofluorescence analysis was applied to show synapsin I and PSD95 signals in hippocampus. Synapsin I and PSD95 protein level and CXCL5 concentration were determined by western blotting and ELISA, respectively. Organotypic hippocampal slice cultures were used to investigate the effect of DEX on CXCL5 production in vitro.ResultsBoth male and female DEX offspring displayed impairment of spatial learning and memory in adulthood. Synapsin I and PSD95 signals and CXCL5 levels were decreased in DEX offspring. DEX offspring with antalarmin and CP154526 treatment showed improved spatial learning and memory. Antalarmin and CP154526 treatment increased synapsin I and PSD95 signals and CXCL5 concentration in hippocampus. Bilaterally hippocampal injection of AAV9 carrying CXCL5 gene improved the spatial learning and memory and increased CXCL5 concentration and synapsin I and PSD95 levels in hippocampus. DEX dose-dependently suppressed CXCL5 production in cultured hippocammpal slices, which was prevented by antalarmin treatment.ConclusionCRHR1 and CXCL5 signaling in the hippocampus are involved in spatial learning and memory deficits caused by prenatal DEX exposure. CRHR1 activation contributes to decreased CXCL5 production in hippocampus induced by prenatal DEX treatment. Our study provides a molecular basis of prenatal GC exposure programming spatial learning and memory.

Age-related muscle wasting (sarcopenia) is accompanied by a decrease in estrogen levels which can compromise the health of aging women. Recent studies have shown that the key enzyme of estrogen synthesis (aromatase) is detected in the skeletal muscle. The purpose of this study was to investigate the effects of exercise on the expression of aromatase and the synthesis of sex steroid hormones in skeletal muscle following exercise training. Ovariectomized rats were divided into two groups, treadmill running group (25 m/min, 60 min/day, 6 days/week) and sedentary group. We found that in ovariectomized rats, exercise training significantly increased the soleus and plantar muscles mass. The level of aromatase expression and 17-β-estradiol (E2) were increased significantly in skeletal muscle following exercise training. In addition, activation of the down-stream Akt-FoxO1-MyoD signaling pathway was significantly increased in both soleus and plantaris muscles following exercise. These results demonstrate that exercise training increased the expression of aromatase and local estrogen production in skeletal muscle, which potentially influences skeletal muscle in ovariectomized rats through activation of the Akt-FoxO1-MyoD signaling pathway.

Background Diverse clinical and serological manifestations of systemic lupus erythematosus (SLE) compromise its diagnosis and treatment. A more reliable biomarker for SLE, which can play a critical role in either diagnosis, monitoring the disease progress or evaluating the response to treatment for individualized therapeutic, is necessary. DNA sensor is an important mediator of inflammation in systemic autoimmune diseases. However, the potential role for DNA sensor as disease activity biomarkers for SLE remained obscure. We detected the aberrant activation of DNA sensors and the corresponding IFN-β response in SLE patients, and to evaluate their potential role as disease biomarkers for SLE. Methods We quantified the expressions of IFN-I and DNA sensor, such as cGAS, IFI16, DDX41, DAI and their down-stream adaptor STING in PBMC derived from patients with SLE (n=100), healthy controls (HCs) (n=62) by real-time PCR. The relationships between the expression of cGAS or IFI16 and clinical features in SLE patients were investigated. ROC curve analysis was performed to examine the predictive value of cGAS and IFI16 in SLE diagnosis, disease activity monitoring, specific organ manifestation and therapeutic response. RNA interference-mediated depletion of IFI16 or cGAS was conducted to evaluate their impact on IFN-I response. Results The expressions of cGAS and IFI16 were significantly higher in PBMC from SLE patients, closely correlated with the SLEDAI scores and high anti-dsDNA antibody titers. While the AUC for cGAS (0.767) was less than that of IFI16 and IFN-β, the AUC for IFI16 (0.856) and IFN-β (0.856) were similar. Expression of cGAS and IFI16 combine with IFN-β in PBMC showed high sensitivity (89.2%) and specificity (89.1%) for discrimination between mild and moderate/severe disease activity in SLE. Higher expression of IFI16 was association with ocular disorder in SLE patients. Neither IFI16 nor cGAS was a reliable indicator of therapeutic response. RNA interference-mediated depletion of IFI16 or cGAS prevented active SLE serum-induced upregulating in both IFN-α and IFN-β. Conclusions High expression levels of cGAS and IFI16 in PBMC from SLE patients correlated strongly with disease activity. Both cGAS and IFI16 mediated signaling pathway were account for the robust production of IFN-β. Expression of cGAS and IFI16 combined with IFN-β in PBMC might serve as potential biomarkers for early diagnosis and monitoring disease activity in SLE.

Nowadays, there are a wide variety of thickeners developed for dry CO2 fracturing worldwide, but numerous problems remain during in situ testing. To address problems in CO2 fracturing fluid operation (high frictional drag, low viscosity, low proppant-carrying capacity, narrow reservoir fractures, etc.), the authors have synthesized the novel hydrophobic long-chain ester thickener, studied viscosity, frictional drag, and proppant-carrying capacity of CO2 fracturing fluid and core damage by CO2 fracturing fluid by varying the temperature, pressure, and level of injection of the novel thickener and explored the thickening mechanism for this thickener in CO2. Based on the study results, as the temperature, pressure, and amount of injected thickener increased, fracturing fluid viscosity increased steadily. In the case of shearing for 125 min under conditions of 170 S−1, 40°C, and 20 MPa, when the thickener level increased from 1% to 2%, fracturing fluid viscosity increased and then decreased, varying within 50–150 mPa·s, and the viscosity-enhancing effect was evident; under conditions of 20°C and 12 MPa, as the flow rate increased, drag reduction efficiency reached 78.3% and the minimal proppant settling speed was 0.09 m/s; under conditions of 40°C and 20 MPa, drag reduction efficiency reached 77.4% and the proppant settling speed was 0.08 m/s; with the increases in temperature, pressure, and injection amount, core damage rates of the thickener varied within 1.77%–2.88%, indicating that basically no damage occurred. This study is of significant importance to the development of CO2 viscosity enhancers and CO2 fracturing operation.

With development of power distribution automation systems, the distribution network has gradually evolved into a highly coupled distribution network CPS system with information physics. Certain security risks to the distribution network CPS have been brought to the distribution network CPS system when the information system supports the stable operation of the physical system. Such as the presence of a cyber-attack and other methods attack the information system. It may lead the failure of power services or functions, and affect the safe and stable operation of the distribution network CPS in turn. The security definition and security analysis objectives of the distribution network CPS are given in this paper firstly. Then the information security indicators and physical security indicators of the distribution network CPS are constructed. The information physical indicators are integrated and expanded from the perspective of security risk. And information security index and physical security index are constructed, also cyber physical indicators are integrated and expanded from the perspective of security risks. The causal interaction logic of the cyber-attack on the distribution network CPS is analyzed. The cyber-attack is classified according to the impact of the cyber-attack on the distribution network CPS. The impact of the distribution network system under the cyber-attack is deeply analyzed. Finally considering the combination of expected failures, a security assessment process of distribution network under the action of cyber-attack is proposed and verified in the calculation example.

To prevent the occurrence of large-scale power outages accidents in extreme ice disasters and to evaluate the weak links during power grid operation, a technique for identifying weak links in power grids based on risk indicators under extreme ice disasters is proposed. This technology mainly considers extreme weather conditions such as large temperature difference, multiple strong winds, and thick ice coating when extreme ice disasters occur, calculates the total load on transmission lines and towers, and uses strength-stress interference models to determine transmission line and tower failures Rate, and then determine the overall probability of line failure based on the principle of series reliability. Then, the non-sequential Monte Carlo method and the comprehensive probability of line faults are used to set the expected fault set, and the DC load flow optimization model is used to calculate the load loss of each line. Secondly, comprehensively consider the load level and emergency repair recovery time, determine the economic value of the line load loss, and define it as the fault consequence. Finally, the product of the fault consequence and the comprehensive probability of the line fault is used to obtain the risk index of the line and rank it as the basis for evaluating the weak link. On this basis, the IEEE30 node modified by the actual topology is taken as an example to carry out simulation research to prove the reliability and effectiveness of the technology.

Background: Temporomandibular disorder (TMD) is a frequently occurring and common oral and maxillofacial disease with relevant clinical issues (such as pain, clicking sound, and difficulty in opening the mouth). Kinesio taping (KT) is a typical soft tissue taping technique that plays a role in relieving pain, relaxing muscles, and increasing proprioception. Objectives: The study aimed to investigate the function of the KT technique in the rehabilitation of TMD. Methods: In this prospective study, 60 TMD patients (group I disorders, muscle disorders) were recruited from the outpatients of the Department of Rehabilitation Medicine of Shanghai First People’s Hospital, China, between June 2016 and September 2016 based on the inclusion/exclusion criteria. They were randomly divided into the control, short wave, and taping groups using a random number table, with 20 cases in each group. Different rehabilitation methods were applied according to the grouping. The course of treatment was six days. The estimations of the Fricton craniomandibular index (CMI), Self-Rating Anxiety scale (SAS), and Self-Rating Depression scale (SDS) were conducted in pretherapy and post-treatment by a physician who was blinded to the patients’ groups. Results: No significant differences were observed between patients in the three groups (P > 0.05) in pretherapy in the temporomandibular joint dysfunction index (DI), muscle palpation index (PI), CMI, SAS, and SDS. In post-treatment, the CMI in the short wave and taping groups was significantly improved compared to the control group (P < 0.05). The SAS in the taping group improved significantly compared to the control and short wave groups (P < 0.05). The SDS in the short wave group improved significantly compared to the control and taping groups (P < 0.05). Conclusions: Taken together, KT effectively improved the dysfunction and mood of TMD patients with the group I disorders, thereby necessitating further investigation for widespread application.

College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China E-mail: aurock@126.com Manuscript received online 12 November 2019, revised and accepted 01 January 2020 A series of symmetric aryl ether dinitro compounds were synthesized by 4Urea/ZnCl2 as green solvent and catalyst, and halogenated aromatic hydrocarbon derivatives and dihydroxy compounds as raw materials. This method has the advantages of easy operation, simple recrystallization, environmental friendliness and biodegradability. The structures of the products were subjected to 1H NMR, and the reaction conditions, reaction mechanism and greening advantages of deep eutectic solvents were discussed at the end of the experiments. We learned from the results of the experiments that both the aliphatic dihydroxy compounds and the aromatic dihydroxy compounds could proceed effectively in Ullmann reaction, and the desired products could be obtained in acceptable yields. When using this methodology, symmetric aryl ether dinitro compounds could be synthesized simply at 80ºC in 2 h with high yields (66% ~94%). Meanwhile, the DES, called deep eutectic solvent which is composed of 4Urea/ZnCl2 , could be recycled at least five times without an obvious decraese in the catalytic activity.

BACKGROUND Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) are infectious diseases with high mortality. Early diagnosis is crucial. Combining HIV antibody and p24 antigen, the Elecsys HIV combi PT assay is a fourth generation HIV screening assay. The sensitivity and specificity of this assay was examined. METHODS A total of 111,556 samples was conducted from January 1, 2016, to June 30, 2018 in Zhongshan Hospital of Yat-Sen University. We conducted a fourth-generation HIV test of retrospective HIV screening samples and assessed the reliability of using signal-to-cutoff (S/CO) ratios to distinguish false positive HIV antibody reactions and analyzed false positives. RESULTS A total of 122 specimens were confirmed as HIV-1 infected by western blot (WB) and HIV nucleic acid assays. The median S/CO ratio for HIV false positive specimens was 3.27, while for the HIV-infected specimen it was 391.7. Receiver operating characteristic (ROC) analysis showed that the best diagnostic point for HIV was 22.85 S/CO. The sensitivity, specificity, and Youden index were 100%, 97.8%, and 0.978, respectively. The highest false positive rate of 26.4% was found in patients with malignant tumors and blood diseases. CONCLUSIONS The results of this study show that the fourth-generation Elecsys HIV combination PT test can identify early HIV infected and can be a useful adjunct to help clinicians to manage the disease by viral load testing and starting an appropriate therapy. Our research data provides a reference for subsequent research and HIV testing in the region.

Pregnant women at risk of preterm labor usually receive synthetic glucocorticoids (sGCs) to promote fetal lung development. Emerging evidence indicates that antenatal sGC increases the risk of affective disorders in offspring. Data from animal studies show that such disorders can be transmitted to the second generation. However, the molecular mechanisms underlying the intergenerational effects of prenatal sGC remain largely unknown. Here we show that prenatal dexamethasone (Dex) administration in late pregnancy induced depression-like behavior in first-generation (F1) offspring, which could be transmitted to second-generation (F2) offspring with maternal dependence. Moreover, corticotropin-releasing hormone (CRH) and CRH receptor type 1 (CRHR1) expression in the hippocampus was increased in F1 Dex offspring and F2 offspring from F1 Dex female rats. Administration of a CRHR1 antagonist to newborn F1 Dex offspring alleviated depression-like behavior in these rats at adult. Furthermore, we demonstrated that increased CRHR1 expression in F1 and F2 offspring was associated with hypomethylation of CpG islands in Crhr1 promoter. Our results revealed that prenatal sGC exposure could program Crh and Crhr1 gene expression in hippocampus across 2 generations, thereby leading to depression-like behavior. Our study indicates that prenatal sGC can cause epigenetic instability, which increases the risk of disease development in the offspring's later life.-Xu, Y.-J., Sheng, H., Wu, T.-W., Bao, Q.-Y., Zheng, Y., Zhang, Y.-M., Gong, Y.-X., Lu, J.-Q., You, Z.-D., Xia, Y., Ni, X. CRH/CRHR1 mediates prenatal synthetic glucocorticoid programming of depression-like behavior across 2 generations.

At present, learning-based citrus blossom recognition models based on deep learning are highly complicated and have a large number of parameters. In order to estimate citrus flower quantities in natural orchards, this study proposes a lightweight citrus flower recognition model based on improved YOLOv4. In order to compress the backbone network, we utilize MobileNetv3 as a feature extractor, combined with deep separable convolution for further acceleration. The Cutout data enhancement method is also introduced to simulate citrus in nature for data enhancement. The test results show that the improved model has an mAP of 84.84%, 22% smaller than that of YOLOv4, and approximately two times faster. Compared with the Faster R-CNN, the improved citrus flower rate statistical model proposed in this study has the advantages of less memory usage and fast detection speed under the premise of ensuring a certain accuracy. Therefore, our solution can be used as a reference for the edge detection of citrus flowering.

Discoid lupus erythematosus (DLE) is the most common skin manifestation of lupus; however, the molecular mechanisms underlying DLE remain unknown. Therefore, we aimed to identify key differentially expressed genes (DEGs) in discoid lupus skin and investigate their potential pathways. To identify candidate genes involved in the occurrence and development of the disease, we downloaded the microarray datasets GSE52471 and GSE72535 from the Gene Expression Database (GEO). DEGs between discoid lupus skin and normal controls were selected using the GEO2R tool and Venn diagram software (http://bioinformatics.psb.ugent.be/webtools/Venn/). The Database for Annotation, Visualization, and Integrated Discovery (DAVID), Enrichr, and Cytoscape ClueGo were used to analyze the Kyoto Encyclopedia of Gene and Genome pathways and gene ontology. Protein-protein interactions (PPIs) of these DEGs were further assessed using the Search Tool for the Retrieval Interacting Genes version 10.0. Seventy three DEGs were co-expressed in both datasets. DEGs were predominantly upregulated in receptor signaling pathways of the immune response. In the PPI network, 69 upregulated genes were selected. Furthermore, 4 genes (CXCL10, ISG15, IFIH1, and IRF7) were found to be significantly upregulated in the RIG-I-like receptor signaling pathway, from analysis of Enrichr and Cytoscape ClueGo. The results of this study may provide new insights into the potential molecular mechanisms of DLE. However, further experimentation is required to confirm these findings.

The present study aimed to investigate whether serum growth differentiation factor 15 concentration is a valuable and reliable diagnostic biomarker of mitochondrial diseases. We examined consecutive patients with mitochondrial diseases, in comparison with patients with non-mitochondrial disease neuromuscular disorders and healthy controls. The serum concentrations of growth differentiation factor 15 were measured by ELISA, and compared with those of FGF21, lactate, and creatine kinase. We also evaluated the correlations between growth differentiation factor 15 concentrations and the Newcastle Mitochondrial Disease Adult Scale, numbers of ragged-red fibers, and COX-negative fibers in the biopsied muscles. The median serum growth differentiation factor 15 concentration was significantly elevated in 42 patients with mitochondrial diseases, compared with 20 patients with non-mitochondrial disease neuromuscular disorders and 50 healthy controls. The area under the curve of growth differentiation factor 15 for the diagnosis of muscle-manifesting mitochondrial diseases was 0.999, in comparison with those area under the curves of the other biomarkers including fibroblast growth factor 21 (0.935, p

Bone remodeling is highly dynamic and complex in response to mechanical loading, such as exercise. In this review, we concluded that a number of individual factors are disturbing the clinical effects of exercise on bone remodeling. We updated the progress made on the differentiation of osteoblasts and osteoclasts in response to mechanical loading, hoping to provide a theoretical basis to improve bone metabolism with exercise. Increasing evidences indicate that bone is not only a structural scaffold but also an endocrine organ, which secretes osteocalcin and FGF23. Both of them have been known as a circulating hormone to promote insulin sensitivity and reduce body fat mass. The effects of exercise on these bone-derived cytokines provide a better understanding of how exercise-induced "osteokine" affects the whole-body homeostasis. Additionally, we discussed recent studies highlighting the post-transcriptional regulation of microRNAs in bone remodeling. We focus on the involvement of the microRNAs in osteoblastogenesis and osteoclastogenesis, and suggest that microRNAs may be critical for exercise-induced bone remodeling.

Moderate exercise improves glycometabolic disorder and type 2 diabetes mellitus in menopausal females. So far, the effect of exercise-induced estrogen on muscular glycometabolism is not well defined. The current study was designed to explore the effect of mechanical stretch-induced estrogen on glycometabolism in mouse C

Operating overvoltage in power grid is one of the important reasons of high-voltage equipment damage. It is accompanied by the operation of the power grid equipment, and power grid overvoltage calculation must be applied to the new project commissioning, especially the UHV project in order to understand the overvoltage conditions, take protective measures to prevent damage to equipment. Based on power electronics and electromagnetic transient calculation program, in the paper author established an electromagnetic transient model of the ±800 kV converter station ac system. Simulation analysis is carried out for the possible operating overvoltage during the start-up and debugging of the ac system. It is helpful to provide technical basis for debugging scheme, at the same time provide data for the operation and maintenance of the converter station in the future.

As the Inner Mongolia Autonomous Region, UHV AC and DC power transmission and transformation projects have been put into operation successively, the Inner Mongolia area power grid has become UHV AC/DC hybrid power system. However, the development of AC and DC projects is not balanced. The characteristics of “strong DC and weak AC” are obvious. Especially, when the sending end auxiliary thermal power unit is connected to the high voltage AC and DC hybrid power grid, it will be bound to affect the safe and stable operation of the UHV power grid, and the stability of the transmission end system is difficult to be guaranteed. The high capacity synchronous condenser can improve the short circuit ratio of DC power transmission system in AC/DC power grid, enhance the dynamic voltage support capacity of the AC power grid and improve the stability of the power grid. This paper takes the regional power grid of the transmission end of the xilinhaote to Taizhou of jiang su ultra-high voltage dc transmission project (hereinafter referred to as the “Xitai DC”) as the research object, using Power System Analysis Software Package simulation software, through simulation to carry out the comparison analysis. From the angle of AC and DC transmission capacity and single end trip of line, it comprehensively evaluates influence of synchronous condenser on the stability level of the power grid. The results show that the synchronous condenser has good dynamic voltage support ability and strong short-time overload ability and can effectively improve the stability level of UHV AC and DC hybrid power grid.