With the rapid development of China's economy, the whole society's demand for electricity is becoming more and more extensive. Insulator is the guarantee of smooth operation of transmission line, and is also one of the equipment which is prone to failure. How to detect insulator damage with high precision and high efficiency and repair it is one of the key factors of unimpeded power. This paper proposes a method for detection of insulator damage based on improved YOLOv4-tiny network. This method is mainly aimed at improving the main feature extraction module and feature fusion module of traditional YOLOv4-tiny network. In order to solve the problem of missing detection of small targets, adaptive attention mechanism is introduced to improve the module of feature extraction to improve the accuracy of detection. In addition, in order to further improve the detection accuracy of insulator damage and balance the detection time, a multi-attention CSAR model is proposed to improve the performance of the feature fusion module. Finally, images collected from different weather conditions are used as test sets to verify the effect of the improved model proposed in this paper through experiments. According to the experimental results, the detection accuracy of the proposed method can reach 98%, and the detection time is controlled within 10ms, which meets the basic requirements of detection of insulator damage.

总结2019年4月至10月期间使用J-Valve介入瓣膜成功完成介入瓣中瓣技术治疗3例三尖瓣生物瓣膜毁损的临床经验。经本院伦理委员会批准, 术前评估提示外科常规开胸体外循环手术中/高危风险, EuroSCORE Ⅱ评分为19.50%～25.45%。手术成功率100%, 1例术中输送器撤离时出现瓣膜轻度移位, 同时置入第2枚瓣膜。围手术期无死亡, 无脑血管事件, 无介入瓣移位或脱落。术后抗凝方案使用华法林抗凝6个月, 6个月后改为口服阿司匹林100 mg/天。定期复查超声心动图监测心脏功能、瓣膜流速和反流情况。术后随访26～32个月, 无死亡事件, 无脑血管事件, 无感染性心内膜炎等不良事件。术后患者自觉症状明显改善, 心功能分级≤Ⅱ级。肋间切口右心房穿刺使用J-Valve介入瓣中瓣技术可成功治疗三尖瓣生物瓣毁损, 为再次开胸手术风险高的患者提供了相对安全可行的选择。

Objective:To evaluate the mid-term outcomes of patients with rheumatic heart disease who underwent aortic valve repair surgery in a prospective cohort.Methods:From January 2016 to December 2020, a total of 54 patients with rheumatic heart disease underwent aortic valve repair surgery in Beijing Anzhen Hospital, with an average age of (50.61±13.29) years, including 29 females (53.7%). There were 31 patients (57.4%) had pure aortic insufficiency, 2 patients (3.7%) had pure aortic stenosis and 21 patients (38.9%) had mixed lesion. During the same period, 43 patients (80.0%) underwent mitral valve surgery, 36 patients (66.7%) underwent tricuspid valve surgery, and 20 patients (37.0%) underwent atrial fibrillation radiofrequency ablation.The follow-up period was from 1 month to 61 months (median follow-up was 25 months). Paired rank-sum test was used to compare the differences in continuous variables among subjects, and Kaplan- Meier method was used to analyze the clinical outcomes during the follow-up period. Results:Proportion of moderate and severe aortic regurgitation Preoperatively was higher than that of discharge data, aortic valve orifice maximum velocity and left ventricular end-diastolic diameter were significantly lower than discharge data (all P<0.05). The 5-year survival rate was (96.1±2.7)% (2 patients died). The 5-year freedom from reoperation after aortic valve repair was (89.5±4.5)%(5 patients underwent redo surgery). The 5-year freedom from valvular-related complications was (91.3±4.2)%(3 patients suffered from complications). Conclusion:Aortic valve repair surgery for rheumatic aortic valve disease is feasible and has excellent early and mid-term results, it can be a reliable treatment option.

BACKGROUND:The elevation of troponin after coronary artery bypass grafting (CABG) is common This study aimed to investigate the association between very early cardiac troponin I (cTnI) concentration and its longitudinal change within 24 hours after CABG and 30-day adverse events. METHODS:This study prospectively enrolled 633 patients who underwent isolated off-pump CABG from January 2019 to May 2019. Serum cTnI levels were measured in all patients at two examinations within 24 hours postoperatively (1 hour and 12-18 hours), and a proportional hazards model was used to determine the association between cTnI levels and their change with adverse events, which were defined as a composite of 30-day mortality, stroke, heart failure, myocardial infarction (MI), and ventricular fibrillation. RESULTS:cTnI levels of the two examinations and absolute change of cTnI levels were significantly higher in the event group than in the non-event group (P<0.01, both). Earlier and later cTnI concentrations were associated with 30-day complications [adjusted hazard ration (HR) 1.598, 95% confidence interval (CI), 1.158-2.204 and HR 1.499, 95% CI, 1.228-1.831, respectively]. With regard to longitudinal change in cTnI levels, participants with persistently high levels of cTnI and those with progression from a low level to high level concentration experienced a significantly increased risk of adverse events than did participants who had a trend of persistently low cTnI levels (HR 3.105, 95% CI, 1.748-5.517 versus HR 2.944, 95% CI, 1.488-5.824). CONCLUSIONS:Longitudinal change in cTnI levels within 24 hours and early cTnI concentrations, even less than 1 hour after CABG, are associated with adverse events. These data will be useful in identifying patients at an increased risk of complications.

Objective: To evaluate the diagnostic criteria, surgical indications, and prognostic factors in the surgical treatment of infective endocarditis (IE). Methods: A total of 161 cases of post-operative IE treated at our hospital from January 2007 to December 2016 were included. The IE was diagnosed by the modified Duke criteria. Echocardiography and standard blood cultures were performed. These cases were divided into severe and non-severe adverse event groups. The association between prognostic factors and severe versus non-severe outcomes was examined using logistic regression. Results: Thirty patients (20.1%) with post-operative IE had positive pre-operative blood cultures, and 130 patients (80.7%) had valve vegetations. Four patients (2.5%) died within 30 days post-operatively. Twenty-two patients experienced severe adverse events. There were significant differences between the two groups regarding their serum albumin and creatinine concentrations, ejection fraction, and hospitalization, cardiopulmonary bypass, aortic cross-clamp, intensive care unit (ICU), and ventilation times (all p < 0.05). The bypass time, aortic cross-clamp time, and ICU time were identified as prognostic factors for severe adverse events. Conclusion: Echocardiography is an important diagnostic method for IE, and repeated tests might improve the sensitivity of diagnosis. Cardiac surgery seems to be an effective treatment for IE. Patient screening and reducing the operative time may improve the prognosis for patients who undergo surgical treatment for IE.

The fault information collected by the feeder terminal units is easily distorted under the undesirable environment. The traditional fault section location methods of the distribution network are facing problems of poor fault tolerance and low accuracy. In this paper, a novel fault section location method for distribution networks is proposed based on the random forest algorithm. Considering the high-dimension and unbalanced characteristics of the original fault sample sets, the SMOTE oversampling method and the learning-model-based feature selection method are utilized to preprocess the original data. Furthermore, for establishing the fault location prediction model, the relevance between the fault attributes and the fault section is mined by the random forest algorithm. The simulation results show that the proposed method can achieve the single and multiple fault section location in distribution networks. Meanwhile, compared to the traditional methods, the proposed method has two significant advantages, strong fault tolerance to distorted information and high prediction accuracy.

Objective To compare long-term outcomes following mitral valvuloplasty (MVP) andmitralvalve replacement (MVR) for native valve endocarditis (NVE).Methods Between November 1993 and August 2016,consecutive 101 patients with NVE underwent mitral surgery in our department,MVP for 52 patients and MVR for 49 patients.There were 69 males and 32 females at age of 38.1±14.9 years.The mean follow-up was 99.4±75.8 months.Results There was no statistical difference in cardiopulmonary bypass time,aortic cross-clamp time,in-hospital mortality,duration of mechanical ventilation,ICU stay or hospital stay after surgery between the two groups.Survival rate at 1,5,10,20 years after surgery was 100.0％,97.6％,97.6％,97.6％ for MVP,and 93.5％,84.3％,84.3％,66.2％ for MVR with a statistical difference between the two groups (P=0.018).There was no stroke in the patients with MVP during follow-up periods.However,stroke-free survival rate at 1,5,10,20 years after surgery was 100.0％,93.9％,89.4％,70.2％ for MVR patients with a statistical difference between the two groups (P=0.023).There was no statistical difference in recurrence of infection,perivalvular leakage and reoperation between the two groups.Composite endpoint-free survival rate at 1,5,10,20 years after surgery was 100.0％,97.6％,92.9％,92.9％ for MVP,and 91.3％,79.6％,75.8％,51.0％ for MVR with a statistical difference (P=0.006).Conclusion MVP is associated with better outcomes than MVR in the patients with NVE;generalizing MVP technique in the patients with NVE is needed.

Background This study aimed to summarize percutaneous occluder device closure of atrial septal defects (ASD) through the femoral vein, using guidance by transthoracic echocardiography under local anesthesia without radiation or fluoroscopic guidance. Methods This was a case series of fourteen patients, 3 males and 11 females, diagnosed with central ASD, the diameter of the defect ranged from 9 to 32 mm, and the patients had no other heart malformations or organ dysfunction. The patients underwent a novel surgical technique of occluder device closure for ASD. The occluder closure procedures were completed through puncture of the femoral vein, and fluoroscopy-free catheter guidance by transthoracic echography without radiation. Results All of the cases had successful closure of the ASD, without residual shunt or complications. The median operation time was 18.7±22.5 min (range, 12-56 min), with no ICU-stay time and a short hospital stay of 2.3±0.5 days (range, 1-3 days). All patients were followed up for 2 years and there were no cases of residual shunt. All occluders remained in place. Conclusions Percutaneous occluder device closure of ASDs through the femoral vein with fluoroscopy-free guidance by transthoracic echography without radiation under local anesthesia could be an easy choice for some simple ASD patients, and may also be favored by cardiac surgeons.

In the traditional risk assessment of power system, the analysis of transmission system and distribution system were conducted separately. However, the power supply reliability of the distribution network users is not only related to the reliability of the distribution network components, but also to the power supply capability of the transmission system to the distribution system. The risk assessment method of transmission and distribution system that conducted separately cannot reflect the impact of changes in the transmission network on the reliability of power supply in distribution system. In this paper, a risk assessment method for transmission-distribution integrated system is proposed. Risk assessment is carried out in the transmission system first according to the load state of the system to evaluate the operation risk of the transmission system, and to obtain the probability distribution of the bus power of the transmission network. The probability distribution of bus power of transmission network is substituted into the root node of distribution network. Considering the possible island operation mode with the distributed PV connected in the distribution network, the loss of load in the case of component fault of distribution network is analyzed, and the risk index of load loss of the system is calculated. Finally, correctness and effectiveness of the proposed method are validated by a modified IEEE RTS and IEEE 33-bus system.

BackgroundCardiac sympathetic nervous system is usually activated in cardiopulmonary bypass (CPB) surgery, accompanied by excessive release of norepinephrine (NE). Neuropeptide Y (NPY) has been shown to regulate NE release in the terminal of sympathetic fiber, which is a target for regulating heart function. The expression of NPY and NPY receptor (NPYR) genes in the human atrial tissues during CPB in cardiac surgery was investigated in the present study.MethodsA few discarded atrial tissues before and after CPB were collected in 22 patients with rheumatic cardiac valve diseases. The transcriptional levels of NPY and NPYRs were monitored by real-time quantitative polymerase chain reaction (RT-qPCR) method. Moreover, the correlation between the mRNA levels of NPY/NPYRs and the clinical data were investigated in detail.ResultsThe mRNA levels of NPY Y1 and NPY Y5 genes were statistically attenuated in male patients after CPB. Conversely, the expression of NPY, NPY Y1 and NPY Y5 genes were enhanced in female patients. Correlation analysis suggested that there was a significant negative correlation between cardiac ejection fraction (EF) after CPB with the atrial transcriptional level of NPY in male patients.ConclusionsThese results suggested that the expression of NPY/NPYRs in human atrial tissue during CPB was gender specific and activated NPY signaling was only identified in female patients. The elevated expression level of NPY in male patients was correlated with lower cardiac EF after CPB.

The present study was performed to determine an optimal time-point for monitoring the concentration of the immunosuppressive drug cyclosporin A (CsA) in heart transplant patients and its efficacy in the prevention of transplant rejection. A total of 32 transplant recipients were randomly assigned for three treatment approaches. Recipients in groups A (n=11), B (n=13) and C (n=8) received oral administration of CsA at doses of 3.2, 3.5 and 4.4 mg/kg, respectively. The plasma CsA concentrations were examined at 2 h intervals over 12 h. Furthermore, their correlation with the 4 h pharmacokinetic profiles as the area under the plasma CsA concentration vs. time curve (AUC0-4 h) were calculated The efficacy of CsA in inhibiting cardiac allograft rejection was assessed at 2 h after oral CsA intake (C2) and adverse events of the drug were examined in the C2-monitored recipients. The plasma CsA concentration rapidly increased in most recipients with a peak level detected at ~2 h after dosing. Regression analysis revealed that among all time-points assessed, the CsA had the highest correlation with the AUC0-4 h at C2. At C2, increasing CsA doses exhibited a positive association with the measure of AUC0-4 h. The efficacy of increasing CsA target levels at C2 in preventing heart transplant rejection was comparable, as the survival rate was 100% in all of the treatment groups. However, the proportion of recipients with side effects in group A was obviously lower than that in the other two groups. In conclusion, C2 is an ideal time-point for monitoring plasma CsA levels with a utility for individualising the next scheduled dose for each patient to ensure that target levels are maintained and achieve a high efficacy and safety of CsA therapy in heart transplant recipients (clinical trial no. 12002610).

Demand side resources(DSRs) become indispensable for system operation to maintain power balance, when large scale of renewable generation penetrates into the electric power system. Recent studies have shown that the cooperative control is suitable for the control of DSRs, which distributed widely in the power system. In this article, a cooperative control approach that contains load aggregators and individual loads was proposed. In this approach, the clusters of frequency friendly loads(FFLs) can respond to the variations of system frequency efficiently in real time. A frequency tracking control strategy was adopted in the decision-making programs of load aggregators, and a consensus protocol was designed for the interactions among FFLs. In addition, A Kalman filter was implemented in the programs of aggregators to keep their load members from acting too much or too often. At last, the feasibility of this cooperative control system was discussed, and verified via simulation.

Objective:To explore the clinical diagnostic criteria of infective endocarditis in order to provide clinical reference for treatment of IE.Method:Collecting the clinical data (General condition,blood routine test,liver and kidney function,blood culture,electrocardiogram,echocardiography,operation)of patients with infective endocarditis who were admitted to ward 9 in Beijing Anzhen Hospital during 10 years (January 2007 to December 2016).The modified Duke criteria were used as diagnostic criteria.Results:According to the modified Duke criteria,126/161 cases have history of repeated fever,accounting 78.3％.Preoperative blood culture 149 cases,the positive rate was 20.1％;preoperative ultrasound found valve vegetation in 130 cases,the positive rate was 80.7％.In the total of 114 cases,8 cases can be confirmed preoperatively and 106 cases can be suspected to IE.Conclusion:Echocardiography is an important diagnostic method of infective endocarditis,repeated several tests will help to improve the sensitivity of diagnosis.To enhance the understanding of infective endocarditis,full and detailed medical history collection,physical examination,and laboratory data will help improve the clinical diagnosis.