ST-segment elevation predicts the occurrence of malignant ventricular arrhythmia events in patients with acute ST-segment elevation myocardial infarction.

BACKGROUND: ST-segment elevation (STE) represents a repolarization dispersion marker underlying arrhythmogenesis in ST-segment elevation myocardial infarction (STEMI); however, its value for predicting malignant ventricular arrhythmia events (MVAEs) remains uncertain. METHODS: In total, 285 patients with STEMI and those with or without MVAEs who presented within 6 h of symptom onset were enrolled. The relationships between STE and clinical characteristics of MVAEs (defined as ventricular tachycardia or ventricular fibrillation) were analyzed using t-test, chi-square test, binary multivariate logistic regression, and receiver operating characteristic curve analysis. RESULTS: Patients with STEMI and MVAEs had a shorter time from symptom onset to balloon time (p = 0.0285) and greater STE (p < 0.01) than those without MVAEs. The symptom-to-balloon time, age, and STE were associated with MVAEs after stepwise regression analysis in all cases. Only STE was significantly associated with the occurrence of MVAEs (all, p < 0.01). The area under the curve (AUC) of STE for predicting MVAEs was 0.905, and the cut-off value was 4.5 mV. When only infarct-related arteries were included in the analysis, the AUC of the left anterior descending artery was 0.925 with a cut-off value of 4.5 mV, that of the right coronary artery was 0.915 with a cut-off value of 4.5 mV, and that of the left circumflex artery was 0.929 with a cut-off value of 4.0 mV. CONCLUSIONS: In patients with STEMI presenting within 6 h of symptom onset, age, symptom-to-balloon time, and STE were the main predictors for MVAEs. However, among these, STE was the strongest predictor for MVAEs and was an index for repolarization dispersion of cardiomyocytes in infarcted and non-infarcted areas.

Multi-Objective Optimal Planning for Distribution Network Considering the Uncertainty of PV Power and Line-Switch State.

With the construction of the smart grid, the distribution network with high penetration of the photovoltaic (PV) generator relies more and more on cyber systems to achieve active control; thus, the uncertainty of PV power and the line-switch state will inevitably affect the distribution network. To avoid the situation, a min-max multi-objective two-level planning model is proposed. Firstly, the uncertainty of PV power is considered, and a multi-time PV power model is established. Followed by the analysis of the line-switch state uncertainty in the distribution network, and according to Claude Shannon's information theory, the line-switch state uncertainty model is established under multiple scenarios. After the distribution network reconfiguration, the Latin hypercube sampling (LHS) method is used to determine the line-switch state when the uncertainty budget is different. Finally, considering the worstcase by the uncertainty of PV power and line-switch status, the control model is proposed to improve the stability of the distribution network with the minimal maintenance cost. The model feasibility is verified by the test system and the characteristics of PV power uncertainty, the line-switch state uncertainty is analyzed, and the influence of the scheduling strategy is discussed, thus providing practical technical support for the distribution network.

Accurate Instance Segmentation in Pediatric Elbow Radiographs.

Radiography is an essential basis for the diagnosis of fractures. For the pediatric elbow joint diagnosis, the doctor needs to diagnose abnormalities based on the location and shape of each bone, which is a great challenge for AI algorithms when interpreting radiographs. Bone instance segmentation is an effective upstream task for automatic radiograph interpretation. Pediatric elbow bone instance segmentation is a process by which each bone is extracted separately from radiography. However, the arbitrary directions and the overlapping of bones pose issues for bone instance segmentation. In this paper, we design a detection-segmentation pipeline to tackle these problems by using rotational bounding boxes to detect bones and proposing a robust segmentation method. The proposed pipeline mainly contains three parts: (i) We use Faster R-CNN-style architecture to detect and locate bones. (ii) We adopt the Oriented Bounding Box (OBB) to improve the localizing accuracy. (iii) We design the Global-Local Fusion Segmentation Network to combine the global and local contexts of the overlapped bones. To verify the effectiveness of our proposal, we conduct experiments on our self-constructed dataset that contains 1274 well-annotated pediatric elbow radiographs. The qualitative and quantitative results indicate that the network significantly improves the performance of bone extraction. Our methodology has good potential for applying deep learning in the radiography's bone instance segmentation.

Multi-Dimensional Feature Fusion Network for No-Reference Quality Assessment of In-the-Wild Videos.

Over the past few decades, video quality assessment (VQA) has become a valuable research field. The perception of in-the-wild video quality without reference is mainly challenged by hybrid distortions with dynamic variations and the movement of the content. In order to address this barrier, we propose a no-reference video quality assessment (NR-VQA) method that adds the enhanced awareness of dynamic information to the perception of static objects. Specifically, we use convolutional networks with different dimensions to extract low-level static-dynamic fusion features for video clips and subsequently implement alignment, followed by a temporal memory module consisting of recurrent neural networks branches and fully connected (FC) branches to construct feature associations in a time series. Meanwhile, in order to simulate human visual habits, we built a parametric adaptive network structure to obtain the final score. We further validated the proposed method on four datasets (CVD2014, KoNViD-1k, LIVE-Qualcomm, and LIVE-VQC) to test the generalization ability. Extensive experiments have demonstrated that the proposed method not only outperforms other NR-VQA methods in terms of overall performance of mixed datasets but also achieves competitive performance in individual datasets compared to the existing state-of-the-art methods.

Aggravated endothelial endocrine dysfunction and intimal thickening of renal artery in high-fat diet-induced obese pigs following renal denervation.

BACKGROUND: Renal denervation (RDN) targeting the sympathetic nerves in the renal arterial adventitia as a treatment of resistant hypertension can cause endothelial injury and vascular wall injury. This study aims to evaluate the risk of atherosclerosis induced by RDN in renal arteries. METHODS: A total of 15 minipigs were randomly assigned to 3 groups: (1) control group, (2) sham group, and (3) RDN group (n = 5 per group). All pigs were fed a high-fat diet (HFD) for 6 months after appropriate treatment. The degree of intimal thickening of renal artery and the conversion of endothelin 1 (ET-1) receptors were evaluated by histological staining. Western blot was used to assess the expression of nitric oxide (NO) synthesis signaling pathway, ET-1 and its receptors, NADPH oxidase 2 (NOX2) and 4-hydroxynonenal (4-HNE) proteins, and the activation of NF-kappa B (NF-κB). RESULTS: The histological staining results suggested that compared to the sham treatment, RDN led to significant intimal thickening and significantly promoted the production of endothelin B receptor (ETBR) in vascular smooth muscle cells (VSMCs). Western blotting analysis indicated that RDN significantly suppressed the expression of AMPK/Akt/eNOS signaling pathway proteins, and decreased the production of NO, and increased the expression of endothelin system proteins including endothelin-1 (ET-1), endothelin converting enzyme 1 (ECE1), endothelin A receptor (ETAR) and ETBR; and upregulated the expression of NOX2 and 4-HNE proteins and enhanced the activation of NF-kappa B (NF-κB) when compared with the sham treatment (all p < 0.05). There were no significant differences between the control and sham groups (all p > 0.05). CONCLUSIONS: RDN aggravated endothelial endocrine dysfunction and intimal thickening, and increased the risk of atherosclerosis in renal arteries of HFD-fed pigs.

Diagnosis of left ventricular hypertrophy using convolutional neural network.

BACKGROUND: Clinically, doctors obtain the left ventricular posterior wall thickness (LVPWT) mainly by observing ultrasonic echocardiographic video stream to capture a single frame of images with diagnostic significance, and then mark two key points on both sides of the posterior wall of the left ventricle with their own experience for computer measurement. In the actual measurement, the doctor's selection point is subjective, and difficult to accurately locate the edge, which will bring errors to the measurement results. METHODS: In this paper, a convolutional neural network model of left ventricular posterior wall positioning was built under the TensorFlow framework, and the target region images were obtained after the positioning results were processed by non-local mean filtering and opening operation. Then the edge detection algorithm based on threshold segmentation is used. After the contour was extracted by adjusting the segmentation threshold through prior analysis and the OTSU algorithm, the design algorithm completed the computer selection point measurement of the thickness of the posterior wall of the left ventricle. RESULTS: The proposed method can effectively extract the left ventricular posterior wall contour and measure its thickness. The experimental results show that the relative error between the measurement result and the hospital measurement value is less than 15%, which is less than 20% of the acceptable repeatability error in clinical practice. CONCLUSIONS: Therefore, the measurement method proposed in this paper has the advantages of less manual intervention, and the processing method is reasonable and has practical value.

Acute changes in morphology and renal vascular relaxation function after renal denervation using temperature-controlled radiofrequency catheter.

BACKGROUND: Resistant hypertension and renal sympathetic hyperactivity are closely linked, and catheter-based renal denervation (RDN) is regarded as a new treatment strategy. However, the acute changes in vascular morphology and relaxation function have yet to be evaluated, and these may be important for the efficacy and safety of the procedure. In this study, we explored these questions by conventional temperature-controlled cardiac radiofrequency catheter-based RDN in a pig model. METHODS: Six mini-pigs were randomly divided into the renal denervation (RDN) group (n = 3) and the Sham-RDN group (n = 3). Animals in the RDN group underwent unilateral radiofrequency ablation, and those in the Sham-RDN group underwent the same procedure except for the ablation. The pigs were examined by angiography pre- and post-RDN and were euthanized immediately thereafter. Renal arteries were processed for histological and molecular biology analyses as well as for in vitro vascular tension testing. RESULTS: Compared with the Sham-RDN group, the RDN caused vascular intima and media injury, renal nerve vacuolization, mild collagen fiber hyperplasia and elastic fiber cleavage (all p < 0.05). The RDN group also significantly exhibited nitric oxide synthase pathway inhibition and decreased endothelium-independent vascular relaxation function Compared to the Sham-RDN group (all p < 0.05). CONCLUSIONS: In this porcine model, renal artery denervation led to vascular wall injury and endothelial dysfunction in the acute phase, which negatively affected vascular relaxation function. Thus, this process may be detrimental to the prognosis and progress of hypertension patients.

Rationale and design of the Henan ST elevation myocardial infarction (STEMI) registry: a regional STEMI project in predominantly rural central China.

BACKGROUND: Cardiovascular disease including ST elevation myocardial infarction (STEMI) is increasing and the leading cause of death in China. There has been limited data available to characterize STEMI management and outcomes in rural areas of China. The Henan STEMI Registry is a regional STEMI project with the objectives to timely obtain real-world knowledge about STEMI patients in secondary and tertiary hospitals and to provide a platform for care quality improvement efforts in predominantly rural central China. METHODS: The Henan STEMI Registry is a multicentre, prospective and observational study for STEMI patients. The registry includes 66 participating hospitals (50 secondary hospitals; 16 tertiary hospitals) that cover 15 prefectures and one city direct-controlled by the province in Henan province. Patients were consecutively enrolled with a primary diagnosis of STEMI within 30 days of symptom onset. Clinical treatments, outcomes and cost are collected by local investigators and captured electronically, with a standardized set of variables and standard definitions, and rigorous data quality control. Post-discharge patient follow-up to 1 year is planned. As of August 2018, the Henan STEMI Registry has enrolled 5479 patients of STEMI. DISCUSSION: The Henan STEMI Registry represents the largest Chinese regional platform for clinical research and care quality improvement for STEMI. The board inclusion of secondary hospitals in Henan province will allow for the exploration of STEMI in predominantly rural central China. TRIAL REGISTRATION: [NCT02641262] [29 December, 2015].

ST-segment elevation and the Tpeak-Tend/QT ratio predict the occurrence of malignant arrhythmia events in patients with vasospastic angina.

BACKGROUND: ST-segment elevation (STE) and an increased Tpeak-Tend interval (Tp-e) have prognostic value for malignant arrhythmia events (MAEs) in patients with ST-segment elevation myocardial infarction (STEMI) and Brugada syndrome. Whether STE could predict MAEs and has an electrophysiological relationship with Tp-e in electrocardiogram (ECG) of vasospastic angina (VA) patients needs to be elucidated. METHODS: Sixty-five patients with VA and 23 patients with VA complicated by MAEs were enrolled. The relationship of ECG parameters and MAEs (defined as ventricular tachycardia/ventricular fibrillation (VT/VF), syncope, and aborted sudden death) was analyzed by t-test, regression and receiver operating characteristic (ROC) curve analyses. RESULTS: Patients with MAEs showed greater STE (P<0.001) and corrected QT dispersion (cQTd) (P=0.021), a longer corrected Tp-e interval (cTp-e) (P<0.001), and a larger Tp-e/QT ratio (P<0.001) than those in non-MAE groups. Univariate analysis revealed that cQTd (odds ratio (OR)=1.065; P=0.020), cTp-e (OR=1.159; P=0.001), Tp-e/QT (OR=1.344, P=0.002), and STE (OR=5.655, P<0.001) were significantly associated with MAEs. In the multivariate analysis, Tp-e/QT and STE remained predictors of MAEs. ROC curve analysis showed that the areas under curve (AUCs) for Tp-e/QT (AUC=0.944) and STE (AUC=0.974) were not significantly different (P>0.05), but both were significantly different than AUCs for cQTd (AUC=0.724) and cTp-e (AUC=0.841) (all P<0.05). STE was well fitted with the Tp-e/QT ratio in a multivariable linear regression model. CONCLUSIONS: STE and increased Tp-e/QT ratio had related electrophysiological properties and were independent prognostic indicators of MAEs in patients with VA.

A Randomized Comparative Study on the Efficacy of Intracoronary Infusion of Autologous Bone Marrow Mononuclear Cells and Mesenchymal Stem Cells in Patients With Dilated Cardiomyopathy.

Stem cell therapy has shown therapeutic benefit in dilated cardiomyopathy (DCM), but doubt remains about the most appropriate stem cell subpopulation. The current study compared the efficacy of intracoronary administration of bone marrow mononuclear cells (BMMC) or mesenchymal stem cells (BMSC) in patients with DCM.Fifty-three patients with DCM and reduced (< 40%) left ventricular ejection fraction (LVEF), were randomized to intracoronary infusion of BMMC (BMMC group, n = 16) or BMSC (BMSC group, n = 17) or equal volume normal saline (CTRL group, n = 20). LVEF, New York Heart Association (NYHA) class, left ventricular end-diastolic diameter (LVEDd), and myocardial perfusion were assessed at baseline and at 3-month and 12-month follow-ups. Major adverse cardiovascular events (MACE) were also recorded.At the 3-month follow-up, LVEF, NYHA class, and myocardial perfusion had improved significantly in the BMSC group (P = 0.004, 0.020 and 0.019, respectively) along with significant changes in LVEF and NYHA class in the BMMC group compared with CTRL (P = 0.042 and 0.047, respectively), however, LVEDd remained unchanged. In comparison with CTRL, LVEF, NYHA class, and myocardial perfusion improved significantly in the BMSC group at the 12-month follow-up (P = 0.005, 0.050 and 0.038 respectively), but not in the BMMC group (P > 0.05). There were no significant differences between the transplantation groups during follow-up (P > 0.05). There were no differences in MACE among the 3 groups (P = 0.817).Intracoronary bone marrow stem cell transplantation in DCM is safe and effective, while BMSC and BMMC infusion possess comparable effectiveness.

[Research on Denoising Ultraviolet Spectrum Signal with An Improved Effective Singular Value Selection Method].

Spectrum denoising is an important part of spectrum detection. As we know, spectral signal is susceptible to thermal noise, mechanical vibration on site and random noise, etc. However, online monitoring systems require to reduce the impact of parameter selection caused by human operation on denoising, so a method based on singular value decomposition is proposed to denoise spectrum signal. An improved effective singular value selection method is also proposed. First, the author specify the maximum peak of the difference spectrum of singular value for the lower bound which named θ1, using the integrated information of singular value and its difference spectrum to select the upper bound, which is called θ2. The interval θ1～θ2 is defined as a fuzzy area. Then, the membership is obtained with Fuzzy C-means clusting and corresponding weight coefficients to the singular values in the fuzzy area are given. Finally, the proposed method is used to denoise UV spectrum signal with different signal to noise ratio. The signal to noise ratio, root mean square error, normalied correlation coefficient and smoothness radio are used to evaluate the result of denoising. The result shows that: based on data-driven, the proposed method has a good denoising effect, which can effectively restore the original signal.

Blockade of KCa3.1 Attenuates Left Ventricular Remodeling after Experimental Myocardial Infarction.

BACKGROUND/AIMS: After myocardial infarction (MI), cardiac fibrosis greatly contributes to left ventricular remodeling and heart failure. The intermediate-conductance calcium-activated potassium Channel (KCa3.1) has been recently proposed as an attractive target of fibrosis. The present study aimed to detect the effects of KCa3.1 blockade on ventricular remodeling following MI and its potential mechanisms. METHODS: Myocardial expression of KCa3.1 was initially measured in a mouse MI model by Western blot and real time-polymerase chain reaction. Then after treatment with TRAM-34, a highly selective KCa3.1 blocker, heart function and fibrosis were evaluated by echocardiography, histology and immunohistochemistry. Furthermore, the role of KCa3.1 in neonatal mouse cardiac fibroblasts (CFs) stimulated by angiotensin II (Ang II) was tested. RESULTS: Myocardium expressed high level of KCa3.1 after MI. Pharmacological blockade of KCa3.1 channel improved heart function and reduced ventricular dilation and fibrosis. Besides, a lower prevalence of myofibroblasts was found in TRAM-34 treatment group. In vitro studies KCa3.1 was up regulated in CFs induced by Ang II and suppressed by its blocker.KCa3.1 pharmacological blockade attenuated CFs proliferation, differentiation and profibrogenic genes expression and may regulating through AKT and ERK1/2 pathways. CONCLUSION: Blockade of KCa3.1 is able to attenuate ventricular remodeling after MI through inhibiting the pro-fibrotic effects of CFs.

Effects of Renal Denervation from the Intima and the Adventitia of Renal Arteries on Renal Sympathetic Nerve Activity in Dogs: A Comparative Study.

OBJECTIVES: This study was designed to observe the efficacy and safety of renal denervation from the inside and outside of renal arteries. METHODS: Fourteen beagles were randomly divided into a control group (n = 4) and treatment group (n = 10). One renal artery in every beagle of the treatment group was randomly assigned to an intimal group (10 renal arteries) which underwent percutaneous renal denervation from the inside, and another renal artery was assigned to an adventitial group (10 renal arteries) which underwent renal denervation from the outside by laparotomy. RESULTS: Compared with the intimal group, the renal norepinephrine (NE) concentration in the adventitial group had significantly decreased (p = 0.003) at 3 months postsurgery. Renal artery HE staining showed that the perineurium from the adventitial group appeared thickened. Western blotting showed that renal tissue tyrosine hydroxylase (TH) protein expression in the adventitial group was significantly lower than that in the intimal group (p < 0.01) at 3 months postsurgery. There was a renal artery stenosis and a renal atrophy in the intimal group after 1 month of follow-up. CONCLUSION: The inhibitory effect on renal sympathetic nerve activity was more effective in the adventitial group than the intimal group, and renal denervation in the former group was safe.

[Effect of Kv1.3 and KCa3.1 potassium ion channels on the proliferation and migration of monocytes/macrophages].

This study was aimed to investigate the effects of blockade of Ca(2+) activated channel KCa3.1 and voltage-gated potassium channel Kv1.3 of the monocytes/macrophages on inflammatory monocyte chemotaxis. Chemotaxis assay was used to test the inflammatory Ly-6C(hi) monocyte chemotaxis caused by the monocytes/macrophages. The proliferation of monocytes/macrophages was detected by cell counting kit-8 (CCK8). Enzyme-linked immunosorbent assay (ELISA) was applied to detect the C-C motif ligand 7 (CCL7) in cultured media. The results showed that the recruitment of Ly-6C(hi) monocyte induced by monocytes/macrophages was suppressed by the potent Kv1.3 blocker Stichodactyla helianthus neurotoxin (ShK) or the specific KCa3.1 inhibitor TRAM-34. Meanwhile, the proliferation of monocytes/macrophages was significantly inhibited by ShK. The response of Ly-6C(hi) monocyte pretreated with ShK or TRAM-34 to CCL2 was declined. These results suggest that KCa3.1 and Kv1.3 may play an important role in monocytes/macrophages' proliferation and migration.

[Early warning for various internal faults of GIS based on ultraviolet spectroscopy].

As the basis of accurate diagnosis, fault early-warning of gas insulation switchgear (GIS) focuses on the time-effectiveness and the applicability. It would be significant to research the method of unified early-warning for partial discharge (PD) and overheated faults in GIS. In the present paper, SO2 is proposed as the common and typical by-product. The unified monitoring could be achieved through ultraviolet spectroscopy (UV) detection of SO2. The derivative method and Savitzky-Golay filtering are employed for baseline correction and smoothing. The wavelength range of 290-310 nm is selected for quantitative detection of SO2. Through UV method, the spectral interference of SF6 and other complex by-products, e.g., SOF2 and SOF2, can be avoided and the features of trace SO2 in GIS can be extracted. The detection system is featured by compacted structure, low maintenance and satisfactory suitability in filed surveillance. By conducting SF6 decomposition experiments, including two types of PD faults and the overheated faults between 200-400 degrees C, the feasibility of proposed UV method has been verified. Fourier transform infrared spectroscopy and gas chromatography methods can be used for subsequent fault diagnosis. The different decomposition features in two kinds of faults are confirmed and the diagnosis strategy has been briefly analyzed. The main by-products under PD are SOF2 and SO2F2. The generated SO2 is significantly less than SOF2. More carbonous by-products will be generated when PD involves epoxy. By contrast, when the material of heater is stainless steel, SF6 decomposes at about 300 "C and the main by-products in overheated faults are SO2 and SO2F2. When heated over 350 degrees C, SO2 is generated much faster. SOz content stably increases when the GIS fault lasts. The faults types could be preliminarily identified based on the generation features of SO2.

[Short- or long-outcome of early tirofiban in ST-segment elevated acute myocardial infarction undergoing elective percutaneous coronary intervention].

OBJECTIVE: To explore the optimal timing of tirofiban early treatment in ST-segment elevated acute myocardial infarction (STEMI) undergoing elective percutaneous coronary intervention (PCI). METHODS: A total of 118 consecutive STEMI patients were enrolled in the study. They were randomly assigned to the tirofiban early treatment group with tirofiban administrated routinely at ≥ 4 hours prior to angiography or the control group with tirofiban provisional administrated during or after angiography. Thrombolysis in myocardial infarction (TIMI) flow, creatine kinase MB isoenzyme (CK-MB) levels, acute thrombus events, efficacy and safety endpoints at Day 7, Day 30, 6 months and 1 year (efficacy endpoints: death, myocardial infarction, target vessel revascularization and ischemic stroke; safety endpoints: bleeding and thrombocytopenia) were observed and compared between the two groups. RESULTS: A total of 104 STEMI patients underwent elective PCI with 52 patients in each group and the baseline characteristics were balanced between the two groups. Tirofiban was administered (5.9 ± 2.9) hours earlier in the tirofiban early treatment group than the control group. No statistical difference was observed between the two groups in TIMI flow before[grade 0: 18 (34.6%) vs 19 (36.5%) , grade 3: 28 (53.8%) vs 27 (51.9%)] and after PCI[grade 3: 52 (100.0%) vs 51 (98.1%)]. No difference was shown between the two groups in CK-MB levels before PCI [(12.9 ± 5.1) U/L vs (12.0 ± 5.2) U/L, P > 0.05]; and the increase of CK-MB 12-24 hours after PCI [(1.0 ± 6.2) U/L vs (2.3 ± 8.3) U/L, P > 0.05]. The incidence of acute thrombus events was similar (7.7% vs 15.4%, P > 0.05). No statistical difference was observed between the two groups in the efficacy endpoints at Day 7 (0.0% vs 7.7%, P > 0.05), Day 30 (0.0% vs 7.8%, P > 0.05), 6 months (2.0% vs 9.8%, P > 0.05) and 1 year (2.2% vs 9.8%, P > 0.05). Similar incidence was shown in the slight bleeding (15.4% vs 5.8%, P > 0.05) and the slight thrombocytopenia (0.0% vs 1.9%, P > 0.05), while no severe to moderate bleeding or severe thrombocytopenia happened in both groups. CONCLUSION: Tirofiban early treatment is not better than the tirofiban bailout treatment during or after PCI in STEMI patients undergoing elective PCI. Trail registration ChiCTR-TRC-10000809.

[An ultraviolet spectroscopy method for rapid partial discharge detection in GIS].

By detecting the stable by-products of SF6 through ultraviolet spectroscopy, the present paper achieved the rapid detection of the GIS partial discharge fault. First derivative and the S-G filter were used for the spectral denoising and smoothing. The discharge experiment was used for validating feature selection. Principal component regression was used for the analysis of the concentration of SO2. The concentration of SO2 was used for fuzzy judge. By selecting the appropriate wavelength range (295~305 nm), ultraviolet spectrum can identify SO2 from the complex by-products of SF6. In this paper, firstly, the author reviewed the decomposition mechanism of SF6 under partial discharge, and then verified the rationality of detecting partial discharge by UV, and ultimately achieved the rapid detection of GIS partial discharge and fuzzy judgment of discharge time.

[Relationship of serum free T3 with the coronary artery calcification and major adverse cardiac events in patients with suspected coronary artery disease].

OBJECTIVE: To survey the association of serum free triiodothyronine (FT3) level with coronary artery calcification and major adverse cardiac events (MACE) in outpatients with suspected coronary artery disease (CAD). METHODS: A total of 577 outpatients with suspected CAD, who underwent dual-source computed tomography and FT3 detection were included, patients were followed up for 8-29 months for the major adverse cardiac events (death, MI, PCI, CABG). These patients were divided into low FT3 ( < 3.5 pmol/L, n = 126) and normal FT3 ( ≥ 3.5 pmol/L, n = 451) group based on the FT3 level, and divided into CACS > 100 (n = 235) and CACS ≤ 100 (n = 342) group based on the coronary artery calcium score (CACS). Related factors to CACS and MACE were analyzed using logistic regression (stepwise) analysis. RESULTS: CACS (146.7 (55.8, 599.1) vs. 34.8 (0, 261.9), P < 0.001) and MACE (7.9% (10/126) vs. 2.0% (9/451) , P = 0.003) were significantly higher in the low FT3 group than in normal FT3 group. Logistic regression analysis demonstrated that the FT3 levels are inversely associated with the CACS (OR = 0.442, 95%CI = 0.317-0.618, P < 0.001). Kaplan-Meier analysis displayed that patients with low FT3 levels had a lower cumulative survival rate than patients with normal FT3 levels (P = 0.005), and patients with CACS > 100 also had a lower cumulative survival rate than patients with CACS ≤ 100(P < 0.001). CONCLUSIONS: FT3 levels are associated with coronary artery calcification scores and the incidence rate of MACE in patients with suspected coronary artery disease. A low FT3 level is considered as an important risk factor of high calcification scores and MACE.

Age shock index and age-modified shock index are valuable bedside prognostic tools for postdischarge mortality in ST-elevation myocardial infarction patients.

BACKGROUND: The incidence of mortality is considerable after ST-elevation myocardial infarction (STEMI) hospitalization; risk assessment is needed to guide postdischarge management. Age shock index (SI) and age modified shock index (MSI) were described as useful prognosis instruments; nevertheless, their predictive effect on short and long-term postdischarge mortality has not yet been sufficiently confirmed. METHODS: This analysis included 3389 prospective patients enrolled from 2016 to 2018. Endpoints were postdischarge mortality within 30 days and from 30 days to 1 year. Hazard ratios (HRs) were evaluated by Cox proportional-hazards regression. Predictive performances were assessed by area under the curve (AUC), integrated discrimination improvement (IDI), net reclassification improvement (NRI) and decision curve analysis (DCA) and compared with TIMI risk score and GRACE score. RESULTS: The AUCs were 0.753, 0.746 for age SI and 0.755, 0.755 for age MSI for short- and long-term postdischarge mortality. No significant AUC differences and NRI were observed compared with the classic scores; decreased IDI was observed especially for long-term postdischarge mortality. Multivariate analysis revealed significantly higher short- and long-term postdischarge mortality for patients with high age SI (HR: 5.44 (2.73-10.85), 5.34(3.18-8.96)), high age MSI (HR: 4.17(1.78-9.79), 5.75(3.20-10.31)) compared to counterparts with low indices. DCA observed comparable clinical usefulness for predicting short-term postdischarge mortality. Furthermore, age SI and age MSI were not significantly associated with postdischarge prognosis for patients who received fibrinolysis. CONCLUSIONS: Age SI and age MSI were valuable instruments to identify high postdischarge mortality with comparable predictive ability compared with the classic scores, especially for events within 30 days after hospitalization.

Age and gender mediated the association between anemia and 30-day outcomes in patients with ST-segment elevated myocardial infarction.

Background: The higher prevalence of anemia in females and elderly may be attributed to its association with worsened outcomes in ST-elevation myocardial infarction (STEMI) patients. We aimed to evaluate the precise effects of age and gender on the association between anemia and 30-day outcomes. Method: We identified 4350 STEMI patients and divided into anemia and non-anemia. Effects were analyzed as categories using Cox proportional-hazards regression and as continuous using restricted cubic splines. Propensity score matching (PSM) and mediation analysis were applied to identify intermediate effects. Results: Anemic patients were older, more likely to be female, and experienced doubled all-cause death (7.3 % versus 15.0 %), main adverse cardiovascular and cerebrovascular events (MACCE, 11.1 % versus 20.2 %), heart failure (HF, 5.1 % versus 8.6 %), and bleeding events (2.7 % versus 5.4 %). After adjustment, the association between anemia and all-cause death (Hazard ratio (HR) 1.15, 95 % confidence interval (95 %CI) 0.93-1.14), MACCE (HR 1.14, 95 %CI 0.95-1.36) and HF (HR 1.19, 95 %CI 0.92-1.55) were insignificant, the effects persisted nullified across age classes (P-interaction > 0.05) and PSM (P > 0.05). Ulteriorly, age mediated 77.6 %, 66.2 %, 48.0 %, gender mediated 38.1 %, 15.0 %, 3.2 %, age and gender together mediated 99.8 % 72.9 %, 48.1 % of the relationship. Anemia was independently associated with bleeding events (HR 2.02, 95 %CI 1.42-2.88), the effects consisted significant regardless of PSM (P < 0.05), age, and gender classes (P-interaction > 0.05), and no mediating role of age and gender were observed. Conclusions: In STEMI patients, age and gender largely mediated the relationship between anemia and all-cause death, MACCE, and HF, anemia was independently associated with bleeding complications.