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To get rid of the current transmission line visual monitoring device which only relies on a single photo-monitoring method, this paper proposes a method based on time-delay estimation and equipment coordinates to locate abnormal sound in the transmission line channel. Firstly, the audio-visual equipment is selected to collect the abnormal sound information of any transmission line as the reference warning record, and the relative time difference between other warning records and the reference warning record is determined. Then, the corresponding audio-visual equipment of the reference alarm record is used as a reference point to set up a Cartesian coordinate system, obtain the GPS information of other audio-visual equipment, unify the GPS information, and get the coordinates of other audio-visual equipment; finally, based on the reference point coordinates, other audio-visual equipment coordinates, and the relative time difference, the transmission channel abnormal sound source coordinates are obtained. Through the experiment of firecracker sound, we can get the firecracker sound within 2km in the open environment, which proves that the location method can effectively enhance the monitoring effect of the transmission channel.

Purpose To compare the effects of paclitaxal-coated balloon (PCB) versus conventional balloon (CB) on side branch (SB) lesion and cardiovascular outcomes in patients with de novo true bifurcation lesions. Methods In total, 219 patients with de novo true bifurcation lesions were enrolled and divided into PCB group (102 cases) and CB group (117 cases) according to angioplasty strategy in SB. Drug-eluting stent (DES) was implanted in main vessel (MV) for each subject. All subjects underwent a 12-month follow-up for late lumen loss (LLL), restenosis and major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI). MACEs included cardiac death, nonfatal myocardial infarction and angina pectoris. Results There were no differences in diameter, minimum lumen diameter (MLD) and stenosis for bifurcation lesions between the two groups before and immediately after PCI (P > 0.05). After 12-month follow-up, no differences occurred in MV-MLD and MV-LLL between the two groups (P > 0.05); SB-MLD in PCB group was higher than that in CB group (1.97 ± 0.36 mm vs. 1.80 ± 0.43 mm, P = 0.007); SB-LLL in PCB group was lower than that in CB group (0.11 ± 0.18 mm vs. 0.19 ± 0.25 mm, P = 0.024). Multivariate COX analyses indicated that PCB group had lower MACE risk than CB group (HR = 0.480, 95%CI 0.244–0.941, P = 0.033). Conclusion PCB could decrease SB-LLL and MACE risk in patients with de novo true coronary bifurcation lesion 12 months after single-DES intervention.

One key sequence control of substation is the latest requirement of intelligent substation. The double confirmation in its operation specification requires that when the equipment is operated remotely, there should be at least two non homologous indicators to confirm that the equipment has been operated accurately. In this paper, a fish eye switch on / off status recognition algorithm based on image intelligent analysis is proposed. This algorithm realizes the judgment of on and off as well as abnormal and occlusion status. The on and off angle can also be quantified. The accuracy rate is 99.99% after field verification.

To solve the weather classification problem in outdoor power monitoring, this paper proposes a weather classification algorithm based on improved SqueezeNet. In the proposed network, three modifications are made: Firstly, the input size is increased in the first convolution layer and the convolution kernel is reduced to make it more suitable for high-resolution image classification. Secondly, the combination of global average pooling and small fully connected layers leads to a proper tradeoff between computational burden and classification performance of the proposed network. Thirdly, the introduction of batch normalization not only suppresses the over-fitting phenomenon, but also increases classification accuracy and converging speed. According to the actual application scenario, the multi-weather image dataset is constructed and used for training and test. Experimental results verify the effectiveness of the proposed network, and reveal the proposed network, compared with the original SqueezeNet, could improve the performance of classification accuracy and suppress the over-fitting.

There are still a large number of pointer meters in substations, which mainly rely on manual inspection to detect the readings of pointer meters. In order to solve the above problems, this paper proposes a pointer meter keypoints detection method based on deep learning combined with virtual pointer rotation to determine the meter readings. This method first uses the deep learning algorithm to train data set of pointer meters and obtain the keypoints information of pointer meters. According to the keypoints information, we can further determine the center of rotation and radius of the pointer meter, then the real position of the pointer meter can be determined. Finally, according to the meter range information, as well as the real pointer angle and the meter range angle, we can calculate the readings of the pointer meter. The experiment results show that the proposed method can quickly and accurately obtain the pointer position, and further identify the meter readings. The proposed method can reduce the uncertainty caused by manual inspection and have a great impact on intelligent development of substations.

With the rapid development of science and technology, image processing technology plays an important role in the field of computer vision. In order to improve the matching speed and real-time requirements, this paper proposes an image matching algorithm based on ORB and K-means clustering, which can effectively improve the accuracy of image feature point location and the accuracy and efficiency of image feature matching, and reduce the time consumption. The algorithm uses sub-pixel interpolation to optimize the traditional ORB algorithm, which improves the accuracy and characteristics of clustering calculation.

Power transmission line safety monitoring is one of the important tasks to maintain the security of national power grid. In this paper, the object detection method based on computer vision is applied to automatically monitor the potential safety risk of transmission line. We firstly create a potential safety risk object dataset. Secondly we analyze most state-of-the-art object detection model. Thirdly according to the specific dataset, an object detection model was trained, which uses training tricks to get high performance. Fourthly, we built a monitoring system that feeds the discriminant results back to the display terminal, which can comprehensively grasp the situation of the whole safe area and ensure the safe operation of the transmission network. Our experiments show the excellent results are Cascade R-CNN detection framework based on deep learning and backbone based on high resolution representations network. It gains 81.5 mAP on 26 kinds of objects datasets at IOU threshold 0.5, and show hidden danger detection algorithm based on deep learning can accurately discriminate the dangerous sources. The monitoring system feeds the discriminant results back to the display terminal, which can comprehensively grasp the situation of the whole safe area and ensure the safe operation of the transmission network.

Endothelial progenitor cells (EPC) participate in vessel recovery and maintenance of normal endothelial function. Therefore, pitavastatin-nanoparticles (NPs)-engineered EPC may be effective in repairing injured vasculature. Pitavastatin-loaded poly(lactic-co-glycolic) acid (PLGA) NPs were obtained via ultrasonic emulsion solvent evaporation with PLGA as the carrier encapsulating pitavastatin. The effects and mechanism of pitavastatin-NPs on EPC proliferation in vitro were evaluated. Then, EPC that internalized pitavastatin-NPs were transplanted into rats after carotid artery injury. EPC homing, re-endothelialization, and neointima were evaluated by fluorescence labeling, evans Blue and hematoxylin/eosin (H&E) staining. Pitavastatin-NPs significantly improved EPC proliferation compared with control and pitavastatin group. Those effects were blocked by pretreatment with the pharmacological phosphoinositide 3-kinase (PI3K) blockers LY294002. After carotid artery injury, more transplanted EPC were detected in target zone in Pitavastatin-NPs group than pitavastatin and control group. Re-endothelialization was promoted and intimal hyperplasia was inhibited as well. Thus, pitavastatin-NPs promote EPC proliferation via PI3K signaling and accelerate recovery of injured carotid artery.

Background Endothelial progenitor cell (EPC) differentiation is considered crucial for vascular repair. Vascular endothelial growth factor (VEGF) induces EPC differentiation, but the underlying mechanism of this phenomenon remains unclear. Connexin 43 (Cx43) is reported to be involved in the regulation of stem cell differentiation. Therefore, we sought to determine whether Cx43 is involved in VEGF-induced EPC differentiation and vascular repair. Methods Rat spleen-derived EPCs were cultured and treated with various concentrations of VEGF (0, 10, or 50 ng/mL), and the relationship between EPC differentiation and Cx43 expression was evaluated. Thereafter, fluorescence redistribution after photobleaching was performed to assess the relationship between adjacent EPC differentiation and Cx43-induced gap junction intercellular communication (GJIC). After carotid artery injury, EPCs pretreated with VEGF were injected into the tail veins, and the effects of Cx43 on vascular repair were evaluated. Results EPCs cultured with VEGF exhibited accelerated differentiation and increased expression of Cx43. However, inhibition of Cx43 expression using short interfering RNA (siRNA) attenuated EPC GJIC and consequent EPC differentiation. VEGF-pretreated EPC transplantation promoted EPC homing and reendothelialization, and inhibited neointimal formation. These effects were attenuated by siRNA inhibition of Cx43. Conclusions Our results from in vivo and in vitro experiments indicated that VEGF promotes EPC differentiation and vascular repair through Cx43. Electronic supplementary material The online version of this article (doi:10.1186/s13287-017-0684-1) contains supplementary material, which is available to authorized users.

Background Degradable polymer drug-eluting stents (DP-DES) represent a promising strategy to improve the delayed healing and hypersensitive reaction in the vessel. However, the efficacy and safety of DP-DES vs. permanent polymer drug-eluting stents (PP-DES) are less well defined. The aim of this meta-analysis was to compare the total, short ( 1year) term outcomes of DP-DES vs. PP-DES. Methods PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials to compare any of approved DP- and PP-DES. Efficacy endpoints were target-lesion revascularization (TLR) and in-stent late loss (ISLL). Safety endpoints were death, myocardial infarction (MI), and composite of definite and probable stent thrombosis (ST). Results The meta-analysis included 19 RCTs (n=18,395) with interesting results. As compared with DES, there was a significantly reduced very late ST (OR [95% CI]=0.42 [0.24–0.77], p=0.852) and ISLL (OR [95% CI]=−0.07 [−0.12–0.02], p=0.000) in DP-DES patients. However, there were no differences between DP-DES and PP-DES for other safety and efficiency outcomes, except that the stratified analysis showed a significant decreased TLR with DP-DES as compared to paclitaxel-eluting stent (OR [95% CI]=0.41 [0.20–0.81], p=0.457). Conclusions DP-DES are more effective in reducing very late ST and ISLL, as well as comparable to PP-DES with regard to death, TLR and MI. Further large RCTs with long-term follow-up are warranted to better define the relative merits of DP-DES.

Background: Recrossing the compromised side branch (SB) with a balloon is sometimes technically challenging. The aim of this study was to evaluate whether in-stent anchoring (ISA) is safe and effective to facilitate SB balloon delivery for final kissing. Methods: One hundred and fifty-nine consecutive patients were included (166 bifurcation lesions) in this prospective, single-center registry. ISA was used as a bailout method after unsuccessful SB crossing using conventional techniques, including low-profile balloons. Technique success was defined as SB balloon delivery and final kissing. Results: Kissing-balloon delivery was successfully performed with conventional strategies in 149 of 166 lesions (89.8%). In the remaining 17 lesions (10.2%), recrossing of the main vessel stent strut was not successful; therefore, ISA was attempted. The balloon successfully crossed the stent struts, and final kissing was achieved in 15 of 17 lesions (88.2%). Total final kissing was achieved in 164 of 166 lesions (98.8%), with success rates of 100% in the single-stent group and 97.6% in the two-stent group. Two cases without balloon delivery had complex bifurcation lesions with severe calcification. There was no vessel dissection in the anchoring zone. Conclusions: ISA is safe and effective for recrossing stent struts when conventional low-profile balloons have failed. However, large-scale trials are warranted for further evaluation. Key words: Bifurcation; In-stent Anchoring; Percutaneous Coronary Intervention