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Aortic stiffness is an independent risk factor for aortic diseases such as aortic dissection which commonly occurred with aging and hypertension. Chemokine receptor CXCR6 is critically involved in vascular inflammation and remodeling. Here, we investigated whether and how CXCR6 plays a role in aortic stiffness caused by pressure overload. CXCR6

Objectives: Patients undergoing trans-carotid transcatheter aortic valve replacement (TC-TAVR) are more likely to suffer from a stroke because of cerebral blood hypoperfusion and blood occlusion caused by the introducer sheath compared with the trans-femoral (TF) approach. The present study aimed to compare the incidence of stroke between the TC and TF approaches and explore the causes of stroke after TAVR. Methods: We retrospectively reviewed the medical records of 414 consecutive patients with severe aortic valve stenosis who underwent TC- or TF-TAVR at our center from October 2010 to November 2019; these patients were included in this observational study. The clinical data, such as the incidence of stroke, were compared between TC- and TF-TAVR patients. The correlation between carotid artery blood block interval (CABBI) and neurological events was also analyzed. The study was approved by the Ethics Committee of Zhongshan Hospital of Fudan University (approval No. YL2014-32). Results: Patients undergoing TC-TAVR had a significantly higher incidence of stroke than those undergoing TF-TAVR (12.5% vs. 0, P < 0.001), whereas the baseline data and the incidence of other complications did not differ significantly between the patients undergoing TC- and TF-TAVR (P > 0.05). Moreover, in TC-TAVR patients, the average CABBI of stroke was significantly longer than that of nonstroke patients (61.7 ± 20.7 min vs. 25.1 ± 1.6 min, P = 0.001). The number of patients with CABBI >30 min in the stroke group was greater than that in the nonstroke group (P < 0.001). Conclusions: In the absence of the cerebral and carotid artery evaluation before TAVR, surgeons should take into consideration the time of CABBI

AIMS This study aimed to provide a simple index for predicting the definitive indication for transcatheter closure of atrial septal defect (ASD) with pulmonary arterial hypertension (PAH). METHODS AND RESULTS A positive response after attempted occlusion was defined as mean pulmonary artery pressure (MPAP) ≤30 mmHg or the decrement percentage of it ≥20% compared with baseline. If a positive response was achieved, the occluder would be released, and the procedure was defined as successful. In 209 patients who underwent a successful procedure without PAH-specific medicine, there was a dramatic decrease in the percentage of patients with pulmonary arterial systolic pressure (PASP) ≥50 mmHg from baseline to the one-year follow-up (79.4% to 14.0%, p

The current study aimed to elucidate the efficacy of interatrial shunt device (IASD) for the treatment of acute pulmonary hypertensive crisis (PHC) and chronic pulmonary arterial hypertension (PAH). After establishing chronic PAH models using dehydrogenized monocrotaline (DHMCT), PAH dogs were implanted with IASDs (group A) or received no intervention (group B). One month later, DHMCT was injected again to establish an acute PHC. The prognosis, hemodynamics, ultrasound cardiography, electrocardiogram, and lung pathology of the dogs were observed. The baseline mean pulmonary arterial pressure increased from 12.70 ± 1.03 to 19.95 ± 1.75 mmHg and established a chronic PAH model 2 months after DHMCT injection (1.50 mg/kg). After an additional injection of DHMCT (1.50 mg/kg) in the chronic PAH model, acute PHC occurred. Mean PAP, sPAP, and pulmonary vascular resistance increased to 22.67 ± 1.80 mmHg, 35.70 ± 1.66 mmHg, and 12.50 ± 3.50 WOOD U, respectively. Cardiac output (CO) decreased to 1.31 ± 0.26 L/min, and the right-to-left shunt caused hypoxemia. The survival rates of the dogs with and those without IASD were 70.0% and 22.2% (P = 0.037), respectively. Six months after PHC, the CO between the dogs with and those without IASD were 1.44 ± 0.11 L/min and 1.18 ± 0.04 L/min (P = 0.028). The long-term survival rates were 50.0% and 22.2%, respectively (P = 0.21). IASD might be efficacious and beneficial for treating acute PHC and chronic PAH, as well as improving prognosis.

This design is based on Etap simulation software to complete the following steps: analysis of original data, determination of power grid voltage level and preliminary selection of power grid connection scheme, technical and economic operation of optimal scheme, operation characteristics and material statistical calculation. Through this design, I have mastered the general principles and common methods of power network planning and design. I am skilled in using Etap simulation software to cultivate my analytical ability in various aspects of technology and economy, improve my ability of calculation, data analysis and arrangement, and design specification compilation.

Jixi Museum connects the past and the future. Mr. Li Xinggang uses Jixi’s rich cultural heritage to lay a strong cultural atmosphere for the museum. This paper analyzes and understands its architectural style, spatial layout, material selection and other aspects. Learn the expression techniques and artistic effects of Jixi Museum.

This paper compares and analyzes the insulation structure of the vacuum interrupter, focusing on the influence of the mechanical characteristics and the structure of the shield on the insulation, and establishes an electric field calculation model for the axisymmetric structure of the vacuum interrupter. Finally, the radius of the conductive rod and the thickness of the contact are compared and optimized, and then the thickness of the shield is compared and calculated, and then simulated and analyzed with ANSYS software to verify the optimization direction.

This paper analyzes and compares the principle and structure of the vacuum interrupter, so as to determine the selection of materials for the vacuum interrupter, and further compares the structural materials of the interrupter, and compares them from three angles: the shell, the contact, and the shield.

The electrochemical splitting of water provides an attractive method for the production of hydrogen fuels. Unfortunately, the slow kinetics of oxygen evolution (OER) on the anode side of the electrolyzer hinders the efficient and large-scale hydrogen production. In this study, starting from metal-organic frameworks (MOFs), a series of bimetal phosphides CoxFe1−xP (x = 0.33, 0.50, 0.66, 0.75 and 0.80) were synthesized by low-temperature phosphidiation of corresponding MOFs precursors. The as-prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Studies indicate that the proportion of cobalt and iron elements make a big differences on the structure of the materials. Benefiting from the porous structure and large specific area of the MOFs precursors, as well as the synergistic effect between Co and Fe elements, the as-synthesized Co0.66Fe0.33P shows superior electrocatalytic performances and outstanding stability toward OER in alkaline solution.

Tremendous works to design the Co3O4 with higher catalytic properties towards CO elimination have been carried out about preparing Co3O4 with special morphology to expose more Co3+ on the surface, such as cubes, wires, and rods. However, the fabrication of Co3O4 with controlled morphologies is usually achieved through complex operations and harsh conditions. In this work, we demonstrated a simple way to synthesize mesoporous Co3O4 polyhedrons and plates, via direct annealing metal-organic frameworks (MOFs) with tunable morphologies. The obtained Co3O4 particles not only repeat the size and form of used MFFs but also were constructed by numerous interconnected nanoparticles. Compared with the prepared Co3O4 polyhedrons, the prepared mesoporous Co3O4 plates exhibit a better catalytic performance on CO oxidation, which can achieve total CO conversion at 85 °C. Such performances are superior to many reported catalyzes without noble metals. The higher activity of Co3O4 plates is mainly due to its larger specific surface areas and the higher surface Co3+ concentrations.

The increasingly exhausted fossil energy reserve and the current serious ecological problems make people pay more attention to renewable clean energy sources such as hydrogen. Highly active, low-co...

Objectives: To analyze the predictors of pericardial effusion (PE) during the perioperative period of the left atrial appendage closure procedure in our center.Methods: A total of 624 consecutive patients with non-valvular AF undergoing LAAC from May 2014 to October 2019 were involved in this study. Patients were divided into groups depending on whether they showed no PE, intraoperative PE or postoperative PE. We analyzed the predictors of PE during the perioperative period of the LAAC procedure.Results: (1) Of the 624 patients in our population (age 68.2 ± 9.1 years, 63% male, CHA2DS2-VASc score 3.4 ± 1.6), 30 patients experienced PE in the perioperative period, including 10 intraoperative PE and 20 postoperative PE. (2) A total of 26 (86.6%) patients had mild PE. 4 (13.4%) patients had pericardial tamponade, 2 (6.7%) of which were intraoperative, and the other 2 (6.7%) postoperative. (3) Significant differences were measured in relation to female sex, intraoperative time, combined procedures, changes in sinus rhythm, device retrieval times and duration of hospitalization between 2 groups (no PE occurred, intraoperative PE), P values were 0.039, 0.024, 0.004, 0.015, 0.003 and 0.039.Conclusions: Female sex, paroxysmal AF, changing in sinus rhythm, device retrieval times and intraoperative time all had a positive association with PE during the perioperative period.

Background This study aims to investigate whether small balloon aortic valvuloplasty (BAV) reduces the need for permanent pacemaker implantation (PPMI) after transcatheter aortic valve implantation (TAVI). Methods This was a retrospective analysis using data from our local TAVI database. Small BAV was defined as a small balloon size (=18 mm) pre-dilatation. Normal BAV was defined as a balloon size >18 mm. The primary endpoint was the incidence of new PPMI. Results Of 99 consecutive TAVI patients, five patients were excluded due to pre-existing permanent pacemaker. Patients in the small BAV group (n=57) had a significantly lower PPMI rate compared with the normal BAV group (n=37) (3.5% vs. 18.9%, P=0.026). Moderate or severe aortic valve regurgitation post-procedure was similar between the small BAV and normal BAV groups (5.3% vs. 8.1%, P=0.480); likewise, the mean aortic gradient post-procedure did not differ significantly (11.5±5.2 mmHg vs. 12.2±7.3 mmHg, 1 mmHg=0.133 kPa, P=0.580) between the groups. Device success rates were also similar (94.7% vs. 91.8%, P=0.680). In multivariable analysis, small BAV (P=0.027), the ratio of prosthesis diameter to annulus diameter (P=0.048), and mean aortic gradient by echo in the basement (P=0.021) were independent predictors of PPMI. Conclusions The small BAV strategy is associated with a low rate of permanent pacemaker implantation after transcatheter self-expanding valve implantation in this single-center observational study.

Background: The aim of this study is to investigate the prevalence and outcome of tricuspid regurgitation (TR) in the Chinese population. Methods: The echocardiography database, including 134,874 patients at our heart center from 2010 to 2012, was retrospectively analyzed. Results: The rates of mild, moderate, and severe TR were 2.96, 2.22, and 1.39%, respectively. Of these patients, 4.86% had primary TR, 91.41% had functional TR, and 3.73% had unexplained TR. The rate of TR was increased in elders (odds ratio: 1.038 for 1 year’s increment; 95% confidence interval: 1.037–1.040; p < 0.001) and females (odds ratio: 1.386; 95% confidence interval: 1.327–1.448, p < 0.001). The major etiologies of TR were left-sided valve heart disease (VHD) and dilated cardiomyopathy. The survival rate of severe TR patients with pulmonary artery hypertension (PAH) was lower than in those without PAH (p < 0.0001). There was a positive association between the prevalence of TR and impaired left ventricular ejection fraction. Compared to the non-left-sided VHD group, the left-sided VHD group had a better prognosis among severe TR patients. The 5-year survival rates were 79.69, 71.12, and 77.01% in the groups of left-sided VHD, non-left-sided VHD, and all patients. Conclusions: Patients with severe TR have a bad prognosis, especially those with non-left-sided VHD and those with PAH.

Electrocatalytic water-splitting catalysts play important roles in clean energy conversion systems. Herein, metal–organic framework-derived (MOF-derived) hollow CoSx@MoS2 microcubes were successful...

Metal–organic framework-based supercapacitors have been widely recognized as the best energy storage devices for future portable electronic equipment. Herein, CoP-T (T = 300, 350, and 400 °C) microcubes with a solid and hollow microstructure were successfully synthesized by low-temperature phosphorization of [CH3NH3][Co(HCOO)3] precursor at desired temperatures. The morphology, structure, and composition of the prepared CoP-350 °C samples were analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. Hollow CoP-350 °C microcube has a larger specific surface area (25.9 m2 g–1) than that of solid ones (16.1 m2 g–1). When the two samples were used as electrode raw materials for supercapacitors, the hollow CoP-350 °C electrode exhibits better electrochemical performance (560 F g–1) than that of the solid one (427.6 F g–1) at a current density of 1 A g–1. The enhanced supercapacitor properties may be attributed to the large surface area and the unique hol...

This paper aims to solve the time-constrained problems of knowledge sharing caused by geographical distance and cultural differences in cross-border business models by proposing a novel knowledge sharing model based on principal–agent theory. Given that digital technologies (DTs) can solve the information asymmetry issue, this paper analyses and compares the contract parameters given by the principal, the efforts of the agent, and the changes in the expected profits of both parties before and after the application of DTs and therefore discusses the influence of various relevant factors in incentive contracts, the relationship between the expected profit of both parties and the various relevant factors is analyzed through numerical simulations. The results show that, in cross-border business models considering the time value of knowledge, the principal is affected not only by “information rent” and “channel loss” but also by the “time cost”. The application of DTs can effectively reduce all three of these costs. More importantly, the principal’s incentive coefficient and the agent’s effort are related to this time constraint and the application of DTs.

The bullwhip effect (BWE) and stochastic demand coexist in supply chain operation management, which leads to a lower performance. In recent years, with the development of blockchain, cloud computing, big data, and other digital technologies (DTs), many enterprises hope to use them to weaken the BWE and improve profits. This paper focuses on improving the application level of DTs in the supply chain through coordination for enhancing the performance. We consider a supply chain with one-supplier-one-retailer and coordinate it with the cost-sharing contract and revenue-cost-sharing contract (the improved contract). We find out that the retailer and supplier did not always have the willingness to use DTs to alleviate the BWE. Even if they have the intention to use DTs, their ideal application level is not the same. After coordination, both the application level of DTs and the performance of the supply chain are improved, and we find that the improved contract has a better coordination effect. Finally, we validate our model by numerical simulation.

This paper describes the experiences of deploying distribution ring network self-healing control system in China, including the architecture designing, retrofitting with advanced controller, simulating and testing on site.This decentralized self-healing system consists of nine sets of edging controllers Easergy T300 installed on 20kV feeders. These modular-designed T300s are fully integrated into ring main unit (RMU) switches. It is important specially for existing RMU upgrading that extra space is not needed.These controllers are connected using peer to peer (P2P) communication to build an autonomous system. The principle of the self-healing grid automation system is to start an automatic sequence of re-energizing the healthy part of the MV ring after a short circuit or earth fault somewhere in the ring. The re-energizing operations have to be performed in a minimum time with a maximum of safety and security. No distribution management system (DMS) is required and no operator intervention is needed.To validate this decentralized self-healing system, there are two steps: in the lab, special test bench can verify the whole system which is almost same as a real system just except communication network; on site, a dedicated simulator can be used to "generate" a short circuit fault, then switches are operated automatically according to self-healing algorithm in the real communication network.The project was implemented for State Grid Corporation of China. The main objectives of this program are to improve the feeder automation capability and enhance reliability of power supply in the CBD area of Hangzhou. This self-healing control system help our utility customer to achieve their goals.

With the increase of trading volume and frequency in futures market, manual trading is unable to meet the requirements of investors in many cases. Meanwhile, program trading has advantages of quick reaction and objectivity, which is suitable for realizing complex trading strategies. Therefore, we proposed a program trading platform for futures, making it possible for investors to realize their strategies by programs and execute them automatically. The platform consists of four layers of interface, processing, strategy and user. In the processing layer, we designed an event-driven engine as the processing core of the platform to ensure high instantaneity, stability and concurrency. Then we explained how users realize and manage their trading strategies in the strategy layer. After optimizing the design, we implemented the program trading platform and did system testing on it. The results show that the platform can access the exchanges through the Internet to trade futures, and can achieve our objectives in instantaneity, stability and concurrency.

Developing non-noble and high activity electrocatalysts is the key to electrocatalytic water-splitting. Recently, MoS2 shows vast perspectives due to its excellent catalytic performance and chemical stability in acid condition. Herein, to expand its application in different environment, a unique ternary composite MCNTs@CoSx@MoS2 comprising three-dimensional lamellar heterostructure supported by multiwalled carbon nanotubes was successfully prepared by a two-step solvothermal strategy and used in electrocatalytic field. As a bifunctional electrocatalyst, heterostructure MCNTs@CoSx@MoS2 could catalyst HER with a small overpotential of 196 mV and low Tafel slope of 65 mV dec−1 in acid condition and exhibit outstanding OER performance with a low overpotential of 285 mV and small Tafel slope of 76 mV dec−1 in alkaline solution. Meanwhile, it displayed excellent durability both in an acid and alkaline solution. The remarkable electrochemical performance of MCNTs@CoSx@MoS2 can be attributed to novel construction advantages and synergy of MCNTs, small CoSx nanoparticles and lamellar MoS2. This work can be extended to the design and preparation of a series of composite materials with the advantage of structural diversity.

The electrochemical splitting of water provides an attractive method for the production of hydrogen fuels. Unfortunately, the slow kinetics of oxygen evolution (OER) on the anode side of the electrolyzer hinders the efficient and large-scale hydrogen production. In this study, starting from metal-organic frameworks (MOFs), a series of bimetal phosphides Co

Normally the protection relay tracks the power system frequency in real time. It shall provide precise frequency measurement and adjust its sampling frequency according to the system frequency to ensure the accuracy of protection functions. So the frequency estimation is a fundamental function for the protection relay. This paper analyzes the basic principle and the performance of the conventional frequency estimation solution, which is based on discrete phase locked loop technology. To improve the conventional frequency estimation, this paper proposes to execute DFT calculations on single cycle and multi-cycles timing windows simultaneously. The minimum angle offset derived from the single cycle DFT or multi-cycles DFT is selected to calculate the frequency deviation. Besides, different proportional factors can be applied for the calculations of the frequency measurement and the sampling frequency. These strategies can achieve both the stability and shorter settling time of the frequency response. The improved frequency estimation solution is verified with different test scenarios. The simulation results show the new frequency estimation solution with proper data length has better stability under voltage disturbance. Meanwhile the additional time delay due to the longer data length is limited and acceptable for practical application.

More retailers are now incorporating the Internet as a channel to their existing operations and becoming multichannel retailers. However, not all multichannel retailers are successful in their attempts and even some otherwise successful traditional retailers have failed to capitalize on the Internet as a retail channel.