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Electrocardiography can provide useful prognostic information in acute pulmonary embolism (APE). Several abnormal QRS changes in lead V1, including notched or fragmented QRS, incomplete or complete right bundle branch block (IRBBB or CRBBB) and the QR sign, which are associated with APE, are of prognostic significance. To illustrate this, we describe lead V1 QRS changes in combination with the clinical state of six APE patients. The dynamic ECG changes suggest that a change from a diminution of the S wave amplitude to notched S wave, next to RBBB and then to the QR sign indicate worsening of the patients' condition, and vice versa. Also, a diminution of the S wave amplitude in lead V1 associated with a final R' wave in the right precordial accessory leads indicates the possibility of hidden RBBB. Understanding dynamic QRS changes in APE may aid in risk stratification.

Background The ECG characteristics of simultaneous acute occlusion/sub-occlusion of two coronary arteries involving the left anterior descending (LAD) and right (RCA) coronary artery have been rarely described in the literature. Methods We present two patient cases, where one of the arteries was totally occluded and the other one had a sub-occlusion with severely limited flow to demonstrate the ECG characteristics of this severe presentation of acute coronary syndrome. Results Two ECG patterns suggested simultaneous occlusions of the RCA and LAD. One pattern was ST-segment elevation (STE) in lead III higher than in lead II with concomitant STE in leads V3-V4. The other pattern was STE in lead III higher than in lead II with the concomitant Dressler - de Winter ECG pattern in leads V2-V4. Conclusions We present two ECG presentations of simultaneous RCA and LAD occlusion/sub-occlusion. We consider these ECG features as high-risk markers in acute ST-elevation myocardial infarction.

This letter presents a novel methodology for resistive–resistive series of continuous class-F/ $\text{F}^{{\mathbf {-1}}}$ modes (Res.–Res. SCF/ $\text{F}^{{\mathbf {-1}}}$ Ms) power amplifier (PA) design. The bandwidth is expanded by designing the lower band with resistive second- and third-harmonic impedances and the upper band with resistive second-harmonic impedance and reactive third-harmonic impedance using a waveform engineering method. Mathematical derivation of the methodology is described in detail. The proposed design is experimentally verified using a Res.–Res. SCF/ $\text{F}^{{\mathbf {-1}}}$ Ms PA operating across 0.4–2.3 GHz with 62.3%–80.5% drain efficiency and 39–42 dBm output power.

Aim: The aim is to evaluate serum cysteine-rich protein 61 (Cyr61) levels in patients with coronary artery disease (CAD). Patients & methods: Serum Cyr61 levels were measured in 180 patients with CAD and 74 participants without CAD. Results: Serum Cyr61 levels were significantly higher in CAD patients. Patients with acute coronary syndrome showed significantly higher Cyr61 than those with stable angina pectoris. Serum Cyr61 levels in complex lesion group were significantly higher. Serum Cyr61 was positively correlated with Gensini score and C-reactive protein. Multivariable logistic regression analyses demonstrated that serum Cyr61 levels were independently correlated with the existence of CAD (p = 0.01). Conclusion: Our study suggested Cyr61 as a potential biomarker in characterizing CAD and therapeutic target for CAD.

This paper researches on the kinematics and dynamics of coupling for three-axis flight Simulator based on the high-speed rotation missile. Firstly, to define station body coordinate and the positive direction of rotation according to three-axis flight Simulator based on the high-speed rotation missile, and then the mathematical coupling model is established. Secondly, multivariable nonlinear mathematical model can be decoupling, while substituting the parameters quality attribute analysis solved by ProE into the mathematical model. Lastly, the decoupled linear equations and the decoupling solutions based on inverse system method were given, and then to finish the simulation and to analysis the simulation results.

Isothermal hot compression of 28CrMnMoV steel was conducted on a Gleeble-3500 thermo-mechanical simulator in the temperature range of 1173–1473 K with the strain rate of 0.01–10 s−1 and the height reduction of 60%. Based on the experimental results, constitutive equations and an artificial neural network (ANN) model with a back-propagation learning algorithm were developed for the description and prediction of the hot compressive behavior of 28CrMnMoV steel. Then a comparative evaluation of the constitutive equations and the trained ANN model was carried out. It was obtained that the relative errors based on the ANN model varied from −3.66% to 3.46% and those were in the range from −13.60% to 10.89% by the constitutive equations, and the average absolute relative errors were 0.99% and 4.09% corresponding to the ANN model and the constitutive equations, respectively. Furthermore, the average root mean square errors of the ANN model and the constitutive equations were obtained as 1.43 MPa and 5.60 MPa respectively. These results indicated that the trained ANN model was more efficient and accurate in predicting the hot compressive behavior of 28CrMnMoV steel than the constitutive equations.

The true stress–strain data from isothermal hot compression tests on Gleeble-3500 thermo mechanical simulator, in a wide range of temperatures (1323–1473 K) and strain rates (0.01–10 s−1), were employed to establish the constitutive equations based on modified Zerilli–Armstrong and strain-compensated Arrhenius-type models respectively, and develop the artificial neural network model to predict the high-temperature flow stress of T24 steel. Furthermore, a comparative study has been made on the capability of the three models to represent the elevated temperature flow behavior of this steel. Suitability of the three models were evaluated by comparing the accuracy of prediction of deformation behavior, correlation coefficient and average absolute relative error of prediction, the number of material constants, and the time needed to evaluate these constants. The results showed that the predicted values by the modified Zerilli–Armstrong model could agree well with the experimental values except under the strain rate of 0.01 s−1. The predicted flow stress of the other two models shows good agreement with the experimental data. However, the artificial neural network model could track the deformation behavior more accurately throughout the entire temperature and strain rate range though it is strongly dependent on extensive high quality data and characteristic variables and offers no physical insight.

In continuous tube rolling process, it has an obvious influence on the stability of rolling process, tools wear and the quality of rolled hollow tube that configuration of roll rotational speed per stand. In this paper, various roll working diameters per stand are determined by velocity integral method (VIT) and FEM respectively, and two roll rotational speed schedules are obtained correspondingly based on 133 main pass sequence of 89mm 6-stand semi-floating mandrel mill. With the aid of commercial FE code MSC.SuperForm, the high pressure boiler steel tube continuous rolling process of a typical hollow tube specification 133.0×5.2mm are simulated, and force parameters, transverse wall thickness precision, outline dimension and real roundness of rolled hollow tube and clearance between the mandrel and rolled hollow tube are analyzed and compared on the condition of two different roll rotational speed schedules, which provides scientific basis for configuring reasonable roll rotational speed per stand in pass design and optimization. Analysis results indicate that roll working diameter obtained per stand is smaller and roll rotational speed configured is higher correspondingly using FEM compared to VIT. Using FEM, there exist front and back tensions between stands and maximal rolling force, rolling moment and mandrel axial force decrease 10% or so in continuous tube rolling process, and outline dimension and real roundness of rolled hollow tube is better. However, transverse wall thickness of rolled hollow tube at the bottom of groove is pulled thin slightly, and clearance between the mandrel and rolled hollow tube is less than normal.

the aid of commercially available software MSC.SuperForm, a 3-D finite element model has been established to simulate the rolling process of steel tubes on the stretch reducing mill (SRM) with group centralized differential drive in certain factories. A special effort was made to analyze the fluctuation of transverse wall thickness uniformity. It was found that the wall thickness of each stand was accumulated in the original pass 50°~60° along the circumferential direction, which caused the formation of the inner hexagon defects and worsen. In view of this, this paper proposes a modified roll pass design method which uses the interactive technology of CAD graph curve and MATLAB equation. By means of decreasing the lateral curvature of roll pass contour curve to enlarge the contact length between the tube and groove, also the rolling process using the new pass system were simulated and analyzed. The results indicate that the design of such polygonal roll pass can be effective in improving the inner hexagon defects.

DC micro-grid, as a self-management grid form of integrating distributed energy systems with utility power systems, will efficiently realize the value and benefit of the distributed energy resources. In this paper,the DC micro-grid mainly consists of five parts: a PV source, a DC/DC converter, a battery energy storage unit, a bi-directional DC/DC, and a bi-directional DC/AC which is connected to the main grid. This DC micro-grid has different control strategies according to different operating modes (grid connected, islanded). Then its control mode is designed and investigated by MATLAB/Simulink models. The simulation results verify the validity of the mathematical model and the feasibility of the proposed control strategies. In the grid connected mode, the transfer energy can flow in bi-directional modes, and DC bus voltage level can be stabilized by DC/AC converter. In the islanded mode, the battery converter serves as a voltage source to ensure a stable DC voltage. At last, DC micro-grid experimental system is used to examine its switching functions among different control modes. The experimental results demonstrate that high quality power can be supplied.