Feature-Weighted Echo State Network for Dynamic Frequency Offset Modeling of Quartz Crystal Resonators.

Quartz crystal resonators are widely used as reference frequency sources in modern electronic systems. However, their frequency often deviates from the nominal value due to the significant change in the ambient temperature. Therefore, it is of great value to develop an accurate dynamic frequency offset model regarding temperature changes. In this article, a novel feature-weighted echo state network (FWESN) method is presented to capture the dynamic frequency-temperature ( f - T ) characteristic of quartz crystal resonators. Different from the traditional echo state network (ESN), which simply takes the temperature measurement signal as a single model input variable, the proposed method mines the feature information hidden in the temperature measurement series to construct the model input vector. Specifically, five dynamic features are designed to substitute for the original temperature signal by investigating the influence mechanism of temperature versus frequency. Furthermore, considering the difference in these features' importance, two feature weighting strategies, including the Pearson's correlation coefficient (PCC)-based and particle swarm optimization (PSO)-based, are proposed to assign the different weights to the five features. Finally, the weighted features are fed into the ESN model to implement the dynamic frequency offset estimation. The application results on the real experiment datasets demonstrate that the presented FWESN method can estimate the frequency offset more precisely than the basic ESN method.

Dynamic Frequency-Temperature Characteristic Modeling for Quartz Crystal Resonator Based on Improved Echo State Network.

Quartz crystal resonators are the key component of various kinds of electronic systems because they provide the reference frequency source of the system running clocks. However, the frequency stability is often affected by the temperature. Therefore, the frequency-temperature ( f-T ) characteristic modeling has been an important research topic in the frequency control field. The classic f-T modeling method omits the system dynamics and may lead to a large frequency compensation error in the case of rapid temperature changing. To deal with this issue, this article proposes a dynamic f-T modeling method based on improved echo state network (ESN), called residual scaled ESN (RSESN). In the proposed method, the residual modeling framework is designed for purposes of good physical understandability and high prediction precision. This framework uses the static polynomial f-T model to depict the approximated data relationship and applies the complicated network model to compensate the detailed dynamic error. To estimate the dynamic errors, one effective dynamic modeling tool, ESN, is introduced to build the dynamic compensation model for f-T characteristic of quartz crystal resonators. For a better fitting performance, the ESN activation limitations are analyzed and the scaled echo states are constructed in the improved ESN model. The modeling and testing results on the real experiment data show that the proposed method can capture the dynamic information effectively and provide better frequency deviation predictions.

[Experience of Interventional Thrombolysis Therapy for Massive Pulmonary Thrombosis Embolism after Video-assisted Thoracoscopic Surgery for Lung Cancer].

BACKGROUND: Pulmonary thrombosis embolism (PTE) is one of the most severe complications of perioperative radical mastectomy. Massive PTE is often accompanied by shock and hypotension which is characterized by rapid progression and high mortality. There is no standard for the treatment of these patients, which is thoracic surgery, and it is a critical issue in the thoracic surgeons. This article summarizes and analyzes the treatment of two patients with high-risk PTE at the early stage of postoperative lung cancer in our hospital. In addition, we discusses the diagnosis and treatment strategies of these cases to provide a reference for the thoracic surgeons. METHODS: We presented two patients with high-risk PTE at the early stage after thoracic surgery for radical surgery in our hospital back in 2017. One case was treated with intravenous venous interventional thrombolysis, and the other was treated with thrombolysis alone. The treatment effect of two patients and the complications during the treatment has been recorded to detail and summarized. RESULTS: Both patients were female who aged 66 and 61 years old. The time point of pulmonary embolism was 48 h and 45 h after operation, and the time of interventional thrombolysis was 70 minutes and 50 minutes after onset respectively. After 120 minutes and 100 minutes, the drainage after interventional thrombolysis was 4,690 mL and 520 mL respectively. The hospitalization time after thrombolysis was 21 days and 14 days respectively. There was no obvious complication through a follow-up of 6 months. CONCLUSIONS: Early postoperative acute massive pulmonary embolism in lung cancer should be treated with pulmonary interventional thrombolysis as soon as possible. Compared with intravenous thrombolysis, pulmonary interventional thrombolysis shows accuracy, easy controlling of dosage, fast curative effect and low bleeding risk.

Activated protein C inhibits lung injury induced by LPS via downregulating MAPK signaling.

The aim of the present study was to investigate the effect and the underlying mechanism of activated protein C (APC) in lipopolysaccharide (LPS) induced lung injury, as well as the potential mechanism. According to the treatment, 50 rats were randomly divided into 5 groups: Control, model (LPS), low-dose group [LPS + 0.1 mg/kg recombined human activated protein C (rhAPC)], median-dose group (LPS + 0.3 mg/kg rhAPC) and high-dose group (LPS + 0.5 mg/kg rhAPC). Then, inflammation in the lung was assessed using hematoxylin and eosin (H&E) staining. Following the collection of bronchoalveolar lavage fluid (BALF), the number of leukocytes and neutrophils in BALF was counted, and superoxide dismutase (SOD) activity was assessed, as well as the expression levels of interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α using ELISA. Subsequently, the expression and phosphorylation of P-38, extracellular signal-regulated kinase (Erk)-1/2, and c-Jun N-terminal kinase (JNK) were estimated using western blotting. Based on H&E staining, rhAPC markedly suppressed inflammatory infiltration in the lung induced by LPS in a dose-dependent manner. In addition, rhAPC also significantly attenuated the accumulation of leptocytes and neutrophils, and the reduction of SOD in BALF induced by LPS in a dose-dependent manner. rhAPC also significantly attenuated the elevation of IL-1ß, IL-6 and TNF-α in BALF induced by LPS in a dose-dependent manner. Further mechanistic analysis revealed that rhAPC treatment could evidently attenuate the phosphorylation levels of P-38, Erk1/2 and JNK in the lung induced by LPS in a dose-dependent manner. In conclusion, APC significantly alleviated the lung inflammation induced by LPS by downregulating the phosphorylation of P-38, ERK1/2 and JNK.

Circulating Histones Are Major Mediators of Cardiac Injury in Patients With Sepsis.

OBJECTIVE: To investigate the impact of circulating histones on cardiac injury and dysfunction in a murine model and patients with sepsis. DESIGN: Prospective, observational clinical study with in vivo and ex vivo translational laboratory investigations. SETTING: General ICU and university research laboratory. SUBJECTS: Sixty-five septic patients and 27 healthy volunteers. Twelve-week-old male C57BL/6N mice. INTERVENTIONS: Serial blood samples from 65 patients with sepsis were analyzed, and left ventricular function was assessed by echocardiography. Patients' sera were incubated with cultured cardiomyocytes in the presence or absence of antihistone antibody, and cellular viability was assessed. Murine sepsis was initiated by intraperitoneal Escherichia coli injection (10(8) colony-forming unit/mouse) in 12-week-old male C57BL/6N mice, and the effect of antihistone antibody (10 mg/kg) was studied. Murine blood samples were collected serially, and left ventricular function was assessed by intraventricular catheters and electrocardiography. MEASUREMENTS AND MAIN RESULTS: Circulating histones and cardiac troponins in human and murine plasma were quantified. In 65 patients with sepsis, circulating histones were significantly elevated compared with healthy controls (n = 27) and linearly correlated with cardiac troponin T levels (rs = 0.650; p < 0.001), noradrenaline doses required to achieve hemodynamic stability (rs = 0.608; p < 0.001), Sequential Organ Failure Assessment scores (p = 0.028), and mortality (p = 0.008). In a subset of 36 septic patients without prior cardiac disease, high histone levels were significantly associated with new-onset left ventricular dysfunction (p = 0.001) and arrhythmias (p = 0.01). Left ventricular dysfunction only predicted adverse outcomes when combined with elevated histones or cardiac troponin levels. Furthermore, patients' sera directly induced histone-specific cardiomyocyte death ex vivo, which was abrogated by antihistone antibodies. In vivo studies on septic mice confirmed the cause-effect relationship between circulating histones and the development of cardiac injury, arrhythmias, and left ventricular dysfunction. CONCLUSION: Circulating histones are novel and important mediators of septic cardiomyopathy, which can potentially be utilized for prognostic and therapeutic purposes.