New insights into autophagy in inflammatory subtypes of asthma

Asthma is a heterogeneous airway disease characterized by airway inflammation and hyperresponsiveness. Autophagy is a self-degrading process that helps maintain cellular homeostasis. Dysregulation of autophagy is involved in the pathogenesis of many diseases. In the context of asthma, autophagy has been shown to be associated with inflammation, airway remodeling, and responsiveness to drug therapy. In-depth characterization of the role of autophagy in asthma can enhance the understanding of the pathogenesis, and provide a theoretical basis for the development of new biomarkers and targeted therapy for asthma. In this article, we focus on the relationship of autophagy and asthma, and discuss its implications for asthma pathogenesis and treatment

Sputum inflammatory cell-based classification of patients with acute exacerbation of chronic obstructive pulmonary disease

Background: Patients with chronic obstructive pulmonary disease (COPD) commonly suffer from acute exacerbations (AECOPD) and display varying disease severity. However, there is no available biomarker for the classification of AECOPD. This study is aimed at investigating the sputum cellular profiles to classify patients with AECOPD. Methods: A total of 83 patients with AECOPD and 26 healthy controls were recruited. Their demographic and clinical characteristics were recorded, and their lung function was examined. The phenotypes of sputum inflammatory cells were characterised, and the concentrations of sputum and serum amyloid-A (SAA), C-reactive protein (CRP), interleukin-6 (IL-6), and matrix metalloproteinase-9 (MMP-9) were measured. Based on the sputum inflammatory cell profiles, individual patients were categorized into one of the four subgroups with inflammatory eosinophilic, neutrophilic, paucigranulocytic, and mixed granulocytic AECOPD. Most AECOPD patients were reevaluated within 12-14 months after discharge. Results: There were 10 (12%) eosinophilic, 36 (43%) neutrophilic, 5 (6%) mixed granulocytic, and 32 (39%) paucigranulocytic AECOPD patients. The patients with mixed granulocytic or neutrophilic AECOPD had a higher BODE score, more sputum inflammatory cells, lower lung function, and longer hospital stay, accompanied by higher concentrations of sputum MMP-9, IL-6 and CRP, and serum SAA, IL-6 and CRP. Notably, 83% of patients with neutrophilic AECOPD displayed evidence of bacterial infection and many of them responded poorly to standard therapies. In addition, patients with mixed granulocytic or neutrophilic stable COPD remained at lower lung functions and higher levels of inflammation. Conclusion: Patients with AECOPD display heterogeneous inflammation, and the profiles of sputum inflammatory cells may be used as valuable biomarkers for the classification of AECOPD patients

Pullout Resistance of Reinforcement of Lightweight Cellular Concrete Fill [Technical Summary]

This report presents a series of laboratory tests to evaluate the material properties of LCC and the pullout resistances of geogrid and steel strip in LCC specimens cast in the field. Based on the test results, the following conclusions can be drawn: The average wet densities of LCC ranged from 30 to 36 pcf at the age of 28 days and the average dry densities ranged from 21 to 24 pcf at the same age. The dry density was approximately 67% of the wet density. The density increased as the cement to fly ash ratio increased. All LCC specimens used in this study are considered ultra-low density cellular concrete. The permeability values for LCC measured using the falling head method ranged from 2.1 710-5 to 3.0 710-4 in./s, respectively. In general, the permeability decreased as the hydraulic gradient and the confining stress increased. For the small shear box tests, the cohesion values of the LCC specimens ranged from 19 to 37 psi, while their frictional angles ranged from 19 to 63 degrees. For the large shear box tests, the cohesion values of the LCC specimens ranged from 33 to 50 psi, while their frictional angles ranged from 23 to 79 degrees. The large shear box tests measured higher shear strengths than the small shear box tests

Small-Signal Stability Research of Grid-Connected Virtual Synchronous Generators

The virtual synchronous generator (VSG) technique is used to simulate the external characteristics of a synchronous generator (SG) to provide certain damping and inertia to power systems. However, it may easily cause low-frequency oscillation of the power system. We studied the small-signal stability of a grid-connected virtual synchronous generator. Firstly, the small-signal models of single-VSG and multi-VSG grid-connected systems were established. Subsequently, the system eigenvalues were obtained by solving the state matrix, and the system oscillation modes were analyzed. The eigenvalue analysis method was used to analyze the impacts of parameter changes, such as virtual moment of inertia, virtual damping coefficient, line resistance, and line inductance, on system stability. Finally, our conclusions were verified by numerous simulation models