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Idiopathic pulmonary fibrosis (IPF) is the most common and fatal diffuse fibrotic lung disease accompanied by macrophage M2 activation. ErbB4 is involved in and affects the process of inflammation. In this study, we determined that the mRNA level and protein expression of ErbB4 and M2 cytokine members were increased in the serum of IPF patients. In mouse alveolar macrophage MH-S cells, after knocking down ErbB4 by siRNA, the mRNA level and protein expression of M2 activator induced by interleukin (IL)-4 were decreased compared with the control group. Activating by ErbB4 agonist neuromodulatory protein (NRG)-1, IL-4-induced M2 program was promoted. Mechanistically, treated with NRG-1 in MH-S cells, the phosphorylation level of Akt did not change, while the phosphorylation level of ERK increased. Using SCH772984 to inhibit ERK pathway, the increasing IL-4-induced M2 activation by NRG-1 was inhibited, and the high level of M2 activator protein expression and mRNA expression was restored. Collectively, our data support that ErbB4 and M2 programs are implicated in IPF, and ErbB4 participates in the regulation of M2 activation induced by IL-4 through the ERK pathway.

The fatigue performance of steel–concrete composite beams is crucial for ensuring structural safety. To account for the member's multiaxial stress state, this study employed the critical surface method, using fatigue damage parameters as an evaluation index for assessing fatigue performance. Static and fatigue performance tests on steel–concrete beams were conducted to identify failure characteristics, which informed the development of a finite element model that incorporates concrete damage. Using the SWT model, the most unfavorable loading parameters were determined by analyzing critical paths on the test beams, providing a basis for predicting how initial defects impact fatigue performance. The impact of initial defects on the fatigue performance of the composite beam is assessed using this criterion. The results indicate that the discrepancy between the actual and predicted load capacities of the test beam is within 5%, and cyclic loading significantly affects the test beam's mechanical properties, resulting in a 27% reduction in load capacity and a 48% increase in deflection after 2 million cycles. Finite element modeling reveals that components experience multiaxial stress, with test beam mechanical property changes aligning with predicted fatigue damage parameters, confirming the reliability of using these parameters as a criterion. As the strength of the composite beams diminished due to pore defects, the fatigue damage parameter escalated, increasing the likelihood of crack formation. However, once the concrete's strength fell to a level where the pegs were insufficiently constrained, the structural damage pattern shifted, and the fatigue damage parameter subsequently decreased. [ABSTRACT FROM AUTHOR]

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Objective: The mechanical properties of cells, which are the main characteristics determining their physical performance and physiological functions, have been actively studied in the fields of cytobiology and biomedical engineering and for the development of medicines. In this study, an indentation-vibration-based method is proposed to simultaneously measure the mechanical properties of cells in situ, including cellular mass (m), elasticity (k), and viscosity (c).Methods: The proposed measurement method is implemented based on the principle of forced vibration stimulated by simple harmonic force using an atomic force microscope (AFM) system integrated with a piezoelectric transducer as the substrate vibrator. The corresponding theoretical model containing the three mechanical properties is derived and used to perform simulations and calculations. Living and fixed human embryonic kidney 293 (HEK 293) cells were subjected to indentation and vibration to measure and compare their mechanical parameters and verify the proposed approach. Results: The results that the fixed sample cells are more viscous and elastic than the living sample cells and the measured mechanical properties of cell are consistent within, but not outside of the central region of the cell, are in accordance with the previous studies.Conclusion: This work provides an approach to simultaneous measurement of the multiple mechanical properties of single cells using an integrated AFM system based on the principle force vibration and thickness-corrected Hertz model. Significance: This study should contribute to progress in biomedical engineering, cytobiology, medicine, early diagnosis, specific therapy and cell-powered robots. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore changes in miRNA133 levels as a basis for clinical diagnostic markers in patients with acute myocardial infarction (AMI). A total of 100 chest pain patient cases admitted to a hospital from June 2021 to December 2022 were used. The study involved the selection of 50 patients: 25 patients with unstable undetermined heart pain and 25 healthy subjects were included in the control group of 50 patients with non-AMI patients. Meanwhile, 50 patients with AMI were designated as the experimental group. Changes in miRNA133 levels in patients' plasma were analyzed for expression using quantitative fluorescence analysis. When the serum TPI, plasma NT-ProBNP, glycosylated hemoglobin, and plasma D-dimer index values were compared between the control and experimental groups, there was a statistically significant difference (P < .05). mi-RNA-133 had a mean plasma level value of 2.60 ± 1.01, the mean level value of mi-RNA-133 in patients with non-AMI was 1.34 ± 1.18, and the patients in the AMI group showed significantly high values of the mean plasma level of mi-RNA-133. The relative expression level value of cTnl in patients with AMI was 10.84 ± 12.64. Of the specificity and sensitivity diagnostics, mi-RNA-133 had the best diagnostic effect. The area under mi-RNA-133 in the regression curve was 95.4%, the specificity of the whole combination of indicators was 89.4% and the sensitivity was 100%. Finally, the correlation between mi-RNA-133 and white blood cell count (WBC) and TG was statistically significant (P < .05). In conclusion, changes in the level of mi-RNA-133 may be an important marker for diagnosing the status of patients with AMI, while a faster and more accurate method will emerge along with the improvement of the detection technology, and at the same time, due to the variability of the study cases and other limitations, further research will be carried out subsequently., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)