A nonlinear version of resonance ultrasound spectroscopy (RUS) theory is presented. This is important for NDT-purposes as damage manifests itself more pronounced and in an earlier stage by changes in the nonlinear elastic constants. General equations are derived for the 1-D case, describing the interaction between the modes due to the presence of nonlinearity. An analytical solution of these equations is derived which predicts the shift of the resonance frequency versus amplitude in a bar with localized damage. The damage was modelled as a finite region, having a constant cubic nonlinearity, in an otherwise linear 1-D bar. The analytical expressions for the shifts in resonance frequency at different modes were used to infer information about the position, nonlinearity and width of the damage. Unlike other techniques, the proposed method does not require scanning to locate the defect, as it lets the different modes, each with a different vibration pattern, probe the structure.
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http://dx.doi.org/10.1016/j.ultras.2003.12.030 | DOI Listing |
Mol Plant
January 2025
State Key Laboratory of Wheat Improvement, School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China; Beijing Life Science Academy, Beijing 102299, China. Electronic address:
It has been hypothesized that DNA damage has the potential to induce DNA hypermethylation, contributing to carcinogenesis in mammals. However, there is no sufficient evidence to support that DNA damage can cause genome-wide DNA hypermethylation. Here, we demonstrated that DNA single-strand breaks with 3'-blocked ends (DNA 3'-blocks) can not only reinforce DNA methylation at normally methylated loci but also can induce DNA methylation at normally nonmethylated loci in plants.
View Article and Find Full Text PDFJ Sci Med Sport
January 2025
Department of Health Promotion, School of Public Health, Faculty of Medical and Health Sciences, Sylvan Adams Sports Institute, Tel-Aviv University, Israel. Electronic address:
Objectives: The study aimed to examine the effects of exercise-induced muscle damage on running kinetics.
Design: Twenty-six adult recreational male runners performed 60 min of downhill running (-10 %) at 65 % of maximal heart rate. Running gait changes, systemic and localized muscle damage markers were assessed pre - and post-exercise induced muscle damage protocol.
Atherosclerosis and aortic aneurysms are prevalent cardiovascular diseases in the elderly, characterized by chronic inflammation and oxidative stress. This study explores the role of CircXYLT1 in regulating oxidative stress and vascular remodeling in age-related vascular diseases. RNA sequencing revealed a significant upregulation of CircXYLT1 in the vascular tissues of aged mice, highlighting its potential role in age-related vascular diseases.
View Article and Find Full Text PDFInt J Surg Case Rep
January 2025
Department of Surgery, The University of Hong Kong, The University of Hong Kong - Shenzhen Hospital, Shenzhen, China. Electronic address:
Introduction: Endoscopic resection is suitable for most benign gastric or early stage cancerous polyps. Laparoscopic local resection is performed only for gastric polyps that are difficult to treat with endoscopic resection, such as recurrent or large polyps. However, when polyps are located in difficult regions, such as the gastric cardia and prepyloric antrum, wedge resection may damage the sphincter around the cardia or pylorus, resulting in postoperative deformity or stenosis.
View Article and Find Full Text PDFRedox Biol
January 2025
Department of Reproductive Medicine, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, Jiangsu, 210002, China; State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu, 211166, China; Department of Reproductive Medicine, Affiliated Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, 210002, China. Electronic address:
Oocyte aging is closely related to a decline in female fertility, accompanied by increased reactive oxygen species levels and changes in protein posttranslational modifications. However, the role of protein palmitoylation in oocyte aging has not been investigated. In the present study, a new association between redox and palmitoylation in aging oocytes was found.
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