Purpose: Statistical mechanics establishes a link between microscopic properties of matter and its bulk properties. A. Huxley's equations (1957) [1] provide the necessary phenomenological formalism to use statistical mechanics.
Methods: We compared statistical mechanics in rat diaphragm in tetanus (tet; n=10) and twitch (tw; n=12) modes, in heart in twitch mode (n=20), and in tracheal smooth muscle in tetanus mode (TSM; n=10). This powerful tool makes it possible to determine: (i) statistical entropy (S) which is related to the dispersal of energy and represents a measure of the degree of disorder in muscular system; (ii) thermodynamic force A/T (chemical affinity A and temperature T); (iii) thermodynamic flow (υ); (iv) entropy production rate (A/T×υ), which quantifies irreversible chemical processes generated by myosin crossbridge (CB) molecular motors.
Results: All muscles studied operated near equilibrium, i.e., A<<2500J/mol and in a stationary linear regime, i.e., A/T varied linearly with υ. The heart operated farther from equilibrium than both diaphragm (tet and tw) and TSM, as attested by its high entropy production rate. S was of the same order of magnitude in heart and TSM but lower in diaphragm (tet and tw).
Conclusion: CB kinetics derived from A. Huxley's equations conferred a characteristic profile in terms of statistical mechanics on each muscle type. All studied muscles differed in terms of statistical entropy, chemical affinity, and entropy production rate. Stimulation mode (tet and tw) modulated CB kinetics and statistical mechanics. All muscle types operated near equilibrium and in a stationary linear regime.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.crvi.2011.08.001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Different Internal Fixation Methods for Sanders Type II and III Calcaneal Fractures: A 5-Year Retrospective Study and Finite Element Analysis.
Orthop Surg
January 2025
Orthopedics Department, Gongli Hospital of Shanghai Pudong New Area, Shanghai, China.
Objective: Soft tissue defects and postoperative wound healing complications related to calcaneus fractures may result in significant morbidity. The aim of this study was to investigate whether percutaneous minimally invasive screw internal fixation (PMISIF) can change this situation in the treatment of calcaneal fractures, and aimed to explore the mechanical effects of different internal fixation methods on Sanders type III calcaneal fractures through finite element analysis.
Methods: This retrospective analysis focused on 83 patients with Sanders II and III calcaneal fractures from March 2017 to March 2022.
Effect of Cervical Margin Relocation With Different Injectable Restorative Materials on Fracture Resistance of Molars Received MOD CAD/CAM Onlay Restorations.
J Esthet Restor Dent
January 2025
Operative Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
Objective: To investigate the effect of cervical margin relocation with four different injectable restorative materials on the fracture resistance of molars receiving mesio-occluso-distal CAD/CAM nanoceramic onlay restorations.
Materials And Methods: One hundred and five sound mandibular molars received a standardized mesio-occluso-distal onlay preparation, with cervical margins located 2 mm apical to the cemento-enamel junction. The molars were randomly allocated into five groups (n = 21) according to the cervical relocating materials used: Group I had no cervical margin relocation; Group II used a highly viscous glass ionomer; Group III used a highly-filled injectable resin composite; Group IV used a resin-modified glass ionomer; and Group V used a bioactive ionic resin.
The effectiveness of non-exposure to incarceration in preventing COVID-19 and mitigating associated events: a systematic review and meta-analysis.
BMC Public Health
January 2025
Department of Health Economics and Development, Ministry of Health, Distrito Federal, Brazil.
Background: For a long time, the penalty of imprisonment has been studied and criticized as ineffective in achieving the goals of resocialization and rehabilitation of offenders, and studies have associated incarceration with increased prevalence of disease. In response to the COVID-19 pandemic, the World Health Organization recommended decarceration as a prevention measure. The aim of this review was to analyze the effectiveness of non-exposure to incarceration in preventing COVID-19 and mitigating associated events.
View Article and Find Full Text PDFPredicting extubation failure in neonates: The role of lung ultrasound and corrected gestational age in safe weaning in the NICU.
Eur J Pediatr
January 2025
Hospital de Clinicas de Porto Alegre, Rua Silva Jardim 1155 # 701, Porto Alegre, RS, 90450-071, Brazil.
Unlabelled: To evaluate the accuracy of the lung ultrasound score (LUS) in predicting ventilatory weaning failure during neonatal hospitalization in the NICU and to identify factors associated with weaning failure, including corrected gestational age (CGA). This prospective, longitudinal, pragmatic and observational cohort study included neonates on mechanical ventilation for at least 48 h. The primary outcome was the accuracy of lung ultrasound in predicting 3-day weaning failure, with the ROC curve used to determine the best LUS cutoff (sensitivity and specificity).
View Article and Find Full Text PDFAnaerobic Adhesive Effect on the Counter-Torque of Zirconia Implant Abutment Screws: In Vitro Study.
Clin Implant Dent Relat Res
February 2025
Department of Restorative Dentistry, Faculty of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Introduction: Implantology has become a primary solution for tooth loss due to excellent osseointegration and high long-term success rates. However, complications such as abutment screw loosening, especially in implant-supported single crowns, compromise prosthesis longevity. Anaerobic adhesives (AAs) have shown promise in mechanical fields for preventing screw loosening, but their effectiveness in dental implants, particularly zirconia, remains uncertain.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!