We describe an apparatus that can measure the instantaneous angular displacement and torque applied to a quartz particle which is angularly trapped. Torque is measured by detecting the change in angular momentum of the transmitted trap beam. The rotational Brownian motion of the trapped particle and its power spectral density are used to determine the angular trap stiffness. The apparatus features a feedback control that clamps torque or other rotational quantities. The torque sensitivity demonstrated is ideal for the study of known biological molecular motors.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.92.190801 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Eccentric Training to Restore Persistent Functional Loss Following Ruptured Achilles Tendon: The Role of Fascicle Length and Muscle Excursion.
Transl Sports Med
December 2024
Department of Orthopaedic Surgery, Institute of Sports Medicine Copenhagen, Copenhagen University Hospital Bispebjerg-Frederiksberg, Copenhagen, Denmark.
Persisting deficits are often seen years after an Achilles tendon rupture despite dedicated rehabilitation efforts. A possible reason for reduced function is elongation of the tendon and accompanying shortening of the muscle. Strength training with focus on the eccentric component of loading leads to longer muscle fascicles in healthy persons.
View Article and Find Full Text PDFThe acute effects of dynamic stretching on the neuromuscular system are independent of the velocity.
Exp Physiol
January 2025
Strength and Conditioning Research Laboratory, College of Physical Education, University of Brasília, Brasília, Brazil.
This study examined the acute effects of dynamic stretching at different velocities on the neuromuscular system. Fourteen participants underwent four experimental sessions in random order: (1) control (lying at rest with the ankle in a neutral position); (2) slow velocity dynamic stretching (50 beats/min; SLOW); (3) moderate velocity dynamic stretching (70 beats/min; MOD); and (4) fast velocity dynamic stretching (90 beats/min; FAST). The stretching protocols consisted of four sets of 10 repetitions and targeted the plantar flexor muscles of the right ankle.
View Article and Find Full Text PDFAchilles Tendon Surgical Repair Partially Restores Early Plantar Flexor Structure and Function in a Rat Model.
J Orthop Res
January 2025
Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Achilles tendon ruptures significantly impair long-term patient function, with two-thirds of patients experiencing persistent functional deficits. Although nonsurgical treatment has gained popularity due to its perceived lower risk of complications, the specific effects of this approach on tendon healing, muscle function, and overall performance remain poorly understood. Directly comparing surgical and nonsurgical treatment options in a clinical population is challenging given the diverse nature of the patient population.
View Article and Find Full Text PDFComparative study of torque expression and its biomechanical effects: spherical self-ligating bracket with lock-hook system versus passive self-ligating bracket and conventional bracket.
BMC Oral Health
January 2025
Department of Stomatology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510080, China.
Background: Proper torque control is crucial to the outcome of orthodontic treatment. This study aimed to employ finite element analysis to compare the torque capabilities of a novel spherical self-ligating bracket with a lock-hook system against those of commonly used passive self-ligating and conventional bracket systems, as well as to reveal the biomechanical changes in the periodontal ligament (PDL) during torque expression.
Methods: A maxillary right central incisor, along with its PDL and alveolar bone, were modeled.
Gut microbiome signatures of vegan, vegetarian and omnivore diets and associated health outcomes across 21,561 individuals.
Nat Microbiol
January 2025
Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy.
As plant-based diets gain traction, interest in their impacts on the gut microbiome is growing. However, little is known about diet-pattern-specific metagenomic profiles across populations. Here we considered 21,561 individuals spanning 5 independent, multinational, human cohorts to map how differences in diet pattern (omnivore, vegetarian and vegan) are reflected in gut microbiomes.
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!