We present plasmonic optical trapping of micron-sized particles in biologically relevant buffer media with varying ionic strength. The media consist of 3 cell-growth solutions and 2 buffers and are specifically chosen due to their widespread use and applicability to breast-cancer and angiogenesis studies. High-precision rheological measurements on the buffer media reveal that, in all cases excl...

Fig. 1 (a) MRE wave image and Elastogram (b) UTE spatio-temporal strain map (c) Bland-Altman plot MRE: FOV=14cm,Matrix=256X64,TR/TE=50/26.5ms, flip angle=30 ̊, thickness=10cm, BW=±16kHz, continues vibration=60Hz, average stiffness of ROI drawn on the elastogram was measured as the stiffness of the phantom. UTE: center frequency of transducer=3.5 MHz, transient vibration=20ms (1 cycle of 50 Hz si...

Measurements over the past 30 years have indicated that surface stress can significantly affect the stiffness of microcantilever plates. Several one-dimensional models based on beam theory have been proposed to explain this phenomenon, but are found to be in violation of Newton's third law, in spite of their good agreement with measurements. In this Letter, we review this work and rigorously ex...

Contact resonance atomic force microscopy (CR-AFM) methods currently utilize the eigenvalues, or resonant frequencies, of an AFM cantilever in contact with a surface to quantify local mechanical properties. However, the cantilever eigenmodes, or vibrational shapes, also depend strongly on tip-sample contact stiffness. In this paper, we evaluate the potential of eigenmode measurements for improv...

The aim of the present investigation was to elucidate the elastic properties of the myofilaments during tetanic activity in striated muscle. The study was carried out on intact single muscle fibres from the anterior tibialis muscle of Rana temporaria (2.0-2.5 degrees C). The instantaneous stiffness was measured as the change in force that occurred in response to a high-frequency (2-4 kHz) lengt...

Basilar membrane stiffness measurements were made in the base of the gerbil cochlea. Basilar membrane stiffness was determined by contacting the basilar membrane with a stainless steel needle (tip diameter 25 microns) attached to a force transducer, putting the needle/transducer structure through a low-frequency sinusoidal excursion with amplitude 5 or 25 nm, and measuring the restoring force e...

In the eggs of the newt, Cynops (Triturus) pyrrhogaster, change in stiffness of the cortex was measured in various regions at the time of the cleavage. Measurements were performed by Mitchison and Swann's cell elastimeter method with a modification, in which two fine pipettes were attached to the surface of one egg at the same time, in order to compare the rigidity of two regions. The stiffness...

This study involved a biomechanical examination of the first and second tarsometatarsal (TMT) joints. In the in vitro testing protocol, physiologic joint moments were applied to the first and second TMT joints of 10 cadaver specimens, which had been dissected to yield only the midfoot components comprising the tarsals, metatarsals, and associated ligaments. The isolated joints were placed in a ...

OBJECTIVE The purpose of this article is to establish the range of normal splenic stiffness in healthy volunteers using MR elastography (MRE) and to investigate any correlation with physiologic parameters and driver position. SUBJECTS AND METHODS Sixteen volunteers (mean [+/- SD] age, 37 +/- 9 years) with no history of gastrointestinal, hepatobiliary, or cardiovascular disease were recruited....

The short-range stiffness (SRS) of skeletal muscles is a critical property for understanding muscle contributions to limb stability, since it represents a muscle's capacity to resist external perturbations before reflexes or voluntary actions can intervene. A number of studies have demonstrated that a simple model, consisting of a force-dependent active stiffness connected in series with a cons...