Analysis of transcription factor binding to DNA sequences is of utmost importance to understand the intricate regulatory mechanisms that underlie gene expression. Several techniques exist that quantify DNA-protein affinity, but they are either very time-consuming or suffer from possible misinterpretation due to complicated algorithms or approximations like many high-throughput techniques. We pr...

Heterogeneity in biological molecules, resulting in molecule-to-molecule variations in their dynamics and function, is an emerging theme. To elucidate the consequences of heterogeneous behavior at the single molecule level, we propose an exactly solvable model in which the unfolding rate due to mechanical force depends parametrically on an auxiliary variable representing an entropy barrier aris...

A novel device for distal fixation of a guidewire was tested in regards to deployment and retrieval, deposition in the blood stream and force of fixation in a pig model. Eleven pigs were subjected to full anaesthesia and heparinized to active clotting time 250-350 s. Uninterrupted blood flow during 4 h deposition was assessed by angiography and inspected for thrombus deposition upon retrieval. ...

We investigate the thermodynamics and kinetics of DNA hairpins that fold/unfold under the action of applied mechanical force. We introduce the concept of the molecular free energy landscape and derive simplified expressions for the force dependent Kramers–Bell rates. To test the theory we have designed a specific DNA hairpin sequence that shows two-state cooperative folding under mechanical ten...

We study the base pairing dynamics of DNA with repetitive sequences where local strand slippage can create, annihilate, and move bulge loops. Using an explicit theoretical model, we find a rich dynamical behavior as a function of an applied shear force f: reptationlike dynamics at f=f(c) with a rupture time tau scaling as N3 with its length N, drift-diffusion dynamics for f(c)<f<f(*), and a dyn...

BACKGROUND The objective of this study was to investigate the biomechanical and histological effects of the posterior cruciate ligament (PCL) on the medial tibial plateau. METHODS A total of 12 cadaveric human knee specimens were collected and grouped as follows: the PCL intact group (n = 12), the anterolateral bundle rupture group (n = 6), the postmedial bundle rupture group (n = 6), and the...

Leukocyte adhesion to vascular endothelium is a key initiating step in the pathogenesis of many inflammatory diseases. In this study, we present real-time force measurements of the interaction between monocytic human promyelocytic leukemia cells (HL-60) cells and a monolayer of human umbilical vein endothelial cells (HUVECs) by using atomic force microscopy (AFM). The detachment of HL-60-HUVEC ...

T he early description of the living cell as a reaction vessel of molecules undergoing random collisions has evolved to a much more interesting picture of a small chemical factory of complex and dynamic molecular structures that carry out specialized functions in a highlycoordinated fashion. Traditional solution biochemistry has had extraordinary success in elucidating molecular structures of t...

introduction left ventricular free wall rupture (lvfwr) is a frequent cause of death after acute myocardial infarction, and its repair remains a surgical challenge. conclusions a hemodynamic study was acceptable at a 12-month follow-up, and no complication was seen. case presentation tachosil® is a ready-to-use equine collagen patch which has been successfully used for hemostasis in cardiovascu...