Rheology of fibrous gels under compression.

A number of biological tissues and synthetic gels consist of a fibrous network infused with liquid. There have been a few experimental studies of the rheological properties of such gels under applied compressive strain. Their results suggest that a plot of rheological moduli as a function of applied compressive strain has a long plateau flanked by a steeply increasing curve for large compressive strains and a slowly decreasing curve for small strains.

Effects of laparoscopic radical surgery in the treatment of colorectal cancer and correlations of VEGF and TGF-β1 with prognosis.

Objective: To investigate the effects of laparoscopic radical surgery on the treatment of colorectal cancer (CRC) and explore the correlations of vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) with prognosis.

Methods: The clinical data of 210 patients with CRC admitted to the Yantai Zhifu Hospital from February 2015 to February 2018 were analyzed retrospectively. Among them, 110 patients were treated with laparoscopic radical surgery and assigned to the observation group, and the rest 100 patients were treated with routine open surgery and included in the open group.

Harnessing fluctuation theorems to discover free energy and dissipation potentials from non-equilibrium data.

The Jarzynski relation, as an equality form of the second law of thermodynamics, represents an exact thermodynamic statement that is valid arbitrarily far away from equilibrium. This remarkable relation directly links the equilibrium free energy difference between two states and the probability distribution of the work done along a process that drives the system from one state to the other. Here, we leverage the Jarzynski equality and a local equilibrium assumption, to go beyond the calculation of free energy differences and also extract the dissipation potential from additional measurements of kinematic field variables (strain and velocity fields).

Fibrous gels modelled as fluid-filled continua with double-well energy landscape.

Several biological materials are fibre networks infused with fluid, often referred to as fibrous gels. An important feature of these gels is that the fibres buckle under compression, causing a densification of the network that is accompanied by a reduction in volume and release of fluid. Displacement-controlled compression of fibrous gels has shown that the network can exist in a rarefied and a densified state over a range of stresses.

Stick-slip kinetics in a bistable bar immersed in a heat bath.

Structural transitions in some rod-like biological macromolecules under tension are known to proceed by the propagation through the length of the molecule of an interface separating two phases. A continuum mechanical description of the motion of this interface, or phase boundary, takes the form of a kinetic law which relates the thermodynamic driving force across it with its velocity in the reference configuration. For biological macromolecules immersed in a heat bath, thermally activated kinetics described by the Arrhenius law is often a good choice.