Physical modeling of non-equilibrium processes in biological systems

 
Funding period 2017-2020
 

                                                            Public Outreach Article in "Scientia"

Announcements:

Theory Colloquium

Tue, 10/12/2019 - 14:15
,
Campus Saarbrücken, E2 6, E04

Prof. Dr. Gregory Schehr
(
Host: Prof. Dr. Heiko Rieger
)
LPTMS, Université Paris Sud (Orsay), France

First-passage problems in statistical physics

After a broad introduction to first-passage/persistence probabilities and related first-passage time in statistical physics, I will discuss a specific example: the 2d diffusion equation with random initial conditions. The persistence probability in this problem turns out to be related to the probability of no real root for Kac random polynomials. I will show that this probability can be computed by using yet another connection, namely to the truncated orthogonal ensemble of random matrices.

SFB Seminar

Tue, 17/12/2019 - 14:15
,
Campus SB, Building E2 6 Room E.04

Dr. Baeckkyoung Sung
(
Host: Prof. Dr. Karin Jacobs
)
KIST Europe, Saarbrücken

Ordered and disordered phases of biological matter: fundamentals and applications

Starting from basic concepts of liquid crystalline phases, I will first introduce two experimental studies on the self-organised structures of rod-like viruses and single DNA chains: their morphogenesis, growth kinetics, topological defects, coil-globule transition, etc. In the next part, it will be presented how 3D random networks of biopolymers can be utilised as drug delivery platforms and stem cell niches. Then, I will close the talk by briefly mentioning the current work on cell-laden microgels coupled with droplet microfluidics.

SFB Seminar

Wed, 15/01/2020 - 11:00
,
Campus Homburg, CIPMM, Seminarraum 1. OG

Dr. Liang Liu
(
Host: Dr. Bin Qu
)
CNRS-Université de Lorraine, Nancy

Scanning Gel Electrochemical Microscopy (SGECM): Looking for Biological Applications

Scanning gel electrochemical microscopy (SGECM) is one of the related techniques of SECM. It is based on a gel probe that is in soft contact with the sample. The gel serves as electrolyte allowing electrochemical measurements to be spatially localized. As compared with SECM and SICM, it has the advantage of operating in air, which allows measuring highly reactive samples and complex-shaped samples. As compared with scanning droplet techniques, the electrolyte is immobilized in gel so that it would not spread on the sample surface. This makes the measurement less dependent on the roughness and hydrophobicity of the sample. Proof-of-concept works have been published and our team is continuing to push forward the development of methodology and instrumentation [1, 2].

In this presentation, we will summarize our achievement and discuss about the challenges and prospects of SGECM:

(1) Instrumentation. Flexible instrumentation with motion control, bipotentiostat, lock-in amplifier, data acquisition and micro-controllers have been setup. Other sensors and actuators are also being implemented. The speed of measurement is also being optimized with more efficient feedback loops. For further development, non-electrochemical signals are desired for approaching the gel probe. We optimized the shear force approaching by improving the signal treatment algorithm, and we are currently working on more quantitative capacitive force sensing.

(2) Probe optimization. Probes with lateral resolution of 1-5 m can be prepared reproducibly. The mechanical and electrochemical properties of the gel materials are being optimized.

(3) Quantification. An ideal measurement protocol should consist of the following steps: Probe fabrication  Probe calibration  Imaging or patterning  Data analysis. The quantification is challenging considering that each probe could be different. Nevertheless, a versatile model taking into account the geometry of the probe could still be foreseen.

We also would like to seek for collaborations in any form, especially for broadening the applications of SGECM.