Visitor – Soft Matter Lab

Nazli Demirpehlivan visits the Soft Matter Lab

Nazli Demirpehlivan will visit the Soft Matter Lab from 30th of March to 30th of May 2026.

Nazli is a doctoral candidate at Bruker Nano GmbH in Berlin and also a part of the MSCA-DN SPM4.0 network.
She will be carrying out her secondment as part of the SPM 4.0 network with the University of Gothenburg.
The focus of her secondment will be the development of ASAP, a deep learning based pipeline for atomic force microscopy applications alongside the doctoral candidates Prakhar Dutta and Jiacheng Huang who are also part of the network. She will also take the Deep learning course offered by the department to facilitate her PhD studies and projects.

Steven Smith visits the Soft Matter Lab

Steven Smith will visit the Soft Matter Lab from 17 to 28 January 2026.

Steven brings years of expertise from the laboratory of Professor Carlos Bustamante, where they pioneered the use and development of optical tweezers. As the main developer of the widely used ‘minitweezers’ instrument, which today is used by dozens of research groups, he has helped shape the field of single-molecule biophysics on a global scale. We look forward to his visit, during which he will work on refining cutting-edge single-molecule measurement techniques.

Professor Carlos Bustamante, winner of the Waernska Professorship, visits the Soft Matter Lab

Carlos Bustamante. *(Photo by H. P. Thanabalan.)*

We are delighted to welcome Professor Carlos Bustamante to the Soft Matter Lab as the winner of the prestigious Waernska Professorship.

Professor Bustamante is a world-renowned expert in single-molecule biophysics and a Full Professor of Molecular and Cell Biology, Chemistry and Physics at the University of California, Berkeley, USA.

His pioneering work has significantly advanced our understanding of the physical behaviour of biological molecules. Using techniques such as optical tweezers, atomic force microscopy and fluorescence microscopy, Professor Bustamante has provided key insights into molecular motors, protein and RNA folding, and the mechanisms of gene expression and regulation.

We are honoured to host Professor Bustamante at the Soft Matter Lab and look forward to exciting scientific exchanges and collaborations during his visit.

His visit is currently planned between 28 April and 27 May 2025.
An additional visit, yet to be confirmed, might take place during the fall of 2025.

Antonio Ciarlo joins the Soft Matter Lab

Antonio Ciarlo joined the Soft Matter Lab on 31th January 2022.

Antonio is a PhD student at the Physics Department of the University of Naples, Italy.

He will be working on the modelling and the analysis of the data of his experiments with intracavity optical trapping.

He will stay in our lab for six months.

Alessandro Magazzù and David Bronte Ciriza visit the Soft Matter Lab

Alessandro Magazzù and David Bronte Ciriza are visiting the Soft Matter Lab from 2 to 9 November 2020.
Alessandro is currently Post Doc at the IPCF-CNR Messina, Italy, and David is a PhD student at the same institution, and he is one of the ESRs (Early Stage Researchers) of the ActiveMatter MSCA-ITN-ETN.
They will be working on a neural network approach to the calculation of optical forces and torques on dielectric particles in the geometrical optics approximation.

(Foto by Aykut Argun)

Seminar on Machine Learning and Physics: a long standing relation? by Gorka Muñoz-Gil from ICFO, Nexus, 3 March 2020

Machine Learning and Physics: a long standing relation?
Seminar by Gorka Muñoz-Gil from ICFO, Barcelona, Spain.

In this talk, I will review the recent advances in single trajectory characterization via Machine Learning methods. Then, I will introduce the AnDi challenge, a competition which aims at bringing together a vibrating and multidisciplinary community of scientists working on the problem of anomalous diffusion.

Place: Nexus room, Fysik Origo, Fysik
Time: 03 March, 2020, 16:00

Seminar on Robust automated reading of the skin prick test via 3D imaging and parametric surface fitting by Jesús Pineda from Universidad Tecnologica de Bolivar, Nexus, 3 March 2020

Robust automated reading of the skin prick test via 3D imaging and parametric surface fitting.
Seminar by Jesús Pineda from the Universidad Tecnologica de Bolivar, Cartagena, Colombia.

The conventional reading of the skin prick test (SPT) for diagnosing allergies is prone to inter- and intra-observer variations. Drawing the contours of the skin wheals from the SPT and scanning them for computer processing is cumbersome. However, 3D scanning technology promises the best results in terms of accuracy, fast acquisition, and processing. In this work, we present a wide-field 3D imaging system for the 3D reconstruction of the SPT, and we propose an automated method for the measurement of the skin wheals. The automated measurement is based on pyramidal decomposition and parametric 3D surface fitting for estimating the sizes of the wheals directly. We proposed two parametric models for the diameter estimation. Model 1 is based on an inverted Elliptical Paraboloid function, and model 2 on a super-Gaussian function. The accuracy of the 3D imaging system was evaluated with validation objects obtaining transversal and depth accuracies within ± 0.1 mm and ± 0.01 mm, respectively. We tested the method on 80 SPTs conducted in volunteer subjects, which resulted in 61 detected wheals. We analyzed the accuracy of the models against manual reference measurements from a physician and obtained that the parametric model 2 on average yields diameters closer to the reference measurements (model 1: -0.398 mm vs. model 2: -0.339 mm) with narrower 95% limits of agreement (model 1: [-1.58, 0.78] mm vs. model 2: [-1.39, 0.71] mm) in a Bland-Altman analysis. In one subject, we tested the reproducibility of the method by registering the forearm under five different poses obtaining a maximum coefficient of variation of 5.24% in the estimated wheal diameters. The proposed method delivers accurate and reproducible measurements of the SPT [1].

References:

Jesus Pineda, Raul Vargas, Lenny A. Romero, Javier Marrugo, Jaime Meneses & Andres G. Marrugo (2019) Robust automated reading of the skin prick test via 3D imaging and parametric surface fitting. PLOS ONE 14(10), e0223623.

Place: Nexus room, Fysik Origo, Fysik
Time: 03 March, 2020, 11:00

Yu-Wei Chang visits the Soft Matter Lab. Welcome!

Yu-Wei Chang is an engineer at the Digital Medicine Center at National Yang-Ming University in Taiwan, working on a machine learning approach for phenotyping psychiatric disorders.
He will visit us for 2 months from February 29, 2020, to April 30, 2020, and he will be working on deep learning for Alzheimer’s Disease as well as the development of BRAPH 2.0 (March-April 2020).

Seminar on polymers under local active forces: a simplified stochastic model for motor-induced translocations by Laura Natali from Università di Roma “La Sapienza”, Nexus, 22 January 2020

Polymers under local active forces: a simplified stochastic model for motor-induced translocations.
Seminar by Laura Natali from the University of Rome “La Sapienza”, Rome, Italy.

Molecular motors are a wide class of enzymes that can transport even large macromolecules by converting chemical into mechanical energy, through the process of ATP-hydrolysis. Among those, active nanopore translocation is a common mechanism to carry proteins across biological membranes. The phospholipid bilayer is impenetrable for the folded protein, that requires to be unfolded and pulled across channels such as alpha-hemolysin [1]. Exploiting the translocation process, we can acquire information about the target proteins’ structure, such as the intermediate configurations between the folded and denatured structures [2]. Here follows the interest in modeling the motor proteins complex in a simple simulation setup.
First of all, we characterized the active polymer’s features in free space and subsequently, we confined it inside a nanopore model. The study in free space aims to investigate how activity affects both the global and the local polymer properties. The chosen model for the active force is an Active Ornstein-Uhlenbeck Particle, a model closely related to Active Brownian Particles [3]. The presence of the catalytic head affects the end-to-end distance of the polymer, which describes its degree of compactness. The active chain can be studied through the Rouse mode decomposition [4], which allowed us to analyze the dependence of the second moment of the end-to-end distance as a function of the persistence time of the activity. We considered also the distance between consecutive monomers, which provides an insight into the local effects of the active force and how it is transmitted along the chain.
In this work, we were inspired by an experiment employing the ClpXP complex [5], a protein-degradation machine responsible for unfolding and digesting malfunctioning proteins through unidirectional transport across the nanopore. In the model we propose, we enclose the polymer chain in a confining potential, simulating the effect of the nanopore. The energy generated by the molecular motor translocates the polymers, which means they cross the pore from side to side. In our setup, the effect of the molecular motor [6] is represented as a potential barrier combined with a region that makes active the monomers that are crossing it. The translocation pathways have a step-wise profile typical of their biological counterparts.

References:

J. Nivala, D. B. Marks and M. Akeson, Nature Biotechnol., 2013, 31, 247
M. Bacci, M. Chinappi, C. M. Casciola and F. Cecconi, J. Phys.Chem. B, 2012, 116, 4255–4262
L. Caprini and U. M. B. Marconi, Soft matter, 2018, 14, 9044–9054.
P. E. Rouse, J. Chem. Phys., 1953, 21, 1272.
T. A. Baker and R. T. Sauer, Biochimica et Biophysica Acta (BBA) – Molecular Cell Research, 2012, 1823, 15–28.
L. Caprini, U. Marini Bettolo Marconi, A. Puglisi and A. Vulpiani, J. Chemi. Phys., 2019, 150, 024902.

Place: Nexus room, Fysik Origo, Fysik
Time: 22 January, 2020, 11:00