Seminaria Zakładu Biosystemów i Miękkiej Materii

kolor czcionki + kolor tła = plan do 7 dni.

12:30, Sala: S3 im. W. Fiszdona, piętro III
dr Marcin Lewandowski

MedTech 2020 – how 'digital disruption' can impact healthcare

The continuously rising cost of healthcare and an ageing society threaten even the strongest economies. Today, developed countries spend 9% to 12% (USA 17%) of their GDP on this sector.
Medtech is a broad spectrum of product and technologies for medical and healthcare applications, including prevention, diagnosis, monitoring, therapy, and care. We will look at its complex landscape and how "digital disruption" can impact the future of the medical ecosystem and improve the quality of our lives. We will also discuss the increasing role played by digital health and how it could be used in data-driven decision making, shifting the care paradigm from reactive to proactive.
In addition, I will also present my team and our commitment to medical technologies developed at the Institute. Hopefully, a fruitful discussion on current bio-research that might impact the future of Medtech products will conclude my seminar.

2019-09-18 12:30, Sala: S3 im. W. Fiszdona, piętro III
Massimiliano Lanzi
Department of Industrial Chemistry “Toso Montanari”
University of Bologna, Italy

New functional polythiophene materials: fine-tuning of photovoltaic or chiro-optical properties

The last research activity of our group at Dipartimento di Chimica Industriale “Toso Montanari”-University of Bologna, Italy, concerned the synthesis, characterization and study of the optical and photoactive properties of new organic semiconducting materials based on polythiophenes.
There is a remarkable level of interest in the development of π-conjugated polymers (ICPs) which have been employed, thanks to their promising optical and electronic properties, in numerous applications including photovoltaic cells, light emitting diodes and thin-film transistors. Although high power conversion efficiency can be reached using poly(3-alkylthiophenes) (P3ATs) as electron-donating materials in polymeric solar cells of Bulk-Heterojunction type (BHJ), their relatively large band gap limits the solar spectrum fraction that can be effectively harvested. A common approach to the preparation of narrow band gap polymers consists in the design and synthesis of conjugated architectures where an extended π electronic conjugation is achieved by the alternation of electron-donor and acceptor units along the polymer backbone.
New 4,7-bis(3-alkylthiophen-2-yl)benzo(2,1,3)thiadiazole monomers, functionalized with different alkyl chains, have been synthesized through a palladium-catalyzed Suzuki cross-coupling reactions and then polymerized by oxidative coupling using FeCl3. As the side chain functionalization influences the optical and electrical properties of building blocks and related polymeric derivatives, we have therefore also investigated the effect of the insertion of an oxygen atom into different positions in side chains of similar length. Moreover the synthesis of symmetrical trimers with HH (head-to-head) regiochemistry has allowed to obtain completely regioregular polymers despite the use of a non-regio-specific polymerization method.
The newly synthesized polymers have been characterized by common analytical techniques and thus tested as active media in air-processed Bulk-Heterojunction devices, alone and blended with PC61BM (1:1 w/w) as additional acceptor material.
After the interesting results achieved with these main-chain donor-acceptor polymers, the research project was oriented to the development and study of similar systems but having the acceptor units in the side chain, known as double cable materials.
Starting from soluble, regiorandom and regioregular homopolymeric precursors new alkylthiophenic copolymers, bearing the C60-fullerene group at the end of a hexylic side chain at position 3 of the thiophene ring, have been prepared with a simple and straightforward post-polymerization functionalization procedure based on Grignard coupling. The materials were synthesized with different content of fullerene, in order to study the effect on the final performance of the photoactive layer.
Homo- and copolymers were fully characterized and tested as active media in organic solar devices, respectively blended with PC61BM (1:1 w/w) as the acceptor material and as double-cable materials.
The research activity has also been devoted to investigate the behavior of polythiophenes with chiral side chain, that are fascinating materials capable to assume helix supramolecular structures, exhibiting optical activity in the aggregated state.
In this context, since head-to-tail regioregularity has demonstrated to produce a strong influence on the self-assembly of the macromolecular chains in the solid state, an investigation about the influence of regioregularity on the chiral behaviour of optically active polythiophenes was carried out. The polymers were obtained by regiospecific organometallic coupling (GRIM method) or non-regiospecific oxidative coupling with FeCl3, starting respectively from chiral mono- or bithiophenic monomers. These procedures allow to obtain the corresponding polymeric derivatives with well defined head-to-tail (HT) or head-to-head/tail-to-tail (HH-TT) regioregularity. Moreover, the effect of the presence of a different heteroatom (oxygen or sulfur), connecting the alkyl chiral side chains to the thiophene ring, was studied.
The optical activity of polymers was evaluated by circular dichroism (CD), upon aggregation of the macromolecules by gradual addition of a poor solvent to their chloroform solutions.

Massimiliano Lanzi, Elisabetta Salatelli, Luca Zuppiroli, Martina Marinelli
Conjugated polymers group
Department of Industrial Chemistry “Toso Montanari”
Viale Risorgimento, 4
40136 Bologna Italy

2019-09-05 12:00, Sala: S3 im. W. Fiszdona, piętro III
Aishwarya Dhar, Ph.D. student
Department of Physics, University of Rome Tor Vergata and INFN Sezione di Tor Vergata, Rome, Italy

Aβ peptides and β-sheet breakers. A coarse grained molecular dynamics approach using GoMartini

The problem of protein misfolding is at the origin of a class of pathologies called protein conformational disorders (PCD) to which all neuro-degenerative diseases belong. PCD’s are characterized by the misfolding of proteins that grow in aggregates of fibrillar shape. Among them, Alzheimer Disease (AD) is one of the most studied for its high impact on the modern society. The plaques present in the brain of AD patients show deposition of fibril made of amyloid β (Aβ) peptides [1]. The process that leads to misfolding, aggregation and amyloid plaques formation is not yet fully elucidated. It seems, however, that the “trigger” of the process is an abnormal switch of the peptide secondary structure leading to β-sheet formation.
Several factors are known to affect Aβ aggregation processes. An important role seems to be played by metal ions that have been observed to be quite abundant in fibrils [2-4]. Recently, the observation that short synthetic peptides, called β-sheet breaker (BSB's), are able to directly interact with Aβ, precluding (or disfavouring) amyloid polymerisation. This finding has stimulated a lot of work in the direction of trying to understand the molecular mechanism by which BSB's are able to slow down or even prevent Aβ aggregation and fibrillation [5].
In this presentation we show how one can get a good understanding of the role that BSBs play in the aggregation process of Aβ peptides by means of coarse-grained molecular dynamics simulations based on the Martini force-field. Since the secondary structure switching is a crucial event for the successive aggregation process, we have extended the standard Martini approach to incorporate GO-Martini algorithm [6] that allows to properly model structural switches and study the secondary structure dynamical evolution of Aβ peptides in the presence of BSBs.

1. LC Serpell, BBA, 1502(1):16-30, 2000
2. E De Santis et al., JPCB, 119, 15813-15820, 2015
3. S Morante, GC Rossi, Advance Alz Res,2:100-147, 2014
4. F Stellato et al., Biophys Chem, 229, 110-114, 2017
5. V Minicozzi et al., JBC, 289, 11242-11252, 2014
6. AB Poma et al., J Chem Theory Comput, 13(3):1366-1374, 2017

2019-08-28 10:00, Sala: Aula im. Wacława Olszaka, piętro II
Princeton University, USA

Some multiphase flow problems:
(i) Moderate Reynolds number flows at T-junctions and
(ii) low-Reynolds-number diffusiophoretic flows

I will discuss two distinct multi-phase flow problems that we have worked on in recent years. First, I will illustrate dynamics of bubble and particle flows in bifurcating geometries when the Reynolds number is O(100-1000) and show an unexpected trapping phenomenon. Second I will describe our studies of chemically driven particle motions, which involves the subject of diffusiophoresis.

ArchiwumSeminaria 1996-2010
Strona Zakładu