<h4 align="center">WIGNER SZFI SZEMINÁRIUM</h4>
<h2 align="center">STEPHEN E. SADDOW</h2>
<p align="center">(University of South Florida, USA, vendéglátó: Gali Ádám)</p>
<h2 align="center">"Silicon Carbide Biotechnology"</h2>
<p align="center">Időpont: 2016. június 14. (kedd) 10:00 (1 óra)<br>
Hely: MTA Wigner FK SZFI, I. épület 1. emeleti Tanácsterem</p>
<h3>Összefoglaló:</h3>
<p>Silicon carbide continues to make tremendous inroads into the power electronics market, with projections of ever expanding market share in the next decade. In fact a recent marketing survey reports “The silicon carbide semiconductor market is estimated to grow $3182.89 Million by 2020, at an estimated CAGR of 42.03% from 2014 to 2020”. With this in mind the extensive experience of the USF SiC Group, led by Prof. Saddow, is well poised to contribute at several levels – basic research on materials growth and processing as well device prototyping. This seminar will be presented in three parts in order to answer the following key questions: 1.) Why SiC? 2.) SiC capabilities present at the University of South Florida 3.) What the USF SiC group has contributed to the field of SiC Biotechnology. </p>
<p>Since its inception in the 1970’s, brain-machine-interfaces (BMIs) have held the promise of providing an engineered pathway to restore central and peripheral system function when trauma or disease disrupt signals from the brain to other parts of the body. While impressive demonstrations of this technology have been made over subsequent decades, the lack of a biocompatible semiconductor has prevented BMIs from reaching their full potential. While silicon powers most of the electronics that we use in our everyday life, unfortunately it is not biocompatible and efforts to ‘fool the body’ by applying biocompatible coatings have all failed in vivo. At the University of South Florida a team of electrical engineers and neuroscientists have been developing silicon carbide (SiC) semiconductor devices for use in BMIs. Our group has proven that SiC is indeed biocompatible by showing outstanding in vivo performance in wild type mouse brains. This lecture will discuss both the state of the art of SiC biotechnology as well as review other biomedical devices such as heart stent coatings, bone prosthetic coatings, in vivo sensors, etc.</p>
<p> </p>
<p><b>Részletes információ:</b>
<a href="http://www.szfki.hu/seminar">http://www.szfki.hu/seminar</a></p>
<h4 align="center">Minden érdeklődőt szívesen látunk!</h4><p align="center">Asbóth János<br>szfi-seminar@wigner.mta.hu</p><p> </p>
<h4 align="center">WIGNER SZFI SZEMINÁRIUM</h4>
<h2 align="center">ÜNNEP RENÁTA</h2>
<p align="center">(MTA Wigner FK SZFI)</p>
<h2 align="center">"The ultrastructure and flexibility of thylakoid membranes in different photosynthetic organisms as revealed by small angle neutron scattering (házivédés)"</h2>
<p align="center">Időpont: 2016. június 14. (kedd) 14:00 (1 óra)<br>
Hely: MTA Wigner FK SZFI, I. épület 1. emeleti Tanácsterem</p>
<h3>Összefoglaló:</h3>
<p>The light reactions of oxygenic photosynthesis occur in the thylakoid membranes. For the better understanding of photosynthesis and, in particular, on membrane reorganizations, especially under rapidly changing environmental conditions, non-invasive techniques that provide specific and accurate information on ultrastructural parameters in vivo are needed.</p>
<p>We have measured, for the first time, the small angle neutron scattering (SANS) profiles of intact leaves of a number of plant species and revealed a Bragg peak, providing information on the repeat distances (RDs) of the granum thylakoid membranes. We demonstrated that the most widely used isolation method of plant thylakoid membranes, in which sorbitol is employed as osmoticum, perturbs the native ultrastructure of thylakoid membranes; in contrast, when NaCl is used as osmoticum, the membrane ultrastructure is much better retained. Based on these results we were able to show that the Bragg peak at about 0.02 Å -1 of the SANS curves of thylakoid membranes isolated from higher plants is related to the granum thylakoid membranes, rather than arising from stroma thylakoid membranes - as it was assumed earlier [1,2].</p>
<p>We have studied the relationship between the osmotic pressure and lamellar order of thylakoid membrane system in wild type diatoms, wild type and mutant green algae and higher plants [1,3,4]. By using SANS, we have also shown that the primary fixing chemical for electron microscopy (EM), glutaraldehyde, causes structural changes in the thylakoid membranes [1].</p>
<p>To our knowledge, for the first time on intact leaves, we revealed reversible light-induced changes in the thylakoid membranes’ RD. The magnitude of these light-induced changes resembled more to the light-induced changes in isolated thylakoid membranes suspended in a reaction medium with NaCl, than with sorbitol, as osmoticum [1,2,5]. We have also shown that Monstera deliciosa leaves exhibit a very large and rapid reversible change in the periodicity of granum thylakoid membranes; these changes appear to be kinetically correlated with the build-up and relaxation of the photoprotective non-photochemical quenching (NPQ) of the chlorophyll fluorescence [6]. We also studied the ΔpH-dependent ultrastructural changes in isolated thylakoid membranes [7], while NPQ is triggered by ΔpH. We have found direct experimental evidence, on live algal cells, that the chloroplast structure (stacking and periodicity) is changed upon state transitions in Chlamydomonas reinhardtii [4]. We also studied inorganic phosphate transporter and Cl - channel mutant of Arabidopsis [8,9].</p>
<p>[1] R. Ünnep et al, BBA-Bioenergetics, 1837 (2014) 1572-1580.<br />[2] R. Ünnep, G. Nagy, M. Markó, G. Garab, Plant. Physiol. Bioch., 81 (2014) 197-207.<br />[3] G. Nagy et al, Photosynth. Res., 111 (2012) 71-79.<br />[4] G. Nagy, R. Ünnep, et al, PNAS, 111 (2014) 5042-5047.<br />[5] G. Nagy, et al, Eur. Phys. J E, 36 (2013).<br />[6] R. Ünnep, et al, (unpublished)<br />[7] R. Ünnep, et al, (unpublished)<br />[8] A. Herdean et al, Nat. Commun., 7 (2016)<br />[9] P. Karlsson et al, The Plant Journal, 84 (2015) 99-110</p>
<p><b>Részletes információ:</b>
<a href="http://www.szfki.hu/seminar">http://www.szfki.hu/seminar</a></p>
<h4 align="center">Minden érdeklődőt szívesen látunk!</h4><p align="center">Asbóth János<br>szfi-seminar@wigner.mta.hu</p><p> </p>