У оквиру семинара Групе за гравитацију, честице и поља Института за физику у Београду, у петак, 23. децембра 2022. године у 11 часова на Физичком факултету у Београду у сали 665, др Марко Војиновић (Институт за физику у Београду), одржаће предавање:

Introduction to category theory and n-groups (part 2)

САЖЕТАК:

This is the second of a sequence of lectures about higher category theory and n-groups. We will introduce the notions of a category, a group, and a functor, after which we shall give a couple of examples convenient for physics. If time permits, we will also introduce the notions of a strict and weak 2 category, a 2-group, and a crossed module, also with appropriate examples.

The lecture is based on material from papers arXiv:q-alg/9705009, arXiv:1003.4485.

У оквиру семинара Центра за фотонику Института за физику у Београду, у четвртак, 15. децембра 2022. године у 11 часова у читаоници библиотеке „др Драган Поповић“, др Ив Каудано (професор квантне механике на Универзитету у Намуру, одржаће предавање:

Weak measurements, geometric phases, and quantum paradoxes: from quantum foundations to quantum optical experiments

У оквиру семинара Групе за гравитацију, честице и поља Института за физику у Београду, у петак, 16. децембра 2022. године у 11 часова путем BigBlueButton платформе, др Марко Војиновић (Институт за физику у Београду), одржаће предавање:

Introduction to category theory and n-groups

САЖЕТАК:

This is the first of a sequence of lectures about higher category theory and n-groups. We will discuss the motivation for introducing n-groups, and demonstrate some of their basic properties. After introducing the idea of higher groups and discussing why they should be relevant for physics, we will demonstrate the equivalence between a strict 2-group and a crossed module, which is a technically more convenient tool. We will also discuss everything on the example of the Poincaré 2-group, which should help us to build some intuition.

The lecture is motivated mainly by papers arXiv:q-alg/9705009, arXiv:1003.4485.

Приступите предавању

У оквиру семинара Центра за чврсто стање и нове материјале Института за физику у Београду, у четвртак, 15. децембра 2022. године, у 13 часова у читаоници библиотеке „др Драган Поповић“, др Антон Градишек (Департман за физику чврстог стања, Институт „Јожеф Стефан“, Љубљана) одржаће предавање:

Studies of molecular dynamics in hydrogen storage materials and solid-state electrolytes by nuclear magnetic resonance

САЖЕТАК:

In view of global energy supply crisis and climate emergency, hydrogen is yet again becoming an attractive energy carrier. It can be produced using renewables and leaves only water when using it in a fuel cell. However, before a wider adoption of hydrogen technologies, there are still several technical challenges that need to be addressed. In the first part of the seminar, I will present an overview of some topics related to hydrogen economy. In the second part, I will focus on some of our studies of molecular dynamics by means of nuclear magnetic resonance (NMR). Initially, we started investigating metal hydrides as possible hydrogen storage materials. Our research then shifted to solid-state electrolytes that could be used in fuel cells. I will demonstrate how NMR can be used to study dynamic processes either on a long or on a short scale.

У оквиру семинара Лабораторије за биофизику Института за физику у Београду, у четвртак, 8. децембра 2022. године, у 12 часова у читаоници библиотеке „Др Драган Поповић“, др Себастијан Фрише (Департман за биомедицину, Универзитет у Архусу, Данска) одржаће предавање:

ASP+ Shows Amplified Fluorescence by Binding to Albumin and Is Accumulated In Vivo

САЖЕТАК:

Organic cations (OC) is excreted by the kidney by transcellular transport in the proximal tubule. Since manu OC’s are classified as uremic toxins, which are difficult to remove by dialysis in kidney patients, clinical evaluation of proximal tubular secretion of organic cations is desired, but difficult.  The biomedical knowledge on OC secretion and cellular transport partly relies on studies using the fluorescent tracer
4-dimethylaminostyryl)-N-methylpyridinium (ASP+), which has been used in many studies of renal excretion mechanisms of organic ions and which could be a candidate as a PET tracer. This study is aimed at expanding the knowledge of the tracer characteristics of ASP+ by recording the distribution and intensity of ASP+ signals in vivo both by fluorescence and by positron emission tomography (PET) imaging and at investigating if the fluorescence signal of ASP+ is influenced by the presence of albumin. 
Two-photon in vivo microscopy of male Münich Wistar Frömter rats showed that a bolus injection of ASP+ conferred a fluorescence signal to the blood plasma lasting for about 30 minutes. In the renal proximal tubule, the bolus resulted in a complex pattern of fluorescence including a rapid and strong transient signal at the brush border, a very low signal in the luminal fluid, and a slow transient intracellular signal. PET imaging using 11C-labelled ASP+ showed accumulation in the liver, heart, and kidney. Fluorescence emission spectra recorded in vitro of ASP+ alone and in the presence of albumin using both 1-photon excitation and two-photon excitation showed that albumin strongly enhance the emission from ASP+ and induce a shift of the emission maximum from 600 to 570 nm.

Conclusion. The renal pattern of fluorescence observed from ASP+in vivo is likely affected by the local concentration of albumin, and quantification of ASP+ fluorescent signals in vivo cannot be directly translated to ASP+ concentrations.