Scalable dissolution-dynamic nuclear polarization with rapid transfer of a polarized solid

In dissolution-dynamic nuclear polarization, nuclear spins are hyperpolarized at cryogenic temperatures using radicals and microwave irradiation. The hyperpolarized solid is dissolved with hot solvent and the solution is transferred to a secondary magnet where strongly enhanced magnetic resonance signals are observed. Here we present a method for transferring the hyperpolarized solid. A bullet containing the frozen, hyperpolarized sample is ejected using pressurized helium gas, and shot into a receiving structure in the secondary magnet, where the bullet is retained and the polarized solid is dissolved rapidly. The transfer takes approximately 70 ms. A solenoid, wound along the entire transfer path ensures adiabatic transfer and limits radical-induced low-field relaxation. The method is fast and scalable towards small volumes suitable for high-resolution nuclear magnetic resonance spectroscopy while maintaining high concentrations of the target molecule. Polarization levels of approximately 30% have been observed for 1-13C-labelled pyruvic acid in solution

Praxe studijního programu Učitelství pro mateřské školy: metodická příručka pro studenty

Title in English: Practice of the Study Program Teacher Training for Kindergartens: Methodical Handbook for Students The methodological manual was created with the aim of helping students of the bachelor's study program Teacher Training for Kindergartens to better understand the system of pedagogical and didactic practices so that they have a comprehensive idea of their organization and relationship to some theoretical subjects. At the same time, it should provide a deeper insight into the relationship between theory and practice through the portfolio and approach its function at the very end of the study, ie during the final state examination

Radical-induced hetero-nuclear mixing and low-field 13^{13}C relaxation in solid pyruvic acid

Radicals serve as a source of polarization in dynamic nuclear polarization, but may also act as polarization sink, in particular at low field. Additionally, if the couplings between the electron spins and different nuclear reservoirs are stronger than any of the reservoirs’ couplings to the lattice, radicals can mediate hetero-nuclear polarization transfer. Here, we report radical-enhanced $^{13}$C relaxation in pyruvic acid doped with trityl. Up to 40 K, we find a linear carbon $T_{1}$ field dependence between 5 mT and 2 T. We model the dependence quantitatively, and find that the presence of trityl accelerates direct hetero-nuclear polarization transfer at low fields, while at higher fields $^{13}$C relaxation is diffusion limited. Measurements of hetero-nuclear polarization transfer up to 600 mT confirm the predicted radical-mediated proton–carbon mixing

Radical-Induced Low-Field 1H Relaxation in Solid Pyruvic Acid Doped with Trityl-OX063

In dynamic nuclear polarization (DNP), radicals such as trityl provide a source for high nuclear spin polarization. Conversely, during the low-field transfer of hyperpolarized solids, the radicals’ dipolar or Non-Zeeman reservoir may act as a powerful nuclear polarization sink. Here, we report the low-temperature proton spin relaxation in pyruvic acid doped with trityl, for fields from 5 mT to 2 T. We estimate the heat capacity of the radical Non-Zeeman reservoir experimentally and show that a recent formalism by Wenckebach yields a parameter-free, yet quantitative model for the entire field range

The Study of Dynamic Behaviour and Interactions During the Temperature-Induced Phase Separation in Polymer Solutions

Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be..

Studium dynamického chování a interakcí během teplotně indukované fázové separace v polymerních roztocích

Název práce: Studium dynamického chování a interakcí během teplotně in- dukované fázové separace v polymerních roztocích Autor: Hana Kouřilová Katedra / Ústav: Katedra makromolekulární fyziky, Matematicko-fyzikální fakulta, Univerzita Karlova v Praze Vedoucí doktorské práce: doc. RNDr. Lenka Hanyková, Dr., Katedra makro- molekulární fyziky, Matematicko-fyzikální fakulta, Univerzita Karlova v Praze Abstrakt: Fázová separace v polymerních roztocích byla studována 1 H and 13 C spektroskopií NMR vysokého rozlišení na 3 typech polymerních roztoků: i) poly(N -isopropylmetakrylamid)/D2O/ethanol za/bez přítomnosti negativně nabi- tého komonomeru metakrylátu sodného, ii) statistický kopolymer poly(N -isopro- pylmetakrylamid-co-akrylamid) v D2O, D2O/ethanolu a D2O/acetonu a iii) D2O roztoky polymerních směsí poly(N -isopropylmetakrylamid)/poly(N -vinylkapro- laktam). V prvním případě jsme studovali tzv. efekt cononsolvency a vliv teploty na fázovou separaci. Byly nalezeny rozdíly mezi mesoglobulemi vzniklými vlivem složení rozpouštědla a teploty. V mesoglobulích vzniklých cononsolvency efektem nebyly detekovány molekuly ethanolu, u teplotně indukované fázové separace kromě molekul vody zůstávají v mesoglobulích navázané i molekuly ethanolu. V...Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be...Katedra makromolekulární fyzikyDepartment of Macromolecular PhysicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

The Study of Dynamic Behaviour and Interactions During the Temperature-Induced Phase Separation in Polymer Solutions

Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be..

Studium dynamického chování a interakcí během teplotně indukované fázové separace v polymerních roztocích

Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be...Název práce: Studium dynamického chování a interakcí během teplotně in- dukované fázové separace v polymerních roztocích Autor: Hana Kouřilová Katedra / Ústav: Katedra makromolekulární fyziky, Matematicko-fyzikální fakulta, Univerzita Karlova v Praze Vedoucí doktorské práce: doc. RNDr. Lenka Hanyková, Dr., Katedra makro- molekulární fyziky, Matematicko-fyzikální fakulta, Univerzita Karlova v Praze Abstrakt: Fázová separace v polymerních roztocích byla studována 1 H and 13 C spektroskopií NMR vysokého rozlišení na 3 typech polymerních roztoků: i) poly(N -isopropylmetakrylamid)/D2O/ethanol za/bez přítomnosti negativně nabi- tého komonomeru metakrylátu sodného, ii) statistický kopolymer poly(N -isopro- pylmetakrylamid-co-akrylamid) v D2O, D2O/ethanolu a D2O/acetonu a iii) D2O roztoky polymerních směsí poly(N -isopropylmetakrylamid)/poly(N -vinylkapro- laktam). V prvním případě jsme studovali tzv. efekt cononsolvency a vliv teploty na fázovou separaci. Byly nalezeny rozdíly mezi mesoglobulemi vzniklými vlivem složení rozpouštědla a teploty. V mesoglobulích vzniklých cononsolvency efektem nebyly detekovány molekuly ethanolu, u teplotně indukované fázové separace kromě molekul vody zůstávají v mesoglobulích navázané i molekuly ethanolu. V...Katedra makromolekulární fyzikyDepartment of Macromolecular PhysicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Radical-induced Hetero-Nuclear Mixing and Low-field 13^{13}C Relaxation in Solid Pyruvic Acid

Radicals serve as source in dynamic nuclear polarization, but may also act as polarization sink. If the coupling between the electron spins and different nuclear reservoirs is stronger than any of the reservoirs' couplings to the lattice, radicals can mediate hetero-nuclear mixing. Here, we report radical-enhanced $^{13}$C relaxation in pyruvic acid doped with trityl. We find a linear dependence of the carbon $T_1$ on field between 5 mT and 2 T. We extend a model, employed previously for protons, to carbon, and predict efficient proton-carbon mixing via the radical Non-Zeeman reservoir, for fields from 20 mT to beyond 1 T. Discrepancies between the observed carbon relaxation and the model are attributed to enhanced direct hetero-nuclear mixing due to trityl-induced linebroadening, and a field-dependent carbon diffusion from the radical vicinity to the bulk. Measurements of hetero-nuclear polarization transfer up to 600 mT confirm the predicted mixing as well as both effects inferred from the relaxation analysis.Comment: 6 pages, 3 figure