GigaGauss solenoidal magnetic field inside of bubbles excited in under-dense plasma

Magnetic fields have a crucial role in physics at all scales, from astrophysics to nanoscale phenomena. Large fields, constant or pulsed, allow investigation of material in extreme conditions, opening up plethora of practical applications based on ultra-fast process, and studying phenomena existing only in exotic astro-objects like neutron stars or pulsars. Magnetic fields are indispensable in particle accelerators, for guiding the relativistic particles along a curved trajectory and for making them radiate in synchrotron light sources and in free electron lasers. In the presented paper we propose a novel and effective method for generating solenoidal quasi-static magnetic field on the GigaGauss level and beyond, in under-dense plasma, using screw-shaped high intensity laser pulses. In comparison with already known techniques which typically rely on interaction with over-dense or solid targets, where radial or toroidal magnetic field localized at the stationary target were generated, our method allows to produce gigantic solenoidal fields, which is co-moving with the driving laser pulse and collinear with accelerated electrons. The solenoidal field is quasi-stationary in the reference frame of the laser pulse and can be used for guiding electron beams and providing synchrotron radiation beam emittance cooling for laser-plasma accelerated electron and positron beams, opening up novel opportunities for designs of the light sources, free electron lasers, and high energy colliders based on laser plasma acceleration.Comment: 15 pages, 9 figures. Main text (without abstract, References and Appendix): 12 page

A ferritin szerepe a szőlő stressztűrő képességének fokozásában = The role of ferritin in enhancing the stress tolerance of grapevine

Embriogén kalluszt állítottuk elő Richter110 (alany) és Chardonnay (nemes) szőlő fajták portokajiból. Ezeket Medicago sativa ferritint (MsFerr) tartalmazó Agrobacterium vektorokkal transzformáltunk. A DNS beépülését genomikus PCR-rel ellenőriztük. Poliklonális ellenanyagot állítottunk elő, mellyel megállapítottuk, hogy a transzláció magas szintű volt, a transzkriptumból nagy mennyiségű, megfelelően processzált fehérjetermék keletkezett. A transzgenikus szőlő növények elkészültéig dohányban teszteltük az MsFerr gént tartalmazó konstrukciókat. A teljes növényeken végzett UV-B kezelés, ill. levélkorongok közvetlen oxidatív stresszre adott válaszai alapján megállapítottuk, hogy az MsFerr növények toleránsabbak voltak, mint a nem expresszáló kontrollok. Az MsFerr Richter 110 növények regenerálása, szelekciója és felszaporítása sikeres volt, az MsFerr Chardonnay növények felszaporítása azonban hajtásnövekedési problémák miatt nem sikerült. Három MsFerr Richter 110 vonalat vizsgáltunk. Gyökér stresszként fás szárú dugványok tápoldatához hidrogénkarbonátot adtunk, ami klorotikus és levél száradási tünetek okozott Ebben nem kaptunk lényeges különbséget a transzgenikus és transzformálatlan növények között. Ezzel szemben, a leveleket érő hatásokkal: paraquat, NaCl só-stressz és tBHP indukált lipid peroxidációval szemben az MsFerr expresszáló vonalak toleránsabbak voltak (kisebb stressz-indukált fotoszintézis csökkenést mutattak) mint a transzformálatlanok. | Embryogenic calli were started from anthers of Richter 110 (rootstock) and Chardonnay (scion) grapevine and transformed with Agrobacterium harbouring Medicago sativa ferritin gene (MsFerr). Genomic PCR and protein immunoblotting using a polyclonal antibody confirmed that the transcription and processing of MsFerr was successful. Regeneration, selection and propagation of MsFerr Richter 110 plants was successful, but transformed MsFerr Chardonnay plants did not grow sufficiently. Until transgenic grapevine plants became available, preliminary experiments were carried out with MsFerr expressing tobacco. UV-B irradiation of whole plants as well as treatments of leaf disks with various chemical elicitors showed that MsFerr plants were more stress tolerant than non-expressing controls. After regeneration and propagation, three transgenic MsFerr Richter 110 lines were tested. Roots of green cuttings were stressed by flooding and in this experiment transgenic plants did not show significantly higher tolerance to hypoxia/bicarbonate than non-transferred ones. Leaves, however, showed increased tolerance to paraquat, salt stress and tBHP induced lipid peroxidation: their photosynthesis was less affected by these stressors than those from non-transformed plants

Quadratic operators used in deducing exact ground states for correlated systems: ferromagnetism at half filling provided by a dispersive band

Quadratic operators are used in transforming the model Hamiltonian (H) of one correlated and dispersive band in an unique positive semidefinite form coopting both the kinetic and interacting part of H. The expression is used in deducing exact ground states which are minimum energy eigenstates only of the full Hamiltonian. It is shown in this frame that at half filling, also dispersive bands can provide ferromagnetism in exact terms by correlation effects .Comment: 7 page

Statinok és az emésztőrendszeri daganatok

The antitumour effect of statins has already been proven in animal experiments and human cancer cell lines in several gastrointestinal cancers. The chemopreventive mechanism is not completely clarified but the enhancement of oxidative stress, increased autophagy, altered expression of pro- and antiproliferative proteins and their influence on intracellular signaling pathways may play a role. Randomized studies, however, failed to confirme the expected results obtained from experimental studies. The goal of this review is to summarize the data available in the literature regarding the chemopreventive effects of statins on several gastrointestinal cancers. Results of clinical trials suggest that 10-20 mg statin daily has no or minimal antitumour effect. Chemopreventive effect of hydrophilic statins could not be detected but it seems to be significant in the case of hydrophobic statins. There are only few data available on the long-term daily use of 30-40 mg statins. Further long-term evaluation of the effect of statins regarding gastrointestinal cancers is needed, and an analysis of compound- and dose-related subgroups would be beneficial. Chemoprevention with statins cannot yet be accepted as standard medical practice. Use of statins as chemopreventive agents cannot be a substitute for regular oncological screening or surveillance. Orv. Hetil., 2014, 155(18), 687-693

GigaGauss solenoidal magnetic field inside bubbles excited in under-dense plasma

This paper proposes a novel and effective method for generating GigaGauss level, solenoidal quasi-static magnetic fields in under-dense plasma using screw-shaped high intensity laser pulses. This method produces large solenoidal fields that move with the driving laser pulse and are collinear with the accelerated electrons. This is in contrast with already known techniques which rely on interactions with over-dense or solid targets and generates radial or toroidal magnetic field localized at the stationary target. The solenoidal field is quasi-stationary in the reference frame of the laser pulse and can be used for guiding electron beams. It can also provide synchrotron radiation beam emittance cooling for laser-plasma accelerated electron and positron beams, opening up novel opportunities for designs of the light sources, free electron lasers, and high energy colliders based on laser plasma acceleration

A nonperturbative study of phase transitions in the multi-frequency sine-Gordon model

The phase spaces of the two- and three-frequency sine-Gordon models are examined in the framework of truncated conformal space approach. The focus is mainly on a tricritical point in the phase space of the three-frequency model. We give substantial evidence that this point exists. We also find the critical line in the phase space and present TCSA data showing the change of the spectrum on the critical line as the tricritical endpoint is approached. We find a few points of the line of first order transition as well.Comment: 26 pages, LaTeX, minor modificatio

Disordered proteins and network disorder in network descriptions of protein structure, dynamics and function. Hypotheses and a comprehensive review

During the last decade, network approaches became a powerful tool to describe protein structure and dynamics. Here we review the links between disordered proteins and the associated networks, and describe the consequences of local, mesoscopic and global network disorder on changes in protein structure and dynamics. We introduce a new classification of protein networks into ‘cumulus-type’, i.e., those similar to puffy (white) clouds, and ‘stratus-type’, i.e., those similar to flat, dense (dark) low-lying clouds, and relate these network types to protein disorder dynamics and to differences in energy transmission processes. In the first class, there is limited overlap between the modules, which implies higher rigidity of the individual units; there the conformational changes can be described by an ‘energy transfer’ mechanism. In the second class, the topology presents a compact structure with significant overlap between the modules; there the conformational changes can be described by ‘multi-trajectories’; that is, multiple highly populated pathways. We further propose that disordered protein regions evolved to help other protein segments reach ‘rarely visited’ but functionally-related states. We also show the role of disorder in ‘spatial games’ of amino acids; highlight the effects of intrinsically disordered proteins (IDPs) on cellular networks and list some possible studies linking protein disorder and protein structure networks