181 research outputs found
Fullerénkémiai vizsgálatok különös tekintettel új endohedrális, szupramoekuláris és biokompatibilis fullerén vegyületekre és radiofullerénekre valamint azok alkalmazására = Fullerene chemical investigation with special emphasis on new endohedral, supermolecular and biocompatible fullerene compounds and radiofullerenes
A kutatás Ăşj szempontokat tárt fel a fullerĂ©nek oldhatĂłságárĂłl, szerkezeti vonatkozásairĂłl, amelyek biokompatibilitásuk, toxicitásuk (ezek pillanatnyilag folyamatban vannak) vizsgálatát teszik lehetĹ‘vĂ©. A szerkezeti tisztázást Raman Ă©s nukleáris reaktorban valĂł mĂ©rĂ©sekkel vĂ©geztĂĽk. Ez utĂłbbi mĂ©rĂ©sekkel mutattuk ki, hogy a szĂ©n nanocsövek nyomelemszennyezĂ©se a valĂłszĂnű oka a világszerte folyĂł nanocsĹ‘elektronikai eredmĂ©nyek reprodukálhatatlanságának. A fullerĂ©nek vĂzben teljesen oldhatatlanok Ă©s ez jelentĹ‘s akadály toxicitásuk Ă©s biokompatibilitásuk vizsgálatánál. Eddig kb. 150 szerves oldĂłszert vizsgáltak meg a fullerĂ©nek oldhatĂłságának szempontjábĂłl Ă©s ezek közĂĽl egyesek mint pld. a toluol, nitrobenzol, szĂ©ndiszulfid megfelelĹ‘knek bizonyultak, azaz elfogadhatĂłan oldották a fullerĂ©neket. Sajnos ezek alkalmazása Ă©lĹ‘ szervezetekben lehetetlen. E kĂ©rdĂ©s megoldását jelentettĂ©k azok a vizsgálatok Ă©s eredmĂ©nyek, amelyekben világviszonylatban elsĹ‘ Ăzben bizonyĂtottuk, hogy növĂ©nyi olajok, mint pld. az olĂvaolaj, a napraforgĂłolaj, a tökmagolaj, a repceolaj elfogadhatĂłan oldják a C60 Ă©s C70 fullerĂ©neket, ezáltal lehetĹ‘sĂ©get nyĂşjtva biolĂłgiai, biokĂ©miai Ă©s Ă©lĹ‘ szervezetben valĂł kĂsĂ©rletek vĂ©gzĂ©sĂ©re. Az oldĂłdás mechanizmusára vonatkozĂłan annak hĹ‘mĂ©rsĂ©klet fĂĽggĂ©sĂ©nek mĂ©rĂ©sĂ©vel bizonyĂtottuk, hogy az oldĂłdás exotermikus folyamatkĂ©nt játszĂłdik le. | The research has revealed new vistas on the solubility of fullerenes and their structural aspects which contributed to the possibility of studies of their biocompatibility and toxicity (our measurements on this later aspects are on their way). The structural examinations were using Raman spectrometry. Neutron irradiation in a nuclear reactor using neutron activation analysis has shown that the trace elements determined in carbon nanotubes are the possible ground of the worldwide irreproducibility of nanoelectronics with nanotubes
Vándorbottal a tudományos kutatásban : Interdiszciplináris villáminterjúk kiemelkedő hazai természettudósokkal
SzĂ©nkalitka (fullerĂ©n) Ă©s hosszĂş szĂ©nláncĂş, (C30) fordĂtott fázisĂş szorbensek Ă©s szorpciĂłs viszonyok a folyadĂ©kkromatográfiában = Carbon-cage (fullerene) and long chain reversed phase adsorbents (C30) and investigation of the sorption equilibrium in liquid chromatography
A kutatás negyedik Ă©vĂ©ben a fullerĂ©n kutatások terĂĽletĂ©n kĂ©t terĂĽleten Ă©rtĂĽnk el jelentĹ‘s elĹ‘relĂ©pĂ©st. FullerĂ©nek, mint kromatográfiás állĂłfázisok vizsgálatában kimutattuk, hogy szilikagĂ©l alapĂş, fullerĂ©n C60 borĂtott szorbensek kiválĂłan alkalmazhatĂłk hidrofil biomolekulák (foszfopeptidek, glikált peptidek, flavonoidok) koncentrálására, sĂłmentesĂtĂ©sĂ©re, frakcionálására. Vizsgáltuk ezen Ăşjszerű szorbensek terhelhetĹ‘sĂ©gĂ©t, alkalmasságát fehĂ©rjeszerkezet meghatározásában. MegállapĂtottuk, hogy a szokásos fordĂtott fázisĂş szorbensekhez hasonlĂtva hidrofil biomolekulák prekoncentrálására sokkal hatásosbban alkalmazhatĂłak. FullerĂ©nek, mint a MALDI-TOF tömegspekrometriában alkalmazhatĂł mátrixvegyĂĽletek vizsgálatánál bizonyĂtottuk, hogy a MALDI Tof eljárással csak nehezen analizálhatĂł szteroidhormonok (ösztrogĂ©nek, androgĂ©nek) ionizálására kitűnĹ‘en felhasználhatĂłk. C30-as tölteteinket további alkalmazásokban vörösboranalitikában alkalmaztuk. NagyszámĂş borminta analĂzisĂ©vel kimutattuk, hogy a vörösborok polifenoltartalma erĹ‘sebben fĂĽgg a borkĂ©szĂtĂ©s technolĂłgiájátĂłl (a borásztĂłl), mint földrajzi, vagy idĹ‘járási körĂĽlmĂ©nyektĹ‘l. KĂsĂ©rletesen, a C30 állĂłfázisok hatĂ©kony elválasztási tulajdonságát kihasználva, elsĹ‘kĂ©nt bizonyĂtottuk, hogy a transz rezveratrol (mely a vörösborok fĹ‘ kardioprotektĂv hatĂłanyaga) oxidádáciĂłs termĂ©ke közeli UV fĂ©ny hatására az eddig ismert cisz-rezveratrol mellett egy a szĂ©nláncban hármas kötĂ©ssel rendelkezĹ‘ polifenol (3,4',5-trihidroxidifenilacetilĂ©n). | In the fourth year of our investigations we achieved new results in two fields of fullerene research. It has been demonstrated, that C60 fullerene coated silica stationary phases are excellent for the preconcentration, desalting, fractionating of hydrophilic biomolecules (flavonoids, phosphopeptides, glycopeptides). The loadability of these new phases has been studied. The new phases were found to be excellent for sequence coverage studies of proteins and tryptic digest of proteins. Fullerenes have been used for matrix materials in MALDI TOF mass spectrometry. The ionization of estrogens and androgens were more affective by using C60 or C70 fullerenes as matrices, than any other commonly used matrix material. Our new C30 packings have been extensively used for red wine analysis. It has been found that the most important factor in wine making for high polyphenol contentof wine is the oenologist, rather than geographic or meteorological factors. Exploiting the high separation power of the new C30 phase a new oxidation product of trans-resveratrol has been found. By irradiation of trans resveratrol not only the well known cis-resveratrol has been formed but we detected and described a new tripe-bond polyphenol: 3,4',5-trihydroxy-diphenylacetylene
Intubation-free in vivo imaging of the tracheal mucosa using two-photon microscopy
The mucosal layer of conducting airways is the primary tissue exposed to inhaled microorganisms, allergens and pollutants. We developed an in vivo two-photon microscopic approach that allows performing dynamic imaging studies in the mouse trachea, which is a commonly used in vivo model of human small-diameter bronchi. By providing stabilized access to the tracheal mucosa without intubation, our setup uniquely allows dynamic in vivo imaging of mucociliary clearance and steady-state immune cell behavior within the complex airway mucosal tissue
Magyar TanĂtĂłkĂ©pzĹ‘ 48 (1935) 3
Magyar TanĂtĂłkĂ©pzĹ‘
A TanĂtĂłkĂ©pzĹ‘-intĂ©zeti Tanárok Országos EgyesĂĽletĂ©nek folyĂłirata
48. évfolyam, 3. szám
Budapest, 1935. márciu
Magyar TanĂtĂłkĂ©pzĹ‘ 51 (1938) 1
Magyar TanĂtĂłkĂ©pzĹ‘
A TanĂtĂłkĂ©pzĹ‘-intĂ©zeti Tanárok Országos EgyesĂĽletĂ©nek folyĂłirata
51. évfolyam, 1. szám
Budapest, 1938. januá
Magyar TanĂtĂłkĂ©pzĹ‘ 48 (1935) 8-9
Magyar TanĂtĂłkĂ©pzĹ‘
A TanĂtĂłkĂ©pzĹ‘-intĂ©zeti Tanárok Országos EgyesĂĽletĂ©nek folyĂłirata
48. évfolyam, 8-9. szám
Budapest, 1935. oktĂłber-novembe
NTPDases in the neuroendocrine hypothalamus: Possible energy regulators of the positive gonadotrophin feedback
<p>Abstract</p> <p>Background</p> <p>Brain-derived ectonucleoside triphosphate diphosphohydrolases (NTPDases) have been known as plasma membrane-incorporated enzymes with their ATP-hydrolyzing domain outside of the cell. As such, these enzymes are thought to regulate purinergic intercellular signaling by hydrolyzing ATP to ADP-AMP, thus regulating the availability of specific ligands for various P2X and P2Y purinergic receptors. The role of NTPDases in the central nervous system is little understood. The two major reasons are the insufficient knowledge of the precise localization of these enzymes in neural structures, and the lack of specific inhibitors for the various NTPDases. To fill these gaps, we recently studied the presence of neuron-specific NTPDase3 in the mitochondria of hypothalamic excitatory neurons by morphological and functional methods. Results from those studies suggested that intramitochondrial regulation of ATP levels may play a permissive role in the neural regulation of physiological functions by tuning the level of ATP-carried energy that is needed for neuronal functions, such as neurotransmission and/or intracellular signaling.</p> <p>Presentation of the hypothesis</p> <p>In the lack of highly specific inhibitors, the determination of the precise function and role of NTPDases is hardly feasable. Yet, here we attempt to find an approach to investigate a possible role for hypothalamic NTPDase3 in the initiation of the midcycle luteinizing hormone (LH) surge, as such a biological role was implied by our recent findings. Here we hypothesize that NTPDase-activity in neurons of the AN may play a permissive role in the regulation of the estrogen-induced pituitary LH-surge.</p> <p>Testing the hypothesis</p> <p>We propose to test our hypothesis on ovariectomized rats, by stereotaxically injecting 17beta-estradiol and/or an NTPDase-inhibitor into the arcuate nucleus and determine the consequential levels of blood LH, mitochondrial respiration rates from arcuate nucleus synaptosomal preparations, NTPDase3-expression from arcuate nucleus tissue samples, all compared to sham and intact controls.</p> <p>Implications of the hypothesis</p> <p>Results from these studies may lead to the conclusion that estrogen may modulate the activity of mitochondrial, synapse-linked NTPDase3, and may show a correlation between mitochondrial NTPDase3-activity and the regulation of LH-release by estrogen.</p
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