Nanotechnológiai módszerek alkalmazása modellkatalizátorok kifejlesztésére és vizsgálatára = Application of nanotechnology methods for fabrication and study of model catalysts

TiO2(110) felületen fémgőzöléssel létrehozott Rh, Au, Mo és K ultravékony rétegek hőkezelés hatására bekövetkező morfológiai változásaival és a hordozott részecskék gázokban történő reakcióival foglalkoztunk. Fontosabb eredményeink: (1) a Pt és a TiO2 hordozó közötti erős fém-hordozó kölcsönhatást (SMSI) kihasználva kidolgoztunk egy módszert a részecskék által befolyásolt kráterképződés beindítására Ar+ ion bombázás hatására; (2) STM módszerrel sikerült kimutatnunk, hogy a 3D Mo nanoszemcsék képződése a TiO2 hordozó oxigénhiányos területen indul meg először; (3) alagútáram-spektroszkópiai méréseink szerint a TiO2(110) felületen hordozott Mo nanoszemcsék szigetelő jelleget mutatnak 900 K felett, amely arra utal (XPS méréseket is figyelembe véve), hogy a fémszemcsék felületén TiOx vékonyréteg alakul ki; (4) hasonló dekorálódást Rh esetében is kimutattuk LEIS módszerrel; (5) a TiO2(110) felület redukálása 0.5 keV energiájú Ar+ ionokkal, illetve kis mennyiségű K adalék (<1 monoréteg) rávitele az utólag felvitt Au diszperzitásának növekedését eredményezi a tiszta TiO2 felülethez képest; (6) a TiO2(110)-n hordozott 3-4 nm átmérőjű Au részecskék nagy aktivitást mutatnak a CO alacsonyhőmérsékleti oxidációjában (PROX reakció) 350 K és 500 K között, de 400 K felett jelentősen agglomerálódnak; (7) a TiO2(110) felületen kialakuló Mo nanoszemcsék (5-10 réteg, 6-8 nm átmérő) a C2H4 termikus bontásával 850 K-en (Ar ion bombázás kiséretében) Mo-karbid nanoszemcsékké alakíthatók át. | Properties of ultrathin layers of Rh, Au, Mo and K deposited on TiO2(110) surface were examined in function of annealing and in the reactions with different gases. The most important results are the followings: (1) by exploitation of the strong metal support interaction (SMSI) between Pt and TiO2, a method was worked out for pit-formation driven by the Pt crystallites produced previously on TiO2(110); (2) it was shown by STM that the growing of 3D Mo particles begins first in the oxygen deficient regions of the support; (3) according to the I-V measurements, the Mo crystallites formed at 900 K in UHV exhibit insulator behaviour what suggests (by taking into account also the XPS measurements) that the Mo particles become encapsulated by a thin TiOx layer; (4) in the case of Rh a similar decoration of the supported metal particles was also demonstrated by LEIS; (5) it was shown that the deposition of Au on the support reduced by low energy Ar+ ion bombardment or by pre-exposing the surface to K results in a significantly higher dispersity of Au; (6) the gold particles of 3-4 nm supported on TiO2(110) exhibit high activity in the low temperature CO oxidation (PROX) between 350 K and 500 K, at the same time they exhibit a pronounced agglomeration above 400 K; (7) a method was suggested to transform of the Mo nanoparticles supported on TiO2(110) into Mo-carbide particles in the decomposition of C2H4 (5 x 10-6 mbar) at 850 K accompanied by low energy (1 keV) Ar+ bombardement

Protective effect of resveratrol against caspase 3 activation in primary mouse fibroblasts.

AIM: To study the effect of resveratrol on survival and caspase 3 activation in non-transformed cells after serum deprivation. METHODS: Apoptosis was induced by serum deprivation in primary mouse embryonic fibroblasts. Caspase 3 activation and lactate dehydrogenase release were assayed as cell viability measure by using their fluorogenic substrates. The involvement of PI3K, ERK, JNK, p38, and SIRT1 signaling pathways was also examined. RESULTS: Serum deprivation of primary fibroblasts induced significant activation of caspase 3 within 3 hours and reduced cell viability after 24 hours. Resveratrol dose-dependently prevented caspase activation and improved cell viability with 50% inhibitory concentration (IC50)=66.3+/-13.81 muM. It also reduced the already up-regulated caspase 3 activity when it was added to the cell culture medium after 3 hour serum deprivation, suggesting its rescue effect. Among the major signaling pathways, p38 kinase was critical for the protective effect of resveratrol which was abolished completely in the presence of p38 inhibitor. CONCLUSION: Resveratrol showed protective effect against cell death in a rather high dose. Involvement of p38 kinase in this effect suggests the role of mild stress in its cytoprotective action. Furthermore due to its rescue effect, resveratrol may be used not only for prevention, but also treatment of age-related degenerative diseases, but in the higher dose than consumed in conventional diet

Association between metabolically healthy central obesity in women and levels of soluble receptor for advanced glycation end products, soluble vascular adhesion protein-1, and the activity of semicarbazide-sensitive amine oxidase.

AIM: To determine the levels of circulating soluble receptor for advanced glycation end products (sRAGE), as a biomarker of risk of metabolic syndrome and cardiovascular disease development in centrally obese (CO) women considered metabolically healthy (COH) in comparison with those metabolically unhealthy (COU). METHODS: 47 lean healthy, 17 COH (presenting waist-to-height ratio >/=0.5 but not elevated blood pressure, atherogenic lipid profile, and insulin resistance), and 50 COU (CO presenting >/=2 risk factors) women aged 40-45 years were included. Anthropometric characteristics, blood chemistry and hematology data, adipokines, markers of inflammation, sRAGE, soluble vascular adhesion protein-1 (sVAP-1), and the activity of semicarbazide sensitive amine oxidase (SSAO) were determined. RESULTS: Central obesity associated with low sRAGE levels (lean healthy: 1503+/-633 pg/mL; COH: 1103+/-339 pg/mL, P<0.05; COU: 1106+/-367 ng/mL, P<0.0.1), hyperleptinemia, and elevated markers of inflammation irrespective of the presence or absence of cardiometabolic risk factors. COU women presented high adiponectin levels. SVAP-1 concentrations and the activity of SSAO were similar in all 3 groups. CONCLUSION: COH women present abnormalities in non-standard markers of cardiometabolic risk (sRAGE, leptin, high sensitive C-reactive protein), supporting the view that there is no healthy pattern of obesity. The clinical impact of our findings for future prognosis of metabolically healthy obese subjects remains to be elucidated in longitudinal studies

Association between metabolically healthy central obesity in women and levels of soluble receptor for advanced glycation end products, soluble vascular adhesion protein-1, and the activity of semicarbazide-sensitive amine oxidase

Aim To determine the levels of circulating soluble receptor for advanced glycation end products (sRAGE), as a biomarker of risk of metabolic syndrome and cardiovascular disease development in centrally obese (CO) women considered metabolically healthy (COH) in comparison with those metabolically unhealthy (COU). Methods 47 lean healthy, 17 COH (presenting waist-toheight ratio ≥0.5 but not elevated blood pressure, atherogenic lipid profile, and insulin resistance), and 50 COU (CO presenting ≥2 risk factors) women aged 40-45 years were included. Anthropometric characteristics, blood chemistry and hematology data, adipokines, markers of inflammation, sRAGE, soluble vascular adhesion protein-1 (sVAP-1), and the activity of semicarbazide sensitive amine oxidase (SSAO) were determined. Results Central obesity associated with low sRAGE levels (lean healthy: 1503 ± 633 pg/mL; COH: 1103 ± 339 pg/mL, P < 0.05; COU: 1106 ± 367 ng/mL, P < 0.0.1), hyperleptinemia, and elevated markers of inflammation irrespective of the presence or absence of cardiometabolic risk factors. COU women presented high adiponectin levels. SVAP-1 concentrations and the activity of SSAO were similar in all 3 groups. Conclusion COH women present abnormalities in nonstandard markers of cardiometabolic risk (sRAGE, leptin, high sensitive C-reactive protein), supporting the view that there is no healthy pattern of obesity. The clinical impact of our findings for future prognosis of metabolically healthy obese subjects remains to be elucidated in longitudinal studies

Effects of Cariprazine, Aripiprazole, and Olanzapine on Mouse Fibroblast Culture: Changes in Adiponectin Contents in Supernatants, Triglyceride Accumulation, and Peroxisome Proliferator-Activated Receptor-γ Expression

Background and Objectives: The use of the dopamine-partial agonist subclass (also termed dopamine stabilizers) of atypical antipsychotics for the treatment of negative schizophrenia symptoms and some mood disorders has increased recently. Similar to other second-generation antipsychotics (SGAs), aripiprazole (ARI) and cariprazine (CAR) also influence food intake, but the peripheral effects of these drugs on adipose&#8722;tissue homeostasis, including adipokine secretion as well as lipo- and adipogenesis, are not fully elucidated. In this study, we explored the adipocyte-related mechanisms induced by second-generation antipsychotics (SGAs), leading to changes in peripheral signals involved in energy homeostasis. Materials and Methods: CAR, a new SGA, was compared with ARI and olanzapine (OLA), using cell cultures to study adipogenesis, and the expression levels of peroxisome proliferator-activated receptor-&#947; (PPAR-&#947;) was measured in adipocytes derived from mouse fibroblasts, by western blotting on days 7, 14, and 21 postinduction. The triglyceride (TG) content of the cells was also evaluated on day 15 using Oil Red O staining, and the adiponectin (AN) content in the cell culture supernatants was quantified on days 7 and 15 by enzyme-linked immunosorbent assay. Cells were treated with two concentrations of ARI (0.5 and 20 &#181;g/mL), OLA (1 and 20 &#181;g/mL), and CAR (0.1 and 2 &#181;g/mL). Results: Both concentrations of ARI and OLA, as well as the lower concentration of CAR, significantly increased the TG contents. The AN levels in the supernatants were significantly increased by the higher concentration of ARI on days 7 and 15 (p &lt; 0.05). Although PPAR-&#947; levels were not significantly affected by ARI and OLA, the lower concentration of CAR induced a significant time-dependent decrease in PPAR-&#947; expression (p &lt; 0.05). Conclusions: The in vitro adipogenesis considered from TG accumulation, AN secretion, and PPAR-&#947; expression was differently influenced by ARI, CAR, and OLA. Understanding the adipocyte-related mechanisms of antipsychotics could contribute to understanding their weight-influencing effect

Prenatal dietary load of Maillard reaction products combined with postnatal Coca-Cola drinking affects metabolic status of female Wistar rats.

AIM: To assess the impact of prenatal exposure to Maillard reaction products (MRPs) -rich diet and postnatal Coca-Cola consumption on metabolic status of female rats. Diet rich in MRPs and consumption of saccharose/fructose sweetened soft drinks is presumed to impose increased risk of development of cardiometabolic afflictions, such as obesity or insulin resistance. METHODS: At the first day of pregnancy, 9 female Wistar rats were randomized into two groups, pair-fed either with standard rat chow (MRP-) or MRPs-rich diet (MRP+). Offspring from each group of mothers was divided into two groups and given either water (Cola-) or Coca-Cola (Cola+) for drinking ad libitum for 18 days. Oral glucose tolerance test was performed, and circulating markers of inflammation, oxidative stress, glucose and lipid metabolism were assessed. RESULTS: MRP+ groups had higher weight gain, significantly so in the MRP+/Cola- vs MRP-/Cola-. Both prenatal and postnatal intervention increased carboxymethyllysine levels and semicarbazide-sensitive amine oxidase activity, both significantly higher in MRP+/Cola + than in MRP-/Cola-. Total antioxidant capacity was lower in MRP+ groups, with significant decrease in MRP+/Cola + vs MRP-/Cola+. Rats drinking Coca-Cola had higher insulin, homeostatic model assessment of insulin resistance, heart rate, advanced oxidation of protein products, triacylglycerols, and oxidative stress markers measured as thiobarbituric acid reactive substances compared to rats drinking water, with no visible effect of MRPs-rich diet. CONCLUSION: Metabolic status of rats was affected both by prenatal and postnatal dietary intervention. Our results suggest that combined effect of prenatal MRPs load and postnatal Coca-Cola drinking may play a role in development of metabolic disorders in later life

Felületi nanoszerkezeteken adszorbeált formák IR, elektron-, foton- és ion spektroszkópiai vizsgálata = IR, electron, photon and ion spectroscopic investigations of species adsorbed on nanostructured surfaces

A munkatervnek megfelelően az eddig használt komplex felületvizsgáló berendezést (XPS, AES, TDS) kiegészítettük ionszórásos spektroszkópia (LEIS) lehetőséggel. A tervnek megfelelően a berendezést egy speciális manipulátor beszerzésével szögfüggő spektroszkópiai mérések elvégzésére tettük alkalmassá. Ezen technikai megoldásokon túlmenően vizsgáltuk a molibdén-karbid kialakulását, felületi szerkezetét és reakcióját oxigénnel. Kísérleteket végeztünk és végzünk az ultravékony Mo réteggel borított TiO2 egykristály felületen AES és STM segítségével. Jelentős eredményeket bnértünk el a formiát csoportok, valamint az aldehidek átalakításának mechanizmusának felderítésében. Munkáinkból 22 nemzetközi folyóíratban számoltunk be | According to the research plan, the available complex surface analytical apparatus (XPS. AES, TDS) was complemented by Low Energy Ion Scattering (LEIS) facility. The purchase and installation of a special manipulator allows carrying out angle-dependent ion-scattering measurements. Besides performing technical developments, we investigated the formation and the surface structure of molybdenum carbide and its reactivity towards oxygen. We have been applied AES and STM techniques to characterize single crystalline titania surfaces covered by ultrathin molybdenum layers. We obtained important results regarding the enhanced stability and dispersity of gold nanoparticles through the co-deposition of Rh and Mo nanoparticles of controlled size. We clarified the reaction mechanism of the transformation of aldehydes on mono- and bimetallic catalysts supported on metal oxide semiconductor. We established the stability of NCO species formed on Pd single crystal surface under UHV conditions by means of TPD and RAIRS techniques

Selegiline : a molecule with innovative potential

Monoamine oxidase B (MAO-B) inhibitors have an established role in the treatment of Parkinson's disease as monotherapy or adjuvant to levodopa. Two major recognitions were required for their introduction into this therapeutic field. The first was the elucidation of the novel pharmacological properties of selegiline as a selective MAO-B inhibitor by Knoll and Magyar and the original idea of Riederer and Youdim, supported by Birkmayer, to explore its effect in parkinsonian patients with on-off phases. In the 1960s, MAO inhibitors were mainly studied as potential antidepressants, but Birkmayer found that combined use of levodopa and various MAO inhibitors improved akinesia in Parkinson's disease. However, the serious side effects of the first non-selective MAO inhibitors prevented their further use. Later studies demonstrated that MAO-B, mainly located in glial cells, is important for dopamine metabolism in the brain. Recently, cell and molecular studies revealed interesting properties of selegiline opening new possibilities for neuroprotective mechanisms and a disease-modifying effect of MAO-B inhibitors