Paraméterillesztő szoftver a „Two-Layer Viscoplastic” anyagmodellhez: Parameter calibration software for the „Two-layer Viscoplastic” model

The „Two-Layer Viscoplastic” material model can describe the elastic, plastic, and viscous behaviors as well. The calibration of the material parameters can be defined as a multidimensional optimizationproblem, where the difference between the measured and simulated behaviors has to be minimized via appropriate choice of the material parameters. In this article, a new software is introduced, which can provide results significantly faster, than a previously applied method. Kivonat A „Two-Layer Viscoplastic” anyagmodell egyszerre képes leírni az anyagok rugalmas, képlékeny és viszkózus viselkedését. Az anyagparaméterek meghatározása egy többdimenziós optimalizálási feladatként fogalmazható meg, ahol a paraméterek megfelelő megválasztásával minimalizáljuk a mért és szimulált viselkedés közötti különbséget. A dolgozatban egy saját szoftver kerül bemutatásra, ami a fenti problémára a korábbinál lényegesen hatékonyabb megoldást szolgáltat

A tranziens kifelé haladó áram szerepe a kamrai repolarizációban emlős szívizmon. = The role of transient outward current in the ventricular repolarization in mammalian heart.

A kutatási programunk keretében megvizsgáltuk a tranziens kifelé haladó kálium áramnak (Ito), a kamrai repolarizációban betöltött szerepét emlős szívizomban. Kísérleteinkben a lassú késői egyenirányító kálium áramot (IKs) gátló chromanol 293B nagy koncentrációban szelektíven gátolta az Ito áramot kutya kamrai szívizomban feltéve, hogy a kísérleteket egy IKs blokkoló szer jelenlétében végeztük. Így a chromanol 293B alkalmas eszköz volt a célkitűzésben leírt vizsgálatok elvégzésére. Megállapítottuk, hogy az Ito lassú komponense jelentős repolarizáló erőt jelenthet a plató fázis korai szakaszában, azaz amikor más repolarizáló ionáramok relatíve gyengék, valamint a plató fázis késői szakaszában reaktiválódó áram (Ito “window” áram) szintén hozzájárulhat a repolarizációhoz. Úgy találtuk, hogy Ito gátlás hatására szignifikánsan megnyúlt az akciós potenciál mind epikardiális, mind endokardiális preparátumokon. Dofetilid alkalmazásával beszűkített repolarizációs tartalékkal rendelkező preparátumokon végzett kísérleteinkben az Ito áram gátlása nagyon nagymértékben megnyújtotta a repolarizációt, több esetben korai utódepolarizációt indukálva. Munkánk legfontosabb következtetése az, hogy a tranziens kifelé haladó kálium áram nemcsak közvetett módon, a plató fázis potenciáljának modulálásával, hanem közvetlenül is befolyásolja a repolarizációt kutya kamrai szívizomban, valamint jelentősen hozzájárul a repolarizációs tartalékhoz. | In our research project we studied the role of transient outward potassium current (Ito) in the repolarization of mammalian heart. In our experiments the slow delayed rectifier (IKs) blocker chromanol 293B at high concentration selectively blocked Ito in dog ventricular muscle provided that the experiments were performed in the presence of an IKs blocking compound. Therefore, chromanol 293B was a suitable tool to fulfill the experiments described in the study proposal. We observed that the slowly inactivating component of the current represents significant repolarizing force during the initial phase of the action potential plateau, i.e. when other membrane currents are relatively week. The current reactivated in the later phase of the plateau (Ito “window” current) may also contribute to the repolarization. We found that blockade of Ito significantly lengthened the repolarization in both epicardial and endocardial preparations. Ito block dramatically prolonged the action potential when the repolarization reserve was impaired by previous application of dofetilide frequently inducing early afterdepolarizations. The main finding of the present project is that the transient outward potassium current in addition to indirectly modulate the plateau phase, can also directly alter the repolarization in dog ventricular muscle and can be regarded as an important contributing factor to the repolarization reserve

Az étrend szerepe a húgyúti kövek kialakulásában és megelőzésében

In Hungary and in the developed countries urinary stones occur more often due to nutritional habits, obesity and sedentary lifestyle beside the endocrine and metabolic causes. In the daily urological and family doctor practice prevention should have an important role. Prevention is based not only on body weight control, physical exercise and medical treatment, but on proper diet as well. The nutritional components can change the consistence of urine, causing supersaturation, which is essential in stone formation. Specific nutritional components can either prevent stone formation (increased fluid intake, citrate, magnesium, fruits and vegetables) or either increase stone formation (decreased fluid intake, proteins, carbohydrates, oxalate, salt, increased calcium intake, ascorbic-acid etc). We summarized evidence-based practical dietary suggestions on the primary and secondary prevention of urinary stones. Orv Hetil. 2017; 158(22): 851-855

The assessment of visuospatial skills and verbal fluency in the diagnosis of Alzheimer’s disease

Background: In the diagnosis of Alzheimer’s disease (AD), examining memory is predominant. Our aim was to analyse the potential role of various cognitive domains in the cognitive evaluation of AD. Methods: 110 individuals with clinically defined AD and 45 healthy control participants underwent neuropsychological evaluation including Addenbrooke’s Cognitive Examination (ACE). AD patients were selected in three groups based on disease duration in years (y) (Group 1: ≤2y n=36; Group 2: 2‐4y n=44, Group 3: ≥4y n=30). Covariance weighted intergroup comparison was performed on global cognitive score and subscores of cognitive domains. Spearman’s rho was applied to study the correlation between cognitive subscores and disease duration. Wilcoxon signed ranked test was used for within group analysis among ACE cognitive subscores. Results: Significant difference was found between ACE total scores among groups (χ2=119,1; p<0,001) with a high negative correlation (p<0,001; r: -0,643). With longer disease duration, all the subscores of ACE significantly decreased (p’s <0,001). Visuospatial score showed the strongest negative correlation with disease duration with a linear trajectory in decline (r: -0,85). In the early phase of cognitive decline, verbal fluency was the most impaired cognitive subdomain (normalized value: 0.64), and it was significantly reduced compared to all other subdomains (p’s<0.05). Conclusion: We found that impairment of verbal fluency is the most characteristic feature of early cognitive decline, therefore it might have crucial importance in the early detection of Alzheimer’s disease. Based on our results visuospatial assessment might be an ideal marker to monitor the progression of cognitive decline in AD

Additional polymorphic microsatellite loci for detailed population genetic studies of Lethrus apterus (Coleoptera: Geotrupidae)

In this study we attempted to isolate 13 additional microsatellites from the beetle Lethrus apterus and then to use them to screen for polymorphisms in 35 specimens collected from the northern Hungarian mountains. The newly developed markers presented in this paper are polymorphic, including between two and seven detected alleles per locus. The observed and expected heterozygosity per locus ranged between 0.057 and 0.686 and between 0.056 and 0.756, respectively, while two loci showed significant deviations from Hardy-Weinberg equilibrium. These deviations can be explained by the presence of null alleles. All loci cross- amplified in at least two out of four congeneric Lethrus species (L. bituberculatus, L. scoparius, L. strymonensis and L. perun). The polymorphic microsatellite markers we present for L. apterus will be valuable for future population genetic studies

Control of ovulation after prostaglandin treatment by means of ultrasonography and effect of the time of ovulation on conception rate in dairy cows

Primiparous and multiparous lactating crossbred dairy cows (after Day 40 postpartum) with a mature corpus luteum (CL) (diameter of ≥ 17 mm determined by ultrasonography) and having a follicle with a diameter of ≥ 10 mm were treated with natural prostaglandin F2α (n = 80). Those from the cows that showed oestrus within 5 days after treatment were inseminated (Group 1: n = 39). Other group of cows showing oestrus without treatment (Group 2: n = 41) were inseminated and served as controls. The ovaries of each cow were scanned by transrectal ultrasonography from the day of detected oestrus (Day −1p.m.) until ovulation, to measure the changes in the areas of the CL and the largest follicle and to determine the occurrence of ovulation. Although no significant differences were found between the treated and untreated cows in terms of a reduction in the area of the corpora lutea and of an increase in the area of the dominant follicles, the mean area of these follicles in Group 2 was somewhat greater than in Group 1. The highest conception rate was achieved if AI was performed at the same day as ovulation occurred in both groups (conception rate in treated group was: 62.5%, in untreated group: 66.6%, respectively) between Day 0a.m. to Day 0p.m.. In Group 1, 54.5% conception rate has been achieved if ovulation occurred between Day 0p.m. to Day 1p.m., or 50% between Day 1p.m. to Day 2p.m. after AI, and 53.3% and 44.4% in Group 2, respectively. The conception rate for cows that ovulated before AI in Group 2 was 25%. No ovulation occurred in 7 cows until Day 2p.m. after AI and none of them became pregnant. The overall conception rate was approximately 50% in both groups, but when the cows had ovulated too early or too late relative to the time of AI, the conception rate was significantly lower, thus determination of the optimal time for AI is of great practical importance in dairy herds

Additional polymorphic microsatellite loci for detailed population genetic studies of Lethrus apterus (Coleoptera: Geotrupidae)

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A szívizom-kontraktilitás endogén peptiderg szabályozó mechanizmusainak vizsgálata = Studies on endogenous peptidergic regulation of myocardial contractility

Célunk a szívizom-összehúzódás erejét szabályozó mechanizmusok feltárása volt. Eredményeink szerint a közelmúltban izolált prolaktin-releasing peptid (PrRP) és a neuronostatin (NST) funkcionális szereppel bír a szívben. Izolált patkányszíven a PrRP fokozta a kontrakciók erejét, az NST csökkentette azt. Az endothelin-1 (ET-1), az adrenomedullin (AM), a PrRP és az NST hatását közvetítő intracelluláris jelátvivő utak karakterizálása révén új serkentő illetve ellenszabályozó mechanizmusokat azonosítottunk. Kimutattuk, hogy az ERK1/2 mitogénaktivált-proteinkináz (MAPK) közvetíti az ET-1 és az AM inotrop hatását. A NAD(P)H-oxidáz által termelt reaktív oxigén gyökök, mint jelátvivő molekulák, serkentik az ERK1/2 aktivációját. Leírtuk, hogy az ERK1/2 foszforilációjához elengedhetetlen az epidermális növekedési faktor-receptor transzaktivációja. Az ERK1/2 a Na+-H+ cseremechanizmus fokozása révén növeli a kontrakciók erejét ET-1 illetve AM adásakor. Kimutattuk, hogy a p38-MAPK illetve az nNOS-NO-szolubilis guanilátcikláz-cGMP-proteinkináz-G jelátviteli út aktivációja ellensúlyozni képes az ET-1 inotrop hatását. Továbbá, a proteinkináz-C- és a proteinfoszfatáz-1 gyengíti a PrRP hatását. Kimutattuk, hogy az AM adaptív illetve maladaptív válaszokat vált ki a kamrai remodelláció során kontextusfüggő módon. Az azonosított jelátviteli mechanizmusok szelektív serkentése illetve gátlása a szívizom-kontraktilitás fokozásának új útjait jelentheti a szívelégtelenség kezelésében. | Our aim was to identify novel mechanisms regulating cardiac contractility. We have provided evidence for the functional significance of the recently isolated prolactin-releasing peptide (PrRP) and neuronostatin (NST) in the myocardium. PrRP increased cardiac contractility, whereas NST decreased it in isolated rat heart preparation. We have identified new positive and negative regulators of contractility by characterizing the signaling mechanisms of endothelin-1 (ET-1), adrenomedullin (AM), PrRP and NST. We have demonstrated that the mitogen-activated protein kinase (MAPK) ERK1/2 is an important mediator of the positive inotropic effect of ET-1 and AM. NAD(P)H oxidase-derived reactive oxygen species can act as signaling molecules activating ERK1/2. Moreover, epidermal growth factor receptor transactivation is required for ERK1/2 activation, which enhances contractility via the Na+-H+ exchanger. We have reported that activation of p38-MAPK and nNOS–NO–guanylyl cyclase–cGMP–protein kinase G pathway can counterbalance the inotropic response to ET-1. Moreover, the inotropic effect of PrRP was attenuated by protein kinase C? and protein phosphatase-1. In addition to control contractility, we have shown that AM can induce a context-dependent adaptive or maladaptive response during left ventricular remodeling. The selective activation or inhibition of the identified pathways may represent novel means to support cardiac function in the failing heart