A Distance Model for Safety-Critical Systems

In this paper we introduce a new, theoretical model for safety-critical systems in which the distance from the dangerous conditions can be measured. To describe these systems we use besides the graph model Petri nets, too. We illustrate the theoretical discussion with some simple examples

Az USA-EU kereskedelmi tárgyalások várható hatása a magyar növekedésre

A 2013 eleje óta formálódó Transzatlanti Kereskedelmi és Beruházási Partnerségi tárgyalások védelmi Egyezmény (TTIP) kapcsán az a közgazdasági sejtés, hogy az egyezmény növekedési hatásokkal jár a résztvevő felek számára. Tanulmányunk A cikk Magyarország vonatkozásában becsli a TTIP addicionális növekedési, foglalkoztatási és beruházási hatásait. A szerzők számításaink a számítható általános egyensúly (CGE) alapú modellek árrugalmassági, illetve kereskedelemrugalmassági megközelítésére épül. Lehetőségeinkhez mérten ágazati bontásban vizsgáljuk a hatásokat. Eredményeinket összevetjük más kutatók becsléseive

Vizsgálóbíró-e a történész?

Simon ZB. Vizsgálóbíró-e a történész? In: Papp G, Szijártó IM, eds. Mikrotörténelem másodfokon. Budapest: L'Harmattan; 2010: 82-91

A New Tool for Complement Research: In vitro Reconstituted Human Classical Complement Pathway

The complement, as part of the innate immune system, represents the first line of defense against Gram-negative bacteria invading the bloodstream. The complement system is a zymogen cascade that ultimately assemble into the so-called membrane attack complex (MAC), which lyses Gram-negative bacteria upon insertion into the outer membrane. Traditionally, serum has been used as complement source, for example to study the bactericidal activity of monoclonal antibodies or antibodies raised upon vaccination. Due to the significant donor to donor variability, as well as susceptibility of complement factors to handling and storage conditions, assay reproducibility using human serum is low. Moreover, the presence of pre-existing antibodies and antimicrobial compounds are confounding factors. To remove antibodies from human serum, we applied κ/λ-light chain specific affinity chromatography, however the method severely reduced the complement activity due to the depletion of complement components. Therefore, we attempted to reconstitute human complement—namely the alternative (rAP) and the classical (rCP) pathways—from purified complement factors. We found that adding C1-inhibitor to the mixture was essential to maintain a stable and functional C1 and thus to generate an active rCP. We further confirmed the functionality of the rCP by testing the complement-dependent bactericidal activity of a human monoclonal antibody, A1124 against an E. coli clinical isolate belonging to the ST131 clonal complex, and that of a polyclonal IVIg against a laboratory E. coli strain (MG1655) not expressing LPS O-antigen and capsule. Although the alternative pathway did not have any bactericidal activity by itself, it enhanced MAC deposition induced by rCP and increased the overall bactericidal activity against the ST131 E. coli strain. In conclusion, we report for the first time the successful in vitro reconstitution of the classical pathway of the human complement to establish a serum-free, complement dependent bactericidal assay. This system offers high level of standardization and could support the study of the complement in different research fields

Postconditioning in major vascular surgery: prevention of renal failure

This study investigates teachers in the Swedish ten-year compulsory school who use ICT(Information and communication technology) in their classroom practice. It poses andgives answers to questions about what is contributing most to explain why they choose touse computers and information technology in their work with students/pupils and usesmultiple regression analysis in order to investigate the best pattern of predictive variables.A significant model emerged suggesting that teachers using ICT with students wereinterested in changing their classroom practice. They also felt self-efficacious in usingcomputers in education and they have positive attitudes toward using ICT in education.The present investigation differs from other studies in that it examines teachers whoalready are using technology in their classroom practice and it could be seen as a buildingblock in the development of knowledge about how teachers can become more competentand confident in using ICT in their pedagogical work in classroom practice

Isoform-Dependent Changes in Cytochrome P450-Mediated Drug Metabolism after Portal Vein Ligation in Rat

Surgical removal of complicated liver tumors may be realized in two stages via selective portal vein ligation, inducing the atrophy of portally ligated lobes and the compensatory hypertrophy of nonligated liver lobes. Unlike morphological changes, functional aspects such as hepatic cytochrome P450 (CYP)-mediated drug metabolism remain vaguely understood, despite its critical role in both drug biotransformation and hepatic functional analysis. Our goal was the multilevel characterization of hepatic CYP-mediated drug metabolism after portal vein ligation in the rat.Male Wistar rats (n = 24, 210-230 g) were analyzed either untreated (controls; n = 4) or 24/48/72/168/336 h (n = 4 each) following portal vein ligation affecting approximately 80% of the liver parenchyma. Besides the weights of ligated and nonligated lobes, pentobarbital (30 mg/kg)-induced sleeping time, CYP1A(2), CYP 2B(1/2), CYP2C(6/11/13), CYP3A(1) enzyme activities, and corresponding isoform mRNA expressions, as well as CYP3A1 protein expression were determined by in vivo sleeping test, CYP isoform-selective assays, polymerase chain reaction, and immunohistochemistry, respectively.Portal vein ligation triggered atrophy in ligated lobes and hypertrophy nonligated lobes. Sleeping time was transiently elevated (p = 0.0451). After an initial rise, CYP1A, CYP2B, and CYP3A enzyme activities dropped until 72 h, followed by a potent increase only in the nonligated lobes, paralleled by an early (24-48 h) transcriptional activation only in nonligated lobes. CYP2C enzyme activities and mRNA levels were bilaterally rapidly decreased, showing a late reconvergence only in nonligated lobes. CYP3A1 immunohistochemistry indicated substantial differences in positivity in the early period.Beyond the atrophy-hypertrophy complex, portal vein ligation generated a transient suppression of global and regional drug metabolism, re-established by an adaptive, CYP isoform-dependent transcriptional response of the nonligated lobes

Távoli szervi kondicionálás: rövid távú hepatoprotectiv hatások patkánymodellben = Remote Ischemic Conditioning: Short-Term Effects on Rat Liver Ischemic-Reperfusion Injury

Bevezetés: Az ischaemiás-reperfúziós károsodások mérséklésére kipróbált módszerek között újszerű elképzelés a célszervi ischaemia alatt alkalmazott távoli szervi ischaemiás perkondicionálás. Célkitűzés: Patkánymáj ischaemiás-reperfúziós modellben alkalmazni ezen újszerű kondicionálási technikát. Módszer: Hím Wistar patkányok (n = 30, 10/csoport) 60 perc parciális ischaemiában, majd 60 perc reperfúzióban részesültek. Egy csoportban perkondicionálás került alkalmazásra a májischaemia utolsó 40 percében, az infarenalis aortán. A máj és az alsó végtag mikrokeringésének regisztrálása lézeres Doppler-áramlásmérővel történt. A reperfúziót követően a máj szövettani elváltozásainak analízise és a májszöveti hősokkfehérje-72-expresszió mérése mellett a szérumtranszamináz-aktivitások, továbbá a redox-homeosztázis állapotának meghatározása történt. Eredmények: A máj és az alsó végtag mikrocirkulációt jellemző paraméterei szignifikáns (p<0,05) javulást mutattak a perkondicionált csoportban a kontrollhoz képest. A szérum-alanin-transzamináz-aktivitás és a májszövettani vizsgálatok, továbbá a májszöveti redox-homeosztázis vonatkozásában egyaránt szignifikánsan enyhébb károsodás volt megfigyelhető a perkondicionált csoportban a kontrollhoz képest. Következtetés:A perkondicionálás alkalmas lehet a máj ischaemiás-reperfúziós károsodásának mérséklésére. Introduction: Several techniques have been developed to reduce ischemic-reperfusion injury. A novel method is the remote ischemic perconditioning, applied parallel with target organ ischemia. Aim: The aim of the study was to determine the extent of liver ischemic-reperfusion injury via the application of this novel method. Methods: Male Wistar rats (n = 30, 10/group) were subjected to 60-minute partial liver ischemia and 60-minute reperfusion. Rats in the perconditioned group received conditioning treatment during the last 40 minutes of liver ischemia by infrarenal aortic clamping. Hepatic and lower limb microcirculation was monitored by laser Doppler flowmeter during reperfusion. After reperfusion, liver samples were taken for routine histological examination and redox-state assessment. Serum transaminase activities and liver tissue heat-shock protein-72 expression were measured. Results: Parameters of microcirculation showed significant (p<0.05) improvement in the perconditioned group in comparison with the control. Besides the significant improvement observed in the serum alanine amino-transferase activities, significantly milder tissue injury was detected histologically in the liver sections of the perconditioned group. Moreover, significant improvement was found in the redox-state parameters. Conclusion: Perconditioning may be a reasonable possibility to reduce liver ischemic-reperfusion injury