Development and Micro Manufacturing of Coronary Stents in Hungary

Revascularisation by endovascular implant (stent) has great importance in the treatment of coronary artery diseases. Stents are high-technology implants that are the creation of the knowledge of health sciences, physics, chemistry, material science and engineering. Its development can be carried out only by the involvement of these areas of knowledge. Hungary has a stent production since 1995, which is the only one in the new EU member countries. The aim of the project that has been started within the frameworks of the National Research and Development Program, is the development of a new stent family based on the results of the material science researches have started for 10 years and the clinical and production experiences of experts, which could result an equivalent Hungarian product to the market leader products in case of several product lines. The original wire-mesh cut for those replaced welded stents made of wire later from tubes laser cutted ones. The stents are made of biocompatible materials: 316LVM stainless steel, Co-Cr alloys and nitinol. Stents made from wires are produced by weaving, or reeling and resistance projection welding. Nowadays, stents are produced mostly by high-precision laser cutting. These were large steps forward in the development of production technology, following the appearance of balloon catheters. Independently of what kind of manufacturing process is used, it has to be very precise because a connecting goal of the development is to increase the biocompatibility of the stents with surface treatment and to create a coating that is able to carry drug on the smooth surface. The paper presents the antecedents, achievements and main future objectives in micro manufacturing speciality of that special medical device, that is just before the surface treatment and coating process of the stent

Koszorúér-tágítóbetétek anyagai és gyártástechnológiája

Abstract The paper characterises the materials of coronary stents applied in the therapy of coronary atherosclerosis. Authors emphasise the close relationship between the clinical experiences and the development of technical characteristics and technology of coronary stents. The presented examples demonstrate both of Hungarian and international trends. Kivonat A cikk ismerteti a koszorúér-szűkületek gyógyításában alkalmazott értágítóbetétek anyagait. A szerzők hangsúlyozzák az értágítóbetétek műszaki jellemzőinek és gyártástechnológiájának a klinikai tapasztalatokkal és elvárásokkal párhuzamosan végbement fejlődését. A bemutatott példák a magyarországi és a nemzetközi trendeket egyaránt megvilágítják

Értágítóbetétek lézersugaras hegesztése

The authors give an overview about the application of welding, mainly the laser welding related to the fabrica-tion of stents. The paper demonstrates the welding of markers and the stents, which are made of wire. | A cikkben a szerzők áttekintést adnak az értágítóbetétek gyártásához kapcsolódó hegesztési, főleg lézersugaras hegesztési alkalmazásokról. Bemutatják a markerek hegesztését és a huzalból készült értágítóbetétek gyártását

Csatolási, anizotrópia és domén-jelenségek mágneses vékonyrétegekben = Coupling, anisotropy and domain phenomena in magnetic thin films

Antiferromágnesesen (AF) csatolt fémes multirétegek fontos szerepet játszanak mind az alapkutatásban, mind a mágneses adatrögzítésben és szenzorikában. A projekt célja volt egyes, az óriás mágneses ellenállás (GMR) jelenségén alapuló nanoeszközök teljesítőképességét befolyásoló csatolási és mágneses anizotrópia tulajdonságok, valamint mágneses doménjelenségek felderítése. Kísérleti módszereink a mágnesezettség és a mágneses ellenállás mérése, a neutronreflektometria, a szinkrotron-Mössbauer-reflektometria (SMR) és a Mössbauer-polarimetria voltak. A projekt főbb eredményei: Azonosítottuk a szuperparamágneses tartományok GMR-járulékát elektrolitikusan leválasztott Co/Cu multirétegekben, módszert dolgoztunk ki annak elkülönítésére és minimalizálására. Felderítettük az AF-domének érésének mechanizmusát erősen csatolt Fe/Cr multirétegekben, igazoltuk abban a koercitív erő szerepét. A "túltelítési doménmemória-hatást" a réteg-réteg-csatolás laterális eloszlásával magyaráztuk. Két új doménátalakulást, a hőmérsékletindukált érést és a komplex durvulást találtuk meg és elemeztük. Kifejlesztettük az érés Monte Carlo-szimulációját és általános sejtautomata-modelljét. Megalkottuk a diffúz SMR teljes DWBA-elméletét és -algoritmusát. Kidolgoztuk a laboratóriumi és a szinkrotronos vékonyréteg-Mössbauer-polarimetria elveit és a módszereket Fe/Cr és Fe/Gd multirétegek csatolási tulajdonságainak vizsgálatára alkalmaztuk. Megépítettük és beüzemeltük a világ első CEMS polarimétereit. | Antiferromagnetically (AF) coupled metallic multilayers play an important role in fundamental science as well as in magnetic recording technology and sensorics. The project aimed at clarifying coupling and magnetic anisotropy properties and also magnetic domain phenomena influencing the performance of nanodevices based on giant magnetoresistance (GMR). Experimental methods included measurement of magnetisation and magnetoresistance, neutron reflectometry, synchrotron Mössbauer reflectometry (SMR) and Mössbauer polarimetry. Main results of the project: GMR contribution of superparamagnetic regions in electrodeposited Co/Cu multilayers was identified; a method was developed for separating and minimising it. The mechanism of ripening of AF domains in strongly-coupled Fe/Cr multilayers was elucidated and the role of coercivity was demonstrated. 'Supersaturation memory effect' was ascribed to lateral distribution of the layer-layer coupling. Two new domain transformations, viz. temperature-induced ripening and complex coarsening were found and analysed. A Monte Carlo simulation and a general cellular automaton model of ripening were developed. Full DWBA theory and algorithm of diffuse SMR were established. Principles of laboratory and synchrotron thin-film Mössbauer polarimetry were elaborated and the methods were applied to studying coupling properties of Fe/Cr and Fe/Gd multilayers. The world's first CEMS polarimeters were built and put into operation

ONE-YEAR-LONG CONTINUOUS AND SYNCHRONOUS DATA SET OF FOSSIL CARBON IN ATMOSPHERIC PM2.5 AND CARBON DIOXIDE IN DEBRECEN, HUNGARY

Radiocarbon investigation of atmospheric PM2.5 aerosol synchronized with 14CO2 observations began in Debrecen in the winter of 2010. The aim of the study was to determine the contemporary and fossil carbon fractions in the aerosol and to set them against the fossil CO2 excess data referring to the same period. The mass of the collected PM2.5 mode on prebaked quartz filters was determined gravimetrically, while its total carbon mass was calculated from the pressure of CO2 gas produced after the combustion of the filters. As a result of the applied sampling and preparation method, the stable, nonvolatile carbon forms were principally studied. 14C measurements of the tiny aerosol bulk samples were performed using the EnvironMICADAS accelerator mass spectrometer at ATOMKI. The sample preparation method was tested using several blanks, standards, and real samples. Test results showed good reproducibility for the applied aerosol sample preparation and accelerator mass spectrometry (AMS) 14C analyses. Atmospheric fossil CO2 excess data were calculated according Levin et al. (2003), using the 14C results of collected CO2 samples measured by the gas proportional counting system at ATOMKI. Mass concentration of PM10 involving the PM2.5 mode in the city air exceeded the daily average of 50 μg/m3 (24-hr limit value in the EU) several times in 2011, mainly during the winter. The results showed that recently derived carbon most likely from domestic wood burning was causing the elevated carbon mass concentration of PM2.5 in Debrecen at the time. In the course of the 1-yr-long continuous and systematic comparison of fossil carbon mass concentration of PM2.5 mode and mole fraction of fossil excess of atmospheric CO2, similar and synchronous trends were observed during the studied period in Debrecen