93 research outputs found
Vortex pinning and critical currents in nanostructured novel superconductors
A systematic analysis of the parameters associated with vortex pinning in novel superconductors containing nano-scale strong isotropic pinning centres (such as U/n processed Bi2223/Ag tapes and nanoparticle added MgB_2) has been carried out. Although the systems studied are very different as regards their structures, types of nano-scale defects and vortices, their pinning parameters (irreversibility fields and the fields for the maximum volume pinning force) show distinct common features. In particular, for moderate defect densities nĻ, in all these systems the enhancement of the pinning parameters in nanostructured state is approximately linear in nĻ over sizable field and temperature windows. Accordingly, these systems exhibit a kind of matching effects with the effective matching field BĻ, correlated with the areal density of defects. The field BĻ forms a natural field scale for the vortex pinning phenomena in such systems. However, at fields far from BĻ, an interplay of different pinning mechanisms sets in. The impact of these results for the future enhancement of the flux pinning and critical currents in nanostructured Bi2223 and MgB_2 superconductors is briefly discussed
Zapinjanje magnetskih vrtloga i kritiÄne struje u novim nanostrukturiranim supravodiÄima
A systematic analysis of the parameters associated with vortex pinning in novel superconductors containing nano-scale strong isotropic pinning centres (such as U/n processed Bi2223/Ag tapes and nanoparticle added MgB2) has been carried out. Although the systems studied are very different as regards their structures, types of nano-scale defects and vortices, their pinning parameters (irreversibility fields and the fields for the maximum volume pinning force) show distinct common features. In particular, for moderate defect densities nĻ, in all these systems the enhancement of the pinning parameters in nanostructured state is approximately linear in nĻ over sizable field and temperature windows. Accordingly, these systems exhibit a kind of matching effects with the effective matching field BĻ, correlated with the areal density of defects. The field BĻ forms a natural field scale for the vortex pinning phenomena in such systems. However, at fields far from BĻ, an interplay of different pinning mechanisms sets in. The impact of these results for the future enhancement of the flux pinning and critical currents in nanostructured Bi2223 and MgB2 superconductors is briefly discussed.Predstavljamo sustavnu analizu parametara zapinjanja magnetskih vrtloga u novim supravodiÄima koji sadrže jake izotropne nanoskopske centre zapinjanja kao Å”to su Bi2223/Ag trake obraÄene sa U/n i MgB2 punjen nanoÄesticama silicija. Iako su ti materijali vrlo razliÄiti u pogledu kristalne strukture, prirode vrtloga i nanoskopskih defekata, njihovi parametri zapinjanja vrtloga (ireverzibilna polja i polja maksimalne volumne sile zapinjanja) pokazuju izrazito sliÄna svojstva. Npr., u tim je materijalima pojaÄanje zapinjanja vrtloga pri umjerenim gustoÄama defekata nĻ približno linearno s nĻ u Å”irokom podruÄju temperatura i magnetskih polja. Ukratko, ti materijali pokazuju uÄinke usklaÄivanja s efektivnim poljima usklaÄivanja BĻ razmjernim nĻ. Polje BĻ Äini prirodnu ljestvicu polja za zapinjanje vrtloga u takvim sustavima. Medutim, u poljima daleko od BĻ dolazi do mijeÅ”anja razliÄitih mehanizama zapinjanja vrtloga. Sažeto se razmatra utjecaj ovih saznanja na buduÄe pojaÄanje zapinjanja vrtloga u nanostrukturiranim Bi2223 i MgB2 supravodiÄima
KOPB ā deskriptivna retrospektivna analiza pacijenata lijeÄenih na Odjelu za pluÄne bolesti OB Virovitica u razdoblju od 2006. Ā 2007. (COPD: Descriptive and Retrospective Analysis of Patients that have been trated in Department of Pulmonary Diseases in GH Virovitica for the period 2006 Ā 2007)
Cilj: KroniÄna opstruktivne pluÄna bolest (KOPB) je veliki problem za pacijente i nacionalne zdravstvene sustave. KOPB je znaÄajan uzroÄnik mortaliteta, morbiditeta i bolniÄke potroÅ”nje diljem svjetla. To je globalni zdravstveni problem, koji Äe se poveÄavati u buduÄnosti (1). Rano otkrivanje, ranije zapoÄinjanje lijeÄenja i pravilno praÄenje poveÄava kvalitetu zdravstvene zaÅ”tite oboljelih i smanjuje potrebe za bolniÄkim lijeÄenjem. Cilj je bio istražiti navedene parametre kod pacijenata koji su lijeÄeni na Odjelu za pluÄne bolesti OpÄe bolnice Virovitica u periodu 2006.-2007. Ā Metode: retrospektivnom deskriptivnom analizom za razdoblje 2006.-2007. godine analizirani su slijedeÄi podaci: ukupan broj lijeÄenih bolesnika, broj pacijenata lijeÄenih zbog KOPB, dobna i spolna struktura pacijenata, broj ostvarenih bolno-opskrbnih dana, prosjeÄno vrijeme lijeÄenja u bolnici i broj umrlih.Rezultati: Tijekom analiziranog razdoblja na Odjelu ukupno je lijeÄeno 1314 bolesnika, 260 (19,8%) ispisano je s prvom dijagnozom KOPB. Ukupno je ostvareno 14907 bolno-opskrbnih dana od Äega bolesnici s KOPB Äine 2771 (18,6%). Ukupni prosjek lijeÄenja bio je 11,3 dana. Prosjek lijeÄenja pacijenata s KOPB iznosio je 10,7 dana. Ā ZakljuÄak: KOPB je javnozdravstveni problem u VirovitiÄko-podravskoj županiji. Potrebno je osmisliti i provesti sustavne mjere s ciljem prevencije i ranog otkrivanja KOPB u opÄoj populaciji. Dodatnom edukacijom riziÄnih skupina i zdravstvenog osoblja te Å”to ranijim zapoÄinjanjem terapijskog postupka treba usporiti progresiju bolesti i smanjiti broj hospitaliziranih bolesnika
Percutaneous Coronary Intervention Registry in University Hospital Centre Sestre milosrdnice
UnatoÄ Äinjenici da je koronarna bolest srca (KBS) prvi uzrok smrtnosti, u Hrvatskoj ne postoji sveobuhvatni registar osoba koje boluju od KBS, a registre za perkutanu koronarnu intervenciju (PCI) imaju samo pojedini laboratoriji za kateterizaciju srca, koji se znaÄajno razlikuju i nisu meÄusobno kompatibilni. Laboratorij za invazivnu i intervencijsku kardiologiju KliniÄkog bolniÄkog centra Sestre milosrdnice 1. sijeÄnja 2011. godine je oformio vlastiti registar za PCI. Ovaj registar dostupan je u elektroniÄkom obliku, s visokim stupnjem zaÅ”tite pristupa. U registar se upisuje 45 razliÄitih podataka koji su podijeljeni u pet skupina: opÄi podaci, Äimbenici rizika, simptomi i znakovi akutne bolesti, zahvat i utroÅ”eni materijal te dijagnostiÄki i terapijski nalaz. Osnovne razlike ovog registra, u odnosu na postojeÄe, jest model prema kojem je upis podataka za svakog bolesnika podijeljen izmeÄu medicinskog tehniÄara, inžinjera medicinske radiologije i intervencijskog kardiologa, izrazita jednostavnost, kratko vrijeme potrebno za upis te istovremeno ispisivanje nalaza kateterizacije. Tek nakon Å”to su ispunjeni svi traženi podaci intervencijski kardiolog upisuje dijagnozu i nalaz te se podaci zakljuÄavaju. Na taj smo naÄin osigurali da se u bazu podataka upisuju sve varijable vezane uz svaku pojedinaÄnu uÄinjenu intervenciju, mogu ispisati u Excel ekstenziji te implementirati u bilo koji registar.
Nakon prve godine uporabe zakljuÄili smo da je Registar znaÄajno olakÅ”ao svakodnevni rad te da predstavlja nadopunu novih tehnologija uvedenih u lijeÄenje KBS. Formiranje ovog Registra samo je korak prema zajedniÄkom cilju, formiranju nacionalnog registara PCI te sudjelovanju Republike Hrvatske u europskom registru bolesnika s akutnim koronarnim sindromom.Despite the fact that coronary heart disease (CHD) is the first cause of mortality, in Croatia there is no comprehensive registry of patiens with CHD, while the registries for percutaneous coronary intervention (PCI) are maintained only by specific cardiac catheterization laboratories, which greatly differ from each other and are not mutually compatible. Laboratory of Invasive and Interventional Cardiology of the University Hospital Centre Sestre milosrdnice established its own PCI registry from 1st January 2011. This registry is available in electronic format, with a high access protection level. The registry includes 45 different data which are divided into 5 groups: general data, risk factors, symptoms and signs of acute disease, procedure and materials used, and diagnostic and therapeutic results. The main differences of this registry compared to the existing registries is a model according to which the entry of data for each patient are divided between the medical technician, medical radiology engineer and interventional cardiologist, its utmost simplicity, short time required for the registration and writing the findings of catheterization at the same time. Only after all the required data have been filled in, the interventional cardiologist will enter a diagnosis and findings and the data are locked. In this way we have ensured that all the variables relating to each individual intervention performed are entered in the database, they can be written in Excel extension and implemented in any registry.
After the first year of use, we have reached a conclusion that the Registry has greatly facilitated the daily work and that is complements the new technologies introduced in the treatment of CHD. The establishment of this Registry is only a step towards a common goal, establishment of the national PCI registry and participation of the Republic of Croatia in the European registry of patients with acute coronary syndrome
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