Trends in lung cancer incidence and mortality in Croatia, 1988-2008

Aim To describe and interpret lung cancer incidence and mortality trends in Croatia between 1988 and 2008. Methods Incidence data on lung cancer for the period 1988-2008 were obtained from the Croatian National Cancer Registry, while mortality data were obtained from the World Health Organization mortality database. Population estimates for Croatia were obtained from the Population Division of the Department of Economic and Social Affairs of the United Nations. We also calculated and analyzed age-standardized incidence and mortality rates. To describe time incidence and mortality trends, we used joinpoint regression analysis. Results Lung cancer incidence and mortality rates in men decreased significantly in all age groups younger than 70 years. Age-standardized incidence rates in men decreased significantly by -1.3% annually. Joinpoint analysis of mortality in men identified three trends, and average annual percent change (AAPC) decreased significantly by -1.1%. Lung cancer incidence and mortality rates in women increased significantly in all age groups older than 40 years and decreased in younger women (30-39- years). Age-standardized incidence rates increased significantly by 1.7% annually. Joinpoint analysis of age-standardized mortality rates in women identified two trends, and AAPC increased significantly by 1.9%. Conclusion Despite the overall decreasing trend, Croatia is still among the European countries with the highest male lung cancer incidence and mortality. Although the incidence trend in women is increasing, their age standardized incidence rates are still 5-fold lower than in men. These trends follow the observed decrease and increase in the prevalence of male and female smokers, respectively. These findings indicate the need for further introduction of smoking prevention and cessation policies targeting younger population, particularly women

Influenza della castrazione sulle caratteristiche qualitative della carne di vitello Holstein

Cilj ovog istraživanja bio je ustanoviti utjecaj kastracije muške junadi holštajn pasmine na površinu i fizikalne karakteristike mišića m. longissimus dorsi (MLD). Istraživanje je bilo provedeno na 24 juneta, od kojih je 10 jedinki bilo kastrirano pri prosječnoj tjelesnoj masi od 220 kg. Obje pokusne skupine junadi držane su u istim smještajnim i hranidbenim uvjetima, a ukupno trajanje tova iznosilo je 14 mjeseci. Nakon klanja i hlađenja trupova izvršeno je mjerenje površine, pH vrijednosti, boje, gubitka mesnog soka i kala kuhanja na MLD-u između 12. i 13. rebra. Istraživanjem je utvrđena značajno veća površina MLD-a kod bikova za 10,9% u odnosu na kastrate. Pokazatelji boje L* i b* bili su značajno veći u kastrata, dok se vrijednosti pH i a* mjerene 24 sata nakon klanja nisu značajno razlikovale između skupina. Kalo kuhanja bio je značajno veći u bikova za 15,3 % u odnosu na kastrate. Utvrđen je značajno veći iznos gubitka mesnog soka u kastrata nakon jednog, dva i pet dana čuvanja u hladnjaku za 100,6, 47,0 i 24,9% u odnosu na bikove. Međutim, nakon 7 dana čuvanja u hladnjaku ukupni gubitak mesnog soka nije se značajno razlikovao između skupina. Detaljnijom analizom ustanovljena je značajno veća dnevna razlika iznosa gubitaka mesnog soka u kastrata tijekom prvog dana čuvanja, potom su dnevne razlike bile ujednačene, a tijekom sedmog dana dnevna razlika bila je značajno veća u bikova. Prema dobivenim rezultatima možemo zaključiti da je meso kastrata svjetlije boje s većim gubitkom mesnog soka, ali manjim kalom kuhanja u odnosu na meso bikova.The aim of this paper was to establish the effect of the castration of Holstein young bulls on eye-muscle area and physical characteristics of longissimus muscle. Research was carried out on 24 young bulls, from which 10 were castrated at proximate body weight of 220 kg. Both experimental groups were kept in the same conditions during the total fattening period of 14 months. Eye-muscle area, pH value, colour, drip loss and cooking loss were determined after slaughter and carcass cooling on longissimus muscle between 12th and 13th rib. It was found that bulls had significantly higher longissimus muscle area for 10.9% compared to castrates. Colour traits L* and b* were significantly higher in castrates, while pH value and a* measured 24 h post mortem did not differ among groups. Cooking loss was higher in bulls for 15.3% compared to castrates. Significantly higher drip loss was determined in castrates after one, two and five days of storage in refrigerator for 100.6, 47.0 and 24.9%, respectively. However, drip loss measured after 7 days of storage did not differ between experimental groups. A thorough analysis showed that significantly higher daily difference of drip losses was found in castrates during first day of storage; then the daily differences were similar, and during 7th day there was higher daily difference of drip losses in bulls. According to the results obtained we can conclude that castrates had lighter (paler) meat with higher drip loss, but smaller cooking loss compared to bulls.Das Ziel dieser Arbeit war, den Einfluss von Kastration der Jungstiere der Holstein Rasse auf die Oberfläche und physikalische Charakteristiken der Muskel m. longissimus dorsi (MLD) zu bestimmen. Die Untersuchung wurde auf 24 Stück Jungvieh durchgeführt, von denen 10 Stück bei durchschnittlicher Körpermasse von 220 kg kastriert wurden. Beide Jungvieh -Experimentgruppen wurden in denselben Fütterungs- und Unterbringungsbedingungen gehalten, die Gesamtdauer der Mast war 14 Monate. Nach Schlachten und Kühlen der Rümpfe wurden die Fläche, pH Wert, Farbe, Abscheiden des Fleischsaftes und Kalo des Kochen auf MLD zwischen Rippen 12. und 13. gemessen. Die Untersuchung zeigte eine bedeutend größere Fläche des MLD bei Stieren um 10,9 % in Bezug auf die Kastrate. Die Farbenindikatoren L* und b* waren bedeutend größer bei Kastraten, während die pH Werte und a* gemessen 24 Stunden nach dem Schlachten keine bedeutenden Unterschiede zwischen den Gruppen zeigten. Der Kalo des Kochens war bedeutend größer bei Stieren um 15,3 % in Bezug auf die Kastrate. Es ist auch ein bedeutend größerer Verlust von Fleischsaft bei Kastraten nach einem Tag, zwei und fünf Tagen des Aufbewahrens im Kühlschrank um 100,6, 47,0 und 24,9% in Bezug auf die Stiere festgestellt. Jedoch, nach 7 Tagen des Aufbewahrens im Kühlschrank unterschied sich der Verlust von Fleischsaft bei den Gruppen nicht. Durch Detaillanalyse wurde festgestellt, dass ein größerer täglicher Verlust des Fleischsaftes bei Kastraten im Laufe des ersten Tages des Aufbewahrens stattfand, danach wurden die täglichen Verlüste ausgeglichener und nach dem siebten Tag war der Tagesunterschied bedeutend größer bei Stieren. Laut bekommenen Resultate kann man feststellen, dass das Fleisch der Kastrate heller ist, mit größerem Verlust des Fleischsaftes, jedoch mit kleinerem Kalo des Kochens, in Bezug auf das Fleisch der Stiere.L’obiettivo di questa ricerca è stato quello di determinare l’influenza della castrazione dei vitelli maschi Holstein sulla superficie e sulle caratteristiche fisiche del muscolo m. longissimus dorsi (MLD). La ricerca è stata condotta su 24 vitelli, di cui 10 vitelli sono stati castrati con un peso medio di 220 kg. Entrambi i gruppi di prova, della durata complessiva dell’allevamento di 14 mesi, sono tenuti nelle stesse condizioni di alloggio e di alimentazione. Dopo la macellazione e il raffreddamento delle carcasse sono eseguite le misurazioni della superficie, del valore di pH, del colore, della perdita di gocciolamento (drip loss) e della perdita di liquido per cottura (cooking loss) nel MLD tra la 12a e la 13a costola. La ricerca ha presentato una maggiore superficie (10,9 %) del MLD nei vitelloni rispetto ai castrati. Gli indici del colore L* e b* sono risultati maggiori nei vitelli castrati, mentre il valore di pH e il valore di a* misurati 24 ore dopo la macellazione non hanno evidenziato differenze significative tra i due gruppi. La perdita di liquido per cottura (cooking loss) è risultata notevolmente maggiore (15,3%) nei vitelloni rispetto ai castrati. La perdita di gocciolamento (drip loss) è risultata maggiore nei castrati dopo uno, due e cinque giorni di conservazione in frigorifero (100,6, 47,0, 24,9) rispetto ai vitelloni. Invece, dopo 7 giorni di conservazione in frigorifero la perdita di gocciolamento totale non ha evidenziato differenze significative tra i gruppi. L’ analisi più dettagliata ha rivelato una maggiore differenza nell’apporto della perdita di gocciolamento al giorno nei castrati durante il primo giorno di conservazione, poi le differenze al giorno si sono uniformate e durante il settimo giorno la differenza al giorno è risultata notevolmente maggiore nei vitelloni. Gli esiti ottenuti consentono di concludere che la carne dei castrati è di un colore più chiaro e presenta un maggiore gocciolamento, ma una minore perdita di cottura rispetto alla carne dei vitelloni

Razlike u mikoflori na ovitcima trajnih fermentiranih kobasica prije i šest mjeseci nakon skladištenja u hladnjaku

During the curing period of dry-fermented sausages, the surface mycoflora changes according to the environmental conditions and intrinsic factors, such as nutrient content, water activity, pH value and the presence of antimicrobial substances (starter cultures). In this study, 25 samples of dry-fermented sausages from Croatian family small holdings were examined, the casings peeled off and examined for mycobiota before and after six months of refrigerated storage in plastic bags, at +4 °C in darkness, at a low humidity and evaporation rate. For mycobiota identification, traditional (macroscopic and microscopic) and molecular (Polymerase Chain Reaction, PCR) methods were combined. At the beginning of the study (after sausage curing), the prevalent isolated species were from the genera Penicillium (74%), Aspergillus 14% and Mucor (12%). After the six month period, a different mould structure was observed, with the dominant isolation of Aspergillus genus (64%), followed by the genera Penicillium (34%) and Mucor (2%). In comparison with the literature data, it can be concluded that the casing mycoflora on dry-fermented sausages stored in the refrigerator changed in the same way as if they not been refrigerated, though the process of mycoflora change was slower with refrigeration.Tijekom razdoblja zrenja trajnih fermentiranih kobasica mikoflora koja obrasta i prekriva njihovu površinu mijenja se u ovisnosti o uvjetima okoliša i “unutarnjim čimbenicima”, koji uključuju sadržaj hranjivih sastojaka, aktivitet vode, pH vrijednost i prisutnost antimikrobnih tvari (starter kulture). U ovom je istraživanju uzorkovano dvadeset i pet parova trajnih fermentiranih kobasica s malih hrvatskih obiteljskih poljoprivrednih gospodarstava, odljušten je njihov ovitak te je ispitivana mikoflora prije i nakon skladištenja u hladnjaku tijekom šest mjeseci, u plastičnim vrećicama, na +4 °C, u tami, pri maloj vlažnosti i brzini isparavanja. Za identifikaciju plijesni kombinirane su tradicionalne (makroskopske i mikroskopske) i molekularne (lančana reakcija polimeraze, PCR) metode. Na početku istraživanja (nakon sazrijevanja i uzimanja uzoraka kobasica) prevladavale su izolirane vrste iz roda Penicillium (74 %), Aspergillus 14 % i Mucor (12 %). Nakon razdoblja od šest mjeseci uočena je drugačija struktura plijesni, pri čemu je pretežno izoliran rod Aspergillus (64 %), a zatim Penicillium (34 %) i Mucor (2 %). Sagledavajući literaturne podatke može se zaključiti da se mikoflora na ovitcima trajnih fermentiranih kobasica pohranjenih u hladnjaku mijenjala na isti način kao što bi se i mijenjala bez pohranjene u hladnjaku, jedino što bi proces promjena mikoflore vremenski trajao kraće

WEIGHT GAIN IN LUNG TRANSPLANTATION PATIENTS DURING THE COVID-19 PANDEMIC IN CROATIA

Background: To determine the effect of lockdown measures on lung transplant patients during the COVID-19 pandemic. Subjects and methods: We collected data from Croatian lung transplant patients before and after the lockdown and analyzed changes in weight, BMI, lung function and blood lipid status. Results: An average increase of 3.74 kg (+4.92%) body weight during the 4 month lockdown period was observed. Lung function values and blood lipid status remained stable. Conclusion: Such weight gain could have detrimental effects on the morbidity and mortality of lung transplant patients. Further follow up is needed to determine the long term impacts of this observation

WEIGHT GAIN IN LUNG TRANSPLANTATION PATIENTS DURING THE COVID-19 PANDEMIC IN CROATIA

Background: To determine the effect of lockdown measures on lung transplant patients during the COVID-19 pandemic. Subjects and methods: We collected data from Croatian lung transplant patients before and after the lockdown and analyzed changes in weight, BMI, lung function and blood lipid status. Results: An average increase of 3.74 kg (+4.92%) body weight during the 4 month lockdown period was observed. Lung function values and blood lipid status remained stable. Conclusion: Such weight gain could have detrimental effects on the morbidity and mortality of lung transplant patients. Further follow up is needed to determine the long term impacts of this observation

THE EFFECT OF CASTRATION ON FEEDLOT PERFORMANCE AND CARCASS CHARACTERISTICS OF HOLSTEIN YOUNG BULLS

Cilj rada bio je utvrditi utjecaj kastracije muške junadi holštajn pasmine na rezultate tova i odlike trupova na liniji klanja. Istraživanjem je utvrđeno da su kastrirana junad pri prosječnoj dobi od 420 dana imala značajno manju klaoničku masu, topli randman i kalo hlađenja (P<0,05). Na liniji klanja nije utvrđena značajna razlika u klasi i stupnju zamašćenosti između kastrirane i nekastrirane junadi. Utvrđen je značajno veći (P<0,05) neto dnevni prirast nekastrirane (531,43 g/dan) u odnosu na kastriranu junad (461,38 g/dan). Disekcijom rebrenog isječka na razini od 9. do 11. rebra utvrđen je značajno veći (P<0,01) udio masnog s vezinim te manji udio mišićnog tkiva u kastrirane junadi, dočim je udio kostiju bio podjednak u obje istraživane skupine. Kastrirana junad su na presjeku između 6. i 7. rebra imala značajno veću mramoriranost musculus longissimus dorsia (P<0,05). Rezultati ukazuju na negativan utjecaj kastracije holštajnske junadi na prirast i većinu istraživanih kvalitativnih parametara trupa osim na kalo hlađenja i mramoriranost mesa.The aim of this study was to determine the effect of castration of Holstein young bulls on the fattening results and carcass characteristics at slaughter. Steers at average age of 420 days had significantly lower slaughter weight, hot dressing percentage and chilling loss (P<0.05). Carcass conformation score and carcass fatness were not different between steers and bulls. Bulls had significantly higher (P<0.05) net daily gain (531.43 g/day) compared to steers (461.38 g/day). Dissection of rib clip between 9th and 11th rib showed significantly higher (P <0.01) proportion of fat and connective tissue and lower proportion of muscle tissue in steers, while the proportion of bone was similar in both studied groups. It was found that steers had significantly higher marbling of the musculus longissimus dorsi at the intersection between 6th and 7th ribs (P <0.05). These results indicate the negative effect of castration of Holstein bulls on daily gain and most of the studied parameters except the chilling loss and marbling in meat

L\u27effetto del tipo di pavimento sulle caratteristiche delle carcasse e sulla qualità della carne della razza bovina Simmental dell\u27allevamento intensivo

U radu je istraživan utjecaj vrste poda na svojstva trupa i kakvoću mesa simentalskih bikova iz intenzivnog sustava proizvodnje goveđeg mesa u Republici Hrvatskoj. Tijekom tova životinje su držane u zajedničkim boksovima na cementnom rešetkastom podu (RP skupina, n=15) ili na punom podu uz steljenje slamom (PP skupina, n=15). Prosječna podna površina po biku iznosila je 4.7 m2 u RP i 6.0 m2 PP skupini. Hranidba je bila u obliku kompletno izmiješanog obroka sastavljenog iz silaže kukuruznog zrna i čitave stabljike, super-koncentrata i sijena (prosječni sastav po kg: 599 g of ST, 76 g of SP i 4.59 MJ of ME). Bikovi su zaklani pri sličnoj dobi (494±17 dana) i završnoj tjelesnoj masi (597,5±56,4 kg) te su utvrđena svojstva trupa (klaonička masa topla, klaonički randman %, EUROP klasifikacija trupova). Boja (CIE L*a*b*) i pH mesa izmjereni su na Longissimus thoracis mišiću 24 h post mortem u razini 8.-og rebra. Isti je mišić uzorkovan za kemijsku analizu sadržaja suhe tvari, proteina, pepela, ukupnog željeza te sadržaja intramuskularne masti. Podatci su obrađeni Studentovim t-testom. Generalno, u istraživanju nije utvrđen značajan utjecaj (P>0.05) vrste poda na bilo koje od analiziranih svojstava trupa ili kakvoće i sastava mesa, izuzev za pH24 i sadržaj pepela, čije su vrijednosti bile niže, odnosno više kod RP nego kod PP skupine: 5,61 prema 5,68 (P=0.0168), odnosno 10,53 prema 10,36 g/kg (P=0.0466).This study investigated the effect of floor type on carcass and meat quality of intensively reared Simmental bulls. The animals were housed in common pens on a concrete slatted floor (SF group, n=15) or a full floor with straw bedding (FF group, n=15). The space allowance in SF and FF groups was 4.7 and 6.0 m2 per bull, respectively. Diet in both groups was given as total mixture ration composed from maize grain and stalk silage, super-concentrate and hay (average composition per kg: 599 g of DM, 76 g of crude protein and 4.59 MJ of ME as feed). After the slaughter at similar age (494±17 days) and final body weight (597.5±56.4 kg), the carcass traits (hot carcass weight, dressing-out %, EUROP classes distribution) were determined. Meat pH and colour (CIE L*a*b*) was measured at the Longissimus thoracis muscle 24 h post mortem at the level of the 8th rib. The same muscle was sampled for chemical analysis of dry matter, protein, ash, total iron and intramuscular fat content. Data were analyzed by Student’s t-test. In general, there was no significant effect (P>0.05) of floor type on any of carcass or meat quality traits and chemical composition, except for meat pH24 value and ash content, which in SF group shoved respectively lower and higher results than in the FF group: 5.61 vs. 5.68 (P=0.0168) and 10.53 vs. 10.36 g/kg (P=0.0466).In dieser Arbeit wurde der Einfluss der Bodenart auf Eigenschaften und Fleischqualität der Simmentaler Fleckviehstiere aus intensivem System der Herstellung von Rindfleisch in Republik Kroatien untersucht. Während der Mast wurden die Tiere in gemeinsamen Boxen auf gitterförmigem Zementboden (RP Gruppe, n=15) oder auf vollem Boden mit Strohstreu (PP Gruppe n=15) gehalten. Die durchschnittliche Bodenfläche pro Stier betrug 4.7 m2 in RP Gruppe und 6.0 m2 in PP Gruppe. Die Fütterung erfolgte in Form von kompletten gemischten Portionen, zusammengesetzt aus Ensilage der Maiskörner und der ganzen Stiele, Superkonzentrat und Heu (durchschnittliche Zusammensetzung pro kg: 599 gof ST, 76 g of SP und 4.59 MJ of ME). Die Stiere wurden im ähnlichen Alter (494 ± 17 Tage) und in ähnlicher körperlicher Endmasse (597±56,4 kg) geschlachtet und es wurden die Eigenschaften des Rumpfes bestimmt (Schlachtmasse warm, Schlachtrandman %, EUROP Klassifikation der Rümpfe). Farbe (CIE L *a*b*) und pH des Fleisches wurden auf der Muskel Longissimus thoracis 24 Stunden post mortem in der Ebene der 8. Rippe gemessen. Dieselbe Muskel wurde zur Musterprobe für chemische Analyse des Gehaltes von Trockensubstanz, Proteine, Asche, Gesamteisen und intramuskulärem Fett genommen. Die Angaben wurden mittels Student-t-Test verarbeitet. Generell gesehen, es wurde kein bedeutender Einfluss (P>0.05) von Art des Bodens auf irgendwelche der analysierten Eigenshaften des Rumpfes oder auf Qualität und Zusammensetzung des Fleisches festgestellt, außer für pH24 und Aschegehalt, deren Werte niedriger bzw. höher bei RP als bei PP Gruppe waren: 5,61 gegen 5,68 (P=0.0168), bzw. 10,53 gegen 10,36 g/kg (P=0.0466).Nel presente lavoro è stato esaminato l\u27effetto del tipo di pavimento sulle caratteristiche delle carcasse e sulla qualità della carne della razza bovina Simmental dell\u27allevamento intensivo nel sistema di produzione della carne bovina in Repubblica di Croazia. Durante l\u27allevamento gli animali sono tenuti in box comuni su un pavimento grigliato-fessurato in cemento (il gruppo RP, n=15) o su un pavimento pieno con lettiera di paglia (il gruppo PP, n=15). La superficie media per un vitello è stata 4,7 m² nel gruppo RP e 6.0 m² nel gruppo PP. Sono stati alimentati con un pasto completamente mescolato dell\u27insilato di mais (granella e stelo), super-concentrato e fieno (la composizione media al kg: 599 g di ST, 76 g di SP e 4,59 MJ di ME). I bovini sono stati macellati all\u27età (494±17 giorni) e al peso finale simili (597,5±56,4 kg) e sono state determinate le caratteristiche delle carcasse (il peso a caldo della carcassa alla macellazione, la % di randman, la classificazione (EUROP) delle carcasse). Il colore (CIE L*a*b*) e il valore di pH della carne sono stati misurati 24 ore post mortem sul muscolo Longissimus thoracis a livello dell\u27ottava costa. Sullo stesso campione è stata effettuata l\u27analisi chimica della sostanza secca, delle proteine e delle ceneri, del ferro totale e del contenuto di grasso intramuscolare. I dati sono stati elaborati con il test t di Student. In generale, la ricerca non ha indicato un effetto di rilievo (P>0.05) del tipo di pavimento su qualsiasi caratteristica analizzata della carcassa o della qualità e la struttura della carne, eccetto per il valore di pH e per il contenuto delle ceneri, i cui valori sono stati inferiori nel gruppo PP rispetto al RP: 5,61:5,68 (P=0,0168), ovvero 10,53:10,36 g/kg (P=0.0466)

Klinička obilježja i preživljenje bolesnika s malignim mezoteliomom pleure – iskustvo jednog centra

Maligni pleuralni mezoteliom rijetka je i agresivna primarna novotvorina mezotelnih stanica pleure. Glavni rizični čimbenik je izloženost azbestu, najčešće uz latenciju od 30–50 godina. Unatoč terapiji medijan preživljenja je od 4 do 18 mjeseci, ovisno o izvoru. Cilj istraživanja bio je odrediti karakteristike bolesnika oboljelih od malignoga pleuralnog mezotelioma te ishode njihova liječenja na KBC Zagreb u razdoblju od 1999. do 2012. godine. Ispitane su karakteristike 101 bolesnika dijagnosticiranog i liječenog na KBC Zagreb u razdoblju od rujna 1999. do rujna 2012. Analizirali smo ukupno preživljenje (OS), preživljenje bez progresije bolesti (PFS) te preživljenje ovisno o histološkom podtipu tumora, dobi, kliničkom stadiju, pleurodezi talkom i modalitetu liječenja. Koristili smo Kaplan-Meierovu metodu za izradu krivulje preživljenja. 89 bolesnika bilo je muškog, 12 ženskog spola, a medijan dobi 62 godine. Prema TNM klasifikaciji stadij IV je utvrđen kod 69,3%, stadij III kod 26,73%, te stadij II kod samo 3,96% bolesnika. 73,26% bolesnika imalo je epiteloidni, 4,95% sarkomatoidni, 1% mješoviti te 20,79% NOS (nespecifirani) histološki podtip bolesti. Kirurški je liječeno 14,85% bolesnika, kemoterapijom 55,44%, dok je radioterapija primijenjena kod 9,9% bolesnika. Medijan OS iznosi 11 mjeseci, dok je PFS 10 mjeseci. Prema histološkom podtipu medijan OS iznosio je 11 mjeseci za epiteloidni, 12,5 za NOS te 5,5 za sarkomatoidni, a prema kliničkom stadiju 7 mjeseci za stadij II, 17,5 mjeseci za stadij III te 11 mjeseci za stadij IV. Medijan OS bio je dulji u skupini bolesnika mlađoj od 65 godina (12 naspram 8,5 mjeseci, p=0.28), skupini sa učinjenom pleurodezom (13 naspram 7,5 mjeseci, p=0.06) te u skupini liječenoj kemoterapijom (12,5 naspram 7,5 mjeseci, p=0.10). Očekivano preživljenje bolesnika oboljelih od malignoga pleuralnog mezotelioma u Republici Hrvatskoj u skladu je s podatcima iz literature. Ispitane metode liječenja relativno skromno utječu na preživljenje bolesnika

Advanced gate driving concepts and switching optimization for SiC semiconductors

Silicon carbide (SiC) MOSFETS are increasingly favoured in power electronics for their improved properties compared to silicon-based counterparts, such as IGBTs. Their ability to operate at higher switching frequencies and execute faster switching transients is notable. However, these features also raise significant concerns with electromagnetic interference (EMI). To exploit the full capabilities of SiC-based technology, meticulous design strategies encompassing the power stage, commutation loop, and gate drive are essential. This paper conducts a comprehensive review of existing gate drive techniques aimed at enhancing the performance of SiC devices. Moreover, this study introduces an innovative approach for optimizing switching processes through the use of active gate drivers (AGD). By pre-mapping the gate-source voltage profiles for different conditions (such as load current, temperature, and DC-link voltage), it is possible to achieve a significantly improved switching trajectory. This optimization process can be applied on a cycle-by-cycle basis in practical scenarios. Herein, pre-mapping and optimization have been experimentally confirmed in a half-bridge configuration. Through simulation, it is demonstrated that optimizing the switching trajectory can lead to a balanced compromise between EMI and switching losses, showcasing the potential for significant performance enhancements in SiC device operation