Mechanical properties of materials for 3D printed orthodontic retainers

Aim: The purpose of this study was to compare the mechanical properties of materials used for orthodontic retainers made by direct 3D printing and thermoforming. Materials and methods: Twenty-one specimens (n=7) from 3 different materials (Formlabs Dental LT Clear V2 - Formlabs Inc., Somerville, Massachusetts, USA; NextDent Ortho Flex - Vertex-Dental B.V., Soesterberg, The Netherlands, and Erkodent Erkodur - ERKODENT, Germany) were manufactured and their mechanical properties were evaluated. Two of the specimen groups were 3D printed and the other one was fabricated using a material for thermoforming. The statistical methods we applied were descriptive statistics, the Kruskal-Wallis and Dunn’s post-hoc tests. Results: With respect to Young’s modulus (E), the Kruskal-Wallis test (df=2, χ2=17.121, p=0.0002) showed a significant difference between the materials for direct 3D printing of orthodontic retainers (E=2762.4 MPa±115.16 MPa for group 1 and 2393.05 MPa±158.13 MPa for group 2) and thermoforming foils (group 3, E=1939.4 MPa±74.18 MPa). Statistically significant differences were also found between the flexural strength (FS) (Kruskal-Wallis test, df=2, χ2=17.818, p=0.0001) and F(max) (Kruskal-Wallis test, df=2, χ2=17.818, p=0.0001). Conclusions: The materials tested in the current study showed statistically significant differences in their Young’s modulus, flexural strength, and F(max)

Istraživanje nekih antidota i laboratorijskih pokazatelja pri pokusnom otrovanju pilića ohratoksinom A i penicilinskom kiselinom.

The objects of this study were the main haematological and biochemical changes in experimental ochratoxicosis in 85 broiler chicks fed on a diet containing: 130, 300 and 800 ppb ochratoxin A (OTA) and 1000-2000 ppb penicillic acid (PA), corresponding to those in the field. Biochemical and haematological changes were characteristic in increased serum levels of uric acid and glucose, decreased serum levels of cholesterol and total protein, and slight normocyte anaemia. These changes were induced by several times lower contamination levels of OTA in feed than the levels described in literature of pure OTA, due to the probable synergism between OTA and PA. A positive protective effect of 5% total water extract of Artichoke and Rosallsat against the toxic effect of OTA was established.Istraživane su glavne hematoloske i biokemijske promjene u pokusnoj ohratoksikozi u 85 pilića koji su u hrani primali 130, 300 i 800 ppb ohratoksina A (OTA) i 1000-2000 ppb penicilinske kiseline (PA) te su uspoređeni s nalazima u 20 pilića koji nisu primali OTA i PA. Primijenjeni otrovi su izazvali povišenje razine mokraćne kiseline i krvnog sećera, te smanjenje razine kolesterola i ukupnih bjelančevina u krvnom serumu kao i laganu normocitnu anemiju. Ove promjene su bile izazvane s nekoliko puta manjim koncentracijama OTA u hrani, nego što su opisane u literaturi s čistim OTA, što je vjerojatno posljedica sinergističkog djelovanja OTA i PA. Utvrđeno je pozitivno zaštitno djelovanje 5% vodenog iscrpka artičoke i Rosallsata protiv otrovnog djelovanja ohratoksina A

Siedlungen der späten Bronze- und frühen Eisenzeit in Südwestbulgarien.Vorbericht zu den deutsch-bulgarischen Forschungen 2012 im Struma- und Mestatal

After long-term surveys 2012 a German-Bulgarian team started excavations in the valleys of the rivers Struma and Mesta in south-western Bulgaria. The goal of our research is get a better understanding of the execution of power by the population of these mountain valleys as well as to reveal the processes of transfer and exchange of objects and technologies between the Aegean and the Danube regions. For this reason the excavations were conducted on the Late Bronze/Early Iron Age hillfort Kresna in the Mesta valley near Sandanski and on the Early Iron Age settlement Bresto near Raslog located close to the upper course of the Mesta river. Similar to the hillforts in the valley of Struma near Blagoevgrad, possible large-sized grain storages were exposed in Kresna. Bresto stands out for its massive fortified walls dated to the Early Iron Age as well as for the thousands secondary burnt daub fragments often supplied with plastic decorations. The comparison of various parts of the valleys of the rivers Struma and Mesta demonstrates the difference of interest for foreign objects and the acquisition of technologies on the micro-region levelstatus: publishe

Re-introduction of Griffon Vulture (Gyps fulvus) in the Eastern Balkan Mountains, Bulgaria – completion of the establishment phase 2010-2020

The current study presents and analyses the results from the recently completed 11-year-establishment phase, following the start of the local re-introduction of the Griffon Vulture (Gyps fulvus) in Kotlenska Planina SPA and Sinite Kamani Nature Park in the Eastern Balkan Mountains of Bulgaria in the period 2010-2020. As a result of the re-introduction efforts and release of 153 individuals, the Griffon Vulture has been successfully reproducing again in the Eastern Balkan Mountains since 2016, after more than 40-50 years of absence. At 2020, the local population consists of some 80 local and up to 80-115 birds, together with sojourn individuals. Amongst them, 23-25 breeding pairs, located in five different colonies and two more frequently used roosting sites. The current average productivity remains relatively low: 0.41 fledglings/territorial pair and fledging success of 0.61 fledglings/breeding pair between 2016 and 2020, but shows a trend to increase with time and the growing experience of the young locally re-introduced population. The mortality confirmed between 2010-2021 accounts for 33%, mostly due to electrocution as a post-release effect in the first six months following their release. Our data show that the newly established population in the Eastern Balkan Mountains mostly forages on feeding sites, having a comparatively small 95% home range: 281.88 ± 91 km2 and 50% core area: 6.6 ± 2.28 km2 (range 4.7–8.5 km2). We, therefore, consider the establishment phase of the re-introduction of Griffon Vulture in this particular site as successfully completed, but management should continue. Furthermore, the area of the Eastern Balkan Mountains can currently be regarded as a "source" for the species within the source-sink population regulation concept in the national and Balkan context

Scientific and Practical Conference "Challenges in the Education of Masters of Pharmacy"

Th conference is organised with the fiancial support of European Social Fund within the Project BG051PO001-3.1.07-0046 `Updating and approbation of the curricula of the Faculty of Pharmacy, Medical University of Varna according to the needs of the pharmaceutical business and the requirements of the labor market