Uticaj eksperimentalno zračene hipofize na rast potkolenice, lobanje, gornje i donje vilice pacova

Background/Aim. The reaction of an organism to radiation depends on the level of irradiation and the sensitivity of the affected tissue cells. The biological effects on the cells and tissues are proportional to the absorbed radiation energy. The aim of our study was to examine the effects of hypofunction of the pituitary gland, previously irradiated with x-rays, on the growth of rat’s craniofacial and stomatognathic system as well as rat’s tibia. Methods. A total dose of x-rays of 27.92 Gy was applied in eight sessions in the period from 8 to 63 days of animal age on their heads and the effects of irradiation-induced hypofunction of the pituitary gland on the growth of rat’s craniofacial and stomatognathic system and tibia were examined. In order to differentiate the effects of the irradiated pituitary gland from the direct effects of x-rays on the head, the experiment was set as a double study. One group of animals had the pituitary gland protected with a lead plate set beneath the projection of the gland, while the second group was irradiated with the same dose, but without the protection. The control group of animals were non-irradiated. Results. Growth measurements of numerous parameters of the craniofacial and stomatognathic system as well as tibia in rats with the entire locally irradiated head showed a statistically significant delay, compared to both the non-irradiated control group and the group with the protected pituitary gland. Conclusion. The damage of the stomatognathic and craniofacial system was greater in animals with irradiated head without pituitary gland protection compared to those with the gland protection whereby the growth of the craniofacial system was most affected. Irraduition-induced pituitary gland hypofunction and irradiation itself showed a stronger effect on the lower jaw growth rate impairment compared to the upper jaw. Similarly, the delay in tibia growth was more pronounced in animals without pituitary gland protection during irradiation of their heads compared to non-protected ones.Uvod/Cilj. Reakcija organizma na zračenje zavisi od doze zračenja i osetljivosti ćelija tretiranog tkiva. Biološki efekti zračenja na ćelije i tkiva proporcionalni su apsorbovanoj radijacionoj energiji. Cilj istraživanja je bio da se ispitaju efekti hipofunkcije prethodno x-zracima ozračene hipofize na rast kraniofacijalnog i stomatognatnog sistema pacova. Metode. Primenjena doza x-zračenja od 27,92 Gy aplicirana je na dve grupe pacova u 8 seansi tokom perioda od 8 do 63 dana njihove starosti, uz praćenje efekata zračenja na rast kraniofacijalnog i stomatognatog sistema. U nameri da u merenju brojnih parametara pomenutih sistema razdvojimo efekte ozračene hipofize od direktnih efekata x zraka koje smo primenili na glavu, postavljen je eksperiment sa ozračivanjem glave dvema grupama životinja istim dozama x zraka, ali je jednoj zaštićena hipofiza olovnom pločicom postavljenom iznad hipofiza. Rezultati. Zaostajanje u rastu stomatognatog sistema kod pacova kojima je lokalno ozračena cela glava u odnosu na kontrolne životinje predstavlja zbirni efekat delovanja zračenjem izazvane hipofunkcije hipofize i direktnog delovanja x zračenja, dok zaostajanje u rastu stomatognatog sistema kod pacova sa ozračenom glavom i hipofizom zaštićenom od zračenja predstavlja isključivo efekat x zraka. Zaključak. Oštećenja stomatognatog i kraniofacijalnog sistema bila su veća kod životinja kojima hipofiza tokom zračenja glave nije bila zaštićena u odnosu na one sa zaštitom žlezde prilikom zračenja, pri čemu je rast kraniofacijalnog sistema u sagitalnom pravcu bio najviše pogođen. Veći zaostatak u rastu usled kombinovanoig dejstva hipofunkcije hipofize izazvane zračenjem i samog zračanje ustanovljen je na donjoj vilici u odnosu na gornju vilicu. Slično ovome, zao stajanje u rastu tibije bilo je izraženije kod životinja kojima tokom zračenja cele glave hipofiza nije bila zaštićena u odnosu na neštićene životinje

A bibliometric analysis and future research agenda for online labour platforms

Online labour platforms (OLPs) are profit-oriented companies utilising technology to connect independent contractor workers with short-term service labour needs, offering a digital marketplace for posting tasks, receiving bids, and finalising agreements across various domains such as writing, design, programming, and digital marketing. This paper presents a bibliometric analysis of the concurrent body of knowledge on OLPs, explaining how the specificities of this emerging form of labour are researched from various academic standpoints. The study is based on a dataset of 358 papers on OLPs published from 2013 to August 2023. The main finding of the study is that scholarly interest in OLPs is steadily growing in the observed period. However, geographical dispersion of the scientific output is not in line with the actual level of utilisation of OLPs, and scholarly interest in OLPs spans across diverse disciplines, including industrial relations and labour, management, economics, sociology, law, and computer science. The results of this paper can help better understand the dynamics of scholarly publishing on OLPs and further leverage underexploited subtopics in this field

Effects of the fixed orthodontic therapy on biochemical and microbiological parameters of saliva

Introduction/Objective. Malocclusions are one of the most frequent disorders in dentistry, and pose a risk for the onset of caries and periodontal diseases. Fixed orthodontic treatment solves the problem of malocclusions; however, it requires simultaneous cooperation of the patients, parents, and dentists involved. The objective of this study is to examine the effects of fixed orthodontic therapy on the Streptococcus mutans and Lactobacillus spp. bacteria in saliva, the pH value, and buffering capacity of saliva. Methods. The research was carried out at the Faculty of Medicine in Foča, Department of Dentistry. The study included 100 respondents, aged 13 to 17 years. The respondents were divided into two groups: the study group (respondents wearing fixed braces) and the control group (respondents not subjected to fixed braces therapy). Saliva samples were taken from the respondents four, 12, and 18 weeks after the start of the orthodontic therapy. The study used the bacteria caries risk test (CRT) and CRT buffer (Ivoclar Vivadent). Results. The study showed an increased number of bacteria in saliva of the respondents during all three follow-up periods (χ2 test, p = 0.001). The largest numbers of the Streptococcus mutans and Lactobacillus spp. bacteria were found in week 12 of the therapy. Saliva pH value and buffering capacity of saliva increased statistically significantly in week 12 of the therapy (χ2 test, p = 0.001). Conclusion. Oral conditions in patients changed during the fixed orthodontic therapy: the number of bacteria increased, the pH value and buffering capacity of saliva changed. It was necessary to use preventive measures in order to avoid complications during the fixed orthodontic appliances therapy

Prethodnice sveučilišnoga poduzetništva: empirijski dokazi sa srpskih državnih sveučilišta

The aim of this paper is to portray the effects of individual entrepreneurial orientation of the faculty (professors, teaching assistants and researchers) on entrepreneurial outcomes and outputs of Serbian higher education institutions. Particular objective of the paper is to examine and explore how research mobilization, unconventionality, industry collaboration and university policies affect entrepreneurial outcomes – joint research agreements, contractual agreements, consulting activities, establishment of spin-offs and patenting. For this purpose, primary data were collected at Serbian public universities. In total, 552 respondents correctly fulfilled the questionnaire specifically designed to meet the purpose of the study. The results indicate that entrepreneurial orientation plays a statistically significant role in entrepreneurial outcomes. However, entrepreneurial orientation is more important in commercial than non-commercial research outcomes.Cilj je ovoga rada prikazati utjecaj individualne poduzetničke orijentacije akademika (profesora, asistenata i istraživača) na poduzetničke ishode srpskih institucija visokoga obrazovanja. Posebna zadaća ovoga rada bila je ispitati i istražiti kako pokretanje istraživanja, nekonvencionalnost, suradnja s industrijom i sveučilišna politika djeluju na rezultate u poduzetništvu – zajedničke istraživačke sporazume, ugovorna istraživanja, aktivnosti savjetovanja, osnivanje tvrtki kćeri (spin-off) i patentiranje. Za tu svrhu sakupljeni su primarni podatci na srpskim državnim sveučilištima. Ukupno je 552 ispitanika točno ispunilo upitnike osmišljene za potrebe ovoga istraživanja. Rezultati pokazuju da poduzetnička orijentacija ima statistički značajnu ulogu u poduzetničkim ishodima te da je poduzetnička orijentacija važnija u komercijalnim nego u nekomercijalnim istraživačkim ishodima

Laser treatments of Nimonic 263 nickel-based superalloy

U ovom radu, proučavan je uticaj parametara određenih procesa laserske tehnike obrade materijala superlegure Nimonic 263 - bušenje, rezanje, zavarivanje i mehanička obrada laserom. Bušenje i zavarivanje su vršeni na laseru Nd:YAG laserom model HTS Mobile LS-P160. Prilikom bušenja rupa varirani su parametri frekvencije impulsa (5 Hz, 7Hz i 9 Hz) i dužine trajanja impulsa (1,8 ms do 3,6 ms). Ispitivana je mikrostruktura i određene su geometrijske i metalurške karakteristike rupa dobijenih ovim parametrima, na osnovu čega je izvršena optimizacija parametara obrade. Rezanje je izvedeno na laseru tipa Bistronic laser, (2000), BISTAR 3015. Varirani su parametri srednje snage lasera, brzina lasera, pritisak gasa i položaj fokusa. Na osnovu dobijenih geometrijskih karakteristika rezova i površinske morfologije diskutovani su i određeni optimalni parametri. Laserom zavareni spojevi limova legure Nimonik 263 su, osim mikroskopskih i profilometrijskih ispitivanja površina, ispitivani i metodom sa razaranjem. Prilikom laserskog deformacionog ojačavanja uzorci su bili izloženi laserskom svetlu na talasnoj dužini od 1064 nm i 532 nm, sa brojem akumuliranih impulsa: 50, 100 i 200. U svim delovima eksperimenta strukturna analiza superlegure Nimonic 263 izvedena je pomoću svetlosne mikroskopije (SM), skenirajuće elektronske mikroskopije (SEM) i EDS-analize. Merenja mikrotvrdoće vršena su pomoću metode Vikersa pod opterećenjem od 9,81N. Profilometrija je izvedena na beskontaktnom profilometru Zygo NewView 7100.In this paper, the influence of parameters of laser processing (drilling, cutting, welding and laser shock peening) on microstructure of superalloy Nimonic 263 are investigated. Drilling and welding process are carried out on the Nd: YAG laser model LS-HTS Mobile P160. When drilling the holes, the parameters of pulse frequency (5 Hz, 7 Hz and 9 Hz) and the pulses duration (1.8 ms to 3.6 ms) are varied. The microstructure is investigated and geometrical and metallurgical characteristics of the holes are determined.Cutting is carried out on the laser BISTRONIC, (2000), BISTAR 3015. The parameters that were varied are as follows: the average laser power, laser velocity, the pressure of the assisting gas and the focus position. Based on the geometrical characteristics of the cuts and surface morphology the optimal parameters are discussed and defined. The laser welded joints of Nimonic 263, in addition to microscopic examination and surface profilometry, were subjected to the destructive testing. During the laser shock peening, the samples were exposed to laser light at a wavelength of 1064 nm and 532 nm, with the number of accumulated pulses 50, 100 and 200. The operating laser was Nd: YAG EKSPLO, SL212P model. Structural analysis of Nimonic 263 was carried out using light microscopy, scanning electron microscopy and EDS analysis. Microhardness measurements were carried out using the Vickers method under load of 9,81N. Profilometry was performed on a contactless profilometer Zygo Newview 7100

Učestalost malokluzija i stanje dentalnog zdravlja kod osmogodišnjaka na području opštine Foča

Introduction Caries and orthodontic anomalies in school-age children lead to disturbed aesthetics, oral functions (chewing, swallowing, and speech), predisposition to trauma and the onset of periodontal diseases. The aim was to assess dental health and frequency of orthodontic anomalies in children aged 8-9 years in the municipality of Foča. Methods The research was conducted in the primary school Sveti Sava in Foča, where the total of 112 children age 8-9 years were examined. An informed consent was obtained from parents and school director for each student. Dental examination was performed using standard dental method, a mirror and a probe under artificial lighting. Children received instructions on proper nutrition, oral hygiene, tooth protection and elimination of bad habits. Results Among 112 examined boys and girls of selected ages, very high person caries index (PCI) was found (78.57%). A total of 548 caries affected teeth were found (boys 331 (24.62%), girls 217 (16.14%) (p lt 0.05)). Fifty-nine children had caries lesions on permanent teeth (boys 39 (2.9%), girls 20 (1.5%) (p lt 0.05)). Sagital abnormalities of the bite were present in 39 (34.82%) children, while 38 (33.92%) anomalies were related to vertical bite irregularities, 10 (8.92%) of them had open bite and 28 subjects (25%) had deep bite (p> 0.05). Conclusion Large number of teeth was affected with caries lesions (548) in eighth-year-olds, while orthodontic anomalies, mostly sagital abnormalities of bite were found in 39 subjects.Uvod Karijes i ortodontske anomalije kod dece školskog uzrasta dovode do narušene estetike, poremećaja oralnih funkcija (žvakanje, gutanje i govor), povećane sklonosti nastanku trauma i nastanku parodontalnih bolesti. Cilj ovog rada je bio da se provere dentalno zdravlje i učestalost ortodontskih anomalija kod dece uzrasta 8-9 godina na području opštine Foča. Metode Istraživanje je sprovedeno u Osnovnoj školi 'Sveti Sava' u Foči, gde je pregledano ukupno 112 dece uzrasta 8-9 godina. Kod svakog učenika za koga je postojao informativni pristanak roditelja i direktora škole obavljen je stomatološki pregled standardnom stomatološkom metodom, ogledalom i sondom uz korišćenje veštačkog osvetljenja. Deca su dobila upute o pravilnoj ishrani, higijeni, zaštiti zuba i eliminaciji loših navika. Rezultati Kod 112 pregledanih dečaka i devojčica odabranih uzrasta utvrđen je veoma visok karijes indeks osoba (KIo) - od 78,57%. Ukupno je pronađeno 548 karijesom zahvaćenih mlečnih zuba (dečaci 331 (24,62%); devojčice 217 (16,14%) (p lt 0,05)). Kod ukupno 59 ispitanika pronađen je karijes stalnih zuba (dečaci 39 (2,9%); devojčice 20 (1,5%) (p lt 0,05)). Sagitalne nepravilnosti zagrižaja su bile zastupljene kod ukupno 39 (34,82%) dece, dok se ukupno 38 (33,92%) anomalija odnosilo na vertikalne nepravilnosti zagrižaja, pri čemu je 10 (8,92%) ispitanika imalo otvoren zagrižaj, a 28 ispitanika (25%) dubok zagrižaj (p > 0,05). Zaključak Kod osmogodišnjaka je pronađen veliki broj karijesom zahvaćenih mlečnih zuba (548) i velika zastupljenost ortodontskih anomalija, od kojih su najzastupljenije sagitalne nepravilnosti zagrižaja, koje su pronađene kod 39 ispitanika.

Measuring of mandible bone density in dogs using/digital radiography/radiovisigraphy

Radiological diagnostics serves as one of the basic monitoring techniques in veterinary dental practice. The recent up-to-date literature data based on the findings of digital radiology/radiovisiography (RVG) in general dentistry inspired the authors to present its possible use in clinical veterinary dentistry. The digital radiography used in this study was RVG Trophy Radiologie SA 2001 device equipped with software for linear measurements (readings), densitometry, setting of contrast of radiography image, 3D image manipulation, zooming of detail and orientation handling. The aim of the study was to evaluate the bone mineral density of the alveolar part of the lower jaw in seven Scottish terriers. Bone mineral density measurement was performed around the central lower incisors by converting gray scale values into equivalent aluminum thickness (mm Al). The mean bone mineral density was in the range of 4.31-6.20 mm Al with no significant statistical difference between left and right incisors (p>0.01). Our results showed that the combination of RVG and aluminum step wedge etalon is a reliable tool to measure bone mineral density around the lower central incisors in dogs. This method can be considered as comfortable for manipulation in everyday use in clinical veterinary practice

Forensic DNA databasesin Western Balkan region:retrospectives, perspectives, and initiatives

The European Network of Forensic Science Institutes (ENFSI) recommended the establishment of forensic DNA databases and specific implementation and management legislations for all EU/ENFSI members. Therefore, forensic institutions from Bosnia and Herzegovina, Serbia, Montenegro, and Macedonia launched a wide set of activities to support these recommendations. To assess the current state, a regional expert team completed detailed screening and investigation of the existing forensic DNA data repositories and associated legislation in these countries. The scope also included relevant concurrent projects and a wide spectrum of different activities in relation to forensics DNA use. The state of forensic DNA analysis was also determined in the neighboring Slovenia and Croatia, which already have functional national DNA databases. There is a need for a ‘regional supplement’ to the current documentation and standards pertaining to forensic application of DNA databases, which should include regional-specific preliminary aims and recommendations