Repository of the University of Rijeka
Not a member yet
40085 research outputs found
Sort by
Neuronal-ILC2 interactions regulate pancreatic glucagon and glucose homeostasis
No full textThe immune system shapes body metabolism, while interactions between peripheral neurons and immune cells control tissue homeostasis and immunity. However, whether peripheral neuroimmune interactions orchestrate endocrine system functions remains unexplored. After fasting, mice lacking type 2 innate lymphoid cells (ILC2s) displayed disrupted glucose homeostasis, impaired pancreatic glucagon secretion, and inefficient hepatic gluconeogenesis. Additionally, intestinal ILC2s were found in the pancreas, which was dependent on their expression of the adrenergic beta 2 receptor. Targeted activation of catecholaminergic intestinal neurons promoted the accumulation of ILC2s in the pancreas. Our work provides evidence that immune cells can be regulated by neuronal signals in response to fasting, activating an inter-organ communication route that promotes pancreatic endocrine function and regulation of blood glucose level
The Microbial Diversity and Biofilm Characteristics of d-PTFE Membranes Used for Socket Preservation: A Randomized Controlled Clinical Trial
No full textBackground: Understanding microbial colonization on different membranes is critical for guided bone regeneration procedures such as socket preservation, as biofilm formation may affect healing and clinical outcomes. This randomized controlled clinical trial (RCT) investigates, for the first time, the microbiome of two different high-density polytetrafluoroethylene (d-PTFE) membranes that are used in socket preservation on a highly molecular level and in vivo. Methods: This RCT enrolled 39 participants, with a total of 48 extraction sites, requiring subsequent implant placement. Sites were assigned to two groups, each receiving socket grafting with a composite bone graft (50% autogenous bone, 50% bovine xenograft) and covered by either a permamem® (group P) or a Cytoplast™ (group C). The membranes were removed after four weeks and analyzed using scanning electron microscopy (SEM) for bacterial adherence, qPCR for bacterial species quantification, and next-generation sequencing (NGS) for microbial diversity and composition assessment. Results: The four-week healing period was uneventful in both groups. The SEM analysis revealed multispecies biofilms on both membranes, with membranes from group C showing a denser extracellular matrix compared with membranes from group P. The qPCR analysis indicated a higher overall bacterial load on group C membranes. The NGS demonstrated significantly higher alpha diversity on group C membranes, while beta diversity indicated comparable microbiota compositions between the groups. Conclusion: This study highlights the distinct microbial profiles of two d-PTFE membranes during the four-week socket preservation period. Therefore, the membrane type and design do, indeed, influence the biofilm composition and microbial diversity. These findings may have implications for healing outcomes and the risk of infection in the dental implant bed and should therefore be further explored
Microgrid project for winery operation
No full textOvaj diplomski rad bavi se projektiranjem mikromreže za pogon vinarije, pri čemu se posebno
razmatra hibridni sustav koji kombinira fotonaponsku elektranu i baterijsko skladištenje električne
energije. U uvodnom dijelu objašnjavaju se osnovni pojmovi o mikromrežama te važnost dodatnih
izvora napajanja u industrijskim postrojenjima s osjetljivim procesima, poput vinarija. Nadalje,
detaljno su prikazane komponente mikromreže i načela njihovog odabira, od fotonaponskih
modula i hibridnih pretvarača do baterijskog sustava i pripadajućih zaštitnih elemenata.
Glavni izazov u projektiranju odnosio se na visoku potrošnju energije, osobito pri hlađenju vina.
Analizirani su mjesečni i dnevni profili potrošnje vinarije te je utvrđen način na koji se može
dimenzionirati baterijski sustav tako da omogući kontinuitet napajanja ključnih trošila, čak i kada
dođe do kratkotrajnog nestanka napajanja iz mreže. Ujedno je provedena analiza lokacije i
klimatoloških podataka kako bi se odredila očekivana godišnja proizvodnja električne energije iz
fotonaponskih panela.
Rezultati su pokazali da pravilno projektiran hibridni sustav, temeljen na kombinaciji solarne
energije i baterijskog skladišta, može uspješno zadovoljiti energetske potrebe vinarije uz
zadržavanje visoke razine sigurnosti i neprekinutosti rada. Time se, osim pouzdane opskrbe,
omogućuje i smanjenje troškova električne energije te povećava ekološka održivost cjelokupnog
procesaThis thesis focuses on designing a microgrid to power a winery, specifically exploring a hybrid
system that combines a photovoltaic (PV) power plant and a battery energy storage system. The
introductory section explains the basic concepts of microgrids and the importance of additional
power sources for industrial facilities with sensitive processes, such as wineries. Furthermore, the
key components of the microgrid and their selection criteria are presented in detail, ranging from
photovoltaic modules and hybrid inverters to the battery storage system and associated protective
elements.
The main challenge in this design was the high energy consumption, especially during wine
cooling. Monthly and daily consumption profiles of the winery were analyzed, and a method was
identified to size the battery system so that it can ensure the continuity of power supply to critical
loads, even in the event of a short-term outage of the main grid. Additionally, the chosen location
and climate data were evaluated to estimate the expected annual electricity production from
photovoltaic panels.
The results show that a properly designed hybrid system, based on a combination of solar energy
and battery storage, can successfully meet the winery’s energy requirements while maintaining
high levels of reliability and uninterrupted operation. In addition to guaranteeing a reliable power
supply, this approach reduces electricity costs and enhances the overall environmental
sustainability of the proces
Free vibration analysis of motor ship masts
No full textOd početka postavljanja elektroničkih sustava na jarbole brodova, sam jarbol kao zasebni dio broda, predstavlja bitnu i važnu ulogu za stabilnost i mogućnost nošenje same opreme. Dosadašnji razvitak tipova jarbola (opisani stubni, tronožni, rešetkasti, Mack, zatvoreni i čvrsti) te način integracije jarbola koji će se koristiti odaje tu bitnu ulogu kod broda. Ušteda materijala te dulji životni ciklus su jedni od faktora na koje tržište uvijek obraća pozornost, zbog čega se velika pažnja posvećuje i jarbolu. Na životni ciklus jarbola utječu vibracije koje su posljedica integriranog djelovanja vanjskih sila nastalih vanjskim utjecajima (brzina vjetra, uzburkanost mora) te radom brodskog porivnog sustava.
Opisane vanjske sile uzrokuju pojavu uzbudnih vibracija koje mogu imati značajno štetne posljedice. Ukoliko se vrijednosti uzbudnih vibracija na jarbolu približavaju te izjednače sa vlastitim frekvencijama se postižu veća i najveća amplitudna naprezanja, što će prouzročiti zamorom materijala odnosno nastankom mikropukotine tijekom vremena.
Na temelju prvotne dobivene konstrukcije jarbola su se razradila rješenja s ciljem izbjegavanja zadanog raspona uzbudnih frekvencija uz određene uvjete (fiksna mikrolokacija senzora na jarbolu određena koordinatama i masom te ograničenje dimenzija palube). S dostupnim mogućnostima programa se jedino trećom verzijom geometrije postiglo zadovoljavajuće rješenje izvan raspona uzbudnih frekvencija.Since the beginning of the installation of electronic systems on the ship masts, the mast itself, as a separate part of the ship, represents an essential and crucial role for the stability and ability to carry the equipment itself. The development of the types of masts so far (described pole, tripod, lattice, Mack, enclosed and solid) and the method of integration of the masts will reveal its essential structural role. Material savings and a longer life cycle are some of the factors that the market always pays attention to, which is why great attention is also paid to the ship's mast. The life cycle of the mast is affected by vibrations which are caused by external influence (wind speed, roughness of the sea) and the operation of the ship's propulsion system.
The described external forces cause the appearance of exciting vibrations that can have significant harmful consequences. If the values of the excited vibrations on the ship's mast approach and become equal to their natural frequencies, higher and highest amplitude of stresses are achieved, which will cause material fatigue, i.e. the appearance of microcracks over time.
Based on the initial construction of the ship mast, solutions were developed with the aim of avoiding the given range of exciting frequencies under certain conditions (fixed microlocation of sensors on the mast determined by coordinates and mass and limitation of the deck dimensions). Considering the limitations of the software, only the third version of the geometry achieved a satisfactory solution outside the range of the exiciting frequencies
SIDE GUIDE CONTROL FOR STEEL STRIP
No full textU diplomskom radu je na početku opisan uvod u postrojenje procesa centriranja čelične trake. Predstavljen je cijeloukupan pogon, princip rada bočnih vodilica i objašnjen je proces centriranja čelične trake sa bočnim vodilicama. Sljedeće je opisan softver pisan u TIA portalu i njegove korištene funkcije u radu. Zadnje dolazimo do izrade programske aplikacije koja se dijeli na prvi dio pisanja logike i kontrole procesa bočnih vodilica u softveru, a drugi dio je prikaz simulacije, bitnih pozicija i konrolu određenih režima rada i komandi na HMI panelu.In the thesis, the introduction to the steel strip centering process plant is described at the beginning. The entire drive, the working principle of the side guides and the process of centering the steel strip with the side guides is explained. The following describes the software written in the TIA portal and its functions used in operation. Finally, we come to the creation of a software application, which is divided into the first part of writing the logic and controlling the process of the side guides in the software, and the second part is the display of the simulation, important positions and the control of certain operating modes and commands on the HMI panel
Nacrti : Radionički nacrt klipa : Radionički nacrt brtve : Radionički nacrt kučišta : Sklopni nacrt
No full textHigh-Power Ultrasound and High-Voltage Electrical Discharge-Assisted Extractions of Bioactive Compounds from Sugar Beet (Beta vulgaris L.) Waste: Electron Spin Resonance and Optical Emission Spectroscopy Analysis
No full textTo achieve sustainable extractions, this study examines the impact of different extraction methods to utilize waste from the sugar industry. In addition to conventional thermal extraction, the impact of high-power ultrasound (US) and high-voltage electrical discharge (HVED)-assisted extractions on the yield of bioactive compounds and the antioxidant capacity (AC) value of sugar beet leaf extracts was determined. US extraction proved to be an excellent method for extracting bioactive compounds, while HVED extraction proved to be an excellent method for extracting Vitexin. AC was measured both spectrophotometrically (DPPH and FRAP) and spectroscopically via electron spin resonance (ESR). The AC results correlate with each other, and the highest AC values were found in the US-treated samples with 25% ethanol solution as the extraction solvent. Characterization of the plasma via optical emission spectroscopy (OES) showed that neither the solvent nor the sample influenced the plasma spectra, only the gas used (nitrogen/argon). All of the obtained results provide an excellent basis for future research into the utilization of food waste and by-products
Could systemic infections influence the effectiveness of deep brain stimulation therapy in patients with dystonia?
No full textDystonia is a movement disorder characterized by sustained or intermittent muscle contractions resulting from aberrant sensory integration, enhanced cortical plasticity, and lack of intracortical inhibition. Deep brain stimulation of the globus pallidus internus (GPi-DBS) effectively treats dystonia, reducing abnormal neural oscillations and improving motor function. However, systemic infections can significantly impact brain function, altering brain wave dynamics and cortical excitability. We hypothesize that dystonia patients treated with DBS exhibit altered cortical excitability and changes in brain wave dynamics during early recovery from systemic infections, necessitating DBS parameters adjustment to prevent symptoms exacerbation. We propose a two-year clinical study involving 15 dystonia patients with DBS capable of local field potential (LFP) recording to evaluate this hypothesis. The study will analyze brain activity patterns, symptom severity and infection impact on neural activity. Continuous and infection-triggered LFP recording will provide data for advanced analysis to identify LFP patterns associated with dystonia symptoms and the effects of infections. This paper underscored the importance of individualized and dynamic DBS management, especially post-infection. Systemic infections can induce neuroinflammation, disrupting neural circuits and increasing brain sensitivity to DBS. Timely DBS adjustments are crucial to mitigate overstimulation and optimize outcomes. Enhanced post-infection care, including thorough evaluations and parameter adjustments, is essential for managing dystonia patients with DBS. Future research into the neuroinflammatory mechanism and their effect on neural circuits will improve our understanding and treatment of dystonia in the context of systemic infections
The Influence of Standard and Freeze-Dried Tofu on the Phenols and Quality of Virgin Olive Oil Used as an Immersion Medium
No full textVarious protein-rich foods are traditionally immersed in virgin olive oil (VOO), a medium rich in phenols, which are health-promoting and sensorially important compounds. Immersing tofu in VOO may modify the sensory properties and nutritional value of both due to the oil’s hydrophilic phenol interactions with proteins and water. In this study, cubes of fresh tofu (T) (70% water) and freeze-dried tofu (FD-T) (5% water) were immersed in VOO for 7 days of cold storage. The changes in the phenolic compound content and standard quality parameters of the oil were noted after 1, 3, 5, and 7 days of contact with the tofu. The total phenols in the oil were determined using the Fast Blue BB assay, while single phenols were analyzed by HPLC-UV/VIS. During the 7 days, the total phenols in the oil decreased by up to 56% and 26% under the influence of fresh and freeze-dried tofu, respectively, including a significant decrease in hydroxytyrosol, oleacein, tyrosol, and oleocanthal. The water content and its release from fresh tofu significantly contributed to this decline. The degradation of the quality of the oil in contact with the fresh tofu was observed only in its sensory properties, with a marked reduction in the intensity of its fruitiness, bitterness and pungency
Ocjena stanja i važnost daljnjeg razvoja poljoprivrede i ruralnih područja
No full textRazvoj poljoprivrede i ruralnih područja predstavlja jedan od važnih interesa svake države. U Hrvatskoj je on još važniji zbog izazova s kojima se domaća poljoprivredna proizvodnja suočava već desetljećima, a koji su sad još i veći zbog rastuće opasnosti od daljnje depopulacije hrvatskih sela i eskalacije problema vezanih uz posljedice klimatskih promjena. U ovom su poglavlju analizirani stavovi 1014 ispitanika iz Hrvatske koji su sudjelovali u istraživanju Eurobarometra te su uspoređeni sa stavovima ispitanika iz drugih zemalja Europske unije (ukupni uzorak iznosi 26 511 sudionika). Pritom su analizirani stavovi vezani uza značaj razvoja poljoprivrede ruralnih područja, zadataka poljoprivrednih proizvođača, željena obilježja poljoprivrednih proizvoda i organskih poljoprivrednih proizvoda te stavova o odnosu poljoprivrede i klimatskih promjena. Unatoč sličnostima i trendovima u odgovorima na većinu ispitivanih područja, jasno su uočljive razlike između razvijenih i manje razvijenih članica Europske unije te članica koje pripadaju europskom jugu od ostalih. Hrvatski su ispitanici vrlo afirmativno odgovarali na pitanja vezana uz organske i ekološki proizvedene poljoprivredne proizvode i potrebu za povećanjem kvalitete života u ruralnim područjima, što može poslužiti kao poticaj za ulaganje dodatnog truda u razvoj ovog dijela gospodarstva