Humor u doba COVID-19 pandemije

The research is focused on the very beginning of the COVID-19 pandemic in Croatia – March 2020. The subject of the research are humorous messages related to the pandemic. By combining quantitative and qualitative methods, this research showed how the interviewed respondents experienced the received humorous content related to the coronavirus and what content characteristics of the humorous messages were detected through the content analysis.Istraživanje je usmjereno na sam početak pandemije COVID-19 u Hrvatskoj – ožujak 2020. Predmet istraživanja su humoristične poruke povezane s pandemijom. Kombinacijom kvantitativne i kvalitativne metode, ovo istraživanje je pokazalo kako su ispitanici intervjua doživjeli primljeni humoristični sadržaj vezan uz korona virus te kakve su sadržajne karakteristike humorističnih poruka detektirane kroz analizu sadržaja

Universal complexes in toric topology

We study combinatorial and topological properties of the universal complexes $X(\mathbb{F}_p^n)$ and $K(\mathbb{F}_p^n)$ whose simplices are certain unimodular subsets of $\mathbb{F}_p^n$. We calculate their $\mathbf f$-vectors and their Tor-algebras, show that they are shellable but not shifted, and find their applications in toric topology and number theory. We showed that the Lusternick-Schnirelmann category of the moment angle complex of $X(\mathbb{F}_p^n)$ is $n$, provided $p$ is an odd prime, and the Lusternick-Schnirelmann category of the moment angle complex of $K(\mathbb{F}_p^n)$ is $[\frac n 2]$. Based on the universal complexes, we introduce the Buchstaber invariant $s_p$ for a prime number $p$

Structural and functional changes of fibrinogen in patients on peritoneal dialysis

Cilj disertacije je da se kod bolesnika u završnom stadijumu bubrežne slabosti lečenih peritoneumskom dijalizom (PD-om) analiziraju strukturne i funkcionalne promene fibrinogena i fibrina, i da se ispita povezanost uočenih promena sa nastankom neželjenih događaja kardiovaskularnog sistema (KVS-a), nakon perioda praćenja od 18 meseci. U ispitivanju je učestvovala grupa od 52 bolesnika i grupa od 32 zdrave kontrole, uporediva prema polu i starosti. Fibrinogen je izolovan iz plazme isoljavanjem amonijum-sulfatom, i analiziran spektroskopskim, imuno- i lektin-afinitetnim metodama. Fibrinogeni bolesnika na PD-u imaju značajno viši sadržaj karbonila od fibrinogena zdravih kontrola, a Aα i Bβ lanci su podložniji oksidaciji od γ lanaca. Vreme i brzina koagulacije su slični u obe ispitivane grupe, kao i vrednosti za maksimalnu apsorbancu (UV VIS spektri, na 350 nm) i emisioni maksimum ispitivanih fibrinogena (fluorescentni spektri, na 344 nm). Od 16 korišćenih lektina, kod 10 je odnos signal/šum >10, dok je za dva lektina <3. Fibrinogeni ispitanika iz obe grupe su reagovali sa istim lektinima, i sadrže: a) biantenarne N-glikane sa α2,6-Sia; b) umetnuti GlcNAc i/ ili α1,6-Fuc, i c) α1,3-Fuc. Primećena je mala zastupljenost multiantenarnih i paucimanoznih i/ili visokomanoznih N-glikana, i O-glikana tipa T i Tn antigena sa ili bez Sia. Kao prediktor ultrafiltracione slabosti se izdvojio sadržaj fukozilovanih glikana koje vezuje AAL (sa vrednošću AUC od 72,4%). Povišen sadržaj (pauci)manoznih struktura (koje vezuje GNL) nađen je kod bolesnika koji su preminuli nakon 18 meseci od početka studije. Fibrinogen izolovan iz plazme bolesnika lečenih PD-om ima značajno višu koncentraciju karbonila, izmenjenu sekundarnu i tercijarnu strukturu i izmenjen sadržaj glikana. Stepen fukozilacije ima visok potencijal da bude prediktivni faktor malfunkcije peritoneumske membrane, dok sadržaj paucimanoznih/visokomanoznih struktura korelira sa neželjenim kardiovaskularnim događajima i letalnim ishodom.The aim of the thesis is to analyze the structural and functional changes of fibrinogen and fibrin in patients with end - stage renal disease treated with peritoneal dialysis (PD), and to examine the relationship between the observed changes and the occurrence of adverse cardiovascular (CVD) events after a follow - up period of 18 months. The study involved 52 patients and 32 healthy volunteers, comparable by gender and age. Fibrinogen was isolated from plasma by ammonium sulfate isolation, and analyzed by spectroscopic, immuno- and lectin-affinity methods. The fibrinogens of patients on PD have a significantly higher carbonyl content than the fibrinogens of healthy volunteers, and the Aα and Bβ chains are more susceptible to oxidation than the γ chains. The time and rate of coagulation are similar in both study groups, as well as the values for maximum absorbance (UV VIS spectra, at 350 nm) and emission maximum of analyzed fibrinogens (fluorescent spectra, at 344 nm). Of the 16 lectins used, 10 had a signal-to-noise ratio of > 10, while two lectins had <3. Fibrinogens of both groups reacted with the same lectins, and contain: a) biantenary N-glycans with α2,6-Sia; b) insert GlcNAc and / or α1,6-Fuc, and c) α1,3-Fuc. A small presence of multiantennar and paucimannosidic and/or high-mannose N-glycans, and O-glycans of type T and Tn antigens with or without Sia was observed. The content of fucosylated N-glycans (AAL binding) emerged as a predictor of ultrafiltration strength, (with an AUC value of 72.4%), while an elevated content of (pauci)mannosidic glycans (GNL singal) was found in patients died 18 months after the start of the study. Fibrinogen isolated from the plasma of patients treated with PD has a significantly higher carbonyl concentration, altered secondary and tertiary structure, and altered glycan content. The degree of fucosylation has a high potential to be a predictive factor of peritoneal membrane dysfunction, while the content of paucimannosidic/highly mannose structures correlates with adverse cardiovascular events and lethal outcome

Energija i kvalitet obrade abrazivnim vodenim mlazom

Obrada abrazivnim vodenim mlazom je jedna od nedavno razvijenih nekonvencionalnih proizvodnih tehnologija. Danas se sve više koristi u industriji zahvaljujući svojim mnogobrojnim prednostima nad ostalim tehnologijama rezanja. Međutim, da bi obrada abrazivnim vodenim mlazom našla što širu primenu u industriji i da bi se unapredile njene performanse, neophodno je razumevanje brojnih ulaznih i izlaznih parametara ove obrade, kao i uticaj ulaznih parametara na izlazne parametre. U doktorskoj disertaciji: ―Energija i kvalitet obrade abrazivnim vodenim mlazom― predloženi su novi modeli koji definišu uticaj ulaznih parametara obrade abrazivnim vodenim mlazom (radnog pritiska, brzine kretanja rezne glave, protoka abraziva i rastojanja rezne glave od predmeta obrade) na izlazne parametre kao što su širina reza, nagib reza, hrapavost obrađene površine. Predloženi modeli su dobijeni na osnovu opsežnih eksperimentalnih istraživanja. Takođe, dat je nov pristup definisanju geometrije prednje linije reza u zavisnosti od pojedinih, najznačajnijih ulaznih parametara. Na osnovu energije abrazivnog vodenog mlaza i zapremine uklonjenog materijala predmeta obrade, određena je specifična energija obrade za ispitivani materijal. Na osnovu formiranih modela za definisanje putanje abrazivnog vodenog mlaza kroz materijal predmeta obrade, odnosno prednje linije reza, energije abrazivnog vodenog mlaza i specifične energije obrade abrazivnim vodenim mlazom, dobijen je model za određivanje sile rezanja i otpora rezanja pri obradi abrazivnim vodenim mlazom. Rezultati dobijeni pomoću modela su upoređeni sa eksperimentalno dobijenim rezultatima. Model je pokazao dosta dobro poklapanje sa sprovedenim eksperimentom. Sva saznanja, do kojih se došlo tokom izrade doktorske disertacije, ukazuju na činjenicu da od energije abrazivnog vodenog mlaza i specifične energije obrade zavise izlazni parametri koji su analizirani. Ova činjenica može poslužiti kao osnova za buduća istraživanja u oblasti obrade abrazivnim vodenim mlazom.Abrasive water jet machining is one of the recently developed non-conventional production technologies. Due to its many advantages over other cutting technologies it is often used in industry. However, in order to find a wider application of the abrasive water jet machining in industry and improve its performance, it is necessary to perceive a number of input and output parameters of the abrasive water jet machining process, and the impact of the input parameters on the output parameters. This doctoral dissertation, "The energy and quality of abrasive water jet machining", proposes new models for defining the influence of the input parameters of the abrasive water jet machining (operating pressure, traverse speed of cutting head, abrasive flow rate and distance of the cutting head of the workpiece) on the output parameters, such as the width of cut, cut taper, surface roughness. These models are based on extensive experimental investigations. The doctoral dissertation, also, gives insight into the new model for defining the geometry of the front - line of cut, depending on the most important input parameters. Based on the energy of the abrasive water jet and the volume of the removed material of the workpiece, specific energy of the abrasive water jet machining for the tested material is determined. According to developed model for defining the trajectory of the abrasive water jet through the workpiece, and the model for defining the front line of cutting, abrasive water jet energy and specific energy of the abrasive water jet machining, a model for determining the cutting reaction force for the abrasive water jet machining has been developed. The results obtained by the model were compared with the experimental results. The model showed quite good agreement with the conducted experiments. Entire knowledge, achieved while drafting of this doctoral dissertation, indicates that the energy of the abrasive water jet and specific energy of the abrasive water jet machining affect the output parameters which were analyzed in this doctoral dissertation. This fact can be used as a basis for future research in the field of abrasive water jet machining

Toxicity of phthalate and bisphenol a mixture and assessment of the protective effect of probiotic on rat and zebrafish models

Široka upotreba bis(2-etilheksil)ftalata (DEHP), dibutil ftalata (DBP) i bisfenola A (BPA) otvaraniz mogućnosti za istovremenu izloženost ljudi ovim toksičnim supstancama u svakodnevnomživotu. Cilj ove doktorske disertacije bio je da ispita toksičnost smeše DEHP, DBP i BPA u odnosuna pojedinačne supstance na eksperimentalnim modelima pacova i zebrice, razjasni mehanizmetoksičnosti smeše in silico toksikogenomičkom analizom podataka i utvrdi potencijalnu efikasnostprobiotika u umanjenju štetnih efekata ispitivane smeše kod pacova i zebrica. Nakon subakutneizloženosti pacova, smeša je proizvela značajne promene u telesnoj masi, unosu hrane i vode, nivouhormona, lipidnom profilu, pojedinim hematološkim i biohemijskim parametrima, patohistološkimnalazima tkiva, nivoima parametara oksidativnog stresa/antioksidativne zaštite i bioelementima.Neki od ovih efekata bili su prisutni samo u grupi tretiranoj smešom ili izraženiji u odnosu na grupetretirane pojedinačnim supstancama. Eksperiment na embrionima zebrica potvrdio je da jetoksičnost smeše izraženija u odnosu na toksičnost pojedinačnih supstanci, kao i da je efekat smešeprvenstveno diktiran efektima BPA. In silico analiza ukazala je na povezanost ispitivane smeše irazvoja različitih poremećaja pri čemu su kao dominantni molekularni mehanizmi izdvojenioksidativni stres i apoptoza. Pokazan je zaštitni efekat probiotika protiv štetnih efekata smeše,posebno u slučaju smanjenja telesne mase, unosa hrane, biohemijskih i hematoloških parametara,nivoa hormona, parametara redoks statusa i bioelemenata u plazmi, tkivu pankreasa, pluća, timusa,bubrega i testisa pacova, kao i protiv efekata na rast i razvoj, hepatotoksičnosti i letaliteta ispitivanesmeše kod embriona zebrica.The widespread use of bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and bisphenolA (BPA) opens up a range of possibilities for simultaneous human exposure to these toxicsubstances. The aim of this doctoral dissertation was to examine DEHP/DBP/BPA mixture toxicityin relation to individual substances in rat and zebrafish experimental models, clarify themechanisms of toxicity by conducting in silico toxicogenomic analysis and determine the potentialefficacy of multicomponent probiotic in reducing the adverse effects of the tested mixture in ratsand zebrafish. After subacute exposure of rats, the mixture produced significant changes inbodyweight, food and water consumption, hormone levels, lipid profile, certain hematological andbiochemical parameters, pathohistological findings, redox status parameters and bioelements. Someeffects were present only or more prominent in the group treated with the mixture in relation to thegroups treated with individual substances. Zebrafish embryos experiment confirmed that mixturetoxicity was more pronounced than toxicity of individual substances, and that mixture effects wereprimarily dictated by BPA. In silico analysis indicated an association between the mixture anddevelopment of various disorders, with oxidative stress and apoptosis being the dominant molecularmechanisms. Probiotic protective effect against mixture harmful effects has been shown, especiallyin the case of bodyweight gain, food intake, biochemical and hematological parameters, hormonelevels, redox status parameters and bioelements in plasma, pancreatic, lung, thymus, kidney andtestis in rats, as well as against lethal, teratogenic and hepatotoxic effects in zebrafish embryos